US3879365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydroxyethyl hydroxypropyl methylcellulose as a protective colloid in vinyl chloride polymerization
Assignee: Dow Chemical Co
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Filing: 1974-01-07
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Granted: 1975-04-22
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Expires: 1994-01-07
Abstract
Abstract An improvement in the process for preparing polymers from vinyl chloride monomer in suspension comprising the use, as a protective colloid, in the suspension media, of hydroxyethyl hydroxypropyl methylcellulose having a thermal gel point greater than about 70*C, a hydroxyethoxyl substitution of about 10-22 weight percent, a hydroxypropyl substitution of about 14-32 weight percent, a methoxyl substitution of about 6-12.5 weight percent, and a total degree of substitution of greater than about 1.5.
Inventors
- 👤 Jr George K Greminger
- 👤 Earl H Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:04
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/02; C08F14/04; C08F14/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
109 words
IN THE PROCESS OF POLYMERIZING VINYL CHLORIDE MONOMER IN SUSPENSION IN THE PRESENCE OF A PROTECTIVE COLLOID THE IMPROVEMENT CONSISTING OF: USING AS SAID PROTECTIVE COLLOID FROM ABOUT 0.05 TO 5 PERCENT BASED ON THE WEIGHT OF MONOMER OF A HYDROXYETHYL HYDROXYPROPYL METHYLCELLULOSE ETHER HAVING A THERMAL GEL POINT GREATER THAN ABOUT 70*C., A HYDROXYETHOXYL CONTENT OF ABOUT 10-22 WEIGHT PERCENT, A HYDROXYEHTOXYL CONTENT OF ABOUT 14-32 WEIGHT PERCENT, METHOXYL CONTENT OF ABOUT 6-12.5 WEIGHT PERCENT, A TOTAL DEGREE OF SUBSTITUTION OF FROM GREATER THAN ABOUT 1.5 UP TO 3.0. AND VISCOSITY OF FROM ABOUT 30 TO 4,000 CPS AT TWO PERCENT CONCENTRATION AT 20*C. IN THE POLYMERIZATION SYSTEM.
Claim 2
Dependent Claim
109 words
IN THE PROCESS OF POLYMERIZING VINYL CHLORIDE MONOMER IN SUSPENSION IN THE PRESENCE OF A PROTECTIVE COLLOID THE IMPROVEMENT CONSISTING OF: USING AS SAID PROTECTIVE COLLOID FROM ABOUT 0.05 TO 5 PERCENT BASED ON THE WEIGHT OF MONOMER OF A HYDROXYETHYL HYDROXYPROPYL METHYLCELLULOSE ETHER HAVING A THERMAL GEL POINT GREATER THAN ABOUT 70*C., A HYDROXYETHOXYL CONTENT OF ABOUT 10-22 WEIGHT PERCENT, A HYDROXYEHTOXYL CONTENT OF ABOUT 14-32 WEIGHT PERCENT, METHOXYL CONTENT OF ABOUT 6-12.5 WEIGHT PERCENT, A TOTAL DEGREE OF SUBSTITUTION OF FROM GREATER THAN ABOUT 1.5 UP TO 3.0. AND VISCOSITY OF FROM ABOUT 30 TO 4,000 CPS AT TWO PERCENT CONCENTRATION AT 20*C. IN THE POLYMERIZATION SYSTEM.
Claim 3
Dependent Claim
111 words
In the process of polymerizing vinyl chloride monomer in suspension in the presence of a protective colloid the improvement consisting of: using as said protective colloid from about 0.05 to 5 percent based on the weight of monomer of a hydroxyethyl hydroxypropyl methylcellulose ether having a thermal gel point greater than about 70*C., a hydroxyethoxyl content of about 10-22 weight percent, a hydroxypropyl content of about 14-32 weight percent, a methoxyl content of about 6-12.5 weight percent, a total degree of substitution of from greater than about 1.5 up to 3.0. and a viscosity of from about 30 to 4,000 cps at two percent concentration at 20*C. in the polymerization system.
Claim 4
Dependent Claim
111 words
In the process of polymerizing vinyl chloride monomer in suspension in the presence of a protective colloid the improvement consisting of: using as said protective colloid from about 0.05 to 5 percent based on the weight of monomer of a hydroxyethyl hydroxypropyl methylcellulose ether having a thermal gel point greater than about 70*C., a hydroxyethoxyl content of about 10-22 weight percent, a hydroxypropyl content of about 14-32 weight percent, a methoxyl content of about 6-12.5 weight percent, a total degree of substitution of from greater than about 1.5 up to 3.0. and a viscosity of from about 30 to 4,000 cps at two percent concentration at 20*C. in the polymerization system.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein said hydroxyethyl hydroxypropyl methylcellulose has a thermal gel point of from about 80*-85*C.
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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |