US4309535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of improving dispersibility of anionic cellulose ethers
Assignee: Aqualon Co
•
Filing: 1980-09-05
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Granted: 1982-01-05
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Expires: 2000-09-05
Abstract
Abstract Easily dispersible anionic water-soluble polymers are disclosed which are prepared by lightly treating particulate water-soluble polymer with a water-soluble aluminum salt and an aluminum chelant. Rate of hydration is retarded when the particles are added to aqueous media, allowing the particles to be dispersed completely before their surfaces hydrate sufficiently to gel and prevent complete dissolution.
Inventors
- 👤 Thomas G. Majewicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:03
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20; C08L; C08L33/00; C08L33/24; C08L33/26; C08L5/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
55 words
In the method of preparing aqueous solutions of anionic water-soluble polymers wherein particulate anionic water-soluble polymer is treated with aluminum ion to delay its hydration in aqueous systems, the improvement which comprises dissolving said treated polymer particles in the presence of about 2 to 25% by weight, based on polymer weight, of an aluminum chelant.
Claim 2
Dependent Claim
55 words
In the method of preparing aqueous solutions of anionic water-soluble polymers wherein particulate anionic water-soluble polymer is treated with aluminum ion to delay its hydration in aqueous systems, the improvement which comprises dissolving said treated polymer particles in the presence of about 2 to 25% by weight, based on polymer weight, of an aluminum chelant.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the aluminum chelant is selected from the class consisting of sodium hexametaphosphate and sodium citrate.
Claim 4
Dependent Claim
26 words
The method according to claim 1 wherein the anionic water-soluble polymer is selected from the class consisting of carboxymethyl cellulose, xanthan gum, and acrylamidesodium acrylate copolymer.
Claim 5
Dependent Claim
71 words
In the method of preparing aqueous solutions of carboxymethyl cellulose wherein particulate carboxymethyl cellulose is treated with aluminum ion to delay its hydration in aqueous systems, the improvement which comprises dissolving said treated carboxymethyl cellulose in the presence of about 2 to 25% by weight, based on polymer weight, of an aluminum chelant selected from the class consisting of sodium hexamethylphosphate, sodium citrate, and the sodium salt of ethylenediamine tetraacetic acid.
Claim 6
Dependent Claim
71 words
In the method of preparing aqueous solutions of carboxymethyl cellulose wherein particulate carboxymethyl cellulose is treated with aluminum ion to delay its hydration in aqueous systems, the improvement which comprises dissolving said treated carboxymethyl cellulose in the presence of about 2 to 25% by weight, based on polymer weight, of an aluminum chelant selected from the class consisting of sodium hexamethylphosphate, sodium citrate, and the sodium salt of ethylenediamine tetraacetic acid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-04 | 1985-07-06 | 1986-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-04 | 1989-07-06 | 1990-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-04 | 1993-07-06 | 1994-01-05 | $7700.00 | Window Closed / Lapsed |