Patent EP0240249A2 successfully refreshed from Google Patents.
EP0240249A2
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Polyamide acid solution for forming a polyimide film
Assignee: Nitto Denko Corp
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Filing: 1987-03-26
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Granted: —
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Expires: 2007-03-26
Abstract
Abstract A polyamide acid solution comprises a polyamide acid comprising as main components at least one recurring unit selected from the recurring units shown of the formulae (I) to (IV) and a recurring unit of formula (V) and optionally up to 10 wt% of an epoxy resin, dissolved in an organic solvent comprising at least 50 wt%, preferably at least 70%, of an amide type polar solvent having a boiling point of 170°C or less, e.g. N,N-dimethylacetamide or N,N-dimethylformamide, the balance if any of solvent being a poor solvent of low boiling point. A layer of the viscous solution is coated on a glass plate and heated to cause dehydrocyclisation so as to form a polyimide film which has colorless transparency free from coloration, 1 and strong adhesion to the substrate to prevent penetration of water into interface between the substrate and film. The solution is particularly useful for forming an oriented film in a liquid crystal cell.
Inventors
- 👤 Kazumi Nitto Electric Industrial Co. Ltd Higashi
- 👤 Yuzuru Nitto Electric Industrial Co. Ltd. Noda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 10:06
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1032; C08G73/1057; C08G73/106; C08G73/1064; C08L; C08L79/00; C08L79/04; C08L79/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
219 words
A polyamide acid solution comprising a polyamide acid comprising as main components at least one recurring unit selected from the group consisting of a recurring unit represented by formula (I) wherein X 1 , X 2 , X3 and X 4 , which may be the same or different, each represents H, CH 3 , C 2 H 5 , N0 2' F, COOH or C2; and m represents a positive integer; a recurring unit represented by formula (II) wherein X 5 represents O, SO 2 , CH 2 , S or CO; and m is the same as defined above; a recurring unit represented by formula (III) wherein m is the same as defined above; and a recurring unit represented by formula (IV) wherein X 6 represents SO 2 , C(CH 3 ) 2 or C(CF 3 ) 2 ; and m is the same as defined above, and a recurring unit represented by formula (V) wherein R represents a divalent hydrocarbon group; R' represents a monovalent hydrocarbon group; y represents an integer of from 1 to 4; and n represents a positive integer selected so that n/(m + n) ranges from 0.01 to 0.05, dissolved in an organic solvent comprising as a main component an amide type polar solvent having a boiling point of 170°C or less.
Claim 2
Dependent Claim
219 words
A polyamide acid solution comprising a polyamide acid comprising as main components at least one recurring unit selected from the group consisting of a recurring unit represented by formula (I) wherein X 1 , X 2 , X3 and X 4 , which may be the same or different, each represents H, CH 3 , C 2 H 5 , N0 2' F, COOH or C2; and m represents a positive integer; a recurring unit represented by formula (II) wherein X 5 represents O, SO 2 , CH 2 , S or CO; and m is the same as defined above; a recurring unit represented by formula (III) wherein m is the same as defined above; and a recurring unit represented by formula (IV) wherein X 6 represents SO 2 , C(CH 3 ) 2 or C(CF 3 ) 2 ; and m is the same as defined above, and a recurring unit represented by formula (V) wherein R represents a divalent hydrocarbon group; R' represents a monovalent hydrocarbon group; y represents an integer of from 1 to 4; and n represents a positive integer selected so that n/(m + n) ranges from 0.01 to 0.05, dissolved in an organic solvent comprising as a main component an amide type polar solvent having a boiling point of 170°C or less.
Claim 3
Dependent Claim
32 words
A polyamide acid solution as in Claim 1, wherein said solution further comprises 10 parts by weight or less of an epoxy resin per 100 parts by weight of the polyamide acid.
Claim 4
Dependent Claim
15 words
A polyamide acid solution as in Claim 2, wherein said epoxy resin is triglycidyl isocyanurate.
Claim 5
Dependent Claim
21 words
A polyamide acid solution as in Claim 1, 2 or 3, wherein said amide type polar solvent is N,N-dimethylacetamide or N,N-dimethylformamide.
Claim 6
Dependent Claim
39 words
A polyamide acid solution as in Claim 1, 2, 3 or 4, wherein said amide type polar solvent is present in an amount of at least 50% by weight based on the total weight of the whole solvents used.
Claim 7
Dependent Claim
35 words
A polyamide acid solution as in Claim 5, wherein said amide type polar solvent is present in an amount of at least 70% by weight based on the total weight of the whole solvents used.
Claim 8
Dependent Claim
21 words
A polyamide acid solution as in any preceding claim, wherein said solution has an inherent viscosity of from 0.3 to 5.0.
Claim 9
Dependent Claim
20 words
A polyamide acid solution as in Claim 7, wherein said solution has an inherent viscosity ranging from 0.4 to 2.0.
Claim 10
Dependent Claim
22 words
A polyamide acid solution as in any preceding claim, wherein said solution has a concentration of from 5 to 30% by weight.
Claim 11
Dependent Claim
21 words
A polyamide acid solution as in Claim 9, wherein said solution has a concentration of from 15 to 25% by weight.
Claim 12
Dependent Claim
28 words
A substrate coated with a polyimide oriented film made by coating and heating, to dehydrocyclize the polyamide, a layer of a solution as claimed in any preceding claim.
References Cited (Backward Citations)
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