NO119705B

1,181,255. Cross-linked polyimide polymers. SOC. RHODIACETA. 8 May, 1967 [11 May, 1966], No. 21301/67. Addition to 1,066,390. Heading C3P. A cross-linked polymeric polyimide is claimed which comprises the repeating unit where R 1 is a divalent group containing at least 2 C atoms and is an arylene group which may be substituted, a cycloaliphatic or heterocyclic group or a plurality of the above groups bonded either directly or by at least one of -CH 2 -, -O-, -SO 2 - or where R is an alkyl or aryl group which may be substituted or a cycloaliphatic group; R 2 is a tetravalent group containing at least 2 C atoms, the two valencies of the tetravalent group which are attached at one end to the two carbonyl groups being attached at the other end to two different C atoms of the tetravalent group and the two remaining valencies being attached to two adjacent C atoms of the tetravalent group; and at least one of R 1 and R 2 contains at least one halogen atom. The polymer may be prepared by heating at 80-400‹ C. for sufficient time to obtain the polymer at least one N,N1- bis-imide of an unsaturated dicarboxylic acid of formula where R 1 is as above, and R 3 is one group of the following two formulµ where R 4 and R 5 are H or halogen atoms, and R 6 is a tetravalent group containing at least 4 C atoms of which at least 2 may be substituted by halogen; and at least one of R 1 and R 3 contains at least one halogen. In examples the polymer was obtained by heating (1) N,N1- (3,31 - dichloro - 4,41 - biphenylene) bis - maleimide, (2) N,N1-4,41-diphenylether - bis - dichloromaleimide; (3) N,N1-4,41-diphenyletherbis - hexachloroendomethylene - tetrahydrophthalimide; (4) a mixture of (1) and N,N1- 4,41 - diphenylether - bis - maleimide; (5) and (6) as (4) but replacing (1) by (2) and (3) respectively; (7) N,N1-(3,31-dichloro-4,41-biphenylene)-bis-dichloromaleimide; (8) N,N1-(2,5-dichloro - 1,3 - phenylene) bis - maleimide with dicumyl peroxide; (9) N,N1-(3,31-dibromo-4,41- biphenylene) - bis - maleimide; and (10) N,N1- (4,41 - triphenylphosphine oxide) his - dichloromaleimide.