US3716507A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydroxypropylmethylcellulose as a protective colloid in vinyl monomer polymerization
Assignee: Dow Chemical Co
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Filing: 1971-03-02
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Granted: 1973-02-13
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Expires: 1991-03-02
Abstract
Abstract An improvement in the process for preparing vinyl polymers in aqueous suspension, said improvement comprising the use of hydroxypropylmethylcellulose having a methoxyl degree of substitution of from 0.4 to 1.3 and a hydroxypropyl molar substitution of from 0.2 to 1.4 and a total substitution of at least 1.0 combined degree of methoxyl substitution and degree of hydroxypropyl molar substitution as the protective colloid in the water-phase of an oil-in-water suspension system.
Inventors
- 👤 R Glomski
- 👤 G Greminger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:57
CPC Classifications
C; C08; C08F; C08F251/00; C08F251/02; Y; Y10; Y10S; Y10S526/00; Y10S526/91
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
In the process of polymerizing vinyl chloride monomer in non-emulsified aqueous suspension in the presence of a polymerization catalyst and a protective colloid the improvement consisting of: using as said protective colloid from about 0.05 to 5 percent, based on monomer weight of a water-soluble hydroxypropylmethylcellulose having a methoxyl degree of substitution of from 0.4 to 1.3 and a hydroxypropyl molar substitution of from 0.2 to 1.4 and a total substitution of at least 1.0 combined degree of methoxyl substitution and degree of hydroxypropyl molar substitution.
Claim 2
Dependent Claim
86 words
In the process of polymerizing vinyl chloride monomer in non-emulsified aqueous suspension in the presence of a polymerization catalyst and a protective colloid the improvement consisting of: using as said protective colloid from about 0.05 to 5 percent, based on monomer weight of a water-soluble hydroxypropylmethylcellulose having a methoxyl degree of substitution of from 0.4 to 1.3 and a hydroxypropyl molar substitution of from 0.2 to 1.4 and a total substitution of at least 1.0 combined degree of methoxyl substitution and degree of hydroxypropyl molar substitution.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein said hydroxypropylmethylcellulose has a methoxyl degree of substitution of from 1.0 to 1.3 and a hydroxylpropyl molar substitution of from 0.75 to 1.0.
Claim 4
Dependent Claim
26 words
The process of claim 2 wherein said hydroxypropylmethylcellulose has a viscosity of about 7.3 cps at 2 percent concentration at 20* C. in the polymerization system.
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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |