US4698395A
Expired / Lapsed
US
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Process of purifying maleic anhydride-modified polyolefin
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-05-14
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Granted: 1987-10-06
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Expires: 2006-05-14
Abstract
Abstract A process of purifying maleic anhydride graft polyolefin comprising the steps of adding an aqueous solution of alkali initial hydroxide to a solution of maleic anhydride graft polyolefin containing unreacted maleic anhydride which is dissolved in an organic solvent at a temperature from 80° C. to 160° C., thereby precipitating maleic anhydride graft polyolefin particles to make a W/O emulsion; stirring the W/O emulsion while maintaining the temperature at a same temperature as above for less than 2 hours, thereby selectively forming the alkali metal salt of unreacted maleic anhydride; adding the aqueous solution of alkali metal hydroxide to the W/O emulsion to convert the W/O emulsion into an O/W emulsion; separating the maleic anhydride draft polyolefin particles, and washing the maleic anhydride graft polyolefin particles with water.
Inventors
- 👤 Takayuki Inoue
- 👤 Masafumi Hattori
- 👤 Kazuhide Hayama
- 👤 Riichiro Maruta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:51
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/46; C08F255/00; C08F6/00; C08F6/06; C08F8/44
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A process of purifying maleic anhydride graft polyolefin, comprising the steps of: adding an aqueous solution of alkali metal hydroxide to a solution of maleic anhydride graft polyolefin containing unreacted maleic anhydride which is dissolved in an organic solvent at a temperature from 80° C. to 160° C., thereby precipitating maleic anhydride graft polyolefin particles to make a W/O emulsion; stirring said W/O emulsion while maintaining the temperature at the same temperature as above for less than 2 hours, thereby selectively forming the alkali metal salt of unreacted maleic anhydride; adding said aqueous solution of alkali metal hydroxide to said W/O emulsion to change said W/O emulsion into an O/W emulsion; separating said maleic anhydride graft polyolefin particles; and washing said maleic anhydride graft polyolefin particles with water.
Claim 2
Dependent Claim
128 words
A process of purifying maleic anhydride graft polyolefin, comprising the steps of: adding an aqueous solution of alkali metal hydroxide to a solution of maleic anhydride graft polyolefin containing unreacted maleic anhydride which is dissolved in an organic solvent at a temperature from 80° C. to 160° C., thereby precipitating maleic anhydride graft polyolefin particles to make a W/O emulsion; stirring said W/O emulsion while maintaining the temperature at the same temperature as above for less than 2 hours, thereby selectively forming the alkali metal salt of unreacted maleic anhydride; adding said aqueous solution of alkali metal hydroxide to said W/O emulsion to change said W/O emulsion into an O/W emulsion; separating said maleic anhydride graft polyolefin particles; and washing said maleic anhydride graft polyolefin particles with water.
Claim 3
Dependent Claim
13 words
The purifying process according to claim 1, wherein said organic solvent is chlorobenzene.
Claim 4
Dependent Claim
36 words
The purifying process according to claim 1, wherein the amount of said organic solvent ranges from 100 parts by weight to 2,500 parts by weight per 100 parts by weight of said maleic anhydride graft polyolefin.
Claim 5
Dependent Claim
15 words
The purifying process according to claim 1, wherein said alkali metal hydroxide is sodium hydroxide.
Claim 6
Dependent Claim
26 words
The purifying process according to claim 1, wherein the concentration of said aqueous solution of said alkali metal hydroxide ranges from 0.4 to 1.8% by weight.
Claim 7
Dependent Claim
57 words
The purifying process according to claim 1, wherein the equivalent weight amount of the hydroxide ions in said aqueous alkali metal hydroxide solution ranges from 0.35 to 1.6 equivalent per one equivalent of carboxyl groups in both the graft polyolefin and the unreacted maleic anhydride in order to neutralize the carboxyl groups in the unreacted maleic anhydride.
Claim 8
Dependent Claim
22 words
The purifying process according to claim 1, wherein said W/O emulsion is stirred at a temperature of from 80° to 160° C.
Claim 9
Dependent Claim
25 words
The purifying process according to claim 1, wherein the amount of the maleic anhydride in the graft polyolefin ranges from 0.01 to 15% by weight.
Claim 10
Dependent Claim
29 words
The purifying process according to claim 1, wherein said organic solvent is an aromatic hydrocarbon, an aliphatic hydrocarbon or a halogenated hydrocarbon which has essentially no affinity for water.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |