Fast-setting latex coating and formulations

A method of preparing a fast-setting coating material on a substrate which comprises contacting a stable aqueous dispersion of a polymer that contains strong cationic groups and weak acid groups onto a substrate that is basic or treated to be basic.

BACKGROUND OF THE INVENTION 
The present invention relates to a stable aqueous dispersion that forms a 
water-resistant fast-setting coating when applied to a suitable substrate. 
Coatings are generally used to provide a protective barrier for 
applications such as floors, automobiles, exteriors and interiors of 
houses, as well as painted roads. Protective coatings for floors, for 
example, have been known since the mid 1950s. Many of the early coating 
materials were applied using petroleum- or naphthene-based solvents, and 
as such were undesirable due to the toxicity and flammability of these 
solvents. 
Water-based synthetic emulsion compositions such as styrene resin 
emulsions, styrene-acrylate copolymer resin emulsions, and acrylate 
emulsions, developed in the early 1960s, gradually replaced organic 
solvent-based compositions. Although the water-based compositions are 
preferable to organic solvent-based compositions for safety and 
environmental reasons, coatings prepared from water-based compositions 
require long drying times. During drying, the coatings are susceptible to 
a number of events that may produce a defective coating, such as drips, 
sags and runs. Moreover, until the coating is set, it is vulnerable to 
contamination by dust or water contact, which may also lead to a marred 
coating. These effects can be minimized by the use of volatile cosolvents 
which accelerate the drying process, but the cosolvents reintroduce 
environmental problems that the water-based systems were designed to 
address. 
In addition to the environmental concerns, one of the challenges that 
remains is to develop latexes that coalesce at room temperature, without 
leaving a tacky surface. 
In view of the deficiencies in the art, it would be desirable to provide a 
coating that rapidly becomes resistant to marring, defects, and 
contamination during drying, using a stable aqueous dispersion that does 
not require environmentally unacceptable cosolvents or crosslinking 
curatives. 
SUMMARY OF THE INVENTION 
The present invention addresses a need in the art by providing a way to 
prepare coatings that set quickly upon contact with a substrate. 
Accordingly, in one aspect, the present invention is a coated material 
comprising a substrate having a surface and a coating thereupon, wherein 
the coating is prepared by any of the steps of: 
a) contacting the surface of the substrate with a stable aqueous dispersion 
that contains a polymer having pendant strong cationic groups and pendant 
weak acid groups; or 
b) contacting the surface of the substrate with a stable aqueous dispersion 
containing a first polymer having pendant strong cationic groups, and a 
stable aqueous dispersion of a second polymer having pendant weak acid 
groups, the contact of the polymers with the surface being made in any 
order or concurrently; 
with the proviso that when the coating is prepared by the method of (a), 
the surface of the substrate is, or is treated to be, sufficiently basic 
so that the stable aqueous dispersion sets in less time than the time 
required for a latex that only has pendant strong cation groups or pendant 
weak acid groups to set. 
In a second aspect, the present invention is a method of preparing a 
fast-setting coating on a substrate having a surface comprising either of 
the steps of: 
a) contacting the surface of a substrate with a stable aqueous dispersion 
that contains a polymer having pendant strong cationic groups, and pendant 
weak acid groups; or 
b) contacting the surface of the substrate with a stable aqueous dispersion 
that contains a first polymer having strong cationic groups, and a stable 
aqueous dispersion that contains a second polymer having weak acid groups, 
the contact of the polymers with the surface being made in any order or 
concurrently; with the proviso that when the fast-setting coating is 
prepared by the method of (a), the surface of the substrate is, or is 
treated to be, sufficiently basic so that the stable aqueous dispersion 
sets in less time than the time required for a latex that only contains 
pendant strong cation groups or pendant weak acid groups to set. 
In a third aspect, the present invention is a stable aqueous dispersion 
comprising a polymer having strong cationic groups, weak acid groups, and 
structural units formed from the polymerization of a non-interfering 
monomer, wherein the ratio of structural units formed from the 
polymerization of the non-interfering polymerizable monomer to strong 
cationic groups and the weak acid groups is from about 70:30 to about 
99:1, with the proviso that the strong cationic groups are associated with 
non-alkaline counterions. 
DETAILED DESCRIPTION OF THE INVENTION 
The fast-setting coated material of the present invention can be prepared 
by contacting a substrate with a stable aqueous dispersion that contains a 
polymer having structural units formed from the polymerization of: a) a 
polymerizable strong cationic monomer, and b) a polymerizable weak acid 
monomer. In this aspect of the present invention, the substrate is, or is 
treated to be, sufficiently basic that the stable aqueous dispersion sets 
in a time that is less than the time required for a latex that only 
contains pendant strong cation groups or pendant weak acid groups to set. 
The term "sufficiently basic" refers to sufficiency of amount of base as 
well as base strength. A coating "sets" or is "dry-to-the-touch" when it 
has formed a skin with sufficient mechanical integrity such that no 
portion of the skin is removed when it is touched lightly with a finger, 
and no portion is washed off the substrate when rinsed under a light 
stream of water. 
As used herein, the term "polymerizable strong cationic monomer" refers to 
a monomer that contains ethylenic unsaturation and a cationic group having 
a charge that is independent of pH. Similarly, the term "polymerizable 
weak acid monomer" refers to a monomer that contains ethylenic 
unsaturation and an acid group having a pKa in the range of about 2 to 
about 10. The term "structural units formed from the polymerization of . . 
. " is illustrated by the following example: 
##STR1## 
In addition to structural units formed from the polymerization of a 
polymerizable strong cationic monomer and a polymerizable weak acid 
monomer, the polymer also preferably includes structural units formed from 
the polymerization of a polymerizable non-interfering monomer. The term 
"polymerizable non-interfering monomer" is used herein to refer to a 
monomer that does not adversely affect the fast-setting nature of a 
coating prepared from the stable aqueous dispersion of the polymer. 
Polymerizable weak acid monomers that are suitable for the preparation of 
stable aqueous dispersion used to prepare the water-resistant fast-setting 
coating include ethylenically unsaturated compounds having carboxylic 
acid, phenolic, thiophenolic, or phosphinyl functionality. Preferred 
polymerizable weak acid monomers include acrylic acid, methacrylic acid, 
itaconic acid, .beta.-carboxyethyl acrylate (usually as a mixture of 
acrylic acid oligomers), vinylbenzoic acid, and 2-propenoic acid: 
2-methyl-, (hydroxyphosphinyl) methyl ester. Acrylic acid and methacrylic 
acid are more preferred weak acid monomers. 
The polymerizable strong cationic monomer is associated with a non-alkaline 
counterion, which may be, for example, halide such as chloride, bromide, 
or iodide, as well as nitrate or sulfate. As used herein, the term 
"non-alkaline counterion" refers to a counterion that does not cause 
sufficient ionization of the weak acid to render the stable aqueous 
dispersion unstable. Thus, a bicarbonate counterion would not be 
appropriate if a carboxylic acid were the weak acid, since this counterion 
would, in sufficient quantity, raise the pH of the stable aqueous 
dispersion to an unstable level. For example, for a stable aqueous 
dispersion containing 2.3 mole percent each of a quaternary ammonium salt 
and a carboxylic acid, the presence of a sufficient amount of a 
bicarbonate counterion to raise the pH of the latex to above 5.5 would 
cause the dispersion to become unstable. 
Suitable polymerizable strong cationic monomers include salts of 
ethylenically unsaturated compounds having quaternary ammonium, sulfonium, 
cyclic sulfonium, and phosphonium functionality. Examples of suitable 
monomers having quaternary ammonium functionality include ethylenically 
unsaturated trialkylammonium salts such as vinylbenzyl tri-C.sub.1 
-C.sub.4 -alkylammonium chloride or bromide; trialkylammoniumalkyl 
acrylates or methacrylates such as 
2-[(methacryloyloxy)ethyl]-trimethylammonium chloride and 
N,N-diethyl-N-methyl-2-[(1-oxo-2-propenyl)oxy] ethanaminium methyl sulfate 
(Chem. Abstracts Reg. No. 45076-54-8); and trialkylammoniumalkyl 
acrylamides such as 
N,N,N-trimethyl-3-[(2-methyl-1-oxo-2-propenyl)amino]-1-propanaminium 
chloride (Chem. Abstracts Reg. No. 51441-64-6) and 
N,N-dimethyl-N-[3-[(2-methyl-1-oxo-2-propenyl)amino]propyl]-benzenemethami 
nium chloride (Chem. Abstracts Reg. No. 122988-32-3). A preferred 
polymerizable quaternary ammonium salt is 
2-[(methacryloyloxy)ethyl]trimethylammonium chloride. 
Examples of polymerizable unsaturated sulfonium salts include 
dialkylsulfonium salts such as 
[4-ethoxy-3-(ethoxycarbonyl)-2-methylene-4-oxobutyl]dimethylsulfonium 
bromide (Chem. Abstracts Reg. No. 63810-34-4); and vinylbenzyl 
dialkylsulfonium salts such as vinylbenzyl dimethylsulfonium chloride. 
Examples of polymerizable cyclic sulfonium salts include 
1-[4-[(ethenylphenyl)methoxy]phenyl]tetrahydro-2H-thiopyranium chloride 
(Chem. Abstracts Reg. No. 93926-67-1); and vinylbenzyl 
tetrahydrothiophenonium chloride, which can be prepared by the reaction of 
vinylbenzyl chloride with tetrahydrothiophene. 
Examples of polymerizable phosphonium salts include 
2-methacryloxyethyltri-C.sub.1 -C.sub.20 -alkyl-, aralkyl-, or 
aryl-phosphonium salts such as 
2-methacryloxyethyltri-noctadecylphosphonium halide (Chem. Abstracts Reg. 
No. 166740-88-1); tri-C.sub.1 -C.sub.18 -alkyl-, aralkyl-, or 
aryl-vinylbenzylphosphonium salts such as 
trioctyl-3-vinylbenzylphosphonium chloride, 
trioctyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 
15138-12-4), tributyl-3-vinylbenzylphosphonium chloride, 
tributyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 
149186-03-8), triphenyl-3-vinylbenzylphosphonium chloride, and 
triphenyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 
145425-78-1); C.sub.3 -C.sub.18 -alkenyltrialkyl-, aralkyl-, or 
aryl-phosphonium salts such as 7-octenyltriphenylphosphonium bromide 
(Chem. Abstracts Reg. No. 82667-45-6); and 
tris(hydroxymethyl)(1-hydroxy-2-propenyl)phosphonium salts (Chem. 
Abstracts Reg. No. 73082-48-1). 
An example of a polymerizable monomer that contains both a weak acid group 
and a strong cationic group is 
N-(4-carboxy)benzyl-N,N-dimethyl-2-[(2-methyl-1-oxo-2-propenyl)-oxy] 
ethanaminium chloride. 
It is possible to add strong cationic functionality to an already prepared 
polymer. For example, a polymerizable monomer having a weak acid group can 
be copolymerized with a polymerizable non-interfering monomer containing 
an electrophilic group, such as a vinylbenzyl halide or a glycidyl 
methacrylate, to form a polymer having a weak acid group and an 
electrophilic group. This polymer can then be post-reacted with a 
nucleophile such as a tertiary amine or a dialkyl sulfide, which can 
displace the halide group or oxirane groups and form a benzylonium salt as 
illustrated: 
##STR2## 
where A is a pendant weak acid group; Ar is an aromatic group, preferably 
a phenyl group; L is a leaving group, preferably a halide group, more 
preferably a chloride group; and Nu is preferably a dialkyl sulfide such 
as dimethyl sulfide and diethyl sulfide; a cyclic sulfide such as 
tetrahydrothiophene; or a tertiary amine such as trimethyl amine, triethyl 
amine, tripropyl amine, tributyl amine, and triethanol amine. 
In another example of adding strong cationic functionality to an already 
prepared polymer, a polymer backbone that contains pendant acid groups and 
a tertiary amine or a sulfide can be post-reacted with a suitable 
alkylating reagent such as an alkyl halide to form a polymer that contains 
acid groups and strong cationic groups: 
##STR3## 
where RL is an alkylating reagent. 
Examples of non-interfering polymerizable monomers include acrylates such 
as methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl 
acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, and allyl acrylate; 
methacrylates such as methyl methacrylate, ethyl methacrylate, butyl 
methacrylate, allyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl 
methacrylate, and 2-hydroxypropyl methacrylate; alkenyl aromatic 
hydrocarbons such as 4-methacryloxy-2-hydroxy-benzophenone, 
2-(2'-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole; and C.sub.1 
-C.sub.4 alkyl- or alkenyl-substituted styrenes, preferably styrene, 
.alpha.-methylstyrene, vinyltoluene, and vinylbenzyl chloride. Other 
examples of non-interfering species include C.sub.3 -C.sub.18 
-perfluoroalkyl methacrylates such as 2-(perfluorooctyl)ethyl 
methacrylate; C.sub.3 -C.sub.18 -perfluoroalkyl acrylates such as 
2-[ethyl[(heptadecafluorooctyl)-sulfonyl]amino]ethyl 2-propenoate; and 
C.sub.3 -C.sub.18 -perfluoroalkyl vinylbenzenes. (See U.S. Pat. No. 
4,929,666, column 4, lines 54 to 68, and column 5, lines 1 to 30.) 
The ratio of the pendant weak acid groups to the pendant strong cationic 
groups is application dependent, but is generally in the range of about 
4:1 to about 1:4. The ratio of the structural units formed from the 
polymerization of the polymerizable non-interfering monomer to the weak 
acid groups and the strong cationic groups varies depending on the percent 
solids of the stable aqueous dispersion, but is preferably not less than 
70:30, more preferably not less than 80:20, more preferably not less than 
90:10, and most preferably not less than 94:6; and preferably not greater 
than 99.5:0.5, more preferably not greater than 99:1, and most preferably 
not greater than about 98:2. 
In general, the higher the solids content, the lower the concentration of 
the total ionic species that is required to form the quick-set coatings. 
The solids content of the stable aqueous dispersion is application 
dependent, but preferably not less than 10, more preferably not less than 
20, and most preferably not less than 30 weight percent, and preferably 
not more than 60, more preferably not more than 55, and most preferably 
not more than 50 weight percent. 
The stable aqueous dispersion can be prepared by any suitable means, and is 
advantageously prepared by the steps of: 1) preparing a seed latex; 2) 
diluting the seed latex with water; 3) contacting the diluted solution 
with a radical initiator, a polymerizable non-interfering monomer, a 
polymerizable weak acid monomer, and a strong cationic monomer; and 4) 
polymerizing the solution from step 3 under such conditions to form a 
stable aqueous dispersion having non-interfering groups, pendant strong 
cationic groups, and pendant weak acid groups. 
The seed latex is preferably prepared by emulsion polymerization in a batch 
process using a cationic surfactant. The seed latex acts as a locus of 
polymerization for subsequent monomer addition, so that the formation of 
new particles is minimized and greater uniformity in the distribution of 
particle size in the final product is achieved. Thus, the monomer or 
monomers used to prepare the seed latex are chosen to form particles that 
have an affinity for the monomers subsequently added, so that 
polymerization occurs preferentially in or on the seed latex particles. 
The extent to which the seed latex is diluted in step 2 is a function of 
the desired particle size and the percent solids in the final latex, and 
can be readily determined by one of ordinary skill in the art. 
It is also possible to prepare a stable aqueous dispersion from a preformed 
polymer. The preformed polymer can be dissolved in a suitable solvent, 
then dispersed in water by any suitable method. The solvent can then be 
removed and the solids content adjusted to form a so-called artificial 
latex. 
The stable aqueous dispersion may optionally contain fillers, pigments, 
dyes, fungicides, bateriacides, thickeners, coalescing aids, and 
defoamers, that do not cause premature coagulation of the dispersion. 
Fillers may include clays, silica, ceramics, and other stable aqueous 
dispersions. 
A fast-setting coated material can be prepared when the stable aqueous 
dispersion that contains the polymer having the strong cationic groups, 
the weak acid groups, and optionally, structural units formed from the 
polymerization of the polymerizable non-interfering monomer, is contacted 
with a substrate having a contact surface which is, or is treated to be, 
sufficiently basic so that the stable aqueous dispersion sets in less than 
the time required for a latex that only contains pendant strong cation 
groups or pendant weak acid groups (but not both) to set, preferably 
within 5 minutes, and more preferably within 3 minutes, and most 
preferably within 1 minute. The basicity of the substrate required to 
cause the dispersion to set rapidly depends on the pK.sub.a of the weak 
acid groups on the polymer. The lower the pK.sub.a of the weak acid, the 
weaker the base required to cause rapid setting. The stronger the base and 
the higher the concentration of the base, the faster the setting. 
Though not bound by theory, it is believed that the rapid dry-to-the-touch 
coating is formed by a coacervation process. In this process, the basic 
substrate acts as a proton sink by extracting protons from the weak acid 
groups to form the conjugate base, which can then bind irreversibly and 
rapidly with the strong cationic group to form an irreversible 
crosslinking network. This crosslinked network is believed to represent 
the coating after it has set. 
##STR4## 
In the above illustration, B.sup.- is a basic moiety that is associated 
with the substrate. BH, the conjugate acid of B.sup.-, preferably has a 
higher pK.sub.a than the weak acid (which is a carboxylic acid group in 
the illustration). However, this need not be the case. For example, if 
there is a sufficient amount of B.sup.- present on the substrate, the 
conjugate acid BH may actually have a pK.sub.a that is the same as, or 
lower than, the pK.sub.a of the weak acid, presumably because once the 
proton is abstracted by B.sup.-, the process is irreversible. 
An indication of the surface basicity may be provided, for example, by 
contacting the surface of the substrate with water-wetted pH paper. The pH 
necessary to induce coacervation will be depend on the pK.sub.a of the 
weak acid; for a polymer containing pendant carboxylic acid units, for 
example, the pH of the water in contact with the substrate is not less 
than 6, more preferably not less than 8, and most preferably not less than 
10. 
The substrate may be inherently basic. Such substrates include cementatious 
materials such as Portland cement, aluminous cement, inorganic mortar, or 
cementatious fiber board. The substrate, if not inherently basic, may be 
treated to be sufficiently basic to cause the coated material to quickly 
set. For example, the surface of the substrate may be treated with an 
aqueous solution having a pH that is greater than the pK.sub.a of the weak 
acid, prior to, or concurrent with, the application of the stable aqueous 
dispersion of the polymer to the surface of the substrate. Such basic 
aqueous solutions include, but are not restricted to, alkali metal and 
alkaline earth metal phosphates, carbonates, bicarbonates, and hydroxides. 
Preferred substrates that can be treated with base include metal, glass, 
paper, plastic, cloth, wood, and leather. The substrate may also take a 
specific shape such as the shape of a hand, for the purposes of forming a 
latex glove. 
The substrate may also include a filler material that renders the surface 
of the substrate sufficiently basic to cause the stable aqueous dispersion 
of the polymer to form a fast-setting coating. Lime and calcium carbonate 
are examples of such filler materials. 
In another embodiment of the present invention, fast-setting coatings can 
be prepared by contacting a substrate with a first stable aqueous 
dispersion that contains a polymer having structural units formed from the 
polymerization of a polymerizable strong cationic monomer; and a second 
stable aqueous dispersion that contains a polymer having structural units 
formed from the polymerization of a weak acid monomer. The stable aqueous 
dispersions may be contacted with the substrate in any order or 
substantially concurrently, preferably substantially concurrently, and 
surprisingly, the substrate need not be basic or rendered basic. The 
second stable aqueous dispersion is preferably stabilized in the presence 
of an anionic surfactant such as a sulfate, including sodium lauryl 
sulfate, or DOWFAX EB.TM. surfactant (obtained by The Dow Chemical 
Company). The sulfate may also be present as end-groups on the polymer 
chains resulting from the use of persulfate initiator during the 
polymerization of the anionic latex. The first and second stable aqueous 
dispersions are preferably applied to the substrate using a plural 
component sprayer. 
Both the first and the second stable aqueous dispersions preferably have 
structural units formed from the polymerization of the polymerizable 
non-interfering monomer. The mole percent of structural units formed from 
the polymerization of the strong cationic monomer in the first stable 
aqueous dispersion of the polymer is preferably not less than 0.5, more 
preferably not less than 1, and most preferably not less than 2 mole 
percent, and preferably not greater than about 20, more preferably not 
greater than 10, and most preferably not greater than 5 mole percent, 
based on the total mole percent of strong cationic monomer and 
non-interfering monomer. The mole percent of structural units formed from 
the polymerization of the weak acid monomer in the second stable aqueous 
dispersion of the polymer is also preferably not less than 0.5, more 
preferably not less than 1, and most preferably not less than 2 mole 
percent, and preferably not greater than about 20, more preferably not 
greater than 10, and most preferably not greater than 5 mole percent, 
based on the total mole percent of strong cationic monomer and 
non-interfering monomer. 
The coated materials of the present invention have wide applicability, 
including painted concrete roads, where a fast-setting coating can be 
prepared in the absence of solvents or crosslinking curatives, by merely 
applying the stable aqueous dispersion of the polymer (or polymers) to the 
surface of the road. Other uses include primers for stucco houses or 
cementatious fiber boards. The aqueous dispersions can also be used to 
coat cured or uncured cement to reduce water evaporation, thereby 
improving the physical properties of the final concrete. The dispersions 
can also be used to prepare latex gloves or condoms by dipping a basic 
form or mold into the stable aqueous dispersion to cause rapid setting of 
the dispersion on the form. 
In the most preferred formulations, the stable aqueous dispersions used to 
prepared the coated materials have a shelf-stability of at least 6 months, 
preferably at least one year. The formulations may also contain additives 
such as pigments, dyes, fungicides, and bacteriacides. 
The following examples are for illustrative purposes only and are not 
intended to limit the scope of this invention.

EXAMPLE 1--PREATION OF A FAST-SETTING CLEAR COATING 
The stable aqueous dispersion was prepared in a two-step process. First, a 
cationic surfactant stabilized polystyrene seed latex prepared using a 
batch process. Next, a portion of the seed latex is used in a continuous 
addition process to prepare a second, film-forming latex containing a 
carboxylic acid and a quaternary ammonium functional monomer. 
The cationic latex seed was prepared in the following manner. To a 1-liter, 
3-neck, glass reaction flask equipped with a nitrogen inlet, a reflux 
condenser with a nitrogen outlet, and a mechanical stirrer was added 
styrene (100 g), ARQUAD.TM.18-50 octadecyltrimethlammonium chloride 
surfactant (a trademark of AkzoNobel, 20 g active), hydrogen peroxide (3.3 
g, 1.0 g active) water (200 g) and iron sulfate solution (0.25 g in 100 g 
water). The flask was heated to 70.degree. C. over 2 hours with stirring 
under nitrogen, after which the stirring was stopped and the heating 
source removed. The latex seed was allowed to sit overnight in the flask. 
The result was an opaque, high viscosity dispersion with 35.8 percent 
solids. The particle size was 407 .ANG. (mean value and 393 .ANG. (median 
value). 
The film-forming latex was prepared from the cationic seed latex using a 
continuous addition polymerization method. Syringe pumps were used as the 
continuous addition control means. To a 2-liter, 3-neck, glass reaction 
flask equipped with a nitrogen inlet, a reflux condenser with a nitrogen 
outlet, and a mechanical stirrer was added water (452.3 g) and the 
cationic seed latex (8.8 g). The flask was heated to 60.degree. C. and 
stirred. Table 1 shows the solutions that were prepared for continuous 
addition. 
TABLE 1 
______________________________________ 
Stream Component Amount 
______________________________________ 
1 Butyl Acrylate 176 g 
Methyl Methacrylate 124 g 
Methacrylic Acid 5.3 g 
2 M-Quat.sup.a 17.3 g (12.8 g active) 
3 t-Butylhydroperoxide 
1.8 g (1.3 g active) 
4 Sodium Formaldehyde Sulfoxylate 
0.96 g in 10 ml water 
______________________________________ 
.sup.a 2[(methacryloyloxy)ethyl] trimethylammonium chloride obtained as a 
74 percent aqueous solution from Bimax Inc., 717 Chesapeake Ave., 
Baltimore, MD 21225 
The components from the four streams were added over the first four hours 
of polymerization. After completion of addition, polymerization was 
continued at 60.degree. C. for 0.5 hour. The resulting latex was filtered 
and found to have a solids content of 37.0 percent. Table 2 shows the 
composition of the latex. 
TABLE 2 
______________________________________ 
Molecular 
Monomer Weight percent 
Mole percent 
weight g/mol 
______________________________________ 
Butyl Acrylate 
55.3 50.2 128.1 
Methyl Methacrylate 
39.0 45.3 100.1 
Methacrylic Acid 
1.7 2.3 86.1 
M-Quat 4.0 2.3 207.7 
______________________________________ 
The particle size was 1550 .ANG. (mean) and 1450 .ANG. (median). 
A clear, fast-setting coating was prepared by applying a coat of the latex 
to a cementations fiber board using a paint brush. The sample was observed 
at 22.4.degree. C. and 65 percent relative humidity. Thirty seconds after 
application of the latex, the coated, cementations fiber board was placed 
under running water. The coating showed no signs of bleeding, running or 
any detrimental effects. Within twenty minutes of application the latex 
dried to a clear film. 
EXAMPLE 2--Preparation of a Fast-Setting Pigmented Coating 
A titanium dioxide pigment slurry is used to prepare a pigmented latex 
coating to demonstrate that a fast-setting coating can be obtained on an 
alkaline surface using pigmented coating formulations. The composition of 
the titanium dioxide pigment slurry is given in Table 3. 
TABLE 3 
______________________________________ 
Amount 
Component (weight percent) 
______________________________________ 
Water 31.0 
Ti-Pure .TM. R-900 Titanium Dioxide.sup.a 
66.5 
RHODAQUAT .TM. M242C/26 Cationic Surfactant.sup.b 
2.20 
FOAMASTER .TM. V Nonionic Surfactant.sup.c 
0.30 
______________________________________ 
.sup.a (a trademark of E. I. du Pont de Nemours and Company) 
.sup.b (a trademark of RhonePoulenc) 
.sup.c (a trademark of Henkel) 
The titanium dioxide pigment slurry was prepared by mixing the titanium 
dioxide into the water containing the surfactants under high speed 
shearing to form a smooth, viscous dispersion. To a glass jar was added 
29.4 g of this slurry, then 5.5 g of deionized water. The diluted slurry 
was mixed to form a uniform suspension. The latex having the composition 
shown in Table 2 and a total solids content of 37.4 wt % was then mixed 
with the slurry at about 350 rpm for 3 minutes. The resulting dispersion 
had the consistency and color of whole milk. A coating of this dispersion 
was applied with a paint brush onto a cementations fiber board. After 1 
minute the coating on the board was placed under a stream of running 
water. There was no indication of pigment loss or any detrimental effect 
to the coating. About 10 mL of the pigmented latex was transferred to a 
spray bottle pressurized with nitrogen to about 30 psig. A small amount of 
the pigmented latex was spayed onto a cementatious fiber board. A uniform 
coating of the cementations fiber board was obtained. Again, after about I 
minute, the coated board was placed under a stream of running water. There 
was no indication of pigment loss or any detrimental effect on the 
coating. 
EXAMPLE 3--Forming a Fast-Setting Coating on Base-Treated Filter Paper 
A 9.0-cm circle of Whatman #1 qualitative filter paper was cut into a 5.7 
cm.times.7.0 cm rectangle, then taped to a glass plate along all edges. 
The paper was soaked with saturated sodium bicarbonate solution, then 
blotted with paper towels to remove excess fluid. A coating of latex 
having a composition described in Table 2 was then spread on the coated 
paper. Rapid setting of the latex film on the paper was apparent in less 
than 15 seconds. After about 2 minutes the coating was completely 
dry-to-the-touch. After 3 minutes, a drop of water was place onto the 
coated paper and beaded with no visible signs of bleeding. This drop test 
was repeated several times with the same results. 
EXAMPLE 4--Forming a Fast-Setting Coating on Base-Treated Newspaper 
An 11-inch.times.17-inch (28-cm.times.43-cm) sheet of paper was suspended 
in a hood and lightly sprayed with a 1.0 percent solids sodium bicarbonate 
solution, then allowed to dry overnight. The following day, the sample was 
coated with a thin layer of the latex having a composition described in 
Table 2. The coating set in less than 10 seconds, it displayed no 
indications of bleeding into the paper, and it produced a glossy surface. 
EXAMPLE 5--Forming a Fast-Setting Coating on Base-Treated Cloth 
A swatch of common clothing material (60% cotton, 40% polyester) was dipped 
into a 1.0 percent by weight solution of sodium bicarbonate and allowed to 
soak for 5 minutes. The swatch was then removed, squeezed as dry as 
possible and taped to a glass plate. An 8-mil drawdown bar was then used 
to spread across the swatch a sample of the latex having a composition 
described in Table 2. The latex was dry-to-the-touch within 10 seconds. 
Within 2 minutes, the excess water could be squeezed from the coated 
material using a high-pressure laminated plastic roller. Within 30 minutes 
the latex dried to a clear flexible coating with some level of gloss. 
EXAMPLE 6--Plural Component Spraying with Alkaline Material 
A Binks Mach 1 PCX Plural Component paint sprayer was used to apply a 
blended stream of a latex having a composition described in Table 2, and a 
3.0 percent by weight solution of K.sub.2 HPO.sub.4 to a sample of 
oak-laminated plywood. The atomizing pressure was set at about 72 psig and 
both storage vessels were set at approximately 35 psig. The coating became 
dry-to-the-touch rapidly (less than 30 seconds). Two aluminum coupons 
(Q-panel, Inc.) were also coated with similar results. The atomizing 
pressure was decreased to 45 psig and the storage vessels pressured 
dropped to 10 psig. The procedure was then repeated. The rate at which the 
coating became dry-to-the -touch was unaffected, but the surface of the 
coating was improved. A "Cold Rolled Steel" coupon (Q-panel) was also 
coated easily using the same operating conditions and obtaining similar 
results. 
EXAMPLE 7--Plural Component Spraying Using an Anionic Latex 
The paint sprayer described in Example 6 was used to apply a blended stream 
of a latex having a composition described in Table 2, and an anionic latex 
having a composition described in Table 4. 
TABLE 4 
______________________________________ 
Monomer Weight Percent 
Mole Percent 
______________________________________ 
Butyl Acrylate 50.5 43.9 
Methyl Methacrylate 
43.0 47.9 
Methacrylic Acid 
5.95 7.7 
Allyl Methacrylate 
0.52 0.46 
______________________________________ 
The atomizing pressure was set to 40 psig and the storage vessel pressure 
was set to 7.5 psig. The spray was applied to a glass plate and the 
resultant coating set in less than 30 seconds. 
EXAMPLE 8--Plural Component Spraying with an Anionic Material 
The paint sprayer described in Example 6 was used to apply a blended stream 
of latex, having a composition described in Table 2, and an aqueous 
anionic corrosion inhibiting solution, consisting of 4.45% by weight of 
MIRANOL CS.RTM. (manufactured by Rhone Poulenc). The atomizing pressure 
was set at 35 psig and the storage vessel pressure was set at 5 psig. The 
coating was applied to an untreated aluminum coupon, a pre-treated 
aluminum coupon (Q-panel, Inc.) and a pre-coated sample of PTO. The spray 
formed an acceptable coating and set in less than 30 seconds on all three 
test panels. 
EXAMPLE 9--Plural Component Spraying with Cationic Latex and Anionic Latex 
The paint sprayer described in Example 6 was used to apply a blended stream 
of cationic latex, having a composition described in Table 5, and an 
anionic latex, having a composition as described in Table 4. The atomizing 
pressure was set at 35 psig and the storage vessel pressures were set at 
10 psig. The coating was applied to an untreated glass plate. The spray 
formed an acceptable coating and coacervated in less than 20 seconds. It 
set in less than 30 seconds. The plate was placed under running water 
after 1 minute with no detrimental effect to the coating. Two aluminum 
coupons, one of which was pretreated with phosphate (Q-panel, Inc.), were 
also coated. The spray formed an acceptable coating and coacervated in 
less than 15 seconds on both test panels. 
TABLE 5 
______________________________________ 
Monomer Weight Percent 
Mole Percent 
______________________________________ 
Butyl Acrylate 56.2 51.3 
Methyl Methacrylate 
39.7 46.5 
M-Quat 4.1 2.3 
______________________________________