HK1162039B

HK1162039B - Dispersant containing a copolymer mixture

Info

Publication number: HK1162039B
Application number: HK12102462.1A
Authority: HK
Inventors: Mario Vierle; Klaus Lorenz; Gerhard Albrecht; Christian Scholz; Petra Wagner; Barbara Wimmer
Original assignee: Construction Research & Technology Gmbh
Priority date: 2008-12-08
Filing date: 2009-11-25
Publication date: 2014-03-28

Description

Dispersing agent containing copolymer mixture

The present invention relates to a polymer composition, a dispersant, a process for the preparation of the polymer composition and the dispersant and the use of the polymer composition.

Known admixtures in the form of dispersants are frequently added to aqueous slurries of pulverulent inorganic or organic substances, such as clays, silicate powders, chalk, carbon black, crushed stone and hydraulic binders, for improving their processability, i.e. kneadability, spreadability, sprayability, pumpability or flowability. The admixture is capable of preventing the formation of solid agglomerates of already present dispersed particles and newly formed particles by hydration and in this way improves the processability. This action is intended in particular for the preparation of building material mixtures containing aqueous hard binders, such as cement, lime, gypsum, hemihydrate or anhydrite.

To convert these building material mixtures based on the binder into a ready-to-use, workable form, more mixing water is generally required than is required for the subsequent hydration or hardening process. The mechanical strength and durability are significantly reduced due to the cavity portion formed in the concrete body by the excessive amount of water which is subsequently evaporated.

To reduce excess water at a particular processing consistency, and/or to improve processability at a particular water/binder ratio, blends commonly referred to as water reducers or superplasticizers are used. Such agents in practical use are in particular copolymers prepared by free-radical copolymerization of acid monomers and/or acid-derived monomers and polyether macromers.

WO 2005/075529 describes copolymers which, in addition to acid monomer building blocks, have ethyleneoxybutylene poly (ethylene glycol) building blocks as polyether macromonomer building blocks. The copolymers are widely used as high performance superplasticizers due to their excellent performance characteristics.

Although the described copolymers have been considered as economical high performance superplasticizers, there is still a desire to further improve the cost efficiency and quality (particularly with respect to robustness and versatility) of the copolymers.

The object of the present invention is therefore to provide an economical dispersant for hydraulic binders, particularly suitable as a superplasticizer for concrete.

This object is achieved by a polymer composition comprising 5 to 95% by weight of a copolymer H and 2 to 60% by weight of a copolymer K, the copolymers H and K each having polyether macromonomer structural units and acid monomer structural units, which are each present in the copolymers H and K in a molar ratio of from 1:20 to 1:1, and at least 20mol% of all structural units of the copolymer H and at least 25mol% of all structural units of the copolymer K each being present in the form of acid monomer structural units, the polyether macromonomer structural units of the copolymer H having side chains each containing at least 5 ether oxygen atoms, the number of ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H varying in the following manner: their corresponding frequency distribution plot, in which the number of ether oxygen atoms of each side chain of the polyether macromonomer structural units is plotted along the abscissa and the frequency of correlation of the copolymer H is plotted along the ordinate, contains at least 2 maxima whose abscissa values differ from one another by more than 8 ether oxygen atoms, all polyether macromonomer structural units of the copolymer K either having side chains with a higher number of ether oxygen atoms or having side chains with a lower number of ether oxygen atoms, the side chains with a higher number of ether oxygen atoms being those which each have more ether oxygen atoms than the sum of the arithmetic mean of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the value 4, and the side chains containing a small amount of ether oxygen atoms are those each having an ether oxygen atom smaller than the difference between the arithmetic average of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the numerical value of 4.

