CA1159196A - Polymeric resin, and its production and use - Google Patents

Abstract

Abstract of the Disclosure The invention relates to an aqueous emulsion comprising a polymeric resin and prepared by polymerizing (a) at least one amino acid of either one of the formula: (Ia) and of the formula: (Ib) with (b) at least one other polymerizable monomer, in an aqueous medium, the component (a) and at least a portion of the component (b) being introduced separately into the reaction system. The resulting emulsion is stable in the absence of surfactants, which means that the problems associated with the use of surfactants can be entirely avoided.

Description

~ 159 ~96 The pr~sent invention relates to a polymerlc resin, and its production and use. More particularly, it relates to a polymeric resin, an aqueous emu:Lsion comprising such resin and a coating composition comprising such aqueous emulsion, and their production and use.
I;rom the viewpoints of ecomony in chemicals and prevention of environmental pollution, attention is increasingly beiny paid to water type resin compositions rather than organic solvent type resin compositions for a variety of applications. Of various water type resin compositions, resinous emulsions are characteristic in using particularly high molecular weight polymers as the resin components. In such resinous emulsions, the polymeric particles are usually dispersed into the aqueous medium by means of lower molecular weight surfactants. When these resinous emulsions are applied onto substrates, the surfactants remain on the substrates, and consequently the physical properties of the substrates, e.g., water resistance and strength, are often adversely affected.
It is therefore an object of the invention to overcome this inherent disadvantage of such emulsions.
As the result of an extensive study, it has now been found that a polymeric resin produced by polymerizing a polymerizable amino acid with any other polymerizable compound according to a certain specific procedure can afford a polymeric resin which is per se dispersible into an aqueous medium without any surfactant to give an aqueous emulsion. This aqueous emulsion is highly stable and, even when the solid content is relatively high, shows no tendency to form lumps. The resulting aqueous emulsion is useful as a coating composition.

~i ~ 15g~96 Accordillg to the present inverltion, there is provided a process for preparing a po]ymeric resin, which comprises polymerizing: (a) at least one ami.no acid of either one of the formulae:
Rll R2 R3 R5

2 CH2 O~C~12-C C-N-R -A (Ia) OH R~
wherein Rl, R2, R3 and R4 are each hydrogen, methyl or ethyl, R5 is hydrogen or Cl-C20 alkyl optionally having at least one of the groups -So-, -COO- and -O- in the alkyl chain, R6 is Cl~C12 alkylene optionally substituted with one or more of the groups -OH, -SH, -SR7 (wherein R7 is Cl-C4 alkyl) and Cl-C4 alkyl or phenylene optionally substituted with one or more Cl-C4 alkyl groups and A is -COOH or -SO3H; and the formula:
CH2=C ~ Rg 1ll (Ib) wherein R8, Rg and Rlo are each hydrogen or C1-C6 alkyl, Rll is hydrogen, Cl-C20 alkyl optionally having at least one of the groups -SO-, -COO- and -O- in the alkyl chain or a group of the formula: CH2=C ~ Rg ( 8' 9 10 are each as defined above) and R12 is C2-C12 alkylene optionally substituted with one or more Cl-C6 alkyl groups or phenylene optionally substituted with one or mo~e Cl-C4 alkyl groups; with (b) at least one other polymerizable monomer, in an aqueous medium; the component (a) and at least a portion of the component (b) being introduced ~ 1 59 19~

separately into the reaction systcm.
The resulting coating composition can be thermoset at low temperatures to afford a coating film having a good water resistance, particularly when the polymeric resin in the aqueous emulsion has a hydroxyl group and is used in eombination with an aminoplast resin.
The amino acids (Ia) and (Ib) and their production are known and disclosed in Japanese Patent Publications (unexamined) Nos. 51050/1980 and 53251/1980. The amino groups and the acid residues in the molecules of these eompounds may be considered to be in a tautomeric state as shown by the following formula:
~N-R6-B-H ~ ` -N- R6-BQ
wherein R6 is as defined above and B is -COO- or -SO3-.
Depending upon the environment, the above ionic part may be further varied as shown by the following formula:

-N~R6-B-H -~R6-B --- -N-R6-B
H H
wherein R6 and B are each as defined above. Accordingly, the state of the ionie part ean be optionally ehosen by eontrolling the eonditions of the environment, e.g., the pH.
The amino aeids (Ia), whieh have good reactivity, surface active properties, electro-chemical properties and biochemical properties, may be produced by reacting oxirane compounds with amino acid compounds having a primary or secondary amino group. Typieal examples are as follows:
N-(2-Hydroxy-3-allyloxypropyl)taurine;
2- N-(2-Hydroxy-3-allyloxypropyl) aminopropane-sulfonie aeid-(l);

~ 159196 - l-[N-(2-Hydro~y-3-allyloxypropyl)]aminopropane s~ll fOlli.C aci~-(2);

3-[N-(2-11ydroxy-3-allyloxypropyl)]aminobutane-sulfonic acid-(2);
2-[(N-(2-~ydroxy-3-allyloxypropyl)]aminobutane-sulfonic acid-(1);
1-[N-(2-~ydroxy-3-allyloxypropyl)]amino-2-methyl-propanesulfonic acid-(2);
3-[(N-(2-Hydroxy-3-allyloxypropyl)]aminopentane-sulfonic acid-(2);

4-[N-(2-Hydroxy-3-allyloxypropyl)]amino-2-methyl-pentanesulfonic acid-(3);
3-[N-(2-Hydroxy-3-allyloxypropyl)]aminopropane-sulfonic acid-(l);
4-[N-(2-Hydroxy-3-allyloxypropyl)]aminobutane-sulfonic acid-(2);
4-[N-(2-Hydroxy-3-allyloxypropyl)]amino~utane-sulfonic acid-(l);

5-[N-(2-Hydroxy-3-allyloxypropyl)]aminopentane-sulfonic acid-(l);
10-[N-(2-Hydroxy-3-allyloxypropyl)]aminodecane-sulfonic acid-(l);
N-Methyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
N-Ethyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
- N-Propyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
N-Butyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
N-Heptyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
N-Dodecyl-N-(2-hydroxy-3-allyloxypropyl)taurine;
N-Heptadecyl-N-(2-hydroxy-3-allyloxypropyl)-taurine;

.~

~ l~gl96 - r~- (2--Oet.l(lccylsulEinot'rlyl) -N- (2-hydroxy-3-allyloxy-~ropyl.)t~aurine;
N-(2-Stearoylo,;yetllyl)-N-(2-hydroxy-3-allylcxy-propyl)taurine;
N-(2-llydroxy-3-me-thallyloxyproyyl)t:aurine;
N-(l-Metllyl-2-hydroxy-3-allyloxypropyl)taurine;
N-(2-EIydroxy-3-allyloxypropyl)~Jlycine;
N-(2-1iydroxy-3-methallyloxypropyl)~lycine;
N-(2-Hydroxy-3-methallyloxypropyl)sarcosine;
N-(2-~lydroxy-3-allyloxypropyl)alanine;
N-(2-Hydroxy-3-allyloxypropyl)-~-alanine;
N-Methyl-N-(2-hydroxy-3-allyloxypropyl)-R-alanine;
N-Ethyl-N-(2-hydroxy-3-allyloxypropyl)-~-alanine;
N-Butyl-N-(2-hydroxy-3-allyloxypropyl)-3-alanine;
N-Heptyl-N-(2-1ydroxy-3-allyloxypropyl)-3-alanine;
N-Dodecyl-N-(2-hydroxy-3-allyloxypro.pyl)-~-alanine;
N-Heptadecyl-N-(2-hydroxy-3-allyloxypropyl)-3-alanine;
N-(1-Methyl-2-hydroxy-3-allyloxypropyl)-~-alanine;
N-~2-Hydroxy-3-allyloxypropyl)-~-aminocaproic acid;
N-(2-Hydroxy-3-allyloxypropyl)threonine;
N-(2-Hydroxy-3-allyloxypropyl)cysteine;
N-(2-Hydroxy-3-allyloxypropyl)methionine;
N-(2-Hydroxy-3-allyloxypropyl)anthranilic acid;
N-(2-Hydroxy-3-allyloxypropyl)-m-aminobenzoic acid;
N-(2-Hydroxy-3-allyloxypropyl)-p-aminobenzoic 30 acid;

