US4463138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High molecular weight poly(vinyl acetate) and poly(vinyl alcohol) and processes for their production
Assignee: Honeywell International Inc
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Filing: 1982-09-30
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Granted: 1984-07-31
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Expires: 2002-09-30
Abstract
Abstract An improved poly(vinyl acetate) which on hydrolysis and reacetylation has an intrinsic viscosity of at least about 5 dL/g and an improved poly(vinyl alcohol) which on acetylation yields poly(vinyl acetate) having an intrinsic viscosity of at least about 5 dL/g. Such poly(vinyl acetate) can be prepared by photo-initiated free radical bulk polymerization of vinyl acetate with controlled low initiator concentration, polymerization temperature and reaction time. Such poly(vinyl alcohol) can be prepared by conventional alcoholysis of the poly(vinyl acetate).
Inventors
- 👤 Tse C. Wu
- 👤 James C. West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:14
CPC Classifications
C; C08; C08F; C08F18/00; C08F18/02; C08F18/04; C08F18/08; C08F8/00; C08F8/10; C08F8/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
31 words
An essentially linear poly(vinyl acetate) which upon alcoholysis and reacetylation has an intrinsic viscosity of at least about 6 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.).
Claim 2
Dependent Claim
31 words
An essentially linear poly(vinyl acetate) which upon alcoholysis and reacetylation has an intrinsic viscosity of at least about 6 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.).
Claim 3
Dependent Claim
20 words
A poly(vinyl acetate) according to claim 1 wherein said intrinsic viscosity is between about 6 dL/g and about 9 dL/g.
Claim 4
Dependent Claim
32 words
An essentially linear poly(vinyl alcohol) which upon acetylation yields poly(vinyl acetate) having an intrinsic viscosity of at least about 5 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.).
Claim 5
Dependent Claim
32 words
An essentially linear poly(vinyl alcohol) which upon acetylation yields poly(vinyl acetate) having an intrinsic viscosity of at least about 5 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.).
Claim 6
Dependent Claim
20 words
A poly(vinyl alcohol) according to claim 3 wherein said intrinsic viscosity is between about 6 dL/g and about 9 dL/g.
Claim 7
Dependent Claim
106 words
A process for the photoinitiated free radical bulk polymerization of vinyl acetate to produce an essentially linear poly(vinyl acetate) which upon alcoholysis and reacetylation has an intrinsic viscosity of at least about 5 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.) wherein said process comprises: a. employing a photochemical initiator at a concentration between about 1×10 -3 molar and about 1×10 -5 molar; b. employing ultraviolet radiation to activate said initiator; c. employing a polymerization temperature between about -25° C. and about -45° C.; and d. conducting said polymerization for a period of time between about 24 hours and about 120 hours.
Claim 8
Dependent Claim
106 words
A process for the photoinitiated free radical bulk polymerization of vinyl acetate to produce an essentially linear poly(vinyl acetate) which upon alcoholysis and reacetylation has an intrinsic viscosity of at least about 5 dL/g (calculated from measurement of solution viscosity in tetrahydrofuran at 25° C.) wherein said process comprises: a. employing a photochemical initiator at a concentration between about 1×10 -3 molar and about 1×10 -5 molar; b. employing ultraviolet radiation to activate said initiator; c. employing a polymerization temperature between about -25° C. and about -45° C.; and d. conducting said polymerization for a period of time between about 24 hours and about 120 hours.
Claim 9
Dependent Claim
25 words
A process according to claim 5 wherein said initiator is an azo compound which is decomposed into free radicals upon being subjected to ultraviolet light.
Claim 10
Dependent Claim
21 words
A process according to claim 6 wherein said ultraviolet light has a wavelength of about 260 nm to about 500 nm.
Claim 11
Dependent Claim
11 words
A process according to claim 7 wherein said initiator is azobisisobutyronitrile.
Claim 12
Dependent Claim
20 words
A process according to claim 6 wherein said concentration is between about 3×10 -5 molar and about 6×10 -5 molar.
Claim 13
Dependent Claim
14 words
A process according to claim 9 wherein said concentration is about 5×10 -5 molar.
Claim 14
Dependent Claim
17 words
A process according to claim 5 wherein said time is between about 72 and about 105 hours.
Claim 15
Dependent Claim
13 words
A process according to claim 11 wherein said time is about 96 hours.
Claim 16
Dependent Claim
18 words
A process according to claim 5 wherein said temperature is between about -30° C. and about -40° C.
Claim 17
Dependent Claim
13 words
A process according to claim 13 wherein said temperature is about -40° C.
Claim 18
Dependent Claim
43 words
A process according to claim 5 wherein said concentration is between about 3×10 -5 molar and about 6×10 -5 molar with said time being between about 72 and about 105 hours and said temperature is between about -30° C. and about -40° C.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-31 | 1988-01-30 | 1988-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-31 | 1992-01-30 | 1992-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-31 | 1996-01-30 | 1996-07-31 | $7700.00 | Window Closed / Lapsed |