EP2424905A1

EP2424905A1 - Alkoxylated (meth)acrylate polymers and the use thereof as crude oil demulsifiers

Info

Publication number: EP2424905A1
Application number: EP10711346A
Authority: EP
Inventors: Carsten Schaefer; Carsten Cohrs; Stefan Dilsky
Original assignee: Clariant Finance BVI Ltd
Current assignee: Clariant Finance BVI Ltd
Priority date: 2009-04-28
Filing date: 2010-03-26
Publication date: 2012-03-07
Also published as: CN102791748B; EP2457931B1; BRPI1013543A2; DK2457931T3; CA2760211A1; DE102009019179A1; EP2457931A1; CN102791748A; WO2010124772A1; US20120031813A1; ES2524395T3

Abstract

The invention relates to polymers which contain structural units of monomers (A) according to formula (I), wherein A represents a C₂ to C₄ alkylene group, R¹ represents hydrogen or methyl, and k is a number of 1 to 1000, and to the use thereof for demulsifying oil/water emulsions in amounts of 0.0001 to 5% by weight, based on the oil content of the emulsion to be demulsified.

Description

description

Alkoxylated (meth) acrylate polymers and their use as crude oil emulsion breakers

The present invention relates to alkoxylated (meth) acrylate polymers and their use for the splitting of water-oil emulsions, in particular in crude oil production.

Crude oil accumulates in its promotion as an emulsion with water. Before the

Further processing of crude oil, these crude oil emulsions must be split into the oil and water content. This is generally done by using so-called crude oil or petroleum emulsion breakers, or petroleum breakers for short. "Oil splitters are surface-active polymeric compounds capable of effecting, within a short time, the required separation of the emulsion components.

As demulsifiers are mainly alkoxylated alkylphenol-formaldehyde resins, nonionic alkylene oxide block copolymers and crosslinked with Bisepoxiden variants used. For reviews, see "Something Old, Something New: A Discussion about Demulsifiers," TG Balson, pp. 226-238 in Proceedings in the Chemistry in the Oil Industry Symposium, November 3 - 5, 2003, Manchester, GB, and "Crude Oil Emulsions: A State-Of-The-Art Review ", S. Kokal, pp. 5-13, Society of Petroleum Engineers SPE 77497.

US 4 032 514 discloses the use of alkylphenol-aldehyde resins for the separation of petroleum emulsions. These resins are obtainable from the condensation of a para-alkylphenol with an aldehyde, mostly formaldehyde.

Such resins are often used in alkoxylated form, as disclosed, for example, in DE-A-24 45 873. For this purpose, the free phenolic OH groups are reacted with an alkylene oxide. In addition to the free phenolic OH groups, free OH groups of alcohols or NH groups of amines can also be alkoxylated, as disclosed, for example, in US Pat. No. 5,401,439.

Further petroleum emulsion breakers disclosed in US 4,321,146 are alkylene oxide

Block copolymers and polyethylenimines alkoxylated in US 5,445,765. The disclosed cleavers can be used as individual components, in mixtures with other emulsion breakers, or else as crosslinked products.

Copolymers of hydrophobic, end-capped and z. T. crosslinked (meth) acrylates and hydrophilic comonomers as emulsion breakers are disclosed in EP-O 264 841.

The different properties (eg asphaltene, paraffin and salinity, chemical composition of natural emulsifiers) and water content of various crude oils make it essential to further develop the existing oil splitters. In particular, a low metering rate and broad applicability of the oil separator to be used in addition to the desired higher efficiency from an economic and environmental point of view in the foreground. Furthermore, emulsion breakers are increasingly needed to replace the alkylphenol-based products under discussion.

It has thus been the object to develop new petroleum breakers which are equivalent or superior to the already known alkylphenol-based petroleum breakers and which can be used in even lower doses.

Surprisingly, it turned out that alkoxylated (meth) acrylate polymers show an excellent action as petroleum breakers even at a very low dosage.

The invention therefore relates to the use of polymers containing structural units of monomers (A) of the formula I. wherein

A is a C ₂ - to C ₄ -alkylene, R ^{1 is} hydrogen or methyl, k is from 1 to 1000, for the cleavage of oil / water emulsions in amounts of 0.0001 to 5 wt .-% based on the oil content of the emulsion to be cleaved.

Another object of the invention is the use of polymers containing different structural units of monomers (A) and (B) according to the formulas I and II

(A)

wherein

A is a C ₂ - to C ₄ -alkylene group,

R ^{1 is} hydrogen or methyl, k is a number from 1 to 1000, and

(B)

wherein

B is a C ₂ - to C ₄ -alkylene group, R ^{2 is} hydrogen or methyl, I is a number from 1 to 1000, for the cleavage of oil / water emulsions in amounts of 0.0001 to 5 wt .-% based on the oil content of the emulsion to be cleaved.

Another object of the invention are polymers containing structural units of monomers (A) according to formula I.

wherein

Another object of the invention are polymers containing different structural units of monomers (A) and (B) according to the formulas I and II

(A)

A is a C ₂ -C ₄ -alkylene group, R ^{1 is} hydrogen or methyl, k is a number from 1 to 1000, and

(B)

wherein

B is a C ₂ - to C ₄ -alkylene, R ^{2 is} hydrogen or methyl, I is a number from 1 to 1000, for the cleavage of oil / Vasser emulsions in amounts of 0.0001 to 5 wt .-% based on the oil content of the emulsion to be cleaved.

The preferred embodiments of the invention described below always relate both to the polymers themselves and to their use. This applies regardless of whether in the following reference is made to the polymers or their use.

The term that the polymers contain structural units of the monomers (A) or (A) and (B) means that the polymers are obtainable by the polymerization of the monomers (A) and (B) when subjected to the radical polymerization.

The polymer of the present invention generally has conventional terminal groups which are formed by the initiation of radical polymerization or by chain transfer reactions or by chain termination reactions, for example a proton, a radical initiator group or, for example, a sulfur-containing chain transfer agent group.

The polymers to be used according to the invention may be homopolymers of monomers of the formula I or copolymers of monomers of the structural units I and Il. In a preferred embodiment, the proportions of the structural units of the formula I and II add up to 100 mol%.

If the polymers to be used according to the invention are homopolymers, the group - (AO) _k - may be a uniform or a mixed alkoxy group. If it is a mixed alkoxy group, it preferably corresponds to the formula - (A ¹ -O) _n - (A ² -O) _m -,

wherein n is a number from 1 to 500 m, a number from 1 to 500 A ^{1 is} a C ₂ - to C ₄ alkylene group A ^{2 is} a different from A ¹ C ₂ - to C ₄ alkylene group.

Preferably, A ^{1 is} a propylene and A ^{2 is} an ethylene group. Further preferably, n is a number from 2 to 50. Further, m is preferably a number from 2 to 50. It is further preferred that n + m is a number from 2 to 80, in particular from 4 to 70. The sequence of the alkoxy group A ¹ -O and A ² -O may be random or blockwise.

If - (AO) _k - is a uniform alkoxy group, then A is preferably a propylene group. k is preferably a number from 2 to 15, in particular from 3 to 10.

If the polymer to be used according to the invention is a copolymer, then the monomers of the formulas I and II differ in one or more features. Distinguishing features can be the meanings of R ¹ and R ² , of A and B or of k and I. The monomers may also differ in the sequence of the alkoxy units, which may be blockwise or random. If the polymers to be used according to the invention are copolymers, the groups may be (AO) ι _< - and - (BO) ι -uniform or mixed alkoxy groups. If they are mixed alkoxy groups, they preferably correspond to the formulas - (A ¹ -O) _n - (A ² -O) _m - and - (B ¹ -O) _o - (B ² -O) p-

wherein n is a number from 1 to 500 m, a number from 1 to 500 o, a number from 1 to 500 p, a number from 1 to 500

A ^{1 is} a C ₂ - to C ₄ -alkylene group

A ^{2 is} a C ₂ - to C ₄ -alkylene group other than A ¹

B ^{1 is} a C ₂ - to C ₄ -alkoxy group B ^{2 is} a different from B ¹ C ₂ - to C ₄ alkoxy group.

Preferably, A ^{1 is} a propylene and A ^{2 is} an ethylene group. Further preferably, n is a number from 2 to 50. Further, m is preferably a number from 2 to 50. It is further preferred that n + m is a number from 2 to 80, in particular from 4 to 70.

Preferably, B ^{1 is} a propylene and B ^{2 is} an ethylene group. Further preferably, o is a number from 2 to 50. Further, m is preferably a number from 2 to 50. It is further preferred that n + m is a number from 2 to 80, in particular from 4 to 70.

