ADDITIVE FOR CONSTRUCTION CHEMICAL COMPOSITIONS

Abstract

The present invention concerns an additive for construction chemical compositions, in particular mortar and cement compositions. The additive comprises at least one amide or ester of a sugar acid and at least one water-soluble comb polymer which contains, on the main chain, acid functions and side chains having ether functions. The additive is useful for retarding the hardening of a construction chemical composition.

Claims

1: An additive, suitable for construction chemical compositions and comprising: a) at least one amide or ester of a sugar acid and b) at least one water-soluble comb polymer which comprises, on the main chain, acid functions and side chains comprising polyether moieties, wherein the polyether moieties have a number average molecular weight in a range of from 1000 to 5000 g/mole.

2: The additive of claim 1, comprising an amide or ester of a sugar acid having formula (I): ##STR00021## wherein R.sup.1 is NR.sup.3R.sup.4 or OR.sup.4; R.sup.2 is CH.sub.2OH, COOH or COR.sup.1; R.sup.3 is H, C.sub.1-C.sub.6-alkyl, hydroxy-C.sub.1-C.sub.6-alkyl or -(AO).sub.xR.sup.5; R.sup.4 is -(AO).sub.xR.sup.5, C.sub.1-C.sub.6-alkyl or hydroxy-C.sub.1-C.sub.6-alkyl; R.sup.5 is H, C.sub.1-C.sub.12-alkyl, C.sub.1-C.sub.12-alkyl substituted by NH.sub.2 or XCO(CHOH)n-R.sup.2; X is NH or O; A at each occurrence may be the same or different and is C.sub.mH.sub.2m; m is 2, 3, 4, 5 or 6; n is 2, 3, 4, or 5; and x is 1 to 100.

3: The additive of claim 2, wherein the amide or ester of the sugar acid having formula (I) comprises at least one group -(AO).sub.xR.sup.5.

4: The additive of claim 2, comprising an amide or ester of a sugar acid having formula (I) wherein R.sup.1 is NR.sup.3R.sup.4, R.sup.3 is H or C.sub.1-C.sub.6-alkyl, R.sup.4 is -(AO).sub.xR.sup.5 and R.sup.5 is H, C.sub.1-C.sub.4-alkyl or C.sub.1-C.sub.4-alkyl substituted by NH.sub.2.

5: The additive of claim 2, comprising an amide or ester of a sugar acid having formula (I) wherein R.sup.2 is CH.sub.2OH.

6: The additive of claim 2, comprising an amide or ester of a sugar acid having formula (I) wherein R.sup.1 is NR.sup.3R.sup.4, n is 4, R.sup.2 is CH.sub.2OH, R.sup.3 is H, R.sup.4 is -(AO).sub.xR.sup.5, and R.sup.5 is H or C.sub.1-C.sub.4-alkyl.

7: The additive of claim 2, comprising an amide or ester of a sugar acid having formula (I) wherein R.sup.1 is NR.sup.3R.sup.4 and R.sup.3 and R.sup.4 are hydroxy-C.sub.1-C.sub.6-alkyl.

8: The additive of claim 2, comprising an amide or ester of a sugar acid having formula (I) wherein R.sup.1 is OR.sup.4, R.sup.4 is -(AO).sub.xR.sup.5 and R.sup.5 is H or C.sub.1-C.sub.12-alkyl.

9: The additive of claim 1, wherein the at least one water-soluble comb polymer comprises as units having acid functions at least one structural unit of the general formulae (Ia), (Ib), (Ic) and/or (Id): ##STR00022## 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.2COXR.sup.2; X is NH(C.sub.nH.sub.2n), O(C.sub.nH.sub.2n) with n=1, 2, 3 or 4, where the nitrogen atom or the oxygen atom is bonded to the CO group, or is a chemical bond; R.sup.2 is OM, PO.sub.3M.sub.2, or OPO.sub.3M.sub.2, with the proviso that X is a chemical bond if R.sup.2 is OM; ##STR00023## 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 OPO.sub.3M.sub.2; ##STR00024## 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; 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, and n is 1, 2, 3 or 4; ##STR00025## in which R.sup.6 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, or (C.sub.6H.sub.4)OPO.sub.3M.sub.2, n is 1, 2, 3 or 4; and each M independently is H or a cation equivalent.

