FORMULATION FOR THE PRODUCTION OF ACID AND HEAT-RESISTANT CONSTRUCTION PRODUCTS

Abstract

The present invention suggests novel inorganic binder formulations and the use of these formulations for the production of acid and heat-resistant construction products.

Claims

1. A formulation comprising: at least two inorganic binders, wherein the first inorganic binder is selected from hydraulic binders, latent hydraulic binders, and mixtures thereof, and the second inorganic binder is selected from pozzolanic binders; at least one activator selected from alkali metal silicates, alkali metal carbonates, alkali metal hydroxides, alkali metal aluminates, alkali metal sulfates, and mixtures thereof; and at least one polycondensation product comprising as monomer components: a) at least one aromatic compound of the formula
ArV[CHR.sub.1CHR.sub.2(OCHR.sub.1CHR.sub.2).sub.mR.sub.3].sub.n, wherein Ar is an aryl group, V is O, NH or N, R.sub.1 and R.sub.2 each independently of one another are selected from H, methyl and ethyl m is an integer from 0 to 300, n is 1 if V?O or NH, and is 2 if V?N, and R.sub.3 is selected from OH, alkoxy, aryloxy, arylalkoxy, alkylaryloxy, phosphate, phosphonate, sulfate, sulfonate, carboxylate, and mixtures thereof; b) at least one aromatic carboxylic acid; and c) at least one aldehyde.

2. The formulation of claim 1, wherein the hydraulic binder is selected from portland cement, aluminate cement, sulfoaluminate cements, and mixtures thereof, and the content of portland cement, aluminate cement and/or sulfoaluminate cement in the binder system is ?30% by weight.

3. The formulation of claim 1, wherein the latent hydraulic binder is selected from blast furnace slag, granulated blast furnace slag, ground granulated blast furnace slag, electrothermal phosphorus slag, steel slag and mixtures thereof.

4. The formulation of claim 1, wherein the pozzolanic binder is selected from precipitated silica, pyrogenic silica, microsilica, glass powder, brown coal fly ash, mineral coal fly ash, rice husk ash, metakaolin, volcanic ash, tuff, trass, pozzolana and zeolites and mixtures thereof.

5. The formulation of claim 1, wherein the ratio of the first inorganic binder to the second inorganic binder is from 1:50 to 50:1 by weight.

6. The formulation of claim 1, wherein the alkali metal silicate is selected from compounds having the empirical formula mSiO.sub.2.nM.sub.2O, in which the alkali metal M represents Li, Na or K, or a mixture thereof, and the molar ratio m:n is from 1.0 to 4.0.

7. The formulation of claim 6, comprising at least two activators, wherein the first activator is selected from powdered alkali metal silicates, and the second activator is selected from alkali metal carbonates, alkali metal hydroxides, alkali metal aluminates, alkali metal sulfates, and mixtures thereof, wherein the alkali metal has the above meaning.

8. The formulation of claim 7, wherein the ratio of the powdered alkali metal silicate to the second activator is from 1:100 to 100:1 by weight.

9. The formulation of claim 1, additionally comprising inert fillers and/or further additives.

10. The formulation of claim 1, wherein the polycondensation product comprises as monomer components: a) at least one aromatic compound of the formula
ArOCHR.sub.1CHR.sub.2(OCHR.sub.1CHR.sub.2).sub.mR.sub.3, wherein Ar is an aryl group, R.sub.1 and R.sub.2 each independently of one another are selected from H, methyl and ethyl, m is an integer from 0 to 300, and R.sub.3 is selected from OH, alkoxy, aryloxy, arylalkoxy, alkylaryloxy, phosphate, phosphonate, sulfate, sulfonate, carboxylate, and mixtures thereof; b) at least one aromatic carboxylic acid; and c) at least one aldehyde.

11. The formulation of claim 10, wherein Ar is an aryl group having 6 to 10 carbon atoms in the ring system.

12. The formulation of claim 10, wherein both R.sub.1 and R.sub.2 are H.

13. The formulation of claim 10, wherein m is an integer from 0 to 280, preferably from 10 to 160 and more particularly from 12 to 120.

14. (canceled)

15. The formulation of claim 10, wherein the aromatic carboxylic acid is selected from 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, salicylic acid and mixtures thereof.

16. The formulation of claim 10, wherein the aldehyde is selected from the group consisting of formaldehyde, paraformaldehyde, glyoxylic acid, benzaldehyde, benzaldehydesulfonic acid, benzaldehydedisulfonic acid, vanillin, isovanillin, and mixtures thereof.

17. The formulation of claim 10, wherein the polycondensation product is in the form of a comb polymer having a novolak structure.

18. The formulation of claim 17, wherein the polycondensation product has a molecular weight in the range from 1000 to 100,000 g/mol.

19. A method for producing an acid-resistant construction product comprising combining together at least two inorganic binders, wherein the first inorganic binder is selected from hydraulic binders, latent hydraulic binders, and mixtures thereof, and the second inorganic binder is selected from pozzolanic binders; at least one activator selected from alkali metal silicates, alkali metal carbonates, alkali metal hydroxides, alkali metal aluminates, alkali metal sulfates, and mixtures thereof; and at least one polycondensation product comprising as monomer components: a) at least one aromatic compound of the formula
ArV[CHR.sub.1CHR.sub.2(OCHR.sub.1CHR.sub.2).sub.mR.sub.3].sub.n, wherein Ar is an aryl group, V is O, NH or N, R.sub.1 and R.sub.2 each independently of one another are selected from H, methyl and ethyl, m is an integer from 0 to 300, n is 1 if V?O or NH, and is 2 if V?N, and R.sub.3 is selected from OH, alkoxy, aryloxy, arylalkoxy, alkylaryloxy, phosphate, phosphonate, sulfate, sulfonate, carboxylate, and mixtures thereof; b) at least one aromatic carboxylic acid; and c) at least one aldehyde.

20. A method for producing a heat-resistant construction product comprising combining together at least two inorganic binders, wherein the first inorganic binder is selected from hydraulic binders, latent hydraulic binders, and mixtures thereof, and the second inorganic binder is selected from pozzolanic binders; at least one activator selected from alkali metal silicates, alkali metal carbonates, alkali metal hydroxides, alkali metal aluminates, alkali metal sulfates, and mixtures thereof; and at least one polycondensation product comprising as monomer components: a) at least one aromatic compound of the formula
ArV[CHR.sub.1CHR.sub.2(OCHR.sub.1CHR.sub.2).sub.mR.sub.3].sub.n, wherein Ar is an aryl group, V is O, NH or N, R.sub.1 and R.sub.2 each independently of one another are selected from H, methyl and ethyl, m is an integer from 0 to 300, n is 1 if V?O or NH, and is 2 if V?N, and R.sub.3 is selected from OH, alkoxy, aryloxy, arylalkoxy, alkylaryloxy, phosphate, phosphonate, sulfate, sulfonate, carboxylate, and mixtures thereof; b) at least one aromatic carboxylic acid; and c) at least one aldehyde.

21. The formulation of claim 2, wherein the content of portland cement, aluminate cement and/or sulfoaluminate cement in the binder system is ?20% by weight.

Description

EXAMPLES

Sample Preparation:

[0058] The starting materials were mixed in a laboratory mortar mixing device according to DIN EN 196-1. Mixing was carried out as described in DIN EN 196-1, except that the quartz sand was first placed in the mixing vessel. Sodium hydroxide dissolved in the mixing water was used as one alkaline activator. Melflux DF 93 (4 wt.-% solids, based on the dispersant, of an aqueous emulsion of polyalkylene glycols, modified with polycarboxylate ethers, of BASF SE) was used as a defoamer. The dispersants were used in aqueous solution.

[0059] The dispersant was prepared according to the modified procedure from the Example 30 of WO 2013/152963 A1. 787.5 weight parts of poly(ethyleneoxide) monophenyl ether (number average molecular weight Mn=750 g/mol) and 145.07 parts of 2-phenoxyethanol were placed into a heatable glass reactor equipped with mechanical stirrer, reflux condenser and dosage pump. 231 parts of polyphosphoric acid were added to the reaction mixture under vigorous stirring over 25 min, while the temperature of reaction mixture was maintained below 30? C., followed by heating of the resulting mixture at 95? C. for 1 hour. Thereafter 290.05 parts of 2-hydroxybenzoic acid, 139.38 parts of paraformaldehyde and 150 parts of water were added under stirring and constant nitrogen flow, followed by the adjustment of the reaction temperature to 90? C. 201.81 parts of methanesulfonic acid (70% aqueous solution) were dosed to the reaction mixture over 1 hour under maintaining the reaction temperature below 110? C., followed by further heating and stirring the reaction mixture at ca. 100-105? C. over 2 hours. The reaction was stopped by the addition of 2911 parts of cold water and subsequently neutralized with 680 parts NaOH (50% aqueous solution) to pH value?7. The resulting polymer solution was analyzed by gel permeation chromatography (GPC) (PEG/PEO calibration, RI detection, column combination OH-Pak SB-G, OH-20 Pak SB 804 HQ and OH-Pak SB 802.5 HQ from Shodex, Japan; eluent 80 Vol.-% aqueous ammonium formate solution (0.05 mol/l) and 20 Vol.-% acetonitrile; injection volume 100 ?l; flow rate 0.5 ml/min). GPC Data: Mw=11.2 kDa; Mn=6.1 kDa; PDI=1.8.

