Aqueous cold setting paint

In an aqueous cold setting paint, a specific copolymer and an epoxy resin being soluble in an alcoholic sovlent are incorporated. The specific copolymer is obtained by a solution polymerization of (a) a monomer having ethylenic unsaturated double bond and a nitrogen-containing base, (b) a monomer having ethylenic unsaturated double bond and a phosphoric acid group or a salt thereof or an ester thereof, (c) a monomer having ethylenic unsaturated double bond and carboxylic acid group or a salt thereof and (d) a monomer having ethylenic unsaturated double bond which is copolymerizable with a component (a), (b) or (c) or further treatment of the resulting copolymer with a base.

BACKGROUND OF THE INVENTION 
1. Field of the Invention: 
The present invention relates to a novel aqueous cold setting paint which 
is preferably used as paints for outer parts, iron constructions and 
concretes. 
2. Description of the Prior Arts: 
The cold setting paints used for these usages can be classified to solvent 
type paints and aqueous type paints. The solvent type paints have been 
mainly used. However, it has been required to use the aqueous type paints 
instead of the solvent type paints from the viewpoints of environmental 
problem, fire, labour safety and hygiene problems. 
The aqueous type paints are further subclassified to emulsion type paints, 
microemulsion type paints and water soluble type paints. 
The emulsion type paints have been widely used in practice. However, the 
emulsion type paints have inferior to the conventional solvent type paints 
since the water resistance and the durability are disadvantageously low. 
The water soluble type paints can not be replaced to the conventional 
solvent type paints since the water resistance, the durability and the 
weathering resistance are remarkably low. 
The microemulsion type paints have been developed but they can not be 
replaced to the conventional solvent type paints since the chemical 
resistance and the weathering resistance are still inferior in the present 
technical level. 
There have been many paints which are hardened by a heating or a radiation. 
Various processes for preparing these type paints have been known. 
However, it has been rare to obtain an aqueous cold setting paint. 
Processes for preparing emulsions of vinyl type polymers with an emulsifier 
of a maleinized polybutadiene have been disclosed in Japanese Pat. 
Publication No. 43381/1974 and Japanese Unexamined Pat. Publications Nos. 
73488/1973 and 34683/1972. However, the emulsions obtained by these 
processes have disadvantages of inferior alkali resistance and weathering 
resistance. 
Aqueous compositions containing a drying oil, a semidrying oil and an 
unsaturated aliphatic acid or a derivative thereof or processes for 
preparing the compositions have been disclosed in Japanese Pat. Nos. 
32414/1972, 4214/1975 and 18503/1975. However, the compositions obtained 
by these processes have disadvantages of inferior alkali resistance and 
weathering resistance. 
In order to overcome these disadvantages, the inventors have studied and 
found that aqueous paints prepared by admixing a specific acryl type 
copolymer with a water soluble epoxy resin have excellent solvent 
resistance, weathering resistance, chemical resistance, water resistance, 
adhesiveness, processibility and economical advantage. 
The inventors have further studied to improve these aqueous paints and have 
found that aqueous paints comprising a specific copolymer and an alcoholic 
solvent soluble epoxy resin impart superior water resistance. The present 
invention has been attained by the finding. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to overcome these disadvantages 
and to provide an aqueous cold setting paint which imparts excellent 
characteristics being superior to those of the conventional solvent type 
paints. 
It is another object of the present invention to obtain an improved aqueous 
cold setting paint which has excellent water resistance. 
The foregoing and other objects of the present invention have been attained 
by providing an aqueous cold setting paint which comprises 
(A) a copolymer obtained by a solution polymerization of 
(a) a monomer having ethylenic unsaturated double bond and a 
nitrogen-containing base, 
(b) a monomer having ethylenic unsaturated double bond and a phosphoric 
acid group or a salt thereof or an ester thereof, 
(c) a monomer having ethylenic unsaturated double bond and carboxylic acid 
group or a salt thereof, and 
(d) a monomer having ethylenic unsaturated double bond which is 
copolymerizable with the component (a), (b) or (c); or 
(B) a copolymer obtained by treating the copolymer (A) with a base and 
(C) an epoxy resin being soluble in an alcoholic solvent. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The monomers used in the present invention will be illustrated as follows. 
(a) The monomers having ethylenic unsaturated double bond and a 
nitrogen-containing base include, 
(1) aminoalkyl acrylates (monomers) having the formula 
##STR1## 
wherein R.sub.1 represents hydrogen or a halogen atom or a C.sub.1 
-C.sub.5 alkyl group; and R.sub.2 represents hydrogen atom or a C.sub.1 
-C.sub.6 alkyl group and R.sub.3 represents hydrogen atom or a C.sub.1 
-C.sub.6 alkyl group and n represents an integer of 1 to 6, for example 
acrylates such as dimethylamino methyl acrylate, diethylamino methyl 
acrylate, dibutylamino methyl acrylate, dihexylamino methyl acrylate, 
methylamino methyl acrylate, butylamino methyl acrylate, dimethylamino 
ethyl acrylate, diethylamino ethyl acrylate, di(t-butyl)amino ethyl 
acrylate, diisohexylamino ethyl acrylate, methylamino ethyl acrylate, 
butylamino ethyl acrylate, amylamino ethyl acrylate, cyclohexylamino ethyl 
acrylate, dihexylamino propyl acrylate, di(t-butyl)amino hexyl acrylate 
and hexylamino hexyl acrylate; and methacrylates such as dimethylamino 
ethyl methacrylate, diethylamino ethyl methacrylate, dimethylamino 
pentacrylate and dimethylamino chloroacrylate. 
(2) the vinyl pyridines such as 4-vinyl pyridine, 2-vinyl pyridine and 
2-methyl-5-vinylpyridine. 
One or more than one of the monomers can be used. 
The amount of the monomers is usually in a range of 0.01 to 20 wt.% 
preferably 0.5 to 8 wt.% based on the total monomers. 
When the content of the monomer is less, the solvent resistance is inferior 
whereas when the content of the monomer is greater, the chemical 
resistance is inferior. 
It is most preferable to use dimethylamino ethyl methacrylate or 4-vinyl 
pyridine as the monomer having nitrogen-containing base group. 
(b) The monomers having ethylenic unsaturated double bond and a phosphoric 
acid group, a salt thereof or an ester thereof include monomers having the 
formula 
##STR2## 
wherein R.sub.1 represents hydrogen atom or a C.sub.1 -C.sub.5 alkyl group 
and R.sub.2 represents a C.sub.2 -C.sub.10 straight chain or branched 
chain alkylene group or a halogen substituent of the alkylene group and 
R.sub.3 represents hydrogen atom or a C.sub.1 -C.sub.10 alkyl group and 
salts such as ammonium, amine, sodium and potassium salts thereof and 
esters thereof, for examples, primary phosphoric esters of acrylates and 
methacrylates having hydroxyl group such as mono(2-hydroxyethyl acrylate) 
acid phosphate, mono(2-hydroxyethyl methacrylate) acid phosphate, 
mono(2-hydroxypropyl acrylate) acid phosphate, mono(2-hydroxypropyl 
methacrylate) acid phosphate, mono(3-hydroxypropyl acrylate) acid 
phosphate, mono(3-hydroxypropyl methacrylate) acid phosphate and 
mono(3-chloro-2-hydroxypropyl methacrylate) acid phosphate, and salts 
thereof and esters thereof. 
One or more than one of the monomers can be used. 
The amount of the monomer is usually in a range of 0.01 to 20 wt.% 
preferably 0.5 to 8 wt.% based on the total monomers. 
When the content of the monomer is less, the solvent resistance is inferior 
whereas when the content of the monomer is greater, the chemical 
resistance is inferior. 
It is most preferable to use mono(2-hydroxyethyl methacrylate) acid 
phosphate or amine salt thereof. 
(c) The monomers having ethylenic unsaturated double bond and a carboxylic 
acid group or salts thereof include acrylic acid, methacrylic acid, maleic 
acid, and itaconic acid and salts thereof. 
One or more than one of the monomers can be used. 
The amount of the monomer is usually in a range of 0.01 to 20 wt.% 
preferably to 0.5 to 8 wt.% based on the total monomers. 
(d) The monomers having ethylenic unsaturated double bond which is 
copolymerizable with the component (a), (b) or (c) include, 
(1) nonfunctional monomers for example, acrylates such as methyl acrylate, 
ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl 
acrylate and cyclohexyl acrylate; methacrylates such as methyl 
methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl 
methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate; 
aliphatic acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl 
butyrate and vinyl stearate; aromatic monoolefins such as styrene, 
chlorostyrene, .alpha.- or .beta.-methyl styrene and vinyl toluene; vinyl 
esters such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl 
ether, octyl vinyl ether, lauryl vinyl ether, stearyl vinyl ether, phenyl 
vinyl ether, alkyl substituted phenyl vinyl ether and ethoxyphenyl vinyl 
ether; and others such as acrylonitrile and methacrylonitrile; 
(2) functional monomers for example, hydroxyalkyl acrylates such as 
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 3-hydroxypropyl 
acrylate; hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate, 
2-hydroxypropyl methacrylate and 3-hydroxypropyl methacrylate, 
nitrogen-containing unsaturated compounds such as acrylamide, ethyl 
acrylamide, vinyl pyrrolidone and vinyl methyl imidazole; hydroxy group 
containing unsaturated compounds such as allyl alcohol, and N-methylol 
acrylamide; sulfur containing unsaturated compounds such as sulfomethyl 
acrylate, 2-sulfoethyl methacrylate, vinyl sulfonic acid and paratoluene 
sulfonic acid and salts thereof. 
One or more than one of the monomers can be used. 
The amount of the monomer is usually in a range of 0 to 20 wt.% preferably 
0 to 8 wt.% based on the total monomers. 
When the content of the monomer is greater, the durability and the chemical 
resistance is inferior. 
The copolymer (A) obtained by using the components (a), (b), (c) and (d) or 
the copolymers (B) obtained by adding a base can be prepared by a 
conventional solution polymerization. 
In this case, it is possible to use a solvent, an organic solvent or an 
aqueous solution containing a solvent. 
Suitable solvents include alcohols such as methanol, ethanol, isopropanol 
and butanol; cellosolves such as methyl cellosolve, ethyl cellosolve and 
butyl cellosolve; and ethyl acetate, methyl ethyl ketone, toluene and 
xylene and mixtures of water and a solvent. 
One or more than one solvent can be used. 
It is especially effective to use isopropanol. 
The monomers can be charged at the beginning of the polymerization or can 
be sequentially added during the polymerization. 
The copolymers (B) can be also prepared by adding a base such as ammonia, 
monomethylamine, dimethylamine, trimethylamine, monoethylamine, 
triethylamine, ethylenediamine, pyridine, sodium hydroxide, potassium 
hydroxide and dimethylamino ethanol to the copolymer (A) after the 
polymerization. 
It is preferable to add amines especially effective to add triethylamine. 
The epoxy resins being soluble in an alcoholic solvent are compounds having 
two or more epoxides which are soluble in ethyl cellosolve but sparingly 
soluble (substantially insoluble) in water. 
Suitable epoxy resins include aliphatic polyglycidyl ethers such as 
neopentylglycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 
trimethylolpropane triglycidyl ether, and glycerine triglycidyl ether; 
aromatic diglycidyl ethers such as 2,2-bis(4-hydroxyphenyl)propane 
diglycidyl ether and polyoxyalkylene bisphenol A glycidyl ether; alicyclic 
diglycidyl ethers such as 2,2-bis(4-hydroxycyclohexyl)propane diglycidyl 
ether, cyclohexanediol glycidyl ether and polyoxyalkylene hydrogenated 
bisphenol A diglycidyl ether, glycidyl amines such as diglycidyl aniline. 
It is most preferable to use trimethylpropane triglycidyl ether as the 
epoxy resin being soluble in an alcoholic solvent. 
One or more than one epoxy resins can be used. 
The amount of the epoxy resin being soluble in an alcoholic solvent is 
usually in a range of 0.1 to 98 wt.% preferably 1 to 50 wt.% based on the 
total amounts of the copolymer (A) or the copolymer (B) and the expoxy 
resin. 
The aqueous paint comprising the copolymer (A) or the copolymer (B) and the 
epoxy resin (C) being soluble in an alcoholic solvent can be prepared by 
the conventional simple mechanical processes such as blending and 
kneading. It is also possible to add water soluble or hydrophilic solvents 
such as acetone, isopropanol, ethyl cellosolve, butanol and methyl ethyl 
ketone. 
In the preparation of the paint, suitable commercially available pigments 
and additives can be incorporated, and suitable conventional apparatus for 
preparing a paint such as a ball mill, a sand grind mill and a three 
rolling mill, can be used. 
The aqueous cold setting paints of the present invention have the following 
significant industrial effects and advantages. 
(1) The paints are aqueous paints whereby they are advantageous from the 
viewpoints of saving of raw materials, environmental problem, fireproof 
and labour safety and hygiene. 
(2) The paints are cold settable whereby savings of energy and raw 
materials can be expected. 
(3) The paints are cold settable whereby any energy source (apparatus) such 
as heat source and radiation source is not required in the application to 
be advantageous in industrial applications. 
(4) It is possible to remarkably increase a setting speed by heating it 
with a simple heat source and to increase processing efficiency. 
(5) The aqueous cold setting paints of the present invention have excellent 
solvent resistance, chemical resistance, weathering resistance, 
adhesiveness processibility and economical advantage whereby they can be 
used for various applications.

Having now generally described the invention, a further understanding can 
be attained by reference to certain specific Examples which are provided 
herein for purposes of illustration only and are not intended to be 
limiting in any manner, unless otherwise specified. 
EXAMPLE 1 
In a 1 liter reactor equipped with a stirrer and a condenser, 170 wt.parts 
of isopropyl alcohol was charged and the reactor was purged with nitrogen 
and a mixture of 3 wt.parts of dimethylamino ethyl acrylate, 2 wt.parts of 
mono(2-hydroxyethyl methacrylate) acid phosphate, 5 wt.parts of 
methacrylate, 30 wt.parts of styrene, 61 wt.parts of methyl methacrylate, 
99 wt.parts of ethyl acrylate, 3 wt.parts of triethylamine, 20 wt.parts of 
isopropyl alcohol and 1.6 wt.part of azobisisobutyronitrile was added 
dropwise to the isopropyl alcohol under stirring during 2 hours. Two hours 
after the addition, 10 wt.parts of isopropyl alcohol and 0.4 wt.part of 
azobisisobutyronitrile were added to the mixture and a solution 
polymerization was continued at 82.degree. C. for 2 hours to obtain a 
copolymer (A). 
Then, 267 wt.parts of water was added to the copolymer (A) and the mixture 
was stirred for 30 minutes and 210 wt.parts of the solvent was removed at 
75.degree. to 80.degree. C. under a reduced pressure and 66 wt.parts of 
ethyl cellosolve and 3 wt.parts of triethylamine were added to the 
residue. The mixture was stirred at 82.degree. C. for 1 hour to obtain an 
aqueous resin slurry (B) having a solid content of 37.7%, pH of 9.3 and a 
viscosity of 1200 cps (rotary viscometer: 20.degree. C.). 
Then, 28 wt.parts of a rutile form titanium oxide was added to 100 wt.parts 
of the aqueous resin slurry and the mixture was kneaded in a test paint 
shaker and 2 wt.parts of trimethylolpropane triglycidyl ether was added to 
the mixture to obtain a paint. The paint was coated on a concrete. The 
coated layer was kept at 72 hours in the room and tests for the paint were 
carried out. The results are shown in Table 1. 
REFERENCE 1 
In accordance with the process of Example 1 the polymerization was carried 
out without using dimethylamino ethyl ethacrylate and the resulting 
copolymer was used for the preparation of the paint and the tests were 
carried out. The results are shown in Table 1. 
REFERENCE 2 
In accordance with the process of Example 1, the polymerization was carried 
out except using methacrylate instead of mono(2-hydroxyethyl methacrylate) 
acid phosphate and the resulting copolymer was used for the preparation of 
the paint and the tests were carried out. The results are shown in Table 
1. 
EXAMPLE 2 
In a 1 liter reactor equipped with a stirrer and a condenser, 150 wt.parts 
of isopropyl alcohol and 50 wt.parts of ethyl cellosolve were charged and 
the reactor was purged with nitrogen and a mixture of 10 wt.parts of 
4-vinyl pyridine, 6 wt.parts of mono(2-hydroxyethyl methacrylate) acid 
phosphate, 6 wt.parts of acrylic acid, 83 wt.parts of methyl methacrylate, 
95 wt.parts of ethyl acrylate, 6 wt.parts of triethylamine, 30 wt.parts of 
isopropyl alcohol and 1.6 wt.parts of benzoyl peroxide was added dropwise 
during 4 hours. Two hours after the addition, 20 wt.parts of isopropyl 
alcohol and 0.4 wt.part of benzoyl peroxide were added to the mixture and 
the solution polymerization was continued at 80.degree. C. for 4 hours to 
obtain a copolymer (A). 
Then, 280 wt.parts of water was added to the copolymer (A) and the mixture 
was stirred for 30 minutes and then, 200 wt.parts of the solvent was 
removed at 75.degree. to 80.degree. C. under a reduced pressure and then, 
the residue was cooled to 50.degree. C. and 15 wt.parts of 10% ammonia 
water was added and the mixture was stirred for 1 hour to obtain an 
aqueous resin slurry (B) having a solid content of 34.7%, pH of 9.5 and a 
viscosity of 5700 cps (rotary viscometer: 20.degree. C.). 
Then, 26 wt.parts of a rutile form titanium oxide and 100 wt.parts of the 
aqueous resin slurry (B) were kneaded in a ball mill and 10 wt.parts of 
2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether to obtain a paint. 
The paint was coated on an aqueous primer-precoated mild steel sheet. 
The coated layer was kept for 48 hours in the room and tests for the paint 
were carried out. The results are shown in Table 1. 
REFERENCE 3 
In accordance with the process of Example 2, the polymerization was carried 
out without using 4-vinyl pyridine and the resulting copolymer was used 
for the preparation of the paint and the tests were carried out. The 
results are shown in Table 1. 
REFERENCE 4 
In accordance with the process of Example 2, the polymerization was carried 
out except using acrylic acid instead of mono(2-hydroxyethyl methacrylate) 
acid phosphate and the resulting copolymer was used for the preparation of 
the paint and the tests were carried out. The results are shown in Table 
1. 
EXAMPLE 3 
In a 1 liter reactor equipped with a stirrer and a condenser, 150 wt.parts 
of isopropyl alcohol was charged and the reactor was purged with nitrogen 
and a mixture of 5 wt.parts of dimethyl aminoethyl methacrylate, 4 
wt.parts of mono(3-chloro-2-hydroxypropyl methacrylate) acid phosphate, 8 
wt.parts of itaconic acid, 8 wt.parts of 2-hydroxyethyl methacrylate, 80 
wt.parts of methyl methacrylate, 95 wt.parts of ethyl acrylate, 50 
wt.parts of isopropyl alcohol and 1 wt.parts of azobiscyano valoric acid 
was added dropwise under refluxing with stirring during 3 hours. After the 
addition, the solution polymerization was continued at 82.degree. C. for 5 
hours to obtain a copolymer (A). 
Then, 270 wt.parts of water and 2 wt.parts of dimethylamino ethanol were 
added to the copolymer (A) and the mixture was stirred for 30 minutes and 
180 wt.parts of the solvent was removed at 75.degree. to 80.degree. C. 
under a reduced pressure and 50 wt.parts of butyl cellosolve and 10 
wt.parts of triethylamine were added and the mixture was stirred at 
75.degree. C. for 30 minutes to obtain an aqueous resin slurry (B) having 
a solid content of 34.5%, pH of 9.7 and a viscosity of 8500 cps (rotary 
viscometer: 20.degree. C.). 
Then, 28 wt.parts of a rutile form titanium dioxide was added to 100 
wt.parts of the aqueous resin slurry and the mixture was kneaded in a test 
paint shaker and 5 wt.parts of neopentylglycol glycidyl ether was added to 
the mixture to obtain a paint. The paint was coated on an aqueous 
primer-precoated mild steel sheet. The coated layer was kept at 72 hours 
in the room and tests for the paint were carried out. The results are 
shown in Table 1. 
REFERENCE 5 
In accordance with the process of Example 3, the polymerization was carried 
out without using dimethylamino ethyl methacrylate, and the resulting 
copolymer was used for the preparation of the paint and the tests were 
carried out. The results are shown in Table 1. 
REFERENCE 6 
In accordance with the process of Example 3, the polymerization was carried 
out except using acrylic acid instead of mono(3-chloro-2-hydroxypropyl 
methacrylate) acid phosphate and the resulting copolymer was used for the 
preparation of the paint and the tests were carried out. The results are 
shown in Table 1. 
__________________________________________________________________________ 
Tests Exp. 1 
Ref. 1 
Ref. 2 
Exp. 2 
Ref. 3 
Ref. 4 
Exp. 3 
Ref. 5 
Ref. 6 
__________________________________________________________________________ 
Adhesive- 
ness *1 5 4 2 5 4 3 5 3 3 
Hardening 
*2 4 1 3 5 1 3 5 1 3 
Pencile 
hardness 
*3 F F F HB HB HB HB HB HB 
Water re- 
sistance 
*4 5 2 2 5 2 2 4 1 2 
Alkali re- 
sistance 
*5 5 2 2 5 1 2 5 2 2 
Acid resist- 
ance *6 5 4 3 3 2 2 4 2 2 
Weathering 
*7 5 2 2 5 1 1 5 1 1 
__________________________________________________________________________ 
Note:- 
*1 Chess board cut test; 
*2 Toluene finger scraping test; 
*3 Japanese Industrial Standard 
*4 Dipping test in water for 7 days; 
*5 Dipping test in 5% NaOH for 24 
*6 Dipping test in 5% H.sub.2 SO.sub.4 for 24 hours; 
*7 Exposing test in natural condition for 6 months. 
In the tests *1, *2, and *3, a mild steel sheet was used as a test piece. 
Rating: 
5 excellent 
4 good 
3 fair 
2 slightly bad 
1 bad