EP1948573A2 - Comb polymers and their use as additives for preparations of mineral binders - Google Patents

Abstract

The invention relates to novel comb polymers supporting, on a carbon backbone, poly-C2-C4-alkylene ether side chains A and functional groups B, which exist in the form of anionic groups at a pH > 12, and to the salts of comb polymers of this type. The invention also relates to the use of these comb polymers as additives in preparations containing a mineral binder. The polyalkylene ether side chains A have the following formula *-U-(C(O))k-X-(Alk-O)n-Y-Z A, wherein: * represents the binding site to the carbon backbone of the comb polymer; U represents a chemical bond or an alkylene group with 1 to 8 C atoms; X represents oxygen or a group NR; k represents 0 or 1; n represents an integer whose mean value, with regard to the comb polymer, ranges from 5 to 300; Alk represents C2-C4 alkylene, Alk being able to be the same or different within the group (Alk-O)n; Y represents a linear or branched alkylene group with 2 to 8 C atoms, which can support a phenyl ring; Z represents a 5- to 10-membered nitrogen heterocyclic compound that, as ring members, can comprises, in addition to the nitrogen atom and the carbon atoms, 1, 2 or 3 additional heteroatoms selected among oxygen, nitrogen and sulfur, the nitrogen ring members being able to contain a group R', and 1 or 2 carbon ring members can exist in the form of a carbonyl group; R represents hydrogen, C1-C4 alkyl or Benzyl, and; R' represents hydrogen, C1-C4 alkyl or Benzyl.

Description

Comb polymers and their use as additives for preparations of mineral binders

description

The present invention relates to novel comb polymers which carry on a carbon backbone poly-C ₂ -C ₄ -alkylene ether side chains A and functional groups B, which are present at pH> 12 in the form of anionic groups, and the salts of such comb polymers , The invention also relates to the use of these comb polymers as additives in preparations of mineral binders.

Comb polymers having a carbon backbone bearing poly-C ₂ -C ₄ -alkylene ether side chains and anionic groups, in particular carboxylate groups, are found as additives for mineral binders and binders, in particular for cement and cementitious binders such as mortars, cementitious plasters and in particular for concrete, but also for gypsum and gypsum-based binding materials such as model, stucco or plaster, plaster, gypsum, etc. Use.

It is believed that the comb polymers contain the mineral binder particles in the ready-to-use formulation of the binder, i. H. a water-based preparation, dispersing and that the dispersing effect of the comb polymers causes a liquefaction of the ready-to-use preparations. Thus, to set a specific processing viscosity of the ready-to-use preparation during mixing, less water, based on the mineral binder, is required than in the case of a non-additized preparation, which results in an increased final strength of the additized preparation in the set condition. Conversely, additivierte preparations for the same amount of water, based on the mineral binder, a reduced viscosity than non-additive preparations, which is desirable for many applications such as cast concrete or screed.

The EP-A 331 308 describes comb polymers for the dispersion of cement, which sulfonic acid, a monoethylenically unsaturated carboxylic acid, a monoethylenically unsaturated sulfonic and an ester containing a poly-C ₂ -C ₃ alkylene glycol mono Ci-C ₃ alkylether lymerisiert Single-pole.

EP-A 560 602 in turn describes the use of comb polymers which comprise an alkenyl ether of a poly-C ₂ -C 8 -alkylene glycol mono-C ₁ -C ₄ -alkyl ether and maleic acid or maleic anhydride in copolymerized form as additives for concrete. From EP-A 753 488, in turn, is the use of comb polymers which are monoethylenically unsaturated carboxylic acids and esters of monoethylenically unsaturated carboxylic acids of polyoxy-C ₂ -C ₄ -alkylenmono-Ci-C ₄ -alkyl as copolymerized units and having a specific molecular weight distribution than Dispersants for cement known. Similar polymers are described for this purpose in EP-A 792 850.

EP-A 725 044, in turn, describes the use of comb polymers of monoethylenically unsaturated monocarboxylic acids and esters of monoethylenically unsaturated carboxylic acids with polyoxyethylene mono-C 1 -C ₅ -alkyl ethers in hydraulically setting compositions based on a mixture of cement and anhydrous gypsum.

EP-A 799 807 in turn describes the use of comb polymers based on monoethylenically unsaturated monocarboxylic acids and alkylpolyalkylene glycol mono (meth) acrylic acid esters, the latter being obtainable by a transesterification process, as dispersants for cement.

US 5,728,207 and US 5,840,114 describe the use of comb polymers obtained by polymer modification of polymers having cyclic anhydride groups with alkylpolyalkylene ether amines as additives for cementitious compositions.

WO 98/28353 discloses comb polymers having a carbon backbone bearing alkyl polyalkylene ether groups and carboxylate groups. The comb polymers can be prepared both by modifying polymers containing carboxylate groups with polyalkylene ethers and by copolymerizing suitable alkylpolyalkylene ether group-containing monomers with ethylenically unsaturated carboxylic acids.

WO 01/74736 in turn describes comb polymers of poly-C ₂ -C ₄ -alkylene glycol (meth) acrylates with (meth) acrylic acid, wherein the preparation of the poly-C ₂ -C ₄ - alkylene glycol (meth) acrylic esters by reacting Alkylpolyalkylenglykolen with (meth) acrylic anhydrides in the presence of amines.

The earlier patent application PCT / EP009466 describes comb polymers similar to those of WO 01/74736, wherein the poly-C ₂ -C ₄ -alkylene glycol (meth) acrylates used for the preparation of the polymers by reacting alkylpolyalkylene glycols with (meth) acrylic anhydrides in the presence of a reaction medium insoluble base are available. No. 3,651,029 describes the use of oil-soluble comb polymers with polyalkylene ether side chains which carry a morpholin-4-yl radical at their ends as additives for lubricants.

EP-A 704 504 describes homo- and copolymers of esters of ethylenically unsaturated carboxylic acids with polyalkylene etherols which carry a nitrogen heterocycle at one end. The polymers described there are used as temperature-dependent thickeners in ink-jet inks.

The dispersing effect of the comb polymers of the prior art is often insufficient, so that their liquefying action in preparations based on mineral binders such as gypsum or cement is not satisfactory. Our own investigations by the inventors of the present application have also shown that the comb polymers prepared according to the prior art frequently contain even greater amounts of unreacted polyalkylene glycol monomethyl ethers which themselves do not have a liquefying effect, so that larger amounts of comb polymer are needed to achieve the desired effect , which on the one hand represents an additional cost factor and on the other hand is also undesirable in view of a thereby increased foaming.

The present invention is therefore based on the object to provide additives for preparations based on mineral binders, which show a good liquefying effect in such preparations. The additives should also be preparable in a way that they contain little or no amounts of by-products.

It has surprisingly been found that this object is achieved by comb polymers having a carbon backbone which carry on the polymer backbone polyether groups of the formula A defined below and functional groups B which are present at pH> 12 in the form of anionic groups.

Accordingly, the present invention relates to the use of comb polymers having a carbon backbone, the polyether groups of the formula A.

^* -U- (C (O)) _k -X- (Alk-O) _n -YZ A

wherein

^* indicates the binding site to the carbon backbone of the comb polymer, U represents a chemical bond or an alkylene group of 1 to 8 carbon atoms, X represents oxygen or a group NR, k is 0 or 1, n is an integer whose mean value, based on the comb polymer, is in the range from 5 to 300,

Alk is C ₂ -C ₄ -alkylene, where Alk within the group (AIk-O) _{n may be} identical or different,

Y is a linear or branched alkylene group having 2 to 8 C atoms, which may carry a phenyl ring,

Z is a nitrogen-bonded 5- to 10-membered nitrogen heterocycle which, as ring members, besides the nitrogen atom and besides carbon atoms, 1, 2 or 3 can have additional heteroatoms selected from oxygen, nitrogen and sulfur, the nitrogen ring members having a Group R ', and where 1 or 2 carbon ring members may be present as the carbonyl group,

R is hydrogen, dC ₄ alkyl or benzyl, and R 'is hydrogen, C _r C ₄ alkyl or benzyl;

and functional groups B which are present in the form of anionic groups at pH> 12,

and their salts as additives in preparations containing a mineral binder. The invention also relates to preparations of mineral binders containing such a comb polymer, in particular ready-to-use preparations and the articles produced therefrom.

Such comb polymers are new when the mean of n, based on the

Comb polymer, is in the range of 11 to 300 and on average 90 mol% of units AIk-O in the group (AIk-O) _{n are} CH ₂ -CH ₂ -O.

Accordingly, the present invention also relates to comb polymers having a carbon-fabric backbone carrying polyether groups of the general formula A and functional groups B which are present at pH> 12 in the form of anionic groups, wherein in the formula A the variables ^* , U, X , k, Alk, Y, Z, R and R 'have the abovementioned meanings and n is an integer whose mean value, based on the comb polymer, is in the range from 1 to 300 and in which at least 90 mol% of the units AIk-O in the group (AIk-O) _{n are} CH ₂ -CH ₂ -O.

According to the comb polymers are used to additize preparations containing mineral binders. With the comb polymers used according to the invention, liquefaction of the preparations can be achieved in a particularly effective manner, ie, for the adjustment of the desired Processing viscosity required amount of mixing water, based on the mineral binder, compared to non-additive preparations or compared to additiverten preparations of mineral binders in which the additives have a lower liquefying effect can be reduced or, alternatively, for setting a The application rate of comb polymer required for the specific viscosity of the preparation is lower in comparison with the comb polymers of the prior art.

Mineral binders for the purposes of the present invention are inorganic, usually mineral substances which, when mixed with water, harden to a solid. Here, a distinction is made among substances which harden in the air (non-hydraulic binders or air binders), for. Gypsum, corrosive cement, magnesia binder and white lime, as well as hydraulic binders such as lime and especially cement, including latent hydraulic binders such as blast furnace slags. The term "gypsum" as used herein includes both anhydrite and calcium sulfate hemihydrate.

The comb polymers of the invention are particularly suitable for the addition of formulations of hydraulic binders and especially for the addition of cementitious preparations, but also for the addition of preparations of latent hydraulic binder.

The comb polymers according to the invention are furthermore suitable for the addition of preparations of non-hydraulic binders, in particular for the addition of gypsum and gypsum-containing preparations, such as model stucco or plaster, gypsum plaster, gypsum plaster.

The comb polymers according to the invention are also particularly suitable for the addition of preparations which, as a mineral binder, a mixture of a hydraulic and a non-hydraulic binder, for. As a mixture of gypsum and cement.

The comb polymers can be used both to additize preparations that consist essentially of the mineral binder. However, they are particularly suitable for the addition of binders, ie preparations containing as main ingredient additives that are bound by the mineral binder, for example, for the addition of concrete and mortar. The preparations of the mineral binder which are additively formulated according to the invention may be storage forms of the mineral binder, storage forms of the binding material, or ready-to-use preparations, ie preparations which, in contrast to the storage forms, already require the binding agent or building material to be set Amount of water (mixing water) included.

Here and below, C ₂ -C ₄ -alkylene is a linear or branched alkanediyl group which has 2 to 4 C atoms, in particular for a 1, 2-ethanediyl group which carry one or two methyl groups or one ethyl group can, ie for 1, 2-ethanediyl, 1, 2-propanediyl, 1, 2-butanediyl, 1, 1-dimethylethane-1, 2-diyl or 1, 2-dimethylethane-1, 2-diyl.

C 1 -C 6 -alkylene represents a linear or branched alkanediyl group which has 1 to 8 and in particular 1 to 4 C atoms, eg. B. for CH ₂ , 1, 1-ethanediyl, 1, 2-ethanediyl, 1, 1-propanediyl, 1, 3-propanediyl, 2,2-propanediyl, 1, 2-propanediyl, 1, 1-butanediyl,

1, 2-butanediyl, 1, 3-butanediyl, 1, 4-butanediyl, 2,2-butanediyl, 1, 1-dimethylethane-1, 2-diyl or 1, 2-dimethylethane-1, 2-diyl.

C 1 -C ₄ -alkyl represents a linear or branched alkyl group which has 1 to 4 carbon atoms, eg. For example, methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl,

2-methylpropan-1-yl or tert-butyl. C 1 -C 10 -alkyl is a linear or branched alkyl group having 1 to 10 carbon atoms, e.g. B. for dC ₄ alkyl, as mentioned above, and for pentyl, hexyl, 1-methylpentyl, 2-methylpentyl, heptyl, octyl, 1-methylheptyl, 2-methylheptyl, 2,4,4-trimethylpentan-2-yl, 2-ethylhexyl, 1-ethylhexyl, nonyl, isononyl, decyl, 1-methylnonyl, 2-propylheptyl and the like.

Ci-C ₄ alkoxy represents a linear or branched alkyl group which is bonded via an oxygen atom and which has 1 to 4 carbon atoms, for. For example, methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, 2-butyloxy, 2-methylpropan-1-ylxoy or tert-butoxy. C 1 -C 10 alkoxy represents a linear or branched alkyl group which is bonded via an oxygen atom and which has 1 to 10 C atoms, eg. B. for C 1 -C ₄ -alkoxy, as mentioned above, and for pentyloxy, hexyloxy, 1-methylpentyloxy, 2-methylpentylxoy, heptyloxy, octyloxy, 1-methylheptyloxy, 2-methylheptylxoy, 2,4,4-trimethylpentan-2 yloxy, 2-ethylhexyloxy, 1-ethylhexyloxy, nonyloxy, isononyloxy, decyloxy, 1-methylnonyloxy, 2-propylheptyloxy and the like.

With regard to the use according to the invention, it has proven to be advantageous if the average number of repeating units AIk-O in the groups (AIk-O) _n , ie the mean value of n in formula A, based on the comb polymer, at least 10, in particular is at least 20 and especially at least 50 and has a value of 250, in particular 200 and especially does not exceed 150. Preferably, the value is in the range of 10 to 250, in particular in the range of 20 to 200 and especially in the range of 50 to 150. The mean value of n or the average number of repeating units AIk-O is the number average, based on the comb polymer.

In the group (AIk-O) _n , the alkylene moieties of the individual repeat units AIk-O may be the same or different. Particularly preferred AIk-O is 1, 2-ethanediyl or mixtures of 1, 2-ethanediyl with 1, 2-propanediyl. If the groups (AIk-O) have _n different units AIk-O from one another, they may be arranged randomly or in blocks, wherein a block-wise arrangement is preferred. In particular, that group AIk-O attached to X is a group of the formula CH ₂ CH ₂ O.

Furthermore, it has proved to be advantageous if at least 50 mol%, in particular at least 80 mol%, particularly preferably 90 mol% and in particular all groups AIk-O are CH ₂ -CH ₂ -O. These% data are the number average, based on the total amount of comb polymer.

If the group (AIk-O) _{n has} different repeating units AIk-O, it has proved to be advantageous if on average at least 50 mol%, z. B. 50 to 99 ιmol-%, in particular at least 80 ιmol-%, z. B. 80 to 99 ιmol-%, and especially at least 90 ιmol-%, z. B. 90 to 98 mol% of the groups AIk-O are CH ₂ -CH ₂ -O. Of these, preference is given to those mixtures in which the remaining repeating units AIk-O are CH (CH ₃ ) -CH ₂ -O.

The group Z in formula A is preferably a 5- or 6-membered nitrogen heterocycle which, in addition to the nitrogen atom bonded to Y and the carbon ring members a selected from O, S, N, a group NR ring member and / or a carbonyl group as Ring member has. In the group NR, R has the abovementioned meanings and is in particular hydrogen or methyl. Of these, preference is given to those heterocycles which have a ring member selected from O, N or a group NR and / or a carbonyl group as ring member. Examples of preferred Z radicals are pyrrolidon-1-yl, morpholin-4-yl, piperazin-1-yl, piperidone-1-yl, morpholin-2-on-4-yl, morpholin-3-on-4-yl, Piperazin-1-yl, 4-methylpiperazin-1-yl, imidazolin-2-one-1-yl, 3-methylimidazolin-2-one-1-yl and imidazol-1-yl. Of these, in particular morpholin-4-yl and pyrrolidone-1-yl are preferred.

Furthermore, it has proved to be advantageous if Y in formula A is C ₂ -C ₄ -alkylene and in particular 1, 2-ethanediyl or 1, 3-propanediyl. U is preferably a chemical bond, CH ₂ or CH (CH ₃ ). In a particularly preferred embodiment, U is a chemical bond.

In particular, k stands for 1.

In formula A, X is preferably O or NH and in particular O.

In particular, in formula A, the variables U, k, X, Y and Z and the variable n together have the meanings mentioned as preferred.

The groups B present in the comb polymers used according to the invention are typically present at pH values above 12 in the form of anionic groups, ie in deprotonated form. Examples of such groups are carboxylate (COOH or COO ^" ), sulfonate (SO ₃ H or SO ₃ ^" ), phosphonate (PO ₃ H ₂ or PO ₃ H ^" or PO ₃ ^2" ). Preferably at least 50 mol%, in particular at least 80 mol% of the groups B are carboxylate groups.

In a preferred embodiment of the invention, group B is substantially (i.e., at least 95 mole%, especially at least 99 mole%) or exclusively carboxylate groups. In another embodiment of the invention, the comb polymers have at least two different functional groups B, wherein in this embodiment preferably 50 to 99 mol%, in particular 80 to 99 mol% of the functional groups B carboxylate groups and the remaining 1 to 50 ιmol-% , In particular 1 to 20 mol%, sulfonate groups.

The functional groups B can be bonded directly or via a spacer to the carbon backbone of the polymer chain. Typical spacers are C 1 -C ₄ -alkanediyl, phenylene and groups of the formula ^* -C (O) -X'-Alk ',

in which X 'is O, NH or N (C _r C ₄ alkyl), Alk' is C ₂ -C ₄ alkylene, in particular 1, 2-ethanediyl, 1, 3-propanediyl, 1, 2-propanediyl or 1-methyl-1, 2-propanediyl and ^{* represents} the binding site of the spacer to the polymer backbone. In a preferred embodiment of the invention, the group B is bonded directly, ie via a single bond, to the carbon backbone of the comb polymer.

Furthermore, in addition to the abovementioned groups of the formula A and the functional groups B, the comb polymer can also be groups of the formula C ^* -U '- (C (O)) pX "- (Alk" -O) _q -R ^a C

wherein

U 'has the meanings given for U, p is O or 1, X "has the meanings given for X, Alk" has the meanings given above for alk, q is an integer whose mean value, based on the Comb polymer in the range from 2 to 300, in particular in the range from 10 to 250, more preferably in the range from 20 to 200 and especially in the range from 50 to 150 (number average) and R ^{a is} selected from hydrogen, C 1 -C 10 -alkyl, d- Cio-alkylcarbonyl, benzyl or benzoyl. In formula C, p is in particular 1. U 'is in particular a chemical bond. X "stands for oxygen in particular. R ^a stands in particular for C 1 -C ₄ -alkyl and especially for methyl. With regard to the preferred meanings of Alk", the statements made above for alk apply analogously.

In principle, the polyether groups A and also the polyether groups C within the comb polymer may be identical or different with respect to the number of repeating units n or q in the groups (AIk-O) _n or (Alk "-O) _q , that the groups A and C or the groups (AIk-O) _n or (Alk "-O) _{q have} a molecular weight distribution and accordingly represent n and q means (number average) of these molecular weight distributions. The term

"equal" therefore means that the molecular weight distribution of the groups A and C each have a maximum. Accordingly, the term "different" means that the molecular weight distribution of the groups A and C corresponds to several superimposed distributions and accordingly have several maxima. Comb polymers in which the molecular weight distributions of the groups A or, if present, the molecular weight distributions of the groups A are different from those of the groups C are preferred. In particular, those comb polymers are preferred in which the number average molecular weight to be assigned in each case to one another deviates from one another by at least 130 daltons and in particular at least 440 daltons. Accordingly, comb polymers are preferred which contain at least two, e.g. B. 2, 3, 4, 5 or 6 types of different groups A have (hereinafter groups A1 and A2 or A1, A2 ... Ai; i an integer, eg 3, 4, 5 or 6) in which the respective average values n (A1) and n (A2) or n (Ai) differ by a value of at least 3 and in particular by at least 10. Accordingly, comb polymers having groups of the formula A and of the formula C are preferred in which the mean values of n and q differ by a value of at least 3 and in particular by at least 10.

In the comb polymers used according to the invention, the polyether groups of the formula A and the functional groups B are typically in one Molar ratio A: B in the range from 2: 1 to 1:20, often in the range of 1, 5: 1 to 1:15, in particular in the range of 1: 1 to 1:10 and especially in the range of 1: 1, 1 to 1: 8 before (averaged over the total amount of comb polymers). If the comb polymer has polyether groups of the formula C, the molar ratio of polyether groups of the formula A and C to the functional groups B, ie the molar ratio (A + C): B is typically in the range from 2: 1 to 1:20, often in the range from 1, 5: 1 to 1:15, in particular in the range of 1: 1 to 1:10 and especially in the range of 1: 1, 1 to 1: 8 (averaged over the total amount of comb polymers)

In addition to the abovementioned groups of the formula A, the functional groups B and the optionally present groups C, the comb polymer may to a lesser extent also carry functional groups C on the carbon backbone. These include in particular C-i-Cβ-alkoxycarbonyl groups in which the alkoxy radical can carry one or more hydroxyl groups, nitrile groups and groups of the formula Z as defined above.

The proportion of the functional groups C will, based on the total amount of the functional groups A, B, optionally C and C, preferably not exceed 30 .mu.m%, in particular 20 mol% and, if present, is typically in the range of 1 to 30 mol% and especially in the range of 2 to 20 mol%. In a preferred embodiment, the comb polymer has no or less than 2 mol%, in particular less than 1 mol% of functional groups C.

In a preferred embodiment, the comb polymer has 5 to 80 mol%, in particular 10 to 60 mol%, in each case based on the total amount of the functional groups A, B, C and optionally C groups of the formula C. In this embodiment, the molar ratio of the side chains A to the groups C, d. H. the molar ratio A: C is preferably in the range from 1:10 to 20: 1, in particular in the range from 1: 2 to 10: 1. In another preferred embodiment of the invention, the comb polymer has no or less than 5 .mu.mol%, in particular less than 1 mol%, of groups of the formula C, in each case based on the total amount of the groups A, B, C and C.

In addition, the comb polymer may also have hydrocarbon residues on the carbon backbone, eg. B. dC ₄ alkyl groups or phenyl groups. In a preferred embodiment of the invention, the carbon backbone has dC ₄ -alkyl groups, in particular methyl groups, on at least every 4 C atom of the polymer chain.

Furthermore, it has proved to be advantageous if on average (number average) at least every 4th carbon atom of the polymer backbone and in particular at least every 3rd carbon atom a group of the formulas A or optionally C or a functional group B. Furthermore, it has proven to be advantageous if at least one carbon atom is arranged atomically (number average) between two by A, B or optionally C-substituted carbon atoms of the polymer backbone, which is not substituted by a group A, B or optionally C.

The number-average molecular weights (M _N ) of the comb polymers are generally in the range from 1000 to 200,000 daltons. With regard to the use of the comb polymers, those having a number average molecular weight of 5,000 to 100,000 daltons are preferred. The number average molecular weight M _N can be determined in the usual way by gel permeation chromatography, as explained in the examples. The K values of the copolymers obtainable according to the invention, determined by the method indicated below, are generally in the range from 10 to 100, preferably in the range from 15 to 80 and in particular in the range from 20 to 60.

The comb polymers can be used in the form of the free acid or in the form of their salts, it being possible for the groups B to be partially or completely neutralized in the salt form. If the comb polymers are used in the form of the salts, they have cations as counterions for reasons of electroneutrality. Suitable cations are alkali metal cations such as Na ⁺ and K ⁺ , alkaline earth metal cations such as Mg ⁺⁺ and Ca ⁺⁺ , and ammonium ions such as NH ₄ ⁺ , [NR ^b R ^c R ^d R ^e ] ⁺ , where R ^{b is} C _r C ₄ -alkyl or hydroxy-C ₂ -C ₄ -alkyl and the radicals R ^c, R ^d and R ^e are independently selected from hydrogen, dC ₄ -alkyl and hydroxy-C ₂ -C ₄ alkyl. Preferred counterions are the alkali metal cations, especially Na ⁺ and K ⁺ .

The preparation of the comb polymers according to the invention can be carried out in analogy to known processes for the preparation of such comb polymers, for. B. in analogy to the methods described in the cited prior art and in analogy to the methods described in WO 01/40337, WO 01/40338, WO 01/72853 or WO 02/50160, the disclosure of which hereby Reference is made.

Suitable production processes are in particular:

i) copolymerization of ethylenically unsaturated monomers M comprising

a) neutral monoethylenically unsaturated monomers M1 which have one or two groups of the formula A, and b) monoethylenically unsaturated monomers M2 which have one or two functional groups B, ii) homo- or copolymerization of ethylenically unsaturated monomers M comprising

a) monoethylenically unsaturated monomers M3, which is a group of the formula

A and a functional group B, and optionally b) monoethylenically unsaturated monomers M2 which have one or two functional groups B,

such as

iii) polymer-analogous reaction of homopolymers or copolymers having a carbon backbone which have free carboxyl groups or ester-forming derivatives of carboxyl groups with alcohols of the formula HO- (Alk-O) _n -YZ or amines of the formula HNR- (Alk-O) _n -YZ wherein n, Alk, R, Y and Z have the meanings given above.

The three production processes i), ii) and iii) all lead to comb polymers according to the invention, the structure of the comb polymers obtainable thereby naturally being dependent on the particular production method chosen and the amount and type of starting materials used in a manner known per se. Thus, for example, in the case of the comb polymers obtainable by preparation methods i) and ii), the type and amount of side chains A or of functional groups B depends on the type and relative amounts of monomers M1 and M2 or M3 used and, if appropriate, M2 in in a known manner. The molecular weight of the comb polymers in turn can be in the production methods i) and ii) by the reaction conditions selected in the polymerization, for. B. by the initiator used, optionally used regulators, the temperature, the reaction medium, concentration of monomers, etc. in a conventional manner. In the case of the comb polymers obtainable by the preparation method iii), the structure and the molecular weight are naturally determined by the homo- or copolymers used and by the alcohols HO- (AIk-O) _n -YZ used for the modification or amines of the formula HNR- (alkoxy) O) _n -YZ largely determined.

Preferred according to the invention are the comb polymers obtainable by the method i), which thus form a particularly preferred subject of the invention.

In the preparation process i) the type and amount of the monomers M determine the type and number of side chains of the formula A. Preferred monomers M1 are those in which k in formula A is 1. Preferred monomers M1 are therefore selected from the esters of monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acids and diesters of monoethylenically unsaturated C ₄ -C 6 -dicarboxylic acids with alcohols of the formula HO- (Al k-O) _n -YZ, where n, Alk, Y and Z have the meanings given above, and the amides of monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids with amines of the formula NHR- (AIk-O) _n -YZ, wherein n, Alk, R, Y and Z have the meanings given above.

Preferred esters of monoethylenically unsaturated Cs-Cβ monocarboxylic acids are the esters of acrylic acid and of methacrylic acid.

Examples of diesters of monoethylenically unsaturated C ₄ -C -dicarboxylic acids are the esters of fumaric acid, itaconic acid and maleic acid.

Preferred amides of monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids are the amides of acrylic acid and of methacrylic acid.

Further suitable monomers M1 are vinyl, allyl and methallyl ethers of alcohols of the formula HO- (Alk-O) _n -YZ, in which n, Alk, Y and Z have the meanings mentioned above.

The monomers M1 preferably comprise at least 80 μmol, in particular at least 90 mol%, based on the total amount of the monomers M1, esters of monoethylenically unsaturated C ₃ -C 6 monocarboxylic acids, in particular esters of acrylic acid and methacrylic acid. In particular, the monomers M1 are selected from the aforementioned esters of monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids, and especially selected from the esters of acrylic acid and methacrylic acid.

The monomers M2 include:

M2a monoethylenically unsaturated mono- and dicarboxylic acids with 3 or 4 to 8

C atoms such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid and itaconic acid.

M2b monoethylenically unsaturated sulfonic acids having preferably 2 to 10 C atoms and salts thereof, in particular their alkali metal salts such as vinylsulfonic acid, allysulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 2-acryloxyethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and M2c monoethylenically unsaturated phosphonic acids with preferably 2 until 10

C atoms such as vinylphosphonic acid, allylphosphonic acid, 2-acryloxyethanephosphonic acid, 2-acrylamido-2-methylpropanephosphonic acid, M2d monoesters of monoethylenically unsaturated dicarboxylic acids having 4 to 8 C atoms, in particular half esters of maleic acid, fumaric acid and itaconic acid with C 1 -C 10 -alkanols, in particular with C 1 -C ₄ -alkanols, eg. B. the monomethyl, monomethyl or Monobutylester of these acids and the monoesters of these acids with alcohols of the formula HO (Alk "-O) _q -R ^a , wherein q, Alk" and R ^{a have} the meanings given above,

and the salts of these monomers, especially their alkali metal salts.

Preferred monomers M2 comprise at least 50 mol%, in particular at least 70 mol%, based on the total amount of the monomers M2, of monoethylenically unsaturated mono- and dicarboxylic acids having 3 or 4 to 8 carbon atoms, and of these particularly preferably acrylic acid and methacrylic acid , In a preferred embodiment, the monomers M2 are selected from monoethylenically unsaturated mono- and dicarboxylic acids having 3 or 4 to 8 C atoms, in particular from acrylic acid and methacrylic acid. In another embodiment of the invention, the monomers M2 comprise from 50 to 99 μmol, in particular from 70 to 95 mol%, based on the total amount of the monomers M2, of monoethylenically unsaturated mono- and dicarboxylic acids having 3 or 4 to 8 carbon atoms, and among these, particularly preferably acrylic acid and methacrylic acid, and 1 to 50 mol%, in particular 5 to 35 mol%, based on the total amount of the monomers M2, monoethylenically unsaturated sulfonic acids having preferably 2 to 10 carbon atoms.

Monomers M3 include, in particular, monoesters of monoethylenically unsaturated C ₄ -C ₈ -dicarboxylic acids with alcohols of the formula HO- (Al k-O) _n -YZ, in which n, Alk, Y and Z have the abovementioned meanings, especially the half esters of maleic acid , fumaric acid and itaconic acid.

In addition, the monomers M can comprise further monomers M4 and M5.

Monomeric M4 are monoethylenically unsaturated monomers which have one or two groups of the formula C and, if appropriate, a functional group B. These include vinyl, AlIIy- and methallyl ethers of alcohols of the formula HO (Alk "-O) _q -R ^a , wherein q, Alk" and R ^{a have} the meanings mentioned above, further the esters of these alcohols of monoethylenically unsaturated mono-C3 -Cβ- carboxylic acids and the diesters and half of these alcohols with monoethylenically unsaturated di-C ₄ -C ₈ -carboxylic acids. Preferred monomers M4 are esters of monoethylenically unsaturated mono-Cs-Cβ-carboxylic acids, in particular of acrylic acid and of methacrylic acid, with alcohols of the formula HO (Alk "-O) _q -R ^a , where q, Alk" and R ^{a have} the meanings given above and diesters monoethylenically unsaturated ter di-C ₄ -C 8 -carboxylic acids, in particular maleic acid, fumaric acid, citra-aconic acid and itaconic acid, with alcohols of the formula HO (Alk "-O) _q -R ^a Particularly preferred monomers M 4 are the esters monoethylenically unsaturated Mono-C ₃ -C ₈ - carboxylic acids, in particular of acrylic acid and methacrylic acid.

Preferably, the monomers M4 not more than 80 mol%, in particular not more than 60 mol%, based on the total amount of the monomers M, from. In a preferred embodiment of the invention, the proportion of the monomers M4 is 5 to 80 mol%, in particular 10 to 60 mol%, based on the total amount of the monomers M in the preparation process i) or ii). In another embodiment of the invention, their proportion of the monomers M is less than 5 mol%, in particular less than 1 mol%. With regard to the molar ratio of monomers M1 to M4 or of monomers M3 to M4, what has been said previously for the molar ratio of the functional groups A: C applies in an analogous manner.

The monomers M5 include the monomers M5a, M5b, M5c, M5d and M5e:

M5a C ₁ -C 10 -alkyl esters and C ₅ -C 10 -cycloalkyl esters of monoethylenically unsaturated mono-C ₃ -C ₆ -carboxylic acids, in particular of acrylic acid and of methacrylic acid, with C ₁ -C 10 -alkanols or C ₃ -C 10 -cycloalkanols, such as methyl acrylate, ethyl acrylate , n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate and the corresponding methacrylic acid esters, and corresponding di-d-Cio-alkyl esters and di-C ₅ - C 1 -C ₆ -cycloalkyl esters of monoethylenically unsaturated di-C ₄ -C ₈ -carboxylic acids;

M5b hydroxy-C ₂ -C ₀ -alkyl esters of monoethylenically unsaturated mono- and

Di-C3-Ce-carboxylic acids, in particular of acrylic acid and of methacrylic acid such as 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate and 4-hydroxybutyl methacrylate,

M5c monoethylenically unsaturated nitriles such as acrylonitrile, M5d vinylaromatic monomers such as styrene and vinyltoluenes, M5e olefins having preferably 2 to 12 C atoms such as ethylene, propene, 1-butene, isobutene, 1-hexene, diisobutene, 1-octene, 1-decene, 1-dodecene etc.

Preferred monomers M5 are the monomers M5b.

Preferably, the monomers M5 not more than 30 mol%, in particular not more than 20 mol%, based on the total amount of the monomers M from. If desired, their proportion is generally 1 to 30 mol%, in particular 5 to 20 mol%. %, the monomer M in the preparation process i) or N). In particular, their proportion of the monomers M is less than 5 mol%, in particular less than 1 mol%.

In the method i), the molar ratio of side chains A to functional groups B, optionally C and C usually results directly from the molar ratio of the monomers M1 to the monomers M2 or from the molar ratio of the monomers M1: M2: M4: M5. Accordingly, in the case of monohydric acids, the molar ratio M1: M2 or (M1 + M4): M2 is generally in the range from 2: 1 to 1:20, in particular in the range from 1: 1 to 1:10, especially in the range from 1: 1, 1 to 1: 8. If the monomers M in the preparation process i) comprise monomers M2 having more than one acid group or monomers M3, the molar ratio of the monomers results in a corresponding manner.

Accordingly, the amount of the monomers M1 in the preparation process i) is typically 5 to 65 mol%, in particular 10 to 50 mol%, and the amount of the monomers M2 35 to 95 mol%, in particular 50 to 90 mol%, wherein the Proportion of any further monomers M3 or M5, up to 30 mol%, in particular up to 20 mol% may be and the proportion of the monomers M4 up to 80 mol%, in particular up to 60 mol%, z. B. 5 to 80 mol%, in particular 10 to 60 mol%, in each case based on the total moles of monomers M, may be, of course, the molar numbers of all monomers M add up to 100 mol%, unless otherwise stated.

In method ii), the molar ratio of side chains A to functional groups B in the method i) results analogously from the molar ratio of the monomers M3 to the optionally used monomers M2 or M1 or M4. The same applies to the relationship between the molar ratio of side chains A to side chains C or to functional groups B.

Accordingly, the amount of monomers M3 in preparation process ii) is typically 40 to 100 mol%, in particular 50 to 95 mol%, and the amount of monomers M2 0 to 60 mol%, in particular 5 to 50 mol%, wherein the Mol number of any further monomers M2 or M5, up to 30 mol%, in particular up to 20 mol%, and the proportion of the monomers M4 up to 80 mol%, in particular up to 60 mol%, z. B. 5 to 80 mol%, in particular 10 to 60 mol%, in each case based on the total moles of monomers M, may be, of course, the molar numbers of all monomers M add up to 100 mol%, unless otherwise stated.

It may also be useful to increase the molecular weight of the polymers, the polymerization of the monomers M in the presence of small amounts of polyethylenically unsaturated monomers with z. B. 2, 3 or 4 polymerizable Perform double bonds (crosslinker). Examples thereof are diesters and triesters of ethylenically unsaturated carboxylic acids, in particular the bis- and tris-acrylates of diols or polyols having 3 or more OH groups, eg. As the bisacrylates and the bis methacrylates of ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol or polyethylene glycols. If desired, such crosslinkers are used in an amount of generally 0.01 to 5% by weight, based on the total amount of monomers M to be polymerized. Preferably, less than 0.01 wt .-% and in particular no Vernetzermonomere be used.

The polymerization of the monomers M is usually carried out in the presence of free-radical-forming compounds, so-called initiators. Such compounds are usually used in amounts of up to 30 wt .-%, preferably 0.05 to 15 wt .-%, in particular 0.2 to 8 wt .-%, based on the monomers to be polymerized. In the case of initiators consisting of several constituents (initiator systems, for example, in the case of redox initiator systems), the above weights refer to the sum of the components.

Suitable initiators are, for example, organic peroxides and hydroperoxides, furthermore peroxodisulfates, percarbonates, peroxide esters, hydrogen peroxide and azo compounds. Examples of initiators are hydrogen peroxide, dicyclohexyl peroxydicarbonate, diacetyl peroxide, di-tert-butyl peroxide, diamyl peroxide, dioctanoyl peroxide, dicanoanoyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, bis (o-toluyl) peroxide, succinyl peroxide, methyl ethyl ketone peroxide, di-tert. Butyl hydroperoxide, acetylacetone peroxide, butyl peracetate, tert-butyl permalate, tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl peroctoate, tert-butyl perodecanoate, tert-butyl perbenzoate, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxide. Butylperneodecanoate, tert-amyl perpivalate, tert-butyl perpivalate, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate and diisopropyl peroxydicarbamate; furthermore lithium, sodium, potassium and ammonium peroxodisulfate, azo initiators 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis [2-methyl-N- ( -2-hydroxyethyl) propionamide,

1, 1 'azobis (1-cyclohexanecarbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (N, N'-dimethyleneisobutyroamidine) dihydrochloride, and 2,2'-azobis ( 2-amidinopropane) dihydrochloride. as well as the redox initiation systems explained below.

Redox initiator systems contain at least one peroxide-containing compound in combination with a redox coinitiator, e.g. B. a reducing sulfur compound, for. Bisulfites, sulfites, thiosulfates, dithionites and tetrathionates of alkali metals or of ammonium compounds. So you can use combinations of peroxodisulfates with alkali metal or ammonium hydrogen sulfites, z. B. ammonium peroxo disulfate and ammonium bisulfite. The amount of the peroxide-containing compound to the redox coinitiator is 30: 1 to 0.05: 1.

The initiators can be used alone or mixed with each other, for. B. mixtures of hydrogen peroxide and sodium peroxodisulfate.

The initiators can be either water-soluble or not soluble in water or only slightly soluble. For the polymerization in an aqueous medium, water-soluble initiators are preferably used, i. H. Initiators which are soluble in the aqueous polymerization medium in the concentration usually used for the polymerization. These include peroxodisulfates, azo initiators with ionic groups, organic hydroperoxides having up to 6 C atoms, acetone hydroperoxide, methyl ethyl ketone hydroperoxide and hydrogen peroxide, and the abovementioned redox initiators. In a particularly preferred embodiment of the polymerization process i) or ii), the initiator used comprises at least one peroxodisulfate, for. For example, sodium peroxodisulfate.

In combination with the initiators or the Redoxinitiatorsystemen transition metal catalysts may additionally be used, for. Salts of iron, cobalt, nickel, copper, vanadium and manganese. Suitable salts are, for. As iron (II) sulfate, cobalt (II) chloride, nickel (II) sulfate, or copper (I) chloride. Based on the monomers, the reducing transition metal salt is used in a concentration of 0.1 ppm to 1000 ppm. So you can use combinations of hydrogen peroxide with iron (II) salts, such as 0.5 to 30% hydrogen peroxide and 0.1 to 500 ppm Mohr's salt.

Also in the polymerization of the monomers M in organic solvents, redox coinitiators and / or transition metal catalysts can be used in combination with the initiators mentioned above, for. B. benzoin, dimethylaniline, ascorbic acid and soluble in organic solvents complexes of heavy metals, such as copper, cobalt, iron, manganese, nickel and chromium. The amounts of redox coinitiators or transition metal catalysts usually used are about 0.1 to 1000 ppm, based on the amounts of monomers used.

In order to control the average molecular weight of the comb polymers obtainable according to the invention, it is often expedient to carry out the polymerization of the monomers M in the presence of regulators. Conventional regulators may be used for this purpose, in particular compounds containing organic SH groups, in particular water-soluble compounds containing SH groups such as 2-mercaptoethanol, 2-mercaptopropanol, 3-mercaptopropionic acid, cysteine, N-acetylcysteine, furthermore phosphorus (III) or phosphorus ( l) compounds such as alkali metal or alkaline earth metal hy- pop-phosphites, e.g. As sodium hypophosphite, and hydrogen sulfites such as sodium hydrogen sulfite. The polymerization regulators are generally used in amounts of from 0.05 to 10% by weight, in particular from 0.1 to 2% by weight, based on the monomers M. Preferred regulators are the abovementioned compounds bearing SH groups, in particular compounds which carry water-soluble SH groups, such as 2-mercaptoethanol, 2-mercaptopropanol, 3-mercaptopropionic acid, cysteine and N-acetylcysteine. In these compounds, it has proven particularly useful to use these in an amount of 0.05 to 2 wt .-%, in particular 0.1 to 1 wt .-%, based on the monomers. The abovementioned phosphorus (III) compounds and phosphorus (I) compounds as well as the hydrogen sulfites are usually obtained in relatively large quantities, eg. B. 0.5 to 10 wt .-% and in particular 1 to 8 wt .-%, based on the monomers to be polymerized. Also by the choice of the appropriate solvent can be influenced on the average molecular weight. Thus, the polymerization in the presence of diluents with benzylic or allylic H atoms to a reduction in the average molecular weight by chain transfer.

The polymerization of the monomers can be carried out by the customary polymerization processes, including solution, precipitation, suspension or bulk polymerization. Preferably, the method of solution polymerization, d. H. the polymerization in solvents or diluents.

Suitable solvents or diluents include both aprotic solvents, e.g. B. the aforementioned aromatics such as toluene, o-xylene, p-xylene, cumene, chlorobenzene, ethylbenzene, technical mixtures of alkylaromatics, aliphatic and cycloaliphatic compounds such as cyclohexane and technical Aliphatenmischungen, ketones such as acetone, cyclohexanone and methyl ethyl ketone, ethers such as tetrahydrofuran, dioxane, Diethyl ether, tert-butyl methyl ether, and dC ₄ alkyl esters of aliphatic Ci-C ₄ -carboxylic acids such as methyl acetate and ethyl acetate, further protic solvents such as glycols and glycol derivatives, polyalkylene glycols and their derivatives, CrC ₄ alkanols, eg. For example, n-propanol, n-butanol, isopropanol, ethanol or methanol, and water and mixtures of water with dC ₄ alkanols such. B. isopropanol / water mixtures. The copolymerization process according to the invention is preferably carried out in water or a mixture of water with up to 60% by weight of C 1 -C ₄ -alkanols or glycols as solvent or diluent. With particular preference, water is used as the sole solvent.

The polymerization of the monomers M is preferred with substantial or complete exclusion of oxygen, preferably in an inert gas stream, e.g. B. a nitrogen Ström, performed. The polymerization process of the monomers M can be carried out in the apparatuses customary for polymerization methods. These include stirred tanks, stirred tank cascades, autoclaves, tube reactors and kneaders.

The polymerization of the monomers M is usually carried out at temperatures in the range of 0 to 300 ° C, preferably in the range of 40 to 120 ° C. The polymerization time is usually in the range of 0.5 hours to 15 hours, and more preferably in the range of 2 to 6 hours. The pressure prevailing in the polymerization is of minor importance for the success of the polymerization and is generally in the range from 800 mbar to 2 bar and often at ambient pressure. When using volatile solvents or volatile monomers, the pressure may be higher.

For further details on the polymerization process, reference is made to EP-A 560602, EP-A 734359, EP-A 799807, EP-A 994290, WO 01/40337, WO 01/40338 and PCT / EP 2005/009466. The polymerization conditions described therein can be used in an analogous manner for the preparation of the comb polymers of the invention.

The monomers M2, M4 and M5 are known compounds which are predominantly commercially available.

Some of the monomers M1 and M3 have already been described in the prior art, where the monomers M1 or M3, where n in group A is on average, have a number in the range from 11 to 300, in particular in the range from 20 to 200, especially in Range of 50 to 200 and especially in the range of 50 to 150 and in which at least 90 mol% of repeating units AIk-O in the group A are CH ₂ CH ₂ O, are new and form a further object of the present invention. Their preparation can be carried out in analogy to known methods of the prior art. With regard to the statistical and blockwise arrangement of different units AIk-O, what has been said previously for group A applies.

Preferred monomers M1, in which k in formula A is 1, can be obtained by esterification of monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acids or monoethylenically unsaturated C ₄ -C ₈ -dicarboxylic acids with alcohols of the formula HO- (Alk-O) _n - YZ, wherein n, Alk, Y and Z have the meanings mentioned above, or by amidation of monoethylenically unsaturated Cs-Cβ monocarboxylic acids with amines of the formula NHR- (Alk-O) _n -YZ, wherein n, Alk, R, Y and Z have the meanings mentioned above, are produced. Instead of the C ₃ -C ₈ -monocarboxylic acids or C ₄ -Ce-dicarboxylic acids, it is also possible to use ester- or amide-forming derivatives of these acids are used, in particular the anhydrides of the acids. Such methods are known in the art.

Thus, for example, the preparation of esters of monoethylenically unsaturated Cs-Cβ monocarboxylic acids or C ₄ -Ce dicarboxylic acids with alcohols of the formula HO- (Al k O) _n -YZ by one of the following measures a), b) or c) take place :

a) acid catalyzed esterification of monoethylenically unsaturated Cs-Cβ monocarboxylic acids or C ₄ -C dicarboxylic acids with alcohols of the formula HO- (Al k O) _n -YZ, for example in analogy to DE-A 2516933,

EP-A 884290, EP-A 989108, EP-A 989109, WO 01/40337, WO 01/40338 and WO 02/50160; b) transesterification of mono- or di-C ₁ -C ₄ -alkyl esters of monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acids or C ₄ -C ₈ -dicarboxylic acids with alcohols of the formula HO- (Alk-O) _n -YZ in the presence of basic or acidic transesterification catalysts in analogy to the process described in DE-A 19602035, US Pat. No. 5,037,978, EP-A 799807 or under enzyme catalysis by the process described in EP-A 999,229; c) Reaction of anhydrides of monoethylenically unsaturated C ₃ -Ce monocarboxylic acids or C ₄ -Ce dicarboxylic acids with alcohols of the formula HO- (Al k O) _n -YZ, for example in analogy to that described in WO 01/74736 or in US Pat the older application PCT / EP 2005/009466 described method, which deviates from the methods described therein on the addition of a base in some cases can be omitted.

The preparation of amides of monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acids with amines of the formula HNR- (Alk-O) _n -YZ can in analogy to known amidation reactions by amidation of monoethylenically unsaturated Cs-Cβ monocarboxylic acids or of their amide-forming derivatives such as acid chlorides, acid anhydrides or C 1 -C ₄ -alkyl esters, with amines.

The preparation of ethylenically unsaturated ethers or amines, ie monomers M1 with a group A, wherein k = 0, by etherification or vinylation of alcohols of the formula HO- (AIk-O) _n -YZ or by alkenylation or enamine Bidlung of Amines of the formula HNR- (AIk-O) _n -YZ be carried out in analogy to standard methods of the prior art.

The monomers M3 can be prepared in analogy to the methods described here for the monomers M1. In particular, the preferred monomers M3 are prepared by reacting anhydrides with monoethylenically unsaturated C ₄ -C ₈ dicarboxylic acids with alcohols of the formula HO- (AIk-O) _n -YZ under conditions which lead to a monoester formation.

According to a preferred embodiment of the invention, the preparation of the particularly preferred monomers M1 by reacting anhydrides monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids, in particular of acrylic anhydride or methacrylic anhydride, with alcohols of the formula HO- (AIk-O) _n -YZ , This process, in contrast to the processes known from the prior art when using alcohols of the formula HO- (AIk-O) _n -YZ to particularly good yields and therefore constitutes a further subject of the invention.

It has proven to be advantageous to use the anhydride equimolar or in a slight excess, preferably 10 mol%, often 9.5 mol%, preferably 9 .mu.m%, in particular 8.5 .mu.m%, and especially 8 ιmol-%, based on 1 mole of alcohol will not exceed d. H. the amount of anhydride is typically not more than 1, 095 mol, preferably not more than 1, 09 mol, especially not more than 1, 085 mol and especially not more than 1, 08 mol per mole of alcohol. Preference is given to using at least 1.005 mol, in particular at least 1.01 mol and more preferably at least 1.02 mol of anhydride per mole of alcohol.

In one embodiment of the invention, the reaction of the anhydride with the alcohol takes place in the absence of a base, in particular when the nitrogen heterocycle Z is a basic radical. In another embodiment of the invention, the reaction of the anhydride with the alcohol takes place in the presence of a base. Of these, bases are preferred which are not or only slightly soluble in alcohol at 90 ° C, d. H. the solubility of the base in the alcohol at 90 ° C is not more than 10 g / l and especially not more than 5 g / l.

Examples of such bases include hydroxides, oxides, carbonates and hydrogen carbonates of monovalent or divalent metal cations, in particular of elements of the first and second main group of the periodic system, ie of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ and Ba ²⁺ and of monovalent or divalent transition metal cations or cations of the fourth main group of the periodic table such as Ag ⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ²⁺ , Cd ²⁺ , Sn ²⁺ , Pb ²⁺ , Ce ²⁺ . The hydroxides, oxides, carbonates and bicarbonates are preferably cations of the alkali and alkaline earth metals and of Zn ²⁺ and in particular of Mg ²⁺ or Ca ²⁺ and particularly preferably of Na ⁺ or K ⁺ . Preferred among these are the hydroxides and carbonates of these metal ions, in particular the alkali metal carbonates and alkali metal hydroxides and especially sodium carbonate, potassium carbonate, potassium hydroxide and sodium hydroxide. In particular, lithium hydroxide and lithium carbonate are also suitable. The base is preferably used in an amount of 0.05 to 0.5 base equivalents and in particular in an amount of 0.1 to 0.4 base equivalents, based on the alcohol, wherein larger amounts of base z. B. to 1 base equivalent usually not disadvantageous. It should be noted that in the case of hydroxides and bicarbonates, the base equivalents correspond to the molar equivalents used, whereas 1 molar equivalent of a carbonate or oxide corresponds in each case to 2 base equivalents.

The reaction of the anhydride with the alcohol is preferably carried out at temperatures in the range of 0 and 150 ° C, in particular in the range of 20 to 130 ° C and particularly preferably in the range of 50 and 100 ° C. The pressure prevailing in the reaction is of minor importance for the success of the reaction and is generally in the range from 800 mbar to 2 bar and often at ambient pressure. Preferably, the reaction is carried out in an inert gas atmosphere. The reaction of the anhydride with the compound P can be carried out in all the usual for such reactions Appaatura, z. B. in a stirred tank, in stirred tank cascades, autoclaves, tubular reactors or kneaders.

The reaction of the anhydride with the alcohol is preferably carried out until a conversion of the alcohol used of at least 80%, in particular at least 90% and particularly preferably at least 95% is achieved. The reaction times required for this purpose will generally not exceed 5 hours and often times less than 4 hours. The conversion can be monitored by ¹ H-NMR spectroscopy of the reaction mixture, preferably in the presence of a strong acid such as trifluoroacetic acid.

The reaction of the anhydride with the alcohol may be carried out in bulk, i. H. without addition of solvents, or in inert solvents or diluents. Inert solvents are usually aprotic compounds. The inert solvents include optionally halogenated aromatic hydrocarbons such as toluene, o-xylene, p-xylene, cumene, chlorobenzene, ethylbenzene, technical mixtures of alkylaromatics, aliphatic and cycloaliphatic hydrocarbons such as hexane, heptane, octane, isooctane, cyclohexane, cycloheptane, technical Aliphatenmi - Further, ketones such as acetone, methyl ethyl ketone, cyclohexanone, further ethers such as tetrahydrofuran, dioxane, diethyl ether, tert-butyl methyl ether, and mixtures of the aforementioned solvents such. For example, toluene / hexane. Preferably, without solvent or only with very small amounts of solvent, usually less than 10 wt .-%, based on the starting materials, d. H. in substance, worked.

It has proven to be advantageous to carry out the reaction of the anhydride with the alcohol in a reaction medium which contains less than 0.2% by weight and in particular contains less than 1000 ppm of water (determined by Karl Fischer titration). The term "reaction medium" refers to the mixture of the reactants with the base and with optionally used solvent and inhibitor. In the case of moisture-containing feedstocks, it has been proven to remove the water before the reaction, for. Example by distillation and particularly preferably by distillation with addition of an organic solvent that forms a low-boiling azeotrope with water. Examples of such solvents are the abovementioned aromatic solvents such as toluene, o-xylene, p-xylene, cumene, benzene, chlorobenzene, ethylbenzene and technical aromatic mixtures, furthermore aliphatic and cycloaliphatic see solvents such as hexane, heptane, cyclohexane and technical Aliphatenmi - Schungen and mixtures of the aforementioned solvents.

The reaction is usually carried out by reacting the reaction mixture containing the alcohol, the anhydride and the base and optionally the solvent and optionally inhibitor in a suitable reaction vessel at the temperatures indicated above. Preferably, the alcohol and the base and, if appropriate, the solvent are added and the anhydride is added for this purpose. Preferably, the addition of the anhydride is carried out at the reaction temperature.

If the starting materials contain water, the water is preferably removed before the addition of the anhydride. For example, one can proceed by initially introducing alcohol and optionally the base and optionally the solvent in a reaction vessel, then removing any moisture present in the manner described above and then adding the anhydride, preferably at reaction temperature.

In addition, it has proven to avoid uncontrolled polymerization to carry out the reaction of the anhydride with the alcohol in the presence of a polymerization inhibitor. Suitable polymerization inhibitors are known for such reactions, in particular phenols such as hydroquinone, hydroquinone monomethyl ether, especially sterically hindered phenols such as 2,6-di-tert-butylphenol or 2,6-di-tert-butyl-4-methylphenol , furthermore, thiazines such as phenothiazine or methylene blue, cerium (III) salts such as cerium (III) acetate and nitroxides, in particular sterically hindered nitroxides, ie nitroxides of secondary amines adjacent to the C atoms adjacent to the nitroxide group, respectively Each carry 2 of these alkyl groups, in particular those which are not on the same carbon atom, with the nitrogen atom of the nitroxide or the carbon atom to which they are attached, a saturated 5- or θ-membered ring form such as in 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (OH-TEMPO), mixtures of the called inhibitors, mixtures of the aforementioned inhibitors with oxygen, for. In the form of air, and mixtures of mixtures of the aforementioned inhibitors with oxygen, e.g. B. in the form of air. Preferred inhibitors are the abovementioned sterically hindered nitroxides, cerium (III) compounds and sterically hindered phenols and mixtures thereof with one another and mixtures of such inhibitors with oxygen and mixtures of mixtures of these inhibitors with oxygen, eg. B. in the form of air. Particularly preferred are inhibitor systems comprising at least one sterically hindered nitroxide and another component selected from a hindered phenol and a cerium (III) compound, and mixtures thereof with oxygen, e.g. B. in the form of air. The amount of inhibitor may be up to 2% by weight, based on the total amount of anhydride + alcohol. The inhibitors are advantageously used in amounts of from 10 ppm to 1000 ppm, based on the total amount of anhydride + alcohol. In the case of inhibitor mixtures, this information refers to the total amount of the components, with the exception of oxygen.

The reaction of the alcohol with the anhydride of a monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acid naturally leads primarily to a mixture of the ester with the monoethylenically unsaturated Cs-Cβ-monocarboxylic acid used and, if appropriate, residues of excess anhydride and unreacted alcohol.

However, the excess anhydride usually constitutes not more than 10% by weight, and more preferably not more than 5% by weight, of the amount of anhydride originally used. It has been proven to destroy any anhydride by reaction with water. The proportion of unreacted alcohol is preferably not more than 10 wt .-% and in particular not more than 5 wt .-% of the amount of alcohol used.

To separate the alcohol from the monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acid formed in the reaction, the latter can in principle be obtained by distillation or in any other way, for. B. by extraction of the acid remove. Also, one can isolate the ester, for. Example, by crystallization of the ester from an aqueous medium, wherein the acid and optionally present anhydride remains in the mother liquor. As a rule, however, no isolation or separation of the ester will be carried out. Rather, it will be preferable to subject the mixture of esters with monoethylenically unsaturated Cs-Cβ monocarboxylic acid, optionally with the addition of further monomers M2 and optionally further ethylenically unsaturated monomers M3, M4 and / or M5 directly to a radical copolymerization. In an analogous manner, it is also possible to use the monomers M1 or M3 prepared by esterification according to the method a) or by transesterification according to the method b) directly, ie without prior isolation or purification in the subsequent polymerization of the monomers M.

If the polymerization of the monomers M is carried out as a solution polymerization in water, removal of the water is not required for many applications. Incidentally, an isolation of the polymer obtainable according to the invention can be carried out in a conventional manner, for. B. by spray drying of the polymerization mixture. If the polymerization is carried out in a steam-volatile solvent or solvent mixture, the solvent can be removed by passing in steam, thereby obtaining an aqueous solution or dispersion of the comb polymer.

The comb polymers are preferably obtained in the form of an aqueous dispersion or solution. The solids content is preferably 10 to 80 wt .-%, in particular 30 to 65 wt .-%.

Another embodiment of the invention relates to comb polymers which are obtainable by the production process iii). Herein, a homo- or copolymer having a carbon backbone having carbon-free carboxylic groups or ester-forming derivatives of carboxyl groups, with alcohols of the formula HO- (AIk-O) _n -YZ or amines of the formula HNR- (AIk-O) _n - YZ implemented in the sense of a polymer-analogous reaction. Process for the polymer-analogous reaction of homo- or copolymers containing free carboxyl groups or ester-forming derivatives of

Carboxyl groups are known from the prior art, for example from US 5,840,114, US 5,728,207, WO 98/31643 and WO 01/72853. The processes described there can be used in an analogous manner for the preparation of the comb polymers according to the invention.

Examples of polymers having free carboxyl groups or ester-forming derivatives of free carboxyl groups, in particular anhydride groups, are homopolymers and copolymers of monoethylenically unsaturated C ₃ -C ₈ -monocarboxylic acids and / or C ₄ -C ₈ -dicarboxylic acids or their anhydrides, for example homo- and Copolymers of acrylic acid, methacrylic acid, maleic acid, maleic anhydride into consideration. These polymers may contain other monomers M2, e.g. B. monomers carrying sulfonic acid groups such as vinylsulfonic acid, acrylamidomethylpropanesulfonic acid, Methallylsulfonsäu- re or their alkali metal or ammonium salts, but also monomers M4 and / or M5, for example, vinylaromatic monomers or olefins, in copolymerized form contained. Suitable carboxyl-containing polymers are, in particular, copolymers which consist of

From 5 to 100% by weight, in particular from 50 to 100% by weight, of at least one mono- ethylenically unsaturated C ₃ -C ₈ -monocarboxylic acid and / or C ₄ -C ₈ -dicarboxylic acid or its anhydrides, in particular acrylic acid, methacrylic acid acrylic acid, maleic acid or maleic anhydride, or mixtures thereof; 0 to 95% by weight, in particular 0 to 50% by weight, of monoethylenically unsaturated sulfonic acids, such as vinylsulfonic acid, acrylamidomethylpropanesulfonic acid, methyllylsulfonic acid and / or their alkali metal or ammonium salts and 0 to 95% by weight, in particular 0 to 50% by weight .-% of one or more esters of monoethylenically unsaturated Cs-Cβ monocarboxylic acids or C ₄ -C ₈ dicarboxylic acids, eg. As esters of acrylic acid, methacrylic acid or maleic acid esters of monohydric alcohols having 1 to 8 carbon atoms in the molecule.

Particularly preferred polymers containing carboxyl groups are homopolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid and maleic acid, copolymers of methacrylic acid and maleic acid, copolymers of acrylic acid and an ester of a monoethylenically unsaturated carboxylic acid, copolymers from methacrylic acid and an ester of a monoethylenically unsaturated carboxylic acid and the alkali metal or ammonium salts of said copolymers.

Particularly preferred are the carboxyl group-containing polymers which are obtainable by radical polymerization of the abovementioned monomers in the presence of one of the abovementioned molecular weight regulators, in particular those obtained by free-radical polymerization in aqueous solution in the presence of at least 4% by weight, based on the polymerization used monomers, a water-soluble sulfur compound are available in which the sulfur has the oxidation number +4. Such water-soluble sulfur compounds are, for. For example, sulfur dioxide, sulfurous acid, alkali metal, alkaline earth metal and ammonium salts of sulfurous acid or the desulfurous acid, sodium, potassium, calcium or ammonium formaldehyde sulfoxylate, dialkyl sulfites or mixtures thereof. Of these compounds, in particular potassium, ammonium or calcium sulfite, sodium, potassium, calcium or ammonium disulfite, sodium, potassium, calcium or ammonium hydrogen sulfite or mixtures thereof. For further details on the polymerization, reference is made to WO 01/72853. The molecular weight (number average) of these polymers is typically in the range of 500 to 100,000, preferably in the range of 1000 to 50,000. Particular preference is given to homopolymers of acrylic acid or methacrylic acid or copolymers of methacrylic acid and acrylic acid.

Specific examples of acid group-containing polymers (percentages are% by weight) are:

Molecular weight 2000 polyacrylic acid, molecular weight 4000 polyacrylic acid, molecular weight 8000 polyacrylic acid, molecular weight 20000 polyacrylic acid,

Copolymer of 70% acrylic acid and 30% maleic acid with molecular weight 70000, copolymer of 50% acrylic acid and 50% maleic acid with molecular weight 5000, copolymer of 70% methacrylic acid and 30% maleic acid with molecular weight 5000, copolymer of 70% acrylic acid and 30% methacrylic acid with molecular weight 10000, copolymer of 90% acrylic acid and 10% vinyl sulfonic acid with molecular weight 10,000, copolymer of 50% acrylic acid and 50% methacrylic acid with molecular weight 6000, copolymer of 20% acrylic acid and 80% methacrylic acid with molecular weight 5000, copolymer of 80% acrylic acid and 20% methacrylic acid with molecular weight 4000,

Terpolymer of 40% acrylic acid, 40% methacrylic acid and 20% maleic acid with molecular weight 5000.

The molecular weights given here are each the number average molecular weight.

The reaction of the carboxyl-containing polymers with the alcohols or amines can be carried out in the presence or in the absence of catalysts. The catalysts used are, for example, strong oxo acids such as sulfuric acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, phosphoric acid, phosphorous acid or hydrohalic acids such as hydrochloric acid. If an acid which acts as a catalyst is used in the reaction, the amounts are up to 10% by weight, preferably up to 5% by weight, based on the total amount of polymers and alcohols or amines containing carboxyl groups.

The weight ratio in which the carboxyl group-containing polymer and the

Alcohols or amine can be implemented, can be between 99: 1 to 1: 99 and is preferably in the range of 1: 1 to 5:95 and more preferably in the range of 3: 7 to 1: 9 reacted. The reaction is carried out, for example, by adding the aqueous solutions of the polymer optionally with an acid and the alcohol or amine which acts as catalyst and distilling off the water. The distillation of the water from the mixture is usually carried out under atmospheric pressure, but can also be carried out in vacuum. It is often advantageous to pass a gas stream through the reaction mixture during distillation to more rapidly remove the water and other volatiles. As gas stream, air, nitrogen or water vapor can be used. However, it is also possible to remove the water under reduced pressure and additionally to pass a gas stream through the reaction mixture. To distill the water from the reaction mixture, you must add energy to the mixture. Suitable apparatus for this purpose are heatable stirred tank, stirred tank with external heat exchangers, stirred tank with internal heat exchangers, thin film evaporator, kneader or extruder. The evaporating water is removed via a vapor line from the reaction medium and condensed in a heat exchanger. It contains only small amounts of organic ingredients and can be disposed of via a wastewater treatment plant.

Following or simultaneously with the removal of water from the reaction mixture, a condensation reaction between the polymer and the alcohol or amine occurs. The resulting water is also removed from the reaction medium. The reaction is carried out for example at temperatures in the range of 100 to 250 ⁰ C. The temperature depends on the reactor and the residence time. For example, when condensed in a continuously operated extruder or thin film evaporator in which the residence time is only a few seconds or minutes, it is advantageous to temperatures between 150 ° C and apply 250 ⁰ C. In discontinuously operated stirred tanks or kneaders, for example, one requires 1 to 15 hours and performs the condensation mostly in the temperature range of 100 to 200 ⁰ C.

In one process variant, it is possible first to dehydrate the carboxyl-containing polymers and to condense the powder or granules obtained with the alcohol and / or amine.

After condensation, the reaction mixture is cooled and optionally dissolved in water. Aqueous solutions of the reaction mixture can be prepared, for example, by adding water to the still 50 to 150 ⁰ C warm reaction mass with stirring or by stirring the liquid at temperatures of 50 to 150 ⁰ C liquid reaction mass in water. Usually, enough water is used to obtain a 20 to 95% strength by weight, preferably 30 to 50% strength by weight, aqueous solution of the comb polymer. At the same time or following the If necessary, a neutralization of the remaining acid groups can be carried out by dissolving the condensation product. As the neutralizing agent, alkali metal, alkaline earth metal oxides or hydroxides in solid form or in the form of 10 to 50% by weight aqueous solutions or slurries in water are used. Examples of suitable bases are lithium hydroxide, sodium hydroxide, calcium hydroxide, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, aluminum oxide and aluminum hydroxide. Depending on the degree of neutralization, the aqueous solutions of the comb polymers may have pH values in the range from 1 to 12.

After condensation, the reaction mass may also remain undiluted. Upon cooling, it usually solidifies to a waxy mass, which can be easily remelted. This results in variations for the transport. For example, you can fill the reaction mass in barrels from which the condensation product can be melted again. It can also be transported and stored in a molten state. But it is also possible to prepare and handle aqueous solution.

The anhydrous melt can also be mixed with inert powders to obtain free-flowing compacts. For example, kieselguhr, silica gel, amorphous silica and / or amorphous silica can be used as the inert powder.

The comb polymers according to the invention are outstandingly suitable as additives (additives) for preparations of mineral binders, in particular for the addition of cementitious preparations, such as concrete or mortar, and are distinguished in particular by superior properties with respect to their liquefying effect.

By cement is meant, for example, Portland cement, alumina cement or mixed cement, such as pozzolanic cement, slag cement or other types. In particular, the comb polymers according to the invention are suitable for cement mixtures which comprise Portland cement predominantly and in particular at least 80% by weight, based on the cement constituent, of the cement constituents. The comb polymers according to the invention are used for this purpose generally in an amount of 0.01 to 10 wt .-%, preferably 0.05 to 3 wt .-%, based on the total weight of the cement in the cement preparation.

The comb polymers of the invention are also particularly suitable for the addition of gypsum and gypsum-containing preparations. The comb polymers according to the invention are used for this purpose generally in an amount of 0.01 to 10 wt .-%, preferably 0.05 to 3 wt .-%, based on the total weight of the gypsum in the gypsum preparation. The comb polymers can be added in solid form or as an aqueous solution to the ready-to-use preparation of the mineral binder. It is also possible to formulate comb polymer present in solid form with the mineral binder and to prepare the ready-to-use cement-containing preparations therefrom. The comb polymer is preferably used in liquid, ie dissolved, emulsified or suspended form, for example in the form of the polymerization solution, in the preparation of the preparation, ie during mixing.

The comb polymers according to the invention can also be used in combination with the known concrete flow improvers and / or concrete liquefiers based on naphthalene formaldehyde condensate sulfonate, melamine-formaldehyde condensate sulfonate, phenolsulfonic acid-formaldehyde condensate, lignosulfonates and gluconates. Furthermore, together with celluloses, e.g. As alkyl or Hydroxyalkylcellulo- sen, starches or starch derivatives are used. Also, they may be used in combination with high molecular weight polyethylene oxides (weight-average molecular weight M _w in the range of 100,000 to 8,000,000 daltons).

Furthermore, customary additives such as air-entraining agents, expansion agents, water repellents, setting retarders, setting accelerators, antifreeze agents, sealants, pigments, corrosion inhibitors, flow agents, injection aids, stabilizers or hollow microspheres can be added to the preparation of the mineral binder. Such additives are described for example in EN 934.

