WO2007059857A1 - Polymer dispersions, process for their preparation and use - Google Patents

Abstract

What are described are stable dispersions of selected copolymers in (poly)alkylene glycols and/or ethers thereof. The copolymers derive from i) at least one N-vinylamide of a carboxylic acid or of a nitrogen-containing heterocycle, from ii) at least one olefinically unsaturated sulphonic acid, and optionally from iii) at least one amide of an olefinically unsaturated carboxylic acid which is not an N-vinylamide, optionally from iv) at least one olefinically unsaturated phosphonic acid, and optionally from at least one olefinically unsaturated carboxylic acid, and optionally from v) up to 20% by weight, based on the amount of monomers used, of further monomers copolymerizable with them. The dispersions can be used as assistants in oil extraction.

Description

AllessaChemie GmbH Attorney's file = 205al01.wo

description

Polymer dispersions, process for their preparation and use

The present invention relates to dispersions of selected hydrophilic polymers, which can be used in particular in oil extraction.

To increase the productivity or the yield of Ölfeldem mineral oil-containing sand and rock masses are rinsed with water to expel the mineral oil. The use of water alone, however, leads to problems, since the vast majority of the mineral oil contained in the treated sand and rock masses adhere, because the water, the adhesive forces between oil and

Stone and the pores in the rock caused capillary forces can not overcome. When flooding of oil reservoirs has therefore already been trying to add tools to solve the problems mentioned. As auxiliaries are surface-active substances, such as alkanesulfonates, and / or thickeners based on water-soluble polymers or of

Polysaccharide derivatives used.

Particular preference is given to the use of water-soluble copolymers which find various industrial uses, e.g. as flocculants in wastewater treatment and mining, for absorption of aqueous liquids, as consistency regulator in cosmetic formulations, as textile and dyeing auxiliaries, in the petroleum industry as cementing and Bohrspüladditive as additives in stimulation processes, e.g. in fracturing fluids or as so-called watercontrol additives, as well as tertiary funding.

Examples of such copolymers are disclosed in U.S. Patents 4,309,523; 4,357,245; 4,451,631; 4,499,232; 4,500,437; 4,507,440; 4,551, 513 and 5,735,349. These copolymers are prepared by precipitation polymerization, for example by free-radical polymerization of a solution of the monomers in lower alcohols, for example in tert-butanol. In the course of the polymerization, the resulting copolymer precipitates, is isolated as a powder, usually in powder form, marketed as granules or beads, and then converted to aqueous solutions or gels at the point of use. For this purpose, the use of mechanical equipment, such as mixing units and dissolving stations is necessary to produce homogeneous aqueous preparations, which can occur significant pollution with particulate matter. Often it takes several hours of swelling times to achieve the desired settings.

For use e.g. In the oil field, the polymer powder is dissolved in water and transported to the site of application as typically 2% aqueous solution. The high water content has correspondingly high transport costs. The offering transport of the powder to the site for the production of aqueous

Solution directly before use fails due to the difficult handling of the fine polymer powder (dusts) and problems of processability. The use of these high molecular weight and hydrophilic polymers in the form of aqueous solutions or gels already results in low concentrations due to extremely high viscosities, sensitivity to light and oxidative

Influences often to unmanageable products.

Another delivery form of high molecular weight hydrophilic copolymers are the so-called inverse emulsions. These are water-in-oil emulsions in which the hydrophilic polymers are emulsified as microgel particles in the oil phase. These inverse emulsions can be converted by stirring in water into the aqueous application forms. An example of this is found in US-A-4,299,755. The inverse emulsions described there are characterized by the use of selected emulsifiers. This document discloses a process for preparing anhydrous dispersions of water-soluble polymers, wherein in the first step, the polymer is prepared by inverse emulsion polymerization. In the second step, the aqueous phase is then separated with a portion of the oil phase used by distillation. By adding ethoxylated fatty alcohols to the oil phase, which contains the polymer dispersed, polymer dispersions are obtained, which can be easily distributed in water. For a number of applications, however, the remaining residues of the oil phase and emulsifiers are problematic.

Inverse microlatices of water-soluble copolymers which are obtainable by copolymerization of water-soluble monomers emulsified with the aid of emulsifiers in an organic phase are described in DE-A-35 20 507, DE-AS-1, 089,173, DE-A-33 12 711 and DE-A-2432699. It is known from US Pat. No. 4,521,317 that transparent and stable microlatices dispersed in water can be used in oil production.

It is also already known to carry out radical polymerizations in polyethylene glycol as a solvent or as a dispersing aid.

Thus, JP-A-59 / 108,074 describes a viscosity-increasing agent prepared by copolymerizing (meth) acrylate, (meth) acrylamide and methyl acrylate in an aqueous polyethylene glycol solution.

From KR-A-90/02459 it is known to polymerize water-soluble monomer mixtures of a selected cationic monomer and a water-soluble acrylic monomer and thereby to use among other things polyethylene glycol as a dispersing aid.

JP-A-2002 / 212,895 describes the preparation of a means for controlling the

Viscosity in papermaking. For this purpose, a water-soluble polymer is prepared by polymerization of acrylamide, optionally acrylic acid and optionally lower proportions of a further comonomer in an aqueous solution of polyethylene glycol.

JP-A-2002 / 146,029 describes a process for stabilizing a polymer dispersion based on acrylamide. In this case, an aqueous dispersion of the acrylamide polymer which has a high salt content and additionally a Contains vinylpyrrolidone homo or copolymer, added polyethylene glycol and / or polypropylene glycol.

US-A-4, 380,600 describes aqueous dispersions of water-soluble polymer compositions.

DE-A-102 06 596 discloses graft copolymers for use in cosmetic formulations. These are derived from polyalkylene glycols, to the N-vinylformamide, ethylenically unsaturated carboxylic acids and optionally other ethylenically unsaturated monomers, such as unsaturated sulfonic and / or

Phosphonic acids have been grafted. This document discloses a wide variety of monomer combinations that can be used for grafting. However, no graft copolymers are described in which amides of an olefinically unsaturated carboxylic acid, which are not N-vinyl amides, such as acrylamide or methacrylamide, are used. When used in oil extraction has been found that graft copolymers containing amides of an olefinically unsaturated carboxylic acid, which are not N-vinyl amides, are particularly preferred because these copolymers show little tendency to form insoluble salts with the present in the rock formations calcium and magnesium ions and therefore cause no formation damage.

