EP2855392A1

EP2855392A1 - Method for the production of solid accelerators for construction material mixtures

Info

Publication number: EP2855392A1
Application number: EP13725942.0A
Authority: EP
Inventors: Diana EIßMANN; Jutta Karin LANGLOTZ; Stefan Friedrich; Christoph Hesse
Original assignee: Construction Research and Technology GmbH
Current assignee: Construction Research and Technology GmbH
Priority date: 2012-05-29
Filing date: 2013-05-27
Publication date: 2015-04-08
Also published as: CN104350023B; CN104350023A; WO2013178560A1; US20150148456A1

Abstract

The invention relates to a method for producing solid compositions containing calcium silicate hydrate and at least one water-soluble polymer that has cationic, neutral, and/or sulfonic group-containing anionic structural units. In said method, an aqueous suspension of calcium silicate hydrate is brought in contact with the polymer, and the mixture is dried using a drum drying process.

Description

The present invention relates to a process for the preparation of solid compositions comprising calcium silicate hydrate and at least one water-soluble cationic, ampholytic, neutral or sulfo-containing anionic polymer.

Powdered hardening accelerators for cementitious building material mixtures, which are basically suitable for use in dry mortar mixtures because of their solid state of aggregation, are known in the prior art. Examples of such accelerators are calcium nitrate, calcium formate, calcium chloride and lithium carbonate. A disadvantage of chloride or nitrate-containing accelerators are their negative effects on the corrosion resistance of, for example, steel-reinforced concrete. Due to national standards, use restrictions exist. Efflorescence on the surface of hardened building materials can also be a problem, especially when using calcium salts (for example, calcium formate).

In many applications, there is a need to achieve even greater acceleration of setting and higher early strengths in cementitious systems, such as in mortar or concrete. However, the abovementioned accelerator types and other commercially available accelerators currently make it impossible for a person skilled in the art to achieve this goal, and a naturally undesirable loss of ultimate strength is to be observed in the case of conventional accelerators, especially at higher dosages. Thus, there is a great need in many applications to achieve higher early strengths, which is not possible with the accelerators currently known in the art.

Calcium silicate hydrate (CSH) suspensions have recently been used as highly efficient accelerators in (portland) cementitious building material mixtures such as concrete. They make it possible to achieve significantly higher early strengths (6 hours) compared to conventional accelerators. There is essentially no decrease in the final strengths (28 days). Corresponding suspensions are described in WO 2010026155 Al. However, for practical reasons it is not possible to use dry mortar mixtures which essentially contain (Portland) cement as binders. To formulate with the aqueous suspensions of calcium silicate hydrate (CSH), since the water content would lead to unacceptable, at least partial premature hydration of the binder. WO 2012/072466 describes solid compositions comprising calcium silicate hydrate and at least one water-swellable polymer which can form a hydrogel. The water-swellable polymer is a superabsorber which is insoluble in water. The water-swellable polymer, which can form a hydrogel with water or aqueous solutions, is selected from the group of anionic crosslinked polyelectrolytes, cationic crosslinked polyelectrolytes, ampholytic crosslinked polyelectrolytes and / or nonionic crosslinked polymers.

In the preparation of the C-S-H based powder hardening accelerators, large amounts of water must be removed. This process is tedious at low temperatures. At higher temperatures there is a risk that the accelerator effect and the dispersibility of the solid obtained are impaired.

In the field of cementitious dry mortar mixtures, as well as for non-dry mortar applications such as concrete, there is a need for suitable, highly effective accelerators, thus also in dry mortar systems a significant increase in early strengths, preferably without losses at the final strengths (strengths after 28 days) enable. In addition, there is a need for easy manufacture of the accelerators.

The present invention is therefore based on the object to provide a method for producing the accelerator available, which is quick and easy to carry out. The method should thus be feasible even at high drying temperatures and accelerators result, the effect is not adversely affected. In addition, the accelerators should be readily dispersible in aqueous media. The accelerators should enable an effective increase in early strengths without adversely affecting the final strength of the building material mixtures and be well compatible with water-sensitive, or water-binding binders such as (Portland) cement. Surprisingly, it has now been found that this object is achieved by a method in which the drying is carried out by a contact drying method.

The invention therefore relates to a process for the preparation of solid compositions containing calcium silicate hydrate (CSH) and at least one water-soluble polymer having cationic and / or neutral and / or sulfo-containing anionic structural units, comprising the following process steps: A) bringing into contact an aqueous, preferably as setting and curing accelerators for (portland) cementitious binder systems suitable suspension of calcium silicate hydrate with at least one polymer having cationic and / or neutral and / or sulfo-containing anionic structural units and B) drying the product of step A) by a contact drying method

Temperatures between 100 and 250 ° C, especially at temperatures between 120 and 250 ° C.

Preferably, the drying is carried out by a roller-drying method. The roll temperatures are preferably between 120 and 250 ° C, in particular between 150 and 230 ° C and particularly preferably at 160 to 220 ° C.

It has surprisingly been found that the (co) polymers used according to the invention are suitable as stabilizing additive in the drying process of the accelerator suspensions containing calcium silicate hydrate. It is therefore possible to dry the compositions with drum drying in comparison with other drying methods (drying in a circulating air dryer, fluidized bed drying, spray drying) particularly quickly and effectively even at high temperatures, the activity as accelerator and the dispersibility being largely retained. In addition, drum drying can effectively cure high viscosity (preferably 10,000 to 100,000 mPa * s) accelerator compositions where spray drying is not applicable since the compositions are not sprayable because of their high viscosity. Suitable stabilizing additives in the drum drying process of calcium silicate hydrate-containing accelerator suspensions are cationic, sulfo-containing anionic, ampholytic (containing cationic and sulfo-containing anionic structural units) or neutral polymers. These are homopolymers or copolymers (in the context of the present invention also collectively referred to as "(co) polymers" hereinafter). The polymers can be prepared by free-radical (co) polymerization of corresponding unsaturated monomers are prepared. Typically, _{w is} the molecular weight M of the thus produced (Co) polymers more than 100,000 g / mol, more preferably more than 300,000 g / mol.

Preference is given to solid compositions comprising calcium silicate hydrate and at least one such (co) polymer, the weight ratio of the (co) polymer to the calcium silicate hydrate being from 5: 1 to 1: 3, preferably from 2: 1 to 1: 2. Furthermore, comb polymer flow agents can be added as further additives to the suspension of calcium silicate hydrate to be dried in addition to the stabilizing additives. Conveniently, a calcium silicate hydrate suspension is used, which already contains the comb polymer superplasticizer. Such calcium silicate hydrate suspensions are described in WO 2010/026155 Al, wherein the comb polymer superplasticizers are already added during the preparation of the calcium silicate hydrate suspensions. The weight ratio of comb polymer flow medium to calcium silicate hydrate from 2: 1 to 1:10, preferably from 1: 1 to 1: 5.

With regard to the structure of the comb polymers and their preparation, reference is made in their entirety to the disclosure of WO 2010/026155. The comb polymers comprise, by copolymerization of at least one acid monomer, a structural unit in the copolymer corresponding to the general formulas (Ia), (Ib), (Ic) and / or (Id) (the structural units of each formula may be identical or different):

(Ia) wherein

R ^{1 is} H or an unbranched or branched C ¹ -C ⁴ -alkyl group;

X is NH- (C _n H ₂ ") with n = 1, 2, 3 or 4 or 0- (C _n H ₂ ") where n = 1, 2, 3 or 4 or is absent;

R ^{2 is} OH, P0 ₃ H ₂ , or 0-P0 ₃ H ₂ , with the proviso that if X is not present, R ^{2 is} OH;

(Ib)

wherein

R ^{3 is} H or an unbranched or branched C ¹ -C 4 -alkyl group; n = 0, 1, 2, 3 or 4

R ^{4 is} P0 ₃ H ₂ , or 0-P0 ₃ H ₂ ;

wherein

R ^{5 is} H or an unbranched or branched C 1 -C 4 -alkyl group;

Z is O or NH;

(Id)

wherein R ^{6 is} H or an unbranched or branched C ¹ -C ⁴ -alkyl group;

Q is NH and / or O;

R ^{7 is} H, (C _n H _2n ) -SO 3 H with n = 0, 1, 2, 3 or 4, preferably 1, 2, 3 or 4, (C _n H _2n ) - OH where n = 0, 1, 2, 3 or 4, preferably 1, 2, 3 or 4; (C _n H ₂ n) -P0 ₃ H ₂ with n = 0, 1,

2, 3 or 4, preferably 1, 2, 3 or 4, (C _n H ₂ n) -OPO ₃ H ₂ with n = 0, 1, 2, 3 or 4, preferably 1, 2, 3 or 4, (C ₆ H ₄ ) -SO ₃ H, (C ₆ H ₄ ) -PO ₃ H ₂ , (C ₆ H ₄ ) -OPO ₃ H ₂ or

(C _m H _2m ) _e -O- (A ^, O) _a -R ⁹ where m = 0, 1, 2, 3 or 4, preferably 1, 2, 3 or 4, e = 0, 1, 2, 3 or 4, preferably 1, 2, 3 or 4, A "= C _x H _2x with x '= 2, 3, 4 or 5 or CH ₂ C (C ₆ H ₅ ) H-, α = an integer of 1 to 350 with R ⁹ = unbranched or branched Ci-C ₄ alkyl group.

Typically, copolymerization of the polyether macromonomer produces a structural unit in the copolymer corresponding to general formulas (IIa), (IIb) and / or (IIc) (the structural units of each formula may be the same or different):

(IIa)

With

R ¹⁰ , R ¹¹ and R ^{12 may} each be the same or different and are independently H or an unbranched or branched C 1 -C ₄ alkyl group;

E represents a straight or branched Ci-C ₆ alkylene group, preferably a C ₂ -C ₆ alkylene group, a cyclohexylene group, CH ₂ -CeHio, ortho-, meta- or para- substituted is C ₆ H ₄ or absent is;

G is O, NH or CO-NH, with the proviso that if E is not present then G is not present; may be the same or different and is C _x H _2x with x = 2, 3, 4 or 5 (preferably x 2) or CH ₂ CH (C ₆ H ₅ ); n is 0, 1, 2, 3, 4 and / or 5; a is an integer from 2 to 350 (preferably 10 -200);

R ^{13 is} H, an unbranched or branched C 1 -C 4 -alkyl group, CO-NH ₂ and / or COCH ₃ ;

R ^{14 is} H or an unbranched or branched C 1 -C 4 -alkyl group;

E is an unbranched or branched C ₁ -C ₆ -alkylene group, preferably a C ₂ -C ₆ -alkylene group, a cyclohexylene group, CH ₂ -C ₆ Hi ₀ , ortho-, meta- or para-substituted C ₆ H ₄ or not existing is;

G is absent or is O, NH or CO-NH, with the proviso that if E is not present, G is also absent;

A can be the same or different and for C _x H _2x with x = 2, 3, 4 or 5 or

CH ₂ CH (C ₆ H ₅ ); n is 0, 1, 2, 3, 4 and / or 5; a is an integer from 2 to 350;

D is absent or is NH or O, with the proviso that if D is not present: b = 0, 1, 2, 3 or 4 and c = 0, 1, 2, 3 or 4, where b + c = 3 or 4, and with the proviso that when D is NH or O, b = 0, 1, 2 or 3, c = 0, 1, 2 or 3, where b + c = 2 or 3;

R ^{15 is} H, an unbranched or branched C 1 -C 4 -alkyl group, CO-NH ₂ or COCH ₃ ;

(IIc)

wherein

R ¹⁶ , R ¹⁷ and R ^{18 may} each be the same or different and are independently H or an unbranched or branched C 1 -C 4 -alkyl group;

E is an unbranched or branched C ₁ -C ₆ -alkylene group, preferably a C ₂ -C ₆ -alkylene group, a cyclohexylene group, CH ₂ -C ₆ Hi ₀ , ortho-, meta- or para-substituted C ₆ H ₄ or not is available; preferably E is present; A can be the same or different and for C _x H _2x with x = 2, 3, 4 or 5 or

CH ₂ CH (C ₆ H ₅ ); n is 0, 1, 2, 3, 4 and / or 5;

L may be the same or different and is C _x H _2x with x = 2, 3, 4 or 5 or CH ₂ CH (C ₆ H ₅ ); a is an integer from 2 to 350; d is an integer from 1 to 350;

R ^{19 is} H or an unbranched or branched C 1 -C 4 -alkyl group, R is H or an unbranched C 1 -C 4 -alkyl group.

In a further embodiment of the invention, a structural unit in the polymer is produced by copolymerization of the polyether macromonomer, which corresponds to the general formula (IId):

(IId)

O

wherein

R 21, R 22 and R 23 may be the same or different and represent H or an unbranched or branched C 1 -C 4 -alkyl group;

A is C _x H _2x with x = 2, 3, 4 or 5 or CH ₂ CH (C ₆ H ₅ ); a may be the same or different and is an integer from 2 to 350;

R ^{24 is} H or an unbranched or branched C 1 -C 4 -alkyl group, preferably a C 1 -C 4 -alkyl group.

The polyether macromonomer used is preferably alkoxylated isoprenol and / or alkoxylated hydroxybutylvyl ether and / or alkoxylated (meth) allyl alcohol and / or vinyl oxide. Lated methylpolyalkylene glycol, each preferably having an arithmetic mean of 4 to 340 oxyalkylene groups used. The acid monomer used is preferably methacrylic acid, acrylic acid, maleic acid, maleic anhydride, a monoester of maleic acid or a mixture of several of these compounds.

The invention also relates to solid compositions which are obtainable by the process according to the invention.

The composition of the invention is in the solid state. The composition is preferably pulverulent and is preferably suitable as a setting and curing accelerator for (portland) cement-containing binder systems. The proportion of water in the solid composition according to the invention should preferably be less than 15% by weight, particularly preferably less than 10% by weight. The solid composition of the present invention is preferably an accelerator composition.

The finely-dispersed calcium silicate hydrate (C-S-H) contained in the solid composition of the present invention may be modified by impurity ions such as magnesium, aluminum or sulfate.

The calcium silicate hydrate (as educt for further processing) can be prepared in the form of an aqueous suspension, preferably in the presence of a comb polymer flow as described above, see WO 2010/026155 Al, to which reference is made in its entirety. Preferably, the suspensions can be prepared by a process according to any one of claims 1 to 14 or 15 to 38 of WO 2010/026155 Al by reaction of a water-soluble calcium compound with a water-soluble silicate compound in the presence of an aqueous solution containing said water-soluble, as a hydraulic fluid Binder contains suitable comb polymer.

Usually, a suspension containing the calcium silicate hydrate (CSH) in finely dispersed form is obtained. The solids content of the suspension is preferably between 5 and 35% by weight, more preferably between 10 and 30% by weight, particularly preferably between 15 and 25% by weight. The inorganic component calcium silicate hydrate (CSH) can in most cases be described in terms of their composition by the following empirical formula: a CaO, Si0 ₂ , b A1 ₂ 0 ₃ , c H ₂ 0, d Z ₂ 0, e WO

Z is an alkali metal

W is an alkaline earth metal, preferably W is an alkaline earth metal, which is different from calcium,

0.1 <a <2, preferably 0.66 <a <1.8

0 <b <1, preferably 0 <b <0, 1

1 <c <6 preferably 1 <c <6.0

0 <d <1, preferably 0 <d <0.4

0 <e <2, preferably 0 <e <0, 1

More preferably, the molar ratios are selected such that in the above formula the preferred ranges for a, b and e are satisfied (0.66 <a <l, 8; 0 <b <0, l; 0 <e <0.1 ).

The calcium silicate hydrate is preferably present in the compositions according to the invention in the form of foshagite, hillebrandite, xonotlite, nekoite, clinoto-bermorite, 9A-tobiterite (riversiderite), 11A-tobermorite, 14% tobermorite (plombierite), tajennite, calcium chondrodite, afwillite, α-C ₂ SH, dellaite, jaffeite, rosehahnite, killalait and / or suolunite before, more preferably as xonotlite, 9A-tobermorite (riversiderite), 11A-tobermorite, 14A-tobermorite (plombierite), Jennit, Metajennit, Afwillit and / or Jaffeite. The molar ratio of calcium to silicon in the calcium silicate hydrate is preferably from 0.6 to 2 and more preferably from 1.0 to 1.8. The molar ratio of calcium to water in the calcium silicate hydrate is preferably from 0.6 to 6, more preferably from 0.6 to 2 and particularly preferably from 0.8 to 2.

The particle size of the calcium silicate hydrate (CSH) in the solid compositions according to the invention is preferably less than 1000 nm, particularly preferably less than 500 nm and in particular preferably less than 200 nm, measured by light scattering with the ZetaSizer Nano device from Malvern.

The (co) polymer can be crosslinked, i. swellable in water, or uncrosslinked. It preferably contains no structural units which are derived from monomers which have more than one free-radically polymerizable, ethylenically unsaturated vinyl group and / or no other crosslinking structural units. The (co) polymer used according to the invention is thus preferably uncrosslinked and not water-swellable.

The (co) polymer used according to the invention as a stabilizing additive preferably comprises the following structural units (the proportions of all structural units complement each other to 100 mol%): a) 0 to 100 mol% of cationic structural units of the general formula (I)

- CH ₂ - CR ¹ - CO YV

R ² - N - R ³ X ^" R ⁴

(I) wherein

R ^{1 is} H or a methyl radical,

R ² and R ^{3 may} each be identical or different and are each independently H, an aliphatic hydrocarbon radical having 1 to 20 C atoms (branched or unbranched, preferably methyl, ethyl radical), a cycloaliphatic hydrocarbon radical having 5 to 8 C Atoms (especially cyclohexyl) xylrest) or an aryl radical having 6 to 14 C atoms (in particular phenyl radical),

R ^{4 is} one of the meanings given for R ² or R ³ or - (CH ₂ ) _x -SO ₃ M _k ,

S0 ₃ M _k and / or

-S0 ₃ M _K and / or

preferably represents methyl or ethyl, M is a mono- or divalent metal cation, ammonium cation (NH ₄ ) or quaternary ammonium cation (NRiR ₂ R ₃ R ₄ ) ⁺ ,

k stands for Vi and / or 1,

Y is -O-, -NH- and / or -NR ² -, preferably -O-,

V for - CH ₂ ) _X -,

and or

stands,

x is an integer from 1 to 6 (preferably 1 or 2),

X is a halogen atom (preferably Cl or Br), Ci- to C ₄ -alkyl sulfate (preferred

Methylsulfate) or C 1 to C ₄ alkylsulfonate (preferably methylsulfonate); b) 0 to 100 mol% of cationic structural units of the general formula (II) -C

(Π) are identical or different and are H, an aliphatic hydrocarbon radical having 1 to 6 C atoms, or a phenyl radical optionally substituted by one, two or three methyl groups (preferably a methyl group), c) 0 to 100 mol% of anionic sulfo-containing Structural units of the general formula (III)

- CH ₂ - CR ¹ - CO NH R ⁵ --C - R ⁶ CH - R ⁷ S0 ₃ M _k (III) k, M, R ¹ , R ⁵ and R ^{6 have} the meanings given above,

R ^{7 is} H, an aliphatic hydrocarbon radical having 1 to 6 C atoms, or a phenyl optionally substituted by one, two or three methyl groups (preferably a methyl group); d) 0 to 100 mol% of amido group-containing structural units (neutral structural units) of the general formulas (IVa) and / or (IVb) -CH ₉ - CR ¹ - -CH ₉ - CR ¹ -

CO N-CO-R

NR ² R ³ Q

(IVa) (IVb) wonn

Q is H or -CHR ² R ⁵ ,

R ¹ , R ² and R ^{3 are} each as defined above with the proviso that, in the case of Q is not hydrogen, R ² and R ³ in the general formula (IVb) together for -CH ₂ - (CH ₂ ) y - can stand so that the general formula (IVb) has the following structure (IVc):

(IVc) wherein

R ^{8 is} H, a Ci to C ₄ alkyl, a carboxylic acid group and / or a

Carboxylate group -COOM _k , where y is an integer from 1 to 4 (preferably 1 or 2), and

R ⁵ , M and k each have the meanings given above, or

of esters of acrylic acid or methacrylic acid with C ₁ -C 8 -alkanols, such as methanol, ethanol or 2-ethylhexanol, esters of acrylic acid or methacrylic acid with C ₂ -C 5 -alkanediols, such as glycol or 1,3-propanediol and ethers of vinyl alcohol with Cs alkanols, such as vinyl ethyl ether or vinyl butyl ether, derived structural units. The structural units derived from the abovementioned esters and emers are in particular together with the units of the formulas (IVa), (IVb) and / or (IVc), preferably in a molar ratio of 1: 2 to 1:20, in particular 1: 3 to 1 : 10, included. The compositions of the invention may thus be polymers made up of structural units of one type. These are homopolymers. They can also be composed of different structural units. These are then copolymers. These may contain exclusively cationic, or exclusively neutral, or exclusively sulfo-containing anionic structural units. The copolymers may also be designed to contain anionic and cationic sulfonic acid-containing anionic and neutral, cationic and neutral or sulfo-containing anionic, cationic and neutral structural units.

The structural unit a) preferably results from the polymerization of one or more of the monomer species [2- (acryloyloxy) ethyl] trimethyl ammonium chloride, [2- (acryloylamino) ethyl] trimethyl ammonium chloride, [2- (acryloyloxy) ethyl] trimethyl ammonium methoxide, [2- (methacryloyloxy) ethyl] trimethyl ammonium chloride or methosulfate, [3- (acryloylamino) propyl] trimethyl ammonium chloride, [3- (methacryloylamino) propyl] trimethyl ammonium chloride , N- (3-sulfopropyl) -N-methyacryloxyethyl-N'-N-dimethyl-ammonium-betaine, N- (3-sulfopropyl) -N-methyacrylamidopropyl-N, N-dimethyl-ammonium-betaine and / or 1 - (3-sulfopropyl) -2-vinyl-pyridinium-betaine. Preference is given to [2- (acryloyloxy) ethyl] trimethylammonium chloride, [2- (acryloylamino) ethyl] trimethylammonium chloride, [2-

(Methacryloyloxy) ethyl] trimethyl ammonium chloride, [3- (acryloylamino) propyl] trimethyl ammonium chloride and [3- (methacryloylamino) propyl] trimethyl ammonium chloride. Particularly preferred are [2- (methacryloyloxy) ethyl] trimethyl ammonium chloride, [3- (acryloylamino) propyl] trimethyl ammonium chloride, and [3- (methacryloylamino) propyl] trimethyl ammonium chloride.

The structural unit b) is preferably derived from N, N-dimethyl-diallyl-ammonium chloride and / or Ν, Ν-diethyl-diallyl-ammonium chloride.

The structural unit c) is preferably derived from monomers such as 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutane-sulfonic acid and / or 2-acrylamido-2,4,4-trimethylpentanesulfonic acid. Particularly preferred is 2-acrylamido-2-methylpropanesulfonic acid (ATBS). In general, the structural unit d) from the polymerization of one or more of the monomer species acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-ethylacrylamide, N-cyclohexylacrylamide, N-benzylacrylamide, N-methylolacrylamide, N-tertiary Butyl acrylamide, etc. Examples of monomers as the basis for the structure (IVb) are N-methyl-N-vinylformamide, N-vinylformamide, N-methyl-N-vinylacetamide, N-vinylacetamide N-vinylpyrrolidone, N-vinylcaprolactam and / or N- Vinylpyrrolidone-5-carboxylic acid, forth. Preference is given to acrylamide, methacrylamide and / or N, N-dimethylacrylamide.

If the polymer used according to the invention is a copolymer, it may be structured as follows:

5 to 90 mol%, preferably 10 to 70 mol%, of structural units of the general formula (I) and 10 to 95 mol%, preferably 30 to 90 mol%, of structural units of the general formula (II), (III ), (IVa), (IVb), and / or (IVc);

5 to 90 mol%, preferably 10 to 70 mol%, of structural units of the general formula (II) and 10 to 95 mol%, preferably 30 to 90 mol%, of structural units of the general formula (III), (IVa ), (IVb), and / or (IVc); c) from 2 to 95 mol%, preferably from 5 to 90 mol%, in particular from 10 to 70 mol%, of structural units of the general formula (III) and from 5 to 98 mol%, preferably from 10 to 95 mol% %), in particular 30 to 90 mol .-%>, structural units of the general formula (IVa), (IVb), and / or (IVc); d) from 5 to 90 mol%), preferably from 10 to 70 mol%, of structural units of the general formula (III) and from 10 to 95 mol%, preferably from 30 to 90 mol%, of structural units of the general formula (IVa), (IVb), and / or (IVc); e) 5 to 90 mol%, preferably 10 to 70 mol%, of structural units of the general formula (IVa) and 10 to 95 mol%, preferably 30 to 90 mol%, of structural units of the general formula (IVb ), and / or (IVc); f) from 5 to 90 mol%), preferably from 10 to 70 mol%, of structural units of the general formula (IVb) and from 10 to 95 mol%, preferably from 30 to 90 mol%, of structural units of the general formula (IVc).

(The term "and / or" in this context means that the structural unit specified first may be contained alone or in combination with one or more of the other structural units).

Preference is given to copolymers having the structure specified under a) and c).

The polymers used according to the invention may also contain further monomers in copolymerized form. Examples of such monomers are acrylic acid, methacrylic acid, maleic acid, itaconic acid, esters of acrylic acid or methacrylic acid with C 1 -C 5 -alkanols, such as methanol, ethanol or 2-ethylhexanol, esters of acrylic acid or methacrylic acid with C 2 -C 8 -alkanediols, such as glycol or 1, 3-propanediol, etc. These monomers can be copolymerized in amounts of 0.1 to 30 mol% (the proportions of all monomers are complementary to 100 mol%). In the case of monomers containing carboxyl groups, however, not more than 20 mol% are copolymerized in.

The aqueous suspension of calcium silicate hydrate which is preferably used as setting and curing accelerator for (portland) cementitious binder systems is expediently prepared by reacting a water-soluble calcium compound with a water-soluble silicate compound, the reaction of the water-soluble calcium compound with the water-soluble silicate compound in Presence of an aqueous solution is carried out, which preferably contains a water-soluble, suitable as a flow agent for hydraulic binder comb polymer.

The aqueous, preferably as setting and curing accelerator for (portland) cementitious binder systems suitable suspension of calcium silicate hydrate is suitably prepared by reacting a water-soluble calcium compound with a water-soluble silicate compound, wherein the reaction of the water-soluble calcium compound with the water-soluble silicate compound is carried out in the presence of an aqueous solution which preferably contains a (co) polymer having carboxylic acid groups and / or carboxylate groups and sulfonic acid groups and / or sulfonate groups where the molar ratio of the number of carboxylic acid groups and / or carboxylate groups to the sulfonic acid groups and / or sulfonate groups is from 1/20 to 20/1, preferably 1/5 to 5/1, particularly preferably 1/2 to 2/1. Preferably, the calcium silicate hydrate is not derived from a hydration reaction of (Portland) cement with water.

The drying in step B) is preferably carried out at temperatures (roll temperature) between 120 and 250 ° C, preferably between 150 and 230 ° C. The drying apparatus used are customary apparatuses for contact drying, in particular

Drum drying devices. Such devices are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th ed., Vol. B2, 4-25.

According to the invention, a process step C) can be followed, which comprises the grinding of the dried product from process step B) to form a powder.

The invention also relates to the use of the compositions according to the invention as a hardening accelerator in (Portland) cement, blastfurnace, fly ash, silica fume, meta-tocolin, natural pozzolans, burnt oil shale and / or calcium aluminate cement-containing building material mixtures or in building material mixtures containing (Portland ) cement and based on calcium sulfate binders, preferably in building material mixtures containing as a hydraulic binder substantially (Portland) cement. Preferably, the building material mixtures contain water, particularly preferably in a weight ratio of water to powder (W / P) of 0.2 to 0.8, where powder is the sum of the binder contained in the building material, preferably (Portland) cement understood.

The invention also relates to the use of the compositions according to the invention as grinding aids in the production of (Portland) cement. The invention further relates to building material mixtures comprising the compositions according to the invention and (Portland) cement, blastfurnace slag, fly ash, silica fume, metakaolin, natural pozzolans, burnt oil shale and / or calcium aluminate cement, or building material mixtures comprising the compositions according to the invention (Portland). cement and calcium sulfate-based binders, preferably building material mixtures containing cement as a hydraulic binder substantially (Portland).

Preference is given to compositions according to the invention which contain no (Portland) cement. Particular preference is given to compositions according to the invention which contain no (Portland) cement which has come into contact with water. Under (Portland) cement, which has come into contact with water, it should also be understood dried mixtures of (Portland) cement and water, which may contain a small proportion of water.

The (co) polymerization of the monomers is preferably carried out by free-radical bulk, solution, gel, emulsion, dispersion or suspension polymerization. Since the products according to the invention are hydrophilic (co) polymers, preference is given to polymerization in the aqueous phase, reverse-emulsion polymerization or inverse-suspension polymerization. In particularly preferred embodiments, the reaction takes place as solution polymerization, gel polymerization or as inverse suspension polymerization in organic solvents.

The preparation of the (co) polymers can be carried out in a particularly preferred embodiment as adiabatic polymerization and can be started both with a redox initiator system and with a photoinitiator. In addition, a combination of both start variants is possible. The redox initiator system consists of at least two components, an organic or inorganic oxidizing agent and an organic or inorganic reducing agent. Frequently, compounds with peroxide units are used, for example inorganic peroxides such as alkali metal and ammonium persulfate, alkali metal and ammonium perphosphates, hydrogen peroxide and its salts (sodium peroxide, barium peroxide) or organic peroxides such as benzoyl peroxide, butyl hydroperoxide or peracids such as peracetic acid. In addition, however, it is also possible to use other oxidizing agents, for example potassium permanganate, sodium or potassium liumchlorate, potassium dichromate, etc. Sulfur-containing compounds such as sulfites, thiosulfates, sulfamic acid, organic thiols (for example, ethylmercaptan, 2-hydroxyethanethiol, 2-mercaptoethylammonium chloride, thioglycolic acid) and others may be used as the reducing agent. In addition, ascorbic acid and low-valency metal salts are possible [copper (I); Manganese (II); Iron (II)]. Phosphorus compounds can also be used, for example sodium hypophosphite.

In the case of photopolymerization, this is started with UV light, which causes the decomposition of a photoinitiator. For example, benzoin and benzoin derivatives such as benzoin ethers, benzil and its derivatives such as benzil ketals, aryl diazonium salts, azo initiators such as e.g. 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-amidinopropane) hydrochloride and / or acetophenone derivatives.

The proportion by weight of the oxidizing and the reducing component in the case of the redox initiator systems is preferably in the range from 0.00005 to 0.5% by weight, more preferably in each case from 0.001 to 0.1% by weight. For photoinitiators, this range is preferably between 0.001 and 0.1% by weight, more preferably between 0.002 and 0.05% by weight. The stated percentages by weight for oxidizing and reducing components and photoinitiators in each case relate to the mass of the monomers used for the copolymerization.

The (co) polymerization is preferably carried out batchwise in aqueous solution, preferably in concentrated aqueous solution, in a polymerization vessel (batch process) or continuously according to the "endless belt" method described in US-A-485 7610. Another possibility is polymerization in one The process is usually started at a temperature between -20 and 20 ° C, preferably between -10 and 10 ° C and carried out at atmospheric pressure without external heat, wherein the heat of polymerization a depending on the monomer content maximum end temperature of 50 up to 150 ° C. After the end of the (co) polymerization, one usually takes place

Comminution of the polymer. The comminuted polymer is dried in the case of a laboratory scale in a convection oven at 70 to 180 ° C, preferably at 80 to 150 ° C. On an industrial scale, drying may also be carried out in a continuous manner, for example on a belt dryer or in a fluidized bed dryer respectively. (These changes have been made because it is stated above that the polymers are not swellable)

In a further preferred embodiment, the (co) polymerization takes place as an inverse suspension polymerization of the aqueous monomer phase in an organic solvent. In this case, the procedure is preferably such that the monomer mixture dissolved in water and optionally neutralized is polymerized in the presence of an organic solvent in which the aqueous monomer phase is insoluble or sparingly soluble. Preference is given to working in the presence of "water in oil" emulsifiers (W / O emulsifiers) and / or protective colloids based on low or high molecular weight compounds in proportions of 0.05 to 5 wt .-%, preferably 0.1 to 3 wt .-%, based on the monomers used. The W / O emulsifiers and protective colloids are also referred to as stabilizers. It is possible to use customary compounds known as stabilizers in the inverse suspension polymerization technique, such as hydroxypropylcellulose, ethylcellulose, methylcellulose, cellulose acetate butyrate blends, copolymers of ethylene and vinyl acetate, of styrene and butyl acrylate, polyoxyethylene sorbitan monooleate, laurate or stearate and block copolymers of propylene and / or or ethylene oxide.

Suitable organic solvents are, for example, linear aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, branched aliphatic hydrocarbons (isoparaffins), cycloaliphatic hydrocarbons such as cyclohexane and decalin, and also aromatic hydrocarbons such as benzene, toluene and xylene , In addition, alcohols, ketones, carboxylic acid esters, nitro compounds, halogen-containing hydrocarbons, ethers and many other organic solvents are suitable. Preference is given to those organic solvents which form azeotropic mixtures with water, particularly preferred are those which have the highest possible water content in the azeotrope.

The (co) polymers initially accumulate as finely divided aqueous droplets in the organic suspension medium and are preferably isolated by removing the water as solid spherical particles in the organic suspending agent. After separation of the suspending agent and drying, a powdery solid remains. The inverse suspension polymerization is known to have the advantage that the particle size distribution of the powders can be controlled by varying the polymerization conditions and thus an additional process step (grinding process) for adjusting the particle size distribution can usually be avoided.

The solid compositions according to the invention are preferably used in dry mortar mixtures, in particular in powder form.

The invention also relates to the use of the compositions according to the invention as grinding aids in the production of (Portland) cement, preferably in the milling of the clinker or clinker blend to (Portland) cement. Clinker blend is preferably understood to mean a mixture of clinker and substitutes such as slag, fly ash and / or pozzolans. The compositions are used in amounts of from 0.001% by weight to 5% by weight, preferably in amounts of from 0.01% by weight to 0.5% by weight, in each case based on the clinker or clinker blend to be milled. It is possible to use the compositions according to the invention as grinding aids in ball mills or in vertical mills. The compositions according to the invention can be used as grinding aids alone or else in combination with other grinding aids, for example mono-, di-, tri- and polyglycols, polyalcohols (for example glycerol of different degrees of purity, for example from biodiesel production), amino alcohols (eg MEA , DEA, TEA, TIPA, THEED, DIHEIPA), organic acids and / or their salts (eg acetic acid and / or salts thereof, formates, gluconates), amino acids, sugars and residues from sugar production (eg molasses, vinasse), inorganic salts (Chlorides, fluorides, nitrates, sulfates) and / or organic polymers (eg polyether carboxylates (PCEs)). It has been found that in particular the early strengths of the (Portland) cement thus produced can be improved. Likewise, the accelerator suspensions (liquid) disclosed in WO 2010026155 A1 and the pulverulent accelerators disclosed in WO 2010026155 A1 are suitable as grinding aids in the production of (Portland) cement from clinker or clinker blends. These grinding aids may also be used alone or in combination with the aforementioned list of grinding aids. Again, both a ball mill and a vertical mill can be used.

Preference is given to building material mixtures comprising solid compositions of calcium silicate hydrate and at least one (co) polymer according to the invention and (Portland) cement, blast furnace slag, fly ash, silica fume, metakaolin, natural pozzolans, burnt oil shale ferric and / or calcium aluminate cement, the solid composition containing no (Portland) cement which has come into contact with water. Under (Portland) cement, which has come into contact with water, it should also meanwhile understood dried mixtures of (Portland) cement and water, which may contain a preferred low water content.

The building material mixtures may contain defoamers, air-entraining agents, fillers, redispersible polymer powders, retarders, thickeners, water retention agents and / or wetting agents as other additives.

Preparation Examples Polymer 1 (cationic)

A 2 l polymerization reactor with stirrer, reflux condenser, thermometer and inert gas connection was charged with 592.6 g of water. With stirring, 400 g (0.91 mol) of [3- (methacrylamido) propyl] trimethylammonium chloride (50% by weight solution in water) was added and then the pH was adjusted to 7.0. The solution was rendered inert by flushing with nitrogen for 30 minutes and heated to 70 ° C. Then, 1.2 g of tetraethylenepentamine (20% by weight solution in water) and 8.0 g of sodium peroxodisulfate (20% by weight solution in water) were successively added to start the polymerization. It was stirred for 2 hours at 70 ° C to complete the polymerization.

Polymer 2 (ampholytic)

A 2 l polymerization reactor with stirrer, reflux condenser, thermometer and inert gas connection was charged with 592.6 g of water. With stirring, 356.3 g (0.81 mol) of [3- (methacrylamido) propyl] trimethylammonium chloride (50% by weight solution in water) and 43.7 g (0.10 mol) of 2-acrylamido-2 Methylpropanesulfonsäure sodium salt (50 wt .-% solution in water) was added, and then adjusted the pH to 7.0. The solution was rendered inert by flushing with nitrogen for 30 minutes and heated to 70 ° C. Then, 1.2 g of tetraethylenepentamine (20% by weight solution in water) and 8.0 g of sodium peroxodisulfate (20% by weight solution in water) were successively added to start the polymerization. It was stirred for 2 hours at 70 ° C to complete the polymerization. Polymer 3 (anionic)

A 2 l polymerization reactor with stirrer, reflux condenser, thermometer and inert gas connection was charged with 791.0 g of water. With stirring, 105.0 g (0.23 mol) of 2-acrylamido-2-methylpropanesulfonic acid sodium salt (50 wt .-% solution in water) and 48.0 g (0.48 mol) of N, N-dimethylacrylamide added, and then the pH is adjusted to 7.0. The solution was inerted by nitrogen purge for 30 minutes and heated to 70 ° C. Then, 0.9 g of tetraethylenetetamine (20% by weight solution in water) and 6.5 g of sodium peroxodisulfate (20% by weight solution in water) were added successively to start the polymerization. It was stirred for 2 hours at 70 ° C to complete the polymerization.

