CA1196144A - Elastomeric coating compositions - Google Patents

Abstract

Abstract of the Disclosure High solids thermosetting elastomeric coating compositions are disclosed. The resinous binder of the coating compositions is based on a hard polyester polyol containing cyclic moieties plasticized with a soft polyurethane polyol and cured with a curing agent capable of reacting with active hydrogens, for example, an aminoplast curing agent. The coating compositions are particularly useful on elastomeric substrates such as high density polyurethane foams, as will as on metal substrates such as steel and aluminum.

Description

ELASTOMERIC COATING COMPOSITIONS

Background of the Invention The invention relates to thermose~ting resinous coating composi-tions, particularly to elastomeric coating compositions, and more particu-larly, to high solids elastomeric coating compositions.
Elastomeric coating compositions are those which have excellent flexibility, particularly at low temperature, along with good hardness and durability. Such coating compositions are particularly useful on elasto-meric parts of automobiles and trucks such as bumpers, front end hood sections and the side ~oldings.
Examples of elastomeric coating compositions are shown in U.S.
Patent No. 3,962,522~ These coating compositions are based on polyester-urethane polyols cured with aminoplast. Another example of an elastomeric coating composition is that disclosed in U.S. Patent No. 4,154,891. These coating compositions are based on polymeric polyols such as soft polyure-thane polyols cured with a stoichiometric excess of an aminoplast curing agent.
~.K. Patent No. 1,477,008 discloses coating compositions compris-ing thermosetting resins, for example, hard polyester polyol~9 soft poly-urethane polyols and aminoplast curing agents.
The coating compositions of the aforementioned patents are not high resin solids type, that is, they are not sprayable at high resin solids contsnt. This i8 a disadvantage in that more coating applications are required to get the desired coating thickness and appearance. Also, future air pollution standards ~ill require a reduction of organic solvent emissions of today's organic solvent-based coating compositions. Ther~fore, the coating compositions described in the aforement;oned patents may not be environmentally acceptable in the future.

Summary of the Invention In accordance with the present invention, thermosetting elasto- -meric coating compositions sprayable at resin solids content of at least 40 percent by weight are provided. The film-forming constituents of the coating composition comprise:
(A) a polyester polyol having at least 10 percent by weigh~
cyclic moieties and having a hydroxyl value of at least 80 and a S~ard Hardness valu~ of at least 15, (B) a polyurethane polyol having a Sward ~ardness value of less than 10, and (C) a curing agent capable of reacting with the active hydrogens in (A) and ~B) to form a crosslinked coating;
the difference in Sward Hardness values between (A) and (B) being greater than 10.

Detailed Description The coating compositions of the present ;nvention are character-ized as being thermosetting, liquid and elastomeric in nature. By ~Ithermo-setting" i5 meant the coating composition, upon heating, will solidify or set to form a coating which will not remelt on further heating.
By "liquid" is meant the composition is free flowing and not a solid or a gas.

a6~

The elastomeric behavior of the coating compositions of the pres-ent invention can be determined by measuring the tensile strength, elonga-tisn and flexibility of the coating, particularly the low temp~rature flexibility of the coating over an elastomeric substrate. The tensile strength and percent elongation of the coatings is determined according to ASTM D-639-72 on free films of the cured resinous ingredients. Accordingly, coatings deposited from the resinous components of the present invention have tensile strengths within the range of 2000 to lQ,000 psi, elongations of at least 25, preferably at least 40, and most preferably from 75 to 200 percent.
The flexibility of the coatings can be determined by co~ting an elastomeric substrate such as 1/8 inch thick thermoplastic polyurethane commercially available from Mobay Company as TEXIN 3202 and bending the coated substrate around a 1/4 inch diameter (1.13 cm) mandrel with the coating side outwardly facing. After bending, the coating is examined for breaks and cracks. Testing can be conducted at rvom temperature, i.e., 70-75F., or at low temperature, i.e., cooling substrate to 32 F. or even 0F., before bending. ~hen formulated for automotive use on elastomeric parts, the coatings of the present invention exhibit no breaks or cracks when tested at 70-75F. and 32F. in the above described manner, and preferably e~hibit no breaks or cracks when tested a~ 0F.
The hardness of the coating can be determined by the S~ard method using a S~ard rocXer as described in ORGANIC COATINGS TECHNOLOGY, Payne, Vol. 1, 1965, pages 642-643. Cured coatings of the present invention usu-ally have a Sward hardness within the range of 4 to 40, preferably 10 to 40, and more preferably 15 to 40.

~6~

For outdoor use of such elastomeric coatings for automobiles, the exterior durability of the coatings is important. The durability of the coating can be determined by exposing the coated substrates in Florida.
The gloss of the substrate is measured immediately prior to testing and then after 3 months, 6 months and 9 months exposure. Accordingly, with coating compositions of the present invention properly formulated for out-door exposure with U.V. light stabili~ers, anti-oxidants, etc., the loss of gloss should be no more than about 10 percent of the initial value after exposure for 3 months, no more than 20 percent after 6 months, and no more than 60 percent after 9 months.
The hydrolyti~ stability can also be determined by measuring the humidity resistance of the coating. Humidity resistance of the coating can be determined by using a coated metal subst~ate as the ceiling of a humidity chamber (QCT chamber) with the coating directed in~ardly towards the chamber. The chamber is heated to 100F. (3~C.~ and about a 2 inch ~9 cm) level of water is located 3 ~o 5 inches below the coated panel (panel sloped~. The coatings of the present invention, after being sub-jected to these conditions for ~40 hours, show no blistering nor 109s of gloss.
The coating compositions of the present invention are of the high solids type. By high solids is meant the coating composition i8 sprayable at a resin solids content of a~ least 40 percent, preferably at least 45 percent, and usually within the range of 45 to 65 percent by weight.
The sp~ayability is the maximum concentration of the resin solids in solution such that the resin can be atomiæed sufficiently to form a uniformly deposited coating. Above the ma~imum concentration9 the spraying solution strings and gives a web-like spray pattern. The sprayability of the resin solids is determined by first dissolving the resin in a sultable solvent such as N-methyl pyrrolidone to a viscosity of about 500 to 1000 centipoises measured at 78~. and then thinning with a mixture of 2 parts methyl ethyl ketone, 2 parts of n-butanol and 1 part of 2-ethoxyethylacetate (all parts by volume) to the maximum spray solids. The sprayability is then determined on the thinned solutions using a spray gun such as an air suction spray gun operating at 60 psi with a No. 30 air cap.
As mentioned above, the coating compositions of the present invention comprise 3 principal resinous components: a polyester polyol, a polyurethane polyol and a curing agent.
The polyester polyol component of the coating composition contains at least 10 percent, preferably at least 20 percent, more preferably at least 25 percent and most preferably from 25 to 40 perrent by weight cyclic moieties. The percentage by weight of cyclic moieties is determined by ta~ing the weight of the ingredients which contain cyclic moieties used in preparing the polyester divided by the total weight of reactive ingredients.
Cyclic moieties contribute hardness and durability to the cured coatings.
Polyesters containing less than 10 percent by weight cyclic moieties are undesirable because the coatings will have insufficient hardness and dura-bility ~or elastomeric use. The upper limit of cycl;c moieties is prefera-bly less than 70 pPrcent. Polyesters containing greater than 70 percent by weight cyclic moieties are not preferred because of insufficient flexibility in the r~sultant coating. Preferably, the cyclic moieties are cycloaliphatic because they give a better combination of flexibility and hardness than other cyclic moieties such as aromatic moieties.

l`he hydroxyl value of the polyester polyol should be at least 80, preferably at least 120, and more preferably at least 200. The hydroxyl value is based on resin solids and determined according to ASTM E-222-76;
Method B (reflu~ 1 hour). The high hydroxyl value of the polyester polyol is important because it contributes to hardness and ~oughness of the cured film. Also, high hydroxyl values are necessary to f~rmula~e high solids compositions. Hydroxyl values less than 30 are undesirable because of the difficulty in formulating high solids compositions. The upper limit of the hydroxyl value is preferably less than 350. Polyesters having hydroxyl values greater than 350 are not preferred because of poor flexibility in the resultant coating.
The polyester polyol used in the pra~tice of the present inven-tion should have a Sward Hardness value greater than 15, usually 15 to 50, preferably 20 to 40.
The Sward Hardness value is a measure of hardness; the higher the value, ~he harder the polyol as determined wi~h a cured film of the polyol. The Sward Hardness value is the Sward Hardness of a cured film of the polyol. The cured film has a thickness of 3 mils ~ 0.5 mils. The polyol is cured by the following method: The polyol on which the hard-20 ness is to be measured is mixed with 160 grams of hexakis~methoxymethyl)- -melamine per 1 gram equivalent of polyol and 0.5 percent by weight based on total solids of para-toluenesulfonic acid. The mixture is drawn down over a steel substrate with a draw bar (i.e., 5 mil draw bar), and cured at 300F. (149C.) or 30 minutes. The Sward Hsrdness of the cured film is determined and reported as the Sward HQrdness value of the polyol.

