Stable fine-particle suspensions of functionalised, wholly or partially hydrated nitrile rubbers

摘要

Aqueous suspension of a carboxyl group containing, completely or partially hydrogenated nitrile rubber with an emulsifier content of maximum 1 part by weight, is claimed, where the nitrile rubber in the suspension has an average particle diameter of 0.01-0.9 (preferably 0.08-0.5) mu m, as measured by dynamic light scattering. Independent claims are included for: (1) a process for preparing the aqueous suspension of the nitrile rubber, comprising dissolving the nitrile rubber in an organic solvent to form an organic phase, contacting the organic phase with an aqueous phase having a pH of at least 6, preferably 9-13, where the water in the organic solvent is completely or partially dissolved, and the nitrile rubber is precipitated to form a suspension, and completely or partially removing the organic solvent; (2) a process for coating substrates, preferably plastics, metals or fibers, such as glass fibers, metal fibers or organic synthetic fibers, fibers from polyesters, aliphatic and/or aromatic polyamides or polyvinyl alcohol, comprising contacting the aqueous suspension with the substrates; (3) a binder composition comprising the aqueous suspension, a mixture containing resin and/or curing agent, preferably resorcinol-formaldehyde, resorcinol-chlorophenol/formaldehyde, isocyanates, blocked isocyanates and/or urea derivatives, and optionally one or more other rubber additives, preferably crosslinking agents, crosslinking accelerators and fillers, such as carbon black or mineral filler; (4) the coated substrate, obtained by the above process; (5) a process for producing composite materials, comprising embedding and vulcanizing the coated substrate in a mixture of one or more further rubbers and auxiliary agents, where the rubber is natural rubber, butadiene rubber, styrene-butadiene rubber, ethylene propylene monomer rubber, ethylene propylene diene monomer rubber, epichlorohydrin rubber, ethylene vinylacetate monomer rubber, chlorosulfonated polyethylene synthetic rubber, acrylate copolymer, silicone rubber, fluorocarbon rubber, nitrile butadiene rubber and/or the hydrogenated acrylonitrile-butadiene rubber, and the auxiliary agent is fillers, crosslinking agents and crosslinking accelerator; and (6) the composite materials, obtained by the above process in the form of belts, membranes, bellows, air cushion, rubber hoses and tubes.