Thermosetting powder paints

The invention pertains to thermosetting powder paints adapted to fuse and thermoset upon exposure to heat. The powder paint is based upon a two-component binder system comprising a polymeric glycoluril adapted to cross-link a matrix polymer having reactive hydroxyl, carboxyl, or amide groups.

BACKGROUND OF THE INVENTION 
This invention relates to improved thermosetting powder paints and more 
particularly pertains to polymeric glycoluril derivatives for 
cross-linking reactive polymers having reactive hydroxyl, carboxyl, or 
amide groups upon exposure to heat. 
Powder paints are ordinarily manufactured from raw batch ingredients 
comprising resinous binders, opacifying and filler pigmentary solids, 
plasticizers, and other additives to provide opacity, good film 
properties, and adhesion to substrates. The raw batch ingredients are 
uniformly mixed, formed into coherent extrudate by hot extrusion, and then 
comminuted to form small particle powder paints which are ordinarily free 
flowing at normal room temperature. Powder paints usually are uniform 
small powders passing 325 mesh or less than about 44 microns. Powder 
paints contain little or no fugitive solvents and depend upon their own 
inherent characteristics of the powder to melt, level, coalesce, and fuse 
to form an attractive coherent film on the substrate. The powder must not 
fuse in the container and cannot be subjected to cold flow so as to 
maintain individual powder particles prior to use. 
In recent years, thermosetting powder paints have become particularly 
suitable for use in commercial industrial process particularly since 
powder paints are essentially free of organic solvents whereby economic 
and social benefits are achieved by reduced air pollution, reduced energy 
use, and reduced health and fire hazards. Present commercial powder 
coatings often exhibit poor weathering properties although some expensive 
powder paints can obtain satisfactory weathering. Other difficulties often 
encountered in powder paints are caking or blocking of the powder in use 
and other mechanical application properties. Recently issued U.S. Pat. 
Nos. 4,118,437 and 4,064,191 disclose cross-linkable powder coatings 
wherein the cross-linking component is an alkylated glycoluril derivative. 
It now has been found that an economical and substantially improved powder 
coating composition can be achieved by utilizing a polymeric cross-linker 
comprising an alkoxy methyl or methylol functional polymer produced by 
copolymerizing a glycoluril with a diol or another glycoluril. The 
polymeric glycoluril can comprise as low as 10% by weight of the 
thermosetting powder coating binder composition which exhibits excellent 
minimum tack greater than 70.degree. C. and particularly important for 
non-fusing and non-blocking powder coatings. These and other advantages of 
this invention will become more apparent by referring to the Detailed 
Description of the Invention. 
SUMMARY OF THE INVENTION 
Briefly, the invention pertains to a powder coating composition comprising 
on a weight basis a mixture of 10% to 70% of a polymeric glycoluril 
cross-linker, and 30% to 90% of a reactive polymer whereby the polymeric 
glycoluril cross-links with reactive hydroxyl, carboxyl, and/or amide 
groups upon exposure to heat.

DETAILED DESCRIPTION OF THE INVENTION 
This invention pertains to thermosetting powder coatings primarily based 
upon a polymeric glycoluril cross-linking polymer adapted to cross-link a 
reactive matrix polymer upon application of heat. 
Referring first to the Drawings, FIG. 1 illustrates the tack temperature as 
a function of matrix polymer/cross-linking component for compositions of 
this invention as well as prior art compositions. The x-axis in FIG. 1 
indicates a weight ratio of matrix polymer/cross-linker wherein the 
cross-linking components are varied. Curve A illustrates the composition 
of this invention based on a polymeric glycoluril cross-linker. Curve B 
illustrates the same composition containing a monomeric glycoluril 
cross-linker in accordance as proposed in U.S. Pat. No. 4,118,437. Curve C 
similarly illustrates a melamine cross-linker consisting of 
hexamethoxymethyl melamine (cymel 300). The highly desirable Curve A 
provides approximately a consistent flat curve relative to Curves B and C 
which progressively depress tack temperatures and consequently increase 
undesirable caking or agglomeration of powder. 
