Patent US3446485A successfully refreshed from Google Patents.
Patent US3880771A successfully refreshed from Google Patents.
US3880771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aqueous suspension vehicle useful in suspension polymerization system for spheres
Assignee: Normac Inc
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Filing: 1972-01-17
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Granted: 1975-04-29
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Expires: 1992-01-17
Abstract
Abstract There is disclosed an aqueous suspension vehicle consisting essentially of water having dissolved therein a water-soluble suspending agent, such as one or more hydroxyethylcelluloses, in a concentration below about 0.4 weight percent, and about 0.01 to about 0.5 percent of a water-soluble organic solvent for said suspending agent, such as dimethylformamide.
Inventors
- 👤 Max Klein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:52
CPC Classifications
C; C08; C08F; C08F12/00; C08F12/02; C08F12/04; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/06; Y10S526/00; Y10S526/909
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
AN AQUEOUS SUSPENSION VEHICLE USEFUL IN SUSPENSION POLYMERIZATION OF A STYRENE-MONOMER IN THE PRESENCE OF A STYRENEMONOMER-POLYMERIZATION EFFECTIVE AMOUNT OF A STYRENEMONOMER-POLYMERIZATION FREE RADICAL-PROVIDING CATALYST, WHICH SUSPENSION CONSISTS ESSENTIALLY OF (A) WATER AND DISSOLVED THEREIN (B) A WATER-SOLUBLE SUSPENDING AGENT INERT TO REACTION WITH STYRENE, WHICH IS AT LEAST ONE OF (I) A HYDROXYETHYLCELLULOSE HAVING A VISCOSITY WITHIN THE RANGE OF ONE WHOSE 2 PERCENT BY WEIGHT, ON DRY BASIS, AQUEOUS SOLUTION AT 20*C. HAS A HOOPLER VISCOSITY OF FROM 6175 TO 7600 CENTIPOISES, (II) A HYDROXYETHYLCELLULOSE WHOSE SUCH 5 PERCENT AQUEOUS SOLUTION AT 20*C. HAS A HOOPLER VISCOSITY OF FROM 120 TO 160 CENTIPOISES, (III) CARBOXYMETHYLCELLULOSE, (IV) POLYACRYLIC ACID, (V) POLYMETHACRYLIC ACID, (VI) THE SODIUM OR AMMONIUM SALT OF ANY OF THE CARBOXYLIC ACID SUBSTANCES (III), (IV), AND (V), AND (VII) POLYVINYL ALCOHOL; SAID SUSPENDING AGENT BEING PRESENT IN A CONCENTRATION ABOVE THAT WHICH WILL ALLOW THE PRODUCED STYRENE-POLYMER TO AGGLOMERATE UNDER THE POLYMERIZATION CONDITIONS AND BELOW ABOUT 0.4 WEIGHT PERCENT, AND (C) FROM ABOUT 0.01 TO ABOUT 0.5 PERCENT OF A WATER-SOLUBLE ORGANIC SOLVENT FOR SAID SUSPENDING AGENT, WHICH SOLVENT IS SELECTED FROM THE GROUP CONSISTING OF FORMIC ACID, DIMETHYLFORMAMIDE, DIMETHYL-ACETAMIDE, TETRAHYDROUFURAN, ETHYLENEDIAMINE, DIETHYLENETRIAMINE, 2-BROMOPYRIDINE, AND 3-CYANOPYRIDINE.
Claim 2
Dependent Claim
199 words
AN AQUEOUS SUSPENSION VEHICLE USEFUL IN SUSPENSION POLYMERIZATION OF A STYRENE-MONOMER IN THE PRESENCE OF A STYRENEMONOMER-POLYMERIZATION EFFECTIVE AMOUNT OF A STYRENEMONOMER-POLYMERIZATION FREE RADICAL-PROVIDING CATALYST, WHICH SUSPENSION CONSISTS ESSENTIALLY OF (A) WATER AND DISSOLVED THEREIN (B) A WATER-SOLUBLE SUSPENDING AGENT INERT TO REACTION WITH STYRENE, WHICH IS AT LEAST ONE OF (I) A HYDROXYETHYLCELLULOSE HAVING A VISCOSITY WITHIN THE RANGE OF ONE WHOSE 2 PERCENT BY WEIGHT, ON DRY BASIS, AQUEOUS SOLUTION AT 20*C. HAS A HOOPLER VISCOSITY OF FROM 6175 TO 7600 CENTIPOISES, (II) A HYDROXYETHYLCELLULOSE WHOSE SUCH 5 PERCENT AQUEOUS SOLUTION AT 20*C. HAS A HOOPLER VISCOSITY OF FROM 120 TO 160 CENTIPOISES, (III) CARBOXYMETHYLCELLULOSE, (IV) POLYACRYLIC ACID, (V) POLYMETHACRYLIC ACID, (VI) THE SODIUM OR AMMONIUM SALT OF ANY OF THE CARBOXYLIC ACID SUBSTANCES (III), (IV), AND (V), AND (VII) POLYVINYL ALCOHOL; SAID SUSPENDING AGENT BEING PRESENT IN A CONCENTRATION ABOVE THAT WHICH WILL ALLOW THE PRODUCED STYRENE-POLYMER TO AGGLOMERATE UNDER THE POLYMERIZATION CONDITIONS AND BELOW ABOUT 0.4 WEIGHT PERCENT, AND (C) FROM ABOUT 0.01 TO ABOUT 0.5 PERCENT OF A WATER-SOLUBLE ORGANIC SOLVENT FOR SAID SUSPENDING AGENT, WHICH SOLVENT IS SELECTED FROM THE GROUP CONSISTING OF FORMIC ACID, DIMETHYLFORMAMIDE, DIMETHYL-ACETAMIDE, TETRAHYDROUFURAN, ETHYLENEDIAMINE, DIETHYLENETRIAMINE, 2-BROMOPYRIDINE, AND 3-CYANOPYRIDINE.
Claim 3
Dependent Claim
25 words
An aqueous suspension vehicle as claimed in claim 1, wherein the styrene-monomer is styrene, and said suspending agent is at least one of said hydroxyethylcelluloses.
Claim 4
Dependent Claim
43 words
An aqueous suspension vehicle as claimed in claim 1, wherein the suspending agent is a mixture of approximately equal parts of each of said hydroxyethylcelluloses having the respective viscosities of those at the beginning and end of the range expressed in claim 1.
Claim 5
Dependent Claim
15 words
An aqueous suspension vehicle as claimed in claim 2, wherein said organic solvent is dimethylformamide.
Claim 6
Dependent Claim
26 words
An aqueous suspension vehicle as claimed in claim 4, wherein the dimethylformamide is replaced in part or entirely by one or both of dimethylacetamide or tetrahydrofuran.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |