Title of Invention

METHOD FOR THE CONTROLLED RADICAL POLYMERISATION OF ACRYLIC ACID AND THE SALTS THEREOF & POLYMERS THUS OBTAINED

Abstract A process for controlled radical homopolymerisation, in an aqueous solution, ofacrylic acid and its salts, or ofcopolymerisation, in aqueous solution, ofacrylic acid with one or more hydrosoluble monomers, wherein said process is in batch or semi-batch mode, and wherein said process comprises two stages, the first stage is undertaken with equimolar quantities of potassium xanthate and the sodium salt of2-bromopropionic acid that is synthesizing "in situ" an hydrosoluble transfer agent used in the second stage of polymerisation in which the limits of quantity of transfer agent are determined, such that the molar ratio of transfer agent to monomer is between 0.001% and 20%, and the mass ratio of transfer agent to monomer is between 0.01% and 60%.
Full Text
FORM 2
THE PATENTS ACT, 197 0
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10, rule 13)
1. TITLE OF INVENTION
METHOD FOR THE CONTROLLED RADICAL POLYMERISATION OF ACRYLIC ACID AND THE SALTS THEREOF & POLYMERS THUS OBTAINED
2. APPLICANT (S)
(a) NAME : COATEX S.A.S
(b) NATIONALITY : FRENCH Company
(c) ADDRESS : 35, rue Ampere, Z.I. Lyon Nord, F-6973 0
Genay, FRANCE
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of the invention and the manner in which it is to be performed : -


PROCESS FOR CONTROLLED RADICAL POLYMERISATION OF ACRYLIC ACID AND ITS SALTS, THE POLYMERS OBTAINED AND APPLICATIONS THEREOF.
The present invention concerns a new process for controlled radical polymerisation of acrylic acid and its salts in a reactive medium consisting solely of water. The invention also concerns homopolymers of acrylic acid obtained by the new polymerisation process as well as copolymers of acrylic acid with at least one hydrosoluble ethylenically unsaturated monomer, or one of which the copolymer is hydrosoluble. Finally, the invention concerns the use of the said homopolymers and copolymers of acrylic acid in the fields of industry such as, notably, the paper field and in particular in the coating of paper and the mass-filling of paper, in the oil field, or again in the fields of paint, water treatment, detergency, ceramics, cements or hydraulic binders, public works, inks and varnishes, sizing of textiles or again finishing of leather, and more specifically concerns the application of these polymers as a dispersant and/or grinding aid agent of mineral matter such as natural calcium carbonate, precipitated calcium carbonate, kaolin, titanium dioxide or clays.
Lastly, the invention concerns aqueous suspensions of mineral fillers containing the said
polymers and more specifically containing between 0.05% and 5% by dry weight, relative to
the total dry weight of the mineral fillers, of the said polymer according to the invention.
Controlled radical polymerisation of ionic monomers is a special means of synthesis
requiring the use of specific transfer agents.
Thus, in order to polymerise the sodium methacrylate, the work of Armes (Armes, Chem. Commun, 1999,1285) implements in a method called Atom Transfer Radical Polymerization (ATRP), 4-cyanopentanoic dithiobenzoate acid, just as Mc Cormick (Macromolecules 2002, 35, 4570-4572 and Macromolecules 2001, 34, 2248) uses it to polymerise, by a method called Reversible Addition Fragmentation Transfer (RAFT), 2-acrylamido 2-methyl propane sodium sulfonate or 3-acrylamido 3-methyl sodium butanoate.
J. Claverie and his team (Macromolecules 2001, 34(16), 5370) as well as the unpublished patent application (FR 01 02848) describe that the choice of substituents for a xanthate or a trithiocarbonate must be made judiciously to obtain RAFT polymerisation. By judiciously made, we mean having high polymerisation yields (higher than 90 %) and low polymolecularity indices (lower than 2). We shall note in this regard that the polymolecularity index and the molecular masses are, in the publication of Claverie and his team, measured by a chromatographic method called Gel Permeation Chromatography (GPC) in an aqueous medium with polyacrylates as standards, which enables the value of the molecular masses and the polymolecularity indices to be estimated very accurately.
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Plowever, the molecules of interest/ i.e. the transfer agents, are not soluble in water and it is
necessary to use a protic solvent to undertake the syntheses.
Other documents (WO 99/31144; WO 00/75207; WO 01/27176; WO 01/42312; WO
02/08307; WO 02/22688) require tine use of a reactive medium for synthesis of the transfer
agent other than water. These transfer agents synthesised in a solvent medium other than
water do not allow acrylic acid to be polymerised in the same reactive medium as that which
allowed synthesis of the transfer agent.
Furthermore, the work of Destarac: (Macromol.Rapid.Commun. 2001, 22 (18), 1497-1503 or
again WO 98/58974) concerns notably the polymerisation of acrylic acid using xanthates
with the following structures:
one of 'me limitations oi which is "thai they also reqmie a "reaction co-sorverrt which is essential for solvation of these said xanthates to obtain a uniform medium.

