Aqueous vinyl plastics dispersion containing water soluble salt of polybasic phosphonic acid derivative

In the manufacture of plastics dispersions on the basis of vinyl polymers water-soluble salts of polybasic phosphonic acid derivatives, especially alkane-phosphonic acids and phosphonomethyl amines are used as dispersing auxiliaries. The dispersions obtained are suitable as coating agents and for impregnating, coating or glueing solid materials.

Vinyl polymers can be produced by emulsion polymerization in the presence 
of surface-active compounds. However, the latices obtained are generally 
unstable if they do not contain further stabilizers. By the use of larger 
amounts of anionically active emulsifiers the stability of the latex to 
mechanical stress, such as pumping and stirring, can be improved but 
simultaneously the thermostability of the polymer or the resistance to 
water of the films made from the latex is affected. The results are 
similar with the additional use of protective colloids or copolymers of 
unsaturated acids. 
It is the object of the present invention to provide an aqueous plastics 
dispersion with low viscosity and high pigment binding capacity which is 
suitable as binder, for example for spread coating pastes for paper. 
The invention relates to an aqueous plastics dispersion on the basis of 
vinyl polymers and is characterized in that the dispersion contains a 
water-soluble salt of a polybasic phosphonic acid derivative having 2, 3 
or 4 phosphorus atoms. 
Further, the invention relates to a process for the manufacture of an 
aqueous plastics dispersion by polymerizing at least one vinyl monomer in 
aqueous dispersion in the presence of an emulsifier under known 
conditions, which comprises carrying out the polymerization in the 
presence of a water-soluble salt of a polybasic phosphonic acid derivative 
having 2, 3 or 4 phosphorus atoms. 
Suitable phosphonic acid derivatives are diphosphono-alkanes preferably 
having from 1 to 8 and more preferably from 1 to 4 carbon atoms, and 
phosphono-methyl amines having 1 or 2 nitrogen atoms. 
Preferred compounds are salts of alkane-phosphonic acids of the formula I 
##STR1## 
in which R.sup.1 is a hydrogen atom or an alkyl group having from 1 to 8 
carbon atoms, R.sub.2 is a hydrogen atom, hydroxy group or an alkyl group 
having from 1 to 8 carbon atoms and n is an integer from 1 to 10, 
preferably 1, 2, or 3. Methyl and ethyl groups are preferred as alkyl 
groups. Especially suitable compounds of formula I are, for example, 
methanediphosphonic acid, ethane-1,1-diphosphonic acid, 
ethane-1,2-diphosphonic acid, n-propane-1,3-diphosphonic acid, 
n-butane-1,4-diphosphonic acid, n-propane-1,1-diphosphonic acid, 
n-propane-2,2-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid and 
1-hydroxy-n-propane-2,2-diphosphonic acid. 
Salts of phosphono-methyl amines of formula II are also suitable 
##STR2## 
in which R is an alkyl group having from 1 to 6, preferably 1, 2, or 3 
carbon atoms and x is zero or 1. Methyl and ethyl groups are preferred as 
alkyl groups. Especially suitable compounds of formula II are, for 
example, tris (phosphonomethyl)-amine, 
N-methyl-N,N-bis(phosphonomethyl)-amine, 
N-ethyl-N,N-bis(phosphonomethyl)-amine, 
N-propyl-N,N-bis(phosphonomethyl)-amine, 
N-butyl-N,N-bis(phosphonomethyl)-amine and 
N-hexyl-N,N,-bis(phosphonomethyl)-amine. 
Further suitable compounds are the salts of phosphonomethyl-amines of the 
formula III 
##STR3## 
in which m is an integer from 2 to 14, preferably from 2 to 6. Especially 
suitable compounds of formula III are, for example 
N,N,N',N'-tetrakis(phosphonomethyl)-ethylene diamine, 
N,N,N',N'-tetrakis(phosphonomethyl)-trimethylene diamine and the 
corresponding derivatives of tetramethylene diamine and hexamethylene 
diamine. 