Polyesters with Sward ~ardne~s values les8 than 15 are undesirable because the resultant c~red coating will haYe insufficient durability ~nd hardness. PolyPster~ having Sward Hardness values grea~er than 50 are le&8 preferred because the resultant coatings have le5s than optimum flexibility a~ low tempera~ureO
The polyester polyol i5 prepared by polyesterification of ~n org~nic polycarboxylic acid or a functional equivalent thereof ~uch as ~n anhydride o~ a lower alkyl ester with an organic polyol and/or an epoxide.
The cyclic ~oieties can be incorpora~ed into the polyester ei~her f~om the organic polycarboxylic acid componen~ or ehe organic polyol component or from both. Exanples of 3uitable cyclic polyca~boxylic acids or thei~ func-tional equivalent~ thereof are phthalic anhydride; tetrahydrophthalîc anhy-dride, hexahydrophthalic anhydside and dimethylcyclohexane dica~boxylate;
with the latter two being preferred. Exa~ples of ~uitable cyclic organic polyol6 are bisphenol A, hydrogenated bisphenol A, cyclohexanediol and cyclohexanedimethanol.
Besides the cyclic polycarboxylic acids or their funceional equivalents thereof, acyclic polycarboxylic acids contai~ing :Erom about

2 to 18 carbon atoms may also bc used. Examples include ~uccinic acid, glutaric acid, adipic acid~ suberic acid and sebacic acid . Further, mix~ures of cyclic polycarboxylic acids with acyclic polycarboxylic acids csn be used.
Besides the cyclic polyols men~ioned above, acyclic polyol~ co~
~aining ~rom 2 to 12 carbon ato~s can be u~ed. E~amples include 1j2-butanediol, 1,4-butanediGl~ neopentyl glycol and 1,6 hexanQdiol. Ala~3 ~ixtures of cyclic polyols and acyclic polyols can be u~ed.

Preferably, the polyol componen~ will contain neopentyl groups such as the aforemPntioned neopentyl glycol and 2~2-dimethyl-3-hydroxypr 2,2-dimethyl-3-hydroxypropionate. Preferably, the polyester will ooneain from abo~t 15 to 80, more preferably from about 40 to 70, percent by weight of such bran~hed moieties, the percentage by weight being based on weighe of the polyol which contains branching divided by the ~oeal weight of ingredients ~hich are used in preparin~ the polyester polyol. Neopentyl groups are preferred because of better durability in the resultant coa~ing.
The polycarboxylic acid and the polyol ~sed in preparing the 10 polyester are preferably difunctionalO Vse of hi~her functionality mate- -rials such as tricarboxylic acids or triols, although they can be used, are not preferred because they result in lower flexibility and higher resin viscositie6, which are more difficult to prooass. Examples of polyfunc-tional ~aterial~ would be tri~ellitic anhydride and trimethylolprop~ne.
Besides the organic polycarboxylic acids and polyols mentioned above, polyester polyols of the invention can be prepared with minor amounts, i.e., less than 30 percent by wei~he based on total weight of ingredients u~ed in making the polyester of c~mpound~ containin~ both hydroxyl and carboxyl groups. Examples of such materials are dimethylol-propionic acid and 6-hydroxyhexanoic acid.
Al~o, amines or hydroxyl-containing amines ran be uBed in prepa ration of the polyester polyols. The resul~ane polyester would be more accurately defined in this ins~ance as a polyestera~ide and pGlyeseeræmide6 are included within the definition of p~lyester polyols for the purp~ses of this i~vention. Examples of ~uit~ble polyamine~ or ~ino p~lyol~ ~re hexa~ethylenedia~ine and monoe~hanolamine.

Xn order to achieve the high resin 301ids content~ and spray-abili~ies, the polyester polyol used in the pra~tice of the invention preferably should have a molecular weight (on 8 number aver~ge basis) of l~UO or less, more preferably about 300 to 800. ~sing polyesters having molecular weights ~uch higher than 100~ presentr9 difficul~i~s in f3rmulat- -ing high solids compositions; whereas molecular weights less th~n 300 are not preferred because of relatively poor flexibility in the resultant coating.

Besides the polyes~er polyol described above, ~he fil~-formi~g compositions o~ the present invention also contain a polyurethane polyol having a S~ard Nardness val~e determined as described above of less than 10, usually sbout 2 to 10, preferably 2 to 6. Swsrd Hardnes~ values ~reater than 10 are undesirable because of insufficient flexibility in ~he re rul tsnt coating.
The polyurethane polyol iB referred ~o ~s ~ plasticizer, however, it is a seactive mat~rial in that ît, along ~i~h ~he polye~ter, partici-pates in the curing with the curin~ agen~.
Besides having Swsrd Hardness values as described abo~e~ the dif-ference in Sward ~ardness values of the poly~ster and polyurethane should be at leas~ 10, preferably within the range of lO to 40 inclusi~e3 ~ore preferably 20 ~o 40 inclusive, ~o as ~o provide for ehe bes~ combina~ion of durabili~y, hardness and 1exibility.
The polyurethane polyol i~ formed from reacting an org~nic polyirocyanate with a poly~eric polyol or with a ~ixture of a polymeric polyol and option~lly a low molecular ~eight polyolO Th~ lvw ~ol~cular weight polyol, if ured, will have ~ ~olecular wei8ht less than 2509 ~here~s the polymeric polyol will haY~ a molec~lar weight ~reater than S00.

~ he organic polyisocyanate i~ reacted with the polyol BO ~hat the OH/NCU equivalent ratio is greater than 1:1 so ~ha~ the result~nt prod-uct contains free hydroxyl groups. Preferably, the polyurethane polyol will hsve a hydroxyl valu~ calculated as described above of about 10 to 100, more preferably 30 to 70. `
The organic polyisocyanate which i5 used in preparing the poly-urethane polyols can be an aliphatic or an aromatic polyi60cyanate or a mixCure of the t~oO Aliphatic polyisocyanates (including cycloaliphatic polyi~ocyanates) arP preferred because of be~ter color ~tability in the re~ultant coating. Also, diisocyanates are preferred, although higher polyisocyanate6 such as triisocyanates can be used. However, their use does result in ~ome chain branchin~ which results in increased viscosity and difficulti~s in formulating the high solids coating~ of the invention.
Examples of suitable diisocyanates are 4,4'-diphenyl~ethane diisocyAnate, 1,4~tetramethylene diisocyanate, isophoro~e diisocyanate and 4~4' methylene-bi6-(cyclohexyl isocyanate). Examples of suitable higher functionality polyisocyanates are polymethylene polyphenyl isocy~nates.
~ xa~ples of suit2ble polyols which can be used ~ith the polyi60 cyana~es are those having a molecular weight greater ~han 500 and these ~o would include polye~ter polyols 3 which are pseferred, polyether polyols and ~ixed polyester-polyether polyols. Ex~mples of suitable polyester polyols are those prepared by reacting an organic polycarboxylic acid or its func~ional equivalent thereof such as an anhydride or a lower ~lkyl ester with a~ organic polyol ~nd/or an epo~ide such as de~cribed ~bove~
~ esides polyeste~ polyol~ formed from polycarboxylic acids and polyolj, polylac~one-type polye~ters can sl~o be e~ployed. These products are formed from reaction of a l~ctone such a~ ep6ilon~caprolactone and ~n ~ 10 --~6~

active hydrogen-containing ~at~rial such as a polyol. Such produc~s are described in U.S. Patent No. 3,169,945 to Hos~ettler3 and the portion of thf6 patent relating to the description of pGlycapr~lactone polyols being incorporated by reference. While not disclosed in the aforementioned pat-ent, ~he reaction produc~ of a lac~one with an acid containing polyol such as described in U.S. Patent No. 4,098,743 can also be used. Typically, the polyesters used will have a hydroxyl value of 50 to 250.
Besides the polyester polyol~, polyether polyols c~n al60 be employed~ E~amples of polyether polyol~ are polyalkylene ether polyols 10 which include those havin~ the ~tructural formula: -H - - O - 1CH~ OH and ~R J
m __ _ H ~ O - ~CH2 - CH~ OH

-- n where ehe substi~uent R i5 hydro~en or lower alkyl containing from 1 to 5 carbon atoms including mi~ed sub6tituent6 and n i6 typically from 2 to 6, and ~ is from 10 to 1000. lncluded are poly(oxytetramethylene) glycol~, poly(oxyethylene) glycols, poly(oxy 1,2 propyl~ne) glycols and the reaction product of ethylene glycol ~ith ~ mixture of 192-propylene oxide and e~hyl-ene oxide.

