Use of polyol for reducing shrinkage of construction chemical compositions

Abstract

The use of polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol as a composition for reducing shrinking of construction chemicals on the basis of a hydraulic binder comprising a) alumina cement and/or calcium sulfoaluminate cement, b) calcium sulfate, and c) optionally Portland cement.

Claims

1. A method for reducing the shrinkage of a construction chemical composition based on a hydraulic binder, the method comprising (i) adding at least one polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol to the construction chemical composition, wherein the polyol is selected from erythritol, (ii) adding water to the dry construction chemical composition, (iii) mixing the construction chemical composition, and (iv) applying the construction chemical composition to a substrate, wherein the hydraulic binder comprises a) aluminate cement and/or calcium sulfoaluminate cement, b) calcium sulfate, and c) optionally portland cement.

2. The method as claimed in claim 1, wherein the hydraulic binder consists of the following constituents (in each case based on the total dry mass of the binder): a) aluminate cement and/or calcium sulfoaluminate cement, b) 1-80% by weight of calcium sulfate, and c) optionally portland cement.

3. The method as claimed in claim 1, wherein the hydraulic binder comprises aluminate cement and portland cement in a weight ratio of aluminate cement to portland cement of from 10:1 to 1:10.

4. The method as claimed in claim 1, wherein polyol is used in an amount of at least 0.5% by weight based on the amount of aluminate cement and/or calcium sulfoaluminate cement.

5. The method as claimed in claim 1, wherein polyol is used in an amount of not more than 10% by weight based on the amount of aluminate cement and/or calcium sulfoaluminate cement.

6. A method as claimed in claim 1, further comprising hardening the construction chemical composition.

7. A reduced-shrinkage construction chemical composition comprising a) a hydraulic binder comprising a1) aluminate cement and/or calcium sulfoaluminate cement, a2) calcium sulfate, and a3) optionally portland cement, and b) at least one polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol, wherein the polyol is selected from erythritol.

8. The reduced-shrinkage construction chemical composition as claimed in claim 7, wherein the construction chemical composition comprises 5-70% by weight based on the total mass of the construction chemical composition, of a hydraulic binder consisting of aluminate cement and/or calcium sulfoaluminate cement and also calcium sulfate.

9. The reduced-shrinkage construction chemical composition as claimed in claim 7, wherein the construction chemical composition comprises 5-70% by weight based on the total mass of the construction chemical composition, of a hydraulic binder consisting of aluminate cement and/or calcium sulfoaluminate cement, calcium sulfate, and portland cement.

10. The reduced-shrinkage construction chemical composition as claimed in claim 7, wherein polyol is used in an amount of at least 0.5% by weight based on the amount of aluminate cement and/or calcium sulfoaluminate cement.

11. The reduced-shrinkage construction chemical composition as claimed in claim 7, wherein polyol is used in an amount of not more than 10% by weight based on the amount of aluminate cement and/or calcium sulfoaluminate cement.

12. The reduced-shrinkage construction chemical composition as claimed in claim 7, wherein it comprises water or is mixed with water, wherein a water to powder weight ratio of between 0.1-1.0 is present.

13. The reduced-shrinkage chemical composition as claimed in claim 7, wherein the chemical composition is formulated for use as a cementitious tile adhesive, self-leveling or sag-resistant spackling compound, grouting material, self-leveling base, self-leveling layer, plaster, repair mortar, joint mortar, masonry mortar or concrete, screed, leveling compound for indoor or outdoor areas, thin-bed mortar, waterproofing mortar, waterproofing slurry, anchoring mortar or isolating membrane.

14. A hardened body obtained by the setting and hardening of a construction chemical composition as claimed in claim 12.

15. A reduced-shrinkage construction chemical composition comprising, in each case based on the total dry mass of the construction chemical composition, a) 5-70% by weight of a hydraulic binder comprising a1) aluminate cement and/or calcium sulfoaluminate cement, a2) calcium sulfate, and a3) optionally portland cement, b) at least one polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol, wherein the polyol is selected from erythritol, c) 10-80% by weight of aggregates, and e) optionally additives selected from the group consisting of accelerators, retardants, flow aids, rheological aids, thickeners, pigments, and biocides.

16. A method for reducing the shrinkage of a construction chemical composition based on a hydraulic binder, the method comprising (i) adding at least one polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol to the construction chemical composition, (ii) adding water to the dry construction chemical composition, (iii) mixing the construction chemical composition, and (iv) applying the construction chemical composition to a substrate, wherein the hydraulic binder comprises a) aluminate cement, b) calcium sulfate, and c) portland cement, wherein a weight ratio of aluminate cement to portland cement of from 10:1 to 1:1, and wherein the at least one polyol is used in an amount of between 1.2% by weight to 2% by weight, based on the amount of aluminate cement.

17. A reduced-shrinkage construction chemical composition comprising, in each case based on the total dry mass of the construction chemical composition, a) 5-70% by weight of a hydraulic binder comprising a1) aluminate cement, a2) calcium sulfate, and a3) portland cement, b) at least one polyol having a functionality of 4 or less and an OH group density of at least 0.033 mol OH per g polyol, c) 10-80% by weight of aggregates, and e) optionally additives selected from the group consisting of accelerators, retardants, flow aids, rheological aids, thickeners, pigments, and biocides, wherein a weight ratio of aluminate cement to portland cement of from 10:1 to 1:1, and wherein the at least one polyol is used in an amount of between 1.2% by weight to 2% by weight, based on the amount of aluminate cement.

Description

Example 1

(1) The inventive mixtures 1-1 to 1-4 and noninventive comparison mixtures V-1 and V-2 shown in Table 2 were prepared. For this, OPC, CAC, CaSO.sub.4.Math.H.sub.2O, quartz sand, CaCO.sub.3, RDP, additives, and erythritol were weighed out in the amounts specified in Table 2 and intimately mixed until an optically homogeneous powder had formed. The specified amount of water was added to this dry mixture and it was mixed on an IKA stirrer at 600 rpm for 60 sec. The resulting mass was poured into prismatic molds of the dimensions shown in Table 2 and allowed to harden under the stated conditions. The shrinkage was measured after the times specified in Table 2.

(2) TABLE-US-00002 TABLE 2 Compositions and results for example 1 (raw materials in the compositions are specified in g) Raw material V-1 1-1 1-2 1-3 V-2 1-4 OPC 0 0 0 0 23 23 CSA 18 18 18 18 CAC 8 8 CaSO.sub.4H.sub.2O 46 46 46 46 4 4 Quartz sand 25.8 25.8 25.8 25.8 47 47 CaCO.sub.3 7.5 7.5 7.5 7.5 15 15 RDP 2 2 2 2 2.5 2.5 Additives 0.9 0.9 0.9 0.9 0.5 0.5 Erythritol 0.1 0.25 0.50 0.25 Water 22 22 22 25 18 18 Shrinkage in samples 160 40 10 mm @ 20 C./55% RH [mm/m] 1 h +0.07 0.05 0.03 0.05 0.1 0.1 24 h 0.05 0.3 0.05 0.1 0.25 0.15 7 d 0.2 0.45 0.31 0.35 0.42 0.31 28 d (end value E) 0.25 0.46 0.33 0.38 0.43 0.31 Max. expansion L +0.18 0.05 0.03 0.05 0.1 0.1 Ratio L/E 0.72 0.11 0.09 0.13 0.23 0.32 Shrinkage in samples 160 40 10 mm @ 20 C./75% RH [mm/m] 1 h +0.13 +0.05 0.01 +0.01 0.02 0.02 24 h +0.22 +0.25 +0.4 +0.1 0.05 0.02 7 d +0.17 +0.2 +0.23 +0.21 0.25 0.22 28 d +0.08 +0.15 +0.14 +0.15 0.36 0.35 Max. expansion L +0.29 +0.25 +0.4 +0.21 0.02 0.02 Ratio L/E 3.63 1.67 2.85 1.4 0.06 0.06

(3) As can be seen from the results in Table 2, the use of erythritol results in a reduction in the L/E ratio. A low L/E ratio means little deformation of the hardening construction chemical composition. This is desirable, since it allows for example the formation of cracks to be avoided. In the case of construction chemical compositions having a content of portland cement (i.e. based on ternary binders), the L/E ratio is not improved in all cases (example 1-4 versus V-2). However, in these cases the shrinkage behavior is still reduced overall.

Example 1a

(4) The slump of mixtures V-1 and 1-2 from example 1 was measured on the basis of standard EN 12350-5 3 minutes and 20 minutes after having been made up with water. In addition, the setting start and end times were measured (according to the Vicat method as described in standard EN 196). These measurements were in each case recorded with a freshly produced powder and with a powder that had been stored in an open container for 7 d at 20 C./55% RH. Table 3 below gives an overview of the results.

(5) TABLE-US-00003 TABLE 3 Measurement results for experiments V-1 (noninventive) and 1-2 (inventive). Property V-1 1-2 Slump after 3 and after 20 min [cm] 31.5 and 31.0 32.3 and 31.8 Powder freshly produced Slump after 3 and after 20 min [cm] 33.8 and 30.5 33.0 and 33.0 Powder stored Factor of increase in slump between 0 1.07 and 0.98 1.02 and 1.04 and 7 d Setting time, initial and final [min] 62 and 68 76 and 82 Powder freshly produced Setting time, initial and final [min] 144 and 150 108 and 114 Powder stored Factor of increase in setting time 2.3 and 2.2 1.4 and 1.4 between 0 and 7 d

(6) As can be seen from Table 3, an inventive construction chemical composition containing erythritol has better storage stability than the same composition without erythritol.

Example 1b

(7) Mixtures V1-1 and V1-2 were produced. These correspond in their production and compositions to mixtures 1-2 from example 1. However, in V1-1 erythritol was replaced by sorbitol and in V1-2 erythritol was replaced by mannitol.

(8) The setting times of mixtures V1-1 and V1-2 were measured as described in example 1a. Table 3 below gives an overview of the results.

(9) TABLE-US-00004 TABLE 3 Setting times of mixtures 1-2 (inventive) and V1-1 and V1-2 (noninventive) Setting time 1-2 V1-1 V1-2 Initial [min] 76 >180 >180 Final [min] 82 >180 >180

(10) As can be seen from Table 3, the use of the noninventive polyols sorbitol and mannitol results in clear retardation of setting.

Example 2

(11) The inventive mixtures 2-1 to 2-4 and noninventive comparison mixtures V-3 and V-4 shown in Table 4 were prepared. For this, OPC, CAC, CaSO.sub.4.Math.H.sub.2O, quartz sand, CaCO.sub.3, RDP, additives, and glycerol were weighed out in the amounts specified in Table 4 and intimately mixed until an optically homogeneous powder had formed. The specified amount of water was added to this dry mixture and it was mixed on an IKA stirrer at 600 rpm for 60 sec. The resulting mass was poured into prismatic molds of the dimensions shown in Table 4 and allowed to harden under the stated conditions. The shrinkage was measured after the times specified in Table 4.

(12) TABLE-US-00005 TABLE 4 Compositions and results for example 2 (raw materials in the compositions are specified in g) Raw material V-3 2-1 2-2 V-4 2-3 2-4 OPC 23 23 23 20 20 20 CAC 8 8 8 20 20 20 CaSO.sub.4H.sub.2O 4 4 4 10.4 10.4 10.4 Quartz sand 46.7 46.7 46.7 29.5 29.5 29.5 CaCO.sub.3 15 15 15 17.5 17.5 17.5 RDP 2.4 2.4 2.4 2 2 2 Additives 0.6 0.6 0.6 0.9 0.9 0.9 Glycerol 0.2 0.5 0.2 0.5 Water 18 18 18 23.5 23.5 23.5 Shrinkage in samples 160 40 10 mm @ 20 C./55% RH [mm/m] 1 h 0.08 0.06 0 +0.03 +0.01 +0.01 24 h 0.19 0.08 0 0.12 0.09 0.03 7 d 0.42 0.34 0.25 0.39 0.42 0.29 28 d 0.43 0.35 0.25 0.45 0.49 0.35 Max. expansion L 0.08 0.06 0 +0.03 +0.01 +0.01 Ratio L/E 0.18 0.17 0 0.07 0.02 0.03 Shrinkage in samples 160 40 10 mm @ 20 C./75% RH [mm/m] 1 h 0.03 0 0 +0.08 +0.06 n.m. 24 h 0.08 0.02 0.02 0.01 +0.01 n.m. 7 d 0.24 0.06 0.06 0.19 0.19 n.m. 28 d 0.51 0.39 0.21 0.35 0.33 n.m. Max. expansion L 0.03 0 0 +0.08 +0.06 n.m. Ratio L/E 0.06 0 0 0.23 0.18 n.m. n.m.: not measured

(13) From the results in Table 4 it is clear that in a construction chemical composition based on a hydraulic binder comprising aluminate cement and portland cement in a ratio of portland cement to aluminate cement of 2.9:1, dosing with as little as 2.5% by weight of glycerol, based on the amount of aluminate cement, is sufficient to achieve a clear reduction in shrinkage (compare example 2-1 with V-3). Dosing with 5% by weight of glycerol reduces shrinkage to an even greater extent (example 2-2). At a ratio of aluminate cement to portland cement of 1:1, dosing with 1.0% by weight of glycerol, based on the amount of aluminate cement, is not sufficient to bring about a reduction in shrinkage. On the other hand, dosing with 2.5% by weight brings about a considerable reduction in the shrinkage of this construction chemical composition too (compare examples 2-2 and 2-4 and also V-4). The L/E ratios too are in each case lower for the inventive construction chemical compositions than for the comparison mixtures.

Example 2a

(14) A composition as in example 2-1, but containing 35% by weight of portland cement CEM I 42.5 R and without aluminate cement and also without CaSO.sub.4.Math.H.sub.2O was produced. This mixture contained 0.2% by weight of glycerol. Just 30 seconds after adding the water, the mixture could no longer be processed and production of test specimens for the measurement of shrinkage was not possible. In this portland cement-based composition, glycerol acted as a powerful accelerator.

Example 3

(15) The inventive mixtures 3-1 to 3-4 and noninventive comparison mixtures V-5 and V-6 shown in Table 5 were prepared. For this, OPC, CAC, CaSO.sub.4.Math.H.sub.2O, quartz sand, CaCO.sub.3, RDP, additives, and glycerol were weighed out in the amounts specified in Table 5 and intimately mixed until an optically homogeneous powder had formed. The specified amount of water was added to this dry mixture and it was mixed on an IKA stirrer at 600 rpm for 45 sec. The resulting mass was poured into prismatic molds of the dimensions shown in Table 5 and allowed to harden under the stated conditions. The shrinkage was measured after the times specified in Table 5.

(16) TABLE-US-00006 TABLE 5 Compositions and results for example 3 (raw materials in the compositions are specified in g) Raw material V-5 3-1 3-2 V-6 3-3 3-4 OPC 13.8 13.8 13.8 5.2 5.2 5.2 CAC 41.5 41.5 41.5 25.5 25.5 25.5 CaSO.sub.4H.sub.2O 9.3 9.3 9.3 10.5 10.5 10.5 Quartz sand 27.5 27.5 27.5 55 55 55 RDP 7 7 7 2.8 2.8 2.8 Additives 1 1 1 1 1 1 Glycerol 0.2 0.5 0.2 0.5 Water 28 28 28 31.5 31.5 31.5 Shrinkage in samples 160 40 40 mm @ 20 C./75% RH [mm/m] 1 h 0.03 0.02 0.01 n.m. n.m. n.m. 24 h 1.3 1.1 0.4 n.m. n.m. n.m. 7 d 2.7 2.10 2.5 n.m. n.m. n.m. 28 d 3.5 4.3 3.1 n.m. n.m. n.m. Max. expansion L 0.03 0.02 0.01 n.m. n.m. n.m. Ratio L/E 0.008 0.005 0.003 n.m. n.m. n.m. Deformation in 43 41 27 14 12 10 samples 1000 50 10 mm @ 20 C./55% RH after 14 d [mm] Deformation in 43 42 28 14 13 10 samples 1000 50 10 mm @ 20 C./55% RH after 28 d [mm] n.m.: not measured

(17) From the results in Table 5 it is clear that in a construction chemical composition based on a hydraulic binder comprising aluminate cement and portland cement in a ratio of aluminate cement to portland cement of 3:1, dosing with as little as 0.5% by weight of glycerol, based on the amount of aluminate cement, is not sufficient to achieve a reduction in shrinkage (compare example 3-1 with V-5). On the other hand, dosing with 1.2% by weight of glycerol reduces shrinkage significantly (example 3-2). This becomes particularly clear from the measured deformation. At a ratio of portland cement to aluminate cement of 1:5, dosing with 0.8% by weight of glycerol, based on the amount of aluminate cement, is likewise not sufficient to bring about a significant reduction in shrinkage (compare example 3-3 with V-6). On the other hand, dosing with 2% by weight brings about a considerable reduction in the shrinkage of this construction chemical composition too (compare examples 3-3 and 3-4 and also V-6). The L/E ratios too are in each case lower for the inventive construction chemical compositions than for the comparison mixtures.

Example 4

(18) Table 6 below gives an overview of the measured TVOC values for a leveling compound, which was classified as Emicode EC1+ in the made-up state with water and after hardening for 3 days and for 28 days. In addition, Table 6 gives measured TVOC values of polyol selected from glycerol or erythritol and of two commercial shrinkage-reducing agents. The two commercial shrinkage-reducing agents and erythritol were measured both as the bulk substance (powder) and dissolved in water.

(19) TABLE-US-00007 TABLE 6 TVOC measurement results TVOC [g toluene equivalent/g sample] Low Medium High Sample boilers boilers boilers EC1+ leveling compound 0.15 0.09 0 Hardening for 3 d 0 0 0 Hardening for 28 d 0.06 0 0 Glycerol 0 0.40 0 Erythritol 0 0 0 Erythritol 0 0 0 (50% by weight dissolved in H.sub.2O) Shrinkage-reducing agent 1 0.64 2.51 0.28 Shrinkage-reducing agent 1 0.07 1.62 0.47 (50% by weight dissolved in H.sub.2O) Shrinkage-reducing agent 2 0.84 42.67 0 Shrinkage-reducing agent 2 0.35 62.92 0 (50% by weight dissolved in H.sub.2O) Shrinkage-reducing agent 1: Sitren SRA P270 Shrinkage-reducing agent 2: Pentachem Pentamix EX3

(20) From the results in Table 6, it can be seen that glycerol releases substantially lower levels of TVOC than commonly used commercial shrinkage reducers. Erythritol does not release any TVOC at all. When using polyol selected from glycerol or erythritol in accordance with the present invention, it is therefore to be expected that construction chemical compositions will release virtually no additional TVOC.