MATERIAUX DE REVETEMENT ET LEURS COMPOSITIONS

COATING MATERIALS AND COMPOSITIONS

Abrégé anglais

A B S T R A C T
Process for the preparation Or resinous compounds,
suitable for making water-dilutable coating compositions,
which resinous compounds have an acid value of at least
35 mg KOH/g and having at least 200 milli-equivalents
aliphatic hydroxyl per 100 g, by reacting at temperatures
from 100 to 150°C a cyclic dicarboxylic acid anhydride
with an epoxy resin ester having at least 260 milli-
equivalents aliphatic hydroxyl per 100 g.

Revendications

-23-
C L A I M S
1. A process for the preparation of resinous compounds
suitable for making water-dilutable coating compositions
after neutralization, wherein (a) a component (I) having
the formula:
<IMG>
wherein n1 is a number which is on average from 3 to 7,
Q stands for a <IMG> group with R" being a hydroxyalkyl
group when n1 is on average from 3 to 5, and R" being an alkyl
or hydroxyalkyl group when n1 is on average greater than 5,
<IMG>
when n1 is on average from 3 to 5, and wherein for values of
n1 greater than 5, M has the same meaning with the proviso
that at least one M in the above formula is represented by
a <IMG> group, wherein m is a number from 2 to
10, and Q1 is the same as Q or hydroxyl, component (I) having
at least 260 milli-equivalents aliphatic hydroxyl per 100 g,
is reacted (b) with a component (II) reacting as a cyclic
carboxylic acid anhydride with a hydroxy compound in the
temperature range of from 100 to 150°C, in an amount

sufficient to obtain a product (III) having an acid value of
at least 35 mg KOH/g and having at least 200 milli-equivalents
aliphatic hydroxyl per 100 g.
2. A process as claimed in claim 1, wherein component
(I) has at least 320 milli-equivalents aliphatic hydroxyl per
100 g.
3. A process as claimed in claim 1, wherein product (III)
has at least 250 milli-equivalents aliphatic hydroxyl per 100 g.
4. A process as claimed in claim 1, wherein product (III)
is reacted with a monoepoxide in such amount that the acid
value is reduced to a value corresponding with about 2 carboxyl
groups per molecule.
5. A process as claimed in claim 1, wherein component (I)
is a reaction product of (A) one epoxy equivalent of a poly-
glycidyl ether of 2,2-bis(4-hydroxyphenyl)propane of the general
formula
<IMG>
wherein R represents the divalent group
<IMG>
with (B) from 0.8 to 1.0 molar amounts of a compound having at
least one aliphatic hydroxyl group and one carboxyl group per
molecule, at reaction temperature below 150°C.
6. A process as claimed in claim 5, wherein component
(I) is a reaction product of (A) one epoxy equivalent of a
polyglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having a
molecular weight of from 700 to 2000 and an epoxy equivalent
weight of from 400 to 1200 with (B) from 0.8 to 1.0 molar amounts
-24-

of a hydroxyalkane monocarboxylic acid, at reaction temperature
below 150°C.
7. A process as claimed in claim 1, wherein component
(I) is a reaction product of (1) 4 epoxy equivalents of a
polyglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having
an epoxy equivalent weight of from 400 to 500 with (2) from 1.8
to 2.2 acid equivalents of an aliphatic dicarboxylic acid, and
(3) from 1.6 to 2.2 acid equivalents of a hydroxyalkane mono-
carboxylic acid, the reaction having been performed below 150°C.
8. A process as claimed in claim 1, wherein component
(I) is a reaction product of (1) from 5 to 7 epoxy equivalents
of a polyglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having
an epoxy equivalent weight of from 170 to 250 with (2) from 3 to
5 carboxy equivalents of an aliphatic dicarboxylic acid, (3)
from 3 to 5 phenolic equivalents of a dihydric phenol, and (4)
from 1.9 to 2.1 epoxy equivalents of a glycidyl ester of a mono-
carboxylic acid, the reaction having been performed below 150°C.
9. A process as claimed in claim 1, wherein component
(II) is a cyclic dicarboxylic acid anhydride.
10. A process as claimed in claim 1, wherein component
(II) is trimellitic anhydride.
11. A process as claimed in any of claims 1 or 10, wherein
component (II) is a product prepared by reacting trimellitic
anhydride with a glycidyl ester of saturated aliphatic monocar-
boxylic acids in which the carboxyl group is attached to a
tertiary or quaternary carbon atom and which carboxylic acids
have 9 to 11 carbon atoms per molecule in a molar ratio of
from 0.8:1 to 1:1.2 at temperatures below 100°C.
12. A process according to claim 1 including a further
-25-

neutralization step wherein at least 50% of the carboxyl
groups of a product (III) are neutralized.
13. A process for the preparation of a thermosetting
coating composition, wherein an aqueous solution of 100 parts
by weight of a neutralized product prepared according to claim
12 is combined with from 1 to 7 weight per cent of a cross-
linking resin.
14. Resinous compounds prepared according to claim 1.
15. Water-dilutable binder prepared according to claim 12.
16. Thermosetting coating composition, prepared according
to claim 13.
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Description

-2- ~3~
The invention relates to coating materials and com-
positions, their preparation, and their use on metal substrates.
~poxy resins are well-known binder materials in the
coating industry; they can be applied in combination with
hardeners (cross-linking agents) of various types, such as
amines~ carboxylic compounds,or amino- or phenol-formal-
dehyde resins, or t~ley can be converted first to soluble,
~usible derivatives such as esters, for specific applications,
such as in primers on steel. For application in aqueous
systems it is preferred to use a resinous material having
a certain amount of carboxyl groups which are at least
partly neutralized with an alkaline compound, such as an
alkali metal hydroxide, ammonia~ or an amine,to make it
water-dilutable; examples of such epoxy resin-based binders
and their use can be found in British patent specifications
962,974 and 972,169, according to which epoxy resins are
esterified with fatty acids and the esters reacted with
certain dicarboxylic acids or anhydrides thereof to introduce
a sufficient number o~ free carboxyl groups in the ester
molecule For good salt-spray resistance (a requirement
for automotive primers) the steel has to be phosphatized,
; before application of these or similar epoxy resin-based
primers.
It has now been found that good salt-spray resistance
can also be obtained on non-phosphatized steel, with epoxy
resin-based primers.

~3~
The invention provides a process for the preparation
of resinous compounds, suitable for making water-dilutable
coating compositions a~ter neutralization, wherein (a) a
component (I) having the formula:
Q t CH2-CH-CH2-M ~ CH2-CH-CH2-Q
dH n~ OH
wherein n1 is a number which is on average from 3 to 7,
Q stands ~or R"~C-O- , with R" being a hydroxyalkyl group
when n is on average from 3 to 5, and R" being an alkyl or
hydroxyalkyl group when nl is on average greater t~a~ 5,
/ CH3
M is a ~O-Ph-C ~ ---Ph-O group
CH3
when nl is on average from 3 to 5, and wherein for values of
n greater than 5, M has the same meaning with the proviso
that at leas.t one M in the above formula is represented by a
-O-C-(CH2)m-C-O- group, wherein m is a number ~rom 2 to 10,
0 ~0
and Q is the same as Q, or hydroxyl, component (I) having
at least 260, and pre~erably at least 320 milli-equivalents
aliphatic hydroxyl per 100 g, is reacted with (b) a component
(II) reacting as a cyclic carboxylic acid anhydride with a
hydroxy compound in the temperature range of from 100 to

- 4- ~
150C, in an amount sufficient to obtain a product (III)
having an acid value of at least 35 mg KOH/g and having at
least 200, and preferably at least 250 milli-equivalents
aliphatic hydroxyl per 100 g.
The carboxyl-contai.ning reaction product (LII) can
then, if desired, be reacted with a monoepoxide, in such
an amount that the aci~ value is reduced to a value corre-
sponding with about 2 carbo~yl groups per molecule; or
prodllct (III) can be used as such~ if desired after partial
or complete neutralization, in coating compositions~
One group of starting materia~ for the preparation of
component (I) is formed by polyglycidyl ethers of
2,2-bis(4-hydroxyphenyl)propane. Such glycidyl ethers may
be represented by the general formula:
. /o\ I OH l ~\
CH2-cH-cH2 _ - O-R-O C~2~CH-CH2- -o-R-o-c~2-cH-cH2
.~ _ n
in which R represents the dival.ent group:
_ ~ ~ C9 ~
and n has an average value of from O to~ preferably, 5.
Theoretically polyglycidyI ethers ~rom a dihydric phenol
have two epoxy groups per molecule but during the
preparation some of the kerminal glycidyl groups may be
hydrated to CH2-CH-CH2- groups by reaction with water.
OH OH

-5~ 7~
Polyglycidyl means that the ether has on average more than
one epoxy group per nolecule.
The component (I) can be prepared in various ways, by
reacting a polyglycidyl ether of 2,2 bis(4-hydroxyphenyl)-
propane with other compounds capable to build up the re--
quired molecular structure~ which is essential linear,
while avoiding cross~linking reactions which would raise
the viscosity too much, and could give rise to gelatinous
materials.
One type of preferred component (I) can be prepared
by reacting (A) one epoxy equivalent of a polyglycidyl
ether of 2,2-bis(4-hydroxyphenyl)propane having a molecular
weight in the range of from 700 to 2000 and an epoxy
equivalent weight in the range of from 400 to 1200, and
in particular a molecular weight in the range of from
1000 to 2000 and an epoxy equivalent weight in the range
of from 700 to 1200, with (B) from o.8 to 1.0 molar amounts
of a hydroxy alkane monocarboxylic acid, at a temperature
below 150C.
In the above formula of component (I)~ n has then a
value of on average from 3 to 5;Q is then the same as Q1,
and both are residues o~ hydroxy alkane monocarboxylic acids.
Examples of hydroxy alkane monocarboxylic acids are:
hydroxy acetic acid, lactic acid, hydroxy butyric acid,
hydroxy valeric acid3 hydroxycaprylic acid, 12-hydroxy
stearic acid, and dimethy~ol propionic acid.

-6~
Another preferred component (I) can be prepared
by reacting a~ a temperature below 150C (1) 4 epoxy
equivalents of a polyglycidyl ether of 2,2-bis(4-hydroxy-
phenyl)propane having an epoxy equivalent weight of from
400 to 500 with (2) from 1.8 to 2.2 acid equivalents of
an aliphatic dicarboxylic acid, and (3) from 1.6 to 2.2
acid equivalents of a hydroxyalkane monocarboxylic acid.
Other preferred components (I) can be prepared by
reacting at a temperature below 150C (1) from 5 to 7
epoxy equivalents of a polyglycidyl ether of 2,2-bis-
(4-hydroxyphenyl)propane having an epoxy equivalent weight
of from 170 to 250 with (2) from 3 to 5 carboxy equi-valents
of an aliphatic dicarboxylic acid, (3) from 3 to 5 phenolic
equival.en~s of a dihydric phenol, and (4) from lo9 to 2.1
epoxy equivalents of a glycidyl ester of a monocarboxylic
acid.
; All these types of component (I) are prepared at
temperatures below 150C, to avoid reaction of aliphatic
hydroxy groups with epoxy groups or carboxy groups, and
to promote reaction o~ epoxy groups with carboxy and with
phenolic hydroxy groups. Preferably a catalyst is used,
examples of which are quaternary ammonium salts, quaternary
phosphonium salts, quaternary ammonium hydroxide~ tertiary
amines or phosphines or salts thereof, al~ali metal hydroxides,
lithium halides, and stannous salts of monocarboxylic acids,
such catalysts may be used in amountsof preferably from 0.1

7 ~3t7,,~g3
to 5 per cent by weight, based upon the total weight of
reactants. Volatile solvents may be used to keep the
viscosity low.
In the ranges of reackants indicated, the mean of
each range is preferred.
The pre-'erred dihydric phenol (2) is 2,2-bis-
~-hydr~xyphenyl)propane, a commercial product also known
under the name "Bisphenol A'l.
The dlcarboxylic acids can be identified with the
formula:
H2C`- ~ CH2 ) nïC2~1'
wherein m is from 2 to 10.
They are well-known saturated aliphatic dicarboxylic
acids. Preferred is adipic acid.
Glycidyl esters to be used in the above reaction scheme
for preparation of component (I) are preferably glycidyl
esters of saturated aliphatic monocarboxylic acids in
which the carboxyl group is attached to a tertiary or
quaternary carbon atom, and which carboxylic acids have
preferably 9 to 11 carbon atoms per molecule; such acids
will later be named 'lalpha-branchedl acids.
The reaction or reactions to obtain the intermediate
component (I~ may be per~ormed by mixing the components
and heating the mixture to the required reaction temper-
ature3 or by heating one component to be used in excess
to the reaction temperature and adding the other component

-8- ~ t~
or components gradually, in one or more stages.
The last two processes for making a component ~I)
have the advantage that the incorporation of saturated
aliphatic dicarboxylic acid provides an improved flexibility
to the ultimate eoating, The last process has the additional
advantage that all the base materials are readily available
commercial products of reasonable price.
The eomponent (I) is then reacted in a separate step
(b) with a compound (II) which reacts as a cyclic carboxylic
acid anhydride with a hydroxy compound in the temperature
range of ~'rom 100 to 150C in an amount sufficient to
obtain a half-ester product having an acid value of at
least 35. Acid value is the r.umber of mg KOH for titration
o~ 1 gram of product. The reactiGn conditions in step (b)
are so chosen that reaction of anhydride groups with
hydroxyl groups predominates, the reaction temperature
is preferably kept below 150C, for example at 100-140C.
Cyclic earboxyli.c acid anhydrides for the purpose of this
invention are defined as compounds having one carboxylic
acid anhydride ring:

\~/ \
\o
/l \c/
~o
per molecule; khey may contain further a carboxylic acid
group. Examples are cyclic anhydrides o~ aliphatic,
aromatic or allcyclic dicarboxylic acids, such as maleic,
succinic, dodecenyl succinic, phthalic~ tetrahydrophthalic,
hexahydrophthalic, endomethylene tetrahydrophthalic, and
methyl endomethylene tetrahydrophthalic anhydride. Examples
of compounds containing one carboxylic acid anhydride ring
and further a carboxylic acid group are trimellitic an-
hydride and adducts of maleic anhydridé and ethylenically
unsaturated fatty acidsj with trimellitic anhydride preferred.
Further, certain combinations and reaction products
of trimellitic anhydride with glycidyl esters of alpha-
branched saturated aliphatic monocarboxylic acids can be
used. These two compounds can be added separately to
component (I) in reaction (b). A further possibility is
to react first the trimellitic anhydride and the glycidyl
esters in a molar ratio of from 0.~:1 to 1:1.2 (for example
from 1:1 to 1:1.2) at a temperature below 100C; this
type of reaction has been described in British patent
specification 9349407. The product lS an acidic polyester,

most probably formed by addition of epoxy groups to
carboxyl groups, and half-ester formation of the hydroxyl
groups with anhydride groups. Although the exact reaction
scheme with such a precondensate in reaction (b) has not
been investigated, such a precondensate reacts with the
hydroxy-rich component (I) as a cyclic carboxylic acid an-
hydride. Probab]y the half-es-ter groups in such a pre-
condensate decompose above 100C to give anhydride groups
and O~-groups (a phenomenon known for half-esters), and
the anhydride groups react then preferentially with OH-
groups of component (I), which are present in large excess.
An advantage in the use of trimellitic anhydride/
glycidyl ester precondensate as described above is the
improved storage stability of the aqueous solutions of
the neutralized final resinous compounds.
For the production o~ water-dilutable resinous
materials having suitable properties as paint binders
the products of step (b) can be neutralized partly or
completely.
The acid value of the reaction product of step (b)
can, if desired~be reduced by reaction with a monoepoxide
in such an amount that the acid value of the product is
still at least 35 (an acid value of at least 35 is a
practical lower limit for water dilutability of the
neutralized product) under conditions at which reaction
of carboxyl with epoxy prevails~ that is at temperatures

below 150C, and preferably in the presence of catalysts;
the conditions are essentially the same as described
above for the preparation of component (I).
The amount of monoepoxide to be used for this
modification is preferably such that the acid value of
the final resinous product is reduced to a value corre-
sponding with about 2 carboxyl groups per molecu]e.
Monoepoxides for use in this modification are
exempliI`ied by monoepoxy alkanes, monoepoxy ethers, and mono-
epoxy esters of monocarboxylic acids. Examples of mono-
epoxy alkanes are ethylene oxide~ propylene oxide, butylene
oxide, octylene oxide. Examples of monoepoxy ethers are
butyl glycidyl ether, octyl glycidyl ether, phenyl
glycidy~ ether5 and cresyl glycidyl ether. Preferred are
glycidyl esters of '~alpha~branched' acids as defined above.
The hydroxy-containing resinous materials prepared
according to the present invention have preferably an
aliphatic hydroxyl content of from 200 to 500, more prefer-
ably from 250 to 500, milliequivalent per 100 g.
The range of reactions and conditions to perform them
properly has advantages over those used in earlier
processes as indicated above: the temperature during the
whole series of reactions is rather low, which improves
selectivity, reduces side reactions, and improves the
colour of the final product.

~3~7~
If desired the reactions may be carried out in the
presence of suitable non-reactive solvents, such as
hydrocarbons or ketones; volatile solvents are pre~erred.
For preparation of water-dilutable binders, e.g.
for electro-deposition purposes the products may be
neutralized partly (e.g., for at least 50%), or com-
pletelyj lyotropic ~lvents such as ethylene glycol
monobutyl ether may be added as well. An adjustment to
a certain pH by partial neutralization may be desirable
in connection with proper dispersion of pigrnents.
Pigments, fillers, dispersing agents, and other
components known in the art of paint formulation may
be added, and also cross~linking resins such as phenol
formaldehyde resins~ or a~lino formaldehyde resins. The
amount of such cross-linking resins is preferably small~
e.g. 1 to 7 weight per cent of the neutralized product
for improved adhesion on bare steel. For use on
phosphatized steel a higher amount of cross-linking
resin may be used, for example 20 to 30 parts by weight
per 80 to 70 parts by weight of the neutralized product.
The water dilutable paints and lacquers can be
applied by a variety of methods as known in the art, for
example by electro-deposition, by spraying, dipping, roller coating,
curtain coating. The coatings can be hardened by stoving.
The invention is illustrated by examples. Parts and
percentagestherein are by weight~ unless otherwise indicated.

-13~
"Bare" steel is degreased steel. "Cymel" 301 is hexa-
methoxymethyl melamine ("Cymel" is a re~istered trade
mark). The glycidyl ester of'alpha-branched"acids had
an epoxy equivalent weight of 246. Aliphatic hydroxy
content was on non-volatiles.
EXAMPLE I
A polyglycidyl ether of 2,2-bis(4-hydroxy phenyl)-
propane having an epoxy equivalent weight of 893 (1786 g;
2 epoxy equivalents) was reacted in a reaction flask with
stirrer~ thermometer, and heating mantle with dimethylol
propionic acid t268 g; 2 mol.) in the presence of benzyl
dimethyl amine as catalys~ (5 g) during 4 hours at 140C
until the acid value was below 4. The aliphatic hydroxyl
content was 600 meq./100 g. Then succinic anhydride
(400 ~; 4 mol.) was added, and the mixture was kept at
140C during one hour.
Then a commercial glycidyl ester of "alpha-branched"
acids (492 g; 2 mol.) was added~ and the mixture was
further reacted at 140C during 12 hours. The acid value
was then 38.1 and the aliphatic hydroxyl content 340 meq.
per 100 g.
After cooling to 80C ethylene glycol monobutyl ether
was added (20 parts per 80 parts o~ reaction product), and
the mixture was neutralized with 90 per cent. of the
theoretical amount of triethyl amine. A melamine formaldehyde
resin (XM 1116, or "Cymel" 301 of American Cyanamid Company)

-l L~ 3 7~
was added (5 parts per 95 parts of reaction product); and
the soluticn was diluted with demineralized water to a
solids content of 10 per cent.
This solution was electro deposited on bare sceel
panels at 150-200 V at 30C. The panels were stoved at
180C during 30 minutes. The coating thickness was
18-22 microns.
In the salt spray test (ASTM B 117) the underrust
creep was less than 3 mm after 240 hours. The impact
resistance (BS 1391), reverse, was the equivalent of
90 cm.kg.
Similar corrosion resistance was obtained when the
solution was applied by spraying or dipping (coatings
20-25 microns thick).
EXAMPLE II
_~,
A "liquid" polyglycidyl ether of 2,2-bis(4-hydroxy
phenyl)propane having an epoxy equivalent weight of 186
(1118 g; 6 epoxy equivalents) was mixed and heated to
120C with a mixture of adipic acid (292 g; 2 moles),
diphenylolpropane (456 g; 2 moles) and glycidyl esters of
alpha-branched acids (492 g; 2 moles). Catalyst was added
(benzyl dimethylamine; 4.5 g) and the mixture heated /luring
1 hour at 120C,
2 hours at 130C, and
1 hour at 140C.

-15- ~ ~ 7 ~
The clear yellow product had analytical values as
follows:
acid content : < 0.01 meq. C02H/g
epoxy content : 0.09 meq./g
phenolic 0~l content : o.48 meq./g
aliphatic OH content: 340 meq./100 g
At 140C succinic anhydride (200 g; 2 moles) was
added, and heating was continued during 2 hours at
135C. The aliphatic OH content was 230 rneq/100 g.
l'his mixture was then diluted wi~h ethylene glycol mono-
butyl ether to a solids content of 80%, and further cooled
; to ambient temperature.
This binder solution was neutralized with 90% of the
theoretical amount of triethylamine, blended with a com- -
mercial mela~ine resin ("Cymel" 301 of American Cyanamid
Company) at a 95:5 weight ratio and diluted with de-
mineralized water to a solids content of 10%w. This
solution was used for application of a primer by electro-
deposition at 150 V onto bare steel panels. The coatings
were 20 25 microns thick, after stoving at 180C during
30 minutes they had an excellent impact resistance
(~ 30 cm.kg in the reverse ~S 1391 test) and a rust
creep of 5 mm in the ASTM B117 salt spray test (after
240 hours).

-16~ 3'~
EXAMPLE III
Example II was repeated, with the exception that in
the second stage the succinic anhydride was replaced by
trime]litic anhydride (576 g; 3 molesj at a temperature
of 140C, immediately followed by glycidyl esters of
alpha-~,ranched acids (861 g; 3.5 epoxy equivalents).
The reaction mass exothermed to about 150C, and was
kept then at 145C during 1.5 hours; the acid value of
the product was 35, the aliphatic 0~l content 220 meq./100 g.
The resin was diluted with ethylene glycol monobutyl ether to
give a solids content of 70%w, and neutralized and further
t~eated as described in Example II.
Bare steel panels, electro-coated with this binder
(10% solids; weight ratio of this binder/"Cymel": 95/5,
200 V ED; stoved at 180C during 30 minutes, coating
16-20 microns thick) had in the ASTM B117 salt spray test
a rust creep of 5 mm.
E~A~IPLE I~l
Example III was repeated with slight modifications.
A condensation product from "liquid" polyglycidyl ether,
adipic acid, diphenylol propane, and glycidyl esters of
alpha-branched acids as prepared in E~ample II (2360 g)
was heated in a 10 l glass reactor to 140-145C. Powdered
trimellitic anhydride (4~0 gg 2.5 moles~ was added, and
the mlxture was kept with stirring at 140-145C during
15 minutes. Glycidyl ester of alpha-branched acids (640 g,

7 ~3t7~
2.6 moles) was added, and th(~rllix~ure was kept with
stirring at 140C during 1.5 hours. The product, a clear,
yellow resin (acid value 36 mg KOH/g, aliphatic hydroxyl
230 meq./100 g) was diluted with ethylene glycol monobutyl
ether (1492 g), the solution (70~w solids) was cooled
to ambient temperature and neutralized with 80/o of the
theoretical amount of triethyl amine. This solution was
blended with hexamethoxymethyl melamine in a 95:5 solids
weight ratio, and thinned with water to lO~w solids. The
clear solution hada pH = 7.2.
The storage stability Or this solution was examined
by keeping the solution at 40C in a closed container,
and taking at regular intervals a sample for electro-
deposition (150 V/25C, bare steel anodes). The results
are shown in the following Table:
Storage time Film thickness Film
weeks at 40C (micron) appearance
.... ..
0 18-20 smoothg
glossy
1 18-20 smoot~,
glossy
2 20-22 smooth
3 20-22 rough, no
gloss
4 25-30 film
ruptured

The Table shows that satis~actory films were obtained
for storage ~imes of up to 2 weeks only.
EXAMPLE V
This example demonstrates the improved storage time
when using a prereaction product Or trimellitic anhydride
and "Cardura" E 10.
A. Prereaction product, preparation
__
A mixture o~ trimellitic anhydride (4~0 g, 205 moles),
glycidyl ester of alpha-branched acids (640 g, 2.6 moles),
methyl ethyl ketone (747 g) and benzyl dimethyl amine
(2.3 g) was heated in a 3-litre glass reactor equipped with
thermometer, stirrer, and reflux condenser. A slightly
exothermic reaction started at about 70C, and brought
the temperature to a maximum of 93C with re~lux. The
solution was kept at 90-95C during 6 hours, and then
cooled. The solution had the following properties:
colour :slightly hazy yellow
solids :60%w
epoxy :0.03 meq./g (on solids)
acid value:127 mg KOH/g (on solids)
viscosity
(Gardner-Holt): M (25C; solution)
B. A condensation product as descrlbed in Example II
(2360 g) was heated in a 10 1 glass reactor equipped with
stirrer, thermometer, dropping funnel and distillation
head to 145C. Through the dropping funnel a pre-reaction

-19~ 7~ ~
product of part A of this Example (1870 g) was added in
30 minutes while the methyl ethyl ketone was distilled off
and the batch temperature was kept at 130-135C. Then
the batch temperature was raised to 145C, and kept there
for 1- hour. The resulting clear yellowish resin has an
acid value of 35 mg KQH~g and an aliphatic hydroxyl content
of 230 meq./100 g; it was diluted with ethylene glycol mono-
butyl ether to 70%w solids and the clear solution was cooled
to room temperature.
A 10%w aqueous solution was prepared as described in
Example IV and evaluated for storage stability (by the same
procedure)~ the results of which ~e shown in the following
Table:
15Storage time Film thickness Film
weeks at 40C (microns) appearance
0 17-1~ smooth,
glossy
; 2 18-20 smooth~
glossy
4 20-22 smooth,
glossy
It is apparent that the storage stability of the
neutralized aqueous solution of this binder is con-
siderably better than that of Example IV.
Films from neutralized products of this example, applied
by electrodeposition on bare steel panels and baked
(3 minutes/180C; thickness about 20 microns) had excellent
propertles? as shown in the fol3owing table:
.

-2~
Reverse Impact (British Standard): ~ 90 inch.lb
(101 cm.kg)
Rust creep (ASTM salt spray 240
hours) < 5 mm
Conical mandrel bend : passed 1/8 inch
(passed 0.3 cm)
Hardness (pencil) : F-H
Eiardness (Konig) : 180 seconds
Adhesion (Gitterschnitt) : excellent
Solvent resistance : xylene 15 minutes
slight softening
EXAMPLE VI
A 10-litre reactor equipped with anchor stirrer~ reflux
condenser, thermometer, and dropping funnel is provided with
a polyglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having
an epoxy equivalent weight of 483 (4 epoxy equivalents,
1(332 g) and toluene (235 g)g and heated to 140-145C.
Adipic acid ~146 g, 1~0 mole), dimethylol propionic
acid (268 g, 2.0 moles) and benzyl dimethyl ~mine (5.8 g)
; are added~ and the mixture is stirred at 140-145C until
the acid value is below 2 mg KOH/g (on solids); this takes
about 4 hours. The aliphatic hydroxyl content is then
340 meq./100 gO
The reflux condenser is then rearranged for distillation,
and a resin solution prepared according to Example V A(1870 g)
is gradually added through the dropplng funnel while
distilling off the volatile matker (mainly methyl ethyl
ketone) with stirring, at a batch temperature of about

-21~
135C; this takes about 2 hollr. The batch is then further
heate~ with stirring (batch ternperature about 135-140C)
~ntil the acid value is 36 mg KOH/g (about 1 hour)~
with preferably a slight stream of inert gas (e.g., nitrogen)
passing through to promote removal of solvent. The
aliphatic hydr-oxyl content of` the resin was 230 meq./100 g.
EXAMPLE `VI_
Paint and evaluation of product obtained by Example VI.
This product (140 g, 137 g non-volatiles), diethylene
glycol moncbutyl ether (35 g) and isophorone (17.5 g)
are charged to a 1 litre flask equipped with anchor
stirrer, dropping funnel~ re~lux condenser~ and thermometer;
the mixture is heated to about 80C until homogeneous, and
then cooled to about 35C; then an oil-soluble phenolic
resin ("Setalite" lOO*in 71.2%w solution in monobutyl
ether of diethylene glycol~isophorone 2:1 wto ratio) is
added and then triethylamine (7.4 g).
When the mixture is homogeneous, demineralized water
(424 g) is added slowly and gradually at a temperature of
about 30C with stirring. The resulting solukion had a
bluish-milky appearance; the solids content was 24.5%w
and the degree of neutralization Oo830
200 g of this solution were ballfmilled for 48 hours
with titanium dioxide (36 g)~ carbon black (2 g) and clay
(2 g). A ~urther 390 g of the aqueous binder solution was
added, and the mixture further ballmilled during 30 minutes.
* trademark
. . . :

-22~
This mixture was diluted with ~20 g of demineralized water,
to a paint with solids content 14.8~w and pl~ 7.1. This
paint was electrodeposited on bare steel panels at
150-200 V at 30C. The panels were stoved at 180C
durirlg 30 minutes, The properties of the stoved coating
were:
thickness 18-22 microns
salt spray (ASTM B 117) underrust creep after
240 hours: 3 mm
hardness (Konig) 180 seconds
impact (reverse) 90 cm.kg
mandrel behd (conical) passed 3 mm