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US5097002A Expired / Lapsed US ⏱️ 0.0 years remaining

Melt, catalytic process for preparing polycarbonates from carbonic acid diester

Assignee: SABIC Global Technologies BV
•
Filing: 1991-05-10
•
Granted: 1992-03-17
•
Expires: 2011-05-10
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Abstract

Abstract A process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using an aromatic dihydroxy compound and a carbonic acid diester, wherein the combined content of hydrolyzable chlorine in those monomers falls within the particular range. Another process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using a catalyst comprising (a) a nitrogen containing basic compound and (b) aromatic dihydroxy compound of an alkali metal or alkaline earth metal compound, or (a) and (b) and (c) boric acid or boric ester.

Inventors

  • 👤 Takeshi Sakashita
  • 👤 Tomoaki Shimoda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 12:47
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/30; C08G64/307

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 62 words
A process for preparing polycarbonates by melt polycondensation of at least one aromatic dihydroxy compound and at least one carbonic acid diester in the presence of a catalyst comprising (a) a nitrogen containing basic compound, and (b) from 10 -8 to 10 -3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound.
Claim 2
Dependent Claim 62 words
A process for preparing polycarbonates by melt polycondensation of at least one aromatic dihydroxy compound and at least one carbonic acid diester in the presence of a catalyst comprising (a) a nitrogen containing basic compound, and (b) from 10 -8 to 10 -3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound.
Claim 3
Dependent Claim 52 words
The process as claimed in claim 1, wherein the catalyst comprises, based on 1 mole of the aromatic dihydroxy compound, (a) from 10 -6 to 10 -1 mole of the nitrogen containing basic compound, and (b) from 10 -8 to 10 -3 mole of the alkali metal or alkaline earth metal compound.
Claim 4
Dependent Claim 51 words
The process as claimed in claim 1, wherein the catalyst comprises, based on 1 mole of the aromatic dihydroxy compound, (a) from 10 -5 to 10 -2 mole of the nitrogen containing basic compound, and (b) from 10 -7 to 10 -4 mole of the alkalimetal or alkaline earth metal compound.
Claim 5
Dependent Claim 51 words
The process as claimed in claim 1, wherein the catalyst comprises, based on 1 mole of the aromatic dihydroxy compound, (a) from 10 -5 to 10 -2 mole of the nitrogen containing basic compound, and (b) from 10 -7 to 10 -5 mole of the alkalimetal or alkaline earth metal compound.

References Cited (Backward Citations)

US3544514A Cited
USRE27682E Cited
GB1097058A Cited
US4267303A Cited
US4330664A Cited
USRE31262E Cited
EP0130512A2 Cited
US4590257A Cited
US4699971A Cited
US4788276A Cited
US4775739A Cited
US4839458A Cited
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US4880896A Cited
US5026817A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-03-17 1995-09-16 1996-03-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-03-17 1999-09-16 2000-03-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-03-17 2003-09-16 2004-03-17 $7700.00 Window Closed / Lapsed

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