Adhesive composition for adhering textiles to EPDM rubber
View Patent ↗An improved adhesive composition and method for adhering textile reinforcing elements to rubber, particularly ethylene-propylene-diene rubber in the manufacture of rubber articles such as power transmission belts, wherein the adhesive composition comprises a latex of a hydrogenated styrene-butadiene rubber, a carboxylated hydrogenated styrene-butadiene rubber, a hydrogenated nitrile-butadiene rubber, a carboxylated hydrogenated nitrile-butadiene rubber, a chlorosulfonated polyethylene or blends thereof; an aqueous solution of a half-ester of maleinized liquid poly butadiene; and, optionally, up to about 15% by weight carbon black in an aqueous solution.
1. An adhesive composition having improved adhesion characteristics for use in bonding a textile reinforcing element to rubber, said adhesive composition comprising:
a latex of at least one of a hydrogenated styrene-butadiene rubber, a carboxylated hydrogenated styrene-butadiene rubber, a hydrogenated nitrile-butadiene rubber, a carboxylated hydrogenated nitrile-butadiene rubber and a chlorosulfonated polyethylene; and
an aqueous solution of an isobutyl half-ester of maleinized liquid polybutadiene resin, with the proviso that said adhesive composition does not contain resorcinol-formaldehyde resin.
2. The adhesive composition of claim 1 wherein said composition comprises about 50 to 99% by weight of said latex having a solids content of about 25 to 50%.
3. The adhesive composition of claim 2 wherein said composition comprises about 65 to 90% by weight of said latex.
4. The adhesive composition of claim 2 wherein said latex has a solids content of about 32 to 45%.
5. The adhesive composition of claim 1 wherein said aqueous solution comprises about 1 to 50% by weight said isobutyl half-ester of maleinized liquid polybutadiene resin.
6. The adhesive composition of claim 3 wherein said aqueous solution contains about 10 to 35% by weight said isobutyl half-ester of maleinized liquid polybutadiene resin.
7. The adhesive composition of claim 1 wherein said aqueous solution of isobutyl half-ester of maleinized liquid polybutadiene resin is neutralized.
8. The adhesive composition of claim 7 wherein said aqueous solution of isobutyl half-ester of maleinized liquid polybutadiene resin is neutralized with ammonia.
9. The adhesive composition of claim 1 wherein the concentration of said half-ester of maleinized liquid polybutadiene resin in said solution is about 15 to 30% by weight.
10. The adhesive composition of claim 9 wherein the concentration of said half-ester of maleinized liquid polybutadiene resin in said solution is about 19 to 25% by weight.
11. The adhesive composition of claim 1 wherein said composition further comprises and aqueous dispersion containing carbon black.
12. The adhesive composition of claim 11 wherein said aqueous dispersion contains up to about 15% carbon black, said dispersion having a solids content of about 30 to 50%.
13. The adhesive composition of claim 12 wherein said aqueous dispersion contains about 0.01 to 12% carbon black.
14. The adhesive composition of claim 12 wherein said aqueous dispersion contains about 8 to 10% carbon black.
15. The adhesive composition of claim 1 wherein said latex is further blended with a second latex containing one of styrene-butadiene rubber, nitrile rubber butyl rubber, natural rubber, polyurethane, polychloroprene, and polymers, copolymers and terpolymers of acrylonitrile, ethylene-vinyl acetate, vinyl alcohol, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid and vinylidine chloride.
16. The adhesive composition of claim 15 wherein said latex contains up to about 75% of said second latex, said second latex having a solids content of about 30 to 50%.
17. The adhesive coniposition of claim 16 wherein said latex contains about 0.01 to 75% of said second latex.
18. The adhesive composition of claim 1 wherein said textile reinforcing element is selected from the group consisting of polyamide fiber, met and para-amid fiber, polyester fiber, polyethylene terephthalate fiber, polyethylene naphthalate fiber, cotton fiber, carbon fiber, glass fiber, poly (p-phenylene-2,6-benzobisoxazole) fiber, acrylic fiber, rayon fiber, and liquid polymer fiber.
19. The adhesive composition of claim 18 wherein said textile reinforcing element is polyester fiber.
20. The adhesive composition of claim 1 wherein said rubber is ethylene-propylene-diene rubber.