Use of water-soluble acrylic copolymers in optionally pigmented aqueous formulations and resulting formulations

The present invention concerns the sector of possibly pigmented aqueous formulations.

The invention concerns firstly the use as a thickening agent, in possibly pigmented aqueous formulations, such as coating formulations such as paints in aqueous phase and notably dispersion paints, varnishes, paper coatings, cosmetics, detergence, textile formulations and drilling muds, of a water-soluble acrylic copolymer consisting of at least one monomer with ethylenic unsaturation and a carboxylic function, at least one non-ionic monomer with ethylenic unsaturation, at least one oxyalkylated monomer with ethylenic unsaturation terminated by a hydrophobic branched and non-aromatic chain with 10 to 24 carbon atoms, and possibly at least one monomer called a crosslinking monomer, having at least two ethylenic unsaturations.

The invention also concerns the thickening agent enabling an optimum development and/or optimum maintenance of the viscosity of the aqueous formulations to be obtained in the presence of compounds, whether or not water-soluble, or when the said compounds are added to the said aqueous formulations.

The invention also concerns the process of manufacture of the said possibly pigmented aqueous formulations.

Finally, the invention concerns the possibly pigmented aqueous formulations obtained according to the invention.

In the field of aqueous formulations possibly containing one or more mineral fillers, and more particularly in the sector of paints in the aqueous phase, and notably dispersion paints, controlling the rheology of the said formulations, both at the stage of manufacture and during their transport and storage, and during their use, is one of the fundamental goals for the skilled man in the art. The wide variety of practical constraints in each of these stages relates to a multiplicity of different rheological properties. Nevertheless, it is possible to summarise the requirement of the skilled man in the art in obtaining an effect of the thickening of the aqueous formulation, both for reasons of stability over time, and for a possible application of the paint to a vertical surface, lack of splashing during use, or of dripping after application, etc. As a consequence, the products which contribute to this regulation of the rheological properties have been designated under the term “thickening agents”.

Historically, since the 1950s cellulose-based gums and thickening agents have been used, one of the essential characteristics of which is their high molecular weight. However, these compounds have a number of disadvantages, such as their instability over time, as is recalled by document U.S. Pat. No. 4,673,518, the need of using a large quantity of them, highlighted in document EP 0 250 943, and the production costs which they engender (notably in terms of waste treatment), as indicated in document U.S. Pat. No. 4,384,096.

The skilled man in the art then turned towards a new category of thickening agents, known as the “associative” thickening agents, the operational mechanism and the characteristics of which are now well-known, and recalled in document “Rheology modifiers for water-borne paints” (Surface Coatings Australia, October 1985, pp 6). These are water-soluble polymers with insoluble hydrophobic groupings, creating the associative effect through the interaction of these hydrophobic groupings with the surface of the binder particles in dispersion, thus producing a three-dimensional network which causes the viscosity of the medium to increase.

It is possible to distinguish very schematically among the synthetic polymers the polyurethane associative thickening agents from the acrylic associative thickening agents.

Such thickening agents are now commonly used, among other sectors, in the sector of paints in aqueous phase, and notably dispersion paints. However, their use is not devoid of disadvantages, including two major ones, which the Applicant wishes to develop here. The first concerns the “sensitivity to compounds, whether or not water-soluble” (and notably salts and surfactants), and the second the “pigmentary compatibility” or “colour acceptance”. These problems are encountered in a large number of aqueous formulations, such as paints in aqueous phase, and notably dispersion paints, but also formulations such as cosmetic or detergent formulations. Each of these problems will subsequently be envisaged from the standpoint of the solutions proposed by the state of the technique, from the viewpoints of both the associative acrylic thickening agents, and the associative polyurethane thickening agents.

“Sensitivity to compounds, whether or not water-soluble” designates the properties of a thickening agent which, when it is put in presence of such compounds, and notably salts and surfactants, tends no longer to maintain the viscosity at a satisfactory degree for the skilled man in the art or the user of these aqueous formulations. The resulting loss of viscosity is prejudicial for the storage and application qualities of the said formulations. This type of phenomenon is widely reported in the literature, particularly in respect of the associative acrylic thickening agents, as is emphasised by document EP 0 013 836, which relates the sensitivity to salts, and notably sodium chloride, of such additives. This document teaches the skilled man in the art the manufacture of associative acrylic thickening agents from a monomer chosen from among acrylic acid and methacrylic acid, from a monomer which is an alkyl ester, and from a hydrophobic monomer with a radical having 8 to 30 carbon atoms. Its principal function is to improve the rheological profile of the aqueous paints in which it is used. Similarly, document EP 0 011 806 teaches the manufacture of other associative acrylic thickening agents, from a carboxylic monomer, from ethyl acrylate, and from a hydrophobic monomer with an alkyl radical or phenyl alkyl having 8 to 20 carbon atoms. Finally, document EP 0 577 526 describes associative acrylic thickening agents having a base of a carboxylic monomer, a monomer with ethylenic but not carboxylated unsaturation, and an oxyalkylated monomer terminated by a hydrophobic fatty chain. Nevertheless, in terms of insensitivity to the salts, these copolymers do not give the skilled man in the art satisfaction.

Another problem with which the skilled man in the art is faced is that of pigmentary compatibility. In terms of paint formulation, the term “base” or “white base” designates the pigmented aqueous composition charged with white colour, which acts as the base of the coloured pigmentary or final pigmented composition.

This aqueous composition charged and/or pigmented with white colour is formed from a liquid phase which may be water, or an organic solvent which is miscible in water or, again, a blend of both, from one or more polymers in solution or in suspension in the liquid phase called “binders”, from fillers and/or pigments, from at least one filler and/or pigment dispersing agent, which may be a water-soluble polymer or copolymer, from additives as diverse as coalescence agents, biocides, anti-foaming agents, or others, and finally from at least one thickening agent which is a natural or synthetic polymer or copolymer. When the coloured pigments are added to the said “bases” of white colour, in the form of pigmentary concentrates or pigmentary pastes, the resulting pigmentary formulation is obtained.

The composition of the coloured pigment concentrates or pigmentary concentrates or pigmentary pastes generally also contains additives or compounds of the surfactant type or electrolyte salt type, or a co-solvent miscible in water in large quantities.

The pigmentary concentrates most commonly used are said to be universal, since they can be added not only to paints in the aqueous phase, but also to paints in solvent phase.

In practice, if the final formulation has insufficient pigmentary compatibility, firstly there may be an effect on the rheology of the resulting pigmentary formulation, and secondly there may be an effect on the colouring force developed by the pigment or pigments of the pigmentary concentrate or concentrates in the resulting pigmentary formulation.

This loss of colouring force may lead to a paint film the hue of which is uniformly more “washed out”, soiled or degraded towards white compared to the reference. Clearly, this loss of colouring force is very prejudicial to the tinting of paint by an automated system according to the measurement of a spectrophotocolorimeter, as this is practised in large DIY stores or in paint retailers.

Indeed, the computer will compute that a certain quantity of universal pigmentary concentrates should enable the desired hue to be approached, but the loss of colouring force relating to this poor compatibility will distort the result.

This phenomenon may be measured by the use of a spectrophotocolorimeter enabling the three-chromatic coordinates to be measured (Huntsmann: L*,a*,b*) and thus the colour of a dry paint film.

L* will give a value in the scale of greys (the higher and more positive L* the lighter the film; the smaller and the more negative L* the darker the film). The second coordinate, a*, characterises the colour in a scale ranging from green to red (the higher and more positive a* the more red the film; the smaller and more negative a* the more green the film). The third coordinate, b*, characterises the colour in a scale ranging from blue to yellow (the higher and more positive b* the more yellow the film; the smaller and more negative b* the more blue the film).

