Process for Continuous Solution Polymerization
US-2016362506-A1 · Dec 15, 2016 · US
Polyvinyl alcohol and purification method thereof
US2016215076A1 · US · A1
| Field | Value |
|---|---|
| Publication number | US-2016215076-A1 |
| Application number | US-201615006513-A |
| Country | US |
| Kind code | A1 |
| Filing date | Jan 26, 2016 |
| Priority date | Jan 27, 2015 |
| Publication date | Jul 28, 2016 |
| Grant date | — |
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Abstract
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Highly purified polyvinyl alcohol (PVA) which meets the standard of pharmaceutical grade is provided. The PVA has of less than 0.1 wt % of residual methanol, less than 0.1 wt % of residual methyl acetate, and less than 0.3 wt % of residual sodium acetate. A method for obtaining highly purified PVA is further provided.
First claim
Opening claim text (preview).
What is claimed: 1 . A method for purifying polyvinyl alcohol, comprising the steps of: (a) adding polyvinyl alcohol prepared by hydrolyzing polyvinyl acetate with catalysis by a base into an ethanol solution with an ethanol concentration of 95 wt % or higher; (b) heating and stirring the ethanol solution of comprising the polyvinyl alcohol; and (c) retrieving the polyvinyl alcohol from the ethanol solution comprising the polyvinyl alcohol, and drying the retrieved polyvinyl alcohol. 2 . The method of claim 1 , wherein the polyvinyl alcohol prepared by hydrolyzing polyvinyl acetate with catalysis by a base is a cluster of polyvinyl alcohol particles in the form of lamellae or granules. 3 . The method of claim 1 , wherein, in step (a), the polyvinyl alcohol prepared by hydrolyzing polyvinyl acetate with catalysis by a base is completely soaked in the ethanol solution. 4 . The method of claim 1 , wherein, in step (a), the ethanol solution has an ethanol concentration of from 95 wt % to 100 wt %. 5 . The method of claim 1 , wherein, in step (a), the polyvinyl alcohol prepared by hydrolyzing polyvinyl acetate with catalysis by a base has a degree of alkaline hydrolysis of from 70 to 99 mole % and a degree of polymerization of from 200 to 4000. 6 . The method of claim 1 , wherein, in step (b), the polyvinyl alcohol is heated and stirred in the ethanol solution at a temperature of from 50 to 100° C. 7 . The method of claim 6 , wherein, in step (b), the temperature of the ethanol solution comprising the polyvinyl alcohol is from 65 to 85° C. 8 . A polyvinyl alcohol, comprising less than 0.1 wt % of methanol, less than 0.1 wt % of methyl acetate, and less than 0.3 wt % of sodium acetate, based on the total weight of the polyvinyl alcohol. 9 . The polyvinyl alcohol of claim 8 , which has a degree of alkaline hydrolysis of from 70 to 99 mole % and a degree of polymerization of from 200 to 4000. 10 . The polyvinyl alcohol of claim 8 , which is a cluster of polyvinyl alcohol particles in the form of lamellae or granules. 11 . The polyvinyl alcohol of claim 8 , which is obtained according to the method of claim 1 .
Assignees
Inventors
Classifications
- C08F6/12Primary
Separation of polymers from solutions · CPC title
Hydrolysis · CPC title
Polyvinyl alcohol {; Vinyl alcohol} · CPC title
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Frequently asked questions
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- What does patent US2016215076A1 cover?
- Highly purified polyvinyl alcohol (PVA) which meets the standard of pharmaceutical grade is provided. The PVA has of less than 0.1 wt % of residual methanol, less than 0.1 wt % of residual methyl acetate, and less than 0.3 wt % of residual sodium acetate. A method for obtaining highly purified PVA is further provided.
- Who is the assignee on this patent?
- Chang Chun Petrochemical Co Ltd
- What technology area does this patent fall under?
- Primary CPC classification C08F6/12. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Thu Jul 28 2016 00:00:00 GMT+0000 (Coordinated Universal Time) (A1). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).