The acid monomer building blocks are formed by introducing the corresponding acid monomer in the form of polymerized units. In the context of the present invention, acid monomers are understood to be monomers which are capable of free-radical copolymerization, have at least one carbon-carbon double bond, comprise at least one acid function and react as acid in an aqueous medium. Acid monomers are furthermore understood to be monomers which are capable of free-radical polymerization, have at least one carbon-carbon double bond, form at least one acid function as a result of hydrolysis reactions in aqueous medium and react as acid in aqueous medium (examples: maleic anhydride or base-hydrolyzable esters, such as ethyl acrylate). Polyether macromonomer building blocks are formed by incorporating the corresponding polyether macromonomer in the form of polymerized units. In this connection, in the present invention, the polyether macromonomer is a compound capable of radical copolymerization and having at least one carbon-carbon double bond and having an ether oxygen atom. Thus, the polyether macromonomer structural units present in the copolymer each have at least one side chain containing an ether oxygen atom.

In general, it is believed that the mode of action of the relevant copolymers having polyether macromonomer building blocks and acid building blocks is determined by their structural parameters. The spectrum of action of the corresponding high-performance copolymer covers the entire range from extreme water reduction to extreme consistency maintenance, ensuring that the structural parameters of water reduction contradict good slump retention. Thus, in addition to the loading per unit mass, the length of the side chains is also decisive, for example in terms of water-reducing capacity. The relevant superplasticizer copolymers are usually metered in as a percentage of the cement weight of the cementitious mixture, i.e. on a mass basis. In general, not only the quality of application, but also the number of active substance molecules is decisive for the mode of action. However, long side chains have a high mass, which is in contradiction to the number of copolymer molecules per unit mass being as large as possible. By targeted introduction of short side chains in addition to long side chains, the molar mass of the copolymer can be reduced without adversely affecting the dispersing action, because of the long side chains. It is therefore often advantageous for short and long polyether side chains to be introduced into the copolymer molecule each together and to proceed according to the principle of "longer polyether side chains in each case suffice but as few as possible". The copolymer superplasticizer can be optimized in this way in terms of its mass efficiency. This optimization can be done separately for the two extremes of the spectrum of action (water reduction, consistency maintenance). In applications requiring both water reduction and consistency maintenance, a mixture of the respective mass-optimized superplasticizer copolymer with a copolymer having only short or long side chains may be advantageous. The advantages are greater consistency in terms of cement quality (alkali and sulphate content), the possibility of temperature changes or easy adaptation of the mixture. Briefly, the polymer composition of the present invention relates to a mixture of a copolymer having mixed side chains and another copolymer having only long side chains or only short side chains. While long polyether side chains lead to good dispersion, long polyether side chains lead to high viscosities of the concrete (which are generally undesirable) in the case of large amounts of water reducing agents, short polyether side chains lead to much lower viscosities. For the respective practical application, a "compromise" with respect to the choice of short and long side chains is often optimal, and a mixture of short and long side chains often gives good results. The present invention achieves a way to efficiently provide the mixture: copolymers having mixed side chains are often provided in relatively large amounts as a standard and mixed with relatively small amounts of short-chain or long-chain copolymers to achieve the desired performance properties. This is accompanied in particular by the advantage of low requirements for storage and mixing in order to achieve the desired application properties.

Typically, the polymer composition comprises 15 to 80% by weight of copolymer H and 5 to 40% by weight of copolymer K.

Typically, at least 50mol% of all structural units of copolymer H and at least 50mol% of all structural units of copolymer K are each present in the form of acid monomer structural units.

Frequently, the number of ether oxygen atoms per side chain of the polyether macromonomer building blocks of copolymer H varies in the following manner: their corresponding frequency distribution plot, in which the number of ether oxygen atoms per side chain of the polyether macromonomer structural units is plotted along the abscissa and the correlation frequency of the copolymer H is plotted along the ordinate, contains at least 2 maxima whose abscissa values differ from one another by more than 10 ether oxygen atoms.

The number of ether oxygen atoms per side chain of the polyether macromonomer structural units of copolymer H varies in many embodiments in the manner of a corresponding frequency distribution diagram, wherein the number of ether oxygen atoms per side chain of the polyether macromonomer structural units is plotted along the abscissa and the associated frequency of copolymer H is plotted along the ordinate, comprising at least 2 maxima whose abscissa values differ from one another by more than 10 ether oxygen atoms, all polyether macromonomer structural units of copolymer K either having side chains with a high number of ether oxygen atoms or having side chains with a low number of ether oxygen atoms, the side chains with a high number of ether oxygen atoms being those side chains each having more ether oxygen atoms than the sum of the arithmetic mean of the ether oxygen atoms per side chain of the polyether macromonomer structural units of copolymer H and the value of 10, and the side chains with a low number of ether oxygen atoms being those side chains each having ether oxygen atoms than the ether oxygen atoms per side chain of the polyether macromonomer structural units of copolymer H Those side chains of ether oxygen atoms which differ less from the value of 10 by the arithmetic mean of (A).

Preferably, the acid monomer building blocks of the copolymers H and K are each present according to one of the general formulae (Ia), (Ib), (Ic) and/or (Id)

Wherein

R¹Identical or different and denotes H and/or linear or branched C₁-C₄An alkyl group;

x is the same or different and represents NH- (C)_nH_2n) (wherein n ═ 1, 2, 3, or 4) and/or O- (C)_nH_2n) (wherein n ═ 1, 2, 3, or 4) and/or absent units;

R²are the same or different and represent OH, SO₃H、PO₃H₂、O-PO₃H₂And/or para-substituted C₆H₄-SO₃H, with the proviso that R is absent if X is a unit²Represents OH;

(Ib)

wherein

R³Identical or different and denotes H and/or linear or branched C₁-C₄An alkyl group;

n is 0, 1, 2, 3 or 4;

R⁴are the same or different and represent SO₃H、PO₃H₂、O-PO₃H₂And/or para-substituted C₆H₄-SO₃H；

Wherein

R⁵Are identical or different and represent H and/or linear or branched C₁-C₄An alkyl group;

z is identical or different and denotes O and/or NH;

wherein

R⁶Are identical or different and represent H and/or linear or branched C₁-C₄An alkyl group;

q is identical or different and denotes O and/or NH;

R⁷are the same or different and represent H, (C)_nH_2n)-SO₃H (wherein n is 0, 1, 2, 3 or 4), (C)_nH_2n) -OH (wherein n ═ 0, 1, 2, 3, or 4), (C)_nH_2n)-PO₃H₂(wherein n is 0, 1, 2, 3 or 4), (C)_nH_2n)-OPO₃H₂(wherein n is 0, 1, 2, 3 or 4), (C)₆H₄)-SO₃H、(C₆H₄)-PO₃H₂、(C₆H₄)-OPO₃H₂And/or (C)_mH_2m)_e-O-(A`O)_α-R⁹(where m is 0, 1, 2, 3 or 4, e is 0, 1, 2, 3 or 4, a ═ C_x′H_2x′Wherein x' is 2, 3, 4 or 5 and/or CH₂C(C₆H₅) H-, α ═ an integer of 1 to 350, and R⁹Are the same or different and represent a linear or branched C₁-C₄An alkyl group).

Typically, the acid monomer building blocks of copolymers H and K are each generated by introducing the acid monomers methacrylic acid, acrylic acid, maleic anhydride and/or maleic acid monoesters in the form of polymerized units.

Depending on the pH, the acid monomer building blocks may also be present in deprotonated form as salts, in which case the typical counterion is Na⁺、K⁺And Ca²⁺。

In general, the polyether macromonomer building blocks of copolymers H and K are each present according to one of the formulae (IIa), (IIb) and/or (IIc),

wherein

R¹⁰、R¹¹And R¹²Each of which is the same or different and independently represents H and/or straight or branched C₁-C₄Alkyl radicalA group;

e are identical or different and denote a linear or branched C₁-C₆Alkylene group, cyclohexyl group, CH₂-C₆H₁₀Ortho-, meta-or para-substituted C₆H₄And/or absent units;

g is the same or different and denotes O, NH and/or CO-NH, with the proviso that if E is a non-existent unit, then G is also a non-existent unit;

a is the same or different and denotes C_xH_2x(wherein x is 2, 3, 4 and/or 5 (preferably x is 2)) and/or CH₂CH(C₆H₅)；

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

a is the same or different and represents an integer of 5 to 350 (preferably 10-200);

R¹³are the same or different and represent H, straight or branched C₁-C₄Alkyl radical, CO-NH₂And/or COCH₃；

(IIb)

Wherein

R¹⁴Are identical or different and represent H and/or linear or branched C₁-C₄An alkyl group;

g is the same or different and denotes absent units, O, NH and/or CO-NH, with the proviso that if E is absent, then G is also absent;

a is the same or different and denotes C_xH_2x(wherein x is 2, 3, 4 and/or 5) and/or CH₂CH(C₆H₅)；

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

a is the same or different and represents an integer of 5 to 350;

d is the same or different and represents absent units, NH and/or O, provided that if D is one absent unit: b is 0, 1, 2, 3 or 4 and c is 0, 1, 2, 3 or 4, wherein b + c is 3 or 4, and with the proviso that if D is NH and/or O: b is 0, 1, 2 or 3, c is 0, 1, 2 or 3, wherein b + c is 2 or 3;

R¹⁵are the same or different and represent H, straight or branched C₁-C₄Alkyl radical, CO-NH₂And/or COCH₃；

Wherein

R¹⁶、R¹⁷And R¹⁸Each of which is the same or different and independently represents H and/or straight or branched C₁-C₄An alkyl group;

e are identical or different and denote a linear or branched C₁-C₆Alkylene group, cyclohexyl group, CH₂-C₆H₁₀And/or ortho-, meta-or para-substituted C₆H₄；

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

l are the same or different and represent C_xH_2x(wherein x is 2, 3, 4 and/or 5) and/or CH₂-CH(C₆H₅)；

a is the same or different and represents an integer of 5 to 350;

d is the same or different and represents an integer of 1 to 350;

R¹⁹are identical or different and represent H and/or linear or branched C₁-C₄An alkyl group, a carboxyl group,

R²⁰are the same or different and represent H and/or straight C chain₁-C₄An alkyl group.

Frequently, the polyether macromonomer building blocks of copolymers H and K are each formed by incorporating the following polyether macromonomers in the form of polymerized units: alkoxylated hydroxybutyl vinyl ether and/or alkoxylated diethylene glycol monovinyl ether and/or alkoxylated isoprenol (isoprenol) and/or alkoxylated (meth) allyl alcohol and/or vinylated methyl polyalkylene glycol, each preferably having an alkylene oxide group with an arithmetic mean of from 6 to 300.

The alkoxy units of the polyether macromers are usually present as ethoxy groups or as a mixture of ethoxy and propoxy groups (these polyether macromers can be obtained from the ethoxylation or propoxylation of the corresponding monomeric alcohols).

The copolymers H and K may each have polyether macromonomer building blocks and/or acid monomer building blocks of the same or different types.

In general, at least 45mol%, preferably at least 80mol%, of all structural units of the copolymers H and K are in each case formed by introducing the acid monomers and polyether macromonomers in the form of polymerized units.

The invention also relates to a dispersant containing at least 30% by weight of water and at least 10% by weight of the above-mentioned polymer composition.

The dispersant is preferably present in the form of an aqueous solution.

The invention also relates to a method for producing the polymer composition and the dispersant, wherein the copolymers H and K are each produced separately in an aqueous solution and the separately produced copolymers or the separately produced aqueous solutions are subsequently mixed with one another. Typically, the acid monomer and polyether macromonomer are reacted in aqueous solution by free radical polymerization using a peroxide-containing redox initiator system, the aqueous solution having a temperature of 10-45 ℃ and a pH of 3.5-6.5 during polymerization.

Finally, the invention also relates to the use of the above-mentioned polymer composition as a dispersant for hydraulic binders and/or for latent hydraulic binders. The polymer compositions of the invention can also be used, for example (in particular in dehydrated form), as additives for cement production (grinding aids and "water reducers" for fine portland cement or composite cement).

Hereinafter, the present invention is explained in more detail with reference to working examples.

Synthesis example 1

250.0g of deionized water and 330.0g of vinyloxybutylpolyglycol-1100 (adduct of 22mol of ethylene oxide and 4-hydroxybutyl 1-monovinyl ether) are initially charged in a reactor equipped with stirrer, pH electrode and various feed devices and then cooled to a temperature of 15 ℃.

