Composition containing a semi-ordered calcium silicate hydrate

Patent metadata

Field	Value
Publication number	US-11667569-B2
Application number	US-201816487702-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 22, 2017
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A curing accelerator composition for building chemical mixtures comprises a mineral constituent and a polymeric water-soluble dispersant. The mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate. The composition displays a more pronounced accelerating effect than comparative compositions in which the mineral component comprises a calcium silicate hydrate having a higher degree of crystallinity.

First claim

The invention claimed is:

1. A composition, comprising a mineral constituent and a polymeric water-soluble dispersant, wherein the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate.

2. The composition of claim 1 , wherein a molar ratio of calcium to silicon in the mineral constituent is in a range of from 0.5 to 2.5.

3. The composition of claim 1 , comprising 2% by weight or less of alkali metals, based on the mineral constituent.

4. The composition of claim 1 , wherein a specific BET surface area of the mineral constituent is in a range of from 30 to 150 m 2 /g, determined in accordance with DIN ISO 9277:2003-05.

5. A process for producing a composition comprising calcium silicate hydrate, the process comprising contacting a mineral constituent with at least one water-soluble polymeric dispersant in an aqueous medium by introducing kinetic energy, where the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate.

6. The process of claim 5 , wherein the mineral constituent has been produced by reacting calcium oxide or calcium hydroxide with silicon dioxide in the presence of water under hydrothermal conditions at a temperature in a range of from 100° C. to 400 C for a period of from 5 hours to 30 hours.

7. The process of claim 6 , wherein the mineral constituent has been produced in the presence of a foaming agent.

8. The process of claim 5 , wherein the contacting of the mineral constituent with the at least one water-soluble polymeric dispersant is effected by introduction of mixing or shearing energy.

9. The process of claim 8 , wherein the contacting of the mineral constituent with the water-soluble polymeric dispersant is effected by milling.

10. The process of claim 9 , wherein the milling is carried out to a particle size d(50) of the mineral constituent of ≤400 nm, determined by static light scattering.

11. The process of claim 5 , wherein a comb polymer having polyalkylene oxide side chains is used as a polymeric dispersant.

12. A building material mixture, comprising the composition of claim 1 and optionally a hydraulic binder or latent hydraulic binder.

13. A process of accelerating the curing of a building chemical mixture comprising a hydraulic binder or latent hydraulic binder, the process comprising adding the composition of claim 1 to the building chemical mixture.

14. The composition of claim 1 , wherein the semi-ordered calcium silicate hydrate has a higher degree of order than amorphous calcium silicate hydrate and a lower degree of order than macroscopic crystalline calcium silicate hydrate.

15. The composition of claim 1 , wherein the semi-ordered calcium silicate hydrate has a main diffraction peak with a half width at least 1.25 times the half width of a corresponding main diffraction peak of the crystalline form of calcium silicate hydrate with a crystallite size of 50 nm or larger.

16. A composition, comprising a mineral constituent and a polymeric water-soluble dispersant, wherein the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate;
wherein the mineral constituent has a molar ratio of Ca to Si in the range of from 1.6 to 2.5.

17. The composition according to claim 16 , wherein the composition is a curing accelerator for hydraulic binders or latent hydraulic binders.

Assignees

• Basf Se

Inventors

• Hesse Christoph
• Dietzsch Michael
• Dal Attila
• Becker Maria

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• C04B2103/14

  Hardening accelerators · CPC title

• C04B20/002

  Hollow or porous granular materials · CPC title

• C04B40/00

  Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability (active ingredients C04B22/00 - C04B24/00; hardening of a well-defined composition C04B26/00 - C04B28/00; making porous, cellular or lightening C04B38/00; mechanical aspects B28, e.g. conditioning the materials prior to shaping B28B17/02) · CPC title

• C04B14/043 Primary

  Alkaline-earth metal silicates, e.g. wollastonite · CPC title