In certain rarer cases one even observes variations of hues in different zones in a given paint film. These variations are related to the shear differences to which these different zones are subjected when the paint film is applied with a tools such as, for example, a paintbrush. Universal colouring pigments which are poorly dispersed in the paint will express a colouring force which will depend on the shear stress to which the paint containing them is subjected. In the case of the use of a paintbrush, this phenomenon will emphasise the brushstrokes (where the hairs of the brush are more strongly applied), giving them a colour different from the rest of the paint film. To visualise this phenomenon, the skilled man in the art may apply to the paintbrush or use a test known as a rub-out test, consisting in applying a paint film uniformly, without any shear difference, using a block, and then in shearing a part of the paint film which is still fresh, non-dry, with a finger. The sheared zone may become lighter or darker than the non-sheared zone.

Along the same lines, the skilled man in the art is familiar with document U.S. Pat. No. 5,973,063, which describes a polyurethane associative thickening agent, and also with document FR 2 826 014, which teaches that it is possible, by selecting a polyisocyanate-based compound having at the end of the chain hydrocarbonated groupings with at least three aromatic cycles, to manufacture a polyurethane thickening agent having a satisfactory pigmentary compatibility, and developing a high viscosity under a low shear value.

Consequently, the skilled man in the art, who is seeking to make available to the end user an aqueous composition the Theological profile of which remains acceptable in the presence of compounds, whether or not water-soluble, or when the said compounds are added, such as the salts or surfactants in the field of detergence or cosmetics, or again such as the universal pigmentary concentrates in the field of paint, notably under a low shear value, to obtain satisfactory spreading of the paint, is faced with the problems of the greatly reduced viscosity of the formulation in the presence of the said compounds, and naturally turns towards the associative thickening agents of the polyurethane type. The latter, as we have just seen, are well known to offer a high resistance to salts, and to develop an appropriate viscosity under a low shear.

The final document FR 2 826 014 finally demonstrated that the “polyurethane approach” also authorises the manufacture of such thickening agents having a satisfactory pigmentary compatibility.

And, continuing their research with a view to improving the stability of the viscosity of the aqueous formulations in the presence of compounds, whether water-soluble or non-water-soluble, or when the said compounds are added to the said aqueous formulations, and of improving the pigmentary compatibility, whilst maintaining a viscosity of the formulation acceptable for the end user, the Applicant found in a completely surprising manner that all these problems may be resolved by the selection of the oxyalkylated monomer with ethylenic unsaturation of the copolymer which is an associative acrylic thickening agent, and by its use as an additive in the formulation.

This water-soluble acrylic copolymer consists of a least one monomer with ethylenic unsaturation and with a carboxylic function, at least one non-ionic monomer with ethylenic unsaturation, at least one oxyalkylated monomer with ethylenic unsaturation terminated by a hydrophobic branched, non-aromatic chain with 10 to 24 carbon atoms, and possibly at least one monomer called a crosslinking monomer, with at least two ethylenic unsaturations.

The object of the invention is thus the use in possibly pigmented aqueous formulations, such as coating formulations such as paints in the aqueous phase and notably dispersion paints, varnishes, paper coatings, cosmetics, detergence, textile formulations and drilling muds, of this copolymer as a thickening agent enabling a development and/or maintenance of the viscosity of the aqueous formulations to be obtained in the presence of compounds, whether or not water-soluble, or when the said compounds are added to the said aqueous formulations.

Another object of the invention is the thickening agent constituted by this water-soluble acrylic copolymer consisting of a least one monomer with ethylenic unsaturation and with a carboxylic function, at least one non-ionic monomer with ethylenic unsaturation, at least one oxyalkylated monomer with ethylenic unsaturation terminated by a hydrophobic branched, non-aromatic chain with 10 to 24 carbon atoms, and possibly at least one monomer called a crosslinking monomer, with at least two ethylenic unsaturations.

Another object of the invention is the process of manufacture of the possibly pigmented aqueous formulations.

A final object of the invention lies in the possibly pigmented aqueous formulations obtained according to the invention.

These possibly pigmented aqueous formulations containing the thickening agent according to the invention are coating aqueous formulations chosen from among dispersion paints, varnishes, paper coatings, cosmetic formulations, detergent formulations, textile formulations (preparation, printing or colouring), and drilling muds.

These formulations are also formulations for plasterboard such as joint filler for plasterboard, formulations for ceramics, formulations for leather, plaster formulations or again formulations for hydraulic binders such as mortar formulations.

According to the invention, the copolymers added to the aqueous formulations as thickening agents enable the possibly pigmented aqueous formulations to be given satisfactory rheological properties with a view to their application, and notably an increase of their viscosity under an average shear value.

The Applicant indicates that the expression “average shear value” is taken to mean in the present application any shear value, also called a velocity gradient, of between 20 s −1 and 1000 s −1 .

In addition, these copolymers develop an excellent tolerance in relation to salts and surfactants which these formulations may contain. Finally, such copolymers give the aqueous formulations in which they are used a very satisfactory pigmentary compatibility.

These aims are attained thanks to the use, as a thickening agent enabling a development and/or maintenance of the viscosity of the aqueous formulations to be obtained in the presence of compounds, whether or not water-soluble, or when the said compounds are added to the said aqueous formulations, of water-soluble acrylic copolymers characterised in that the said copolymer consists:

a) of at least one monomer with ethylenic unsaturation and a carboxylic function, b) of at least one non-ionic monomer with ethylenic unsaturation, c) of at least one oxyalkylated monomer with ethylenic unsaturation terminated by a hydrophobic, non-aromatic branched chain with 10 to 24 carbon atoms, d) and possibly of at least one monomer called a crosslinking monomer, having at least two ethylenic unsaturations.

This copolymer is also characterised in that:

a) the monomer or monomers with ethylenic unsaturation and a carboxylic function are chosen from among the monomers with ethylenic unsaturation and with a monocarboxylic function such as acrylic or methacrylic acid, or again the diacid hemiesters such as the monoesters in C 1 to C 4 of maleic or itaconic acids, or their blends, or chosen from among the monomers with ethylenic unsaturation and a dicarboxylic function, such as crotonic, isocrotonic, cinnamic, itaconic, maleic acid, or again the anhydrides of carboxylic acids, such as maleic anhydride, b) the non-ionic monomer or monomers with ethylenic unsaturation are chosen from among the esters, amides or nitriles of acrylic and methacrylic acids, such as the acrylates or methacrylates or methyl, ethyl, butyl, 2-ethyl-hexyl, or from among acrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactame, c) the oxyalkylated monomer or monomers with ethylenic unsaturation and terminated by a hydrophobic and non-aromatic branched chain with 10 to 24 carbon atoms, have the following formula:

where:

m and p represent a number of alkylene oxide units of between 0 and 150, n represents a number of ethylene oxide units of between 5 and 150, q represents a whole number at least equal to 1 and such that 5≦(m+n+p)q≦150, and preferentially such that 15≦(m+n+p)q≦120, R 1 represents the methyl or ethyl radical, R 2 represents the methyl or ethyl radical, R represents a radical containing a polymerisable unsaturated function belonging to the group of acrylic, methacrylic, maleic, itaconic or crotonic esters, R′ represents a hydrophobic and non-aromatic branched chain with 10 to 24 carbon atoms,

d) the possible monomer or monomers, called crosslinking monomers, with at least two ethylenic unsaturations, are notably chosen from the group constituted by ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropanetriacrylate, trimethylolpropanetrimethacrylate, allyl acrylate, methylenebisacrylamide, methylenebismethacrylamide, tetrallyloxyethane, the triallylcyanurates, the allylic ethers obtained from polyols chosen from among pentaerythritol, sorbitol, or again sucrose.

In a preferential manner, the said copolymer is characterised in that the hydrophobic and non-aromatic branched chain has 12 to 24 carbon atoms, and has 2 branchings having at least 6 carbon atoms.

In a more preferential manner, the said copolymer is characterised in that the hydrophobic and non-aromatic branched chain has 16 to 20 carbon atoms, and has 2 branchings having at least 6 carbon atoms.

In an even more preferential manner, the hydrophobic non-aromatic branched chain is chosen from among 2-hexyl 1-decanyl and 2-octyl 1-dodecanyl.

This copolymer used as a thickening agent according to the invention is also characterised in that it contains, expressed by weight of monomers:

a) 2 to 95%, and preferentially 5 to 90% of at least one monomer with ethylenic unsaturation and a carboxylic function chosen from among the monomers with ethylenic unsaturation and with a monocarboxylic function such as acrylic or methacrylic acid, or again the diacid hemiesters such as the monoesters in C 1 to C 4 of maleic or itaconic acids, or their blends, or chosen from among the monomers with ethylenic unsaturation and a dicarboxylic fluction, such as crotonic, isocrotonic, cinnamic, itaconic, maleic acid, or again the anhydrides of carboxylic acids, such as maleic anhydride, b) 2 to 95%, and preferentially 5 to 90%, of at least one monomer with ethylenic unsaturation without a carboxylic function chosen from among the esters, amides or nitriles of acrylic and methacrylic acids, such as the acrylates or methacrylates or methyl, ethyl, butyl, 2-ethyl-hexyl, or from among acrylonitrile, vinyl acetate, styrene, methylstyrene, diisobutylene, vinylpyrrolidone, vinylcaprolactame, c) 2 to 25%, and preferentially 5 to 20%, of at least one monomer with ethylenic unsaturation and terminated by a hydrophobic and non-aromatic branched chain with 10 to 24 carbon atoms, having the following formula:

In a preferential manner, this copolymer used according to the invention as a thickening agent is characterised in that it contains, expressed by weight, 2 to 25%, and preferentially 5 to 20%, of at least one oxyalkylated monomer with ethylenic unsaturation and terminated by a hydrophobic and non-aromatic branched chain with 12 to 24 carbon atoms, and having 2 branchings with at least 6 carbon atoms.

In a preferential manner, this copolymer thickening agent is characterised in that it contains, expressed by weight, 2 to 25%, and preferentially 5 to 20%, of at least one oxyalkylated monomer with ethylenic unsaturation and terminated by a hydrophobic and non-aromatic branched chain with 16 to 20 carbon atoms, and having 2 branchings with at least 6 carbon atoms.

In an even more preferential manner, the hydrophobic non-aromatic branched chain of the monomer c) is chosen from among 2-hexyl 1-decanyl and 2-octyl 1-dodecanyl.

In an equally preferential variant, this copolymer does not contain the crosslinking monomer d).

This copolymer is also characterised in that it is in its acid form, or partially or totally neutralised by one or more neutralisation agents having a monovalent neutralising function, such as those chosen from the group constituted by the alkaline cations, in particular sodium, potassium, lithium, ammonium or the aliphatic and/or cyclic primary, secondary, tertiary amines such as stearylamine, the ethanolamines (mono-, di- or tri-ethanolamine), mono- di-ethylamine, cyclohexylamine, methylcyclohexylamine, 2-amino 2-methyl 1-propanol and morpholine.

This water-soluble acrylic copolymer is obtained by the copolymerisation techniques well known to the skilled man in the art, such as the techniques of radical copolymerisation in solution, in a direct or reverse emulsion, in suspension, or precipitation in appropriate solvents, in the presence of catalytic systems and known transfer agents

Another object of the invention also concerns the process of manufacture of possibly pigmented aqueous formulations characterised in that the said copolymer is added to the said formulations in the presence of compounds, whether or not water-soluble, such as salts or surfactants, or when the said compounds are added to the said aqueous formulations.

A final object of the invention concerns, lastly, possibly pigmented aqueous formulations containing these said copolymers, such as coating formulations such as paints in their aqueous phase, and notably dispersion paints, varnishes, paper coatings, cosmetics, detergence, textile formulations and drilling muds, or again plaster formulations, formulations for plasterboard, for hydraulic binders such as mortar formulations, or again formulations for ceramics and for leather.