The few transfer agents capable of controlling polymerisation of acrylic acid must be solvated in another solvent, which may engender subsequent complex purifications such as distillations. In addition, a co-solvent may generate secondary transfer reactions which then come into competition with the transfer reaction of the RAFT type.
By "transfer agents" the Applicant designates throughout the present application, including the claims, compounds capable of stopping the growth of polymer chains but in a non-irreversible manner.
Thus, the skilled man in the art encounters the problem which consists at once in having a hydrosoluble transfer agent which is genuinely effective with acrylic acid, and in finding a transfer agent the synthesis of which does not require on the one hand the use of often harmful solvents and on the other hand of purification stages such as extractions or distillations (WO 00/75207 - WO 01/42312).
The outcome of this is a difficulty of accomplishment since the transfer agent must be synthes\sed in several operations, since the polymer is. obtained in a new reactive medium., and since it must be purified again of all traces of solvent in order to be able to be used in the abovementioned aqueous industrial applications.
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Another related problem also lies in the obligation to seek, for industrial applications,
transfer agent molecules which are relatively simple and easy to use, with a cost acceptable
in industry.
Thus, until now there has been no process for homopolymerisation or copolymerisation of
acrylic acid using a transfer agent capable of enabling controlled radical
homopolymerisation or copolymerisation of acrylic acid in a reactive medium consisting
solely of water, and excluding all other solvents, and not posing the abovementip'ned
problems.
There is thus, despite the progress recorded by the "RAFT" technology, a major and
acknowledged need for a process for homopolymerisation or copolymerisation of acrylic
acid in a reactive medium consisting solely of water and using a transfer agent the synthesis
of which does not require on the one hand the use of often harmful solvents and on the other
hand purification stages such as extractions or distillations.
The Applicant then found, surprisingly, that a batch or semi-batch process of
homopolymerisation of acrylic acid, or of copolymerisation of acrylic acid with at least one
hydrosoluble ethylenically unsaturated monomer or one of which the copolymer is
hydrosoluble, in a reactive medium consisting solely of water, a process which comprises
two stages, the first of which consists of "in situ" synthesis of a hydrosoluble transfer agent,
used in the second stage of polymerisation, enables the abovementioned problems to be
resolved.
By batch process, the Applicant means a process for polymerisation in solution in which all
the monomers are introduced in the initial stage. This process thus enables polymers
different from block polymers to be obtained.
By semi-batch process, the Applicant means a process for polymerisation in solution in
which all the monomers are introduced throughout the polymerisation. This process also
enables polymers different from block polymers to be obtained.
Another variant of the batch or semi-batch process consists in a process of polymerisation in
solution in which a part of the monomers is present in the reactor in the initial stage, the
other part being introduced throughout the polymerisation. This other variant of the process
also enables polymers different from the block polymers to be obtained.
One aim of the present invention is thus a new batch or semi-batch process for controlled
radical polymerisation of acrylic acid, enabling a hydrosoluble transfer agent to be obtained
which is genuinely effective with acrylic acid, and enabling a transfer agent to be obtained
the synthesis of which does not require on the one hand the use of often harmful solvents,
and on the other hand a purification stage such as extractions or distillations.
The process in according to the invention, for controlled radical homopolymerisation, in an
aqueous solution, of acrylic acid, or/for controlled radical copolymerisation, in an aqueous
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solution, of acrylic acid, with at least one hydrosoluble ethylenically unsaturated monomer, or one of which the copolymer is hydrosoluble, is characterised in that it is in batch or semi-batch mode, and in that it has two stages the first of which is "in situ" synthesis of the hydrosoluble transfer agent.
This "in situ" synthesis of the catalyser means that it does not to have to be handled as such, even if it can be advantageous to remove the residue from the synthesis of the transfer agent which is potassium or sodium bromide. This operation is not in any sense indispensable. When the process according to the invention consists of a controlled radical copolymerisation, in batch or semi-batch mode, of acrylic acid with at least one hydrosoluble ethylenically unsaturated monomer, or one of which the copolymer is hydrosoluble, the hydrosoluble ethylenically unsaturated monomer or monomers, or ones of which the copolymer is hydrosoluble, are chosen from among methacrylic acid, itaconic acid, maleic, 2-acrylamido-2-rnethyl-l-propane sulphonic acid in acid form or partially neutralised, 2-methacrylamido-2-methyl-l-propane sulphonic acid in acid form or partially neutralised, 3-methacrylamido-2-hydroxy-l-propane sulphonic acid in acid form or partially neutralised, allylsulphonic acid, methallylsulphonic acid, allyloxybenzene sulphonic acid, methallyloxybenzene sulphonic acid, 2-hydroxy-3-(2-propenyloxy)propane sulphonic acid, 2-methyl-2-propene-l-sulphonic acid, ethylene sulphonic acid, propene sulphonic acid, 2-methyl sulphonic acid, styrene sulphonic acid and all their salts, vinyl sulphonic acid, sodium methallylsulfonate acid, sulfopropyl acrylate or methacrylate, sulfomethylacrylamide, sulfomethylmethacrylamide, or from among acrylamide, methylacrylamide, n-methylolacrylamide, n-acryloylmorpholine, ethylene glycol methacrylate, ethylene glycol acrylate, propylene glycol methacrylate, propylene glycol acrylate, propene phosphonic acid, acrylate or methacrylate phosphate of ethylene or propylene glycol, or from among vinylpyrrolidone, methacrylamido propyl trimethyl ammonium chloride or sulphate, methacrylate of trimethyl ammonium ethyl chloride or sulphate, as well as their acrylate or acrylamide counterparts, whether quaternised or not, and/ or ammonium dimethyldiallylchloride, as well as mixtures of them. More particularly, the process according to the invention is characterised in that the hydrosoluble transfer agent is an a-substitute p-carboxylate xanthate salt. In an even more particular manner, the hydrosoluble transfer agent according to the invention is an a-substitute p-carboxylate sodium xanthate, and completely preferably the a-substitute p-carboxylate sodium xanthate according to the invention is an a-methyl p-carboxylate sodium xanthate.
In an equally particular manner, the process according to the invention is characterised in that the reactive medium of the first stage of synthesis of the transfer agent and of the second stage of polymerisation is identical and is water.
5

