Bonding agents based on carbodiimides, aqueous resorcinol-formaldehyde-latex dispersions comprising bonding agent, adhesion-improved fibres, processes for production thereof and use thereof

1. An aqueous resorcinol-formaldehyde-latex dispersion comprising at least one bonding agent wherein the bonding agent comprises at least one carbodiimide, wherein the carbodiimide comprises compounds of the formulae II, III and IV

where R═C 1 -C 18 -alkylene, C 5 -C 18 -cycloalkylene, arvlene and/or C 7 -C 18 -aralkylene and j is identical or different within the molecule and is from 1 to 5, and p =from 0 to 500, and/or

where x =from 1 to 500, and

where these have been surface-deactivated via reaction with at least one amine.

2. An aqueous resorcinol-formaldehyde-latex dispersion according to claim 1 , wherein the resorcinol-formaldehyde-latex dispersion comprises a dispersion of the individual components resorcinol and formaldehyde, and/or formaldehyde together with a precondensate made of resorcinol and formaldehyde and of one or more of the latex dispersions selected from the following group consisting of carboxylated styrene-butadiene copolymers (XSBR latex), nitrile-butadiene copolymers (NBR latex), polychloroprene (CR latex), pyridine-styrene-butadiene copolymers (PSBR latex), acrylate-only copolymers, styrene-acrylate copolymers (acrylate latex), and styrene-butadiene-vinylpyridine copolymer latices.

3. A process for producing aqueous resorcinol-formaldehyde-latex dispersions according to claim 1 , comprising incorporating at least one bonding agent into the resorcinol-formaldehyde-latex dispersion by stirring.

4. A process for producing aqueous resorcinol-formaldehyde-latex dispersions according to claim 1 wherein the surface deactivation of the at least on carbodiimide according to formulae (II) to (IV) comprises incorporating at least one amine either

a) via dispersion of at least one pulverulent carbodiimide according to the formulae (II) to (IV) in a solution of at least one amine or

b) via addition of at least one amine or one solution of at least one amine to a dispersion of at least one of the carbodiimides according to the formulae (II) to (IV), and then

by stirring into the resorcinol-formaldehyde-latex dispersion, or the resorcinol-formaldehyde-latex dispersion is incorporated by stirring into these solutions from a) or b).

5. Adhesive formulation, comprising an aqueous resorcinol-formaldehyde-latex dispersion according to claim 1 and at least one activator.

6. The adhesive formulation according to claim 5 , wherein the activator is at least one epoxide.

7. A process for improving the adhesion of reinforcement fibres to crosslinked rubber and/or elastomers, comprising

introducing the fibres into an adhesive formulation according to claim 5 and subsequently drying, or

treating the fibres in one or more steps with one or more of the constituents of the adhesive formulation according to claim 5 .

8. A process for improving the adhesion of reinforcement fibres to crosslinked rubbers or elastomers, comprising introducing preactivated fibres into an aqueous resorcinol-formaldehyde-latex dispersion according to claim 1 and subsequently drying.

9. Adhesion-improved fibres, obtainable by contacting activator-pretreated fibres with at least one aqueous resorcinol-formaldehyde-latex dispersion according to claim 1 , or by contacting a non-pretreated fibre with at least one adhesive formulation according to claim 8 and subsequently drying (setting) at temperatures of from 180 to 260° C.

10. The aqueous resorcinol-formaldehyde-latex dispersion according to claim 1 wherein the amines comprises 1,6-hexamethylenediamine; di-sec-butylamine; ethylenediamine; 1,3-propylenediamine; diethylenetriamine; triethylenetetramine; 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane; methylnonanediamine; isophoronediamine; 4,4′-diaminodicyclohexylmethane; alkanolamines and diamines.