Additive for hydraulically setting compounds

Abstract

The present invention relates to an additive for hydraulically setting compositions, comprising a colloidally disperse preparation of at least one water-soluble salt of a polyvalent metal cation, at least one compound capable of releasing an anion which forms a sparingly soluble salt with the polyvalent metal cation, and at least one polymeric dispersant which comprises anionic and/or anionogenic groups and polyether side chains.

Claims

1. Additive for hydraulically setting compositions, comprising a colloidally disperse preparation of at least one water-soluble salt of a polyvalent metal cation, at least one compound able to release an anion which forms a sparingly soluble salt with the polyvalent metal cation, and at least one polymeric dispersant which comprises anionic and/or anionogenic groups and polyether side chains, the polyvalent metal cation being selected from Al.sup.3+, Fe.sup.3+, Fe.sup.2+, Zn.sup.2+, Mn.sup.2+, Cu.sup.2+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+ and mixtures thereof, the metal cation being present in an amount such that the following relation according to formula (a) is greater than 0 and less than or equal to 1: $\begin{array}{cc}0<\frac{{.Math.}_i{z}_{K,i}\times n_{K,i}}{{.Math.}_j{z}_{s,j}\times n_{s,j}}\le 1& \left(a\right)\end{array}$ and where z.sub.K,i is the amount of the charge number of the polyvalent metal cation, n.sub.K,i is the number of moles of the polyvalent metal cation, z.sub.S,j is the amount of the charge number of the anionic and anionogenic group present in the polymeric dispersant, and n.sub.S,j is the number of moles of the anionic and anionogenic group present in the polymeric dispersant, the indices i and j are independent of one another and are an integer greater than 0, where i is the number of different polyvalent metal cations and j is the number of different anionic and anionogenic groups present in the polymeric dispersant.

2. The additive according to claim 1, the polyvalent metal cation and the anion being present in amounts which are calculated according to the following formulae: $\begin{array}{cc}0<\frac{{.Math.}_i{z}_{K,i}\times n_{K,i}}{{.Math.}_j{z}_{s,j}\times n_{s,j}}\le 1& \left(a\right)\\ 0<\frac{{.Math.}_l{z}_{A,l}\times n_{A,l}}{{.Math.}_i{z}_{K,i}\times n_{K,i}}\le 3& \left(b\right)\end{array}$ where z.sub.K,i is the amount of the charge number of the polyvalent metal cation, n.sub.K,i is the number of moles of the polyvalent metal cation, z.sub.S,j is the charge number of the anionic and anionogenic groups present in the polymeric dispersant, n.sub.S,j is the number of moles of the anionic and anionogenic groups present in the polymeric dispersant, z.sub.A,l is the charge number of the anion, n.sub.A,l is the number of moles of the anion, the indices i, j and I are independent of one another and are an integer greater than 0, where i is the number of different polyvalent metal cations, j is the number of different anionic and anionogenic groups present in the polymeric dispersant, and I is the number of different anions which are able to form a sparingly soluble salt with the metal cation.

3. The additive according to claim 1, the anion being selected from carbonate, oxalate, silicate, phosphate, polyphosphate, phosphite, borate, aluminate, sulfate and mixtures thereof.

4. The additive according to claim 1, the anion being phosphate and/or aluminate.

5. The additive according to claim 1, the metal cation being selected from Al.sup.3+, Fe.sup.3+, Ca.sup.2+ and mixtures thereof.

6. The additive according to claim 1, the polyvalent metal cation and the anion being present in amounts which are calculated according to the following formula: $\begin{array}{cc}0.25<\frac{{\left({.Math.}_i{z}_{K,i}\times n_{K,i}\right)}^2}{\left({.Math.}_l{z}_{A,l}\times n_{A,l}\right)\left({.Math.}_j{z}_{s,j}\times n_{s,j}\right)}<25.& \left(c\right)\end{array}$

7. The additive according to claim 1, having a pH of 2 to 11.5.

8. The additive according to claim 1, the polymeric dispersant comprising as anionic or anionogenic group at least one structural unit of the general formulae (Ia), (Ib), (Ic) and/or (Id): ##STR00025## in which R.sup.1 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group, CH.sub.2COOH or CH.sub.2CO—X—R.sup.2; X is NH—(C.sub.nH.sub.2n), O(C.sub.nH.sub.2n) with n=1, 2, 3 or 4, the nitrogen atom or the oxygen atom, respectively, being attached to the CO group, or is a chemical bond; R.sup.2 is OM, PO.sub.3M.sub.2, or O—PO.sub.3M.sub.2; with the proviso that X is a chemical bond when R.sup.2 is OM; ##STR00026## in which R.sup.3 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; n is 0, 1, 2, 3 or 4; R.sup.4 is PO.sub.3M.sub.2, or O—PO.sub.3M.sub.2; ##STR00027## in which R.sup.5 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; Z is O or NR.sup.7; and R.sup.7 is H, (C.sub.nH.sub.2n)—OH, (C.sub.nH.sub.2n)—PO.sub.3M.sub.2, (C.sub.nH.sub.2n)—OPO.sub.3M.sub.2, (C.sub.6H.sub.4)—PO.sub.3M.sub.2, or (C.sub.6H.sub.4)—OPO.sub.3M.sub.2, n is 1, 2, 3 or 4; ##STR00028## in which R.sup.9 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; Q is NR.sup.7 or O; R.sup.7 is H, (C.sub.nH.sub.2n)—OH, (C.sub.nH.sub.2n)—PO.sub.3M.sub.2, (C.sub.nH.sub.2n)—OPO.sub.3M.sub.2, (C.sub.6H.sub.4)—PO.sub.3M.sub.2, (C.sub.6H.sub.4)—OPO.sub.3M.sub.2 or (C.sub.nH.sub.2n)—O-(AO).sub.α—R.sup.9, A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); α is an integer from 1 to 350; R.sup.9 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; n is 1, 2, 3 or 4; and each M in the abovementioned formulae independently of any other is H or one cation equivalent.

9. The additive according to claim 1, the polymeric dispersant comprising as polyether side chain at least one structural unit of the general formulae (IIa), (IIb), (IIc) and/or (IId): ##STR00029## in which R.sup.10, R.sup.11 and R.sup.12 independently of one another are H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; Z is O or S; E is an unbranched or branched C.sub.1-C.sub.6 alkylene group, a cyclohexylene group, CH.sub.2—C.sub.6H.sub.10, 1,2-phenylene, 1,3-phenylene or 1,4-phenylene; G is O, NH or CO—NH; or E and G together are a chemical bond; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); n is 0, 1, 2, 3, 4 and/or 5; a is an integer from 2 to 350; R.sup.13 is H, an unbranched or branched C.sub.1-C.sub.4 alkyl group, CO—NH.sub.2 and/or COCH.sub.3; ##STR00030## in which R.sup.15, R.sup.17 and R.sup.18 independently of one another are H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; E is an unbranched or branched C.sub.1-C.sub.5 alkylene group, a cyclohexylene group, CH.sub.2—C.sub.8H.sub.10, 1,2-phenylene, 1,3-phenylene or 1,4-phenylene or is a chemical bond; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); L is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2—CH(C.sub.6H.sub.5); a is an integer from 2 to 350; d is an integer from 1 to 350; R.sup.19 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; R.sup.20 is H or an unbranched C.sub.1-C.sub.4 alkyl group; and n is 0, 1, 2, 3, 4 or 5; ##STR00031## in which R.sup.21, R.sup.22 and R.sup.23 independently of one another are H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; W is O, NR.sup.25 or N Y is 1, if W═O or NR.sup.25, and is 2 if W═N; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); a is an integer from 2 to 350; R.sup.24 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; R.sup.25 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; ##STR00032## in which R.sup.6 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; Q is NR.sup.16, N or O; Y is 1 if Q=O or NR.sup.10, and is 2 if Q=N; R.sup.10 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; R.sup.24 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5, or CH.sub.2C(C.sub.6H.sub.5)H; a is an integer from 2 to 350; and M is H or one cation equivalent.

