MXPA98005801A - Use of a copolymer as an active structure superficially as a dispersion agent and / or triturac - Google Patents

Abstract

The present invention relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, such as a dispersing agent or grinding aid for mineral substances in aqueous suspension, regardless of the nature of the substance miner

Description

USE OF A COPOLYMER WITH AN ACTIVE STRUCTURE SUPERFICIALLY AS AN AGENT OF DISPERSION AND / OR CRUSHING Field of the Invention The present invention relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, such as a dispersing agent or adjuvant for grinding or shredding mineral substances in an aqueous suspension, regardless of the nature of the mineral substance.

Background of the Invention It has already been common practice as a means of preparing industrial products for use in the paper industry, particularly as a filler or to coat paper, to compose aqueous suspensions of different mineral substances or mineral pigment fillers, whose particles have surfaces with different affinities towards water. The first category of mineral substances covers mineral substances with a charged hydrophilic surface such as calcium carbonates Ref .27917 synthetic or natural, for example, particularly chalks, calcites or marbles, dolomites or kaolins as well as calcium sulphate or titanium oxides, satin white, aluminum hydroxides and others. The second includes mineral fillers with a hydrophobic surface such as talc, mica and others, for example. These two types of mineral substances do not exhibit the same rheological behavior when placed in suspension in water, particularly when they are prepared in large concentrations for supplying paper mills. However, they exhibit the same quality criteria for the user, ie the Brookfield viscosity of the same must be such that there will be no risk of sedimentation or hardening of the particles of the sedimented mineral substances to ensure that they will be easy to be handled by the user even after storage in tanks for several days without agitation. In addition, these suspensions should have as high a content of mineral substances as possible to reduce all costs inherent in transportation due to the amount of water present. So far, dispersing agents or grinding aids used for mineral fillers with a hydrophilic surface are polyacrylates with a low molecular weight or with a specific viscosity less than or equal to 25 (EP 100 947, EP 542 643, EP 542 644). However, these agents have a disadvantage in that they are not very efficient when placed in hydrophobic substances of suspension and / or grinding, such as talc or mica, which are commonly used alone or mixed. The person skilled in the art is familiar with other agents which can be used for this purpose, these are copolymers in which one of the monomers has a surface active structure (EP 0 003 235, EP 0 215 565). These copolymers, however, have a disadvantage in that they are not efficient when they come to be placed in mineral substances of suspension and / or grinding with a hydrophilic surface such as calcium carbonates or kaolins, calcium sulfate or titanium oxides . Accordingly, so far, in order to disperse and / or grind a mineral substance with a hydrophobic surface, it has been extremely difficult for the skilled person to use a dispersing and / or grinding agent known for its dispersion efficiency and / or an adjuvant. to grind mineral substances with a hydrophilic surface and vice versa.

Facing this problem of the use of dispersing agents and / or an adjuvant for the specific grinding for a type of mineral substance and after a good achievement in the search, the applicant has found that by selecting the radical of the hydrophobic chain of the active monomer on the surface, it allows the copolymer to be used as a dispersing agent and / or crushing aid regardless of the nature of the surfaces of the mineral substances to be dispersed and / or ground. The purpose of the invention, therefore, is to obtain aqueous suspensions of mineral substances that are easy for the user to handle and regardless of the nature of the surfaces of the mineral substances. This objective is achieved by using as a dispersing agent and / or crushing aid, a copolymer which consists of: a) at least one monomer which is ethylenically unsaturated and has a carboxylic function b) optionally, at least one monomer which is ethylenically unsaturated and has a sulfonic or phosphoric function or a mixture thereof c) optionally, at least one monomer which is ethylenically unsaturated and has no carboxylic function d) at least one surface-active oxyalkylated monomer which is ethylenically unsaturated and ends with a hydrophobic chain.

The use, according to the invention, of a copolymer as a dispersing and / or grinding agent of the mineral substances in an aqueous suspension is characterized in that the copolymer consists of: a) at least one ethylenically unsaturated monomer having a carboxylic function, which must be selected from monoacids such as acrylic, methacrylic, crotonic, isocrotonic or cinnamic acid, to which diacids such as itaconic, fumaric, maleic or citraconic acid or alternatively the anhydrides of carboxylic acids such as maleic anhydride and hemi-esters of diacids such as monoesters of 1 to 4 carbon atoms, of maleic or itaconic acids or mixtures thereof. same, b) optionally, at least one ethylenically unsaturated monomer having a sulfonic function, selected from acrylamido-methyl-propane-sulfonic acid, sodium methallylsulfonate, vinyl sulfonic acid and styrene sulfonic acid, or having a phosphoric function selected from the ethylene glycol methacrylate phosphate, ethylene glycol methacrylate phosphate, ethylene glycol acrylate phosphate, propylene glycol acrylate phosphate and their ethoxylates or mixtures thereof, c) optionally, at least one ethylenically unsaturated monomer having no carboxylic function, selected from the group comprising the esters of acrylic or methacrylic acids such as the methyl, ethyl, butyl, 2-ethylhexyl, or acrylonitrile acrylates or methacrylates, methacrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactam, or alternatively unsaturated amides such as acrylamide, methacrylamide or its substituted derivatives such as, for example, dimethylaminopropyl acrylamide or methacrylamide, acrylic or methacrylic esters of flicol, chloride or methacrylamido-propyltrimethylammonium sulfate, sulfate or ethyl chloride / trimethylammonium methacrylate as well as their acrylate and quaternized acrylamide and / or dimethyldiallylammonium chloride counterparts, d) at least one ethylenically unsaturated oxyalkylated monomer ending with a hydrophobic chain having the general formula (I): í 1 R L (CH2_CH_0) m (_CH2_CH2_0) n (_CH2_CH_0) p | , ^ _ R 'L I I J in which: m and p represent a number of alkylene oxide units less than or equal to 100, n represents a number of ethylene oxide units less than or equal to 100, - q is a number at least equal to 1 and such that: 0 < q (n + m + p) < 100 Ri is hydrogen or the methyl or ethyl radical, R2 is hydrogen or the methyl or ethyl radical.

R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic, vinylphthalic esters as well as unsaturated urethanes such as, for example, acryl urethane, methacrylurethane, aa'dimethyl-m-isopropenyl-benzylurethane, allyl urethane . R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having at least 8 15 carbon atoms or dialkylamines having at least 8 carbon atoms when R represents a unsaturated radical which belongs to the group of unsaturated urethanes and R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having more than 30 carbon atoms or the dialkylamines which have at least 22 carbon atoms when R represents the unsaturated radicals polymerizable that belong to the group of acrylic, methacrylic, maleic, itaconic, crotonic or vinylphthalic esters the total constituents of (a), (b), (c) and (d) is equal to 100 and in that it has a viscosity at most equal to 50 and preferably at most equal to 25. In the whole following description , the monomer (d) is the special monomer. More specifically, the use of the aforementioned copolymer is characterized in that the copolymer is composed as follows, expressed by weight: a) from 99 to 10% and even more particularly for reasons inherent in the copolymerization process from 97% to 50% of at least one ethylenically unsaturated monomer having a carboxylic function, which must be selected from monoacids such as acrylic, methacrylic, crotonic, isocrotonic, cinnamic acid, to which diacids may be optionally added such as itaconic, fumaric, maleic, citraconic acid, or carboxylic acid anhydrides such as maleic anhydride and diacid hemi-esters such as the monoesters with 1 to 4 carbon atoms, of maleic or itaconic acids or mixtures thereof, b) from 0 to 50% of at least one ethylenically unsaturated monomer having a sulfonic function selected from acrylamido-methyl-propan-sulphonic acid, sodium methallylsulfonate, vinyl sulfonic acid and styrene sulfonic acid, or having a phosphoric function selected from the ethylene glycol methacrylate phosphate, the propylene glycol methacrylate phosphate, the ethylene glycol acrylate phosphate, the propylene glycol acrylate phosphate and its ethoxylates or mixtures thereof, c) from 0% to 50% of at least one ethylenically unsaturated monomer having no carboxylic function, selected from the group comprising esters of acrylic or methacrylic acid such as the acrylates or methacrylates of methyl, ethyl, butyl, 2-ethyl- hexyl or acrylonitrile, methacrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactam, or unsaturated amides such as acrylamide, methacrylamide or their substituted derivatives such as acrylamide or dimethylaminopropyl methacrylamide, acrylic or methacrylic esters of methacrylamido-propyltrimethylammonium glycol, chloride or sulfate, trimethyl ammonium-ethyl chloride or sulfate methacrylate as well as their quaternized acrylate and acrylamide and / or sodium chloride counterparts dimethyldiallylammonium, d) from 1% to 90% and even more particularly for reasons relating to the copolymerization process of 3% to 50% of at least one ethylenically unsaturated oxyalkylated monomer ending with a hydrophobic chain of the general formula (I): r i R l_ (CH2_CH_0) m (_CH2_CH2_0) n (_CH2_CH_0) p | q_R 'L I 1 - J in which: m and p represent a number of alkylene oxide units less than or equal to 100, n represents a number of ethylene oxide units less than or equal to 100, q is a number at least equal to 1 and such that: 0 < q (n + m + p) < 100 Ri is hydrogen or the methyl or ethyl radical, R2 is hydrogen or the methyl or ethyl radical.

R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic, vinylphthalic esters as well as the unsaturated urethanes such as, for example, the acryl urethane, methacryl urethane, a-a 'dimethyl-m-isopropenyl-benzylurethane, allyl urethane.

R 'represents the hydrophobic radical such as tristyrylphenyl as well as the groups of Linear or branched alkyl, alkylaryl, arylalkyl, aryl having at least 8 carbon atoms or dialkylamines having at least 8 carbon atoms when R represents an unsaturated radical belonging to the group of unsaturated urethanes and R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having more than 30 carbon atoms or dialkylamines having at least 22 carbon atoms when R represents the unsaturated radicals polymerizable that belong to the group of acrylic, methacrylic, maleic, itaconic, crotonic or vinylphthalic esters the total constituents of (a), (b), (c) and (d) is equal to 100 and in that it has a viscosity at most equal to 50 and preferably at most equal to 25.

The copolymer used for the purposes of the invention is obtained by known methods of radical copolymerization in solution, direct or reverse emulsion, suspension or precipitation in appropriate solvents in the presence of known catalyst systems and transfer agents. This copolymer obtained in the acidic and possibly distilled form, can be neutralized partially or totally by one or more neutralization agents that they have a monovalent function or a polyvalent function such as, for example, those selected from the group comprising the alkali cations, in particular sodium, potassium, ammonium or the primary, secondary or tertiary aliphatic and / or cyclic amines such as, for example , stearylamine, ethanolamines (mono-, di-triethanolamine), mono- and diethyl amine, cyclohexylamine, methylcyclohexylamine or those selected from the group consisting of divalent alkaline earth cations, in particular magnesium or calcium or alternatively zinc, as well as trivalent cations, including in particular aluminum, or alternatively certain cations with a higher valence. Each neutralization agent is used in an amount suitable for the rates of neutralization appropriate to each function of the valence. In another variant, the copolymer produced by the copolymerization reaction can be treated and separated into several phases, either before or after the partial or total neutralization reaction, using static or dynamic processes familiar to those skilled in the art, by one or more polar solvents which belong in particular to the group comprising water, methanol, ethanol, propanol, isopropanol, the butanols, acetone, tetrahydrofuran or mixtures thereof. One of the phases then corresponds to the copolymer used for the purposes of the invention as a dispersing agent and / or grinding agent for the mineral substances in aqueous suspension. The specific viscosity of the copolymer is symbolized by the letter "?" and it is determined as follows: A polymer solution is made until a solution corresponding to 2.5 g of the dry polymer neutralized with soda and 50 ml of a bi-mutated aqueous solution is obtained. Using a capillary viscometer with a Baume constant equal to 0.000105 placed in a thermostatically controlled bath at 25 ° C, a measurement is taken from the flow time of a given volume of the solution mentioned above containing the polymer as well as the flow time of the same solution of the bi-permuted water without said copolymer. Then it will be possible to define the specific viscosity "?" by means of the following equation: (Flow time of flow of polymer solution) permuted aqueous solution) "?" = flow time of the permuted aqueous solution The capillary tube is generally selected so that the flow time of the permuted aqueous solution without the copolymer is from about 90 to 100 seconds, thereby giving highly accurate specific viscosity readings. A practical form of dispersion or placement of the mineral substances that are to be dispersed in suspension is to prepare an aqueous suspension of the dispersing agent under agitation, to which the mineral substances or substances to be dispersed are added., which can be of very diverse origins that fall into two categories. The first category is composed of mineral substances with a charged hydrophilic surface such as natural or synthetic calcium carbonates, for example chalks, calcites, marbles or dolomites or kaolins, calcium sulphate, titanium or satin white oxides or hydroxides of aluminum or any other mineral with a hydrophilic surface.

The second includes mineral fillers with a hydrophobic surface such as talc, mica and other minerals with a hydrophobic surface. Similarly, in practice, the grinding operation of the substance or mineral substances to be refined consists in grinding the mineral substance or substances with a grinding medium in very fine particles in an aqueous medium containing the agent of grinding The grinding medium added to the suspension of the substance or mineral substances that are to be comminuted advantageously has a grain size of between 0.20 and 4 millimeters. The grinding medium is generally present in the form of particles of substances as diverse as silicon oxide, aluminum oxide, zirconium oxide or mixtures thereof as well as very hard synthetic resins, steels or others. An example of a composition for such a grinding medium is given in patent FR 2 303 681 which describes a grinding medium composed of up to 30 to 70% by weight of zirconium oxide, 0.1 to 5% of aluminum oxide and from 5 to 20 5 of the silicon oxide. Preferably, the grinding medium is added to the suspension in an amount such that the weight ratio of this grinding media with With respect to the mineral substance to be crushed is at least 2/1, this ratio is preferably within the ranges of 3/1 and 5/1. The mixture of the suspension and the grinding medium is then subjected to mechanical agitation, such as that produced in a conventional crusher with microelements. According to the invention, the dispersing agent and / or the grinding aid is also introduced into the mixture comprising the aqueous suspension of mineral substances and the grinding medium in an amount of 0.05% to 5% by weight of the fraction dry of the polymers in relation to the dry weight of the substance or mineral substances that are going to be refined. The time necessary to produce an excellent fineness of the mineral substances after grinding will depend on the nature and amount of the mineral substances to be ground as well as the method of agitation used and the ambient temperature during the grinding operation. The scale of importance of the invention will be more readily appreciated from the following examples, which are given by way of illustration only: EXAMPLE 1: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, for the preparation of aqueous suspensions of calcium carbonate. For this purpose, for each of the following tests, carried out on a marble from the Gummern deposit (Austria) in which the grain size is such that 90% of the particles are of a diameter smaller than 2 micrometers, an amount of Marble necessary to obtain a suspension with a concentration of 65% of the dry substance is added, pouring it and with agitation, into a two-liter laboratory beaker containing water. This laboratory vessel also contains an amount of the copolymer to be tested, which corresponds to 0.5% by weight of the dry copolymer in relation to the total weight of the dry substance present in the suspension. After 20 minutes of agitation, the Brookfield viscosities are measured at room temperature using a Brookfield viscometer of the RVT type at 10 revolutions per minute (r / min.) And 100 r / min. using the appropriate spindle.

Test No. 1: This test, which illustrates the prior art, uses a sodium polyacrylate with a specific viscosity of 0.45.

Test No 2 : This test, which illustrates the prior art, uses a mixture consisting of 25 parts by weight of a sodium polyacrylate with a specific viscosity of 0.45 and 75 parts by weight of an alkylene polyoxide marketed under the name of Pluronic PE 4300 by BASF .

Test No. 3: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 4: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 4.38 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 40 moles of ethylene oxide.

Test No. 5: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 4.43 and composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 60 moles of ethylene oxide.

Test No. 6: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 2.54 and composed, in percent by weight, of: 95% acrylic acid 5% of methacrylurethane of general formula (I) in which the hydrophobic radical R 'is a linear alkyl group with 22 carbon atoms, m and p are equal to zero, q = 1 and n equals 25.

Test No. 7: This test, which illustrates the invention, uses a 100% polymer neutralized by soda having a specific viscosity of 1.52 and compound, in weight percentage, of: 95% acrylic acid 5% methacrylate of the general formula (I) in which the hydrophobic radical R 'is a group -N- (R "R' '') wherein R "and R '' 'are linear alkyl chains with 12 carbon atoms, m and p are equal to 0, q = l and n equals 50.

Test No. 8: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 2.47 and composed, in percent by weight, of: 95% acrylic acid % methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is a branched alkyl group with 28 carbon atoms, m and p are equal to 0, q = l and n equals 25.

Test No. 9: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 1.79 and composed, in percent by weight, of: 95% acrylic acid 5% methacryl urethane of the general formula (I) in wherein the hydrophobic radical R 'is a branched alkyl group with 30 carbon atoms, m and p are equal to 0, q = lyn equals 25.

Test No. 10: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 2.59 and composed, in weight percentage, of: 90% acrylic acid 10% methacrylate of the general formula (I) in which the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, m and p are equal to 0, q = l and n equals 25.

Test No. 11: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 5.49 and compound, in weight percentage, of: 80% acrylic acid 2% ethyl acrylate 8% methacrylic acid 10 % methacrylurethane of the general phormula (I) in which the hydrophobic radical R 'is a tristyrylphenyl radical, m and p are equal to 0, q = lyn is equal to 25.

Test No. 12: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 3.02 and compound, in weight percentage, of: 97% acrylic acid 3% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 13: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 3.94 and compound, in weight percentage, of: 93% acrylic acid 7% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 14: This test, illustrating the invention, uses a polymer 100% neutralized by soda having a specific viscosity of 3.74 and made up, by percentage weight, of: 85% acrylic acid d 15%, and methacrylate tristyryl phenol ethoxylate with 25 moles of ethylene oxide.

Test No. 15: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 7.53 and compound, in weight percentage, of: 85% acrylic acid 5% methacrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 16: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 5.58 and compound, in weight percentage, of: 85% acrylic acid 5% itaconic acid 10% tristyryl phenol methacrylate Ethoxylated with 25 moles of ethylene oxide.

Test No. 17: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 7.16 and compound, in weight percentage, of: 85% acrylic acid 5% maleic acid 10% tristyryl methacrylate phenol Ethoxylated with 25 moles of ethylene oxide.

Test No. 18: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 6.68 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamido-methyl-propan-sulfonic acid 10 % tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 19: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol ethoxylated methacrylate with 25 moles of ethylene oxide.

Test No. 20: This test, which illustrates the invention, uses a 100% polymer neutralized with soda that has a specific viscosity of 5.71 and compound, in percentage by weight, of: 85% acrylic acid 5% phosphate of ethylene glycol methacrylate 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 21: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 5.49 and compound, in weight percentage, of: 80% acrylic acid 2% ethyl acrylate 8% methacrylic acid 10 % methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is a tristyrylphenyl radical, m and p are equal to 0, q = lyn is equal to 25.

Test No. 22: This test, which illustrates the invention, uses a 100% polymer neutralized with soda that has a specific viscosity of 0.67 and compound, in percentage by weight, of: 95% acrylic acid 5% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 23: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 1.94 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 24: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 2.66 and composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 25: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 12.04 and composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 26: This test, which illustrates the invention, uses a 70% polymer neutralized with soda having a specific viscosity of 4.35 and composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

The results of all these experiments are shown in Table 1, which is given below.

TABLE 1 Table 1 highlights the fact that by applying the invention, aqueous suspensions of calcium carbonate with low Brookfield viscosities are obtained. It is also obvious from the reading of the table that using a polyacrylate in conjunction with an alkylene polyoxide, a formula commonly used to place mineral substances with a hydrophobic surface in suspension, does not produce suspensions of calcium carbonate with a low Brookfield viscosity.

EXAMPLE 2 This example illustrates the invention and relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, for the preparation of an aqueous suspension of calcium carbonate with a calcium content of the dry substance of the same to 45%. For this purpose, for the purposes of the test No. 27 which is given subsequently, carried out using a marble from the Gummern deposit (Austria) in which the grain size is such that 90% of the particles are of a diameter of less than 2 microns, a quantity of the marble needed to obtain a suspension with a concentration of 45% of the substance dry is added, pouring it and with agitation, into a two-liter laboratory beaker containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 0.23% by weight of the dry copolymer in relation to the total weight of the dry substance present in the suspension. The copolymer used is a 75% neutralized polymer by soda and the product of a fractionation process, having a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate Ethoxylated with 25 moles of ethylene oxide. After 20 minutes of agitation, the Brookfield viscosities are measured at room temperature using a Brookfield viscometer of the RVT type at 10 revolutions per minute (r / min) and 100 r / min using the appropriate spindle. These viscosities are respectively 790 mPa.s and 100 mPa.s.

EXAMPLE 3 This example also relates to the use of a polymer, in which at least one of the monomers has a surface active structure, to prepare the aqueous suspensions of calcium carbonate but with a coarser grain size. For this purpose, for each of the following tests carried out on marble from a Norwegian reservoir in which the grain size is such that 60% of the particles are of a diameter less than 2 microns, a quantity of the marble necessary to obtain a suspension with a concentration of 75% of the dry substance is added, pouring it and under agitation, into a two-liter laboratory beaker containing water. This laboratory beaker also contains an amount of the copolymer to be tested, which corresponds to 0.5% by weight of the dry copolymer in relation to the total weight of the dry substance present in the suspension. After 20 minutes of agitation, the Brookfield (TO) vicosities are measured at room temperature, using a Brookfield viscometer of the DVII type at 100 r / min. Using the appropriate spindle. The Brookfield viscosities are also determined after 24 hours, 2 days, 3 days and one week of storage without agitation. Once a Brookfield viscosity reading has been taken before agitation (AVAG viscosity) after 7 days of storage, the sample is stirred to find Brookfield viscosity after agitation (viscosity APAG). In addition, these samples were diluted to 72% and stored for 7 days to verify if there was any sedimentation by inserting a spatula down to the base of the container.

Test No. 28: This test, which illustrates the prior art, uses a sodium polyacrylate with a specific viscosity of 0.45.

Test No. 29: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 1.94 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 30: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 3.02 and compound, in weight percentage, of: 97% acrylic acid 3% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.e.

Test No. 31: This test, which illustrates the invention, uses a 100% polymer neutralized with soda having a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% maleic acid 10% tristyryl phenol methacrylate Ethoxylated with 25 moles of ethylene oxide.

Test No. 32: This test, which illustrates the invention, uses a 100% polymer neutralized with soda that has a specific viscosity of 5.49 and compound, in weight percentage, of: 80% acrylic acid * 2% ethyl acrylate 8% methacrylic acid 10% methacrylurethane, of the general formula (I), in which the hydrophobic radical R 'is a tristyrylphenyl radical, m and p are equal to 0, q = lyn equals 25.

The results of all these tests are described in Table 2 below. or - TABLE 2 - Ul oa The table highlights the fact that aqueous suspensions of calcium carbonate can be obtained, which have low Brookfield viscosities, are stable over time and do not exhibit any tendency to sedimentation despite the fact that the size of the grain of the constituent particles is not so fine.

Example 4: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare aqueous suspensions of talc. For this purpose and using the same method of operation except that the agitation duration is 45 minutes and using the same equipment as that used in Example 1, talc, Finntalc CIO sold by Finnminerals, is mixed with an amount of water necessary for producing a suspension with a 65% concentration of the dry substance and a quantity of fully neutralized polymer to be tested corresponding to 2.0% by dry weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

Test No. 33: This test, which illustrates the prior art, uses a sodium polyacrylate with a specific viscosity of 0.45. It can not be placed in suspension due to the fact that the agitator becomes blocked due to a too high viscosity.

Test No. 34: This test, which illustrates the prior art, uses a mixture consisting of 25 parts by weight of a sodium polyacrylate having a specific viscosity of 0.45 and 75 parts by weight of an alkylene polyoxide marketed under the name of Pluronic PE 4300 by BASF.

Test No. 35: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 7.5 and is composed, in weight percentage, of: 90% acrylic acid % tristyryl phenol methacrylate ethoxylated with 16 moles of ethylene oxide.

Test No. 36: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.0 and is composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 8 moles of ethylene oxide and oxypropyl with 13 moles of ethylene oxide.

Test No. 37: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.35 and is composed, in percent by weight, of: 90% acid Acrylic 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 38: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.38 and is composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 40 moles of ethylene oxide.

Test No. 39: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.43 and is composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 60 moles of ethylene oxide.

Test No. 40: This test, which illustrates the invention, uses a polymer which, after being neutralized 100% with soda, it is a polymer having a specific viscosity of 2.59 and is composed, in percent by weight, of: 90% acrylic acid 10% methacrylate of the general formula (I) in which the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, myp equals 0, q = lyn equals 25.

Test No. 41: This test, which illustrates the invention, uses a polymer which, after being neutralized to 100% conoseous, is a polymer having a specific viscosity of 5.49 and is composed, in weight percentage, of: 80% acid acrylic 2% ethyl acrylate 8% methacrylic acid 10% methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is a tristyrylphenyl radical, m and p are equal to 0, q = lyn is equal to 25 .

Test No. 42: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 3.02 and is composed, in percent by weight, of: 97% acrylic acid 3% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 43: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 3.31 and is composed, in weight percentage, of: 95% acrylic acid 5% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 44: This test, which illustrates the invention, uses a polymer which, after being neutralized 100% with soda, it is a polymer having a specific viscosity of 3.94 and is composed, in percent by weight, of: 93% acrylic acid 7% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 45: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 3.74 and is composed, in weight percentage, of: 85% acrylic acid 15% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 46: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 7.53 and is composed, in weight percentage, of: 85% acrylic acid % methacrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 47: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 5.58 and is composed, in percent by weight, of: 85% acrylic acid 5% itaconic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 48: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 7.16 and is composed, in percent by weight, of: 85% acrylic acid 5% maleic acid % tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 49: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 6.68 and is composed, in weight percentage, of: 85% acrylic acid 5% acrylamido-methyl-propan-sulphonic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 50; This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.38 and is composed, in percent by weight, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 51: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 5.71 and is composed, in weight percentage, of: 85% acrylic acid 5% ethylene glycol methacrylate phosphate 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 52: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 5.49 and is composed, in weight percentage, of: 80% acrylic acid 2% ethyl acrylate 8% methacrylic acid 10% methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is a tristyrylphenyl radical, m and p are equal to 0, q = lyn = 25.

Test No. 53: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 1.94 and is composed, in weight percentage, of: 90% acrylic acid 10% ethoxylated tristyryl phenol methacrylate with 25 moles of ethylene oxide.

Test No. 54: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 2.66 and is composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 55: This test, which illustrates the invention, uses a polymer which, after being neutralized 100% with soda, it is a polymer having a specific viscosity of 3.38 and is composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 56: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 12.04 and is composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 57: This test, which illustrates the invention, uses a neutralized polymer, in molar percentage, 75% with soda and 25% with lime, which has a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acid acrylic % tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 58: This test, which illustrates the invention, uses a neutralized polymer, in molar percentage, 50% with soda and 50% with lime, which has a specific viscosity of 4.35 and compound, in percentage by weight, of: 90% acid Acrylic 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 59: This test, which illustrates the invention, uses a neutralized polymer, in molar percentage, 25% with soda and 75% with lime, which has a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acid Acrylic 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 60: This test, which illustrates the invention, uses a neutralized polymer, in molar percentage, 75% with soda and 25% with lime, which has a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acid Acrylic 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 61: This test, which illustrates the invention, uses a polymer 100% neutralized with potash, having a specific viscosity of 4.35 and composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25% strength. moles of ethylene oxide.

Test No. 62: This test, which illustrates the invention, uses a polymer 100% neutralized with ammonia, which has a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

The results of all the tests are described in Tables 3.1 and 3.2 given below.

- TABLE 3.1 - - TABLE 3.2 - Tables 3.1 and 3.2 enhance the fact that aqueous talc suspensions can be produced by the invention, which have Brield viscosities at an elevated concentration of the dry substance. The Tables also show that the use of a polyacrylate commonly used to place mineral substances with a hydrophilic substance in Suspension will not allow talc suspensions of a low Brield viscosity to be produced.

EXAMPLE 5: As with the preceding example, this example relates to the use of a copolymer in which at least one of the monomers has a surface active structure for preparing aqueous suspensions of talc but in a different amount. For this purpose and using the same operating method and the same equipment as those used in the preceding example, the Finntal CIO sold by Finnminerals is mixed with an amount of water necessary to produce a suspension with a concentration of 65% of the dry substance and an amount of the copolymer to be tested corresponding to 1.0% by dry weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

Test No. 63: This test, which illustrates the prior art, uses a sodium polyacrylate with a specific viscosity of 0.45. It could not be suspension since the agitator became blocked due to too high a viscosity.

Test No. 64: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 24 and is composed, in weight percentage, of: 85% acrylic acid 15% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 65: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 19 and is composed, in weight percentage, of: 80% acrylic acid 20% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide and oxypropyl with 13 moles of propylene oxide Test No. 66: This test, which illustrates the invention, uses a polymer compound, in percentage by weight, of: 70% acrylic acid 30% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 67: This test, which illustrates the invention, uses a polymer compound, in percentage by weight, of: 60% acrylic acid 40% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 68: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 4.47 and is composed, in percent by weight, of: 50% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide 40% acrylamido-2-methyl-2-propan sulfonic acid.

Test No. 69: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 3.0 and is composed, in percent by weight, of: 50% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide 40% of ethylene glycol methacrylate phosphate.

Test No. 70: This test, which illustrates the invention, uses a polymer which, after being 100% neutralized with soda, is a polymer having a specific viscosity of 3.67 and is composed, in percent by weight, of: 40% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide 50% acrylamide.

The results of all the tests are described in Table 4 given below: - TABLE 4 - Table 4 enhances the effect that the invention is capable of producing aqueous suspensions of talc with low Brookfield viscosities at an elevated concentration of the dry substance. It is also shown that using polyacrylate such as is commonly used to place or suspend mineral substances With a hydrophilic surface, it will not produce talc suspensions with a low Brookfield viscosity.

EXAMPLE 6: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare aqueous suspensions of mica. For this purpose, using the same operating method and the same equipment as those used in example 1, the mica, sold under the name of Ascoat 30 by Jungbunzlauer GmbH, is mixed with an amount of water necessary to obtain a suspension with a concentration 68% of the dry substance and an amount of the copolymer to be tested corresponding to 0.6% by dry weight of the dry copolymer in relation to the total weight of the dry substance present in the suspension.

Test No. 71: This test, which illustrates the prior art, uses a 100% neutralized copolymer with soda, which has a specific viscosity of 4.7 and composed, in percent by weight, of 90% acrylic acid and 10% methacrylate of ethoxylated lauryl alcohol with 23 moles of ethylene oxide.

Test No. 72: This test, which illustrates the prior art, uses a 100% neutralized copolymer with soda having a specific viscosity of 4.66 and is composed, in weight percentage, of 90% acrylic acid and 10% nonyl phenol methacrylate ethoxylated with 30 moles of ethylene oxide.

Test No. 73: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 4.0 and composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 8 moles of ethylene oxide and oxypropyl ether with 13 moles of propylene oxide.

Test No. 74: This test, which illustrates the invention, uses a 100% neutralized polymer with soda, having a specific viscosity of 4.35 and composed, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25% by weight. moles of ethylene oxide.

Test No. 75: This test, illustrating the invention, uses a 100% neutralized polymer with soda, having a specific viscosity of 4.38 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 40% by weight. moles of ethylene oxide.

Test No. 76: This test, which illustrates the invention, uses a 100% neutralized polymer with soda, having a specific viscosity of 4.43 and composed, in percent by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 60 moles of ethylene oxide.

Test No. 77: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 2.54 and composed, in weight percentage, of: 95% acrylic acid 5% methacrylurethane of the general formula (I ) in which the hydrophobic radical R 'is a linear alkyl group with 22 carbon atoms, m and p are equal to 0, q = lyn = 25.

Test No. 78: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 1.52 and compound, in weight percentage, of: 95% acrylic acid 5% methacrylate of the general formula (I ) in which the hydrophobic radical R 'is a group -N- (R "R' '') wherein R "and R '' 'are linear alkyl chains with 12 carbon atoms, m and p are equal to 0, q = 2 and n = 25.

Test No. 79: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 2.47 and compound, in weight percentage, of: 95% acrylic acid 5% methacrylate of the general formula (I ) in which the hydrophobic radical R 'is a branched alkyl group with 28 carbon atoms, m and p are equal to 0, q = lyn = 25.

Test No. 80: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 1.79 and compound, in weight percentage, of: 95% acrylic acid 5% methacrylurethane of the general formula (I ) in which the hydrophobic radical R 'is a branched alkyl group with 30 carbon atoms, m and p are equal to 0, q = lyn = 25.

Test No. 81: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 2.59 and composed, in weight percentage, of: 90% acrylic acid 10% methacrylate of general formula (I) wherein the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, m and p are equal to 0, q = l, and n = 25.

Test No. 82: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 3.02 and compound, in weight percentage, of: 97% acrylic acid 3% tristyryl phenol methacrylate ethoxylated with 25% by weight. moles of ethylene oxide.

Test No. 83: This test, which illustrates the invention, uses a 100% neutralized polymer with soda, which has a specific viscosity of 3.94 and compound, in weight percentage, of: 93% acrylic acid 7% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

Test No. 84: This test, which illustrates the invention, uses a 100% neutralized polymer with soda, having a specific viscosity of 3.74 and compound, in weight percentage, of: 85% acrylic acid 15% tristyryl phenol methacrylate ethoxylated with 25% by weight. moles of ethylene oxide.

Test No. 85: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl methacrylate phenol ethoxylated with 25 moles of ethylene oxide.

Test No. 86: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 0.67 and compound, in weight percentage, of: 95% acrylic acid 5% tristyryl phenol methacrylate ethoxylated with 25% by weight. moles of ethylene oxide.

Test No. 87: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 1.94 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25% by weight. moles of ethylene oxide.

Test No. 88 This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 2.66 and compound, in weight percentage, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide.

All the test results are described in table 5 given below: - TABLE 5 - Table 5 enhances the effect that the invention can be used to obtain aqueous suspensions of mica with low Brookfield viscosities at high concentration of the dry substance. The table also shows that aqueous suspensions of mica with a low Brookfield viscosity can not be obtained using a prior art copolymer.

EXAMPLE 7: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare aqueous suspensions of kaolin. For this purpose and using the same operating method and the same equipment as those used in the previous example, kaolin, sold under the name of SPS by ECC, is mixed with an amount of water necessary to produce a suspension with a concentration of 66%. % of the dry substance and an amount of the copolymer to be tested which corresponds to 0.52% by dry weight of the dry acid copolymer in relation to the total weight of the dry substance present in the suspension.

Test No. 89: This test, which illustrates the prior art, uses a sodium polyacrylate with a specific viscosity of 0.45.

Test No. 90: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 0.40 and compound, in weight percentage, of: 95% acrylic acid 5% tristyryl phenol methacrylate ethoxylated with moles of ethylene oxide.

Test No. 91: This test, which illustrates the invention, uses a polymer 100% neutralized with soda, having a specific viscosity of 0.42 and compound, in weight percentage, of: 95% acrylic acid 5% methacrylate of the general formula (I ) in which the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, m and p are equal to 0, q = l and n = 25. The results of the tests are described in table 6 given below: - TABLE 6 - Table 6 enhances the fact that the invention can be used to produce aqueous suspensions of kaolin with low Brookfield viscosities at a high concentration of the dry substance.

EXAMPLE 8: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare aqueous suspensions of the mixtures of mineral substances regardless of whether they have a hydrophilic or hydrophobic surface.

Test No. 92: This test illustrates the invention and consists in the parallel preparation of an aqueous suspension of calcium carbonate and an aqueous suspension of kaolin, then forming a mixture of equal weight of the dry substance of the two aqueous suspensions produced. For this purpose, using a marble from a Norwegian tank in which the grain size is such that 60% of the particles are less than 2 micrometers in diameter, an aqueous suspension of calcium carbonate is introduced, by pouring and under stirring, a quantity of the marble necessary to make up a suspension with a concentration of 70% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 0.5% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after 100% neutralization with soda, it is a polymer with a specific viscosity of 4.35 and composed, in percentage by weight, of: 90% acrylic acid 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of kaolin (sold under the name of SPS by ECC) is prepared simultaneously, which has a concentration of 63% of the dry substance and a content of copolymer that is going to be tested 0.5% by weight of the dry acid in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 714.3 grams of the first and about 793.7 grams of the other, to produce an aqueous suspension which is 50% by dry weight of the carbonate. of calcium and 50% dry weight of kaolin. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle.

The Brookfield viscosity measured is 1900 mPa.s. The aqueous suspension obtained according to the invention is therefore a mixed suspension (50% / 50% dry weight) of calcium carbonate and kaolin, which is easy to handle at a high concentration of the dry substance (66.3%).

Test No. 93: This test illustrates the invention and consists of the parallel preparation of an aqueous suspension of calcium carbonate and an aqueous suspension of kaolin, then form a mixture to produce a suspension of 70% by dry weight of calcium carbonate and 30% by dry weight of kaolin. For this purpose, using a marble from a Norwegian tank in which the grain size is such that 60% of the particles are less than 2 micrometers in diameter, an aqueous suspension of calcium carbonate is introduced, by pouring and under stirring, a quantity of the marble necessary to make up a suspension with a concentration of 70% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 0.5% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acrylic acid 10% methacrylate of tristyryl phenol ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of kaolin (sold under the name of SPS by ECC) is prepared simultaneously, which has a concentration of 63% of the dry substance and a content of copolymer that is going to be tested 0.5% by weight of the dry acid in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 1000 grams of the first and about 476.2 grams of the other, to produce an aqueous suspension which is 70% by dry weight of the carbonate. of calcium and 30% dry weight of kaolin. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 1100 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (70% / 30% by dry weight) of calcium carbonate and kaolin, which is easy to handle at an elevated concentration of the dry substance (67.7%).

Test No. 94: This test illustrates the invention and consists in the parallel preparation of an aqueous suspension of kaolin and an aqueous suspension of mica, then forming a mixture to obtain a suspension of 50% by dry weight of kaolin and 50% by dry weight of mica. For this purpose, an aqueous suspension of kaolin is prepared by introducing, by pouring and under stirring, an amount of kaolin (sold under the name of SPS by ECC) necessary to compose a suspension with a concentration of 65.1% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 2.54 and composed, in weight percentage, of: 95% acrylic acid 5% methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is an alkyl group linear with 22 carbon atoms, myp equals 0, q = lyn = 25. In the same way and using the same equipment, an aqueous suspension of mica (sold under the name Ascoat 30 by Jungbunzlauer GmbH) is prepared simultaneously, having a concentration of 67.4% of the dry substance and a content of copolymer to be tested of 0.6% dry weight relative to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them in a laboratory beaker, 760 grams of the first and about 742 grams of the other, to produce an aqueous suspension which is 50% by dry weight of the kaolin and 50% dry weight of the mica. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 732 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (50% / 50% by dry weight) of kaolin and mica, which is easy to handle at a high concentration of the dry substance (66.2%).

Test No. 95: This test illustrates the invention and consists in the parallel preparation of an aqueous suspension of kaolin and an aqueous suspension of mica., then form a mixture to obtain a suspension of 75% by dry weight of kaolin and 25% by dry weight of the mica. For this purpose, an aqueous suspension of kaolin is prepared by introducing, by pouring and stirring, an amount of kaolin (marketed under the name of SPS by ECC), necessary to compose a suspension with a concentration of 65.1% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory vessel also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 2.54 and composed, in weight percentage, of: 95% acrylic acid 5% methacrylurethane of the general formula (I) in which the hydrophobic radical R 'is an alkyl group linear with 22 carbon atoms, myp equals 0, q = lyn = 25. In the same way and using the same equipment, an aqueous suspension of mica (sold under the name Ascoat 30 by Jungbunzlauer GmbH) is prepared simultaneously, which it has a concentration of 67.4% of the dry substance and a content of copolymer to be tested of 0.6% by dry weight in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 1152 grams of the first and about 371 grams of the other, to produce an aqueous suspension which is 75% by dry weight of the kaolin and 25% dry weight of the mica. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 1380 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (75% / 25% dry weight) of kaolin and mica, which is easy to handle at a high concentration of the dry substance (65.6%).

Test No. 96: This test illustrates the invention and consists in the parallel preparation of an aqueous suspension of talc and an aqueous suspension of kaolin, then forming a mixture to obtain a suspension of 75% by dry weight of talc and 25% by dry weight of kaolin. For this purpose, an aqueous suspension of the talc is prepared by introducing, by pouring and stirring, an amount of talcum (sold under the name of Finntalc CIO by Finnminerals) necessary to compose a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of kaolin (sold under the name of SPS by ECC) is prepared simultaneously, which has a concentration of 65.1% of the dry substance and a copolymer content that is going to be tested of 1.0% by weight of the dry acid in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 1155.6 grams of the first and about 384 grams of the other, to produce an aqueous suspension which is 75% by dry weight of the talc. and 25% dry weight of kaolin. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 1230 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (75% / 25% by dry weight) of talc and kaolin, which is easy to handle at a high concentration of the dry substance (65.0%).

Test No. 97 This test illustrates the invention and consists of the parallel preparation of an aqueous suspension of talc and an aqueous suspension of kaolin, then form a mixture to obtain a suspension of 50% by dry weight of the talc and 50% by dry weight of the kaolin. For this purpose, an aqueous suspension of the talc is prepared by introducing, by pouring and stirring, an amount of talcum (sold under the name of Finntalc CIO by Finnminerals) necessary to compose a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory vessel also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of kaolin (sold under the name of SPS by ECC) is prepared simultaneously, which has a concentration of 65.1% of the dry substance and a content of copolymer that is going to be tested of 1.0% by weight of the dry acid in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 770.5 grams of the first and about 768 grams of the other, to produce an aqueous suspension which is 50% by dry weight of the talc. and 50% dry weight of kaolin. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 2380 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (50% / 50% dry weight) of talc and kaolin, which is easy to handle at a high concentration of the dry substance (65.0%).

Test No. 98: This test illustrates the invention and consists in the parallel preparation of an aqueous slurry of talc and an aqueous suspension of kaolin, then forming a slurry to obtain a slurry of 25% by dry weight of talc and 75% by dry weight of kaolin. For this purpose, an aqueous suspension of the talc is prepared by introducing, by pouring and stirring, an amount of talcum (sold under the name of Finntalc CIO by Finnminerals) necessary to compose a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of kaolin (sold under the name of SPESWHITE by ECC) is prepared simultaneously, which has a concentration of 65.1% of the dry substance and a content of copolymer that is going to be tested of 1.0% dry weight in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 385.2 grams of the first and about 1152 grams of the other, to produce an aqueous suspension which is 25% by dry weight of talc. and 75% dry weight of kaolin. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle.

The Brookfield viscosity measured is 1860 mPa.s.

The aqueous suspension obtained according to the invention is therefore a mixed suspension (25% / 75% dry weight) talc and kaolin, which is easy to handle at a high concentration of the dry substance (65.0%).

Test No. 99: This test illustrates the invention and consists of the parallel preparation of an aqueous suspension of talc and an aqueous suspension of calcium carbonate., then form a mixture to obtain a suspension of 75% by dry weight of talc and 25% by dry weight of calcium carbonate. For this purpose, an aqueous suspension of talc is prepared by introducing, by pouring and under stirring, an amount of talcum (sold under the name of Finntalc CIO by Finnminerals) necessary to compose a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory vessel also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension.

The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of calcium carbonate is prepared simultaneously, using a marble from a Norwegian tank with a grain size such that 75% of the particles are less than 1 micrometer in diameter, having a concentration of 65% dry of the substance and a sodium polyacrylate content equal to 1.0% by dry weight relative to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 1155.5 grams of the first and about 384.6 grams of the other, to produce an aqueous suspension which is 75% dry weight of talc. and 25% dry weight of calcium carbonate. After stirring the mixture for 10 minutes, the viscosity of Brookfield (To), at room temperature, is measured using a Brookfield viscometer.

DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 150 mPa.s. The aqueous suspension obtained according to the invention is therefore a mixed suspension (75% / 25% by dry weight) of talc and calcium carbonate, which is easy to handle at an elevated concentration of the dry substance (65.0%) ), and it is done using a single dispersant.

Test No. 100: This test illustrates the invention and involves the parallel preparation of an aqueous slurry of talc and an aqueous suspension of calcium carbonate, then forming a slurry to obtain a suspension of 50% by dry weight of talc and 50% by dry weight of calcium carbonate. To this end, an aqueous suspension of talc is prepared by introducing, by pouring and under stirring, an amount of talcum (sold under the name Fininate CÍO by Finnminerals) necessary to compose a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer that is going to be tested, which corresponds to 1. 0% by weight of the dry acid copolymer in relation to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and a compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10 % tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of calcium carbonate is prepared simultaneously, using a marble from a Norwegian tank with a grain size such that 75% of the particles are less than 1 micrometer in diameter, having a concentration of 65% dry of the substance and a content of the copolymer to be tested of 1.0% dry weight relative to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a beaker, 770.4 grams of the first and about 769.2 grams of the other, to produce an aqueous suspension which is 50% by dry weight of talc and 50% by dry weight of calcium carbonate.

After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 350 mPa.s. The aqueous suspension obtained according to the invention is therefore a mixed suspension (50% / 50% by dry weight) of talc and calcium carbonate, which is easy to handle at an elevated concentration of the dry substance (65.0%) ), and is thus done using a single dispersing agent.

Test No. 101: This test, which illustrates the invention, consists of the parallel preparation of an aqueous suspension of talc and an aqueous suspension of calcium carbonate, then forming a mixture to obtain a suspension of 25% by dry weight of talc and 75% by weight dry calcium carbonate. To this end, an aqueous suspension of talc is prepared by introducing, by pouring and under stirring, an amount of talcum (sold under the name Fininate CÍO by Finnminerals) necessary to obtain a suspension with a concentration of 64.9% of the dry substance, in a two-liter laboratory beaker Equipped with a Pendraulik agitator and containing water. This laboratory vessel also contains an amount of the copolymer to be tested which corresponds to 1.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after 100% neutralization with soda, is a polymer with a specific viscosity of 4.38 and compound, in weight percentage, of: 85% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. In the same way and using the same equipment, an aqueous suspension of calcium carbonate is prepared simultaneously, using a marble from a Norwegian tank with a grain size such that 75% of the particles are less than 1 micrometer in diameter, having a concentration of 65% of the dry substance and a content of the copolymer to be tested of 1% by weight of the dry acid in relation to the total weight of the dry substance present in the suspension. After stirring these two suspensions for 20 minutes, they are mixed by pouring them into a laboratory beaker, 385.2 grams of the first and about 1153.8 grams of the other, to produce an aqueous suspension which is 25% by dry weight of talc and 75% by dry weight of calcium carbonate. After stirring the mixture for 10 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle.

The Brookfield viscosity measured is 220 mPa.s. The aqueous suspension obtained according to the invention is therefore a mixed suspension (25% / 75% by dry weight) of talc and calcium carbonate, which is easy to handle at an elevated concentration of the dry substance (65.0%) ), and it is done using a single dispersant.

Test No. 102: This test, which illustrates the invention, consists in the preparation directly of a mixed aqueous suspension of 50% by dry weight of calcium carbonate and 50% by dry weight of talc. For this purpose, starting with a marble from a Norwegian tank with a grain size such that 60% of the particles are of a diameter smaller than 2 micrometers and of a talc (marketed under the name of Finntalc).