Finally, from EP-A-90,920 a method for the extraction of oil from underground deposits known. This is characterized in that aqueous solutions of polyethylene glycol and / or polypropylene glycol having a molecular weight of 600 to 6000 are used as flooding medium in the tertiary petroleum production and thereby, in particular under high-salt conditions, the adsorption of polymers also used can drastically reduce. The polymers can be used as an aqueous solution before or after treatment with polyethylene glycol or polypropylene glycol or together with it. Anhydrous dispersions of polyethylene glycol and / or polypropylene glycol and polymers are not disclosed in this document. Examples of possible polymers include copolymers derived from vinylsulfonate, vinylacylamide and acrylamide. Based on this prior art, the object was to provide storage-stable dispersions of selected hydrophilic polymers, which are characterized by good handling and storage stability, which can be easily converted into aqueous preparations without the use of expensive equipment and which are used as Aids in oil extraction are suitable.

The present invention relates to dispersions having a water content of less than 10% by weight comprising a) alkylene glycol, polyalkylene glycol, alkylene glycol ethers, polyalkylene glycol ethers or mixtures of two or more compounds from this group and b) dispersed in component a) particles of copolymer derived from i) at least one N-vinylamide of a carboxylic acid or a nitrogen-containing heterocycle, of ii) at least one olefinically unsaturated sulfonic acid and optionally of iii) at least one amide of an olefinically unsaturated carboxylic acid which is not N-vinylamide, and optionally of iv) at least one olefinically unsaturated phosphonic acid and optionally of v) at least one olefinically unsaturated carboxylic acid, and optionally of vi) up to 20% by weight, based on the amount of the monomers used, of further monomers copolymerizable therewith.

The component a) used according to the invention as a dispersing agent is polyalkylene glycols or mono- or polyethers derived therefrom.

Typical components a) are ethylene glycol (1, 2-ethanediol), propylene glycol (1, 2 or 1, 3-propanediol), tetramethylene glycol (1, 4-butanediol), polyethylene glycols, polypropylene glycols and polybutylene glycols. Some or all of the hydroxyl

End groups of these polyols can be etherified with monovalent organic radicals, such as alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl or heterocyclylalkyl groups. The compounds of component a) are to be selected so that they are liquid at 25 ° C. Optionally, mixtures of these compounds can be used which is solid at 25 ° C contained components, provided the mixture is liquid at 25 ⁰ C.

The average molecular weights of the polyalkylene glycols used according to the invention can vary over a wide range, provided that these compounds or mixtures prepared therefrom are liquid at 25 ° C. Typical molecular weights are in the range from about 60 to 6000. Preference is given to using polyalkylene glycols or their mono- or dialkyl ethers whose mean molecular weights (number average) range from 200 to 800, preferably from 300 to 600.

Preferred components a) are compounds of the formula I.

worin R¹ und R³ unabhängig voneinander Wasserstoff, Alkyl, Cycloalkyl, Aryl, Aralkyl, Heterocyclyl oder Heterocyclylalkyl bedeuten,

in which R ¹ and R ^3, independently of one another, denote hydrogen, alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl or heterocyclylalkyl,

R ^{2 is} hydrogen or methyl and n is an integer from 1 to 100, preferably 5 to 50.

Component a) serves as a dispersant. In finely divided there are copolymers of component b).

In addition to components a) and b), the dispersions of the invention may contain other conventional additives.

In addition to additives which the stability of the dispersions and / or their

Improvements in processability are above all additives which may be beneficial for the intended field of application. Additives which improve the stability of the dispersions include emulsifiers and / or protective colloids. The emulsifiers which can be used are the ionic or nonionic surfactants known per se. As protective colloids it is possible to use high molecular weight substances which sterically stabilize the stability of the copolymer particles, for example polyvinyl alcohol or

Cellulose ethers.

The dispersions according to the invention preferably contain neither emulsifiers nor protective colloids. It has been found that the copolymers b) used according to the invention are self-emulsifying in the dispersants of component a) and give dispersions with high stability.

Additives which improve the processability of the dispersions include viscosity regulators, antifreeze additives, biocides and dyes.

Additives which may be conducive to the intended field of use include acids, especially mineral acids, mineral fillers such as sand, or complexing agents, corrosion inhibitors, wetting agents, oxidizers, defoamers and scale inhibitors.

Further, in addition to component a), there may be further liquids miscible with component a), which may be a solvent or a non-solvent for copolymer b). Examples of additional liquids are water, alcohols, phenols, hydrocarbons, esters or ketones. Water may be present in small quantities; however, it is preferably not added or is completely absent.

The dispersions of the invention have a low water content or are anhydrous. Typically, the water content is less than 10% by weight, based on the total composition, preferably less than 4% by weight, in particular less than 2% by weight, more preferably less than 1% by weight and most preferably less than 0.1% by weight %. At higher water contents gelled the copolymer used and there is no more dispersion, but it forms a gel.

Preferred dispersions are anhydrous and contain as dispersant only component a) or component a) and one or more mono- or polyhydric water-soluble aliphatic alcohols, such as. Methanol, ethanol, propanol, butanol, glycerol, trimethylolpropane and pentaerythritol, and / or mono- and polysaccharides, such as water-soluble starch, and / or cellulose derivatives, and / or carboxylic acids, their salts or their amides, including the cyclic amides, e.g. Carprolactams, and / or water-soluble esters including the lactones, e.g. Butyrolactone, and / or water-soluble amines, their salts and quaternization products, and / or cyclic ethers, e.g. Dioxane and tetrahydrofuran.

The copolymers of component b) are known in some cases and described in the above-mentioned patent documents.

These are copolymers derived from the monomers of groups i) and ii) defined above, and optionally from the monomers from one or more of groups iii) to vi).

The proportion of monomers i), based on the total amount of all monomers is typically 2 to 60 wt.%, Preferably 2 to 55 wt.%.

The proportion of the monomers ii), based on the total amount of all monomers is typically 10 to 90 wt.%, Preferably 20 to 60 wt.%.

The proportion of monomers iii), based on the total amount of all monomers, is typically 0 to 88% by weight, preferably 10 to 80% by weight, in particular 20 to 80% by weight and very particularly preferably 40 to 60% by weight.

The proportion of monomers iv), based on the total amount of all monomers is typically 0 to 10 wt.%, Preferably 0 to 5 wt.%. The proportion of monomers v), based on the total amount of all monomers is typically 0 to 10 wt.%, Preferably 0 to 5 wt.%.

The proportion of the monomers vi), based on the total amount of all monomers is typically 0 to 20 wt.%, Preferably 0 to 10 wt.%.

The copolymers of component b) typically have K values of 50 to 750, preferably K values of 150 to 350.

Particularly preferably used copolymers are derived from 2 to 55% by weight of monomers i), 10 to 90% by weight of monomers ii), 10 to 80% by weight of monomers iii) and 0 to 5% by weight of monomers iv).

Preferably used copolymers b) are derived from at least one N-

Vinylamide of a carboxylic acid and of at least one olefinically unsaturated sulfonic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid and of at least one olefinically unsaturated phosphonic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid, of at least one olefinically unsaturated phosphonic acid and of at least one amide of an olefinically unsaturated carboxylic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid, of at least one amide of an olefinically unsaturated carboxylic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid, of at least one amide of an olefinically unsaturated carboxylic acid and of at least one olefinically unsaturated carboxylic acid.

In addition, these copolymers may contain up to 20% by weight, based on the amount of the monomers used, of further monomer units copolymerizable with the abovementioned monomers. Furthermore, the copolymers can be crosslinked via crosslinkable groups, for example amidocarbonyl groups, by the use of bifunctional and thus reactive compounds, so that swellable polymer networks or higher-viscosity crosslinked polymers are formed. Examples of this can be found in US Pat. No. 4,499,232.

Examples of N-vinylamides of a carboxylic acid i) are monomers derived from the amide of a saturated aliphatic carboxylic acid, such as formic acid or acetic acid, which carry an N-vinyl group. These monomers preferably carry an additional functional group on the amide nitrogen, such as a methylol residue or an N-alkyl residue. In addition to straight-chain N-vinylamides, it is also possible to use N-vinylamides of lactams. Preferred N-vinylamides of a carboxylic acid are N-vinylacetamide, N-vinylformamide, N-vinyl-N-methylformamide, N-vinyl-N-methylacetamide, N-methylol-N-vinylformamide, N-methylol-N-vinylacetamide, N - Vinylpyrrolidone or N-vinylcaprolactam. These monomers are released via the N-

Vinyl group incorporated into the copolymer and can be converted by hydrolysis of the amide group in recurring structural units of the formula -CHk-CH (NH ₂ ) - or -CH ₂ CH (NHR) - or -CH ₂ CH (NRR ^' ) - where R and R ^'are monovalent organic radicals.

Further examples of N-vinylamides of nitrogen-containing heterocycles i) are N-vinyl heterocycles having one or more ring nitrogen atoms, for example N-vinylpyridine or N-vinylimidazole.

Examples of olefinically unsaturated sulfonic acids ii) are vinylsulfonic acid, 2-

Acrylamido-2-methylpropane-sulfonic acid ("AMPS"), 2-methacrylamido-2-methylpropane-sulfonic acid or its alkali metal or ammonium salts.

Examples of amides of olefinically unsaturated carboxylic acids iii) are the amides of the abovementioned carboxylic acids, preferably acrylamide or

Methacrylamide. Particular preference is given to using N-functionalized derivatives of these amides, such as N-alkyl derivatives or N-methyloldehvates. Examples of particularly preferred monomers of this type are N-methylolacrylamide, N- Methylolmethacrylamid, N-methylacrylamide, N-methylmethacrylamide, N-tert-butylacrylamide or N-tert-butylmethacrylamide.

Examples of olefinically unsaturated phosphonic acids iv) are vinylphosphonic acid or its alkali metal or ammonium salts.

Examples of olefinically unsaturated carboxylic acids v) are olefinically unsaturated compounds having one or two carboxyl groups or their anhydrides and salts thereof. Preferred monomers of this type are acrylic acid, methacrylic acid, fumaric acid, maleic acid or itaconic acid. Preference is given to acrylic acid or

Methacrylic acid and the corresponding alkali or ammonium salts.

Examples of further monomers vi) which can be copolymerized with the abovementioned monomers are compounds which do not impair the water-solubility of the resulting copolymer and optionally impart to the copolymer a further desired property. Examples of monomers of this type are esters of olefinically unsaturated carboxylic acids, such as alkyl esters of acrylic acid or methacrylic acid or vinyl esters of saturated carboxylic acids, such as vinyl acetate.

Further examples of monomers vi) are crosslinkers, ie monomers having more than one olefinically unsaturated group. These can be very different classes of substances, such as bis-amides, e.g. Methylene-bis-acrylamide; bis-, tris- or tetra-ethers derived from di-, tri- or tetravalent alcohols and olefinically unsaturated halides, such as trimethylolpropane diallyl ether, pentaerythritol triallyl ether and tetraallyloxyethane; or to esters of olefinically unsaturated

Carboxylic acids with polyhydric alcohols, for example di-, tri- or Tetraacryl- or - methacrylic acid esters derived from ethylene glycol, of trimethylolpropane or of pentaerythritol, or on the nitrogen atom with olefinically unsaturated radicals substituted di-, tri- or polyamines such as NN ^{'diallyl-ethylenediamine} or triallylamine. Crosslinkers are typically used in amounts of 0.01 to 2 wt.%, Preferably 0.1 to 1, 5 wt.%, Based on the total amount of monomers used.

Further particularly preferred components b) are graft polymers derived from

Polyalkylene glycols or polyalkylene glycol-containing polyesters, have been grafted to the monomers of the above-defined groups i), ii) and iii) and optionally monomers of one or more of the groups iv) to vi) defined above.

These graft polymers are new and are also the subject of the invention.

The proportions of the monomers of groups i), ii) and iii) and optionally groups iv) to vi) in the monomer mixtures used for the grafting and the preferred amounts used correspond to the proportions described above for the preparation of the non-grafted copolymers.

Particularly preferred graft polymers are derived from 2 to 55% by weight of monomers i), from 10 to 90% by weight of monomers ii), from 10 to 80% by weight of monomers iii) and from 0 to 5% by weight of monomers iv).

The proportion of the graft base is usually 0.5 to 20 wt.%, Preferably 1 to 10 wt.%, Based on the total amount of graft and monomers used for grafting.

The proportion of the monomer mixtures used for grafting is usually from 80 to 99.5% by weight, preferably from 90 to 99% by weight, based on the total amount of graft base and monomers used for grafting.