In a separate addition device, 64.9g of acrylic acid and 34.3g of a 40% strength potassium hydroxide solution were mixed homogeneously with 187.4g of deionized water and cooled. Then 2.43g of 3-mercaptopropionic acid (solution A) were added.

At the same time, 3% strength Bruggolit is preparedAn aqueous solution of FF6 (commercially available from Bruggeemann GmbH) (solution B).

107.8g of solution A and subsequently 17.4g of 20% strength aqueous sodium hydroxide solution and 0.61g of 3-mercaptopropionic acid were added to the initially introduced mixture and stirred and cooled.

Thereafter, 0.093g of iron (II) sulfate heptahydrate was added to the initially introduced mixture and the reaction was started by adding 5.74g of hydrogen peroxide (30% aqueous solution). At the same time, the addition of solution a and solution B to the stirred initially introduced mixture is started.

The metering rate of the remaining solution A is shown in the following metering table.

Solution B was metered in at a steady metering rate of 37g/h during the metering of solution A and, after the metering of solution A had ended, metering was continued until the reaction mixture was free of peroxide.

During the reaction, a 20% strength aqueous sodium hydroxide solution was added dropwise as needed to maintain the pH at least at 5.65.

The resulting polymer solution was then adjusted to a pH of 6.5 with 20% strength sodium hydroxide solution.

The resulting copolymer was obtained as a yellowish solution having a solids content of 39.0%. The weight-average molar mass of the copolymer was 39000 g/mol; total conversion (determined by GPC) was 94%.

Synthesis example 2:

208.0g of deionized water and 229.2g of vinyloxybutylpolyglycol-1100 (adduct of 22mol of ethylene oxide and 4-hydroxybutyl 1-monovinyl ether) and 104.2g of vinyloxybutylpolyglycol-500 (adduct of 10mol of ethylene oxide and 4-hydroxybutyl 1-monovinyl ether) are initially charged into a reactor equipped with stirrer, pH electrode and various charging devices and then cooled to 12 ℃ (initially introduced mixture).

In a separate addition device, 33.1g of acrylic acid, 26.1g of 2-hydroxypropyl acrylate and 19.6g of a 40% strength potassium hydroxide solution were mixed homogeneously with 180.4g of deionized water and cooled. Then 2.64g of 3-mercaptopropionic acid (solution A) were added.

78.0g of solution A and 0.6g of a 25% strength aqueous sulfuric acid solution and 1.4g of 3-mercaptopropionic acid were added to the initially introduced mixture and stirred and cooled.

When this pH was reached, 0.078g of iron (II) sulfate heptahydrate was added and the reaction was started by adding 4.8g of hydrogen peroxide (30% aqueous solution). At the same time, the addition of solution a and solution B to the stirred initially introduced mixture is started.

The rate of addition of the remaining solution A is shown in the following metering table.

Solution B was metered in at a steady metering rate of 31g/h during the metering of solution A and, after the metering of solution A had ended, metering was continued until the reaction mixture was free of peroxide.

During the reaction, 7.6g of a 20% strength aqueous sodium hydroxide solution was added dropwise to maintain the pH at least at 5.7.

The resulting polymer solution was then adjusted to a pH of 6.5 with about 20% strength sodium hydroxide solution.

The resulting copolymer was obtained as a yellowish solution having a solids content of 45.0%. The weight-average molar mass of the copolymer is 27000 g/mol; total conversion (determined by GPC) was 98%.

The performance characteristics of the copolymers will be illustrated by the following use examples.

Examples of the use

Self-compacting concrete (hereinafter, referred to as SCC) is intentionally selected as an example of use, and has become very important in recent years because such concrete does not require vibration. Superplasticizers for self-compacting concrete must be particularly strong and adaptable, since, for example, in the case of premature loss of consistency, the fluidity of the concrete is greatly reduced and thus uniform filling of the concrete form is no longer ensured.

SCC was prepared according to the following ratio:

components	Amount, kg/m³
		Cement CEM I52.5R	310
Limestone powder	218
		0-4mm of sand	670
Gravel 4-16mm	970
		Water (W)	189
Superplasticizer	According to the requirements

All dry components were pre-mixed in a forced mixer for 30 seconds, then water and superplasticizer were added and mixed for 4 minutes. Fresh concrete properties were determined over time by determining slump without a blocking ring.

First, the specific robustness of the polymer composition with respect to the use of I52.5R type cements from different manufacturers will be described below. Concrete was prepared according to the procedure described above using two cements of the CEM I52.5R type from different manufacturers.

¹Polymer a 1: use of high performance superplasticizer Glenium27 (commercial product of BASF SE); polymer B1: physical mixture of the polymer of Synthesis example 1 and the polymer of Synthesis example 2 in a mixing ratio (amount) of 1: 2;

²dosage data of mass percent of polymer solids, based on the weight of cement used

From the above examples, it is clear that the metered amount of polymer a1 depends largely on the type of cement used. Thus, with cement 1, good initial slump can be obtained with economic metering, but the consistency loss within 90 minutes is significant. With cement 2, good slump and good consistency maintenance can be obtained at the same time, but a very large amount of superplasticizer has to be metered for this purpose (340% compared to the case of concrete with cement 1). For polymer composition B1 of the present invention, both good initial slump and optimum consistency maintenance were achieved with cement 1 and with cement 2. The difference in the required metered amounts compared with the use examples of polymer A1 is very small (cement 2: 130% compared with the case of concrete using cement 1), which should be noted in particular. This implies a high cost efficiency of the polymer mixture and a considerable flexibility for different cements.

In particular, CO in cement production due to the use of secondary fuel₂The gradual reduction in emissions, as well as naturally occurring changes in clinker composition, often results in changes in cement quality. The polymer mixtures according to the invention also make possible rapid and simple adjustment to these quality changes. This will be clearly illustrated below.

On the basis of the concrete formulation described above, various SCCs were made with different production batches of cement from manufacturer 1 and performance characteristics were determined:

¹polymer B1: physical mixture of the polymer of Synthesis example 1 and the polymer of Synthesis example 2 in a mixing ratio (amount) of 1: 2; polymer B2: physical mixture of the polymer of Synthesis example 1 and the polymer of Synthesis example 2 in a mixing ratio (amount) of 0.9: 2.1;

Concrete segregation was more severe with batch 2 cement with the same dosage of polymer composition B1, as was the case after the polymer dosage was reduced. Good slump and optimum consistency maintenance were again achieved by slight adjustment of the mixing ratio of the polymers of synthetic examples 1 and 2 (generation: polymer composition B2). This result is not possible when using a superplasticizer comprising only one polymer. Good initial slump can be achieved by reducing the dose but this will be accompanied by a gradual loss of consistency over time.

The use examples thus illustrate the particular cost-effectiveness of the polymer compositions of the invention.

Claims

1. A polymer composition comprising 5-95 wt% of a copolymer H and 2-60 wt% of a copolymer K, each of said copolymers H and K having polyether macromonomer structural units and acid monomer structural units, each present in a molar ratio of 1:20 to 1:1 in the copolymers H and K, and at least 20mol% of all structural units of the copolymer H and at least 25mol% of all structural units of the copolymer K each present in the form of acid monomer structural units, the polyether macromonomer structural units of the copolymer H having side chains each containing at least 5 ether oxygen atoms, the number of ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H varying in the following manner: their corresponding frequency distribution plot, in which the number of ether oxygen atoms of each side chain of the polyether macromonomer structural units is plotted along the abscissa and the frequency of correlation of the copolymer H is plotted along the ordinate, contains at least 2 maxima whose abscissa values differ from one another by more than 8 ether oxygen atoms, all polyether macromonomer structural units of the copolymer K either having side chains with a higher number of ether oxygen atoms or having side chains with a lower number of ether oxygen atoms, the side chains with a higher number of ether oxygen atoms being those which each have more ether oxygen atoms than the sum of the arithmetic mean of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the value 4, and the side chains containing a small amount of ether oxygen atoms are those each having an ether oxygen atom smaller than the difference between the arithmetic average of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the numerical value of 4.

