CA1124431A

CA1124431A - Coating compositions including hydroxy phosphate catalyst

Info

Publication number: CA1124431A
Application number: CA317,997A
Authority: CA
Inventors: Mohinder S. Chattha
Original assignee: Ford Motor Company of Canada Ltd
Current assignee: Ford Motor Company of Canada Ltd
Priority date: 1977-12-27
Filing date: 1978-12-14
Publication date: 1982-05-25
Also published as: IT7852401A0; GB2011423A; IT1192317B; FR2413452A1; GB2011423B; DE2855846A1; JPS6158501B2; JPS54116031A; FR2413452B1; DE2855846C2

Abstract

ABSTRACT OF THE DISCLOSURE
An improved thermosetting coating composition of the type comprising a film forming component and an amino compound, wherein the composition cures by reaction between the amino compound and hydroxy functionality present on the film forming material. The improvement comprises including in the composition a catalyst comprising at least one hydroxy functional organophosphate ester selected from certain mono- and diesters of phosphoric acid. Preferred coating compositions within the scope of the invention are fast curing, high solids coating compositions adapted for use as automotive topcoats.

Description

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COATING COMPOSITIONS INCLUDING
_ HYDROXY PHOSPHATE CATALYST
BACKGROUND OF THE INVENTION
This invention relates to coating compositions of the type comprising a film Eorming component and an amino compound, wherein the composition cures by reaction between the amino compound and hydroxy functionality present on the film forming material. More particularly, the invention relates to thermosetting coating compositions of the afore-mentioned type wherein the composition includes a catalyst for the hydroxy/amino curing reaction comprising at least one hydroxy functional organophosphate ester selected from certain mono- and diesters of phosphoric acid.
Thermosetting coating compositions which cure by reaction of hydroxy functionality with an amino compound are well known in the art. It is also well recognized in the art that it is desirable to catalyze the hydroxy/
amino crosslinking reaction in order to attain a quicker and more complete cure of the coating composition. To this end, catalysts for this reaction have been developed and are also well known.
Particularly preferred compositions within the scope of the invention are fast curing, high solids, thermo-setting coating compositions. More particularly, these preferred compositions are adapted to provide an automotive topcoat which demonstrates, hardness, high gloss, out-standing durability and excellent resistance to solvents and water. Still more particularly, the preferred compo-sitions are fast curing, high solids, thermosetting coating compositions adapted to be used as an automotive topcoat including metallic flake as a pigment.
Because of increasingly strict solvent emissions regulations in recent years, low solvent emission paints have become very desirable. A number of high solids paint compositions have been proposed to meet these low solvent emission requirements.- Howeverj many of these compositions are deficient because of difficulty in application, slow curing rates, lack of flexibility, poor durability and low solvent and water resistance. Many of the proposed compo-sitions have been particularly deficient as automotive 4~

topcoats, particularly when the topcoat is to include metallic flake as a pigment.
The deficiency in compositions including metallic flake results from undesired reorientation of the metallic flake during application and cuxe of the coating. Flake reorientation results primarily because of the very low viscosity resins used in the paint compositions to accommo-date high solids. The low viscosity is not sufficient to immobilize the flakes which tend to redistribute them-selves to show "reverse flop" and nonuniform distribution.
The preferred coating compositions of thisinvention combine the above discussed desired properties and low application viscosity with rapid cure so as to overcome deficiencies of previously proposed high solids materials and thereby achieve a high solids coating composition particularly adapted for automotive topcoats - and still more particularly adapted for automotive top-coats including metallic flake as a pigment.

SUMMARY OF THE INVENTION
It has been discovered that thermosetting coating compositions of the aforementioned type wherein the crosslinking reaction consists essentially of a reaction between hydroxy functionality and an amino com-pound are significantly improved when catalyzed by a catalyst comprising at least one hydroxy functional organophosphate ester having a formula:
o (R ~ ~n P ~OH)3 _ n wherein n = 1 to 2 and R is selected from the group con-sisting of mono- or dihydroxy alkyl, cycloalkyl or aryl radicals. In particular, it has been found that such hydroxy functional organophosphate catalyzed compositions .
exhibit rapid cure at low temperature and produce coatings with superior properties. In addition, the hydroxy functional organophosphate catalyst does not become in-volved in deleterious side reactions as is the case withmany conventional catalysts and has the further advantage of not leaching out of the coating composition after curing rS~

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is completed.
: More specifically, the catalyzed coating compo-sitions of the invention inclucle the broad class of thermosetting compositions wherein hydroxy functionality 5 of the film forming component, which hydroxy functionality is either initially present, generated in situ, or both initially present, and generated in situ, is crosslinked with conventional amino functional crosslinking agents. As will be more fully described hereinafter, the hydroxy func-tionality which may be generated in situ may be generatedin any manner known to the art with respect to this type of composition or it may be generated by a reaction between the catalyst itself and functionality in the film forming material, in particular, between the catalyst and epoxy functionality on the film forming material. In this case, the catalyst serves as a reactant which helps generate the hydroxy functionality subsequently engaged in the cross-linking reaction with the amino compound.
The preferred compositions of the invention con-tain greater than about 60 percent by weight of nonvolatile solids, prererably greater than about 70 percent by weight, and are capable of curing rapidly at a low temperature.
These compositions, exclusive of pigments, solvents and other nonreactive components, consists essentially of:
(A) a film-forming resin bearing epoxy functionality or both epoxy and hydroxy functionality; (B) the catalyst des-cribed above; (C) anamino crosslinking agent; and (D) up to about 45 weight percent based on the total of (A), (B), (C) and (D) of a hydroxy functional additive.
The organophosphate ester is included in the composition in an amount sufficient to provide between about .67 and about 1.4 equivalents, preferably between about .8 and about 1 equivalents, of acid functionality for each equivalent of epoxy functionality on the film-35 forming resin. The amino resin crosslinking agent is in-cluded in the composition in an amount sufficient to provide at least about .4 equivalents, preferably between about .6 and 2.1 equivalents, of nitrogen crosslinking

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functionality for each equivalent of hydroxy functionality included in the composition either as (i) an organic hydroxyl group on the organophosphate ester, (ii) hydroxy functionality on the film-forming resin, (iii) a hydroxyl group on the optional hydroxy functional additive, or (iv) as a result of esterification of the epoxy functionality of the film-forming resin during cure of the coating composition. Other ingredients of the composition may in-clude additives such as catalysts, antioxidants, U.V.
absorbers, flow control or wetting agents, antistatic agents, pigments, plasticizers, solvents, etc.

PRIOR ART
U.S. Patents 3,960,979 and 4,018,848 to Khanna teach high solids coating compositions adapted for use as a can coating material. The compositions consist essen-tially of (i) aromatic epoxide compositions having two ormore epoxy groups on an epoxy resin which has a molecular weight not exceeding 2500; (ii) an amino crosslinking agent; (iii) an inorganic or organic monomeric or polymeric acid which acts as a reactive catalyst; and (iv) a flexibilizing polyol.
The compositions of Khanna have the advantage of quick reaction and low application viscosity, but lack durability, and, therefore, do not weather well.
This is, in part, because of the presence of ether linkages in the aromatic epoxides. As such, the compo-sitions of Khanna are not desirable for use as auto-motive topcoats. The Khanna patents describe the compo-sitions as a low cure system. However, when considering the specific teachings of the patents one finds that the composition includes an excess of epoxide resin, apparently with the purpose of "killing off" excess catalyst after completion of the curing reaction. Excess epoxy resin in the composition remains uncured at the low temperature bake range of the baking temperatures disclosed, not giving a complete cure and desirable hardness, durability or solvent resistance. If heated to higher temperatures, ~L~ 2~

as called for in the examples, the excess epoxy does react with excess hydroxy functionality to give still further ether linkages. These ether linkages so obtained have a further deleterious effect on durability and make the materials particularly unsuitable for use as an automotive topcoat. Also, the necessary high bake temperatures to achieve the utilization of this excess epoxy makes the composition undesirable from an energy point of view. Still further, because the epoxy/catalyst reaction occurs in early stages of the cure, thus "killing off" the catalyst, the melamine-hydroxy curing reaction muxt proceed substantially without benefit of catalysis. The curing reaction thus proceeds slowly and requires the higher temperatures of the Khanna examples.

DETAILED DESCRIPTION OF THE INVENTION
As discussed generally above, the coating compo-sitions of the invention are thermosetting materials com-prising a film-forming material bearing hydroxy function-ality which is either initially present in the composition or which is formed by in situ reaction, an amino compound crosslinking agent, and the improved catalyst of the invention comprising at least one hydroxy functional organophosphate ester selected from certain mono- and diesters of phosphoric acid.
The preferred high solids coating composition of the invention overcome disadvantages of prior art high solids compositions, including those of the Khanna patent discussed above, to provide a system which is particularly suitable for those applications re~uiring high gloss, hardness, durability, and high solvent and water resistance as well as a fast cure rate at low temperatures, e.g., between about 75C. and about 150C., preferably between about ll0~C. and-about 130C;- The~
desirable characteristics of these preferred compositions of the invention result from the carefully controlled admixture of the particular components, including a hydroxy functional organophosphate ester, to achieve substantially complete utilization of reactant functionality and a resul-tant highly crosslinked coating in a fast and efficient manner.
Each of the components of the compositions of the invention, in general, and the high solids coating compositions in particular, are described hereinafter in greater detail.
Organophosphate Ester The novel hydroxy functional organophosphate ester is present in the composition of the invention as a mono- or diester of phosphoric acid or as a mixture of such mono- and diesters. The hydroxy functional organo-phosphate esters useful in the compositions of the invention are those 'having the formula:
o (R ~ ~n P ~OH)3 _ n wherein n = 1 to 2 and R is selected from the group con-sisting of mono- or dihydroxy alkyl, cycloalkyl, or aryl radicals. Preferably, the hydroxy bearing alkyl, cyclo-alkyl, or aryl radicals contain 3 to 10 carbon atoms.
Among the numerous suitable mono- or dihydroxy functional radicals are: 2-ethyl-3-hydroxyethyl; 4-methyl-ol-cyclohexylmethyl; 2,2 diethyl-3-hydroxypropyl; 8-hydroxy-octyl; 6-hydroxyhexyl; 2,2 dimethyl-3-hydroxypropyl; 2-ethyl-2-methyl-3-hydroxypropyl; 7-hydroxyheptyl; 5-hydroxy-pentyl; 4-methylolbenzyl; 3,-hydroxyphenyl; 2,3-dihydroxy-propyl; 5,6-dihydroxyhexyl; 2-(3-hydroxycyclohexyl)-2-hydroxyethyl; and 2-(3-hydroxypentyl)-2-hydroxyethyl. The above radicals are intended to be only exemplary and numerous other radicals falling within the defined scope of the organophosphate esters useful in the compositions of the invention will be apparent to those skilled in the art.
Among the most preferred-~adicals are-mono-~ or~ ydroxy functional alkyl radicals containing 3 to 10 carbon atoms.
A preferred method for preparing the hydroxy-functional organophosphate esters useful in the compo-sitions of the invention is by an esterification reaction between an excess of an alkyl, cycloalkyl or aryl diol or ~ ~ f~9~43~

triol and phosphorus pentoxide. When a triol is used as a reactant, preferably at least one of the hydroxyl groups should be secondary. The reaction between the diol or triol and the phosphorus pentoxide is generally carried out by 5 adding phosphorus pentoxide portionwise to an excess of diol or triol in a liquid state or in a solution in a suitable solvent.
Suitable solvents include, but are not limited to, butyl acetate, methyl ethyl ketone, methyl amyl 10 ketone, toluene, xylene, etc.
A preferred temperature for carrying out the reaction is between about 50C. and about 60C. Due to the multiple hydroxy functionality of the diol or triol reactant, minor amounts of polymeric acid phosphate as 15 well as certain cyclophosphates are also generated during the synthesis. These polymeric and cyclic materials also serve as a reactive catalyst and, therefore, need not be separated from the hydroxyphosphate esters described above.
In fact, it has been found advantageous in preferred 20 embodiments of the invention to employ all reaction pro~
ducts, i.e., the hydroxy functional organophosphate esters and the minor amount of polymeric acid phosphate, cyclophosphates, as well as excess diol or triol in the coating compositions. The excess diol or triol serves 25 in those compositions as the optional hydroxy functional additive.
Reactive catalysts prepared by the above pre-ferred method will generally include about a 1 to 1 ratio of the mono- and diester organophosphate.
Still another preferred method of preparing the hydroxy functional organophosphate esters useful in compo-sitions of the invention is by an esterification reaction between phosphoric acid and an alkyl, cycloalkyl or aryl monoepoxide. This reaction is carried out by: adding be-35 tween about 1 and about 2 moles, preferably between about 1 and about 1.5 moles of the monoepoxy material to 1 mole of phosphoric acid or its solution in a suitable solvent, as above. During the esterification reaction which occurs, ~L~ 2~

a hydroxyl group is formed. If a dihydroxy radical is desired in the organophosphate ester, a monoepoxide bearing hydroxy functionality may be used as a reactant. Preferred monoepoxide materials useful in this method are well known 5 monoepoxides selected from monoepoxy ethers, monoepoxy esters and alkylene oxides. Exemplary of preferred mono-epoxides for use in this esterification reaction are:
propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide, n-butyl glycidyl ether, ethyl glycidyl ether, n-butyl epoxy stearate and glycidyl acetate.
As will be understood by those skilled in the art, the proportion of monoester and diester formed by the reaction will vary with the selected molar ratio of the monoepoxide and the phosphoric acid. When 1 mole of monoepoxide is used per mole of phosphoric acid primarily monoester is formed while a molar ratio of 2 to 1 results in primarily diester. A molar ratio of l.S to 1 will result in`an approximately 1 to 1 mixture of mono- and diesters. In all cases, a minor amount of the triester will be formed. While the triester obviously will not serve as a reactive catalyst, it will crosslink with the amino crosslinking agent of the composition and, thus, may be safely included.
The hydroxy functional organophosphate ester component of the thermosetting coating compositions of the invention is a reactive catalyst which allows the composition to cure rapidly at a low temperature. In all cases, the hydroxy functionality present on the hydroxy functional organophosphate ester engages in the cross-linking reaction by reacting with the amino compound inaddition to catalyzing the reaction between the amino compound and the hydroxy functionality present in the film-forming materials. It is this reaction of the hydroxy functionality of the hydroxy functional organophosphate ester which probably accounts for the fact that the catalyst does not l~oach out of the finally cured composition. Thus, the catalyst serves not only to catalyze the reaction between the film forming material and the crosslinking agent, ~2~
g but also to more completely tie up the matrix of the compo-sition and provide a more completely integrated crosslinking composition. In those embodiments of the invention wherein the film forming material also includes an epoxy 5 material, either on the same compound as the hydroxy functionality or on a separate compound forming a part of the film forming material, the hydroxy functional organo-phosphate ester catalyst of the invention serves as a reactive catalyst in another sense. In this case, the 10 acid functionality of the mono- or diester or mixture of such esters reacts with the epoxy functionality of the film forming material to form an ester and a hydroxyl group. This hydroxyl group, as well as the organic hy-droxyl groups on the hydroxy functional organophosphate 15 ester and the other hydroxy functionality which may be present in the film forming material is available for crosslinking with the amino crosslinking agent.
The amount of the hydroxy functional organophos-phate catalyst which is included in the compositions of 20 the invention in general will vary depending upon the nature of the film forming material employed and is a matter of choice which will be made by one skilled in the art.
Film Forming Material As discussed above, film forming materials which either include hydroxy functionality initially, generate hydroxy functionality as a result of insitu reactions during the coating process or both include hydroxy function-ality initially and generate it in situ, are well known 30 to those skilled in the art. Selection of those materials will be a matter of choice and it will be recognized that the hydroxy functional organophosphate catalyst is equally applicable to all such hydroxy bearing film forming mater-ials crosslinked with amino compound.-While it is intended that all such hydroxy bearing film forming materials be included within the scope of the invention, several of these materials will be discussed below in greater detail for purposes of exemplification.

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As discussed above, the film forming material may consist essentially of a compound which bears hydroxy functionality prior to initiation of the curing reaction.
In most coating compositions, such materials should have a number average molecular weight (Mn) of at least 150. A
preferred type of hydroxy functional material which meets these limitations consists essentially of a copolymer bearing pendent hydroxy functionality. One class of such materials have a number average molecular weight (Mn) of between about 1000 and about 20,000 and a glass transition temperature (Tg) of between about -25C. and about 70C.
Such a copolymer may, for example, consist of between about 5 and about 30 weight percent of monoethylenically unsat-urated monomers bearing hydroxy functionality and between about 95 and about 70 weight percent of other monoethyleni-cally unsaturated monomers.
The long list of hydroxy functional monomers which may be employed in these hydroxy functional copolymers in-cludes, but is not limited to, the following esters of acrylic or methacrylic acid and aliphatic alcohols: 2-hydroxyethyl acrylate; 3-chloro-2-hydroxypropyl acrylate;
2-hydroxy-1-methylethyl acrylate; 2-hydroxypropyl acrylate;

3-hydroxypropyl acrylate; 2,3-dihydroxypropyl acrylate;
2-hydroxybutyl acrylate; 4-hydroxybutyl acrylate; diethyl-eneglycol acrylate; 5-hydroxypentyl acrylate; 6-hydroxyhexyl acrylate; triethyleneglycol acrylate; 7-hydroxyheptyl acrylate; 2-hydroxymethyl methacrylate; 3-chloro-2-hydroxy-propyl methacrylate; 2-hydroxy-1-methylethyl methacrylate;
2-hydroxypropyl methacrylate; 3-hydroxypropyl methacrylate;
2,3-dihydroxypropyl methacrylate; 2-hydroxybutyl methacry-late; 4-hydroxybutyl methacrylate; 3,4-dihydroxybutyl methacrylate; 5-hydroxypentyl methacrylate; 6-hydroxyhexyl methacrylate; 1,3-dimethyl-3-hydroxybutyl methacrylate;
5,6-dihydroxyhexyl methacryl-ate;~-and-7-hydroxyheptyl-methacrylate.
Although one of ordinary s~ill in the art willreco~nize that many different hydroxy bearing monomers including those listed above could be employed, the pre-~ ~ Z L~ 3 ~ .

ferred hydroxy functional monomers for use in the hydroxyfunctional resin of the invention are C5 - C7 hydroxy alkyl acrylates and/or C6 - C8 hydroxy alkyl methacrylates, i.e., esters of C2 - C3 dihydric alcohols and acrylic or methacrylic acids.
The remainder of the monomers forming the hydroxy functional copolymer, i.e., between about 90 and about 70 weight percent, are other monoethylenically unsaturated monomers. ~hese monoethylenically unsaturated monomers, are preferably alpha, beta olefinically unsaturated mono-mers, i.e., monomers bearing olefinic unsaturation between the two carbon atoms in the alpha and beta positions with respect to the terminus of an aliphatic carbon to carbon chain.
Among the alpha, beta olefinically unsaturated monomers which may be employed in such copolymers are acry-lates (meaning esters of either acrylic or methacrylic acids) as well as mixtures of acrylates and vinyl hydro-carbons. Preferably, in excess of 50 weight percent of the total of the copolymer monomers are esters of Cl - C12 monohydric alcohols and acrylic or methacrylic acids, e.g., methylmethacrylate, ethylacrylate, butylacrylate, butylmethacrylate, hexylacrylate, 2-ethylhexylacrylate, laurylmethacrylate, etc. Among the monovinyl hydrocarbons 25 suitable for use in forming the copolymers are those con-taining 8 to 12 carbon atoms and including styrene, alpha methylstyrene, vinyl toluene, t-butylstyrene and chloro-styrene. When such monovinyl hydrocarbons are employed, they should constitute less than 50 weight percent of the 30 copolymer. Other monomers such as vinyl chloride, acrylo-nitrile, methacrylonitrile, and vinyl acetate may be in-cluded in the copolymer as modifying monomers. However, when employed, these modifying monomers should constitute only between about 0 and about 30 weight percent of the 35 monomers in the copolymer.
As mentioned above, the film forming material may contain both hydroxy functionality and a material which reacts in situ to form hydroxy functionality. Exemplary -~ 2~

of one such film forming material would be a material which consists essentlally of a single copolymer bearing both hydroxy and epoxy functionality, the epoxy functionality reacting with the acid functionality of the hydroxy function-al organophosphate ester as discussed above to form hydroxyfunctionality which thereafter may also react with the amino crosslinking agent. Such a bifunctional copolymer may be of the acrylic type similar to the hydroxy functional copolymer discussed above. A preferred bifunctional copolymer of this type has a number average molecular weight (Mn) of between about 1500 and about 10,000 preferably between about 2,000 and about 6,000, and a glass transition temperature ~Tg) of between about -25C. and about 70C., preferably between about -10C.
and about 50C. Such a copolymer preferably is formed from between about 5 and 25 weight percent of monoethylenically unsaturated monomers bearing glycidyl functionality and between about 5 and about 25 weight percent of monoethylenically unsat-urated monomers, hydroxy functionality, with the total of the monoethylenically unsaturated monomers bearing either said glycidyl functionality or said hydroxy functionality being not greater than 30 weight percent of the monomers in the copolymer. The monoethylenically unsaturated monomers bearing glycidyl functionality may be either glycidyl ethers or glycidyl esters. Preferably, however, the epoxy functional monomers are glycidyl esters of monoethylenically unsaturated carboxylic acids. Examples are glycidyl acrylates and glycidyl methacrylates. The remainder of the monomers in the copolymer, i.e., between about 90 and about 70 weight percent, consist of other monoethylenically un-saturated monomers, such as those described above.
Also as mentioned above, the film forming materialmay consist essentially of a compound which reacts in situ to form hydroxy functionality, i.e., a compound not initially including hydroxy functionality. Such a compound could be, for example, a copolymer such as those described above, but bearing only glycidyl functionality. Such a copolymer bearing pen-dent epoxy functiona~ty would have a number average molec-ular weight (Mn) of between about 1500 and about 10,000 preferably between about 2,000 and about 6,000, ~2~

and a glass transition temperature ~Tg) of between about -25C. and about 70C., preferably between about -10C.
and about 50C. A preferred copolymer of this type con-sists of between about 10 and about 30 weight percent of monoethylenically unsaturated monomers bearing glycidyl functionality and between about 90 and about 70 weight percent of other monoethylenically unsaturated monomers, as discussed above.
Still another compound bearing epoxy functionality 10 which may be employed when solely epoxy functionality, which in turn will react with the acid functionality of the organophosphate ester to form hydroxy functionality, if desired,is a polyepoxide resin having a number average molecular weight of between about 140 and about 3,000, 15 preferably between about 300 and about 2,000. The term polyepoxide resin as used herein means epoxide compounds or polymers containing two or more epoxide groups. Such polyepoxide resins are preferably selected from aliphatic, cycloaliphatic and aromatic polyepoxides falling within 20 the stated molecular weight range. Such polyepoxides are well known compositions and any of these may be employed.
Among the many suitable types of polyepoxides are those dis-closed by U.S. Patents 3,404,018; 2,528,359; 2,528,360;
3,198,850; 3,960,979; and 4,018,848.
U.S. Patent 3,404,018 discloses several particu-larly suitable types of polyepoxides including: ~1) poly-glycidyl ethers of polyhydric alcohols and polyhydric phenols; (2) epoxidized esters of polyethylenically un-saturated monocarboxylic acids; (3) glycidyl esters of 30 polybasic acids; (4) epoxidized esters of unsaturated monohydric alcohols and polycarboxylic acids; and (5) epoxidized polymers and copolymers of diolefins. Many polyepoxides other than those recited in this or other referenced patents will be apparent to those skilled in the 35 art.
As also mentioned above, there may be those in-stances when the film forming material desirably com-prises separate compounds, one or more bearing hydroxy

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functionality and one or more others bearing functionality which reacts in situ to form hydroxy functionality. Such film forming materials might, for example, consist of the above noted hydroxy functional copolymer combined with the epoxy functional copolymer discussed above or the poly-epoxide resin discussed above. Various other combinations of materials, of course, will be apparent to those ski~ed in the art. Still other film forming materials are exemplified in the detailed examples set forth hereinafter.
Amino Crosslinking Agent Amino crosslinking agent suitable for cross-linking hydroxy functional bearing materials are well known in the art and their selection will be obvious to those skilled in the art. Typically, the crosslinking materials are products of reactions of melamine or urea with formaldehyde and various alcohols containing up to and including four carbon atoms. Among the numerous materials which may be employed are the amine aldehyde resins such as condensation products of formaldehyde with melamine, substituted melamine, urea, benzoguanamine or substituted benzoguanamine. Preferred members of this class are methylated melamine-formaldehyde resins such as hexamethoxy-methyl-melamine. These liquid crosslinking agents have substantially one hundred percent (100~) nonvolatile content as measured by the foil method at 45C. for 45 minutes.
Some particularly well known crosslinking agents are the amino resins sold by American Cyanamid under the trademark "Cymel". In particular, Cymel 301, Cymel 303, and Cymel 1156, which are alkylated melamine-formaldehyde resins are useful in compositions falling within the scope of this invention.
Of course, the amount of crosslinking agent employed in any given composition is a matter of choice depending-upon the final properties desired and~the nature of the other materials in the coating composition.

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- Preferred High Solids Coating Compositions As indicated above, the high solids coating compositions within the scope of the invention include a film-forming resin bearing epoxy functionality or both

5 epoxy and hydroxy functionality. Materials suitable for use in preparing the high solids compositions of the in-vention are the acrylic copolymers bearing glycidyl functionality or glycidyl and hydroxy functionality and the polyepoxide resins, all of which are described herein-10 before.
In addition to the film-forming resin and the organophosphate ester the compositions also include an amino crosslinking agent generally described above and an optional hydroxy functional additive in an amount up to 45 weight percent of the total of the four major components of the composition. The hydroxy functional additives pro-vide additional hydroxy functionality so as to provide a more intimate crosslinked structure in the final cured product. These additives are typically selected from various polyols having a number average molecular weight (Mn) of between about 150 and about 6,000, preferably between about 400 and about 2,500. As used herein the term polyol means a compound having two or more hydroxyl groups.
The polyols useful for the preferred high solids compositions of the invention preferably are selected from the group consisting of: (i) hydroxy functional polyesters; (ii) hydroxy functional polyethers;
(iii) hydroxy functional oligoesters; (iv) monomeric polyols; (v) hydroxy functional copolymers produced by free radical polymerization of monoethylenically unsaturated monomers, one of which bears hydroxy functionality and which is included in the copolymer in an amount ranging from about 2.5 to about 30 weight percent of the copolymer and (vi)- mixtures-of (i)-- -(v).- ---The hydroxy functional polyesters useful in these preferred compositions are preferably fully saturated products prepared from aliphatic dibasic acids containing 2-20 carbon atoms, such as succinic acid, glutaric acid, ~.2~

adipic acid, azelaic acid, etc., and short chain glycols of up to and including 21 carbon atoms, such as ethylene gly-col, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,4-cyclohexane dimethylol, 1,6-hexa-methylene glycol and 2-ethyl-2-methyl-1,3 propane diol.
; The molecular weight of these materials ranges from about 200 to about 2,500 and the hydroxyl number ranges from about 30 to about 230. The hydroxyl number is defined as the number of milligrams of potassium hydroxide needed for each gram of sample to neutralize the acetic acid gen-erated during the reaction between the polyol and the excess acetic anhydride. The polyester polyols utilized in the compositions are low melting, soft waxy solids which are easily maintained in the molten state.
Among preferred polyesters are products derived from the esterification of ethylene glycol and 1,4 butane diol with adipic acid, ethylene glycol and 1,2 propylene glycol with adipic acid, azelaic acid and sebacic acid copolyester diols, and mixtures thereof.
Among useful polyether diols are polytetra-methylene ether glycol, polyethylene glycol, poly-propylene glycol and the like.
The hydroxy functional oligoesters useful as hydroxy functional additives in the preferred compositions of the invention are oligoesters preferably having a molecular weight of between about 150 and about 3,000. Such oligoesters may be selected from the group consisting of:
(i) oligoesters prepared by reacting a dicarboxylic acid 30 with a monoepoxide such as an alkylene oxide; (ii) oligo-esters prepared by reacting a polyepoxide with a mono-carboxylic acid; and (iii) oligoesters prepared by reacting a hydroxy functional monocarboxylic acid with either a mono- or polyepoxide; ~
The oligoester prepared by reacting a di-carboxylic acid with an alkylene oxide is a low molecular weight adduct which has a narrow molecular weight distri-bution when compared to similar compositions made by ~.2~

normal polyester manufacturing techniques. The adduct is prepared by reacting a dibasic carboxylic acid with alkylene oxides, preferably ethylene oxide or propylene oxide, in the presence of a catalyst. Preferred dicar-boxylic acids are C6 - C12 aliphatic acids such as adipic acid, azelaic acid, sebacic acid or dodecane dicarboxylic acid. Mixtures of these acids or mixtures of the aliphatic dicarboxylic acids with aromatic dicarboxylic acids also yield suitable hydroxy functional oligoesters.
The preparation of oligoesters from monocarboxylic acids and polyepoxides is well known and is described, for example, in U.S. Patents 2,456,408 and 2,653,141. Numerous hydroxy functional oligoesters within this general category will be apparent to those skilled in the art.
A third type of hydroxy functional oligoester, i.e., those prepared by reaction of a hydroxy functional monocarboxylic acid with an epoxide is described in U.S.
Patent 3,404,018. While the epoxides employed in accordance with the teachings of that patent are polyepoxides, oligo-esters may be prepared in a similar manner to that described therein by employing a monoepoxide, such as an alkylene oxide, and a hydroxy functional monocarboxylic acid as described therein. Numerous monoepoxide materials suitable for this purpose will be apparent to those skilled in the art, Among the numerous monomeric polyols which may be employed as the hydroxy functional additive are the various short chain glycols of up to and including 21 carbon atoms which are useful in preparing the hydroxy functional polyesters discussed above. Other conventional polyhydric alcohols such as glycerols and sugar alcohols are also among the numerous monomeric polyols which will be apparent to those skilled in the art.
The hydroxy bearing copolymer described above for use as a film-forming material for compositions of the invention, in general may also be used as a hydroxy-functional additive in the preferred high solids coating compositions of the invention.

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It is the reactive nature of the hydroxy-func-tional organophosphate ester component which allows the composition to cure rapidly at a low temperature. As indicated generally above, the acid functionality of the mono- or diester or mixture of such esters reacts with the epoxy functionality of the epoxy functional film-former to form an ester and a hydroxyl group. This hydrox-yl group, as well as the organic hydroxyl groups on the hydroxy functional organophosphate ester, any hydroxyl groups in the film-former in addition to the epoxy functionality and any optional hydroxy groups included in the composition in the form of hydroxy functional additive, including any diol or triol present from the synthesis of the - hydroxy functional organophosphate ester, crosslinks with the amino resin crosslinking agent. It is critical to achieving the desired results of the high solids coating compositions of this invention, i.e., in making them suitable for use as automotive topcoats, that the amount of organophosphate ester be sufficient to convert substantially all of the epoxy functionality on the film-former to the desired hydroxy functionality by esterification reaction.
Therefore, the organophosphate ester is included in the composition in an amount sufficient to provide between about .67 and about 1.4 equivalents, preferably between about .8 and about 1 equivalents, of acid functionality for each equivalent of pendent epoxy functionality on the copolymer. As will be noted from the equivalent amounts of epoxy and organophosphate ester acid functionality stated above, the amount of acid functionality need not be in stoichiometric amounts to the epoxy functionality. This is because of the fact that during curing of the high solids coating composition, residual water present in the compo-sition hydrolyzes some of the esterified product back to - acid and-this hydrolyzed product then~ in turn, reacts with additional epoxy functionality.
As also indicated above, the amino resin materials function as a crosslinking agent by reacting with hydroxy functionality present in the composition. In the preferred high solids compositions of the invention this hydroxy z~

functionality may be present (i) in an organic hydroxyl group on the hydroxy functional organophosphate ester, (ii) as a hydroxyl group on the film-former in those cases where that component bears hydroxy as well as epoxy S functionality; (iii) as a hydroxyl group on the optional hydroxy functional additive including any excess diol or triol from the organophosphate synthesls or (iv) as a result of esterification of the epoxy functionality of the film-former.
In order to achieve the outstanding properties which make these preferred high solids coating compositions particularly useful as automotive topcoat materials, it is essential that the amount of amino crosslinking agent be sufficient to substantially completely crosslink the hydroxy functionality in the coating composition. There-fore, the amino resin crosslinking agent should be included in the composition in an amount sufficient to provide at least about .4 equivalents, preferably between about .6 and about 2.1 equivalents, of nitrogen crosslinking functionality for each equivalent of hydroxy functionality included in the eomposition.
Other Materials Of eourse, it should be recognized that coating compositions within the scope of this invention including the preferred high solids compositions may include other conventional components. These include, but are not limited to, antioxidants, U.V. absorbers, solvents, surface modifiers, wetting agents, pigments, fillers, ete.
The invention will be further understood by re-ferring to the following detailed examples. It should beunderstood that the specifie examples are presented by way of illustration and not by way of limitation. Unless other-wise specified, all references to "parts" are intended to mean parts by weight.~

~ 2~4~

Example l (a) In a three-necked round bottom flask equipped with a stirrer, dropping funnel and a thermometer are placed five hundred (500) grams of dry (dried over molecular sieves) 2-ethyl-1,3-hexane-diol. Phosphorus pentoxide is added portionwise with continuous stirring and an exothermic reaction occurs. The addition of phos-phorus pentoxide is regulated to maintain the temperature at 50C. Test portions of the reaction mixture are with-drawn at short intervals of time and titrated with po-tassium hydroxide solution. The addition of P2O5 is con-tinued until the acid equivalent weight reaches about 280.
The reaction mixture is stirred at 50C. for one more hour and then filtered. Its acid equivalent weight, by titra-tion with KOH solution, is 271.
(b) A hydroxy acrylic copolymer is prepared from the following monomers:
Wt/grams Wt.%
Hydroxyethyl acrylate 400 20 20 Methylmethacrylate 400 20 Styrene 200 10 Butyl methacrylate 1000 50 One hundred (100) grams tert-butyl perbenzoate is added to the above monomer mixture and the resulting solution added dropwise over a period of two hours to 1600 grams of refluxing (145) methyl amyl ketone (under nitrogen). The heating and stirring is continued for half an hour after the addition is complete and then five (5) grams of tert-butyl perbenzoate are added portionwise to the reaction mixture. The reaction mixture is refluxed for an additional ninety minutes and then allowed to cool to room temperature.
The molecular weight is determined by Gel Permeation Chromatography: ~n = 2,540, MW/Mn = 1.94 Calculated Tg - 2~Cc - -Theoretical solids = 60~
Determined solids = 59.2%
Viscosity, #4 Ford Cup = 44 sec.
Hydroxy equivalent weight = 980 z~

Fifty (50) parts of the polymer solution (b) are mixed with twenty (20) parts of Cymei* 301 (American Cyanamid) and ten (10) parts of butyl acetate. One part of hydroxy phosphate (a) is added to the above solution and the resulting formulation is spray applied to primed steel test panels in three coats. The panels were baked at 120C. for lS minutes to obtain hard, glossy coatings with excellent solvent (xylene and methyl amyl ketone) resistance.

Example 2 Three hundred fifty (350) parts of TiO2 are mixed~with 350 parts of Acryloid~ OL-42 (Rohm and Haas Chemical Company) and 25 parts of butyl acetate. The above mixture is taken up in a porcelain bottle containing porcelain beads and put on a roller mill for 16 hours.
Thirty parts of this mill base are mixed with 20 parts of hydroxy polymer from example l(b), 15 parts of Cymel*301, .
two parts of hydroxy phosphate from example l(a) and eleven parts of butylacetate. The resulting formulation is spray applied to primed steel panels and is cured at 110C. for 20 minutes to obtain coatings with excellent physical properties.

Example 3 Eighty (80) parts of acrylic copolymer solution described in Example l(b) are mixed with 40 parts of Araldite*CY 178 and 50 parts of Cymel*301. This mixture is dissolved in 30 parts of butyl acetate and 46 parts of hydroxy phosphate prepared in Example l(a) are added to it. The resulting solution is stirred for one minute and then spray applied to primed steel panels. The panels are baked at 120C. for 20 minutes to obtain hard clear coatings. wlth.,excellen.t.hardness,. a.dhesi~n~.. ~lQs.s.. and,........... ..
solvent (xylene and methyl ethyl ketone) resistance. After 14 days in a Cleveland. Humidity Chamber panels show no loss of gloss and no peeling, blistering or discoloration.
~r", * ~ Trader.narks ~.~ 2~

~ Example 4 One hundred grams of carboxy-terminated poly-butadiene rubber (Hycar*CTBN 1300 x 8) are mixed with 100 grams of Araldite*CY178 and 25 ml. of butylacetate.
Two grams of Cordova*Accelerator AMC-2 are dissolved in 25 - ml. butylacetate and are added to the reaction mixture.
The reaction mixture was stirred at 50C. for 15 hours.
Three parts of the above adduct, 7 parts of Araldite*CY178 and 9 parts Cymel* 301 are dissolved in 10 parts of butylacetate. 8.9 parts of hydroxy phosphate from Example l(a) (eq. wt. 271) are added to the above solution and the resulting formulation is applied to un-polished steel test panels. The panels are heated at 140C.
for 30 minutes to obtain a moisture resistant and corrosion inhibiting coating.

Example 5 One hundred (100) grams of 1,4-cyclohexanedimeth-anol are dissolved in 80 grams of butyl acetate at 50C.
and the procedure outlined in Example l(a) followed to obtain a hydroxy phosphate with acid equivalent weight of 645.
Twenty (20) parts of the polymer solution from Example l(b) are mixed with 11.6 parts of Araldite*CY178, 18 parts of Cymel*301 and 5 parts of butyl acetate. The hydroxy phosphate described above, 34.7 parts, is added to the above solution and the resulting formulation applied by spraying to primed steel test panels. The panels are baked at 125C. for 20 minutes to obtain a coating with excellent gloss, hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 6 (a) Hydroxyphosphate is p~repared-b~-foll~wing the - -procedure described is Example l(a) to obtain an acid equivalent weight of 485.
(b) In a round-bottom four-necked flask, equipped with a stirrer, a dropping funnel, a thermometer and a * Trademarks , ~

~.2~9~33L

condenser, 500 ml. of methyl amyl ketone is brought to reflux under nitrogen. The following mixture of monomers is employed for polymer synthesis:
Wt./grams Wt.%
; 5 Butyl methacrylate 127.5 17 Ethylhexyl acrylate 180 24 Glycidyl methacrylate 195 26 Methyl methacrylate 210 28 Styrene 37.5 5 Thirty-seven (37) grams of tert-butyl perbenzoate is added to the above monomers and the resulting solution added dropwise to refluxing methyl amyl ketone over a period of one hour and ten minutes. The heating and stirring is continued for half an hour after the addition is complete and then two more grams t-butyl perbenzoate are added portionwise. The reaction mixture is refluxed for two more hours and then allowed to cool to room temperature.
The molecular weight of the copolymer is determined by Gel Permeation Chromatography and found to be Mn = 3250 and MW/Mn = 2.2. The calculated Tg of the polymer is 9C.
and the solution viscosity (#4 Ford cup) is 41 seconds.
Eighty (80) parts of the copolymer solution prepared in (b) and 40 parts of Cymel 301 are dissolved in 20 parts of butyl acetate and 44.5 parts of the hydroxy phosphate prepared in (a) are added to this solution. The resulting formulation is spray applied to steel test panels and the panels are baked at 130C. for 20 minutes to obtain a glossy (81/20) coating with excellent hardness, adhesion and solvent (xylene and methyl amyl ketone) resistance. The coating does not show any loss of gloss or adhesion after 14 days exposure in the Cleveland Humidity Chamber.

Example 7 Five (5) parts of aluminum flakes (65% in naphthal~ -are mixed well with 80 parts of the copolymer solution from Example 6(b). Thirty-nine (39) parts Cymel 301 and 30 parts of butyl acetate are added to the above mixture and the resulting material is filtered through a coarse filtering cloth. Forty-five (45) parts of hydroxy phosphate from Example 6(a) are added to the filtrate and the resulting formulation spray applied to primed steel test panels in a three-coat application. The intermediate flash time is one minute and the final flash is five minutes. The panels are baked at 115C. for 20 minutes to obtain a silver metallic coating with excellent hardness, adhesion and solvent (xylene and methyl amyl ketone) resistance.

Example 8 In a three-necked, round bottom, two liter flask, equipped with a stirrer, a condenser and a dropping funnel, ; 750 ml. of toluene is brought to reflux under nitrogen.
The following mixture of monomers, containing 15 grams of 2,2'-azobis'(2-methylpropionitrile) dissolved in 50 ml acetone, is added dropwise to the refluxing toluene.
Wt./Grams Wt. %
Butyl methacrylate150 50 ; Glycidyl methacrylate 45 15 2Q Hydroxypropyl methacrylate 30 10 `~ Methyl methacrylate60 20 ; Styrene 15 5 The addition of the initiator and monomer solution is completed in three hours. The reaction mixture is refluxed for half an hour more and 10 ml of acetone solution of 2 ; grams of the above initiator is added dropwise and the reaction mixture refluxed for half an hour. Part of the solvent is distilled out to bring the solids content to 66% by weight.
3Q Twenty (20) parts of this polymer solution are mixed with 7 parts of Cymel 301 and the mixture dissolved in ten (10) parts of butyl acetate. ~.5 parts of hydroxy phosphate from Example l~a) is added to the above solution and the resulting formulation drawn on a steel test panel.
35 The panel is baked at 100C. for 20 minutes to obtain a glossy (86/20) panel with excellent harcness, adhesion and solvent (xylene and methyl ethyl :~etone) resistance.

~2~

Example 9 ~ a~ A copolymer is prepared by following the procedure described in Example 8 in methyl amyl ketone at 125C. and by using the following monomers:
Wt. %
; Butyl methacrylate 50 Ethylhexyl acrylate 10 Glycidyl methacrylate 15 Hydroxypropyl methacrylate 10 10 Methyl methacrylate 10 Styrene 5 Tert-butyl peroctoate (5.25% of monomers) is used as initi-ator and aetermined solids content is 56.6% by weight. The calculated Tg of the copolymer is 25C. and the molecular weight from Gel Permeation Chromatography is found to be n 4220 and MW/Mn = 1.90 (b) By following the procedure described in Example l(a), hydroxy phosphate with an acid equivalent weight of 400 is prepared from phosphorus pentoxide and 2-ethyl-1,3 hexanediol.
A millbase is prepared by dispensing titanium dioxide in the polymer (a) with a high speed Cowl's blade.
The composition of the millbase is: 15% polymer (100%
nonvolatile), 65~ titanium dioxide and 20% methyl amyl ketone. Seventy-two (72) parts of this millbase, 31 parts of the polymer, 12.5 parts of bis-(hydroxypropyl) azelate, 34 parts of Cymel*301 and 29 parts of methyl amyl ketone are taken up in a plastic bottle. Twelve (12) parts of hydroxy phosphate (equivalent weight 400), described under (b), are added to the above mixture and the resulting formulation spray applied to both primed and unprimed steel panels. The panels are baked at 120C. for 20 minutes to obtain ~ard, glossy coatings with excellent adhesion.
The coating has an excellent solvent and humidity resistance.

Example 10 ~a~ 3y ~ollowing the pr3cPcure described in ~2 ~ * Trademark Example 9(a) a copolymer is prepared from the following monomers:
Wt.
Butyl methacrylate 60 5 Glycidyl methacrylate 20 Hydroxyethyl acrylate 10 Styrene 10 The calculated Tg of the polymer is 25C. and solids con-tent is found to be 54.9% by weight. The molecular weight by Gel Permeation Chromotography is found to be Mn = 1809 and Mw/Mn = 2.44.
(b) By following the procedure described in Example l(a) a hydroxy phosphate with acld equivalent weight of 212 is prepared from phosphorus pentoxide and 2-ethyl-1,3 hexanediol.
As described in Example 9, a mill base is preparedfrom the following materials:
Copolymer (a) 21% (100~ nonvola-tile) 2Q Titanium dioxide 61~
Methyl amyl ketone 18%
Sixty-Eive (65) parts of this millbase, 26.4 parts polymer (a), 12.5 parts bis-(hydroxyl propyl) azelate, 24.9 parts Cymel 301 and 25 parts of methyl amyl ketone are taken up in a plastic bottle. Hydroxy phosphate (~) (Equivalent weight 212), 9.5 parts, is added to the above mixture and the resulting formulation spray applied to both primed and unprimed panels. The panels are baked at 120C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent resistance. The coatings, when put in a Cleveland Humidity Chamber for 14 days, do not show any deterioration in general physical properties.

Example 11 Fifty (50~ grams of 1,4-ben2enedimethanol are dissolved in 150 grams of 2-ethyl-1,3-hexanediol and 40 ml.
of butyl acetate. Phosphorus pentoxide ls added to the above solution as descrlbed in Exa.npl- l~a) to obtain a hydroxyphosphate with an acid equivalent weight of 364.

~Z4~

Thirty ~30) parts of the polymer solution from Example 8, 11 parts of-Cymel*-301, and 2 parts of caprolactone--based hydroxypolyester (PCPO*300, Union Carbide) are dis-solved in 10 parts of butyl acetate. The above hydroxy-phosphate (8.9 parts) is added to the above solution andthe resulting formulation applied by spraying to primed steel test panels. The panels are baked at 130C. for 20 minutes to obtain a hard, glossy coating with excellent ; adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 12 One hundred (100) grams of 1,4-cyclohexanedimeth-'! anol are dissolved in 80 grams of butyl acetate at 50C.
and the procedure outlined in Example l(a) is followed to obtain a hydroxyphosphate with an acid equivalent weightof 645.
The procedure of Example 9 is modified by sub-stituting 19.4 parts of the above hydroxyphosphate for the hydroxyphosphate used therein and three more parts of Cymel*301 are added to the formulation. The resulting paint is applied by spraying to primed steel test panels and the panels baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent ~xylene and methyl ethyl ketone) resistance.

Example 13 ~ydroxy polymer is prepared as described in Example 1 with the only change that only 10 grams of tert-butyl perbenzoate is employed. Fifty (50) parts of this polymer solution are mixed with 20 parts of ~eetle*80 (American Cyanamid), 40 parts of butylacetate and 2 parts - - of hydroxyph-o~phate f~ x~mpl-e l(a). The for~latiGn is spray applied to primed stee-l panels and baked at 90C.
for lS minutes to obtain a hard, glossy coating with excel-lent soivent ~ylene and methyl amyl ~etone) resistance.
* Trademarks ~,,,,,~

; Example 14 Sixty (60) parts of the polymer from Example 13 are mixed with 4 parts of aluminum flakes (65% in naphtha), 18 parts of Cymel 301, 1.5 parts of hydroxyphosphate from Example 1, 30 parts butyl acetate and 10 parts acetone.
The resulting formulation was spray applied in three coats to primed steel test panels. The panels were baked at 110C. for 15 minutes to obtain silver metallic coating with excellent physical properties.