The following examples illustrate the invention without however limiting its scope.

This example illustrates the use of copolymers according to the invention in aqueous paint formulations, and seeks to highlight the pigmentary compatibility Theological properties contributed by the copolymers according to the invention for formulations for matt paint in the aqueous phase, and with a constant dosage.

Thus, starting with a matt decoration paint formulation in aqueous phase with a vinyl-acrylic dispersion binder base, “UCAR™ latex 300” from Dow, the formula of which is shown in table 1, the aim consisted in checking in this formula the pigmentary compatibility (or compatibility provided with the addition of universal pigmentary concentrates), as influenced by different associative acrylic thickening agents, including thickening agents of the prior art, the hydrophobic groupings of which are linear, and thickening agents according to the invention, the hydrophobic groupings of which are branched.

To do so in each test, the above-mentioned matt paint formulation was prepared, and 0.3% by dry weight relative to the total weight of the white paint formula (but before addition of the universal pigmentary concentrate) of the thickening agent for testing was added to it, and then 36 millilitres of the universal pigmentary concentrate (of the Colortrend™ M 888 type from the company Hüls/Creanova) was added on to a kilogram of a white paint base which had been previously thickened with one of the associative acrylic thickening agents.

Two used universal pigmentary concentrates were chosen from the Colortrend™ M 888 range in order to represent the main families of organic pigments: phtalocyanine blue and quinacridone magenta.

At this stage, as limited as possible a reduction or an increase (relative to the white base) of the Stormer™ viscosity expressed in Krebs Units (KU) reflects a satisfactory compatibility with the universal pigmentary concentrate.

This Stormer™ viscosity test is used by the skilled man in the art as a selection test enabling them to eliminate formulations posing problems of compatibility with universal pigmentary concentrates.

Indeed, the skilled man in the art appreciates in particular that the Stormer™ viscosity, which is a viscosity with an average velocity gradient perceptible by the client (stirring with a spatula or brush, painting with a brush or roller), should be changed as little as possible by this addition of universal pigmentary concentrate.

This test illustrates the prior art and uses 0.3% by dry weight of a copolymer consisting of:

a) 37.2% methacrylic acid, b) 52.8% of ethyl acrylate, c) 10.0% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25.

This test illustrates the invention and uses 0.3% by dry weight of a copolymer consisting of:

a) 37.2% methacrylic acid, b) 52.8% of ethyl acrylate, c) 10.0% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25.

This test illustrates the prior art and uses 0.3% by dry weight of a copolymer consisting of:

a) 37.3% methacrylic acid, b) 52.6% of ethyl acrylate, c) 10.1% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.05% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 0.3% by dry weight of a copolymer consisting of:

a) 37.3% methacrylic acid, b) 52.6% of ethyl acrylate, c) 10.1% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25

and obtained by use of 0.05% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the prior art and uses 0.3% by dry weight of a copolymer consisting of:

a) 43.5% methacrylic acid, b) 47.6% of ethyl acrylate, c) 8.9% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 0.3% by dry weight of a copolymer consisting of:

a) 43.5% methacrylic acid, b) 47.6% of ethyl acrylate, c) 8.9% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the prior art and uses 0.3% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 20 carbon atoms, m=p=0, q=1, n=25.

This test illustrates the invention and uses 0.3% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 20 carbon atoms 2-octyl 1-dodecanyl, m=p=0, q=1, n=25.

This test illustrates the prior art and uses 0.3% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 20 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.05% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 0.3% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 20 carbon atoms 2-octyl 1-dodecanyl, m=p=0, q=1, n=25

and obtained by use of 0.05% by weight of dodecylmercaptan relative to the weight of the monomers.

All the results are shown in the following table 2.

In all cases, the variation of the absolute value of the Stormer™ viscosity of the paints after addition of the colorants is smaller with the paints containing the thickening agents according to the invention, compared to that of the paints containing the corresponding thickening agents of the prior art.

