Inorganic polymers and use thereof in composite materials

Abstract

The invention relates to a new inorganic polymer which is based on modified water glass, is characterized by numerous unusual properties and can be used as a substitute for, for example, concrete, cement, and ceramics.

Claims

1. An inorganic polymer comprising Si, Al, Ca, alkali metal and O, wherein a .sup.27Al MAS-NMR spectrum of the solid inorganic polymer, compared with the .sup.27Al MAS-NMR spectrum of calcium aluminate, there is an additional signal whose chemical shift lies between that of the main peak of calcium aluminate and the calcium aluminate peak next upfield to the main peak.

2. The inorganic polymer of claim 1, wherein a solid-state IR spectrum of the inorganic polymer has a band at about 950-910 cm.sup.−1.

3. The inorganic polymer of claim 1, comprising: (a) waterglass in an amount, calculated as solid, of about 2.5 to about 12.5 wt %; (b) alkali metal hydroxide in an amount of about 0.7 to about 7.0 wt %; (c) water in an amount of about 6.8 to about 20 wt %; (d) calcium aluminate in an amount of about 10 to about 70 wt %; (e) optionally one or more aggregates in an amount of 0 to about 80 wt %, and/or (f) optionally one or more additives in an amount of 0 to about 10 wt %, with the proviso that the amounts add up to 100 wt %.

4. The inorganic polymer of claim 1, having a molar ratio of alkali metal cations to calcium of about 1:1 to about 1:5.

5. A method for producing the inorganic polymer of claim 1, the method comprising: (a) providing waterglass, alkali metal hydroxide, water, calcium aluminate; (b) mixing or contacting the substances from step (a), and optionally (c) curing the mixture from step (b).

6. The method of claim 5, wherein the curing is carried out at temperatures in the range from about 25 to about 40° C.

7. A composite material comprising (a) the inorganic polymer of claim 1; and (b) one or more aggregates and/or one or more additives.

8. The composite material of claim 7, wherein the one or more aggregates are selected from the group consisting of sand, coarse broken stone, finely ground quartz, rubber, organic polymers, wood, fibers, fabrics, salts, pollutants, radioactive wastes, and mixtures thereof.

9. The composite material of claim 7, wherein the one or more aggregates comprise marine sand, desert sand or fine sand having a mean particle diameter of ≤150 μm.

10. The composite material of claim 7, wherein the one or more additives are selected from the group consisting of iron phosphate, calcium phosphate, magnesium phosphate, iron oxides, lead oxides, BaSO.sub.4, MgSO.sub.4, CaSO.sub.4, Al.sub.2O.sub.3, metakaolin, kaolin, inorganic pigments, wollastonite, rockwool, and mixtures thereof.

11. The composite material of claim 7, comprising: (a) about 20 to about 80 wt % of inorganic polymers and (b) about 80 to about 20 wt % of aggregates and/or additives.

12. The composite material of claim 7, wherein the composite material is an adhesive bonding agent, a coating material, a binder, a material for 3D printing, a fiber composite, a wood composite, a ceramic, a concrete substitute or a cement substitute.

13. A method for producing a composite material, the method comprising: (a) providing waterglass, alkali metal hydroxide, water, calcium aluminate; (b) providing one or more aggregates and/or one or more additives; (c) mixing or contacting the substances from steps (a) and (b); and (d) curing the mixture from step (c).

14. A method comprising using an inorganic polymer of claim 1 to produce an adhesive bonding agent, a coating material, a binder, a material for 3D printing, a fiber composite, a wood composite, a ceramic, a concrete substitute, or a cement substitute.

15. The method of claim 14, wherein the inorganic polymers are used in amounts of about 5 to about 80 wt %.

Description

DESCRIPTION OF THE FIGURES

[0136] The invention is elucidated in more detail by means of the following figures, without being limited to them. The significations of the figures are set out below.

[0137] FIG. 1 Compressive strengths attained for different Si/Al.sup.− ratios (reaction with nsodium waterglass, NaOH, calcium aluminate and different amounts of finely ground quartz for setting identical initial viscosities for the reaction mixture).

[0138] FIG. 2 .sup.27Al MAS-NMR spectrum (Si—Al ratio 0.875) with the binding peak maximum at 59.3 ppm and at 943 cm.sup.−1 in the IR.

[0139] FIG. 3 .sup.27Al MAS-NMR spectrum (Si—Al ratio 0.625) with the binding peak maximum at 59.1 ppm and at 940 cm.sup.−1 in the IR.

[0140] FIG. 4 .sup.27Al MAS-NMR spectrum (Si—Al ratio 0.375) with the binding peak maximum at 63.4 ppm and at 943 cm.sup.−1 in the IR.

[0141] FIG. 5 .sup.27Al MAS-NMR spectrum (Si—Al ratio 0.125) with the binding peak maximum at 65.0 ppm and at 952 cm.sup.−1 in the IR.

[0142] FIG. 6 .sup.27Al MAS-NMR spectrum of calcium aluminate (Almatis® C-14)

[0143] FIG. 7 .sup.27Al MAS-NMR spectrum of the solid obtained in example 5

[0144] FIG. 8 .sup.27Al MAS-NMR spectrum of the solid obtained in example 6

[0145] FIG. 9 .sup.27Al MAS-NMR spectrum of the solid obtained in example 7

[0146] FIG. 10 IR spectrum of calcium aluminate, waterglass+NaOH and end product (after 8 min reaction time and after 80 min reaction time)

[0147] FIG. 11a+b Kinetics of polymerization. The figure shows the change over time in the IR absorption spectrum of a mixture of waterglass and calcium aluminate after activation with NaOH. Shown at the top is the change in the IR spectra in transmission between 650 and 2000 cm.sup.−1, at the bottom in absorption between 650 and 1200 cm.sup.−1. Absorptions above 1300 cm.sup.−1 come from water. Particularly evident is the transformation of an Si—O—Si bonding into an Al—O—Si bonding with a shift from 995 to 930-960 cm.sup.−1 as the dominant bonding.

[0148] FIG. 12 Overview of concrete applications.