Free-flowing powder comprising a porous substrate functionalized with at least one accelerator

Patent metadata

Field	Value
Publication number	US-2023174435-A1
Application number	US-202117924071-A
Country	US
Kind code	A1
Filing date	Jun 28, 2021
Priority date	Jul 3, 2020
Publication date	Jun 8, 2023
Grant date	—

Abstract

A free-flowing powder composition includes at least one substrate having pores and an external surface between said pores, said surface functionalized with at least one accelerator for a hydraulic setting composition, said accelerator being liquid, hygroscopic, or deliquescent, and wherein after 15 minutes of immersion of free-flowing powder composition in water at 20° C. at least 80% in weight of said accelerator is solubilized, said free-flowing powder composition being immersed in an amount of water sufficient so that the saturation concentration of said accelerator cannot be reached. There is also a method for preparing said free-flowing powder composition. The use of said free-flowing powder composition as an additive for mortar or concrete composition provides an accelerating effect, an anti-ageing effect and an anti-dusting effect. A dry mortar or concrete composition includes a hydraulic binder, said free-flowing powder composition and a granulate, wet mortar or concrete composition and hardened body obtained therefrom.

First claim

1 . Free-flowing powder composition comprising at least one substrate, said substrate having pores and an external surface between said pores, wherein said external surface is functionalized with at least one accelerator for a hydraulic setting composition, said accelerator being liquid, or hygroscopic or deliquescent, and wherein after 15 minutes of immersion of said free-flowing powder composition in water at 20° C. at least 80% in weight of said accelerator is solubilized, provided that said free-flowing powder composition is immersed in an amount of water sufficient so that the saturation concentration of said accelerator cannot be reached.

2 . Free-flowing powder composition according to claim 1 , wherein the substrate is selected from the group comprising or consisting of calcined clay, exfoliated vermiculite, zeolites, expanded perlite, precipitated silica, ground calcium carbonate, precipitated calcium carbonate, diatomaceous earth, calcined diatomaceous earth, and crushed cementitious foam.

3 . Free-flowing powder composition according to claim 1 , wherein the substrate is a powder consisting of porous particles having a d50 diameter of at least 10 μm.

4 . Free-flowing powder composition according to claim 1 , wherein the accelerator is selected from the group comprising or consisting of sodium chloride, potassium chloride, magnesium chloride, calcium chloride, lithium hydroxide, lithium sulfate, lithium carbonate, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bi-carbonate, alkali metal nitrates, alkali metal nitrites, alkali metal thiocyanates, alkali metal salts or earth alkali metal salts of any of citric acid, formic acid, malonic acid, acetic acid, propionic acid, malic acid, or succinic acid, alkali metal silicates, alkanolamines, and mixtures thereof.

5 . Free-flowing powder composition according to claim 1 wherein the accelerator is selected from the group comprising or consisting of calcium chloride, triethanolamine and triisopropanolamine and mixtures thereof.

6 . Free-flowing powder composition according to claim 1 wherein the weight ratio S/A, substrate (S) to accelerator (A), is comprised between 0.01 and 5.

7 . Free-flowing powder composition according to claim 1 wherein the accelerator is calcium chloride and the weight ratio S/Acl, substrate (S) to Calcium Chloride accelerator (Acl) is comprised between 0.2 and 5.

8 . Free-flowing powder composition according to claim 1 , wherein the accelerator is an alkanolamine and the weight ratio S/Aam substrate (S) to alkanolamine accelerator (Aam) is comprised between 0.01 and 3.

9 . Method for the preparation of a free-flowing powder composition according to claim 1 , comprising a step of contacting the solid substrate with a solid hygroscopic or deliquescent accelerator in such a manner that the particle sizes of said substrate and said hygroscopic or deliquescent accelerator are constant during the contacting step.

10 . Method for the preparation of a free-flowing powder composition according to claim 1 , comprising a step of spraying an accelerator on the substrate, said accelerator being liquid and used as such, or said accelerator being liquid, hygroscopic or deliquescent and diluted in a solvent.

11 . The free-flowing powder composition according to claim 1 , wherein the free-flowing powder composition is present as an additive in a mortar or concrete composition so as to provide an accelerating effect, an anti-ageing effect and/or an anti-dusting effect.

12 . Dry mortar or concrete composition comprising a hydraulic binder, the free-flowing powder composition according to claim 1 and a granulate having a d50 comprised between 50 μm and 3 mm.

13 . Dry mortar or concrete composition according to claim 12 , wherein the content of hydraulic binder is comprised between 10% by weight and 60% by weight, the content of the free-flowing powder composition is comprised between 0.1% by weight and 15% by weight and the content of granulate is comprised between 30% by weight and 90% by weight.

14 . Wet mortar or concrete composition obtained by mixing the dry mortar or concrete composition according to claim 12 with water in a water/powder ratio between 0.1 and 0.6.

15 . Hardened body, obtained by hardening the wet mortar or concrete composition of claim 14 .

Assignees

• Sika Tech Ag

Inventors

• Soudier Jerome
• Harrath Alexandre Ben

Classifications

• C04B2111/00646

  Masonry mortars · CPC title

• C04B40/0042 Primary

  Powdery mixtures · CPC title

• C04B2111/27

  Water resistance, i.e. waterproof or water-repellent materials · CPC title

• C04B2111/62

  Self-levelling compositions · CPC title

• C04B2111/00672

  Pointing or jointing materials · CPC title