High viscosity crosslinked ethoxy-starch

Patent metadata

Field	Value
Publication number	US-9732163-B2
Application number	US-201414653464-A
Country	US
Kind code	B2
Filing date	Jan 2, 2014
Priority date	Jan 3, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Described herein is an ethoxylated starch crosslinked with a cross linking agent having surprisingly high viscosity in water. The ethoxylated crosslinked starch described has a degree of ethoxy substitution from 1 % to 3 % and the crosslinking agent is from 0.02 % to 0.05 % of the weight of starch. Within this narrow range of values, a 7 % wt/wt aqueous solution of the crosslinked ethoxylated starch exhibits a viscosity of at least 1600 cps at 95 ° C. This ethoxylated crosslinked starch is particularly useful in the formation of ceiling tiles with stucco, borax and steel wool, and should be useful in enhancing the viscosity of hydraulic fracturing fluids.

First claim

What is claimed is:

1. An ethoxylated starch crosslinked with a cross linking agent, wherein the degree of ethoxy substitution on the starch is from 1% to 3%; the crosslinking agent is from 0.01% to 0.05% of the weight of starch; and a 7% wt/wt aqueous solution of the crosslinked ethoxy starch exhibits a viscosity of at least 1600 cps at 95° C., wherein said viscosity surpasses that of a crosslinked starch not having an ethoxy substitution from 1% to 3% and having less than 0.01% or greater than 0.05% crosslinking by +16% to +20%.

2. The ethoxylated crosslinked starch of claim 1 where the degree of substitution is from 1.4% to 2.4%.

3. The ethoxylated crosslinked starch of claim 1 wherein the cross linking agent is epichlorohydrin.

4. A mixture comprising the ethoxylated crosslinked starch of claim 1 combined with borax, stucco, steel wool in water.

5. The mixture of claim 4 wherein with respect to the volume of water, borax is 0.15%-0.35% wt/vol, the stucco 4%-5% wt/vol and the ethoxylated crosslinked starch is 3.25% to 4.25% wt/vol.

6. The mixture of claim 5 wherein the borax is about 0.25%, wt/vol and the stucco is about 4.5% wt/vol.

7. The mixture of claim 5 wherein and the crosslinked ethoxylated starch is 3.25% to 4% wt/vol.

8. The ethoxylated starch of claim 1 wherein the 7% solution exhibits a viscosity of 1700-1900 cps.

9. The ethoxylated starch of claim 1 wherein the 7% solution exhibits a viscosity of 1700-1800 cps.

10. The ethoxylated starch of claim 1 wherein the starch is corn starch.

11. The ethoxylated starch of claim 1 wherein the starch is a waxy starch.

12. A hydraulic fracturing fluid having a viscosity enhancing agent comprised of the crosslinked ethoxylated starch according to claim 1 .

13. A ceiling tile made from the mixture of claims 4 .

14. A ceiling tile made from the mixture of claims 5 .

15. A ceiling tile made from the mixture of claims 6 .

16. A ceiling tile made from the mixture of claims 7 .

Assignees

• Archer Daniels Midland Co
• Archer Daniels Midland Co

Inventors

• Mcclain James

Classifications

• C09K8/90

  of natural origin, e.g. polysaccharides, cellulose · CPC title

• C04B28/145

  Calcium sulfate hemi-hydrate with a specific crystal form · CPC title

• C09K8/68

  containing organic compounds · CPC title

• C04B24/38

  Polysaccharides or derivatives thereof {(C04B24/243 takes precedence)} · CPC title

• C09K8/62

  Compositions for forming crevices or fractures · CPC title