Patent US5051222A successfully refreshed from Google Patents.
US5051222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making extrudable polyvinyl alcohol compositions
Assignee: Sekisui Specialty Chemicals America LLC
•
Filing: 1989-09-01
•
Granted: 1991-09-24
•
Expires: 2009-09-01
Abstract
Abstract A method for extruding polyvinyl alcohol which includes adding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, and simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol and rapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.
Inventors
- 👤 F. Lennart Marten
- 👤 Amir Famili
- 👤 James F. Nangeroni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:03
CPC Classifications
C; C08; C08L; C08L29/00; C08L29/02; C08L29/04
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
66 words
In a method for extruding polyvinyl alcohol which is at least partially crystalline, the improvement which comprises adding at least 0.27 KW hr/kg of specific energy to the polyvinyl alcohol to both melt it and substantially eliminate the crystallinity in the melt by shearing the areas of crystallinity, and simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.
Claim 2
Dependent Claim
66 words
In a method for extruding polyvinyl alcohol which is at least partially crystalline, the improvement which comprises adding at least 0.27 KW hr/kg of specific energy to the polyvinyl alcohol to both melt it and substantially eliminate the crystallinity in the melt by shearing the areas of crystallinity, and simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.
Claim 3
Dependent Claim
22 words
The method of claim 1 in which about 0.3 to 0.6 KW hr/kg of specific energy is added to the polyvinyl alcohol.
Claim 4
Dependent Claim
21 words
The method of claim 1 in which about 0.35 to 0.45 KW hr/kg of specific energy is added to the PVOH.
Claim 5
Dependent Claim
21 words
The method of claim 1 in which the polyvinyl alcohol melt is rapidly cooled to yield an essentially gel-free polyvinyl alcohol.
Claim 6
Dependent Claim
15 words
The method of claim 1 in which the polyvinyl alcohol is 85-99+ mole % hydrolized.
Claim 7
Dependent Claim
15 words
The method of claim 1 in which the polyvinyl alcohol is mixed with a plasticizer.
Claim 8
Dependent Claim
11 words
The method of claim 6 in which the plasticizer is glycerol.
Claim 9
Dependent Claim
16 words
The method of claim 1 in which the polyvinyl alcohol is mixed with a dispersing agent.
Claim 10
Dependent Claim
13 words
The method of claim 8 in which the dispersing agent is glycerol mono-oleate.
Claim 11
Dependent Claim
35 words
The method of claim 1 in which the polyvinyl alcohol is mixed with sufficient mineral acid to provide an extruded polyvinyl alcohol which as a 4 wt % aqueous solution has a pH of 5.5-7.0.
Claim 12
Dependent Claim
12 words
The method of claim 10 in which the acid is phosphoric acid.
Claim 13
Dependent Claim
55 words
In a method for melt extruding 85-99+ mole % hydrolyzed polyvinyl alcohol, the improvement which comprises adding 0.27 to 0.6 KW hr/kg to the polyvinyl alcohol to yield a melt and to shear the areas of crystallinity in the melt, and simultaneously removing sufficient energy from the melt to avoid decomposition of the polyvinyl alcohol.
Claim 14
Dependent Claim
55 words
In a method for melt extruding 85-99+ mole % hydrolyzed polyvinyl alcohol, the improvement which comprises adding 0.27 to 0.6 KW hr/kg to the polyvinyl alcohol to yield a melt and to shear the areas of crystallinity in the melt, and simultaneously removing sufficient energy from the melt to avoid decomposition of the polyvinyl alcohol.
Claim 15
Dependent Claim
24 words
The method of claim 12 in which the polyvinyl alcohol melt is extruded as a strand which is rapidly cooled and cut into pellets.
Claim 16
Dependent Claim
18 words
The method of claim 12 in which 0.35 to 0.45 KW hr/kg is added to the polyvinyl alcohol.
Claim 17
Dependent Claim
30 words
The method of claim 12 in which 1 to 30 wt % polyhydric alcohol plasticizer and optionally 0.05 to 1.0 wt % dispersing agent are added to the polyvinyl alcohol.
Claim 18
Dependent Claim
69 words
In a method for making extrudable polyvinyl alcohol pellets by melt extruding a polyvinyl alcohol composition containing a plasticizer, the improvement which comprises adding 0.35 to 0.45 KW hr/kg of specific energy to the polyvinyl alcohol composition to obtain a melt and to shear any areas of crystallinity in the melt and simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.
Claim 19
Dependent Claim
69 words
In a method for making extrudable polyvinyl alcohol pellets by melt extruding a polyvinyl alcohol composition containing a plasticizer, the improvement which comprises adding 0.35 to 0.45 KW hr/kg of specific energy to the polyvinyl alcohol composition to obtain a melt and to shear any areas of crystallinity in the melt and simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.
Claim 20
Dependent Claim
36 words
The method of claim 16 in which the polyvinyl alcohol composition also contains phosphoric acid added in about a 1:2 molar ratio with the sodium acetate content and, optionally, 0.5 to 1.0 wt % dispersing agent.
Claim 21
Dependent Claim
18 words
The method of claim 17 in which the plasticizer is glycerol and the dispersing agent is glycerol mono-oleate.
Claim 22
Dependent Claim
15 words
The method of claim 18 in which the polyvinyl alcohol is 85-99+ mole % hydrolyzed.
Claim 23
Dependent Claim
16 words
The method of claim 16 in which the plasticizer is a polyhydric low molecular weight alcohol.
References Cited (Backward Citations)
CA712071A
Cited
US3365413A
Cited
US3425979A
Cited
US3409598A
Cited
US3555616A
Cited
US3843757A
Cited
US3607812A
Cited
US3742093A
Cited
JPS4842950A
Cited
US4206101A
Cited
US4267145A
Cited
US4215169A
Cited
US3997489A
Cited
US4244914A
Cited
US4119604A
Cited
US4156047A
Cited
US4155971A
Cited
JPS5371168A
Cited
US4107422A
Cited
US4243629A
Cited
JPS5515885A
Cited
US4320041A
Cited
US4452750A
Cited
US4871410A
Cited
US4469837A
Cited
US4493807A
Cited
US4672087A
Cited
US4611019A
Cited
JPS6195053A
Cited
JPS6195054A
Cited
US4753760A
Cited
US4822547A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-23 | 1995-03-25 | 1995-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-23 | 1999-03-25 | 1999-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-23 | 2003-03-25 | 2003-09-24 | $7700.00 | Window Closed / Lapsed |