Accelerator for mineral binders

Patent metadata

Field	Value
Publication number	US-10759716-B2
Application number	US-201414894649-A
Country	US
Kind code	B2
Filing date	May 21, 2014
Priority date	May 30, 2013
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A method for preparing a setting and hardening accelerator for mineral binders including a step of: (i) reacting a calcium compound CV with a silica sol SL, a molar ratio of Si:Ca being less than 0.1 during the reaction.

First claim

What is claimed is:

1. A process for the production of a setting and hardening accelerator for mineral binders, comprising the following step:
(i) reaction of a calcium compound CV with silica sol SL; wherein during the course of the reaction of step (i) a molar Si:Ca ratio is in the range from 0.027 to 0.058; wherein the setting and hardening accelerator increases a compressive strength, after 8 hours, of a mineral binder composition by a percentage in a range from 488% to 500% relative to an index of 100% for the same mineral binder composition without said setting and hardening accelerator.

2. The process as claimed in claim 1 , wherein in step (i) the reaction of the calcium compound CV with silica sol SL takes place in the presence of water, with a proportion of water that is based on the weight of the entire reaction mixture.

3. The process as claimed in claim 1 , wherein the calcium compound CV and silica sol SL are added separately from one another to the water.

4. The process as claimed in claim 1 , wherein the calcium compound CV is selected from the group consisting of calcium chloride, calcium nitrate, calcium formate, calcium acetate, calcium bicarbonate, calcium bromide, calcium citrate, calcium chlorate, calcium hydroxide, calcium oxide, calcium hypochloride, calcium iodate, calcium iodide, calcium lactate, calcium nitrite, calcium phosphate, calcium propionate, calcium sulfate, calcium sulfate hemihydrate, calcium sulfate dihydrate, calcium sulfide, calcium tartrate, calcium gluconate, calcium sulfamate, calcium thiocyanate, calcium maleate, calcium fumarate, calcium adipate, and calcium aluminate.

5. The process as claimed in claim 4 , wherein the calcium compound CV is calcium nitrate.

6. The process as claimed in claim 1 , wherein the pH of the silica sol SL is from 3 to 12.

7. The process as claimed in claim 1 , wherein the silica sol SL is a silica sol with average particle diameter from 1 to 150 nm.

8. The process as claimed in claim 1 , wherein
a) the calcium compound CV is calcium nitrate, and
b) the average particle diameter of the silica sol SL is from 2 to 9 nm, and
c) during the course of the reaction of step (i) the molar Si:Ca ratio is in the range from 0.01 to 0.08, and
d) the reaction of the calcium compound CV with silica sol SL takes place in the presence of water at pH from 3 to 6.5.

9. The process as claimed in claim 1 , wherein at least one other hardening-accelerator substance is added, wherein the at least one other hardening-accelerator substance comprises one or more aminoalcohols, one or more α-hydroxycarboxylic acids, one or more alkali metal and/or alkaline earth metal thiocyanates, one or more alkali metal and/or alkaline earth metal halides, glycerol, and/or glycerol derivatives.

10. The process as claimed in claim 9 , wherein another hardening-accelerator substance comprises an aminoalcohol, and/or one or more alkali metal and/or alkaline earth metal thiocyanates.

11. The process as claimed in claim 9 , wherein the proportion of the at least one other hardening-accelerator substance is from 1 to 20% by weight, based on the total weight of the setting and hardening accelerator.

12. A setting and hardening accelerator produced by a process as claimed in claim 1 .

13. A binder-containing mixture comprising at least one mineral binder, and at least one setting and hardening accelerator as claimed in claim 12 , wherein the setting and hardening accelerator increases a compressive strength, after 8 hours, of binder containing mixture by a percentage in a range from 488% to 500% relative to an index of 100% for the same mineral binder composition without said setting and hardening accelerator.

14. A method comprising: accelerating the setting and the hardening of the mineral binder composition by mixing the setting and hardening accelerator as claimed in claim 12 into the mineral binder composition, wherein the setting and hardening accelerator increases a compressive strength, after 8 hours, of the mineral binder composition by a percentage in a range from 488% to 500% relative to an index of 100% for the same mineral binder composition without said setting and hardening accelerator.

15. The process as claimed in claim 1 , wherein the calcium compound CV is selected from the group consisting of calcium nitrate and calcium sulfamate.

Assignees

• Sika Tech Ag

Inventors

• Mäder Gilbert
• Kurz Christophe
• Marazzani Beat
• Bürge Christian

Classifications

• C04B22/00863

  Calcium silicate hydrate · CPC title

• C04B40/0039 Primary

  Premixtures of ingredients · CPC title

• C04B28/04

  Portland cements · CPC title

• C01B33/24

  Alkaline-earth metal silicates · CPC title

• C04B22/0086 Primary

  Seeding materials · CPC title