If - (AO) _k - and - (BO) ι- represent identical alkoxy groups, then A preferably denotes a propylene group and B denotes an ethylene group. k preferably represents a number from 2 to 15, in particular 3 to 10. 1 preferably represents a number from 2 to 15, in particular 3 to 10. If - (AO) _k - and - (BO) ι- represent identical alkoxy groups, A furthermore preferably denotes a propylene group and B denotes a propylene group, where k and I are different, k preferably represents a number from 2 to 15, in particular 3 to 10. 1 represents a number different from k, preferably a number from 2 to 15, in particular from 3 to 10.

In a preferred embodiment 1 is - (AO) _k - for a block of ethylene oxide units and - (BO) ι- for a block propylene oxide units, wherein k and I are different, k is preferably a number from 5 to 80. 1 represents a of k different number, preferably for a number of 5 to 80.

In a further preferred embodiment 1 is - (AO) _k - for a block propylene oxide units and - (BO) ι- for a block propylene oxide units. k preferably represents a number from 5 to 80. 1 preferably represents a number from 5 to 80.

The molar proportion of the monomers in the preferred embodiment 1 is 0.1 to 99.9% for the monomer (A) and 0.1 to 99.9% for the monomer (B), in particular 1 to 95% for the monomer ( A) and 5 to 99% for the monomer (B), especially 10 to 90% for the monomer (A) and 10 to 90% for the monomer (B).

In a further preferred embodiment (embodiment 2) of the polymer of the monomers (A) and (B), (A ¹ -O) _{m stands} for a block of propylene oxide units and (A ² -O) _n for one block of ethylene oxide units, or (A ¹ -O) _m for one block of ethylene oxide units and (A ² -O) _n for one block of propylene oxide units, wherein the molar proportion of ethylene oxide units is preferably 30 to 98%, especially 50 to 95%, especially preferably 60 to 93%, based on the sum (100%) of the ethylene oxide and propylene oxide units is. (B ¹ -O) _o and (B ² -O) _p represent one block of ethylene oxide units, or preferably one block of propylene oxide units. m is preferably from 2 to 50. n is preferably from 2 to 50. The sum of o and p is preferably from 2 to 80.

The molar ratio of the monomers in the preferred embodiment is 2 1 to 99% for the monomer (A) and 1 to 99% for the monomer (B), more preferably 5 to 95% for the monomer (A) and 5 to 95% for the monomer (B), especially 10 to 90% for the monomer (A) and 10 to 90% for the monomer (B). The monomers (A) and (B) complement each other to 100 mol%.

In the case of different alkylene oxide units (A ¹ -O) _m , (A ² -O) _n , in the monomer (A) according to embodiment 2, these may be present either randomly or, as in the case of a preferred embodiment, arranged in a block.

In a further preferred embodiment (embodiment 3) of the polymer of the monomers (A) and (B), (A ¹ -O) _{m stands} for a block of propylene oxide units and (A ² -O) _n for one block of ethylene oxide units, or (A ¹ -O) _m for one block of ethylene oxide units and (A ² -O) _n for one block of propylene oxide units, wherein the molar proportion of ethylene oxide units is preferably 30 to 98%, especially 50 to 95%, especially preferably 60 to 93%, based on the sum (100%) of the ethylene oxide and propylene oxide units, and (B ¹ -O) o for one block of propylene oxide units and (B ² -O) _p for one block of ethylene oxide units or (B ¹ -O) _o for one block of ethylene oxide units and (B ² -O) _p for one block of propylene oxide units, the molar proportion of the ethylene oxide units preferably being 30 to 98%, in particular 50 to 95%, more preferably 60 to 93%, based on the sum (100%) of the ethylene oxide and propylene oxide units.

The molar ratio of the monomers in the preferred embodiment is 3 to 99% for the monomer (A) and 1 to 99% for the monomer (B), more preferably 5 to 95% for the monomer (A) and 5 to 95% for the monomer (B), especially 10 to 90% for the monomer (A) and 10 to 90% for the monomer (B). The monomers (A) and (B) complement each other to 100 mol%

m is preferably from 2 to 50. n is preferably from 2 to 50. o is preferably from 2 to 50. p is preferably from 2 to 50

The number of alkylene oxide units (n + m) is preferably 2 to 500, in particular 4 to 100, particularly preferably 5 to 80.

The number of alkylene oxide units (o + p) is preferably 2 to 500, in particular 4 to 100, particularly preferably 5 to 80.

In the case of different alkylene oxide units (A ¹ -O) _m , (A ² -O) _n , in

Monomer (A) according to Embodiment 3 may be present either randomly or, as in the case of a preferred embodiment, arranged in a block.

In the case of different alkylene oxide units (B ¹ -O) _o , (B ² -O) _p in the monomer (B) according to embodiment 3, these may be present either randomly or, as in the case of a preferred embodiment, arranged in a block.

The polymers according to the invention have a number average molecular weight of preferably from 10 ³ g / mol to 10 ⁹ g / mol, particularly preferably from 10 ³ to 10 ⁷ g / mol, in particular from 10 ³ to 10 ⁶ g / mol.

The preparation of the polymers according to the invention can be carried out by means of free-radical polymerization. The polymerization reaction may be carried out continuously, discontinuously or semi-continuously.

The polymerization reaction is preferably carried out as precipitation polymerization, emulsion polymerization, solution polymerization, bulk polymerization or Gel polymerization led. Particularly advantageous for the property profile of the polymers according to the invention is the solution polymerization.

Solvents used for the polymerization reaction are all organic or inorganic solvents which are largely inert with respect to free-radical polymerization reactions, for example ethyl acetate, n-butyl acetate or 1-methoxy-2-propyl acetate, and alcohols such. For example, ethanol, isopropanol, n-butanol, 2-ethylhexanol or 1-methoxy-2-propanol, also diols such as ethylene glycol and propylene glycol. Also, ketones such as acetone, butanone, pentanone, hexanone and methyl ethyl ketone, alkyl esters of acetic, propionic and butyric acids such as ethyl acetate, butyl acetate and amyl acetate, ethers such as tetrahydrofuran, diethyl ether and ethylene glycol and polyethylene glycol monoalkyl ethers and dialkyl ethers may be used. Likewise, aromatic solvents such. As toluene, xylene or higher boiling alkylbenzenes can be used. Likewise the use of

Solvent mixtures conceivable, with the choice of solvent or solvent based on the intended use of the polymer of the invention. Preferably use find water; lower alcohols; preferably methanol, ethanol, propanols, iso-, sec- and t-butanol, 2-ethylhexanol, butylglycol and butyldiglycol, particularly preferably isopropanol, t-butanol, 2-ethylhexanol, butylglycol and butyldiglycol; Hydrocarbons having 5 to 30 carbon atoms and mixtures and emulsions of the aforementioned compounds.

The polymerization reaction is preferably carried out in the temperature range between 0 and 180 ⁰ C, more preferably between 10 and 100 ⁰ C, both at atmospheric pressure and under elevated or reduced pressure. Optionally, the polymerization can also be carried out under a protective gas atmosphere, preferably under nitrogen.

To initiate the polymerization can high-energy, electromagnetic radiation, mechanical energy or the usual chemical polymerization initiators such as organic peroxides, eg. B. benzoyl peroxide, tert-butyl hydroperoxide, methyl ethyl ketone peroxide, cumyl peroxide, dilauroyl peroxide (DLP) or azo initiators, such as. As azobisisobutyronitrile (AIBN), azobisamidopropyl hydrochloride (ABAH) and 2,2'-azobis (2-methylbutyronitrile) (AMBN) can be used. Also suitable are inorganic peroxy compounds, such as. B. (NhU) ₂ S ₂ O ₈ , K ₂ S ₂ O ₈ or H ₂ O ₂ , optionally in combination with reducing agents (eg., Sodium hydrogen sulfite, ascorbic acid, iron (II) sulfate) or redox systems which as reducing component an aliphatic or aromatic sulfonic acid (e.g., benzenesulfonic acid, toluenesulfonic acid).

As molecular weight regulator, the usual compounds are used. Suitable known regulators are z. As alcohols, such as methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol and amyl alcohols, aldehydes, ketones, alkylthiols, such as. As dodecylthiol and tert-dodecylthiol, thioglycolic acid, isooctylthioglycolate and some halogen compounds, such as. As carbon tetrachloride, chloroform and methylene chloride.

A preferred subject of the present invention is the use of the alkoxylated (meth) acrylate polymers as splitters for oil / water emulsions in petroleum production.

