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US 4,539,392 AGranted
Method of preparing polyimide prepolymer from ethylenically unsaturated dicarboxylic acid compound
AssigneeToray Industries, Inc.
InventorsSho Kadoi, Toshihiko Aya
Life of this patent
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Abstract
Polyimide prepolymers having excellent heat resistance can be prepared in one stage by the reaction of polyamines and aromatic double bond-containing dicarboxylic acids or derivatives thereof in the presence of oxide compounds of phosphorus without isolating any intermediate in the course of said reaction.
Claims15
A method for preparing a polyimide prepolymer, which comprises effecting reaction between a polyamine which has the following general formula (I),
- R(NH.sub.2).sub.n (I)
- in which R is an organic group having not less than 2 carbon atoms ad n is an integer of 2 or above, and a compound selected from the group consisting of dicarboxylic acids having at least one aliphatic double bond and derivatives thereof in the ratio of 0.52-0.95 mole of the latter per mole of amino group contained in the polyamine used, in contact with an effective ring closing amount of an oxide of phosphorus.
Dependencies are inferred from the claim text.