According to a preferred production method, in the second stage of polymerisation the limits of quantity of transfer agent are determined such that the molar ratio of transfer agent to monomer is between 0.001% and 20%, and the mass ratio of transfer agent to monomer is between 0.01 % and 60%.
In a particularly specific manner, the process according to the invention thus consists in bringing into contact in the first stage:
a potassium xanthate,
2-bromopropionic acid sodium salt,
water, and then in adding in a second stage acrylic acid and at least one hydrosoluble initiator of free radicals.
The free radical initiators used in the process of polymerisation according to the invention
are the initiators of hydrosoluble free radicals which are very familiar to the skilled man in
the art and are, notably, chosen from among the hydroxylamine based compounds or from
the bisulphites such as sodium metabisulphite or from the peroxides such as, among others,
hydrogen peroxide or tertio-butyl hydroperoxide, or from among the persalts such as,
notably, sodium, ammonium or potassium persulphate or perborate or perchlorate or
similar, or are chosen from among the azo compounds such as notably 4-4'-azobis (4-
cyanopentanoic) acid, 2-2'-azobis (2-methyl-N-hydroxyethyl)-propionamide, 2-2'-azobis (2-
methyl-N-(l,l~bis(hydroxymethyl)ethyl)propionamide, 2-2'-azobis(N,N'-
dimethyleneisobutyramidine) dichloride, 2-2'-azobis(2-amidinopropane) dichloride, 2-2'-azobis(N,N'-dimethyleneisobutyramide) dichloride, 2-2'-azobis(isobutyramide) dihydrate, or are chosen from among sodium hypophosphite, hypophosphorous acid, or phosphorous acid and/or their salts, possibly in the presence of metal salts, for example of iron or copper, or are chosen from mixtures of at least two of the abovementioned initiators. In an even more specific manner, the first stage is accomplished with equimolar quantities of potassium xanthate and the sodium salt of 2-bromopropionic acid, while the second stage takes place with the abovementioned limits in terms of quantity of monomer transfer agent. The invention also concerns the transfer agents used in the above process. These hydrosoluble transfer agents according to the invention are characterised in that they are obtained in the polymerisation reactive medium, namely water.
In a very particular manner, the hydrosoluble transfer agent according to the invention is characterised in that it is sodium a-methyl p-carboxylate xanthate. Another aim of the invention is to provide the polymers obtained by the above process. The polymers according to the invention are obtained in a very simple manner and require no or very little purification.
6

The polymers according to the invention are characterised in that they are obtained by the
process of polymerisation according to the invention and in that they have an average
molecular mass by weight (Mw) of between 1000 g/mole and 60,000 g/mole, and more
particularly between 4500 g/mole and 8000 g/mole, with a polymolecularity index of less
than or equal to 2 for a conversion rate relative to acrylic acid higher than 90%.
The conversion rate of acrylic acid into poly(acrylic acid) is measured by high-pressure
liquid chromatography (HPLC). In this method, the components constituting the mixture are
separated on a stationary phase and detected by a UV detector. After calibration of the
detector, it is possible, starting from the area of the peak corresponding to the acrylic
compound, to obtain the quantity of residual acrylic acid. This methods forms part of the
state of the art, and is described in many reference works such as, for example, in the manual
"Experimental Organic Chemistry", by M. Chavanne, A. Julien, G. J. Beaudoin, E. Flamand,
second Edition, Editions Modulo, chapter 18, pages 271-325.
The average molecular mass by weight is determined by a GPC method the standard for
which is a serie of 5 sodium polyacrylate standards supplied by Polymer Standard Service as
references PAA 18K, PAA 8K, PAA 5K, PAA 4K and PAA 3K.
The Applicant stipulates in this respect that polyacrylate calibration is chosen since it feels
that it is the most appropriate one for acrylic acid polymers, and since the results obtained
depend on the type of calibration used.
These homopolymers and/or copolymers according to the invention are either in their acid
form, i.e. non-neutralised, or partially or totally neutralised by one or more monovalent,
divalent, trivalent neutralisation agents, or neutralisation agents with higher valencies, or
mixtures thereof.
Monovalent neutralisation agents are chosen from the group constituted by the compounds containing alkaline cations, particularly sodium and potassium, or again lithium, ammonium, or again the aliphatic and/or cyclic primary or secondary amines such as, for example, the ethanolamfnes, mono- and diethylamine or cyclohexylamine.
Divalent or trivalent neutralisation agents, or neutralisation agents with higher valency, are chosen from the group constituted by the compounds containing divalent cations belonging to the alkaline earths, particularly magnesium and calcium, or again zinc, and also by the trivalent cations, particularly aluminium, or again by certain compounds containing cations with a higher valency.
Finally, another aim of the invention is the use of these polymers according to the invention in the fields of industiy such as, notably, the paper field and in particular in the coating of paper and the mass-filling of paper, in the oil field, or again in the fields of paint, water treatment, detergency, ceramics, cements or hydraulic binders, public works, inks and
7