Chemical Resistance Tests:

[0060] Mixtures as described below were used for chemical resistance tests. After six minutes of resting, the mortars were again stirred and applied to forms that were impressed in a silicone mat, thus giving cylindrical specimen of 25 mm diameter and 25 mm height. The specimen were removed from the forms after 24 hours of storage (23? C., 50% rel. hum.) and subsequently stored for 27 days (23? C., 50% rel. hum.). After a total of 28 days the specimen were tested for chemical resistance.

[0061] Chemical resistance tests were carried out by weighing a specimen and placing it in a plastic bottle (250 ml) that was filled with 200 ml of a medium. 50 g of coarse quartz sand was additionally placed inside that bottle. The bottle was subsequently rotated for 2.5 hours in an overhead mixer. This simulates an accelerated attack of the specimen by the medium through mechanical wear. The specimen was then removed from the bottle, dried and weighted again. The percentage of mass loss during the test was used to assess the resistance of the specimen. The resistance was assessed in three different media: water, H.sub.2SO.sub.4 (pH=2) and lactic acid (pH=2).

Example 1

[0062] Four different mortars were prepared, i.e. reference mortars M1.1 and M2.1 (without dispersant) and mortars M1.2 and M2.2 (with dispersant and thus less water). The formulations are given in Table 1 and 2. The spread was measured after 6 and 30 minutes, applying each time 15 lifts on a H?germann table after removing the conus (DIN EN 1015-3). The compressive strength values after 7 and 28 days (DIN EN 197-1) (prisms of 40?40?160 mm) are also listed in Tables 1 and 2.

TABLE-US-00001 TABLE 1 Starting Materials M1.1 M1.2 Fly ash (class F) [g] 675 675 CEM I [g] 75 75 Quartz sand [g] 900 900 NaOH aq. [g] (solid content) 37.5 37.5 Na metasilicate pentahydrate [g] 3.75 3.75 Dispersant [g] (solid content) 0 15 Water [g] 270 225 Spread after 6 min [cm] 15.3 30.0 Spread after 30 min [cm] 11.0 30.0 Compress. strength [MPa] (7 d) 5.3 9.5 Compress. strength [MPa] (28 d) 8.4 21.3

TABLE-US-00002 TABLE 2 Starting Materials M2.1 M2.2 Blast furnace slag [g] 675 675 Metakaolin [g] 75 75 Quartz sand [g] 900 900 NaOH aq. [g] (solid content) 15 15 K waterglass powder [g] (mod. 4) 37.5 37.5 Dispersant [g] (solid content) 0 3.75 Water [g] 300 232.5 Spread after 6 min [cm] 14.0 30.0 Spread after 30 min [cm] 10.5 27.1 Compress. strength [MPa] (7 d) 10.2 33.4 Compress. strength [MPa] (28 d) 11.6 37.4

[0063] The chemical resistance (i.e. the weight loss) of specimen cured for 28 days are given in Table 3 hereinbelow. Especially the chemical resistance in acids is significantly improved for the formulations M1.2 and M2.2.

TABLE-US-00003 TABLE 3 Medium M1.1 M1.2 M2.1 M2.2 H.sub.2SO.sub.4 24.5% 9.2% 0.9% 0.9% Lactic acid 64.0% 27.6% 9.5% 7.1% Water 7.8% 2.1% 1.1% 0.2%

Example 2

[0064] Cylindrical specimens of 25 mm diameter and 25 mm height were used for testing of heat resistance. Samples of M1.2 and M2.2, after 35 days of curing, were heat treated to 400? C. for half an hour (heating rate 2 K/min) and cooled down. Compressive strength was measured after cooling. Table 4 summarizes compressive strength values of samples before and after heat treatment. The samples had essentially maintained their strengths during heating.

TABLE-US-00004 TABLE 4 Samples M1.2 M2.2 Compressive strength before heating [MPa] 20.4 38.9 Compressive strength after heating [MPa] 15.7 31.0