Akzo N.v.

Willem E Weening

Stephanus Willemsen

Anne Steenbergen

Freerk R Van Calker

Hendricus A Van Aalten

A process for the improvement of the adhesion to rubber or a thermoplastic elastomer of synthetic yarns, cords or fabrics made therefrom by applying thereto an adhesive consisting of an aqueous solution or dispersion of a polyurethane with ionic groups, capped isocyanate groups and groups with a Zerewitinoff-active H atom, followed by drying the product thus treated. The polyurethane corresponds to the structure: ##STR1## wherein X has the meaning of an O or S atom or of an O-, S-, N- or P-containing group with a Zerewitinoff-active H atom or to which prior to reaction with an isocyanate group a Zerewitinoff-active H atom had been attached,

Process for the improvement of the adhesion to rubber or a thermoplastic

A multifilament yarn of an aromatic polyamide, in particular poly-p-phenylene terephthalamide, is provided with an adhesive coating of a cured epoxy compound, the yarn having a free epoxide content not higher than 10 mmoles/kg. The yarn is made by spinning a solution of an aromatic polyamide into a coagulation bath and subjecting the resulting filaments to the subsequent steps of washing, applying a curable epoxy compound and one or more alkaline curing agents, curing and winding the yarn thus treated into a package. The resulting yarn can be processed into a reinforcing element for, e.g., tires in a one-step dipping process. A cord made from the yarn displays an improved resorcinol-formaldehyde-latex dip pickup.

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Zevenaar, Netherlands

Willem E Weening