[0001] The invention is concerned with novel resinous binders containing tertiary amino
groups which are useful for coating articles by means of cathodic electrodeposition.
The present invention is also concerned with the preparation of such binders as well
as coating compositions containing them.
[0002] It is known to coat electrically conducting articles with resinous binders containing
tertiary amino groups by means of cathodic electrodeposition. Generally such articles
are immersed in an aqueous coating composition comprising the resinous binder in the
form of a salt thereof and a cross-linking agent, and an electrical current is passed
between the article (cathode) and an anode which deposits the resinous binder on the
article which is then stoved to cure or cross-link the resinous binder.
[0003] Known resinous binders having tertiary amino groups may be represented by the formula:-

wherein m is 0 or an integer of from 1 to 6, each A
1 is the same or different tertiary amino group, B
1, or each B, which may be the same or different, is a group of formula:- OH

wherein n is 0 or an integer of from 1 to 10, and R is the hydrocarbon residue of
a dihydric phenol, and C1, or each C, which may be the same or different, is a group
derived from a compound having at least two sites capable of reacting with glycidyl
ether groups.
[0004] Resinous binders of this type, wherein C
1 is derived from a diamine or a primary monoamine, are known from U.K.1,461,823. A
disadvantage of such binders is that they produce rough, incoherent coatings having
poor corrosion resistance on bare steel substrates i.e. steel which has not been phosphated.
It has also been proposed to incorporate residues of unsaturated fatty acids into
such resinous binders e.g. see U.K. 1,307,585. Although such binders form smoother
coatings on bare steel substrates they still have a poor corrosion resistance.
[0005] We have now found that if such binders contain at least one group derived from a
glycidyl ester of a C
6 to C
20 carboxylic acid then the coatings prepared therefrom are smooth and glossy and have
good corrosion resistance even when deposited upon bare steel substrates.
[0006] Accordingly, the present invention is concerned with a resinous binder of formula:-

wherein m is 0 or an integer of from 1 to 6, each A is the same or different tertiary
amino group, B, or each B which may be same or different, is a group of formula:-

wherein n is 0 or an integer of from 1 to 10, and R is the hydrocarbon residue of
a dihydric phenol; and C, or each C which may be the same or different, is a group
derived from a compound having at least two sites capable of reacting with glycidyl
ether groups, with the proviso that at least one of the groups A, B or C is substituted
by at least one group R
1 having the formula:-

wherein R
2 is a C
6 to C
20 alkyl group.
[0007] The group R may be directly attached to at least one of the groups A, B, or C, or
indirectly through an intermediate group which is preferably the residue of a di-
or tricarboxylic acid; m is preferably an integer of from 1 to 3, n is preferably
an integer of from 1 to 4, and R
2 is preferably a secondary or tertiary C
B to C
10 alkyl group.
[0008] The preferred resinous binders of formula III will be described with reference to
the following description of the methods of preparing such resinous binders. In general
the group R is incorporated by the reaction between a glycidyl ester of formula:-

wherein R
2 is a C
6 to C
20 alkyl group, preferably a secondary or tertiary C
8 to C
10 alkyl group, and a primary or secondary amino, hydroxyl or acidic, e.g. carboxylic
acid, group. This reaction may take place as the final step in the preparation of
the binder i.e. by reacting a resinous binder of formula I directly or indirectly
with a glycidyl ester of formula VI or may take place by pre-reacting at least one
of the components from which the binder is prepared with a glycidyl ester of formula
VI. In other words, the preferred resinous binders can be prepared by the reaction,
in one or more stages, of
(a) a secondary monoamine,
(b) a diglycidyl ether of a dihydric phenol,
(c) a compound having at least 2 sites capable of reacting with glycidyl ether groups,
and
(d) at least the glycidyl ester, in amounts such that the number of epoxy equivalents
of (b) is substantially equal to the number of reactive sites of (a) and (c).
[0009] It will be understood by those skilled in the art that the structures given herein
represent the average structure of a mixture of reaction products.
[0010] One suitable method (method I) of preparing resinous binders of formula III comprises
reacting a resinous binder of formula I with
(A) a glycidyl ester of formula VI, or
(B) a cyclic carboxylic acid anhydride and a glycidyl ester of formula VI.
[0011] The resinous binders of formula I are prepared by reacting a diglycidyl ether of
formula:-

wherein n and R are as hereinbefore defined, with a secondary monoamine and, optionally,
a compound having at least two sites capable of reacting with glycidyl ether groups,
in amounts such that the number of epoxy equivalents of the diglycidyl ether is substantially
equal to the number of reactive sites of the other reactants, that is to say that
deviations from equality are in general below 10%.
[0012] The amounts of the reactants which are used depend upon the desired "m" value of
the resinous binder of formula I. For example, resinous binders, wherein m is 0, are
obtained by reacting about 2 epoxy equivalents of the diglycidyl ether with about
2 moles of the secondary monoamine; resinous binders, wherein m is 1, are obtained
by reacting about 4 epoxy equivalents of the diglycidyl ether with about 2 moles of
the secondary monoamine and about 1 mole of the compound having at least two sites
capable of reacting with glycidyl ether groups; resinous binders, wherein m is 2,
are obtained by reacting about 6 epoxy equivalents of the diglycidyl ether with about
2 moles of the secondary monoamine and about 2 moles of the compound having at least
two sites capable of reacting with glycidyl ether groups; and resinous binders, wherein
m is 3, are obtained by reacting about 8 epoxy equivalents of the diglycidyl ether
with about 2 moles of the secondary monoamine and about 3 moles of the compound having
at least 2 sites capable of reacting with glycidyl ether groups.
[0013] The diglycidyl ethers of formula VII are well known compounds and are available commercially
usually as mixtures of compounds having on average more than one glycidyl group per
molecule. Theoretically diglycidyl ethers of dihydric phenols have two epoxy groups
per molecule but some of the terminal glycidyl groups may be hydrated during the preparation
to

groups. Therefore the amount of diglycidyl ether to be used is indicated by its number
of epoxy equivalents. Preferred diglycidyl ethers are those wherein R is a group of
formula:-

