Readily dissolvable polysaccharide compositions

• US 4,373,959 A
• Filed: 06/22/1981
• Issued: 02/15/1983
• Est. Priority Date: 06/22/1981
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Socha, Gregory E.
• Primary Examiner(s): Morris, Theodore
• Application Number:
  US06/276,437
• Time in Patent Office: 603 Days
• Field of Search: 106/193, 106/197, 106/205, 106/209, 106/194, 536/85, 536/88
• US Class Current: 106/162.82
• CPC Class Codes: C08L 1/08 Cellulose derivatives
• CPC Class Codes: C08L 1/26 Cellulose ethers
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials

Abstract

A mixture of (1) a cross-linked, aqueous soluble polysaccharide or derivative thereof and (2) an aqueous soluble polysaccharide or derivative having essentially no cross-linking readily dissolves in an aqueous liquid to form a homogeneous solution. For example, a mixture of a cellulose ether, e.g., hydroxypropyl methylcellulose, lightly cross-linked with a dialdehyde such as glyoxyl and a cellulose ether which has not been cross-linked can be added to an aqueous liquid and readily dissolved without lumping or the like to form a clear, stable solution in the absence of continuous agitation.

Claims

1. A polysaccharide composition comprising a dry blend of (a) a particulate aqueous liquid soluble, polysaccharide or polysaccharide derivative having essentially no cross-linkages which forms substantial amounts of soft lumps, nodules or other agglomerations upon addition to water at ambient conditions and (b) a particulate polysaccharide or polysaccharide derivative being sufficiently cross-linked such that the cross-linked polysaccharide or polysaccharide derivative does not form soft lumps, nodules or other agglomerations upon its addition to water;

said uncross-linked polysaccharide or derivative and cross-linked polysaccharide or derivative being employed in amounts such that upon the composition'"'"'s dispersion and subsequent dissolution in an aqueous solution at ambient temperature, the uncross-linked polysaccharide or derivative thereof does not form substantial amounts of soft lumps, nodulus or other agglomerations and the viscosity of the aqueous liquid is increased at a sufficient rate that the cross-linked polysaccharide is maintained in dispersion without significant amounts thereof settling prior to dissolution.

2. The polysaccharide composition of claim 1 wherein the polysaccharide or polysaccharide derivative is a cellulose ether.

3. The polysaccharide composition of claim 2 wherein the cellulose ether is in particulate form having a number average particle size from about 0.074 to about 2 mm.

4. The polysaccharide composition of claim 3 wherein the uncross-linked cellulose ether is methylcellulose, hydroxyalkyl cellulose or hydroxyalkyl methylcellulose and the cross-linked cellulose ether is methylcellulose, hydroxyalkyl cellulose or hydroxyalkyl methylcellulose cross-linked using an aldehyde.

5. The polysaccharide composition of claim 4 wherein the cross-linked cellulose ether is prepared by cross-linking the cellulose ether using from about 0.2 to about 5 weight percent of glyoxal gased on the total weight of the polysaccharide being cross-linked.

6. The polysaccharide composition of claim 3 wherein the composition further comprises a normally solid basic material.

7. The polysaccharide composition of claim 6 wherein the normally solid basic material is an alkali metal carbonate or bicarbonate.

8. A polysaccharide composition comprising a dry blend of from about 5 to about 20 weight percent of an uncross-linked polysaccharide or polysaccharide derivative and from about 80 to about 95 weight percent of a cross-linked polysaccharide or polysaccharide derivative wherein said weight percents are based on the total amount of uncross-linked and cross-linked polysaccharides in the composition.

9. The polysaccharide composition of claim 8 wherein the polysaccharides are cellulose ethers.

10. The polysaccharide composition of claim 9 wherein the uncross-linked cellulose ether is methylcellulose, hydroxyalkyl cellulose or hydroxyalkyl methylcellulose and the cross-linked cellulose ether is methylcellulose, hydroxyalkyl cellulose or hydroxyalkyl methylcellulose cross-linked using an aldehyde.

11. The polysaccharide composition of claim 10 wherein the cross-linked polysaccharide is a cross-linked hydroxypropyl methylcellulose prepared by cross-linking a hydroxypropyl methylcellulose using from about 0.2 to about 5 weight percent of an aldehyde based on the weight of the methylcellulose or derivative.

12. The polysaccharide composition of claim 11 wherein the composition further comprises an amount of a normally solid, basic material, said amount being sufficient to impart a pH of from about 7.0 to about 10 to an aqueous liquid upon addition of the polysaccharide composition thereto.

13. The polysaccharide composition of claim 12 wherein the normally solid basic material is an alkali metal carbonate or bicarbonate.