Particularly preferred graft polymers whose graft base is a hydroxyl-terminated, alkoxy-terminated or alkanoyloxy-terminated polyalkylene glycol, in particular a polyethylene glycol or polypropylene glycol or Polyethylene glycol-polypropylene glycol block copolymer is. These are typically compounds of the formula XI

in which R ²⁰ and R ^22, independently of one another, are hydrogen, C ₁ -C 6 -alkyl or R ²³ -CO-, R ^{21 is} hydrogen or C ₁ -C ₂ -alkyl,

R ^{23 is} hydrogen or C _r C ₄ alkyl, and m is an integer from 2 to 300.

Particularly preferred graft polymers are derived from compounds of the formula XI as grafting base, to which at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted.

Particularly preferred are graft polymers whose graft base is a hydroxyl-terminated, alkoxy-terminated or alkanoyloxy-terminated polyether containing polyalkylene glycol units. These are typically compounds of formula XII

in which R ²⁶ and R ²⁷ independently of one another are hydrogen, C ₁ -C ₆ -alkyl, R ²⁸ -CO- or R ²⁸ -CO-R ²⁴ -CO-,

R ²¹ and R ²⁵ are independently hydrogen or -C ₂ are alkyl, R ²⁸ is hydrogen or C _r C ₄ alkyl,

R ^{24 is} C ₁ -C ₆ -alkylene, C ₂ -C ₆ -alkenylene, phenylene or sulfonyl-substituted phenylene, m and o independently of one another are integers from 2 to 300 and p is an integer from 1 to 100.

Particularly preferred graft polymers are derived from compounds of the formula XII as the graft base, to which at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted.

Particularly preferred are graft polymers whose graft base is a hydroxyl-terminated, alkoxy-terminated or alkanoyloxy-terminated polyether containing polyalkylene glycol units of the formula XIII

worin R²⁶, R²⁷, R²¹, R²⁵, m, o und p die oben definierte Bedeutung besitzen.

wherein R ²⁶ , R ²⁷ , R ²¹ , R ²⁵ , m, o and p have the meaning defined above.

Particularly preferred graft polymers are derived from compounds of the formula XIII as graft base, to which at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted.

Polymers derived from the graft bases of the formula XI, XII and XIII but to which other monomers have been grafted are known from DE-A-37 38 602, DE-A-39 11 433 and DE-A-39 10 563. The grafting of olefinic monomers onto polyalkylene glycols is known from DE-AS-1, 111, 394.

Particularly suitable polymers as component b) are copolymers which are derived from N-vinylformamide and / or N-vinylpyrrolidone, from AMPS and / or vinylsulfonic acid, from vinylphosphonic acid and from acrylamide and / or from methacrylamide; or of N-vinylformamide and / or N-vinylpyrrolidone, of AMPS and / or vinylsulfonic acid and of acrylamide and / or methacrylamide; or of N-vinylformamide and / or N-vinylpyrrolidone, of AMPS and / or vinylsulfonic acid,

Acrylamide and / or methacrylamide and acrylic acid and / or methacrylic acid; or they are graft polymers derived from the graft bases of the formulas XI, XII or XIII, to which the above-mentioned monomer mixtures have been grafted.

Instead of the abovementioned acids, their salts or esters can also be used. Further suitable co-monomers for the abovementioned particularly preferred monomer mixtures are, for example, vinyl esters, such as vinyl acetate and vinyl propionate, crotonic acid and salts thereof, acrylonitrile, vinylidene carbonate, allyl compounds, for example allylsulfonic acids and their salts, maleic acid, their salts, half esters, amides and anhydrides, and also vinyl ethers ,

For the synthesis of highly swelling hydrogels come as co-monomers multiply olefinically unsaturated compounds in question. Examples are listed above.

Highly swelling hydrogels can also be produced by complex formation of vinylphosphonic acid units with metal ions.

Preferred components b) are copolymers comprising, in random distribution, 5 to 60% by weight of the structural units of the formula II, 2 to 40% by weight of the structural units of the formula III and 35 to 95% by weight of the structural units of the formula IV

wherein M is hydrogen or a cation of a metal, Y is a covalent bond or a radical of the formula -CO-NH-C (CH ₃ ) ₂ -CH ₂ -,

R ⁴ and R ⁵ independently of one another are hydrogen or alkyl, in particular methyl and / or ethylene, where not both radicals together are hydrogen, or R ⁴ and R ⁵ together form an alkylene group, preferably trimethylene, and R ^{5 is} hydrogen or methyl. Such copolymers are described in EP-A-

23,712 and EP-A-44,508.

Further preferred components b) are copolymers which comprise, in random distribution, at least 5% by weight of the structural units of the formula V, at least 10% by weight of the structural units of the formula IV and optionally up to 85% by weight of the structural units of the formula VI

wherein R ^{5 is} hydrogen or methyl,

R ^{6 is} hydrogen, methyl or hydroxymethyl,

R ^{7 is} hydrogen or methyl, and

X is selected from the radicals consisting of sulfonic acid or its

Ammonium or alkali salts or sulfonyl-alkylamidocarbonyl with one to four

Carbon atoms.

Such copolymers are described in US-A-4, 500,437.

Further preferred components b) are copolymers which, in statistical distribution, contain at least 5% by weight of the above-defined structural units of the formula

V, at least 10% by weight of the above-defined structural units of the formula IV and, if appropriate, up to 85% by weight of the above-defined structural units of the formula

VI, wherein at least a portion of the formylamido groups in the structural units of formula V have been crosslinked by reaction with a reagent of formula X.

wherein R ¹³ and R ¹⁶ independently of one another are hydrogen, alkyl having one to four carbon atoms or hydroxymethyl,

R ^{14 is} a group C _n H _2n in which n is an integer from 1 to 3 and R ^{15 is} a group (OC _n H _2n ) m in which n is an integer from 1 to 3 and m is an integer Number is 0 or 1. Such copolymers are described in US-A-4,499,232.

The dispersions of the invention can be prepared in different ways.

In one embodiment (variant 1), the copolymer b) is prepared in a manner known per se by free-radical precipitation polymerization of a monomer solution, if appropriate in the presence of a grafting base in alkanols. The resulting copolymer is separated and processed into powder or granules. This is going through

Mixing in the dispersant a) converted into the dispersion of the invention. In this case, the use of emulsifiers or other dispersants can be omitted, since the copolymers b) in the dispersant a) self-disperse.