In principle, the comb polymers according to the invention can also be used together with film-forming polymers. These are to be understood as meaning those polymers whose glass transition temperature is <65 ° C., preferably <50 ° C., more preferably <25 ° C. and very particularly preferably <0 ° C. With reference to the relationship between the glass transition temperature of homopolymers and the glass transition temperature of copolymers established by Fox (TG Fox, Bull. Am. Phys. Soc. (Ser.ll) 1, 1956, 123, one skilled in the art will be able to select suitable polymers. Examples of suitable polymers are the styrene-butadiene polymers and styrene-acrylates which are commercially available for this purpose (see, for example, BH Lutz in D. Distler (ed.), "Wiley Polymer Dispersions" Wiley-VCH, Weinheim 1999, Chapter 10.3 and 10.4, pp. 230-252).

Furthermore, it is often advantageous to use the comb polymers according to the invention together with antifoams. This prevents that when preparing the ready-made mineral building materials too much air in the form of air pores are registered in the concrete, which the strength of the set would degrade mineral building material. Suitable antifoams include, in particular, polyalkylene oxide-based antifoam agents, trialkyl phosphates, such as tributyl phosphate, and silicone-based defoamers. Also suitable are the ethoxylation products and the propoxylation products of alcohols having 10 to 20 carbon atoms. Likewise suitable are the diesters of alkylene glycols or polyalkylene glycols and also other customary antifoams. Antifoams are usually used in amounts of from 0.05% to 10%, and preferably from 0.5% to 5% by weight, based on the comb polymers.

The antifoams can be combined with the polymer in a variety of ways. For example, if the polymer is an aqueous solution, the antifoam agent may be added solid or dissolved to the solution of the comb polymer. If the antifoam agent is not soluble in the aqueous polymer solution, then emulsifiers or protective colloids may be added for its stabilization.

Is the comb polymer in the form of a solid, as z. B. from a spray-drying or Sprühwirbelschichtgranulierung, so the antifoam agent may be mixed as a solid or be assembled together with the polymer in the spray-drying process or Sprühgranulierungsprozess.

The following examples are intended to illustrate the invention.

analytics:

a) Determination of the K value:

The K values of the aqueous sodium salt solutions of the copolymers were determined according to H. Fikentscher, Cellulose-Chemie, Volume 13, 58-64 and 71-74 (1932) in aqueous solution at a pH of 7, a temperature of 25 ° C and a polymer concentration of the sodium salt of the copolymer of 1 wt .-% determined.

b) Determination of the solids content:

The determination is carried out by means of the MA30 analyzer from Satorius.

For this purpose, a defined amount of the sample (about 0.5 to 1 g) is weighed into an aluminum tray and dried to constant weight at 90 ° C. The percentage solids (FG) is calculated as follows: FG = weight x 100 / weight [% weight]. c) Molecular weight determination:

The number-average and weight-average molecular weight was determined by gel permeation chromatography (= GPC) with aqueous eluents.

The GPC was performed with a device combination from Agilent (1100 series). This includes:

Begasser Model G 1322 A

Isocratic pump model G 1310 A

Autosampler model G 1313 A

Column oven Model G 1316 A

Control Module Model G 1323 B Differential Refractometer Model G 1362 A

The eluent used in the case of polymers dissolved in water is a 0.08 mol / L TRIS buffer (pH = 7.0) in distilled water + 0.15 mol / L chloride ions of NaCl and HCl.

The separation took place in a separation column combination. The columns No. 787 and 788 (each 8 x 30 mm) from PSS are used with GRAL BIO linear separator material. The flow rate was 0.8 mL / min at a column temperature of 23 ° C.

The calibration is carried out with polyethylene oxide standards from the company PPS with molecular weights of M = 194-1700000 [mol / g].

d) Preparation of alcohols of the formula HO- (Alk-O) _n -YZ

Preparation Example 1 Alcohol HO- (CH ₂ CH ₂ O) ₂₀ -CH ₂ CH ₂ - (Morphon-yl)

98.3 g of N- (2-hydroxyethyl) morpholine and 0.87 g of potassium hydroxide were placed in a 1 L pressure vessel with 2 propeller stirrers (diameter 30/50 mm). The kettle was evacuated to 9 mbar and dehydrated at 80 ° C internal temperature for 1 h. It was then aerated with nitrogen, inertized to 0.5 bar and 660.8 g of ethylene oxide added with stirring over a period of 5.7 h and an internal temperature of 120 ° C. The batch was stirred at 120 ° C for 1 h and cooled to room temperature and relaxed. It was then heated at normal pressure to 100 ° C, evacuated to 100 mbar and stripped for 30 min at 100 mbar with nitrogen. It was then aerated again with nitrogen, cooled to <80 ° C and neutralized with 0.81 g of acetic acid. In this case, a total of 760 g of the alcohol having an OH number of 61, 8 were obtained.

Preparation Example 2: Alcohol HO- (CH ₂ CH ₂ θ) ii ₂ -CH ₂ CH ₂ - (morpholin-4-yl)

The procedure was as in Preparation Example 1, however, only 19.7 g of N- (2-hydroxyethyl) morpholine were initially charged and a total of 740.0 g of ethylene oxide in 6.6 added h. 755 g of the alcohol with an OH number of 11.4 were obtained.

Preparation Example 3: Alcohol HO- (CH ₂ CH ₂ O) ₂₀ -CH ₂ CH ₂ - (pyrrolidin-2-one-1-yl)

The procedure was as in Preparation Example 1, but 105.9 g of N- (2-hydroxyethyl) pyrrolidin-2-one were initially charged and a total of 660.8 g of ethylene oxide in 5.7 h. 766 g of the alcohol having an OH number of 60.1 were obtained.

Preparation of monomers M1:

Comparative Example 1) Preparation of the Methacrylic Ester of Methylpolyethylene Glycol (M = 3000 g / mol)

In a 1-liter glass reactor with anchor stirrer, thermometer, gas inlet, reflux condenser and dropping funnel were 601, 2 g of methyl polyethylene glycol (M = 3000 g / mol), 190 mg of 2,6-di-tert-butyl-4-methylpenol, 19 , 0 mg of 4-hydroxy-N, N-2,2,6,6-tetramethylpiperidin-1-oxyl and 3.3 g of sodium carbonate (anhydrous) presented. The mixture was heated to 80 ° C while introducing air. Then, 38.5 g of methacrylic anhydride was added and allowed to react at 80 ° C for 3 hours. After dilution with 346.4 g of water and cooling to room temperature, about 970 g of an aqueous solution of the ester of methacrylic acid were obtained together with methacrylic acid in a molar ratio of 1: 1 with a solids content of 65% and a pH of 6.9.

Comparative Example 2) Preparation of the Methacrylic Ester of Methylpolyethylene Glycol (M = 1000 g / mol)

In a 1 l glass reactor with anchor stirrer, thermometer, gas inlet, reflux condenser and dropping funnel, 350 g of methyl polyethylene glycol (M = 1000 g / mol), 0.315 g of 2,6-di-tert-butyl-4-methylpenol, 31 mg of 4 -Hydroxy-N, N-2,2,6,6-tetramethylpiperidine-1-oxyl and 5.56 g sodium carbonate (anhydrous). The mixture was heated to 80 ° C while introducing air. Then 57.74 g of methacrylic anhydride were added and allowed to react at 80 ° C for 3 hours. Thereafter, 225.4 g of water were added and allowed to cool to room temperature. An aqueous solution of the ester of methacrylic acid was obtained together with methacrylic acid in a molar ratio of 1: 1 with a solids content of 65%.

Example 1 Preparation of the Methacrylic Ester of the Alcohol from Preparation Example 1

The procedure was as in Comparative Example 1, but 50.0 g of the alcohol from Preparation Example 1 with 69.9 g of methacrylic anhydride (90%) in the presence of 0.035 g of 4-hydroxy-N, N-2,2,6,6 -tetramethylpiperidine-1-oxyl and 0.35 g of 2,6-di-tert-butyl-4-methylphenol and reacted in the absence of sodium carbonate. After dilution with 118.0 g of water, about 230 g of an aqueous solution of the ester in a mixture with methacrylic acid in a molar ratio of 1: 1 with a solids content of 65% and a pH of 6.8.

Example 2 Preparation of the Methacrylic Ester of the Alcohol from Preparation Example 2

The procedure was as in Comparative Example 1, but 625.7 g of the alcohol from Preparation Example 2 with 28.4 g of methacrylic anhydride (90%) in the presence of 0.014 g of 4-hydroxy-N, N-2,2,6,6 Tetramethylpiperidin-1-oxyl and 0.14 g of 2,6-di-tert-butyl-4-methylphenol and reacted in the absence of sodium carbonate. After dilution with 352.3 g of water, about 1 kg of an aqueous solution of the ester in a mixture with methacrylic acid in a molar ratio of 1: 1 with a solids content of 65% and a pH of 6.9.

Example 3 Preparation of the Methacrylic Ester of the Alcohol from Preparation Example 3

200.0 g of the alcohol from Preparation Example 3, 79.3 g of methacrylic acid, 3.4 g of p-toluenesulfonic acid, 0.15 g of phenothiazine and 55.9 g of toluene were placed in a 1 L stirred vessel with nitrogen inlet and water separator and stirred and nitrogen heated to 140 ° C bath temperature. Was under reflux

Esterified for 7 h and thereby separated the resulting reaction water. After cooling, about 330 g of a toluene solution of the ester in a mixture with excess methacrylic acid in a molar ratio 1: 3.3.

Preparation of the comb polymers of the invention Example 4 Preparation of the Polymer 1 According to the Invention

In a 1 L glass reactor with anchor stirrer, thermometer, nitrogen inlet, toluene separator and several feed vessels, 298.7 g of water were initially charged and heated to 100.degree. While nitrogen was being introduced, feeds 1 and 3 were then metered in continuously, with reflux and stirring, within 5 h, and feed 2 was continuously fed at 5.25 h at a constant rate of addition. The toluene introduced with feed 1 was continuously separated off at the separator. To complete the copolymerization, polymerization was allowed to continue for a further 1 hour after completion of the feeds, then the contents of the reactor were cooled and neutralized with 25% strength by weight sodium hydroxide solution.

The resulting solution had a solids content of 34.1% by weight and a pH of 6.8. The K value of the polymer was 37.0.

Feed 1: 224.7 g of the ester from Example 3 (toluene solution). Feed 2: 2.9 g of sodium peroxodisulfate dissolved in 39.1 g of water. Feed 3: 17.0 g of 40% strength by weight aqueous sodium bisulfite solution.

Example 5 Preparation of the Polymer 2 According to the Invention

The polymerization was carried out as in Example 4, 241, 9 g of water were presented and the feeds 1 and 2 had the following composition.

Feed 1: 366 g of the reaction mixture from Example 2 (65% strength by weight), 5.8 g of methacrylic acid and 0.4 g of mercaptoethanol.

Feed 2: 21, 0 g of a 7.5 wt .-% solution of sodium peroxodisulfate in water.

The pH and solids content of the resulting polymerization mixture and the K value of the polymer are shown in Table 1.

Example 6 Preparation of the Polymer 3 According to the Invention

The polymerization was carried out as in Example 4, to give 224.6 g of water and the feeds 1 and 2 had the following composition.

Feed 1: 341, 5 g of the reaction mixture from Example 2 (65 wt .-%), 12.9 g of methacrylic acid and 1, 0 g mercaptoethanol. Feed 2: 30.0 g of a 7.5% strength by weight solution of sodium peroxodisulfate in water.

The pH and solids content of the resulting polymerization mixture and the K value of the polymer are shown in Table 1.

Example 7: Preparation of the polymer 4 according to the invention

The polymerization was carried out as in Example 4, 388.3 g of water were submitted and the feeds 1 and 2 had the following composition.

Feed 1: 248.7 g of the reaction mixture from Example 2 (65 wt .-%), 69.8 g of the reaction mixture from Comparative Example 2 (65 wt .-%), 22.7 g of methacrylic acid and 1, 7 g mercaptoethanol. Feed 2: 42.0 g of a 7.5% strength by weight solution of sodium peroxodisulfate in water.

The pH and solids content of the resulting polymerization mixture and the K value of the polymer are shown in Table 1.

Example 8: Preparation of the Polymer 5 According to the Invention

The polymerization was carried out as in Example 4, to give 279.8 g of water and the feeds 1 and 2 had the following composition.

Feed 1: 123.4 g of the reaction mixture from Example 2 (65 wt .-%), 89.1 g of the reaction mixture from Comparative Example 1 (65 wt .-%), 34.6 g of the reaction mixture from Comparative Example 2 (65 % by weight), 22.7 g of methacrylic acid and 0.7 g of mercaptoethanol. Feed 2: 25.7 g of a 7.5% strength by weight solution of sodium peroxodisulfate in water.

The pH and solids content of the resulting polymerization mixture and the K value of the polymer are shown in Table 1. Table 1 :

Determination of the liquefying effect of the comb polymers 1 to 5 according to the invention

Apparatus:

Two 300 ml plastic cups and a stirring motor with propeller stirrer. For the evaluation of the truncated cone test specimen (inner diameter base 3.5 cm / peak 2 cm, height 6 cm), a glass plate and a 5 mm wide spatula.

Approach:

0.20 g of polymer (calculated at 100% by weight)

36.00 g of demineralised water (including water content of the respective polymer solution)

100.00 g cement CEM I 32.5 R (HeidelbergCement, Leimen plant)

Method:

Weigh the cement into the one beaker, in the second dilute the polymer with the specified amount of water. Add the cement to the dilute polymer solution and stir at 500 rpm for 1 min. Allow the modified cement paste to rest for 3 minutes, then stir for 15 seconds and pour into the truncated cone within 45 seconds. Vent with the spatula 2x lateral and 5x vertically, if necessary refill and smooth. Examine the test specimen exactly 5 minutes after the start of mixing and allow to drip for 10 seconds. Measure the horizontal and vertical diameter of the cement paste cake and average the two measurements. receive the following metrics:

results show that the polymers of the invention show good to very gulüssigungswirkung in cement paste.

Claims

claims

1. Use of comb polymers having a carbon backbone, the

Polyether groups of the formula A

^* -U- (C (O)) _k -X- (Alk-O) _n -YZ A

wherein

^* indicates the binding site to the carbon backbone of the comb polymer, U represents a chemical bond or an alkylene group of 1 to 8 carbon atoms,

X is oxygen or a group NR, k is 0 or 1, n is an integer whose mean value, based on the comb polymer, is in the range from 5 to 300,

Alk is C ₂ -C ₄ -alkylene, where Alk within the group (AIk-O) _{n may be} identical or different,

Y is a linear or branched alkylene group having 2 to 8 C atoms, which can carry a phenyl ring, Z is a nitrogen-bonded 5- to 10-membered nitrogen heterocycle, which is in the form of ring members, in addition to the nitrogen atom and in addition to carbon atoms, 1, 2 or 3 may have additional heteroatoms selected from among oxygen, nitrogen and sulfur, where the nitrogen ring members may have a group R 'and in which 1 or 2 carbon ring members may be present as the carbonyl group,

R is hydrogen, C 1 -C ₄ alkyl or benzyl, and

R 'is hydrogen, C _r C ₄ alkyl or benzyl;

and functional groups B, which are in the form of anionic groups at pH> 12,

and their salts as additives in preparations containing a mineral binder.

2. Use according to claim 1, wherein on average at least 50 mol% of the units AIk-O in the group (AIk-O) _{n are} CH ₂ -CH ₂ -O.

3. Use according to one of the preceding claims, wherein Z in formula A is a 5- or 6-membered nitrogen heterocycle which, in addition to the nitrogen atom bound to Y and carbon ring members, is one of O, S, N and a group NR selected ring member and / or a carbonyl group as a ring member, wherein R is hydrogen or methyl.

4. Use according to claim 3, wherein Z in formula A is pyrrolidone-1-yl, morpholin-4-yl, piperazin-1-yl, piperidone-1-yl, morpholin-2-one-4-yl,

Morpholin-3-one-4-yl, piperazin-1-yl, 4-methylpiperazin-1-yl, imidazolin-2-one-1-yl, 3-methylimidazolin-2-one-1-yl and imidazole-1 yl is selected.

5. Use according to one of the preceding claims, wherein on average at least every 4th carbon atom of the polymer backbone of the comb polymer forms a group

A or a group B carries.

6. Use according to one of the preceding claims, wherein the group B are carboxyl groups.

Use according to any one of the preceding claims, wherein the comb polymer additionally comprises groups of the formula C:

^* -U '- (C (O)) pX "- (Alk" -O) _q -R ^a C

wherein

U 'is a chemical bond or an alkylene group having 1 to 8 C atoms,

X "is oxygen or an NR group, wherein R is hydrogen Ci-C ₄ -alkyl or benzyl, p is 0 or 1, Alk" is C ₂ -C ₄ -alkylene, Alk '(within the group Alk "-O) _{q may be the} same or different, q is an integer whose mean value, based on the comb polymer, is in the range from 2 to 300,

R ^{a is} selected from hydrogen, C 1 -C 10 -alkyl, C 1 -C 10 -alkylcarbonyl, benzyl or benzoyl.

8. Use according to one of the preceding claims, wherein the Kammpo- lymer is available

by copolymerization of ethylenically unsaturated monomers M, comprising

a) neutral monoethylenically unsaturated monomers M1, which have one or two groups of the formula A, and b) monoethylenically unsaturated monomers M2 which have one or two functional groups B,

or

by homo- or copolymerization of ethylenically unsaturated monomers M, comprising

a) monoethylenically unsaturated monomers M3 which have a group of formula A and a functional group B, and optionally b) monoethylenically unsaturated monomers M2 which have one or two functional groups B.

9. Use according to claim 8, wherein the monomers M1 are selected from the esters of monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids and

Diesters of monoethylenically unsaturated C ₄ -Ce dicarboxylic acids with alcohols of the formula HO- (AIk-O) _n -YZ, wherein n, Alk, Y and Z have the meanings mentioned above, and the amides of monoethylenically unsaturated C ₃ -Ce monocarboxylic acids Amines of the formula NHR- (AIk-O) _n -YZ, wherein n, Alk, R, Y and Z have the meanings given above.

10. Use according to claim 8, wherein the monomers M3 are selected from the monoesters of monoethylenically unsaturated C ₄ -Ce-dicarboxylic acids with alcohols of the formula HO- (AIk-O) _n -YZ, wherein n, Alk, Y and Z are those mentioned above Have meanings.

1 1. Use according to claim 8, 9 or 10, wherein the monomers M2 are selected from monoethylenically unsaturated Cs-Cβ monocarboxylic acids and monoethylenically unsaturated C ₄ -C ₈ dicarboxylic acids.

12. Use according to any one of claims 8 to 11, wherein the copolymerization of the monomers M takes place in the presence of a molecular weight regulator.

13. Use according to any one of claims 1 to 7, wherein the comb polymer is lent by polymer-analogous reaction of homo- or copolymers with a carbon backbone having free carboxyl groups or ester-forming derivatives of carboxyl groups, with alcohols of the formula HO- (AIk-O ) _n -YZ or amines of the formula HNR- (AIk-O) _n -YZ in which n, Alk, R, Y and Z have the meanings given above.

Use according to any one of the preceding claims, wherein the mineral binder comprises at least 90% cement, gypsum or a mixture of gypsum cement.

A composition comprising at least one mineral binder and at least one comb polymer according to any one of the preceding claims.

16. comb polymers having a carbon backbone, the polyether groups of the formula

A ^* -U- (C (O)) _k -X- (Alk-O) _n -YZ A

wherein

^* indicates the binding site to the carbon backbone of the comb polymer,

U is a chemical bond or an alkylene group having 1 to 8 carbon atoms,

X is oxygen or a group NR, k is 0 or 1, n is an integer whose average, based on the comb polymer, is in the range from 1 to 300, Alk is C ₂ -C ₄ -alkylene, where Alk within the group (AIk-O) _{n may be the} same or different,

Y is a linear or branched alkylene group having 2 to 8 C atoms, which may carry a phenyl ring,

Z stands for a nitrogen-bonded 5- to 10-membered nitrogen heterocycle, which is in the form of ring members, next to the nitrogen atom and next to

Carbon atoms, 1, 2 or 3 additional heteroatoms selected from among oxygen, nitrogen and sulfur, wherein the nitrogen ring members may have a group R ', and wherein 1 or 2 carbon ring members may be present as the carbonyl group, R is hydrogen, C _r C ₄ - Alkyl or benzyl, and

R 'is hydrogen, C _r C ₄ alkyl or benzyl;

and functional groups B which are present in the form of anionic groups at pH> 12,

wherein on average at least 90 mol% of the units AIk-O in the group (AIk-O) _{n are} CH ₂ -CH ₂ -O,

and the salts of the comb polymers.

17. The comb polymer according to claim 16, wherein Z in formula A is a 5- or 6-membered nitrogen heterocycle which, in addition to the nitrogen atom bound to Y and carbon ring members, is a ring member selected from O, S, N and a group NR and / or a carbonyl group as a ring member, wherein R is hydrogen or methyl.

18. A comb polymer according to claim 17, wherein Z in formula A is pyrrolidone-1-yl, morpholin-4-yl, piperazin-1-yl, piperidone-1-yl, morpholin-2-one-4-yl, morpholine-3 -on-4-yl, piperazin-1-yl, 4-methylpiperazin-1-yl, imidazolin-2-one-1-yl, 3-methylimidazolin-2-one-1-yl and imidzol-1-yl ,

19. A comb polymer according to any one of claims 16 to 18, wherein on average at least every 4th carbon atom of the polymer backbone of the comb polymer carries a group A or a group B.

20. A comb polymer according to any one of claims 16 to 19, wherein the group B are xyloxyl groups.

21. Comb polymer according to one of claims 16 to 20, which additionally has groups of the formula C:

^* -U '- (C (O)) _p -X "- (Alk" -O) _q -R ^a C

where U 'is a chemical bond or an alkylene group having 1 to 8 C atoms, X "is oxygen or a group NR in which R is hydrogen or C 1 -C ₄ -alkyl, p is 0 or 1, Alk" is C ₂ C ₄ -alkylene, where Alk "within the group (Alk" -O) _{q may be} identical or different, q is an integer whose mean value, based on the comb polymer, is in the range from 2 to 300,

R ^{a is} selected from hydrogen, C 1 -C 10 -alkyl, C 1 -C 10 -alkylcarbonyl, benzyl or benzoyl.

22. A comb polymer according to any one of claims 16 to 21, which is obtainable

by copolymerization of ethylenically unsaturated monomers M, comprising a) neutral monoethylenically unsaturated monomers M1 which have one or two groups of the formula A, and b) monoethylenically unsaturated monomers M2 which have one or two functional groups B,

or

by homo- or copolymerization of ethylenically unsaturated monomers M, comprising

a) monoethylenically unsaturated monomers M3 which have a group of formula A and a functional group B, and optionally b) monoethylenically unsaturated monomers M2 which have one or two functional groups B.

23. A comb polymer according to claim 22, wherein the copolymerization of the monomers M takes place in the presence of a molecular weight regulator.

24. Comb polymer according to one of claims 16 to 21, which is obtainable by polymer-analogous reaction of homo- or copolymers having a carbon backbone, the free carboxyl groups or ester-forming derivatives of carboxyl have xylgruppen, with alcohols of the formula HO- (AIk-O ) _n -YZ or amines of the formula HNR- (AIk-O) _n -YZ wherein n, Alk, R, Y and Z have the meanings mentioned in claim 16.

25. comb polymers in the form of an aqueous solution of the alkali metal salts.