USE OF PARTICULAR POLYMERS OR COPOLYMERS AS LATEX-STABILIZING SURFACTANTS
DESCRIPTION
TECHNICAL FIELD
The present invention relates to the use of particular polymers or copolymers as surfactants ior stabilizing latices, in particular acrylic iatices.
The general field of the invention is thus that of latices.
Latices are in the form of a composition comprising, in suspension, microscopic particles of polymer chains in a continuous liquid medium, which is usually aqueous, which raay serve as a base, among other applications, for adhesives, paints, textile binders and inks (especially acrylic latices).
To ensure the stability of latices durina their synthesis and over time, it is necessary to incorporate surfactants therein.
The current surfactants often generate foams, which, when they are generated during the preparation or use of the latex, may lead to the fouling of equipment.
The inventors set rhemselves the aim of proDOsing novel surfactants that afford good stabilization of latices, especially acrylic latices, and that generate little or no foam during the manufacture or use of the latices.
DESCRIPTION OF THE INVENTION
Thus, the invention relates to a

compcsition comprising ai leasz one latex and at least one surfactant that may be obtained via a process of polymerizing one or more monomers, the said process comprising a step of placing in contact, for examp] e, in a medium comprising water, the said monomer(s) with at least one initiator corresponding to formula ; I! below:

in which:
- R1 represents a hydrogen atom, a linear or
branched alkyl group containing f roni 1 to b
carbon a~oms, a phenyl group, a metal chosen from
alkali metals, alkaline-earth metals and
transirion metals, in particular an alkali metal
(Na, Li or K) , or alternatively HN", BujN' or
BuiHN, Bu representing an n-butyl group;
R3 and P, which may be Identical or different,
represent a linear or branched alkyl group
containing from 1 to 3 carbon atoms;
- R= represents a hydrogen atom or a group -OCOR-:,
Rfe representing a linear or branched aikyl group
containing from 1 to 20 carbon atoms;
RG and RT represent, indepertdently, a linear or branched alkyl group containing from 1 to 3 carbon atoms;

R4: represen-s :
an aryl group bearing a.z least one acid group comprising at least one heteroatom chosen froF: S and P, the said acid group possibly existing in the form of a salt; or
* a heterocyclic group comprising one or more
heteroatoir.a chosen frorr: 0, N and/or S, the said
heterocyclic group optionally bearing an acid
group corriprising at least one heteroatoir, chcsen
from 3 and P cr bearing at least one hydrocarbon-
based group optionally comprising one or more
heteroatoms ! for example N, S and/or 0) , the said
hydrocarbon-based group bearing at least one acid
group as defined above, the said heterocycli c
group possibly existing in the forrri of a salt; or
3 group -CO-NR-Y or -CO-O-Y, with Y representing
a hydrocarbon-based group optionally comprising
one or more heteroatoms (for example N, S and/or
0) bearing at least one acid group comprising a
heteroatom chosen from 3 and P or representing a
hydrocarbon-based group optionally comprising one
or more heteroatoms (for example N, S and/or 0)
containing at least one heterocyclic group
comprising one or more heteroatoms chosen from, K,
0 and S, the sard group -CO-NR-Y or -CO-O-Y
possibly existing in the form of a salt and R
representing a hydrogen atom or an alkyl group,
preferably containing from i to 24 carbon atoms.
According to a first alternative, R.i may be an aryl group comprising, for example, from 5 to 2 0

carbon atorr.s [fcr example a phenyl grous), t.h,e said aryl group bearing (i.e. being substituted with) at least one acid group comprising at least one heteroatoin chosen from S and P, the said acid group possibly existing in rhe form of a salt. As example of an acid group comprising at least one heteroatom chosen from S and P, mention may be made of a sulfonic, phosphonic, phosphoric or phosphinic group, and the salts thereof.
According T-O a second alternative, R,] may be a heterocyclic group comprising one or more netsroatcms chosen from 0, N and/or S, such as a pyrrole, pyridine, indole, thiophene, furan or pyrimidine group, optional]v bearing at least one acid group comprising at least one heteroatom chosen from S and P as defined above or the said heterocyclic group bearing a hydrocarbon-based group, such as an alkyl group containing from 1 to 24 carbon atoms, optionally comprising one or more heteroatoms, the said hydrocarhon-based group bei ng substituted one or more times with an acid group as defined above (i.e. an acid group comprising at least one heteroatom chosen from S and ?}.
According to a third alternative, R,, may represent a group -CO-HR-Y or -CO-O-Y, with Y representing a hydrocarbon-based group, such as an alkyl group possibly containing from 1 to 24 carbon atoms, optionally comprising one or more heteroatoms, and substituted with at least one acid group comprising at least one heteroatom chosen from S and P, such as a sulfonic, ohosphonic, phosphoric or phosphinic group. An example of such a group Y that may be mentioned is rhe group -C (CH-i -CH_-SO-,H. Y m.ay also be a

nydrocarbon-based group, sue':: as an slkyl croiiv-containing from 1 to 2 4 carbon atoms, optionally comprising one or more heteroatoms, and bearing at least one heterocyclic group comprising one or mere heteroatoms chosen from N, 0 and S, such as an imidazole, imidazoline, imidazolidone, pyrazole, triazole, tetrazole, thiadiazole or oxadiazole group. The group Y cannot be an unsubstituted alkyl group, insofar as it is necessarily substituted with an acid group or a heterocyclic group as defined above.
Among the initiators of formula (1) , it is most particularly preferred to use those for which R is an aryl group bearing at least one acid group comprising at least one heteroatom chosen from S and P, the said acid group possibly existing in the form of a salt . In particular, Rt may advantageously be a phenylene group bearing a group -SO3R:,, R-, representing a hydrogen atom, a metal chosen from alkali metals, alkaline-earth metals and transition metals, in particular an alkali metal (Na, Li 01 K) , or alternatively HM"*, BUN' or BU-,HN', BU representing an n-butyl group.


The initiators described above mav be obtained by radical addition of t.he 1,2- type, of an olefin to a starting alkoxyarr.ine, according to the following reaction scheme:


a Tiedium in particular comprising water. T\;:s niedium may be an aqueous or predominantly aqueous solution or an aqueous phase/organic phase dispersed niedium (dispersion, emulsion, miniemuision, microemulsion, suspension, micellar, reverse suspension, reverse emulsion or reverse microemulsion).
The surfactants present in the compositions of the invention are very advantageously in the form of an amphiphilic copolymer, i.e. a copolymer containing both hydrophilic parts and hydrophobic parts, the hydrophilic parts resulting from the polymerization of one or more hydrophilic monomers, and the hydrophobic parts resulting from the polymerization of one or more hydrophobic monomers.
It is understood that the hydrophilic monomers will be, in particular, monomers whose units after polymerization will be other than the unit -CH--CHR- present in the polymerization ini tiaror as defined above.
The hydrophilic monomer(sj may be chosen f r omi:
- water-soluble styrene derivatives such as
sodium styrenesulfonate;
- water-soluble acrylic monomers such as
acrylic acid and salts thereof, methyl acrylate, 2-
hydroxyethyl acrylate, 2-methoxyethyl acrylate,
methoxypolyethylene glycol acrylates, ethoxypoly-
ethylene glycol acrylates, methoxypolyethylene glycol-
polypropylene glycol acrylates and mixtures thereof, 2-
J (dimethylamino)ethyl acrylate (DMAEA), [2-(acryloyl-oxyj ethyl j trimethylan-imonium, chloride or sulfate, [2~

I. acrylcyicxy; ethyl j dimethyiberizylaiiinonium chloride or sulfate, and alkylene glycol phosphate acrylate?;:
- :n e t h a c r y 11 c rp c n ome r s such as m e t 'r. a c r y 1 i c acid and salts thereof, 2-hydroxyethyl methacrylate, 2-ethoxyethyl methacrylate, methoxypolyethylene glycol methacrylates, ethoxypolyethylene glycol methacrylates, methoxypolyethylene glycol-polypropylene glycol meth¬acrylates and mixtures thereof, 2-vdireethylamino)ethyl methacrylate (DMAEMA) , [2- (methacryloyloxyj ethylj-trimethylammonium chloride or sulfate, 2-(methacryl-oyloxy) ethyl]dimethylbenzylammonium chloride or sulfate, alkylene glycol phosphate methacrylates, hydroxyethylimidazolidone methacrylate, hydroxyethyl-imidazolidinone methacrylate and 2-(2-oxo-l-imidazo-lidinylI ethyl methacrylate;
- acrylam.ide or substituted a or yl amides, N-methylolacrylamide, a cr y1ami dopropyltrimethylammonium chloride (APTAC), acrylamidomethylpropanesulfonic acia (AMPS) and salts thereof;
iTfethacrylamide or substituted methacrylamides, 2-methyl-N-{2-(2-oxoimidazol idinyl )-ethyl]acrylamide, N-methylolmethacrylamide, methacryl-amidopropyltrimethylamrrionium chloride (HAPTAC) ;
itaconic acid, maleic acid and salts thereof, maleic anhydride, al}:yl or allcoxy- or aryloxypolyalkylene glycol maleates or hemimaleates, vinylpyridine, vinylpyrrolldinone; and
a mixture of at least two of the
abovem.entioned monomers.
) Water-soluble monomers that are
particularly advantageous in the context of this

invenr-ion are:
- imethlacrylic acid and salts thereof;
- fiTieth) acryiates of amine salts, such as
;2-(methacryloyloxy)ethyl]trimethyiammonium chloride or
sulfate, [2- (methacryloyloxyj ethyl]dimethylbenzyl-
ammonium chloride or sulfate;
- hydroxyalkyl (meth)acrylates, such as 2-hydroxyethyi methacrylate;
- polyethylene glycol, alkoxy- or aryloxy-pDlyalkylene glycol (meth)acrylates, such as mathoxy-polyethylene glycol (meth)acrylates or ethoxypoly-ethylene glycol (meth)acrylates; and
- mixtures thereof.
The hydrophobic monomer(s) may be chosen f r om.:
- vinylaromatic monomers such as styrene or
a-methylstyrene;
diene monomers, such as butadiene or isoprene;
hydrophobic acrylate monomers, such as ethyl acrylate, n-butyl acrylate, ethylhexyl acrylate or phenyl acrylate, methoxypoiypropylene glycol acrylates, fluoro acrylates or silyl acrylates;
methacrylate monomers, such as methyl methacrylate, lauryl methacrylate, cyclohexyi meth¬acrylate, allyl methacrylate or phenyl methacrylate, methoxypoiypropylene glycol methacrylates, 2-(tert-butylamino)ethyl methacrylate (TBAEMA), fluoro meth¬acrylate s, such as 2,2,2-trifluoroethyl methacrylate, J and silyl methacrylates such as 3-methacryloyl-propylmimethylsiiane;

- a c r y 1 o n i r. r 11 e ; ana
mixtures "In ere of.
A surfactant in accordance wir.h the invention is, for example, a copolymer comprising hydrophillc units derived from the polymerization of methacrylic acid and hydrophobic units derived from the polymerization of methyl mechacrylate.
The initiator is) of formula ■' I ) mav be present in a content ranging from 0.005% to 40';- and preferably in a content ranging from 0.01% to 10'i: by weight relative to the total weight of the monomer(s) used. The monomer(s) and/or the initiator of alkoxyamine type may optionally be introduced continuously into the polymerization medium.
According to one embodiment of the invention, the step of placing in contact may be performed, in addition tc rhs ini tiator of f ormuj a ; I :■ , in the presence of an initiator chosen fro.TL hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxy esters, peroxydicarbonates, peroxyacetsls and azo compounds.
Examples of hydroperoxides that may be mentioned include tert-butyl hydroperoxide, tert-amyl hydroperoxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, diisopropylbenzene monohydro-peroxide and para-menthane hydroperoxide.
Examples of dialkyl peroxides that may be
mentioned include 2,5-dimethyl-2,5-di(tert-butyl-
peroxy}hexyne-(3) , di-tert-butyl peroxide, di-tert-amyl
) peroxide, 1,3-di (tert-butylperoxyisopropyl)benzene,
2, 5-dim,ethyl-2, 5-di ! tert-burylperoxy) hexyne,

1, :, - , 4 , 7, 7-hexarfLe-r.ylcy:-:lc-4, 7-,:iiperozyr.onane and
3,3,6,6,9, 9-hexame:-hylcyclo-l, 2,4, 5--etraoxanonane .
Examples of diacyl peroxides thaT: may be mentioned include benzoyl peroxide, lauroyl peroxide, decanoyl peroxide, 3,5, 5-trimethyihexanoyl peroxide, and acetylcyclohexylsulfonyl peroxide,
Examples of peroxy esters that may be mentioned include t.ert-buLyl peroxybenzoate, tert-butyl peroxyacetate, tert-butyl peroxy-3,5, 5-trimethyl~ hexanaate, tert-amyl percxy-3,5,5-trimethylhexanoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 00-tert-butyl -0- is opropyl monoperoxycarbonatG, 0 0-tert-butyl-0-
(2-ethylhexyi) monoperoxycarbonate, 00-tert-amyl-0-(2-ethylhexyl) monoperoxycarbonate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-ethylhexanoate,
tert-amyl peroxy-2-et.hylhexanoate, 2, 5-dimethyl-2, 5-bis {2~ethylheK5noylpercxy J hexane, ter!;-butyl peroxy-neodecanoate, tert-butyl peroxyisononanoar,e, tert-butyl peroxypivalate, tert-amyl peroxypivalate, a-cumyl peroxyneodecanoate, cert-amyl peroxydecanoate, tert-butyl 3-nydroxy-l,1-dimethylbutylperoxyneodecanoate and
tert-butyl peroxymaleate.
Examples of peroxydicarbonates that may be mentioned include di(2-ethylhexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, di(n-propyl; peroxydicarbonate and di{4-tert-butylcyclohexyl) peroxydicarbonate.
Examples of peroxyacetals that may be m.entioned include 1, 1-di ( tert-butylperoxyj cyclohexane, ) 1,1-di(cert-butylperoxy)-3,3,6-trimethylcyclohexane,
etnyi 3,3-di(tert-butylperoxy)buty-ate, ethyl 3,3-

di i rert-arrivlperoxy; buyrste, n-buLyl -5, 4-di ( r.err-butylperQxy; valerate, 2,2-di(tert-butylperoxyiDUtane, i, 1-cli ' rrern-amylperoxy; cyciohexane and 2 , 2-bis | 4 , -1-di i tert-butylperoxyj eyelohexyl]propane.
The step of placing in contact may also be performed in the presence of mineral oxidizing agents such as sodium, potassium or ammonium persnlfates, hydrogen peroxide, perchlorates, percarbonates or ferric salts. These oxidizing agents may be used alone or in combination with mineral or organic reducing agents such as sodium or potassium bisulfite or metabisulfite, vitamin C, and sodium or potassium hypophosphite, These organic or mineral reducing agents may also be used alone, i.e. in the absence of mineral oxidizing agents.
The process of the invention may include a step of in situ preparation of nhe initiator of formula (I), preferably before the step of placing in contact.
From 3 structural point of view, t.he surfactants, besides che repeating units derived from the polymerization of the monomers, contain at least one reactive end having the following formula:

The polymers or copolymers will in particular contain a unit of formula -CH:-CHR- derived from the alkoxyamine present at the end of the chains, the other units resulting frorri the polymerization of

the monomers, vjhich uni-s vjill be di f f erent from i-he said unit -CH_—CHR-.
This pol;j;rr,er or copolyrner containing such a reactive end may be made to undergo a chemical trans-■formation of this end by reacting it with suitable reagents.
The latices present in the compositions of the invention miay be latices obtained by emulsion polymerization, in particular latices of slkali-swe_lable emulsion type, more comimonly known as ASE latices.
Examples of ASE latices that may be mentioned include:
the latex obtained by emulsion polymerization in aqueous medium of methacrylic acid, ethyl acrylate and diallyl phthalate;
the latex obtained by emulsion polymerization in aqueous medium of methacrylic acid, styrene and ethylene glycol dimethacrylate;
the latex obtained by emulsion polymerization in aqueous medium of methacrylic acid, methyl methacrylate and diallyl phthalate.
These latices have the characteristic of having thickening properties.
These comoositions may be prepared by mixing the surfactant copolymer with the precursor monomers of the latex, followed by a step of polymerization of the said monomers. The surfactant may be prepared in situ prior to the addition of the monomers, as may the initiator required for the synthesis of the surfactant.
The compositions in accordance v/ith the i.nvencion m.ay be used in any field using latices.

