The invention comprises nitrogen-containing polymers consisting of benzoid or quinoid nuclei linked by substituted or unsubstituted methylene groups at one ortho position and at either the other ortho or the para position, the remaining ortho or para position on each nucleus having an oxynitrogen group which is (a) NO or N(NO)OM (where M is a cation) when the I position of the nucleus is substituted by OH, NHR, NO or N(NO)OM (where R is a hydrocarbon radical or hydrocarbon ether radical) and the nucleus is benzoid, or (b) the oxynitrogen group is NOH when the I position is occupied by O, NR or NOH and the nucleus is quinoid. The polymers are obtained by reacting a condensation product of an aldehyde or ketone with a molar excess of phenol or a secondary aniline, with a nitrite to obtain a nitroso substituted resin, e.g. containing units of formula: (-NHR is present instead of -OH when a secondary aniline is used to form the initial polymer); the units of these polymers are tautomeric isomers of the corresponding oxime units. These polymers may be reacted with hydroxylamine to obtain quinone oxime imine polymers, e.g. containing units of formula: When these polymers are reacted with nitric oxide and a base the polymers obtained contain N-nitrosohydroxylamine salt units, i.e.: where T is OM or R and R1 and R2 are hydrogen atoms or hydrocarbon or hydrocarbon ether radicals. Finally, these polymers may be reacted with an acid to obtain polymers containing units of formula: where Z is NO or NHR. The polymers may be used in adhesive compositions together with chlorinated rubber, brominated dichlorobutadiene polymer, solvent, zinc oxide, magnesium oxide and carbon black. Examples are given.