varnishes, sizing of textiles or again finishing of leather, and more specifically concerns the application of these polymers as a dispersant and/or grinding aid-agent of mineral material such as natural calcium carbonate, precipitated calcium carbonate, kaolin, titanium dioxide or clays.
Thus, the invention also concerns aqueous suspensions of mineral fillers containing the said polymers and more specifically containing between 0.05% and 5% by dry weight of the said polymer relative to the total dry weight of the mineral fillers.
These aqueous suspensions of mineral fillers are also characterised in that the mineral filler is chosen from among natural calcium carbonate such as, notably, calcite, chalk or marble, synthetic calcium carbonate also called precipitated calcium carbonate, dolomites, magnesium hydroxide, kaolin, talc, gypsum, titanium oxide, or aluminium hydroxide, or any other mineral filler habitually used in fields such as, notably, the paper field, in particular in the coating of paper and the mass-filling of paper, oil, paint, water treatment, detergency, ceramics, cements or hydraulic binders, public works, inks and varnishes, sizing of textiles or finishing of leather.
Papers manufactured and/or coated according to the invention are characterised in that they contain the said aqueous suspensions of mineral fillers according to the invention. Paint formulations according to the invention are characterised in that they contain the said aqueous suspensions of mineral fillers according to the invention.
Drilling muds according to the invention are characterised in that they contain the said aqueous suspensions of mineral fillers according to the invention.
In practice the disintegration operation, also called the dispersal operation, of the mineral substance to be dispersed can be accomplished in two different manners. One of the manners consists in preparing by stirring a suspension of mineral fillers by introducing all or part of the dispersant agent according to the invention in the aqueous phase, followed by the mineral material, so as to obtain the aqueous suspension of mineral fillers used in the abovementioned fields of application.
Another manner consists in preparing the suspension of mineral fillers by introducing into the mineral filler cake the full quantity of dispersant agent to be tested so as to obtain the aqueous suspension of mineral fillers used in the abovementioned fields of application. This disintegration operation may follow the grinding operation described below or may be implemented in a completely independent manner.
Thus, in practice, the operation to grind the mineral substance to be refined consists in grinding the mineral substance with a grinding body into very fine particles in an aqueous medium containing the grinding aid agent.
The grinding body, of granulometry preferably between 0.20 and 4 millimetres, is added to the aqueous suspension of the mineral substance for grinding. The grinding body generally
8

has the form of particles of materials as diverse as silicon dioxide, aluminium oxide,
zirconium oxide or mixtures thereof, as well as synthetic resins of great hardness, steels or
other. An example of the composition of such grinding bodies is given by patent FR 2303681
which describes the grinding elements formed 30% to 70% by weight of zirconium oxide,
0.1% to 5% of aluminium oxide, and 5% to 20% of silicon dioxide.
The grinding body is preferably added to the suspension in a quantity such that the ratio by
weight between this grinding material and the mineral substance for grinding is at least 2/1,
this ratio being preferably between the limits 3/1 and 5/1.
The mixture of the suspension and of the grinding body is then subjected to the mechanical
stirring action, as this occurs in a traditional grinder with micro-elements.
e time required to arrive at the desired refinement of the mineral substance after grinding
varies according to the nature and quantity of the mineral substances to be ground, and
according to the stirring method used and the temperature of the medium during the
grinding operation.
The aqueous suspensions thus obtained can be used in the field of mass filling or coating of
paper.
During manufacture of the paper sheet, i.e. during their use as a mass load, these
suspensions can be used with the coating brokes.
They can also be used in the field of paints or drilling muds.
Papers manufactured and/or coated according to the invention are characterised in that
they contain aqueous suspensions of mineral fillers according to the invention.
Paint formulations according to the invention are characterised in that they contain the said
aqueous suspensions of mineral fillers according to the invention.
Other characteristics and advantages of the invention will be better understood on reading
the non-limitative examples which follow.
EXAMPLE 1:
This example concerns the preparation of different polymers according to the invention.
To do so, according to the following reaction:
O O

S Br S
synthesis of hydrosoluble xanthate is stoichiometric and is accomplished completely in water.
Test n° 1:
9

For this test, the following is introduced into a 1 litre reactor fitted with a stirring mechanism:
> 5.14 g of potassium xanthate,
> 4.91 g of 2-bromopropionic acid dissolved in 10 g of water,
> 2.57 g of 50% soda, diluted in 10 g of water;
and a solution with a pH of approximately 5.6 is obtained, to which 5 g more water is added.
A clear, slightly orangey solution is then obtained, which is stirred for two hours at ambient temperature (approximately 25°C).
The substitution of bromide by xanthate is then checked by dosing the free bromide Br - by capillary electrophoresis.
The following are then loaded into this reactor:
- 202.8 g of bipermuted water,
- 67.6 g of acrylic acid,
- 0.54 g of hydrosoluble initiator of the acid type, 4,4' azobis (4-cyanopentanoic) sold by
the company Vopak under the name V501.
The medium is then reflux heated (to a temperature of approximately 101°C) for seven hours.
A yellow uniform medium is then obtained which is neutralised with 50% soda until a pH of 8.2 is obtained.
The concentration of dry matter, measured by dissecation, is 25.7%.
The concentration in unreacted acrylic acid is 430 ppm measured by HPLC as stated above; which gives a conversion rate relative to acrylic acid of 99.2%.
A GPC measurement of the solution gives, for a calibration undertaken with polyacrylic acid standards (sodium polyacrylates sold by the company Polymer Standard Service under the names PSS-PAA of 18K to 2K), a molecular mass by weight of 4960 g/mole for a polymolecularity index of 1.97.
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Test n°2:
The operational conditions, the equipment and the compounds used in this test are identical in all points to the previous test, except for the neutralisation of the polymer obtained after 7 hours' heating, which is undertaken up to a pH of 8.2 using a soda-lime mixture in a 50/50 molar ratio.
The characteristics of the polymer obtained in terms of molecular weight, unreacted acrylic acid and polymolecularity index are identical to those of the previous test.
This example enables it to be shown that it is possible to synthesise in an aqueous medium a totally hydrosoluble xanthate salt, and that this totally hydrosoluble xanthate salt is capable of polymerising acrylic acid with high yields with a control of the reaction enabling the low polymolecularity indices to be obtained; by low we mean values which are less than or equal to 2.
Test n°3
This test also concerns the preparation of a polymer according to the invention implementing in a first stage the synthesis "in situ" of the hydrosoluble transfer agent, followed by the stage of polymerisation of acrylic acid. To do so, the following is introduced into a 500 ml reactor fitted with a stirring mechanism:
30 g of water;
5 g of alpha bromo phenyl acetic acid;
the medium is then neutralised with 3.85 g of 50% soda;
- 3,727 g of potassium xanthate ethyl is then added.
The medium is clear and the measured pH is equal to 4.
This is left under stirring for two hours at ambient temperature. The following are then loaded into this reactor:
- 214 g of water;
- 71.4 g of acrylic acid;
- 0.57 g of hydrosoluble initiator of the acid type, 4,4' azobis (4-cyanopentanoic) sold by the company Vopak under the name V501.
The medium is then reflux heated for two hours.
An orange-coloured uniform medium is then obtained, which is neutralised partially (90%
molar) using a soda-lime mixture in a molar ratio of 50/40.
The rate of conversion measured by HPLC under the same conditions as above is 99.0%
relative to the acrylic acid.
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A GPC measurement under the conditions described in the previous tests gives us a
molecular mass by weight of 7725 g/mole for a polymolecularity index of 1.96.
EXAMPLE 2:
This example illustrates the use of a polymer obtained according to the invention as a
grinding aid agent of mineral material and more specifically calcium carbonate. This
example also illustrates the process of obtaining of an aqueous suspension of calcium
carbonate according to the invention.
It should also be noted that these suspensions of calcium carbonate according to the
invention are refined, highly concentrated with mineral material and easily handled by the
end user, i.e. easily used both for coating of paper and for mass-filling of paper.
To do so, an aqueous suspension is prepared from calcium carbonate from the Orgon
deposit (France), of median diameter of around 7 micrometers.
The aqueous suspension has a dry matter concentration of 78% by weight relative to the
total mass.
The grinding aid agent is introduced into this suspension according to the quantities
indicated in the table below, expressed as a percentage of dry weight relative to the dry
calcium carbonate mass to be ground.
The suspension circulates in a grinder of the Dyno-Mill™ type with a fixed cylinder and
rotating pulser, the grinding body of which is constituted by corundum balls of diameter in
the range 0.6 millimetre to 1.0 millimetre.
The total volume occupied by the grinding body is 1,150 cubic centimetres while its mass is
2,900 g.
The grinding chamber has a volume of 1,400 cubic centimetres.
The circumferential speed of the grinder is 10 metres per second.
The calcium carbonate suspension is recycled at a rate of 18 litres per hour.
The outlet of the Dyno-Mill™ is fitted with a 200 micron mesh separator enabling the
suspension resulting from the grinding and the grinding body to be separated.
The temperature during each grinding test is maintained at 60°C approximately.
On completion of the grinding (To)/ a sample of the pigment suspension is recovered in a
flask. The granulometry of this suspension (% of particles of under 1 micrometer) is
measured using a Sedigraph™ 5100 granulometer from the company Micromeritics.
The Brookfield™ viscosity of the suspension is measured using a Brookfield™ viscometer
type RVT, at a temperature of 20°C and rotational speeds of 10 revolutions per minute and
100 revolutions per minute with the adequate mobile.
Test n° 4:
This test illustrates the prior art and uses 1.28% by dry weight, relative to the dry weight of
calcium carbonate, of a polyacrylate, obtained by a traditional process of radical
12

polymerisation, of molecular weight by weight equal to 5500 g/mole, of polymolecularity
index equal to 2.2 and neutralised by a lime-magnesia mixture in a molar ratio equal to
50/50.
Test n° 5:
This test illustrates the invention and uses the polyacrylate in the invention of test No. 2.
All these experimental results are recorded in table 1 below, which also indicates the
consumption by percentage by weight of the grinding aid agent used to obtain the indicated
granulometry.
TABLE 1
A reading of the results of table 1 shows that it is possible to use the polymers according to
the invention as a grinding aid agent of mineral material in aqueous suspension, and in
particular natural calcium carbonate, and that it is possible to obtain aqueous suspensions of
natural calcium carbonate containing the polymer according to the invention.
This table also shows that the results obtained with the polymer according to the invention
are better, in terms of consumption of the grinding aid agent and in terms of viscosity of the
suspension obtained, than those obtained with a polymer, commonly used in the prior art.
These suspensions according to the invention can advantageously be used in the fields of
industry such as notably the paper field, or the field of paint, and in particular in paper
coating and mass-filling of paper.
EXAMPLE 3:
This example illustrates the use of a polymer obtained according to the invention as a
grinding aid agent of mineral material and more specifically calcium carbonate. This
example also illustrates the process of obtaining of an aqueous suspension of calcium
carbonate according to the invention.
In this example, the equipment and the operating conditions are identical to those used in
the previous example, except for the fact that a predetermined quantity is added, namely
1.16% by dry weight, relative to the dry weight of calcium carbonate, of the grinding aid
agent, and that the granulometries obtained for an equivalent dose of grinding aid agent are
compared, with the grinding operation being stopped when the viscosity of the suspension
no longer allows the grinding operation to be continued.
Test n° 6:
This test illustrates the prior art and uses a polyacrylate, obtained by a traditional process of
radical polymerisation, of molecular weight by weight of 5500 g/mole, of polymolecularity
index equal to 2.4 and totally neutralised by soda.
The calcium carbonate suspension obtained at a granulometry such that 79.2% of the
particles have a diameter of under 1 micrometer, measured using the Sedigraph™5100.
Test n° 7:
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This test illustrates the invention and uses the polyacrylate according to the invention of test
No. 1.
The calcium carbonate suspension obtained at a granulometry such that 89.3% of the
particles have a diameter of under 1 micrometer, measured using the Sedigraph™5100.
A reading of the abovementioned results shows that it is possible to use the polymers
according to the invention as a grinding aid agent of mineral material in aqueous
suspension, and in particular natural calcium carbonate, and that it is possible to obtain
aqueous suspensions of natural calcium carbonate containing the polymer according to the
invention.
In addition, these results show that the polymer according to the invention enables a finer
granulometry to be attained than that obtained with a polymer commonly used in the prior
art.
These suspensions according to the invention can advantageously be used in the fields of
industry such as notably the paper field, or the field of paint, and in particular in paper
coating and mass-filling of paper.
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WE CLAIM:
1. A process for controlled radical homopolymerisation, in an aqueous solution, ofacrylic acid and its salts, or ofcopolymerisation, in aqueous solution, ofacrylic acid with one or more hydrosoluble monomers, wherein said process is in batch or semi-batch mode, and wherein said process comprises two stages, the first stage is undertaken with equimolar quantities of potassium xanthate and the sodium salt of2-bromopropionic acid that is synthesizing "in situ" an hydrosoluble transfer agent used in the second stage of polymerisation in which the limits of quantity of transfer agent are determined, such that the molar ratio of transfer agent to monomer is between 0.001% and 20%, and the mass ratio of transfer agent to monomer is between 0.01% and 60%.
2. The process according to the claim 1, wherein the reactive media of the first stage of synthesis of the transfer agent and of the second stage of polymerisation are identical and solely water.
3. The process according to claim 1, wherein said process is a process of controlled*, radical homopolymerisation, in an aqueous solution, ofacrylic acid, and is undertaken in batch mode.
4. The process according to claim 1, wherein the hydrosoluble transfer agent is an [alpha]-substitute [beta]-carboxy late xanthate salt.
5. The process according to claim 1, wherein said process consists in putting in contact in the first stage:
a potassium xanthate,
2-bromopropionic acid sodium salt,
water,
and then in adding, in the a second stage, acrylic acid and at least one hydrosoluble initiator of free radicals.
6. The process according to claim 1, wherein the hydrosoluble copolymerised monomers are
selected from the group consisting ofmefhacrylic acid, itaconic acid, maleic acid, 2-acrylamido-2-
methyl-1-propane sulphonic acid in acid form or partially neutralised, 2-methacrylamido-
2"methyl-l -propane sulphonic acid in acid form or partially neutralised, 3-methacrylamido-2-
15

