Advanced epoxy resins crosslinked with polyisocyanates

Coatings are prepared from epoxy resin compositions prepared by reacting an epoxy resin composition containing an aliphatic diepoxide with a dihydric phenol. These coatings are useful as anti-chip coatings for automobiles and as coil coatings.

BACKGROUND OF THE INVENTION 
The present invention concerns advanced epoxy resins and coatings 
containing same. 
Automotive manufacturers are being required by Federal mandate to reduce 
volatile organic emissions from the paint operations. Increased emphasis 
on quality has caused manufacturers to install chip resistant coatings 
between the primer and top coat to resist damage by stone chipping. These 
stone chips are esthetically unpleasing and can also lead to rusting. 
Presently used antichip coatings tend to be low in solids and frequently 
require the use of heating equipment to reduce the viscosity for proper 
applications. 
Coil coating has become an increasingly important method for applying 
industrial coatings. In this method a metal coil, usually steel or 
aluminum, is ordinarily coated and the substrate is then post-formed into 
the final object. Such a coating requires a high degree of flexibility and 
elongation. Conventional epoxy resins are widely used as primers for these 
applications. These resins are typically based on the diglycidyl ether of 
bisphenol A advanced with bisphenol. Typical resins have an epoxide 
equivalent weight of about 1800-2000. Such resins, however, are lacking 
where extreme flexibility is required. While resins in the 3000-5000 
epoxide equivalent range will give improved flexibility, large amounts of 
solvent are required to obtain the proper application viscosity. Similar 
problems are encountered with other applications requiring high 
flexibility and high formability such as can ends. 
The present invention provides high solids coating compositions having 
improved flexibility and resistance to stone chipping relative to known 
compositions. 
SUMMARY OF THE INVENTION 
The present invention is directed to a coating composition comprising 
(I) an advanced epoxy resin prepared by reacting in the presence of a 
suitable catalyst 
(A) a composition comprising 
(1) at least one aliphatic diepoxide and 
(2) optionally at least one aromatic diepoxide; with 
(B) at least one compound having two aromatic hydroxyl groups per molecule 
and an average molecular weight of at least about 188; wherein components 
(A-1) and (A-2) are employed in quantities such that from about 10 to 
about 100, preferably from about 50 to about 100, most preferably from 
about 75 to about 100 percent of the epoxide equivalents contained in 
component (A) are contributed by component (A-1); from about 0 to about 
90, preferably from about 0 to about 50, most preferably from about 0 to 
about 25 percent of such epoxide equivalents are contributed by component 
(A-2) and wherein components (A) and (B) are employed in quantities which 
provide an advanced epoxy resin having an epoxide equivalent weight (EEW) 
of from about 350 to about 15,000, preferably from about 500 to about 
7500, most preferably from about 500 to about 6000; 
(II) a curing quantity of at least one curing agent for component (I) 
selected from the group consisting of blocked and unblocked 
polyisocyanates; and 
(III) at least one solvent 
in a sufficient quantity such that the coating composition including 
components (I), (II) and (III) and any other desirable components has a 
suitable application viscosity. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Suitable aliphatic diepoxides which can be employed herein include the 
diglycidyl ethers of dihydric aliphatic compounds such as, for example, 
water, propylene glycol, dipropylene glycol, tripropylene glycol, butylene 
glycol, dibutylene glycol, tributylene glycol, 1,4-butane diol, 1,6-hexane 
diol, neopentyl glycol, mixtures thereof and the like. 
Also suitable are the glycidyl ethers of polyoxyalkylene glycols having an 
average molecular weight of from about 200 to about 800, preferably from 
about 200 to about 400, which polyoxyalkylene glycols are prepared by 
reacting an aliphatic initiator compound with propylene oxide, butylene 
oxide or mixtures thereof. 
Suitable aromatic diepoxides which can be employed herein include the 
diglycidyl ethers of polyhydric phenols such as, for example, catechol, 
resorcinol, hydroquinone, bisphenol A, mixtures thereof and the like. 
Particularly suitable diglycidyl ethers of bisphenols and dihydric phenols 
which can be employed herein include those mentioned by P. H. Martin in 
U.S. 3,931,109 which is incorporated herein by reference. 