This example illustrates the use of copolymers according to the invention in the field of drilling fluids, and particularly that of synthetic muds, and seeks to highlight the maintenance of the thickening conferred by the copolymers according to the invention for formulations with a constant dosage by dry weight of thickening agent.

In the field of drilling fluids, and particularly of synthetic muds, the skilled man in the art may be induced to use a mud consisting solely of a thickening agent and of water, in order to reduce the quantity of non-recyclable matter. These muds must have a suspensivant power which, although becoming reduced during pumping, must remain relatively high under stress conditions, such as the passage of the fluid in the annular space when debris is brought up. Traditional muds based on thickening agents of the prior art have the defect that they are too pseudoplastic, i.e. lose most of their viscosity when subjected to shearing. This phenomenon is easily measured by calculating the ratio of the Brookfield™ viscosities measured at 100 RPM to the Brookfield™ viscosities measured at 10 RPM. A low figure is an indication of a substantial reduction of viscosity under shearing.

A comparison of the various polymers was made by making aqueous gels of these products at concentrations such that the Brookfield™ viscosities obtained are situated between 1000 mPa·s and 5000 mPa·s at 10 RPM. The pHs of these gels were all adjusted to 8.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 37.2% methacrylic acid, b) 52.8% of ethyl acrylate, c) 10.0% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 37.2% methacrylic acid, b) 52.8% of ethyl acrylate, c) 10.0% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m p=0, q=1, n=25.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 42.83% methacrylic acid, b) 52.97% of ethyl acrylate, c) 2.66% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25,

d) 1.54% ethylene glycol dimethacrylate.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 42.83% methacrylic acid, b) 52.97% of ethyl acrylate, c) 2.66% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25,

d) 1.54% ethylene glycol dimethacrylate.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 43.5% methacrylic acid, b) 47.6% of ethyl acrylate, c) 8.9% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 43.5% methacrylic acid, b) 47.6% of ethyl acrylate, c) 8.9% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 20 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 36.7% methacrylic acid, b) 53.1% of ethyl acrylate, c) 10.2% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 20 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 42.68% methacrylic acid, b) 53.12% of ethyl acrylate, c) 2.66% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 16 carbon atoms, m=p=0, q=1, n=25,

d) 1.54% ethylene glycol dimethacrylate.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 42.68% methacrylic acid, b) 53.12% of ethyl acrylate, c) 2.66% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 16 carbon atoms 2-hexyl 1-decanyl, m=p=0, q=1, n=25,

d) 1.54% ethylene glycol dimethacrylate.

This test illustrates the prior art and uses 1% by dry weight of a copolymer consisting of:

a) 34.2% methacrylic acid, b) 60.4% of ethyl acrylate, c) 5.4% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents a linear hydrophobic chain with 20 carbon atoms, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

This test illustrates the invention and uses 1% by dry weight of a copolymer consisting of:

a) 34.2% methacrylic acid, b) 60.4% of ethyl acrylate, c) 5.4% of the monomer of formula (I), where

R represents a methacrylate radical, R′ represents the non-aromatic hydrophobic chain with 20 carbon atoms 2-octyl 1-dodecanyl, m=p=0, q=1, n=25

and obtained by use of 0.30% by weight of dodecylmercaptan relative to the weight of the monomers.

All the results are shown in the following table 3.

Table 3 above perfectly illustrates the clear superiority of the polymers according to the invention compared to the polymers of the prior art, since the ratio of the Brookfield™ viscosities measured at 100 RPM over the Brookfield™ viscosities measured at 10 RPM are, respectively, much higher for the tests illustrating the invention.

This example illustrates the use of copolymers according to the invention in the field of detergence and cosmetics, and seeks to highlight the maintenance of the thickening conferred by the copolymers according to the invention for formulations with a constant dosage by dry weight of thickening agent, despite the addition of salts.

Both in the previous application (drilling muds) and in a cosmetic or detergence application, the presence of salt is sometimes unavoidable or inevitable. Indeed, synthetic drilling muds can be manufactured from seawater or, being manufactured from fresh water, can be brought into contact with saline geological strata. It is important that the viscosity of the mud should resist this contamination in order to guarantee its effectiveness in bringing up debris during the drilling. Similarly, many cosmetic or detergent formulations contain salts, used among other things as viscosity exhausters in relation to surfactants, in addition to thickening agents; it is therefore important that the said thickening agents should resist the addition of salts. The comparison of the various polymers was made by making aqueous gels of these products at concentrations such that the Brookfield™ viscosities obtained are situated between 1000 and 5000 mPa·s at 10 RPM. The pHs of these gels were all adjusted to 8. After measurement of the Brookfield™ viscosities, quantities of sodium chloride corresponding to 1 and 2% of the formulation were added and dissolved. The Brookfield™ viscosities were then measured again.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 11.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 12.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 17.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 18.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 21.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 22.

All the results are shown in the following table 4.

Table 4 above illustrates perfectly the superiority of the polymers according to the invention compared to the polymers of the prior art.

This example illustrates the use of copolymers according to the invention in the field of detergence and cosmetics, and seeks to highlight the development of the thickening conferred by the copolymers according to the invention for formulations with a constant dosage by dry weight of thickening agent, despite the addition of surfactants.

Detergent and cosmetic formulations contain one or more ionic and non-ionic surfactants. The skilled man in the art has constantly used combinations of the solublising/insolubilising properties of these pairs of surfactants to thicken the formulations containing them. The thickening polymers to be found in the market now enable the quantities of surfactants to be reduced appreciably, and the latter are now used only for their detergent properties. Use of the polymers according to the invention enables the viscosity of the formulations containing them to be improved significantly compared to the thickening polymers of the prior art. The comparison of the polymers was made by the production of aqueous formulations containing 11% of sodium lauryl alkylsulfate and 9% of cocoamidopropyl betaine. The pH of the formulations was adjusted to 8 using triethanolamine. The viscosity of the blend of surfactants without thickening agent is 20 mPa·s at 10 RPM.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 11.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 12.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 19.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 20.

This test illustrates the prior art and uses 1% by dry weight of the copolymer used in test n° 21.

This test illustrates the invention and uses 1% by dry weight of the copolymer used in test n° 22.

All the results are shown in the following table 5.

Table 5 above illustrates perfectly the superiority of the polymers according to the invention compared to the polymers of the prior art

This example illustrates the use of copolymers according to the invention in the field of paper coatings, and seeks to highlight the maintenance of the thickening conferred by the copolymers used according to the invention for formulations with a constant dosage by dry weight of thickening agent despite the addition of salts.

To accomplish this, for each of the tests the thickening agent to be tested is added to a paper coating consisting of 100 parts of an aqueous suspension of calcium carbonate at a rate of 78% of dry matter, sold by the company Omya™ under the name Hydrocarb™ 60, and of 10 parts of latex at a rate of 50% of dry matter, sold by the company Dow under the name DL 940, and then, after 15 minutes' stirring, the Brookfield™ viscosity at 100 revolutions per minute is measured, using a Brookfield™ viscometer fitted with the appropriate module.

Once the Brookfield™ viscosity at 100 revolutions per minute has been determined, for each of the tests 1.6 parts of powdery sodium chloride is added, and then, after 15 minutes' stirring, the Brookfield™ viscosity is measured at 100 revolutions per minute using a Brookfield™ viscometer fitted with the appropriate module.

This test illustrates the prior art and uses the copolymer used in test n° 11.

The Brookfield™ viscosities at 100 revolutions per minute obtained are:

Before addition of the sodium chloride: 3100 mPa·s

After addition of the sodium chloride: 2400 mPa·s

This test illustrates the invention and uses the copolymer used in test n° 12.

The Brookfield™ viscosities at 100 revolutions per minute obtained are:

Before addition of the sodium chloride: 2700 mPa·s

After addition of the sodium chloride: 3020 mPa·s

A reading of the results of the previous two tests shows the superiority of the polymers according to the invention.