Example 15 Seventy-five (75) parts of acrylic copolymer described in Example 13 are mixed with 40 parts of Araldite CY178, 41 parts of Cymel 301 and 75 parts of butylacetate.
Forty-seven (47) parts of hydroxyphosphate prepared in Example l(a) are added to it and the resulting formulation is spray applied to primed steel test panels. The panels are baked at 90C. for 20 minutes to obtain hard, clear coatings with excellent adhesion, gloss and solvent (xylene and methyl ethyl ketone) resistance.
, xample 16 Six (6) parts of aluminum flakes (65~ in naphtha) are mixed well with 70 parts of the polymer solution from Example 6(b). Forty-nine (49) parts Cymel 301, 20 parts of polymer from Example 13 and 75 parts of butyl acetate are added to the above mixture and the resulting material is filtered through a coarse filtering cloth. Twenty-five (25) parts of hydroxy phosphate from Example l(a) are added to the filtrate and the resulting formulation spray applied to primed steel test panels in a three-coat appli-cation; the intermediate flash time is one minute and thefinal flash five minutes. The panels are baked at 115C.
for 20 minutes to obtain silver-metal-lic coatings with- ------excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

3~

Example 17 By following the procedure described in Example 9(a), a copolymer is prepared in refluxing toluene from the following monomers:
Wt.%
Butyl methacrylate 55 Ethylhexyl acrylate 20 Glycidyl methacrylate 5 Hydroxypropyl methacrylate 10 10 Sytrene 10 One thousand (1000) grams of the total monomers, 900 ml.
toluene and 10 grams of tert-butyl peroctoate are used.
Seventy-five (75) parts of this polymer solution, 23 parts Cymel 301 and 4.2 parts of hydroxy phosphate from Example 1 are dissolved in 70 parts of butylacetate. This formulatian is spray applied in three coats to primed panels which are baked at 110C. for 15 minutes to obtain coating with excellent physical properties.

Example 18 Fifty (50) parts of the polymer solution from Example 6(b) is mixed with 24 parts of hexamethoxymethyl melamine, 5 parts of polypropylene glycol (Pluraco~ P710, BASF Wyandotte Co.) and 15 parts of butyl acetate. 14.9 parts of hydroxyphosphate from Example l(a) is added to the above solution and the resulting formulation is spray applied to steel test panels. The panels are baked at 130C.
for~20 minutes to obtain glossy (85/20) coatings with excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance. The coating does not show any loss of gloss or adhesion after 14 days exposure in a Cleveland Humidity Chamber.

Example-lg - -Six (6) parts of aluminum flakes (65~ in naphtha) are mixed well with 70 parts of the polymer solution from Example 6(b). Thirty-nine (39) parts Cymel 301 and 30 parts of butyl acetate are added to the above mixture and * Trademark ~.~ 24~3~

the resulting material is filtered through a coarse fil-tering cloth. Twenty-five (25) parts of hydroxy phosphate from Example l(a) are added to the filtrate and the re-sulting formulation spray applied to primed steel test 5 panels in a three-coat application; the intermediate flash time is one minute and the final flash five minutes. The panels are baked at 115C. for 20 minutes to obtain silver metallic coatings with excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 20 The following monomers are utilized in the synthesis of a glycidyl methacrylate polymer.
Wt./gramsWt.
Butyl methacrylate 120 16 15 Ethylhexyl acrylate 142.5 19 Glycidyl methacrylate 195 26 Methyl methacrylate 255 34 Styrene 37.5 5 The polymerization is carried out as outlined in Example 1 by employing S00 grams of methyl amyl ketone and 30 grams of tert-butyl perbenzoate. The addition of initiator and the monomer mixture is complete in two hours and the reaction mixture refluxed for one additional hour. Two grams of initiator are then added and the reaction mixture ! 25 refluxed for two hours. The molecular weight determined by Gel Permeation Chromatography is found to be Mn = 3168 and MW/Mn = 2.15. The Tg of this polymer is calculated to be 20C.
Thirty-two (32) parts of the above polymer solu-tion, fourteen (14) parts of hexamethoxymethyl melamine~Cymel 301) and two parts of 1,4-cyclohexanedimethanol are dissolved in ten parts of butyl acetate. 9.9 parts of hydroxyphosph-ate from Example l~a~ are- added ta:t~e ahove-solution and the resulting formulation spray applied to primed steel panels; the panels are baked at 120C. for 20 minutes to obtain a coating with excellent physical properties.

4~31 Example 21 Twenty-seven (27) parts of the polymer described in Example 20, 16 parts of Cymel 301 and 5 parts of Acry-loid OL-42 (Rohm and Haas Chemical Co.) are dissolved in 10 parts of butyl acetate. 8.4 parts of hydroxyphosphate from Example l(a) is added to the above solution and the resulting formulation drawn on a steel test panel and baked at 130C. for ten minutes to obtain a glossy coating with excellent hardness, adhesion and solvent resistance.

Example 22 (a) One hundred (100) grams of 1,4-cyclohexane-methanol are dissolved in 80 grams of butyl acetate at 50C.
and the procedure outlined in Example 6(a) is followed to obtain a hydroxyphosphate with an acid equivalent weight of 645.
(b) Eighty (80) parts of the polymer solution prepared in Example 6(b), 10 parts of bis-(hydroxypropyl) azelate (product of propylene oxide and azelaic acid) and 45 parts of ethoxy methoxymethylbenzoguanamine (Cymel 1123, American Cyanamid) are dissolved in 25 parts of butyl acetate and 58.2 parts of hydroxyphosphate from (a) are added to this solution. The resulting formulation is spray applied to primed steel panels and baked at 130C.
for 20 minutes to obtain hard, glossy coatings with excel-lent adhesion and solvent resistance.

Example 23 Thirty-five (35) parts of the polymer solution prepared in Example 20, 17 parts of hexamethoxymethyl melamine (Cymel 301, American Cyanamid) and 5 parts of caprolactone based hydroxyester PCP0300 (Union Carbide) are dissolved in 10 parts of butyl acetate. 10.7 parts of hydroxyphosphate from Example-l(a)- are added-t~-the above solution and the resulting formulation spray applied to primed steel test panels. The panels are baked at 130C. for 20 minutes to obtain coatings with excellent hardness, adhesion, gloss and solvent resistance (xylene and methyl ethyl ketone).

l~ Z~3~

' Example 24 - The following mixture of monomers is used in the polymer synthesis:
Wt.%
5 Butyl methacrylate 25 Glycidyl acrylate 30 Methyl methacrylate 40 Styrene 5 The polymerization is carried out as outlined in Example 1 to obtain a 50% solution of the polymer.
Seventy (70) parts of the above polymer solution, 15 parts of bis-(hydroxypropyl) azelate (reaction product of propylene oxide and azelaic acid) and 35 parts of hexamethoxymethyl melamine (Cymel 301) are dissolved in 10 parts of butyl acetate. 22.3 parts of hydroxyphosphate from Example l(a), are added to the above solution and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 15 minutes to obtain glossy (88/20) coatings with excellent adhesion, hardness and solvent (xylene and methyl ethyl ketone) resistance.

Example 25 (a) A hydroxy acrylic copolymer is prepared from the following monomers:
Wt./grams Wt.%
Butyl methacrylate 1000 50 Hydroxyethyl acrylate 400 20 Methyl methacrylate 400 20 Styrene 200 10 One hundred (100) grams tert-butyl perbenzoate is added to the above monomer mixture and the resulting solution added dropwise over a period of two hours to 1400 grams of - refluxing methyl--amy~l ketone~under-nitrog~;-;The heating.
and stirring is continued for half an hour after the addi-tion is complete and then five grams of tert-butyl per-benzoate are added portionwise to the reaction mixture.
The reaction mixture is refluxed for an additional ninety (90) minutes and then allowed to cool to rocm temperature.

. - . .

43~

The molecular weight is determined by Gel Permeation Chromatography Mn ~ 2540 and MW/M = 1.94.
(b) A solution of 1250 grams of 2-ethyl-1,3 hexane diol in 1250 grams of butyl acetate is placed under nitrogen in a three-necked round bottom flask equipped with a mechanical stirrer. Phosphorus pentoxide (442 grams) is added portionwise with continuous stirring, an exothermic reaction occurs and the addition of P2O5 is regulated to maintain the temperature between about 50 and about 60C. After completing the addition (about 4 hours), the reaction mixture is stirred for three more hours. The acid equivalent weight, by titration with KoH
solution, is found to be 315.
Forty(40) parts of the polymer from (a), 45 parts by weight of the glycidyl methacrylate polymer from Example

6(b) and 34 parts of hexamethoxymethyl melamine (Cymel 301) are dissolved in 20 parts of butyl acetate. 16.3 parts of hydroxyphosphate from (b) is added to the above solution and the resulting formulation spray applied to primed steel test panels. The panels are baked at 130C. for 20 minutes to obtain glossy coatings with excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 26 Twenty-five (25) parts of polymer from Example 20, 25 parts of the hydroxypolymer from Example 25 and 27 parts of hexabutoxymethyl melamine (Cymel 1156) are dissolved in 15 parts of butyl acetate. 9.1 parts of hydroxyphosphate from 25tb) is added to the above solution and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 20 minutes to obtain glossy coatings with excellent hardness, adhesion and solvent resistanGe~

Example 27 (a) Fifty (50) grams of 1,4-benzenedimethanol are dissolved in 150 grams of 2-ethyl-1,3-hexanediol and 40 ml. of butyl acetate. Phosphorus pentoxide is added ~L~ Z~4~1 portionwise to the above solution as described in Example l(a) to obtain a hydroxyphosphate with an acid equivalent weight of 364.
(b) Thirty (30) parts of glycidyl methacrylate polymer from Example 20. 5 parts of bis-(hydroxypropyl) azelate and 18 parts of ethoxymethoxymethyl ben70guanamine (Cymel 1123, American Cyanamid) are dissolved in 10 parts of butyl acetate. 13.2 parts of the hydroxyphosphate are added to the above solution and the resulting formula-tion spray applied to primed steel panels. The panels are baked at 180C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 28 (a) Example l(a) is repeated to obtain a hydroxy phosphate with acid equivalent weight of 212.
(b) Twenty-five (25) parts of glycidyl methac-rylate polymer from Example 6, 20 parts of hydroxy polymer from Example 25, 5 parts of bis-(hydroxypropyl) azelate and 19 parts of butoxymethyl glycoluril (Cymel 1170, Ameri-can Cyanamid) are dissolved in lS parts of butyl acetate.
5.8 parts of the hydroxyphosphate are added to the above solution and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 29 Thirty (30) parts of glycidyl methacrylate polymer from Example 20, 7 parts of Acryloid OL42 (Rohm and ~aas Chemical Co.) and 27 parts of butoxymethyl urea resin - (Beetle 80,--American Cyan-amid) ~are dissolv~ 1n 201:part~
of butyl acetate. 7.3 parts of hydroxyphosphate from Example 28(a) are added to the above solution and the resulting formulation spxay applied to primed steel panels.
The panels are baked at 130C. for 20 minutes to obtain a hard and glossy coating.

Example 30 The following mixture of monomers is employed in the synthesis of a polymer:
Wt.%
Allyl glycidyl ether 30 Butyl methacrylate 25 Methyl methacrylate 30 Styrene 15 The polymerization is carried out as outlined in Example 1 to obtain a 52% solution of the polymer in methyl amyl ketone.
Thirty-one (31) parts of the above polymer, 20 parts of the hydroxy polymer from Example 23, 17 parts of hexamethoxymethyl melamine (Cymel 301, American Cyanamid) are dissolved in 10 parts butyl acetate. 8.9 parts of hydroxyphosphate from Example 28(a) are added to the above solution and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene, and methyl ethyl ketone) resistance.

Example 31 The following monomers are employed in the syn-25 thesis of this polymer.
Wt.
Butyl methacrylate 40 Glycidyl methacrylate 15 Methyl methacrylate 40 30 Styrene 5 The polymerization is carried out in methyl amyl ketone by - employing 1~.8~ tby wt.~of the monomers)- of-~the ~nitiator.~
The molecular weight from Gel Permeation Chromatography is found to be Mn = 5750~ MW/Mn = 24. The solids content is found to be 54% by weight Sixty (60) parts of this polymer solution, 70 parts of the polymer from Example 20 and 50 parts of hexa-methoxymethyl melamine (Cymel 301) are dissolved in 30 3~

parts of butyl acetate. 15.4 parts of hydroxyphosphate from Example l(a) is added to the above solution and the resulting formulation spray applied to primed steel panels.
The panels are baked at 130C. for 20 minutes to obtain coatings with excellent hardness and adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 32 Three hundred fifty (350) grams of titanium dioxide are mixed with 350 parts of Acryloid OL-42 (Rohm and Haas Chemical Co.) and 25 parts of butyl acetate. The above mixture is taken up in a porcelain bottle containing porce}ain beads and is put on a roller mill for 16 hours.
Forty (40) parts of the above mill base are mixed with 28 parts of polymer from Example 6, 5 parts of hydroxy ester Desmophen`*KL5-2330 (Rohm and Haas Chemical Co.), 13 parts of hexamethoxymethyl melamine (Cymel* 301) and 20 parts of butyl acetate. 7.6 parts of hydroxyphosphate from Example 28 are added to the above mixture and the resulting formu-lation spray applied to primed steel panels. The panels are baked at 120C. for 20 minutes to obtain coatings with excellent physical properties.

Example 33 Five hundred (500) parts of titanium dioxide and 250 parts of Ferrite yellow are mixed with 500 parts of Acryloid*OL-42 (Rohm and Haas Chemical Co.), 7.8 parts of dispersing agent BYK*P104S (Mellinckrodt) and 200 parts of butyl acetate. The mill base is prepared as described in Example 32.
Thirty-five parts of this millbase are mixed with 50 parts of polymer from Example 20, 25 parts of hexa-methoxymethyl melamine, 3 parts of 1,4-cyclohexanedimethan-- ol and 22 parts af butyl acetate~ 7.9-parts af-hydr~xy-~
phosphate from Example 25(b) are added to the above mix-ture and the resulting formulation spray applied to primed steel panels. The panels are baked at 115C. for 20 minutes to obtain coatings with excellent physical proper-! ties.
* Trademarks Twenty-five (25) parts of the copolymer described in Example 8, 15 parts of Cymel 301 and 16 parts of polyester Desmophen KL5-2330 (Mobay Chemical Company) are dissolved in 16 parts of butyl acetate. Hydroxyphosphate from Example l(a), 5.7 parts,is added to the above solution and the resulting formulation spray applied to primed test panels. The panels are baked at 100C. for 20 minutes to obtain a glossy (93/20) coating with excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance. The coating, when placed in a Cleveland Humidity Chamber for 14 days does not show any blistering or loss of adhesion, gloss or solvent resis-tance.

Example 35 By following the procedure described in Example 9, a copolymer is prepared from the following monomers:
Wt.
Butyl methacrylate 49 Glycidyl methacrylate 20 20 Hydroxypropyl methacrylate 10 Methyl methacrylate 16 Styrene 5 The calculated Tg of the copolymer is 43C. and solids content is found to be 52%. The molecular weight, by Gel Permeation Chromatography, is found to be, Mn = 2904 and Mw/ n 2.31.
As described in Example 9, a millbase is prepared with the following composition:
Wt.%
30 Titanium dioxide 65 The above copolymer 13 (100% non-volatile) Methyl amyl ketnne 22 Sixty-nine (69) parts of this millbase, 37 parts of the polymer, 17.5 parts bis-(hydroxypropyl) azelate, 29.2 parts Cymel 301 and 22 parts methyl amyl ketone are taken up in a plastic bottle. Hydroxyphosphate (eq. wt. 212) from Example lO(b), 815 parts is added to the above mix-3~

- ture and the resulting formulation spray applied to primed test panels. The panels are baked at 115C. for 20 minutes to obtain glossy, hard coatings with excellent solvent (xylene and methyl ethyl ketone) resistance. These coatings do not show any loss of gloss, adhesion or solvent resis-tance upon exposure in a Cleveland Humidity Chamber for 14 days.
Example 36 By following the procedure described in Example 8, a copolymer is prepared in refluxing methyl amyl ketone from the following monomers:
Wt.
Glycidyl methacrylate 20 Hydroxyethyl acrylate 10 15 Butyl methacrylate 60 Styrene 10 Two percent tert-butyl peroctoate is used as initiator;
the solids content is found to be 53.6%. From Gel Permea-tion Chromotography the molecular weight of the polymer is found to be Mn = 2746 and MW/Mn = 2-33-As described in Example 9, a millbase is prepared with the following ingredients.
Wt.
Titanium dioxide 56 25 The above polymer 26 (100% non-~ volatile) - Methyl amyl ketone 18 Seventy-one (71) parts of this millbase, 14.6 parts polymer, 12.5 parts bis-(hydroxypropyl) azelate, 24.9 parts Cymel 301, 30.6 parts methyl amyl ketone and 8.5 parts hydroxy phosphate (eq. wt. 212) from Example lO(b) are mixed in a plastic container. This formulation is spray applied to primed test panels. The panels are baked at 120C. for 20 minutes to obtain glossy, hard coatings with excellent solvent (xylene and methyl amyl ketone) resistance. The coatings do not show any loss of gloss, adhesion or solvent resistance upon expo-sure in a Cleveland Humidity Chamber for 14 days.

~ 2~3~

Example 37 (a) By following the procedure described in Example 8, a copolymer is prepared in refluxing toluene from the following monomers:
Wt.%
Butyl methacrylate 50 Ethylhexyl acrylate 20 Glycidyl methacrylate 15 Hydroxypropyl methacrylate 10 10 Styrene 5 One thousand grams of the total monomers and 700 ml. toluene and 50 grams tert-butyl peroctoate are used. The calcu-lated Tg of this polymer is 6C. and solid content is found to be 59% by weight; a Gel Permeation Chromatogram shows its molecular weight to be: Mn = 4337 and MW/Mn =
2.14. Viscosity of this polymer solution is 1.33 stokes.
(b) A solution of 1250 grams of 2-ethyl-1,3 hexane diol in 1250 grams of butyl acetate is placed under nitrogen in a three-necked round bottom flask equipped with a mechanical stirrer. Phosphorus pentoxide t442 grams) is added portionwise with continuous stirring, an exo-thermic reaction occurs and the addition of P2O5 is regu-lated to maintain the temperature between about 50C. and about 60C. After the addition is completed (4 hours), the reaction mixture is stirred for three more hours. The acid equivalent weight, by titration with KOH solution, is found to be 315.
Fifty (50) parts of (a), 20.1 parts Cymel 301 and 9.81 parts of hydroxy phosphate (b) are dissolved in 14 parts of butyl acetate. This formulation spray applied in three coats to primed panels which are baked at 120C.
for 25 minutes to obtain coatings with excellent physical properties.

Example 38 In the formulation described in Example 34, 18 parts of ethoxymethoxy benzoguanamine (Cymel 1123) are employed as a crosslinking resin instead of Cymel 301. The resulting formulation is applied by spraying to primed ~ ~2443~

steel test panels. The panels are baked at 130C. for 20 minutes to obtain glossy coatings with excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 39 In this formulation, resins described in Example 9 are employed in exact quantities as described therein except that 42 parts of butoxymethyl glycoluril (Cymel 1170) are used as the crosslinking agent instead of Cymel 301.
The formulation is applied by spraying to primed steel panels and baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 40 In the formulation described in Example 10, 35 parts of butoxymethylurea resin (Beetle 80, American Cyanamid) are substituted for Cymel 301, and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 41 Ninety-eight (98) grams of phosphoric acid and 50 ml. of butyl acetate are placed in a round bottom flask fitted with a condenser and a dropping funnel and cooled with an ice-water mixture. Propylene oxide, 136 grams, is added dropwise with continuous stirring. The addition is complete in two hours. Six parts of this hydroxyphosphate are substituted for the hydroxyphosphate used in Example 10.
The resulting formulation is applied by spraying to primed -- steel test panel-s,-and the-panel--s~ ke~--at^ ~20~. fQr 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent resistance.

Example 42 Fifty (50) grams of 1,4-benzenedimethanol are dissolved in 150 grams of 2-ethyl-1,3-hexanediol and 40 ml. of butyl acetate. Phosphorus pentoxide is added to the above solution as described in Example l(a) to obtain a hydroxyphosphate with an acid equivalent weight of 364.
Thirty (30) parts of the polymer solution from Example 8, 11 parts of Cymel 301, 2 parts of caprolactone based hydroxypolyester (PCPO 300, Union Carbide) are dissolved in 10 parts of butyl acetate. The above hydroxy-phosphate (8.9 parts) is added to the above solution and the resulting formulation applied by spraying to primed steel test panels. The panels are baked at 130C. for 20 minutes to obtain a hard, glossy coating with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 43 One hundred (100) grams of 1,4-cyclohexanedimeth-anol are dissolved in 80 grams of butyl acetate at 50C.
and the procedure outlined in Example l(a) is followed to obtain a hydroxyphosphate with an acid equivalent weight of 645.
The procedure of Example 9 is modified by sub-stituting 18.9 parts of the above hydroxyphosphate for the hydroxyphosphate used therein and three more parts of Cymel 301 are added to the formulation. The resulting paint is applied by spraying to primed steel test panels and the panels baked at 130C. for 20 minutes to obtain hard, glossy coatings with excellent adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 44 -- A copolymer is-prepare*-from the ~ollowing ~ono~
mers by following the procedure described in Example l(a).
Wt.%
Butyl methacrylate 50 Ethylhexyl acrylate 10 Glycidyl methacrylate 15 Wt.%
Hydroxypropyl methacrylate 10 Methyl methacrylate 10 Styrene 5 Toluene is used as solvent to obtain a 60% solution of the polymer; tert-butyl peroctoate (3.7% of monomers) is used as an initiator. Toluene (60%) is distilled off and butyl acetate is added to bring the solids level to 60~ by weight.
The calculated Tg of the polymer is 25C. and the molecular weight by Gel Permeation Chromatography is found to be n 5301, MW/M = 2 9 Three hundred (300) parts of this polymer are mixed well with 10.69 parts of aluminum flakes (65% in naphtha), 3.40 parts of zinc naphthanate, and 92 parts of hexamethoxymethyl melamine (Cymel 301) are added to this mixture. 59.98 parts of the hydroxyphosphate from Example 37(b), and 40 parts of bis-(hydroxypropyl) azelate are dissolved in 50 ml. of cellusolve acetate; this solution is added to the above mixture and the resulting formulation applied by spraying to primed steel panels in three coats.
The panels are baked at 130C. for 20 minutes to obtain silver metallic coatings with excellent physical properties.
The coatings show no blistering, discoloration, or loss of gloss or adhesion.

Example 45 The polymer synthesis described in Example 44 is repeated by employing 5% (based on monomers) of the initiator. Toluene is distilled out to the extent of 90~
and butyl acetate is then added to bring the solids level to 60% by weight. The molecular weight from Gel Permeation Chromatography is found to be Mn = 3262, M ~ Mn = 3.63.
One hundred twenty-six (126) parts of the above - polymer solution,~39;1-parts-of^Cymel-30~ 6.3 parts,o,~
aluminum flakes (65~ in naphtha), and 2.1 parts of zinc naphthanate are mixed well. 15.5 parts of hydroxyphosphate from Example 10(b) and 13 parts of bis-(hydroxypropyl) azelate are dissolved in 50 ml. methyl amyl ketone and this ~.2~31 solution is added to the above mixture. The viscosity of this coating is 38 seconds ~4 Ford Cup and the solids level is 61% by weight. The panel is applied and baked as described in Example 15. This coating has excellent adhesion, gloss, hardness and solvent (xylene and methyl amyl ketone) resistance.

Example 46 Eighty (80) parts of polymer from Example l(b) are mixed with 20 parts of bis-(3,4-epoxy-6-methylcyclo-hexanemethyl) adipate (Araldite CY 178 from Ciba-Geigy) and 26 parts of hexamethyoxymethyl melamine (Cymel 301, American Cyanamid). The above mixture is dissolved in 12 parts of cellosolve acetate and a solution of 23.5 parts of hydroxyphosphate from Example l(a) in 15 parts of butyl acetate is added to it. The resulting mixture is stirred for one minute and then spray applied to primed panels in three coats with an intermediate flash of one ' minute and a final flash of five minutes. The panels are baked at 120C. for 20 minutes to obtain clear coatings with excellent hardness, adhesion, gloss and solvent (methyl ethyl ketone and xylene) resistance.

Example 47 Eighty (80) parts of acrylic copolymer solution described in Example l(b) are mixed with 40 parts of Aral-25 dite CY 178 and 50 parts of Cymel 301. This mixture is dissolved in 30 parts of butyl acetate and 47 parts of hydroxy phosphate prepared in Example l(a) are added to it.
The resulting solution is stirred for one minute and then spray applied to primed steel panels. The panels are baked 30 at 120C. for 20 minutes to obtain hard clear coatings with excellent hardness, adhesion, gloss and solvent (xylene - and methyl ethyl ket~ne) r~sistan~.- -Aft~r 14~ays i~a~
Cleveland Humidity Chamber panels show no loss of gloss and no peeling, blistering or discoloration.

~.2~43~

Example 48 An acrylic copolymer is prepared from the following monomers:
Parts by Weight 5 Butyl methacrylate 26 Ethylhexyl acrylate 20 Hydroxyethyl acrylate 30 Styrene 24 The preparation is carried out in the same way as outlined in Example l(b) by using cellusolve acetate as the solvent and tert-butyl peroctoate (5% of monomers) as initiator to obtain a 70% solution of the polymer. The calculated Tg is -7C. and the molecular weight of from Gel Per-meation Chromatography is Mn = 3070 and MW/Mn = 2.2.
Twenty (20) parts of the above polymer solution are mixed with 11.4 parts of Araldite CY 178, 15 parts of Cymel 301 and five parts of butyl acetate. 16.5 parts of hydroxyphosphate, described in Example l(a), are added to the above solution and the resulting formulation spray applied to primed steel panels. The panels are baked at 120C. for 25 minutes to obtain a coating with excellent gloss, hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 49 Three hundred fifty (350) parts of Ti02 are mixed with 350 parts of Acryloid OL-42 (Rohm & Haas Chemical Co.) and 25 parts of n-butyl acetate. The above mixture is taken up in a porcelain bottle containing procelain beads and put on a roller mill for 16 hours. Thirty-one (31) parts of this mill base are mixed with 10 parts of hydroxy ester Desmophen KL5-2330 (Rohm & Haas Chemical Co.), 5 parts of 1,4-butanediol diglycidyl ether and 16 parts of Cymel ~ 301. In~ a separate~flask 5-`pa-rts-of-Desm~phen^KL5-2330=
are mixed with 13.6 parts of hydroxyphosphate from Example l(a). The above two solutions are mixed together and the resulting formulation sprayed on primed panels in a four-coat application (thickness 3.2-3.9 ml.) with an intermediate ~.2~

flash of 1.25 minutes. After 5 minutes final flash the panels are baked at 90C. for 28 minutes to obtain a glossy (95/20) coating with excellent xylene and methyl ethyl ketone resistance. The solids by weight are determined (130C./30 min.) to be 74~.

Example 50 Five hundred (500) parts of Ti02 and 250 parts of Ferrite yellow are mixed with 500 parts of Acryloid OL-42, 7.8 parts o dispersing agent BYK P 104S (Mellinc-krodt) and 200 parts of n-butyl acetate; the mill base is prepared as described in Example 49.
(a) Thirty-six (36) parts of the above mill base are mixed with 10 parts of 1,4-butanediol diglycidyl ether and 16 parts of Cymel 301.
(b) A fresh sample of hydroxyphosphate with an equivalent weight of 212 is prepared in accordance with Example l(a). Eleven (11) parts of this phosphate are mixed with 5 parts of hydroxy ester Desmophen KL5-2330 (Rohm and Haas). Components (a) and (b) are mixed and the resulting formulation spray applied to primed panels in a three-coat application and baked at 130C. for 20 minutes to obtain yellow coatings with excellent gloss, adhesion, hardness and solvent (xylene and methyl ethyl ketone) resistance. Solids content by weight is 80~.

Example 51 Fifty (50) parts of Phthalo Blue pigment are mixed with 500 parts of Acryloid OL-42 and 44 parts of n-butyl acetate and the mill base is ground as described in Example 49.
(a) Twenty-five (25) parts of the above mill base are mixed with 29 parts of Acryloid OL-42, 15 parts - of 1,4-butanediol diglycidyl~-etherj -35 parts ~ ymel ,~
301, 5 parts of aluminum flakes (65% naphtha) and 10 parts of n-butyl acetate.
(b) Twenty (20) parts of Acryloid OL-42 are mixed with 17.1 parts of the hydroxyphosphate (eq. wt. 212) ~ 2~`3~

described in Example 50(b). Components (a) and (b) are mixed and the resulting formulation sprayed on primed panels in three coats with one minute flash times between coats.
After seven minutes final flash the panels are baked at 130C. for 20 minutes to obtain blue metallic coatings with excellent hardness, adhesion, and solvent resistance. The gloss is 63/20 and the film thickness is 1.2-1.3 ml.

Example 52 (a) Thirteen (13) parts of the mill base des-cribed in Example 51 are mixed with 9 parts of Acryloid*OL-42, 9 parts of Epon*828 (Shell Chemical Co.), 14 parts of Cymel*301, 3 parts of aluminum flakes (65% in naphtha) and 8 parts of n-butyl acetate.
(b) Ten parts of the hydroxyphosphate (e.g.
; 15 wt. 212) described in Example 50(b) are mixed with 10 parts of Acryloid*OL-42. Components (a) and (b) are mixed together and spray applied in three coats to primed steel panels. The intermediate flash time is one minute and the final flash is seven minutes. The panels are baked at 50C. for 10 minutes and then the temperature is raised from 50C. to 100C. over a period of 5 minutes. The film thickness is 1.5-1.6 ml. and gloss is 62/20. The coating has excellent hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance. Solids content is found to be 74%.

Example 53 (a) A solution of 1250 grams of 2-ethyl-1,3 hexane diol in 1250 grams of butyl acetate is placed under nitrogen in a three-necked round bottom flask equipped with a mechanical stirrer. Phosphoruspentoxide (442 grams) is added portionwise with continuous stirring; an exothermic reaction occurs and-the--~dd-ition--f--P2-O5-i-s~-regulated to~
maintain the temperature between about 50 and about 60C.
After completing the addition (about 4 hours) the reaction mixture is stirred for three more hours. The acid equiva-lent weight, by titration with KOH solution, is found to be 315.
* Trademarks 3~

(b) Forty (40) parts of yellow mill base des-cribed in Example 49 are mixed with 10 parts of hydroxy ester PCP-0300 (Union Carbide), 10 parts of 1,4-butanediol diglycidyl ether and 17 parts of Cymel 301.
(c) Five (5) parts of hydroxy ester PCP-0300 (Union Carbide) are mixed with 31.2 parts of hydroxy phosphate from (a). Component (c) is added to component (b) and the mixture shaken for one minute. The paint is spray applied in three coats (1 min. flash time). After

7 minutes of final flash, the coating is baked at 100C.
for 25 minutes. The film thickness is 2.2-2.5 ml. and the gloss is 83/20. This coating has excellent hardness, adhesion and solvent resistance (xylene and methyl ethyl ketone). Solids content is found to be (30 min/140C.) 80.5% by weight.

Example 54 (a) Forty (40) parts of the yellow mill base described in Example 50 are mixed with 6 parts of Acryloid OL-42 (Rohm and Haas), 15 parts Cymel 301 and 10 parts of 1,4-butanediol diglycidyl ether.
(b) Five (5) parts of Acryloid OL-42 are mixed with 12 parts of the hydroxyphosphate described in Example 50(b). Components (a) and (b) are mixed well and the paint applied to steel panels in three spray coats. The panels are baked at 100C. for 25 minutes to form a yellow coating with good gloss (76/20), adhesion, hardness and excellent solvent (xylene and methyl ethyl ketone) resis-tance. Film thickness is 2.1 to 2.2 mls. Mandrel bend does not show any cracks at all. The coating passed 100 in lbs. direct impact and 72 in lbs. reverse impact. A
primed test panel when put in a Cleveland Humidity Chamber shows no blistering, scribe creep, peeling or discoloration.
The gloss is 56/20 and the-soli~s-conlent-~f---t~e fo-rmu~
lation are found to be 79% by weight.

Example 55 (a) Twenty-five (25) parts of the mill base described in Example 51, 19 parts of Acrylold OL-42, 25 ~ 2~43~

parts of Epon 828, 35 parts of Cymel 301 and 5 parts of aluminum flakes (65~ in naphtha) are mixed with 25 parts by weight of n-butyl acetate.
(b) Twenty parts of OL-42 are mixed with 27 parts of hydroxy phosphate (eq. wt. 212) described in Example 50(b). Component (a) is filtered and component (b) added to it. The mixture is shaken for thirty seconds and then spray applied to primed panels in three coats ; with one minute flash time between coats and seven minutes final flash. The paint is baked at 50C. for 10 minutes and then at 100C. for 20 minutes. The thickness of the film is found to be 1.5-1.7 mls. Xylene and methyl amyl ketone re.sistance is excellent.

Example 56 (a) Thirty (30) parts of Acryloid OL-42, 20 parts of Epon 828, forty (40) parts of Cymel 301, 4.2 parts of aluminum flakes (65% in naphtha) and 26.5 parts of n-butyl acetate are mixed in a plastic bottle.
(b) Ten (10) parts of Acryloid OL-42 and 22.6 parts of the hydroxyphosphate (eq. wt. 212) from Example 50(b) are dissolved in 5 parts of n-butyl acetate. Compo-nents (a) and (b) are mixed together and the resulting formulation spray applied in three coats to primed panels.
The panels are baked at 100C. for 25 minutes to obtain a hard, glossy silver metallic coating with excellent solvent resistance. The solids level of this formulation is 66% by weight.

Example 57 Twenty (20) parts of the polymer solution from Example 48 are mixed with 11.4 parts of Araldite CY 178, 18 parts of butoxymethyl glycoluril (Cymel 1170), 2 parts - of polypropyleneglyco~ tPluracol-~-110., BASF.Wyandotte~
Chemical) and 5 parts of butyl acetate. To the above formulation, 16.85 parts of hydroxyphosphate described in Example 53(a) are added and the resulting formulation spray applied to primed steel panels. The panels are baked at 130C. for 20 minutes to obtain coatings with excellent ~.2~43~
_ 49 _ gloss, hardness, adhesion and solvent (xylene and methyl ethyl ketone) resistance.

Example 58 Ninety-eight (98) grams of phosphoric acid and 50 ml. of butyl acetate are placed in a round-bottom flask fitted with a condenser and a dropping funnel and cooled with an ice-water mixture. Propylene oxide, 136 grams, is added dropwise with continuous stirring. The addition is complete in two hours.
Twenty-eight (28) parts of the above hydroxy--- phosphate are substituted for the catalyst employed in Ex-ample 55. The resulting formulation is sprayed on primed steel test panels and baked at 120C. for 20 minutes to ob-tain a blue metallic coating with excellent hardness, ad-hesion and solvent (xylene and methyl ethyl ketone) re-sistance.
In view of this disclosure, many modifications of this invention will be apparent to those skilled in the art. It is intended that all such modifications which fall within the true scope of this invention be included within the terms of the appended claims.

