Adhesion of polyester to rubber using an adhesive containing added metal compounds

Claim 1

In a shaped polyester article bearing from 2 to about 30% by weight of an adhesive coating composition comprising the reaction products of: a first component (I) comprising I. a. a polyepoxide having an average of at least two epoxy groups in each molecule, a melting point below about 150° C., an average molecular weight below about 3,000 and an epoxide equivalent below about 2,500 and B. an aromatic polyisocyanate from the class consisting of Ar(NCO) n [Ar(NCO) n ] m , and Ar(NHCOX) n ; wherein Ar is an organic residue containing at least one aromatic nucleus, X is a radical, selected from the group consisting of aryloxy, arylthio, iminoxy and lactam-N-yl, and m and n are whole numbers of at least 2; the weight ratio of (A)/(B) being within the range of from about 0.01 to about 5.0 and the % by weight being 0.2 to 5.0; in combination, with Ii. .[.the residue amounting to.]. .Iadd.a second component (II), of from about .Iaddend. 1.8 to 25% by weight of a .[.rubber latex containing the reaction product of a phenol.]. .Iadd.mixture of the dried reaction products of a phenolicformaldehyde resin, a rubber latex .Iaddend.and formaldehyde, said rubber latex being selected from the group consisting of natural rubber, SBR and butadiene-vinylpyridine-styrene rubber; the improvement comprising having added to said .[.coating composition.]. .Iadd.first component I while in admixture with a liquid carrier and .Iaddend.prior to deposit on said polyester article, .Iadd.a .Iaddend.sufficient amount of a metal-containing compound in the range between 0.00001 and 0.010 moles per 1,000 grams of said .[.coating composition.]. .Iadd.first component I in its liquid carrier .Iaddend.to result in an adhesive bond which has at least a 5% improvement in appearance rating using the hot strip adhesion test, said improvement being compared with a rubber-polyester article control that contains no metal containing compound in said adhesive coating composition, said metal being selected from the group consisting of sodium, potassium rubidium, cesium, strontium, silver, cadmium, barium, cerium, uranium, titanium, vanadium, chromium, tin, antimony, maganese, iron, cobalt, nickel, copper, zinc, lead, bismuth, calcium and zirconium whereby less adhesive is required to achieve the same degree of adhesion as when an adhesive containing no metal-containing compound is used.