For use as petroleum breakers, the alkoxylated (meth) acrylate polymers are added to the water in oil emulsions, preferably in solution. As solvents for the alkoxylated (meth) acrylate polymers, alcoholic solvents are preferred. The alkoxylated (meth) acrylate polymers are used in amounts of 0.0001 to 5, preferably 0.0005 to 2, in particular 0.0008 to 1 and especially 0.001 to 0.1 wt .-% based on the oil content of the emulsion to be cleaved used. Examples

General Polymerization Procedure (homopolymer of monomer A)

In a flask with stirrer, reflux condenser, internal thermometer and

Nitrogen introduction, the monomer A and possibly the molecular weight regulator in solvent was introduced under nitrogen. Then the temperature was brought to 80 ^° C. with stirring and within one hour a solution of the initiator was added. Subsequently, stirring was continued for 5 hours at this temperature. The molecular weight of the polymer was analyzed by GPC (reference: polyethylene glycol). The yield is> 95%.

General Polymerization Procedure (Polymer of Monomer A and B)

In a flask equipped with stirrer, reflux condenser, internal thermometer and nitrogen inlet, the monomer A, monomer B and, if appropriate, the molecular weight regulator were initially introduced in a solvent under nitrogen inlet. Then the temperature was brought to 80 ^° C. with stirring and within one hour a solution of the initiator was added. Subsequently, stirring was continued for 5 hours at this temperature. The molecular weight of the polymer was analyzed by GPC (reference: polyethylene glycol). The yield is> 95%. ,

The following tables contain synthetic examples in which the polymers were prepared according to the general synthesis instructions.

Table 1

Examples of homopolymers:

Monomer (A): - (A ¹ -O) _k - = Propenyloxy MW = Average molecular weight regulator = dodecanethiol

Table 2

Examples of polymers according to embodiment 1:

Monomer (A): (A ¹ -O) _m = (A ² -O) _n = propenyloxy monomer (B): (B ¹ -O) _o = (B ² -O) _p = Propenyloxy MW = Average molecular weight regulator dodecanethiol

Table 3

Example of polymers according to embodiment 2:

m = average number of monomer units (A ¹ -O), n = average number of monomer units (A ² -O) _n Monomer (A): (A ¹ -O) _m = Propenyloxy, (A ² -O) _n = Ethenyloxy monomer (B): (B ¹ -O) _o = (B ² -O) _p = Propenyloxy MW = Average molecular weight Regulator = dodecanethiol

Table 4

Examples of Polymers According to Embodiment 3:

m = average number of monomer units (A ¹ -O) _m n = average number of monomer units (A ² -O) _n o = average number of monomer units (B ¹ -O) _o p = average number of monomer units (B ² -O) _p monomer ( A): (A ¹ -O) _m = propenyloxy, (A ² -O) _n = ethenyloxy monomer (B): (B ¹ -O) _o = propenyloxy, (B ² -O) _p = ethenyloxy MW = average molecular weight Regulator = dodecanethiol Determination of the splitting efficiency of petroleum emulsion separators

To determine the effectiveness of an emulsion breaker, the water separation from a crude oil emulsion per time and the drainage of the oil was determined. In each case, 100 ml of the crude oil emulsion were introduced into breaker glasses (conically tapered, screwable, graduated glass bottles), in each case a defined amount of the emulsion separator was metered with a micropipette just below the surface of the oil emulsion, and the breaker was mixed into the emulsion by intensive shaking. Thereafter, the breaker glasses were placed in a tempering bath (50 ⁰ C) and the water separation followed.

After the demulsification of the emulsion samples were taken from the oil from the upper part of the splitter glass (so-called top oil) and determined their water content according to Karl Fischer. In this way, the new splitters were assessed after water separation and drainage of the oil.

