The invention relates to an aqueous composition comprising a copolymer obtained by a specific polymerization reaction employing an anionic monomer comprising a polymerizable olefinic unsaturation and a carboxylic acid function and a monomer of formula (I):

(D

The invention also relates to the copolymer as such and a process for its preparation and its use as superplasticizer.

The composition according to the invention is advantageously used in the technical field of mortars, concretes, plasters and other compositions based on compounds or hydraulic binders, especially cement or plaster. Such compositions can advantageously be implemented in the fields of construction, public works or exploitation of hydrocarbons.

Dispersants compounds of hydraulic binders are normally used for their ability to modify the rheology of the medium in which they are present, in particular for their ability to control the maneuverability of that environment.

The workability is generally defined as the property of a composition comprising a hydraulic binder, in particular a milk or a slurry of cement or mortar or of a concrete, for example a concrete ready-To- job or a precast concrete, to remain manageable for a time as long as possible. Advantageously, control the maneuverability can carry or move the aqueous composition comprising the hydraulic binder, for example during transport or displacement from a reservoir to another reservoir. Maneuverability also control the storage conditions of such an aqueous composition. It also helps to pump or pump easily, this composition. Check the workability of such a composition allows therefore to improve the conditions of use, in particular to increase its service life under satisfactory conditions or effective. Generally, the handling of an aqueous composition comprising a hydraulic binder may be evaluated by measuring the time of flow of the hydraulic binder. In particular, the hydraulic binder or superplasticizer should allow to obtain a composition having a controlled viscosity and stable, preferably a stable viscosity over a prolonged period.

Preferably, the improvement in workability of the hydraulic aqueous compositions comprising a hydraulic binder should be possible for compositions comprising a small amount of water.

Thus, an important aspect of the invention resides in the provision of an aqueous composition comprising a hydraulic binder having an improved workability time. maneuverability of the control should not lead to an alteration of other properties, including mechanical properties, especially at young ages.

The handling of the aqueous compositions comprising a hydraulic binder can be assessed by measuring the subsidence (slump in English), for example according to EN 12350-2 standard. Indeed, sagging and maneuverability are proportional.

Fluidity retention (slump retention in English) is also a property to control for aqueous compositions comprising a hydraulic binder.

These properties are particularly desirable for certain applications, for example during filling of a formwork by means of an aqueous composition comprising a hydraulic binder.

Another aspect of the invention relates to obtaining an aqueous composition comprising a hydraulic binder to limit or reduce shrinkage during drying.

The improvement of the properties of aqueous compositions comprising a hydraulic binder should be obtained without changing the setting of the composition, in particular without delay this jack.

The aqueous compositions comprising a hydraulic binder should also have a weight ratio water / hydraulic binder, usually water / cement or E / C, the lowest possible, without undergoing alteration of their properties.

Also a desired effect for aqueous compositions comprising a hydraulic binder is capable of controlling the amount of air entrained in the material resulting from the use of this composition, thus avoiding or reducing the presence of anti-foaming agent in the hydraulic composition.

In general, aqueous compositions comprising a hydraulic binder should improve the mechanical properties of the materials obtained in

especially their mechanical properties at early ages, properties that can be evaluated by measuring the evolution over time of the compression strength.

Also, the compounds used for the preparation of aqueous compositions comprising a hydraulic binder should be used at lower doses.

They should also possess a high compatibility even total with the other components of the aqueous compositions comprising a hydraulic binder, in particular by being miscible in all proportions with the other components to prevent or limit the risks of segregation of the components of the aqueous composition comprising a hydraulic binder.

Increasing the duration of maintenance of properties of aqueous compositions comprising a hydraulic binder should also be sought.

Are known compounds or superplasticizers dispersing agents usable in aqueous compositions comprising a hydraulic binder. However, these compounds fail to provide a solution to problems. In particular, these compounds do not maintain a good degree of initial flow of aqueous compositions comprising a hydraulic binder in which they are incorporated, while maintaining maneuverability and without altering their mechanical properties or induce segregation.

Patent application US 2014 0051801 discloses a comb polymer based maleic acid unspecified its polydispersity. Patent application US 2010 0168282 discloses a hydraulic composition comprising a terpolymer resulting from the polymerization of a particular monomer with quaternary ammonium groups with a monomer having ester functions, in the presence of ammonium persulfate but without compound comprising oxidation of phosphorus degree I.

There is therefore a need for dispersants or superplasticizers for aqueous compositions comprising a hydraulic binder compounds that help provide a solution to any or all of the compounds of the prior art.

The invention provides a solution to any or all of the problems with the polymer compositions of the state of the art. In particular, the invention provides copolymers with a particularly effective method of preparation, for example as regards the temperature control of the polymerization reaction. In particular, it is essential to have preparation methods that allow to overcome maintaining low reaction temperature used during polymerization reactions known in the art.

Furthermore, it is also essential to have available methods of preparation that can polymerize unsaturated monomers of different molecular weights Mw, for example Mw of from 800 to 5000 g / mol measured by SEC in the presence of comonomers comprising vinyl functions.

Similarly, it is essential to implement polymerization reactions to copolymerize monomers having reactivities limiting or preventing their polymerization during the implementation of the methods of the prior art.

It is also essential to control these polymerization reactions, particularly to control the proportions of the comonomers polymerized with respect to the proportions of these comonomers introduced during the reaction. Thus, the prepared copolymers can comprise residues of comonomers in identical proportions or near the proportions of monomers used.

Thus, the invention provides an aqueous composition comprising at least one copolymer whose polydispersity index PI is less than 3, obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C ,

(A) at least one anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof, and

(B) at least one monomer of formula (I):

(I)

in which :

R 1 and R 2 , identical or different, independently represent H or C¾, L 1 independently represents a group selected from C (O), CH 2 , CH 2 -CH 2 and 0-CH 2 -CH 2 -CH 2 -CH 2 ,

L 2 independently represents a group selected from (CH 2 -CH 2 0) x ,

(CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150 and x + y + z is between 10 and 150;

in the presence:

(I) at least one compound comprising phosphorous in the oxidation state I; and

(ii) at least one radical generating compound selected from hydrogen peroxide, ammonium persulfate, alkali metal persulfate, and mixtures thereof or their respective associations with ammonium bisulfite with an alkali metal bisulfite or with an ion selected from Fe 11 , Fe m , Cu 1 , Cu 11 .

The conditions for preparing the composition according to the invention are particularly advantageous. In fact, these conditions of preparation of the composition according to the invention reduce or avoid the formation of homopolymer of monomer (a). Thus, preferably, the composition according to the invention does not include a homopolymer of the monomer (a) relative to the quantity by weight of dry copolymer. Also preferably, the composition according to the invention comprises an amount by weight reduced, low or very low homopolymer of monomer (a) relative to the quantity by weight of dry copolymer. Similarly, the invention allows to avoid or strongly reduce the formation of copolymers of monomers (a) different.

According to the invention, the absence or presence of a reduced amount, low or very low homopolymer of monomer (a) in the composition according to the invention allows to avoid or limit the risk of inhibition the crystallization of the concrete when the composition according to the invention is used for its plasticizing properties in a concrete formulation. Typically, a homopolymer of the monomer (a) has dispersant properties of inorganic material particles and can thus disrupt or inhibit crystallization in a concrete formulation. The properties of the formulation of concrete or of the final material prepared from the concrete formulation can then be modified or altered.

In a particularly advantageous and particularly effective manner, the invention allows to prepare a copolymer from monomers (a) and (b) while controlling the polymerization reaction of the monomers (a) and (b). The invention therefore provides an aqueous composition comprising a very low amount of residual monomer (a)

relative to the amount by dry weight of copolymer. Preferably, the aqueous composition of the invention comprises less than 2000 ppm by weight or less than 1500 ppm by weight of residual monomer (a) relative to the quantity by weight of dry copolymer. More preferably, the aqueous composition of the invention comprises less than 1000 ppm by weight or less than 500 ppm by weight of residual monomer (a) relative to the quantity by weight of dry copolymer. In particular, the aqueous composition of the invention may comprise less than 200 ppm by weight or less than 100 ppm by weight of residual monomer (a) relative to the quantity by weight of dry copolymer.

The aqueous composition according to the invention comprises at least one copolymer whose polydispersity index PI is less than 3. Preferably according to the invention, the polydispersity index PI is from 1.5 to 3, more preferably 1 5 to 2.8, more preferably 1.5 to 2.5.

The copolymer of the aqueous composition of the invention is obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C, preferably from 30 to 85 ° C, more preferably at a temperature ranging from 40 to 75 ° C or from 50 to 70 ° C. More preferably, only one radical polymerization reaction is implemented.

The preparation of the aqueous composition according to the invention implements a radical polymerization reaction which is conducted in water in the presence of at least one compound (i) oxidation comprising phosphorus degree I. Preferably according to the invention, the polymerization reaction implements a compound (i) mineral. More preferably according to the invention, the polymerization reaction implements a compound (i) selected from hypophosphorous acid (H3PO2), a derivative of hypophosphorous acid (H3PO2). Much more preferably according to the invention, the polymerization reaction implements a compound (i) comprising at least a hypophosphite ion (H2PO2), more preferably a compound selected from sodium hypophosphite (IHhPC Na), potassium hypophosphite ( H2PO2K) calcium hypophosphite ([IH PC hCa) and mixtures thereof. Sodium hypophosphite (IH PC Na) is particularly preferred.

The preparation of the aqueous composition according to the invention uses at least one

compound (ii) radical generator which is particularly. It is preferably selected from hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, mixtures thereof or combinations thereof with sodium bisulfite, potassium bisulfite with or with an ion selected from Fe 11 , Fe 111 , Cu 1 , Cu 11 . According to the invention, the ions Fe 11 , Fe 111 , Cu 1 or Cu 11 can be implemented by means of at least one compound selected from iron sulfate, iron sulfate hydrate, sulphate hemi-hydrate iron, iron sulfate heptahydrate, iron carbonate, iron carbonate hydrate, iron carbonate hemi- hydrated iron chloride, copper carbonate, hydrated copper carbonate, copper carbonate hemi-hydrate, copper acetate, copper sulfate, copper sulfate pentahydrate, copper hydroxide, copper halide.

According to the invention, the particular radicals generator compound is more preferably selected from hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, especially sodium persulfate.

In addition to the compounds (i) and (ii), the polymerization reaction according to the invention can also implement at least one compound (iii) of formula (II):

xooc s-^-s cœx

(PI)

in which :

- X independently represents H, Na or K,

- R independently represents a Ci-Cs-alkyl.

Preferably according to the invention, the compound (iii) is a compound of formula (II) wherein R represents a Ci-C3-alkyl, preferably methyl. The compound of formula (II) preferred according to the invention is the disodium trithiocarbonate dipropionate (DPTTC - 86470-33-2 CAS number).

Preferably according to the invention, the compound (iii) is implemented in an amount by weight ranging from 0.05 to 5% by weight, based on the amount of monomers. Also preferably according to the invention, the polymerization reaction implements the compound (iii) of formula (II) in an amount of 0.05 to 4% by weight, 0.05 to 3% by weight, 0.05 to 2% by weight, 0.5 to 4% by weight, 0.5 to 3% by weight, 0.5 to 2% by weight, 1 to 4% by weight, 1 to 3% by weight, from 1 to 2% by weight relative to the amount of monomers.

When preparing the copolymer according to the invention, the amounts of monomers (a) and (b) used can vary quite widely. Preferably, the polymerization reaction is implementing:

from 1 to 25% by weight of monomer (a) and

from 75 to 99% by weight of monomer (b).

Also preferably, the polymerization reaction is implementing:

- from 2 to 25% by weight of monomer (a) and

from 75 to 98% by weight of monomer (b).

Also preferably, the polymerization reaction is implementing:

3 to 15% by weight of monomer (a) and

85 to 97% by weight of monomer (b).

Also preferably, the polymerization reaction is implementing:

of 3 to 10% by weight of monomer (a) and

90 to 97% by weight of monomer (b).

Also preferably, the polymerization reaction is implementing:

from 5 to 10% by weight of monomer (a) and

- from 90 to 95% by weight of monomer (b).

The invention includes the implementation of a radical polymerization reaction in water of at least one monomer (a) anionic comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof . Preferably, the composition according to the invention comprises a copolymer prepared by a polymerization reaction employing a monomer (a) comprising an anionic polymerizable olefinic unsaturation and a carboxylic acid function or a salt thereof. More preferably, monomer (a) used is selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, an acrylic acid salt, methacrylic acid salt, a salt of itaconic acid, maleic acid salt and mixtures thereof.

When the radical polymerization reaction in water, the invention also comprises the implementation of at least one monomer (b) of formula (I).

Preferably, the compound (b) of formula (I) is a compound wherein:

x represents an integer or decimal number between 15 and 140, y + z is an integer or decimal number between 10 and 135 and x is strictly greater than y + z, and x + y + z is between 10 and 150 .

More preferably, the compound (b) is a compound of formula (I) in which x represents an integer or decimal number between 10 and 150 or between 30 and 120, y + z is an integer or decimal number between 10 and 135, x is strictly greater than y + z, and x + y + z is between 10 and 150.

Also more preferably, the compound (b) is a compound of formula (I) in which x represents an integer or decimal number between 20 and 130 or between 30 and 120, and y and z are 0.

Also more preferably, the compound (b) is a compound of formula (I) in which x represents an integer or decimal number between 15 and 80 and y + z is an integer or decimal number between 10 and 65, of preferably a compound of formula (I) in which x represents an integer or decimal number between 30 and 65 and y + z is an integer or decimal number between 15 and 40, in particular a compound of formula (I) in which x represents an integer or decimal number between 40 and 60 and y + z is an integer or decimal number between 20 and 30, for example a compound of formula (I) wherein x is 50 and y is 25.

Also more preferably, the monomer (b) is a compound of formula (I) wherein x is strictly greater than y + z.

According to the invention, a compound (b) is selected from the preferred compounds of formulas (Ia),

(Ib), (Ic) and (Id):

(La) (A)

(Id) (Ic) wherein:

R 1 and R 2 , identical or different, independently represent H or CH 3 , L 2 independently represents a group selected from (CH 2 CH 2 0) x, (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

- x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150 and x + y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (bl) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 and R 2 represent H,

L 2 independently represents a combination of groups selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z and

x, y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum x + y + z is between

10 and 150.

According to the invention, a compound (b) More preferred is a compound (b2) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents H,

- R 2 represents CH 3 ,

L 2 independently represents a combination of groups selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z and

x, y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum x + y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b3) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents CH 3 ,

R 2 is H,

- L 2 independently represents a combination of groups selected

from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z and

x, y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum x + y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b4) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 and R 2 represent CH 3 ,

L 2 independently represents a combination of groups selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z and

- x, y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum x + y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b5) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

- R 1 and R 2 represent H,

L 2 represents a group (CH 2 -CH 2 0) x and

x independently represents an integer or decimal number between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b6) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents H,

R 2 represents CH 3 ,

L 2 represents a group (CH 2 -CH 2 0) x and

x independently represents an integer or decimal number between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b7) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents CH 3 ,

R 2 is H,

- L 2 represents a group (CH 2 -CH 2 0) x and

x independently represents an integer or decimal number between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b8) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 and R 2 are CH 3,

L 2 represents a group (CH 2 CH 2 0) x and

x independently represents an integer or decimal number between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (b9) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 and R 2 represent H,

L 2 independently represents a group selected from (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (BLO) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents H,

R 2 represents CH 3 ,

L 2 independently represents a group selected from (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (bl l) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 represents CH 3 ,

R 2 is H,

L 2 independently represents a group selected from (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum y + z is between 10 and 150.

According to the invention, a compound (b) More preferred is a compound (BL2) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id) wherein:

R 1 and R 2 represent CH 3 ,

L 2 independently represents a group selected from

(CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

y and z, which are identical or different, independently represent an integer or decimal number between 1 and 150 and the sum y + z is between 10 and 150.

More preferably, the monomers (b) may be selected from the monomers:

- (blb) which is a compound (bl) of formula (Ib),

- (bld) which is a compound (bl) of formula (Id),

(B3a) which is a compound (b3) of the formula (la),

(B3b) which is a compound (b3) of formula (Ib),

(B3c) which is a compound (b3) of formula (Ic),

(B4A) which is a compound (b4) of the formula (la),

(B5b) which is a compound (b5) of formula (Ib),

- (B5D) which is a compound (b5) of formula (Id),

(B7A) which is a compound (b7) of the formula (la),

- (B7B) which is a compound (b7) of the formula (Ib),

(B7C) which is a compound (b7) of formula (Ic),

- (b7d) which is a compound (b7) of formula (Id),

(B8a) which is a compound (b8) of the formula (la),

- (B9b) which is a compound (b9) of the formula (Ib),

- (b9d) which is a compound (b9) of formula (Id),

(Bl Ia) which is a compound (b-1) of formula (Ia),

(Bl lb) which is a compound (b-1) of formula (Ib),

(Bl a) which is a compound (b-1) of formula (Ic),

- (bl2a) which is a compound (BL2) of the formula (Ia).

The aqueous composition according to the invention may also comprise at least one copolymer whose polydispersity index PI is less than 3, obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C of at least one monomer (a) and at least two monomers (b) different.

Preferably, the monomers (b) may be selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id). Also preferably, they may be chosen from the monomers (bl) to (bl2) or from the monomers (blb) (bld), (b3a)

(B3b), (b3c), (b4a), (b5b), (b5d), (b7a), (b7b), (b7c), (b7d), (b8a), (b9b), (b9d), (bl la), (bl lb), (bl lc), (bl2a).

The aqueous composition according to the invention comprises at least a copolymer obtained by at least one radical polymerization reaction in water of at least one monomer (a) and at least one monomer (b) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id). The polymerization reaction may also implement one or more other monomers.

The polymerization reaction starts then also implement at least one other monomer selected from:

• other anionic monomer, preferably selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, their salts and mixtures thereof;

• a nonionic monomer comprising at least one polymerizable olefinic unsaturation, preferably at least one polymerizable ethylenic unsaturation and including a polymerizable vinyl group, more preferably a nonionic monomer selected from esters of an acid comprising at least one monocarboxylic acid function, in particular an ester of an acid selected from acrylic acid, methacrylic acid, and mixtures thereof, for example hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, styrene, vinylcaprolactam, alkyl acrylate, especially acrylate Ci-Cio-alkyl, preferably acrylate, Ci-C 4alkyl, more preferably methyl acrylate, ethyl acrylate, propyl acrylate, isobutyl acrylate, n-butyl acrylate, alkyl methacrylate, especially methacrylate Ci-Cio-alkyl, preferably Ci-C methacrylate 4 alkyl, more preferably methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobutyl methacrylate, n-butyl acrylate, aryl, preferably phenyl acrylate, benzylacrylate, phenoxyethylacrylate, aryl methacrylate, preferably phénylméthacrylate, benzylméthacrylate, phénoxyéthylméthacrylate, a compound of formula (III):

Q!-CL CL Q2

(III)

in which :

Q 1 represents a polymerizable acrylate group or a polymerizable methacrylate group,

Q 2 represents a group H or a CH 3 ,

L 1 and L 2 , identical or different, independently represent an ethylenoxy group or a propyleneoxy group and

m and n are identical or different and at least one is different from 0, represent a number less than or equal to 150 and the sum m + n is less than 150;

• one other monomer selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id), different from compound (b), wherein:

- R 1 and R 2 , identical or different, independently represent H or CH 3 ,

- L represents a group selected from (CH 2 CH 2 0) x,

- x represents 1;

• one other monomer selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id), different from compound (b), wherein:

- R 1 and R 2 , identical or different, independently represent H or CH 3 ,

- L independently represents a group selected from (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof,

- y + z is 1 or 2; and

• 2-acrylamido-2-methylpropane sulfonic acid, a salt of sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2- (methacryloyloxy) ethanesulfonic acid, a salt 2- (methacryloyloxy) ethanesulfonic acid, methallyl sulfonate sodium styrene sulphonate and mixtures thereof.