Referring next to the polymeric glycoluril cross-linker, the glycoluril 
polymer is alkoxy-methyl or alkoxy methylol polymer having a molecular 
weight between 500 and 5000 and preferably between 600 and 1500. The 
glycoluril polymer can b formed by self-condensation of 
tetra-alkoxy-methyl glycoluril and/or a tetra-methylol glycoluril, or a 
condensation copolymer of a diol or diacid or diamide or polymer diol or 
polymer diacid or diamide with a tetra-alkoxymethyl glycoluril and/or a 
tetra-methylol glycoluril wherein the resulting glycoluril polymer 
contains reactive methylol or alkoxy methyl groups. Diols are preferred 
and suitable diols for the copolymer can include simple monomer diols such 
as glycols, low molecular weight polyester diols, and polyurethane diols 
such as for example, hydrogenated bisphenol-A, cyclohexane dimethanol, and 
neopentyl terephthalate. The low molecular weight diols can be 
advantageously utilized to increase the molecular weight of the polymeric 
glycoluril or achieve highly desirable tack temperatures above about 
70.degree. C. which are necessary to prevent caking and blocking of the 
powder paint particles. Preferably, the finished powder paint has a tack 
temperature in the range of 75.degree. C. to 95.degree. C. Suitable 
monomeric diols ordinarily are free of alkyl ether groups, are liquid 
although can have melting points as high as 150.degree. C., a hydroxyl 
content by weight of 10% to 55%, and molecular weights between about 60 
and 350. Polyester diols can have a resin tack temperature of about 
40.degree. C. to 70.degree. C., hydroxyl of 3% to 15% by weight, and 
molecular weights between about 200 and 1000. Glycoluril copolymers 
containing copolymerized diols can contain between 10% and 70% by weight 
diol copolymerized with alkoxy methyl or methylol glycoluril. 
Self-condensation glycoluril polymer can be produced by homopolymerizing 
units of tetra-alkoxy methyl glycoluril, or homopolymerizing tetra 
methylol glycoluril, or by copolymerizing a tetra-alkoxy methyl glycoluril 
and a tetra-methylol glycoluril. In either the diol copolymer or the 
self-condensation polymers, and alkoxy methyl groups and/or the methylol 
groups comprise between about 5% and 40% by weight of the polymeric 
glycoluril cross-linking component. 
Glycolurils are disclosed in U.S. Pat. No. 4,064,191 and are also known as 
acetylenediureas. Glycolurils are derived by reacting two moles of urea 
with one mole of glyoxal to provide a complex ring structure illustrated 
as follows: 
##STR1## 
The foregoing glycoluril is referred to as "G" in the following polymeric 
structures illustrating the polymeric glycoluril in accordance with this 
invention. The preparation of various glycolurils are illustrated in U.S. 
Pat. No. 4,064,191 such as tetramethylol glycoluril, tetrabutoxymethyl 
glycoluril, partially methylolated glycoluril, tetramethoxymethyl 
glycoluril, and dimethoxydiethoxy glycoluril. Useful glycoluril 
derivatives include for example, mono- and dimethylether of dimethylol 
glycoluril, the trimethylether of tetramethylol glycoluril, the 
tetramethylether of tetramethylol glycoluril, tetrakisethoxymethyl 
glycoluril, tetrakisopropoxymethyl glycoluril, tetrakisbutoxymethyl 
glycoluril, tetrakisamyloxymethyl glycoluril, tetrakishexoxymethyl 
glycoluril and the like. A self-condensate glycoluril polymer can be 
illustrated as follows: 
##STR2## 
wherein: G=said glycoluril structure 
R.sub.1 =H or alkyl group having 1 to 4 carbon atoms 
R.sub.2 =--CH.sub.2 or (--CH.sub.2 --O--CH.sub.2 --) 
n=1 to 5 units 
Similarly, a diol condensate copolymer is illustrated as follows: 
##STR3## 
wherein: G=said glycoluril structure 
R.sub.1 =H or alkyl group having 1 to 4 carbon atoms 
R.sub.3 =diol with hydroxyl groups removed 
n=1 to 4 units 
Thus, the polymeric glycoluril contains at least two polymerized glycoluril 
monomer units to provide a polymer chain containing at least two 
glycoluril structures (G). The molecular weight of useful polymeric 
glycoluril condensate polymers is between 500 and 5000 and preferably 
between 600 and 1500. The polymeric glycoluril provides an excellent 
cross-linking component for reactive matrix polymers in powder coating 
compositions. 
Preparation of the polymeric glycoluril can be facilitated by the inclusion 
of between 0.5% and 5% by weight acid catalyst. Amine or ammonia can be 
added to buffer the acid catalyst and moderate the reaction rate whereby 
the acid catalyst is neutralized up to about 300%. The rate of reaction 
can be varied depending on the acid and amine strength, the degree of 
neutralization, and the level of acid catalyst used. Acid can be added 
first to promote the reaction and then amine can be added to control and 
prevent further reaction while the polymer is being discharged. 
Referring next to the reactive polymer adapted to be cross-linked by the 
polymeric glycoluril cross-linker, the reactive polymer can be a polymer 
having reactive hydroxyls, or carboxyls, or amide groups. The polymer can 
have a molecular weight between about 100 and 100,000 and contains by 
weight between 1% and 50% reactive carboxyl, hydroxyl or amide groups, or 
combinations thereof. These reactive groups are adated to react with the 
methylol and/or alkoxy-methyl groups on the polymeric glycoluril. 
Generally, the polymers can be epoxy polymers, polyester polymer, acrylic 
polymers, phenolic polymers, vinyl polymers, and similar polymers, 
provided such polymers have a tack temperature above 75.degree. C. to 
provide adequate storage stability and prevent caking. A tack temperature 
is the lowest temperature above which dry solid polymer particles tend to 
cake or block within a 60 second time period. The reactive polymers are 
preferably polymers with a melt temperature or Tg above about 75.degree. 
C., generally between 80.degree. C. and 200.degree. C., and preferably 
between 100.degree. C. and 140.degree. C. All polymers can have reactive 
hydroxyl, carboxyl or amide groups attached to the polymer such as by 
esterification in polyester polymer or by addition polymerization of 
carboxyl or hydroxyl monomers in acrylic or vinyl polymers. Particularly 
preferred reactive polymers contain reactive hydroxyl groups. Hydroxyl or 
carboxyl terminated polyester polymers can be produced by an 
esterification reaction of glycols together with saturated, unsaturated, 
aliphatic, or aromatic dicarboxylic acids such as phthalic, isophthalic, 
terephthalic, maleic, fumaric, succinic, adipic, azelaic, malonic and 
similar dicarboxylic acids. The preferred glycols are aliphatic glycols 
such as 1,3-butylene glycol or 1,4-butylene glycol; ethylene glycol and 
propylene glycol; neopentyl glycol as well as minor amounts of polyols 
such as trimethylol propane or ethane, or petaerythritol. The glycols are 
reacted with the dicarboxylic acids at temperatures preferably above about 
200.degree. C. to substantially coreact all the available carboxylic acid 
to provide a hydroxyl polyester. Conversely, excess dicarboxylic acid is 
reacted completely with lesser equivalents of polyol to provide a carboxyl 
terminated polyester polymer. The excess glycol or carboxylic component 
can be about 20% to 100% molar equivalent excess of the other component to 
provide a hydroxyl or carboxyl terminated polyester adapted to be 
cross-linked by the polymeric glycoluril component. Vinyl and acrylic 
polymers produced from copolymerization of ethylenic monomers can contain 
reactive hydroxyl, carboxyl, or amide groups by copolymerizing minor 
amounts of functional ethylenic monomers such as acrylic or methacrylic 
acid for carboxyl groups, hydroxyethyl, or hydroxy-propyl acrylate or 
similar hydroxyl alkyl acrylates or methacrylates to provide for hydroxyl 
groups, and acrylamide or similar alkylamides for amide groups. Epoxy and 
phenolic polymers can have reactive functional groups esterified or 
grafted onto the polymer chain to provide a reactive polymer. Reactive 
polymers in accordance with this invention contain between 1% and 50% by 
weight functional hydroxyl, carboxyl, and/or amide groups, and preferably 
1 % to 12% of said reactive functional groups. 
The polymeric glycoluril cross-linker and the reactive polymer can be 
combined to provide a homogeneous mixture on a weight basis of preferably 
10% to 70% of polymeric glycoluril mixed with 30% to 90% reactive polymer. 
The most preferred and optimized combination comprises 10% to 30% 
polymeric glycoluril and 70% to 90% reactive polymer. The combination 
exhibits a tack temperature of at least 70.degree. C. 
The polymeric glycoluril and the reactive polymer can be thoroughly and 
uniformly mixed by mildly heating the solid materials with pigmentary 
solids, plasticizers and other components to uniformly blend the polymeric 
components with the pigmentary solids. Pigments can ordinarily include 
opacifying pigments such as titanium dioxide, zinc oxide, leaded zinc 
oxide, titanium calcium, as well as tinting pigment such as carbon black, 
yellow oxides, brown oxides, tan oxides, raw and burnt sienna or umber, 
chromium oxide green, phthalocyanine green, phthalonitrile blue, 
ultra-marine blue, cadmium pigments, chromium pigments, and the like. 
Filler pigments such as clay, silica, talc, mica, wollastonite, wood 
flower and the like can be added. The raw batch ingredients can be 
thoroughly premixed in a high intensity mixer such as a high speed dry 
blender whereby the materials are discharged in a uniform mixture. The 
high intensity mixer discharges the batch components to a heated screw 
extruder wherein the extruder is internally heated by an indirect heating 
fluid such as steam, hot water, or synthetic oil whereupon the exit 
extruder temperature is regulated according to the type of powder paint 
being produced but generally is between about 90.degree. C. and 
150.degree. C. at the heated exit die of the screw fed extruder. The 
extrudate emerges from the extruder as a rope which is chilled and 
squeezed to a thin ribbon by cooling rolls then passes onto a water-cooled 
stainless steel conveyor belt whereby the plastic ribbon extrudate fully 
hardens. The cooled extrudate then passes through a mechanical comminuter 
disposed at the end of the cooled stainless steel belt to efficiently 
break the fragile brittle ribbon into very small flakes. The small flakes 
are then discharged into a cooled mill, such as a hammer mill, to grind 
the small flakes into powder paint of less than 325 mesh and preferably 
passing a 200 mesh U.S. Standard Sieve Screen whereupon the powder can be 
further classified into particle size if desired. The resulting powder 
coatings advantageously exhibit a tack temperature well above 70.degree. 
C. whereby the dry powder does not cake or block, can be easily spray 
applied, and fused with moderate heat to provide a thermoset continuous 
surface coating. 
The powder paints in accordance with this invention can be applied to a 
steel panel substrate and moderately heated between temperatures of about 
140.degree. C. and 205.degree. C. for 5 to 30 minutes to obtain desirable 
flow out and cure. The advantages of this invention are further 
illustrated in the following examples. 
EXAMPLE 1 
Glycoluril Prepolymer Condensate A 
Into a reaction vessel equipped with stirrer, thermometer, nitrogen inlet 
tube, distillation head and condenser, was charged 2000 grams of 
tetramethoxymethyl glycoluril which was melted and heated to 110.degree. 
C. 32 grams sulfamic acid (Polycat 200) catalyst was added over a 
30-minute period at 110.degree. C. to 120.degree. C. to control foaming. 
The contents were then upheated to a temperature of 170.degree. C. over a 
period of 2 hours. The batch was held at 170.degree. C. until a tack 
temperature of 80.degree. to 85.degree. C. was reached and then 32 grams 
of amine (Quadrol, i.e. 1 mole ethylene diamine reacted with 4 moles 
propylene oxide) were added and stirred in. The batch was then discharged 
into a tray and cooled to room temperature. This self-condensed prepolymer 
of TMMGU had a tack temperature of 84.degree. C., a viscosity at 50% 
non-volatile in meta-pyrol of D on the Gardner-Holdt Scale, and a methoxy 
equivalent weight (MEW) of 143. 
The distillate (296 grams) consisted of 161 grams dimethylformal, 108 grams 
methanol, and 27 grams formaldehyde by gas chromatographic analysis. The 
presence of methanol and formaldehyde in the distillate indicates the 
presence of some methylol (--CH.sub.2 OH) groups in the original TMMGU. 
The methoxy equivalent weight (MEW) was determined by reaction of a sample 
with a large excess of ethylene glycol mono-butyl ether using 3.0%, based 
on the TMMGU, of Polycat 200 catalyst. The distillate was analyzed for 
methanol content by gas chromatographic analysis. MEW is given by the 
formula: 
EQU MEW=(32.0.times.S)/M 
where, 
S=sample size 
M=Methanol content of distillate in grams 
Glycoluril Prepolymer Condensate B 
Into a reaction vessel equipped as in Example A was charged 1064 grams 
tetramethoxymethyl glycoluril (TMMGU) and 532 grams hydrogenated 
bisphenol-A which was melted and heated to 120.degree. C. 14 grams of 
Polycat 200 catayst was added slowly over a 30-minute period at 
110.degree.-120.degree. C. to control foaming. The batch temperature was 
then raised slowly to 160.degree. C. and foaming controlled with 2 grams 
additions of Quadrol. Total Quadrol added is 10.4 grams. Upon reaching a 
tack temperature of 80.degree.-85.degree. C., the batch was discharged 
into a tray. The product, a methoxy-methyl-functional copolymer of TMMGU 
and HBPA, has a tack temperature of 84.degree. C., a viscosity at 50% 
non-volatile content in meta-pyrol of K and a methoxy equivalent weight of 
212. A small amount of self-condensation had also occurred in this 
reaction in addition to the primary methoxyhydroxyl reaction. 
Glycoluril Prepolymer Condensate C 
Into a reaction vessel equipped as in Example A but also fitted with a 
fractionating columing was charged 1006 grams neopentyl glycol, 1266 grams 
terephthalic acid plus 0.8 grams butyl stannoic acid as the esterification 
catalyst. This polyester diol was processed by usual condensation 
polymerization techniques to an acid number of 4.0 mg. KOH per gram. It 
had a tack temperature of 54.degree. C., a hydroxyl content of 3.3% and a 
calculated molecular weight of 909. The batch was cooled to 150.degree. C. 
and then 1020 grams of TMMGU were added and melted in. 30 grams Quadrol 
and 30 grams Polycat 200 were then added at 120.degree. C. The temperature 
was raised slowly to 160.degree. C. distilling off methanol all the time. 
The batch was held at 160.degree. C. for a tack temperature of 75.degree. 
C. to 85.degree. C. and then discharged into a tray. The final product had 
a tack temperature of 75.degree. C., a viscosity at 50% non-volatile in 
metapyrol of U-V, and a methoxy equivalent weight of 383. 
EXAMPLE 2 
Examples of hydroxyl-functional resins which can be used in combination 
with the alkoxy-methyl or methylol functional cross-linking prepolymer 
condensates of the present invention are as follows: 
Polyester Resin 1 
VPE 5802 is a hydroxyl-functional polyester resin supplied by Goodyear. The 
polyester had an acid no. of 12-13 mg. KOH per gram, a hydroxyl content of 
1.75%, a tack temprature of 84.degree. C., and a viscosity at 50% 
non-volatile in meta-pyrol of X-Y. 
Styrene-Allyl Alcohol Copolymer 2 
RJ100 is a copolymer of styrene and allyl alcohol supplied by Monsanto. It 
has a tack temperature of 88.degree. C., a hydroxyl content of 5.7%, a 
molecular weight of 1500, and a viscosity at 50% non-volatile in 
meta-pyrol of P. The percent by weight composition calculated from the 
hydroxyl content is 80.7% styrene and 19.3% allyl alcohol. 
Acrylic Resin 3 
This is a resin prepared by the bulk (solvent-free) polymerization process 
from 64 grams styrene, 10 grams butyl acrylate, 24 grams hydroxy propyl 
methacrylate, 2 grams tertiary butyl penbenzoate, 2 grams methacrylic acid 
and 1 gram mercaptoethanol. It has a calculated hydroxyl content of 2.7%, 
an acid no. of 13, a tack temperature of 89.degree. C., and a viscosity of 
X at 50% NV in meta-pyrol 
EXAMPLES 3-12 
In order that the concept of the present invention be more completely 
understood, the following examples are set forth in which all parts are 
parts by weight unless otherwise stated. In particular, Examples 3-12 of 
Table I illustrate a series of powder paints in which the prepolymer 
condensates of the present invention are compared to similar paints made 
from unmodified TMMGU as described by U.S. Pat. No. 4,118,437. All powder 
paints were compounded by standard methods well-known to powder aint 
chemists. The pigment (titanium dioxide) in binder ratio was 0.5 in all 
cases and all paints were applied by standard electrostatic spray 
equipment to 24 guage 4".times.12" phosphate-treated steel panels, and 
baked in an air-circulated oven at 177.degree. C. for a period of 20 
minutes. Cured film thicknesses ranged between 1.0 and 1.5 mils. 
TABLE I 
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TMMGU and TMMGU PREPOLYMER CONDENSATE-BASED POWDER PAINT PROPERTIES 
Example No. 
3 4 5 6 7 8 9 10 11 12 
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Cross-Linker 
TMMGU TMMGU TMMGU TMMGU TMMGU TMMGU Ex. A 
Ex. B 
Ex. 
Ex. A 
PBW 
Cross-Linker 
3.28 3.93 4.59 5.24 5.90 6.55 6.55 6.55 13.1 8.52 
VPE5802 
(Ex. 1) 62.3 61.6 60.9 60.3 59.6 59.0 59.0 59.0 52.4 57.0 
TiO.sub.2 
32.8 32.8 32.8 32.8 32.8 32.8 32.8 32.8 32.8 32.8 
Polycat 200 
0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 
Quadrol 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 
Flow Agent 
0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 
Degassing 
Agent 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 
(Benzoin) 
% of 
Theoretical 
60 73 86 99 112 126 75 51 63 100 
Cross-Linker 
Phys. Stab. at 
Good Good Fair Fair V. Poor 
V. Poor 
Excel. 
