MIXTURE COMPRISING GLYOXYLIC ACID OR CONDENSATION OR ADDITION PRODUCTS THEREOF

Abstract

The present application relates to a mixture comprising at least one compound A selected from glyoxylic acid, salts thereof, and condensation or addition products of glyoxylic acid or salts thereof; and at least one polyhydroxy compound B. Furthermore, the present application relates to a construction material composition comprising said mixture, and to the use of said mixture for modifying the hardening of inorganic binder containing building material formulations, and/or for producing building products.

Claims

1.-15. (canceled)

16. A construction material composition comprising at least one inorganic binder and a mixture comprising a) at least one compound A selected from the group consisting of glyoxylic acid, salts thereof, condensation or addition products of glyoxylic acid or salts thereof, and mixtures thereof; and b) at least one polyhydroxy compound B and/or salts or esters thereof, wherein the polyhydroxy compound B is selected from the group consisting of polyalcohols with a carbon to oxygen ratio of from C/O≥1 to C/O≤1.5 and mixtures thereof.

17. The construction material composition according to claim 16, wherein the compound A is selected from ##STR00030## and A3) an amine-glyoxylic acid condensate selected from the group consisting of a melamine-glyoxylic acid condensate, an urea-glyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate and a polyacrylamide-glyoxylic acid condensate; and mixtures thereof; wherein X is in each case independently selected from H or a cation equivalent K.sub.a, wherein K is an alkali metal, alkaline earth metal, zinc, iron, aluminium, ammonium, or a phosphonium cation, and wherein a is 1/n, wherein n is the valence of the cation.

18. The construction material composition according to claim 16, wherein the polyhydroxy compound B is selected from polyalcohols with a carbon to oxygen ratio of from C/O≥1 to C/O≤1.25, and mixtures thereof.

19. The construction material composition according to claim 16, wherein the polyhydroxy compound B is selected from sugar alkohols and their condensation products, alkanolamines and their condensation products, carbohydrates, pentaerythritol, trimethylolpropane, and mixtures thereof.

20. The construction material composition according to claim 16, wherein the polyhydroxy compound B has a molecular weight of from 62 g/mol to 25000 g/mol.

21. The construction material composition according to claim 16, wherein the compound(s) A and the compound(s) B are present in a weight ratio of from 10:1 to 1:10.

22. The construction material composition according to claim 16, wherein the mixture further comprises c) at least one compound C selected from i) a borate source, ii) a carbonate source, wherein the carbonate source is selected from inorganic carbonates and organic carbonates, and mixtures thereof.

23. The construction material composition according to claim 22, wherein the compound C is an inorganic carbonate.

24. The construction material composition according to claim 16, wherein the mixture further comprises d) at least one compound D, which is selected from polycarboxylic acids or salts thereof whose milliequivalent number of carboxyl groups is 5.00 meq/g or higher, assuming all the carboxyl groups to be in unneutralized form; phosphonates which comprise two or three phosphonate groups and no carboxyl groups; and α-hydroxy carboxylic acids or salts thereof; a polyhydroxycompound with a carbon to oxygen ratio of C/O>1.5; and mixtures thereof.

25. The construction material composition according to claim 24, wherein the compound D is a α-hydroxy carboxylic acids or salts thereof.

26. The construction material composition according to claim 16, wherein the mixture further comprises e) at least one dispersant, which is selected from comb polymers having a carbon-containing backbone to which are attached pendant cement-anchoring groups and polyether side chains, non-ionic comb polymers having a carbon-containing backbone to which are attached pendant hydrolysable groups and polyether side chains, the hydrolysable groups upon hydrolysis releasing cement-anchoring groups, sulfonated melamine-formaldehyde condensates, lignosulfonates, sulfonated ketone-formaldehyde condensates, sulfonated naphthalene-formaldehyde condensates, phosphonate containing dispersants, cationic (co)polymers, and mixtures thereof.

27. The construction material composition according to claim 16, wherein the inorganic binder is a hydraulic binder, which is selected from Portland cement, calcium aluminate cement, sulfoaluminate cement, and mixtures thereof.

28. The construction material composition according to claim 16, wherein the inorganic binder is a latent hydraulic binder.

29. A mixture comprising a) at least one compound A selected from an amine-glyoxylic acid condensate selected from the group consisting of a melamine-glyoxylic acid condensate, an urea-glyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate, a polyacrylamide-glyoxylic acid condensate, and mixtures thereof; and b) b) at least one polyhydroxy compound B and/or salts or esters thereof, wherein the polyhydroxy compound B is selected from polyalcohols with a carbon to oxygen ratio of from C/O≥1 to C/O≤1.5 and mixtures thereof.

30. The use of the mixture as defined in claim 29 for modifying the hardening of inorganic binder containing building material formulations, and/or for producing building products.

31. The construction material composition according to claim 16, wherein the polyhydroxy compound B is glycerol.

32. The construction material composition according to claim 16, wherein the polyhydroxy compound B has a molecular weight of from 62 g/mol to 10000 g/mol.

33. The construction material composition according to claim 16, wherein the polyhydroxy compound B has a molecular weight of from 62 g/mol to 1000 g/mol.

34. The construction material composition according to claim 16, wherein the compound(s) A and the compound(s) B are present in a weight ratio of from 1:1 to 1:8.

Description

EXAMPLES

Preparation of Glyoxylic Acid Addition or Condensation Products and Dispersants

[0273] Retardant 1:

[0274] 148 g glyoxylic acid hydrate (50% in water) were charged into a reaction vessel and mixed with 594 g ethanol. 380 g sodium pyrosulfite (Na.sub.2S.sub.2O.sub.5) dissolved in 750 g of water were then added to the mixture. After stirring for 4 h the obtained suspension was cooled to 1° C. and allowed to stand for 24 h. The product crystallized and was isolated and dried. It was characterized by means of NMR.

[0275] Retardant 2:

[0276] 14.81 g Glyoxylic acid (50% solution in water) was added into a vessel and neutralized to a pH of 5 with potassium hydroxide. After adding 10.0 g urea, the mixture was heated to 80° C. After 7 h, the highly viscous substance was analyzed by gel permeation chromatography method (GPC) as described below. The molecular weight was M.sub.w=1500 g/mol.

[0277] Dispersant 1: The dispersant is a Polycarboxylic ether, more specifically a copolymer of 4-hydroxybutyl monovinyl ether ethoxylated with 64 moles of ethylene oxide in average and acrylic acid in a ratio of 1/10.

[0278] Gel Permeation Chromatography Method (GPC):

[0279] Column combination: OH-Pak SB-G, OH-Pak SB 804 HQ and OH-Pak SB 802.5 HQ by Shodex, Japan; eluent: 80 Vol.-% aqueous solution of HCO.sub.2N H.sub.4 (0.05 mol/l) and 20 vol.-% methanol; injection volume 100 μl; flow rate 0.5 ml/min. The molecular weight calibration was performed with poly(acrylate) standards for the RI detector. Standards were purchased from PSS Polymer Standards Service, Germany.

Example 1

[0280] The following additives were used: As a reference, Retardant 1 was used alone (Ex.-No. Ref-1). Furthermore, Retardant 1 was used as a mixture with glycerol in a weight ratio of 4:1 (Ex.-No. 1).

[0281] The additive was added to dry mortar mixture comprising 1100 g Portland cement and 1650 g sand according to DIN EN 196-1 available from Normensand GmbH. After adding the mixing water (w/c=0.35), the mortar mixture was mixed analogous to DIN EN 196-1 in a Toni-Mixer as follows:

0-60 s: Rilem level 1
60-90 s: Rilem level 2

90-180 s: Pause

[0282] 180-240 s: Rilem level 2

[0283] The compressive strength was measured after 3 h and 24 h at 4×4 cm prisms. At each time 3 prisms were tested and the average of the values was calculated.

[0284] The results are shown in the following table 1.

TABLE-US-00001 TABLE 1 Compressive strength [MPa] Ex.-No. Additive 3 h 24 h Ref-1 2% Retardant 1 2.1 7.8 1 2% Retardant 1 + 0.5% glycerol 4.5 12.8

[0285] The early compressive strength and the final compressive strength is improved in case of the additive comprising the Retardant 1 and glycerol in comparison to the use of Retardant 1 alone.

Example 2

[0286] The effect of polyhydroxy compounds in an additive is demonstrated in a mortar with the following recipe according to Table 2. Water to cement ratio is w/c=0.37. The weight percent amount of the compounds used as additive is provided in Table 3.

TABLE-US-00002 TABLE 2 Mortar ingredient Amount Fillers Calcit MS-12 Pa. 1 134.43 g CEM I 42.5R 1075.44 g Quarz 0.1/0.3 250.22 g Quarz 0.3/1 200.17 g Sand 0/4 2175.13 g Splitt 2/5 565.00 g

[0287] The cement mortar was prepared in a 5 L RILEM mixer. The mixer was charged with cement, aggregate and sand. Thereafter, mixing was started at low speed (140 rpm). After 30 s mixing water and the therein dissolved additives was uniformly added to the mixture. The mixing speed was then increased (285 rpm) and continued for 90 s.

[0288] The slump was determined using a cone with height of 15 cm and an internal diameter at the top of 5 cm and 10 cm at the bottom. The cone is completely filled immediately after mixing, the cone is lifted, and the slump of the concrete measured. Furthermore the compressive strength was measured as described in Example 1. The results are provided in Table 3.

TABLE-US-00003 TABLE 3 Na- Slump flow Compressive Strength [MPa] Dispersant 1 Retardant 2 Na.sub.2CO.sub.3 Gluconate Glycerol 5 min 15 min 2 h 5 h 24 h 0.1% 0.3% 0.50% 0.10% 0.00% 12 12 4.7 5.9 15 0.1% 0.3% 0.50% 0.10% 0.2% 11.6 10.2 6.4 6.4 17.8

[0289] The addition of glycerol improves early strength of the mortar by up to 30%.