10. The additive according to claim 1, the polymeric dispersant being a polycondensation product comprising structural units (III) and (IV): ##STR00033## in which T is a substituted or unsubstituted phenyl radical, substituted or unsubstituted naphthyl radical or a substituted or unsubstituted heteroaromatic radical having 5 to 10 ring atoms, of which 1 or 2 atoms are heteroatoms selected from N, O and S; n is 1 or 2; B is N, NH or O, with the proviso that n is 2 if B is N and the proviso that n is 1 if B is NH or O; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); a is an integer from 1 to 300; R.sup.25 is H, a branched or unbranched C.sub.1 to C.sub.10 alkyl radical, C.sub.5 to C.sub.8 cycloalkyl radical, aryl radical, or heteroaryl radical having 5 to 10 ring atoms, of which 1 or 2 atoms are heteroatoms selected from N, O and S; the structural unit (IV) being selected from the structural units (IVa) and (IVb): ##STR00034## in which D is a substituted or unsubstituted phenyl radical, substituted or unsubstituted naphthyl radical or a substituted or unsubstituted heteroaromatic radical having 5 to 10 ring atoms, of which 1 or 2 atoms are heteroatoms selected from N, O and S; E is N, NH or O, with the proviso that n is 2 if E is N and with the proviso that n is 1 if E is NH or O; A is C.sub.xH.sub.2x with x=2, 3, 4 or 5 or is CH.sub.2CH(C.sub.6H.sub.5); b is an integer from 1 to 300; M independently at each occurrence is H or one cation equivalent; ##STR00035## in which V is a substituted or unsubstituted phenyl radical, substituted or unsubstituted naphthyl radical and is optionally substituted by 1 or two radicals selected from R.sup.8, OH, OR.sup.8, (CO)R.sup.8, COOM, COOR.sup.8, SO.sub.3R.sup.8 and NO.sub.2; R.sup.7 is COOM, OCH.sub.2COOM, SO.sub.3M or OPO.sub.3M.sub.2; M is H or one cation equivalent; and R.sup.8 is C.sub.1-C.sub.4 alkyl, phenyl, naphthyl, phenyl-C.sub.1-C.sub.4 alkyl or C.sub.1-C.sub.4 alkylphenyl.

11. The additive according to claim 1, obtained by precipitating the salt of the polyvalent metal cation in the presence of the polymeric dispersant, to give a colloidally disperse preparation of the salt, or obtained by dispersing a freshly precipitated salt of the polyvalent metal cation in the presence of the polymeric dispersant, to give a colloidally disperse preparation of the salt.

12. The additive according to claim 1 in the form of a powder.

13. A building material mixture comprising an additive according to claim 1 and a binder selected from (Portland) cement, slag sand, flyash, silica dust, metakaolin, natural pozzolans, burnt oil shale, calcium aluminate cement, and mixtures thereof.

14. The additive according to claim 8, wherein X is a chemical bond or O(C.sub.nH.sub.2n).

15. A process for preparing the additive for hydraulically setting compositions according to claim 1, comprising a step wherein the salt of the polyvalent metal cation is precipitated in the presence of the polymeric dispersant, to give a colloidally disperse preparation of the salt, or a freshly precipitated salt of the polyvalent metal cation is dispersed in the presence of the polymeric dispersant, to give a colloidally disperse preparation of the salt, and optionally a drying step.

16. A process comprising adding the additive according to claim 1 as a slump retainer in water-containing building material mixtures which comprise a hydraulic binder.

17. The process according to claim 16, the hydraulic binder being selected from (Portland) cement, slag sand, flyash, silica dust, metakaolin, natural pozzolans, burnt oil shale, calcium aluminate cement, and mixtures of two or more thereof.

Description

EXAMPLES

Gel Permeation Chromatography

(1) The sample preparation for the determination of molar weights took place by dissolving the polymer solution in the GPC eluent, to give a polymer concentration in the GPC eluent of 0.5% by weight. Thereafter this solution was filtered through a syringe filter with polyethersulfone membrane and a pore size of 0.45 μm. The injection volume of this filtrate was 50-100 μl.

(2) The average molecular weights were determined on a GPC instrument from Waters with the model name Alliance 2690, with a UV detector (Waters 2487) and an RI detector (Waters 2410).

(3) Columns: Shodex SB-G Guard Column for SB-800 HQ series Shodex OHpak SB 804HQ and 802.5HQ (PHM gel, 8×300 mm, pH 4.0 to 7.5)

(4) Eluent: 0.05 M aqueous ammonium formate/methanol mixture=80:20 (parts by volume)

(5) Flow rate: 0.5 ml/min

(6) Temperature: 50° C.

(7) Injection: 50 to 100 μl

(8) Detection: RI and UV

(9) The molecular weights of the polymers were determined with two different calibrations. Determination took place first of all relative to polyethylene glycol standards from the company PSS Polymer Standards Service GmbH. The molecular weight distribution curves of the polyethylene glycol standards were determined by means of light scattering. The masses of the polyethylene glycol standards were 682 000, 164 000, 114 000, 57 100, 40 000, 26 100, 22 100, 12 300, 6 240, 3 120, 2 010, 970, 430, 194, 106 g/mol.

(10) Polymer Synthesis

(11) The polymeric dispersant P1 is based on the monomers maleic acid, acrylic acid and vinyloxybutylpolyethylene glycol-5800. The molar ratio of acrylic acid to maleic acid is 7. Mw=40 000 g/mol (determined by GPC). The solids content is 45% by weight. The synthesis of the comb polymer P1 is described in WO 2010/066470 at page 10 line 1 to line 38.

(12) The polymeric dispersant P2 is a condensate of the building blocks PhenolPEG5000 and phenoxyethanol phosphate. The molecular weight is 23 000 g/mol. The synthesis is described in DE102004050395. The solids content is 31%.

(13) Phosphoric Ester-Containing Polymeric Dispersant P3

(14) A glass reactor equipped with stirrer, thermometer, pH electrode and a number of feed ports was charged with 180 g deionized water, and this initial charge was heated to a polymerization starting temperature of 80° C. In a separate feed vessel, 4669 g (240 mmol) of a 25.7% strength aqueous methylpolyethylene glycol (5000) methacrylic ester solution were mixed with 251.8 g (1198 mmol) of hydroxyethyl methacrylate phosphoric ester (HEMA phosphate) and 190.2 g of a 20% strength NaOH solution (corresponding to solution A). In a further separate feed vessel, 13.71 g of sodium peroxodisulfate were mixed with 182.1 g of water (solution B). In a third feed, a 25% strength solution was prepared with 13.2 g of 2-mercaptoethanol and 39.6 g of deionized water (solution C).

(15) Following the preparation of solutions A, B and C, the addition of all three solutions to the stirred initial charge was commenced simultaneously. All of the additions were fed linearly into the initial charge over a period of 60 minutes.

(16) After the end of the addition, the temperature was held at 80° C. for a further 30 minutes, after which the solution was cooled and was neutralized to a pH of 7.3 using 158 g of 50% strength aqueous sodium hydroxide solution. The resulting copolymer was obtained as a clear solution, which had a solids content of 27.8%. The average molecular weight of the copolymer was Mw 39 000 g/mol and Mp 34 000 g/mol, and the polydispersity was 1.55.

(17) The HEMA phosphate used is prepared by mixing polyphosphoric acid with HEMA, the mixture being of 156 g of HEMA and 141.6 g of polyphosphoric acid. This means that the fraction of the pure HEMA phosphate in the reaction mixture is 251.8 g.