10: The additive of claim 1, wherein the at least one water-soluble comb polymer comprises as units having a side chain with polyether moieties at least one structural unit of the general formulae (IIa), (IIb), (IIc) and/or (IId): ##STR00026## 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.2C.sub.6H.sub.10, 1,2-phenylene, 1,3-phenylene or 1,4-phenylene; G is O, NH or CONH; 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 or 5; a is selected such that a number average molecular weight of the moiety -(AO).sub.a- is in a range of from 1000 to 5000; R.sup.13 is H, an unbranched or branched C.sub.1-C.sub.4 alkyl group, CONH.sub.2 and/or COCH.sub.3; ##STR00027## in which R.sup.16, 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.6 alkylene group, a cyclohexylene group, CH.sub.2C.sub.6H.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); n is 0, 1, 2, 3, 4 and/or 5; L is C.sub.xH.sub.2x with x=2, 3, 4 or 5, or is CH.sub.2CH(C.sub.6H.sub.5); a and d are selected such that a number average molecular weight of the moieties -(AO).sub.a- and -(LO).sub.d together are in a range of from 1000 to 5000; 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; ##STR00028## 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 is N; Y is 1 if WO or NR.sup.25, and is 2 if WN; 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 selected such that a number average molecular weight of the moiety -(AO).sub.a- or both moieties -(AO).sub.a- together are in a range of from 1000 to 5000; R.sup.24 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; and R.sup.25 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; ##STR00029## in which R.sup.6 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; Q is NR.sup.10, N or O; Y is 1 if WO or NR.sup.10 and is 2 if WN; R.sup.10 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; and A is C.sub.xH.sub.2x with x=2, 3, 4 or 5, or is CH.sub.2C(C.sub.6H.sub.5)H; R.sup.24 is H or an unbranched or branched C.sub.1-C.sub.4 alkyl group; M is H or a cation equivalent; and a is selected such that a number average molecular weight of the moiety -(AO).sub.a- or both moieties -(AO).sub.a- together are in a range of from 1000 to 5000.

11: The additive of claim 1, wherein the side chains of the at least one water-soluble comb polymer have a molecular weight in a range of from 1000 to 4000.

12: The additive of claim 1, wherein a weight ratio of (a) to (b) is in a range of from 10:1 to 1:5.

13: The additive of claim 1, further comprising a calcium silicate hydrate.

14: A construction chemical composition, comprising the additive of claim 1 and an inorganic binder.

15: The construction chemical composition of claim 14, wherein the binder is an aluminate comprising cement.

16: The construction chemical composition of claim 14, wherein a weight ratio of the inorganic binder to the additive is in a range of from 10:1 to 10000:1.

17: A method for retarding the hardening of an inorganic binder-comprising building material formulation and/or for producing a building product, the method comprising adding the additive of claim 1 to the inorganic binder-comprising building material formulation or a construction chemical composition.

Description

APPLICATION EXAMPLES

[0150] The additives were tested in cement mortar using the following polymers as water-soluble comb polymer:

Polymer 1: A polymer from radical polymerization of ethoxylated hydroxybutyl monovinylether with 67 EO and 10 equivalents of acrylic acid per ethoxylated side chain.
Polymer 2: A phosphate-based polyether (example 2, WO15091461A1).
Polymer 3: Melamine-Sulfonate-Formaldehyde resin (Melment F10).
Polymer 4: Naphthalene sulfonic acid-formaldehyde condensation product (Melcret 500 L).
Polymer 5: A polymer from radical polymerization of ethoxylated hydroxybutyl monovinylether with 67 EO and 5 equivalents of acrylic acid per ethoxylated side chain.

[0151] Polymers 3 and 4 are comparative polymers.

[0152] The cement mortar contained 50.0 wt % of Portland cement (CEM I 52,5 N, Milke) und 50.0 wt % norm sand (DIN EN 196-1). The water/cement weight ratio was 0.30. The water-soluble comb polymer and the sugar derivatives of table 1 were added to the mortar in the amounts given in table 2.

[0153] The cement mortar was prepared on the basis of the method described in DIN EN 196-1:2005 in a 5 L RILEM mixer. The mixer was charged with water, additive and then cement. Thereafter, mixing was started at low speed (140 rpm). After 30 s norm sand was uniformly added to the mixture within 30 s. The mixing speed was then increased (285 rpm) and continued for 30 s. The mixing was then stopped for 90 s and thereafter continued for 60 s at 285 rpm. The total mixing time was 4 min.

[0154] Immediately after the mixing process the slump flow of the samples was determined using the Haegermann conus without applying compression energy. The testing method was on the basis of SVB-Richtlinie des Deutschen Ausschusses fr Stahlbeton (Deutscher Ausschuss fr Stahlbetonbau (Ed.): DAfStbRichtlinie Selbstverdichtender Beton (SVBRichtlinie) Berlin, 2003). The Haegermann conus (d at the top=70 mm, d at the bottom=100 mm, h=60 mm) was placed in the middle of a dry glass plate having a diameter of 400 mm and filled with the cement mortar. 5 min. after the first contact between cement and water the conus was removed and the average diameter of the cake formed was determined. In order to follow the development of slump flow the test was repeated after the mortar was allowed to stand for 10, 30 and 60 min. Prior to each test the mortar was remixed for 10 s at 140 rpm. The results are given in tables 2 to 4 (bwoc: by weight of cement).

TABLE-US-00003 TABLE 2 Amount Polymer of Sugar Slump flow SF [cm] delta Sugar 1 derivative 5 10 30 60 SF derivative [% bwoc] [% bwoc] min min min min. [cm] 1 0 0.05 0.216 0 27.3 19.7 12.3 12.1 15.2 1 0.182 0.05 26.7 21.7 19.9 19.1 7.6 2 0.189 0.05 25.7 19.3 18.2 17.7 8 3 0.181 0.05 25.6 19.5 13.9 12.5 13.1 4 0.155 0.05 25.1 24.1 18.5 15.2 9.9 5 0.195 0.05 26.3 20.9 15.1 13.6 12.7 6 0.185 0.05 26.1 21.1 19.6 19.1 7 7 0.150 0.05 28.4 23.4 18.3 18.0 10.4 8 0.191 0.05 26.6 20.1 15.9 14.7 11.9 Gluconolactone 0.125 0.05 27.0 20.1 11.6 10.0 17 Na-Gluconate 0.150 0.05 28.7 22.2 15.2 10.8 17.9 V1 0.216 0.05 32.5 25.4 19.8 17.7 14.8 V2 0.216 0.05 22.1 16.0 10.8 10.0 12.1

[0155] Table 2 includes data for the use of the polymer alone and the sugar derivative alone. Further, it includes comparative data for the use of gluconolactone and sodium gluconate as sugar derivative. As can be seen, the use of the additive of the invention results in a reduced slump loss, i.e. an improved processing profile, due to a synergistic effect between the comb polymer and the sugar derivative.

[0156] The following table 3 describes the synergistic effect of PEG-containing polymers 1 and 2 with sugar derivative 1.

TABLE-US-00004 TABLE 3 Dosage 1d Dosage sugar Delta compressive Sugar Polymer derivative slump Strength Polymer derivative [% .sup.1)] [% .sup.1)] [cm] [MPa] 1 0.223 0 15 38.0 1 1 0.148 0.1 3 36.1 1 Sodium 0.148 0.1 9 12.0 Gluconate (Sodium Gluconate) 2 0.29 0 18 11.4 2 1 0.20 0.05 12 13.5 3 (compar- 0.68 0 18 7.2 ative) 3 (compar- 1 0.67 0.1 18 6.9 ative) 4 (compar- 1 Formulation not possible ative) .sup.1) % solid on cement

[0157] The application of the additives of the invention results in a better slump retention with only slight increase or even reduced overall dosage. In case of polymer 3 (melamine-formaldehyde resins (PEG-free)), the strongly increased overall dosage did not lead to a better slump retention. A formulation of sugar derivative 1 with polynaphthalene sulfonate was not possible due to a strong gelling.

[0158] Table 4 shows the influence of the charge density and side chain length of the comb polymer 1 on the performance of the retarder. The dosage of the comb polymer was adjusted to achieve a slump flow of 26 cm and the dosage of the sugar derivative 1 was adjusted to achieve a delta slump of <7 cm+/1 cm after 60 min.

TABLE-US-00005 TABLE 4 Acrylic acid Ethoxylated Dosage PCE Dosage 1 Delta slump 1d compressive [eq. per ethoxy- VOBPEG Charge [% solid on [% solid on [cm] after strength lated side chain] [g/mol] density cement] cement] 60 minutes [MPa] 5 3000 1.49 0.12 0.05 2 44 5 3000 1.49 0.14 12 42 3 3000 0.93 0.12 0.03 2 45 3 3000 0.93 0.14 8 38 3 1100 2.46 0.14 0.1 1 51 3 1100 2.46 0.23 10 37 2.5 1100 2.11 0.11 0.07 3 50 2.5 1100 2.11 0.15 5 43 7 5800 1.11 0.05 0.5 5 40 7 5800 1.11 0.18 14 48 5 5800 0.81 0.05 0.5 5 37 5 5800 0.81 0.15 14 50 2 750 2.23 0.38 0.02 0 33 2 750 2.23 0.38 2 35 2 500 3.10 0.42 0.02 0 28 2 500 3.10 0.42 5 29

[0159] It can be seen that the best performance in terms of slump retention and early strength can be obtained when using a side chain length of 1000 g/mol to 5000 g/mol. In this range, the compressive strength increases when using a combination of comb polymer and sugar-compound. The best efficiency can be obtained using a polyethylene glycol side chain of about 3000 g/mol. Here, the dose efficiency of the retarder with respect to slump retention performance gain is highest.

[0160] It is known that the slump flow activity of comb polymers is temperature dependent and decreases with decreasing temperature. Surprisingly, it has been found that the temperature dependency of the slump flow is significantly reduced when using the additive of the invention. This is shown in FIGS. 1 and 2 for the comb polymer 5. Whereas there is a significant temperature dependency if polymer 5 is used without any sugar derivative, there is practically no change in the flow value if polymer 5 is used together with sugar derivative 1.