namely in r.he field of paints, textiles, cosmetics, paper, floorcoverings, construction and decoration.
More particularly, the composi tions of the invention may be used as dispersants in cosmetic compositions, paint compositions and ink compositions.
Finally, according to a second subject, the invention relates to the use, as a latex-stabilizing surfactant, of a polymer or copolymer that may be obtained via a process of polymerization of one or more monomers, comprising a step of placing in contact, in a medium comprising water, the said monomer(s) with at least one initiator corresponding to formula (1) below:

branched alkyl group containing from 1 to 8 carbon atoms, a phenyl group, a metal chosen from alkali metals, alkaline-earth metals and transition metals, in particular an alkali metal (Ka, Li or K) , or alternatively HjN"", 3uN* or Bu-jMN"", Bu representing an n-butyl group; - R? and R,i, which may be identical or different, represent a linear or branched alkyl group containing from 1 to 3 carbon atoms; 1 - R; represents a hydrogen atom or a group -OCOR,-,, Rg representing a linear or branched alkyl group

con~aining iror: 1 -,0 2 0 carbon atop.s ; - Rr:, and R; represent, independently, e linear or branched alkyZ group contain!ng from 1 to 3 carbon atoms; R represents:
* an aryl group bearing at least one acid group comprising at least one heteroatom chosen from S and P, the said acid group possibly existing in the form of a salt; or
* a heterocyclic group comprising one or more heteroatoms chosen from 0, N and/or S, the said heterocyclic group optionally bearing at least one acid group comprising at least one heteroatom chosen from S and P or bearing a hydrocarbon-based group optionally comprising one or more heteroatoms {for example N, S and/or 0) , the sa id hydrocarbon-based group bearing at least one acid group as defined above, the said heterocyclic group possibly existing in the form of a salt; or
* a group -CO-NR-Y or ~CO-0-Y, with Y representing a hydrocarbon-based group optionally compr ising one or more heteroatoms {for example N, S and/or 0) bearing at least one acid group comprising a heteroatom chosen from S and P or representing a hydrocarbon-based group optionally comprising one or m,ore heteroatoms (for example N, S and/or 0) containing at least one heterocyclic group comprising one or more heteroatoms chosen from N, 0 and S, the said group -CO-NR-Y or -CO-O-Y possibly existing in the form of a salt and R representing a hydrogen atom or an aJ kyl group,

preferably conraining from 1 -o 1:4 .jarh&n at OFS .
The polymers or copolymers "chat may be used in this sense are the same as those described above for whe compositions of the invention.
The invention will now be described wi th reference to the following examples, which are given as non-liiTLiting illustrations .



1 litre of ethanol and 0.5 litre of degassed water are placed in a 2-iitre glass reactor purged with nitrogen, 54 g of sodium 4~styrenesulfonate (0.262 moi) and 100 g of alkoxyamine of formula (la) (0,262 mol) are added. The mixture is heated to 70°C and left to react for 6 hours with stirring. The product is recovered by evaporation under vacuum at a temperature of 30"C. 179 g of a yellow oil that crystallizes on storage at 4°C in the form of a wax are obtained.
The product obtained is analysed by 'H, ' 'C and ''p NMR, by negative elecCrospray mass spectrometry and by Karl Fischer analysis. It contains S4% by weight of initiator of formula (II) in the form of two diastereoisomers in 59/41 proportions and 16« water.
The characteristics of the initJator

ind methyl methacrylate.
430 g of demineralized water are introduced into a 1-litre glass reactor equipped wit-h a variab]e-3peed stirring motor, inlets for the introducrion oi reagents, lines for the introduction of inert gases for stripping our oxygen, for instance nitrogen, and measuring probes a system of vapour condensation with reflux, and a jacket for heating/cooling the contents of the reactor by means of circulation therein of a heat-exchange fluid; the stirring is started ar moderate speed, the heating system is switched on to reach 50°C in the reactor, and the system is degassed by bubbling nitzogen into the liquid for at least

_5 iT.iniir.es .
The following are separately prepared, in suitable containers:
1! a mixture of 1.38 g of methacrylic acid and 1.6 g
of methyl methacrylate; 2) an aqueous solution containing 1.32 g of the
initiator (II) ipurity of 84% by weight) and 20 g
of demineralized water.
All of solution 2 is added to the reactor and the stirring speed is ser at 344 rpm. Mext, mixture 1 is added to the reactor using a metering pump, over a period of 20 minutes. The reactor is then maintained at a temperature of at least 50°C for a duration of at least 4 hours. At the end of this temperature maintenance period, the medium is " cooled and the contents of the reactor are discharged into a suitable container. The product thus obtained has a milky arid slightly foamy appearance, with a particle size of 169 nm measured by quasi-elastic light scattering with a Malvern LoC machine.
EXAMPLE_3
The icllowing example illustrates the synthesis of a latex of the ASE type stabilized with a surfactant polymer.
30 3 g of the product prepared according to Example 2, consisting of a dilute aqueous dispersion of a surfactant polymer according to the invention, are introduced into a 1-litre glass reactor equipped with a variable-speed stirring motor, inlets for the introduction of reagents, lines for the introduction of

inert gases for STzripping out oxygen, for instance nitrogen, and measuring probes (for SKample temperature probes), a system of vapour condensation with refiux, and a jacket for hsating/cooling the contents of the reactor by means of circulation therein of a heat-exchange fluid. Stirring is started at moderate speed, the heating system is switched on to reach 7 20 in the reactor, and the system is degassed by bubbling nitrogen into the liquid for at least 15 minutes.
The following are separately prepared, in suitable containers:
1} a mixture comprising 41.68 g of methacrylic acid,
90 g of ethyl aery late and 0.40 g of diallyl
phthalate; and 2) an aqueous solution comprising 0.16 g of ammonium
persuliate and 5 g of demineralized water.
The reactor is Drought to 7 8" C and = il of solution 2 is added to the reactor while stirring at a speed of 344 rpiu. Seven minutes after the introductj on of solution 2; , mixture 1 is metered into the reactor using a metering pump, so as ro complete the additi on of this mixture to the reactor in 2.5 hours, during which time the temperature is maintained at at least 73 "C. After the addition, the medium is maintai ned at at least 78''C for at least a further 3 hours. The reactor is then cooled and its contents are poured into a suitable container. The product obtained is a stable latex of the .ASE type with a solids content of 27.6%, measured by gravimstry, and a particle size of 124 nm, measured with a Malvern LoC machine.
In order to conf irmi the thick-en: ng power of

he latex of the ASE type, an aqueous dispers:on wi th a
olids conteni of 3% is prepared by diluting sortie of
he producr obtained with demineralized water ifoi
xanr.ple 38 g of latex wirh a solids coni;.ent o; 17. cV
i luted with 312 g of demineralized water ;■ . The pH of
he diluted latex is then 3.5, measured oy
otentiometry, and its viscosity is very close to that
'f water. 3 6% sodiuni hydroxide solution is then added
lowly with stirring of the latex, so as to obi;ain
.Ikaline swelling and the thickening effect. The
laximum viscosity is obtained at about pH 7., at which
'alue the dispersion at 3% takes the form of a
:ranslucent, virtually transparent aqueous gel with a
riscosity of 8826 mPa. s at 30 rpm, measured with a
/ariable spin-speed Brookfield viscometer. The gel
noreover has coloured tints ranging from red to blue
oassing through green, depending on the angle of
observation. These optical phenomena may be observed on
gels obtained using the latex of the ASE type prepared
in the absence of standard surfactants.
EXAMPLE 4
In order to make the manufacture of the latex of Example 3 more productive, its synthesis may oe performed in the continuation of that of the surfactant polymer of Example 2. To do this, the total amount of product of Example 2 may be adjusted so as to have only 30 3 g, and the step of maintenance at 50 "C after the addition of the monomers of Example 2 may be limited to a minimum of 1 or 2 hours, after which the reactor may be brought to 78 "C to follow on with the

operations of Example 3.
EXAMPLE 5
In order ro make the manufacture of the latex of Example 4 more productive, its synthesis may be performed in the continuation of that of the water-aoljble initiator of Example 1. To do this, the synthesis of the water-soluble initiator of Example 1 may be performed in the polymerization reactor, by adjusting the dilution rate with water and a small amount of ethyl alcohol, and also the amounts of sodium 4-styrenesulfonate and of alkoxyarr.ine (la), so as to obtain only the amount of water-soluble initiator (II) necessary for the preparation of the surfactant of Example 2. The heating time at TOC for the preparation of the water-soluble initiator may be optimized by reducing it to a minimum, of 1 hour, after which oeri od the operations of Example 4 may follow on. Advantageously, this method does not require the separation and/or purification of the initiator (11/ or its handling in the form, of wax, since it is produced directly in the polymerization reactor (in dilute solution and in the required amount) in which it will be used for the rrianufacrure of the surfactant polymer, which will, in turn, be used for the manufacture of the final ASE latex.

CLAIMS
1. Composition comprising at lasr one latex and at. least one surfactant that may be obtained via a monomer polymerization proess, comprising a step of placing the said monomer(s) in contact with at least one initiaror corresponding to formula (I) below:

- R; represents a hydrogen atom, a linear or
branched alkyl group containing from 1 to 8
carbon atoms, a phenyl group, a metal onesen from
alkali metals, alkaline-earth metals and
rransitio.n metals, H4N+ BU4N+ or BU4N+, Bu
representing an n-butyl group;
- R3 and R4, which may be identical or dif ferent,
represent a linear or branched alkyl group
containing from 1 to 3 carbon atoms;
- R7, represents a hydrogen atom or a group -OCORs,
R8. representing a linear or branched alkyl group
containing from 1 to 20 carbon atoms;
- R6 and R3 represent, independently, a linear or
branched alkyl group containing from 1 to 3
carbon atoms;
^ P ^G'^^ss'^nt-s '
* an aryl group bearing at least one acid group

comprising at. least, one heteroatom chosen from S and p, the said acid group possibly exsting in the form of a salt; or
a heterocyclic group comprising one or more
heteroatoms chosen from 0, N and/or 3, the said
heterocyclic group optionally bearing at least
one acid group comprising at least one heteroatom
chosen from S and P or bearing a hydrocarbon-
based group optionally comprising one cr more
heteroitems, the said hydrocarbon-based group
bearing at least one acid group as defined above,
the said heterocyclic group possibly existing in
the form of a salt; or
a group -CO-NR-Y or -CO-O-Y, with Y representing
a hydrocarbon-based group optionally comprising
one or more heteroatoms bearing at least one acid
group comprising a heteroatom chosen from S and ?
or representing a hydrocarbon-based group
optionally comprising one cr more heteroatoms
containing at least one heterocyclic group
comprising one or more heteroatoms chosen from N,
0 and S, the said group -CO-NR-Y cr -CO-O-Y
possibly existing in the form of a salt, and R
representing a hydrogen atom or an alkyl group.
2. Composition according to Claim ] , in which Rg rs an aryl group bearing at least one sulfonic, phosphonic, phosphoric or phosphinic group, these groups possibly existing in the form of salts.
3. Composition according to Claim 1, in

furan or pyrimidine group.
4. Composition according to Claim 1, in
which R4 represents a group -CO-NR-Y or -CO-O-Y, with Y
representing a hydrocarbon-based group bearing at ieast
one imidazole, imidazoline, imidazolidone, pyrasole,
triazcie, tetrazole, thiadiazole or oxadiazole group.
5. Composition according to Claim 1, in which
R^ is a phenylene group bearing a group -SOBR',, R9
representing a hydrogen atom or a metal chosen from arxali
metals, alkaline-earth metals and transition nietals, H^N' ,
BU4N+ or BU4N+, Bu representing an n-butyl group.
6. Composition according to Claim 5, in
which the initiator corresponds to formula (II) below:

7. Coxr.position according to any one of the
preceding claims, in which the copolymer is an
arnphiphilic copolymer, comprising repeating units
derived from the polymerization of one cr more

hydrophilic mcnomers and repeating units derived f rorr. the polyrrierization of one or more hydrophobic monomers.
6. Composition according to Claim 7, in which the hydrophilic inonomer (s is (are) chosen from:
- {meth)acrylic acid and salts thereof;
- (meth)acrylates of amine salts ;

- hydroxyalkyl (meth)acrylates;
- polyethylene glycol, alkoxy- or arylc/.y-polyalkylene glycol (meth;acrylates; and
- mixtures "chereof,
9. Composition according to Claim 7, in which the hydrophobic rr.onomer !s) is (are) chosen from:
- vinylaromatic monomers such as styrene or
a-methylstyrene;
diene monomers, such as butadiene or Isoprene;
hydrophobic acrylate monomers, such as ethyl acrylate, n-butyl acrylate, ethylhexyi acrylate or phenyl acrylate, methoxypolypropylene glycol acrylates, fluoro acrylates or silyl acrylates;
methacrylate monomers, such as methyl methacrylate, lauryl methacrylate, cyclohe^yl meth¬acrylate, allyl methacrylate or phenyl methacrylate, methoxypolypropylene glycol methacrylates, 2-(tert-butylaminoiethyl methacrylate (TBAEMA), fluoro meth¬acrylates, such as 2,2,2-trifluoroethyl methacrylate, and silyl methacrylates such as 5-methacryloyl- propyltrimethylsilane;
- acrylonitrile; and

mixtures thereof.
10. Composition according to Claim 1, in which the latex is an ASE latex.
11. Composition according to Claim 1, in which the latex is chosen from:
latices obrained by emulsion -polymerization in aqueous medium, of methacrylic acid, ethyl acrylaTie and diallyl phthalate;
1atices obtained by emulsion polymerization in aqueous mediurr. of methacrylic acid, styrene and ethylene glycol dimethacrylate,
1atices obtained by emulsion polymerization in aqueous medium of methacrylic acid, methyl methacrylate and diallyl phthalate.
12. Use, as a latex-stabilizing surfactant,
of a polymer or copolymer that may be obtained via a
process of polymerization of one or more monomers,
comprising a step of placing the said monomer (s) in
contact with at least one initiator corresponding to


branched alyl group corntaining from 1 to 8
carbon stoms, a phenyl group, a metal chosen from
alkali. metals, alkaline-earth merals and
transition metals, HjN+, Bu4N+ or Bu3HN+, Bu representing an n-butyl group;
R2 and R3, which may be identical or different, represent a linear or branched alkyl group containing from 1 to 3 carbon atoms;
R5, represents a hydrogen atom or a group -DCOR8.,, R9 representing a linear or branched alkyl group containing from 1 to 20 carbon atoms;
R6, and R7 represent, independently, a linear or
branched alkyl group containing from 1 to 3
carbon atoms;
- R4 represents:
* an aryl group bearing at least one acid group comprising at least one hsteroat om chosen from S and ?, nhe said acid group possibly existing in the form of a salt; or
* a heterocyclic group comprising one or more heteroatoms chosen from 0, N and/or S, the said heterocyclic group optionally bearing at least one acid group comprising at least one heteroatom chosen from S and ? or bearing a hydrocarbon-based group optionally comprising one or more heteroatoms, the said hydrocarbon-based group bearing at least one acid group as defined above, the said heterocyclic group possibly existing in the form of a salt; or
* a group -CO-NR-y or -CO-0-Y, with Y representing a hydrocarbon-based aroup optionally compri sing

one or more heteroatoms bearing at least one acid group comprising a heteroatom chosen from S and P or representing a hydrocarbon-based group optionally comprising one or more heteroatoms containing at least one heterocyclic group comprising one or more heteroatoms chosen from N, 0 and S, the said group -CO-NR-Y or -CO-O-Y possibly existing in the form of a salt and R representing a hydrogen atom or an alkyl group.
13. Use according to Claim 12, in which the
copolymer is an amphiphilic copolymer, comprising
repeating units derived from the polymerization of one
or more hydrophilic monomers and repeating units
derived from the polymerization of one or more
hydrophobic monomers.
14. Use of a composition as defined in
Claim 1, as a dispersant in cosmetic compositions,
1 paint compositions or ink compositions.