2. The polymer composition of claim 1, comprising 15 to 80% by weight of copolymer H and 5 to 40% by weight of copolymer K.

3. A polymer composition according to claim 1 or 2, characterized in that at least 50mol% of all structural units of copolymer H and at least 50mol% of all structural units of copolymer K are each present in the form of acid monomer structural units.

4. A polymer composition according to any one of claims 1 to 3, characterized in that the number of ether oxygen atoms per side chain of the polyether macromonomer building blocks of copolymer H varies in the following manner: their corresponding frequency distribution plot, in which the number of ether oxygen atoms per side chain of the polyether macromonomer structural units is plotted along the abscissa and the correlation frequency of the copolymer H is plotted along the ordinate, contains at least 2 maxima whose abscissa values differ from one another by more than 10 ether oxygen atoms.

5. A polymer composition according to any one of claims 1 to 4, characterized in that the number of ether oxygen atoms per side chain of the polyether macromonomer building blocks of copolymer H varies in the following manner: their corresponding frequency distribution plot, in which the number of ether oxygen atoms of each side chain of the polyether macromonomer structural units is plotted along the abscissa and the frequency of correlation of the copolymer H is plotted along the ordinate, contains at least 2 maxima whose abscissa values differ from one another by more than 10 ether oxygen atoms, all polyether macromonomer structural units of the copolymer K either having side chains with a higher number of ether oxygen atoms or having side chains with a lower number of ether oxygen atoms, the side chains with a higher number of ether oxygen atoms being those which each have more ether oxygen atoms than the sum of the arithmetic mean of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the value of 10, and the side chains containing a small amount of ether oxygen atoms are those each having an ether oxygen atom smaller than the difference between the arithmetic average of the ether oxygen atoms of each side chain of the polyether macromonomer structural units of the copolymer H and the value of 10.

6. Polymer composition according to one of claims 1 to 5, characterized in that the acid monomer building blocks of the copolymers H and K are each present according to one of the general formulae (Ia), (Ib), (Ic) and/or (Id)

(Ia)

Wherein

x is the same or different and represents NH- (C)_nH_2n) Wherein n =1, 2, 3 or 4, and/or O- (C)_nH_2n) Wherein n =1, 2, 3 or 4, and/or absent;

(Ib)

wherein

n =0, 1, 2, 3 or 4;

(Ic)

Wherein

z is identical or different and denotes O and/or NH;

(Id)

wherein

q is identical or different and denotes O and/or NH;

R⁷are the same or different and represent H; (C)_nH_2n)-SO₃H, wherein n =0, 1, 2, 3 or 4; (C)_nH_2n) -OH, wherein n =0, 1, 2,3 or 4; (C)_nH_2n)-PO₃H₂Wherein n =0, 1, 2, 3 or 4; (C)_nH_2n)-OPO₃H₂Wherein n =0, 1, 2, 3 or 4; (C)₆H₄)-SO₃H；(C₆H₄)-PO₃H₂；(C₆H₄)-OPO₃H₂(ii) a And/or (C)_mH_2m)_e-O-(A`O)_α-R⁹Wherein m =0, 1, 2, 3 or 4, e =0, 1, 2, 3 or 4, a' = C_x′H_2x′Wherein x' =2, 3, 4 or 5, and/or CH₂C(C₆H₅) H-, α = an integer of 1 to 350, and R⁹Are the same or different and represent a linear or branched C₁-C₄An alkyl group.

7. A polymer composition according to any one of claims 1 to 6, characterized in that the acid monomer building blocks of copolymers H and K are each formed by introducing the following acid monomers in the form of polymerized units: methacrylic acid, acrylic acid, maleic anhydride and/or maleic acid monoesters.

