Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
337
COATING ~,O~POSITIO~
Back~round of the Invention
The present invention relates generally to coatin~
compositions and specifically to a solvent soluble
resin paint or varnish having water dispersed ~herein.
It has been a desideratum in the coatings art to formu-
late a paint, varnish or other protective coating
composition which employs an organic solvent soluble
film-forming component and which further includes
water as part of the evaporative vehicle.
Presently such compositions, commonly called solvent
or solution resin coatings, comprise organic solvPnts
as the evaporative vehicle, often in amounts in excess
of 60% of the total composition. As this solvent
evaporates during the drying of the coating, consi-
derable irritation and odor may be caused by the escape
of these fumes in the atmosphere. Also, organic sol-
vents are not inexpensive, and contribute substantiallyto the cost of the coating composition. In addition,
as organic solvents are highly flammable they are
haæardous during the manufacture and use of the coatings,
and add to the fireload and insurance costs of manufac-
turing and warehouse facilities. For these reasons, ithas been desirable to substitute water for part of the
solvents previously employed.
Heretoore, water containing coatings have required water
soluble or dispersable film-forming components, and
latex paint, for example, has met with wide acceptance.
Latex paint is composed of two dispersions. First, a
dispersion of pigments and various extenders in water,
and second; a dispersion of the resin in the water. The
`~ 35 resin dispersion is either a latex formed by emulsion
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~.,.
~3~33'7
polymerization or a resin in emulsion form. Such
paints are characterized by the fact ~hat the film-
forming component is in a water-dispersed form. The
principle film-for~ing components in latex paints are
styrene-butadiene, polyvinyl acetate, and acrylic resins.
However, latex coating compositions are not without
~heir disadvantages, First, as the latex composition
is a double dispersion, it requires two emulsifiers
which may conflict and may, in particular, cause prob-
lems in formulation due to the fact that the emulsifier
used in the polymerization of the resin may be un-
known and have an unpredictable effect on the final
product. In addition, the oil-in-water emulsion found
in latex compositions will not dry to produce the clear
or gloss finish found in solvent coatings such as
varnish and the like. Oil-in-water emulsion clear
coatings, due to the latex resins used, tend to form
with brush marks or surface disruptions and cannot be
easily sanded or otherwise refinished as can traditional
solvent varnishes.
Also, latex coatings are not easily adaptable to use
in pressurized cans commonly referred to as aerosol
containers~ This is due to the high viscosity of the
late~ composition and the tendency of the latex oil-in-
water emulsion to foam excessively when sprayed from an
aerosol container. This foaming begins, as the composi-
tion leaves the nozzle and becomes apparent after th~
coating has been applied to the substrate or workpiece,
~or example, previous water base spray pain~s dry with
small craters rather than a smooth surface which indi-
cates that foaming has occurred during the application
process. Thus, when the foam dries there is left a
,~; 35 penetrable film which seriously affects the protective
.. . . ... . _ _ . .. . . . . _ ,
" ~2S~337
value of the coating. In addition, as the propellant must be mis-
cible in the continuous phase in order to properly atomize the
emulsion for spraying, suitable i.e. water soluble propellants
have led to an excessive product cost and have been otherwise
unsatisfactory.
Summary of the Inve tio
This invention comprises a water-in-oil emulsion coating composi-
tion having a continuous phase including an organic solvent and a
film-forming resin dissolved in said solvent, with water dispersed
in the continuous phase through the use of a suitable emulsifier
The composition rnay be applied by brush, roller or compressed air
spraying apparatus as well as being advantageously suited to being
sprayed from aerosol containers such as by the inclusion of an oil-
phase soluble propellant. As hereinafter described, the water-in-
oil emulsion is maintained through the use of an emulsifier or an
emulsifier system having a hydrophile-lipophile balance, or EILB
value, of from two to about six.
Among the advantages of the present composition is that water is
substituted for a large proportion of the evaporative vehicle in
traditional solvent coating compositions. Thus, the invention
allows the known advantages of solvent resin films to be retained
in a composition havlng the benefits of a water base product, and
a wide range of resins, including any organic solvent Eilm-forming
resin, ma~ be used.
Substantial cost savings are atta.ined because of the lower cost of
33~
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water as compared to organic solvents. The hazards and costs of
unneeded flammable solvents are also markedly reduced. Cost sav~
ings are further realized since the traditional organic solvent
soluble resins are often
33
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less expensive than the resins heretofore used in latex
oil~in-water emulslon pain~s. The ~resent invention
also enhances the functional utility of the ~int as the
resultant film ~ay be sanded, stripped or otherwise re-
finished throup,h the use of traditional methods.
The water-in-oil emulsion of the present invention may
be sprayed from aerosol con~ainers, which are known in
~he art, and atomizes readily upon spraying to produce
a smooth, non-foaming coating on the workpiece to which
it is applied.
The coatings referred to herein and the compositions
contempla~ed by the present invention include those
products ~nown as varnish, paint, enamel, primers, lac-
quer and commercial protective coatings or any coating
or composition wherein the film-forming resin is organic
solvent soluble and which will form a water-in-oil emul-
sion as hereinafter described.
Description of the Preferred Embodiment
The percentages expressed herein, both in the specifica-
tion and the claim~ appended thereto, are intended and
expressed as percentages by weight of the total composi-
tion to which they refer.
Solvents which are contemplated by and have been found
useful in the present invention include aliphatic and
ar~matic hydrooarbons, esters, ketones, glycol ethers
and alcohols having a distillation range of from 100
to 500 ~,
Although any organic solvent soluble film`forming resin
is suitable for use in the present invention, resins
~hich are preferred for use in the water-in-oil emulsion
~$~337
system are those with the greatest resistance to hydrolysis.
Aliphatic and aromatic hydrocarbon resins possess this character-
istic to a high degree, as do vinyl toluene and styrene modified
resins. Epoxy ester resins also have a high resistance to hydro-
lysis because of the ether groups in the molecule and resultant
steric hindrance found in these resins.
The water-in-oil emulsion of the present invention is adaptable to
produce varnishes, wherein a clear or gloss coating is produced
from the polymerization of the resin or the evaporation of the
volatile portion of the vehicle. Paints such as enamels may also
be produced by the addition of various organic and inorganic pig-
ments, including carbon black, and both natural or synthetic
oxides and other known colorants as hereinafter described, along
with conventional pigment dispersants and anti-settling agents.
Additional ingredients known in the art may also be added, such as
mar resistance agents and drier catalysts.
Water is dispersed in the oil phase according to the present inven-
tion, dependent upon the required coating composition or use, in
any ratio which allows the coating to form. Specifically, water
has been dispersed in amounts of up -to 80% of the liquid composi-
tion through the use of appropriate emulsifying agents. Emulsi-
fiers which have been found useful in the formation of the composi-
tion of the present invention are emulsifiers having a hydrophile-
lipophile balance number of from one/half to twelve.
me HLB system is a semi-empirical procedure for the selection of
an appropriate emulsifier. The procedure is based on the concept
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that the molecule of any emulsifier contains both hydrophobic and
hydrophilic groups, and the ratio of their respective weiyht per-
centages should influence emulsification behavior.
The HLB value can be calculated from the theoretical composition
of the emulsifier. For example, in determining the HLB for
ethylene oxide condensation products, HLB equals one-fifth of the
weight percent of the oxyethylene hydrophlic content of the mole-
cule. The HLB of ester emulsifiers may be calculated by the
formula HLB=20 (1-S/A), wherein S is the saponfication of the
emulsifier and A is the acid number of the fatty acid moiety.
Such methods of calculation are known in the art and expressed in
a wide variety of publications.
HLB values have also been determined by titration, spreading
coefficients, gas-liquid chromatograph -techniques and other labora-
tory methods. Generally, suppliers of commercial proprietary
emulsifiers provide an HLB number for their products, and
published HLB indices of these materials are known in the art.
According to the present invention, a single emulsifier having an
~I,B of from two to about six may be used. However, it is prefer-
able to use a blend of emulsifiers, including a continuous phasecomponent as well as an emulsifier for the dispersed phase, which
produce an emulsifier system having an HLB of from two to abou-t
six. When two or more of these emulsifiers are to be blended the
HLB of the combination is calculated by the formula xA+(l-x)B
wherein x is the percent proportion of the emulsifier having an
HLB of A and B is the HLB of the second emulsifier~ It has been
~L~S~337
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found that the most stable emulsion systems consis-t of blends of
two or more emulsifiers, one portion having lipophilic tendencies
(HLB 0.5 to 5.0), and the other portion having hydrophilic tendenc-
ies (HLB 5.0 to 12.0).
