Patent US4579957A successfully refreshed from Google Patents.
US4579957A
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Process for producing polymaleimide
Assignee: Mitsubishi Chemical Corp
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Filing: 1985-05-21
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Granted: 1986-04-01
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Expires: 2005-05-21
Abstract
Abstract A process for producing a polymaleimide which comprises reacting an aromatic dialdehyde with 2 to 60 moles, per mole of the aromatic dialdehyde, of aromatic amine represented by the formula (I): <IMAGE> wherein X is a hydrogen atom, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms to obtain a polyamine, reacting the polyamine with maleic anhydride to obtain a polyamide acid, and dehydration-cyclizing the polyamide acid to obtain a polymaleimide.
Inventors
- 👤 Kaoru Kanayama
- 👤 Yoshinobu Ohnuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:05
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/44; C07D207/444; C07D207/448; C07D207/452; C08; C08G; C08G12/00; C08G12/02; C08G12/04; C08G12/06; C08G12/08; C08G12/40; C08G73/00; C08G73/06; C08G73/10; C08G73/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A polymaleimide prepared by a process which comprises reacting an aromatic dialdehyde of the formula (II): ##STR16## which may be substituted with one or more halogen atoms and alkyl groups; with 2 to 60 moles of an aromatic amine per mole of the aromatic dialdehyde to obtain a polyamine: wherein said aromatic amine is represented by the formula (I): ##STR17## wherein X is a hydrogen atom, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms; and reacting said polyamine with maleic anhydride to obtain a polyamide acid to obtain a polymaleimide.
Claim 2
Dependent Claim
98 words
A polymaleimide prepared by a process which comprises reacting an aromatic dialdehyde of the formula (II): ##STR16## which may be substituted with one or more halogen atoms and alkyl groups; with 2 to 60 moles of an aromatic amine per mole of the aromatic dialdehyde to obtain a polyamine: wherein said aromatic amine is represented by the formula (I): ##STR17## wherein X is a hydrogen atom, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms; and reacting said polyamine with maleic anhydride to obtain a polyamide acid to obtain a polymaleimide.
Claim 3
Dependent Claim
47 words
A polymaleimide prepared by the process of claim 1, wherein the polymaleimide is represented by the formula: ##STR18## where X's, which may be the same or different, each is a hydrogen, a halogen atom or an alkyl or alkoxy group each having 1 to 4 carbon atoms.
Claim 4
Dependent Claim
32 words
A polymaleimide prepared by the process claimed in claim 1, wherein the aromatic amine is a compound selected from the group consisting of aniline, toluidine, chloroaniline, bromoaniline, ethylaniline, butylaniline, anisidine, and phenitidine.
Claim 5
Dependent Claim
28 words
A polymaleimide prepared by the process claimed in claim 1, wherein the aromatic dialdehyde is selected from the group consisting of 1,2-benzene dialdehyde, 1,3-benzene dialdehyde, and 1,4-benzene dialdehyde.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |