Note: Descriptions are shown in the official language in which they were submitted.
L~20~0
33
TITLE: WATER DISPERSED RUST I~HIBITVE COATING COMPOSITIONS
Field of the Invention
This invention relates to water dispersed coating
compositions capable of irreversibly forming hardened,
corrosion inhibitive coatings or films. More particularly,
this invention relates to protective water dispersed film
forming compositions comprising in intimate admlxture, a
film forming organic polymer and a non-Newtonian colloid
disperse system Articles of manufactures wherein metallic
surfaces are coated with such film forming compositions also
form a part of this invention.
Background of the Invention
The corrosion of metal surfaces is of obvious eco-
nomic significance in many industrial applications and, as a
consequence, the inhibition of corrosion is a matter of
prime consideration. It is of particular significance to
users of steel and other ferrous alloys. The corrosion of
such ferrous metal alloys is largely a matter of rust forma-
tion which in turn involves the overall conversion of the
2G free metal to its oxides.
The theory which best explains such oxidation of
ferrous metal articles postulates the essential presence of
both water and oxygen. Even minute traces of moisture are
sufficient, according to this theory, to induce dissolution
of the iron therein and the formation of ferrous oxide until
the water becomes saturated with ferrous ions. The pr~sence
of oxygen causes oxidation of the resulting ferric hydroxide
whicn settles out of solution and is ultimately converted to
ferric oxide or rust.
~5~
--2--
The above sequence of reactions can be prevented
or at leas-t to a large measure inhibited, by relative im-
permeable coatings or films which have the effect of ex-
cluding moisture and/or oxygen from contact with the metal
5 surface. Sucn coatings are often exposed to high humidity,
corrosive atmosphere, etc., and to the extent that these
coatings or films are penetrated or otherwise harmed by such
influences they become inefective for the desired purpose.
It is also important that such coatings adhere tightly to
lO the metal surface and resist flaking, crazing, blistering,
powdering and other forms of loss of adhesion. A satisfac-
tory corrosion-proofing coating or film then, must have the
ability to resist weathering, high humidity, and corrosive
atmospheres such as salt-laden mist or fogs, air contaminated
15 with industrial wastes, road dirt, calcium chloride, etc ,
so that the protective coating or film is maintained on
most, if not all, of the metal surface
The corrosion of metal sufaces is of particular
economic concern to owners and manufacturers of automotive
20 vehicles. For instance, every car owner is aware of the
corrosion which begins on the inner or underside of auto-
mobile bodies such as inside rocker panels, fender wells,
headlight assemblies and door panels. The corrosive rate is
especially high in certain geographic areas which are sub-
25 jected to severe weather during the winter months neces-
sitating the use of sand, salt, calcium chloride, cinders,
etc., to maintain roads in usable condition. Under these
conditions, it generally is only a matter of time before the
relatively light gauge automotive body steel is completely
30 converted to ferric oxide or rust. When this point is
reached, the high quality exterior finishes flake off and
reveal tne metal destruction which has occurred to the body
of the vehicle.
Automotive manufacturers have waged a constant
35 battle against such body corrosion. Mastics and sealers
have been used extensively as physical barriers to corrosive
agents, and corrosion inhibiting primers have been used on
underbody surfaces when they do not lnterfere with produc-
5~3~
~ion line welding operations. When possible, zinc coatedgalvanized steel is used in substantial amounts to produce
many body components directly exposed to corrosive agents.
These efforts and many others, however, have onl~ reduced
underbody corrosion problems; the problem remains. The
asphaltic mastic undexcoatings failed to give the desired
permanent protection against corrosion since on hardening
due to age, these coatings would crack and lose adhesion,
especially when exposed to low ambient temperatures.
Corrosion inhibiting paints have also been utilized
as underbody coatings, but these are not particularly desir-
able because of the degree of metal preparation required
prior to their application.
It is therefore, an object of this invention to
pxovide novel rust inhibitive water dispersed coating compo-
sitions for the protection of metals.
It is also the object of this invention to provide
novel rust-inhibitive coating compositions which composi-
tions may be easily and inexpensively applied to metal
surfaces.
It is also the object of this invention to provide
novel rust lnhibitive coating compositions which can be
applied to such metal surfaces in the form of water dis-
persed coating compositions.
These and o~her objects of the invention will
become apparent from a reading of this specification.
Summary of the Invention
The above objects are attained in accordance with
the present invention by providing water dispersed coating
compositions which coalesce at drying temperatures into
hardened, rust-inhibitive coatings or films said water
dispersed compositions comprising
(A) at least one film forming organic polymer
(B) at least one non-Newtonian colloidal disperse
system comprising (1) solid, metal containing colloidal par-
ticles, (2) a liquid dispexsing medium and (3) an organic
compound, tne molecules of which contain a hydrophobic
portion and at least one polar substituent said disperse
system being characterized by having a base neutraliæation
number of ~bout 7.~ or less.
lS~
--4--
Detailed Descr ption of the Invention
The water dispersed coating compositions of the
present invention are comprised of two major, essential in-
gredients. The first of these is a film forming, organic
polymer, component (A). Representative classes of suitable
film forming organic polymers suitable for use in the
coating compositions of the present invention include poly-
olefins, polyamides, acrylics, polystyrenes, polyethers,
polyfluorocarbons, polymercaptans, polyesters, polymethanes,
acetal resins, polyterpenes, phenolics, cellulosics, melamine
resins, furane resins, alkyd resins, silicone resins, natural
resins, mixtures of natural resins, mixtures of natural and
synthetic resins and the like. These classes of resins are
well known as evidenced by such prior art publications as
Modern Plastics Encyclopedia, Vol. 56, No. lOA (1979-1980),
McGraw-Hill Publications. This publication contains many
illustrative examples falling within the above classes of
polymers including cellulosics such as cellulos~ nitrates,
cellulose acetates, cellulose proprionates, cellulose buty-
rates, ethyl cellulose and the like; and mixed ester cellu-
losics such as cellulose acetate butyrate and the like;
polyolefins such as polyethylene, polypropylene, polybu-
tenes, polyisobutylenes, ethylene-propylene copolymers and
ethylene-propylene copolymers containing up to 3 weight
percent of a diolefin such as isoprene and butadiene; poly-
halo olefins such as polytetrafluoroethylenes, polychloro
trifluoroethylenes and the like; polyamides including poly-
coprolactum, polyhexamethylenediamide, polyhexamethylene-
sebacamide and polyamide derived bassylic acid or tere-
phthalic acid and alkylene diamines such as hexamethylenediamine, 2,2,4- or 2,4,4-trimethylhexamethylene diamine;
polystyrene and styrene containing copolymers and terpoly-
mers such as copolymers of styrene and acrylonitrile or
terpolymers of styrene, 1,3-butadiene and acrylonitrile;
copolymers of vinyl chloride, vinylidene chloride, and vi-
nyl esters such as vinyl acetate; polyvinyl acetates such as
polyvinyl acetyl per se and polyvinyl butyral; urea formal-
dehyde resins; melamine-formaldehyde resins; phenol-formal-
dehyde resins, phenol-fufural resins and the like.
A more preferred class of fllm formlng organlc
polymers useful in the coating composltlons of the present
inventlon are the acryllc polymers such as the polymers and
5 copolymers of acrylic and methacrylic acids and copolymers
derlved from mlxtures of two or more acryllc type monomers
selected from the group conslsting of esters of acrylic and
methacryllc aclds wherein the alcohollc molety ls derlved
from (1) alkanols of one to about 20 carbon atoms, e.g.
10 methanol, ethanol, butanol, octanol, lauryl alcohol, stearyl
alcohol, ethylene glycol, polyethylene glycol and the like;
(2) halo-alkanols such as 2-chloroethanol; (3) aminoalkanols,
e.g., 2-(tert-butylamino) ethanol and 2-diethylamino-ethanol;
(4) alkoxy alkanols exempllfied by 2-methoxy-ethanol, 2-
15 ethoxy-ethanol and 3-ethoxy-propanol; and (5) cycloalkanols
such as cyclohexanol and cyclopropanol and the corresponding
amides and polyamides of these acids including acrylamides
and methacrylamides, alkylene bis-amides and N-substituted
amides such as N-tert-butylacrylamide. Further representa-
20 tive examples of suitable acrylic polymers usefu] as compo-
nent (A) of the invention are those derived from mixtures of
at least one of the above described acrylic or methacrylic
acid esters and amldes wlth at least one monomer containing
vinyl double bond unsaturation such as for example, vinyl
25 esters as represented by vinyl acetate, vinyl proprlonate,
vinyl butyrates, vinyl benzoate and the like; styrene, ring-
substituted alkyl and alkoxy styrene such as, for example,
the ortho-, meta- and para-methyl and ethyl styrenes, the
meta- and para-isopropyl styrenes, para-butyl styrene, para-
30 heptyl styrene, para-cyclohexyl styrene, the ortho-, meta-
and para-methoxy and ethoxy styrenes, 2,6-dimethoxy styrene
and 2-methoxy-isopropyl styrene and the like, alpha methyl
styrene and ring-substituted alpha methyl styrene such as,
for example, 4-methyl alpha methyl styrene, 4-isopropyl
alpha methyl styrene, 2,3-dimethyl alpha methyl styrene and
the like. Preferred acrylic polymers for use as component
Jl.~ r~3
--6--
(A) of the coating compositions of this inventlon are those
derived from mixtures of two or more esters of acryLic and
methacrylic acids wherein the alcohol moiety is derived from
Cl to C4 alkanols and amides of acrylic and methacryllc
5 acids and one or more of such esters and amides with one or
more monomers containing vinyl double bond unsaturation such
as the above described substituted and unsubstituted sty-
renes and alpha methyl styrenes. Most preferred acrylic
polymers are those dexived Erom two or more of the lower C
10 to C4 alkyl esters of acrylic acid and methacrylic acid or
one or more of such esters with styrenes. A most preferred
class of polymers for use in this invention has been found
to be those derived from the lower Cl to C4 esters of acrylic
acid or methacrylic acid and styrene.