hydroxy-1-propane sulphonic acid in acid form or partially neutralised, allylsulphonic acid,
methallylsulphonic acid, allyloxybenzene sulphonic acid, methallyloxybenzene sulphonic^acid, 2-
hydroxy-3-(2-propenyloxy)propane sulphonic acid, 2-methyl-2-propene-l-sulphonic acid,
ethylene sulphonic acid, propene sulphonic acid, 2-methyl sulphonic acid, styrene sutphonic acid,
as well as all their salts, vinyl sulphonic acid, sodium methallylsulfonate, sulfopropyi acrylate or
methacrylate, sulfomethylacrylamide, sulfomethylmethacrylamide, acrylamide,
methylacrylamide, n-methylolacrylamide, n-acryloylmorpholine, ethylene glycol methacrylate, ethylene glycol acrylate, propylene glycolmethacrylate, propylene glycol acrylate, propene phosphonic acid, ethylene or propylene glycolacrylate or methacrylate phosphate, vinylpyrrolidone, methacrylamido propyi trimethyl ammonium chloride or sulphate, trimethyl ammonium ethyl chloride or sulphate methacrylate, as well as their acrylate or acrylamide counterparts, whether quatemised or not, ammonium dimethyldiallylchloride, and mixtures thereof.
7. A hydrosoluble transfer agent used in the process according to claim 1, wherein said agent is obtained in the polymerisation reactive medium, namely water.
8. The hydrosoluble transfer agent according to claim 7, wherein said agent is chosen from among the [alpha]-substitute [beta]-carboxylate xanthate salts.
9. A polymer ofacrylic acid and of its salts, obtained by the process according to claim 1, and wherein said polymer has an average molecular mass by weight (Mw) between 1000 g/mole and 60,000 g/mole, measured by the GPC method, using as a standard, 5 standards of sodium polyacrylate, and wherein said polymer has a polymolecularity index of less than, or equal to, 2, for a conversion rate, relative to acrylic acid, higher than 90%, determined according to an HPLC method.
10. The polymer ofacrylic acid and of its salts, according to claim 9, wherein said polymer has an average molecular mass by weight (Mw) of between 4500 g/mole and 8000 g/mole, measured by the GPC method, using as a standard, 5 standards of sodium polyacrylate, and wherein said polymer has a polymolecularity index of less than, or equal to, 2, for a conversion rate, relative to acrylicacid, higher than 90%, determined according to an HPLC method.
11. The polymer of acrylic acid and of its salts, according to claim 9, wherein said polymer is a homopolymer ofacrylic acid.
16

12. The polymer ofacryhc acid and of its salts, according to claim 9, wherein said polymer comprises monomeric units derived from at least one hydrosoluble copolymerised monomer selected from the group consisting ofmethacrylic acid, itaconic acid, maleic acid, 2-acrylamido-2-mefhy 1-1 -propane sulphonic acid in acid form or partially neutralised, 2-methacrylamido-2-methyl-l -propane sulphonic acid in acid form or partially neutralised, 3-methacrylamido-2-hydroxy-l-proparie sulphonic acid in acid form or partially neutralised, allylsulphonic acid, methallylsulphonic acid, allyloxybenzene sulphonic acid, methallyloxybenzene sulphonic acid, 2-hydroxy-3-(2-propenyloxy)propane sulphonic acid, 2-methyl-2-propene-l-sulphonic acid, ethylene sulphonic acid, propene sulphonic acid, 2-methyl sulphonic acid, styrene sulphonic acid, as well as all their salts, vinyl sulphonic acid, sodium methallylsulfonate, sulfopropyi acrylate or rnethacrylate, sulfomethylacrylamide, sulfomethylmethacryl amide, acrylamide, methylacrylamide, n-methylolacrylamide, n-acryloylmorpholine, ethylene glycol rnethacrylate, ethylene glycol acrylate, propylene glycol rnethacrylate, propylene glycol acrylate, propene phosphonic acid, ethylene or propylene glycol acrylate or rnethacrylate phosphate, vinylpyrrolidone, methacrylamido propyi trimethyl ammonium chloride or sulphate, trimethyl ammonium ethyl chloride or sulphate rnethacrylate, as well as their acrylate or acrylamide counterparts, whether quaternised or not, ammonium dimethyldiallyl chloride, and mixtures thereof.
13. The polymer ofacryhc acid and its salts, according to claim 9, wherein said polymer is in its acid form, or is totally or partially neutralised by one or more monovalent, divalent, trivalent neutralization agents, neutralisation agents of higher valency, or mixtures thereof.
14. The polymer ofacrylic acid and its salts, according to claim 13, wherein said polymer is partially or totally neutralised, and wherein the monovalent agents are selected from the group consisting of compounds containing alkaline cations, and compounds containing ammonium, or primary or secondary aliphatic and/or cyclic amines, and wherein the divalent, or trivalent neutralisation agents, or agents of higher valency, are selected from the group consisting of compounds containing divalent cations belonging to the alkaline earths, compounds containing trivalent cations, and compounds containing cations of higher valency.
15. The polymer ofacrylic acid and of its salts, according to claim 14, wherein said polymer is a homopolymer ofacrylic acid, which is totally neutralised by soda, or totally neutralised by a soda-lime mixture in a 50/50 molar ratio, or partially neutralised by a soda-lime mixture in a 50/40 molar ratio.
17

16. A composition, comprising the polymer according to claim 9, and one or more additives, and wherein the composition is selected from the group consisting of a composition for paper coating and mass-filling of paper, a composition for oil, a composition for paint, a composition for water treatment, a composition for detergency, a composition for ceramics, a composition for cements and/or hydraulic binders, a composition for public works, a composition for inks and/or varnishes, a composition for sizing of textiles and/or finishing of leather, and a composition for a dispersant and/or grinding aid agent of mineral materials.
17. An aqueous suspension, comprising the polymer according to claim 9 and one or more mineral fillers, and wherein me polymer is present in an amount from 0.05% to 5%, by dry weight, relative to the total dry weight of the one or more mineral fillers.
18. The aqueous suspension according to claim 17, wherein the one or more mineral fillers are selected from the group consisting of natural calcium carbonate, synthetic cafcium carbonate, dolomites, magnesium hydroxide, kaolin, talc, gypsum, titanium oxide, and aluminium hydroxide.
19. A manufactured and/or coated paper, comprising the aqueous suspension according to claim 17, and one or more paper additives.
20. A paint formulation, comprising the aqueous suspension according to claim 19, and one or more paint additives.
21. A method of coating or filling paper, comprising, contacting a composition, comprising the polymer of claim 9, with a paper substrate or one or more paper additives.
22. A method of treating mineral materials, comprising contacting a composition, comprising the polymer of claim 9, with one or more mineral materials.
Dated this 7th Day of January, 2005
HIRAL CHANDRAKANT JOSHI
AGENT FOR
COATEX S.A.S
18

Documents:

19-mumnp-2005-abstract(10-1-2005).pdf

19-mumnp-2005-abstract(granted)-(21-7-2006).pdf

19-mumnp-2005-cancelled page(25-11-2006).pdf

19-mumnp-2005-cancelled pages(25-4-2006).pdf

19-mumnp-2005-claim(granted)-(25-11-2006).pdf

19-mumnp-2005-claims(10-1-2005).pdf

19-mumnp-2005-claims(granted)-(21-7-2006).pdf

19-mumnp-2005-claims(granted)-(25-11-2006).doc

19-mumnp-2005-correspondence(12-5-2006).pdf

19-mumnp-2005-correspondence(ipo)-(13-10-2006).pdf

19-mumnp-2005-correspondence(ipo)-(21-7-2006).pdf

19-mumnp-2005-description(complete)-(10-1-2005).pdf

19-mumnp-2005-description(granted)-(21-7-2006).pdf

19-mumnp-2005-fo0rm 1(25-4-2006).pdf

19-mumnp-2005-form 1(25-4-2006).pdf

19-mumnp-2005-form 18(31-3-2005).pdf

19-mumnp-2005-form 2(complete)-(10-1-2005).pdf

19-mumnp-2005-form 2(granted)-(21-7-2006).pdf

19-mumnp-2005-form 2(granted)-(25-11-2006).doc

19-mumnp-2005-form 2(granted)-(25-11-2006).pdf

19-MUMNP-2005-FORM 2(TITLE PAGE)-(10-1-2005).pdf

19-mumnp-2005-form 2(title page)-(granted)-(21-7-2006).pdf

19-mumnp-2005-form 3(25-4-2006).pdf

19-mumnp-2005-form 3(7-1-2005).pdf

19-mumnp-2005-form 5(7-1-2005).pdf

19-mumnp-2005-form-pct-ipea-409(25-4-2006).pdf

19-mumnp-2005-form-pct-isa-210(31-3-2005).pdf

19-mumnp-2005-petition under rule 137(15-5-2006).pdf

19-mumnp-2005-power of attorney(30-7-2004).pdf

19-mumnp-2005-specification(amended)-(25-4-2006).pdf

19-mumnp-2005-wo international publication report(10-1-2005).pdf


Patent Number 202303
Indian Patent Application Number 19/MUMNP/2005
PG Journal Number 41/2008
Publication Date 10-Oct-2008
Grant Date 21-Jul-2006
Date of Filing 17-Jan-2005
Name of Patentee COATEX S. A. S.
Applicant Address FRENCH COMPANY, 35, RUE AMPERE, Z. I. LYON NORD, F - 69730 GENAY,
Inventors:
# Inventor's Name Inventor's Address
1 JEAN-BERNARD 17, IMPASSE DU MOULIN CARRON, F-69130 ECULLY,
2 SUAU, JEAN - MARC LE PERRAULT, F-69480 LUCENAY,
PCT International Classification Number N/A
PCT International Application Number N/A
PCT International Filing date 2003-07-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA