US4839458A
Expired / Lapsed
US
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Preparation with controlled amounts of polycarbonate carbon tetrachloride
Assignee: Mitsubishi Chemical Corp
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Filing: 1987-06-17
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Granted: 1989-06-13
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Expires: 2007-06-17
Abstract
Abstract Disclosed herein is a process for producing a resin having carbonate bonding, comprising polymerizing a hydroxydiaryl compound and phosgene in an organic solvent of methylene chloride such that the concentration of carbon tetrachloride in phosgene and methylene chloride in the polymerization system satisfies the following equation: A+5B</=200 (wherein A represents carbon tetrachloride concentration (ppm) in phosgene and B represents carbon tetrachloride concentration (ppm) in methylene chloride).
Inventors
- 👤 Shinichiro Koga
- 👤 Akira Matsuno
- 👤 Katsuyuki Sakata
- 👤 Yoshiaki Ohtani
- 👤 Isao Akihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:59
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/22; C08G64/24; C08G64/40; C08G64/406
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
67 words
A process for producing a resin having carbonate bonding, comprising polymerizing a dihydroxydiaryl compound and phosgene containing carbon tetrachloride in an organic solvent of methylene chloride such that the concentration of carbon tetrachloride in the phosgene and methylene chloride satisfies the following equation: A+5B≦200 wherein A represents the ppm carbon tetrachloride concentration in the phosgene and B represents the ppm carbon tetrachloride concentration in the methylene chloride.
Claim 2
Dependent Claim
67 words
A process for producing a resin having carbonate bonding, comprising polymerizing a dihydroxydiaryl compound and phosgene containing carbon tetrachloride in an organic solvent of methylene chloride such that the concentration of carbon tetrachloride in the phosgene and methylene chloride satisfies the following equation: A+5B≦200 wherein A represents the ppm carbon tetrachloride concentration in the phosgene and B represents the ppm carbon tetrachloride concentration in the methylene chloride.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein the starting phosgene is a phosgene containing not more than 200 ppm of carbon tetrachloride concentration.
Claim 4
Dependent Claim
16 words
A process according to claim 1, wherein the methylene chloride is recycled in the polymerization process.
Claim 5
Dependent Claim
24 words
A process according to claim 1 or 2, wherein the carbon tetrachloride concentration in the starting phosgene is reduced by distillation of the phosgene.
Claim 6
Dependent Claim
25 words
A process according to claim 3, wherein the carbon tetrachloride concentration in the methylene chloride is reduced by distilling the methylene chloride prior to recycling.
Claim 7
Dependent Claim
45 words
A process according to claim 1, wherein the carbon tetrachloride concentration in the methylene chloride is reduced by decreasing any dissolved oxygen in the methylene chloride solution to a concentration of not more than 20 ppm before distilling the methylene chloride to separate the resin.
Claim 8
Dependent Claim
29 words
A process according to claim 6, wherein the dissolved oxygen concentration is reduced to not more than 20 ppm by blowing an inert gas into said methylene chloride solution.
Claim 9
Dependent Claim
15 words
A process according to claim 1, wherein the resin having carbonate bondings is a polycarbonate.
Claim 10
Dependent Claim
24 words
A process according to claim 1, wherein the carbon tetrachloride concentration in the resultant resin having carbonate bondings is not more than 20 ppm.
Claim 11
Dependent Claim
24 words
A process according to claim 9, wherein the carbon tetrachloride concentration in the resultant resin having carbonate bondings is not more than 10 ppm.
References Cited (Backward Citations)
JPS5922743A
Cited
JPH0681245A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |