阅读说明：本技术 作为膨胀粘土的封闭添加剂的梳型聚合物 (Comb polymers as blocking additives for swelling clays ) 是由 U·韦尔滕 J·韦德曼 L·佛伦兹 P·朱兰德 于 2019-10-01 设计创作，主要内容包括：一种梳型聚合物,特别是用作粘土惰性剂的,包含：a)至少一种不含离子基团的带有聚(亚烷基氧)侧链的单体单元M1,b)任选地至少一种阳离子单体单元MC,c)任选地至少一种阴离子单体单元MA,c)任选地至少一种非离子单体单元M3,其中阳离子单体单元MC与带有侧链的单体单元M1的摩尔比等于或小于10,阴离子单体单元MA与带有侧链的单体单元M1的摩尔比小于1、优选等于或小于0.5,和非离子单体单元M3与带有侧链的单体单元M1的摩尔比小于5。(A comb polymer, particularly for use as a clay inerter, comprising: a) at least one monomer unit M1 with a poly (alkylene oxide) side chain free of ionic groups, b) optionally at least one cationic monomer unit MC, c) optionally at least one anionic monomer unit MA, c) optionally at least one non-ionic monomer unit M3, wherein the molar ratio of cationic monomer unit MC to monomer unit with a side chain M1 is equal to or less than 10, the molar ratio of anionic monomer unit MA to monomer unit with a side chain M1 is less than 1, preferably equal to or less than 0.5, and the molar ratio of non-ionic monomer unit M3 to monomer unit with a side chain M1 is less than 5.)

1. Comb polymers, particularly for use as clay inerts, comprising:

a) at least one monomer unit M1 having a poly (alkylene oxide) side chain free of ionic groups,

b) optionally at least one cationic monomer unit MC,

c) optionally at least one anionic monomer unit MA,

d) optionally at least one non-ionic monomer unit M3,

wherein the molar ratio of cationic monomer units MC to monomer units with side chains M1 is equal to or less than 10, the molar ratio of anionic monomer units MA to monomer units with side chains M1 is less than 1, preferably equal to or less than 0.5, and the molar ratio of nonionic monomer units M3 to monomer units with side chains M1 is less than 5.

2. A comb polymer according to claim 1, wherein the monomer unit M1 with a side chain comprises the structure of formula I

Wherein

R¹And R²Independently in each case H or alkyl having 1 to 5 carbon atoms,

R³independently at each occurrence, H, alkyl having 1 to 5 carbon atoms, preferably H or CH₃Or mixtures thereof, or of the formula- (CH)₂)_m-[C＝O]_p-X-R₄A group of (1), wherein

m is 0,1 or 2,

p is 0 or 1, and p is 0 or 1,

x is independently in each occurrence-O-or-NH-,

R⁸is of the formula [ AO]_n-R^aGroup (d) of

Wherein A ═ C₂-to C₄Alkylene radical, R^aIs H, C₁-to C₂₀-alkyl, -cycloalkyl or-alkylaryl,

and n-2-250, especially 10-200.

3. A comb polymer according to any preceding claim, wherein the cationic monomer unit MC in the polymer comprises or consists of a monomer having the structure of formula II:

wherein

R⁵Independently in each occurrence- [ D]_d-[E]_e-F, wherein

D ═ - (COO) -and/or- (CONH) -,

e ═ alkylene having 1 to 5 carbon atoms,

F＝-N⁺R¹⁰R¹¹R¹²、-S⁺R¹⁰R¹¹R¹²and/or-P⁺R¹⁰R¹¹R¹²，

Wherein R is¹⁰、R¹¹And R¹²Independently of one another, H, an aliphatic hydrocarbon radical having 1 to 20C atoms, an alicyclic hydrocarbon radical having 5 to 8C atoms and/or an aryl radical having 6 to 14C atoms;

wherein

d is 0 or 1, and d is a linear or cyclic alkyl group,

e is 0 or 1, and the total of the two,

R⁶、R⁷and R⁸In each case independently H or an alkyl group having from 1 to 5 carbon atoms.

4. A comb polymer according to any preceding claim, wherein the anionic monomer unit MA comprises or consists of a monomer having the structure of formula III:

wherein

R¹³In each case independently-COOM, -SO₂–OM、-O–PO(OM)₂and/or-PO (OM)₂，

R¹⁴And R¹⁵Independently in each case H or alkyl having 1 to 5 carbon atoms,

R¹⁶independently in each case H, -COOM or alkyl having 1 to 5 carbon atoms,

or wherein R is¹³And R¹⁶Together form a ring to give-CO-O-CO-,

m independently of one another is H⁺Alkali metal ions, alkaline earth metal ions, divalent or trivalent metal ions, ammonium ions and organic ammonium groups.

5. A comb polymer according to any preceding claim, wherein the non-ionic monomer M3 has the structure of formula IV:

wherein

R^5',R^6',R^7'And for R⁶,R⁷And R⁸Defined as being the same, and m 'and p' are the same as defined for m and p as described above in the context of the copolymers,

y is independently in each occurrence a bond or-O-,

z independently each occurrence is a bond, -O-, or-NH-,

R²⁰independently in each case an alkyl, cycloalkyl, alkylaryl, aryl, hydroxyalkyl or acetoxyalkyl group, each having from 1 to 20 carbon atoms.

6. A comb polymer according to any one of claims 1 to 5, wherein the comb polymer comprises, relative to the total number of monomer units present in the comb polymer:

a)95 to 100 mol%, in particular 97 to 100 mol%, in particular 98 to 100 mol%, preferably 99.5 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain,

b)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one nonionic monomer unit M3.

7. A comb polymer according to any one of claims 1 to 5, wherein the comb polymer comprises, relative to the total number of monomer units present in the comb polymer:

a)30 to 70 mol%, in particular 40 to 60 mol%, in particular 40 to 50 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain, and

b)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d)30 to 70 mol%, in particular 40 to 60 mol%, in particular 40 to 50 mol%, of at least one nonionic monomer unit M3.

8. A comb polymer according to any one of claims 1 to 5, wherein the comb polymer comprises, relative to the total number of monomer units present in the comb polymer:

a)10 to 99 mol%, in particular 40 to 95 mol%, in particular 50 to 75 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain, and

b) from 1 to 90 mol%, in particular from 5 to 60 mol%, preferably from 25 to 50 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d) from 0 to 75 mol%, in particular from 5 to 60 mol%, in particular from 25 to 50 mol% or 0 mol%, of at least one nonionic monomer unit M3.

9. A comb polymer according to any one of the preceding claims, wherein the comb polymer consists essentially of at least one monomer unit M1 bearing a poly (alkylene oxide) side chain and optionally a nonionic monomer unit M3.

10. A comb polymer according to any preceding claim, wherein the comb polymer consists of at least one monomer unit M1 bearing a poly (alkylene oxide) side chain and at least one cationic monomer unit MC.

11. A comb polymer according to any one of the preceding claims, wherein the comb polymer is a block polymer, wherein at least 75 mol%, in particular at least 90 mol%, preferably at least 99 mol% of the total number of at least one monomer unit M1 bearing a side chain is arranged in a first block of the block copolymer, and wherein the block copolymer comprises a second block, wherein at least 75 mol%, in particular at least 90 mol%, preferably at least 99 mol% of the total number of at least one cationic monomer unit MC is arranged.

12. Kit of parts comprising a plasticizer according to any of claims 1 to 11 and a mineral binder composition, in particular a polycarboxylate ether chemically and/or structurally different from the comb polymer.

13. A composition comprising a comb polymer according to any one of claims 1 to 11, and further comprising a mineral binder, an aggregate and/or an expandable clay.

14. Method, in particular for plasticizing a mineral binder composition, comprising the steps of: adding to a composition comprising an expandable clay, in particular a mineral binder composition comprising an expandable clay, (i) a comb polymer according to any one of claims 1 to 11, and (ii) a plasticizer for the mineral binder composition.

15. Use of a comb polymer according to any one of claims 1 to 11 as a clay inerting agent and/or for reducing or inhibiting the adverse effect of swellable clay on the effectiveness of dispersing agents, in particular PCE-based dispersing agents, in mineral binder compositions.

Technical Field

The invention relates to a comb polymer, in particular for use as a clay inerting agent. In addition, the present invention relates to kits of parts and compositions comprising comb polymers. Other aspects of the invention relate to a process, in particular for plasticising a mineral binder composition, and the use of a comb polymer as a clay inerting agent.

Background

Dispersants or superplasticizers are used in the construction industry as plasticizers or water reducers for mineral binder compositions (e.g. concrete, cement mortar, mortar or lime mortar). The dispersant is typically an organic polymer that is added to the mixing water or mixed with the binder composition in solid form. In this way, both the consistency and the properties in the hardened state of the binder composition during processing can be advantageously varied.

Particularly effective dispersants are known, for example, polymers based on polycarboxylate ethers (PCE). Such polymers have a polymer main chain and side chains bonded thereto. Corresponding polymers are described, for example, in EP1138697A1(Sika AG).

High quality river sand, typically used as an aggregate for mortar or concrete production, is becoming an increasingly scarce resource. Therefore, more and lower quality sand must be used, which contains undesirable impurities or contaminants from natural resources or recovery processes.

Unfortunately, the presence of certain contaminants, such as swelling clays, even in very low amounts, can have a dramatic impact on the effectiveness of PCE-based admixtures in mortar or concrete production.

This is because the PCE is intercalated in the swelling clay, and thus a large portion of the added PCE is lost and can no longer be adsorbed on the cement or cement hydrate, thereby failing to achieve the desired water-reducing effect. Thus, if swelling clay is present, the fluidity of mortar or concrete with a given PCE dose will be significantly reduced.

Concrete producers usually solve this problem by either using higher PCE doses to compensate for the loss of PCE performance, or by adding special additives that can reduce or prevent the effects of swelling clays (i.e., so-called swelling clay sealers).

While in principle increasing the PCE dose is a simple solution, it is economically inefficient and may be problematic if the swelling clay content fluctuates. In such cases, to maintain a certain fluidity, concrete producers are often forced to adjust the dose of PCE, which is very time consuming.

With regard to clay blocking additives, various methods are currently known. For example, WO2010/005117a1(w.r.grace) describes a method in which a polycationic compound is used in combination with a hydroxycarboxylic acid or salt thereof to enhance slump retention in cement and concrete with clay-containing aggregates, which would otherwise absorb or reduce the efficiency of polycarboxylic acid-based superplasticizers.

WO 2016/096970A 1(BASF SE) describes a method of inhibiting clay swelling in a subterranean formation using a polyimidazolium compound.

In addition, products based on the sealing properties of expanded clays with a strong water-reducing effect are also on the market. Mention may be made here of the products sold by basf under the brand "MasterSuna".

However, these methods must be improved in terms of effectiveness, robustness to swelling clay fluctuations, compatibility with concrete admixtures or lower chloride contents.

Therefore, there is a need to develop new and improved solutions that reduce or overcome the above-mentioned disadvantages.

Disclosure of Invention

It is an object of the present invention to provide materials and methods that can reduce or prevent the problem of swelling clays in mineral binder compositions. Ideally, these materials or methods should reduce the negative impact of swelling clays on the effectiveness of dispersants, particularly PCE-based dispersants. Preferably, the action time should be as long as possible. In particular, these substances or methods should be as effective as possible, while having the best robustness. Preferably, such a substance or method should itself affect the flowability of the mineral binder composition as little as possible. Furthermore, preferably, these substances and methods should be as insensitive as possible to fluctuations in the content of swelling clay in the mineral binder composition. In particular, these substances or methods should be compatible with the conventional additives or corresponding processes, respectively, used for producing mineral binder compositions. In particular, the material or method should be compatible with lignosulfonates, gluconates, naphthalenesulfonates, sulfonated naphthalene-formaldehyde condensates, melamine sulfonates, vinyl copolymers, sulfonated vinyl copolymers, and/or polycarboxylates, especially polycarboxylates ethers. In particular, these materials or methods should be compatible with PCE-based dispersants. Also, the chloride content of these materials or processes should be as low as possible, or should be essentially chloride free.

Surprisingly, it has been found that the problem of the present invention can be solved by the features of claim 1. The core of the present invention is therefore a comb polymer, particularly for use as a clay inerter, comprising:

a) at least one monomer unit M1 having a poly (alkylene oxide) side chain free of ionic groups,

b) optionally at least one cationic monomer unit MC,

c) optionally at least one anionic monomer unit MA,

d) optionally at least one non-ionic monomer unit M3,

wherein the molar ratio of the cationic monomer units MC to the monomer units with side chains M1 is equal to or less than 10, the molar ratio of the anionic monomer units MA to the monomer units with side chains M1 is less than 1, preferably equal to or less than 0.5, and the molar ratio of the nonionic monomer units M3 to the monomer units with side chains M1 is less than 5.

As has been shown, the comb polymers of the present invention allow for a highly effective reduction of the negative impact of swelling clay on the effectiveness of dispersants, particularly PCE-based dispersants, in mineral binder compositions containing swelling clay. Thus, the solution of the invention proves to be highly stable and the comb polymer has little effect on the flowability of the mineral binder composition. In particular, the dosage of the comb polymer according to the invention is not important, especially if a certain threshold value has been reached. Thus, fluctuations in the content of swelling clay in the mineral binder composition are hardly a problem for the comb polymer of the invention. Thus, the comb polymers according to the invention can be used as clay inerts or clay sealers, in particular in combination with PCE-based dispersants.

In particular, comb polymers according to the present invention typically have a relatively high graft density of poly (alkylene oxide) side chains, which is in particular higher than that of conventional PCE-based dispersants. Without being bound by theory, it is believed that the comb polymer according to the invention intercalates into the expanded clay through its side chains.

In view of this theory, a single poly (alkylene oxide) side chain such as methyl polyethylene glycol (which is not part of the comb polymer structure) should also be a good blocking additive. However, it has surprisingly been found that the comb polymer according to the invention is a better blocking additive when compared to a single poly (alkylene oxide) side chain. Even when the same or higher doses of individual poly (alkylene oxide) side chains are used, these individual side chains do not reduce or prevent intercalation of the PCE-based dispersant to the same extent as the comb polymer of the present invention.

Furthermore, the comb polymers of the invention exhibit at least as good effectiveness as known blocking additives such as polycations or similar known blocking additives having a strong plasticizing action.

Other aspects of the invention are the subject of other independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims.

Modes for carrying out the invention

The first aspect of the present invention relates to a comb polymer, particularly for use as a clay inerting agent, comprising:

a) at least one monomer unit M1 having a poly (alkylene oxide) side chain free of ionic groups,

b) optionally at least one cationic monomer unit MC,

c) optionally at least one anionic monomer unit MA,

d) optionally at least one non-ionic monomer unit M3,

wherein the molar ratio of cationic monomer units MC to monomer units with side chains M1 is equal to or less than 10, in particular less than 5, the molar ratio of anionic monomer units MA to monomer units with side chains M1 is less than 1, preferably equal to or less than 0.5, and the molar ratio of nonionic monomer units M3 to monomer units with side chains M1 is less than 5.

Thus, the monomer units M1, MC, MA and M3 are chemically and/or structurally different from each other. In particular, the at least one non-ionic monomer unit M3 does not comprise a poly (alkylene oxide) group, in particular it does not comprise a poly (ethylene oxide) group.

In the context of the present application, a "polymer" is a substance which comprises or consists of at least 2, in particular at least 3, preferably at least 5 polymerized monomer units.

A "comb polymer" is a polymer comprising a polymer backbone and side chains attached thereto.

The term "mineral binder" denotes a binder that reacts in a hydration reaction in the presence of water to form a solid hydrate or hydrate phase. This may be, for example, a hydraulic binder, a latent hydraulic binder, and/or a pozzolanic binder. Highly preferred are hydraulic binders. Hydraulic binders can be cured in water. However, it may also be advantageous for the mineral binder to contain other binders in addition to or instead of the hydraulic binder. These are in particular latent hydraulic binders and/or pozzolanic binders. Suitable latent hydraulic and/or pozzolanic binders are, for example, slag, fly ash, silica fume and/or natural pozzolanas.

In particular, the mineral binder comprises or consists of cement, in particular of a cement of the CEM I, CEM II, CEM III, CEM IV and/or CEM V (according to the EN 197-1 standard) type.

In a preferred embodiment, the mineral binder contains at least 5% by weight, in particular at least 20% by weight, preferably at least 35% by weight, in particular at least 65% by weight, of hydraulic binder, in particular cement, and optionally 5 to 95% by weight, in particular 5 to 65% by weight, in particular 15 to 35% by weight, of latent hydraulic and/or pozzolanic binder, relative to the total mineral binder content.

The terms "clay inerting agent", "clay capping agent" and "clay capping agent" refer to an agent capable of reducing or inhibiting the adverse effect of swellable clay on the effectiveness of dispersing agents, particularly PCE-based dispersing agents, in mineral binder compositions.

The term "swelling clay" or "swelling clay" especially denotes clay minerals that swell and/or increase their volume when wetted with an aqueous solution. Structurally, the swelling clays are phyllosilicate minerals, and more particularly phyllosilicate minerals, which are based on tetrahedral MO₄Sheet (M ═ Si)⁴⁺，Al³⁺) And octahedron M (O, OH)₆Tablet (M ═ Al)³⁺、Mg²⁺、Fe^2+/3+Etc.). They differ from each other in the way they stack tetrahedral and octahedral sheets, which strongly affects their ability to add or lose water molecules or cations in the structure. The most common swelling clays are 2: part of the type 1 clay family. These are clays such as: wherein an octahedral sheet (O) is sandwiched between two tetrahedral sheets (T) forming a base unit, in this case a T-O-T layer. The basic cells are bonded to each other to form a laminate. This bonding is the result of the formation of an intermediate layer between the two elementary units, called Z-sheets, which contain cations in the swollen clay that hold the two layers together. As an example, in the non-swelling clay muscovite, potassium ions are located in the Z-sheets. The potassium ions in these 2:1 clays may be lost due to the weathering process, forming potassium-poor Z-sheets, which in aqueous solution will cause the Z-sheets to swell. In addition, potassium may be partially replaced by other ions calcium, sodium or even other ions. Weathering of rock is an important natural process that enhances the formation of these minerals. Swelling clays which can be formed are, for example, minerals of the smectite family, such as montmorillonite, nontronite, beidellite, saponite, hectorite, sauconite.Other swelling clays not explicitly mentioned herein are also included in the term "swelling clay", for example vermiculite. After the rock weathering process, the expanded clay is migrated and present in the aggregate, e.g., sand aggregate.

Thus, in particular, the comb polymers according to the invention are used in compositions comprising such swelling clays, in particular montmorillonite, nontronite, beidellite, saponite, hectorite, sauconite and/or vermiculite.

In particular, the swellable clay is a clay that is part of the type 2:1 clay family. Thus, in particular, the comb polymers according to the invention are used in compositions comprising such swelling clays which are part of the type 2:1 clay family.

The term "ionic group" especially refers to a group which is present in negatively or positively charged form at pH >10, especially at least at pH > 12. In the present context, a group present in a negatively charged form is referred to as an "anionic group". Groups that exist in a positively charged form are referred to as "cationic groups". Thus, as far as the charge of the ionic group is concerned, counterions bound only by ionic bonds should not be considered.

The terms "cationic monomer" and "cationic monomer unit" especially refer to monomers or polymerized monomers that are present in a positively charged form at least at a pH >10, especially at least at a pH > 12. Thus, in terms of the charge of the "cationic monomer" or "cationic monomer unit", no counterions bound by ionic bonds should be considered.

Likewise, the terms "anionic monomer" and "anionic monomer unit" especially refer to monomers or polymerized monomers which are present in negatively charged form at least at pH >10, especially at least pH > 12. Also in this case, the counterions bound by ionic bonds should not be taken into account in terms of the charge of the "anionic monomers" or "anionic monomer units".

In particular, anionic monomers are monomers comprising anionic groups, for example hydrogen donor groups or acid groups. More preferably, the anionic groups are acid groups, such as carboxylic, sulfonic, phosphoric and/or phosphonic acid groups. Carboxylic acid groups are preferred. The anionic or acid groups may also take the form of anions in deprotonated form or salts with counterions or cations.

Cationic monomers are monomers that contain cationic groups. Thus, the cationic group is covalently attached to the cationic monomer. It may be a common cationic group, in particular an ammonium, sulfonium and/or phosphonium group, which may be attached to the organic polymer. The cationic groups may also take the form of salts with counterions or anions.

The cationic groups are in particular grafted onto the backbone of the comb polymer. This means that it is not part of the backbone or skeleton of the comb polymer. Thus, it does not link the subunits of the main chain to each other. It is therefore different from the condensate of dimethylamine and epichlorohydrin of, for example, US 20070287794 a 1.

The terms "nonionic monomer" and "nonionic monomer unit" especially refer to monomers or polymerized monomers which do not have any ionic groups, in particular they do not have any anionic groups nor any cationic groups. In particular, the nonionic monomers are present in uncharged form at pH >10, in particular at pH > 12.

Furthermore, at least one monomer unit M1 bearing a poly (alkylene oxide) side chain does not contain any ionic groups, in particular it does not have any anionic groups nor any cationic groups. In particular, at least one monomer unit M1 bearing a poly (alkylene oxide) side chain does not contain any carboxylic, sulfonic, phosphoric and phosphonic acid groups and/or at least one monomer unit M1 bearing a poly (alkylene oxide) side chain does not contain any ammonium, sulfonium and/or phosphonium groups, in particular quaternary ammonium groups.

In particular, at least one monomer unit M1 with a poly (alkylene oxide) side chain is present in uncharged form at pH >10, in particular at pH > 12.

In particular, at least one monomer unit M1 with a poly (alkylene oxide) side chain is attached to the polymer backbone via an ester, ether, amide and/or imide group. The at least one monomer unit M1 having a poly (alkylene oxide) side chain preferably includes a poly (ethylene oxide) side chain, a poly (propylene oxide) side chain, and/or a poly (ethylene oxide/propylene oxide) side chain. In particular, the number average molecular weight of the poly (alkylene oxide) side chains is in the range of 100 to 10'000g/mol, especially 250 to 5'000g/mol, preferably 500 to 3'500g/mol, especially 900 to 2'500g/mol, for example 950 to 1'500g/mol or 1'000 to 1'400 g/mol.

In particular, monomer unit M1 with a side chain includes the structure of formula I:

wherein

R¹And R²Independently at each occurrence, H or an alkyl group having 1 to 5 carbon atoms, preferably H or CH₃Or a mixture thereof,

R³independently at each occurrence, H, an alkyl group having 1 to 5 carbon atoms, preferably H or CH₃Or mixtures thereof, or of the formula- (CH)₂)_m-[C＝O]_p-X-R₄The group of (a) or (b),

wherein

m is 0,1 or 2,

p is 0 or 1, and p is 0 or 1,

x is independently in each occurrence-O-or-NH-,

R⁴is of the formula [ AO]_n-R^aWherein a ═ C₂-to C₄Alkylene radical, R^aIs H, C₁-to C₂₀-alkyl, -cycloalkyl or-alkylaryl, and n ═ 2 to 250, especially 10 to 200, especially 15 to 50 or 20 to 25.

More particularly, R¹H or CH₃And R²＝R³＝H。

The X groups in the monomer units M1 are advantageously at least 75 mol%, in particular at least 90 mol%, in particular at least 95 mol% or at least 99 mol%, of the total number of monomer units M1-O- (═ oxygen atoms).

In a further advantageous embodiment, m is 0, p is 1 and preferably X is-O-. In this case, the copolymer can be prepared based on commercially available (meth) acrylates.

In a further advantageous embodiment, m is 0-2, p is 0 and preferably X is-O-. Thus, copolymers can be prepared based on commercially available vinyl ether, (meth) allyl ether or isoprenyl ether monomers.

In a particularly advantageous embodiment, R¹40 to 60 mol% of H and 40 to 60 mol% of-CH₃A mixture of (a).

R in monomer unit M1 with side chain⁴Radical based on R in the monomer unit⁴The total number of radicals, in particular including poly (ethylene oxide), is in particular at least 50 mol%, in particular at least 75 mol%, preferably at least 95 mol% or at least 99 mol%.

The proportion of ethylene oxide units, based on the total number of ethylene oxides in the copolymer, is in particular greater than 75 mol%, in particular greater than 90 mol%, preferably greater than 95 mol% and in particular 100 mol%.