Claims

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

1. In a thermosetting coating composition comprising a film-forming resin component and an amine aldehyde cross-linking agent which composition cures by reaction between said amine aldehyde crosslinking agent and hydroxy group(s) present on said film-forming material said hydroxy group(s) being (i) present initially on said film-forming component; (ii) generated in situ on said firm-forming component during cure of said com-position; or (iii) both present initially and generated in situ, the improvement comprising including in said composition a catalyst for said reaction comprising at least one hydroxy group containing organophosphate ester having the formula:

wherein n = 1 to 2 and R is selected from the group consisting of mono- or dihydroxy alkyl, cycloalkyl or aryl radicals.

2. A composition in accordance with Claim 1 wherein said film-forming material consists essentially of a compound bearing hydroxy functionality.

3. A composition in accordance with Claim 2 wherein said film-forming material has a number average molecular weight of at least 150.

4. A composition in accordance with Claim 2 wherein said film-forming material consists essentially of a copolymer bearing pendant hydroxy functionality, having a number average molecular weight (?n) of between about 1000 and about 20,000 and a glass transition temperature (Tg) of between about -25°C.
and about 70°C., said copolymer consisting of between about 5 and about 30 weight percent of monoethylenically unsaturated monomers bearing hydroxy functionality and between about 95 and about 70 weight percent of other monoethylenically unsaturated monomers.

5. A coating composition in accordance with Claim 1 wherein said film-forming material consists essentially of a compound which reacts in situ during cure of said composition to form hydroxy functionality.

6. A coating composition in accordance with Claim 5 wherein said reaction in situ forms substantially all of the crosslinking functionality in said film-forming material.

7. A coating composition in accordance with Claim 5 wherein said film-forming material includes hydroxy function-ality in addition to that which is formed by said reaction in situ.

8. A coating composition in accordance with Claim 5 wherein said compound bears epoxy functionality which reacts with said organophosphate ester during cure of said composition to form hydroxy functionality which, in turn, reacts with said amine aldehyde crosslinking agent.

9. A coating composition in accordance with Claim l wherein said film-forming material consists essentially of a compound bearing both epoxy and hydroxy functionality.

10. A coating composition in accordance with Claim 1 wherein said film-forming material consists essentially of a mixture of a compound bearing hydroxy functionality and a compound bearing epoxy functionality.

11. A thermosetting coating composition in accordance with Claim 1 which is adapted for low temperature bake appli-cations, which contains greater than about 60% by weight of nonvolatile solids, and which, exclusive of pigments, solvents and other nonreactive components, consists essentially of:
(A) a copolymer bearing pendent epoxy functionality having a number average molecular weight (?n) of between about 1500 and about 10,000 and a glass transition temperature (Tg) of between about -25°C.
and about 70°C., said copolymer consisting of between about 10 and about 30 weight percent of monoethylenically unsaturated monomers bearing glycidyl functionality and between about 90 and about 70 weight percent of other mono-ethylenically unsaturated monomers;
(B) a reactive catalyst comprising at least one hydroxy functional organophosphate ester having the formula:
wherein n = 1 to 2 and R is selected from the group consisting of mono- or dihydroxy alkyl, cycloalkyl, or aryl radicals;
(C) an amino resin crosslinking agent; and (D) up to 45 weight percent based on the total weight of (A), (B), (C) and (D) of a hydroxy functional additive having a number average molecular weight (?n) of between 150 and about 6000, said hydroxy functional organophosphate ester being in-cluded in said composition in an amount sufficient to provide between about .67 and about 1.4 equivalents of acid functionality for each equivalent of pendent epoxy func-tionality on said copolymer, and said amino resin cross-linking agent being included in said composition in an amount sufficient to provide at least about 0.4 equivalents of nitrogen crosslinking functionality for each equivalent of hydroxy functionality included in said composition either as (i) an organic hydroxyl group on said organo-phosphate ester, (ii) a hydroxyl group on said hydroxy functional additive, or (iii) as a result of esterification of said pendent epoxy functionality of said copolymer during cure of said coating composition.

12. A thermosetting coating composition in accordance with Claim l, which is adapted for low tempera-ture bake applications, which contains greater than about 60% by weight of nonvolatile solids, and which, exclusive of pigments, solvents and other nonreactive components, consists essentially of:
(A) a bifunctional copolymer bearing hydroxy functionality and pendent epoxy functionality, having a number average molecular weight (?n) of between about 1500 and about 10,000 and a glass transition temperature (Tg) of between about -25°C. and about 70°C., said copolymer consisting essentially of (i) between about 5 and about 25 weight percent of monoethylenically unsaturated monomers bearing glycidyl func-tionality and between about 5 and about 25 weight percent of monoethylenically unsaturated monomer bearing hydroxy functionality, with the total of said glycidyl and hydroxy functional monomers being not greater than about 30 weight percent of the monomers in said bifunctional copolymer and (ii) between about 90 and about 70 weight percent of other monoethylenically unsaturated monomers;
(B) a reactive catalyst comprising hydroxy functional organophosphate ester having the formula:
wherein n = 1 to 2 and R is selected from the group consisting of mono or dihydroxy alkyl, cycloalkyl, or aryl radicals;
(C) an amino resin crosslinking agent; and (D) up to about 45 weight percent based on the total weight of (A), (B), (C) and (D) of a hy-droxy functional additive having a number average molecular weight (?n) of between about 150 and about 6000, said organophosphate ester being included in said composition in an amount sufficient to provide between about .67 and about 1.4 equivalents of acid functionality for each equivalent of pendent epoxy functionality on said bifunctional copolymer, and said amino resin crosslinking agent being included in said composition in an amount sufficient to provide at least about .4 equivalents of nitrogen cross-linking functionality for each equivalent of hydroxy functionality included in said composi-tion either as (i) an organic hydroxyl group on said organophosphate ester, (ii) a hydroxyl group on said bifunctional copolymer, (iii) a hydroxyl group on said hydroxy functional addi-tive, or (iv) as a result of esterification of said pendent epoxy functionality of said bifunc-tional copolymer during cure of said coating composition.

13. A composition in accordance with Claim 11 or 12, wherein said monoethylenically unsaturated monomers bearing glycidyl functionality in said bifunctional copolymer are selected from glycidyl esters and glycidyl ethers.

14. A composition in accordance with Claim 13, wherein said monoethylenically unsaturated monomers bearing glycidyl functionality are selected from glycidyl esters of monoethylenically unsaturated carboxylic acids.

15. A composition in accordance with Claim 12, wherein said monoethylenically unsaturated monomers bearing hydroxy functionality in said bifunctional copolymer are selected from the group consisting of hydroxyalkyl acrylates formed by the reaction of C2 - C5 dihydric alcohols and acrylic or methacrylic acids.

16. A composition in accordance with Claims 11 or 12, wherein said other monoethylenically unsaturated monomers in said copolymer are selected from the group consisting of acrylates and other monoethylenically unsaturated vinyl monomers.

17. A composition in accordance with Claim 16, wherein said acrylate monomers comprise at least about 50 weight percent of the total monomers in said copolymer and are selected from its group consisting of esters of C1 -C12 monohydric alcohols and acrylic or methacrylic acids.

18. A thermosetting coating composition in accordance with Claim 1, which is adapted for low tempera-ture bake applications which contains greater than about 60% by weight of nonvolatile solids, and which, exclusive of pigments, solvents and other nonreactive components, consists essentially of:
(A) a polyepoxide resin having a number average molecular weight (?n) of between about 140 and about 3000;
(B) a reactive catalyst comprising at least one organophosphate ester having the formula:

wherein n = 1 to 2 and R is selected from the group consisting of mono- or dihydroxy alkyl, cycloalkyl or aryl radicals;
(C) an amino resin crosslinking agent; and (D) up to about 45 weight percent based on the total weight of (A), (B), (C) and (D) of a hy-droxy functional additive having a number average molecular weight (?n) of between about 140 and about 3000, said organophosphate ester being included in said composition in an amount sufficient to provide between about .67 and about 1.4 equivalents of acid functionality for each equivalent of epoxy functionality on said polyepoxide resin, and said amino resin cross-linking agent being included in said composition in an amount sufficient to provide at least about .4 equivalents of nitrogen crosslinking functionality for each equivalent of hydroxy functionality included in said composition either as (i) an organic hydroxyl group on said organo-phosphate ester,(ii) a hydroxyl group on said hydroxy functional additive, or (iii) as a result of esterification of said epoxy functionality of said polyepoxide resin during cure of said coating composition.

19. A composition in accordance with Claim 18, wherein said polyepoxide resin is selected from the group consisting of aliphatic, cycloaliphatic and aromatic polyepoxides having a number average molecular weight of between about 300 and about 2000.

20. A composition in accordance with Claims 11, 12 or 18, wherein said hydroxy functional organophosphate ester is an ester wherein R is a mono- or dihydroxy alkyl, cycloalkyl or aryl radical containing 3 to 10 carbon atoms.

21. A composition in accordance with Claims 11, 12 or 18 wherein said organophosphate ester is a monoester.

22. A composition in accordance with Claims 11, 12 or 18 wherein said organophosphate ester is a diester.

23. A composition in accordance with Claims 11, 12 or 18, wherein said organophosphate ester is a mixture of mono- and diesters.

24. A composition in accordance with Claim 23, wherein said hydroxy functional organophosphate esters are esters wherein R is a mono- or dihydroxy alkyl, cyclo-alkyl or aryl radical containing 3 to 10 carbon atoms.

25. A composition in accordance with Claim 23, wherein at least a portion of said organophosphate esters are esters wherein R is a mono- or dihydroxy alkyl radical containing 3 to 10 carbon atoms.

26. A composition in accordance with Claims 11, 12 or 18, wherein said reactive catalyst including said organophosphate ester is the reaction product of an excess of an alkyl, cycloalkyl or aryl diol or triol and phosphorus pentoxide.

27. A composition in accordance with Claims 11, 12 or 18 wherein said reactive catalyst including said hy-droxy functional organophosphate ester is the reaction product of an excess of an alkyl, cycloalkyl or aryl triol in which at least one of the hydroxyl groups is secondary and phosphorus pentoxide.

28. A composition in accordance with Claims 11, 12 or 18, wherein said reactive catalyst including said hydroxy functional organophosphate ester is the reaction product of an alkyl, cycloalkyl or aryl monoepoxide and phosphoric acid in a molar ratio of between about 1:1 and about 2:1.

29. A composition in accordance with Claim 28 wherein said monoepoxide also bears hydroxyl functionality.

30. A composition in accordance with Claim 28 wherein said monoepoxide is selected from monoepoxy esters, monoepoxy ethers and alkylene oxides.

31. A composition in accordance with Claims 11, 12 or 18, wherein said amino resin crosslinking agent is an amine-aldehyde resin selected from the group consisting of condensation products of formaldehyde with melamine, substituted melamine, urea, benzoguanamine, and substituted benzoquanamine, and mixtures of said condensation products, and is included in an amount sufficient to provide between about .6 and about 2.1 equivalents of nitrogen crosslinking of functionality per equivalent of hydroxy functionality.

32. A composition in accordance with Claims 11, 12 or 18, wherein said hydroxy functional additive is selected from the group consisting of (i) hydroxy functional polyesters, (ii) hydroxy functional polyethers, (iii) hydroxy functional oligoesters, (iv) monomeric polyols, (v) hydroxy functional copolymers formed from mono-ethylenically unsaturated monomers, one or more of which bears hydroxy functionality and which is included in said copolymer in amounts ranging from about 10 to about 30 weight percent of said copolymer, and (vi) mixtures of (i)-(v).

33. A composition in accordance with Claims 11, 12 or 18 wherein sold organophosphate ester is included in said composition in an amount sufficient to provide between about 1 and about 1.2 equivalents of acid function-ality for each equivalent of epoxy functionality on said polyepoxide resin.