Production Example Accelerator Powder:

The preparation of the calcium silicate hydrate-containing powders was carried out by mixing one or more of several stabilizing additives (as aqueous solution or solid) with the CSH suspension DPI. DPI is an aqueous calcium silicate hydrate suspension prepared from calcium acetate and Na ₂ Si0 ₃ according to WO 2010026155 Al, which contains 5.4% by weight of MVA® 2500 (product of BASF Construction Polymers GmbH), solids content 45.4% by weight. DPI contains 1.85 wt.% CaO and 1.97 wt.% Si0 ₂ . The percentages given in% by weight relate in each case to the entire aqueous suspension. The CSH suspension DPI was placed in a container and stirred with a finger stirrer. Carefully, the appropriate amount (see Table 1) of the respective stabilizing additive was added (as an aqueous solution or solid). The resulting mixture was stirred for about 30 minutes and then dried with a roller dryer (roller temperature 200 ° C). The dried powder was then converted into a powdery state by means of a centrifugal mill. The average particle diameter of the polymer powder was 40 to 60 μιη. The particle size is determined according to the norm edana 420.2-02. applications

Table 1 contains example compositions of the powders according to the invention.

Table 1: Compositions according to the invention and comparative examples

² Starvis ^® 2006 F is an ampholytic polymer product from BASF Construction Polymers GmbH. ³ Starvis ^® 4500 F is a sulfo-containing anionic polymer product from BASF Construction Polymers GmbH. ⁴ MVA 2500 ^® is an anionic comb polymer plasticizer product from BASF Construction Polymers GmbH.

In order to check the effectiveness of the resulting powders according to the invention, 6-hour strengths were determined in a standard mortar (prisms analogous to DIN EN 196-1, used in Styrofoam prism shapes). Formulation standard mortar: 225 g of water

1350 g of standard sand

450 g of CEM I 52.5 R Milke

The following mixtures were tested as reference experiments:

Comparison 1: blank value without addition of accelerator

Comparison 2: with aqueous C-S-H suspension (DPI)

Comparison 3: with a powder obtained from the C-S-H suspension DPI by drying at 200 ° C on the roller dryer without any additives.

Table 2: Flexural and compressive strengths

DosieBiegezugfestigDruckfestigung [g] speed [N / mm ² ] speed [N / mm ² ]

after 6 h after 6 h

Comparison 1 not measurable, not measurable,

(Blank value without addition of prism breaks prism breaks

Accelerator) when stripping when stripping

Comparison 2 ¹ 59.1 3.4 14.3

(aqueous C-S-H suspension

DPI)

Comparison 3 4.7 0.2 0.8

(at 200 ° C roller-dried C-S-H suspension DPI)

Powder 1 7.0 2.0 7.2

Powder 2 9.2 3.0 10.8

Powder 3 7.0 1.5 4.7

Powder 4 9.2 2.9 11.3

Powder 5 7.0 2.5 9.3

Powder 6 9,2 3,8 14,2

Powder 7 7.0 3.8 1.3 Powder 8 8.1 2.1 7.1

Powder 9 7.0 3.7 1.2

Powder 10 8.1 2.0 6.5

Powder 11 7.0 4.1 12.4

The mixing water of this mortar mix was reduced by 54.4 grams to set the same water cement level.

When using the powders according to the invention, it was possible to show that the activity of the powders according to the invention as drying accelerator is markedly improved in comparison with reference experiment 3 with the C-S-H powder dried without addition of polymer, ie. the 6h strengths are significantly higher.

Claims

claims

1. A process for the preparation of solid compositions comprising calcium silicate hydrate and at least one water-soluble polymer having cationic, neutral and / or sulfo-containing anionic structural units, comprising the following process steps:

A) bringing into contact an aqueous suspension of calcium silicate hydrate with at least one polymer having cationic, neutral and / or sulfo-containing anionic structural units and

B) drying the product of step A) by a roller-drying process at temperatures between 100 and 250 ° C.

2. The method of claim 1, wherein the drying in step B) takes place at temperatures between 150 and 230 ° C.

3. The method of claim 1 or 2, wherein one or more successively arranged drying rollers used.

4. The method according to any one of the preceding claims, wherein the (co) polymer

The following structural units comprise: a) 0 to 100 mol% of cationic structural units of the general formula (I)

CH ₂ - CR ¹ CO YV

R ² - N ⁺ - R ⁴

(I) wonn

R ^{1 is} H or a methyl radical,

R ² and R ^{3 may be the} same or different and are each independently

H, an aliphatic hydrocarbon radical having 1 to 20 C atoms, a cycloaliphatic hydrocarbon radical having 5 to 8 C atoms or an aryl radical having 6 to 14 C atoms,

S0 ₃ M _k or

or stands,

M is a monovalent or divalent metal cation, ammonium cation (NH ₄ ⁺ ) or quaternary ammonium cation (NRiR ₂ R ₃ R ₄ ) ⁺ ,

k stands for Vi or 1,

Y is -O-, -NH- or -NR ² -,

V for - CH ₂ ) _X -,

or

is an integer from 1 to 6,

represents a halogen atom, C 1 to C ₄ alkylsulfate or C 1 to C ₄ alkylsulfonate;

0 to 100 mol% of cationic structural units of the general formula (II)

-C

(Π)

wherein

R ⁵ , R ^{6 are} identical or different and are H, an aliphatic hydrocarbon radical having 1 to 6 C atoms, or a phenyl radical optionally substituted by one, two or three methyl groups, c) 0 to 100 mol% of anionic sulfo-containing structural units of the general Formula (III)

- CH ₂ - CR ¹ - CO NH R ⁵ --C - R ⁶ CH - R ⁷ S0 ₃ M _k (III) where

k, M, R ¹ , R ⁵ and R ^{6 have} the meanings given above, R is H, an aliphatic hydrocarbon radical having 1 to 6 C atoms or a phenyl radical optionally substituted by one, two or three methyl groups; d) 0 to 100 mol% of amido group-containing structural units of the general formulas (IVa) and / or (IVb)

CO N CO

NR ² R ³ Q

(IVa) (IVb) in which

Q is H or -CHR ² R ⁵ ,

R, R and R each have the meanings given above with the proviso that, in the case of Q other than hydrogen, R ² and R ³ in the general formula (IVb) together may be -CH ₂ - (CH ₂ ) y- in that the general formula (IVb) has the structure (IVc):

-CH _? - CR ¹ -

(IVc) wherein

R ^{8 is} H, a C 1 to C ₄ alkyl radical, a carboxylic acid group or a carboxylate group -COOM _k , where y is an integer from 1 to 4, and

R ⁵ , M and k each have the meanings given above.

5. The method according to claim 4, wherein the polymer has a composition selected from: 5 to 90 mol% of structural units of the general formula (I) and 10 to 95 mol% of structural units of the general formula (II), (III ), (IV a), (IVb), and / or (IVc); and

2 to 95 mol% of structural units of the general formula (III) and 5 to 98 mol% of structural units of the general formula (IVa), (IVb), and / or (IVc).

6. The method of claim 4, wherein the polymer has a composition selected from:

10 to 70 mol% of structural units of the general formula (I) and 30 to 90 mol% of structural units of the general formula (II), (III), (IVa), (IVb), and / or (IVc); and 5 to 90 mol% of structural units of the general formula (III) and 10 to 95 mol% of structural units of the general formula (IVa), (IVb), and / or (IVc).

A process according to any one of the preceding claims, wherein the polymer has a molecular weight greater than 100,000 g / mol.

A process according to any one of the preceding claims wherein the weight ratio of polymer to calcium silicate hydrate is from 5: 1 to 1: 3.

9. The method according to any one of the preceding claims, wherein an uncrosslinked polymer is used lymer.

10. The method according to any one of claims 1 to 8, wherein a water-swellable polymer is used.

11. The method according to any one of the preceding claims, wherein in step (A) additionally a comb polymer flow medium is used.

12. The method according to any one of the preceding claims, wherein the aqueous suspension of calcium silicate hydrate is prepared by reacting a water-soluble calcium compound with a water-soluble silicate compound.

13. A solid composition obtainable by a process according to any one of claims 1 to 12.

14. Solid composition containing calcium silicate hydrate and at least one uncrosslinked water-soluble polymer having cationic, neutral and / or sulfo-containing anionic structural units.

15. The solid composition according to claim 14, wherein the (co) polymer comprises the following structural units: a) 0 to 100 mol% of cationic structural units of the general formula (I)

- CH ₂ - CR ¹ - CO YV

R ² - N ⁺ - R ³ XR ⁴

(I) wherein

R ^{1 is} H or a methyl radical,

R ² and R ^{3 may be the} same or different and are each independently

H, an aliphatic hydrocarbon radical having 1 to 20 C atoms, a cycloaliphatic hydrocarbon radical having 5 to 8 C atoms or an aryl radical having 6 to 14 C atoms, R ^{4 is} one of those given for R ² or R 'meanings or for - (CH ₂ ) _x -S0 ₃ Mk, S0 ₃ M _k or

stands,

M is a mono- or divalent metal cation, ammonium cation (NH ₄ ⁺ ) or quaternary ammonium cation (NRiR ₂ R R4) ⁺ ,

k stands for Vi or 1,

Y is -O-, -NH- or -NR ² -,

V for - CH ₂ ) _X -,

stands

x is an integer from 1 to 6,

X is a halogen atom, C 1 to C ₄ alkylsulfate or C 1 to C ₄ alkylsulfonate; b) 0 to 100 mol% of cationic structural units of the general formula (II)

-C

(Π)

wherein R ⁵ , R ^{6 are} identical or different and are H, an aliphatic hydrocarbon radical having 1 to 6 C atoms, or a phenyl radical optionally substituted by one, two or three methyl groups, c) 0 to 100 mol% of anionic sulfo-containing structural units of the general Formula (III)

- CH ₂ - CR ¹ - CO NH R ⁵ --C - R ⁶ CH - R ⁷ S0 ₃ M _k (III) where

k, M, R ¹ , R ⁵ and R ^{6 have} the meanings given above,

R ^{7 is} H, an aliphatic hydrocarbon radical having 1 to 6 C atoms or a phenyl radical optionally substituted by one, two or three methyl groups; d) 0 to 100 mol% of amido group-containing structural units of the general formulas (IVa) and / or (IVb)

- CH ₂ - CR ¹ - - CH ₂ - CR ¹ -

CO N-CO-R ³

NR ² R ³ Q wherein

Q is H or -CHR ² R ⁵ , R ¹ , R ² and R ^{3 are} each as defined above with the proviso that, in the case of Q is not hydrogen, R ² and R ³ in the general formula (IVb) together for -CH ₂ - (CH ₂ ) y - can stand so that the general formula (IVb) has the following structure (IVc):

(IVc) wherein

R ⁵ , M and k each have the meanings given above.

A solid composition according to claim 15, wherein the polymer has a composition selected from:

5 to 90 mol% of structural units of the general formula (I) and 10 to 95 mol% of structural units of the general formula (II), (III), (IVa), (IVb), and / or (IVc) ; and

The solid composition of claim 15, wherein the polymer has a composition selected from:

A solid composition according to any one of claims 14 to 17, wherein the weight ratio of polymer to calcium silicate hydrate is from 5: 1 to 1: 3.

19. A building material mixture containing a composition according to any one of claims 13 to 18 and (Portland) cement, blastfurnace, fly ash, silica fume, metakaolin, natural pozzolans, burnt oil shale, calcium aluminate cement, or mixtures of two or more of these components or building material mixture containing a composition according to any one of claims 13 to 18, (Portland) cement and calcium sulfate based binder.

20. Use of the composition according to any one of claims 13 to 18 as a hardening accelerator in building material mixtures, the (Portland) cement, blastfurnace, fly ash, silica fume, metakaolin, natural pozzolans, burnt oil shale, calcium aluminate cement or mixtures of two or more of these components or in building material mixtures containing (Portland) cement and calcium sulfate-based binders, or in building material mixtures which contain cement as a hydraulic binder substantially (Portland).

21. Use of the composition according to any one of claims 13 to 18 as a grinding aid in the production of (Portland) cement.