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US4965339A
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Method of preparing soluble aromatic polyimides and varnish compositions using same
Assignee: Central Glass Co Ltd
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Filing: 1989-08-08
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Granted: 1990-10-23
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Expires: 2009-08-08
Abstract
Abstract Aromatic polyimides having a repeating unit represented by the general formula (1) are prepared by cyclization reaction of corresponding polyamic acids in an organic solvent in the presence of a lower monocarboxylic acid anhydride and a tertiary amine, e.g. triethylamine. The polyimides obtained by this method have high solubilities in various organic polar solvents and are soluble also in some organic nonpolar solvents. A solution of a polyimide prepared by this method in an organic solvent provides a varnish composition useful for wide purposes. ##STR1## wherein Rf is a perfluoroalkyl group, R is a tetravalent organic group, and each -N═ is at the meta- or para-position with respect to the aromatic ether bond --O--.
Inventors
- 👤 Yutaka Maruyama
- 👤 Haruhiko Komoriya
- 👤 Kentaro Tsutsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:13
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/105; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1032
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
140 words
A method of preparing an aromatic polyimide soluble in organic solvents, the polyimide having a repeating unit represented by the general formula (1), ##STR11## wherein Rf is a perfluoroalkyl group, R is a tetravalent organic group, and each --N= is at the meta- or para-position with respect to the aromatic ether bond --O--, the method comprising subjecting an aromatic polyamic acid having a repeating unit represented by the general formula (2) to cyclization reaction in an organic solvent in the presence of an aliphatic monocarboxylic acid anhydride having not more than 6 carbon atoms and a tertiary amine, ##STR12## wherein Rf and R are as defined above with respect to the general formula (1), R' is hydrogen atom or a monovalent organic group, and each --NH-- is at the meta- or para-position with respect to the aromatic ether bond --O--.
Claim 2
Independent Claim
140 words
A method of preparing an aromatic polyimide soluble in organic solvents, the polyimide having a repeating unit represented by the general formula (1), ##STR11## wherein Rf is a perfluoroalkyl group, R is a tetravalent organic group, and each --N= is at the meta- or para-position with respect to the aromatic ether bond --O--, the method comprising subjecting an aromatic polyamic acid having a repeating unit represented by the general formula (2) to cyclization reaction in an organic solvent in the presence of an aliphatic monocarboxylic acid anhydride having not more than 6 carbon atoms and a tertiary amine, ##STR12## wherein Rf and R are as defined above with respect to the general formula (1), R' is hydrogen atom or a monovalent organic group, and each --NH-- is at the meta- or para-position with respect to the aromatic ether bond --O--.
Claim 3
Dependent Claim
27 words
A method according to claim 1, wherein said monocarboxylic acid anhydride is selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride and valeric anhydride.
Claim 4
Dependent Claim
25 words
A method according to claim 1, wherein the amount of said monocarboxylic acid anhydride is at least 0.5 mol per mol of said polyamic acid.
Claim 5
Dependent Claim
22 words
A method according to claim 1, wherein said tertiary amine is selected from the group consisting of pyridine, trimethylamine, triethylamine and triethylenediamine.
Claim 6
Dependent Claim
24 words
A method according to claim 1, wherein the amount of said tertiary amine is at least 0.5 mol per mol of said polyamic acid.
Claim 7
Dependent Claim
30 words
A method according to claim 1, wherein said cyclization reaction is carried out at a temperature in the range from room temperature to the boiling point of said organic solvent.
Claim 8
Dependent Claim
37 words
A method according to claim 1, wherein the tetravalent organic group represented by R in the general formulas (1) and (2) is the residue of benzene, biphenyl, biphenyl ether, benzophenone, diphenylmethane, diphenylpropane, diphenylhexafluoropropane, diphenylsulfone, naphthalene or perylene.
Claim 9
Dependent Claim
22 words
A varnish composition, comprising a solution of an aromatic polyimide prepared by a method according to claim 1 in an organic solvent.
Claim 10
Dependent Claim
15 words
A varnish composition according to claim 8, wherein said organic solvent comprises a polar solvent.
Claim 11
Dependent Claim
23 words
A varnish composition according to claim 9, wherein said polar solvent is selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone and pyridine.
Claim 12
Dependent Claim
26 words
A varnish composition according to claim 10, wherein said organic solvent further comprises a nonpolar solvent selected from the group consisting of cyclohexanone and ethyl acetate.
Claim 13
Dependent Claim
24 words
A method according to claim 7, wherein each perfluoroalkyl group represented by Rf in the general formulas (1) and (2) is --CF 3 .
References Cited (Backward Citations)
US4203922A
Cited
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