wherein each R
3, which may be the same or different, is H or a c
1 to C
4 alkyl group. Most preferred diglycidyl ethers are those wherein both R
3 groups are methyl groups. Suitably n has an average value of from 0 to 4.
[0014] Suitable secondary monoamines are heterocyclic amines, e.g. piperidine and morpholine;
dialkylamines, such as di(C
1 to C
6)alkylamines e.g. dimethylamine, diethylamine, dipropylamines, dibutylamines, dipentylamines
and methylethylamine; dialkanolamines, such as di(C to C
6)alkanolamines e.g. diethanolamine and dipropanolamines such as diisopropanolamine,
and N-alkyl-alkanolamines such as N-(C
1 to C
6)alkyl(C
1 to C
6)alkanolamines e.g. N-methyl-ethanolamine. The secondary monoamines may be further
substituted e.g. by alkoxy or carboxyl groups. It can be seen from formula I that
such resinous binders have at least two secondary hydroxyl groups which are capable
of reacting in method I (A) or (B). However, it is considered desirable to use as
the secondary monoamine an alkanolamine since the resulting resinous binders have
additional hydroxyl groups which may also react in method I (A) or (B); consequently
it is possible to react more of the components in (A) or (B) and to produce a resinous
binder of formula III which in addition to having R groups also has several unreacted
hydroxyl groups which is considered to be advantageous insofar as such binders are
to be used in cathodic electrodeposition processes. The most preferred secondary monoamines
are diethanolamine and di-iso-propanolamine.
[0015] Suitable compounds having at least two sites capable of reacting with glycidyl ether
groups, and which therefore form the linking groups C
1 or C, are polyols, adducts of polyols and polycarboxylic acid anhydrides, and polycarboxylic
acids. Preferred are amines having as reactive sites one or more primary or at least
2 secondary amine groups. Examples of polyols are alkylene glycols and polyoxyalkylene
glycols e.g. hexylene glycol, polyoxyethylene glycol and polyoxypropylene glycol;
polyhydric phenols e.g. diphenylolmethane and diphenylolpropane. Examples of polycarboxylie
acids and anhydrides are maleic, succinic, dodecenylsuccinic, glutaric, adipic, phthalic,
tetrahydrophthalic, hexahydrophthalic, endomethylene tetrahydrophthalic, methyl endomethylene
tetrahydrophthalic acid and trimellitic acid and their anhydrides. Examples of amines
having one or more primary amine or at least 2 secondary amine groups per moleculare
are: C
2 to C
10 alkylene primary diamines, such as ethylene diamine, hexylene diamine (1,6-diaminohexane);
pol
y(C
2 to C
10) alkylene polyamines, such as diethylene triamine, triethylenetetramine, piperazine,
N-(2-aminoethyl)piperazine; polyether primary diamines such as 4,9-dioxa-1,12-dodeoane
diamine; primary mono(C
1 to C
6)alkyl and (C
1 to C
6)alkanol amines such as methylamine, butylamine, monoethanolamine, mono-isopropanolamine,
from which the alkanolamines are preferred. These types of amines may further contain
tertiary amine groups; examples are 1-(N,N-dimethyl)-3-aminopropane, 1-(N,N-diethyl)amino-4-aminobutane,
and 1-N,N-bis (3-aminopropyl)methylamine.
[0016] Primary monoamines may be further substituted by alkoxy, carboxy or sulphonyl groups;
examples are 3-ethoxy propylamine, glycine, alanine, p-amino benzoic acid, sulphanilic
acid, and sulphanilamide. Presence of a built-in acidic group may improve the cure
with cross-linking resins. A built-in sulphonic acid group is preferably deactivated
at room temperature by reacting the resinous binder with an excess of glycidyl ester;
at stoving temperature the sulphonic acid group is set free and can exert its cure-improving
properties. The preparation of the resinous binders of formula I may be carried out
at elevated temperatures e.g. at a temperature in the range of from 50 to 150°C and
in the presence of non-reactive solvents such as glycol ethers and ketones. Glycol
ethers are usually non-reactive below 100°C. It will be appreciated that mixtures
of diglycidyl ethers of formula VII, mixtures of secondary monoamines and/or mixtures
of compounds having at least two reactive sites capable of reacting with glycidyl
groups may be used. For example, a preferred component (c) is a mixture of
(1) a mono alkanolamine,
(2) a disecondary amine, and
(3) a carboxyl- or sulphonyl substituted primary monoamine such as sulphanilic acid.
[0017] The resinous binders of formula I may then be etherified with a glycidyl ester of
formula VI (method I(A)). Preferred esters are glycidyl esters of saturated aliphatic
monocarboxylic acids in which the carboxyl group is attached to an alpha-branched
carbon atom, i.e. a tertiary or quaternary carbon atom, and which carboxylic acids
have preferably 9 to 11 carbon atoms per molecule. The amount of glycidyl ester used
may vary considerably and will depend on the number of reactive sites available in
the resinous binder of formula I. The reaction may be carried out at a temperature
of from 50 to 150°C and in the presence of non-reactive solvents such as glycol ethers
and ketones. Catalysts may be used e.g. quaternary ammonium salts or hydroxides, phosphonium
salts, tertiary amines or phosphines or salts thereof, alkalimetalhydroxides, lithium
halides and stannous salts of monocarboxylic acids.
[0018] Alternatively the resinous binders of formula I may be reacted with a cyclic carboxylic
acid anhydride and a glycidyl ester of formula VI (method I(B)). Preferred glycidyl
esters are those described above. Preferred cyclic carboxylic acid anhydrides which
may also contain a carboxylic acid group, are the anhydrides of aliphatic cyclic dicarboxylic
acids such as maleic, succinic, dodecenylsuccinic, glutaric and adipic acids, and
carbocyclic anhydrides such as the anhydrides of aromatic or alicyclic dicarboxylic
acids e.g. phthalic, tetrahydrophthalic, hexahydrophthalic, endomethylene tetrahydrophthalic
and methyl endomethylene tetrahydrophthalic acids. Examples of anhydrides containing
a further carboxylic acid group are trimellitic anhydride and adducts of maleic anhydride
and ethylenically unsaturated fatty acids. The amount of anhydride used may vary considerably
and depends on the number of reactive sites of the resinous binder 2 of formula I
but is suitably from 0.5 to 4.5 moles per mole of resinous binder of formula I. The
amount of the anhydride and glycidyl ester may vary considerably but is preferably
such that the resinous binder of formula III is substantially free of carboxylic acid
groups. The reaction is suitably carried out at a temperature of from 50 to 150°C
and may be carried out in the presence of non-reactive solvents such as glycol ethers
and ketones.
[0019] Another suitable method (method II) of preparing resinous binders of formula III
comprises reacting a diglycidyl ether of formula VII with a secondary monoamine and,
optionally, a compound having at least two sites capable of reacting with glycidyl
ether groups, wherein at least one of the reactants is substituted by at least one
R group as defined above and wherein the amounts of the reactants are such that the
number of epoxy equivalents of the diglycidyl ether is substantially equal to the
number of reactive sites of the other reactants.
[0020] Method II is particularly suitable for preparing resinous binders of formula III
wherein m is 1 to 6 by reacting
(a) a secondary monoamine,
(b) a diglycidyl ether of formula VII, and a reaction product of
(c) a compound having at least three sites capable of reacting with glycidyl groups
wherein the amounts of (c) and (d) are such that the reaction product has at least
two sites capable of reacting with glycidyl ether groups, and
(d) a glycidyl ester of formula VI.
[0021] The amounts of the reactants which are used in the preferred method II depend upon
the desired "m" value of the resinous binder in the same way as described above for
the preparation of resinous binders of formula I. For example, resinous binders of
formula III, wherein m is 1, are obtained by reacting about 4 epoxy equivalents of
the diglycidyl ether with about 2 moles of the secondary monoamine and about 1 mole
of the reaction product of (c) and (d) and so on. Suitable diglycidyl ethers, secondary
monoamines and glycidyl esters are described above. Suitable compounds of type (c)
are polyamines containing at least two primary amino groups, such as C
2 to C
10 alkylene primary diamines,
poly(C
2 to C
10)alkylene polyamines and polyether primary diamines of the type discussed above with
hexamethylene diamine being preferred, and compounds containing a cyclic carboxylic
anhydride group and a carboxylic acid group of the type discussed above with trimellitic
anhydride or trimellitic anhydride/polyoxyalkylene glycol adducts being preferred.
Such adducts may be prepared by reacting a polyoxyalkylene glycol with about 200 mole
% of trimellitic anhydride. Insofar as compound (c) is a polyamine, preferred reaction
products are obtained by reacting about 1 mole of an'alkylene primary diamine with
about 2 epoxy equivalents of the glycidyl ester of formula VI. Insofar as compound
(c) is the above trimellitic anhydride/polyoxyalkylene glycol adduct, preferred reaction
products are obtained by reacting the adduct with about 2 epoxy equivalents of the
glycidyl ester of formula VI. The above method may be carried out in several stages
e.g. the diglycidyl ether of formula VII may be pre-reacted with the secondary monoamine.
All of the above reactions may be carried out at elevated temperature, e.g. at a temperature
of from 50 to 150°C, and in the presence of non-reactive solvents such as glycol ethers
and ketones.
[0022] Preferred are those reaction products of (c) and (d) wherein (c) has at least three
sites capable of reacting with glycidyl groups and the reaction product has two sites
capable of reacting with glycidyl ether groups; an example is the reaction product
of 1 mole of 1,6-diaminohexane and two moles of (d). However, reaction products of
this type may have more than two, for example 3 or 4, sites reactive with glycidyl
ether groups, as exemplified by the reaction products of 1 mole of diethylene triamine
or triethylene tetramine with 2 moles of (d); such products have 3 and 4 reactive
sites, respectively, and will form with adducts of (a) and (b) resinous binders which
are "star-shaped", that is to say that the group C in the formula III contains one
or more side chains -B-A.
[0023] The resinous binders of formula III may contain from 1 to 6 preferably 2 to 4 groups,
derived from the glycidyl ester of formula VI. Usually the weight of such groups varies
from about 10 to 50% weight of the resinous binder. Moreover, preferred resinous binders
of formula III have a hydroxyl content of from 200 to 600 meq/100 g, more preferably
from 200 to 400 meq/100 g, for improved corrosion resistance on bare steel. In addition,
preferred resinous binders have preferred calculated average molecular weights of
from 2000 to 5000.
[0024] As stated above, the resinous binders of formula III are particularly suitable as
components of aqueous coating compositions for use in cathodic electrodeposition processes.
Accordingly the. invention is also concerned with thermosetting coating compositions,
such as water-dilutable binder concentrates and aqueous coating compositions comprising
a resinous binder of formula III, which may have been prepared as hereinbefore described,
wherein at least about 20% of the amino groups are neutralized by an acid.
[0025] Suitable aqueous coating compositions comprise about 2 to 20 %w of the resinous binder
of formula III. The acid, which has the effect of making the resinous binder water-soluble
as well as making it susceptible to cathodic electrodeposition may be inorganic e.g.
hydrochloric, sulphuric acid, or organic e.g. formic, acetic, maleic,citric or lactic
acid, with lactic acid being preferred. Usually from 20 to 100% of the amino groups
are neutralized by the acid. The binder concentrate and the aqueous coating composition
contains preferably a cross-linking agent such as melamine/formaldehyde; benzoguan-
amine/formaldehyde; urea/formaldehyde and phenol/formaldehyde resins, with alkoxylated
melamine e.g. hexamethoxymethylmelamine resins being preferred. Suitable amounts of
cross-linking agents are from 1 to 50 %w, preferably from 5 to 25 %w, based on the
weight of the resinous binder of formula III. The aqueous compositions may also contain
other components such as solvents e.g. glycol ethers, pigments, fillers, dispersing
agents, stabilizers etc.
[0026] The aqueous coating compositions are preferably prepared by dissolving the resinous
binder in a solvent such as a glycol ether, adding the cross-linking agent and acid
followed by the addition of water, preferably demineralized water. Values for pH are
usually of from 3.0 to 6.0 but may be above 6.0. Although the compositions are particularly
suitable for coating bare steel substrates they may also be used for coating phosphatized
steel substrates.
[0027] The invention will be illustrated with reference to the following Examples.
[0028] The diglycidyl ethers (named Polyethers) used therein were commercial polyglycidyl
ethers of 2,2-bis(4-hydroxyphenyl)propane (also known as Bisphenol A) having the following
properties:

[0029] The glycidyl ester C10E was a commercial glycidyl ester of saturated aliphatic monocarboxylic
acids in which the carboxyl group is attached to a tertiary or quaternary carbon atom,
and which carboxylic acids have on average 10 carbon atoms per molecule; the epoxy
molar mass was 250.
[0030] Aliphatic hydroxy content was on non-volatiles.
Example 1 (comparative)
[0031] Polyether E (1786 g; 2.0 epoxy equivalents) was melted and reacted with diethanolamine
(210 g; 2.0 mole) at 135
oC for 5 hours.
[0032] The resulting resinous binder had a nitrogen content of 1.00 meq/g, a residual epoxy
content of below 0.02 meq/g and a calculated aliphatic hydroxy content of about 600
meq/100 g.
Example 2
[0033] A resinous binder (200 g, 0.1 mole) prepared according to Example 1 was melted and
mixed with succinic anhydride (20 g, 0.2 mole) for 5 minutes at 145°C. Glycidyl ester
C10E (60 g; 0.24 epoxy equivalents) was added and the reaction continued for 1 hour
at 135°C. The resulting resinous binder had a nitrogen content of 0.71 meq/g, an acid
content of 0.04 meq/g and a calculated aliphatic hydroxy content of about 430 meq/100
g. About 21.4 %w of the resinous binder was derived from the glycidyl ester.
Example 3
[0034] A resinous binder (200 g; 0.1 mole) prepared according to Example 1 was melted and
reacted with glycidyl ester C10E (74.4g; 0.3 epoxy equivalents) in the presence of
benzyldimethylamine (0.27 g), as etherification catalyst, for 6 hours at 140°C. The
resulting resinous binder had a nitrogen content of 0.73 meq/g; a residual epoxy equivalent
of 0.03 meq/g and a calculated aliphatic hydroxy content of about 440 meq/100 g. About
27.1 %w of the resinous binder was derived from the glycidyl ester.
Example 4 (comparative)
[0035] A mixture of Polyether D (566 g; 1.2 epoxy equivalents) diisopropanolamine (79.8
g; 0.6 mole) and isopropanolamine (22.5 g; 0.3 mole) was melted and reacted at 140°C
for 3 hours.
[0036] The resulting resinous binder had a nitrogen content of 1.35 meq/g, a residual epoxy
content of 0 and a calculated aliphatic hydroxy content of about 670 meq/100 g.
Example 5
[0037] A resinous binder (223 g; 0.3 mole) prepared according to Example 4 was melted and
a blend of trimellitic anhydride (19.2 g; 0.1 mole), glycidyl ester C10E (62.5 g;
0.25 epoxy equivalents) and dry acetone (40 g) added gradually (over 0.5 hour) thereto
whilst maintaining the temperature at 130°C and distilling off the acetone. After
addition, the reaction was continued for 2 hours at 135
0C. The resulting resinous binder had a nitrogen content of 0.98 meq/g, an acid content
of 0.02 meq/g, an epoxy content of 0.08 meq/g and a calculated aliphatic hydroxy content
of about 500 meq/100 g. About 20.5 %w of the resinous binder was derived from the
glycidyl ester.
Example 6 (comparative)
[0038]
(a) Polyether D (944 g; 2 epoxy equivalents) was dissolved in ethylene glycol monobutylether
(450 g) and reacted with diisopropanolamine (133 g; 1.0 mole) at 80°C for 3 hours
after which 50% of the epoxy groups had reacted. The resulting solution had a residual
epoxy content of 0.65 meq/g solution and a solids content of 70.53 %w.
(b) This solution (615 g; containing 0.4 epoxy equivalents) was added gradually over
a period of 1 hour to a solution of hexamethylene diamine (23.2 g; 0.2 mole) in ethylene
glycol monobutylether (20 g) at a temperature of 80oC, after which the reaction was continued at 80°C for 2 hours. The resulting solution
of resinous binder had a nitrogen content of 1.22 meq/g solution, an epoxy content
of 0 and a calculated solids contents of 69.4 %w.
Example 7
[0039] Example 6 was repeated with the difference that in step (b) the solution obtained
in step (a) was added to a solution obtained as follows.
[0040] 1.6-Diamino hexane (23.2 g, 0.2 mole) was heated in ethylene glycol monobutylether
(20 g) to 80°C, after which glycidyl ester C10E (100 g, 0.4 epoxy equivalents) was
added gradually for a period of 1 hour at 80
oC. The reaction was continued for 1 hour at 80°C.
[0041] The resulting solution of resinous binder had a nitrogen content of 1.05 meq/g solution
and a calculated solids content of 73.5 %w.
[0042] About 17.9 %w of the resinous binder was derived from the glycidyl ester.
Example 8
[0043]
(a) A solution was prepared by dissolving trimellitic anhydride (192 g; 1.0 mole)
in dry acetone (300 g) and adding thereto glycidyl ester C10E (250 g; 1.0 epoxy equivalent).
(b) Polypropylene glycol having a molecular weight of 420 (210 g; 0.5 mole) was heated
to 1350C after which the solution obtained in (a) above was added gradually (over 1 hour)
whilst maintaining the temperature at 130°C and distilling off the acetone. After
addition the reaction was continued for 3 hours at 135°C. The product, a viscous liquid,
had an acid content of 1.58 meq/g.
(c) The product (130.4 g; 0.1 mole) obtained in (b) above was reacted with Polyether
D (189 g; 0.4 epoxy equivalent value of about 2) and diethanolamine (21.0 g; 0.2 mole)
at a temperature of 130°C for 2 hours. The resulting resinous binder had a nitrogen
content of 0.62 meq/g, an acid content of 0.09 meq/g and a calculated aliphatic hydroxyl
content of 470 meq/100 g. About 14.7 %w of the resinous binder was derived from the
glycidyl ester.
Example 9
[0044] Glycidyl ester C10E (250 g; 1.0 epoxy equivalents) was added gradually (over 0.5
hour) to a solution of ethylene diamine (30 g; 0.5 mole) in ethylene glycol monobutyl
ether (50 g). The temperature was not allowed to exceed 80°C. The resulting clear
solution had an epoxy value of 0. A solution of sulphanilic acid (17.3 g, 0.1 mole)
and diethanolamine (42.0 g. 0.4 mole) in water (30 g) was then added followed by a
solution of Polyether A (304 g; 1.6 epoxy equivalents) in ethylene-glycol monobutyl
ether (170 g). The mixture was then stirred at 80°C for 1 hour and at 110°C for 2
hours. The resulting clear solution had a nitrogen content of 1.81 meq/g solution,
an epoxy content of 0, a residual acid content of 0.10 meq/g solution and a solids
content of 72.0 %w. About 38.8 %w of the resinous binder was derived from the glycidyl
ester.
Example 10 (comparative)
[0045] A resinous binder (200 g; 0.1 mole) prepared according to Example 1 was reacted with
linseed oil fatty acid (54.6 g, 0.2 mole) in the presence of toluene (25 g) and stannous
octoate (0.8 g) at 220°C for 1 hour whilst removing the water of esterification (335
g) and toluene (20 g) azeotropically. The resulting resinous binder had a nitrogen
content of 0.76 meq/g and a residual acid value of 0.02 meq/g.
Examples 11 to 20
[0046] Coating compositions were prepared from the resinous binders, or solutions thereof,
obtained in Examples 1 to 10. The general procedure was to dissolve the resinous binder,
if necessary, in a solvent (ethylene glycol monobutyl ether was used except in Examples
14, 15 and 18 where a mixture of this ether (16.7 g) and isophorone (8.3 g) was used)
followed by the addition of a cross-linking agent "Cymel" 301 (hexamethoxymethyl melamine)
and lactic acid. Demineralized water was then added slowly. In all Examples the compositions
had a 10 %w solids content. The amounts of the components are given in Table 1.

Examples 21 to 30
[0047] The coating compositions prepared according to Examples 11 to 20 were cathodically
electrodeposited onto solvent degreased steel panels at a temperature of 25±1°C and
voltages of from 50 to 200 volts (direct current). The coatings were cured at 180°C
for 30 minutes. The panels were examined visually and the thickness of the coatings
determined. The coated panels obtained from compositions of the present invention
were then subjected to a salt spray corrosion resistance test (ASTM B 117-64; 10 days).
The appearances of the coated panels prepared from the comparative compositions, except
Example 30, were such that it was not considered worthwhile to carry out this salt
spray test. The results are given in Table II.
[0048] In addition the procedure was repeated after storing the compositions of the present
invention for 4 weeks at 40°C. Substantially the same results were obtained.

Example 31
[0049]
(a) Hexamethylene 1,6-diamine (116 g; 1 mole) was heated to 100°C in a reactor equipped
with stirrer, thermometer and nitrogen blanket. Glycidyl ester C10E (500 g; 2 epoxy
equivalents) were added gradually in about hour from a dropping funnel at a reaction
temperature between 100 and 110oC, and the mixture was heated for 2 hours at 110°C to complete the reaction; the combined
epoxy + N content was 3.30 meq/g (total 2.02 equivalents).
(b) Polyether D (2832 g; 6 epoxy equivalents) was dissolved in ethylene glycol monobutyl
ether (1610 g) at 750C in a reactor equipped with stirrer, nitrogen blanket, and means for cooling and
heating. Diethanolamine (210 g; 2 moles), the adduct prepared at (a), and 1-N,N-dimethylamino-3-amino
propane (102 g; 1 mole) were added to the solution; the temperature was kept below
100 C by cooling, and the mixture was kept for 3 hours at 95-100oC. The residual epoxy content was zero, the N content 1.12 meq/g solution; the calculated
solids content was 70 %w.
(c) An aqueous binder solution was prepared by adding to the final solution of (b)
(114 g) a cross-linking agent (hexamethoxymethyl melamine; 20 g) and lactic acid (3.8
g of 90 %w aqueous lactic acid). Demineralized water (956 g) was added slowly. The
aqueous solution had the following properties:

(d) The aqueous binder solution was evaluated by cathodic electrodeposition as described
in Examples 21 to 30. The cured films (thickness 20-22 micrometer) were smooth and
glossy; salt spray resistance 8-10 mm loss from scratch.
Example 32
[0050] Binder with sulphanilamide and trimellitic anhydride.
(a) Polyether D (283.2 g; 0.6 epoxy equivalent), sulphanilamide (34.4 g; 0.2 mole)
and diethanol amine (21.0 g; 0.2 mole) were dissolved in dioxane (148 g) at 70-80
C, the mixture was kept at 1150C for 3 hours when analysis for (epoxy + N) indicated complete conversion of epoxy.
Trimellitic anhydride (19.2 g; 0.1 mole) and glycidyl ester C10E (50 g; 0.2 mole)
were added and the mixture was kept at 115°C for 2

hours. Analysis for epoxy+N indicated no further reaction (complete conversion of
epoxy). The dioxane was removed in vacuum, and ethylene glycol monobutyl ether was
added to make a solution with 74 %w solids.
(b) An aqueous binder containing 10 %w of the resinous adduct was prepared by adding
hexamethoxymethylmelamine (5.7 g) and lactic acid (2.0 g of 90 %w aqueous acid; 0.02
acid equivalent) to 70 g of the binder solution of (a) and adding slowly demineralized
water (440 g). The milky-blue aqueous solution had pH 3.8; neutralization degree 40%,
no visible change after 4 weeks at 40°C.
(c) The aqueous binder solution was evaluated by cathodic electrodeposition as described
in Examples 21 to 30. The cured films (25 micrometer) were smooth and glossy; the
impact resistance (Erichsen reverse) was > 90 kgcm () 9 Nm), the methylethyl ketone
resistance 50 double rubs, and the salt spray resistance 5-10 mm from scratch.
Example 33
[0051] A pigmented binder.
(a) An adduct of 1,6-diamino hexane and glycidyl ester C10E was prepared as in Example
31 (a).
(b) Polyether D (2832 g; 6 epoxy equivalents) was dissolved in ethylene glycol monobutyl
ether (1432 g) at 120°C in a reactor equipped with stirrer, reflux condensor, and
thermometer. A homogeneous mixture of diethanolamine (210 g; 2.0 mole), ethanolamine
(45.8 g; 0.75 mole), sulphanilic acid (43.3 g; 0.25 mole) and demineralized water
(50 g) was added at once, followed by the adduct prepared at (a). The mixture is kept
at 120°C for 3 hours, then more glycidyl ester C10E (186 g: 0.75 epoxy equivalent)
is added, and the mixture is kept at 120°C for another 1.5 hour. The (epoxy + N) content
is then below 1.35 meq/g solids, the acid content is 0.04 meq/g solids, and the solids
content is 72.7 %w.
(c) An aqueous binder solution (degree of neutralization about 55%) was prepared by
dissolving in 165 g of the final solution of (b): hexamethoxymethyl melamine (21.1
g) and lactic acid (8.3 g of a 90 %w lactic acid in water); then demineralized water
(395 g) was added slowly.
(d) Pigmented paint. 200 g of the solution of (c) were ballmilled with Ti02 (36 g), carbon black (2 g) and clay (2 g). A further 390 g of solution (c) and water
(620 g) were added, and the mixture further ballmilled until homogeneous. The pH was
4.7.
(e) The paint was cathodically electrodeposited onto degreased steel panels for 2
minutes at 150 to 200 V, cure was effected by stoving at 180°C for 30 minutes.
[0052] Properties of the films.

Example 34
[0053] Preparation of a "star-shaped" binder.
(a) Triethylenetetramine (146 g; 1 mole) is heated to 100°C, and glycidyl ester C10E
(500 g; 2 epoxy equivalents) is added gradually in 30 minutes while keeping the temperature
between 100 and 110oC; the mixture is further kept at 110°C for 2 hours to complete the reaction. The
product is an adduct having on average 4 NH functions per molecule.
(b) Polyether D (189 g; 0.4 epoxy equivalent) was dissolved in ethylene glycol monobutyl
ether (103 g) at 60°C. Diethanolamine (21 g; 0.2 mole) was added in 5 minutes, and
the temperature was kept at 65°C for 1 hour, then the epoxy value indicated that the
reaction was substantially completed. Adduct prepared at (a) was added (32.3 g; 0.2
NH equivalents) and the mixture was kept at 120°C for 1 hour; analysis for (epoxy
+ N) indicated that the reaction was substantially completed.
(c) 114 g of this 70 %w adduct solution was mixed with hexamethoxymethylmelamine (20
g) and lactic acid (5.3 g of 90 %w aqueous lactic acid; 53 meq acid); slow addition
of demineralized water (911 g) provided an aqueous solution (10 %w solids, 40% neutralization)
with pH 5.2.
(d) Cathodic electrodeposition (2 minutes, 150-200 V) onto degreased steel panels,
and cure (30 minutes at 180°C) provided films of very good appearance, 20 micrometers
thick, with a salt spray resistance of 5-10 mm.
Example 35
[0054] Binder with sulphanilamide, cure with phenolic resin.
(a) Polyether D (283.2 g; 0.6 epoxy equivalent) and Polyether A (111.6 g; 0.6 epoxy
equivalent) were dissolved in ethylene- glycol monobutylether (75 g) with stirring
at 75°C; the solution was cooled to 50°C. Diethanolamine (31.5 g; 0.3 mole) dissolved
in ethylene glycol monobutylether (35 g) was added, and the solution was kept at 40-450C until analysis for epoxy + N indicated complete conversion of epoxy. A solution
of sulphanilamide (25.8 g; 0.15 mole), adduct prepared in Example 31(a) (92.4 g; 0.15
mole), and 1-N, N dimethylamino-3-amino propane (15.3 g; 0.15 mole) in dioxane (51
g) was added, followed by more ethylene glycol monobutylether (79 g). The mixture
was stirred at 76-78°C for 2 hours and at 1150C for 1 hour. The residual epoxy content was zero, the solids content 70 %w.
(b) An aqueous binder solution was prepared by adding to the final solution of (a)
(71.4 g) a commercial phenolic resin ("Setaliet" 100; 12.5 g; "Setaliet" is a registered
Trade Mark) dissolved in ethyleneglycol monobutyl ether (3.2 g) and isophorone (1.6
g), and lactic acid (2.0 g of 90 %w aqueous lactic acid). Demineralized water (536
g) was added slowly.
[0055] The aqueous solution had the following properties:
(c) The aqueous binder solution was evaluated by cathodic electrodeposition as described
in Examples 21 to 30. The cured films were smooth and glossy; the acetone resistance
was good, and the salt spray resistance 10 mm loss from scratch.
1. Resinous binder of formula

wherein m is 0 on an integer of from 1 to 6, each A is the same or different tertiary
amino group, B, or each B which may be the same or different, is a group of formula:-

wherein n is 0 or an integer of from I to 10, and R is the hydrocarbon residue of
a dihydric phenol; and C, or each C which may be the same or different, is a group
derived from a compound having at least two sites capable of reacting with glycidyl
ether groups, characterized in that at least one of the groups A, B, or C is substituted
by at least one group R
1 having the formula:-

wherein R
2 is a C
6 to C
20 alkyl group.
2. Resinous binder as claimed in claim 1, characterized in that R2 is a secondary or tertiary C8 to C10 alkyl group.
3. A process for the preparation of a resinous binder as claimed in claim 1 or 2,
characterized in that the group R1 is incorporated by the reaction of (1) at least a glycidyl ester of an aliphatic
monocarboxylic acid with 7 to 21 carbon atoms per molecule and (2) a primary or secondary
amino, hydroxyl, or acidic group of a compound of formula A1-B1(̵C1-B1)̵mA1 m as hereinbefore defined, or at least one of its components.
4. A process as claimed in claim 3, characterized in that the compound of formula
A1-B1(̵C1-B1)̵mA1 is reacted with the glycidyl ester and a cyclic carboxylic acid anhydride.
5. A process as claimed in claim 3, characterized in that the resinous binder is prepared
by the reaction, in one or more stages, of
(a) a secondary monoamine,
(b) a glycidyl ether of a dihydric phenol, and
(c) a compound having at least 2 sites capable of reacting with glycidyl ether groups,
and
(d) at least the glycidyl ester, in amounts such that the number of epoxy equivalents
of the diglycidyl ether (b) is substantially equal to the number of reactive sites
of (a) and (c), or to the number of reactive sites of (a) and a reaction product
(e) of (c) and (d), the reaction product (e) having at least 2 sites capable of reacting
with glycidyl ether groups.
6. A process as claimed in claim 5, characterized in that component (a) is a di(hydroxyalkyl)amine.
7. A process as claimed in claim 5 or 6, characterized in that component (c) has as
reactive sites one or more primary or at least 2 secondary amine groups per molecule.
8. A process as claimed in claim 7, characterized in that component (c) is a mixture
of (1) a mono alkanol amine, (2) a di secondary amine, and (3) a carboxyl or sulphonyl
substituted primary monoamine.
9. A process as claimed in claim 8, characterized in that component (c) (3) is sulphanilic
acid.
10. Thermosetting coating composition, comprising a resinous binder as claimed in
claim 1 or 2, or prepared according to any of claims 3 to 9, characterized in that
at least 20% of the amino groups of the binder are neutralized by an acid.