More particularly, R⁴Substantially free of hydrophobic groups, especially alkylene oxides having no three or more carbon atoms. This means in particular that the proportion of alkylene oxides having three or more carbon atoms is less than 5 mol%, in particular less than 2 mol%, preferably less than 1 mol% or less than 0.1 mol%, based on the total number of alkylene oxides. In particular, alkylene oxides having three or more carbon atoms are not present, i.e. the proportion thereof is 0 mol%.

R^aAdvantageously H and/or methyl groups. Particularly advantageously, a ═ C₂Alkylene and R^aIs H or methyl.

More particularly, n is 10 to 150, especially n is 15 to 100, preferably n is 17 to 70, especially n is 19 to 45 or n is 20 to 25. In particular, this achieves an excellent sealing effect.

Particularly preferred are copolymers wherein R is¹Selected from H, -CH₃And mixtures thereof; r²And R³＝H；R⁴Based on R in the monomer unit⁴A poly (ethylene oxide) comprising, based on the total number of groups, in particular at least 50 mol%, in particular at least 75 mol%, preferably at least 95 mol%, or at least 99 mol%;and X is-O-in at least 75 mol%, in particular at least 90 mol%, in particular at least 99 mol%, of the total number of monomer units M1.

According to a preferred embodiment, the cationic groups of the cationic monomer units MC in the comb polymer comprise or consist of ammonium, sulfonium and/or phosphonium groups, in particular quaternary ammonium groups.

In a preferred embodiment of the invention, the cationic group is an ammonium group. It is particularly preferred that it is a quaternary ammonium group. In this case, the positively charged nitrogen atom is substituted with four organic groups. Preferably, the cationic group has the formula-N⁺R¹⁰R¹¹R¹²Wherein R is¹⁰、R¹¹And R¹²Independently of one another, H, an aliphatic hydrocarbon radical having 1 to 20C atoms, an alicyclic hydrocarbon radical having 5 to 8C atoms and/or an aryl radical having 6 to 14C atoms. As shown by the hyphen, of the formula-N⁺R¹⁰R¹¹R¹²The positively charged nitrogen atom of the group(s) is chemically or covalently bonded (optionally through a chemical linking group) to the cationic monomer. Preferably, R¹⁰、R¹¹And R¹²In addition to H, particular preference is given to the radicals selected from methyl and ethyl.

In particular, the cationic monomer unit MC in the polymer comprises or consists of a cationic monomer having the structure of formula I I:

wherein

R⁵Independently in each occurrence- [ D]_d-[E]_e-F, wherein

D ═ - (COO) -and/or- (CONH) -,

e ═ alkylene having 1 to 5 carbon atoms,

F＝-N⁺R¹⁰R¹¹R¹²、-S⁺R¹⁰R¹¹R¹²and/or-P⁺R¹⁰R¹¹R¹²，

Wherein R is¹⁰、R¹¹And R¹²Independently of one another, H, an aliphatic hydrocarbon radical having 1 to 20C atoms, an alicyclic hydrocarbon radical having 5 to 8C atoms and/or an aryl radical having 6 to 14C atoms;

wherein

d is 0 or 1, and d is a linear or cyclic alkyl group,

e is 0 or 1, and the total of the two,

R⁶、R⁷and R⁸In each case independently H or an alkyl group having from 1 to 5 carbon atoms.

Thus, preferably, R⁶H or CH₃，R⁷＝R⁸H, D ═ 1 and in particular D ═ COO) -.

According to a preferred embodiment, F ═ N⁺R¹⁰R¹¹R¹²And E ═ 1 and preferably E ═ alkylene groups having 2 to 3 carbon atoms.

In a preferred embodiment of the present invention, the ionic monomer is selected from the group consisting of [2- (acryloyloxy) -ethyl ] trimethyl ammonium chloride, [2- (acryloylamino) -ethyl ] trimethyl ammonium chloride, [2- (acryloyloxy) -ethyl ] trimethyl ammonium methylsulfate, [2- (methacryloyloxy) -ethyl ] trimethyl ammonium chloride or methylsulfate, [3- (acryloylamino) -propyl ] trimethyl ammonium chloride, [3- (methacryloylamino) -propyl ] trimethyl ammonium chloride.

The use of [2- (methacryloyloxy) -ethyl ] trimethylammonium salts, in particular the chloride, has proven particularly advantageous according to the invention. Commercially available from Evonik Industries, DE (under the trade designation "Visiomer TMAMC") or from Sigma-Aldrich, DE may be used.

According to another preferred embodiment, the comb polymer is substantially free of cationic monomer units MC. This means that the proportion of cationic monomer units MC in the comb polymer is from 0 to 1 mol%, in particular from 0 to 0.1 mol%, preferably 0 mol%, relative to the total number of monomer units present in the comb polymer.

In a further preferred embodiment, the anionic groups of the anionic monomer units MA in the comb polymer comprise or consist of carboxylic, sulfonic, phosphoric and/or phosphonic acid groups.

Preferably, the anionic monomer units MA in the polymer comprise or consist of anionic monomers having the structure of formula III:

wherein

R¹³In each case independently-COOM, -SO₂–OM、-O–PO(OM)₂and/or-PO (OM)₂，

R¹⁴And R¹⁵Independently in each case H or alkyl having 1 to 5 carbon atoms,

R¹⁶independently in each case H, -COOM or alkyl having 1 to 5 carbon atoms,

or wherein R is¹³And R¹⁶Together form a ring to give-CO-O-CO-,

m independently of one another is H⁺Alkali metal ions, alkaline earth metal ions, divalent or trivalent metal ions, ammonium ions and organic ammonium groups.

More particularly, R¹³＝COOM，R¹⁴H or CH₃，R¹⁵＝R¹⁶H. Thus, it is possible to prepare copolymers based on acrylic or methacrylic monomers, which is of interest from an economic point of view.

Also advantageously, R¹³＝COOM，R¹⁴＝H，R¹⁵H and R¹⁶COOM. The corresponding comb polymers can be prepared based on maleic acid monomers.

According to another preferred embodiment, the comb polymer is substantially free of anionic monomer units MA. This means that the proportion of anionic monomer units MA in the comb polymer is from 0 to 1 mol%, in particular from 0 to 0.1 mol%, preferably 0 mol%, relative to the total number of monomer units present in the comb polymer.

It may also be advantageous for the comb polymer to comprise at least one further nonionic monomer unit M3 which is chemically and/or structurally different from the monomer units M1, MC and MA. In particular, a plurality of different further monomer units M3 may be present. In this way, the properties of the comb polymer can be further modified and adjusted, for example, according to the particular application.

Particularly advantageously, the nonionic monomer unit M3 is a monomer unit of formula IV:

wherein R is^5'、R^6'、R^7'In the context of the copolymers for R⁶、R⁷And R⁸Defined as being the same, and m 'and p' are the same as defined for m and p in the context of the relevant copolymers,

y is independently at each occurrence a bond or-O-;

z is independently at each occurrence a bond, -O-, or-NH-;

R²⁰independently each occurrence is alkyl, cycloalkyl, alkylaryl, aryl, hydroxyalkyl or acetoxyalkyl, each having from 1 to 20 carbon atoms.

Advantageous examples of nonionic monomer units M3 are those wherein M '═ 0, p' ═ 0, Z and Y denote a bond and R²⁰Those which are alkylaryl groups having from 6 to 10 carbon atoms.

Also suitable are especially those in which m '═ 0, p' ═ 1, Y is-O-, Z represents a bond and R²⁰Other monomer units M3 which are alkyl radicals having from 1 to 4 carbon atoms.

Further suitable are those in which m '═ 0, p' ═ 1, Y is a bond, Z is — O-, and R²⁰Other monomer units M3 which are alkyl and/or hydroxyalkyl radicals having from 1 to 6 carbon atoms.

Particularly advantageously, the nonionic monomer units M3 consist of polymerized vinyl acetate, styrene and/or hydroxyalkyl (meth) acrylates, in particular styrene.

According to another preferred embodiment, the comb polymer is substantially free of nonionic monomer units M3. This means that the proportion of nonionic monomer units M3 in the comb polymer is from 0 to 1 mol%, in particular from 0 to 0.1 mol%, preferably 0 mol%, relative to the total number of monomer units present in the comb polymer.

According to a preferred embodiment, the comb polymer comprises 20 to 100 mol%, in particular 50 to 100 mol%, especially 65 to 100 mol%, for example 80 to 100 mol% or 95 to 100 mol%, relative to the total number of monomer units present in the comb polymer, of at least one monomer unit M1 having a poly (alkylene oxide) side chain.

In particular, preferred comb polymers comprise, relative to the total number of monomer units present in the comb polymer:

a)95 to 100 mol%, in particular 97 to 100 mol%, in particular 98 to 100 mol%, preferably 99.5 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain,

b)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one nonionic monomer M3.

In this or other preferred comb polymers,

the molar ratio of cationic monomer units MC to monomer units M1 bearing side chains is equal to or less than 0.5, in particular equal to or less than 0.1, in particular equal to or less than 0.01 or 0.

The molar ratio of anionic monomer units MA to monomer units M1 bearing side chains is equal to or less than 0.5, in particular equal to or less than 0.1, in particular equal to or less than 0.01 or 0.

The molar ratio of nonionic monomer units M3 to monomer units M1 bearing side chains is equal to or less than 0.5, in particular less than or equal to 0.1, in particular less than or equal to 0.01 or 0.

In particular, the comb polymer comprises 100 mol% of at least one monomer unit M1 having a poly (alkylene oxide) side chain, relative to the total number of monomer units present in the comb polymer. In this case, the comb polymer may be a homopolymer of the monomer unit M1 having the same side chain or a copolymer of at least two monomer units M1 having different side chains.

Such comb polymers are preferred if they comprise a monomer unit M1 with side chains comprising or consisting of a structure of formula I as described above wherein the parameter p is equal to 1. These are, for example, poly (alkylene oxide) (meth) acrylate-based monomer units M1.

According to another preferred embodiment, the comb polymer consists essentially of at least one monomer unit M1 with a poly (alkylene oxide) side chain and a nonionic monomer unit M3. In this case, the comb polymer is a copolymer based on at least one monomer unit M1 with a side chain and a nonionic monomer unit M3.

Such a comb polymer is preferred if it comprises a monomer unit M1 with side chains comprising or consisting of a structure of formula I as shown above wherein the parameter p is equal to 0. These are, for example, poly (alkylene oxide) alkenyl ether-based monomer units M1.

For example, a preferred comb polymer comprises, relative to the total number of monomer units present in the comb polymer:

a)30 to 70 mol%, in particular 40 to 60 mol%, in particular 40 to 50 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain, and

b)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d)30 to 70 mol%, in particular 40 to 60 mol%, in particular 40 to 50 mol%, of at least one nonionic monomer unit M3.

In this or other preferred comb polymers,

the molar ratio of cationic monomer units MC to monomer units M1 bearing side chains is equal to or less than 0.5, in particular equal to or less than 0.1, in particular equal to or less than 0.01 or 0.

The molar ratio of anionic monomer units MA to monomer units M1 bearing side chains is equal to or less than 0.5, in particular equal to or less than 0.1, in particular equal to or less than 0.01 or 0.

The molar ratio of nonionic monomer units M3 to monomer units M1 having side chains is from 0.1 to 5, in particular from 0.5 to 2.5, in particular from 0.8 to 2 or from 1 to 1.5.

In a further preferred embodiment, the comb polymer comprises at least one cationic monomer MC. Thus, preferably, the comb polymer has at least 30 mol%, in particular at least 50 mol%, in particular at least 65 mol%, in particular at least 90 mol% or 95 mol%, of monomer units M1 with side chains and cationic monomer units MC, relative to the total number of monomer units present in the comb polymer. The remaining monomer units may be, for example, nonionic monomer unit M3. In particular, the comb polymer is composed of at least one monomer unit M1 with a poly (alkylene oxide) side chain and at least one cationic monomer unit MC.

For example, other preferred comb polymers comprise, relative to the total number of monomer units present in the comb polymer:

a)10 to 99 mol%, in particular 40 to 95 mol%, in particular 50 to 75 mol%, of at least one monomer unit M1 having a poly (alkylene oxide) side chain, and

b) from 1 to 90 mol%, in particular from 5 to 60 mol%, preferably from 25 to 50 mol%, of at least one cationic monomer unit MC,

c)0 to 1 mol%, in particular 0 to 0.1 mol%, preferably 0 mol%, of at least one anionic monomer unit MA,

d) from 0 to 75 mol%, in particular from 5 to 60 mol%, in particular from 25 to 50 mol% or 0 mol%, of at least one nonionic monomer unit M3.

In this or other preferred comb polymers,

the molar ratio of cationic monomer units MC to monomer units M1 with side chains is from 0.1 to 5, in particular from 0.5 to 2.5, in particular from 0.8 to 2 or from 1 to 1.5,

the molar ratio of anionic monomer units MA to monomer units M1 bearing side chains is equal to or less than 0.5, in particular equal to or less than 0.1, in particular equal to or less than 0.01 or 0,

the molar ratio of nonionic monomer units M3 to monomer units M1 having side chains is from 0 to 5, in particular from 0.1 to 2.5, in particular from 0.5 to 2 or from 0.8 to 1.5.

Thus, in particular, the molar ratio of anionic monomer units MA to cationic monomer units MC is from 0 to 1, in particular from 0 to 0.9, in particular from 0 to 0.5 or from 0 to 0.05.

In a particularly preferred embodiment, the comb polymer is a block copolymer in which at least 75 mol%, in particular at least 90 mol%, preferably at least 99 mol%, of the total number of at least one monomer unit M1 bearing a side chain is arranged in the first block of the block copolymer.

In particular, the block copolymer comprises a second block in which at least 75 mol%, in particular at least 90 mol%, preferably at least 99 mol%, of the total number of at least one cationic monomer unit MC is arranged.

In a further preferred embodiment, between the first and second blocks, there is a third block comprising at least one monomer unit M1 with a side chain, at least one cationic monomer unit MC and/or at least one non-ionic monomer unit M3. In particular, the third block has a non-random distribution of monomer units M1 and/or cationic monomer units MC in the direction along the polymer backbone.

In the present application, "non-random distribution" is understood to mean a non-statistical distribution of monomer units M1 and/or monomer units MC. This means that the monomer units M1 and/or the ionic units MC with side chains are arranged in the third block, for example in an alternating manner and/or in a gradient structure.

The structure of the copolymer can be analyzed and determined, for example, by nuclear magnetic resonance spectroscopy (NMR spectroscopy). By passing¹³C and¹h NMR spectroscopy in particular, the sequence of monomer units in a copolymer can be determined based on proximity group effects in the copolymer and by using statistical evaluation.

In all of the above structures, nonionic monomer unit M3 may be added, for example to control the density of other monomer units in the comb polymer and/or to adjust the comb polymer to specific needs.

Preferably, the molar proportion of the nonionic monomer unit M3, if used, is from 0.0001 to 50 mol%, in particular from 0.0002 to 30 mol%, in particular from 0.001 to 25 mol%, advantageously from 0.1 to 10 mol% or from 1 to 9 mol%, relative to the total number of monomer units in the comb polymer. This is particularly effective for block copolymers.

Comb polymers are in particular prepared by free-radical polymerization, for example by conventional free-radical polymerization or by controlled free-radical polymerization (also known as living free-radical polymerization). These polymerization techniques are well known to the skilled person.

Thus, monomer units M1 'bearing pendant unilaterally ethylenically unsaturated poly (alkylene oxide) side chains according to formula V, optionally at least one ionic monomer unit MC' and/or MA 'bearing pendant ethylenic unsaturation according to formula VI and/or VII and optionally at least one nonionic monomer unit M3' bearing pendant ethylenic unsaturation according to formula VIII are polymerized together such that the molar ratio of cationic monomer units MC to monomer units M1 bearing side chains is equal to or less than 10, in particular less than 5, the molar ratio of anionic monomer units MA to monomer units M1 bearing side chains is less than 1, preferably equal to or less than 0.5 and the molar ratio of nonionic monomer units M3 to monomer units M1 bearing side chains is less than 5.

Wherein R is¹–R¹⁶、R^5'-R^7'、R²⁰X, Y, Z, m ', n and p, p' are as defined above.

Among the controlled radical polymerization techniques, reversible addition-fragmentation chain transfer polymerization (RAFT), Nitroxide Mediated Polymerization (NMP), and/or Atom Transfer Radical Polymerization (ATRP) can be used.

In reversible addition-fragmentation chain transfer polymerization, control of the polymerization is achieved by a reversible chain transfer reaction. In particular, an ever-growing chain of radicals is added to the so-called RAFT agent, resulting in the formation of intermediate radicals. The RAFT agent is then cleaved in a manner to reform another RAFT agent and free radicals available for chain propagation. In this way, the probability of chain growth is evenly distributed across all chains. The average chain length of the polymer formed is directly proportional to the RAFT agent concentration and reaction conversion. The RAFT agent used is especially an organosulphur compound. Particularly suitable are dithioesters, dithiocarbamates, trithiocarbonates and/or xanthates. The polymerization can be initiated in a conventional manner by means of initiators or thermal self-initiation.

In nitroxide mediated polymerization reactions, the nitroxide reacts reversibly with the active chain ends to form so-called dormant species. The equilibrium between the active and inactive chain ends is strongly located to one side of the dormant species, which means that the concentration of the active species is very low. Thus, the chance of two living chains meeting and terminating is minimized. An example of a suitable NMP reagent is material CA number 654636-62-1, which is commercially available under the trade name "Block builder MA".

In Atom Transfer Radical Polymerization (ATRP), the concentration of radicals is reduced to such an extent by the addition of transition metal complexes and control agents (halogen-based) that chain termination reactions (for example disproportionation or recombination) are very markedly suppressed.

In the context of the present application, it has been found that reversible addition-fragmentation chain transfer polymerization (RAFT) is particularly preferred, especially if block copolymers are to be prepared.

The initiator used for polymerization is more preferably an azo compound and/or a peroxide as a radical initiator, which is represented by at least one selected from dibenzoyl peroxide (DBPO), di-t-butyl peroxide, diacetyl peroxide, Azobisisobutyronitrile (AIBN), α' -azobisisobutylamidine dihydrochloride (AAPH) and/or azobisisobutylamidine (AIBA).

If the polymerization is carried out in aqueous solution or water, α' -azobisisobutylamidine dihydrochloride (AAPH) is advantageously used as initiator.

For the controlled polymerization, use is made in particular of one or more representatives selected from among dithioesters, dithiocarbamates, trithiocarbonates and/or xanthates.

It has additionally been found to be advantageous to carry out the polymerization at least partially, preferably completely, in aqueous solution.

In a second method, known as polymer-analogous transformation, a polycarboxylic acid backbone is synthesized in a first step. Subsequently, the side chains are attached to the polycarboxylic acid backbone, for example, by esterification, amidation or etherification reactions with alcohols, amines, etc. Such polymers are described, for example, in WO 97/35814, WO 95/09821, DE 10015135A 1, EP1138697A1, EP 1348729A 1 and WO 2005/090416 for a similar conversion reaction and the comb polymers obtained. Details concerning polymer-analogous transformations are disclosed, for example, on page 7, line 20 to page 8, line 50 of EP 1138697B 1 and examples thereof, or on page 4, line 54 to page 5, line 38 of EP 1061089B 1 and examples thereof.

To form copolymers with block and/or gradient structure, the monomeric units M1 'with pendant poly (alkylene oxide) side chains which are mono-ethylenically unsaturated and the ethylenically unsaturated ionic monomeric units MC' and/or MA 'and/or the ethylenically unsaturated nonionic monomeric units M3' are preferably added at different times, at least in part.

In a further preferred embodiment, in the polymerization, after a portion of the monomer units M1' has been converted or polymerized in the first step a) and a predetermined conversion has been reached, in the second step b) the monomer units M1' (if present) which have not been converted are polymerized together with the ionic monomer units MC ' and/or MA ' and/or the nonionic monomer units M3 '. Step a) is in particular carried out substantially in the absence of ionic monomer units MC ' and/or MA ' and M3 '.

In this way, in a simple and inexpensive manner, it is possible to prepare copolymers having a fraction consisting essentially of polymerized monomer units M1' and a subsequent fraction having a gradient structure.

It is advantageous here to carry out steps a) and b) immediately consecutively. In this way, the polymerization in steps a) and b) can be kept to the best possible extent.

The polymerization in step a) is carried out in particular until from 0.1 to 100 mol%, in particular from 1 to 95 mol%, preferably from 10 to 90 mol%, in particular from 25 to 85 mol%, in particular from 60 to 85 mol%, of the monomer units M1' have been converted or polymerized.

The progress of the conversion or polymerization of the monomers can be monitored in a manner known per se, for example by means of liquid chromatography, in particular High Performance Liquid Chromatography (HPLC).

Another aspect of the invention relates to a kit of parts comprising a comb polymer as described above and a plasticizer for the mineral binder composition. Thus, plasticizers and comb polymers are different from a chemical and/or structural standpoint. The kit of parts may also be present in the form of a pre-mixed composition comprising the comb polymer and the plasticizer for the mineral binder composition.

In the present context, the term "plasticizer" means in particular a substance capable of improving the fluidity of mineral binder compositions (for example mortar and/or cement compositions which have been mixed with water), and/or reducing the water demand of such compositions. Such materials are also known as "superplasticizers".

More particularly, the plasticizer comprises at least one representative selected from the group consisting of: lignosulfonates, gluconates, naphthalenesulfonates, sulfonated naphthalene formaldehyde condensates, melamine sulfonates, vinyl copolymers, sulfonated vinyl copolymers, polycarboxylates, especially polycarboxylate ethers, or mixtures thereof.

More particularly, the plasticizer is a polycarboxylate, especially a polycarboxylate ether. More preferred are comb polymers having a polycarboxylate backbone and polyether side chains, wherein the polyether side chains are bonded to the polycarboxylate backbone via ester, ether, amide and/or imide groups. More particularly, the polycarboxylates have a random, statistical, block, alternating or gradient-like monomer distribution.

More preferably, the superplasticizer is a polymer P having or consisting of the following structural units:

a) a molar parts of a substructure unit S1 of the formula X

b) b molar parts of a substructure unit S2 of the formula XI

c) c molar parts of a substructure unit S3 of the formula (XII)

d) d molar parts of a substructure unit S4 of the formula (XIII)

Wherein

L independently represents H⁺Alkali metal ions, alkaline earth metal ions, divalent or trivalent metal ions, ammonium ions or organic ammonium groups,

each R^uIndependently of one another, is hydrogen or methyl,

each R^vIndependently of one another, hydrogen or COOM,

r is 0,1 or 2,

t is 0 or 1, and t is 0 or 1,

G¹and G²Independently is C₁-to C₂₀-alkyl, -cycloalkyl, -alkylaryl or is- [ A' O]_s-G⁴，

Wherein A ═ C₂-to C₄Alkylene radical, G⁴Is H, C₁-to C₂₀-alkyl, -cycloalkyl or-alkylaryl,

and s is 2-250, and,

G³independently is NH₂、-NG⁵G⁶、-OG⁷NG⁸G⁹，

Wherein G is⁵And G⁶Independently is

C₁-to C₂₀-alkyl, -cycloalkyl, -alkylaryl or-aryl,

or is hydroxyalkyl or is acetoxyethyl (CH)₃-CO-O-CH₂-CH₂-) or hydroxyisopropyl (HO-CH (CH)₃)-CH₂-) or acetoxyisopropyl (CH)₃-CO-O-CH(CH₃)-CH₂-)；

Or G⁵And G⁶Together forming a ring in which the nitrogen is part to construct a morpholine or imidazoline ring, G⁷Is C₂-C₄-an alkylene group,

G⁸and G⁹Each independently represents C₁-to C₂₀-alkyl, -cycloalkyl, -alkylaryl, -aryl or hydroxyalkyl,

and wherein a, b, c and d represent the molar ratio of the individual sub-building blocks S1, S2, S3 and S4, wherein

a/b/c/d＝(0.1-0.9)/(0.1-0.9)/(0-0.8)/(0-0.8)，

In particular a/b/c/d ═ 0.3 to 0.9)/(0.1 to 0.7)/(0 to 0.6)/(0 to 0.4),

preferably, a/b/c/d is (0.5-0.8)/(0.2-0.4)/(0.001-0.005)/0

And with the proviso that a + b + c + d is 1.