In a preferred embodiment (variant 2), the monomers are dissolved in component a) or a mixture of component a) and / or further graft bases and / or solvents for the monomers and polymerized in this medium. The resulting dispersion is optionally freed from the further solvent for the monomers, for example by distillation and the resulting dispersion can be used directly, optionally after addition of further additives.

These methods are also the subject of the present invention.

The processes according to the invention thus avoid the intermediate step via an inverse emulsion polymerization in that the hydrophilic polymers are prepared directly in the presence of polyalkylene glycols and / or their esters and obtained as a dispersion or in that the hydrophilic polymers are prepared in a known manner by precipitation polymerization and then in polyalkylene glycols and / or their esters are dispersed. In this way, anhydrous, storage-stable dispersions of hydrophilic polymers are obtained in suitable polyglycols, optionally in combination with other water-soluble and hydrophilic components, which are particularly characterized in that they are easy to handle and storage stable and can be easily converted into aqueous preparations.

Preferred combinations of polymerization media are mixtures of polyethylene glycol and aliphatic monohydric alcohols having one to four carbon atoms, preferably tertiary butanol.

The synthesis of the copolymers b) for the preparation of the dispersions of the invention (variant 1) is preferably carried out as so-called precipitation polymerization, wherein the monomers used are soluble in the reaction medium used, while the resulting polymers are insoluble therein and precipitate in solid form.

Suitable reaction media for the preparation according to variant 1 are, for example, hydrocarbons having boiling points of up to 130 ^° C., such as hexane, heptane, cyclohexane, octane, isooctane, aliphatic n-iso- and tert.-alcohols in the boiling range up to 130 ^° C., cycloaliphatic alcohols, tert-butyl ether, cyclic ethers such as dioxane and

Tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, esters of formic and acetic acid with alcohols up to 4 carbon atoms.

The polymerization (variant 1 or variant 2), in the temperature range between 0 ⁰ C and 150 ⁰ C, preferably between 20 ⁰ C and 11 0 ° C in both

Normal pressure can also be carried out under elevated pressure. As usual, the polymerization can also be carried out under a protective gas atmosphere, preferably under nitrogen or argon.

To initiate the polymerization (variant 1 or variant 2) can high-energy

Radiation or the usual polymerization initiators are used, for example, organic peroxides such as benzoyl peroxide, tert-butyl hydroperoxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dilauryl peroxide, azo compounds, such as azodiiso butyronitrile, ABAH and inorganic peroxide compounds, such as alkali metal peroxodisulfate, hydrogen peroxide optionally in combination with reducing agents such as sodium hydrogen sulfite, thionyl chloride or ascorbic acid and Ce ^ιv ions.

After completion of the polymerization, the polymers are present as a 5 to 50% suspension in organic medium (variant 1).

The polyalkylene glycols and / or polyalkylene glycol ethers are then added to component a) and the organic solvent used as the reaction medium is optionally distilled off under reduced pressure or the copolymers are isolated and then the polyalkylene glycols and / or polyalkylene glycol ethers are added to component a).

After completion of the distillation, other water-soluble substances such as alcohols, polyols, alkyl polyglycols, amines for adjusting the desired

Property profiles are added to obtain the inventive, preferably anhydrous, polymer dispersions.

In a further process variant, the synthesis of the polymers can be carried out according to the processes described in US-A-3,957,937 or US-A-4,396,752, wherein after completion of the polymerization, the appropriate polyalkylene glycol and / or Polyalkylenglykoletherkomponenten are added and then the water content together with that as Reaction medium used cyclohexane is distilled off azeotropically.

The dispersions of the invention have a high solids content. Typical values range from 5 to 60% solids, preferably from 10 to 40% solids, based on the dispersion. The dispersions of the invention can be formulated without problems with water to homogeneous dilute aqueous polymer solutions, without causing lumping. In this way, aqueous solutions of component b) can be obtained in a simple manner from the highly concentrated dispersions. The erfindungsgmäßen dispersions or in particular the aqueous solutions prepared therefrom can be used as aids in oil production, especially as cementing and Bohrspüladditive, as additives in stimulation processes, such as in fracturing fluids, as Watercontrol additives and tertiary promotion, and as a thickener or textile auxiliaries.

The invention also relates to these uses.

The following examples illustrate the invention without limiting it. All amounts are by weight unless otherwise stated.

example 1

In a 1 L laboratory flask (equipped with reflux condenser, gas inlet tube,

Stirrer and a controllable oil bath) 200 ml of tert-butanol and 70 g PEG 400 were submitted. 15 g of AMPS were added while stirring to the laboratory flask. The AMPS was adjusted to pH 7-8 with ammonia gas. Then, with stirring, 27.5 g of acrylamide, 7.5 g of N-vinylformamide, 30 ml of acetone and 0.5 g of crosslinker (1) (1, 1, 1-tris (hydroxymethyl) -propane-trimethacrylate) in the neutralized AMPS

Solution entered. The flask contents were heated to 35 ° C. 0.5 g starter (A) was introduced. The mixture was then heated to 56 ° C. under nitrogen blanketing. The polymerization started. After reaching the maximum temperature of 69-72 ⁰ C, the mixture for two hours at 70-80 ⁰ C was stirred.

Example 1A

After completion of the polymerization, the dispersion of solvent and polymer in the laboratory flask was evaporated to dryness, optionally under vacuum. Subsequently, with the aid of a high-speed stirrer / mixer or an Ultra-Turax, the dry polymer (50 g) was dispersed in 367 g of polyethylene glycol 400 (PEG 400) until a homogeneous, stable dispersion was obtained.

Example 1 B

As an alternative to Example 1A was after completion of the polymerization at 75-8O ⁰ C and approximately 200 mbar distilling off the solvent mixture. At the same time, 367 g of polyethylene glycol 400 (PEG 400) were continuously added to the batch. The distillation was complete when the tert-butanol / acetone mixture had been completely removed by distillation. A homogeneous, stable dispersion was obtained.

Example 1 C

As an alternative to Example 1A, after the end of the polymerization, 367 g of polyethylene glycol 400 (PEG 400) were metered into the batch. Thereafter, the solvent mixture was distilled off at 75-80 ⁰ C and 200 mbar. The distillation was complete when the tert-butanol / acetone mixture had been completely removed by distillation. Again, a homogeneous, stable dispersion was obtained.

Analogously to Example 1, mixtures were prepared in which the monomers, the crosslinker or the initiator were varied. An overview of the experiments carried out can be found in Table 1. The percentages in the table refer to the amount of the main monomers (without crosslinker).

Table 1 - Copolymer Variations for Example 1

¹⁾ AMPS = acrylamido-2-methylpropane-sulphonic acid

²⁾ AAM = acrylamide

³⁾ VFA = N-vinylformamide

⁴⁾ VA = vinyl acetate

⁵⁾ AS = acrylic acid

⁶⁾ VP = N-vinylpyrrolidone

⁷⁾ VPS = vinylphosphonic acid (this monomer was treated with prior to neutralization

Ammonia gas added together with AMPS)

⁸⁾ AN = acrylonitrile

⁹⁾ crosslinker; the quantity refers to the total amount of the main monomers, ie monomers without crosslinker; the total amount of the main monomers adds up to 100%

1 = 1, 1, 1-tris (hydroxymethyl) propane trimethacrylate 2 = trimethylolpropane diallyl ether

3 = trimethylolpropane ethoxylate trimethacrylate

4 = pentaerythritol triallyl ether

5 = methylenebisacrylamide

6 = tetraallyloxyethane

¹⁰⁾ A = AIBN (2,2 ^'-Azodi (isobutyronitrile))

B = ABAH ^{(2,2'-azobis-} (2-amidinopropane) dihydrochloride) C = DLP (dilauryl peroxide)

Examples 23 to 44

The copolymer prepared according to Example 1 was treated with different dispersants. The results are listed in the following table. In all cases, stable dispersions were obtained.

Table 2 - Dispersant Variations

Example 45

250 ml of tert-butanol were placed in a 1 l laboratory flask (equipped with reflux condenser, gas inlet tube, stirrer and an adjustable heating bath) and, while stirring as a grafting base, a mixture of 20 g of the reaction product (described in Example A in DE-A-A). 39 11 433) dissolved in 70g of polyethylene glycol 400 registered. Subsequently, with further stirring, 15 g of AMPS were dissolved and this solution was adjusted to pH 7-9 while introducing ammonia gas; then 27.5 g acrylamide, 7.5 g vinyl formamide and 0.5 g

Crosslinker (trimethylolpropane diallyl ether) registered. The flask contents were heated to 35 ° C while introducing a gentle stream of nitrogen. 0.5 g of initiator (B) was added. The reaction mixture was then heated to 50 ⁰ C. After a short induction time, the polymerization started, as evidenced by precipitation of the polymer and temperature rise. After reaching the

Maximum temperature of 70-75 ⁰ C was stirred for a further hour at 80 ° C. Then, with the continuous addition of 360 g of polyethylene glycol 400 (PEG 400), the tert-butanol was removed by distillation. It became a stable homogeneous Polymer dispersion which, in a simple manner by stirring in water formed a viscous solution.

Vicosity measurements gave a K value (according to Fikentscher) of 266 for the polymer.

Further graft copolymers according to the invention were prepared analogously using other graft bases described in DE-A-39 11 433 and graft bases described in DE-A-37 38 602 and DE-A-39 10 563. Details are given in Table 3 below.

Table 3 - Copolymer Variations for Example 45

¹⁾ AMPS = acrylamido-2-methylpropane-sulphonic acid

²⁾ AAM = acrylamide

³⁾ VFA = N-vinylformamide

⁴⁾ VA = vinyl acetate

⁵⁾ AS = acrylic acid

⁶⁾ vp = N-vinylpyrrolidone

⁷⁾ VPS = vinylphosphonic acid (this monomer was treated with prior to neutralization

Ammonia gas added together with AMPS)

⁸⁾ AN = acrylonitrile

⁹⁾ crosslinker

1 = 1, 1 J-tris-hydroxymethyl-propane trimethacrylate

2 = trimethylolpropane diallyl ether

3 = trimethylolpropane ethoxylate trimethacrylate

4 = pentaerythritol triallyl ether

5 = methylenebisacrylamide

6 = tetraallyloxyethane

Examples 59 and 60 and Comparative Example 61

The anhydrous dispersion of Example 1 was mixed with different amounts of water.

With an addition of 5% by weight of water (Example 59) and of 10% by weight of water (Example 60), lumpy dispersions of ointment-like consistency were obtained.

With an addition of 20 wt.% Water (Comparative Example 61) was formed

Hydrogelklumpen.

Claims

Claims: 205al01.wo 1. Dispersions having a water content of less than 10 wt.% Containing a) alkylene glycol, polyalkylene glycol, alkylene glycol ethers, polyalkylene glycol ethers or mixtures of two or more compounds from this group and b) dispersed in component a) particles of copolymer derived from i) at least one N-vinyl amide of a carboxylic acid or a nitrogen-containing heterocycle, of ii) at least one olefinically unsaturated sulfonic acid, and optionally of iii) at least one amide of an olefinically unsaturated carboxylic acid which is not an N-vinylamide, and optionally iv) at least one olefinically unsaturated phosphonic acid, and optionally of at least one olefinically unsaturated carboxylic acid, and optionally of v) up to 20 wt.%, Based on the amount of the used Monomers, further monomers copolymerizable therewith. 2. Dispersions according to claim 1, characterized in that component a) is selected from the group consisting of ethylene glycol (1, 2-ethanediol), propylene glycol (1, 2 or 1, 3-propandil), tetramethylene glycol (1, 4- Butanediol), polyethylene glycols, polypropylene glycols, polybutylene glycols or mixtures containing two or more of these compounds, with the Provided that these compounds or mixtures thereof are liquid at 25 ° C. 3. Dispersions according to claim 2, characterized in that component a) contains polyalkylene glycols or their mono- or dialkyl ethers whose mean Molecular weights (number average) ranging from 200 to 800, preferably from 300 to 600 move. 4. Dispersions according to claim 1, characterized in that component a) contains compounds of the formula I.

wherein R ¹ and R ³ independently of one another are hydrogen, alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl or heterocyclylalkyl, R ^{2 is} hydrogen or methyl and n is an integer from 1 to 100, preferably 5 to 50. 5. Dispersions according to claim 1, characterized in that they contain neither emulsifiers nor protective colloids. 6. dispersions according to claim 1, characterized in that these additionally Viscosity regulators, antifreeze additives, biocides, dyes, acids, in particular mineral acids, corrosion inhibitors, wetting agents, Oxyydationsmittel, defoamers, scale inhibitors and / or mineral fillers. 7. dispersions according to claim 1, characterized in that in addition Component a) present other miscible liquids, in particular water, alcohols, phenols, hydrocarbons, esters and / or ketones. 8. Dispersions according to claim 1, characterized in that their Water content, based on the total composition, less than 4 wt.%, Preferably less than 2 wt.%, In particular less than 1 wt.% And most preferably less than 0.1 wt.% Is. 9. dispersions according to claim 8, characterized in that they are anhydrous and as a dispersant only component a) or component a) and one or more mono- or polyhydric water-soluble aliphatic alcohols and / or mono- and polysaccharides and / or cellulose derivatives and / or Carboxylic acids, their salts or their amides and / or water-soluble esters and / or water-soluble amines their salts and Quaternization products, and / or cyclic ethers. 10. Dispersions according to claim 1, characterized in that component b) is a copolymer which is derived from at least one N-vinylamide of a carboxylic acid and at least one olefinically unsaturated sulfonic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid and of at least one olefinically unsaturated phosphonic acid; or of at least one N-vinylamide of one Carboxylic acid, of at least one olefinically unsaturated sulfonic acid, of at least one amide of an olefinically unsaturated carboxylic acid; or of at least one N-vinylamide of a carboxylic acid, of at least one olefinically unsaturated sulfonic acid, of at least one amide of an olefinically unsaturated carboxylic acid and of at least one olefinically unsaturated carboxylic acid. 11. Dispersions according to claim 1, characterized in that component b) is a graft polymer which is derived from polyalkylene glycols or polyalkylene glycol-containing polyesters, to the monomers of the following groups i) and ii) and optionally monomers of one or more of the groups iii) to vi) have been grafted: i) at least one N-vinylamide of a carboxylic acid or a nitrogen-containing heterocycle, ii) at least one olefinically unsaturated sulfonic acid, and optionally iii) at least one amide of an olefinically unsaturated Carboxylic acid, which is not N-vinylamide, and optionally iv) at least one olefinically unsaturated phosphonic acid, and optionally v) at least one olefinically unsaturated carboxylic acid, and optionally vi) up to 20 wt.%, Based on the amount of monomers used, further copolymerizable with it monomers. 12. Dispersions according to claim 11, characterized in that the polyalkylene glycol is a compound of the formula XI

where R ²⁰ and R ²² independently of one another are hydrogen, C 1 -C 6 -alkyl or R ²³ - CO mean, R ²¹ is hydrogen or C _r C ₂ alkyl; R ^{23 is} hydrogen or C _r C ₄ alkyl, and m is an integer from 2 to 300. 13. Dispersions according to claim 12, characterized in that the Graft polymer is derived from compounds of the formula XI as a graft base, on the at least one N-vinylamide of a carboxylic acid and at least one olefinically unsaturated sulfonic acid; or at least one N-vinylamide one Carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one olefinically unsaturated phosphonic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted. 14. Dispersions according to claim 11, characterized in that the Polyalkylenglykoleinheiten containing polyester is a compound of formula XII

in which R ²⁶ and R ²⁷ independently of one another are hydrogen, C ₁ -C ₆ -alkyl, R ²⁸ -CO- or R ²⁸ -CO-R ²⁴ -CO-, R ²¹ and R ²⁵ are independently hydrogen or -C ₂ are alkyl, R ²⁸ is hydrogen or C _r C ₄ alkyl, R ²⁴ Ci -C ₆ -alkylene, C ₂ -C ₆ alkenylene, phenylene, or substituted phenylene sulfonyl, m and o represent independently of each other integers from 2 to 300 and p is an integer from 1 to 100. 15. Dispersions according to claim 14, characterized in that the graft polymer is derived from compounds of formula XII as a graft base, on the at least one N-vinylamide of a carboxylic acid and at least and at least one olefinically unsaturated sulfonic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated Sulfonic acid and at least one olefinically unsaturated phosphonic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted. 16. Dispersions according to claim 11, characterized in that the polyester containing polyalkylene glycol units is a compound of the formula XIII is in which R ²⁶ and R ²⁷ independently of one another are hydrogen, C 1 -C 6 -alkyl, R ²⁸ -CO- or R ²⁸ -CO-CH = CH-CO-, R ²¹ and R ²⁵ independently of one another are hydrogen or C ₁ -C ₂ -alkyl, R ^{28 is} hydrogen or C _r C ₄ alkyl, m and o are independently integers from 2 to 300 and p is an integer from 1 to 100. 17. Dispersions according to claim 16, characterized in that the Graft polymers derived from compounds of formula XIII as a grafting base, on the at least one N-vinylamide of a carboxylic acid and at least one olefinically unsaturated sulfonic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one olefinically unsaturated phosphonic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated Carboxylic acid have been grafted. 18. Dispersions according to claim 1, characterized in that component b) is a copolymer which is derived from N-vinylformamide and / or N-vinylpyrrolidone and AMPS and / or vinylsulfonic acid; or from N- Vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid and vinylphosphonic acid; or of N-vinylformamide and / or N-vinylpyrrolidone, of AMPS and / or vinylsulfonic acid and of acrylamide and / or methacrylamide; or of N-vinylformamide and / or N-vinylpyrrolidone, of AMPS and / or vinylsulfonic acid, acrylamide and / or methacrylamide and acrylic acid and / or methacrylic acid. 19. Dispersions according to any one of claims 12, 14 or 16, characterized in that component b) is a graft polymer, which is derived from a graft base of formula Xl, XII or XIII, to which the following monomer mixtures have been grafted: N-vinylformamide and / or N-vinylpyrrolidone and AMPS and / or vinylsulfonic acid; or N-vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid and vinylphosphonic acid; or N-vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid and acrylamide and / or methacrylamide; or N-vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid, acrylamide and / or methacrylamide and acrylic acid and / or methacrylic acid. 20. Dispersions according to claim 1, characterized in that component b) is a copolymer having in statistical distribution 5 to 60 wt.% Of the structural units of the formula II, 2 to 40 wt.% Of the structural units of the formula III and 35 to 95 wt .% Of the structural units of the formula IV contains

wherein M is hydrogen or a cation of a metal, Y is a covalent bond or a radical of the formula -CO-NH-C (CH ₃ ) ₂ -CH ₂ -, R ⁴ and R ^{5 are} independently hydrogen or alkyl, in particular Methyl and / or ethylene, where not both radicals together Represent hydrogen, or R ⁴ and R ⁵ together form an alkylene group, preferably trimethylene, and R ^{5 is} hydrogen or methyl. 21. Dispersions according to claim 1, characterized in that component b) is a copolymer which in random distribution at least 5 wt.% Of the structural units of the formula V, at least 10 wt.% Of the structural units of the formula IV and optionally up to 85 wt. % of the structural units of the formula VI contains

wherein R ^{5 is} hydrogen or methyl, R ^{6 is} hydrogen, methyl or hydroxymethyl, R ^{7 is} hydrogen or methyl, and X is selected from the radicals consisting of sulfonic acid or its ammonium or alkali salts or Sulfonalkylamidocarbonyl having one to four carbon atoms or their ammonium or alkali metal salts. 22. Dispersions according to claim 1, characterized in that component b) is a copolymer having a random distribution of at least 5 wt.% Of defined in claim 10 structural units of the formula V, at least 10 wt.% Of the structural units defined in claim 10 of the formula IV and optionally up to 85% by weight of the structural units of formula VI as defined in claim 10, wherein at least part of the formylamido groups in the structural units of formula V have been crosslinked by reaction with a reagent of formula X.

wherein R ¹³ and R ^{16 are} independently hydrogen, alkyl of one to four Carbon atoms or hydroxymethyl, R ¹⁴ denotes a group C _n Hb _n , in which n is an integer from 1 to 3 and R ^{15 is} a group (OC _n H _2n ) _m in which n is an integer from 1 to 3 and m is an integer from 0 or 1. 23. graft polymers derived from polyalkylene glycols or from Polyesters containing polyalkylene glycol units, to which monomers of the following groups i) and ii) and optionally monomers of one or more of groups iii) to vi) have been grafted: i) at least one N-vinylamide of a carboxylic acid or a nitrogen-containing heterocycle, ii) at least one olefinically unsaturated sulfonic acid, iii) at least one amide of an olefinically unsaturated carboxylic acid which is not an N-vinylamide, and optionally iv) at least one olefinically unsaturated phosphonic acid, and optionally at least one olefinically unsaturated carboxylic acid, and optionally v) up to 20% by weight, based on the amount the used Monomers, further monomers copolymerizable therewith. 24. Graft polymers according to claim 23, characterized in that the Polyalkylene glycol is a compound of formula Xl

wherein R ²⁰ and R ²² are independently hydrogen, Ci-Cβ alkyl or R ²³ -CO-, R ²¹ is hydrogen or C ₂ alkyl, R ²³ is hydrogen or C _r C ₄ alkyl, and m is an integer from 2 to 300 means. 25. Graft polymers according to claim 24, characterized in that they are derived from compounds of the formula XI as a graft, to the at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide one Carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted. 26. Graft polymers according to claim 23, characterized in that the Polyalkylenglykoleinheiten containing polyester is a compound of formula XII

in which R ²⁶ and R ²⁷ independently of one another are hydrogen, C 1 -C 6 -alkyl, R ²⁸ -CO- or R ²⁸ -CO-R ²⁴ -CO-, R ²¹ and R ²⁵ independently of one another are hydrogen or C 1 -C 2 -alkyl, R ^{28 is} hydrogen or C 1 -C ₄ -alkyl, R ²⁴ Ci-C ₆ alkylene, C ₂ -C ₆ -alkenylene, phenylene or sulphonyl-substituted Phenylene means m and o independently represent integers from 2 to 300 and p is an integer from 1 to 100. 27. graft polymers according to claim 26, characterized in that these are derived from compounds of formula XII as a graft, to the at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide one Carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted. 28. graft polymers according to claim 23, characterized in that the Polyalkylenglykoleinheiten containing polyester is a compound of formula XIII

in which R ²⁶ and R ²⁷ independently of one another are hydrogen, C ₁ -C ₆ -alkyl, R ²⁸ -CO- or R ²⁸ -CO-CH = CH-CO-, R ²¹ and R ²⁵ independently of one another are hydrogen or C ₁ -C ₂ -alkyl, R ^{28 is} hydrogen or C ₁ -C ₄ -alkyl, m and o independently of one another are integers from 2 to 300 and p is an integer from 1 to 100 is. 29. Graft polymers according to claim 28, characterized in that they are derived from compounds of the formula XIII as the graft base, to the at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one olefinically unsaturated phosphonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide of a carboxylic acid, at least one olefinically unsaturated sulfonic acid and at least one amide of an olefinically unsaturated carboxylic acid; or at least one N-vinylamide one Carboxylic acid, at least one olefinically unsaturated sulfonic acid, at least one amide of an olefinically unsaturated carboxylic acid and at least one olefinically unsaturated carboxylic acid have been grafted. 30. graft polymers according to any one of claims 24, 26 or 28, characterized in that they are derived from a graft base of the formula XI, XII or XIII, to which the following monomer mixtures have been grafted: N-vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid and vinylphosphonic acid and acrylamide and / or methacrylamide; or N- Vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid and acrylamide and / or methacrylamide; or N-vinylformamide and / or N-vinylpyrrolidone, AMPS and / or vinylsulfonic acid, acrylamide and / or methacrylamide and acrylic acid and / or methacrylic acid. 31. A process for the preparation of the dispersions according to claim 1, characterized in that copolymers b) are prepared and isolated in a conventional manner by precipitation of a monomer solution, and the copolymer b) then in a dispersant a), optionally further miscible liquids contains, is mixed. 32. A process for the preparation of the dispersions according to claim 1, characterized in that the monomers for the preparation of the copolymer b) in component a) or a mixture of component a) and other solvents mittein dissolved for the monomers and polymerized in this medium and the resulting dispersion is optionally freed from the further solvent for the monomers. 33. The method according to any one of claim 31 or 32, characterized in that a mixture of polyethylene glycol and aliphatic monohydric alcohols having one to four carbon atoms, preferably tert-butanol, is used as the dispersant. 34. Use of the dispersions according to claim 1 or the aqueous solutions prepared therefrom as aids in oil extraction and as Thickener or as textile auxiliaries. 35. The use as claimed in claim 34, characterized in that the dispersions or the aqueous solutions prepared therefrom are used as cementing and Bohrspüladditive, as additives in stimulation processes, in particular in Fracturing fluids, as watercontrol additives and in the tertiary promotion.