WO2020084046A1

WO2020084046A1 - Process for preparing propylenoxy-containing hydrophobically associating monomers by dmc catalysis

Info

Publication number: WO2020084046A1
Application number: PCT/EP2019/079019
Authority: WO
Inventors: Christian Bittner; Bjoern Langlotz; Tobias Joachim Zimmermann; Roland Reichenbach-Klinke
Original assignee: Basf Se
Priority date: 2018-10-26
Filing date: 2019-10-24
Publication date: 2020-04-30

Abstract

The invention relates to a process, using DMC catalysis, for preparing hydrophobically associating monomers, which comprise a copolymerizable, ethylenically unsaturated group and a polyether structure in block form that consists of a polyethylenoxy block and a polypropylenoxy block. The invention further relates to water-soluble hydrophobically associating copolymers, which contain hydrophobically associating monomers obtained by this process, and to the use of the water-soluble hydrophobically associating copolymers in enhanced oil recovery.

Description

Process for the preparation of propyleneoxy-containing hydrophobically associating monomers by means of DMC catalysis

description

The present invention relates to a process by means of DMC catalysis for the production of hydrophobically associating monomers which comprise a copolymerizable, ethylenically unsaturated group and a polyether structure in block form which consists of a polyethyleneoxy block and a polypropyleneoxy block. The invention further relates to water-soluble hydrophobically associating copolymers containing hydrophobically associating monomers thus produced, and to the use of the water-soluble hydrophobically associating copolymers in tertiary petroleum production.

In natural oil deposits, oil is present in the cavities of porous storage rocks, which are sealed off from the earth's surface by impermeable cover layers. The cavities can be very fine cavities, capillaries, pores or the like. Fine pore necks, for example, can have a diameter of only about 1 pm. In addition to crude oil, including natural gas, a deposit also contains more or less saline water.

When it comes to oil production, a distinction is made between primary, secondary and tertiary production.

In primary production, after drilling into the reservoir, the petroleum flows naturally through the borehole to the surface due to the intrinsic pressure of the reservoir. The autogenous pressure can be caused, for example, by gases such as methane, ethane or propane present in the deposit. The intrinsic pressure of the deposit generally diminishes relatively quickly when crude oil is extracted, so that depending on the type of deposit, only around 5 to 10% of the amount of petroleum in the deposit can usually be extracted using the primary production. After that, the autogenous pressure is no longer sufficient to extract oil.

After the primary funding, the secondary funding is usually used. In the case of secondary production, in addition to the wells that serve to extract the oil, the so-called production wells, further wells are drilled in the petroleum-bearing formation. Through these so-called injection holes, water is injected into the reservoir (the so-called “water flooding”) in order to maintain or increase the pressure. By injecting the water, the petroleum is slowly pushed through the cavities in the formation, starting from the injection well in the direction of the production well. However, this only works as long as the cavities are completely filled with oil and the more viscous oil is pushed through the water in front of it. As soon as the thin water breaks through cavities, from this point on it flows through the path of least resistance, i.e. through the channel formed, and no longer pushes it Oil ahead. As a rule, only around 30 to 35% of the amount of oil in the deposit can be extracted using primary and secondary production.

After the measures of secondary oil production, measures of tertiary oil production, also known as “Enhanced Oil Recovery (EOR)”, are used to further increase the oil yield. These include processes in which certain chemicals, such as surfactants and / or polymers, are used as auxiliaries for oil production. An overview of tertiary oil production using chemicals can be found, for example, in the article by D.G. Kessel, Journal of Petroleum Science and Engineering, 2 (1989) 81-101.

The so-called “polymer flooding” is one of the techniques of tertiary oil production. In polymer flooding, an aqueous solution of a thickening polymer is pressed into the petroleum deposit through the injection holes, the viscosity of the aqueous polymer solution being adapted to the viscosity of the petroleum. By injecting the polymer solution, the crude oil is pushed through the cavities in the formation from the injection well in the direction of the production well, as in the case of water flooding, and the crude oil is conveyed through the production well. However, the fact that the polymer formulation has approximately the same viscosity as the petroleum reduces the risk that the polymer formulation will break through to the production well without any effect, and thus the mobilization of the petroleum takes place much more evenly than when using low-viscosity water. This means that additional petroleum can be mobilized in the formation. Details on polymer flooding and polymers suitable for this are disclosed, for example, in "Petroleum, Enhanced Oil Recovery, Kirk-Othmer, Encyclopedia of Chemical Technology, Online Edition, John Wiley & Sons, 2010".

A variety of different thickening polymers have been proposed for polymer flooding, in particular high molecular weight polyacrylamide, copolymers of acrylamide and other comonomers such as vinylsulfonic acid or acrylic acid. Polyacrylamide can in particular be partially hydrolyzed polyacrylamide, in which part of the acrylamide units is hydrolyzed to acrylic acid. Furthermore, naturally occurring polymers can also be used, such as, for example, xanthan or polyglycosylglucan, as described, for example, in US Pat. No. 6,392,596 B1 or CA 832 277.

It is also known to use hydrophobically associating copolymers for polymer flooding. The person skilled in the art understands this to mean water-soluble polymers which have pendant or terminally hydrophobic groups, such as, for example, longer alkyl chains. In aqueous medium, such hydrophobic groups can associate with themselves or with other substances having hydrophobic groups. This creates an associative network through which the medium is thickened. Details on the use of hydrophobically associating copolymers for tertiary oil production can be found, for example, in the review article by Taylor, K.C. and Nasr-El-Din, H.A. in J. Petr. Be. Closely. 1998, 19, 265-280.

WO 2010/133527 discloses water-soluble, hydrophobically associating copolymers. The copolymers described comprise hydrophilic, monoethylenically unsaturated monomers such as for example acrylamide and monoethylenically unsaturated hydrophobically associating monomers. The monoethylenically unsaturated hydrophobically associating monomers here comprise copolymerizable ethylenically unsaturated groups and a polyether structure in block form, the polyether structure comprising a polyethyleneoxy block and a hydrophobic polyalkyleneoxy block containing butyleneoxy or pentyleneoxy units, and optionally a terminal polyethyleneoxy block. Such hydrophobically associating monomers are preferably prepared by base-catalyzed alkoxylation of a hydroxybutyl vinyl ether with ethylene oxide and another alkylene oxide, preferably pentylene oxide. The copolymers described can be used in the field of construction chemistry and tertiary oil production for thickening aqueous phases. The copolymers can be formulated on their own or together with surfactants to form a thickening system.

WO201 1/015520 A1 discloses a process for producing hydrophobically associating copolymers by polymerizing water-soluble, monoethylenically unsaturated surface-active monomers and monoethylenically unsaturated hydrophilic monomers in the presence of non-polymerizable surfactants and the use of such copolymers for polymer flooding. Here, monoethylenically unsaturated monomers used which, in addition to an ethylenically unsaturated group, have a polyethyleneoxy block and a hydrophobic polyalkyleneoxy block containing alkyleneoxy units with at least 4 carbon atoms.

WO 2012/069438 describes a method for oil production using an aqueous formulation. This contains a water-soluble, hydrophobically associating copolymer and 0.005 to 1% by weight of a surfactant, which serves to increase the viscosity of the formulation. The copolymers described contain hydrophobically associating monomers which are preferably prepared first by base-catalyzed alkoxylation of a hydroxybutyl vinyl ether with ethylene oxide and a further alkylene oxide, preferably pentylene oxide.

CN 102146159 A describes a process for the preparation of a polyvinyl ether monomer, the polyether monomer having the general formula H ₂ C = C (R ² ) -0-R ¹ -0- (C _a H _a O) _n - (C _b H _b O) _m -H, where a and b are integers from 2 to 4, a is not equal to b and R ^{1 is} a Ci-Cs-alkylene group. The monomers described in the document have a polyalkyleneoxy block which is composed of ethylene oxide, propylene oxide and / or butylene oxide. The alkoxylation is preferably carried out at a temperature in the range from 120 to 160 ° C. and with the addition of an alkyl catalyst, for example potassium methoxide.

WO2014 / 095608 A2 and WO 2014/095621 A1 describe a process for the preparation of hydrophobically associating monomers and water-soluble, hydrophobically associative copolymers produced therefrom. The hydrophobically associating monomers have a copolymerizable ethylenically unsaturated group and a polyether structure in block form, the polyether structure comprising a polyethyleneoxy block and a hydrophobic polyalkyleneoxy block containing butyleneoxy or pentyleneoxy units, and optionally a terminal polyethyleneoxy block. The hydrophobically associating monomers are prepared in a multi-stage, base-catalyzed process, wherein a critical concentration of potassium ions is not exceeded in the alkoxylation with butylene oxide or pentylene oxide.

WO 2015/086468 A1 describes a method for tertiary oil production using water-soluble hydrophobically associating copolymers which comprises at least acrylamide and / or derivatives thereof and a mixture of two amphiphilic macromonomers. The amphiphilic macromonomers have an ethylenically unsaturated group and a polyether structure in block form, the polyether structure of the first macromonomer having a polyethyleneoxy block and a hydrophobic polyalkyleneoxy block containing alkyleneoxy units having at least 4 carbon atoms and the second macromonomer having additional blocks comprising polyalkyleneoxy units having at least Have 4 carbon atoms and a terminal ethyleneoxy block. The amphiphilic monomers are preferably prepared in a multistage, base-catalyzed process as described in WO2014 / 095608 A2 and WO 2014/095621 A1.

EP 1 069 139 describes monomers comprising an ethylenically unsaturated group and a polyether structure which preferably has a propyleneoxy block, an ethyleneoxy block and again a propyleneoxy block, the first propyleneoxy block having 2 to 35 propyleneoxy units and the ethyleneoxy block 10 to 45 ethyleneoxy units and the second propylene oxy block comprises 8 to 35 propyleneoxy units.

WO 2013/017328 A1 describes associative monomers containing an ethylenically unsaturated group and a polyether structure, the polyether structure having ethyleneoxy and / or propyleneoxy units, for example 20 ethyleneoxy and 20 propyleneoxy units.

WO 93/06142 A1 describes block copolymers which can be obtained by the alkoxylation of hydroxyalkyl vinyl ether first with ethylene oxide and then with propylene oxide.

WO 2009/052864 A1 discloses a process for the preparation of polyether alcohols, an unsaturated starter compound having at least one active hydrogen atom per molecule being alkoxylated with ethylene oxide or propylene oxide in an at least two-stage, base-catalyzed process.

WO 2010/076093 A2 relates to copolymers which have an isoprenol polyether derivative structural unit a, a vinyloxypolyether derivative structural unit β and an acid structural unit y, the structural units a and β having alkyleneoxy units having 2 to 5 carbon atoms.

EP 23737813 B1 describes copolymers of a (meth) acrylic acid monomer and a macromonomer, comprising an ethylenically unsaturated functional group which is alkoxylated with ethyleneoxy and propyleneoxy units, the alkyleneoxy units preferably being randomly distributed. The known processes for the production of hydrophobically associating monomers sometimes have certain disadvantages. Monomers are often used which, in addition to an ethyleneoxy block, have an alkyleneoxy block comprising pentyleneoxy and / or butyleneoxy units. Butylene oxide and pentylene oxide are comparatively expensive and are not available everywhere. If, however, monomers with a comparatively long propylene oxy block are instead produced, disadvantageous rearrangement reactions can be observed during the propoxylation, particularly in the production of monomers with more than X propyleneoxy units. The by-products obtained in this way can lead to disadvantageous properties of the copolymers produced therefrom.

The known hydrophobically associating butyleneoxy (BuO) or pentyleneoxy (PeO) units have further disadvantages. For example, butylene oxide and pentylene oxide are available from a few manufacturers and therefore only at a few locations. Furthermore, monomers containing BuO or PeO have a comparatively high melting point. For example, the melting point of HBVE-24.5 EO -16 BuO - 3.5 EO is 20 to 21 ° C. This leads to problems in handling and transport in unheated systems or tanks, especially at night and in winter.

The object of the invention was therefore to provide an improved process for the preparation of hydrophobically associating monomers with a propyleneoxy block, which can be converted into hydrophobically associating copolymers with advantageous properties, in particular in the case of tertiary petroleum production.

Accordingly, a process for the preparation of a hydrophobically associating monomer (a) of the general formula (I)

H ₂ C = CR-X- (CH2) x-0- (CH2-CH2-0-) y- (CH2-CH (CH3) -0-) _z -R ¹ (I) found, where the units - ( -CH ₂ -CH ₂ -0-) _y - and - (- CH ₂ -CH (CH ₃ ) -0-) _z - in

Block structure are arranged in the order shown in formula (I), and wherein the radicals and indices have the following meanings:

X is a single bond, -O-, -C (0) -0- or -C (0) -NH-;

R is H or methyl;

R ¹ is H or a hydrocarbon radical having 1 to 4 carbon atoms;

x is a number from 0 to 6;

y is a number from 5 to 100;

z is a number from 5 to 150; with the proviso that X stands for a single bond if x = 0; comprising the following steps: a) reacting a monoethylenically unsaturated alcohol A1 of the general formula (II)

H ₂ C = C (R) -X- (CH ₂ ) _x -0- (CH ₂ -CH ₂ -0) _d -H (II), with ethylene oxide; wherein the radicals R and X and the index x have the meaning given above and d is a number from 0 to 5; with the proviso that X is a single bond when x = 0 to give an alkoxylated alcohol A2; b) reacting the alkoxylated alcohol A2 with propylene oxide, the reaction being carried out in the presence of a double metal cyanide compound as a catalyst, an alkoxylated alcohol A3 according to the formula (III),

H ₂ C = C (R) -X- (CH ₂ ) x-0 - (- CH ₂ -CH ₂ -0-) y - (- CH ₂ -CH (CH ₃ ) -0-) zR ¹ (III ) with R ¹ = H, the radicals R and X and the indices x, y and z having the meanings defined above; c) optionally etherifying the alkoxylated alcohol A3 with a compound

R ¹ -X 'where R ^{1 is} a hydrocarbon radical having 1 to 4 carbon atoms and X' is a leaving group, preferably selected from the group of CI, Br, I, -0-S0 ₂ -CH ₃ (mesylate), -0-S0 _{2 is} -CF ₃ (triflate) and -0-S0 ₂ -0R ¹ ; wherein a monomer (a) according to formula (I) with R ¹ = hydrocarbon radical having 1 to 4 carbon atoms is obtained. It was surprisingly found that fewer undesired by-products, in particular fewer rearrangement products, were obtained in the DMC-catalyzed process according to the invention. The monomers (a) according to the invention have a narrow molar mass distribution, which leads to a low product viscosity and a low content of high molecular weight constituents.

Monomers (a)

The at least one hydrophobically associating monomer (a) of the general formula (I) comprises, in addition to the ethylenically unsaturated group, a hydrophobic group which, after the polymerization, is responsible for the hydrophobic association of the copolymer formed. It also preferably comprises hydrophilic parts of the molecule which impart a certain water solubility to the monomer.

Monomers (a) according to the invention have the general formula (I)

H ₂ C = CR-X- (CH2) x-0- (CH2-CH2-0-) y- (CH2-CH (CH3) -0-) _z -R ¹ (I), where the units - ( -CH ₂ -CH ₂ -0-) _y - and - (- CH ₂ -CH (CH ₃ ) -0-) _z - are arranged in block structure in the order shown in formula (I), and wherein the radicals and indices have the following meanings:

R is H or methyl;

X is a single bond, -O-, -C (0) -0- or -C (0) -NH-;

R ¹ is H or a hydrocarbon radical having 1 to 4 carbon atoms;

x is a number from 0 to 6;

y is a number from 5 to 100;

z is a number from 5 to 150; with the proviso that X stands for a single bond if x = 0.

In the case of the monomers (a) of the formula (I), an ethylenic group H2C = C (R) - via a linking group -X- (CH ₂ ) _x -0- with a polyalkyleneoxy radical with a block structure - (CFh-CH- 0) y- (CH ₂ -CH (CH ₃ ) -0) zR, the blocks - (CH ₂ -CH-0) _y and - (CH ₂ -CH (CH ₃ ) -0) _z in the in Formula (I) shown order are arranged. The polyalkyleneoxy radical has either a terminal OH group or a terminal ether group OR ¹ .

In the above formulas, R is H or methyl, preferably H.

X stands for a single bond, for -O-, -C (0) 0- or COHN, preferably for -O-. X is accordingly an ether group -O-, an ester group -C (0) 0- or an amide group - C (0) -NH-, preferably an ether group -0-. R ¹ represents H or a hydrocarbon radical having 1 to 4 carbon atoms, preferably H or an aliphatic hydrocarbon radical having 1 to 4 carbon atoms, preferably H, methyl or ethyl, particularly preferably H or methyl and very particularly preferably H.

In the above formulas, x stands for a number from 0 to 6, preferably 2 to 6, particularly preferably for 4. The (CH2) _x group can be straight-chain or, if x stands for a natural number from 3 to 6 , also act as branched aliphatic hydrocarbons. The group - (CH2) _x - is preferably linear aliphatic hydrocarbon groups. The group - (CH2) _x - is therefore preferably a divalent, linking methylene- (-CH2-), ethylene- (-CH ₂ -CH ₂ -), propylene- (-CH ₂ -CH ₂ -CH ₂ ), Butylene- (-CH2-CH2-CH2-CH2-CH2-), Pentylene- (-CH2-CH2-CH2-CH2-CH2-CH2) or hexylene group (-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2 -), preferably around a butylene group.

The monomers (a) according to the formula (I) furthermore have a polyalkyleneoxy radical which consists of the units - (CH ₂ -CH-0) _y and - (CH ₂ -CH (CH ₃ ) -0) _Z , the Units in

Block structure are arranged in the order shown in formula (I). The transition between the two blocks can be abrupt or continuous.

In the case of a continuous transition, there is still a transition zone between the two blocks, which comprises monomers of both blocks. If the block boundary is set at the middle of the transition zone, the first block - (CH ₂ -CH ₂ -0) _{y can} still contain small amounts of units -CH ₂ -CH (CH ₃ ) -0- and the second block - ( CH ₂ -CH (CH ₃ ) -0) _{Z have} small amounts of units -CH2-CH2-O-, but these units are not statistically distributed over the block, but are arranged in the transition zone mentioned.

The block - (CH ₂ -CH ₂ -0) _k - is therefore a polyethyleneoxy block, which may optionally still have certain proportions of propyleneoxy units, preferably a pure polyethyleneoxy block.

The number of ethyleneoxy units y is a number from 5 to 100, preferably 10 to 50, particularly preferably 20 to 30 and very particularly preferably 23 to 26.

The second block - (CH ₂ -CH (CH ₃ ) -0) _Z - is a block which consists essentially of propyleneoxy units.

It is clear to the person skilled in the art in the field of polyalkylene oxides that the orientation of the hydrocarbon radicals -CH3 in the propyleneoxy units z can depend on the conditions of the alkoxylation, for example on the catalyst chosen for the alkoxylation. The alkylene oxide groups can thus be incorporated into the monomer (a) both in the orientation - (CH ₂ -CH (CH ₃ ) -0) - or also in the inverse orientation - (CH (CH ₃ ) -CH ₂ -0). The representation in formula (I) should therefore not be regarded as being restricted to a specific orientation of the CFh group. Usually the ratio of alkylene oxide groups is ib Orientation - (CH ₂ -CH (CH ₃ ) -0) - to alkylene oxide groups can therefore both in the orientation - (CH (CH ₃ ) -CH ₂ -0) - 95: 5).

The number of propyleneoxy units z is a number from 5 to 150, preferably 10 to 125, preferably 35 to 125, preferably 40 to 100, preferably 55 to 95, preferably 70 to 90, particularly preferably 80.

It is clear to the person skilled in the art in the field of polyalkoxylates that the definitions of y and z are each the definition of a single monomer (a) of the formula (I). If mixtures of several monomers (a) of the formula (I) or formulations which comprise several monomers (a) of the general formula (I) are present, the numbers y and z are average values over all molecules of the monomers, since the alkoxylation of alcohol with alkylene oxides gives a certain distribution of chain lengths.

In a preferred embodiment, the invention relates to a monomer (a), where the radicals and indices have the following meanings:

X is -0-;

R is H or methyl;

R ¹ is H or a hydrocarbon radical having 1 to 4 carbon atoms;

x is a number from 2 to 6;

y is a number from 10 to 50;

z is a number from 10 to 125, z preferably being greater than y.

The invention further preferably relates to a monomer (a), where the radicals and indices have the following meanings:

X is -0-;

R is H or methyl, preferably H;

R ¹ is H or a hydrocarbon radical with 1 to 4 carbon atoms, preferably H; x is a number from 2 to 6, preferably 4;

y is a number from 20 to 30, preferably 23 to 26;

z is a number from 40 to 100, preferably 70 to 90.

X is -0-;

R is H;

R ¹ is H x is 4;

y is a number from 10 to 50;

z is a number from 10 to 125.

In a preferred embodiment of the method, z> y.

X is -0-;

R is H;

R ¹ is H

x is 4;

y is a number from 20 to 30;

z is a number from 35 to 125.

In a particularly preferred embodiment, the invention relates to a monomer (a), the radicals and indices having the following meanings:

X is -0-;

R is H;

R ¹ is H

x is 4;

y is a number from 23 to 26;

z is a number from 40 to 100.

It is particularly preferably a monomer (a), the radicals and indices having the following meanings:

X is -0-;

R is H;

R ¹ is H

x is 4;

y is a number from 23 to 26;

z is a number from 70 to 90.

In the case of the monomers (a) of the formula (I), a terminal monoethylenic group is therefore preferably linked to a polyalkyleneoxy group with a block structure, first of all with a hydrophilic block which comprises polyethyleneoxy units, preferably consisting of polyethyleneoxy units, and this in turn with a second terminal, hydrophobic block, which is composed of propyleneoxy units. The second block has a terminal -OR ¹ group, in particular an OH group. The terminal block - (CH ₂ -CH (CH ₃ ) -0) _Z is responsible for the hydrophobic association of the copolymers produced using the monomers (a). Etherification of the OH end group is an option which can be chosen by the person skilled in the art depending on the desired properties of the copolymer. A terminal hydrocarbon group is not necessary for the hydrophobic association, but the hydrophobic association also works with a terminal OH group.

Preparation of the monomers (a) of the formula (I)

Suitable monoethylenically unsaturated alcohols A1 of the general formula (II) are used to prepare the monomers (a), which are then first ethoxylated (step a)) and then propoxylated (step b)) in a two-stage process, see above that the block structure mentioned is obtained. Monomers (a) of the formula (I) with R ¹ = H are obtained. These can optionally be etherified in a further process step (step c)).

The type of ethylenically unsaturated alcohols A1 of the general formula (II) to be used

H ₂ C = C (R) -X- (CH ₂ ) _x -0- (CH ₂ -CH ₂ -0) _d -H (II), where the radicals R, R ¹ , X and the index x are the same as above have the meaning given and d is a number from 0 to 5; provided that X stands for a single bond, if x = 0, depends in particular on the meaning of the group -X- (CH ₂ ) _x - in the desired monomer (a) of the formula (I).

If X is a single bond and x is 0, alcohols A1 are used, where d is a number from 1 to 5, preferably 1 or 2. Examples of such alcohols include diethyl engylene glycol vinyl ether H ₂ C = CH-0-CH ₂ -CH ₂ -0-CH ₂ -CH ₂ -0H or dipropylene glycol vinyl ether H ₂ C = CH-0-CH ₂ -CH (CH ₃ ) -0 -CH ₂ -CH (CH ₃ ) -0H, diethylene glycol vinyl ether is preferred.

Alcohols A1 of the general formula (II) can be used to prepare monomers (a) in which x is a number from 1 to 6, the radicals and indices having the following meanings:

R is H or methyl;

X is a single bond, -O-, -C (0) -0- or -C (0) -NH-;

x is a number from 1 to 6,

d is a number from 0 to 5 In particular, the preparation of the monomers with the group HC = CR- (CH) _x - (ie X stands for a single bond) is preferably carried out using alcohols of the formula H2C = C (R) - (CH2) _x -OH, in particular H2C = CH- (CH2) _x -OH or alcohols of the formula H ₂ C = C (R) -0- (CH ₂ -CH ₂ -0) _d -H from (d = 1 -5). Examples of preferred alcohols include allyl alcohol HC = CH-CH -OH or isoprenol H ₂ C = C (CH ₃ ) -CH ₂ -CH ₂ -OH.

To prepare the monomers with linking group -0- (CH ₂ ) _x - one starts from vinyl ethers of the formula H ₂ C = C (R) -0- (CH ₂ ) _x -0H, preferably H ₂ C = CH- 0- (CH ₂ ) _x -0H off. It is particularly preferred to use w-hydroxybutyl vinyl ether H ₂ C = CH-0-CH ₂ -CH ₂ -CH ₂ -CH ₂ -0H.

For the preparation of the monomers with a linking group -C (0) -0- (CH ₂ ) _x - one starts from hydroxyoxy (meth) acrylates of the general formula H ₂ C = C (R) -C (0) -0- (CH ₂ ) _x -0H, preferably H ₂ C = CH-C (0) -0- (CH ₂ ) _X -0H. Examples of preferred hydroxyalkyl (meth) acrylates include hydroxyethyl (meth) acrylate H ₂ C = C (R) -C (0) -0-CH ₂ -CH ₂ -0H and hydroxybutyl (meth) acrylate H ₂ C = C (R) -C (0) -0-CH ₂ -CH ₂ -CH ₂ -CH ₂ -0H.

If an alcohol A1 of the general formula (II) is used in the reaction in step a), where d stands for a number from 1 to 5, i.e. an alcohol already containing ethyleneoxy units, the amount of ethylene oxide is adjusted in step a) so that an ethoxylated alcohol A2 is obtained which has the desired number of ethyleneoxy units.

In a preferred embodiment, an ethylenically unsaturated alcohol A1 of the general formula (II) is used in the process according to the invention, the radicals and indices having the following meanings:

R is H or methyl;

X is -O-,

x is a number from 2 to 6,

d is 0.

The radicals and indices in the formula (II) particularly preferably have the following meanings:

R is H;

X is -O-,

x is 4,

d is 0.

Accordingly, an alcohol of the formula H ₂ C = CH-0- (CH ₂ ) ₄ -0H is particularly preferably used. The starting compounds mentioned are alkoxylated, specifically in a two-stage process, first in a first step S1 with ethylene oxide and in a second step S2 with propylene oxide.

Step a) of the method according to the invention can be carried out according to methods known in principle to the person skilled in the art.

The ethoxylation can be carried out using base catalysis, double metal cyanide catalysis or double hydride clay catalysis.

Step a) of the process according to the invention preferably comprises the reaction of a monoethylenically unsaturated alcohol A1 of the formula (II) with ethylene oxide with the addition of an alkaline catalyst K1, an alkoxylated alcohol A2 being obtained.

The alkaline catalyst K1 is an alkali metal hydroxide (such as, for example, sodium hydroxide, potassium hydroxide or cesium hydroxide) and / or an alkali metal alcoholate (such as, for example, potassium methoxide, potassium ethanolate, potassium isopropoxide, potassium tert-butoxide or sodium methoxide, sodium ethanolate, sodium butopropoxide).

The alkaline catalyst K1 is preferably KOMe (potassium methoxide), NaOMe (sodium methoxide), or a mixture of two or more thereof, preference is given to the alkaline catalyst K1 KOMe, NaOMe or a mixture thereof,

The preferred conditions mentioned below (e.g. pressure and / or temperature ranges) in the reactions according to step a), b), and / or c) mean that the respective step is carried out in whole or in part under the specified conditions.

Step a) preferably comprises first the reaction of the monoethylenically unsaturated alcohol A1 with the alkaline catalyst K1. Typically, the alcohol A1 used as the starting material is mixed with an alkaline catalyst K1 in a pressure reactor. Reduced pressure of typically less than 100 mbar, preferably in the range from 50 to 100 mbar and / or increase in temperature, typically in the range from 30 to 150 ° C., allows water and / or low boilers still present in the mixture to be drawn off. The alcohol is then essentially present as a corresponding alcoholate. The reaction mixture is then typically treated with inert gas (e.g. nitrogen).

Step a) preferably comprises the addition of ethylene oxide to a mixture of alcohol A1 and alkaline catalyst K1 (as described above). After the addition of the ethylene oxide has ended, the reaction mixture is typically allowed to react further. The addition and / or post-reaction is typically carried out over a period of 1 to 36 hours, preferably 5 to 24 hours, particularly preferably 5 to 15 hours, particularly preferably 5 to 10 hours. Step a) is typically carried out at temperatures from 60 to 180 ° C., preferably from 130 to 150 ° C., particularly preferably from 140 to 150 ° C. In particular, step a) comprises adding the ethylene oxide to the mixture of alcohol A1 and alkaline catalyst K1 at a temperature of 60 to 180 ° C., preferably 130 to 150 ° C., particularly preferably 140 to 150 ° C.

The ethylene oxide is preferably added to the mixture of alcohol A1 and alkaline catalyst K1 at a pressure in the range from 1 to 7 bar, preferably in the range from 1 to 6 bar, particularly preferably from 1 to 4 bar. In particular, the addition of ethylene oxide and / or the after-reaction are carried out at the pressures mentioned above.

Step a) preferably comprises the addition of the ethylene oxide to a mixture of alcohol A1 and alkaline catalyst K1 over a period of less than or equal to 36 h, preferably less than or equal to 32 h, particularly preferably over a period of 2 to 32 h, in particular preferably over a period of 5 to 15 h, and at a pressure of less than or equal to 7 bar, preferably at 1 to 5 bar, particularly preferably 1 to 4 bar. In particular, the period specified above includes the addition of ethylene oxide and / or the after-reaction.

In particular, the reaction of a monoethylenically unsaturated alcohol A1 with ethylene oxide with addition of an alkaline catalyst K1 in step a) of the process according to the invention can take place in one or more ethoxylation steps. If, for example, the ethoxylation takes place in several steps, a further amount of catalyst can be added during the interruption.

A method as described above is preferred, step a) comprising the following steps:

Reaction of the monoethylenically unsaturated alcohol A1 with the alkaline catalyst K1,

Reacting the mixture of alcohol A1 and catalyst K1 with part of the ethylene oxide, in particular 10 to 50% by weight, in particular 10 to 30% by weight, of the total amount of ethylene oxide,

an intermediate step comprising a resting phase and / or a pressure release, and the reaction with the remaining part of the ethylene oxide.

A method as described above is further preferred, step a) comprising the following steps

Reacting the mixture of alcohol A1 and catalyst K1 with part of the ethylene oxide, in particular 50 to 98% by weight, in particular 80 to 98% by weight, of the total amount of ethylene oxide, a step for removing low boilers under pressure release to a pressure of less than 100 mbar, preferably 50 to 100 mbar and / or increasing the temperature typically in the range from 30 to 150 ° C.,

Reaction of the ethoxylation product obtained with the alkaline catalyst K1 and reaction of the remaining part of the ethylene oxide with the mixture of ethoxylation product and alkaline catalyst K1.

A method as described above is particularly preferred, step a) comprising the following steps

Reaction of the mixture of alcohol A1 and catalyst K1 with the total amount of ethylene oxide,

a step to remove low boilers under pressure release to a pressure less than 100 mbar, preferably 50 to 100 mbar and / or increase in temperature typically in the range from 30 to 150 ° C.

The alkaline catalyst K1 contains in particular 10 to 100% by weight, preferably 20 to 90% by weight of KOMe and / or NaOMe. In addition to KOMe and / or NaOMe, the catalyst K1 can contain further alkaline compounds and / or a solvent (in particular a C1 to C6 alcohol). For example, a further alkaline compound can be selected from alkali metal hydroxides, alkaline earth metal hydroxides, C2 to C6 potassium alkanolates, C2 to C6 sodium alkanolates (preferably ethanolate), alkaline earth metal alkanolates (in particular C1 to C6 alkanolates, preferably methanolate and / or ethanolate). In addition to KOMe and / or NaOMe, the catalyst K1 preferably contains at least one further alkaline compound selected from sodium hydroxide and potassium hydroxide. In another preferred embodiment, the alkaline catalyst K1 consists of KOMe or a solution of KOMe in methanol (MeOH). A solution of 20 to 50% by weight of KOMe in methanol (MeOH) can typically be used. In another preferred embodiment, the alkaline catalyst K1 consists of NaOMe or a solution of NaOMe in methanol. In a further preferred embodiment, the catalyst K1 consists of a mixture of KOMe and NaOMe or a solution of KOMe and NaOMe in methanol.

It is advantageous to use the catalyst K1 in an amount such that an upper limit of 2,500 ppm (approx. 0.4 mol%) KOMe is observed with respect to the alcohol A1 used in order to avoid the decomposition of the monoethylenically unsaturated alcohol A1. The concentration of potassium ions in step a) is preferably less than or equal to 0.4 mol%, based on the total amount of alcohol A1 used, particularly preferably 0.1 to 0.4 mol%.

If KOMe is added in such an amount that the concentration is above 0.9 mol% based on the alkoxylated alcohol A2 (product of process step a)), KOMe completely or partially separated before step b) in order to obtain a potassium ion concentration of less than 0.9 mol% in process step b). This can be done, for example, by isolating the alkoxylated alcohol A2 after step a) and optionally cleaning it. This can also be done by first adding a potassium ion-binding substance such as, for example, magnesium silicates such as Ambosol (magnesium silicate), and then preferably isolating and optionally cleaning the alkoxylated alcohol A2 after step a). The potassium ion concentration is reduced to less than 50 ppm, preferably less than 10 ppm.

In a further preferred embodiment, KOMe is used in such an amount that the concentration of potassium ions after the reaction in step a) is already less than or equal to 0.9 mol% based on A2.

Step b) of the process according to the invention comprises the reaction of the alkoxylated alcohol A2 with propylene oxide, the reaction being carried out in the presence of a double metal cyanide compound (DMC compound) as a catalyst, an alkoxylated alcohol A3 according to the formula (III)

H ₂ C = C (R) -X- (CH2) x-0 - (- CH2-CH2-0-) y - (- CH2-CH (CH3) -0-) _z -R ¹ (III) with R ¹ = H is obtained, the radicals R and X and the indices x, y and z having the meanings defined above.

The alkoxylated alcohol A3 of the formula (III) corresponds to the monomer (a) of the formula (I), where R ^{1 is} H.

Step b) preferably first comprises adding the double metal cyanide compound to the alkoxylated alcohol A2. Typically, alcohol A2 is initially charged in a pressure reactor at a temperature of 40 to 100 ° C., preferably 50 to 70 ° C. and typically approx. 60 ° C., the double metal cyanide compound is added and the mixture is preferably stirred vigorously, for example by means of an ultraturax (e.g. 10,000 rpm). By reducing the pressure, typically less than 100 mbar, preferably in the range from 10 to 100 mbar, and / or increasing the temperature, typically in the range from 30 to 150 ° C., water and / or low boilers still present in the mixture can be drawn off. The reaction mixture is then typically treated with inert gas (e.g. nitrogen).

Step b) preferably comprises adding the propylene oxide to the above-described mixture of alcohol A2 and double metal cyanide compound. After the addition of the propylene oxide has ended, the reaction mixture is typically allowed to react further. The addition of propylene oxide and / or the after-reaction typically takes place over a period of from 2 to 36 h, preferably from 5 to 24 h, particularly preferably from 5 to 20 h, particularly preferably from 5 to 15 h. According to the invention, the concentration of potassium ions in the reaction in step b) is less than or equal to 0.9 mol%, preferably less than 0.9 mol%, preferably from 0.01 to 0.9 mol%, particularly preferably from 0.1 to 0.6 mol%, based on the alcohol A2 used. In a preferred embodiment, the concentration of potassium ions in the reaction in step b) is 0.01 to 0.5 mol%, based on the alcohol A2 used.

In a particularly preferred embodiment, the concentration of potassium ions in the reaction in step b) is less than or equal to 0.9 mol%, preferably 0.1 to 0.5 mol%, based on the alcohol A2 and the reaction in step b) is carried out at temperatures from 120 to 130 ° C.

According to the invention, the addition of propylene oxide in step b) is carried out at a temperature of less than or equal to 135 ° C., preferably less than or equal to 130 ° C. The reaction in step b) is preferably carried out at temperatures from 60 to 135 ° C., preferably at 100 to 135 ° C., particularly preferably at 120 to 135 ° C., very particularly preferably at 120 to 130 ° C.

In particular, step b) comprises adding the propylene oxide to a mixture of alcohol A2 and double metal cyanide compound at a temperature of less than or equal to 135 ° C., preferably at less than or equal to 130 ° C., particularly preferably at temperatures of 60 to 135 ° C., particularly preferably at 100 to 135 ° C, particularly preferably at 120 to 130 ° C.

Step b) is preferably carried out at a pressure in the range from 1 to 7 bar, preferably from 1 to 6 bar, particularly preferably 1 to 5 bar. In particular, the addition of propylene oxide and / or the after-reaction are carried out at the pressure mentioned above.

Step b) preferably comprises adding the propylene oxide to a mixture of alcohol A2 and double metal cyanide compound at a pressure in the range from 1 to 7 bar, preferably from 1 to 6 bar, particularly preferably from 1 to 5 bar.

Step b) is particularly preferably carried out at a pressure in the range from 1 to 5 bar and at a temperature from 120 to 130.degree.

Step b) preferably comprises the addition of the propylene oxide to a mixture of alcohol A2 and double metal cyanide compound over a period of less than or equal to 36 h, preferably less than or equal to 32 h, particularly preferably over a period of 2 to 32 h particularly preferably over a period of 5 to 24 h, and at a pressure of less than or equal to 5 bar.

After the reaction, volatile components are typically removed at a reduced pressure of typically less than 100 mbar, preferably in the range from 10 to 100 mbar, and / or an increase in temperature, typically in the range from 30 to 150 ° C., of the alkoxylated alcohol A3 Step b) isolated and optionally cleaned. In one embodiment of the invention, step b) can be repeated one or more times. For example, the isolated propoxylated alcohol A3 can be reacted once or more with other propylene oxide under the conditions mentioned above and by means of DMC catalysis.

The process according to the invention can optionally comprise step c), the alkoxylated alcohol A3 being etherified with a compound R ¹ -X ', where X' is a leaving group, preferably selected from CI, Br, I, -O-SO2-CH3 (mesylate ), -O-SO2-CF3 (triflate), and -O-SO2-OR ¹ . If the alkoxylated alcohol A3 of the formula (III) is to be etherified with a terminal OH group (ie R ¹ = H), this can be done using conventional alkylating agents known in principle to the person skilled in the art, for example alkyl sulfates and / or alkyl halides. Typically, the compound R ¹ -X 'can be alkyl halides. Dimethyl sulfate or diethyl sulfate in particular can also be used for etherification. Etherification is only one option which can be selected by the person skilled in the art depending on the desired properties of the copolymer.

In one embodiment, the process according to the invention accordingly comprises a step c), wherein the alkoxylated alcohol A3 is etherified with a compound R ¹ -X '.

In a preferred embodiment, the method according to the invention does not include a treatment step c).

DMC catalysts

DMC compounds suitable as catalysts are described, for example, in WO 99/16775, DE 101 17273.7, DE 102 43 361 A1, DE10200501 1581 and in particular WO 20061 17364 A2. Double metal cyanide compounds of the general formula (IV) are particularly suitable as catalysts for the alkoxylation:

M ² _a [M ¹ (CN) rX * t] b (IV), where

M ¹ is a metal ion selected from the group consisting of Zn (II), Fe (II), Co (III), Ni (II), Mn (II), Co (II), Sn (II), Pb (II) , Fe (lll), Mo (IV), Mo (VI), Al (lll), V (IV), V (V), Sr (ll), W (IV), W (VI), Cu (ll) and Cr (III), preferably Ni (II), Mn (II), Zn (II), Co (II), Co (III), Fe (II) and Fe (III);

M ² is a metal ion selected from the group consisting of Sr (I), Mg (II), Zn (II), Fe (II), Fe (III), Co (III), Cr (III), Mn (II) , Mn (III), Ir (III), Rh (III), Ru (II), V (IV), V (V), Co (II), Cr (II), Ti (IV), preferably Ni (II ), Mn (II), Zn (II), Co (II), (Co (III), Fe (II) and Fe (III);

X 'is a group other than cyanide, which forms a coordinative bond with M ¹ , selected from the group consisting of carbonyl, cyanate, isocyanate, nitrile, thiocyanate and nitrosyl; a, b, r, t are integers that are chosen so that the electroneutrality condition is fulfilled. This means that the sum of the positively charged ions of the atoms and groups and the sum of the negatively charged ions are the same. Compound (IV) therefore represents an uncharged connection to the outside.

The double metal cyanide compound according to the general formula (IV) described above is preferably obtained by the process described in WO 2006/1 17364 A2, comprising the reaction of a) a cyanometalate hydrochloric acid of the general formula (IVa)

Hw [M ¹ (CN) r (X ') t] (IVa) where M ¹ _, X', r and t are as defined above, and w is a number chosen so that the electroneutrality condition is satisfied with b) an easily protolyzable metal compound (IVb1) M ² R ' _W and / or (IVb2) M ² R' _u Y _v , where M ^{2 is} as defined above,

R \ same or different,

is the anion of a very weak protonic acid with a pKs value of> 20, and Y is the anion of an inorganic mineral acid or a moderately strong to strong organic acid with a pKs value of -10 to +10,

w corresponds to the valence of M ² ,

u + v corresponds to the valence of M ² , where u and v are each at least 1, the reaction being carried out in a non-aqueous, aprotic solvent.

Preferred in cyanometalate hydrochloric acid ((IVa) r = 4-6, t = 0-2.

In the metal compound (IVb1) or (IVb2) w = 2 or u + v = 2 are preferred.

Particularly preferred metal ions M ² are Co (III) and Fe (III). A particularly preferred metal ion M ¹ is Zn (II).

Cyanometalate hydrogen acids (IVa) are compounds that are very easy to handle in aqueous solution. There are several for the production of cyanometalate hydrogen acids

Process known. For example, starting from the alkali metal cyanometalate, they can be prepared via the silver cyanometalate, as described in W. Klemm et al., Z. Anorg. General Chem. 308 (1961) 179. Furthermore, alkali metal or alkaline earth metal cyanometalates can be converted into cyanometalate hydrogen acid using an acidic ion exchanger, see F. Hein, H. Lilie, Z. Anorg. General Chem. 270 (1952) 45, A. Ludi et al., Helv. Chim. Acta 50 (1967) 2035. Further synthesis possibilities are listed in G. Brauer (editor) "Handbook of preparative inorganic chemistry", Ferdinand Enke Verlag, Stuttgart 1981.

Preferred cyanometalate hydrogen acids (IVa) are hexacyanocobalt (III) acid and hexacyanoic (III) acid.

Suitable metal compounds (IVb1) and (IVb2) are, for example, dimethyl zinc, diethyl zinc, di-n-butyl zinc, diisopropyl zinc, diisobutyl zinc, diethyl aluminum cyanide, trimethyl aluminum, triisobutyl aluminum, triethyl aluminum, tri-n-propyl aluminum, tri-n-aluminum, tri-n-aluminum , T ri-n-hexylaluminium, bis (tetramethylcyclopentadienyl) manganese,

Diethylmagnesium, di-n-butylmagnesium, n-butylethylmagnesium, strontium (2, 2,6,6-tetramethyl-3,5-heptanedionate), bis (pentamethylcyclopentadienyl) strontium, 1, 1'-dimethylferrocene, ferrocene, benzoylferrocene, cyclopentadienylleis Dimer, bisindenyl iron, bis (pentamethylcyclopentadienyl) iron, nickelocene,

Cyclopentadienylnickel carbonyl dimer, bis (pentamethylcyclopentadienyl) nickel, cobaltocene, bis (ethylcyclopentadienyl) cobalt, bis (pentamethylcyclopentadienyl) cobalt,

Bis (cyclopentadienyl) manganese, bis (pentamethylcyclopentadienyl) manganese,

Bis (cyclopentadienyl) titanium dichloride, bis (pentamethylcyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) dicarbonyltitanium (II) and bis (cyclopentadienyl) dimethyltitanium.

Preferred metal compounds (IVb1) are dialkyl zinc compounds such as dimethyl zinc, diethyl zinc, di-n-butyl zinc, diisopropyl zinc and diisobutyl zinc, in particular diethyl zinc.

The reaction of the cyanometalate hydrogen acid (IVa) with the metal compound (IVb1) or (IVb2) is generally carried out in a non-aqueous, dipolar or apolar aprotic solvent. Suitable aprotic solvents are, for example

Dimethyl sulfoxide (DMSO), dimethylformamide (DMF), sulfolane, carbon disulfide,

Ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and N-methylpyrrolidone (NMP), DMSO, DMF and NMP are preferred.

The reaction can be carried out in the presence of one or more other organic

Component, which as surface-active components for controlling the

Catalyst morphology and / or act as chemically bound ligands. This further organic component can just as well be added only after the reaction of the product solution or suspension containing the DMC compound (IV). Preferred further organic components are selected from the group consisting of polyethers, polyesters, polycarbonates, polyalkylene glycol sorbitan esters,

Polyalkylene glycol glycidyl ethers, polyacrylamide, poly (acrylamide-co-acrylic acid), polyacrylic acid, poly (acrylamide-co-maleic acid), polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates, polyvinyl methyl ethers, polyvinyl ethyl ethers, polyvinyl acetate, polyvinyl alcohol, poly-N-vinyl pyrrolidone co-acrylic acid), polyvinyl methyl ketone, poly (4-vinylphenol), poly (acrylic acid-co-styrene), oxazoline polymers, polyalkyleneimines, maleic acid and maleic anhydride copolymer, hydroxyethyl cellulose, polyacetates, ionic Surface and surface active compounds, bile acid and its salts, esters and amides, carboxylic acid esters of polyhydric alcohols and glycosides.

The reaction can be carried out batchwise, semi-continuously or continuously.

The concentration of DCM compounds is typically 0.0005 to 0.5% by weight, preferably 0.001 to 0.1% by weight, particularly preferably 0.002 to 0.02% by weight, based on the alcohol A2 used.

The invention further relates to a hydrophobically associating monomer (a) of the general formula (I), obtainable in the processes described above.

The preferred embodiments of the monomers (a) correspond to the preferred embodiments given for the process according to the invention for the preparation of the monomers (a).

Hydrophobically Associating Copolymers (A)

The invention further relates to a water-soluble, hydrophobically associating copolymer (A) comprising

(a) 0.1 to 15.0% by weight of at least one hydrophobically associating monomer (a) of the general formula (I) as described above, and

(b) 85.0 to 99.9% by weight of at least one hydrophilic monomer (b) different from monomer (a), where at least one of the monomers (b) is a neutral, monoethylenically unsaturated hydrophilic monomer ( b1) selected from the group consisting of (meth) acrylamide, N-methyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide; where the amounts of the monomers (a) and (b) are based in each case on the total amount of all monomers used in the reaction and preferably in the reaction of the at least one monomer (a) with the at least one hydrophilic different from monomer (a) Monomer (b) before the initiation of the polymerization reaction, at least one further, non-polymerizable surface-active compound (O) is used.

The term “water-soluble hydrophobically associating copolymer” is known in principle to the person skilled in the art. It is a water-soluble copolymer which, in addition to hydrophilic molecule parts which ensure sufficient water solubility, has side or terminally hydrophobic groups. In aqueous solution, the hydrophobic groups of the polymer can associate with themselves or with other substances having hydrophobic groups due to intermolecular forces. This creates a polymer network that is linked by intermolecular forces and that thickens the aqueous medium.

Ideally, the copolymers used according to the invention should be miscible with water in any ratio or should be soluble in water. According to the invention, however, it is sufficient if the copolymers are water-soluble at least at the desired use concentration and at the desired pH. As a rule, the solubility of the copolymer in water at room temperature should be at least 25 g / l in the neutral pH range under the conditions of use.

According to the invention, it is a water-soluble, hydrophobically associating copolymer

The water-soluble, hydrophobically associating copolymer (A) according to the invention is obtainable from the reaction of 0.1 to 15.0% by weight of at least one monoethylenically unsaturated, hydrophobically associating monomer (a) according to the invention and 85.0 to 99, 9% by weight of at least one of (a) different hydrophilic monomer (b), where at least one of the monomers (b) is a neutral, monoethylenically unsaturated hydrophilic monomer (b1) selected from the group from (meth) acrylamide, N-methyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide.

Monomer (a) imparts hydrophobically associating properties to the copolymer and is therefore referred to as “hydrophobically associating monomer”.

In addition to the ethylenically unsaturated group, the at least one hydrophobically associating monomer (a) comprises a hydrophobic group which, after the polymerization, is responsible for the hydrophobic association of the copolymer formed. It preferably further comprises hydrophilic parts of the molecule which impart a certain water solubility to the monomer.

Amount of monomers (a)

The amount of the monoethylenically unsaturated, hydrophobically associating monomers (a) is 0.1 to 15% by weight, based on the total amount of all monomers used in the reaction, in particular 0.1 to 10.0% by weight, preferably 0 , 2 to 5.0 wt .-% and particularly preferably 0.5 to 2.0 wt .-%.

Monomers (b) In addition to the monomers (a), at least one different hydrophilic monomer (b) is used in the reaction, at least one of the monomers (b) being a neutral, monoethylenically unsaturated hydrophilic monomer (b1) selected from the group from (meth) acrylamide, N-methyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide. Mixtures of one or more monomers (b1) or mixtures of one or more monomers (b1) with one or more hydrophilic monomers (b) other than monomer (b1) can of course also be used.

The hydrophilic monomers (b) other than monomer (b1) are preferably monoethylenically unsaturated monomers.

The hydrophilic monomers (b) furthermore preferably comprise one or more hydrophilic groups in addition to the ethylenic group. Because of their hydrophilicity, these impart sufficient water solubility to the copolymer according to the invention. The hydrophilic groups are, in particular, functional groups which comprise O and / or N atoms. In addition, they can include, in particular, S and / or P atoms as heteroatoms.

The monomers (b) are particularly preferably soluble in water in any ratio, but for carrying out the invention it is sufficient that the hydrophobically associating copolymer according to the invention has the water solubility mentioned at the outset. As a rule, the solubility of the monomers (b) in water at room temperature should be at least 100 g / l, preferably at least 200 g / l and particularly preferably at least 500 g / l.

Examples of suitable functional groups include carbonyl groups> C = 0, ether groups - O -, in particular polyethyleneoxy groups - (CH ₂ -CH ₂ -0) ₀ -, where o is preferably from 1 to 200, hydroxyl groups -OH, ester groups -C (0) 0-, primary, secondary or tertiary amino groups, ammonium groups, amide groups -C (0) -NH-, carboxamide groups - C (0) -NH2 or acidic groups such as carboxyl groups -COOH, sulfonic acid groups -SO3H, phosphonic acid groups -PO3H2 or phosphoric acid groups -OP (OH) ₃ .

Examples of preferred functional groups include hydroxyl groups -OH, carboxyl groups -COOH, sulfonic acid groups -SO3H, carboxamide groups -C (0) -NH2, amide groups -C (O) - NH- and polyethyleneoxy groups - (CH2-CH2-0) ₀ -H, where o preferably represents a number from 1 to 200.

The functional groups can be attached directly to the ethylenic group, or else can be connected to the ethylenic group via one or more linking hydrocarbon groups. The hydrophilic monomers (b) are preferably monomers of the general formula H2C = C (R ²⁰ ) R ²¹ (XI), where R ²⁰ for H or methyl and R ²¹ for a hydrophilic group or one, one or group comprising several hydrophilic groups.

Examples of suitable monomers (b) include monomers comprising acid groups, for example monomers comprising COOH groups such as acrylic acid or methacrylic acid, crotonic acid, itaconic acid, maleic acid or fumaric acid, monomers comprising sulfonic acid groups such as vinylsulfonic acid, allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid ( AMPS), 2-methacrylamido-2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methyl-butanesulfonic acid or 2-acrylamido-2,4,4-trimethylpentanesulfonic acid or monomers comprising vinylphosphonic acid, allylphosphonic acid, N- ( Meth) acrylamidoalkylphosphonic acids or (meth) acryloyloxyalkylphosphonic acids.

Also to be mentioned are acrylamide and methacrylamide and derivatives thereof, such as N-methyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide and N-methylolacrylamide, N-vinyl derivatives such as N-vinylformamide, N-vinylacetamide, N-vinyl pyrrolidone or N-vinyl caprolactam and also vinyl esters, such as vinyl formate or vinyl acetate. After polymerization, N-vinyl derivatives can be hydrolyzed to vinylamine units, vinyl esters to vinyl alcohol units.

Further examples include monomers comprising hydroxyl and / or ether groups, such as, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, allyl alcohol, hydroxyvinylethyl ether, hydroxyvinyl propyl ether, hydroxyvinyl butyl ether or compounds of the formula H2C = C (R ¹ ) -0 - (CH2-CH (R ²² ) -0) bR ²³ (XII) where R ^{1 is} as defined above and b is a number from 2 to 200, preferably 2 to 100. The radicals R ²² are, independently of one another, H, methyl or ethyl, preferably H or methyl, with the proviso that at least 50 mol% of the radicals R ²² are H. At least 75 mol% of the radicals R ²² are preferably H, particularly preferably at least 90 mol% and very particularly preferably exclusively H. The radical R ²³ is H, methyl or ethyl, preferably H or methyl. The individual alkyleneoxy units can be arranged randomly or in blocks. For a block copolymer, the transition between the blocks can be abrupt or gradual.

The above-mentioned hydrophilic monomers can of course not only be used in the acid or base form shown, but also in the form of corresponding salts. It is also possible to convert acidic or basic groups into corresponding salts after the formation of the polymer.

Preferred is a copolymer in which at least one of the monomers (b) is a monomer comprising acidic groups, the acidic groups being at least one group selected from the group consisting of -COOH, -SO3H and - PO3H, and their salts. At least one of the monomers (b) is preferably a monomer selected from the group consisting of (meth) acrylic acid, vinylsulfonic acid, allylsulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), particularly preferably acrylic acid and / or APMS or their salts.

In a preferred embodiment, the at least one hydrophilic monomer (b) comprises two different monomers.

The at least one hydrophilic monomer (b) further preferably comprises at least two different, monoethylenically unsaturated hydrophilic monomers (b1) and (b2), where

(b1) is as defined above; and

(b2) at least one anionic, monoethylenically unsaturated hydrophilic monomer

(b2), which contains at least one acidic group selected from the group consisting of -COOH, -SO ₃ H or -PO ₃ H ₂ .