Advantageously, the aqueous composition of the invention comprises at least a copolymer obtained by at least one radical polymerization reaction into the water conducted in the absence of maleic acid or in the absence of maleic anhydride.

The invention provides an aqueous composition comprising at least one copolymer obtained by at least one radical polymerization reaction in water of at least one anionic monomer (a) comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof and at least one monomer (b) selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id).

The invention also relates to such a copolymer as such, especially such a copolymer obtained from an aqueous composition according to the invention and separation of the copolymer according to the invention, including separation of the water from the aqueous composition according to 'invention.

The invention therefore provides a copolymer whose polydispersity index PI is less than 3, obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C,

(A) at least one anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof, and

(B) at least one monomer of formula (I):

R 1

(I)

in which :

R 1 and R 2 , identical or different, independently represent H or CH 3 , L 1 independently represents a group selected from C (O), CH 2 , CH 2 -CH 2 and 0-CH 2 -CH 2 -CH 2 - CH 2 ,

L 2 independently represents a group selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150, preferably x is strictly greater than y + z, and x + y + z is between 10 and 150;

in the presence:

(I) at least one compound comprising phosphorous in the oxidation state I; and

(ii) at least one radical generating compound selected from hydrogen peroxide, ammonium persulfate, alkali metal persulfate, and mixtures thereof or their respective associations with ammonium bisulfite with an alkali metal bisulfite or with an ion selected from Fe 11 , Fe m , Cu 1 , Cu 11 .

Particularly advantageously, the copolymer according to the invention comprises:

from 1 to 25% by weight of monomer (a) and

from 75 to 99% by weight of monomer (b).

Preferably, the copolymer according to the invention comprises:

from 2 to 25% by weight of monomer (a) and

from 75 to 98% by weight of monomer (b).

Also preferably, the copolymer according to the invention comprises

3 to 15% by weight of monomer (a) and

85 to 97% by weight of monomer (b).

Also preferably, the copolymer according to the invention comprises

of 3 to 10% by weight of monomer (a) and

90 to 97% by weight of monomer (b).

Also preferably, the copolymer according to the invention comprises

from 5 to 10% by weight of monomer (a) and

from 90 to 95% by weight of monomer (b).

The copolymer according to the invention can also be characterized by its molecular weight (Mw). Preferably, it has a molecular weight ranging from 8000 g / mol to 600 000 g / mol or 10,000 g / mol to 500 000 g / mol or 12 000 g / mol to 200 000 g / mol. More preferably, it has a molecular weight ranging from 15 000 g / mol to 150 000 g / mol or 15,000 g / mol to 90 000 g / mol or 15 000 g / mol to 90 000 g / mol or 25,000 g / mol to 75 000 g / mol.

According to the invention, the molecular weight and the polydispersity index of the copolymers is determined by Steric Exclusion Chromatography (CES) or English "Steric Exclusion Chromatography" (SEC). This technique uses a Waters brand liquid chromatograph equipped with a detector. This detector is a refractive concentration detector Waters brand. This liquid chromatography apparatus has a size exclusion column to separate the different molecular weights of the copolymers studied. The elution liquid phase is an aqueous phase adjusted to pH 9.00 by means of 1N sodium hydroxide containing 0.05 M NaHC0 3 , 0, 1 M NaN0, 0.02 M triethanolamine and 0.03% Nope .

In a first step, 0.9% diluted dry the copolymer solution in the CES solubilization solvent, which corresponds to the liquid phase eluting the CES to which is added 0.04% of dimethylformamide playing the role of flow marker or internal standard. Then, filtered to 0.2 μιη. 100 μΐ ^ are then injected into the apparatus of

chromato graphy (eluent: an aqueous phase adjusted to pH 9.00 with sodium hydroxide IN containing 0.05 M NaHC0 3 , 0.1 M NaN0, 0.02 M triethanolamine and 0.03% NaN 3 ) .

The chromato liquid chromatography apparatus contains an isocratic pump (Waters 515) whose flow rate is set at 0.8 mL / min. The chromatography apparatus further comprises an oven which itself comprises in series the following column system: a type precolumn Guard Column Ultrahydrogel Waters 6 cm in length and 40 mm internal diameter and a linear column type Ultrahydrogel Waters 30 cm length and 7.8 mm internal diameter. The detection system consists of a refractometric detector type RI Waters 410 The furnace is heated to a temperature of 60 ° C and the refractometer is heated to a temperature of 45 ° C.

Molecular weights are measured by dynamic diffusion of light detection by means of a Viscotek 270 Dual Detector whereby the molecular weight is determined from the hydrodynamic volume of the copolymer.

The special features, advantageous or preferred of the aqueous composition according to the invention define copolymers of the invention are also special, advantageous or preferred.

The aqueous composition and the copolymer of the invention possess properties particularly desirable in many technical fields. Thus, according to the technical field in which these properties are implemented, the aqueous composition or the copolymer of the invention may take different forms. They can notably be implemented in different formulations.

The invention therefore provides a formulation (Fl) comprising:

- at least one aqueous composition according to the invention;

- at least one hydraulic binder; eventually

- some water ; eventually

- at least one aggregate; eventually

- at least one adjuvant.

The invention also provides a formulation (A2) comprising:

- at least one copolymer according to the invention;

- at least one hydraulic binder; eventually

- some water ; eventually

- at least one aggregate; eventually

- at least one adjuvant.

Preferably, the formulations (Fl) and (F2) according to the invention include:

- from 0.01 to 5% by dry weight of copolymer, respectively in the form of at least one aqueous composition according to the invention or at least one copolymer according to the invention as such;

- from 95 to 99.9% by dry weight of at least one hydraulic binder. More preferably, the formulations (Fl) and (F2) according to the invention include:

- from 0.01 to 4% by dry weight or from 0.01 to 3% by dry weight of copolymer, respectively in the form of at least one aqueous composition according to the invention or at least one copolymer according to the invention as such;

- from 96 to 99.9% by dry weight or from 97 to 99.9% by dry weight of at least one hydraulic binder.

Also more preferably, the formulations (Fl) and (F2) according to the invention include:

- from 0.03 to 5% by dry weight or from 0.03 to 4% by dry weight or from 0.03 to 3% by dry weight of copolymer, respectively in the form of at least one aqueous composition according to the invention or at least one copolymer according to the invention as such;

- from 95 to 99.7% by dry weight or from 96 to 99.7% by dry weight from 97 to 99.7% by dry weight of at least one hydraulic binder.

Also more preferably, the formulations (Fl) and (F2) according to the invention include:

- from 0.05 to 5% by dry weight or from 0.05 to 4% by dry weight or from 0.05 to 3% by dry weight or 0.05 to 2% by dry weight or from 0.05 to 1.5% by weight dry copolymer, respectively in the form of at least one aqueous composition according to the invention or at least one copolymer according to the invention as such;

- from 95 to 99.5% by dry weight or from 96 to 99.5% by dry weight or from 97 to 99.5% by dry weight or from 98 to 99.5% by dry weight or 98.5 to 99.5% by dry weight of at least one hydraulic binder.

Also preferably, the formulations (Fl) and (F2) according to the invention comprise water in an amount by weight relative to the quantity by weight of hydraulic binder of less than 0.7, less than 0.65 or less 0.6, preferably less than 0.5 or less than 0.4 or less than 0.3 or less than 0.2. The amount of water preferred ranges in weight relative to the quantity by weight of hydraulic binder in formulations (Fl) and (F2) are from 0.2 to 0.65 or 0.2 to 0.6 or 0.2 to 0.5 or 0.3 to 0.65 or 0.3 to 0.6 or from 0.3 to 0.5.

According to the invention, the hydraulic binder or hydrolithe may be selected from cement, mortar, plaster, grout, concrete.

The cement can be selected from Portland cement, white Portland cement, artificial cement, blast furnace cement, high strength cement, cement alumina, rapid cement, cement magnesium phosphate, cement-based products of incineration, cement fly ash and mixtures thereof.

Other hydraulic binders can be selected from latent hydraulic binders, pozzolanic binders, ash, slag, clinker.

The plaster can be selected from gypsum, calcium sulphate dihydrate, calcium sulfate, calcium sulfate hemihydrate, calcium sulfate anhydride, and mixtures thereof. The aggregate may be selected from sand, coarse aggregate, gravel, crushed stone, slag, recycled aggregate.

Generally, depending on their size, the aggregates are classified into categories known as such by the art, for example according to French standard XP P 18-540. This standard defines particular values ​​d and D, aggregates families include:

fillers 0 / D where D <2 mm with at least 70% passing 0.063 mm, the sablons 0 / D where D <1 mm with less than 70% passing 0.063 mm,

sand 0 / D with 1 6.3 mm,

gravel d / D where d> 1 mm and D <125 mm,

ballasts d / D where d> 25 mm and D <50 mm.

Examples of fillers are fumed silica or siliceous additions, or limestone additions such as calcium carbonate.

According to the invention, the adjuvant formulations (Fl) or (F2) can be selected from an anti-foam agent, a plasticizer or superplasticizer, an agent for improving the workability, a slump reducing agent, a drive reducing agent from the air, a coloring agent, a pigment, a water reducing agent, a retarding agent outlet, a control agent of the hygroscopicity, an anti-corrosion agent, an anti-agent withdrawal, an inhibitor of alkaline silico-reactions, a water repellent agent, a foaming agent.

The special properties of the aqueous composition according to the invention or copolymer according to the invention allow the use in many technical areas, including their control properties or rheology control.

Thus, the invention provides a method of modifying the rheology of a hydraulic formulation comprising adding at least one aqueous composition according to the invention or at least one copolymer according to the invention in the hydraulic formulation comprising water and a hydraulic binder.

The properties of the composition according to the invention and the copolymer are particularly useful in the field of hydraulic formulations.

The invention therefore provides a method of control of the workability of a hydraulic formulation comprising adding at least one aqueous composition according to the invention or at least one copolymer according to the invention in a hydraulic formulation. Particularly advantageously, the invention provides a method of controlling the workability for which the workability of the hydraulic formulation is kept constant for a period of at least 1 hour, preferably at least 2 hours, more preferably at least 3 hours, even more preferably at least 3.5 hours or at least 4 hours.

The invention also provides a method of reducing the setting time of a hydraulic formulation comprising adding at least one aqueous composition according to the invention or at least one copolymer according to the invention in a hydraulic formulation comprising water and a hydraulic binder.

Preferably for the methods of control of the workability of a hydraulic or formulation to reduce the setting time of a hydraulic formulation

the invention, the hydraulic formulation is selected from a hydraulic formulation (Fl) and a hydraulic formulation (F2).

The particular features, convenient or preferred hydraulic formulations (Fl) and (F2) according to the invention define the methods of control of the workability of a hydraulic or formulation to reduce the setting time of a hydraulic formulation according to the invention are also special, advantageous or preferred.

The following examples illustrate various aspects of the invention.

Example 1: preparation of copolymers according to the invention and a comparative copolymer

Example 1.1: copolymer (PI) according to the invention

In a stirred reactor, water (80 g), a monomer (B7B) of molecular weight 2400 g / mol to 60% by mass solution in water (380.37 g) and hypophosphite sodium monohydrate (1.02 g). The reactor was heated to 65 ± 2 ° C. Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9.18 g) and a mixture of water (60 g) and sodium persulfate (4.09 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (44.5 g). The aqueous polymer solution comprises less than 1 ppm of dry residual acrylic acid based on the total amount of dry copolymer. A copolymer was obtained (PI) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (B7B). Its molecular weight Mw is 33 300 g / mol and polydispersity index PI is 1.9.

Example 1.2: copolymer (P2) according to the invention

In a stirred reactor was charged with water (150 g), iron sulphate heptahydrate (0.214 g), copper sulphate pentahydrate (0.030 g) and a monomer (B7B) of molecular weight 2400 g / mol solution at 60% by mass in water (456.87 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (50.4 g), a mixture of water (65 g) and sodium hypophosphite monohydrate

(25.6 g) and a mixture of water (50 g) and hydrogen peroxide in aqueous solution at 35% by mass (20.5 g).

The reactor is maintained at temperature of 65 ± 2 ° C for lh.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (7.9 g). The aqueous polymer solution comprises less than 1 ppm of dry residual acrylic acid based on the total amount of dry copolymer. A copolymer (P2) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (B7B). Its molecular weight Mw is 26 700 g / mol and polydispersity index PI is 2.0.

Example 1.3: copolymer (P3) according to the invention

In a stirred reactor was charged with water (100 g), a monomer (B7B) of molecular weight 2400 g / mol to 60% by mass solution in water (380.37 g) and hypophosphite sodium monohydrate (2.04 g). The reactor was heated to 55 ± 2 ° C. Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (18.36 g) and a mixture of water (60 g) and sodium persulfate (8, 17 g).

The reactor is maintained at temperature 55 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (44.3 g). The aqueous polymer solution comprises less than 115 ppm of dry residual acrylic acid relative to the total amount of dry copolymer. A copolymer (P3) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (B7B). Its molecular weight Mw of 16 700 g / mol and polydispersity index PI is 2.0.

Example 1.4: copolymer (P4) according to the invention

In a stirred reactor, water (10 g), a monomer (B7B) of molecular weight 2400 g / mol to 60% by mass solution in water (684.67 g) and hypophosphite sodium monohydrate (1.84 g). The reactor was heated to 75 ± 2 ° C. Then for 2 hours, is injected in parallel into the reactor a mixture of water (10 g) and acrylic acid (75.51 g), a mixture of water (90 g) and sodium hypophosphite monohydrate (16.52 g) and a mixture of water (70 g) and sodium persulfate (7.36 g).

The reactor is maintained at temperature 75 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (81.5 g). The aqueous polymer solution comprises less than 2 ppm of dry residual acrylic acid based on the total amount of dry copolymer. There is obtained a copolymer (P4) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (B7B). Its molecular weight Mw is 25 900 g / mol and polydispersity index PI is 1.8.

Example 1.5: copolymer (P5) according to the invention

In a stirred reactor was charged with water (157 g), a monomer (b7d) of molecular weight 2400 g / mol (201 g) and sodium hypophosphite monohydrate (0.57 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (21.23 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.3 g) and a mixture of water (40 g) and sodium persulfate (2.28 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7. The aqueous polymer solution comprises less than 10 ppm of dry residual acrylic acid based on the total amount of dry copolymer .

There is obtained a copolymer (P5) of molecular weight of 38 430 g / mol and polydispersity index PI is 1.9.

Example 1.6: copolymer (P6) according to the invention

In a stirred reactor, water (40 g), a 60% monomer solution (b3b) for which x = 42 and y + z = 15.5, molecular weight 3000 g / mol (368 g) and sodium hypophosphite monohydrate (0.63 g). The reactor was heated to 65 ± 2 ° C. Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (23.34 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulfate (2.51 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7.1. The aqueous polymer solution comprises 880 ppm of dry residual acrylic acid relative to the total amount of dry copolymer. A copolymer was obtained (P6) of molecular weight of 49 890 g / mol and polydispersity index PI is 1.2.

Example 1.7: copolymer (P7) according to the invention

In a stirred reactor, water (40 g), a 60% monomer solution (b3b) for which x = 42 and y + z = 15.5, molecular weight 3000 g / mol (478 g) and sodium hypophosphite monohydrate (0.63 g). The reactor was heated to 65 ± 2 ° C. Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (20,97g), a mixture of water (50 g) and sodium hypophosphite monohydrate ( 5.64 g) and a mixture of water (40 g) and sodium persulfate (2.51 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7.4. The aqueous polymer solution comprises 850 ppm of dry residual acrylic acid relative to the total amount of dry copolymer. A copolymer was obtained (P7) of molecular weight of 44 880 g / mol and polydispersity index PI is 2.

Example 1.8: copolymer (P8) of the invention

In a stirred reactor, water (40 g), a 60% solution of (b3b) for which x = 52 and y + z = 11, molecular weight 3000 g / mol (368 g) and of sodium hypophosphite monohydrate (0.63 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (23,34g), a mixture of water (50 g) and sodium hypophosphite monohydrate ( 5.64 g) and a mixture of water (40 g) and sodium persulfate (2.51 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7.6. The aqueous polymer solution comprises 1670 ppm of dry residual acrylic acid based on the total amount of dry copolymer.

A copolymer (P8) of molecular weight of 31 330 g / mol and polydispersity index PI is 1.2.

Example 1.9: copolymer (P9) according to the invention

In a stirred reactor was charged with water (157 g), a monomer (b7d) of molecular weight 2400 g / mol (220 g) and sodium hypophosphite monohydrate (0.63 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g), acrylic acid (18.67 g) and methacrylic acid (4,67g), a mixture of water ( 50 g) and

of sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulfate (2.28 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7.1. The aqueous polymer solution comprises less than 50 ppm of dry residual acrylic acid and 2 ppm of dry methacrylic acid relative to the total amount of dry copolymer.

A copolymer was obtained (P9) of molecular weight of 38 585 g / mol and polydispersity index PI is 1.4.

Example 1.10: copolymer (P10) according to the invention

In a stirred reactor, water (80 g), a monomer (b3b) for which x = 42 and y + z = 15.5, molecular weight 3000 g / mol (45.64 g), a solution to 60% monomer (b7d) of molecular weight 2400 g / mol (274g) and sodium hypophosphite monohydrate (1.02 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g), acrylic acid (42 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9 , 2 g) and a mixture of water (40 g) and sodium persulfate (4.09 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7.2. The aqueous polymer solution comprises less than 2 ppm of dry residual acrylic acid based on the total amount of dry copolymer. A copolymer was obtained (PI) of molecular weight of 51 720 g / mol and polydispersity index PI is 1.8.

Example 1.11: copolymer (P i) according to the invention

In a stirred reactor was charged with water (320 g), a monomer (b7d) of molecular weight 3500 g / mol (294.8 g) and sodium hypophosphite monohydrate (1.02 g). The reactor was heated to 65 ± 2 ° C.

Then for 2 hours, is injected in parallel into the reactor a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9.18 g) and a mixture of water (40 g) and sodium persulfate (4.09 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass to pH 7. The aqueous polymer solution comprises less

10 ppm of dry residual acrylic acid based on the total amount of dry copolymer.

A copolymer (P i) of molecular weight of 36 610 g / mol and polydispersity index PI is 1.7.

Example 1.12: comparative copolymer

In a stirred reactor, water (50 g), iron sulphate heptahydrate (0, 11 g), a monomer (B7B) of molecular weight 2400 g / mol in solution at 60% by mass in the water (264.56 g) and DMDO (l, 8-dimercapto-3,6-dioxaoctane) (0.62 g). The reactor is heated at 37 ± 2 ° C. hydrogen peroxide is added in aqueous solution at 35% by mass (5.6 g).

Then, during one HL5 is injected in parallel into the reactor a mixture of water (30 g) and acrylic acid (32.49 g), a mixture of water (25 g), monomer (B7B) of molecular mass 2400 g / mol to 60% by mass solution in water (32.7 g) and DMDO (4.93 g) and a mixture of water (55 g) and sodium bisulfite solution at 40% by mass in water (5.64 g), LH40 for the latter mixture.

The reactor is maintained at temperature at 37 ± 2 ° C for 1 h30.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (36.6 g). The aqueous polymer solution includes more than 12,000 ppm of dry residual acrylic acid based on the total amount of dry copolymer. Moreover, almost 20% by weight of monomer (B7B) unreacted.

Example 1.13: comparative copolymer

In a stirred reactor was charged with water (400 g) and heated to 65 ± 2 ° C.

Then, during 3 hours, is injected in parallel into the reactor a mixture of water (40 g), acrylic acid (49.35 g) and monomer (b3a) of molecular weight 3000 g / mol (312, 81 g), a mixture of water (30 g), DMDO (1.80 g) and monomer (BL2) of molecular weight

3 000 g / mol (50.00 g), ainsi qu'un mélange d'eau (84.9 g) and ammonium persulfate of (1.51 g).

The reactor is maintained at temperature of 65 ± 2 ° C for 1 h30.

The product is cooled and partially neutralized by adding an aqueous solution of soda at 50% by mass (4.1 g). The aqueous polymer solution comprises greater than

4930 ppm of dry residual acrylic acid based on the total amount of dry copolymer.

Example 2: evaluation of power water reducer in a mortar

Is prepared mortar formulations whose composition is shown in Table 1 according to the procedure:

incorporation of the additive and water in the bowl of a Perrier automatic mixer for cements and mortars standardized,

incorporation of all fines (cement and / or hydraulic binders), mixing at low speed of 140 rev / min,

- incorporation of the sand after 30 s,

mixing at low speed of 140 rev / min for 60 s,

judgment for 30 s and cleaning of the walls of the bowl,

slow speed mixing 140 rev / min for 90 s.

Similarly preparing a formulation (CF) Comparative mortar not comprising copolymer.

The power water reducing copolymers of the invention is evaluated based mortar formulations.

Maneuverability T0 mortars formulated with the copolymers of the invention was evaluated by measuring the spread diameter (slump flow English) according to EN 12350-2 suitable for mortar (Abrams mini cone).

To perform the spreading, it raises the cone filled with mortar made perpendicularly to a horizontal plate while performing a quarter turn. The spreading is measured after 5 minutes according to two diameters at 90 ° with a ruler. The result of the averaging measure is the average of two values ​​of ± 1 mm.

The tests are performed at 20 ° C. The dosage of adjuvant is determined so as to reach a target spread 220 mm ± 5 mm. The assay is expressed as% by dry weight relative to the weight of the hydraulic binder or the mixture of hydraulic binders. The results are presented in Table 1.

FC formulation Fl-1 according to the invention

AFNOR sand (g) 1350 1350

VICAT cement CEM I 52.5N (g) 450 450

Copolymer (% dry weight / dry weight of

/ PI (0.10) cement)

antifoaming agent (/ adjuvant) / 0.5

Water (g) 266 200

weight in water / cement ratio 0.59 0.44

Maneuverability T0 220 215

Water reduction (%) 0 25

Table 1

The implementation of the copolymers according to the invention reduces the amount of water 25% of the hydraulic formulation, while maintaining an initial fluidity (workability) similar to that of the comparative formulation not comprising copolymer.

The copolymers of the invention can be described as high water reducing agents according to standard EN 934-2 BUILDER. Indeed, they allow a water reducing admixture for mortar the at least 12% compared to the control mortar.

The implementation of the copolymers according to the invention would achieve similar results in concrete admixture by reduction of at least 12% of the amount of water with respect to a concrete control not comprising the copolymer according to the invention.

WE CLAIMS

1. An aqueous composition comprising at least one copolymer whose polydispersity index PI is less than 3, obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C,

(A) at least one anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof, and

(B) at least one monomer of formula (I):

in which :

- R 1 and R 2 , identical or different, independently represent H or CH 3 ,

- L 1 independently represents a group selected from C (O), CH 2 , CH 2 -CH 2 and 0-CH 2 -CH 2 -CH 2 -CH 2 ,

- L 2 independently represents a group selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

- x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150 and x + y + z is between 10 and 150; in the presence:

(I) at least one compound comprising phosphorous in the oxidation state I; and

(ii) at least one radical generating compound selected from hydrogen peroxide, ammonium persulfate, alkali metal persulfate, and mixtures thereof or their respective associations with ammonium bisulfite with an alkali metal bisulfite or with an ion selected from Fe 11 , Fe 111 , Cu 1 , Cu 11 .

2. Composition according to claim 1 containing no homopolymer of the monomer (a) or comprising a reduced amount in weight, low or very low homopolymer of monomer (a) relative to the quantity by weight of dry copolymer.

3. Composition according to one of claims 1 and 2 for which the polymerization reaction implements:

from 1 to 25% by weight of monomer (a) and

from 75 to 99% by weight of monomer (b).

4. Composition according to one of claims 1 to 3 wherein the copolymer comprises:

from 1 to 25% by weight of monomer (a) and

from 75 to 99% by weight of monomer (b).

5. Composition according to one of claims 1 to 4 comprising less than 2000 ppm by weight or less than 1500 ppmw, preferably less than 1000 ppm by weight or less than 500 ppm by weight, in particular less than 200 ppm by weight or less than 100 ppm by weight of residual monomer (a) relative to the quantity by weight of dry copolymer.

6. Composition according to one of claims 1 to 5 wherein the polymerization reaction implements a compound (i) mineral or hypophosphorous acid (H3PO2) or a derivative of hypophosphorous acid (H3PO2), of preferably a compound (i) comprising at least a hypophosphite ion (H2PO2), more preferably a compound selected from sodium hypophosphite (H 2 P0 2 Na), potassium hypophosphite (H2PO2K), calcium hypophosphite ([H 2 P0 2 ] 2 Ca) and mixtures thereof.

7. Composition according to one of claims 1 to 6 wherein the polymerization reaction also implements another anionic monomer, preferably a monomer selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid and mixtures thereof.

8. Composition according to one of claims 1 to 7 wherein the compound (b) is selected from compounds of formulas (Ia), (Ib), (Ic) and (Id):

(La) (A)

The R ' :

"O R' O

(Id) (Ic) wherein:

R 1 and R 2 , identical or different, independently represent H or CH 3 , L 2 independently represents a group selected from (CH 2 CH 2 0) x, (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150 and x + y + z is between

10 and 150.

9. Composition according to one of claims 1 to 8 wherein x is strictly greater than y + z.

10. Composition according to one of claims 1 to 9 wherein the polymerization reaction is carried out at a temperature ranging from 30 to 85 ° C, preferably from 40 to 75 ° or from 50 to 70 ° C.

11. Composition according to one of claims 1 to 10 wherein the polymerization reaction also implements another monomer (c) chosen from:

• other anionic monomer, preferably selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, their salts and mixtures thereof;

• a nonionic monomer comprising at least one polymerizable olefinic unsaturation, preferably at least one polymerizable ethylenic unsaturation and including a polymerizable vinyl group, more preferably a nonionic monomer selected from esters of an acid comprising at least one monocarboxylic acid function, in particular an ester of an acid selected from acrylic acid, methacrylic acid, and mixtures thereof, for example hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, styrene, vinylcaprolactam, alkyl acrylate, especially acrylate Ci-Cio-alkyl, preferably acrylate, Ci-C 4alkyl, more preferably methyl acrylate, ethyl acrylate, propyl acrylate, isobutyl acrylate, n-butyl acrylate, alkyl methacrylate, especially methacrylate Ci-Cio-alkyl, preferably Ci-C methacrylate 4 alkyl, more preferably methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobutyl methacrylate, n-butyl acrylate, aryl, preferably phenyl acrylate, benzylacrylate, phenoxyethylacrylate, aryl methacrylate, preferably phénylméthacrylate, benzylméthacrylate, phénoxyéthylméthacrylate, a compound of formula (III):

Q!-CL CL Q2

(III)

in which :

Q 1 represents a polymerizable acrylate group or a polymerizable methacrylate group,

Q 2 represents a group H or a CH 3 group,

L 1 and L 2 , identical or different, independently represent an ethylenoxy group or a propyleneoxy group and

m and n are identical or different and at least one is different from 0, represent a number less than or equal to 150 and the sum m + n is less than 150;

• one other monomer selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id), different from compound (b), wherein:

- R 1 and R 2 , identical or different, independently represent H or CH3,

- L represents a group selected from (CH2-CH20) X ,

- x represents 1;

• one other monomer selected from compounds of formulas (I), (Ia), (Ib), (Ic) and (Id), different from compound (b), wherein:

- R 1 and R 2 , identical or different, independently represent H or CH3,

- L independently represents a group selected from (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof,

y + z is 1 or 2; and

Acid • 2-acrylamido-2-methylpropanesulfonic acid salt of 2-acrylamido-2-methylpropanesulfonic acid, 2- (methacryloyloxy) ethanesulfonic acid, a salt of 2-

(Methacryloyloxy) ethanesulfonic acid, sodium methallyl sulfonate, styrene sulfonate and mixtures thereof.

Composition according to one of claims 1 to 11 wherein the polymerization reaction is carried out in the presence also (iii) from 0.05 to 5% by weight, based on the amount of monomers of at least one compound of formula (II):

(PI)

in which :

- X independently represents H, Na or K,

- R independently represents a Ci-Cs-alkyl.

Copolymer whose polydispersity index PI is less than 3, obtained by at least one radical polymerization reaction in water and at a temperature ranging from 10 to 90 ° C,

(A) at least one anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or a salt thereof, and

(B) at least one monomer of formula (I):

(I)

in which :

R 1 and R 2 , identical or different, independently represent H or CH 3 , L 1 independently represents a group selected from C (O), CH 2 , CH 2 -CH 2 and 0-CH 2 -CH 2 -CH 2 - CH 2 ,

L 2 independently represents a group selected from (CH 2 -CH 2 0) x , (CH 2 CH (CH 3 ) 0) y (CH (CH 3 ) CH 2 0) z , and combinations thereof and

x, y and z, which are identical or different, independently represent an integer or decimal number between 0 and 150, preferably x is strictly greater than y + z, and x + y + z is between 10 and 150;

in the presence:

(I) at least one compound comprising phosphorous in the oxidation state I; and

(Ii) at least one radical generating compound selected from hydrogen peroxide, ammonium persulfate, alkali metal persulfate, and mixtures thereof or their respective associations with ammonium bisulfite with an alkali metal bisulfite or with an ion selected from

Fe11, Fe111, Cu1, Cu11.

14. The copolymer of claim 13 comprising:

- from 1 to 25% by weight of monomer (a) and

- from 75 to 99% by weight of monomer (b).

15. A formulation comprising:

- at least one aqueous composition according to one of claims 1 to 12 or at least one copolymer according to one of claims 13 and 14;

- at least one hydraulic binder; eventually

- some water ; eventually

- at least one aggregate; eventually

- at least one adjuvant.

16. Formulation according to claim 15 comprising:

- from 0.01 to 5% by dry weight of copolymer, respectively in the form of at least one aqueous composition according to one of claims 1 to 12 or at least one copolymer according to one of claims 13 and 14 as such ;

- from 95 to 99.9% by dry weight of at least one hydraulic binder.

17. Formulation according to one of claims 15 and 16 comprising water in an amount by weight relative to the quantity by weight of hydraulic binder of less than 0.7, less than 0.65 or less than 0.6, preferably less than 0.5 or less than 0.4 or less than 0.3 or less than 0.2 or from 0.2 to 0.65 or 0.2 to 0.6 or 0.2 to 0.5 or 0.3 to 0.65 or 0.3 to 0.6 or from 0.3 to 0.5.

18. A method of modifying the rheology of a hydraulic formulation comprising adding at least one aqueous composition according to one of claims 1 to 12 or at least one copolymer according to one of claims 13 and 14 in hydraulic formulation.

A method of controlling the workability of a hydraulic formulation comprising adding at least one aqueous composition according to one of claims 1 to 12 or at least one copolymer according to one of claims 13 and 14 in a hydraulic formulation.

A method of controlling the workability according to claim 19 for which the workability of the hydraulic formulation is kept constant for a period of at least 1 hour, preferably at least 2 hours, more preferably at least 3 h , even more preferably at least 3.5 hours or at least 4 hours.

Method of reducing the setting time of a hydraulic formulation comprising adding at least one aqueous composition according to one of claims 1 to 12 or at least one copolymer according to one of claims 13 and 14 in a hydraulic formulation.