Also useful are polyether polyols formed from oxyalkylation of various polyols, for example, glycols such a~ ethylene glycol, 196-hexanedio1, bi~phenol A and ~he like, or other higher polyols such a6 ~rimethylolpropane~ -pentaerythritol ~nd the like. If these higher function~lity polyols are ~6~

used, ho~ever, ehey should be u~ed in minor amounts ~o ag to minimize ohain branching and the resultant high vi3cositieQ which are obtained.
The polyurethane polyol described above p~eferably ha~ a molecul~r weigh~ of 20,000 or less, preferably from about ~,000 to 10~000D more pref-erably 5,000 to 8,000. The molesular ~eights are de~ermined by gel permea- -tion chromatogr~phy using a polystyrene standard. Therefore, it is not the actual molecular weight whieh is measured but an indication of the ~olecu-lar weight compared to polys~yrene. The values which are obtained nre co~monly referr~d to a~ polystyrene numbers. However, for the purpose3 of this applicati.on, they are referred ~o as ~olecular weights. Further, the molecular weight6 are the peak molecular weights as determined by ehe fol-lowing method.
In measuring ~he peak ~olecular weight using the polystyrene as the standard, a Waters Associates gel per~eation chromatograph M~del 201 was u~ed. Six ~-Styragel columns were used. Each column has the dime~-sions of 30 centimeters long and 7.8 millimeters in B ide diameter. A dif-ferential refrsctometer ~as uscd ~s d~tector, and the colu~ns ~ere arranged according to their pore aize on the order of 106-105-104 103-500~100 Ang-stroms with the 103 Angstrom column b~ing the first one. Tetrahydrofuran was used as a solvent with a flow rate of 2.0 ~illiliters/minut~. The quality of the columns i8 checked by their "theoretical plate number"
determined fro~ ortho~dichloroben~ene and ehose columns with theoretical plate nu~ber~ greater than 3000/3Q c~ were used~
To d~termine molecular weight by ~el permeation chromatography (GPC3, the ins~rument ia first calibra~ed u~ing a polystyrene 6tandard.

Polystyrene standards used were purchased from Pre~sure Chemicals Comp~ny, Pitt~burgh, Pennsylvania, and Waeer6 Asaocia~es. ~he polysty~ene a~and~rds ~ 12 -have dispersities (dispersity = weight aver~ge molecular weight/nu~ber ~verage ~olecular weight) ranging from 1.05 to 1.10. The ~eight average molecular weights of the polystyrene standards used ~ere 900,000; 233,000;
50~000; 17,500; 4,000. To obtain a calibration curve, a see of 0.1 percent (10 milli~r&m polystyrene/l.0 ml tetrahydrofuran) polyseyrene solutions in tetrahydrofuran were prepared and a 0.5 ml sample 8i7e was injected into the columns and a GPC chromatogram was obtained. The elution volume of each peak corresponding to ~ g * en mol~cular weigh~ of tbe polystyrene standa~d w~s measured and the data was plotted on a semilogarithmie paper (logarithm 8Cale in the ordinate and linear scale in the ab6cissa). A
linear least squares plot of loglo ~molecular weight~ versuæ elucion volu~e i~ milliliters is used a~ ~ calibration curve. The lowest moleculas weight of the polyRtyrene standard used was 4,000 and the calibration eurve beyond that was extrapolated down to 100. The upper and lower exclusion limits of this fiet of columns are 5,000,000 and 100, respectively, in ~erm~
of polystyrene molecular weight. The sa~ple whose molecular weights are to be determined was prepared as a 1.0 percent tetrahydrofuran solution.
After filtration through a 0.5 micron filter, avail2ble from Gehman Corp~-ration, Catalog No. 4219, a 0.5 ml sample size was injec~ed into the col-20 umnB and ~ GPC chromatogr~m obtained under the same experi~n~al conditionsas the calibration. The ~olècular w~ight which is reported is the p~ak molecular weigh~ which is the polystyr~ne nu~ber in the molecular weight distribution ~urve at the peak. Where there is more than one peak, the highest peak is intended.
Molecular ~eights much higher than 107000 are less preferred because of highe~ resin Yiscosities and the difficul~ies associated in formul~ting high ~lids coating compositions~ Molecular weights le~ ~han 2,000 are less preferred because of insufficien~ toughness and flexibility in the resultant coating.
The polyol component described abo~e is mixed with curing agent whirh is capable of reacting wi~h the active hydrogens in ~he polyes~er and polyurethane polyol to give a thermoset coating. Examples of curing agents are aminoplasts, which are preferred~ and polyi60cyanaSe curing agent~ such as blocked i~ocyanates. Theae three ingredient~, i.e., polyester polyol, polyurethane polyol and curing agent, provide the ~ajor resinous components of the coating compositions of the inventiQn.
Aminoplast condensates are obtained from the reaction of formal- -dehyde with an amine or an amide. The mo~t common ~nines or ~mides are melamine, urea or benzoguanamine, and are preferred. Ho~ever, condensates with other amines and amides can be ~ployed, for exa~ple, aldehyd~ con-densates or diazines, triazoles, guanilines9 guanamines and alkyl and aryl di-sub~tituted deri~atives of such compounds including alkyl and aryl- -substituted ureas and alkyl and aryl-~ubstituted melaminez ~nd ben~oguan-amines. Some examples of such compounds are N,N-dimethylurea, N~phenylurea, dicyandiamide, formoguanamine, acetoguanamine~ 6-methyl 2,4-diamino-1,3,5-triazine, 3~5-di~minotria~ole, triaminopyrimidine, 2,6-triethyltriamine-1,3,5-triazine and the like.
While the aldehyde employed i6 most of~en formaldehyde, other ald hydes such as acetaldehyde, crotonaldehyde, benzaldehyde and furfuryl may be used.
~ he aminopla~t contains methylol or ~i~ilar alkylol group~ and preferably ~t least a portion of ~he~e alkylol groups are etherified by reactio~ wi~h ~n ~lc~hol ~o provide organic ~olvent-soluble re~in3~ ~ny monohydric slcohol can be employed for ~his purpose includin~ ~uch slcohvls as methanol~ ethanol, ~ut~nol and hexanol.

Preferably, the aminoplasts which are used are melamine ~ urea or benzoguanamine-formaldehyde condensates etherified with an alcohol containing 1 to 4 carbon atom~ s~ch as me~hanol, e~hanol, but~nol or ~ixtures thereof.
Polyisocyanates and block~d polyisocyanates may al~o be u~ed as curing agents. Examples of suitable polyisocyanates include monomeric polyîso~y2nates ~urh ~s toluene diisocyanate and 4,4'-methylene-bi~-(cyclohexyl isocyanate3, isophorone diisocyanate a~d NC0-prepolyDers such as the reactio~ products of monomerio polyi~ocyanate such as those men-tioned above with polyester or polyether polyols. Par~icularly usefulisocyanates are the isocyanurate from isophorone isocyanPte c~mmercially available from Veba Co~p~ny as T1890 and the biuret fro~ 1,6-hexdmethylene diisocyanate c = ercially available from Bayer as D~SMO~UR N. The polyi~o-cyanate may optionally be blocked. Example~ of ~uitable blocking agent~
are those material~ ~hich would unblock at elevated temperatures such as low ~liphatic alcohols such as methanol, oximes suoh as methyl ethyl ketone oxime, and lacea~s such ~8 caprolactam. Blocked isocyanates can be used to form ~table one-package syste~s. Polyfunctionàl isocyanate6 with free isocyanate groups can be used to for~ two-package room semperature curable systems. In these 8y6~e~8, the polyester and isocyana~e curing agent are mixed just prior to eheir application.
The smounts of polyester polyol, polyurethane polyol and curing agent which are u~ed in ehe prac~ice of ~he inv~ntion are preferably adju~ted ~o ~ha~ the ra~iG sf polyest~r polyol plus polyu~ethane poly~l:
curing ~gent is within the r~nge of 5 to 0~5:1, prefer~bly 2 to l:l. Pref- -erably, ~he weighe ra~io of polye~ter polyol plus curing agene:polyu~eehane polyol i~ within the range of 100 to 1:1, preferably 9 to 1:1. Ratios ~f polyester polyol plus polyurethane pclyol:curing agent greater ~han 5:1 are not preferred becau~e hardness and durabiliey of the resultant coa~ing will suffer; ~hereas ratioa less than 1 1 are not preferred ~ecaus flexibility of the resultant coating will suffer. Ratios of p31yester pclyol plu~ ur-in~ agent:polyurethane polyol greater than 100:1 are not preferred because of relatively poor flexibility in ~he resultant coating; wherea~ rPtios less than l:l are not preferred because the resultant coatings are rela-tively ~oft and lack toughness.
The abo~e described resinous component~ can be formulated into clear coating composi~ions or~ all:ernately, they can be fonnulated with pigments to form paint~. The pigments ~ay be any of the conventional type~
comprising, for exa~ple, iron oxides, lead oxides, st~ontium chrcmate, c~rbon black, coal du~t, titanium dioxide, talc, barium sulfate, as ~ell as color pig~ents such as c~d~ium yellow~ cadmium red, chromium yellowJ and metallic pigments such ~s aluminum ~lake.
The pigment content of the paint is usually expressed as the pigmen~-to-resin weight ratio. In the prac~ice of the invention, when the film-forming coating compositions of the present invention contain pigmen~, the pigment-to-~esin weight ratios may be a~ high as 2:l and for most pig~nented coatings, are within the range of 0.05 to 1:1. -Altholl~h the coating compositions o~ the present invention are of the high Rolid~ type, a liquid diluent i8 usu~lly presene in the composi-tion. By liquid diluent is meant a solvent or non-solvent which i6 vola-~ile ~nd i~ removed a~ter ~he coa~ing is applied and is needed ~o reduce viscosity sufficiently ~o enable forces available in simple coating te h-nique.~, namely, spr~ying, to 6pread ~he coating to ronerollable3 desired and uni~orm thicknesses. Al~o, diluents a~sist in sub6tr~te ~etting, ~esinous component compatibility, pnckage ~tabili~y and coalegcence or film formation. Ex~mples of 3uitable diluents include ar~satic hydrocarbo~
~uch a~ toluene and xylene, ketones such as methyl ethyl ~etone and methyl isobutyl ketone, alcohols such as i~opropyl ~lcohol, normal-bu~yl alcohol, monoethess of glycol~ such as the monoethers of ethylene glycol and diethyl- -ene glycol, a~ well as c~mpatible mixCures Chereof. The diluent i~ present in ~mounts up to 60 percent by weigh~, usually 35 to 55 percent by ~ei8ht~
baaed on tot~l wei~ht of dil~ent ~nd resin solids.
In ~ddi~ion to the zbove ingredients, v~riou~ filler~, pla~ti-cizers, anti-oxidants9 U.V. li~ht absorbers, flow control agent~, 6urf~ct-ant~ and other Qnnulating additives can be employed if desired. Tile~e materials are optional and generally constitute up to ~ percent by ~eighe3 based on total solids in the coating formulaeion.
For coating c~mpositions, the u~e of polyme~ic microparticles such as described in U.S. Patent No. 4,147~688 is preferred for sag con trol and metallic pigmene pattern control. The polymeric microparticles help to align me~allic pigments such l~hat they ~iYe the coating a lustrous appe ar anc~ .
The co~ting ~omposition6 of the present inven~ion ~re designed for application by spraying, although other conventional ~ethods of coating including brushing, dipping and flow coating can be employed if de6ired.
However, as mentioned above, they are especially formulat~d for sprayin~.
U6ual ~pray ~echnique~ and equi~ment are uCili~ed. Coating~ of the present invention can be ~pplied vir~ually over ~ny substrste including wood, metal, glaaa, cloth, pl~stic~9 foam8 and the like, ~8 well as over various primer~, The coating~ are particularly useful or~ resilient and rubbery substrate~ ~uch as fo~nn rubber, polyurethane fo~n and vinyl fo~m, arld on ~oft metal surfaces ~uch a~ mild ~teel lmd alu~inu~s.

The rombination of outstand~ng properti~s of ~he coating co~po si~ion~ of the presene invention make the~ useful for a wide variety of applications. They can be used for coa~ing auto~tive parts 8U h s auto-~obile bodies and truck cabs. Al~o, they can be ~ed for other coating applications suoh as coatings for ~ppli~nce parts guch a0 refriger~tors and washing ~achines, and they can al~o be used for coil coating applications.
In general~ coating thicknezs will vary depending upon the appli-cation desired. In general, coatin&s from about 0.1 to 5 mils have been found to be u~eful in most applications~
Af~er application ~o the sub6trste, the coatings are c~red. Cur- -ing is usually conducted at tet~peratures of about 100U to 200~C., and in most cases, a cure schedule is from ~bout 20 to 30 minutes a~ about 120 ~o 150C. ~i~hes or lower temperatures with correspondingly shorter or longer ti~es can be utilized, although ehe exact oure sohedule best employed depends upon the nature of the substrate as well as the particular compo- -nents used in formulating the coating compositions. With aminopl~st curing ~gent, acid catalys~s ~an be employed, if d~sired, as they usually permit use of lower temperatures and shorter times for cure.
The coating compositions of the present invention can be applied to the substrate in a clear-over-color ~pplication in which ~ pigme~ted or colored base coat is first applied to a subserate~ followed by application of a cleas top coat. In both coatings, the reQinous ingredients employed in the coating compositions of the pre~ent invention are used.
The following exampleR illustrate ehe invsntion. All quantieie~
are cn a weight basis unless otherwi~e indica~ed.

LXA~PLES
A series of hard polye0ter polyolP were prepared as follow~:

-- 18 ~

Example A
A polyester ~Sward Hardnesq value of 34, con~aining 42.5 perce~t cyclic moieties and MW = 344) was prepared from the following mixture of ingredient~.

Part~ by Weight In&redient~ (in grams~ ~
Meopen~yl glycol 2255.8 Hexahydrophthal ic anhydride 1744 Butyl stannoic acid 0.2 ~ethyl amyl ketone 43S
~he ingredient~ ~ere charged to a reaction vessel ~nd heated to reflux. Reaction was continued with water being removed until ~n acid value of about 7.3 was obtained. The reaction mixture wa~ thinned with tbe methyl ~myl ketone~ me poly~ter resin had a ~heoretical ~olids content of 90 percen~, an OH value of 321 (100 percent resin solids) and an scid value of 8. 27 .

~xample B
A polye~ter (Sward Hardness value of 24, co~taining 27.4 percent cyclic moieties and MW = S44) wa~ prepared as generally described in E~ample A from the follo~ing mixture of ingredient~:
Parts by Weight Ingredient~ (in grams3 ESTER DIOL 2041 435.6 Hex~hydrophthalic anhydride 164.4 Butyl ~t~nnoic acid 0.05 Methyl smyl ketone 64.0 12,2-Dimethyl-3~hydroxypropyl 2,2 dimethyl-3-hydroxypropionate available from Union C~rbide C~rp.

The polyes~er had a Gardner-Holdt letter viscofiity of Zl, a solid3 content (105~C.) of 82.7 percent, acid value of 8.76 and a hydroxyl value of 188.6 ~210 at 100 percent resin solid~).

Example C
A polyester (Sward Hardnes~ value of 32, containing 38.8 percene cyclic moieties snd ~W = 428~ was prepared aæ generally de~cribed in Example A fro~ the following mixture of ingredient~:

Parts by ~ei~h~
Ingredients ~in gram~
Trimethylpentanediol 2265 ~e~ahydrophthalic anhydride 1435 Butyl 6t~nnoic acid 0.2 Methyl a~yl keeone 435 l~e polyester resin had a Gardner-Holdt letter viscosity of 21-z solid~ content (105C.) of 75.7, acid value of 9.3 and OU value of 191.6 (213 at 100 percent resin 601ids).

Example D
A polyester (Sward Hardness value of 40, containin~ 36.5 percenL
cyclic moieties and MW 5 404) ~s prepared as generally described in 20 Example A from the following mixture of ingredient~:

Parts by Weight Ing~edients ~in grams) Trimethylolpropane 2497 Hexahydrophthalic anhydside 1435 Butyl stannoic acid 0.2 Methyl $myl ketone 12003 The polyester resin had a Gardner-Holdt le~c~er ViliC06ity of V-'W, solids coneent (105C.~ of 60.3 percent, acid value of 6.5 and OH value of 404.1 ~538.S at 100 percent resin solids).

Exa~ple E
A polyester (containing 100 percent ~yclic moieties and ~ = 424~ -was prepared as generally described in Example A from the following mixture of ingredients:
P~rts by Weight Ingredient~ (in grams) Hexahydrophthalic anhydride 935.0 Cyclohexanedimethanol 1559.0 Butyl stannoic acid 0.25 Methyl amyl ketone 422 The polyester resin had a Gardner-Holdt letter viscosity of Z3, a solids content (i50 C.3 of 86.9 percent, acid value o~ 10.9 and 0~ value of 98 (220 at 100 percent solid~).

