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US 4,684,714 AGranted
Method for making polyimide oligomers
AssigneeThe Boeing Company
InventorsHyman R. Lubowitz, Clyde H. Sheppard
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Abstract
Polyimide oligomers are made by the condensation of suitable anhydrides, dianhydrides, and diamines. To a chilled solution of diamine, a mixture of anhydride and dianhydride is added under an inert atmosphere. The cooling is discontinued following the mixing, and the resulting three reactant mixture is allowed to react.
Claims18
A method of making polyimide oligomers, comprising the steps of:
- (a) dissolving a diamine in a suitable solvent;
- (b) chilling the diamine solution;
- (c) mixing together an unsaturated monoanhydride and a dianhydride to form a premix;
- (d) in an inert atmosphere, adding the premix to the diamine solution while continuing to chill the diamine solution;
- and
- (e) removing the cooling source after the addition of the premix to the diamine solution is completed.
3 more elements
A method of making polyimide oligomers, comprising the steps of:
- (a) dissolving n+1 moles of a diamine in a suitable solvent, the diamine being selected from the group consisting of:
- ##STR17## wherein R'= ##STR18## R"= ##STR19## q=--SO.sub.2 --, --S--, --CO--, or --(CF.sub.3).sub.2 C--;
- and m=a small integer, generally less than 5;
- (b) chilling the diamine solution to about 0.degree.-5.degree. C.;
- (c) mixing together about 2 moles of an unsaturated monoanhydride selected from the group consisting of:
- ##STR20## wherein R.sub.1 =lower alkyl, lower alkoxy, aryl, aryloxy, substituted aryl, halogen, or mixtures thereof;
- and
- j=0, 1, or 2
- and n moles of a dianhydride selected from the group consisting of pyromellitic dianhydride, or benzophenonetetracarboxylic dianhydride (BTDA), 5-(2,5-diketotetrahydrofuryl-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (MCTC)
- (d) in an inert atmosphere, adding the mixed monoanhydride and dianhydride to the chilled diamine solution while continuing to chill the diamine solution;
- and
- (e) removing the cooling source after addition of the mixed monoanhydride and dianhydride to the diamine solution is completed.
9 more elements
Dependencies are inferred from the claim text.