The salts of phosphonic acid derivatives to be used according to the 
invention as dispersing auxiliaries must be soluble in water. Especially 
suitable are alkali metal salts, for example the sodium and potassium 
salts, and ammonium salts, i.e. salts of ammonia, and salts of primary, 
secondary or tertiary aliphatic amines, preferably mono-, di- and trialkyl 
amines the alkyl radicals of which are either identical or different and 
each contain from 1 to 4 carbon atoms and which may be substituted by a 
hydroxy group. There are mentioned by way of example methyl amine, ethyl 
amine, propyl amine, dimethyl amine, diethyl amine, dipropyl amine, 
trimethyl amine, triethyl amine, tripropyl amine, ethanol amine, diethanol 
amine, triethanol amine, N,N-dimethylamino-ethanol and 
2-amino-2-methyl-propanol-(1). Cyclic amines such as piperidine, 
morpholine and piperazine and linear polyamines such as ethylene diamine, 
diethylene triamine and triethylene tetramine can also be used. 
Diphosphonomethyl-alkanes of formula I are prepared by reacting dialkyl 
phosphites with dihalogeno-alkanes, while diphosphonomethyl-hydroxyalkane 
are obtained by reacting phosphorous acid with the corresponding 
carboxylic acid anhydrides, preferably acetic anhydride. 
Phosphonomethyl amines of formulae II and III are prepared by reacting 
phosphorous acid with formaldehyde and ammonia or ammonium chloride or the 
corresponding amines or diamines in the presence of hydrogen chloride at a 
temperature of from 50.degree. to 120.degree. C., preferably 80.degree. to 
100.degree. C. 
The essential feature of the process of the invention is that the 
polymerization of the vinyl monomer(s) is carried out in the presence of 
an emulsifier and at least one salt, acting as dispersing auxiliary, of a 
phosphonic acid derivative having 2, 3, or 4 phosphorus atoms. The salts 
can be added to the polymerization mixture per se or they can be formed in 
situ by neutralization of a phosphonic acid derivative contained in the 
mixture. The neutralization need not be complete so that acid salts can 
also be formed. As neutralizing agents, compounds having a basic reaction 
are used, preferably alkali metal hydroxides, alkali metal carbonates, 
ammonia and ammonium carbonate as well as the aforesaid primary, secondary 
or tertiary aliphatic amines. The neutralizing agents are added in an 
amount of from 0.1 to 1.2 mols, preferably 0.3 to 0.9 mol (calculated on 1 
mol of the phosphonic acid derivative). The neutralization is preferably 
carried out in aqueous solution generally having a pH of from 2 to 10, 
preferably 4 to 8. 
The phosphonic acid salt is added in an amount of from 0.005 to 5% by 
weight, preferably 0.01 to 2% by weight (calculated on the total amount of 
vinyl monomer(s)). It can be added to the polymerization mixture prior to 
the beginning of polymerization, or preferably a portion is added prior to 
the beginning of polymerization with the remaining portion being added in 
dosed quantities during the course of polymerization. According to a 
special embodiment of the process of the invention, an aqueous solution of 
5 to 30% by weight of the salt is placed in the reaction vessel prior to 
the beginning of polymerization, then 30 to 55% by weight of the salt is 
metered in together with the vinyl monomer(s) and finally 15 to 65% by 
weight of the salt is added in dosed quantities to the polymerization 
mixture after termination of the monomer addition. The salts can be used 
either individually or in admixture with one another. 
The phosphonic acid salt is used in combination with known, preferably 
anionic, surface-active substances such as alkyl sulfates, alkane 
sulfonates, sulfosuccinic acid esters and sodium salts of oxethylated or 
sulfonated alcohols or alkyl phenols. The surface-active substance is used 
in an amount of from 0.1 to 3% by weight, preferably 0.5 to 2% by weight 
(calculated on the total amount of vinyl monomer(s)). The proportion by 
weight of surface-active substance to phosphonic acid salt is in the range 
of from 10:1 to 10:50, preferably 3:1 to 1:1. 
Within the scope of the invention all vinyl monomers, i.e. olefinically 
unsaturated compounds, being polymerizable in aqueous dispersion can be 
used, above all compounds of the formula V 
EQU H.sub.2 C=CH--R.sup.4 
in which R.sup.4 is a hydrogen atom, an alkyl group having from 1 to 4 
carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, an 
alkylcarboxyl group having from 2 to 12, preferably from 2 to 10 carbon 
atoms, a nitrile group, a halogen atom, preferably a chlorine atom, a 
phenyl group, or an alkoxycarbonyl group having from 2 to 12, preferably 
from 2 to 9 carbon atoms. Instead of one single vinyl monomer also a 
mixture of several vinyl monomers can be used. 
Suitable vinyl monomers are especially olefins, for example ethylene and 
isobutylene; vinyl ethers, for example vinylmethyl ether, vinylethyl ether 
and vinyl-n-butyl ether; vinyl esters of aliphatic monocarboxylic acids, 
for example vinyl acetate, vinyl propionate, vinyl butyrate, vinyl laurate 
and vinyl decanates; vinylidene chloride; acrylonitrile; vinyl chloride; 
styrene; acrylic acid esters of monohydric alkanols, for example methyl 
acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate; 
methacrylic acid esters of monohydric alkanols, for example methyl 
methacrylate, ethyl methacrylate, butyl methacrylate and 2-ethylhexyl 
methacrylate. Best results are obtained with a vinyl ester, optionally in 
admixture with one or two further vinyl monomers. 
The polymerization of the respective vinyl monomer(s) is carried out under 
known conditions in the presence of a radical forming initiator, 
preferably a peroxy compound or an aliphatic azo compound. Suitable 
initiators are, for example, the alkali metal and ammonium salts of 
peroxydisulfuric acid or peroxydiphoshoric acid and 
azo-.gamma.,.gamma.'bis(4-cyanovaleric acid). The initiator is used in an 
amount of from 0.05 to 1% by weight, preferably 0.1 to 0.4% by weight 
(calculated on the total amount of vinyl monomer(s)). The initiator may be 
used together with a reducing agent, for example an alkali metal sulfite, 
alkali metal thiosulfate, alkali metal dithionite, formaldehyde sodium 
sulfoxylate or a heavy metal salt. The initiator can be placed in the 
reaction vessel prior to the beginning of polymerization or added to the 
reaction mixture in dosed quantities during polymerization. The conditions 
are the same with the reducing agent. The polymerization is carried out at 
a temperature of from 25.degree. to 90.degree. C., preferably 40.degree. 
to 75.degree. C., the polymerization time being in the range of from 2 to 
10 hours, preferably 3 to 8 hours, depending on the type and amount of 
vinyl monomer(s). 
The plastics dispersion according to the invention may contain further 
additives having a favorable effect on the viscosity, the wetting and 
dispersing properties, the stability to freezing and to electrolytes and 
the foaming behavior. In general, at most 10% by weight, preferably 1 to 
5% by weight (calculated on the plastics dispersion) of said additives are 
used. 
Suitable thickening agents are cellulose derivatives, for example methyl 
cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl 
cellulose; poly(vinyl alcohol), poly(vinylpyrrolidone), poly(ethylene 
glycol), salts of poly-(acrylic acid) and salts of acrylic acid/acrylamide 
copolymers. 
As wetting and dispersing agents sodium polyphosphate, salts of low 
molecular weight poly(acrylic acid), salts of poly(ethylene-sulfonic 
acid), salts of poly(vinylphosphonic acid), salts of poly(maleic acid) and 
salts of copolymers of maleic acid with ethylene, 1-olefins having from 3 
to 18 carbon atoms, vinylalkyl ethers with 3 to 14 carbon atoms and/or 
styrene. 
To improve the stability to freezing and to electrolytes monomeric and 
polymeric 1,2-diols, for example glycol, propylene glycol-(1,2) and 
butylene glycol-(1,2), or oxethylated compounds, for example reaction 
products of ethylene oxide with long chain alkanols, amines, carboxylic 
acids, carboxylic acid amides, alkyl phenols, poly(propylene glycol) or 
poly(butylene glycol) can be added to the dispersion. 
The minimum film forming temperature (white point) of the plastics 
dispersion can be lowered by adding solvents, for example ethyl glycol, 
butyl glycol, ethyl glycol acetate, ethyl diglycol acetate, butyl glycol 
acetate, butyl diglycol acetate, gasoline or alkylated aromatic compounds. 
Suitable antifoaming agents are, for example, poly(propylene glycol) and 
polysiloxanes. 
The plastics dispersion according to the invention has a solids content of 
40 to 65% by weight, preferably 45 to 55% by weight. The minimum film 
forming temperature is in the range of from -10.degree. to 30.degree. C., 
preferably 0.degree. to 20.degree. C., and the viscosity is from 10 to 
1,000 mPa.s, preferably 30 to 400 mPa.s (measured by the Epprecht method). 
The dispersion has a pH of from 3.5 to 9.0, preferably 4.5 to 8.0, and the 
dispersed polymer particles have an average diameter of from 0.05 to 5.0 
.mu.m, preferably 0.08 to 2.0 .mu.m. The reduced specific viscosity 
.eta..sub.spec /c of the polymer ranges from 1 to 30 dl/g, preferably 2 to 
20 dl/g (measured in dimethyl formamide at 20.degree. C.). The dispersion 
is used as coating material and for impregnating, coating and glueing 
natural or synthetic materials such as wood, paper, metals, textile 
materials and plastics materials. It is especially suitable as binder for 
pigments and for fillers in dispersion paints and in spread coating pastes 
for paper. A special advantage of the plastics dispersion resides in the 
fact that it is not colored by heavy metal ions, particularly iron ions. 
It is also distinguished by a good storing stability.

The following examples illustrate the invention, the parts and percentages 
being by weight unless otherwise stated. 
The abbreviations used in the examples have the following meaning: 
VA=vinyl acetate 
VC=vinyl chloride 
ET=ethylene 
MMOE=maleic acid mono-(2-ethylhexyl) ester 
NaLS=sodium lauryl sulfate 
NaDBS=sodium dodecyl sulfate 
PPG=polypropylene glycol 
HEDP=1-hydroxyethane 1,1-diphosphonic acid 
TPMA=tris(phosphonomethyl)-amine 
TPMEA=N,N,N',N'-tetrakis(phosphonomethyl)-ethylene diamine 
TPMHA=N,N,N',N'-tetrakis(phosphonomethyl)-hexamethylene diamine 
MDP=methane-diphosphonic acid 
RSV reduced specific viscosity .eta..sub.spec /c 
MFT=minimum film forming temperature. 
EXAMPLE 1 
10,000 Parts of water free from electrolytes are drawn by vacuum into an 
autoclave provided with stirring means and the water is washed with 
nitrogen while stirring. 20 bar of ethylene are then pressed in, and the 
temperature in the autoclave is adjusted to 45.degree. C. Next, 25% of a 
solution I of 19 parts of sodium sulfite, 180 parts of sodium lauryl 
sulfate and 60 parts of tris(phosphonomethyl)-amine in 2,000 parts of 
water, which solution has been adjusted to a pH of 6.8 with concentrated 
aqueous ammonia, is metered in over a period of 5 minutes. 10% of a 
mixture of 8,890 parts of vinyl acetate and 3,810 parts of vinyl chloride 
are added, the ethylene pressure is raised to 45 bar and, after addition 
of a solution of 45 parts of ammonium persulfate in 400 parts of water, 
the internal temperature is adjusted to 60.degree. C. During the course of 
6 hours the remaining 75% of solution I and the remaining 90% of the VA/VC 
mixture are metered in, while the ethylene pressure is maintained at 45 
bar by adding ethylene. Then the addition of ethylene is discontinued, a 
solution of 15 parts of ammonium persulfate in 600 parts of water is 
metered in and the content of the autoclave is heated to 85.degree. C. 
During heating and during the first 30 minutes at 85.degree. C. a solution 
II of 120 parts of sodium lauryl sulfate and 40 parts of 
tris(phosphonomethyl)-amine in 1,170 parts of water, adjusted to pH 6.8 by 
adding concentrated aqueous ammonia solution, is metered in, whereupon the 
reaction mixture is stirred for another 30 minutes at 85.degree. C. and 
finally cooled to 30.degree. C. while stirring. 
A fine-particle, low viscous ET/VA/VC terpolymer dispersion stable to 
shearing and having a solids content of 51.1%, a minimum film forming 
temperature of 7.degree. C., a viscosity of 40 mPa.s and a pH of 5.0 is 
obtained. The polymer particles have an average diameter of 0.169 .mu.m. 
The terpolymer has an ethylene content of 12.3% and an RSV value of 3.42 
dl/g. To test the stability to shearing the dispersion is stirred for 2 
minutes at a speed of 5,000 rpm. No coagulum is formed and the average 
particle diameter remains unaltered. When 4% of a 5% ferric chloride 
solution is added to a sample of the dispersion, the iron solution is 
decolorized. After drying at room temperature, the dispersion forms a 
limpid film which becomes opaque after 12 minutes only when wetted with 
water. 
EXAMPLE 2 (example of application) 
A pigment paste is prepared from the following substances by blending and 
stirring for 10 minutes at 3,000 rpm: 
______________________________________ 
water 320 parts 
10% aqueous sodium tripolyphosphate solution 
18 parts 
polysiloxane antifoaming agent 
1.4 parts 
25% aqueous ammonia solution 
1.4 parts 
titanium dioxide 70 parts 
calcium carbonate (mean particle diameter 
310 parts 
1-8 .mu.m) 
calcium carbonate (mean particle diameter 
275 parts 
0.5-0.6 .mu.m) 
methylcellulose (Hoeppler viscosity of a 2% 
3 parts 
aqueous solution 30 Pa.multidot.s) 
methyl cellulose (Hoeppler viscosity of a 2% 
2 parts 
aqueous solution 0.2 Pa.multidot.s) 
______________________________________ 
190 parts of the pigment paste obtained are homogeneously mixed with 19.55 
parts of the dispersion of Example 1. Next, 4.2 parts of a hydrocarbon 
mixture on the basis of alkyl-benzenes (alkyl-benzenes having at least 10 
carbon atoms, boiling temperature 161.degree. to 182.degree. C.) are 
incorporated while stirring. The resulting dispersion paint contains 4.7% 
of the ET/VA/VC terpolymer. 
Black PVC foil is painted with the dispersion paint in a layer thickness of 
200 .mu.m (wet) and the coatings are dried at 23.degree. C. at a relative 
humidity of 50%, After 1 and 3 days, respectively, the dried paints are 
examined as to their wet abrasion resistance (cf. DIN 53 778). The 
coatings dried for 1 day are frayed after 1,116 double strokes of the 
brush and the coatings dried for 3 days are frayed after 1,602 double 
strokes of the brush. 
EXAMPLES 3 TO 10 
Examples 1 and 2 are repeated with the modifications indicated in the 
following Table 1. 
The data measured and test results are also indicated in Table 1. 
In Example 5 solutions I and II have a pH of 5.0 instead of 6.8, and in 
Example 6 solution I does not contain sodium sulfite. 
The indicated amounts are parts by weight unless otherwise stated. 
TABLE 1 
__________________________________________________________________________ 
Example 3 4 5 6 7 8 9 10 
__________________________________________________________________________ 
VA amount 
7,620 
10,160 
10,160 
10,160 
10,160 
10,160 
8,890 
8,890 
VC amount 
5,080 
2,540 
2,540 
2,540 
2,540 
2,540 
3,810 
3,810 
polymerization 
temperature (.degree.C.) 
60 60 53 53 60 60 60 60 
emulsifier 
NaLS 
NaLS NaLS NaLS 
NaLS NaLS NaDBS 
NaLS 
amount in 
solution I 
90 120 120 120 120 120 120 120 
amount in 
solution II 
60 80 80 80 80 80 80 80 
phosphonic acid 
derivative 
HEDP 
TPMA TPMA TPMA 
TPMEA 
TPMHA 
TPMA TPMA 
amount in 
solution I 
30 60 60 30 60 60 60 60 
amount in 
solution II 
20 40 40 20 40 40 40 40 
proportion of 
emulsifier/phos- 
phonic acid der- 
ivative 3:1 2:1 2:1 4:1 2:1 2:1 2:1 2:1 
solids content (%) 
50.7 
51.8 51.1 51.4 
51.1 51.4 48.2 49.7 
RSV (dl/g) 
1.17 
1.77 4.1 3.7 2.12 -- 2.82 2.52 
MFT (.degree.C.) 
12 1 4 4.5 1.5 -- 3 3 
mean particle 
diameter (.mu.m) 
0.270 
0.212 
0.235 
0.173 
0.192 
0.256 
0.176 
0.187 
double strokes 
of brush after 
1 day 1,120 
3,600 
&gt;3,000 
2,860 
2,030 
1,866 
1,460 
2,490 
3 days 1,920 
&gt;5,000 
2,724 
2,100 
4,785 
1,751 
1,470 
2,330 
__________________________________________________________________________ 
EXAMPLE 11 
A vessel provided with stirrer, internal thermometer, reflux condenser, gas 
inlet and 2 dropping funnels is charged with 500 parts of water free from 
electrolytes and washed with nitrogen. 7% of a solution I of 7.5 parts of 
NaLS and 2.5 parts of TPMA in 200 parts of water, adjusted to pH 6.8 with 
20% sodium hydroxide, and a solution of 0.9 part of ammonium persulfate in 
20 parts of water are then added to the water. The temperature of the 
mixture is raised to 60.degree. C., and a further 53% of solution I and a 
mixture of 600 parts of vinyl acetate and 150 parts of a commercial 
mixture of vinyl esters of tertiary, saturated aliphatic carboxylic acids 
having 10 carbon atoms is metered in during the course of 3 hours. Next, a 
solution of 0.45 part of ammonium persulfate in 30 parts of water is added 
and the internal temperature is raised to 75.degree. C. During heating the 
residual 40% of solution I are metered in and the reaction mixture is 
stirred for another 30 minutes at 75.degree. C., whereupon it is cooled to 
room temperature while stirring. 
A fine-particle, low viscous copolymer dispersion is obtained having a 
solids content of 50.4%, a minimum film forming temperature of 16.degree. 
C., a viscosity of 30 mPa.s and a pH of 5.2. The polymer particles have an 
average diameter of 0.215 .mu.m. The copolymer has an RSV value of 4.38 
dl/g (measured in dimethyl formamide at 20.degree. C.). When 4% of a 5% 
ferric chloride solution are added to a sample of the dispersion, the iron 
salt solution is decolorized. 
EXAMPLES 12 TO 22 
Example 11 is repeated with the modifications indicated in Tables 2 and 3. 
In Examples 18 and 19 concentrated ammonia solution and triethanol amine, 
respectively, are used as neutralizing agent instead of sodium hydroxide 
solution. The measured data and test results are also indicated in Tables 
2 and 3. 
TABLE 2 
__________________________________________________________________________ 
Example 12 13 14 15 16 17 
__________________________________________________________________________ 
emulsifier NaLS 
NaLS 
NaLS 
NaLS 
NaDBS 
NaDBS 
amount 15 10 15 15 7.5 15 
phosphonic acid 
TPMA 
TPMA 
MDP HEDP 
TPMA TPMA 
derivative 5 10 5 5 7.5 5 
amount 
proportion of 
emulsifier/phosphonic 
acid derivative 
3:1 1:1 3:1 3:1 3:1 3:1 
solids content (%) 
51.1 
52.0 
51.8 
52.0 
50.9 51.9 
RSV (dl/g) 3.98 
4.98 
3.19 
0.6 
10.5 2.84 
MFT (.degree.C.) 
16 16 16 13 -- -- 
mean particle 
0.207 
0.500 
0.248 
0.191 
-- -- 
diameter (.mu.m) 
__________________________________________________________________________ 
TABLE 3 
______________________________________ 
Example 18 19 20 21 22 
______________________________________ 
emulsifier NaLS NaLS NaLS NaLS NaLS 
amount 15 15 15 15 15 
phosphonic acid 
TPMA TPMA TPMA TPMA TPMA 
derivative 5 5 2.5 5 7.5 
amount 
proportion of 
emulsifier/phosphonic 
acid derivative 
3:1 3:1 6:1 3:1 3:1 
solids content (%) 
51.8 51.9 50.0 52.0 52.3 
RSV (dl/g) -- -- 3.1 4.3 3.68 
______________________________________ 
EXAMPLES 23 AND 24 
The dispersion is prepared as described in Example 11 with the exception 
that 750 parts of vinyl acetate are used as sole monomer. The other 
modifications and the measured data and test results are indicated in 
Table 4. 
TABLE 4 
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Example 23 24 
______________________________________ 
emulsifier NaLS NaLS + PPG 
amount 8 8 + 9 
phosphonic acid 
derivative TPMA TPMA 
amount 2 2 
proportion of 
emulsifier to phos- 
phonic acid derivative 
4:1 4:1 
neutralizer ammonia triethanol 
solution amine 
solids content (%) 
50.6 51.6 
______________________________________ 
EXAMPLE 25 
Example 11 is repeated with a monomer mixture of 375 parts of butyl 
acrylate and 375 parts of methyl methacrylate. Solution I consists of 15 
parts of NaLS and 5 parts of TPMA. A fine-particle, low viscous copolymer 
dispersion having a solids content of 51.4%, a minimum film forming 
temperature of 9.degree. C., a viscosity of 50 mPa.s and a pH of 6.6 is 
obtained. The particles have an average diameter of 0.125 .mu.m. When 4% 
of a 5% ferric chloride solution are added to a sample of the dispersion, 
the iron salt solution is decolorized. 
COMATIVE EXAMPLES A TO D 
Examples 1 and 2 are repeated using a further comonomer instead of the 
phosphonic acid derivative. The other modifications and the measured data 
and test results are indicated in the following Table 5. The dispersions 
obtained do not decolorize ferric chloride solution. 
TABLE 5 
______________________________________ 
Example A B C D 
______________________________________ 
emulsifier NaLS NaLS NaLS NaLS 
amount in 
solution I 120 120 120 120 
amount in 
solution II 
80 80 80 80 
comonomer crotonic MMOE acrylic 
acrylic acid/ 
acid acid acryl amide 
amount in 
solution I 60 180 60 30/30 
amount in 
solution II 
40 120 40 20/20 
solids content (%) 
45.2 48.8 50.1 50.5 
mean particle 
diameter (.mu.m) 
0.169 0.190 0.161 0.164 
double strokes 
of the 
brush after 
1 day 445 641 880 1078 
3 days 585 696 1096 1180 
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