Disclosed is a process of improving the adhesion of polyester material to various other materials using the azidoformates of omega-hydroxyalkyl phthalates, their related low molecular weight condensation polymers and their mixtures represented by the general formula ##SPC1## Where R is an alkylene radical containing 2 to 10 carbon atoms and x is an integer of from about 1 to about 10. In particular, there is disclosed a process of improving the adhesion of polyester tire cord to rubberr tire stock using the said azidoformate compounds.
This application is a division of my copending application Ser. No. 549,229, filed Feb. 12, 1975, now U.S. Pat. No. 3,914,262, which application is a division of copending application Ser. No. 425,906, filed Dec. 18, 1973, now U.S. Pat. No. 3,900,683, which application is a division of copending application Ser No. 231,741, filed Mar. 3, 1972, now U.S. Pat. No. 3,814,657, which application is a division of application Ser. No. 93,399, now U.S. Pat. No. 3,686,231, which application is a continuation-in-part of application Ser. No. 887,382, filed Dec. 22, 1969, now abandoned.
A process for treating metal surfaces to obtain improved susceptibility to bonding with adhesive compositions is disclosed. A metal surface is oxidized with a halogen to form a monolayer of halide ions on the surface. The halide ions are then exchanged with azide ions to form an azide monolayer on the metal surface. Upon contact of the treated surface with an adhesive composition, the azide layer may be thermally or photochemically decomposed to form active nitrene species, which react to bond the adhesive composition to the metal surface.
