| abstract |
Coordination complexes of chromium (III) and fumaric acid and certain substituted fumaric acids; the preparation of aqueous solutions of such complexes; and the use of such solutions for treating metal, metal oxide and glass substrates for the purpose of improving the bonding thereto of subsequently applied organic polymer adhesives. Preferred coordination compounds of fumaric acid have the approximate formulas (Cr(H2O)5(C4H3O4))aX2, (Cr(H2O)4(C4H2O4))aX, and (Cr2(H2O)10(C4H2O4))aX4, where X is a noncoordinated anion and a is its valence. The preferred anion is nitrate. Also a method for treating substrates to improve adhesion of polymers thereto, by contacting the substrate with an aqueous solution of fumaric acid or certain substituted fumaric acids and a Cr 3 salt which yields the Cr(H2O)6 3 ion, at 90*100*C. and a pH of 1.8-2.4. |