8. Polymer composition according to any one of claims 1 to 7, characterized in that the polyether macromonomer building blocks of copolymers H and K are each present according to one of the general formulae (IIa), (IIb) and/or (IIc),

(IIa)

wherein

R¹⁰、R¹¹And R¹²Each of which is the same or different and independently represents H and/or straight or branched C₁-C₄An alkyl group;

e are identical or different and denote a linear or branched C₁–C₆An alkylene group,Cyclohexyl radical, CH₂-C₆H₁₀Ortho-, meta-or para-substituted C₆H₄And/or absent units;

a is the same or different and denotes C_xH_2xWherein x =2, 3, 4 and/or 5, and/or CH₂CH(C₆H₅)；

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

a is the same or different and represents an integer of 5 to 350;

(IIb)

Wherein

e are identical or different and denote a linear or branched C₁–C₆Alkylene group, cyclohexyl group, CH₂-C₆H₁₀Ortho-, meta-or para-substituted C₆H₄And/or absent units;

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

a is the same or different and represents an integer of 5 to 350;

d is the same or different and represents absent units, NH and/or O, with the proviso that if D is absent units: b =0, 1, 2, 3 or 4 and c =0, 1, 2, 3 or 4, wherein b + c =3 or 4, and with the proviso that if D is NH and/or O: b =0, 1, 2 or 3, c =0, 1, 2 or 3, wherein b + c =2 or 3;

(IIc)

Wherein

n is identical or different and denotes 0, 1, 2, 3, 4 and/or 5;

l are the same or different and represent C_xH_2xWherein x =2, 3, 4 and/or 5, and/or CH₂-CH(C₆H₅)；

a is the same or different and represents an integer of 5 to 350;

d is the same or different and represents an integer of 1 to 350;

R¹⁹are identical or different and represent H and/or linear or branched C₁-C₄An alkyl group;

R²⁰are the same or different, andrepresents H and/or straight chain C₁-C₄An alkyl group.

9. A polymer composition according to claim 8, wherein in the formula (IIa), A are identical or different and represent C_xH_2xWherein x =2, and/or CH₂CH(C₆H₅)。

10. A polymer composition according to claim 8, wherein in the general formula (IIa), a is the same or different and represents an integer from 10 to 200.

11. A polymer composition according to any one of claims 1 to 10, characterized in that the polyether macromonomer building blocks of copolymers H and K are each formed by incorporating the following polyether macromonomers in the form of polymerized units: alkoxylated hydroxybutyl vinyl ether and/or alkoxylated isoprenol and/or alkoxylated (meth) allyl alcohol and/or vinylated methylpolyalkylene glycol.

12. A polymer composition according to any one of claims 1 to 10, characterized in that the polyether macromonomer building blocks of copolymers H and K are each formed by incorporating the following polyether macromonomers in the form of polymerized units: alkoxylated hydroxybutyl vinyl ether and/or alkoxylated isoprenol and/or alkoxylated (meth) allyl alcohol and/or vinylated methylpolyalkylene glycol, each having an arithmetic mean of from 6 to 300 alkylene oxide groups.

13. A polymer composition according to any one of claims 1 to 12, characterized in that the copolymers H and K each have polyether macromonomer building blocks and/or acid monomer building blocks of the same or different type.

14. A polymer composition according to claim 1 or 2, characterized in that at least 45mol% of all structural units of the copolymers H and K are formed in each case by incorporating the acid monomers and polyether macromonomers in the form of polymerized units.

15. A polymer composition according to claim 1 or 2, characterized in that at least 80mol% of all structural units of the copolymers H and K are formed in each case by incorporating the acid monomers and polyether macromonomers in the form of polymerized units.

16. A dispersant comprising at least 30% by weight of water and at least 10% by weight of the polymer composition of any one of claims 1 to 11.

17. The dispersant of claim 16 in the form of an aqueous solution.

18. Process for the preparation of a polymer composition according to any one of claims 1 to 15 or a dispersant according to claim 16 or 17, characterized in that the copolymers H and K are each prepared separately in an aqueous solution and subsequently the separately prepared copolymers or the separately prepared aqueous solutions are mixed with one another.

19. A process according to claim 18, characterized in that the acid monomer and the polyether macromonomer are reacted in aqueous solution by free radical polymerization using a peroxide-containing redox initiator system, the temperature of the aqueous solution during polymerization being between 10 and 45 ℃ and the pH being between 3.5 and 6.5.

20. Use of a polymer composition according to any one of claims 1 to 15 as a dispersant for hydraulic binders and/or as a dispersant for latent hydraulic binders.