~ 1 ~9 ~
r~- (2~ ydroz~y-3-al]ylo~ypropvl)orthanilic acid;
N-(2-liydro~y-3-allylocypropyl)metanilic acid;
N-(2-~1ydroxy-3--a].lylo:~ypropyl)sulfanilic acid, ~tc.
Tlle amino acids (Ib) also have cJood reactivity, surface activity, electro-chemical. properties and hio-chemical properti.es and may be produced by reacting bcnzyl halide compounds wi-th aminosulfonic acid compounds having a primary or secondary amino group. Typical specific examples are as follows:
N-(Vinylbenzyl)taurine;
N-(Isopropenylbenzyl)taurine;
2-[N-(Vinylbenzyl)]aminopropanesulfonic acid-(l);
2-[N-(Isopropenylbenzyl)]aminopropanesulfonic acid-(l);
l [N-(Vinylbenzyl)]aminopropanesulfonic acid-(2);
l-[N-(Isopropenylbenzyl)]aminopropanesulfonic acid-(2);
3-[N-(Vinylbenzyl)]aminobutanesulfonic acid-(2);
3-[N-(Isopropenylbenzyl)]aminobutanesulfonic acid-(2);
2- [N- (Vinylbenzyl)]aminobutanesulfonic acid-(l);
2-[ N-(Isopropenylbenzyl)]aminobutanesulfonic acid-(l);
l-[N-(Vinylbenzyl)]amino-2-methylpropanesulfonic acid-(2);
l-[N-(Isopropenylbenzyl)]amino-2-methylpropane-sulfonic acid-(2);
3-[N-(Vinylbenzyl)]aminopentanesulfonic acid- (2 );
3-[N-(Isopropenylbenzyl)]aminopentanesulfonic 1 15919~
acid-(2);
~ }-[N--(Vinylbenzyl)lami.no-2-1nethylpentalleSulfonic ~ci~-(3);
4-[N-(Isopropenylbenzyl)]amino-2-methylpentane-sulEonic acid-(3)i 3-[N-(Vinylbenzyl)]aminopropanesulfonic acid-(l);
3-[N-(Isopropcnyl.benzyl)]aminopropanesulfonie acid-(1);
4-LN-(vi.nylbenzyl)~aminobutanesulfonic acid-(2);
4-[N-(Isopropenylbenzyl)]aminobutanesulfonic acid-(2);
4-[N-(Vinylbenzyl)]aminobutanesulEonic acid-(l);
4-[N-(Isopropenylbenzyl)]aminobutanesulfonie aeid-(l);
5-[N-(Vinylbenzyl)]aminopentanesulfonic aeid-(l);
5-[N-(Isopropenylbenzyl)]aminopentanesulfonie aeid-(l);
1O-LN-(Vinylbenzyl)]aminodeeanesulfonie aeid-(l);
10-[N-(Isopropenylbenzyl)]aminodeeanesulfonic aeid-(l);
N-Methyl-N-(vinylbenzyl)taurine;
N-Methyl-N-(isopropenylbenzyl)taurine;
N-Ethyl-N-(vinylbenzyl)taurine;
N-Ethyl-N-(isopropenylbenzyl)taurine;
N-Propyl-N-(vinylbenzyl)taurine;
N-Propyl-N-(isopropenylbenzyl)taurine;
N-Butyl-N-(vinylbenzyl)taurine;
N-Butyl-N-(isopropenylbenzyl)taurine;
N-Heptyl-N-(vinylbenzyl)taurine;
N-Heptyl-N-(isopropenylbenzyl)taurine;

~ ~9196 N-D(:)~ecyl-N-(vinvlbenzyl)tanrine;
~-Dc~clecyl~ (i.sopro~ellylhcllz.yl)taurine;
~ Ieptadecyl-N-(vinylbcnzyl)taurine;
N-~leptadecy].-~-(i.sopropenylberlzyl)taurine;
~-(2-Octaclecylsu1firlethyl)-N-(vinylbenzyl)taurine;
N- (2-Octadecylsulf:Lnethyl) -N- (isopropenylbenzyl)-taurirle;
N- (2-stearoyloxyethyl)-N-(vinylbenzyl)taurine;

N- ( 2-Stearoylo~yethvl)-~-(isoproperlylbenzyl)-taurine;

2-LN-(Vinylbenzyl)-~-methyl]aminopropanesulfonic acid-(l);
2-[N-(Isopropenylbenzyl)-N-me-thyl]aminopropane-sulfonic acid-(1);
2-[N-Dodecyl-N-(vinylbenzyl)]aminopropanesulfonic acid-(1); ~
2-[N-Dodecyl-N-(isopropenylbenzyl)]àminopropane-sulfonic acid-(l);

2-[N-Octadecyl-N-(vinylbenzyl)]aminopropane-sulfonic acid-(l);

2-[N-(Isopropenylbenzyl)-N-octadecyl]amirlopropane-sulfonic acid-(l);
l-[N-Methyl-N-(vinylbenzyl)]amino-2-methylpropane-sulfonic acid-(2);
1-[N-(Isopropenylbenzyl)-N-methyl]amino-2-methyl-propanesulfonic acid-(2);
3-[N-Methyl-N-(vinylbenzyl)]aminopropanesulfonic acid-(l);

3-[N-(Tsopropenylbenzyl)-N-methyl]aminopropane-sulfonic acid-(l);

~.,'' ~15919~
N~ invlben%yl)o~thanilic acid;
N-(Vinyl~)enzyl)methanilic acid;
N-(vinylbenzy:L)sulfalliIic acid, etc.
'rhe other polymerizable monomer may be any one ha~ g an ethylenic unsaturation, which is usually employed for polymerizati.on. Specific e.~amples are as o]10ws:
(1) Carboxyl grOUp-COntclinillg monc)mers: acrylic acid, methacrylic aeict, crotonie acid, itaconic acid, maleie aeid, f~lmaric acid, ete.
(2) ~iydroxyl group-containing monomers: 2-hydroxy-ethyl acrylate, hydroxypropyl acrylate, 2-hyclroxyethyl meth-aerylate, hydroxypropyl methaerylate, hydroxybutyl acrylate, hydroxybutyl methaerylate, allyl aleohol, methallyl aleohol, ete.
(3) Nitrogen-eontaining alkyl aerylates and methaerylatè`6: dime~hylaminoethyl aerylate, d~.methylamino-ethyl methaerylate, ete.
(4) Polymerizable amides: aerylie aeid amide, methaerylie aeid amide, ete.
(5) Polymerizable nitriles: aerylamide, meth-aerylamide, ete.

(6) ~lkyl aerylates and methacrylates: methyl aerylate, methyl methaerylate, ethyl aerylate, n-butyl aerylate, n-butyl methaerylate, 2-ethylhexyl aerylate, ete.

(7) Polymerizable aromatic compounds: styrene, c~-methylstyrene, vinyltoluene, t-butylstyrene, ete.
($) c~-Olefi.n eompounds: ethylene prol~ylene, ete.
(9) Vinyl eompounds: vinyl aeetate, vinyl propionate, ete.
(10) Diene eompounds: butadiene, isoprene, ete.

~ 1S9196 When any water-soluble monomer, e.g., one of the monomers (1) to (5), is chosen from the above and subjected to polymerization as the component (b) with the amino acid as the component (a), the units of the amino acid and of the water-soluble monomer arrange themselves from the outer shell of each particle of the produced polymeric resin in the aqueous emulsion towards the inside with concentration variations, and as a resu]-t, the physical properties of the aqueous emulsion and of the coating film produced there-from are extremely satisfactory.
The polymerization may be carried out with theamino acid as the component (a) and the other polymerizable monomer as the component (b) in any appropriate proportion determined according to the desired stability and coating performances of the aqueous emulsion comprising the polymeric resin thus produced. Usually, the amount of the amino acid may be from 0.2 to 30 ~ by weight, particularly from 0.5 to 15 % by weight, on the basis of the total weight of the monomeric components. When the amount is less than 0.2 % by weight, the dispersion stability of the particles of the polymeric resin in an aqueous medium is inferior. When the amount is more than 30 % by weight, the water resistance of the coated film formed from aqueous emulsion of the polymeric resin is reduced. When using a water-soluble monomer as the other polymerizable monomer, the amount thereof is usually not more than 40 % by weight on the basis of the total weight of the monomeric components. The use of a water-soluble monomer in an amount of more than 40 % by weight may result in reduction of the water resistance of the coated film.
The polymerization is effected by the so-called "two liquid addition method". Namely, the amino acid and ~ 159~96 tlle other polymerizahle monomer arc separately introduced into the reaction system, i.e., an aqueous medium containing a polymerization initiator, by dropwise addition. When a water-soluble monomer, e.g., one of the monomers (1) to (5), is used as a part of the other polymerizable monomer as the component (b), a portion of the entire amount of such water-soluble monomer may be introduced into the reaction system not separately from but in combination with the amino acid.
The polymerization initiator may be a conventional 10 one. Specific examples are organic peroxides (e.g., benzoyl peroxide, t-butyl peroxide, cumene hydroperoxide), organic azo compounds (e.g., azobisisobutyronitrile, azobiscyanovaleric acid, azobis(2,4-dimethyl)valeronitrile, azobis(2-amidino-propane) hydrochloride), inorganic peroxides (e.g., potassium persulfate, ammonium persulfate, sodium persulfate, hydrogen peroxide), etc. Redox system initiators comprising said inorganic peroxides with sodium pyrosulfite, sodium hydrogensulfite, divalent ferric ion or the like are also usable. The polymerization initiator may be incorporated into the reaction system prior to the introduction of the monomeric components, or it may be added to the reaction system together with any of the monomeric components. The amount of the polymerization initiator is usually from 0.05 to 5 % by weight, preferably from 0.1 to 3 % by weight, on the basis of the total weight of the monomeric components.
If necessary, a conventional chain transfer agent may be incorporated into the reaction system. Examples of such chain transfer agent are mercaptans (e.g., lauryl-mercaptan, hexylmercaptan). This is usually employed in combination with the other polymerizable monomer as the component (b). While any conventional lower molecular ~ 159~96 weiyht emulsifier or dispersing agent may be used in such an amount as not to e~ert an adverse influence on the polymeric resin -thus produced or the aqueous emulsion cornprising the same, its use can normally be omitted since thc amino acid as the componcnt (a) itself has an emulsifying or dispersing effect.
A typical example of the pol~merization is as follows:
In an inert atmosphere at a-tmospheric or elevated pressure, an aqueous medium (e.g., water or a mixture thereof with any water-miscible organic solvent) containing a poly-merization initiator is maintained at a temperature suitable for polymerization, usually between 4 and 100C. The amino acid or a mixture thereof with the other polymerizable monomer soluble in water, or their aqueous solution optionally containing any baslc substance and the other polymerizable monomer, are separately and simultaneously introduced into the aqueous medium over 10 to 300 minutes by dropwise addition, and after the dropwise addition is completed, the resultant mixture is maintained at the same temperature as mentioned above for a period of 5 minutes to 10 hours.
The polymerization above produces an aqueous emulsion comprising the produced polymeric resin stably dispersed therein, of which the appearance is milky to creamy, the viscosity at 25C is from 10 to 50,000 cps and the content of non-volatile components is from 2 to 65 %
by weight.
If desired, the polymeric resin can be recovered from the aqueous emulsion by a per se conventional separation procedure. The glass transition temperature (Tg) of the polymeric resin is from -60 to 100C. Since, however, the ~ ~ 59 ~ g6 aqueous emulsioll is ~_ se useful as a coating composition,the separation of ~he polymeric resin -therefrom is usually not required.
~ s stated above, -the aqueous emulsion of the invention is per se useful as a coatiny composition. In general, however, other resinous vehicles, e.g., aminoplast resins (e.g., melamine resin, urea resin, guanamine resin), phenoplast resins and epoxy resins, organic or inorganic pigments, additives e.g., fillers, viscosity enhancers and adhesive agents, surfactants, pH regulators, water, organic solvents, etc., may be incorporated into the aqueous emulsion to make a coating composition.
In particular, when the a~ueous emulsion comprises the pol-ymeric resin produced by the use of a hydroxyl group - containing polymerizable monomer as the other poly-mexizable monomer, the incorporation of an aminoplast resin therein affords a coating composition having very desirable thermosetting properties at low temperatures capable of producing a coated film having good water resistance.
The coating composition of the invention as prepared above may be applied onto an appropriate substrate (e.g., metal plate, wooden plate, paper sheet, plastic sheet) by conventional procedure to form a coating layer 5 to 500 microns in thickness, followed by curing at a temperature of 60 to 240~C for a period of 20 seconds to 60 minutes to give a thermoset film having good physical properties.
Practical and presently preferred embodiments of this invention are illustratively shown in the following Examples wherein part(s) and ~ are by weight unless otherwise indicated.

~i159196 _eference Example 1 Deionized water (400 g), N-methyltaurine sodium salt (161 g) and ethylene glycol monomethyl ether (300 g) were charged to a 2 liter volume flask equipped with a stirrer, and the temperature was elevated to 70C. A
mixture of vinylbenzyl chloride (153 g), ethylene glycol monomethyl ether (100 g) and p-nitrosophenol (0.15 g) was added dropwise over 1 hour to the resultant Mixture with stirring, during which time sodium hydroxide (each 8 g) was added thereto 6 times at 10 minute intervales. Stirring was further continued for 5 hours.
The reaction mixture was mixed with conc. hydro-chloric acid (120 g) and concentrated in a rotary evaporator to one third of its volume. The concentrated liquor was added to four ti~es its volume of acetone, and the separated sodium chloride was eliminated by filtration. The filtrate was concentrated in a rotary evaporator to remove 70 % or more of the solvent in the filtrate. Five times its volume of acetone was added to the concentrated liquor and a pale yellow solid material was precipitated. The solid material was collected and recrystallized from deionized water to give N-methyl-N-(vinylbenzyl)taurine (hereinafter referred to as "Compound A") (180 g) having the formula:

Reference Example 2 Taurine (125 g), sodium hydroxide (40 g), deionized water (200 g) and ethylene glycol monoethyl ether (600 g) were charged to a 2 liter volume flask equipped with a stirrer and, while maintaining the temperature at 60C with stirring, allyl glycidyl ether (114 g) and p-nitrosophenol ~ ~59~i~6 (0.1 g) were added drop~isc ~hereto over 20 minutes, ~ollowedby ~urther s~irrirlg for an additionai 2 hours.
The ~eaction mixture at pH g was treated with an ion exchange resin (~mberlite~ IR-120) to eliminate the sodium ion. The resul-ting solution at pEI 4 was concentrated in a rotary evaporator to remove 30 % of the solvent therein, whereby needle crystals were precipitated. ~y NMR and IR, these crystals were identified as unreacted taurine. The liquid portion was added to three times its volume of acetone to deposit a brown oily material, which was collected and dried in vacuo to give N-(2-hydroxy-3-allyloxypropyl)-taurine (hereinafter referred to as "Compound B") (96 g) having the formula:
CH =CH-CH2OCH2-CH-CH2NH CH2 2 3 OH
_xample 1 Deionized water (216 parts) was charged to a reactor equipped with an agitator and, while maintaining the temperature at 80C with stirring, a mixture of azobis-cyanovaleric acid (4.5 parts), triethylamine (4.9 parts) anddeionized water (45 parts) was added thereto. A first mixture comprising Compound A (6 parts), triethylamine (2.4 parts) and deionized water (90 parts) and a second mixture comprising methyl methacrylate (159 parts) and n-butyl acrylate (135 parts) were separately and simultaneously added dropwise to the resultant mixture maintained at the same temperature as above over 60 minutes. After completion of the dropwise addition, a mixture of azobiscyanovaleric acid (1.5 parts), triethylamine (1.6 parts) and deionized water (15 parts) was added to the resulting mixture main-tained at the same temperature as above, and stirring was ~ 1 59 ~g6 continued for 60 minutes to give an aqueous emulsioncomprisin~ particles of the polyrneric rcsin. The aqueous emulaion had a content sf non-volatile components of 45 ~, a pH of 7.5 and a vis50sity oE 52 cps at 25~C The aqueous emulsion did not contain any lumps and had good mechanical stability. The particle size of the polymeric resin was 0.213 ~ and, upon electron microscopic observation appeared substantially even. The polymeric resin had a high molecular weight and was insoluble in tetrahydrofuran so that the gel permeation chromatography (GPC) could not be measured~
