SINGLE-STEP METHOD FOR PREPARING COPOLYIMIDES BASED ON AMINOPHENOXYPHTHALIC ACIDS Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a single-step method for preparing copolyimides based on aminophenoxyphthalic acids that can be used in making materials eliciting high thermal stability. Copolyimides comprise at least one repeating link taken among links order of the general formula (I):

or (II):

wherein R means hydrogen atom or N-morpholinyl radical; R₁ means hydrogen atom or hydroxyphenyl radical in combination with at least one repeating link taken among links order of the general formula (III):

wherein Ar means bivalent radical of formulae (IIIa) , (IIIb) , (IIIc) or (IIId) ; P means tetravalent radical of the formula (IV) or (V) wherein X represents an ordinary bond, -O-, -SO₂-, -S- or radical of the formula (VI):

. Method for preparing copolyimides involves copolycondensation reaction of at least one aminophenoxyphthalic acid taken among acids order of the formula (VIII):

or (VIII):

wherein R and R₁ have values given above in combination with at least one aromatic diamine taken among diamines of the general formula: H₂N-Ar-NH₂ wherein Ar has value given above and at least one tetracarboxylic acid among acids order of the general formula (IX):

or its dianhydride of the general formula (X):

wherein P and X have values given above. The copolycondensation process is carried out in melt of at least one aromatic monocarboxylic acid at temperature 110-180°C for 1.5-4.5 h. Invention provides significant reducing temperature and duration of synthesis and to expand assortment of copolyimides significantly.

EFFECT: improved preparing method.

8 cl, 2 tbl, 31 ex