Aqueous dispersions of plastics in which the average diameter of the dispersion particles is in the range from about 50 to 500 nm, and a process for their preparation

An aqueous dispersion of a synthetic polymer of average diameter in the range of 50 to 500 nm and especially above 75 nm is disclosed, the aqueous dispersion having a solids content of 5 to 50 parts by weight per 100 parts per weight of total dispersion. The aqueous dispersion is provided by effecting polymerization in the presence of an emulsifier which comprises an alkali metal salt of a polysulfonic acid of an alkane of medium chain length e.g. 8 to 22 carbon atoms.

The invention relates to aqueous dispersions of plastics in which the 
average diameter of the dispersion particles is in the range from about 50 
to 500 nm, and to a process for establishing the average particle 
diameter. 
It is known to establish the average particle diameter of dispersion 
particles in a controlled manner by the so-called "seeding latex process" 
(Houben-Weyl, Volume XIV/1 (1961), pages 339 to 342 and pages 878 to 880). 
In the seeding latex process, a certain amount of a latex is initially 
introduced as seeds and the dispersion is then prepared, starting from 
these seeds, by polymerization of a monomer. According to a correlation 
known from Houben-Weyl, Volume XIV/1 (1961), on page 340, providing that 
no new latex particles are formed as seeds during the polymerization and 
that the density of the polymer remains constant during the 
polymerization, the average diameter of the latex particles thus obtained 
depends on the average diameter of the particles in the seeding latex and 
on the cube root of the quotient of the amount of polymer after the 
polymerization and the amount of polymer in the seeding latex. If the 
average diameter of the latex particles is to be substantially increased 
by this process, the amount of polymer in the seeding latex must therefore 
be kept as small as possible. Under these conditions, the polymerization, 
especially emulsion polymerization, proceeds very slowly and it is very 
difficult to meter in a further quantity of the emulsifier such that on 
the one hand no new particles are formed and on the other hand no 
coagulation occurs. 
According to a correlation known from J. Chem. Physics 16, 592 (1948), the 
number of latex particles in a dispersion is proportional to the 
concentration of the initiator and of the emulsifier which are added, in a 
manner which is in itself customary, in the polymerization. A reduction in 
the number of particles, which is necessary for the seeding latex process, 
can thus only be achieved by reducing the concentration of the emulsifier 
and/or of the initiator. However, this is possible only to a very limited 
extent, since when the emulsifier concentration is greatly reduced in a 
polymerization, coagulation as a rule occurs, and the initiator 
concentration cannot be reduced at will, in the interests of as 
quantitative as possible a polymer yield (low yields, polymerization does 
not start). 
Attempts have also been made (Houben-Weyl, Volume XIV/1, page 336 (1961)) 
to influence the size of the latex particles in the dispersion of the 
plastic by the choice of emulsifier. Thus, for example, the use of 
non-ionic emulsifiers to prepare coarse-particled dispersions is proposed. 
However, these emulsifiers retard the polymerization and impart to the 
dispersions a stability to electrolytes and freezing, which is frequently 
undesired. 
It is furthermore known that certain emulsifiers which belong to the 
surface-active class of carboxylates give larger latex particles than, for 
example, alkylsulphonates or alkyl-sulphates with carbon chain lengths of 
10 to 18 carbon atoms (literature: Houben-Weyl, Volume XIV/1, page 336 and 
page 203 (1961)). 
Carboxylate emulsifiers are, however, effective only in an alkaline 
reaction medium. In many cases, however, industrially important monomers 
cannot be polymerized in an alkaline medium without disadvantages 
(literature: Houben-Weyl, Volume XIV 1, pages 167-170 and 985 to 989 
(1961)). 
Alkylsulphonates are known as emulsifiers which can be employed in an acid 
reaction medium and in an alkaline reaction medium. Thus, for example, 
alkali metal alkanesulphonates with a high content of monosulphonate are 
employed, by themselves or in combination with other emulsifiers, in the 
emulsion polymerization of monomers such as, for example, vinyl chloride 
and vinyl chloride comonomer mixture (DE-OS No. (German Published 
Specification) 2,429,326). 
It is known, from DE-OS (German Published Specification) No. 2,429,326, to 
use alkali metal alkanesulphonate together with an alkali metal 
arylsulphonate as an emulsifier in the polymerization of vinyl chloride. 
The alkane radicals of the alkali metal alkanesulphonates have a chain 
length of 10 to 18 carbon atoms. 
The use of the sodium salts of an isomer mixture of alkyl-disulphonic acid 
diaryl esters containing sulphone groups as an emulsifier in the 
preparation of polyvinyl chloride is described in DE-OS (German Published 
Specification) 2,633,835. It is also known to employ alkali metal 
sulphonates with a high monosulphonate content, by themselves or in 
combination with other emulsifiers, in the emulsion polymerization of 
vinyl chloride and of vinyl chloride and comonomers (DE-OS (German 
Published Specification) 2,429,326). 
At the same time, however, it is known that anionic emulsifying agents, 
such as alkyl-sulphates, alkylsulphonates and alkylaryl- and 
arylalkyl-sulphonates, are already adequate at a low concentration as 
particularly effective primary emulsifying agents for the preparation of 
very fine-particled dispersions (Dispersionen synthetischer Hochpolymerer 
(Dispersions of Synthetic High Polymers), Section I (Eigenschaften, 
Herstellung, Prufung) (Properties, Preparation, Testing), Springer Verlag 
Vienna, Heidelberg, New York, page 64 (1969)). 
According to the invention, aqueous stable dispersions of plastics in which 
the dispersion particles have an average diameter in the range from about 
50 to 500 nm and which have a solids content of 5 to 50 parts by weight, 
per 100 parts by weight of the total dispersion, have been found, which 
are characterized in that they are prepared in the presence of an 
emulsifier system which contains 15 to 100 parts by weight, preferably 25 
to 85 parts by weight, per 100 parts by weight of the total emulsifier, of 
an alkali metal salt of polysulphonic acids of alkanes of medium chain 
length. Preferably, the particles have an average latex diameter above 95 
nm, more preferably above 150 nm and especially 175 to 500 nm. The 
invention provide particles in the range of 150 to 530 nm, average latex 
particle diameter. 
According to the invention, polysulphonic acids of an alkane of medium 
chain length contain 2 or more sulphonic acid groups. Mixtures of 
polysulphonic acids of varying degree of sulphonation and essentially with 
2 and 3 sulphonic acid groups are preferably employed. The degree of 
sulphonation is in general in the range from 2 to 4, preferably from 2 to 
3. 
Alkanes of medium chain length are saturated, straight-chain or branched 
hydrocarbons, preferably straight-chain hydrocarbons, with about 8 to 22 
carbon atoms. Polysulphonic acids of alkanes with an average carbon number 
of 13 to 17 carbon atoms can preferably be used. 
Polysulphonic acids of alkanes of different chain lengths are in general 
employed. 
Alkali metal salts which may be mentioned are essentially the sodium and 
potassium salts. 
The preparation of the alkali metal salts of the alkanesulphonic acids is 
in itself known. For example, they can be prepared by sulphochlorination 
of the alkanes and subsequent saponification of the products with an 
alkali metal hydroxide (Chemie und Technologie der 
Paraffin-Kohlenwasserstoffe (Chemistry and Technology of the Paraffin 
Hydrocarbons), Akadamie-Verlag, Berlin, 1956, pages 395 to 474). 
Emulsifiers which are to be employed according to the invention and which 
have a high content of polysulphonic acids or alkali metal salts thereof 
are obtained, for example, when the alkanes are sulphochlorinated to as 
high a degree as possible and the products are then saponified. If 
necessary, monosulphonic acid contents which are still present can be 
separated off. The separation can be effected, for example, by extraction 
with diethyl ether. 
The emulsifier employed in the polymerisation can contain, in addition to 
the content, according to the invention, of polysulphonates of an alkane 
of medium chain length, other emulsifiers which are in themselves 
customary for the polymerisation of monomers. The following customary 
emulsifiers may be mentioned as examples: monosulphonates of alkanes of 
medium chain length with a terminal sulphonate group, such as are 
obtained, for example, by reaction of alkyl-sulphates with sodium sulphite 
or by addition of sodium bisulphite or ammonium bisulphite onto olefines, 
or with a sulphonate group which is bonded to a secondary carbon atom of 
an alkane, such as can be prepared, for example, by saponification of the 
corresponding paraffin sulphonyl chlorides. 
An emulsifier system according to the invention can be particularly 
advantageously prepared when an alkane is sulphochlorinated in a manner 
which is in itself known such that mono- and poly-sulphochlorinated 
alkanes are formed, which are then hydrolysed. The proportion of 
polysulphonates in the emulsifier system can be established by changing 
the degree of sulphochlorination. A change in the degree of 
sulphochlorination is in general achieved by changing the stoichiometric 
proportions of the starting compounds. 
Other customary emulsifiers which can be combined, for example, with the 
emulsifier according to the invention are, for example, 
alkylbenzenesulphonates with straight-chain alkyl radicals with 12 to 14 
carbon atoms, sulphosuccinic acid esters, such as, for example, sodium 
dioctyl-sulphosuccinate, fatty alcohol sulphonates, such as sodium 
lauryl-sulphate, mixtures of fatty alcohol sulphates with 10 to 18 carbon 
atoms, sulphates of substituted polyglycol ethers of fatty alcohols with 
10 to 20 carbon atoms which are reacted with 3 to 20 mols of ethylene 
oxide and subsequently sulphated, or of alkylphenols, such as, for 
example, p-nonylphenols, which are reacted with 3 to 30 mols of ethylene 
oxide and subsequently sulphated (that is to say esterified with sulphuric 
acid). "Grenzflachenaktive Substanzen" ("Surface-active Substances"), 
Chemische Taschenbucher 14 (Chemical Paperbacks 14), Verlag Chemie 
Weinheim (1971)). 
In an alkaline reaction medium, it is also possible to employ, if 
appropriate, emulsifiers belonging to the surface-active class of 
carboxylates, such as sodium laurate, sodium stearate, alkali metal salts 
of modified resin acids which are derived from abietic acid (Houben-Weyl, 
Volume XIV/1, page 195 (1961)) or dimerization products of unsaturated 
fatty acids, such as, for example, of linoleic acid (Houben-Weyl, Volume 
XIV/1, page 203 (1961)). 
It is, of course, also possible to employ mixtures of these emulsifiers. 
Preferred emulsifiers which can be used according to the invention consist, 
for example, of the polysulphonate and of alkylsulphonates and 
alkylsulphates. Emulsifier systems consisting of the polysulphonate and 
alkyl-sulphonates, salts of fatty acids, such as, for example, sodium 
laurate, or salts of resin acids are preferably employed in an alkaline 
medium. 
It is also possible to employ non-ionic surface-active agents, in addition 
to the customary anionic emulsifiers. Non-ionic surface-active agents 
include substances from the surface-active class of polyglycol ethers, 
alkylphenol polyglycol ethers, acyl polyglycol ethers, hydroxyalkyl-fatty 
acid amides and their ethylene oxide adducts, fatty amine polyglycol 
ethers and polyaddition products of ethylene oxide and propylene oxide. 
Preferred emulsifier combinations according to the invention then consist, 
for example, of equal portions of an anionic surface-active agent, a 
non-ionic surface-active agent and a polysulphonate. Combinations 
consisting of a p-nonylphenol which is reacted with 10 to 30 mols of 
ethylene oxide, an alkylsulphate or an alkylsulphonate with 10 to 18 
carbon atoms and sodium polysulphonates are preferably used for the 
preparation of relatively coarse-particled and very stable dispersions. 
With the aid of the emulsifier systems according to the invention, it is 
possible to convert monomers which can be homopolymerized and 
copolymerized in emulsion by free radicals into the corresponding polymer 
dispersions. The products can be homopolymers or copolymers and can be 
thermoplastic or thermosetting resins. 
Examples which may be mentioned of monomers which can be polymerized in the 
presence of the emulsifier system according to the invention are: 
ethylene, butadiene, chloroprene, styrene, 1-methylstyrene, vinyl 
chloride, vinylidene chloride, vinyl acetate, vinyl propionate, vinyl 
esters of mixtures of synthetic saturated monocarboxylic acids with chain 
lengths of about 9 to 11 carbon atoms, which are prepared, for example, 
from an olefine cut with 8 to 10 carbon atoms by a modified "Koch 
reaction", acrylonitrile, methacrylonitrile, acrylates, such as methyl 
acrylate, ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate, and 
methacrylates, such as methyl methacrylate, ethyl methacrylate and n-butyl 
methacrylate. 
In addition to the monomers mentioned or mixtures thereof, it is also 
possible, in a manner which is in itself known, for water-soluble 
monomers, such as methacrylic acid, acrylic acid, methacrylamide, 
acrylamide, maleic acid half-esters and itaconic acid, to be employed in 
customary amounts, for example 2 to 6% by weight, relative to the total 
monomer mixture for the polymerisation. 
Furthermore, monomers having a crosslinking action, such as, for example, 
divinylbenzene, divinyl ether, diol-diacrylates, triallyl compounds, such 
as, for example, triallyl cyanurate, N-methylol acrylamide, 
N-methylolmethacrylamide or the ethers of these methylol compounds, can be 
employed, in addition to the monomers hitherto mentioned, for the 
preparation of crosslinked polymers or polymers which can be subsequently 
crosslinked. 
According to the invention, it is thus possible to prepare polymers which 
have particular properties as a result of the particle size established in 
a definite manner. These properties are essentially determined by the size 
of the latex particles. It is known that the particle size of the 
dispersed polymer and its particle size distribution is of decisive 
importance for the technological properties of dispersions of plastics (F. 
Holscher, Dispersionen synthetischer Hochpolymerer (Dispersions of 
Synthetic High Polymers), Section I, Eigenschaften, Herstellung und 
Prufung (Properties, Preparation and Testing), Springer-Verlag, Berlin, 
Heidelberg, New York, 1969, page 8, last paragraph). The particle size and 
particle size distribution in the dispersion are greatly dependent on the 
nature of the preparation of a dispersion. 
Preferred dispersions of plastics which can be prepared according to the 
invention are: polyvinyl chloride dispersions, 
n-butacrylate/styrene/methacrylic acid copolymer dispersions, 
butadiene/styrene/copolymer dispersions which have a high and low styrene 
content and can contain carboxyl groups incorporated in the copolymer; 
polystyrene dispersions, styrene/divinylbenzene/methacrylic acid copolymer 
dispersions, crosslinked and non-crosslinked poly-n-butyl acrylate 
dispersions, styrene/acrylonitrile copolymer dispersions containing a 
predominant proportion of styrene; copolymer dispersions of methyl 
methacrylate with (meth)acrylates; copolymer dispersions of n-butyl 
acrylate with styrene, hydroxypropyl acrylate with methacrylic acid; 
copolymer dispersions of n-butyl acrylate with acrylonitrile and 
methacrylic acid; and copolymer dispersions of n-butyl acrylate with 
styrene, acrylonitrile and methacrylic acid. 
The aqueous dispersions, according to the invention, of plastics are 
prepared in the presence of one or more initiators. Examples of initiators 
which may be mentioned are the substances or substance mixtures which are 
in themselves known and dissociate into free radicals under the influence 
of heat and initiate free radical polymerisation (literature: Houben-Weyl, 
Volume XIV/1 pages 209 to 297 (1961)). 
It is thus possible to initiate the polymerization with water-soluble 
agents which form free radicals or with agents which form free radicals 
and are only very slightly soluble in water. Examples which may be 
mentioned of inorganic agents which form free radicals are 
peroxodisulphates, such as potassium peroxodisulphate, ammonium 
peroxodisulphate and sodium peroxodisulphate, or combinations of the 
initiators mentioned with reducing compounds, such as, for example, sodium 
bisulphite, sodium pyrosulphite, formamidinesulphinic acid and sodium 
formaldehyde-sulphoxylate. 
Water-soluble derivatives of azodinitriles can also be used as initiators 
(Houben-Weyl, Volume XIV/1, pages 221 and 222 (1961)). 
Hydrogen peroxide or organic peroxides, if appropriate in combination with 
reducing organic compounds, such as benzoin, mono- and di-hydroxyacetone, 
ascorbic acid, sorbose, fructose, glucose, mannose and heavy metal salts 
bonded in the form of complexes, such as, for example, iron-II salts 
complexed with salts of ethylenediaminetetraacetic acid, can be used to 
prepare dispersions which have a particularly low salt content. 
Preferred initiators for the preparation of the aqueous dispersions, 
according to the invention, of plastics are potassium peroxodosulphate, 
sodium peroxodisulphate, ammonium peroxodisulphate or mixtures thereof, 
the said alkali metal peroxodisulphates in combination with sodium 
pyrosulphite, and tert.-butyl hydroperoxide in combination with sodium 
formaldehydesulphoxylate. 
In addition to the initiators, compounds which regulate the molecular 
weight of the polymer, such as mercaptans, for example 
tert.-dodecylmercaptan and dodecylmercaptan, diisopropylxanthogen 
disulphide, methacrolein, oleic acid, carbon tetrachloride or carbon 
tetrabromide, can also be employed in combination with the polysulphonates 
according to the invention. 
The average particle diameter of the dispersion particles in the 
dispersions of plastics can be established, according to the invention, by 
changing the polysulphonic acid content of the emulsifier system to a 
desired value in the range from 50 to 500 nm. 
A process has thus been found for establishing an average particle diameter 
of dispersion particles in aqueous dispersions of plastics which are 
prepared by polymerization of the monomers of the plastic in the presence 
of water, an initiator and an emulsifier system, which is characterised in 
that the total amount of the initiator and of the emulsifier system, which 
contains a proportion of an alkali metal salt of a polysulphonic acid of 
an alkane of medium chain length, is kept approximately constant and the 
proportion of the alkali metal salt of the polysulphonic acid is changed 
in the range from 15 to 100 parts by weight, per 100 parts by weight of 
the total emulsifier system. 
It is a considerable advantage of the process according to the invention 
and surprising that the total amount of the emulsifier system and of the 
initiator system can be kept approximately constant, the course achieved 
for the polymerization reaction is satisfactory with regard to the rate of 
polymerization and, depending on the particular composition of the 
emulsifier system, dispersions of plastics which have a defined average 
particle diameter which is in each case different, according to the 
particular composition of the emulsifier system, are nevertheless 
obtained. 
The emulsifier system can be employed in a total amount of 0.05 to 10 parts 
by weight, per 100 parts by weight of the water present in the 
polymerization. Contents of 0.5 to 5 parts by weight, per 100 parts by 
weight of the water present in the polymerization, are preferred. 
The monomer content, relative to the total weight of monomer and water, is 
5 to 50% by weight, preferably 10 to 35% by weight. 
The greater the content of polysulphate in the emulsifier system, the 
greater is the average particle diameter of the dispersion particles. In 
an individual case, the amount of polysulphonate to be fixed in the 
emulsifier system depends on the particular polymerization conditions and 
on the nature and amount of the particular monomers used for the 
polymerization, and this amount can easily be fixed within the limits 
according to the invention by preliminary experiments. 
Dispersion particles in the range from about 150 to 300 nm are preferably 
produced with the aid of the process according to the invention. 
The expensive seeding latex process can thus advantageously be dispensed 
with. 
However, it is of course also possible, in addition to the process 
according to the invention, to influence the particle size of the latex 
particles by varying the total amount of the emulsifier. 
In another embodiment of the process according to the invention, a defined 
seeding latex with large latex particles can be prepared with the aid of 
the process according to the invention and this latex can be converted 
into an even more coarsely-particled defined form with the aid of the 
"seeding latex process". 
In the case of a precisely fixed total concentration of the emulsifier 
system in water, a precisely fixed polysulphonate content in the 
emulsifier system and a precisely fixed initiator concentration in the 
water at the start of the polymerization, the resulting particle size in 
the dispersion at the end of the polymerization furthermore also depends, 
of course, on the ratio of monomer to water, which was fixed at the start 
of the polymerization. 
If, therefore, the preparation of a particularly coarse-particled 
dispersion is intended, for example, as small as possible an amount of a 
seeding latex which is as coarse-particled as possible is produced in an 
preliminary emulsion polymerization with very small amounts of an 
emulsifier system consisting predominantly of the polysulphonate, and 
thereafter, this seeding latex is coarsened further in a manner which is 
in itself known with the aid of the seeding latex process, water, monomer, 
emulsifier solution and, if appropriate, additional initiator solution 
being added. 
In a particular embodiment of the process according to the invention, a 
seeding latex with a defined diameter of the individual particles is thus 
first prepared by the process according to the invention, and thereafter, 
particles up to a diameter of about 1,000 nm can be prepared by the 
seeding latex process which is in itself known. 
The process according to the invention can be used technologically as a 
discontinuous, semicontinuous or completely continuous process. 
In the case of the discontinuous and semicontinuous process, the emulsifier 
combinations according to the invention are preferably employed in the 
first phase of the polymerisation, which is called the "particle formation 
period" (G. Henrici-Olive and S. Olive, Polymerizsation, 
Katalyse-Kinetic-Mechanismen (Polymerization, 
Catalysis-Kinetics-Mechanisms), Chemische Taschenbucher (Chemical 
Paperbacks), Verlag Chemie Weinheim/Bergstrasse, No. 8, pages 72-77. Known 
emulsifiers which are free from polysulphonates can also be subsequently 
metered in to stabilize the dispersions in the "period of constant rate of 
polymerization". 
According to a preferred embodiment of a continuous process, the 
polymerization is carried out in several polymerisation chambers connected 
in series, dispersion particles of the desired average particle size being 
formed in the first polymerisation chamber using polysulphonate-containing 
emulsifier systems according to the invention. Reaction mixture passes 
from the first to the second, from the second to the third, from the third 
to the fourth etc. reaction chamber at a rate corresponding to that at 
which the starting components are introduced into the first reaction 
chamber. 
Such continuous processes in cascades of stirred kettles or autoclaves are 
in themselves known and are used, for example, for the preparation of 
butadiene/styrene dispersions (Chemische Technologie (Chemical 
Technology), Winnacker-Kuchler, Carl Hanser Verlag, Munich, 1960, page 388 
et seq.). 
The polymerization can, of course, also take place in reactors which are 
divided into individual chambers in which thorough mixing is effected by a 
common stirrer shaft (German Patent Specification No. 1,125,175). 
It is also possible to carry out a continuous polymerization in a single 
reactor through which the reactants flow and are thoroughly mixed 
continuously. Coarse-particled polyvinyl chloride dispersions can be 
prepared particularly advantageously in such a reactor. 
The process according to the invention for establishing a defined particle 
diameter of dispersion particles of an aqueous dispersion of a plastic can 
be carried out, for example, as follows. 
The polymerization is carried out in a measurement series under comparable 
conditions, the total amount of emulsifier remaining constant but the 
polysulphonate content varying. The particle diameters of the dispersions 
obtained are determined by known methods in a manner which is in itself 
known (in an ultracentrifuge or electron microscope, from the angular 
variation of light scattering or by laser correlation spectroscopy). The 
conditions for preparation of a particular defined particle diameter can 
be established for each specific polymer by correlation of the resulting 
particle diameters in the measurement series with the polysulphonate 
content of the total amount of emulsifier. 
Uniform dispersions of approximately constant average particle diameter are 
obtained by the process according to the invention. Since the physical 
properties, which are of particular importance for the application, of 
dispersions of plastics depend not only on the average particle size but 
also on the proportions of particles which deviate from the average 
diameter, by mixing different dispersions with in each case an 
approximately constant particle diameter one can prepare new dispersions 
of plastics which have a defined distribution of latex particles of 
various sizes. The dispersions thus obtained are independent of the 
unavoidable diameter distribution of a particular preparation process and 
can be prepared in any desired particle size distribution. 
The process according to the invention can also be used for the preparation 
of dispersions with a slightly increased average particle diameter. By 
slightly increasing the particle diameter, which can easily be carried out 
in a defined manner with the aid of the process according to the 
invention, the ability to flow can be favourably influenced whilst the 
other properties are virtually unchanged. 
Coarse-particled polyvinyl chloride dispersions with latex particle 
diameters of 500 to 2,000 nm are particularly suitable for the preparation 
of polyvinyl chloride plastisols (Houben-Weyl, Volume XIV/1, page 878 
(1961)), since the ability of polyvinyl chloride plastisols obtained from 
emulsion polymers to flow increases as the particle size increases. 
Particularly favourable paste viscosities are obtained with the aid of the 
process according to the invention. 
Coarse-particled dispersions based on acrylate or butadiene can be used in 
a manner which is in itself known as the graft base in the preparation of 
plastics of high impact strength. The soft particles of the graft base, 
which in most cases are crosslinked chemically on the inside, must have a 
certain minimum particle size in order to achieve high notched impact 
strength values ("Die Makromolekulare Chemie", 101 (1967), pages 200 to 
213.; and "Angew. Makromolekulare Chemie" 29/30 (1973), pages 1 to 23). 
The acrylate or butadiene dispersions prepared by the process according to 
the invention can be particularly advantageously used as graft bases. 
It is also possible to build up dispersion particles which are structured 
in the form of spherical shells and have a soft core and hard shell or 
hard core and soft shell by the process according to the invention.

EXAMPLES 
(A) Starting substances (Monomers, water, initiator) 
Commercially available monomers in the freshly distilled state were used in 
the following experiments. According to analysis by gas chromatography, 
the monomers were in most cases over 99.9% pure. 
The water employed in the experiments was completely desalinated and was 
boiled up before use, N.sub.2 being bubbled through. The potassium 
peroxide-sulphate used was analytically pure. 
(B) Emulsifiers 
To prepare the emulsifier systems used in the examples, emulsifiers 
containing polysulphonate were mixed with commercially available 
emulsifiers. The preparation of two suitable polysulphone-containing 
emulsifier systems which, if desired, can be combined with customary 
emulsifiers is described below: 
B-1. Emulsifier system containing about 70% by weight of sodium 
alkanepolysulphonate 
A mixture of linear alkanes (8 to 20 carbon atoms in the molecule, the 
average number of carbon atoms is 15) is sulphochlorinated, in the 
presence of light, with a gas mixture consisting of 1.1 parts by weight of 
sulphur dioxide and 1.0 part by weight of chlorine at a temperature of 
30.degree. to 40.degree. C., whilst stirring and simultaneously cooling. 
The sulphochlorination is carried out until the reaction mixture has a 
density of 1.165 g/cm.sup.3 at 45.degree. C. The sulphochloride content is 
then 15.5 to 16.0% by weight. 
200 g of the sulphonation mixture are added dropwise to 144 g of 50% 
strength by weight sodium hydroxide solution, which has been warmed to 
50.degree. to 60.degree. C. The reaction mixture is kept at a temperature 
of 95.degree. to 100.degree. C. by cooling. When the reaction has ended, 
the reaction mixture is adjusted to a pH value of 9 to 10 by adding 
concentrated sodium hydroxide solution. The reaction mixture is then 
cooled to 60.degree. to 70.degree. C. 
Sodium chloride precipitates in this temperature range and is filtered off 
or centrifuged off. The solution, which is free from sodium chloride, is 
evaporated to dryness in vacuo. 220 g of sodium alkane-sulphonate are 
thereby obtained. The sodium alkane-sulphonate consists of: 28% by weight 
of sodium alkane-monosulphonate and 67% by weight of sodium 
alkane-polysulphonate. 
The sodium alkanesulphonate thus prepared is used as an emulsifier, by 
itself or with the addition of sodium alkane-monosulphonate or other 
anionic and/or non-ionic surface-active agents which are in themselves 
known, for the polymerization of monomers in emulsion. 
B-2 Preparation of an emulsifier system containing about 90% by weight of 
sodium alkanepolysulphonate 
A mixture of linear alkanes (8 to 20 carbon atoms in the molecule, the 
average number of carbon atoms is 15) is sulphochlorinated, in the 
presence of light, with a gas mixture consisting of 1.1 parts by weight of 
sulphur dioxide and 1.0 part by weight of chlorine at a temperature of 
30.degree. to 40.degree. C., whilst stirring and simultaneously cooling. 
The sulphochlorination is carried out until the reaction mixture has a 
density of 1.250 g/cm.sup.3 at 45.degree. C. The sulphochloride content is 
then 18.0-18.5% by weight. 
200 g of the sulphonation mixture are added dropwise to 170 g of 50% 
strength by weight sodium hydroxide solution, which has been warmed to 
50.degree. to 60.degree. C. The reaction mixture is kept at a temperature 
of 95.degree. to 100.degree. C. by cooling. When the reaction has ended, 
the reaction mixture is adjusted to a pH value of 9 to 10 by adding 
concentrated sodium hydroxide solution. The reaction mixture is then 
cooled to 60.degree. to 70.degree. C. 
Sodium chloride is precipitated in this temperature range and is filtered 
off or centrifuged off. The sodium chloride free solution is evaporated to 
dryness in vacuo. A mixture of 8 g of NaCl and 139 g of sodium 
alkanesulphonate is thereby obtained. The sodium alkanesulphonate consists 
of: 13.2% by weight of sodium alkane-monosulphonate and 86.8% by weight of 
sodium alkane-polysulphonate. 
The sodium alkanesulphonate thus obtained is used as an emulsifier, by 
itself or with the addition of sodium alkane-monosulphonate or other 
anionic and/or non-ionic surface-active agents which are in themselves 
known, for the polymerisation of monomers in emulsion. 
(C) Procedure for the polymerization experiments 
Series polymerization experiments which are described in the following 
examples were carried out in corked glass flasks with a capacity of 500 ml 
and with an additional crown cork closure (in this context, compare Houben 
Weyl, Methoden der organischen Chemie (Methods of Organic Chemistry) 
Volume XIV, 1 page 147 (1961)). The flasks, inserted in steel cartridges, 
were rotated in a thermostatically controlled water-bath at a speed of 25 
revolutions per minute (abbreviation: r/m or rpm). The temperature of the 
water-bath in which the flasks were periodically immersed was kept 
constant. All the batches were carried out with exclusion of atmospheric 
oxygen. If the procedure was otherwise, this is mentioned expressly in the 
subsequent examples. 
(D) Evaluation of the experimental results 
After cooling to room temperature, the 500 ml flasks were emptied 
completely, the contents were sieved through a Perlon fabric with a square 
mesh width of 30.mu. and the coagulate which remained was washed and dried 
to constant weight. If the polymerization was carried out in stirred 
vessels or autoclaves, any coagulate deposited on the stirrers, immersion 
heaters and walls was also taken into consideration. 
The solids content (dry residue in % of the weight of latex) of the latex 
which in each case filtered through the Perlon was determined, as well as 
the particle size, by laser correlation spectroscopy. In this laser light 
scattering method, information from the scattering particles (for example 
latex particles) is obtained from the fluctuations of the scattered light 
with respect to time, which is recorded by a photomultiplier. The 
fluctuations in scattered light are based on the irregular Brownian motion 
of the particles. The translatory diffusion coefficient D of the 
particles, which is linked with particle diameter d, is accordingly 
obtained from autocorrelation analysis of the scattered light signal. 
The second cumulant (C 2) of the correlation function, which is a relative 
measure of the width of the particle size distribution can be determined 
at the same time (literature: H. Z. Cummins, E. R. Pike, Hsg. Photon 
Correlation and Light Beatin Spectroscopy, Plenum Press 1974; B. Chu, 
Laser Light Scattering, Academic Press, 1974; and D. E. Koppel J. Chem. 
Phys. 57 (1972) 4,814). The closer the value of C 2 is to zero, the more 
uniform are the dispersion particles and the narrower is the diameter 
distribution curve. 
(E) Embodiment Examples 
EXAMPLE 1 
The poly/mono-sulphonate ratio of an emulsifier which is prepared according 
to instructions B.2. and has a high polysulphonate content is adjusted to 
85/15, the emulsifier is diluted to a 10% strength aqueous solution and 
increasing amounts of the solution are added to a 10% strength sodium 
lauryl-sulphate solution such that the total amount of emulsifier in the 
batch remains constant. 
______________________________________ 
Batches: 
______________________________________ 
Deionised water 118.3 g 
10% strength polysulphonate/monosulphonate 
emulsifier, poly/mono ratio = 85/15 
0 to 
130 g 
10% strength solution of sodium lauryl- 
sulphate from 130 to 
0 g 
(Sum of the weights of the two 10% 
strength emulsifier solutions in each batch 
is always 130 g) 
2% strength potassium peroxodisulphate 
solution 26.2 g 
n-Butyl acrylate 112.5 g 
Total weight of the batch: 387.0 g 
______________________________________ 
For the polymerization process, compare the procedure in C. The composition 
of the total emulsifier system thus varies in each experiment, and its 
concentration in water is the same in each experiment (compare Table I). 
The reaction parameters are as follows: 
______________________________________ 
Total emulsifier concentration: [E] = 
49.8 g/1,000 g 
(Monosulphonate + polysulphonate + 
of water 
alkyl-sulphate) 
Amount of emulsifier, per 100 parts by 
weight of water: 5 parts by weight 
Content of an alkali metal salt of a 
polysulphonic acid: 0 to 85 parts by 
weight 
per 100 parts by weight of the total 
emulsifier system, 
Weight ratio of monomer/monomer + 
water = 0.3 
Polymerization time: 7 hours 
Polymerization temperature: 
70.degree. C. 
Speed of rotation of the flasks: 
25 (revolutions 
per minute) 
Flask volume: 500 ml 
Maximum solids content which can be 
achieved in the latices: 
32.56% by weight 
______________________________________ 
The results of the polymerization experiments are now summarized in Table 
I. 
The percentage composition of the emulsifier system according to the 
invention is given in the first 3 columns; the batches in lines 1 and 2 do 
not represent an emulsifier system according to the invention since they 
have a polysulfonate content of less than 15% by weight. 
As can be seen from column 4, the solids content of the dispersions remains 
approximately constant and is independent of the composition of the 
particular emulsifier system. As the polysulphonate content of the 
emulsifier system increases, the coagulate content in the dispersions 
increases somewhat (compare column 5), but remains slight throughout. 
The establishment, according to the invention, of particle size can be seen 
from column 6. It is predominantly in the range from about 50 to 300 nm. 
The dispersion particle diameter initially rises only slowly as the amount 
of polysulphonate added increases, for example in the range from 15 to 65% 
by weight of polysulphonate in the emulsifier system. The latex particle 
diameter rises more steeply from a polysulphonate content of about 65% by 
weight. 
As can be seen from column 7, C 2, the measure of the width of the latex 
particle diameter distribution, does not change significantly. 
Before being opened, the flasks, which were filled to the same level, were 
shaken vigorously for 20 minutes. Thereafter, the time which passed until 
the foam collapsed was recorded. This time is given in column 8 for the 
particular experiments, as a measure of the tendency of the latex to form 
a stable foam. 
From column 8, it can be seen that the addition of polysulphonate to the 
emulsifier system initially has an anti-foaming effect, which is very 
desirable. The tendency to foam (increase in the number of seconds before 
the foam disappears) only increases again at high polysulphonate contents, 
as a result of the decreasing internal surface of the dispersions. 
TABLE I 
__________________________________________________________________________ 
Solids 
Coagulate 
Latex 
C 2 
content 
content 
particle 
Numerical 
Composition of the emulsifier system 
of the 
(% by diameter 
measure 
Ability 
(% by weight) latex 
weight), 
d (nm) 
of the d 
to form 
Poly- Mono- Na lauryl- 
(% by 
relative to 
(average 
distribu- 
foam 
sulphonate 
sulphonate 
sulphate 
weight) 
the monomer 
value) 
tion (seconds) 
__________________________________________________________________________ 
0 0 100 31.2 0 51 0.09 187 
13.1 2.3 84.6 31.2 0 50 0.11 140 
32.7 5.8 61.5 31.4 0 59 0.05 95 
42.5 7.5 50 31.3 0 72 0.05 86 
52.3 9.2 38.5 31.5 0 83 0.07 82 
65.5 11.5 23.0 31.7 0.2 129 0.03 80 
68.7 12.1 19.2 31.6 0.3 135 0.04 78 
71.9 12.7 15.4 31.4 0.4 175 0.03 65 
75.2 13.3 11.5 31.6 0.3 196 0.06 88 
78.5 13.8 7.7 31.7 0.2 237 0.07 99 
81.8 14.4 3.8 31.8 0.6 285 0.09 150 
85 15 0 31.0 0.7 310 0.10 205 
__________________________________________________________________________ 
(compare the explanations in the text of Example 1) 
EXAMPLE 2 
An emulsifier which is prepared according to instructions B.2. and has a 
high polysulphonate content is mixed with an alkylmonosulphonate of the 
same carbon chain length such that 4 emulsifier systems (A to D) of 
different polysulphonate/monosulphonate ratios result: 
______________________________________ 
Emulsifier system A B C D 
______________________________________ 
% by weight of monosulphonate 
85 50 30 15 
% by weight of disulphonate 
15 50 70 85 
______________________________________ 
Various monomers and monomer mixtures are now polymerized with the aid of 
these emulsifier systems A to D, according to the polymerization 
conditions C and the following recipe: 
______________________________________ 
Deionised water 118.3 g 
10% strength aqueous emulsifier system 
131.25 g 
2% strength aqueous K.sub.2 S.sub.2 O.sub.8 solution 
26.20 g 
Monomer or monomer mixture 
112.5 g 
Total weight of each batch: 
388.25 g 
______________________________________ 
The composition of total emulsifier system thus varies in each batch, but 
the total emulsifier concentration is in each case the same in each 
experiment (compare Table II). 
The reaction parameters are as follows: 
______________________________________ 
Total emulsifier concentration: [E] = 
50 g/1,000 g of 
(Polysulphonate + monosulphonate) 
H.sub.2 O 
Amount of emulsifier, per 100 parts 
by weight of H.sub.2 O: 
5 parts by weight 
Content of an alkali metal salt of a 
polysulphonic acid: 15 to 
85% by weight 
relative to the weight of the 
emulsifier system 
Initiator concentration: [I] = 
2 g/1,000 g of 
H.sub.2 O 
Weight ratio of monomer/(monomer + 
water) = 0.3 
Polymerization time: 7 hours 
Polymerization temperature: 
70.degree. C. 
Speed of rotation of the flasks: 
25 revolutions 
per minute 
Maximum solids content which can be 
achieved: 32.49% by weight 
Reaction vessel volume: 
500 ml 
______________________________________ 
The results of the experimental series are summarised in Table II. As the 
polysulphonate content of the emulsifier system increases, the particle 
diameter of the particular dispersions increases. 
The average particle diameter d of the dispersions can be established at 
any value, for example in the range from 50 to 300 nm, depending on the 
monomer employed. In the case of emulsion polymerisation of methyl 
methacrylate, dispersions with average particle diameters of greater than 
500 nm are formed. In this case, the coagulate content increases 
considerably as the polysulphonate content increases (compare line 5, 
Table II). 
TABLE II 
__________________________________________________________________________ 
Composition of the emulsifier system polysulphonate : mono- 
sulphonate (% by weight ratio) 
Coagulate Coagulate 
Solids 
%, rela- Solids 
%, rela- 
content 
tive to 
Particles* 
content 
tive to 
Particles* 
Monomer % monomer 
d [nm] 
% monomer 
d [nm] 
__________________________________________________________________________ 
15:85 50:50 
a Ethyl acrylate 
32.2 
0 64 32.1 
1.0 152 
b n-Butyl acrylate 
32.3 
0 60 32.2 
0 105 
c tert.-Butyl acrylate 
30.0 
0 55 28.0 
0 100 
d 2-Ethylhexyl acrylate 
32.0 
0 49 32.3 
0 80 
e Methyl methacrylate 
32.1 
0 62 31.5 
0.7 190 
f n-Butyl methacrylate 
32.2 
0 52 32.3 
&gt;0.1 96 
g Styrene 32.2 
0 63 32.3 
&gt;0.1 75 
h Styrene:n-butyl 
acrylate mixture, 
weight ratio of 1:1 
31.9 
0 58 32.2 
&gt;0.1 115 
i n-Butyl acrylate: 
acrylonitrile mix- 
ture, weight ratio of 
2:1 31.6 
0 61 31.8 
0.1 105 
__________________________________________________________________________ 
70:30 85:15 
a Ethyl acrylate 
36.8 
5.2 200 32.9 
8.2 290 
b n-Butyl acrylate 
32.2 
0 150 32.9 
0.8 260 
c tert.-Butyl acrylate 
27.0 
0 150 27.3 
0.4 240 
d 2-Ethylhexyl acrylate 
31.8 
0 110 32.3 
0 133 
e Methyl methacrylate 
29.1 
0.9 340 30.0 
3.0 950 
f n-Butyl methacrylate 
32.0 
0 130 31.8 
0.3 288 
g Styrene 31.7 
0 95 32.4 
1.1 110 
h Styrene:n-butyl 
acrylate mixture, 
weight ratio of 1:1 
31.4 
0 150 32.1 
0.1 260 
i n-Butyl acrylate: 
acrylonitrile mix- 
ture, weight ratio of 
2:1 29.5 
3.2 220 29.5 
3.5 270 
__________________________________________________________________________ 
*d is the average dispersion particle diameter in nm 
(Compare the explanations in the text of Example 2) 
EXAMPLE 3 (with comparison examples) 
The emulsifier which is prepared according to instruction B.1. and which 
contains about 70% by weight of sodium alkanepolysulphonate and about 30% 
by weight of sodium alkanemonosulphonate is used in four different 
emulsifier concentrations, in particular 50, 10, 1.0 and 0.5 [g/1,000 g of 
H.sub.2 O], for the polymerization of styrene (compare Table III). 
The effectiveness of the emulsifier system according to the invention is 
compared with that of 6 different anionic emulsifiers which are employed 
under the same polymerisation conditions. These anionic emulsifiers have 
no polysulphonate content. 
______________________________________ 
Batches: 
______________________________________ 
Deionised water: 236.7 
Emulsifier(s) (100% of 
detergent substance) 
0.13; 0.26; 2.62; or 13.7 
(compare Table III) 
2% strength K.sub.2 S.sub.2 O.sub.8 solution: 
26.3 
Styrene 112.5 
______________________________________ 
The composition of each emulsifier system thus remains the same and the 
emulsifier concentrations are in each case different for the same 
emulsifier system. 
The reaction parameters are as follows: 
Total emulsifier concentration in each emulsifier system: 50; 10; 1.0; 0.5 
[g/1,000 g of H.sub.2 O] 
Total amount of emulsifier, per 100 parts by weight of water: 5; 1.0; 0.1; 
0.05 parts by weight 
Weight ratio of monomer/(monomer+water)=0.3 
Polymerization time: 7 hours 
Polymerization temperature: 70.degree. C. 
Speed of rotation of the flasks: 25 revolutions per minute 
Reaction vessel volume: 500 ml 
Maximum solids contents which can be achieved: 30.12; 30.15; 30.58; 32.46% 
by weight 
TABLE III 
__________________________________________________________________________ 
Total emulsifier concentration (g of emulsifier/ 
1,000 g of water) 
50 10 1 0.5 
C d C d C d C d 
Emulsifier system S(%) 
(%) (nm) 
S(%) 
(%) (nm) 
S(%) 
(%) (nm) 
S(%) 
(%) 
(nm) 
__________________________________________________________________________ 
Emulsifier according to 
instruction B-1 (according to 
the invention) 32.1 
0 150 
30 1.5 155 
28.5 
3.0 480 
27.0 
0.3 
530 
Sulphosuccinic acid dioctyl 
ester 31.9 
0 75 
coagulation 
coagulation 
coagulation 
Sodium p-dodecylbenzenesulphonate 
32.0 
0 70 
30.2 
0.5 95 
coagulation 
coagulation 
CH.sub.3(CH.sub.2).sub.11O(CH.sub.2CH.sub.2O).sub.10OSO.sub.3.sup..crclbar 
NH.sub.4.sup..sym. 32.0 
0 65 
32.5 
1.5 85 
coagulation 
coagulation 
Mixture of secondary paraffin 
monosulphonates with 14 to 16 
C atoms 32.1 
0 65 
30.1 
0.5 90 
coagulation 
coagulation 
Sodium lauryl-sulphonate 
32.0 
0 60 
30.0 
0.2 77 
coagulation 
" 
##STR1## 32.0 
0 50 
30.0 
0.7 81 
coagulation 
" 
__________________________________________________________________________ 
Explanations for Table III: 
S(%) = solids content of the dispersion; 
C(%) = coagulate content (%), relative to the monomer; 
d(nm) = average latex particle diameter in nm. 
The results of the polymerization experiments are summarized in Table III. 
Each line in Table III relates to a different emulsifier system. The four 
main columns show the solids content (S%), coagulate content (% by weight, 
relative to the monomer) and the average diameter of the dispersion 
particles, d (in nm), as a function of the total emulsifier concentration 
(50:10:1:0.5). 
When the emulsifier system according to the invention is used, dispersions 
with particle diameters of 150 to 530 nm are formed, depending on the 
emulsifier concentration (compare line 1, Table III). 
In contrast, when customary anionic emulsifiers are used, it is not 
possible to obtain coarse-particled dispersions of plastics in a 
comparable manner by reducing the emulsifier content. Rather, when 
customary emulsifiers are used at emulsifier concentrations of about 1 
g/1,000 g of water, complete coagulation of the particular batches occur. 
Example 4 (with comparison example) 
The mode of action of the emulsifier system according to the invention 
which is prepared in accordance with instruction 2.1. is compared with 
that of an alkylmonosulphonate (in this context, compare Houben-Weyl, 
Methoden der organischen Chemie (Methods of Organic Chemistry), 4th 
Edition, Volume XIV/1, Makromolekulare Stoffe (Macromolecular Substances), 
Georg Thieme Verlag, Stuttgart, 1961, page 871): 
The following components are initially introduced into an autoclave which 
is provided with a blade stirrer and has a capacity of 5.5 to 6.1: 
______________________________________ 
Deionised water: 2,325.5 g 
10% strength aqueous emulsifier solution: 
750.0 g 
Potassium peroxodisulphate: 
3.0 g 
Sum of the components: 3.078.5 g 
______________________________________ 
The atmospheric oxygen is removed from the space in the autoclave by 
evacuation and flushing with nitrogen, 1,500 g of vinyl chloride are then 
added and the reaction mixture is warmed to 48.degree. C., whilst stirring 
(125 revolutions per minute). 
After 10 to 12 hours, the polymerization has ended, which can be recognized 
by the drop in pressure of the contents of the autoclave. 
If the commercially available alkylmonosulphonate with about 12 to 18 C 
atoms in the unbranched chain is used as the emulsifier, a coagulate-free, 
viscous, extremely fine-particled polyvinyl chloride dispersion with a 
dispersion particle diameter of about 50 nm and a solids content of about 
34% by weight results. This dispersion is very unstable towards shearing 
stress. 
In contrast, if an emulsifier system according to the invention (compare 
instruction B-1) is employed, a coagulate-free approximately 32% strength 
polyvinyl chloride dispersion which has dispersion particle diameters of 
250 nm, is readily mobile and has a very good stability to shearing stress 
is formed. 
EXAMPLE 5 
The method according to the invention, of establishing the average 
dispersion particle diameter with the aid of polysulphonates can also be 
illustrated using examples of emulsion polymerization in the presence of a 
seeding latex. 
A monomer mixture consisting of 51% by weight of n-butyl acrylate, 45% by 
weight of styrene and 4% by weight of methacrylic acid is summarized. 
The emulsifier systems A to D, as described in Example 2, are employed. 
10% by weight of the monomer mixture are initially introduced to form a 
seeding latex, a further amount of 90% by weight is metered in and the 
seeding latex particles present are polymerised. 
When conversion of the monomer is complete, the solids content of the 
seeding latex is about 10% by weight, and the final latex has a solids 
content of about 46% by weight. 
The emulsifier concentration in the quantity of water initially introduced 
is about 9 g/1,000 g of water, and the initiator concentration is 1.5 
g/1,000 g of water. 
The polymerization experiments are carried out at 75.degree. C. in 
accordance with the recipes summarized in Table IV, in 1.5 l three-necked 
flasks with blade stirrers operating at 250 revolutions per minute, reflux 
condensers, internal thermometers and dropping funnels for solutions 5.3., 
5.4. and 5.5. 
TABLE IV 
__________________________________________________________________________ 
DISPERSION 5a 5b 5c 5d 
__________________________________________________________________________ 
Deionised water 400 
400 
400 
400 
Emulsifier mono/poly-sulphonate 85:15 
4 -- -- -- 
5.1 Emulsifier mono/poly-sulphonate 50:50 
-- 4 -- -- 
Emulsifier mono/poly-sulphonate 30:70 
-- -- 4 -- 
Emulsifier mono/poly-sulphonate 15:85 
-- -- -- 4 
Styrene 22.5 
22.5 
22.5 
22.5 
5.2 n-Butyl acrylate 25.5 
25.5 
25.5 
25.5 
Methacrylic acid 2.0 
2.0 
2.0 
2.0 
5.3 Deionised water 50.0 
50.0 
50.0 
50.0 
(NH.sub.4).sub.2 S.sub.2 O.sub.8 
0.7 
0.7 
0.7 
0.7 
Styrene 202.5 
202.5 
202.5 
202.5 
5.4 n-Butyl acrylate 229.5 
229.5 
229.5 
229.5 
Methacrylic acid 18.0 
18.0 
18.0 
18.0 
Deionised water 140.0 
140.0 
140.0 
140.0 
(NH.sub.4).sub.2 S.sub.2 O.sub.8 
2.3 
2.3 
2.3 
2.3 
Emulsifier mono/poly-sulphonate 85:15 
3.5 
-- -- -- 
5.5 Emulsifier mono/poly-sulphonate 50:50 
-- 3.5 
-- -- 
Emulsifier mono/poly-sulphonate 30:70 
-- -- 3.5 
-- 
Emulsifier mono/poly-sulphonate 15:85 
-- -- -- 3.5 
Solids content (% by weight 
46.3 
46.3 
46.3 
46.3 
Coagulate (g) 3.5 
4.0 
&lt;0.1 
&lt;0.1 
Average dispersion particle diameter d(nm) 
92 133 
260 
280 
Measure of the width of the particle size 
distribution: C2 0.07 
0.03 
0.02 
0.01 
Flow time in a flow cup according to 
DIN 53211, 4 mm nozzle; latex pH = 8.5 (seconds) 
24 14 13 12.5 
Average film-forming temperature according to 
DIN 53787, 90 .mu. wet film thickness, air flow of 
0.6 cm/seconds; temperature of the air entering: 
0.degree. C.; latex pH = 8.5 
19.5 
21 22 22 
__________________________________________________________________________ 
The particular emulsifier solution (compare Table IV, 5.1.) is initially 
introduced under nitrogen, the monomer mixture 5.2. (compare Table IV) is 
then added and the mixture is heated to 75.degree. C. 
After the polymerization temperature (75.degree. C.) has been reached, the 
polymerization is initiated by adding the solution 5.3 (compare Table IV). 
An approximately 10% strength seeding latex is formed. As soon as the heat 
of polymerization has subsided, the monomer mixture 5.4. (compare Table 
IV) and the emulsifier/activator solution 5.5. (compare Table IV) is added 
dropwise in the course of 3 hours, the temperature of the reaction mixture 
being kept at 75.degree. C. 
When the addition of the streams of material 5.4. and 5.5. has ended, the 
mixture is subsequently stirred for a further 3 hours at 75.degree. C. in 
order to bring the conversion of the monomer to completion. 
Stable, almost coagulate-free dispersions, the particle sizes (compare 
Table IV, line 22) of which increase, according to the invention, with an 
increasing content of polysulphonate, were obtained. 
If the dispersions are adjusted to a pH of 8.5 with approximately 20% 
strength aqueous NH.sub.3 solution, a thickening, which depends on the 
size of the latex particle diameter, occurs (compare line 24, Table IV). 
The average film-forming temperature (compare line 26, Table IV) also 
depends on the particle size. 
EXAMPLE 6 
Dispersions with solids contents of up to, for example, 50% by weight can 
be prepared by quite simple polymerization recipes with the aid of 
emulsifier systems according to the invention: 
TABLE V 
______________________________________ 
Experiment number 
6 A 6 B 6 C 6 D 
______________________________________ 
6.1 Deionised water 
1,500 g 1,500 g 
1,500 g 
1,500 g 
Emulsifier system 
according to 
instruction B-2 
(70% by weight of 
polysulphonate) 
150 g 75 g 37.5 g 15 g 
K.sub.2 S.sub.2 O.sub.8 
3 g 3 g 3 g 3 g 
6.2 n-Butyl acrylate 
750 g 750 g 750 g 750 g 
6.3 n-Butyl acrylate 
750 g 750 g 750 g 750 g 
fed in over a period 
of 60 minutes 
______________________________________ 
The aqueous emulsifier/activator solution (compare Table V, 6.1.) is 
introduced into a 3.5 l three-necked flask with a stirrer (250 revolutions 
per minute) reflux condenser, internal thermometer and dropping funnel for 
some of the n-butyl acrylate (compare Table V, 6.3.), followed by half of 
the total amount of n-butyl acrylate to be polymerized (compare Table V, 
6.2). The emulsified mixture, consisting of 6.1. and 6.2., is heated to 
70.degree. C. When the polymerization has started, the remainder of the 
butyl acrylate is metered in over a period of 60 minutes and the mixture 
is subsequently stirred for a further 2 hours in order to bring the 
polymerization to completion. 
The dispersions are characterised as follows: 
______________________________________ 
Dispersion 6 A 6 B 6 C 6 D 
______________________________________ 
Coagulate (g) 
15 0.3 1.0 5.0 
Solids content 
% by weight 52.2 50.8 50.3 50.2 
Latex particle 
diameter (nm) 
330 230 195 195 
K 2 
Measure of the 
uniformity 0.3 0.02 0.01 0.03 
______________________________________ 
In the case of initial emulsifier concentrations in the range from 10 parts 
by weight to 5 parts by weight of emulsifier per 100 parts by weight of 
water, the particle size of the dispersion particles accordingly decreases 
with decreasing emulsifier concentration. 
Compared with a latex prepared in a corresponding manner and containing 
about 30% by weight of solids (compare Table II, line 2, 
polysulphonate:monosulphonate ratio of 70:30), the size of the latex 
particles is presently increased by a factor of 1.3 to 2.2. The latex 
prepared with the highest emulsifier content, that is to say 6A, has a 
broader latex particle diameter distribution than the products 6B, 6C and 
6D. 
EXAMPLE 7 
It will be shown that combinations of polysulphonates with customary 
anionic emulsifiers and non-ionic emulsifiers give coagulate-free 
dispersions with uniform latex particle diameters (compare Table VII, 
experiments a to f). 
In these experiments, the particle size increases, according to the 
invention, with an increasing content of polysulphonate in the emulsifier 
system. 
If the emulsifier system still contains virtually only polysulphonate and 
non-ionic emulsifier (compare Table VII, experiments h and i), relatively 
coarse-particled, coagulate-free dispersions are formed. If only a 
non-ionic emulsifier is employed (compare Table VII, experiment j), a 
coarse-particled dispersion with very non-uniform particles (C2 value is 
0.6!) and a very large amount of coagulate (26 g) is formed. 
Emulsifiers containing polysulphonate can also be advantageously combined 
with resin soaps (compare Table VII, experiments k to n). The uniformity 
of the latex particles is improved and the stability of the dispersions 
towards changes in pH is substantially increased by adding the 
polysulphonate. Remarkably, the latex particle diameters are not 
substantially reduced by the addition of disulphonate to the emulsifier 
system. This effect can be utilized for the preparation of dispersions 
which contain resin soaps, are coarsely dispersed and have an improved pH 
stability, for example for the preparation of coarse-particled butadiene 
dispersions or chloroprene dispersions. 
The experiments indicated in Table VII were carried out according to 
instruction C. 
Polymerization temperature: 70.degree. C. 
Polymerization time: 7 hours 
Speed of rotation of the 500 ml flasks: 25 revolutions per minute 
Total emulsifier concentration (E)=50 g/1,000 g of H.sub.2 O 
Amount of emulsifier, per 100 parts by weight of water: 5 parts by weight. 
TABLE VII 
__________________________________________________________________________ 
a b c d e f g h i 
__________________________________________________________________________ 
(g) 
of deionised water 118.3 
118.3 
118.3 
118.3 
118.3 
118.3 
118.3 
113.8 
118.3 
(g) 
of sec. alkylmonosul- 
phonate with 12 to 18 
C atoms, 10% strength 
aqueous solution 43.3 
32.5 
16.3 
43.3 
32.5 
16.3 
-- -- -- 
(g) 
of a 10% strength 
aqueous solution of 
##STR2## 43.3 
32.5 
16.3 
-- -- -- -- -- -- 
(g) 
of a 10% strength 
aqueous solution of 
##STR3## -- -- -- 43.3 
32.5 
16.3 
-- 52 78 
(g) 
of a 10% strength 
aqueous solution of 
the sodium salt of 
dehydroabietic acid 
(commercially avail- 
able product) -- -- -- -- -- -- -- -- -- 
(g) 
of a 10% strength 
aqueous solution of the 
emulsifier according to 
instruction B.1 (70% of 
polysulphonate) 43.3 
65.0 
97.5 
43.3 
65.0 
97.5 
130 
78 52 
(g) 
of a 2% strength 
aqueous K.sub.2 S.sub.2 O.sub.8 solution 
26.2 
26.2 
26.2 
26.2 
26.2 
26.2 
26.2 
26.2 
26.2 
(g) 
of n-butyl acrylate 112.5 
112.5 
112.5 
112.5 
112.5 
112.5 
112.5 
112.5 
112.5 
amount of latex (g) 386 
386 
386 
386 
386 
385 
386 
386 
387 
precipitate (g) 0 0 0 0 0 0 0 0 0 
solids content in the 
latex (%) 32 32 32 32 32 32 32 32 32 
latex particle 
diameter (nm) 87 95 126 
87 98 129 
160 
150 
161 
C 2 (measure of the 
uniformity of the 
latex particles) 0.15 
0.06 
0.05 
0.06 
0.2 
0.15 
0.10 
0.1 
0.35 
__________________________________________________________________________ 
j k l m n 
__________________________________________________________________________ 
(g) 
of deionised water 118.3 
118.3 
118.3 
118.3 
118.3 
(g) 
of sec. alkylmonosulphonate with 12 to 18 C atoms, 
10% strength aqueous solution 
-- -- -- -- -- 
(g) 
of a 10% strength aqueous solution of 
##STR4## -- -- -- -- -- 
(g) 
of a 10% strength aqueous solution of 
##STR5## 130 
-- -- -- -- 
(g) 
of a 10% strength aqueous solution of the sodium 
salt of dehydroabietic acid (commercially 
available product) -- 130 
65 32.5 
13 
(g) 
of a 10% strength aqueous solution of the emulsi- 
fier according to instruction 2.1. (70% of poly- 
sulphonate) -- 0 65 97.5 
117 
(g) 
of a 2% strength aqueous K.sub.2 S.sub.2 O.sub.8 
26.2tion 
26.2 
26.2 
26.2 
26.2 
(g) 
of n-butyl acrylate 112.5 
112.5 
112.5 
112.5 
112.5 
amount of latex (g) 325 
387 
381 
382 
387 
precipitate (g) 26 1.6 
1.1 
0.4 
0.3 
solids content in the latex (%) 
27 32 32 32 32 
latex particle diameter (nm) 
325 
160 
150 
155 
155 
C 2 (measure of the uniformity of the latex 
particles) 0.6 
0.43 
0.05 
0.06 
0.10 
__________________________________________________________________________ 
Explanation of Table VII: 
*about 30 or 20 ethylene oxide units per mol of pnonylphenol