CÍO por Finnminerals), an aqueous carbonate suspension of calcium and talc is prepared by introducing, by pouring and under stirring, a two-liter laboratory beaker containing water in the same amount of marble and talcum necessary to produce a suspension of a concentration of 65% of the dry substance, in a two-liter laboratory beaker equipped with a Pendraulik stirrer and containing water. This laboratory beaker also contains an amount of the copolymer to be tested which corresponds to 2.0% by weight of the dry acid copolymer relative to the total weight of the dry substance present in the suspension. The copolymer used in this test is a polymer which, after a 100% neutralization with soda, is a polymer with a specific viscosity of 4.35 and compound, in weight percentage, of: 90% acrylic acid 5% acrylamide 10% tristyryl phenol methacrylate ethoxylated with 25 moles of ethylene oxide. After stirring the mixture for 20 minutes, the Brookfield (To) viscosity is measured at room temperature using a Brookfield viscometer of the DVII type at 100 r / min. using the appropriate spindle. The Brookfield viscosity measured is 350 mPa.s. The aqueous suspension obtained according to the invention is therefore a mixed suspension (50% / 50% by dry weight) of calcium carbonate and talc, which is easy to handle at a high concentration of the dry substance (65.0%).

EXAMPLE 9: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare a crude or coarse calcium carbonate suspension by grinding, so that it can be refined to a suspension of microparticles. For this purpose, a coarse or coarse calcium carbonate suspension was prepared from a calcium carbonate marketed under the name of BL 200 by OMYA S.A., using the various grinding agents to be tested.

Test No. 103: This test, which illustrates the invention, uses a 100% neutralized polymer with a specific viscosity of 0.67 and a compound, in percentage by weight, of: 95% acrylic acid % methacrylate of the general formula (I) in which the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, m and p are equal to 0, q = l and n = 25.

Test No. 104: This test, which illustrates the invention, uses a 100% neutralized polymer with soda, having a specific viscosity of 4.6 and compound, in weight percentage, of: 90% acrylic acid 10% tristyrylphenol methacrylate ethoxylated with 25 moles of ethylene oxide. For each test, an aqueous suspension of calcium carbonate from the Orgon deposit (France) is prepared, having a grain size such that 19% of the particles are of a diameter of less than 2 microns. The aqueous suspension has a dry substance concentration of 76% by weight relative to the total weight. The grinding agent is introduced into this suspension in the amounts indicated in the table below, expressed as a percentage by weight dry relative to the weight of dry calcium carbonate that is going to be crushed. The suspension circulates in a shredder of the type Dyno-Mill with a fixed cylinder and rotating impeller, the crushing medium of which corundum balls are of a diameter ranging between 0.6 millimeters and 1.0 millimeters. The total volume occupied by the crushing medium is 1,150 cubic centimeters while its weight is 2,900 g. The volume of the crushing chamber is 1,400 cubic centimeters. The circumferential speed of the crusher is 10 meters per second. The calcium carbonate suspension is recycled at a rate of 18 liters per hour. The output of the Dyno-Mill shredder is equipped with a separator with a mesh size of 200 microns so that the suspension resulting from the shredding and the shredding medium can be separated. The temperature during each grinding test is maintained at approximately 60 ° C. At the end of the grinding, a sample of the suspension of the refined pigment is extracted from a container and the viscosity is measured by means of a Brookfield viscometer of the RVT type at a temperature of 20 ° C and at rotation speeds of 10 revolutions per minute and 100 revolutions per minute using the appropriate spindle. The grain size is determined by measurement using a Sedigraph 5100 produced by Micromeritics. The results of all the experiments are shown in Table 7, which is given below. t O - TABLE 7 - o o Table 7 shows that the aqueous suspensions of the regined calcium carbonate can be obtained with a high concentration of the dry substance.

EXAMPLE 10: This example relates to the use of a copolymer, in which at least one of the monomers has a surface active structure, to prepare an aqueous suspension of coarse or coarse mica. (marketed by Jungbunzlauer GmbH under the name of ASCOAT 30, with a grain size such that 18% of the particles are of a diameter of less than 1 micrometer) which has the ability to refine to a microparticle suspension.

Test No. 105: This test, which illustrates the invention, uses, in the company of the same equipment and the same operating method as those of example 9 with the exception of the dry substance of the suspension, which is equal to 65%, a polymer neutralized at 100% with soda, which has a specific viscosity of 1.85 and compound, in percentage by weight, of: 95% acrylic acid 5% methacrylate of the general formula (I) in which the hydrophobic radical R 'is a branched alkyl group with 32 carbon atoms, m and p are equal to 0, q = lyn = 25. The results obtained they are shown in Table 8, which is given below: t u > OR - TABLE 8 - or Table 8 shows that suspensions twenty

Claims (9)

1. The use of a copolymer as a dispersing agent and / or grinding aid for mineral substances in an aqueous suspension, regardless of the hydrophilic or hydrophobic nature of the mineral substances to be dispersed and / or ground, wherein the polymer consists of from: a) at least one ethylenically unsaturated monomer having a carboxylic function, which must be selected from monoacids such as acrylic, methacrylic, crotonic, isocrotonic or cinnamic acid, to which diacids may be optionally added such as itaconic acid , fumaric, maleic or citraconic or alternatively the anhydrides of carboxylic acids such as maleic anhydride and hemi-esters of diacids such as monoesters of 1 to 4 carbon atoms, of maleic or itaconic acids or mixtures thereof, b) optionally, at least one ethylenically unsaturated monomer having a sulfonic function, selected from acrylamido-methyl-propan-sulfonic acid, sodium methallylsulfonate, vinyl sulphonic acids and styrene sulfonic acids, or with a function phosphoric selected from the ethylene glycol methacrylate phosphate, ethylene glycol methacrylate phosphate, ethylene glycol acrylate phosphate, propylene glycol acrylate phosphate and its ethoxylates or mixtures thereof, c) optionally, at least one ethylenically unsaturated monomer having no carboxylic function, selected from the group comprising the esters of acrylic or methacrylic acids such as the methyl, ethyl, butyl, 2-ethylhexyl, or acrylonitrile acrylates or methacrylates, methacrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactam, or alternatively the unsaturated amides such as acrylamide, methacrylamide or its substituted derivatives such as, for example, dimethylaminopropyl acrylamide or methacrylamide, the acrylic or methacrylic esters of glycol, chloride or methacrylamido-propyl-trimethyl-ammonium sulfate, sulfate methacrylate or trimethyl-ammonium-ethyl chloride as well as their quaternized acrylate and acrylamide counterparts and / or dimethyldiallylammonium chloride, d) at least one ethylenically unsaturated oxyalkylated monomer ending with a hydrophobic chain having the general formula (I): r R L (CH2_CH_0) m (_CH2_CH2_0) n (_CH2_CH_0) i q- • R 'I J R, which: m and p represent a number of alkylene oxide units less than or equal to 100, - n represents a number of oxide units, ethylene less than or equal to 100, q is a number at least equal to 1 and such that : 0 < q (n + m + p) < 100 Ri is hydrogen or the methyl or ethyl radical, R2 is hydrogen or the methyl or ethyl radical. R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic, vinylphthalic esters as well as unsaturated urethanes such as acryl urethane, methacryl urethane, a-a 'dimethyl-m-isopropenyl-benzylurethane, allyl urethane. R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having at least 8 carbon atoms or dialkylamines having at least 8 carbon atoms when R represents an unsaturated radical which belongs to the group of unsaturated urethanes and R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear, branched alkyl, alkylaryl, arylalkyl, aryl groups having more than 30 carbon atoms or dialkylamines having more than 22 carbon atoms when R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic or vinylphthalic esters, the total constituents of (a), (b), (c) and (d) is equal to 100 and in that it has a viscosity at most equal to 50 and preferably at much equal to 25.

2. The use of a copolymer as a dispersing agent and / or crushing aid according to claim 1, wherein the copolymer is composed of: a) from 99 to 10% of at least one ethylenically unsaturated monomer having a carboxylic function, which must be selected from among the monoacids such as acrylic, methacrylic, crotonic, isocrotonic, cinnamic acid, to which the diacids may be optionally added, such as itaconic, fumaric, maleic, citraconic acid, or alternatively carboxylic acid anhydrides such as maleic anhydride and diacid hemi-esters such as monoesters with 1 to 4 carbon atoms, maleic acids or itaconic or mixtures thereof, b) from 0 to 50% by weight of at least one ethylenically unsaturated monomer having a sulfonic function selected from acrylamido-methyl-propan-sulfonic acid, sodium methallylsulfonate, vinyl sulfonic acid and styrene sulfonic acids, or with a function phosphoric selected from the phosphate of ethylene glycol methacrylate, propylene glycol methacrylate phosphate, ethylene glycol acrylate phosphate, propylene glycol acrylate phosphate and its ethoxylates or mixtures thereof, c) from 0% to 50% by weight of at least one ethylenically unsaturated monomer having no carboxylic function, selected from the group comprising acrylic or methacrylic acid esters such as methyl, ethyl, butyl acrylates or methacrylates, 2- ethyl hexyl or acrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactam, or alternatively unsaturated amides such as acrylamide, methacrylamide or its substituted derivatives such as for example dimethylaminopropyl acrylamide or methacrylamide, acrylic esters or methacrylics of glycol, chloride or sulfate of methacrylamido-propyl-trimethyl-ammonium, the methacrylate of the chloride or sulfate of trimethyl-ammonium-ethyl as well as their counterparts of acrylate and quaternized acrylamide and / or dimethyldiallylammonium chloride, d) from 1% to 90% and even more particularly for reasons pertaining to the copolymerization process of 3% to 50% by weight of at least one oxyalkylated monomer ethylenically unsaturated ending with a hydrophobic chain, of the general formula (I): r i l_ (CH2_CH_0) m (_CH2_CH2_0) n (_CH2_CH_0) p | q_R '\ I J Ri R2 in which: - m and p represent a number of alkylene oxide units less than or equal to 100, n represents a number of ethylene oxide units less than or equal to 100, q is a number at least equal to 1 and such that: 0 < q (n + m + p) < 100 Ri is hydrogen or the methyl or ethyl radical, R2 is hydrogen or the methyl or ethyl radical. R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic, vinylphthalic esters as well as urethanes unsaturated such as, for example, acryl urethane, methacryl urethane, α-α 'dimethyl-m-isopropenyl-benzylurethane, allyl urethane. R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having at least 8 carbon atoms or dialkylamines having at least 8 carbon atoms when R represents an unsaturated radical which belongs to the group of unsaturated urethanes and R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear, branched alkyl, alkylaryl, arylalkyl, aryl groups having more than 30 carbon atoms or dialkylamines having more than 22 carbon atoms when R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic or vinylphthalic esters, the total constituents of (a), (b), (c) and (d) is equal to 100 and in that it has a viscosity at most equal to 50 and preferably at most equal to 25.

3. The use of a copolymer as a dispersing agent and / or crushing aid according to claim 2, wherein the copolymer is composed of: a) from 97 to 50% of at least one ethylenically unsaturated monomer having a carboxylic function, which must be selected from monoacids such as acrylic, methacrylic, crotonic, isocrotonic, cinnamic acid, diacids such as itaconic acid, fumaric, maleic, citraconic or alternatively carboxylic acid anhydrides such as maleic anhydride and diacid hemi-esters such as monoesters with 1 to 4 carbon atoms, maleic or itaconic acids or mixtures thereof, b) from 0 to 50% by weight of at least one ethylenically unsaturated monomer having a sulfonic function selected from acrylamido-methyl-propan-sulfonic acid, sodium methallylsulfonate, vinyl sulfonic acid and styrene sulfonic acids, or with a function phosphoric selected from the phosphate of ethylene glycol methacrylate, propylene glycol methacrylate phosphate, ethylene glycol acrylate phosphate, propylene glycol acrylate phosphate and its ethoxylates or mixtures thereof, c) from 0% to 50% by weight of at least one ethylenically unsaturated monomer having no carboxylic function, selected from the group comprising esters of acrylic or methacrylic acid such as methyl, ethyl, butyl acrylates or methacrylates; -ethyl-hexyl or acrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactam, or alternatively unsaturated amides such as acrylamide, methacrylamide or its substituted derivatives such as, for example, dimethylaminopropyl acrylamide or methacrylamide, acrylic esters or methacrylics of glycol, chloride or sulfate of methacrylamido-propyltrimethylammonium, the methacrylate of the chloride or sulfate of trimethylammonium-ethyl as well as their counterparts of acrylate and quaternized acrylamide and / or dimethyldiallylammonium chloride, d) from 3% to 50% by weight of at least one ethylenically unsaturated oxyalkylated monomer terminating with a hydrophobic chain, of the general formula (I): r I L (CH2_CH_0) ra (_CH2_CH2_0) n (_CH2_CH_0) p | ^ R 'L I I J Rl R2 5 in which: m and p represent a number of alkylene oxide units less than or equal to 100, n represents a number of ethylene oxide units less than or equal to 100, q is a number at least equal to 1 and such that: 0 < q (n + m + p) < 100 15 Ri is hydrogen or the methyl or ethyl radical, R2 is hydrogen or the methyl or ethyl radical. R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic, vinylphthalic esters as well as unsaturated urethanes such as, for example, 25 acryl urethane, methacryl urethane, a-a'dimethyl-m-isopropenyl-benzylurethane, allyl urethane. R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear or branched alkyl, alkylaryl, arylalkyl, aryl groups having at least 8 carbon atoms or dialkylamines having at least 8 carbon atoms when R represents the unsaturated radical which belongs to the group of unsaturated urethanes and R 'represents the hydrophobic radical such as tristyrylphenyl as well as linear, branched alkyl, alkylaryl, arylalkyl, aryl groups having more than 30 carbon atoms or dialkylamines having more than 22 carbon atoms when R represents the polymerizable unsaturated radical belonging to the group of acrylic, methacrylic, maleic, itaconic, crotonic or vinylphthalic esters, the total constituents of (a), (b), (c) and (d) is equal to 100 and in that it has a viscosity at most equal to 50 and preferably at most equal to 25.

4. The use of a copolymer as a dispersing agent and / or crushing aid according to any of claims 1 to 3, wherein R 'represents the hydrophobic radical such as tristyrylphenyl when R represents the radical belonging to the ester group methacrylic or the methacrylurethane group.

5. The use of a copolymer as a dispersing agent and / or crushing aid according to any of claims 1 to 4, wherein the copolymer is in an acidic or partially or fully neutralized form by one or more neutralizing agents having a monovalent function selected from the group comprising alkali cations, in particular sodium, potassium or ammonium or alternatively primary, secondary or tertiary aliphatic and / or cyclic amines such as stearylamine, ethanolamines (mono-, di-, triethanolamine) , mono- and diethylamine, cyclohexylamine, methylcyclohexylamine and / or one or more neutralizing agents having a polyvalent function selected from the group comprising divalent alkaline earth cations, in particular magnesium and calcium or alternatively zinc, as well as trivalent cations, including in particular aluminum, or alternatively certain cations with a higher valence.

6. The use of a copolymer as a dispersing agent and / or crushing aid according to any of claims 1 to 5, wherein the copolymer is introduced in an amount of 0.05% to 5% by weight of the dry fraction of the copolymer with relation to the dry weight of the substance or mineral substances.

7. The use of a copolymer as a dispersing agent and / or grinding aid according to any of claims 1 to 6, wherein the mineral substance or substances are selected from the mineral substances with a hydrophilic surface charged and preferably chosen from among natural or synthetic calcium carbonates or dolomite or kaolins, or mixtures thereof and most preferably from chalk, calcite or marble.

8. The use of a copolymer as a dispersing agent and / or crushing aid according to any of claims 1 to 6, wherein the mineral substance or substances are chosen from among the mineral substances with a hydrophobic surface and preferably selected from talc or the mica or the mixtures thereof.

9. The use of a copolymer as a dispersing agent and / or crushing aid according to any of claims 1 to 6, wherein the mineral substances are a mixture of mineral substances with a hydrophilic surface and / or a mixture of mineral substances. with a hydrophobic surface and preferably a mixture of talc and calcium carbonate or talc and kaolin.