The film forming organic polymers suitable for use
in the present invention can be either water soluble or
water insoluble~ When the organic polymers are water in-
soluble, they will generally be present in the water phase
in the form of disperse particles ranging in size from 0.1
20 to about 10.0 microns. ~ more preferred range is from about
0 5 to about 5.0 microns.
In general, the amount of the film forming organic
polymer useful in the coating compositions of this invention
will range from about 10.0 to about 65.0 weight percent
25 based on the total weight of the particular coating composi-
tion. A more preferred range for the polymer is from about
15.0 to about 35.0 weight percent and a most preferred range
is from about 22.0 to about 28.0 weight percent.
The second major essential ingredient of the
coating compositions of the present invention is the non-
Newtonian colloid disperse system, component (B) comprised
of overbased salts of organic acids, said non-Newtonian
colloidal disperse systems having a base neutralization
number, as determined against phenolphthalein, ranging from
0 to about 7Ø
The colloidal disperse systems useful in the pre-
paration of the aqueous coating compositions of this inven
tion exhibit nor-Newtonian flow characteristics, i.e. thixo-
--7--tropic characteristics. The apparent viscosity of a thixo-
tropic material depends on both the rate of shear and length
of time in which said shearing action is applied. The
rheological characteristics of such materials are more fully
ciscussed in such standard texts as s. Jirgensons and M.E.
Straumonis, A Short Textbook on Colloidal Chemistry (2nd
Ed.), The l~acMillan Co., N.Y. 1962, particularly pages 178
through 183.
The terminology "disperse system" as used in the
specification and claims is a term of art generic to col-
loids or colloidal solutions, e.g., "any homogeneous medium
containing dispersed entities of any size and state," Jirgen-
sons and Straumanis, supra. However, the particular dis-
perse systems of the present invention form a subgenus
within this broad class of disperse system, this subgenus
being characterized by several important features.
This subgenus comprises those disperse systems
wherein at least a portion of the particles dispersed
therein are solid, metal-containing particles formed in
situ. At least about 10% to about 50% are particles of this
type and preferably, substantially all of said solid par-
ticles are formed in situ.
So long as the solid particles remain dispersed in
the dispersing medium as colloidal particles the particle
size is not critical. Ordinarily, the particles will not
exceed 5000 A. However, it is preferred that the maximum
unit particle size be less than about 1000 A. In a par-
ticularly preferred aspect of the invention, the unit par-
ticle size is less than about 400 A. Systems having a unit
particle size in the range of 30 A. to 200 A. give excellent
results. The minimum unit particle size is at least 20 A.
and preferably at least about 30 A.
The language "unit particle size" is intended to
designate the average particle size of the solid, metal-con-
taining particles assuming maximum dispersion of the indi~vidual particles throughout the disperse medium. That is,
the unit particle is that particle which corresponds in size
--8--
-to the average slze of -the me-tal-containing particles and is
capable of independent existence within the disperse system
as a discrete colloidal particle. These metal-containing
particles are found in two forms in the disperse systems.
Individual unit particles can be dispersed as such through
out the medium or unit particles can form an agglomerate, in
combination with other materials (e.g , another metal-con-
taining particle, the disperse medium, etc.) whlch are
present in the disperse systems. These agglomerates are
dispersed through the system as "metal-containing particles."
Obviously, the "particle size" of the agglomerate is sub-
stantially greater than the unit particle size. Further-
more, it is equally apparent that this agglomerate size is
subject to wide variations, even within the same disperse
system. The agglomerate size varies, for example, with the
~egree of shearing action employed in dispersing the unit
particles. That is, mechanical agitation of the disperse
system tends to break down the agglomerates into the indi-
vidual components thereof and disperse these individual
components throughout the disperse medium. The ultimate in
dispersion is achieved when each solid, metal-containing
particle is individually dispersed in the medium. Accord-
ingly, the disperse systems are characterized with reference
to the unit particle slze, it being apparent to those skilled
in the art that the unit particle size represents the aver-
age size of solid, metal-containing particles present in the
system which can exist independently The average particle
size of the metal-containing solid particles in the system
can be made to approach the unit particle size value by the
application of a shearing action to the existent system or
during the formation of the disperse system as the particles
are being formed in situ. It is not necessary that maximum
particle dispersion exist to have useful disperse systems.
The agitation associated with homogenization of the over-
based material and conversion agent as hereinafter describedproduces sufficient particle dispersion.
sasically, tne solid, metal-containing particles,
the first component of the colloidal disperse systems, are
~ D~
_9_
in tne forrn of metal salts of inorganic acids and low mole-
cular weight organic acids, hydrates thereoE, or mixtures of
these~ These salts are usually the alkali and alkaline
earth metal forma-tes, acetates, carbonates, hydrogen car-
S bonates, hydrogen sulfides, sulfites, hydrogen sulfites, andhalides, particularly chlorides. In other words, the metal-
containing particles are ordinarily particles of metal
salts, the uni-t particle is the individual salt particle and
the unit particle size is the average particle size of the
salt particles which is readily ascertained, as for example,
by conventional X-ray diffraction techniques. Colloidal
disperse systems possessing particles of this type are
sometimes referred to as macromolecular colloidal systems.
Because of the composition of the colloidal dis-
perse systems, the metal-containing particles also exist as
components in micellar colloidal particles. In addition to
the solid metal-containing particles and the disperse me-
dium, the colloidal disperse systems useful in this inven-
tion are characterized by a third essential component, one
which is soluble in the medium and contains in the molecules
thereof a hydrophobic portion and at least one polar sub-
stituent. This third component can orient itself along the
external surfaces of the above metal salts, the polar groups
lying along the surface of these salts with the hydrophobic
portions extending from the salts into the disperse medium
forming micellar colloidal particles. These micellar col-
loids are formed through weak intermolecular forces, e.g.,
Van der Waals forces, etc. Miscellar colloids represent a
type of agglomerate particle as discussed thereinabove.
Because of the molecular orientation in these micellar
colloidal particles, such particles are characterized by a
metal containing layer (i.e., the solid metal-containing
particles and any metal present in the polar substituent of
the third component, such as the metal in a sulfonic or
carboxylic acid salt group), a hydrophobic layer formed by
the hydrophobic portions of the molecules of the third
component and a polar layer bridging said metal-containing
~ t~j~
--10--
layer and sal~ hydrophobic layer, said polar brldying layer
comprising the polar substituents of the thlrd component of
the system, e.g., the
o
_ ~-o--
group if the third component is an alkaline earth metal
petrosulfonate.
The second component of the colloidal disperse
system is the dispersing medium. The identity of the medium
is not a particularly critical aspect of the invention as
the medium primarily serves as the liquid vehlcle in which
solid particles are dispersed. The disperse medium will
normally consist of inert organic liquids, that is, liquids
which are chemically substantially inactive. Representative
liquids include the alkanes and haloalkanes of five to
eighteen carbons, polyhalo and perhaloalkanes of up to about
slx carbons; the cycloalkanes of five or more carbons; the
corresponding alkyl and/or halo-substituted cycloalkanes;
the aryl hydrocarbons; the alkylaryl hydrocarbons; -the
haloaryl hydrocarbons; ethers such as dialkyl ethers; alkyl
aryl ethers; cycloalkyl ethers; cycloalkylalkyl ethers;
alkanols, alkylene glycols, polyalkylene gylcols and esters
of said glycols; alkyl ethers of alkylene glycols and poly-
alkylene glycols; alkanol amines, amines and liquid poly-
amines; dibasic alkanoic acid diesters; silicate esters;
glycerides;epoxidized glycerides; aliphatic, aromatic es-
ters; petroleum waxes; slack waxes (non-refined paraffinic-
based petroleum fractions); synthetic hydrocarbon waxes and
chlorinated waxes. Specific examples include petroleum
ether, Stoddard Solvent, pentane, hexane, octane, isooctane,
undecane, tetradecane, cyclopentane, cyclohexane, isopro-
pylcyclohexane, l,4-dimethylcyclohexane, cyclooctane, ben-
zene, toluene, xylene, ethyl benzene, tert-butyl-benzene,
nalobenzenes especially mono~ and polychlorobenzenes such as
chlorobenzene per se and 3,4-dichlorotoluene, mineral oils,
35 n-propy'e-tner, isopropylether, isobutylether, n-amylether,
t~ 3
methyl-n-amyletner, cyclohexylether, ethoxycyclo~exane,
methoxybenzene, isopropoxybenzene, p-methoxytoluene, me-tha-
nol, ethanol, propanolf lsopropanol, hexanol, n-octyl alco-
hol, n-decyl alcohol, alkylene glycols such as ethylene
glycol and propylene glycol, diethyl ketone, dipropryl
ketone, methyl-butyl ketone, acetophenone, l,2-difluoro-
tetrachloroethane, dichlorofluoromethane, 1,2-dibromote-tra-
fluoroethane, trichlorofluoromethane, l-chloropentane, 1,3-
dichlorohexane, formamlde, dimethylformamide, acetamide,
~imethylacetamide diethylacetamide, propionamide, diisooctyl
a7elate, ethylene glycol, polypropylene glycols, hexa-2-
ethylbutoxy disiloxane, etc.
Also useful as dispersing medium are low molecular
weight liquid polymers, generally classlfied as oligomers,
which include the dimers, tetramers, pentamers, etc. Illus-
trative of this large class of materials are such liquids as
the propylene tetramers, isobutylene dimers, and the like.
From the standpoint of availability, cost, and
performance, tne alkyl, cycloalkyl, and aryl hydrocarbons
represent a preferred class of disperse mediums. Liquld
petroleum fractions represent another preferred class of
disperse mediums. Included within these preferred classes
are benzenes an~ alkylated benzenes, cycloalkanes and
alkylated cycloalkanes, cycloalkenes and alkylated cyclo-
alkenes such as found in naphthene-based petroleum frac-
tions, and the alkanes such as found in the paraffinic-based
petroleum fractions. Petroleum ether, naphthas, mineral
oils, Stoddard Solvent, toluene, xylene, etc , and mixtures
thereof are examples of economical sources of suitable inert
organic liquids which can function as the disperse medium in
the colloidal disperse systems of the present invention.
The most preferred disperse systems are those con-
taining at least some mineral oil as a component of the dis-
perse medium. However, in this preferred class of systems,
it is desirable that mineral oil comprise at least about 1~
by weight of the total medium, and preferably at least about
5O by weight. Those mediums comprising at least 10~ by
weigh-t mineral oil are especially useful. As will be seen
nerelnaf-ter, mineral oil can serve as the exclusive disperse
medium.
As mentioned hereinabove in addition to the solid,
metal-containing particles and the dlsperse medium, the dis-
perse systems employed in -the aqueous disperse compositions
of this invention require yet a third component. This third
component is an organic compound which is soluble in the
disperse medium, and the molecules of which are character-
ized by a hydrophobic portion and at least one polar subs-ti-
tuent.
The hydrophobic portion of the organic compound is
a hydrocarbon radical or a substantially hydrocarbon radical
containing at least about twelve aliphatic carbon atoms.
1~ Usually the hydrocarbon portion is an aliphatic or cycloal-
iphatic hydrocarbon radical although aliphatic or cycloall-
phatic substituted aromatic hydrocarbon radicals are also
suitable. In other words, the hydrophobic portion of the
organic compound is the residue of the organic material
~0 which is overbased minus its polar substituents. For exam~
ple, if the material to be overbased is a carboxylic acid,
sulfonic acid, or phosphorus acid, the hydrophobic portion
is the residue of these acids which would result from the
removal of the acid functions. Similarly, if the material
to be overbased is a phenol, a nitro-substituted polyolefin,
or an amine, the hydrophobic portion of the organic compound
is the radical resul-ting from the removal of the hydroxyl,
nitro, or amino group respectively. It is the hydrophobic
portion of the molecule which renders the organic compound
soluble in the solvent used in the overbasing process and
later in the disperse medium.
In the examples set forth below~ the third compo-
nent of the disperse system (i.e., the organic compound
which is soluble in the disperse medium and which is charac-
3~ terized by molecules having a hydrophobic portion and apolar substituent) is calcium petrosulfonate,
O O
I, 11
Rl-S-O-Ca-O-S-R
O O
~ D~ "~
-13-
wherein R~ is the residue of the petrosulfonlc acld In
thls case, the hydrophoblc por-tlon of the molecule is the
hydrocarbon molety of pe-trosulfonlc, l.e.,--Rl. The polar
substituent is the metal salt moiety,
O O
-~-O-Ca-O-~-
11 11
O O
Obviously, the polar portion of these organic com-
pounds are the polar substituents such as the acid salt
moiety discussed above. When the material to be ovexbased
contains polar substituents which will react with the basic
metal compound used in overbasing, for example, acid groups
such as carboxy, sulfino, hydroxysulfonyl, and phosphorus
acid groups or hydroxyl groups, the polar and phosphorus
acia groups or hydroxyl groups, the polar substituent of the
thlrd component is the polar group formed from the reaction.
Thus, the polar substi-tuent is the corresponding acid metal
salt group or hydroxyl group metal derivative, e.g., an
alkali or alkaline earth metal sulfonate, carboxylate,
sulfinate, alcoholate, or phenate.
On the othex hand, some of the materlals to be
overbased con-tained polar substituents which ordinarily do
not react with metal bases. These substituents include
nitro, amino, ketocarboxyl, carboalkoxy, etc. In the dis-
perse systems derived from overbased materials of this type
the polar substituents ln the third component are unchanged
from their identity ln the material which was originally
overbased.
The identity of the third component of the dis-
perse system depends upon the identity of the starting
materials (i.e., tne material to be overbased and the metal
base compound) used in preparing the overbased materials.
Once tne identity of tnese starting materials is known, the
identity of the third component in the colloidal disperse
system is automatically established Thus, from the iden-
tity of the original material, the identity of the hydro-
phobic portion of the third component in -the disperse system
--L'~-
is readily establisnecl as being the resi.due of that rnaterials
minus the polar substituen-ts attached thereto. The identlty
of the polar subs-tituents on the third component is estab-
lished as a mat-ter of chemistry. If the polar groups on the
ma-terial tc be overbased unclergo reaction with the metal
base, for example, if they are acid functions, hydroxy
groups, etc., the polar subs-ti-tuent in the final product
will corresponà to the reaction product of the original
substituent and the metal base. On the other hand, if the
polar substituent in the material to be overbased is one
which does not reac-t with metal bases, then the polar sub-
stituent of tne third component is the same as the original
substituent
As previously mentioned, this third component can
orient itself around -the metal-containing particles~to form
micellar colloidal particles. Accordingly, it can exist in
the disperse system as an individual liquid component dis-
solved in the disperse medium or i-t can be associa-ted with
the metal-containing particles as a component of micellar
coll.oidal particles.
Broadly speaking, the non-Newtonian colloidal dis-
perse systems useful in preparing the compositions of the
present invention are prepared by a two step process wherein
a first step single phase homogeneous, Newtonian disperse
system of an "overbased," "superbased," or "hyperbased,"
organic compound is homogenized with a "conversion agent",
usually an active nydrogen containing compound, to convert
tnis disperse system to one exhibiting non-New-tonian flow
characteristics ana tnen, in a second step, treating these
conver-ted systems with additional metal--containing reactant,
and aciaic material to increase the metal ratio and reduce
tne base neutralization numbers of the final disperse
system. This treatment converts the single phase systems
into the non-Newtonian colloidal disperse systems utilized
3~ in conjunction with the film forming compositions of this
invention.
Tne terms "overbased," "superbased," and "hyper-
based," are terms of art which are generic to well known
-15-
classes of metal-containing materials which have generall~
been employed as detergents and/or dispersants in lubri-
cating oil compositions. These overbased materials have
also been referred to as "complexes," "metal complexes,"
5 "high-me-tal containing salts," and the like. Overbased
materials are characterized by a metal content in excess of
that which would be present according to the stoichiometry
of the metal and the particular organic compound reacted
with the metal, e.g., a carboxylic or sulfonic acid. Thus,
if a monosulfonic acid,
o
R - ~ - OH
is neutralized with a basic metal compound, e.gO, calcium
hydroxide, the "normal" metal salt produced will contain one
equivalent of calcium for each equivalent of acid, i.e~,
O O
R - S-- O- Ca - O- S - R
O O
However, as is well known in the art, various processes are
available which result in an inert organic liquid solution
of a product containing more than the stoichiometric amount
of me-tal. The solutions of these products are referred to
herein as overbased materials. Following these procedures,
the sulfonic acid or an alkali or alkaline earth metal salt
thereof can be reacted with a metal base and the product
will contain an amoun-t of metal in excess of that necessary
to neutrali~e the acid, for example, 4.5 times as much metal
as present in the normal salt or a metal excess of 3.5
equivalents. The actual stoichiometrlc excess of metal can
vary considerably, for example, from about 0.1 equivalent to
about 30 or more equivalents depending on the reactions, the
process conditions, and the like. These overbased materials,
employed as intermediates for preparing the non-Newtonian,
aisperse systems usea in the present invention, will contain
from about 3.5 to about 30 or more equivalents of metal for
each equivalent of material which is overbased.
In the present specification the term "overbased"
s~ )
--16--
is used to designa~e materials containiny a stoichiornetric
excess of metal and is, therefore, inclusive of those ma-
terials which have been referred to in the art as overbased,
superbased, hyperbased, etc., as discussed supra.
The terminology "metal ratio" is used in the prior
art and herein to desiynate tne ratio of the -to-tal chemical
equivalents of the metal in the overbased materlal (e.g., a
metal sulfonate or carboxylate) to the chemical equivalents
of the metal in the produc-t which would be expected to
result in the reaction between the oryanic material to be
overbased (e~g., sulfonic or carboxylic acid) and the metal-
containing reac-tan-t (e.g., calcium hydroxide, barium oxide,
etc.~ according to the known chemical reactivity and stoichio-
metry of the two reactants. Thus, in the normal calcium
sulfonate discussed above, the metal ratio is one, and in
the overbased sulfonate, the metal ratio is 4.5~ Obviously,
if there is present in the material to be overbased more
than one compound capable of reacting with the me~al, the
"metal ratio" of the pxoduct will depend upon whether the
number of equivalents of metal in the overbased product is
compared to the nu~ber of equivalents expected to be present
for a given single component or a combination of all such
components.
Generally, these intermediate overbased materials
are prepared by treating a reaction mixture comprising (1)
the organic material to be overbased, (2) a reaction medium
consisting essentially of at least one inert, organic sol-
vent for said organic material, (3) a stoichiometric excess
of a metal base, and (4) a promoter with an acidic material.
The methods for preparing tne overbased ma~erials as well as
an extremely diverse group of overbased materials are well
known in the prior art and are disclosed, for example in the
following U.S. patents: 2,616,904; 2,616,905; 2,616,906;
2,616,~11; 2,616,~4; 2,616,925; 2,617,049; 2,695,910;
2,723,234; 2,723,235; 2,723,236; 2,760,970; 2,767,164;
~,767,209; 2,777,~74; 2,798,852; 2,839,470; ~,856,359;
~,859,360; 2,~56,361; 2,861,951; 2,883,340; 2,915,517;
- L7 --
2,959,55]; 2,968,G~2; 2,971,0L~; 2,989,~G3; 3,001,981; 3,027,325;
3,070,581; 3,108,960; 3,1~7,232; 3,133,019; 3,146,201; 3,152,991;
3,155,616; 3,170,880; 3,170,881; 3,172,855; 3,19~,823; 3,223,630;
3,232,883; 3,2~2,079; 3,2~2,080; 3,250,710; 3,256,186; 3,27~,135.
These patents disclose processes, ma-terials which can be overbased,
suitable me-tal bases, promoters, and acidic ma-terials, as well as a
variety of specific overbased products useEul in producing -the
disperse sys-tems of this inven-tion.
An important characteristic of -the organic materials which are
overbased is their solubility in -the particular reac-tion medium
utilized in the overbasing process. As -the reaction used
previously has normally comprised petroleum fractions,
particularly mineral oils, these organic materials have generally
been oil-soluble. However, if ano-ther reaction medium is employed
(e.g. aromatic hydrocarbons, aliphatic hydrocarbons, kerosene,
etc.) it is not essen-tial that the organic ma-terial be soluble in
mineral oil as long as it is soluble in the given reaction medium.
Obviously, many organic materials which are soluble in mineral
oils will be soluble in many of the other indicated suitable
reaction mediums. It shoulcl be apparen-t that the reaction medium
usually becomes -the disperse medium of the colloidal disperse
system or at least a componen-t thereof depending on whe-ther or not
additional inert organic liquid is added as part of the reaction
medium or the disperse medium.
Organic materials which can be overbased are generally oil-
soluble organic acids including phosphorus acids, thiophosphorus
acids, sulfur acids, carboxylic acids, thiocarboxylic acids, and
the like, as well as the corresponding alkali and alkaline ear-th
metal salts thereof. Representative examples of each of -these
classes of organic acids as well as o-ther organic acids, e.g.,
nitrogen acids, arsenic acids, etc. are disclosed along wi-th
me-thods of preparing overbased products therefrom in the above
cited paten-ts. Patent ....
3 '~ 2 ~
2,777,87~1 identifiecl oryanic acids suitable for preparing
overbased materials which can be conver-tecl to disperse
systems Eor use in the resinuous compositions of the inven-
tion. Similarly, 2,616,90~; 2,695,910; 2,767~16~; 2,7~7,209;
3,1'l7,232; 3,27'1,135; etc. disclose a variety of organlc
acids suitable for preparing overbased ma-terials as well as
representative examples of overbased products prepared from
such acids. Overbased acids wherein the acid is a phosphorus
acid, a thiophosphorus acid, phosphorus acid-sulfur acid
combination, and sulfur acid prepared from polyolefins are
disclosed in 2,883,340; 2,915,517; 3,001,981; 3jlO8,960; and
3,232,883. Overbased phenates are disclosed in 2,959,551
while overbased ketones are found in 2,798,852. A variety
of overbased materials derived from oil-soluble metal-free,
nontautomeric neutral and basic organic polar compounds such
as esters, amines, amides, alcohols, ethers, sulfides,
sulfoxides, and the like are disclosed in 2,968,6~2; 2,971,014;
and 2,989,463. Another class of materials which can be
overbased are the oil-soluble, nitro-substi-tuted aliphatic
hydrocarbons, particularly nitro-substituted polyolefins
such as polyethylene, polypropylene, polyisobutylene, etc.
~Iaterials of this type are illus-trated in 2,959,551 Like-
wise, the oil-soluble reaction product of alkylene poly-
amines such as propylene diamine or N-alkylated propylene
diamine witn formaldehyde or formaldehyde producing compound
(e g., paraformaldehyde) can be overbased. Other compounds
suitable for overbasing are disclosed in the above-cited
patents or are toherwise well-known in the art.
The organic li~uids used as the disperse medium in
the colloidal disperse system can be used as solvents for
the overbasing process.
The metal compounds used in preparing the over-
based materials are normally -the basic salts of metal in
Group l-A and Group ll-A of the Periodic Table although
other metals such as lead, zinc, manganese, etc. can be used
in the preparation of overbased materials. The anionic
portion of the salt can be hydroxyl, oxide, carbonate,
hydrogen carbonate, nitrate, sulite, hydroyen sulfite,
halide, arnide, sulfate etc. as disclosed in the above-cited
patents. For purposes of this invention the preferred
overbased materials are prepared from the alkaline earth
5 metal oxides, nydroxides, and alcoholates such as the alka-
line earth metal lower alkoxidesO The mos-t preferred non-
Newtonian colloidal disperse systems useful in preparing the
coating composltions of -this invention are -those derived
from overbased materials containing calcium and/or barium as
the metal
The promo-ters, that is, the materials which permit
the incorporation of -the excess metal into the overbased
material, are also quite diverse and well known in the art
as evidenced by the cited pa-tents. A particularly compre-
hensive discussion of suitable promoters is found in2,777,874; 2,695,910; and 2,616,904. These include -the
alcoholic and phenolic promoters which are preferred. The
alcoholic promoters include the alkanols of one to about
twelve carbon atoms such as methanol, ethanol, amyl alcohol,
octanol, isopropanol, and mixtures of -these and the like.
Phenolic promoters include a variety of hydroxy-substituted
benzenes and naph-thalenes. A particularly useful class of
phenols are the alkylated phenols of the type listed in
2,777,874, e.g , heptylphenols, octylphenols, and nonyl-
phenols. Mixtures of various promoters are sometimes used.
Suitable acidic materials are also disclosed inthe above cited patents, for example, 2,616,90~. Included
within the known group of useful acidic materials are liquid
acids such as formic acid, acetic acid, nitric acid, sul-
furic acid, hydrochloric acid, hydrobromic acid, carbamicacid, substi-tuted carbamic acids, etc. Acetic acid is a
very useful acidic material although inorganic acidic materials
such as HCl, SO2, SO3, CO2, H2S, N203, etc. are ordinarily
employed as the acidic materials The most preferred acidic
materials are carbon dioxide and acetic acid.
In preparing -the intermediate overbased materials,
the material to be overbased, an inert, non-polar, organic
~ 3
-2~-
solvent tnerefor, the me-tal base, the promoter, and -the
acidic ma-terials are brought together and a chemical reac-
tion ensues. The exact nature of the resulting overbased
product is not known. However, it can be adequately de-
scribed for purposes of the present specification as asingle phase homogeneous mixture of the solvent and (1)
ei-ther a metal complex formed from the metal base, the
acidic material, and the material being overbased and/or (2)
an amorphous metal salt formed from the reaction of the
acidic materials with the metal base and the ma-terial which
is said to be overbased. Thus, if mineral oil is used as
the reaction medium, petrosulfonic acid as the material
which is overbased, Ca(OH) 2 as the metal base, and carbon
dioxide as the acidic material, the resulting overbased
material can be described for purposes of this invention as
an oil solution of either a metal containing complex of the
acidic material, the metal base, and the petrosulfonic acid
or as an oil solution of amorphous calcium carbonate and
calcium petrosulfonate. Since the overbased materials are
well-known and as they are used merely as intermediates in
-the preparation of the disperse systems employed herein, the
exact nature of the materials is not critical to the present
invention.
The temperature at which the acidic material is
contacted with the remainder of the reaction mass depends to
a large measure upon the promoting agent used. With a
phenolic promoter, the temperature usually ranges from about
80C. to 300C., and preferably from about 100C. to about
200C. When an alcohol or mercaptan is used as the pro-
moting agent, the temperature usually will not exceed -the
reflux temperature of the reaction mixture and preferably
will not exceed about 100C.
In view of the foregoing, it should be apparent
that the overbased materials may retain all or a portion of
the promoter. That is, if the promoter is not volatile
(e.g., an alkyl phenol) or otherwise readily removable from
the overbased material, at least some promoter remains in
-21-
the overbasecl product. Accordingly, the disperse sys-tems
made from such products may also contain the promoter. The
presence or absence of -the promoter in the overbased ma-
terials used to prepare the disperse system and likewise,
the presence or absence of the promoter iIl -the colloidal
~isperse systems themselves does not represen-t a critical
aspect of the invention. Obviously, it is within the sklll
of the art to select a volatile promoter such as a lower
alkanol, e.g., methanol, ethanol, etc., so that the promoter
can be readlly removed prior to forming the disperse system
or thereafter.
A preferred class of overbased materials used as
starting materials in the preparation of the disperse sys-
tems of the present invention are the alkaline earth metal
overbased oil-soluble organic acids, preferably those con-
taining at least twelve aliphatic carbons although the acids
may contain as few as eight aliphatic carbon atoms if the
acid molecule includes an aromatic ring such as phenyl,
naphthyl, etc. Representative organic acids suitable for
preparing these overbased materials are discussed and iden-
tified in detail in the above-cited patents. Particularly
2,616,904 and 2,777,874 disclose a variety of very suitable
organic acids. For reasons of economy and performance,
~verbased oil-soluble carboxylic and sulfonic acids are
particularly suitable. Illustrative of the carboxylic acids
are palmitic adid, stearic acid, myristic acid, oleic acid,
linoleic acid, behenic acid, hexatriacontanoic acid, tetra-
propylene-substituted glutaric acid, polyisobutene (M.W.--
5000)-substituted succinic acid, polypropylene, (M.W.--
10,000)-substituted succinic acid, octadecyl-substituted
adipic acid, chlorostearic acid, 9-methylstearic acid,
dichlorostearic acid, stearylbenzoic acid, eicosane-sub-
stituted naphthoic acid, dilauryl-decahydro naphthalene
carboxylic acid, didodecyl-tetralin carboxylic acid, di-
octylcyclohexane carboxylic acid, mixtures of these acids,their alkali and alkaline earth metal salts, and/or their
anhydrides. Of the oil-soluble sulfonic acids, the mono-,
-22-
di-, and tri-al.iphatic hydrocarbon substituted aryl sulfon.ic
acids and the pe-troleum sulfonic acids (petrosulfonic
acids) are particularly preferred. Illustrative examples of
suitable sulfonic acids include mahogany sulfonic acids,
petrolatum sulfonic acids, monoeicosa.ne-substituted naph-
thalene sulfonic acids, dodecylbenzene sulfonic acids, di-
dodecylbenzene sulfonic acids, dinonylbenzene sulfonic
acids, cetylchlorobenzene sulfonic acids, dilauryl beta-
naphthalene sulfoni.c acids, the sulfonic acld derived by the
treatment of polyisobutene having a molecular weight of 1500
with chlorosulfonic acid, ni-tronaphthalenesulfonic acid,
paraffin wax, sulfonic acid, cetylcyclopentane sulfonic
acid, lauryl-cyclohexanesulfonic acids, polyethylene (~.W.--
750) sulfonic acids, etc. Obviously, it is necessary that
the size and number of aliphatic groups on the aryl sulfonic
aclds be sufficient to render the acids soluble. ~ormally
the aliphatic groups will be alkyl and/or alkenyl groups
such that the total number of aliphatic carbons is at least
twelve.
Within this preferred group of overbased car-
boxylic and sulfonic acids, the barium and calcium overbased
mono-, di-, and tri-alkylated benzene and naphthalene (in-
cluding hydrogenated forms thereof), petrosulfonic acids,
and higher fatty acids are especially preferred. Illustra-
tive of the synthetically produced alkylated benzene and
naphthalene sulfonic acids are those containing alkyl sub-
sti-tuents having from 8 to about 30 carbon atoms therein.
Such acids include di-isododecyl-benzene sul.fonic acid, wax-
substituted phenol sulfonic acids, polybutene-substituted
sulfonic acid, cetyl-chlorobenzene sulfonic acid, di-cetyl
naphthalene sulfonic acid, stearylnaphtlsalene sulfonic acid,
~i-lauryldiphenylether sulfonic acid, di-cetylnaphthanlene
sulfonic acid, di-lauryldiphenylehter sulfonic acid, di-
isononylbenzene sulfonic acid, di-isooctadecylbenzenesul-
fonic acid, stearylnaphthalene sulfonic acid, and the like.The petroleum sulfonic acids are a well known art recognized
class of materials which have been used as starting ma-
terials ils preparing overbased products since -the inception
--23-
of overbasing techniques as illustrated by -the above paten-ts.
Petroleum sul:Eonic acids are obtained by -t~eating refined or
semi-refi.ned petroleurn o.ils with concentrated or fuming
sulfuric acid. These acids remain in the oil aE-ter the
settling out of sludges. These petroleum sulfonic acids,
depending on the nature of the petroleum oils from which
they are prepaxed, are oil-soluble alkane sulfonic aclds,
alkyl-substituted cycl.oaliphatic sulfonic acids includlng
cycloalkyl sulfonic acids and cycloalkene sulfonic acids,
and alkyl, alkaryl, or aralkyl substituted hydrocar~on
aromatic sulfonic acids including single and condensed
aromatic nuclei as well as partially hydrogenated forms
thereof. Examples of such petrosulfonic acids include
mahogany sulfonic acld, whit oil sulfonic acid, petrolatum
sulfonic acid, petroleum naphthene sulfonic acid, etc. This
especially preferred group of aliphatic fatty acids includes
the saturated and unsaturated higher fatty acids con-taining
from 12 to about 30 carbon atoms. Illustrative of these
acids are lauric acid, palmitic acid, aleic acid, linoletic
acid, li.nolenic acid, oleo-stearic acid, stearic acid,
myristic acid, and undecalinic acid, alpha-chlorostearic
acid, and alpha-nitrolauric acid.
As shown by the representative examples of -the
preferxed classes of sulfonic and carboxylic acids, the
acids may contain non-hydrocarbon substituents such as halo,
nitro, alkoxy, hydroxyl, and the like.
It is desirable that the intermediate overbased
materials used to prepare the non-Newtonian colloidal dis-
perse systems used in this invention have a metal ratio of
at least about 3.5 and preferably about at least 5.5~ An
especially suitable group of the preferred sulfonic acid
overbased materials has a metal ratio of at least about 7Ø
Normally the maximum metal ratio of the intermediate over-
based materials will not exceed about 30 and, i.n mos-t cases,
not more than about 20.
The overbased materials used in preparing the non-
Newtonian colloidal disperse systems utilized in the coating
-2~-
CompOSltiOnS of the invention contain frorn about 10~ to
ahout 70"~ by weignt of ~netal-containiny components. The
exac-t nature of these metal-containing components ls not
known. It is theorized that the metal base, the acidic
5 material, and -the organic material being overbased form a
metal complex, this complex being the metal-containing
component of the overbased material. On the o-ther hand, it
has also been postulated that the metal base and the acidic
material form amorphous metal compounds which are dissolved
10 in the inert organic reaction medium and the material which
is said to be overbased. The material which is overbased
may itself be a metal-containing compound, e.g., a car-
boxylic or sulfonic acid metal salt. In such a case, the
metal-containing components of the overbased material would
15 be both the amorphous compounds and -the acid salt. The
exact nature of these overbased materials is obviously not
critical in the present invention since these materials are
used only as intermediates. The remainder of the overbased
materials consist essentially of the inert organic reaction
20 medium and any promoter which is not removed from the
overbased product. For purposes of this application, the
organic materials which are subjected to overbasing are con-
sidered a part of the metal-containing components. Nor-
mally, the liquid reaction medium constitutes at least about
25 30% by weight of the reaction mixture utilized to prepare
the overbased materials.
As mentioned above, the non-Newtonian colloidal
disperse systems used in the coating compositions of the
present invention are prepared by a two step process where
in the first step a "conversion agent" and the above de-
scribed overbased starting material are homogenized to
convert -the overbased starting material to one having non-
Newtonian flow characteristics. Homogenization is achieved
by vigorous agitation of the two components, preferably at
tne reflux temperature or a temperature slightly below the
reflux temperature. Tne reflux temperature normally will
~epend upon the boiling point of the conversion agen~.
-25-
However, homogeni~ation may be achieved within the range of
about 25C. to about 200C. or slightly higher. Usually,
there is no real advantage ln exceeding 150C.
The concentra-tion of the conversion agent neces-
sary to achieve conversion of the overbased material is
usually within the range of from about 1~ to about 80~o based
upon the weight of the overbased material excluding the
weight of the inert, organic solvent and any promoter present
therein Preferably a-t least about 10% and usuall~ less
than about 60~ by weight of the conversion agent is eMployed.
Concentrations beyond 60% appear to afford no addi-tional
advantages.
The terminology "conversion agent" as used in the
specification and claims is intended to describe a class of
very diverse materials which possess the property of being
able to convert the Newtonian homogeneous, single-phase,
overbased materials into non-Newtonian colloidal disperse
systems. Tne mechanism by which conversion is accomplished
is not completely understood~ However, with the exception
of carbon dioxide, these conversion agents all possess
active hydrogens. The conversion agents include lower
aliphatic carboxylic acids, water, aliphatic alcohols,
cycloaliphatic alcohols, arylaliphatic alcohols, phenols,
ketones, aldehydes, amines, boron acids, phosphorus acids,
and carbon dioxide. Mixtures of two or more of these con-
version agents are also useful. Particularly useful con-
version agents are also useful. Particularly useful con-
version agents are discussed below.
The lower aliphatic carboxylic acids are those
containing less than about eight carbon atoms in the mole-
cule. Examples of this class of acids are formic acid,acetic acid, propionic acid, butyric acid, valeric acid,
isovaleric acid, isobutyric acid, caprylic acid, heptanoic
acid, cnloroacetic acid, dichloracetic acid, trichloroacetic
acid, etc. Formic acid, acetic acid, and proprionic acid,
are preferred with acetic acid being especially suitable.
It is to be understood that the anhydrides of these acids
--26-
are also useful and, for the purposes of the specificatlon
and claims of this inventlon, the term acid is intended to
include both the acid per se and the anhydride oE the acid.
Useful alcohols include aliphatic, cycloaliphatic,
and arylaliphatic mono- or polyhydroxy alcohols. Alcohols
having less than abou-t twelve carbons are especlally useful
while the lower alkanols, i.e., alkanols having less than
about eight carbon atoms are preferred for reasons of eco-
norny and effectiveness in the process. Illustratlve are the
alkanols such as methanol, ethanol, isopropanol, n-propanol,
isobutanol, ter-tiary butanol, isooctanol, dodecanol, n-
pentanol, etc; cycloalkyl alcohols exemplified by cyclo-
pentathol, cyclohexanol, 4-methylcyclohexanol, 2-cyclo-
hexylethanol, cyclopentylmethanol, etc; phenyl aliphatic
alkanols such as benzyl alcohol, 2-phenylethanol, and
cinnamyl alcohol; alkylene glycols of up to about six carbon
atoms and mono-lower alkyl ethers thereof such as mono-
methylether of ethylene glycol, die~hylene glycol, ethylene
glycol, trimethylene glycol, hexamethylene glycol, tri-
ethylene glycol, l,~l-butanediol, 1,4-cyclohexanediol, gly-
cerol, and pen-taerythritolO
The use of a mixture of water and one or more of
the alcohols is especially effective for converting the
overbased material to colloidal disperse systems. Such
combinations often reduce the length of time required for
the process. Any water-alcohol combination is effective but
a very effective combination is a mixture of one or more
alcohols and water in a weight ratio of alcohol to water of
from about 0.05:1 to about 24:1. Preferably, at least one
lower alkanol is present in the alcohol component of these
water-alkanol mixtures. Water-alkanol mixtures wherein the
alcoholic portion is one or more lower alkanols are es-
pecially suitable. Alchol:water conversions are illustrated
in U.S. Patent No. 3,372,115, filed ~larch 21, 1966.
Phenols suitable for use as conversions agents in-
clude phenol, naphthol, ortho-cresol, para-cresol, catechol,
mixtures of cresol~ para-tert-butylphenol, and other lower
alkyl substitu-te~ phenols, meta-polylsobutene (l`~ W.---350)-
substituted phenol, and the like.
Other useful conversion agents include lower ali-
phatic aldehydes and ke-tones, particularly lower alkyl alde-
hydes and lower alkyl ke-tones such as acetaldehydes, propion-
aldehydes, butyraldehydes, acetone, methylethyl ketone,
diethyl ketone. Various aliphatic, cycloaliphatic, aro-
matic, and heterocyclid amines are also useful providing
they contain at least one amino group having at least one
active hydrogen attached thereto. Illustrative of these
amines are the mono- and di-alkylamines, particularly mono-
and di-lower alkylamines, such as methylamine, ethylamine,
propylamine, dodecylamine, methyl etnylamine, diethylamine;
the cycLoalkylamines such as cyclohexylamine, cyclopentyl-
amine, and the lower alkyl substituted cycloalkylamines suchas 3-methylcyclohexylamine; l,4-cyclohexylenediamine; aryl-
amines such as aniline, mono-, di-, and tri~, lower alkyl-
substituted phenyl amines, naphthylamines, l,4-phenylene
diamines; lower alkanol amines such as ethanolamine and
diethanolmaine; alkylenediamines such as ethylene diamine,
triethylene tetramine, propylene diamines, octamethylene
diamines; and heterocyclic amines such as piperazine, 4-
aminoethylpiperazine, 2-octadecyl-imidazoline, and oxazol-
idine. Boron acids are also useful conversion agents and
include boronic acids (e.g, alkyl-B ~OH) 2 or aryl-B(OE~2,
boric acid (i.e., H3BO3), tetraboric acid, metaboric acid,
and esters of such boron acids.
The phosphrous acids are useful conversion agents
and include the various alkyl and aryl phophinic acids,
phosphinus acids, phosphonic acids, and phosphonous acids.
Phosphorus acids obtained by the reaction of lower alkanols
or unsaturated hydrocarbons such as polyisobutenes with
phosphorus oxides and phophorus sulfides are particularly
useful, e.g., P30s and P2Ss.
3~ Carbon dioxide can be used as the conversion
agent. However, it is preferable to use this conversion
-28-
agen-t in combination with one or more of the foregoing
conversion agents. For example, the combination of water
and carbon dioxide is particularly effective as a conversion
agent for transforming the overbased materials into a col-
loidal dlsperse system.
As previously mentioned, the overbased starting
materials are single phase homogeneous systems. ~owever,
aepending on the reaction conditions and the cholce of reac~
tants in preparing the overbased materials, there sometimes
are presen-t in the product insoluble contaminants. These
contaminants are normally unreacted basic materials such as
calcium oxide, barium oxide, calcium hydroxide, barium
hydroxide, or other metal base materials used as reactant in
preparing the overbased starting material. It has been
found that a more uniform colloidal disperse system results
if such contaminants are removed prior to homogenizing the
overbased materials with the conversion agents. Accord-
ingly, i-t is preferred that any insol~lble contaminants in
the lntermediate overbased materials be removed prior to
converting the material into the non-Newtonian colloidal
aisperse system. Tne removal of such contaminants is easily
accomplished by conventional techniques such as filtration,
centrifugation or by treatment with additional acidic
material. It should be understood however, that while the
removal of these contaminants from the intermediary over-
based materials are desirable, their removal from the final
non-Newtonian colloidal disperse systems used in the coating
composition of the invention is an absolute essential aspect
of the invention if useful coating compositions constituting
this invention are to be obtained.
The conversion agents or a proportion thereof may
be retained in the colloidal disperse system. The con-
version agents are however, not essential components of
these disperse systems and it is usually desirable that as
little of the conversion agents as possible be retained in
the disperse systems. Since these conversion agents do not
react with the overbased materials in such a manner as to be
9,~ 3
-29-
permanently bound thereto through some type of chemical
bonding, i-t is normally a simple ma-tter -to remove a major
proportlon of the conversion agents and yenerally, sub-
stantially all of tne conversion agents. Some of the con-
version agents have physical properties which make themreadily removable from the disperse systems. Thus, most of
the free carbon dioxide gradually escapes from the disperse
system during the homogenization process or upon standing
thereafter. Since the liquid conversion agents are generally
10 more volatile than the remaining components of the disperse
system, they are readily removable by conventional devola-
-tilization techniques, e.g., heating, heating at reduced
pressures, and the like. For this reason, it may be de-
sirable to select conversion agents which will have boiling
1~ points whlch are lower than the remaining components of the
~isperse system. This is another reason why the lower
alkanols, mixtures thereof, and lower alkanol-water mixtures
are preferred conversion agents.
It is not essential that all of the conversion
20 agent be removed from the disperse systems. However, -from
the standpoint of achieving uniform results, it is generally
desirable to remove the conversion gents, particularly where
they are volatile.
The second step in preparing the non-Newtonian
25 colloidal disperse systems used in the coating compositions
of this invention is to treat the homogenized, non-Newtonian
colloidal disperse system prepared in the first step,
described herein above, with further metal-containing reac
tant and acidic material. The metal-containing reactant and
3Q acidic material employed in this second step are the same
reactants and materials described above for preparing the
overbased starting materials. Treatment of the homogenized
colloidal disperse system from the first step in the prepa-
ration of tne disperse systems useful in this invention
generally will be carried out at temperatures ranging from
35 about 50C. to about 90C. and preferably from about 60C.
to about 80C.
"9'~ 3
- 3 o -
The amount of addltional metal-containing reactant
will be that amount sufficient to increase the metal ratio
of the homogenized colloidal disperse sys-tems from ~he first
step in the process for preparing the disperse s~lstems
5 useful in the invention from at least 7.0 to above about
10.0 and preferably above about 20Ø Given the metal ratlo
of the homogenized precursor disperse system, one of skill
in the art can readily determine the amount of metal-con-
taining reactant necessary to increase the metal ratio of
10 ~he homogenized precursor to that in the final disperse
system.
The amount of acidlc material employed in the
second step in the preparation of the non-Newtonian col-
loldal disperse system useful in this invention will be that
15 amount sufficient to reduce the neutralization base number
of the disperse systems to a level wherein the coating
composition of the invention will exhibit a good shelf life
stability. Generally that amount will be that sufficient to
reduce the neutralization base number of the final disperse
20 system to about 7.0 or less. A more preferred disperse
system will be that having a neutralization base number of
about 5.0 or less and most preferred is a disperse system
having a neutralization base number of 2.0 or less.
In the water dispersed coating compositions of
25 this invention, the amount of the non-Newtonian colloidal
dlsperse system, component (B), described immediately above
will range from about 1.0 to about 20.0 percent by weight
based on the total weight of the coating composition. A
more preferred range for the disperse system is from about
10.0 to about 20.0 percent by weight based on the total
weight of the coating composi~ion.
In addition to the two major components comprising
tne water dispersed coating compositions of this inventlon,
it is preferable in most instances to also include a plas-
ticizing material, component (C), for the organic polymersemployed in these composi-tions. The use of a plasticizer
~ r~
-31-
assures that the coatlng composltions wlll exhlbi-t the
reslllence, flexlbill-ty and :impact strength required of them
over a broad range of servlce temperatures. Plastlclzers
wnicn can be utilized as component (C) in the coating compo-
sitions of the present invention include adipates, azelates,sebacates, phthalates, phosphates and the llke. Speclflc
examples of such plasticizers are the dlalkyl adipates such
as dimethyl adipate, dlbutyl adipate, dloctyl adipate,
~iisooc-tyl adipate, di-(2-ethylhexyl) adlpate, octyl decyl
adlpate and -the llke; dialkyl azelates such as dicyclohexyl
azelate, di-n-hexyl azelate, di (2--ethylhexyl) azelate, di-
(2-ethylbutyl) azela-~e, dilsoctylazelate and the like;
dlalkyl sebaca-tes such as dibutyl sebacate, dioctyl sebacate,
diisoctyl sebacate, dibenzyl sebacate and the like; dialkyl
phthalates such as diethyl phthalate, dibutyl phthalate,
dioctylphthalate, butyl octyl phthalate, di(2-ethylhexyl-
)phthalate, dicyclohexylphthalate, butyl benzyl phthalate;
triaryl phosphates such as tricresyl phosphate, triphenyl~
phosphate, cresyldiphenol phosphate and the like; trialkyl
phosphates such as trioctyl phosphate, tri~utylphosphates
and the like; alkyl aryl phosphates such as octyl diphenyl
phospnate and tne like. Other plasticizers include citrates
such as acetyl tri-n butyl citrate, acetyl triethyl citrate,
monoisopropyl citratej triethyl citrate, mono-, di- and tri-
stearyl citrate; trioctin; p-tert-butyl phe~y] salicylate;
butyl stearate; benzoic acid esters derived from diethylene
glycol, dipropylene glycol, triethylene glycol, and poly-
ethylene glycols; proprietary polymeric polyesters such as
those sold by Rohm ~ Haas Company under the trademark Para-
plex, sulfonamides such as toluene sulfonamide and etc. Acomplete listing of illustrative suitable plasticizers can
be found in l~lodern Plastics Encyclopedia, Vol. 56, No. 10A
(1979-1980), ~cGraw-H111 Publications, pages 685-694.
The amount of plasticizer employed, if one is em-
ployed, will depend on the nature of the polymeric resin and
the plasticizer. Generally, however, the amount of plasti-
-3~-
cizer employed will range from 0 to about 15.0 percent by
weigh-t and preferably from about 2.0 to about 7.0 percent by
weight based on the to-tal weight of the coating composition~
In addition to the two major components of the
aqueous emulsion coating compositions of this invention and
tne optional plasticizer component (C) i-t is also preferable
to include in the compositions an effective amount of a
coalescing agent, component (D). As is well known, coa-
lesclng agents are generally high boiling solvents incor-
porated in coating compositions to aid in film formation andto improve leveling, adhesion and enamel holdout of the
coating composition. Typically, the amount of said coa-
lescing agent will range from 0 to about 20.0 percent by
weight based on the total weight of the coating composition.
1~ Preferably the amoun-t will range from about 3.0 to about
10.0 percent by weight. Representative examples of coa-
lescing agents which can be employed in the compositions of
this invention include Carbitol (diethylene glycol),
Carbitol acetate, butyl Cellosolve acetate, butyl Carbi-
tolTM acetate, butoxy ethanol, alkylene glycols, ethyleneglycol, propylene glycol, butylene glycol, hexylene glycol,
polyethylene glycol, alkylene glycol monoalkyl ethers such
as ethylene glycol monomethyl ether, ethylene glycol mono-
ethyl ether, etnylene glycol monobutyl ether, dialkylane
glycol monoalkyl ethers such as diethylene glycol monomethyl
ether, diethylene glycol monoethyl ether, diethylene glycol
monobutyl ether and the like. Esters of these alkylene
glycols, alkylene glycol monoalkyl ethers, and dialkylene
glycol mono-alkyl ethers also can be employed as coalescing
agent (D) and include such representa~ive materials as
ethylene glycol diacetate, ethylene glycol monoace~ate,
propylene glycol monosteara-te, ethylene glycol monoethyl
ether acetate, diethylene glycol monoethyl ether acetate and
the like. Other known coalescing agents useful in the
3~ compositions of this invention include diacetone alcohol,
aliphatic benzenes such as xylene and TexanolTM (2,2,~-
trimethyl-1,3-pentanediol monoisobutyrate).
-33-
rhe compositlons of -the present lnventlon can also
include one or more supplemental additlves or adjuvants.
These supplemental addltlves or adjuvants can include flash
rust lnhibi-tors, pH modifiers, fillers and ex-tending agen-ts
and the like.
Flash rust lnhlbltors are agents which preven-t
rustlng of metal surfaces lmmediately UpOII coating wlth the
water dlspersed coatlng composltions. While the films
formed by water removal from the water dispersed composi-
tions of the present lnvention serve to prevent corrosion ofsuch surfaces once they are formed, flash rust inhlbltors
are used to prevent rust and corrosion before the films have
had a chance to form. Typlcal flash rust inhibitors include
ammonium benzoate and phosphoric acid esters neutralized
with tetraethylene pentamine. Flash rust inhibitors which
are preferred for use in the water dispersed coating com-
positions of this invention include N-(hydroxyl-substituted
hydrocarbyl) amines such as primary, secondary and tertiary
alkanolamines corresponding, respectively, to the following
formulae:
H2~l-RI-OH (I)
N-RI-OH (II)
R
and
R
N_Rl_OH (III)
wherein each R is independently a hydrocarbyl group of one
to about eight carbon atoms or a hydroxyl-substi-tuted hydro-
carbyl group of two to about eight carbon atoms and Rl is a
aivalent hydrocarbyl group of about 2 to about eighteen
carbon atoms. The group -Rl-OH in such formulae represents
a hydroxyl-substituted hydrocarbyl group. The divalent
hydrocarbyl group, Rl, can be an acyclic, alicyclic or
aromatic group. Typically it is an acyclic straight or
3 t .~ 3
-3~-
branched cnain alkylene group such as ethylene; 1,2-propy-
lene; 1,2-butylene; 1,2-octadecylene and etc. Where two R
groups are presen-t in the same molecule, they can be joined
by a dlrect carbon~to-carbon bond or through a he-teroatom
such as oxygen, nitrogen or sulfur to form a five, six,
seven or eight membered ring structure. Examples of such
heterocycllc amines include N-(hydroxyl substituted lower
alkyl)-morpholines, -thiomorpholines, -piperdines, -o~azol-
idines, -thia7olidines and the like. Generally, however,
each R group is a lower alkyl group of up to seven carbon
atOMS. Particularly useful N-thydroxyl-substituted hydrocar-
byl) amines for providing flash rust inhibitors include
mono-, di- and triethanol amine, dimethylethanol amine,
diethylethanol amine, N,N-dl-(3-hydroxyl propyl) amine, N-
(3-hydroxyl butyl) amine, N-(4-hydroxyl butyl) amine, N,N-
di-(2-hydroxyl propyl) amine, N-(2-hydroxyl ethyl) morpho-
line and its thio analog, N-(2-hydroxyl ethyl) cyclohexyl
amine and the like. These N-(hydroxyl substituted hydro-
carbyl) amines can be used either alone or in mixture.
Preferred amines are diethyl ethanol amine, ethanol amine
and dimethyl e-thanol amine.
The above described amines are also useful as pH
modifiers for the water dispersed coating compositions of
this invention and therefore serve a dual purpose in said
compositions. The desired p~ range of the water dispersed
compositions of this invention is from about 7 to about 10 and
the addition of from about 1.0 to about 3.0 percent by
weight, based on the total weight of the coa-ting compositions,
will suffice to maintain the pH of the coating compositions.
It has also been found that this amount will also provide
-the desired level of flash rust inhibitive protection for
-the metal being coated while the water in the coating is
being removed.
Various fillers or extender pigments can also be
added to the water dispersed coating compositions described
and claimed herein. These include clays, talc, wallasto-
nite, barytes, calcium carbonate, silica, mica, carbon
-35--
b:Lack, lamp black and similar fillers and pigmen-ts. These
fillers and pigments can comprise from 0 to about ~0.0
percen-t by weight and preferably between 1.0 and about 15.0
percent by weight based on the total weight of the compo-
sition.
The inventive water dispersed coating compositions
are, in general, prepared by the intimate blending of the
various components under high shear conditions such as a
Cowles disperser. Typically, the film Eorming organic
polymer in aqueous solution or late~ form, water and plasti-
cizer, flash rust inhibitor and pH modifier, if any, are
first blended together under low shear conditions. Once
complete blending has been accomplished, the non-Newtonian
colloidal disperse system, and filler or pigment are added
under high speed, high shear conditions and the blending
continued until an intimate and water dispersed is achieved.
Additional water can be added at this point if necessary to
adjust the viscosity of the composition to that required by
the particular method of application to be used in applying
the coating composition to the metal surface to be coated.
The water dispersed coating compositions of the
invention are useful in forming rust inhibiting coatings or
films for metal surfaces such as surfaces of ferrous metals,
galvanized metal, aluminum, magnesium, etc. They are
especially useful for internally rustproofing and under-
coating automotive bodies and the like. They may be em-
ployed in these applications either alone or in combination
with other known rust-inhibiting materials.
When used for rust inhibiting purposes, the water
dispersed coating compositions of the present invention may
be applied to the metal surface by any of a number of known
methods such as brushing, spraying, dip coating, Elow
coating, roller coating and the like. The viscosity of the
water dispersed coating composition may be adjusted for the
particular method of application employed by adjusting the
amount of water present in the water dispersed coating
composition if a reduced viscosity is required or by the
3~3
--36-
addition of fillers such as talc, silicon, calcium carbona-te
and the like if an increased viscosity is required. Final]y,
mechanical shearing -techniques can also be used to vary the
viscosity of the water dispersed coating compositions since
they are thixotropic in nature. This shearing can be accom-
plished by using agitators or by forcin~ the compositions
through pumps (e.g. gear pumps) or other devices such as
nozzlesO
The film thickness produced on the metal substrate
is not critical although coatings or films of from 0.5 to
about 6.0 mils and preferably from 1.0 to about 4.0 mils are
generally sufficient to provide adequate rust and corrosion
protection. Thicker films can be used if desired, par-
ticularly if the metal article is to be subjected to severe
corrosion enhancing conditions, or to be stored for prolonged
periods of time.
The water dispersed coating compositons of the
present invention are generally applied to the surface to be
protected by any of the means described above and then air
dried. Generally, -this drying of the applied coating will
take place at temperatures ranging from ambient temperature
to temperatures of about 150C. or higher. The preclse
temperature employed and time required to complete drying
will va~y depending on the thickness of the coating and the
Tg of the polymeric resin employed in the coating composi-
tion. Those skilled in the art can readily determine the
time and temperature required to dry the coating completely.
The following non-limiting examples illustrate the
practice of this invention and include the presently known
best mode of practicing the invention. All -temperatures are
in degrees Celcius and all percentages and parts are by
weight unless it is specifically noted to be to the contrary.
xam~le_~
~ calcium mahogany sulfonate is prepared by double
decomposi-tion of a 60s oil solution of 750 parts of sodium
mahogany sulfonate with -the solution of 67 parts of calcium
chloride and 63 par-ts of water. The reaction mass is heated
for four hours at 90 to 100C. to affect the conversion of
the sodium mahogany sulfonate to calcium mahogany sulfona-te.
~'nen 54 parts of 91% calcium hydroxide solution is added and
the material is heated to 150C. over a period of five
hours. When the material has cooled to 40C., 98 parts of
methanol is added and 152 parts of carbon dioxide is in-
troduced over a period of 20 hours at 42-43C. Water and
alcohol are then xemoved by heating the mass to 150C. The
residue in the reaction vessel is diluted with 100 parts of
mineral oil. The filtered oil solution and the desired
carbonated calcium sulfonate overbased material shows the
following analysis: sulfate ash content, 16.46; a neu-
trali~ation number, as measured against phenophthalein of
0.6 (acidic); and a met~l ratio of 2.50.
Exam~le 2
A mixture comprising 1,595 parts of the overbased
material of Example 1 (1.54 equivalents based on sulfonic
acid anion), 167 parts of the calcium phenate prepared as
indicated below (0.19 equivalent), 616 parts of mineral oil,
25 157 parts of 91s calcium hydroxide (3.86 equivalents), 288
parts of methanol, 88 parts of isobutanol and 56 parts of
mixed isomeric primary amyl alcohols (containing about 65%
nor~.al amyl, 3s isoamyl and 32s 2-methyl-1-butyl alcohols)
is stirred vigorously at 40C. and 25 parts of carbon di-
oxide is introduced over a period of two hours at 40-50C.
