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US5011936A
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Process for refining 1,3-dimethyl-2-imidazolidinone
Assignee: Mitsui Chemicals Inc
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Filing: 1989-03-07
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Granted: 1991-04-30
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Expires: 2009-03-07
Abstract
Abstract The present invention is directed to a refining process for removing impurities from 1,3-dimethyl-2-imidazolidinone (DMI) by the use of a composite salt; and a process for preparing an aromatic polyamide having a high polymerization degree from an aromatic diisocyanate and an aromatic dicarboxylic acid by using, as a reaction solvent, DMI purified by the above-mentioned process.
Inventors
- 👤 Tadashi Kobayashi
- 👤 Mitsuo Wada
- 👤 Shouzi Obuchi
- 👤 Hiroshi Takayanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:35
CPC Classifications
C; C07; C07D; C07D233/00; C07D233/04; C07D233/28; C07D233/30; C07D233/32; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
39 words
A process for refining 1,3-dimethyl-2-imidazolidinone which comprises the step of bringing 1,3,dimethyl-2-imidazolidinone into contact with a composite salt containing at least two composition components selected from the group consisting of MgO, SiO 2 and Al 2 O 3 .
Claim 2
Dependent Claim
39 words
A process for refining 1,3-dimethyl-2-imidazolidinone which comprises the step of bringing 1,3,dimethyl-2-imidazolidinone into contact with a composite salt containing at least two composition components selected from the group consisting of MgO, SiO 2 and Al 2 O 3 .
Claim 3
Dependent Claim
79 words
A process according to claim 1 wherein said composite salt is at least one selected from the group consisting of 2MgO·Al 2 O 3 ·xH 2 O, 3MgO·Al 2 O 3 ·xH 2 O, 5MgO·Al 2 O 3 ·-xH 2 O, MgO·Al 2 O 3 ·2SiO 2 ·xH 2 O, 2MgO·Al 2 O 3 ·SiO 2 ·xH 2 O, MgO·-3SiO 2 ·xH 2 O, 2MgO·3SiO 2 ·xH 2 O and Al 2 O 3 ·9SiO 2 ·xH 2 O.
Claim 4
Dependent Claim
30 words
A process according to claim 1 wherein said composite salt is used in an amount of 1 to 50 parts by weight based on 100 parts by weight of 1,3-dimethyl-2-imidazolidinone.
Claim 5
Dependent Claim
27 words
A process according to claim 1 wherein said composite salt has a pH of 7.0 to 11.0 in the state of a 4% by weight aqueous suspension.
Claim 6
Dependent Claim
21 words
A process according to claim 1 wherein said composite salt has a bulk specific gravity of 10 to 60 ml/10 g.
Claim 7
Dependent Claim
22 words
A process according to claim 1 wherein said composite salt has a specific surface area of 50 to 400 m 2 /g.
Claim 8
Dependent Claim
24 words
A process according to claim 1 wherein when brought into contact with said composite salt, 1,3-dimethyl-2-imidazolidinone has a temperature of 5° to 180° C.
Claim 9
Dependent Claim
85 words
A process for refining 1,3 dimethyl-2-imidazolidinone comprising the step of contacting 1,3 dimethyl-2-imidazolidinone with a hydrated composite salt, wherein said salt is selected from the group consisting of (a) a hydrated composite salt including SiO 2 and MgO, and (b) a hydrated composite salt including at least one first component selected from the group consisting of SiO 2 and MgO and at least one second component selected from the group consisting of alkaline metal oxides, alkaline earth metal oxides, amphoteric oxides and carbon group oxides.
Claim 10
Dependent Claim
85 words
A process for refining 1,3 dimethyl-2-imidazolidinone comprising the step of contacting 1,3 dimethyl-2-imidazolidinone with a hydrated composite salt, wherein said salt is selected from the group consisting of (a) a hydrated composite salt including SiO 2 and MgO, and (b) a hydrated composite salt including at least one first component selected from the group consisting of SiO 2 and MgO and at least one second component selected from the group consisting of alkaline metal oxides, alkaline earth metal oxides, amphoteric oxides and carbon group oxides.
Claim 11
Dependent Claim
27 words
The process of claim 8 wherein said alkaline metal oxide is selected from the group consisting of Na 2 O, K 2 O and Li 2 O.
Claim 12
Dependent Claim
22 words
The process of claim 8 wherein said alkaline earth metal oxide is selected from the group consisting of CaO, MgO and BeO.
Claim 13
Dependent Claim
26 words
The process of claim 8 wherein said amphoteric oxide is selected from the group consisting of Al 2 O 3 and B 2 O 3 .
Claim 14
Dependent Claim
23 words
The process of claim 8 wherein said carbon group oxide is selected from the group consisting of CO 2 and SiO 2 .
Claim 15
Dependent Claim
51 words
The process of claim 8 wherein the composite salt is represented by the formula lMgO·mAl 2 O 3 ·nSiO 2 ·xH 2 O wherein l, m and n are an integer of 0 to 10 with the proviso that at least two of l, m and n are 1 or greater.
Claim 16
Dependent Claim
66 words
The process of claim 8 wherein the composite salt is selected from the group consisting of Na 2 O·Al 2 O 3 ·3SiO 2 ·xH 2 O, 6MgO·Al 2 O 3 ·CO 2 ·xH 2 O·CaO·SiO 2 ·xH 2 O, Al 2 O 3 ·9SiO 2 ·xH 2 O, MgO·Al 2 O 3 ·SiO 2 ·xH 2 O, and 3MgO·Al 2 O 3 ·xH 2 O.
References Cited (Backward Citations)
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