E~ample F
A polyester (Sward Hardness valu of 42, containing ~4 per~en~
cyclic moieties and ~W ~ 384) wa6 prepared a~ gener~lly de~cribed in Example A from the following mixtu~e of ingredients: -Parts by Ueight Ingredien~ 8 ( in grams) Cyclohexanedimeehanol 537.1 ~exahydrophthalic ~nhydride 574.5 Neopentyl glycol 3BO.9 Butyl ~tannoic acid 0.15 The polyester (12~6.9 gra~6) was thinned ~ieh 227 gra~s of methyl a~yl ke~one~ Tbe polyester rsin had a re~in ~olids conten~ (105 C.) of 75.7 percent, Gard~er-Holdt b~bble viscosity of 29.6 seconds, acid number of 16.2 ~nd hydro~yl value of 245.2 (288 ~e 100 percent resin ~olid~).

Example G
A polyester (Sward Hardness value of 32, containing 59.4 percent cyclic moieties and MW = 484) ~as prepared aB generally described in Example A from tha following mixture of ingredient6:

Parts by Weight Ingredients tin grams~ _ Cyclohexanedi~e~hanol 432.0 Hexahydrophthalic anhydride 462.0 ESTER DIOL 204 612.0 Butyl stannoic acid 0.15 Ninety parts of polyester was thinned with 10 parts of methyl amyl ke~one. The thinned polyester resin had a resin solid~ conten~
(105~C.) of 78~5, a Gardner-~oldt visco~ity of Z4, acid nu~ber of 10.4 and hydroxyl value of ~03 (225.5 at 100 percent resin solid~).

Example A polyester (containing 62.8 percent cyclic moieties ~d MW
484) was prepared as ~enerally described in Exa~ple A with the excep~io~
~h~t the re~ction was conduceed at 200-230C. wieh the re~oval of 304 ml of ~th~nol~ fro~ the following mixture of ingredient~:

Pares by Wei~ht In~redients ~in gram~) Cyclohexanedimethanol 394.6 Dimethylcyclohexane dicarboxylate 548.0 ESTER DIOL 204 559.0 Butyl 6tannoic acid 0.15 The polyester was thinned with ~ethyl amyl ketone to ~n 85 per-cent total theoreeical solids. The thinned resin had a resin solids con-tent (105~C.) of 80.7 percent, a Gardner-~oldt viscosity of Z-~1, and OH
number of 93.4 (109.9 at 100 percent resin solids~. ~

Exsmple J
A polyester polyol-propylene oxide adduct (Sward Hardness value of 40, containing 44.5 percent cyclic ~oieties and MW = 346) ~s prepared as follows:
A hexahydrophthalic anhydride-trimethylolpropane polyester polyol intermediate W2S first prepared from the following mixture of ingredients:

Parts by Weight Ingredient6 (in gr~s) }~exahydrophthalic anhydride 5347 Trimethylolpropane 4653 Butyl stflnnoic acid 10 The hexahydrophthalic anhydride was charged eo a reaction vessel at 70-80C. 3 followed by the addition of the trimethylolpropane. The eemperature of the reaction mixture was raised to 120Co and the catalys~
added. The reaction mixture be~an to reflux and was held at reflux ~or 30 ~inutes and was ~hen cooled ~ 120DC. ~d beld for one hour un~il an acid value o 182O7 was obtained.

A propylene oxide reaction product ~f the polyester polyol wa~
prepared from ~he following ~ix~ure of ingredients:

Parts by Weight Ingredients (in grams) Polyester polyol intermediate prepared as described above 1069 Propylene oxide 400 ~YAMINE 10~1 5 lDiisobutylcre~oxyethoxyethyl di~ethylben~yl ammonium chloride monohydrste available fro~ Rohm snd Haas Comp~ny.
The polyester polyol wa~ charged to a reaction vessel and heated to 130C. Propylene o~ide (203 grams) was added slowly ~o ~he reaction vessel over ~he period of abou~ 19-1/2 hours. Ihe ~YA~INE lOX wa6 Idded and the remaining por~ion of the propylene oxide added. The reaction ~ixture began to reflux and was held at 120G. for 5 hours. The reaction mixture was thinned witl~ 163 parts of ~ethyl amyl keto~eO The polye~ter resin had a resin ~olids content (105DC~) of 88.1, a Gardner-Holdt letter vi~co~ity of 24~, acid value of n.s and hydroxyl value of 35~.6 (391.5 ~t 100 pe~cent re6in solids)~

~ample ~ -A polyestes (Sward ~ardne3s value of 28, containing 39.3 percent cyclic ~oietiefi and MW ~ 374)~ si~ilar to Example J, W~3 prepared from the following ~ixt~re of ingredient~:

Par~s by Weight Ingredient~ ~in gra~) -Polye~ter polyol intermed~ate of Ex~ple J 11~2 N~opentyl glyc~l 416 ~ 2~ ~

The polyester polyol and neopentyl glycol were charged to a reac tion ve~el and heated to 120C~ to initiate reflux. Reflu~ing conditions were continued with water being removed for about 6 hourg. The resulting polye~ter was cooled and thinned wi.th 167 grams of methyl ~nyl ketone. The polyes~er resin had a resin soIids content (105C.) of Bl.7~ a Gardner-Hnldt 0 letter viscosity of Z7~, acid value of 9.0 and hydroxyl value of 387.0 (430 at 100 percent resin solid~.

~xample L
A polyester (containing 35.5 percent by weight cyclic moieties 10and MW = 416) was prepared as generally described in Example K from ~he following ~ixture of ingredients:

P~rt~ by Weight Ingredient 6 ( in grams) Polyester polyol intermediate of Example J 1152 Tri~ethylpentanediol 584 Bu~yl 6tannoic acid 1.7 ~ethyl amyl keton~ 181 The polyester resin had a resin solids content (105C.) of 77.7 percent, a Gardner-~oldt letter visC03ity of z6~, acid value of 802 Nnd 0~ number of 321.5 (357.2 at 100 peroent re~in ~olid~).

Example M
A poly2ster (containi~g 70 percent by wei~ht cyclic ~oieties ~nd MW ~ 434) was prepared a~ gener~lly de~cribed in Example ~ fr~m ~he follow-ing mi~ture of ingredients: ~

a~

Parts by Weight Ingredi~nts tin gr~ms) Polyester polyol intermedia~e of Example J 1152 Cycl~hexanedimeehanol 576 Methyl ~myl ketone la5 The polyester resin had a resin solids co~en~ (105C.~ of 85.7, a Gardner-Holdt letter viscosity of z7_78, ~cid value of 7~7 and hydroxyl value of 352.l (391 at 100 percent re~in ~olid~).

Example A polye~ter (containing 68~8 percent by weight cyclic moietie~
and MW - 436) was prep~red as generally des~ribed in E~ample ~ (242 ml methanol removed), from the followin~ ~ixeure of ingredient~:

Parts by Weighe Ingredien~ (in ~rams) Cyclohexanedimethanol 432.0 ~imethylcy~lohexan~ dicarboxylate 600.0 ESTER DIOL 204 306.0 Neopentyl glycol 156.0 Butyl s~annoic ~cid 0.15 The polyeiter was thinned with methyl amyl ketone to 90 percent total theoretical ~olids. The polyester resin had a resin solid3 c~nten~
(105~C.) of 78.8, a Gardner-Holdt viscosity of Z2-Z3 and a hydroxyl value of 199.8 (222 at l00 peroent re~in ~olid~.

Polyurethane Polyols ~xample O
A poly(ester-urethane) polyol ~Sward ~ardness valu~ of 2 ~nd M~
19,000) ~as prepared frGm ehe following mixture of ingredients:

Parts by W~ighe Ingr~dients (in grams) Polycaprol~ctone polyol ~MW~1250) 39.26 Dimethylolpropionic acid 1.19 DESMODUR Wl . 9 . 56 Methyl isobutyl ketone 18.29 Methyl ethyl ketone 31.46 Monoethanol~mine 0.23 I0 14,4'-methylene-bi~-(cyclohexyl isocyanate~ obtained from Mob~y Company.

Th~ methyl isobutyl ketoneJ PCP-0230, dimethylolpropionic acid and DESM~DUR W ~ere charged to P reaction vessel under a nitro~en atmosphere and heated to 110C. until a Gardner-Holdt bubble visc~sity of 1209 seconds was reached. The ViSCQSity ~as ~easured by taking a sample of the re6in ~nd thinning ~i~h 46 p~rts Df methyl ethyl ketone per 100 pa~ts of resin. --Af~er ~he required viscosity was obtained, the monoethanol~mine was the~
added, foll~wed by the addition of the ~e~hyl ethyl ketone. The reaction product had a resin 301ids eontent (150C.) of abo~t 49.8 percent, ~
Gardner-Holdt letter viscosity of B~, an acid ~alue o~ 9.~ bas~d on resin solids and a hydroxyl number of 13.8 (37.6 at 100 percen~ re6in solidR).

Exa~ple P
A poly(e~ter urethane) polyol (Sward Hardness value of 4 and MW
6336) was prepared by charging the follo~ing mixt~re of ingredient~ to reactor and heating to 120C. un~il infrared ~pectra sho~ed little or no evidence of epsilon-capsolactone: -~ 27 Parts by Wei~ht Ingredients (in græms~
Dimethylolpropionic acid 33.2 Diethylene glycol 397.6 Epsilon-caprolactone 2889.2 The reaction mixture was cooled to 60C. and ~650 grams poured into a~other reactor. Isophorone diisocyanaee (555 grams) was added and the mixture thinned to 90 percent resin solids with ~ethyl isobu~yl keto~e.
The reaction mixture wa heated to exotherm and held at llO~C. for 3 hour~.
An IR spectrum 6howed no evidence of iocyanate groups. The resin had a resin ~olids content ~150gC.) of 86.9 percen~, a Gardner-Holdt bubble YiS-c08ity of 23.9 seconds, an acid value of 6.4, a hydroxyl nu~ber of 59.6 (66.2 at 100 percent resin solid~). For use in painta described in Example 14, the re~in was iurther th mned to 70 percent sDlid6 in 2-ethoxyethylacetate.
For Example 15, the resin was used at 100 percent soli~

Example Q
A poly(ester-urethane) polyol (Sward ~ardness value of 4 ~nd molecular weight = 6597) was prepsred from the following: 33.2 grams of di~ethylolpropionic acid, 397.7 grams of diethylene glycol, 2889.1 g~ma of epsilon-caprolactone and 3.3 grams of triphenylphosphine. The ingredients were charged to a reaction vessel under A nitrogen blanket and heatçd to about 150~C. and held at thi temperature until an IR spectra indicated the absence of ep~ilon-caprolsc~one.
The reaction mixture described ~bove (2490.0 gr~m~) ~as charged to a reaction vessel ~ith 275.1 gr~ms of D~SMOD~R W and 152 gr~ms of ~ethyl isobutyl ketone.

~ 28 -~a6~

Additional DESMODUR W (96.7 gr~ms) was added to 2417 gr~ms of ~he reactio~ mi~ture and the reaetion mixture heated ~o about llO~C. un~il a Gardner-aoldt vis osity of 158 s2conds was obtained. The reaction was ter minated, Rnd an IR spectra indicated a small amount of NCO. The reaction mixture was hea~ed to 40C. until an IR spectr~ indi~ated th absence of NCO. The reaction mixture was thinned to 90 percent resin solids with methyl isobutyl ketone. The reaction mixture had an acid v61~e of 4.7, a hydroxyl value of 54.2 and a Gardner-Holdt ~iscosity of Z2-Z4.

Paints A first series o~ paints was formulated using the polyester~ and the polyurethane as described aboveO The polyest~r and polyurethane were ~ormulated with an æminoplast curing agent, a catalyst, poly(oxytetramethyl~
ene) glycol plasticizer, a flow control agent ~nd a pigment paste as shown in Table I below:
Table I
P~int Formulation Parts by Weight, solids Ingredients (in ~rams) Polyester polyols as shown in Table II 34 (39 parts for Example 3) Polyurethane polyol of ~xample 0 5 C~MEL 303l 40 TERACOL 10002 lO (5 parts for Example 3 Flow oontrol agene3 7 Cataly~4 0,75 TINUVIN 3284a 2.00 Pigment pas ~5 15 1HexakiG(me~ho~y~ethylol)melamine commercially available fr~m American Cyana~id Company.
2Poly~oxytetrametbylene) glycol having a molecular weight of about lOOG commercially avail~ble fro~ E. I. duPont de Nemours and Co.
3Polymeric microparticlea prepared in accordance with Example II
of ~.S. Pate~t No. 4,147,688.
4A 40 percent by weight para-toluenesulfonic acid solution in isopropanol.
4aU.V. light stabilizer, ~ubsti~uted benzotriazole, c~mmercially available from Ciba~Geigy Company.
~Pigment paste contained aluminum pi~ment, phthalo blue, irga~in blue and carbon black in an imini~ed polyester pigment gri~ding ~ehicle.
The paints formulated as de~cribed above ~ad a spr~yable resin solids cont~nt of about 55-58 percene by weight. Th2 weight ratio of poly- -ester polyol plu~ polyurethane polyol:~minopl~st was about 1:1. The weight ratio of polyester polyol plus aminoplast:polyurethane polyol was about 15:1.
The paints were spr~yed onto 1/8 inch thick BIM thermopla~tic polyurethane substrates commercially available from ~ord Utica as UTICA ~ -114. The coatings were cured at 1~4C. for 30 minutes to give ~ 1.8 mil ~hick cured coating.
The coated substrates were evaluated for initial gloss, hardnes~
and elasticity, and for gloss retention and dirt pick up after 3, 6 and 9 months of Florida exposure. The re~ults are presented in T~ble II below: -OlfO~ 01 /IS O~/TL S~d 1~ 9T S~ N S
6~9~ 6/OS Ol/S9 ~8ea ~5 E?d 9 S~ U 17 6/15 6/L5 0~ 8Y~a ~ea ZZ ,0 01/1~ 01/09 Ol/~L ~8~d 11~ 8 S~ ~ 9Z t~
Ol/Z~ Ol/Z9 0~/8~ ~Ba 85~d ZZ 0 51~:1U0~ 6 8C~:~U0~ 9 ~3y~i~u.O~ U~51 ~ioSL ~pu;~ dloQ zs~aup~H Issol9 OQZ l~8~6loa ~Id~x~
eo,~ ~ln~odx~; ~?p~lO~ a~ P~qS
Sdn ~a ~ p~ 81~ 9 8~ 3do Y~ uI
d~la ~3U~IB
BI, 120 glo8s is messured with a Gardner 20 Glosg Meter ~anufactured by Gardner Instrumen~s.
2Sward hardness i~ measured using a Sward rocker as described in ORGANIC COATINGS TECHNOLOGY, Payne, Vol. 1, l9S5~ pages 642~643.
3Bend is a 180 be~d of the eoat~d ~ubstrate, a~ the temperature indicated ~ith coating side facing outwardly, around a 1/4 inch (1.13 cm~
mandrel. After bending, the coating is e~amined for breaks and crack0. A
rating of pass indicates no break or crack. Fail indica~es breaks and crarks.
4600 gloss i5 measured ~i~h a Gardner 60~ Gloss M~ter manufactured by Gardner Instruments.
5Ratings for Dirt Pickup range from 1 to 10 with 10 indicating essenti~lly no dirt pick up and 1 indicating much dirt pick up.
6Paint contained 5 parts by weigh~ T~RACOL 1000 instead of 10 parts by weight used in the other paintsO

A second series of paints was formulated usin~ the polyes~ers ~nd polyurethanes described above. I~e polyes~er and polyurethane we~e formulated with an aminoplast curing agent, ~atalyst, fl~w cGntrol agent, and a pigment paste as shown in Table III below:
Table III
Paint Formul tion Parts by Weight, solid4 Ingredients (in grams~
Polyester polyol as identified in Table IY 8-25 a8 shown in Table IV
Polyurethane polyol as identiied in Table IV 25-40 as sho~n in Table IV

Flow control agentl 5 C~t~ly~tl D.5 Pigment paste2 4.0 Cellulo~e a~etate butyrate3 1~0 Methyl ~myl ketone 55.0 lIdentified in Table I.

2Pigment paste containing aluminum pi~ment ~nd phthalo blue in an iminiæed polyester pigment grinding v~hicle.
325 percent by weight solution of cellulose acetate butyrate in 75/25 (by volu~2~ ~ethyl isobutyl ketone/l-butanol.
The paints for~ula~ed as described above had a sprayable r~sin solids content of about 55 percene by weight. The wei~ht ra~io of pGly ester polyol plus polyurethane polyol:sminoplast was about 1~2:1, and the weight ratio of polyester polyol plus aminoplast:polyurethane polyol ranged frGm 1.2-2.6~
The paints were sprayed on~o RIM BAYFLEX thermoplastic polyurP~hane substrates co~mercially available f~om Mobay Corporation. The coatings were cured ~t 124C. for 30 minute~ to give 1.8 mil thick cured coatings.
The cured substrates were evaluated Eor Sward hardness, elasti~ity snd humidity resistance. The results ~re presented in Table IV bolow:

~n l_ t O . P
n. t~
: r 0~ t L
r t ~ r ~c ~ C) ~ ~ ~ r~
~t r ", D
- r~ ~ ~
:~ Ul O CD ~ CO S,~ Vl O
. ~3 ~
~,r ~ ~.
r~
C\ ~ ~

::1 5 ~ _ ~_ _ ~. ~r 0~ ~ .
U ~ ..
ID ' ~ ~ ~ ~ ~ ~ W
o o ~ o O

.0 r~
r n :r ID
, r ~
r ,~ CL ~1:1 fll tD

. r 5 ot ~ ~ r ~ ~ r~ Vl ~1 .~
r O
l p~
O ~ ,~ ~ r;~ r~ l L . ~ t~
~ ~7 ~:
nr t~ , _ ~ r ~ O O 0 9 O O O C~
~ ~OL ta. P f~ CL ~ L 7 ~ .
t

3'~ --E~a~ple 14 A paine was prepared from the following mi~ture of iRgredients:
Part 6 by Weight In~redients (in grams~
Pig~ent Paste (I)1 400.37 Inhibitor ~olution2 ~ 173.42 Polymeric microparticles3 6B.80 Polye~ter of Example A 82.06 (90~ solids) CY~EL 11304 149.59 (100X ~olids) Polyurethane of Exa~ple P 106.~5 ~70% solids) 40~ by weight para-toluenesulfonic acid in isopropanol 5.23 Catalyst5 4-4g 1The pi~ment paste ~as prepared by grindin8 TiO~ and polyethylene powder in an iminized polyester grinding vehicle.
2Solution of 3.74 parts of cellulose aceeate butyra~e (CAB), 7.48 part~ of TINUVIN 328 ~ubsti~uted ben~otridzole, ul~raviolet li~h~
sbsorber~ co~mercially available from Ciba~Geigy), 0.94 part~ of ~ilicone fluid in a ~olvent mixture of 44.37 parts of n-propanol, 26.17 part6 o VM & P Naptha, 68.63 p~rts of 2-ethoxyethylace~a~e, 33.31 part~ of 2- -butoxyethylaceta~e.
3Prepared in accordance with E~ample II of U. S. Patent No .

4,147,688 and diluted on A 1' 1 volume basi~ wi~h 2-hexoxyethanolO
4Mixed methylated, butyl~ted melamine formaldehyde re~in can~ercially available from American Cyananid Co~p~ny.
5Dinonylnaphthale~edi6ulfonic acid, 50 percent neutralized wi~h dii60propylamine, u~ed as ~ 30 percent by weight 801utio~ in a miKture of 52.6 perce~t i~opropyl alcGhol, 8.2 percen~ water and 39.2 percent isobu~anol.
The paint prepared from ~he above-described mix~ure of in~redi-ent~ had a ~prayable re~in ~olida content of about 55 perce~t by wæightO
Tbe weight ra io ~f polye~ter polyol plus polyur~thane polyol:~minoplas~
Wd~ nd the weight ratio of ~lyester polyol plus ~mi~oplaBt Opolyu~e~
~hane polyol was 3:1.

~ he paint ~as sprayed onto a 1/~ inch thick RIM thermopl~stic polyurethane commercially available from ~obay as TEXIN 3Z020 The coating ~as cured at 124C. for 30 minutes to give a 1.8 mil thick cured coatingO
The cured ooating had a S~ard hardnes6 of 18 and withstood 8 0~. cold bend as described above without cracking. The coating ~xhibited ~o blis- -terin~ nor loss of gloss after being subjected to humidi~y testing for 240 hours in the QCT chamber a~ described above.
Free fil~s of the resinou~ ingredients of the example have te~-sile ~trengths of 30B0 p~i and elongation~ of 47 percent.

Examples 15 16 Ex2mples 15 and 16 are "clear over color" coating compositions.
With these coating compositions, a pigmented or "eolored" base cGating i6 applied to the ~ubstrate and is overcoated with a clear top coat.

Example 15 A pigmented or "colored" base coating composition was prepared from the fGllowing mixtur~ of ingredi~nt~:

Parts by Weight Resin Ingredient~ (in grams)501ids Pigment pastel 47 14 Polye~ter of Example B 19 16 Polyester2 17 10 Polymeric microparticle c~mposition3 71 45 Inhibitor composition4 20 Polyurethane of Example P 15 15 2/1 volume mixture of methyl alyl ketone and 2-ethoxyethylacetaee 14 20~ dinonylnaphthalenedisulfonic acid catalyat in n-butylacetate 3.75 0.75 - 36 ~

lThe pigment paste was prepared by grindin~ ~luminu~ pig~en~ an an i~ini~ed polyester grinding ~ehicle.
~ The polyester wa~ made fram 703 parts of 1,6~hexanediol, 482 part~ of adipic acid, 821 part6 of i~ophthalic acid and B.6 parts o hydroxy-ethylene imine and 442 parts of trimethylolpropane. The polye~ter was about 59 per~:ent resin solids in 82:18 weight ratio of r~ethyl normal bu~yl ketone and toluene. The polyester resin had an acid value ~f 2. 3 and an oa value of 89.
3~ixture of 23 parts (10 parts solids) of polymeric microparticl~s 10 prepared in accordance with Exampl~ II of U.S. Paten~ NOD 4,147,688~ 13 parts of isopropyl alc~hol and 35 par~s of CYMEL 1130.
4Solution of 2 grams of TINUVIN 328 in 9 gr~ms of methyl ~myl ketone and 99 grams of 2-ethoxyethyl~retace.
Th2 "clearl' coating composi~ion was prepar~d fro~ tlle following ~ixture of ingredients: -Part~ by Weight Resin Ingredient~ (in grams) Solids Polyester of Exa~ple ~ 48 41 Inhibitor solutionl 27 4 CAB solution2 2 0.5 Polymeric microparticle composition3 58 44 ~lethyl nmyl ketone 20 Polyurethane of ~xample P 15 15 20% dinonylnaphthalenedisulfonic acid cat~lys~ in n-butyla~etate3.75 0.75 lSolution oi 4 parts of TINUVIN 328 and 11.25 parts of meeh amyl ketone and 11.25 part~ of 2-e~hoxyethylacetate.
2SD1UtiOn Of 3.21 par~s ~f cellulose acetate butyrs~e in 75l25 (by volume) me~hyl isobutyl ketone and buta~ol.
~ixture of 9 parts (4 parts solid~) polymeric micropa~ticle~ -prepared in accordance ~ith Example II of U.S. Patent No. 4,147,688 in 9 p~rt~ of isopropyl alcohol and 40 parts of CYMEL 1130.
5he p int prepared from the pigmented coating c~mposition had a sprayable resin ~olids content of about 55 percent by ~eight. The ~ei~h~
ratio of lcw ~oleculsr wei~ht polye6ter polyol plu~ polyure~hane polyol:

aminoplast was 0.89:1 ~nd the weight r~tio of 1DW molecular weight poly-e6ter polyol plus ~minopla6t:polyurethane p~lyol was 3.4:l. The p&int was sprayed onto a 1/8 inch ehiek RIM thermoplas~ic polyurethane commer-cially available from Mobay a~ TEXIN 3202.
The clear coatin~ compo~ition had a ~prayable re~in ~olids con- -tent of about 60 percent by weight. The weight ra~io of polyester poly~l plus polyureehane polyol:a~inoplast was 1.4~ nd the weight ratio of polyester polyol plus aminoplast:polyurethane polyol was 5.4:1.
The clear coating composition was spray applied to the colored ba~e coating after flashing the base coating at 20C. for about 90 seconds, and the composiee coating cured at 124C. fo~ 30 minutes to give a 2.2-2.5 ~il thick clear-over-color eured co~ing.
The cured coating composi~ion had a Sward hardnes3 of 6 and ~ithstood a room te~perature and 0F. cold bend as de~cribed aboYe without cra~king. Th~ coa~ing exhihited only ~light cr~cking when ~ubjected to humidity testing for S00 hours in the QCT cha~ber as described above.

Example 16 A pigmented or "col~red" bsse coati~g rompo~ition wa~ prepared fro~ the following mixture of ingredient~:

Parts by Weigh~ ~esin Ing~edients (in gr~m~)Solid~
Pigmen~ paste1 47 14 Polyes~er of Example C 18 16 Poly~eric microparticle compo~i~ion2 71 45 Inhibitor ~olutioD3 20 2 Polyurethane of Ex~mple P 28 25 2Jl volwme ~i~tu~e of methyl ~yl ketone and 2-ethoxyethylaGetate 14 20% dinonylnaphthalen~disulfonic aeid cataly~t in n-butylacetate 3.75 a. 75 - 3~ -1The pigment paste was prepsred by ~rinding aluminum pig~ent in an imini~ed polyester grinding vehicle.
2Polymeric microparti~le compo~ition as used in E~ample 15 3Inhibitor composition as used in Example 15.
The "clear" coating composi~ion was prepared from the following mixture of ingredient~:

Part~ by Weight Resin Ingredients (in grams) Solids 2Jl volume mixture of methyl ~myl ketone and 2-ethoxyethylacetate 40 Inhibitos solution as used in Example 15 20 2 Polymeric microparticle c~mpositionl 405 2 25~ cellulos2 acetate butyraee solution as u~ed in Example 15 2 0.5 Polyurethane of Example P 28 25 Polyester of Ex2mple C 37 33 20~ dinonylnaphthalenedisulfonic acid catalyst in n-butylacet~te 3.75 0.75 lPoly~eric microparticles prepa~ed in accordance with Exa~ple II of U.S. Paeent No. 4,147,688.
The paint prepared from the pigmented coating compositio~ had a sprayable resin solid~ content of about 55 percent by wei~ht. The ~eight satio of polycster polyol plus polyurethane polyol:aminoplast was 1.17~
The weight ratio of polyester polyol plus aminopl~st:polyurethane polyol was 2.04:1. The paint was 3pr~yed onto l/B inch thick RIM thermopla~
eic polyurethane commercially ~vailsble from Mobay aG T~XIN 3202. The coatlng wa~ flashed at 20~G. for about 90 second~.

- 39 ~

~6~

'~he clear coating compo6ition had a sprayable resin solids con-tent oi about 60 percent by wcight. The weigh~ ratio of polyester polyol plu8 polyurethane polyol:~minoplast ~as 1.45:1, and the weight ~atio of polyester polyol plu8 aminoplast:polyurethane po~yol w~s 2.92:1.
The clear coating composition was then spray applied to the colored b~se COatiD~ after flashing the base coating at 20~C. for about 90 seconds, and ehe composite coating ~ured a~ 124C. for 30 mi~utes to give a 2.2-2.5 mil thick clear-over-color composite coating. The final coating had a Sward hardness of 8 and withstood a room temperature and 0~. cold bent as described above without cracking. After 742 hours of humidity testing in the QCT cha~ber as described above9 only slight cracks were ev id enced.

Co~paraeive Examples A series of coating compositions were prepared with ~arious poly-ester polyols. The polyester of Exa~ple A WRS compared with similar poly- -esters in which the hexahydrophthalic anhydride used in Example A was replaced with tetrahydrophthalic anhydride (Example S~ Sward Hardness value=50), phthalic anhydride (Example T, Sward ~ardness value=58) and adipic acid (Example U, Sward Hardness values6). The polyesters ~ere combined with a polyurethane polyol plasticizer of Example Q and an amino plase curing agent and formulated into a coating composition as described generally below. The coating compositiona were ehen applied to an el~to-meric aub~tr~te and cured and the cured film evaluated for Sward hardness, elongation~ ~ensile ~trength ~nd 0Fo cold bend.
Coating c~mpo~itions were for~ulated a~ follow~: --- ~0 --Ingredients Percent by Wei~ht (solids) Polyester of Examples As S, T, U 35 Polyurethane of Example Q 20 `' CYMEL 303 39.5 Para-toluenesulfonic acid 0.5 Polymer ic microparticlel 4.0 Cellulose scetate butyra~e 1.0 lPrepared in accordance with Exampl~ 2 of U.S. Patent No. 4,147,688 and diluted on a 1:1 volume basis with 2-hexoxyethanol.

10 The coating composition prepared from the above-described mix~ure of ingredients had a sprayable resin solids content of about 60 percent by weight. The weight ratio of polyester polyol plus polyurethane polyol:
aminoplaBt W~8 1.4:1 and the weight r&tio ~f polyester polycl plus ami~o-plast: polyurethane polyol was 3 . 7: 1.
The paint was sprayed onto a 1/8-inch thick RIM thermoplastic polyurethane co~mercially available from Mobay as TEXIN 3202. The coa~in~s ~ere cured at 124 C~ for 30 ~inutes to give a 1.8 mil thick cured coating.
The properties o the cured coating are shown in Table V below.

Table Y

Coating Propertie6 Coating P~e-pared With the Sward Percent Tensile Stsength Poly~ster of Hardness Elongation in p~i 0F. Bend Exarnple A 28 54 4118 Pass Ex~nple S 26 53 4?60 Pa~

Exa~nple T 38 25 5680 5mall crackB
Example U 10 45 2130 Pass The results reported in ~able V ~how the prefer~nce oi the cyclo-aliphatic moieties, i.e., hexahydrophthalic anhydride and ~etrahydrophthaliC
anhydride c~pared to the aromatic and acyclic dicarboxylic as d~. In c~m-parison wi~h the aromatic dicarboxylic a~id, the cycloaliphatic materials have superior elongations and low temperature flexibility. Both the cycloaliphatic and the aro~atic dicarboxylic acids are superior ~o the acyclic material~ in terms of hardness and tensile stren~th.
Th~ coating c~mposition of Exa~ple 10 in U.K. Patent No. 1,477,008 was prepared. When the coating composition was applied tO 8 substrate and cured, it was found to have an elongation of i80 percent and a tensile streng~h of 3976 psi. In addition, when applied to an elas~omeric sub-~trste and eested for resist~nce to eold bending, it was found to pas~ the 0F. cold bend. The Sward hardness of the coating ~as ~6. However, the coatin~ composition was of the lcw solids type9 having a sprayability of only 23 percent.

~ 42

Claims (18)

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

1. In a thermosetting, elastomeric coating composition comprising a polyester polyol And a polyurethane polyol, characterized in that the coating composition is sprayable at resin solids content of at least 40 percent by weight and is flexible such that when the coating composition is deposited on an elastomeric substrate and cured, the coated substrate can be bent around a 1/4 inch (1.13 cm) diameter mandrel with the coating facing outwardly, and the coating exhibits no breaks or cracks when tested at 32°F. (0°C), and comprises as the film-forming constituents:
(A) a hard polyester polyol having at least 10 percent by weight cyclic moieties, having a hydroxyl value of at least 30 and a Sward Hardness value of at least 15, the percentage by weight cyclic moieties, the hydroxyl value and the Sward Hardness value each not being greater than that required to achieve said flexibility, (B) a polyurethane polyol having a Sward Hardness value of loss than 10, and (C) a curing agent capable of reacting with the active hydrogens in (A) and (B) to form a crosslinked coating;
the difference in Sward Hardness values between (A) and (B) being greater than 10.

2. The coating composition of Claim 1 sprayable at a resin solids content of 45 to 65 percent by weight.

3. The coating composition of Claim 1 comprising 20 to 70 percent by weight cyclic moieties.

4. The coating composition of Claims 1 or 3 in which the cyclic moieties are cycloaliphatic.

5. The coating composition of Claim 1 in which the polyester contains neopentyl moieties.

6. The coating composition of Claim 1 in which the polyester polyol is formed from reacting a cycloaliphatic dicarboxylic acid or its functional equivalent thereof with a polyol containing neopentyl groups.

7. The coating composition of Claim 6 in which the cycloaliphatic dicarboxylic acid is selected from the class consisting of hexhydrophthalic acid and dimethylcyclohexane dicarboxylic acid or their functional equivalents thereof.

8. The coating composition of Claim 6 in which the polyol containing neopentyl group branching is selected from the class consisting of 2,2-dimethyl-3-hydroxypropyl 2,2-dimethyl-3-hydroxypropionate and neopentyl glycol.

9. The coating composition of Claim 1 in which the polyester polyol has a molecular weight of 1000 or less.

10. The coating composition of Claim 1 in which the curing agent is an aminoplast or polyisocyanate.

11. The coating composition of Claim 10 in which the aminoplast is a melamine-, urea- or benzoguanamine-formaldehyde condensate etherified with an alcohol containing 1 to 4 carbon atoms including mixtures of such alcohols.

12. The coating composition of Claim 10 in which the polyisocyanate is a blocked polyisocyanate.

13. The coating composition of Claim 1 in which the polyurethane polyol is a polyester-polyurethane polyol.

14. The coating composition of Claim 1 in which the polyurethane polyol has a molecular weight less than 5000.

15. The coating composition of Claim 1 in which the weight ratio of (A)+(B):(C) is within the range of 5 to 0.5:1.

16. The coating composition of Claim 15 in which the weight ratio of (A)+(C):(B) is within the range of 100 to 1:1.

17. A costed article coated with the coating composition of Claim 1.

18. The coated article of Claim 17 which has a colored base coat and a clear top coat.