(18) Example calculation of the charge density:

(19) $\frac{{.Math.}_j{n}_{s,j}}{m_{\mathrm{Polymer}}}\mathrm{copolymerized}\mathrm{acid}\mathrm{monomers}\mathrm{per}\mathrm{gram}\mathrm{of}\mathrm{polymer}=\frac{n\left(\mathrm{number}\mathrm{of}\mathrm{moles}\mathrm{of}\mathrm{initial}\mathrm{mass}\mathrm{of}\mathrm{acid}\mathrm{monomers}\mathrm{in}\mathrm{mmol}\right)}{\begin{array}{c}m\left(\mathrm{mass}\mathrm{of}\mathrm{polymer}\mathrm{solution}\mathrm{in}g\right).Math.\\ \mathrm{solids}\mathrm{content}\mathrm{of}\mathrm{the}\mathrm{polymer}\mathrm{solution}\mathrm{in}\%\end{array}}$

(20) Example calculations for polymer P3 (for initial masses see polymer synthesis):

(21) $\frac{{.Math.}_j{n}_{s,j}}{m_{\mathrm{Polymer}}}=\frac{\left(1198\mathrm{mmol}\right)}{\left(5743g.Math.27.8\%/100\right)}=0.75\mathrm{mmol}\text{/}g$

(22) Example calculation of formula (a) on the basis of example 7:

(23) The corresponding masses are taken from the table of initial masses: mass of polymer P3 26.1 g and mass of iron nitrate nonahydrate 4.3 g.

(24) Accordingly

(25) $\frac{{.Math.}_i{z}_{K,i}\times n_{K,i}}{{.Math.}_j{z}_{s,j}\times n_{s,j}}=\frac{\left(4.3g/0.404g\text{/}\mathrm{mmol}\right).Math.3)}{\left(26.1g/0.75\mathrm{mmol}\text{/}g.Math.2\right)}$

(26) TABLE-US-00001 TABLE 1 physical data of the reference polymers P1 P2 P3 Σ.sub.jz.sub.s,j × n.sub.s,j in mmol per 0.93 0.745 1.38 gram of polymer Mw (GPC) 40 000 23 000 34 000
Examples for the Preparation of the Additives of the Invention
General Instructions:

(27) The aqueous solutions of the polymeric dispersants are mixed in accordance with the invention with the salts of polyvalent metal cations, with the compound able to release the anion, and also, optionally, with a base or acid to adapt the pH, with stirring. Mixing was carried out in a 1 l jacketed glass reactor with paddle stirrer, temperature-conditioned at 20° C., at 300 rpm. The sequence of the addition is indicated in table 2 by a letter code. P stands for the aqueous solution of the polymeric dispersant, K for the inventive salt of the polyvalent metal cation, A for the compound of the invention able to release an anion, and B and S for base and acid, respectively. The amounts are always based on the net contents. The final pH of the resulting solutions or suspensions is likewise indicated.

(28) The solution of the polymeric dispersant is charged to a beaker with magnetic stirrer, and dilution takes place with the stated mass of water (see table 2). Subsequently the salt of the invention of the polyvalent metal cation (for amounts see table) was added and was dissolved with stirring at about 200 rpm, using a magnetic stirrer bar. The compound able to release the anion was added with stirring. Adjustment of the pH, to a pH of 7, takes place optionally, using a base. Viscous suspensions were formed in this procedure.

(29) The suspensions are stable on storage.

(30) Samples of example 12 and example 13 were stored for 6 months each at 20° C. and 4° C., and under atmospheric pressure. In this trial the additives proved to be stable with respect to phase separation and retained their activity as slump retainers.

(31) General Instructions: Spray Drying

(32) The additives of the invention can be converted into powder form by spray drying. In that case the aqueous solutions or suspensions of the additives of the invention are dried using a Mobil Minor spray dryer (from GEA Niro) at an entry temperature of 230° C. and an exit temperature of 80° C. For this purpose the aqueous solutions are first admixed with 1% by weight (based on the solids content of the aqueous solution) of a mixture of Additin RC 7135 LD (Rhein Chemie GmbH) and MPEG500 (50% by weight in each case). The powders obtained are admixed with 1% by weight of finely divided silica (N20P, Wacker Chemie AG), ground using a Retsch Grindomix RM 200 mill at 8000 rpm for 10 seconds and filtered through a 500 μm sieve.

(33) TABLE-US-00002 TABLE 2 Composition of the additives No. Polymer Metal salt Anion comp. Base/acid pH Sequence 1 P2 Al(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 NaOH 7.2 PAKB 2 P2 Al(NO.sub.3).sub.3×9H.sub.2O H3PO.sub.4 NaOH 7.6 PAKB 3 P2 Fe(NO.sub.3).sub.3×9H.sub.2O H3PO.sub.4 NH.sub.4OH 7.6 PAKB 4 P2 Fe(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 NH.sub.4OH 5.5 PAKB 5 P2 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 7.0 PAKB 6 P2 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 6.7 PAKB 7 P3 Fe(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 NH.sub.4OH 5.4 PAKB 8 P1 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 10.5 PAKB 9 P3 Fe(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 NH.sub.4OH 3.7 PAKB 10 P3 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 — PAKB 11 P1 Fe(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 — 11 PAK 12* P2 Al(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 — 3.8 PAK 13* P2 Al(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 — 6.2 PAK 14 P3** Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 8.8 PKAB 15 P2** Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 8.4 PKAB 16 P1 Fe(NO.sub.3).sub.3×9H.sub.2O H.sub.3PO.sub.4 NaOH 6.0 PKAB 17 P1 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 8.6 PKAB 18*** P1 Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 9 PKAB 19 50% 18 + Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 50% P1 20 40% 18 + Ca(NO.sub.3).sub.2 H.sub.3PO.sub.4 60% P1 21.sup.# P1 Ca(NH.sub.2SO.sub.3).sub.2 H.sub.3PO.sub.4 NaOH 9 PKAB 22 P1 Ca(NO.sub.3).sub.2 NaAlO.sub.2 HNO.sub.3 10.5 PAKB 23 P2** Ca(NO.sub.3).sub.2 NaAlO.sub.2 NaOH 10.3 PAKB 24 P2** Ca(NO.sub.3).sub.2 NaAlO.sub.2 NaOH 10.3 PAKB     No. Water (% by wt.) Polymer (% by wt.) Metal salt (% by wt.) Anion comp. (% by wt.) Base/ acid (% by wt.) $\frac{\underset{i}{.Math.}{z}_{K,i}*n_{K,i}}{\underset{j}{.Math.}{z}_{S,j}*n_{S,j}}$ 0$\frac{\underset{l}{.Math.}{z}_{A,l}⨯n_{A,l}}{\underset{j}{.Math.}{z}_{K,i}⨯n_{K,i}}$ 1 64 33.6 1.5 0.6 0.4 0.47 1.25 2 64 32.9 2.4 0.5 0.6 0.78 0.75 3 63.6 33.8 1.6 0.6 0.4 0.47 1.25 4 63.6 33.7 1.6 0.6 0.5 0.47 1.25 5 63.4 33.7 2.1 0.6 0.2 0.52 1.12 6 62.5 32.9 3.7 0.5 0.3 0.94 0.62 7 68.0 26.1 4.3 1.4 0.3 0.81 1.02 8 74.1 23.5 1.6 0.3 0.5 0.89 0.38 9 70.0 24.3 4.4 0.9 0.4 0.95 0.72 10 72.3 23.8 2.5 0.8 0.5 0.92 0.74 11 74 24.2 1.5 0.3 0.94 0.36 12* 76.5 21.3 1.8 0.4 0.92 0.64 13* 77.4 21.6 0.9 0.4 0.47 1.25 14 72.3 24.3 2.6 0.3 0.6 0.92 0.23 15 73.4 25.4 0.8 0.1 0.3 0.52 0.38 16 73.2 24.2 2.0 0.3 0.3 0.67 0.5 17 74.0 23.1 1.6 0.6 0.8 0.89 0.75 18*** 73.3 22.6 2.6 0.5 0.8 1.48 0.45 19 0.74 0.22 20 0.59 0.18 21.sup.# 88.6 8.6 0.9 0.5 0.89 0.38 22 76.1 21.4 1.5 0.95 0.05 0.9 0.67 23 77 20.4 1.5 1 0.1 0.9 0.67 24 77.5 20.5 1.5 0.5 0.3 0.9 0.33 *Samples 6 months old; **: dialyzed sample to remove phosphate from monomer solution; ***noninventive example; #: spray-dried sample
Concrete Tests

(34) Concrete tests conducted were standard concrete tests in accordance with DIN EN 12350 with a cement content of 380 kg. The grading curve set corresponds to the NB 16 classification according to DIN 1045-2.

(35) The cements used were Karlstadt CEM I 42.5 R, with a w/c value of 0.47, and Bernburg CEM I 42.5 R, with a w/c of 0.44.

(36) Prior to testing in the concrete, the polymer samples were defoamed with 1% by weight of triisobutyl phosphate, based on the polymer solids content.

(37) Mixing Process

(38) The dried aggregates as per grading curve, and the cement, were introduced into a forced mixer and mixed for 10 seconds. The mixture in the forced mixer was thereafter moistened with 10% of the total water, and mixing was continued for a further 2 minutes. Then the remainder of the water was added, and mixing was continued for 1 minute more. Lastly the additive was added, followed by mixing for 1 minute again.

(39) The slump value is a measure of the extent to which the concrete cake collapses after the metal cone is lifted (difference in height between the top edge of the metal cone and the height of the concrete cake after removal of the metal mold). The slump flow corresponds to the base diameter of the concrete cake after collapse.

(40) The spread is obtained by shaking the slump flow board, in accordance with the abovementioned DIN method, by raising and impacting 15 times. The shearing forces which occur as a result of the tapping produce a further spread of the concrete. The diameter of the concrete cake after tapping is identified as the spread.

(41) The levels of addition indicated (Dos. %) are based on the solids content of the additives employed.

(42) TABLE-US-00003 TABLE 3 Results of the concrete tests, cement: Bernburg CEM I 42.5 R, w/c = 0.44 Delta spread Compres- relative to the sive Slump in cm Slump flow in cm Spread in cm base polymer strength Dos 0 10 30 60 0 10 30 60 0 10 30 60 10-0 30-0 MPa Ex. Additive % Air % min min min min min min min min min min min min min min 24 h C1 P1 0.11 2.9 20.5 8.0 2.0 33.0 21.0 20.0 56.0 45.0 36.5 25.60 19 Mixture 40% by 0.15 2.2 21.0 20.0 5.5 1.0 35.0 31.5 21.0 20.0 57.5 54.5 41.0 34.0 +9.5 +4.5 wt. 18/60% by wt. P1 20 Mixture 50% by 0.17 1.8 22.0 22.0 8.0 1.5 37.0 36.5 22.0 20.0 57.5 57.5 45.0 36.0 +12.5 +8.5 29.7 wt. 18/50% by wt. P1 8 P1 0.17 1.8 17.0 22.5 15.0 2.5 29.0 41.0 27.5 20.5 54.0 60.0 51.5 41.0 +15.0 +15.0 28.1
Applications Tests
Mortar Tests

(43) Mortar tests used were standard mortar tests in accordance with DIN EN 1015-3 using Karlstadt CEM I 42.5 R (w/c 0.44) and Bernburg CEM I 42.5 R (w/c 0.42). The weight ratio of sand to cement was 2.2 to 1. A mixture of 70% by weight standard sand (Normensand GmbH, D-59247 Beckum) and 30% by weight silica sand was used. Prior to testing in the mortar, the additive samples were defoamed with 1% by weight of triisobutyl phosphate, based on the polymer solids content.

(44) Mixing Process

(45) Cement is added to the initial charge of water. This defines the time point Os. Stirring is then carried out on setting 1 for 30 s. After that the sand is added and stirring continues for a further 30 s at setting 1 (140 rpm) and a further 30 s at setting 2 (285 rpm). The stirring is then discontinued for 90 s. In this time interval the plasticizer (either as an aqueous preparation or as a powder) is added. If the aqueous plasticizer preparation is added, then the added water is subjected accordingly from the amount of the batching water. Lastly, stirring takes place again on setting 2 for 60 s. After a total mixing time which is therefore 4 minutes, the first spread is ascertained.

(46) The spread was obtained by shaking the slump flow table, in accordance with the abovementioned DIN method, by raising and impacting it 15 times (tapping). The diameter of the mortar cake after tapping is identified as the spread.

(47) Delta identifies the difference in the spread with inventive additive relative to the spread in a comparative mortar test. In comparative mortar tests, the polymeric dispersant present in the additive of the invention was used as additive in each case.

(48) The levels of addition indicated are based on the solids content of the polymer suspensions employed.

(49) TABLE-US-00004 TABLE 4 Mortar results, Karlstadt cement, w/c 0.44 Additive Basis Dos. Spread [cm] No. polymer [%] 4 min 10 min 30 min 60 min 90 min Delta [cm] P1 0.105 25.4 24.6 22.1 20.7 P2 0.16 24.6 25.4 23.2 21.9 20.5 P3 0.14 23.2 22.3 20.9 20.3 1 P2 0.17 22.8 24.1 23.2 22.3 21.2 +0.7 (90 min) 2 P2 0.20 23 24.8 24.3 23.2 22.2 +1.7 (90 min) 3 P2 0.19 22.5 23.4 23.2 22.1 21.4 +0.9 (90 min) 4 P2 0.265 21.3 23.2 24.1 24.5 24.2 +3.7 (90 min) 5 P2 0.20 22.9 25.7 25.4 24.7 23.3 +2.8 (90 min) 6 P2 0.34 21.2 23.1 23.6 22.9 21.7 +1.2 (90 min) 7 P3 0.14 22.4 24.2 24.7 24.6 23.8 +4.3 (60 min) 8 P1 0.15 24.6 25.7 26.3 26.7 25.8 +6.0 (60 min) 11 P1 0.14 22.8 24.3 24.2 24.7 24.4 +4.0 (60 min) 9 P3 0.23 21.2 23.4 27.5 28.3 27.4 +8.0 (60 min) 10 P3 0.22 21.2 22.3 23.8 24.2 23.4 +3.9 (60 min) 12 P2 0.26 20 22.5 24.2 24.8 24.7 +4.2 (90 min) 13 P2 0.22 24.3 28.2 27.8 28 27.3 +6.8 (90 min)

(50) TABLE-US-00005 TABLE 5 Mortar results, Bernburg cement, w/c 0.42 Additive Basis Spread [cm] Delta [cm] No. polymer Dos. [%] 4 min 10 min 30 min 60 min 90 min 30 min P1 0.105 25.4 20.5 18.2 P2 0.165% 26.2 24.8 20.7 P3  0.14% 24.4 22.1 19.2  4  P2  0.26% 21.8 23.1 22 20.7 +1.3  6  P2  0.30% 24.3 23.4 21.6 20.7 +0.9  7  P1  0.14% 23.7 22.6 20.5 +2.3 14  P3  0.18% 19.4 22.4 26.3 24.8 24.1 +7.1 15  P2  0.20% 26.3 26.6 23.8 21.9 20 +3.1 16  P1  0.14% 25.3 24.5 22.7 21.1 19.3 +4.5 17  P1  0.17% 26.4 25.6 24.7 22.7 21.1 +6.5 21* P1  0.15% 25.8 24 21.6 +3.4 22  P1  0.15% 20.4 22.1 23.1 21.7 20.1 +2.4 23  P2** 0.35 24.3 26.9 27.2 25.6 24.0 +6.5 24  P2** 0.28 24.7 26.1 24.8 23.2 21.3 +4.1 *: Inventive additive in powder form **: dialyzed sample to remove phosphate from monomer solution

(51) As the mortar results show, the additives of the invention comprehensively result in longer retention of consistency, as compared with the unmodified polymeric dispersants.