Suitable compounds having two aromatic hydroxyl groups per molecule which 
can be employed herein include, for example, those represented by the 
formula 
##STR1## 
wherein A is a divalent hydrocarbyl group having from 1 to about 10 carbon 
atoms, 
##STR2## 
each X is independently a monovalent hydrocarbyl group having from 1 to 
about 10 carbon atoms or a halogen; n has a value of zero or 1; and x has 
a value of from zero to 4. 
Suitable such phenolic hydroxyl-containing compounds include, for example, 
bisphenol A, bisphenol K, bisphenol S, tetramethylbisphenol A, 
tetratertiarybutylbisphenol A, tetrabromobisphenol A, 
4,4'-dihydroxybiphenyl, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, 
3,5,3'5'-tetrabromodihydroxybiphenyl, 
3,5,3',5'-tetramethyl-2,6,2',6'tetrabromo-4,4'-dihydroxybiphenyl, mixtures 
thereof and the like. 
It is to be understood, that because of the manner in which the commercial 
epoxy resins prepared from aliphatic dihydric compounds and aromatic 
dihydric compounds are prepared, these epoxy resins contain minor amounts 
of monoglycidyl ether products. However, so long as less than about 10 
percent of the epoxy groups are derived from such monoglycidyl ether 
products, they are suitable. Suitable such commercially available 
diglycidylethers of aromatic dihydric compounds include D.E.R..RTM. 330, 
D.E.R..RTM. 331, D.E.R..RTM. 332 and D.E.R..RTM. 383 commercially 
available from The Dow Chemical Company as well as EPON.RTM. 825, 
EPON.RTM. 826 and EPON.RTM. 828 commercially available from Shell Chemical 
Company. 
Suitable commercially available diglycidyl ethers of aliphatic dihydric 
compounds include D.E.R..RTM. 732 and D.E.R..RTM. 736 available from The 
Dow Chemical Company, and ARALDITE.RTM. RD-2 commercially available from 
Ciba-Geigy. 
The quantities of the aliphatic and aromatic epoxy resins and the compound 
containing two aromatic hydroxyl groups to be employed are those 
quantities which will provide the desired average epoxide equivalent 
weight of the advanced epoxy resin. 
The percent of aliphatic diepoxide depends upon the particular end use for 
which the advanced epoxy resin is to be employed. 
For example, in automotive primer coatings, the desired percent aliphatic 
diepoxide is from about 10% to about 30% by weight based upon the combined 
weight of the aliphatic diepoxide and the aromatic diepoxide and the 
epoxide equivalent weight of the advanced resin is usually from about 350 
to about 700. 
For applications as automotive chip resistant coatings, the desired percent 
aliphatic diepoxide is from about 70% to about 100% and the epoxide 
equivalent weight of the advanced epoxy resin is from about 1200 to about 
6000. 
For beverage can coating applications, the desired percent of aliphatic 
diepoxide is from about 10% to about 100% and the epoxide equivalent 
weight of the advanced resin is from about 1400 to about 5000. 
For coil coating applications, the desired percent of aliphatic diepoxide 
is from about 10% to about 100% and the epoxide equivalent weight of the 
advanced epoxy resin is from about 1400 to about 6000. 
Suitable solvents which can be employed herein include, for example, 
ketones such as acetone, methylethyl ketone, methyl n-amyl ketone, methyl 
isobutyl ketone; glycol ethers such as, for example, the methyl ether of 
diethylene glycol, the methyl ether of propylene glycol, the n-butyl ether 
of ethylene glycol; and esters such as for example, ethyl acetate, butyl 
acetate, the acetate ester of the monomethyl ether of propylene glycol, 
and the like. 
Suitable solvents also include aromatic compounds, such as, for example, 
toluene, xylene and the like. It is also understood that mixtures of such 
solvents can be employed. 
Suitable catalysts which can be employed herein in preparing the advanced 
epoxy resins of the present invention, include any such catalyst suitable 
for catalyzing the reaction between an epoxy group and a phenolic hydroxyl 
group. Particularly suitable catalysts include those phosphonium catalysts 
described by W. O. Perry in U.S. Pat. No. 3,948,855 and Dante et al. in 
U.S. Pat. No. 3,447,990 which are incorporated herein by reference. 
The curing agents employed in the coating compositions of the present 
inventions include, polyisocyanates and blocked polyisocyanates. Suitable 
such isocyanates include, for example, tolylene diisocyanate, 
4,4'-diphenylmethaneisocyanate and its liquid derivatives, some examples 
of which are sold under the tradenames of Rubinate LF-168 or Rubinate 
LF-179 by Rubinate Chemicals Inc. of Wilmington, Del. or Isonate 143L or 
Isonate 181 by Upjohn Polymer Chemicals of LaPorte, Tex., a biuret or 
isocyanurate from hexamethylene diisocyanate, and a cyclic trimer of 
hexamethylene diisocyanate and tolylene diisocyanate. The isocyanates may 
also be prepolymers of the aforementioned isocyanates and polyols such as 
polypropylene glycols, triols such as trimethylpropane or glycerine or 
their reaction products with propylene oxide or butylene oxide having 
hydroxyl equivalent weights from about 85 to about 1000. The isocyanates 
can be blocked with phenols such as phenol, 4-chlorophenol, 
o-secbutylphenol, lactams such as caprolactam and ketoximes or aldoximes 
such as acetaldehyde oxime or methyl ethyl ketoxime. Coatings capable of 
curing at room temperature can be obtained by use of the aforementioned 
isocyanates which contain no blocking agent. From an industrial standpoint 
the blocked isocyanates are preferred since they will provide one package 
systems. The ketoxime and lactam blocked isocyanates are preferred from an 
ecology standpoint and providing the appropriate cure temperatures. 
The coating compositions of the present invention may also contain, if 
desired, colorants, dyes, pigments, fillers, leveling agents, mixtures 
thereof and the like. 
Suitable substrates to which the coating compositions can be applied 
include, for example, metals such as, for example, aluminum, steel and the 
like, laminates and composites such as, for example, fiber reinforced 
plastics such as, for example, polyesters, vinyl esters, epoxy resins and 
the like. 
In the paint of automobiles, the first or primer coating layer is usually 
composed of a cationic epoxy resin coating composition. After the 
anti-chip coating composition of the present invention is applied to the 
primer coating, there is then applied one or more coating layers which can 
be polyester coatings, epoxy resin coatings, acrylic coatings or 
combinations thereof. 
In metal coil coatings, the coating composition of the present invention is 
the first layer applied to the substrate. Thereafter, additional coating 
layers of a coating of any suitable composition can be applied such as, 
for example, polyester coatings, acrylic coatings, alkyd coatings or 
combinations thereof.

The following examples are illustrative of the present invention, but are 
not to be construed as to limiting the scope thereof in any manner. 
The following components were employed in the examples. 
ALIPHATIC DIEPOXIDE A was a diglycidyl ether of dipropylene glycol having 
an average EEW of about 176. 
ALIPHATIC DIEPOXIDE B was a diglycidyl ether of polyoxypropylene glycol 
having an average molecular weight of 425. The EEW of this resin was 300. 
AROMATIC DIEPOXIDE A was a diglycidyl ether of bisphenol A having an 
average EEW of about 189. 
DIHYDRIC PHENOL A was bisphenol A. 
EXAMPLE 1 
An advanced resin having an average EEW of about 1800 was prepared by 
reacting 324.8 grams (1.845 epoxide equivalents) of aliphatic diepoxide A 
and 175.2 grams (1.537 phenolic OH equivalents) of bisphenol A in the 
presence 0.461 grams of a 70% solution of ethyltriphenyl phosphonium 
acetate.acetic acid complex in methanol. The peak exotherm was about 
200.degree. C. and heating was continued thereafter at about 175.degree. 
C. for 1.5 hours (5400 s). The resultant product was diluted to 80% solids 
by weight with the monomethyl ether of propylene glycol. A 408 g sample of 
the 80% solids solution was diluted to 70% solids by the addition of 63.6 
g of 2-methoxypropanol acetate. The resultant solution had a Gardner 
viscosity of Z.sup.+ (.about.2300 cps.) at 25.degree. C. 
EXAMPLE 2 
A. Example 1 was repeated employing 243.6 grams (1.38 epoxide equivalents) 
of aliphatic diepoxide A (75 wt. %), 81.2 grams (0.43 epoxide equivalents) 
of aromatic diepoxide A (25 wt. %) and 175.2 grams (1.537 phenolic 
hydroxyl equivalents) of bisphenol A and 0.464 grams of catalyst solution. 
The peak exotherm was observed to be 204.degree. C. A sample of the resin 
at 80% solids was diluted further with 2-methoxypropanol acetate to give a 
60% solids solution. This solution had a Gardner viscosity of X-Y at 
25.degree. C. 
B. Similar products were prepared using blends of 50% of aliphatic 
diepoxide A and 50% of aromatic diepoxide A. 
EXAMPLE 3 
Preparation of Methyl Ethyl Ketoxime Blocked Prepolymer 
A one-liter five-necked flask was charged with 174.2 g (2.0 eq.) of 80/20, 
2,4-,2,6-tolylene diisocyanate. The flask was heated to 50.degree. C. and 
205 g (1.0 eq.) of a polyoxypropylene glycol having an average molecular 
weight of about 425 containing 0.87 g of dibutyl tin dilaurate solution 
(20% solids in methyl ethyl ketone) was added during 35 minutes (2100 s) 
while maintaining the temperature at 65.degree.-73.degree. C. Fifty grams 
of methyl ethyl ketone was added to facilitate stirring. Heating was 
continued an additional 40 minutes (2400 s) at 55.degree. C. Methyl ethyl 
ketoxime (87.1 g, 1.0 eq.) was added over a 20 minute (1200 s) period 
while applying cooling to keep the temperature below 55.degree. C. An 
additional 25 g of methyl ethyl ketone and 25 g of 2-methoxypropanol was 
added to give a total of 100 g of solvent or 82.3% solids. The product was 
a deep yellow liquid which partially crystallized on standing. A 410 g 
sample at 82.3% solids was diluted further with 79.5 g methyl ethyl ketone 
and 18 g of 2-methoxypropanol to give a 77.5% solids solution. 
EXAMPLE 4 
The products of Examples 1 and 2 were compared to an epoxy resin of about 
1800 epoxide equivalent weight prepared only from an aromatic diepoxide A 
and sold commercially as D.E.R..RTM. 667. The epoxy resins were blended at 
the ratio of 100 parts of epoxy resin to 50 parts of the blocked 
isocyanate of Example 3 (solids basis) and 1 part of dibutyl tin dilaurate 
(T 12 catalyst) per 100 parts of blocked isocyanate. 
Films were drawn down on unpolished cold rolled steel panels using a number 
40 wire wound rod and baked for 30 minutes (1800 s) at 300.degree. F. or 
275.degree. F. The films were evaluated for MEK double rubs, reverse 
impact and X-adhesion. The latter test was performed by scribing an X on a 
panel with a razor blade and pulling with Scotch Brand 610 tape. A pass 
represents no loss of adhesion whereas a fail indicates removal of film 
from all four quadrants of the X-batch. The results are tabulated in Table 
I. 
This example demonstrates that up to about 50 percent of the aliphatic 
diepoxide may be replaced by an aromatic diepoxide and still maintain 
excellent flexibility and increased solids (non-volatiles) content at 
suitable application viscosities relative to a coating derived from 100% 
aromatic diepoxide. 
TABLE I 
__________________________________________________________________________ 
EVALUATION OF 1800 EEW RESINS WITH BLOCK ISOCYANATE 
EPOXY RESIN SAMPLE 1 
SAMPLE 2 
SAMPLE 3 
SAMPLE 4 
__________________________________________________________________________ 
ALIPHATIC DIEPOXIDE A, % 
100 75 50 0 
AROMATIC DIEPOXIDE A, % 
0 25 50 100 
EEW OF ADVANCED RESIN 
1765.sup.1 
1900.sup.2 
1765.sup.2 
1775.sup.3 
EPOXY SOLIDS, pbw 80.0 72.9 73.3 70.0 
EPOXY SOLUTION, pbw 
114.3 121.5 122.2 140.0 
BLOCKED NCO SOLIDS.sup.4, pbw 
40.0 36.5 36.6 35.0 
BLOCKED NCO SOLUTION, pbw 
51.6 47.1 47.2 45.1 
T-12 CATALYST.sup.5, pbw 
4.0 3.6 3.7 3.5 
% SOLIDS OF BLEND 70.8 64.4 64.3 57.9 
GARDNER VISCOSITY OF BLEND 
Y-Z X-Y Z Z-1 
VISCOSITY, CPS OF BLEND 
.about.1900 
.about.1500 
.about.2300 
.about.2700 
CURE 1800 s @ 300.degree. F. 
REVERSE IMT, in.-lbs. 
P160 P160 P160 P80, F100 
MEK RUBS 15 17 45 75 
ADHESION PASS PASS PASS FAIL 25% 
CURE 1800 s @ 275.degree. F. 
REVERSE IMT, in.-lbs. 
P160 P160 P80, F100 
F40 
MEK RUBS 15 13 25 65 
ADHESION PASS FAIL FAIL FAIL 
__________________________________________________________________________ 
.sup.1 Prepared in Example 1 
.sup. 2 Prepared in Example 2 
.sup.3 A commercially available aromatic epoxy resin based upon bisphenol 
A sold by The Dow Chemical Company as D.E.R. .RTM. 667 
.sup.4 Prepared in Example 3 
.sup.5 10% solids in methyl ethyl ketone 
EXAMPLE 5 
A. Employing the procedure of Example 1, an advanced epoxy resin was 
prepared from 2080 g (11.82 eq.) of aliphatic diepoxide A and 1233 g (10.8 
eq.) of bisphenol A. The resultant resin had an EEW of 3230 (100% solids 
basis). 
B. Employing the procedure of Example 1, an advanced epoxy resin was 
prepared from 404 g (1.37 eq.) of aliphatic diepoxide B and 96 g (0.84 
eq.) of bisphenol A. The resultant resin had an EEW of 1010 (100% solids 
basis). 
C. Employing the procedure of Example 1, an advanced epoxy resin was 
prepared from 1149 (3.83 eq.) of aliphatic diepoxide B and 350.5 g (3.07 
eq.) of bisphenol A. The resultant resin had an EEW of 1863 (100% solids 
basis). 
D. Employing the procedure of Example 1, an advanced epoxy resin was 
prepared from 148.9 g (0.496 eq.) of aliphatic diepoxide B and 51.1 g 
(0.448 eq.) of bisphenol A. The resultant resin had an EEW of 3333 (100% 
solids basis). 
E. Employing the procedure of Example 1, an advanced epoxy resin was 
prepared from 884.8 g (2.95 eq.) of aliphatic diepoxide B and 337.4 g 
(2.96 eq.) of bisphenol A. The resultant resin had an EEW of 5500 (100% 
solids basis). The preparation employed 4 g of tetrabutyl phosphonium 
acetate.acetic acid complex instead of ethyltriphenyl phosphonium 
acetate.acetic acid complex as a catalyst. 
EXAMPLE 6 
Preparation of Blocked Isocyanate 
The general procedure of Example 3 was followed. Insonate 191 (340.5 g, 2.5 
eq.), a modified 4,4'-methylenediphenyl diisocyanate available from Upjohn 
Polymer Chemicals, LaPorte, Tex. was placed in a flask. Methyl ethyl 
ketoxime (219.2 g, 2.52 eq.) was added dropwise while maintaining the 
temperature below about 60.degree. C. When about two-thirds of the methyl 
ethyl ketoxime had been added, 139.9 g of 2-methoxypropanol acetate was 
added to facilitate stirring. When the ketoxime addition was complete, an 
additional 99 g of solvent was added to produce a 70% solids solution. The 
solution was heated an additional hour at 60.degree. C. The final product 
was a brown liquid with a Gardner viscosity of Z (.about.22.7 poise) at 
23.degree. C. 
EXAMPLE 7 
Coating compositions were prepared from the various advanced epoxy resins 
prepared in Examples 1, 2 and 5 in the following manner. 
Melamine Systems--The flexible resin solutions were blended with 30 g (30 
PHR) of Resimine 755 (a melamine-formaldehyde available from Monsanto Co., 
St. Louis, Mo.), 2 weight percent (based on epoxy resin solids) of Cycat 
4040 (a 40 percent solids solution of p-toluenesulfonic acid in isopropyl 
alcohol). The solutions were diluted with an equal weight blend of n-butyl 
alcohol, xylene and aromatic 100 to application viscosity. Films were 
drawn down on Bonderite 40 test panels using a doctor blade. The coatings 
were cured for 15 minutes (900 s) at 300.degree. F. (149.degree. C.). 
Blocked Isocyanate Systems--The flexible resin solutions were blended with 
0.35 equivalents of the blocked isocyanate of Example 6 per hydroxyl 
equivalent of epoxy resin. Epoxy resins in Samples 1-6 were considered to 
have a hydroxyl equivalent weight of approximately 330 while resins in 
Samples 7-16 were considered to have a hydroxyl equivalent weight of 
approximately 440. One percent of UL 28 catalyst (dimethyl tin dilaurate 
from Argus Chemical, Chicago, Ill.) based on epoxy resin solids was added. 
The solutions were diluted similar to the melamine coatings. 
The results are given in the following Table II. 
TABLE II 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 1 PLE 2 PLE 3 PLE 4 PLE 5 PLE 6 PLE 7 PLE 
__________________________________________________________________________ 
8 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
50 50 75 75 100 100 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 100 100 
B, % 
AROMATIC DIEPOXIDE 
50 50 25 25 0 0 0 0 
A, % 
EEW OF ADVANCED 
1765 1765 1900 1900 1765 1765 3230 3230 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No Yes No Yes No Yes 
AMINOPLAST Yes No Yes No Yes No Yes No 
THICKNESS, mils 
2.3-2.5 
2.2-2.5 
1.6-2.0 
2.5-2.7 
1.8-2.0 
2.5-2.8 
3.0-3.2 
0.8-1.0 
, mm 0.059-0.064 
0.056-0.064 
0.041-0.051 
0.064-0.069 
0.046-0.051 
0.064-0.071 
0.076-0.081 
0.020-0.025 
REVERSE IMT 
In/lbs 4 160 8 160 15 160 10 160 
Joules .452 18.08 .904 18.08 1.695 18.08 1.13 18.08 
MANDREL BEND 
in. of failure 3.7 0 2.5 0 0 0 0 0 
mm. of failure 9.4 0 6.3 0 0 0 0 0 
Elongation, % 4.5 32 6 32 32 32 32 32 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 9 PLE 10 
PLE 11 
PLE 12 
PLE 13 
PLE 14 
PLE 15 
PLE 
__________________________________________________________________________ 
16 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
100 100 100 100 100 100 100 100 
B, % 
AROMATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
EEW OF ADVANCED 
1010 1010 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No Yes No Yes No Yes 
AMINOPLAST Yes No Yes No Yes No Yes No 
THICKNESS, mils 
3.75-4.0 
1.8-2.0 
3.0-3.5 
1.1-1.2 
3.4-3.6 
1.5-1.6 
3.9-4.0 
0.6-1.1 
, mm 0.095-0.012 
0.046-0.051 
0.076-0.089 
0.028-0.030 
0.086-0.091 
0.038-0.041 
0.010-0.102 
0.015-0.028 
REVERSE IMT 
In/lbs T* T 20 160 40 160 50 160 
Joules 0 0 2.26 18.08 4.52 18.08 5.65 18.08 
MANDREL BEND 
in. of failure T T 3.6 0 2.9 0 3.3 0 
mm. of failure 0 0 9.1 0 7.4 0 8.4 0 
Elongation, % T T 4.5 32 5 32 4.7 32 
__________________________________________________________________________ 
*T = coating was tacky and not evaluated 
EXAMPLE 8 
The solutions of Example 7, the pigments and solvents were placed in a 4 
oz. glass jar. Steel shot was added, the glass bottles carefully packed in 
a steel paint can, and the container agitated on a paint shaker to effect 
a suitable dispersion. The steel shot was filtered off using a paint 
filter. The pigment blend consisted of 20 parts of titanium dioxide and 80 
parts of barytes. The ratio of pigment to binder was 0.3 to 1. 
The coatings were evaluated for anti-chip resistance according to the 
following method. 
Bonderite 40 treated 22 guage steel panels were obtained from Advanced 
Coating Technology, Hillsdale, Mich. The panels as received were treated 
with a cathodic electrodeposition primer from PPG Industries, Pittsburgh, 
Pa. designated Uniprime 3150. The anti-chip coatings described above were 
applied to various thicknesses using a draw down bar. The anti-chip 
coatings were given a prebake for 15 minutes (900 s) at 180.degree. F. 
(82.degree. C.) followed by 15 minutes (900 s) at 300.degree. F. 
(149.degree. C.). A commercially available white enamel top coat was spray 
applied at 1.5-2.0 mils dry film thickness and baked for 15 minutes (900 
s) at 275.degree. F. (135.degree. C.). The panels were evaluated for chip 
resistance according to SAE Test Procedure J 400 except the tests were 
conducted at room temperature. 
The results are given in the following Table III. 
TABLE III 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 1 PLE 2 PLE 3 PLE 4 PLE 5 PLE 6 PLE 7 PLE 
__________________________________________________________________________ 
8 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
50 50 75 75 100 100 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 100 100 
B, % 
AROMATIC DIEPOXIDE 
50 50 25 25 0 0 0 0 
A, % 
EEW OF ADVANCED 
1765 1765 1900 1900 1765 1765 3230 3230 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No Yes No Yes No Yes 
AMINOPLAST Yes No Yes No Yes No Yes No 
THICKNESS, mils 
3.5-5.3 
5.2-6.7 
3.0-3.7 
4.7-6.2 
3.5-4.2 
4.7-6.7 
2.8-3.3 
3.7-4.7 
, mm 0.089-0.135 
0.132-0.170 
0.076-0.094 
0.119-0.158 
0.089-0.107 
0.119-0.170 
0.071-0.084 
0.094-0.119 
GRAVELOMETER 7+ 8+ 8- 8 7 8 7 7 
RATING 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 9 PLE 10 
PLE 11 
PLE 12 
PLE 13 
PLE 14 
PLE 15 
PLE 
__________________________________________________________________________ 
16 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
100 100 100 100 100 100 100 100 
B, % 
AROMATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
EEW OF ADVANCED 
1010 1010 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No No No Yes No Yes 
AMINOPLAST Yes Yes Yes Yes Yes No Yes No 
THICKNESS, mils 
1.7-2.7 
1.7-3.7 
3.1-3.5 
3.2-5.2 
2.7-3.5 
2.9-5.2 
3.3-4.7 
3.7-5.2 
, mm 0.043-0.069 
0.043-0.094 
0.079-0.089 
0.081-0.132 
0.069-0.089 
0.074-0.132 
0.084-0.119 
0.094-0.132 
GRAVELOMETER 5 7 7 8- 8- 7 7+ 9- 
RATING 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 17 
PLE 18 
PLE 19 
PLE 20 
PLE 21 
PLE 22 
PLE 23 
PLE 
__________________________________________________________________________ 
24 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
50 50 75 75 100 100 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 100 100 
B, % 
AROMATIC DIEPOXIDE 
50 50 25 25 0 0 0 0 
A, % 
EEW OF ADVANCED 
1765 1765 1900 1900 1765 1765 3230 3230 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No Yes No Yes No Yes 
AMINOPLAST Yes No Yes No Yes No Yes No 
THICKNESS, mils 
4.8-6.5 
9.3-11.2 
6.5-7.9 
8.7-11.7 
5.4-6.3 
7.2-8.2 
4.7-5.3 
6.7-9.7 
, mm 0.122-0.165 
0.236-0.285 
0.165-0.201 
0.221-0.297 
0.137-0.160 
0.119-0.135 
0.170-0.246 
GRAVELOMETER 7+ 9 7+ 9 8 9 7- 8+ 
RATING 
__________________________________________________________________________ 
SAM- SAM- SAM- SAM- SAM- SAM- SAM- SAM- 
PLE 25 
PLE 26 
PLE 27 
PLE 28 
PLE 29 
PLE 30 
PLE 31 
PLE 
__________________________________________________________________________ 
32 
EPOXY RESIN 
ALIPHATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
ALIPHATIC DIEPOXIDE 
100 100 100 100 100 100 100 100 
B, % 
AROMATIC DIEPOXIDE 
0 0 0 0 0 0 0 0 
A, % 
EEW OF ADVANCED 
1010 1010 
RESIN 
CURING AGENT 
BLOCKED ISOCYANATE 
No Yes No Yes No Yes No Yes 
AMINOPLAST Yes No Yes No Yes No Yes No 
THICKNESS, mils 
3.1-4.3 
3.7-5.7 
4.8-5.5 
4.7-6.7 
4.5-5.1 
3.7-6.2 
4.9-5.9 
5.7-8.2 
, mm 0.79-0.109 
0.094-0.145 
0.122-0.140 
0.119-0.170 
0.114-0.130 
0.094-0.158 
0.125-0.150 
0.145-0.208 
GRAVELOMETER 5 7 8- 8- 8+ 9 9- 8+ 
RATING 
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