Tg, 12C.
The said viscosity was determined by the use of a B type viscosimeter, and the particle size was measured according to the light diffusion method and by using an electron microscope. The mechanical stability was determined by rubbing one drop of the aqueous emulsion five times between the thumb and forefinger, with no occurrence of adhesion being taken as good.
Example 2 Deionized water (180 parts) was charged to a reactor equipped with an agitator and, while maintaining the temper-ature at 80C under a nitrogen atmosphere with stirring, potassium persulfate (0.675 part) and sodium hydrogen sulfite (0.225 part) were added. A first mixture comprising Compound B (6 parts), 2-hydroxyethyl acrylate (30 parts) and deionized water (90 parts) and a second mixture comprising methyl methacrylate (77.4 parts), n-butyl acrylate (103.2 parts) and styrene (77.4 parts) were separately and simultaneously added dropwise to the resultant mixture main-tained at the same temperature as above over 12 minutes. After completion of the dropwise addition, a mixture of potassium persulfate ~1591~6 (0.255 part), sodium hydroc3ensulfite (0.075 part) anddeionlzed water (30 parts) was added thereto while maintaining the same temperature as above, and stirring was continued for 60 minutes to give an aqueous emulsion comprising particles of the polymeric resin and having a content of non-volatile components of 45 50, a p~l of 2.8 and a viscosity of 50 cps at 25C. The aqueous emulsion contained no lumps and had good mechanical stability. The particle size of the polymeric resin was 0.156 ~ and was substantially even.
The polymeric resin had a high molecular weight and was insoluble in tetrahydrofuran so that the GPC could not be measured. Tg, 15C.
Example 3 Deionized water (216 parts) was charged to a reactor equipped with an agitator and, while maintaining the temperature at 80C with stirring, azobiscyanovaleric acid (4.5 parts), dimethylethanolamine (4.28 parts) and deionized water (45 parts) were added thereto. A first mixture comprising Compound A (6 parts), dimethylethanolamine (2.1 parts), 2-hydroxyethyl acrylate (6 parts) and deionized water (90 parts) and a second mixture comprising methyl methacrylate (77.4 parts), n-butyl acrylate (103.2 parts), styrene (77.4 parts) and 2-hydroxyethyl acrylate (24 parts) were separately and simultaneously added dropwise to the resultant mixture maintained at the same temperature as above, over 60 minutes.
After completion of the dropwise addition, a mixture of azobiscyanovaleric acid (1.5 parts), dimethylethanolamine (1.42 parts) and deionized water (1.5 parts) was added thereto, and stirring was continued for 60 minutes to give an aqueous emulsion comprising particles of the polymeric resin and having a content of non-volatile components of 45 %, a pH of 1 1 5 ~

7.5 and a visc05ity of 33 cps at 25C. The aqueous emulsioncontained no lumps and had good mechanical stability. The particle size of the po-lymeric resin was 0.126 ~ and was substantially even. The polymeric resin had a high molecular weight and was insoluble in tetrahydrofuran so that the GPC
could not be measured. Tg, 15~C.
Examples 4 to 23 An aqueous emulsion comprising particles of the polymeric resin was produced in -the same manner as in Example 3 but using the first mixture and the second mixture as shown in Table 1 and taking the time for dropwise addition as indicated in Table 1. The properties of the aqueous emulsion and the polymeric resin are shown in Table 1.

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~1~9 1 ~6 Example 24 An aqueous dispersion comprising the particles of the polymeric resin was produced in the same manner as in Example 3 but using deionized water (110 parts) charged to the reactor at the initial stage. The aqueous emulsion had a content of non-volatile components of 60 % and a pH of 7.5. The particle size of the polymeric resin was 0.103 and was substantially even.
Example 25 An aqueous dispersion comprising particles of the p~lymeric resin was produced in the same manner as in Example 3 but using Com~ound B
(6 parts) in place of C ~ ound A (6 parts) and dimethylethanolamine (2.1 parts). The aqueous emulsion had a content of non-volatile components of 45 ~, a pll of 7.5 and a viscosity of 35 cps. The particle size of the polymeric resin was 0.150 and was substantially even. Tg, 15C.
Example 26 Deionized water (216 parts) and sodium dodecylbenzene-sulfonate (1.5 parts) were charged to a reactor equipped with an agitator and, while maintaining the temperature at 80C with stirring, azobiscyanovaleric acid (4.5 parts), dimethylethanolamine (4.28 parts) and deionized water (45 parts) were added thereto. A first mixture comprising Compound B (6 parts), dimethylethanolamine (2.1 parts), 2-hydroxyethyl acrylate (6 parts) and deionized water (90 parts) and a second mixture comprising methyl methacrylate (77.4 parts), n-butyl acrylate (103.2 parts), styrene (77.4 parts) and 2-hydroxyethyl acrylate (24 parts) were separately and simultaneously added dropwise to the resultant mixture over 20 minutes. After completion of the dropwise addition, a mixture of azobiscyanovaleric acid (1.5 parts), il59~916 dimet}~ylethanolaMine (1.~2 parts) and deionized water (15 parts) was added to the resultant mixture, and stirring was continued for 60 minute~ to give an aqueous emulsion comprising particLes of the polymeric resin and having a content of non-volatile components of 45 %, a pH of 7.5 and a viscosity of 45 cps at 25C. The particle size of the po]ymeric resin was 0.170 ~ and was substantially even.
Tg, 15C.
Example 27 An aqueous emulsion comprising the particles of the polymeric resin was produced in the same manner as in Example 26 but using a compound of the formula:
CH3(cH2)l0-fl~cH2NHc~l2c 2 3 (1.5 parts) and dimethyiethanolamine (0.42 part) in place of sodium dodecylbenzenesulfona-te (1.5 parts). The aqueous emulsion had a content of non-volatile components of 45 %, a pH of 7.5 and a viscosity of 45 cps at 25C. The particle size of the polymeric resin was 0.137 ~ and was substantially even. Tg, 15C.
Example 28 Deionized water (216 parts) was charged to a reactor equipped with an agitator and, while maintaining the temper-ature at 80C with stirring, a mixture comprising azobiscyanovaleric acid (4.5 parts), diethylethanolamine (4.28 parts) and deionized water (45 parts) and a mixture comprising Compound B (3 parts), 2-hydroxyethyl acrylate (3 parts) and deionized water (45 parts) were added thereto.
A first mixture comprising Compound B (3 parts), 2-hydroxy-ethyl acrylate (3 parts) and deionized water (45 parts) anda second mixture comprising methyl methacrylate (79.2 parts), ~ 1 5~ 1 9~

n-b~ltyl acrylate (105.6 parts), styrene (79.2 parts) and 2-hydroxyethyl acrylate (24 parts) wére separately and sim~taneously addcd dro~ise to the resultant mixture maintained at the same ~emperature as above, over 60 minutes. After completion of the dropwise addition, azobiscyanovaleric acid (1.5 parts), dimethylethanolamine (1.42 parts) and deionized water (15 parts) were added to the resultin~
mixture maintained at the same temperature as above, and stirring was continued for 60 minutes to give an aqueous emulsion comprisiny particles of the polymeric resin and having a content of non-volatile components of 45 %, a pH of 7.2 and a viscosity of 40 cps at 25C. The particle size of the polymeric resin was 0.191 1l and was substantial. Tg, 15C.
Comparative Exam~le 1 -An aqueous emulsion comprising particles of the polymeric resin was produced in the same manner as in Example 3 but using a first mixture comprising acrylic acid (6 parts3, dimethylethanolamine (7.41 parts), 2-hydroxyethyl acrylate (6 parts) and deionized water t90 parts). The aqueous emulsion had a content of non-volatile components of 45 %, a pH of 7.7 and a viscosity of 56 cps at 25C. This emulsion contained lumps in an amount of 1 %, and its mechanical stability was inferior. The particle size of the polymeric resin was 0.215 ~.
Comparative Example 2 An aqueous emulsion comprising particles of the polymeric resin was produced in the same manner as in Example 3 but using a first mixture comprising acrylic acid (15 parts), dimethylethanolamine (18.54 parts), 2-hydroxy-ethyl acrylate (6 parts) and deionized water (90 parts)and a second mixture comprising methyl methacrylate (76.5 .~

~ 1~9 19~;

parts), styrene (76.5 parts), n-butyl acrylate (102 par-ts) and 2-hydroxyethyl acrylate (24 parts)~ The aqueous emulsion had a content oE non-vola-ti]e components of 45 %, a pH of 7.9 and a viscosity oE 270 cps at 25C. ~'his emulsion contained lumps in an amount of 0.5 %. The particle size of the polymeric resin was 0.211 ~.
_xample 29 An aminoplast resin solution comprising hexamethoxy-methylolmelamine ("Cymel 303'~ manufactured by American Cyanamid) (5.6 parts), ethylene glycol monobutyl ether t9.2 parts) and deionized water (3.7 parts) were added gradually with stirring with a labomixer to the aqueous emulsion obtained in Example 3 (70 parts) to produce a thermosetting coating composition.
The coàting composition was applied onto a steel plate to form a coating layer of about 20 ~ in thickness after drying, followed by thermosetting at 100C, 120C, 140C or 160C for 20 minutes to give transparent coating films.
The coating films were extracted with acetone in a Soxhlet's extractor for 4 hours, and it was confirmed that the remainders on thermosetting at 100C, 120C, 140C and 160C were respectively 81 %, 86 %, 93 %, and 99 %. The coating films showea good water resistance, no abnormality was observed when immersed in boiling water for 1 hour.
Examples 30 to 42 A coating composition was prepared in the same manner as in Example 29 but using the aqueous emulsion as obtained in any of Examples 4 to 27 (70 parts). The coating composition was applied onto a steel plate to form a coating layer of about 20 ~ in thickness after drying, followed ~ ~ 59 ~ 9 1~

by thermosetting at 100C, 120C, 140C or 160C for 20minutes. The thus formed coating films were extracted with acetone in a Soxhlet's extractor for 4 hours.
The percentaye of the remainders (insolubl.e materials) of the coating films and the appearances o:f the coating films (thermoset at 140C) after immersion in boiling wa-ter for 1 hour are shown in Table 2.
Table 2 Ex- Emulsion Percentage of remainders Appearance ample obtained after acetone extraction after immer-No. in (%) sion in boiling water ___ Ex. 479 84 91 98 Normal 31 Ex. 5~79 85 94 100 Normal 32 Ex. 681 88 93 99 Normal 33 Ex. 776 81 88 96 Normal 34 Ex. 873 83 90 97 Normal Ex. 985 86 92 98 Normal 36 Ex. 1081 87 92 98 Normal 37 Ex. 1183 88 93 98 Normal 38 Ex. 1283 87 93 99 Normal 39 Ex. 1380 88 91 98 Normal Ex. 1482 88 93 99 Normal 41 Ex. 2683 87 93 99 Normal 42 Ex. 2781 86 95 100 Normal ~ 15~i96 Comparative Examples 3 and 4 __ A coating composition was prepared in the same manner as in Example 29 but using the aqueous emulsion obtainecl in Comparative E.~amyle 1 or 2. The coatinc3 corn-position was applied onto a steel plate, followed by thermo-setting to give a coating film. The coating film was extracted with acetone for 4 hou~s, and the percentage of the remainders was determined. The coatiny film was also immersed in boiling water for 1 hour, and the appearance was observed.
The results are shown in Table 3.
Table 3 Compar- Emulsion Percentage of remainders Appearance of ative obtained after acetone extraction coating film Example in (%) after immer-No. sion in boilin 100C 120C 140C 160C water (thermo-3 Compar- 58 71 79 91 Whitening, _ blister 4 Compar- 61 74 80 93 Somewhat ative whitening, 2 blister

Claims (8)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for preparing a polymeric resin, which comprises polymerizing:
(a) at least one amino acid of either one of the formulae:
(Ia) wherein R1, R2, R3 and R4 are each hydrogen, methyl or ethyl, R5 is hydrogen or C1-C20 alkyl optionally having at least one of the groups -SO-, -COO- and -O- in the alkyl chain, R6 is C1-C12 alkylene optionally substituted with one or more of the groups -OH, -SH, -SR7 (wherein R7 is C1-C4 alkyl) and C1-C4 alkyl or phenylene optionally substituted with one or more C1-C4 alkyl groups and A is -COOH or -SO3H; and of the formula:

(Ib) wherein R8, R9 and R10 are each hydrogen or C1-C6 alkyl, R11 is hydrogen, C1-C20 alkyl optionally having at least one of the groups -SO-, -COO- and -O- in the alkyl chain or a group of the formula: (wherein R8, R9 and R10 are each as defined above) and R12 is C2-C12 alkylene optionally substituted with one or more C1-C6 alkyl groups or phenylene optionally substituted with one or more C1-C4 alkyl groups;

with (b) at least one other polymerizable monomer, in an aqueous medium;
the component (a) and at least a portion of the component (b) being introduced separately into the reaction system.

2. The process according to claim 1, wherein the other polymerizable monomer as the component (b) is a member selected from the group consisting of carboxyl group-containing monomers, hydroxyl group-containing monomers, nitrogen-containing alkyl acrylates and methacrylates, poly-merizable amides, polymerizable nitriles, alkyl acrylates and methacrylates, polymerizable aromatic compounds, .alpha.-olefin compounds, vinyl compounds and diene compounds.

3. The process according to claim 1, wherein the other polymerizable monomer as the component (b) comprises as at least a portion a member selected from the group consisting of carboxyl group-containing monomers, hydroxyl group-containing monomers, nitrogen-containing alkyl acrylates, polymerizable amides and polymerizable nitriles.

4. The process according to claim 1, wherein the other polymerizable monomer as the component (b) comprises as at least a portion a member selected from the group consisting of hydroxyl group-containing monomers.

5. A Polymeric resin prepared by the process according to claim 1 and having a glass transition point of -60 to 100°C.

6. An aqueous emulsion comprising the polymeric resin according to claim 5 and having a viscosity of 10 to 50,000 cps at 25°C and a content of non-votatile components of 2 to 65 % by weight.

7. A coating composition comprising the aqueous emulsion according to claim 6.

8. A coating composition according to claim 7, which further comprises an aminoplast resin.