Excel. 
Excel. 
Excel. 
45.degree. C. 
for 7 days 
Tack Temp. .degree.C. 
75 78 74 68 67 66 76 80 76 77 
Gel Time Secs. 
(204.degree. C.) 
60 50 40 45 55 55 30 80 35 70 
GLOSS - 60.degree. 
90 93 93 95 93 87 95 95 95 90 
20.degree. 
32 42 71 73 77 51 74 66 70 61 
.increment. E 
(177/204.degree. C.).sup.(1) 
0.77 0.52 0.98 0.76 1.49 3.58 1.12 1.08 0.87 1.0 
MEK 
DOUBLE 
RUBS.sup.(2) 
150-200 
350-400 
300-350 
450-500 
350-400 
350-400 
300 300 250 300 
Impact 
(DIR/REV) 
In-Lbs. 30/20 160/160 
160/140 
160/160 
160/160 
160/160 
160/160 
160/120 
160/160 
160 
Pencil Hardness 
(Faber) H H H H H H 2H H H 2H 
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.sup.(1) Yellowing Index between 177.degree. C. and 204.degree. C. 
.sup.(2) No. of double rubs to expose the steel substrate. 
It can be seen from the Table I results that excellent physical stability 
cannot be achieved using straight TMMGU as the cross-linking agent 
(Examples 3 to 8). Even at the lowest ratios of TMMGU to resin of 5/95 to 
7/93 (Examples 3 to 5) the physical stability is not as good as with the 
prepolymer condensates of the present invention (Examples 9-12). At the 
5/95 ratio of TMMGU to resin, cure and physical properties of the coating 
are already deficient so that it is not practical to reduce the level of 
TMMGU any farther to improve physical stability. Although the melting 
point of TMMGU (117.degree. C.) is actually higher than the tack 
temperatures of the prepolymer condensates of the present invention 
(75.degree.-85.degree. C.), TMMGU is monomeric and miscible with the resin 
and thus, has a strong Tg--depressant effect in the finished powder blend. 
The data in FIG. 1 provides further strong experimental evidence for 
undesirable Tg--depressant effect of monomeric methoxy-methyl type 
cross-linking agents in blend with a typical polyester (VPE5802 ) powder 
resin, compared to a typical prepolymer condensate of the present 
invention (prepolymer A). The prepolymers of the present invention are a 
much greater improvement, exhibit a minimum "eutectic" effect of mixed 
solids, and provides a substantial improvement in anti-caking effect when 
compared to TMMGU and hexamethoxymethyl melamine (HMMM). 
Thus, it is apparent that the conflict between physical stability (caking) 
and coating performance with the use of TMMGU as a powder cross-linker has 
been resolved by the use of the prepolymer condensates of the present 
invention replacing the simple TMMGU. Increased levels of the prepolymer 
condensates up to stoichiometric proportions in Examples 9-11 provide even 
better properties and still have good package stability. 
EXAMPLES 13& 14 
Table II gives further examples of powder formulae using a resin of Example 
1 and a resin of Example 2. 
TABLE II 
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PROPERTIES OF POWDER COATINGS 
BASED ON RJ100 (Copolymer 2) 
Example No. 13 14 
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Cross-Linker Ex. A Ex. A 
Resin RJ100 RJ100 
PBW-Cross-linker 20.9 13.1 
PBW Resin 44.4 52.4 
TiO.sub.2 32.7 32.7 
Polycat 200 0.36 0.23 
Quadrol 0.36 0.23 
Flow Agent 0.65 0.65 
Benzoin 0.65 0.65 
% of Theoretical Cross-Linker 
100 53 
Phys. Stab. (45.degree. C.) 
Good Excel. 
Tack Temp. .degree.C. 
77 76 
Gel Time (204.degree. C.) 
150 80 
GLOSS - 60.degree. 101 102 
20.degree. 98 96 
.increment. E (177/204.degree. C.) 
1.40 2.20 
MEK Rubs 350-400 350-400 
Impact (DIR/REV) &lt;5/&lt;5 &lt;5/&lt;5 
Pencil Hardness (Faber) 
2H 2H 
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