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33~;)
Example One
A gloss black enamel was prepared having the following
composition:
Carbon black 1.1 %
Vinyl toluene modified alkyd resin 9.5 %
Aromatic hydrocarbon resin 5.7 %
VM & P Naphtha lS.4 ~/D
Toluol 5.7 %
Xylol 3.2 %
Aliphatic hydrocarbon solvent,
boiling range, 300-400~ F. 28.4 %
Pigment dispersant (Nuosperse 657) 0.1 %
Anti-settling agent 0.1 %
Mar resistanee agent 0.3 %
Drier catalyst 0.1 %
Sorbitan trioleate (Span~85, HLB 1.8)0.32%
Polyethylene glycol monooleate
(Mapeg~200 MO, HLB 8.0) 0.08%
Water 30 0 %
100 . 00%
The composition was prepared by first combining the pig-
ment, pigment dispersant, anti-settling agent and a
~5 portion of the resin and solvent in a mixing vessel as
is known in the art. I`he mixing was continued until
the pigment was dispersed ~o a suitable degree of
fineness. Thereafter, the remainder o the resin and
solvent was added along with the mar resistance agen~
an'd drier catalyst. When the mixing was completed, the
oil dispersable emulsifier, HLB 1.8, was stirred into
the enamel with a homogenizer-type intensive mixer.
After five minutes of mi~ing, a solution of~water and
the water dispersable emulsifierl HLB 8.0 is poured into
the enamel while under constant mixing. These two
emulsifierc as hereinbefore described, yielded a total
~ T~ ~4a~k
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emulsifier syst~m value of 80% x 1.8 ~ 20% x 8.0 - 3.04.
The wa~er-in-oil emulsion was formed within five to
te~ minutes.
Example Two
In a like manner, varnish compositions may be made using
the same ingredients, with the omission of the carbon
black pigment and pigment related additives. Speci~ically,
a varnish was made having the following composition:
; Oil modified polyurethane resin
(Urotu ~13-309) 13.9%
Mineral ~pirits ~boiling range
307-389 F.) 13.9%
Aromatic solvent ~SC-100, boiling
range 311U-344 F.) 31.7%
Aromatic sol~ent (SC 150, boiling
range 352-410 F.) 9.4%
Drier catalyst 008%
~0 Anti-skinning agent ` 0.~%
Polyoxyethylene so~b;tol beeswax
derivative (Atla~G-1727, HL~ 4.0~ 0.2%
Water . 30.0%
100, 0%
~5
SC-100 and SC-150 are known naphtha mixtures containing
98% aromatic material of C8 or higher. Aliphatic naph-
thas of like boiling ranges may be used and are intended
as equivalent.
Example Three
According 'co t-he-same method, a gloss white enamel was
prepared ha~ing the following composi~ion:
T~
~2tJ~3~
Titanium dioxide 11.0 %
Vinyl toluene modified alkyd resin 14,7 ~/0
VM & P Naphtha 14 . 5 %
Aliphatic hydrocarbon solvent,
boiling range, ~11-344 D F. (SC-100) 19 6 %
Xylol 7.5 %
Pigment dispersant (Disperse
Ayd No. 1) 0.2 %
Anti-settling agent 1. 8 %
Mar resistance agent 0.3 %
Drier catalyst 0.1 %
Sorbitan trioleate (Span 85,
HLB 1.8) 0.25%
Polye~hylene glycol monool~ate
- (Mapeg 200 MO, HLB 8.0) 0.05%
Water 30.0 %
100.0 ~/0
The compositions described above in examples one through
three were each further processed to form aerosol spray
coating compositions. After the water-in-oil emulsion
described above is formed, the composition was packed
in an aerosol can with a suitable propellant, here pro-
pane or a mixture of propane, isobutane and/or butane
?5 as known in the art. The amount of propellant may vary
in accordance with the intended result, but is generally
in the ratio of twenty to thirty-five percent propellant
by weight in relation to the total composition. A metal
or glass object weighing from ~ive to ten grams is cu~-
tomarily added to the can along with the enamel. Thisobject serves as an aid ;n mixing the pigmçnt, if any,
which settles to the bottom of the can during storage.
Example Four
Black Enamel using an aromatic hydro~arbon resin:
~'h~33~
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Carbon black 1.2 %
Aromatic hydrocarbon ~esin 19.6 %
: Toluene 23.4 %
Hexane 4.9 %
Aromatic solvent, ~oiling
range 300-400D F, 20.0 %
Plgment dispersan~ (Nuosperse 657)0.1 %
Anti-settling agent 0.2 %
Mar reslstance agent O.l %
Drier catalyst 0.1 %
Sorbitan sesquioleate ~Liposorb SQ0,
HLB 3,7~ 0.32%
Diethylene glycol fatty acid ester
(Emcol DP-S0, HLB 5.1) 0.08%
W~ter 30.00%
100 . 00%
Example Five
20 White Ground Marking Paint using an aromatic hydrocarbon
resin:
Titanium dioxide 11.34%
Calcium carbonate 2.59%
Aromatic hydrocarbon resin 14.06%
Toluol . 14.72%
Aromatic hydrocarbon solvent,
boiling range 311 344 F, (SC~lO0~ 4.47%
Anti-settling agent 1.0270
Drier catalyst 0~.22%
Pigment dispersant (Nuosperse 557) 0.34%
Sorbitan trioleate (Span 85,
I~B 1.8) 0.24%
Polyethylene-glycol monoolea-te --- - -
(M~peg 200 M0, HLB 800) Q.06%
Water . . 50.94%
100 . 00%
337
It has been found that when water is used in excess of
60%, particularly when dispersed in resins having a
hi:gh viscosity at high solids conten~, a high viscoslty
emulsion is produced ~ue to the reduction of the ef-
fective amount of solvent for the resin and the internalfriction created by the emulsified water. Thus, while
hi~h water content may ~e advantageous in brushed
coa~ings or industrial s~ray applications, lower vis-
cosity emulsions should ~e used in the aerosol spray
compositions of the present invention.
Exal~le Six
.
Red Enamel using an epoxy ester resin:
Toluidine Red 1,9 %
Epoxy ester resin 14,8 %
Xylol 15.9 %
Aromatic solvent, boiling
; range 311~340 F, (SC-100) ~ 35.3 D/o
Pigment dispersant (Nuosperse 657) 0.06%
~nti~settling agent 0.2 %
Mar resistance agent 0.1 %
Drier catalyst 1.0 %
Anti-skinning agent 0.3 %
Sorbitan tristearate (Liposor ~ TS,
HLB 2.1) 0.56%
Polyethylene glycol 200 dilaurate
(Emerest~ ~22, HLB 6,2) 0,08%
Water 29.8 %
100.~0%
Example Seven
Red Fluorescent Paint using an acrylic resin:
~ ~a~
... ., . . . .,~
12~1C1 33 7
-~2-
Red Fluorescent Pigment 1~,8 %
Acrylic resin 4.2 %
; Aliphatic hydrocarbon solvent,
boiling range 150-200 F. 37.0 %
Xylol 15.6 %
Sorbitan trioleate (Span 85,
HLB 1.8~ 0~35%
Polyethylene glycol monooleate
(Mape~ 200 MO, HLB 8.0~ 0.09%
Water 29.96%
100 . 00%
ExamPle Eight
Red Iron Oxide Primer using an ~poxy Ester:
Red Iron Oxide 5.4 %
Yellow Iron Oxide 1.6 ~/O
Magnesium Silicate 6.8 %
Zinc Phosphate 2.6 %
Carbon Black 0.2 %
Epo~y ester resin 8.7 %
Xylol 30-4 /o
Toluol 11.2 %
Anti-skinning agent 0.03%
Pigment dispersant (Nuosperse 657)0.15%
Anti-settling agent 2.12%
Drier ca~alysts 0.40%
Ethylene glycol distearate (Emerest
2355, HLB 1.2) 0,34%
~ Polyethylene oxide sorbitan tristearate
(Liposorb TS-20, HLB 10.5) 0.0~%
Water 29.97%
100 . 00~
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Each of the compositions hereinbefore described pro-
vided a coatin~ comparable to the solution resin
co~tings as previously known at a markedly lower cost
due to the inclusion of water in the composition, The
amount of water in the composition is dependent upon
the type of film desired and ~ay vary up to 80% of the
total conposition.
Further, each of the compositions, when s~rayed from a
standard aerosol container, resisted foaming and formed
a smooth, continuous coating heretofore unobtainable in
an aerosol water containing paint.
F~rther compositions were made including standard ~aria-
tions in the percentages of resin, solvent, pigments
and other additives as known in the art. Oil modified
polyurethane resins, epoxy ester resin, aromatic hydro-
carbon resin, aliphatic hydrocarbon resin, vinyl toluene
modified oil, solution vinyl resin, silicone resin and
solvent soluble acrylics may be selected in accordance
with the requirements of the desired application.
From the foregoing description, one skilled in the art
can easily ascertain the essential characteristics of
the invention! and without departing from the spirit and
scope thereof, can make various changes and modifications
to adap~ the invention to various usages and conditions.