In a preferred embodiment

(b1) as defined above; and

(b2) at least one anionic, monoethylenically unsaturated hydrophilic monomer

(b2), which contains at least one -COOH or -SOsH group.

The at least one neutral monomer (b1) is preferably

(Meth) acrylamide, especially acrylamide. If mixtures of different monomers (b1) are used, it should be at least 50 mol% of the monomers (b1)

Act (meth) acrylamide, especially acrylamide.

The at least one hydrophilic, monoethylenically unsaturated anionic monomer (b2) is preferably a monomer comprising -COOH groups and / or -SO ₃ H groups, particularly preferably a monomer comprising -SOsH groups. Of course, it can also be a salt of the acidic monomer. Suitable counterions include in particular alkali metal ions such as Li ⁺ , Na ⁺ or K ⁺ and ammonium ions such as NH ₄ ⁺ or ammonium ions with organic radicals.

Examples of monomers comprising COOH groups include acrylic acid, methacrylic acid, cotonic acid, itaconic acid, maleic acid or fumaric acid. Acrylic acid is preferred.

Examples of monomers having sulfonic acid groups include vinylsulfonic acid, allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methyl-butanesulfonic acid or 2-acrylamido-2 , 4,4-trimethylpentanesulfonic acid. Vinyl sulfonic acid, allylsulfonic acid or are preferred 2-acrylamido-2-methylpropanesulfonic acid and particularly preferred or 2-acrylamido-2-methylpropanesulfonic acid.

Examples of monomers comprising phosphonic acid groups include vinylphosphonic acid, allylphosphonic acid, N- (meth) acrylamidoalkylphosphonic acids or (meth) acryloyloxyalkylphosphonic acids, vinylphosphonic acid is preferred.

In a preferred embodiment, the at least one hydrophilic, monoethylenically unsaturated anionic monomer (b2) is (meth) acrylic acid or acrylamido-2-methylpropanesulfonic acid (AMPS), particularly preferably acrylamido-2-methylpropanesulfonic acid.

In a preferred embodiment, the copolymer comprises

(a) 2% by weight of at least one hydrophobically associating monomer (a),

(b) 50% by weight of acrylamide as neutral hydrophilic monomer (b1), and

(c) 48% by weight of acrylamido-2-methylpropanesulfonic acid (AMPS) as anionic hydrophilic monomer (b2), the amounts given in each case being based on the total amount of all monomers in the copolymer.

In a particularly preferred embodiment, the copolymer according to the present invention comprises

(b1) acrylamide as a neutral hydrophilic monomer (b1), and

(b2) acrylic acid or acrylamido-2-methylpropanesulfonic acid (AMPS), preferably acrylic acid.

In a particularly preferred embodiment, the copolymer comprises

(a) 1.0 to 10.0% by weight of at least one hydrophobically associating monomer (a),

(b) 34.0 to 75.0% by weight of acrylamide as a neutral hydrophilic monomer (b1), and

(c) 24.0 to 65.0% by weight of acrylic acid or acrylamido-2-methylpropanesulfonic acid

(AMPS), preferably acrylic acid, as an anionic hydrophilic monomer (b2), the amounts given being based in each case on the total amount of all monomers in the copolymer. For the sake of completeness, it should be mentioned that monomers (b2) other than (meth) acylic acid may at least partially increase in the course of production and use

Can hydrolyze (meth) acrylic acid.

The copolymers used according to the invention can accordingly comprise (meth) acrylic acid units, even if no (meth) acrylic acid units were used for the synthesis. The tendency towards the hydrolysis of the monomers (b2) decreases with increasing content of sulfonic acid groups. Accordingly, the presence of sulfonic acid group in the copolymer used according to the invention is recommended.

In addition, at least one monoethylenically unsaturated, cationic, ammonium ion-containing monomer (b3) can optionally be used in the conversion to the copolymers used according to the invention.

Suitable cationic monomers (b3) include, in particular, monomers having ammonium groups, in particular ammonium derivatives of N- (co-aminoalkyl) (meth) acrylamides or cc> -aminoalkyl (meth) acrylic esters.

In particular, monomers containing ammonium groups (b3) can be compounds of the general formulas H2C = C (R ⁸ ) -C (O) -NR ⁹ -R ¹⁰ -NR ¹ VX “(Xllla) and / or H ₂ C = C (R ⁸ ) -C (O) -OR ¹⁰ -NR ¹ VX “- (XI Mb) act. Here R ⁸ stands for H or methyl, R ⁹ for H or a C to C ₄ alkyl group, preferably H or methyl and R ¹⁰ for a preferably linear C to C ₄ alkylene group, for example a 1,2-ethylene group -CH2 -CH2- or a 1,3-propylene group -CH2-CH2-CH2-.

The radicals R ¹¹ are, independently of one another, C1 to C ₄ alkyl radicals, preferably methyl or a group of the general formula -R ¹² -SOsH, where R ^{12 is} a preferably linear C1 to C ₄ alkylene group or is a phenyl group, with the proviso that, as a rule, no more than one of the substituents R ¹¹ is a substituent containing sulfonic acid groups. The three substituents R ^{11 are} particularly preferably methyl groups, ie the monomer has a group -N (CH3) 3 ⁺ . X "- in the above formula stands for a monovalent anion, for example Ch. Of course, X" - can also stand for a corresponding fraction of a polyvalent anion, although this is not preferred. Examples of preferred monomers (b3) of the general formula (Xllla) or (XI Mb) include salts of 3-trimethylammonium propyl (meth) acrylamides or 2-trimethylammoniumethyl (meth) acrylates, for example the corresponding chlorides such as 3-trimethylammonium propylacrylamide chloride (DIMAPAQUAT) and 2-trimethylammonium ethyl methacrylate chloride (MADAME-QUAT).

When converting to the copolymers used according to the invention, it is also possible to use other monoethylene-unsaturated hydrophilic monomers (b4) other than the hydrophilic monomers (b1), (b2) and (b3). Examples of such mono- mers include monomers comprising hydroxy and / or ether groups, such as, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, allyl alcohol, hydroxyvinyl ethyl ether, hydroxyvinyl propyl ether, hydroxyvinyl butyl ether or compounds of the formula H ₂ C = C (R ¹ ) - C (0) -0- (CH ₂ -CH (R ¹³ ) -0) bR ¹⁴ (XlVa) or H ₂ C = C (R ¹ ) -0- (CH ₂ -CH (R ¹³ ) -0) _b -R ¹⁴ (XIVb) where R ^{1 is} as defined above and b is a number from 2 to 200, preferably 2 to 100. The radicals R ¹³ are, independently of one another, H, methyl or ethyl, preferably H or methyl, with the proviso that at least 50 mol% of the radicals R ¹³ are H. At least 75 mol% of the radicals R ¹³ are preferably H, particularly preferably at least 90 mol% and very particularly preferably exclusively H. The radical R ¹⁴ is H, methyl or ethyl, preferably H or methyl. Further examples of monomers (A2d) include N-vinyl derivatives such as, for example, N-vinylformamide, N-vinyl-acetamide, N-vinylpyrrolidone or N-vinylcaprolactam, and also vinyl esters, such as, for example, vinyl formate or vinyl acetate. After polymerization, N-vinyl derivatives can be hydrolyzed to vinylamine units, vinyl esters to vinyl alcohol units.

According to the invention, the amount of all hydrophilic monomers (b) in the copolymer according to the invention is 85.0 to 99.9% by weight, based on the total amount of all monomers in the copolymer, preferably 90.0 to 99.9% by weight, preferably 95.0 to 99.8% by weight and particularly preferably 98.0 to 99.5% by weight.

The amount of neutral, hydrophilic monomers (b1) is generally 30 to 95% by weight, preferably 30 to 85% by weight and particularly preferably 30 to 70% by weight, based on the total amount of all monomers used.

If the copolymer only comprises neutral monomers (b1) and anionic monomers (b2), it has proven useful to use the neutral monomers (b1) in an amount of 30 to 95% by weight and the anionic monomers (b2) in an amount of 4 , 9 to 69.9% by weight, the amount being based on the total amount of all monomers used. In this embodiment, the monomers (b1) are preferably used in an amount of 30 to 80% by weight and the anionic monomers (b2) in an amount of 19.9 to 69.9% by weight, and are particularly preferred the monomers (b3) in an amount of 40 to 70% by weight and the anionic monomers (b2) in an amount of 29.9 to 59.9% by weight

If the copolymer comprises neutral monomers (b1), anionic monomers (b2) and cationic monomers (b3), it has proven useful to add the neutral monomers (b1) in an amount of 30 to 95% by weight and the anionic (b2) and cationic monomers (b3) together in an amount of 4.9 to 69.9% by weight, with the proviso that the molar ratio (b2) / (b3) is 0.7 to 1.3. The molar ratio (b2) / (b3) is preferably 0.8 to 1.2 and, for example, 0.9 to 1.1. This measure enables copolymers to be obtained which react particularly insensitively to salt load. In this embodiment, the monomers (b1) in an amount of 30 to 80% by weight and the anionic and cationic monomers (b2) + (b3) together in an amount of 19.9 to 69.9% by weight are preferred .-%, and particularly preferred are the monomers (b1) in an amount of 40 to 70 wt .-% and Anionic and cationic monomers (b2) + (b3) are used together in an amount of 29.9 to 59.9% by weight, the molar ratio already mentioned in each case being observed.

Monomers (c)

In addition to the monomers (a) and (b), ethylenically unsaturated monomers, preferably monoethylenically unsaturated monomers (c), which are different from monomers (a) and (b) can optionally be used in the reaction. Mixtures of several different monomers (c) can of course also be used.

Such monomers can be used to fine-tune the properties of the copolymer used according to the invention. If present at all, the amount of such optionally present monomers (c) can be up to 14.9% by weight, preferably up to 9.9% by weight, particularly preferably up to 4.9% by weight, each based on the total amount of all monomers used. No monomers (c) are very particularly preferably present.

The monomers (c) can be, for example, monoethylenically unsaturated monomers which have a more hydrophobic character than the hydrophilic monomers (b) and which are accordingly only slightly soluble in water. As a rule, the solubility of the monomers (c) in water at room temperature is less than 50 g / l, in particular less than 30 g / l. Examples of such monomers include N-alkyl- and N, N ”-dialkyl (meth) acrylamides, the number of carbon atoms in the alkyl radicals together being at least 3, preferably at least 4. Examples of such monomers include N-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide or N-benzyl (meth) acrylamide.

Preparation of the hydrophobically associating copolymers

The water-soluble, hydrophobically associating copolymers (A) according to the invention can be prepared by methods known in principle to those skilled in the art by radical polymerization of the monomers (a) and (b) and optionally (c), for example by solution or gel polymerization in the aqueous phase.

Monomers (a), (b), optionally (c), initiators and optionally further auxiliaries for polymerization in an aqueous medium are used for the polymerization.

In a preferred embodiment, the preparation is carried out by means of gel polymerization in the aqueous phase. For gel polymerization, a mixture of the monomers (a), (b) and optionally (c), initiators and, if appropriate, further auxiliaries, is first provided with water or an aqueous solvent mixture. Suitable aqueous solvent mixtures include water and water-miscible organic solvents, the proportion of water generally being at least 50% by weight, preferably at least 80% by weight and particularly preferably at least 90% by weight. Organic solvents here are to name in particular water-miscible alcohols such as methanol, ethanol or propanol. Acid monomers can be completely or partially neutralized before the polymerization. The concentration of all components with the exception of the solvents in the course of the polymerization is usually approximately 20 to 60% by weight, preferably approximately 30 to 50% by weight. The polymerization should in particular be carried out at a pH in the range from 5.0 to 7.5 and preferably at a pH of approximately 6.0.

Polymerization in the presence of a non-polymerizable, surface-active compound

In a preferred embodiment of the invention, when the at least one monoethylenically unsaturated hydrophobically associating monomer (a) is reacted with the at least one hydrophilic monomer (c) different from monomer (b), at least one further, non-polymerizable surface-active agent is initiated before the polymerization reaction is initiated Connection (O) inserted.

The non-polymerizable, surface-active compound O is preferably at least one surfactant. It is preferably at least one nonionic surfactant, but anionic surfactants and cationic surfactants are also suitable, provided that these do not participate in the polymerization reaction.

They are preferably nonionic surfactants O of the general formula R ²⁰ -Y ', where R ^{20 is} a hydrocarbon radical having 8 to 32, preferably 10 to 20 and particularly preferably 12 to 18 carbon atoms and Y' is a hydrophilic group, preferably one non-ionic hydrophilic group, especially a polyalkyleneoxy group.

The at least one nonionic surfactant O is preferably an ethoxylated long-chain, aliphatic alcohol, which may optionally contain aromatic components.

Examples include his: Ci2Ci4 fatty alcohol ethoxylates, Ci ₆ Ci ₈ fatty alcohol ethoxylates, C13 oxo alcohol ethoxylates, Cio oxo alcohol ethoxylates, CisCis oxo alcohol ethoxylates,

Cio-Guerbet alcohol ethoxylates and alkylphenol ethoxylates. Compounds with 5 to 20 ethyleneoxy units, preferably 8 to 18 ethyleneoxy units, have proven particularly useful. Optionally, small amounts of higher alkyleneoxy units, in particular propyleneoxy and / or butyleneoxy units, may also be present, but the amount as ethyleneoxy units should generally be at least 80 mol%, based on all alkyleneoxy units.

Particularly suitable are surfactants selected from the group of the ethoxylated alkylphenols, the ethoxylated, saturated iso-C-13 alcohols and / or the ethoxylated Cio-Guerbet alcohols, each with 5 to 20 ethyleneoxy units, preferably 8 to 18 ethyleneoxy units are present in alkoxy residues. By adding a non-polymerizable, surface-active compound O during the polymerization of the hydrophobically associating copolymer (A), the application properties of the copolymer can be modified during polymer flooding. In particular, the thickening effect is increased and the gel content of the copolymer is also reduced.

This effect can probably be explained as follows: In the polymerization without the presence of at least one non-polymerizable, surface-active compound (O), the hydrophobically associating monomers (a) form micelles in the aqueous reaction medium. In the case of the polymerization, this leads to the hydrophobically associating regions being built into the polymer in blocks. If an additional surface-active compound (O) is now present in the preparation of the copolymers, mixed micelles form. These mixed micelles contain polymerizable and non-polymerizable components. As a result, the hydrophobically associating monomers (a) are incorporated in shorter blocks. At the same time, the number of these shorter blocks per polymer chain is larger. Thus, the structure of the copolymers produced in the presence of a non-polymerizable, surface-active compound (O) differs from that which was produced in the absence of such a compound.

The non-polymerizable, surface-active compounds (O) can generally be used in an amount of 0.1 to 5% by weight, based on the amount of all monomers used.

The weight ratio of the non-polymerizable, surface-active compounds (O) to the monomers (A1) is generally 4: 1 to 1: 4, preferably 2: 1 to 1: 2, particularly preferably 1.5: 1 up to 1: 1, 5 and for example about 1: 1.

Implementation of the polymerization

For the polymerization, the necessary components are first mixed together. The order in which the components are mixed for the polymerization is not important, it is only important that in the preferred polymerization method the non-polymerizable, surface-active compound (O) is added to the aqueous polymerization medium before the polymerization is initiated.

The mixture is then polymerized thermally and / or photochemically, preferably at -5 ° C to 80 ° C. If thermal polymerization is used, preference is given to using polymerization initiators which can start the polymerization even at a comparatively low temperature, such as redox initiators. The thermal polymerization can be carried out at room temperature or by heating the mixture, preferably to temperatures of not more than 50 ° C. The photochemical polymerization is usually carried out at temperatures from -5 to 10 ° C. It is also possible to combine photochemical and thermal polymerization with one another by using both initiators for the mixture admits the thermal as well as for the photochemical polymerization. The polymerization is first started photochemically at low temperatures, preferably -5 to +10 ° C. As a result of the heat of reaction released, the mixture heats up and the thermal polymerization is additionally started. With this combination, sales of more than 99% can be achieved.

In a further preferred embodiment of the polymerization, the reaction can also be carried out with a mixture of a redox initiator system and a thermal initiator which only decomposes at higher temperatures. This can be, for example, a water-soluble azo initiator that decomposes in the temperature range from 40 ° C to 70 ° C. The polymerization starts here at low temperatures, for example 0 to 10 ° C, through the redox initiator system. As a result of the heat of reaction released, the mixture heats up and, as a result, the polymerization is additionally started by the initiator, which decomposes only at higher temperatures.

As a rule, gel polymerization takes place without stirring. It can be carried out batchwise by irradiating and / or heating the mixture in a suitable vessel with a layer thickness of 2 to 20 cm. The polymerization produces a solid gel. The polymerization can also be carried out continuously. For this purpose, a polymerization apparatus is used, which has a conveyor belt for receiving the mixture to be polymerized. The conveyor belt is equipped with devices for heating and / or for irradiation with UV radiation. The mixture is then poured onto one end of the belt using a suitable device, the mixture is polymerized in the course of transport in the direction of the belt, and the solid gel can be removed at the other end of the belt.

The gel obtained is preferably comminuted and dried after the polymerization. Drying should preferably take place at temperatures below 100 ° C. A suitable release agent can be used for this step to avoid sticking together.

The hydrophobically associating copolymer is obtained as granules or powder.

Further details on how to carry out a gel polymerization are described, for example, in

DE 10 2004 032 304 A1, sections [0037] to [0041].

Since the polymer powder or granulate obtained is generally used as an aqueous solution in the course of application at the place of use, the polymer must be dissolved in water on site. This can lead to undesirable clumping with the described high molecular weight polymers. To avoid this, an auxiliary which accelerates or improves the dissolution of the dried polymer in water can be added to the polymers according to the invention already during the synthesis. This aid can be, for example, urea.

Use of the hydrophobically associating copolymers As already mentioned at the outset, the hydrophobically associating copolymers according to the invention can be used according to the invention for thickening aqueous phases.

The present invention accordingly relates to the use of the copolymers according to the invention in the development, exploitation and completion of underground oil and gas deposits. In particular, the use relates to the preferred embodiments which have been described above in connection with the copolymers according to the invention.

The copolymers can be used alone or in combination with other thickening components, for example with other thickening polymers. For example, they can also be formulated together with surfactants to form a thickening system. The surfactants can form micelles in aqueous solution and the hydrophobically associating copolymers can form a three-dimensional, thickening network together with the micelles.

When used, the copolymer can be dissolved directly in the aqueous phase to be thickened. It is also conceivable to pre-dissolve the copolymer and then add the solution formed to the system to be compressed.

The properties of the copolymers can be adapted to the respective technical requirements by selecting the type and amount of the monomers (a) and (b) and of the component (c).

The copolymers according to the invention can be used, for example, in the field of oil production as an additive for thickening drilling fluids and completion fluids.

The copolymers according to the invention are also used as thickeners in hydraulic fracturing. A highly viscous, aqueous solution is typically pressed into the oil or gas-bearing formation layer under high pressure.

The invention preferably relates to the use of the copolymers according to the invention for the tertiary oil production, an aqueous formulation of the said copolymers in a concentration of 0.01 to 5% by weight being pressed through at least one injection hole into a petroleum deposit and the deposit crude oil is extracted through at least one production well.

The concentration of the copolymer should generally not exceed 5% by weight, based on the sum of all constituents of the formulation, and is usually 0.01 to 5% by weight, in particular 0.1 to 5% by weight, preferably 0.5 up to 3% by weight and particularly preferably 1 to 2% by weight. The formulation is pressed into the petroleum reservoir through at least one injection well and crude oil is withdrawn from the reservoir through at least one production well. In this context, the term “crude oil” is of course not only meant to be phase-pure oil, but the term also includes the usual crude oil-water emulsions. As a rule, a deposit is provided with several injection wells and with several production wells. The pressed-in formulation, the so-called “polymer flood”, creates a pressure that causes the oil to flow in the direction of the production well and is conveyed through the production well. The viscosity of the flood medium should be adapted to the viscosity of the petroleum in the petroleum deposit if possible. The viscosity can be adjusted in particular via the concentration of the copolymer. For polymer flooding, an aqueous formulation is used which, in addition to water, comprises at least one hydrophobically associating copolymer. Mixtures of different copolymers can of course also be used. Of course, other components can also be used. Examples of other components include biocides, stabilizers or inhibitors. The formulation can preferably be prepared by introducing the water and sprinkling in the copolymer as a powder. The aqueous formulation should be exposed to the lowest possible shear forces.

To increase the oil yield, the polymer flooding can advantageously be combined with other techniques of tertiary oil production.

The invention preferably relates to the use of the copolymers according to the invention in the development, exploitation and completion of underground petroleum and natural gas deposits, in particular for tertiary petroleum production, the aqueous formulation of the said copolymers containing at least one surfactant.

In a further preferred embodiment of the invention, the “polymer flooding” can be combined with a preceding so-called “surfactant flooding” using the hydrophobically associating copolymers according to the invention. Before the polymer flooding, an aqueous surfactant formulation is first pressed into the petroleum formation. This reduces the interfacial tension between the formation water and the actual petroleum and thus increases the mobility of the petroleum in the formation. The oil yield can be increased by combining both techniques.

Examples of suitable surfactants for surfactant flooding include sulfate groups, sulfonate groups, polyoxyalkylene groups, anionically modified polyoxyalkylene groups, betain groups, glucoside groups or surfactants containing amine oxide groups, such as, for example, alkylbenzenesulfonates, olefin sulfonates or amidopropyl betaines. Anionic and / or betaine surfactants can preferably be used.

The person skilled in the art knows details of the technical implementation of polymer flooding and surfactant flooding, and he uses a corresponding technique depending on the type of deposit. It is of course also possible to use surfactants and the copolymers according to the invention in a mixture.

The following examples are intended to illustrate the invention:

Part I: Syntheses l-a Preparation of the monomers (a) of the formula HBVE - y EO - XPO

Monomer 1 (M1, according to the invention): alkoxylation (propoxylation by DMC catalysis) of HBVE with 24.5 EO (ethylene oxide), followed by 80 PO (propylene oxide)

1 16.16 g (1.0 mol) of hydroxybutyl vinyl ether (HBVE) (stabilized with 100 ppm potassium hydroxide (KOH)) were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was turned on. 0.76 g of potassium methoxide (KOMe) solution (30% KOMe in methanol (MeOH), corresponds to 0.0033 mol of potassium) was added and the stirred tank was evacuated to a pressure of 20 mbar, heated to 65 ° C, 120 min at 65 ° C and operated at a pressure of 20 mbar. MeOH was distilled off. It was flushed three times with N ₂ (nitrogen). The container was then checked for pressure tightness, set at 0.5 bar gauge pressure (1.5 bar absolute) and heated to 145 ° C. The pressure was released to 1 bar absolute and 1079.2 g (24.5 mol) ethylene oxide (EO) were metered in to p _max 3.9 bar absolute and T _{max was} 150 ° C. The mixture was stirred at a constant pressure at about 145-150 ° C (1 h), cooled to 80 ° C and freed from low boilers at a pressure of less than 10 mbar for 1 h. The reduced pressure was raised with N ₂ and cooled to 60 ° C., 1% by weight of Ambosol (magnesium silicate) was added at 60 ° C. to reduce the potassium ion content, the pressure was reduced to 100 mbar and the mixture was stirred for 2 hours. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, GPC, 1 H-NMR in CDCls, 1 H-NMR in MeOD) confirmed the structure HBVE - 24.5 EO.

239.1 g (0.2 mol) of HBVE-24.5 EO were placed in a 500 ml Schott glass at 60 ° C., and 1.2 g of double metal cyanide catalyst were removed using an Ultraturax (10,000 rpm, 5 min stirring time) Company BASF (DMC catalyst) registered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of <20 mbar was then applied, heated to 100 ° C. and held for 15 minutes in order to distill off any traces of water. One flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), set to 127 ° C. and then the pressure set to 1 bar absolute. 929.3 g (16 mol) of propylene oxide (PO) were metered in over the course of 18 h at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the reaction was allowed to continue for 6 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 2 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled. The analysis (OH number, 1 H-NMR in CDCI3, 1 H-NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 80 PO.

Monomer 2 (M2, not according to the invention): alkoxylation of HBVE with 22 EO, followed by 20 PO (propoxylation by KOH / NaOH catalysis)

135.3 g (1.16 mol) of hydroxybutyl vinyl ether (HBVE) (stabilized with 100 ppm of potassium hydroxide (KOH)) were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was turned on. 1.06 g of potassium methoxide (KOMe) solution (32% KOMe in methanol (MeOH), corresponds to 0.0048 mol of potassium) were added and the stirred tank was evacuated to a pressure of 10-20 mbar, heated to 65 ° C., 70 min operated at 65 ° C and a pressure of 10 - 20 mbar. MeOH was distilled off. It was flushed three times with N2 (nitrogen). The container was then checked for pressure tightness, 0.5 bar gauge pressure (1.5 bar absolute) was set and heated to 120 ° C. The pressure was released to 1 bar absolute and 1 126 g (25.6 mol) ethylene oxide (EO) were metered in to p _max 3.9 bar absolute and T _{max was} 150 ° C. After dosing 300 g EO, the dosing was stopped (approx. 3 h after the start), waited 30 min and completely relaxed to 1.3 bar. The remaining EO was then metered in. The metering to EO including relaxation took a total of 10 hours. The mixture was stirred to constant pressure at about 145-150 ° C (1 h), cooled to 100 ° C and freed from low boilers for 1 h at a pressure of less than 10 mbar. The goods were filled at 80 ° C under N ₂ . The analysis (OH number, GPC, 1 H-NMR in CDCI3, 1 H-NMR in MeOD) confirmed the structure HBVE - 22 EO.

487.6 g (0.454 mol) of HBVE-22 EO were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. Then 2.0 g of 50% NaOH solution (0.025 mol NaOH, 1.0 g NaOH) were added, a vacuum of 10 mbar was applied, the mixture was heated to 100 ° C. and held for 120 minutes in order to distill off the water. You flushed three times with N2. The container was then checked for pressure tightness, 0.5 bar gauge pressure (1.5 bar absolute), heated to 127 ° C. and then the pressure set to 1.5 bar absolute. 526.5 g (9.087 mol) of PO (propylene oxide) were metered in at 127 ° C. in the course of 12 h, p _max was 3.1 bar absolute. After the end of the PO dosage, the mixture was left to react at 127 ° C. for 3 h. It was cooled to 100 ° C., volatile components were drawn off at 100 ° C. and 20 mbar. The vacuum was released with N2. The filling took place at 80 ° C under N2.

The analysis (OH number, GPC, 1 H-NMR in CDCI3, 1 H-NMR in MeOD) confirms the presence of 100 mol% HBVE - 22 EO - (20 - x) PO and 30 mol% allyl - (x - 1) PO. X is approximately 6.

Monomer 3 (M3, according to the invention): alkoxylation of HBVE with 24.5 EO, followed by 20 PO (propoxylation by DMC catalysis)

1 16.16 g (1.0 mol) of hydroxybutyl vinyl ether (HBVE) (stabilized with 100 ppm potassium hydroxide (KOH)) were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was turned on. 0.76 g potassium methoxide (KOMe) solution (30% KOMe in methanol (MeOH), corresponds to 0.0033 mol Potassium) were added and the stirred tank was evacuated to a pressure of 20 mbar, heated to 65 ° C, operated for 120 min at 65 ° C and a pressure of 20 mbar. MeOH was distilled off. It was flushed three times with N ₂ (nitrogen). The container was then checked for pressure tightness, set at 0.5 bar gauge pressure (1.5 bar absolute) and heated to 145 ° C. The pressure was released to 1 bar absolute and 1079.2 g (24.5 mol) ethylene oxide (EO) were metered in to p _max 3.9 bar absolute and T _{max was} 150 ° C. The mixture was stirred at a constant pressure at about 145-150 ° C (1 h), cooled to 80 ° C and freed from low boilers at a pressure of less than 10 mbar for 1 h. The reduced pressure was raised with N ₂ and cooled to 60 ° C., 1% by weight of Ambosol (magnesium silicate) was added at 60 ° C. to reduce the potassium ion content, the pressure was reduced to 100 mbar and the mixture was stirred for 2 hours. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, GPC, 1 H-NMR in CDCI ₃ , 1 H-NMR in MeOD) confirmed the structure HBVE - 24.5 EO.

239.1 g (0.2 mol) of HBVE-24.5 EO were placed in a 500 ml Schott glass at 60 ° C., and 1.2 g of double metal cyanide catalyst were removed using an Ultraturax (10,000 rpm, 5 min stirring time) Company BASF (DMC catalyst) registered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of <20 mbar was then applied, heated to 100 ° C. and held for 15 minutes in order to distill off any traces of water. One flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), set to 127 ° C. and then the pressure set to 1 bar absolute. 232.3 g (4 mol) of propylene oxide (PO) were metered in over 3 h at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the reaction was allowed to continue for 6 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 2 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, 1 H NMR in CDCI ₃ , 1 H NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 20 PO.

Monomer 4 (M4, according to the invention): alkoxylation of HBVE with 24.5 EO, followed by 40 PO (propoxylation by DMC catalysis)

1 16.16 g (1.0 mol) of hydroxybutyl vinyl ether (HBVE) (stabilized with 100 ppm potassium hydroxide (KOH)) were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was turned on. 0.76 g of potassium methoxide (KOMe) solution (30% KOMe in methanol (MeOH), corresponds to 0.0033 mol of potassium) was added and the stirred tank was evacuated to a pressure of 20 mbar, heated to 65 ° C, 120 min at 65 ° C and operated at a pressure of 20 mbar. MeOH was distilled off. It was flushed three times with N ₂ (nitrogen). The container was then checked for pressure tightness, set at 0.5 bar gauge pressure (1.5 bar absolute) and heated to 145 ° C. The pressure was released to 1 bar absolute and 1079.2 g (24.5 mol) ethylene oxide (EO) were metered in to p _max 3.9 bar absolute and T _{max was} 150 ° C. The mixture was stirred at constant pressure at about 145-150 ° C (1 h), to 80 ° C cooled and freed from low boilers at a pressure of less than 10 mbar for 1 h. The reduced pressure was raised with N ₂ and cooled to 60 ° C., 1% by weight of Ambosol (magnesium silicate) was added at 60 ° C. to reduce the potassium ion content, the pressure was reduced to 100 mbar and the mixture was stirred for 2 hours. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

239.1 g (0.2 mol) of HBVE-24.5 EO were placed in a 500 ml Schott glass at 60 ° C., and 1.2 g of double metal cyanide catalyst were removed using an Ultraturax (10,000 rpm, 5 min stirring time) Company BASF (DMC catalyst) registered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of <20 mbar was then applied, heated to 100 ° C. and held for 15 minutes in order to distill off any traces of water. One flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), set to 127 ° C. and then the pressure set to 1 bar absolute. 464.6 g (8 mol) of propylene oxide (PO) were metered in over the course of 3 h at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the reaction was allowed to continue for 6 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 2 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, 1 H-NMR in CDCI ₃ , 1 H-NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 40 PO.

Monomer 5 (M5, according to the invention): alkoxylation of HBVE with 24.5 EO, followed by 60 PO (propoxylation by DMC catalysis)

1 16.16 g (1.0 mol) of hydroxybutyl vinyl ether (HBVE) (stabilized with 100 ppm potassium hydroxide (KOH)) were placed in a 2 l pressure autoclave with anchor stirrer and the stirrer was turned on. 0.76 g of potassium methoxide (KOMe) solution (30% KOMe in methanol (MeOH), corresponds to 0.0033 mol of potassium) was added and the stirred tank was evacuated to a pressure of 20 mbar, heated to 65 ° C, 120 min at 65 ° C and operated at a pressure of 20 mbar. MeOH was distilled off. It was flushed three times with N ₂ (nitrogen). The container was then checked for pressure tightness, set at 0.5 bar gauge pressure (1.5 bar absolute) and heated to 145 ° C. The pressure was released to 1 bar absolute and 1079.2 g (24.5 mol) ethylene oxide (EO) were metered in to p _max 3.9 bar absolute and T _{max was} 150 ° C. The mixture was stirred at a constant pressure at about 145-150 ° C (1 h), cooled to 80 ° C and freed from low boilers at a pressure of less than 10 mbar for 1 h. The reduced pressure was raised with N ₂ and cooled to 60 ° C., 1% by weight of Ambosol (magnesium silicate) was added at 60 ° C. to reduce the potassium ion content, the pressure was reduced to 100 mbar and the mixture was stirred for 2 hours. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled. The analysis (OH number, GPC, 1 H-NMR in CDCI ₃ , 1 H-NMR in MeOD) confirmed the structure HBVE - 24.5 EO.

239.1 g (0.2 mol) of HBVE-24.5 EO were placed in a 500 ml Schott glass at 60 ° C., and 1.2 g of double metal cyanide catalyst were removed using an Ultraturax (10,000 rpm, 5 min stirring time) Company BASF (DMC catalyst) registered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of <20 mbar was then applied, heated to 100 ° C. and held for 15 minutes in order to distill off any traces of water. One flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), set to 127 ° C. and then the pressure set to 1 bar absolute. 696.9 g (12 mol) of propylene oxide (PO) were metered in over the course of 6 hours at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the reaction was allowed to continue for 6 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 2 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, 1 H-NMR in CDCI3, 1 H-NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 60 PO.

Monomer 6 (M6, not according to the invention):

Alkoxylation of HBVE with 24.5 EO, followed by 80 PO (propoxylation by KOH / NaOH catalysis

The analysis (OH number, GPC, 1 H-NMR in CDCI ₃ , 1 H-NMR in MeOD) confirmed the structure HBVE - 24.5 EO. 239.1 g (0.2 mol, 100 mol%) of HBVE-24.5 EO were placed in a 1000 ml round-bottomed flask at 60 ° C. and mixed with 0.9 g of 50% aqueous NaOH solution (0.01 1 mol NaOH, 5.5 mol%) mixed. The mixture was then dewatered on a rotary evaporator at 100 ° C. and 20 mbar for 2 hours. The reaction mixture was completely transferred to a 2 l pressure autoclave with an anchor stirrer and the stirrer was switched on. A vacuum of <20 mbar was then applied, heated to 100 ° C. and held for 15 minutes in order to distill off any traces of water. The mixture was flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), heated to 127 ° C. and then the pressure set to 1.4 bar absolute. 929.3 g (16 mol) of propylene oxide (PO) were metered in at 27 ° C. in the course of 27 h, p _max was 4 bar absolute. After the end of the PO dosage, the reaction was allowed to continue for 6 h. It was cooled to 100 ° C. and volatile components were removed at 20 mbar for 2 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C. under N ₂ (filter K150) and filled.

The analysis (OH number, 1 H-NMR in CDCI3, 1 H-NMR in MeOD) confirmed the presence of 100 mol% HBVE - 24.5 EO - (80 - x) PO and 100 mol% allyl - (x - 1) PO. X is approximately 39.

The examples show that only the process according to the invention led to the desired alkoxylation products, whereas the base-catalyzed preparation (monomer M2, monomer M6) leads to rearrangement products which polymerized poorly.

Monomer 7 (M7, according to the invention):

Alkoxylation of HBVE- 24.5 EO-40 PO with 20 PO (propylene oxide), DMC catalysis

300.0 g (0.085 mol) of HBVE-24.5 EO-40 PO (see previous experiments) were placed in a 500 ml Schott glass at 60 ° C. and an Ultraturax (10000 rpm, 5 min stirring time) 0.5 g of double metal cyanide catalyst from BASF (DMC catalyst) entered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of 20 mbar was then applied, heated to 80 ° C. and held for 20 minutes in order to distill off any traces of water. The vacuum was released by adding N ₂ and then flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute) was set, heated to 127 ° C and then the pressure set to 1.3 bar absolute. 99.1 g (1.71 mol) of propylene oxide (PO) were metered in over the course of 9 h at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the mixture was left to react for 4 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 4 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C under N ₂ (filter K150) and filled. The analysis (OH number, 1 H-NMR in CDCI ₃ , 1 H-NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 60 PO. Monomer 8 (M8, according to the invention): alkoxylation of HBVE -24.5 EO -20 PO, followed by 80 PO (propylene oxide), DMC catalysis

233.0 g (0.099 mol) of HBVE-24.5 EO-20 PO (see previous tests) were placed in a 500 ml Schott glass at 60 ° C. and an Ultraturax (10000 rpm, 5 min stirring time) 0.7 g of double metal cyanide catalyst from BASF (DMC catalyst) entered. The mixture was completely transferred to a 2 l pressure autoclave with anchor stirrer and the stirrer was switched on. A vacuum of 20 mbar was then applied, heated to 90 ° C. and held for 20 minutes in order to distill off any traces of water. The vacuum was released by adding N ₂ and then flushed three times with N ₂ . The container was then checked for pressure tightness, 0.5 bar overpressure (1.5 bar absolute), set to 127 ° C. and then the pressure set to 1.4 bar absolute. 459.3 g (7.91 mol) of propylene oxide (PO) were metered in over the course of 16 h at 127 ° C., p _max was 4.1 bar absolute. After the end of the PO dosage, the mixture was left to react for 3 h. It was cooled to 100 ° C. and volatile components were drawn off at 20 mbar for 4 hours. The reduced pressure was raised with N ₂ and cooled to 60 ° C. The goods were filtered at 60 ° C under N ₂ (filter K150) and filled. The analysis (OH number, 1 H-NMR in CDC, 1 H-NMR in MeOD) confirmed the mean composition HBVE - 24.5 EO - 100 PO.

l-b Preparation of the copolymers based on monomers M1 -M8

Copolymer 1 (C1, according to the invention) from 69.1% by weight (75.2 mol%) of acrylamide, 30% by weight (24.7 mol%) of sodium acrylate and 0.9% by weight (0.031 mol%) of the monomer M3 (HBVE-24.5EO-20PO )

102.04 g of a 35% aqueous solution of Na acrylate were placed in a 1 L screw-top jar with magnetic stirrer, pH meter and thermometer and then 100.00 g of distilled water, 0.4 g of a commercially available silicone defoamer (Xiameter A-FE-0400 - Antifoam emulsion), 1.07 g of monomer M4, 157.97 g of acrylamide (52% solution in water), 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid, pentasodium salt, 1.1 g of the nonionic surfactant iCi3- (EO) isH and 10.00 g of a 0.1% sodium hypophosphite hydrate solution were added. After adjusting to pH 6.75 with a 10% sulfuric acid solution and adding the remaining water to achieve the target monomer concentration of 30% (total amount of water minus the amount of water already added, minus the amount of acid required), the monomer solution was added to the Start temperature set at 4 ° C. The solution was transferred to a thermos flask, the thermocouple attached for temperature recording, flushed with nitrogen for 45 minutes and with 1.6 g of a 10% strength 2,2-azobis (2-amidinopropane) dihydrochloride solution, 0.12 mL of a 1 % / -BHP solution and 0.24 mL of a 1% sodium disulfite solution started the polymerization. When the polymerization started, the temperature rose to 80 to 90 ° C. within 40 to 50 min. A solid polymer gel was obtained. After cooling, the gel block was broken up using a meat grinder and the gel granules obtained in a fluidized bed. dryer dried at 55 ° C for two hours. A white, hard granulate was obtained, which was converted into a powdery state by means of a centrifugal mill.

The intrinsic viscosity of the copolymer was determined to be 17.4 dL / g.

Copolymer 2 (C2, according to the invention) from 68.6% by weight (75.1 mol%) of acrylamide, 30% by weight (24.9 mol%) of sodium acrylate and 1.4% by weight (0.031 mol%) of the monomer M4 (HBVE-24.5EO-40PO )

101.44 g of a 35% aqueous solution of Na acrylate were placed in a 1 L screw-top jar with magnetic stirrer, pH meter and thermometer and then 100.00 g of distilled water, 0.4 g of a commercially available silicone defoamer (Xiameter A-FE-0400 - Antifoam emulsion), 1.66 g of monomer M3, 156.12 g of acrylamide (52% solution in water), 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid, pentasodium salt, 1.7 g of the nonionic surfactant iCi - (EO) i H and 10.00 g of a 0.1% sodium hypophosphite hydrate solution are added. After adjusting to pH 6.75 with a 10% sulfuric acid solution and adding the remaining water to reach the target monomer concentration of 30% (total amount of water minus the amount of water already added, minus the amount of acid required), the monomer solution was started - set temperature of 4 ° C. The solution was transferred to a thermos flask, the thermocouple attached for temperature recording, flushed with nitrogen for 45 minutes and with 1.6 g of a 10% 2,2-azobis (2-amidinopropane) dihydrochloride solution, 0.12 mL of a 1% t-BHP solution and 0.24 mL of a 1% sodium disulfite solution started the polymerization. When the polymerization started, the temperature rose to 80 to 90 ° C. within 40 to 50 min. A solid polymer gel was obtained. After cooling, the gel block was comminuted using a meat grinder and the gel granules obtained were dried in a fluidized bed dryer at 55 ° C. for two hours. A white, hard granulate was obtained, which was converted into a powdery state by means of a centrifugal mill.

The intrinsic viscosity of the copolymer was determined to be 17.1 dL / g.

Copolymer 3 (C3, according to the invention) from 68.1% by weight (75.0 mol%) of acrylamide, 30% by weight (25.0 mol%) of sodium acrylate and 1.9% by weight (0.031 mol%) of the monomer M7 (HBVE-24.5EO-60PO )

100.94 g of a 35% aqueous solution of Na acrylate were placed in a 1 L screw-top jar with magnetic stirrer, pH meter and thermometer and then 100.00 g of distilled water, 0.4 g of a commercially available silicone defoamer (Xiameter A-FE-0400 - Antifoam emulsion), 2.24 g monomer M6, 154.22 g acrylamide (52% solution in water), 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid, pentasodium salt, 2.24 g of the nonionic surfactant iCi - (EO) i H and 10.00 g of a 0.1% sodium hypophosphite hydrate solution are added. After adjusting to pH 6.75 with a 10% sulfuric acid solution and adding the remaining water to reach the target monomer concentration of 30% (total amount of water minus the amount of water already added, minus the amount of acid required), the monomer solution was started - temperature set at 4 ° C. The solution was transferred to a thermos flask, the thermocouple attached for temperature recording, flushed with nitrogen for 45 minutes and with 1.6 g of a 10% 2,2-azobis (2-amidinopropane) dihydrochloride solution, 0.12 mL of a 1% t-BHP solution and 0.24 mL of a 1% sodium disulfite solution started the polymerization. When the polymerization started, the temperature rose to 80 to 90 ° C. within 40 to 50 min. A solid polymer gel was obtained. After cooling, the gel block was comminuted using a meat grinder and the gel granules obtained were dried in a fluidized bed dryer at 55 ° C. for two hours. A white, hard granulate was obtained, which was converted into a powdery state by means of a centrifugal mill.

The intrinsic viscosity of the copolymer was determined to be 16.5 dL / g.

Copolymer 4 (C4, according to the invention) from 67.7% by weight (74.9 mol%) of acrylamide, 30% by weight (25.1 mol%) of sodium acrylate and 2.3% by weight (0.031 mol%) of the monomer M1 (HBVE -24.5EO-80PO)

100.54 g of a 35% aqueous solution of Na acrylate were placed in a 1 L screw-top jar with magnetic stirrer, pH meter and thermometer and then 100.00 g of distilled water, 0.4 g of a commercially available silicone defoamer (Xiameter A-FE-0400 - Antifoam emulsion), 2.7 g of monomer M5, 152.72 g of acrylamide (52% solution in water), 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid, pentasodium salt, 2.7 g of the nonionic surfactant iCi - (EO) i H and 10.00 g of a 0.1% sodium hypophosphite hydrate solution are added. After adjusting to pH 6.75 with a 10% sulfuric acid solution and adding the remaining water to reach the target monomer concentration of 30% (total amount of water minus the amount of water already added, minus the amount of acid required), the monomer solution was started - set temperature of 4 ° C. The solution was transferred to a thermos flask, the thermocouple attached for temperature recording, flushed with nitrogen for 45 minutes and with 1.6 g of a 10% strength 2,2-azobis (2-amidinopropane) dihydrochloride solution, 0.12 ml of a 1% strength solution t-BHP solution and 0.24 mL of a 1% sodium disulfite solution started the polymerization. When the polymerization started, the temperature rose to 80 to 90 ° C. within 40 to 50 min. A solid polymer gel was obtained. After cooling, the gel block was comminuted using a meat grinder and the gel granules obtained were dried in a fluidized bed dryer at 55 ° C. for two hours. A white, hard granulate was obtained, which was converted into a powdery state by means of a centrifugal mill.

The intrinsic viscosity of the copolymer was determined to be 17.9 dL / g.

Copolymer 5 (C5, according to the invention) from 67.3% by weight (74.8 mol%) of acrylamide, 30% by weight (25.2 mol%) of sodium acrylate and 2.7% by weight (0.031 mol%) of the monomer M8 (HBVE-24.5EO-100PO )

100.15 g of a 35% aqueous solution of Na acrylate were placed in a 1 L screw-top glass with magnetic stirrer, pH meter and thermometer and then 100.00 g of distilled water, 0.4 g of a commercially available silicone defoamer (Xiameter A- FE-0400 - Antifoam Emulsion), 3.15 g monomer M7, 151.22 g acrylamide (52% solution in water), 1.2 g of a 5% aqueous solution of diethylenetriaminepentaacetic acid, pentasodium salt, 3.2 g of the nonionic surfactant iCi - (EO) i H and 10.00 g of a 0.1% sodium hypophosphite hydrate solution are added. After adjusting to pH 6.75 with a 10% sulfuric acid solution and adding the remaining water to reach the target monomer concentration of 30% (total amount of water minus the amount of water already added, minus the amount of acid required), the monomer solution was started - set temperature of 4 ° C. The solution was transferred to a thermos flask, the thermocouple attached for temperature recording, flushed with nitrogen for 45 minutes and with 1.6 g of a 10% 2,2-azobis (2-amidinopropane) dihydrochloride solution, 0.12 mL of a 1% t-BHP solution and 0.24 mL of a 1% sodium disulfite solution started the polymerization. When the polymerization started, the temperature rose to 80 to 90 ° C. within 40 to 50 min. A solid polymer gel was obtained. After cooling, the gel block was comminuted using a meat grinder and the gel granules obtained were dried in a fluidized bed dryer at 55 ° C. for two hours. A white, hard granulate was obtained, which was converted into a powdery state by means of a centrifugal mill.

The intrinsic viscosity of the copolymer was determined to be 14.7 dL / g.

Determination of the intrinsic viscosity

To determine the intrinsic viscosity, the transit times of the solvent and the polymer solutions at various concentrations were determined using an Ubbelohde capillary viscometer. The relative viscosities were calculated from the ratio of the running times of the polymer solution and the pure solvent. The specific viscosities were then formed from the difference in relative viscosity and 1. Finally, the reduced viscosity was formed from the quotient of the specific viscosity and the polymer concentration. This was plotted against the polymer concentration and the intrinsic viscosity was obtained from the extrapolation against c = 0.

Part II: Application tests

The following tests were carried out on the copolymers obtained, based on the above monomers, in order to assess their suitability for tertiary oil production. For this purpose, the copolymers were dissolved in synthetic seawater with the following composition:

1. Brookfield viscosity

The viscosity of the copolymer solutions as a function of temperature was measured using a Brookfield LV type viscometer with UL adapter at 6 rpm (= 7.3 S ¹ ).

The results are shown in Figures 1 and 2.

Figure 1 relates to the Brookfield viscosity of the copolymers C1, C2, C3, C4 and C5 (according to the invention) at a copolymer concentration of 1500 ppm.

Figure 2 relates to the Brookfield viscosity of the copolymers C1, C2, C3, C4 and C5 (according to the invention) at a copolymer concentration of 2000 ppm. Figures 1 and 2 show the temperature thickening behavior of the copolymers C1, C2, C3, C4 and C5 with monomers with different PO contents (see Table 1) at a copolymer concentration of 1500 ppm and 2000 ppm.

Table 1: Composition of the copolymers investigated

Here it becomes clear that the temperature-thickening behavior strongly depends on the proportion of propyleneoxy units in the monomer used. With copolymers which contain monomers with 20 propyleneoxy units (example C1) and 40 propyleneoxy units (example C2), no thermo-associative behavior can be observed either at a copolymer concentration of 1500 ppm or at 2000 ppm. For copolymers, which are monomers with 60 propyleneoxy units (copolymer C3), 80 propyleneoxy units (copolymer C4) and 100 Propyleneoxy units (copolymer C5), on the other hand, have a clearly thermo-thickening effect. The effect is most pronounced with copolymers with a PO content (copolymer C4) of 80. However, the somewhat lower molecular weight of the polymer C5 can also play a role here.

Claims

1. Process for the preparation of a hydrophobically associating monomer (a) of the general formula (I),

H ₂ C = CR-X- (CH ₂ ) x-0- (CH ₂ -CH ₂ -0-) y- (CH ₂ -CH (CH ₃ ) -0-) zR ¹ (I), where the units - (- CH ₂ -CH ₂ -0-) _y - and - (- CH ₂ -CH (CH ₃ ) -0-) _z - are arranged in block structure in the order shown in formula (I), and wherein the radicals and indices have the following meanings:

X is -O- ,,

R is H,

R ¹ is H;

x is 4,

y is a number from 10 to 50,

z is a number from 10 to 125, comprising the following steps: a) reacting a monoethylenically unsaturated alcohol A1 of the general formula (II)

H ₂ C = C (R) -X- (CH ₂ ) _x -0- (CH ₂ -CH ₂ -0) _d -H (II), with ethylene oxide; wherein the radicals R and X and the index x have the meaning given above and d is a number from 0 to 5; an alkoxylated alcohol A2 is obtained; b) reacting the alkoxylated alcohol A2 with propylene oxide, the reaction being carried out in the presence of a double metal cyanide compound as catalyst, an alkoxylated alcohol A3 according to formula (III),

H ₂ C = C (R) -X- (CH ₂ ) x-0 - (- CH ₂ -CH ₂ -0-) y - (- CH ₂ -CH (CH ₃ ) -0-) zR ¹ (III ) with R ¹ = H is obtained, the radicals R and X and the indices x, y and z having the meanings defined above; c) optionally etherifying the alkoxylated alcohol A3 with a compound

R ¹ -X 'where R ^{1 is} a hydrocarbon radical having 1 to 4 carbon atoms and X' is a leaving group, preferably selected from the group of CI, Br, I, -O-SO ₂ -CH ₃ (mesylate), -O-SO _{2 is} -CF ₃ (triflate) and -O-SO ₂ -OR ¹ ; wherein a monomer (a) according to formula (I) with R ¹ = hydrocarbon radical having 1 to 4 carbon atoms is obtained.

2. The method according to claim 1, wherein in step b) a double metal cyanide compound of the general formula (IV)

M ² a [M ¹ (CN) _r X * t] b (IV), is used, where

M ² is a metal ion selected from the group consisting of Sr (l), Mg (ll),

Zn (ll), Fe (ll), Fe (lll), Co (lll), Cr (lll), Mn (ll), Mn (lll), Ir (lll), Rh (lll), Ru (ll), V (IV), V (V), Co (II), Cr (II), Ti (IV), preferably Ni (II), Mn (II), Zn (II), Co (II), Co (III) , Fe (II) and Fe (III);

X 'is a group other than cyanide, which forms a coordinative bond to M ¹ , selected from the group consisting of carbony, cyanate, isocyanate, nitrile, thiocyanate and nitrosyl; a, b, r, t are integers that are chosen so that the electroneutrality condition is fulfilled.

is used

3. The method according to claim 1 or 2, wherein the DMC catalyst is used in a concentration of 0.0005-0.5% by weight, preferably 0.001-0.1% by weight, based on the alcohol A2 used .

4. The method according to any one of claims 1 to 3, wherein step b) is carried out at a temperature of less than or equal to 135 ° C and a pressure of 1 to 5 bar.

5. The method according to any one of claims 1 to 4, wherein z> y.

6. The method according to any one of claims 1 to 5, wherein the indices have the following meaning:

y is a number from 20 to 30, preferably 23 to 26;

z is a number from 40 to 100, preferably 70 to 90.

7. The method according to any one of claims 1 to 6, wherein z is 80.

8. Hydrophobically associating monomer (a) of the general formula (I), obtainable in the process according to one of claims 1 to 7.

9. A water-soluble, hydrophobically associating copolymer (A) comprising

(a) 0.1 to 15.0% by weight of at least one hydrophobically associating monomer (a) according to claim 8, and

(b) 85.0 to 99.9% by weight of at least one hydrophilic monomer (b) different from monomer (a), where at least one of the monomers (b) is a neutral, monoethylenically unsaturated hydrophilic monomer ( b1) selected from the group consisting of (meth) acrylamide, N-methyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide; wherein the amounts of the monomers (a) and (b) are each based on the total amount of all monomers used in the reaction, and preferably in the reaction of the at least one monomer (a) with the at least one hydrophilic monomer different from monomer (a) ( b) before the initiation of the polymerization reaction, at least one further, non-polymerizable surface-active compound (O) is used.

10. A copolymer according to claim 9, wherein the at least one hydrophilic monomer (b) comprises at least two different, monoethylenically unsaturated, hydrophilic monomers (b1) and (b2), wherein (b1) as defined in claim 9; and

(b2) at least one anionic, monoethylenically unsaturated hydrophilic monomer (2b) which contains at least one acidic group selected from the group consisting of -COOH, -SO ₃ H or -PO ₃ H ₂ .

1 1. Copolymer according to claim 9 or 10, wherein

(b1) as defined in claim 9; and

(b2) at least one anionic, monoethylenically unsaturated hydrophilic monomer (b2), which contains at least one COOH or SOsH group.

12. A copolymer according to any one of claims 9 to 11, wherein (b1) acrylamide as a neutral hydrophilic monomer (b1), and

(b2) acrylic acid or acrylamido-2-methylpropanesulfonic acid (AMPS).

13. A copolymer according to any one of claims 9 to 11, wherein the copolymer

(c) 24.0 to 65.0% by weight of acrylic acid or acrylamido-2-methylpropanesulfonic acid (AMPS) as an anionic hydrophilic monomer (b2), the amounts given being based in each case on the total amount of all monomers in the copolymer.

14. Use of water-soluble, hydrophobically associating copolymers (A) according to one of claims 9 to 13 in the development, exploitation and completion of underground oil and gas deposits.

15. Use according to claim 14 for tertiary oil production, wherein an aqueous formulation of said copolymers in a concentration of 0.01 to 5% by weight is pressed through at least one injection hole into an oil deposit and the deposit through at least one production hole Crude oil is extracted.