Cleavage action of the splitter described

Origin of the crude oil emulsion: Hebertshausen, Germany water content of the emulsion: 48% Demulgiertemperatur: 50 ⁰ C

The effectiveness of the alkoxylated (meth) acrylate polymers as demulsifiers in comparison to Dissolvan ^® 5022-1 V c. (a polyamine alkoxylate) at different dosage rates is shown in the following tables. Table 5 Activity as a splitter

Table 6 Efficiency as a splitter

Claims

claims

1. Use of polymers containing structural units of monomers (A) according to formula I.

wherein

2. Use of polymers containing structural units of monomers (A) and (B) according to the formulas I and II

(A)

wherein

A is a C ₂ - to C ₄ -alkylene group,

R ^{1 is} hydrogen or methyl, k is a number from 1 to 1000, and (B)

wherein

B is a C ₂ - to C ₄ -alkylene group, R ^{2 is} hydrogen or methyl,

I is a number from 1 to 1000, for the separation of oil / water emulsions in amounts of 0.0001 to 5 wt .-% based on the oil content of the emulsion to be cleaved.

3. Use according to claim 1 or claim 2, wherein the polymer is a homopolymer of the monomers (A) of the formula I or add the structural units of the monomers (A) and (B) of the formulas I and II to 100 mol%.

4. Use according to claim 1 or 3, wherein the group - (AO) _k - is a mixed alkoxy group of the formula - (A ¹ -O) _m - (A ² -O) _n -, wherein n is a number from 1 to 500 m is a number from 1 to 500 A ^{1 is} a C ₂ - to C ₄ -alkylene group

A ^{2 is} a different from A ¹ C ₂ - to C ₄ -alkylene group.

5. Use according to claim 1 or 3, wherein A is a propylene group.

6. Use according to claim 2 or 3, wherein A is a propylene group and B is a propylene group, wherein k and I are different.

7. Use according to claim 2 or 3, wherein - (AO) k- for a mixed alkoxy group of the formula - (A1-O) m- (A2-O) n- and B stand for a propylene group, wherein n is a number of 1 to 500 m, a number from 1 to 500 A1 is a C2 to C4 alkylene group A2 is a C2 to C4 alkylene group other than A1.

8. Use according to claim 2 or 3, wherein - (AO) _k - for a mixed alkoxy group of the formula - (A ¹ -O) _m - (A ² -O) _n - and - (BO) ι- for a mixed alkoxy group of the formula - (B ¹ -O) _O - (B ² -O) _P - wherein n is a number from 1 to 500 m, a number from 1 to 500 o, a number from 1 to 500 p, a number from 1 to 500

A ^{1 is} a C ₂ - to C ₄ -alkylene A ² A ² different from A ¹ C ₂ - to C ₄ -alkylene

B ^{1 is} a C ₂ - to C ₄ alkoxy group

B ^{2 is} a different from B ¹ C ₂ - to C ₄ alkoxy group.

Use according to claim 4 or 8, wherein (n + m) represents a number from 2 to 80.

Use according to claim 8, wherein (o + p) represents a number from 2 to 80.

11. Use according to one or more of claims 1 to 10, wherein the number average molecular weight of the polymers is 10 ³ to 10 ⁹ g / mol.

12. Use according to one or more of claims 1 to 11, wherein the proportion of the monomers A according to formula I is 0.1 to 99 wt .-%.

13. Use according to one or more of claims 2, 3 and 6-12, wherein the proportion of the monomers B is 0.1 to 99 mol%.

14. Use according to one or more of claims 4 and 8 - 13, wherein the alkoxy groups are arranged in blocks.

15. Use according to one or more of claims 2, 3 and 6-14, wherein (A ¹ -O) _m for a block of propylene oxide units and (A ² -O) _n for a block of ethylene oxide units, or (A ¹ -O) _m for one block of ethylene oxide units and (A ² -O) _n for one block of propylene oxide units, and wherein the molar proportion of ethylene oxide units, based on the sum of the ethylene oxide and propylene oxide units, 30 to 98%.

16. Polymers containing structural units of monomers (A) according to formula I.

wherein

A is a C ₂ - to C ₄ -alkylene group,

R ^{1 is} hydrogen or methyl, k is a number from 1 to 1000.

17. Polymers containing different structural units of monomers (A) and (B) according to the formulas I and II (A)

wherein

A is a C ₂ - to C ₄ -alkylene group,

R ^{1 is} hydrogen or methyl, k is a number from 1 to 1000, and

(B)

wherein

B is a C ₂ to C ₄ alkylene group, R ^{2 is} hydrogen or methyl, I is a number from 1 to 1000.

18. Polymers according to claim 16 or claim 17, wherein the polymer is a homopolymer of the monomers (A) of the formula I or the structural units of the monomers (A) and (B) of the formulas I and II add up to 100 mol%.