The sequence of the sub-building blocks S1, S2, S3 and S4 may be alternating, block or random. One or more of the sub-building blocks S1, S2, S3 and S4 may also form a gradient structure. In principle, further building blocks can also be present in addition to the sub-building blocks S1, S2, S3 and S4. In particular, the order of the sub-structural units S1, S2, S3 and S4 in the polymer P is random or statistical.

Preferably, the sub-building blocks S1, S2, S3 and S4 together have a proportion of at least 50 wt.%, in particular at least 90 wt.%, most preferably at least 95 wt.%, of the total weight of the polymer P.

In the polymer P, R^vIn particular hydrogen and R^uHydrogen and/or methyl are preferred.

Preferably, in the polymer P, r-0 and t-1. Also advantageously, r-1-2 and t-0.

More particularly, in the polymer P, R^vIs hydrogen, R^uIs methyl, r-1-2 and t-0.

In polymer P, G¹And/or G²In each case independently advantageously- [ A' O ]]_s-G⁴Wherein s is 8-200, especially 20-70, and A' is C₂-to C₄-an alkylene group.

In the polymer P, G⁴Independently in each case preferably hydrogen or methyl.

In particular, the ratio a/b in the polymer P is greater than the ratio of monomer units MC/M1 and/or the ratio MA/M1 in a comb polymer as described above. In particular, the ratio a/b in the polymer P is from 1 to 10, in particular from 1.5 to 5, especially from 2 to 4.

Very particularly advantageous polymers P are those in which

a)R^uAnd R^vThe radical is hydrogen,

b)r＝0，

c)t＝1，

d)G¹and G²Independently at each occurrence- [ A' O]_s-G⁴Wherein s is 20-70 and

A'＝C₂-an alkylene group,

e)G⁴represents methyl and/or

f)a/b/c/d＝(0.5-0.8)/(0.2-0.4)/(0.001-0.005)/0

Also advantageous polymers P are those in which

a) t-0 and r-1-2,

b)G¹independently at each occurrence- [ A' O]_s-G⁴Where s is 8 to 200, especially 20 to 70,

c)G⁴represents hydrogen or methyl, especially hydrogen, and/or

d) A' is C₂-to C₄Alkylene, especially C₂-an alkylene group.

Weight average molecular weight (M) of Polymer P_W) In particular 5'000-150'000g/mol, preferably 10'000-100'000g/mol, in particular 20'000 to 90'000 g/mol. Weight average moleculeQuantity (M)_W) As determined by Gel Permeation Chromatography (GPC) using polyethylene glycol (PEG) as a standard.

The preparation of the polymers P is known per se to the person skilled in the art. The corresponding superplasticizers or polymers P may also be prepared from Sika Schweiz AGTrade name series.

Other aspects of the invention are compositions comprising the comb polymer described above and further comprising a mineral binder, aggregate, plasticizer and/or expandable clay. Thus, the comb polymer may be present in the form of a premix with at least one of these components, or the comb polymer is present in a mineral binder composition mixed with water.

In particular, the composition comprises a comb polymer as described above, a mineral binder, an aggregate and an expandable clay. In particular, a plasticizer is also present. In particular, swellable clays are clays that are part of the 2:1 clay family.

Furthermore, the invention relates to a method comprising the following steps: to a composition comprising an expandable clay, in particular a mineral binder composition comprising an expandable clay, are added:

(i) a comb polymer as described above, and

(ii) a plasticizer as described above.

Preferably, the comb polymer is added before the plasticizer is added. However, it is also possible, for example, to add the comb polymer and the plasticizer simultaneously. In particular, swellable clays are clays that are part of the 2:1 clay family.

Another aspect of the invention relates to the use of a comb polymer as described above as a clay inerting agent and/or for reducing or inhibiting the adverse effect of swellable clay on the action of dispersants, in particular PCE-based dispersants, in mineral binder compositions comprising swellable clay. Thus, comb polymers, for example, may be used to increase the flowability and/or processing time of mineral binder compositions comprising swellable clay and a dispersant, particularly a PCE-based dispersant. In particular, swellable clays are clays that are part of the 2:1 clay family.

Further advantageous embodiments and combinations of features of the invention will emerge from the following exemplary embodiments and from the complete patent claims.

Exemplary embodiments

1.Preparation examples of comb polymers

1.1Comb polymer P1 (non-ionic homopolymer)

To prepare a nonionic homopolymer by controlled radical polymerization, a round-bottomed flask equipped with a reflux condenser, stirrer system, thermometer and gas inlet tube was initially charged with 57.4g of 50% methoxypolyethylene glycol₁₀₀₀Methacrylate (0.027 mol; average molecular weight: 1000 g/mol; 20 ethyleneoxy units per molecule) and 18 g deionized water. The reaction mixture was heated to 80 ℃ with vigorous stirring. The moderated inert N is allowed to react over the entire reaction time₂The gas stream passes through the solution. 378mg of 4-cyano-4- (thiobenzoylthio) pentanoic acid (1.35mmol) are then added to the mixture. Once the material was completely dissolved, 67mg of AIBN (0.41mmol) was added. Since then, the conversion was checked periodically by HPLC.

The reaction was stopped when the conversion based on methoxypolyethylene glycol methacrylate reached 90%. A clear reddish aqueous solution having a solids content of about 40% by weight was obtained, which was diluted with water to obtain a solids content of about 30% by weight.

The comb polymer thus obtained is a homopolymer comprising monomer units with about 20 side chains and is referred to as comb polymer P1.

1.2Comb polymer P2 (non-ionic homopolymer)

To prepare a nonionic homopolymer by conventional free radical polymerization, a round bottom flask equipped with a reflux condenser, stirrer system, thermometer and gas inlet tube was initially charged with 186g of deionized water. 796 g of 50% methoxypolyethylene glycol are added over 180 minutes at 100 deg.C₁₀₀₀Methacrylate (0.37mol, average molecular weight: 1000 g/mol; per molecule20 ethylene oxide units). A solution of 4.5g of sodium hypophosphite and 6.7g of water was also added over 175 minutes, and a solution of 0.93g of sodium persulfate and 5.0g of water was added over 190 minutes. Once all the solution was added, the reaction mixture was cooled. A clear colorless solution having a solids content of about 40 wt.% was obtained, which was diluted with water to obtain a solids content of about 30 wt.%.

This polymer is referred to as comb polymer P2.

1.3Comb polymer P3 (cationic block copolymer)

To prepare a cationic copolymer by controlled radical polymerization, a round-bottomed flask equipped with a reflux condenser, stirrer system, thermometer and gas inlet tube was initially charged with 57.4g of 50% methoxypolyethylene glycol₁₀₀₀Methacrylate (0.027 mol; average molecular weight: 1000 g/mol; 20 ethyleneoxy units per molecule) and 28.3 g deionized water. The reaction mixture was heated to 80 ℃ with vigorous stirring. The moderate inert N is made to react over the whole reaction time₂The gas stream passes through the solution. 378mg of 4-cyano-4- (thiobenzoylthio) pentanoic acid (1.35mmol) are subsequently added to the mixture. Once the material was completely dissolved, 67mg of AIBN (0.41mmol) was added. Since then, the conversion was checked periodically by HPLC.

When 80% conversion based on methoxypolyethylene glycol methacrylate was reached, 14.81g of [2- (methacryloyloxy) ethyl ] trimethylammonium chloride (0.054mol) were added. The mixture was allowed to react for an additional 2 hours and then cooled. A clear reddish aqueous solution having a solids content of about 40% by weight was obtained, which was diluted with water to give a solids content of about 30% by weight.

The comb polymer thus obtained is a block copolymer comprising a first block having monomer units with about 20 side chains and a second block having monomer units with about 40 cations. This polymer is referred to as comb polymer P3.

1.4Other comb polymers

Other comb polymers were prepared in a similar manner. Thus, the polymer chains were prepared with a polymer having different chain lengths (average molecular weight 500g/mol, 2000g/mol,3000g/mol and 5000g/mol) of methoxypolyethylene glycol methacrylate instead of methoxypolyethylene glycol₁₀₀₀Methacrylate and/or 2- (methacryloyloxy) ethyl]Trimethyl ammonium chloride (cationic monomer unit) is replaced with methacrylic acid (anionic monomer unit).