Thereafter, three additional portions of calcium hydroxide,
each amoun-ting to 157 parts each are added and each such
addition is followed by the introduction of carbon dioxide
as previously illustrated. After the fourth calcium hy-
droxide addition and the carbonation step is completed, thereaction mass is carbonated for an additional hour at 43-
47C. to reduce the neutralization number of the mass to 4.0
(basic). The substantially neutral, carbonated reaction
-38-
mixture is then heated -to 150C. under a nitrogen atmosphere
to remove alcohol and any by-produc-t wa-ter. The residue in
the reactlon vessel is then filtered. The filtrate, an oil
solution of the desired substantially neutral, carbona-ted
calcium sulfonate overbase material of high metal ratio
shows the following analysis: sulfate ash content 41.11%;
neutralization number 0.9 (basic); and a metal ratio of
12.55.
The calcium phenate used above is prepared by
adding 2,550 parts of mineral oil, 960 parts (5 mols) of
heptylphenol, and 50 parts of water into a reaction vessel
and stirring at 25C. The mixture is heated to 40C. and 7
parts of calcium hydroxide and 231 parts (7 mols) of 91%
commercial paraformaldehyde is added over a period of one
hour. The contents are heated to 80C. and 200 additional
parts of calcium hydroxide (making a total of 207 parts or 5
mols) is added over a period of one hour at 80-90C. The
contents are heated to 150C. and maintained at that tem-
perature for twelve hours while nitrogen is blown through
the mixture to assist in the removal of water. If foaming
is encountered, a few drops of polymerized dimethylsilicone
foam inhibitor may be added to control the foaming. The
reaction mass is then filtered. The Eiltrate, a 33 6% oil
solution of the desired calcium phenate of heptaphenol-
formaldehyde condensation product is found to contain 7.56%sulfate ash.
Example 3
A mixture of 1,000 parts of the product of Example
2, 303 parts of mineral oil, 80 parts of methanol, 40 parts
~ of mixed primary amyl alcohols (containing about 65% by
weight of normal amyl alcohol, 3% by weight of isoamyl
alcohol, and 32% by weight of 2-methyl l-butyl alcohol) and
80 parts of water are introduced into a reaction vessel and
heated to 70C. and maintained at that temperature for 4.2
hours. The overbased material is converted to a gelatinous
mass. Stirring and heating of this gelatinous mass at
150C. is continued for a period of about two hours to
remove substantially all the alcchols and water. The
residue i5 a dark green gel.
-39-
-xample 4
~ solution of 1,303 par-ts of t:he gell like col-
loidal disperse sys-tem of Example 3 and 563 parts oE mineral
oil are dissolved in 1,303 parts of toluene by continuous
agitation of these two components for about three hours.
Added to this mixture is ~0 parts of water and 40 parts of
methanol fol:Lowed by the slow addition of 471 parts of 91%
calcium hydroxide with continuous stirring. An exothermic
reaction ta~es place raising the temperature to 32C. The
entire reaction mass is then heated to about 60C. over a
0.25 hour period. Two hundred-eighty parts of carbon di-
oxide i5 then charged over a five hour period while main-
taining the temperature at 60-70C. At the conclusion of
the carbonation, the mass is heated to about 150C. over a
0.75 hour period to remove water, methanol, and toluene.
The resulting product, a clear, light brown colloidal dis-
perse system in the form of a gel has the following analy-
sis: sulfate ash content, 46.8~; a neutralization number,
as measured against phenolphthalein of less than 1.0 (basic);
and a me-tal ratio of 36.0 In the above-described pro-
cedure, additional me-tal containing particles are incor-
porated into the colloidal disperse system of Example 3 and
its base neutralization number decreased to give a non-
Newtonian colloidal disperse system useful in the invention
of this application.
Example 5
To a one gallon glass jar equipped with high speed
agitation is charged 1920 parts of Neocryl A-620, a styrene/
isobutyl acryate copolymer (50/50 mole ratio) latex wherein
said copolymer, on a weight basis, constitutes 40 weight
percent of the total weight of the latex system. This
material is commercially available from Polyvinyl Chemical
Industries. Four hundred-twenty parts of the c~lloidal
material from Example 4 is then added and the contents are
stirred under high speed, high shear agitation conditions
for a period of five minutes. The stirring rate is then
reduced and to this material is then charged 160 parts of
propylene glycol, 300 parts of water, 160 parts of Paraplex
~ 40-
WP-l, a polymeric polyes-ter plasticizer avallable from ~ohm
and Haas, 120 parts of water, 20 parts of 2-amino-2-methyl-
l-propanol, and 45 parts of AquablackTM 115A, a black pig-
ment dispersion available from Bordon Chemical. This mix-
ture is then s-tirred for an addi-tional five minutes to give
the final water-dispersed coating composi-tion.
Example 6
To a one gallon glass jar equipped with a dlsper-
sator fitted with a 1-3/4 inch Cowles blade are charged in
the following order: one thousand eight hundred-eighty
parts of Neocryl A-620, 408 parts of -the colloidal ma-terial
from Example 4, 156 parts propylene glycol, 156 parts di-
octyladipate (DOA), 156 parts water, 56 parts dimethyl
ethanolamine (DMEA). The contents are stirred under high
speed agitation to give a water~dispersed coating composi-
tion of this invention.
Example 7
A water-dispersed coating composition is prepared
employlng the same procedure, materials and quantities as
employed in Example 6 except that 43 parts of Aquasperse
877-~99-7, a black pigment dispersion available from Tenneco,
is added after the DMEA and stirring continued un-til the
pigment was completely incorporated into the coating composi-
tion.
Example 8
To a one gallon glass jar equipped with a disper-
sator fitted with a 1 3/4 inch Cowles blade is charged 2037
parts of Neocryl A-620. With continuous agitation 448
parts water and 167 parts Paraplex M WP-l are charged to
the glass jar. The agitation rate is then lncreased to high
speed, and 64 parts of DMEA and 5 parts A~uasperseTM are
charged to the contents of the jar. The resulting mixture
was stirred for ten minutes during which time the tempera-
ture of the mixture was increased to 50C. At the end of
this time, 434 parts of the material from Example 4 are
charged to the glass jar and high speed agitation continued
for an additional five minutes. An additional 82 parts of
water are added to the contents of the jar to adjust the
final coating composition to the desired viscosity.
-41-
Example 9
'Io a six liter stainless steel po-t equipped with a
dispersator fitted with a 1-3/4 inch Cowles blade are charged
in the order lis-ted: two thousand five hundred-twenty parts
of Neocryl il A-~0, 700 parts of water, 210 parts of Para-
plex WP-l, 110 parts of propylene glycol, 480 parts of red
iron oxide, 300 parts of 325 mesh mica, and 1500 parts of
talc. The contents are mixed together at maximum speed for
15 minutes at which time there is charged to -the pot 120
parts of DMEA, 600 parts of the material from Example 4, and
25 parts of water. Stirring of the contents in the pot is
continued at maximum speed for ten minutes and the contents
then filtered through a 100 mesh screen to give the final
water-dispersed coating compositlon.
1~ _ample 10
To a five gallon pail equipped with a three inch
Cowles blade attached to a shaft connected to a variable
speed motor are charged 6240 parts NeocrylTM A-620, 120
parts of Nopco NDW, a latex defoamer available from
Diamond Snamrock, and 1560 parts of the material from
Example 4. The contents are ground at high speed for five
minutes. At this time the rate of agitation is reduced and
260 parts of Paraplex ~ WP-l, 260 parts of Texanol ester
alcohol, 2,2,4--trimethylpentanediol-1,3-monoisobutyrate
available from Eastman Chemical Products, Inc., 600 parts of
CarbitolTM, diethylene glycol monoethylether available from
Dow Chemical Company, 600 parts of propylene glycol, 60
parts TroykydTM 999, a non-silicone defoamer available from
Troy Chemical Company, 180 parts of 2-amino-2-methyl-1-
propanol, and 600 parts of water, and charged to the previouslyground materials. Agitation is continued at medium speeds
to achieve complete dispersion of the various ingredients
forming tne final water dispersed coating composi-tion.
The anticorrosion characteristics of the water-
dispersed coating compositions prepared above in Examples 5through 10 are determined by the use of the Salt-Fog Corrosion
Test (AST~l test B117-73-(1979)). In this test, steel panels
measuring 4 inches wide by 8 inches long are coated with the
~ 3
-42-
ahove prepared water dispersed coating compos~tions to give
dry film thicknesses of 2 mils. The coated, dr~ panels are
then suspended in a Salt-Fog cabinet and a 5% sodium chlo-
ride solution continuously sprayed onto the panels at
37.8C. for 24 hours. By this test an uncoated panel is
corroded over the entire surface at the end of 24 hours
whereas a panel coated with a water-dispersed coating com-
position prepared by the procedure of Example 6 shows less
than 1% rust at the end of 336 hours and less than 2% rust
10 at the end of 500 hours along a scribed line made through
the coating to the underlying metal. The results of this
testing is set forth in Table 1 below.
~able 1
Example Hours Creep( ) Millimeters (mm~ %Rust
15 5 336 2-8 20
5(b) 500 3-8 40
6(b) 336 3-6 ~1
7(bb) 336 43-8 <22
~ 7 ) 500 4-10 5
8 336 0-1 <1
8 500 1-3 <1
8 1000 4-6 ~5
9 336 0 ~2
25 9 500 1-2 50
336 1-2 <1
500 2-3 <2
(a) extent of corrosion measured from a scribed line made
through the coating to expose the underlying metal
30 (b) 4" X 12" panels employed