The next chapter outlines the comb polymers prepared and their properties.

1.5Overview of comb polymers

TABLE 1 comb polymers

Numbering	Weight of MPEG-MA	Ionic monomer	Ratio of
				P1	1'000g/mol	Is free of	0
P2*	1'000g/mol	Is free of	0
				P3	1'000g/mol	C	2
P4	2'000g/mol	Is free of	0
				P5	1'000g/mol	C	0.2
P6	2'000g/mol	C	0.2
				P7	500g/mol	Is free of	0
V1	Is free of	C	-

MPEG-MA ═ methoxy polyethylene glycol methacrylate

C ═ 2- (methacryloyloxy) ethyl trimethyl ammonium chloride

Ratio of number of ionic monomers/number of MPEG-MA monomers

Prepared by conventional free radical polymerization

2.Mineral binder composition

2.1Mortar composition

The mortar mixture used for test purposes had a dry composition described in table 2:

table 2: dry composition of mortar mixture

To prepare the mortar mixture, sand, limestone filler, cement and bentonite (if added) were dry mixed in a Hobart mixer for 1 minute. Within 30 seconds, mix water (water to cement ratio w/c 0.49) was added and the mixture was mixed for an additional 2.5 minutes. The total wet mixing time was 3 minutes in each case.

Before adding the mortar composition, the respective comb polymer (clay sealer) and plasticizer (C)Available from Sika, Schweiz) was mixed into the mix water (see results section for ratios).3082 are standard polycarboxylate ether based superplasticizers corresponding to the polymer P as described above.

These mortar compositions are referred to as MC.

2.2Cement paste

The cement paste used for testing purposes was based on 100g of cement (CEM I42.5N; Normo 4; available from Holcim Schweiz), 5g of limestone filler with a particle size of less than 0.125mm, bentonite (for proportions, see results section) and water.

To prepare the cement paste, the cement/filler/bentonite mixture is added to a beaker and to another beaker is added a mixture in which the respective comb polymer (clay sealer) and plasticizer(s) (clay sealer) have been previously mixed3082; available from Sika, Schweiz). The cement/filler/bentonite mixture is then carefully poured into a beaker containing water and the wet mixture is pouredMix with propeller IKA stirrer at 1000rpm for 1 minute. For reference, the water to cement ratio of the cement/filler paste comprising the PCE was adjusted to a flow value of 10-12 cm.

These slurries are called CPs.

3.Test program

To determine the effectiveness of the clay-capped comb polymer in mortar mixtures, the plasticizer dispersion effect was determined by measuring the flow bench spread (ABM) of a series of mortar mixtures, which was determined according to EN1015-3 at different times.

The effectiveness of clay-blocking comb polymers in cement pastes was similarly determined. However, in this case, a small slump cone on a dry glass plate was used instead of the standard equipment defined in EN 1015-3.

Tests were carried out on prisms (40X 160mm) to determine the compressive strength (MPa) according to standards EN12390-1 to 12390-4.

In addition, after mixing, the temperature profile of the mineral binder composition (mortar mixture, cement paste) was recorded separately as a control of the hydration and curing behaviour. From this, the time to start reaching the overall maximum temperature was determined as a measure of the curing time.

Air content was determined according to EN 12350-7.

In the tests, all additives (clay blocking agents, plasticizers) were added in the form of aqueous solutions or dispersions with an active ingredient content of 30% by weight. The bentonite is added as a powder.

4.Results

Table 3 summarizes the first tests performed and the results obtained. Experiments R1 to R5 are experiments performed for comparative purposes without the addition of a comb polymer according to the present invention.

Table 3 (all wt% given relative to cement content in mineral binder composition)

B1＝Mas terSuna SBS 3890(BASF)

B2 ═ Floerger Floquat FL 2250(SNF sas, france)

The flow bench spread according to EN 1015-3. The time "0 minutes" corresponds to the first measurement carried out immediately after mixing of the mortar sample.

The data in table 3 clearly show that the comb polymer of the present invention is a highly effective clay blocking agent, which is at least as effective as known clay blocking agents. In addition, the use of the comb polymer of the present invention makes it possible to maintain the clay-capping activity at a relatively high level for a long period of time. Particularly advantageous are comb polymers P1 and P3, i.e.homopolymers with pendant monomers or block copolymers with pendant monomers having cationic monomers. Therefore, the comb polymer P3 having cationic monomer units is most effective.

Table 4 shows the results of a second set of experiments using comb polymers with different side chain lengths.

Table 4 (all wt% given relative to cement content in mineral binder composition)

The flow bench spread according to EN 1015-3. The time "0 minutes" corresponds to the first measurement carried out immediately after preparation of the mortar sample.

From the results given in Table 4, it can be concluded that comb polymers having side chain lengths of at least 1000g/mol or more are most effective when compared to comb polymers having different chain lengths.

Table 5 shows the results of a third set of experiments in which comb polymers were compared to a single MPEG side chain molecule.

Table 5 (all wt% given relative to cement content in mineral binder composition)

B3 ═ methoxypolyethylene glycol₁₀₀₀(average molecular weight: 1'000g/mol)

B4 ═ methoxypolyethylene glycol₃₀₀₀(average molecular weight: 3'000g/mol)

B5 ═ methoxypolyethylene glycol₅₀₀₀(average molecular weight: 5'000g/mol)

The flow bench spread according to EN 1015-3. The time "0 minutes" corresponds to the first measurement carried out immediately after preparation of the mortar sample.

As is apparent from table 5, a single MPEG side chain is less effective when compared to the comb polymer P1 of the present invention.

Table 6 shows the results of a fourth set of experiments in which the dispersing effect of the clay-capped comb polymer of the present invention was compared to the standard PCE in a cement paste without swelling clay.

Table 6 (all wt% given relative to cement content in mineral binder composition)

Using a small slump cone flow bench spread according to EN1015-3 (see above). The time "0 minutes" corresponds to the first measurement carried out immediately after mixing of the mortar sample.

Thus, the clay-capped comb polymers according to the invention do not have a significant plasticizing effect. Similar results were also obtained in mortar composition MC.

Table 7 shows the results of a fifth set of experiments whereby different clay blocking agents have been tested in mortar compositions having different clay contents. Thus, all experiments VC1-VC14 used a mortar mixture MC, a water to cement ratio (w/c) of 0.44, 0.5 wt% plasticizer (C) 3082) And (if added) 0.25 wt% of a clay blocking agent as described in the second column of table 7. In experiments VC13-VC14, the plasticizer was omitted, so that the water reducing capacity of P1 could only be directly compared with B1 in the absence of clay.

Table 7 (all wt% given relative to cement content in mineral binder composition)

B1＝MasterSuna SBS 3890(BASF)

The flow bench spread according to EN 1015-3. The time "0 minutes" corresponds to the first measurement immediately after preparation of the mortar sample.

Relative increase in FTS for a given viscosity of the blocking agent relative to FTS using 1 wt% bentonite

Contains no plasticizer

The data presented in table 7 show that the comb polymers of the present invention are very stable and durable, i.e. have a rather low sensitivity to changes in the content of swelling clay. Specifically, when the comb polymer P1 of the present invention was used as a clay blocking agent, the FTS increased only 11.6% when the clay content was reduced from 1 wt% to 0 wt%. For all other tested clay blocking agents B1, the increase in FTS was > 30% and therefore much higher in this expanded clay content range. The significantly greater increase in B1 (experiment VC14) compared to the comb polymer P1 of the present invention (experiment VC13) can be explained by the significantly greater plasticization of B1 itself (experiment VC 14).

Table 8 compares the effectiveness of comb polymer P1 of the invention prepared by controlled free radical polymerization and comb polymer P2 of the invention prepared by conventional free radical polymerization.

Table 8 (all wt% given relative to cement content in mineral binder composition)

The flow bench spread according to EN 1015-3. The time "0 minutes" corresponds to the first measurement immediately after preparation of the mortar sample.

It is apparent that the polymers P1 and P2 of the present invention having a similar side chain length of 1'000g/mol exhibit a similar clay-blocking effect, although they are produced by different polymerization processes.

It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive.