Research On Application Of High Performance Modified Adhesive Resin In Green Tire

Natural rubber is widely used in the belt layer of green tires due to its high strength,low heat generation and high adhesion.The functional adhesive resin is used as the main auxiliary agent for the belt layer of green tires to ensure that the bonding between rubber and skeleton materials(polyester cord,steel wire,steel cord and fiber,etc.),while improving the aging resistance of the rubber and reducing heat generation.Therefore,the green combination of adhesive resin and natural rubber is the focus of research on the development of modern green tires.Firstly,the effects of silica,cobalt salt and prevulcanization inhibitor on the adhesion of natural rubber to copper-plated steel cord were studied.The research results showed that the cobalt-containing bonding system increased the cross-linking density,and significantly increased the pull-out force and the unit coating amount on the surface of the steel wire.The addition of silica increased the heat generated and improved the adhesion.Adding RF-silica-cobalt bonding system was the fastest to form a cross-linking network.After aging RF,RF-silica,and RF-cobalt bonding system cross-linking density increased,and the RF-silica-cobalt bonding system adhesive performance was the best.The paper studied the influence of four commonly used commercially available high-performance modified adhesive resins on the adhesive properties.Studies found that solid particulate resins(AR1005 and SL-3022)contain more hydroxyl and methine groups,which made the solid particulate resin more polar and could be more polarized even when the number of moles was less.It could better migrate to the bonding interface to form a more stable bond.High-viscosity liquid resin(RFO-100 and cashew nut oil)had better compatibility with the rubber,and had a lower molecular weight,which had a plasticizing effect.The rubber had higher self-adhesiveness and more double bond content,which will reacted with the rubber,and finally decreased adhesion performance.The vulcanization induction period was very important to the adhesion reaction,and the migration of resin and the penetration of rubber into the steel wire were also completed at this stage.The prevulcanization inhibitor CTP could better extend the scorch period and obtain higher adhesion performance,while the prevulcanization inhibitor E could make the rubber compound obtain a higher degree of vulcanization,increased the hardness and constant elongation stress of the rubber compound.As the amount of prevulcanization inhibitor CTP increased,the scorch time and t₉₀ were gradually prolonged,and the crosslinking density of the rubber compound without the bonding system increased,the crosslinking density of the rubber compound with the bonding system increased first and then decreased.The density was higher than that of the compound without bonding system.The crosslink density was relatively highest when 0.75 parts of CTP was added.Different aging methods and conditions had different effects on the crosslinking density and adhesion properties of the rubber compound.Under air aging,the adhesive performance decreased with the extension of the aging time,and the amount of coating on the steel wire surface was gradually reduced.Under the moisture aging,the adhesive performance first increased and then decreased with the increase of crosslinking density.The tendency of salt spray aging to deteriorated the adhesive performance was obviously,and the amount of rubber coating on the surface of the steel wire was very small.In the experiment of exploring the role of binding resin and HMMM,it was found that when the ratio of cashew nut oil(or SL-3022):HMMM was 1.8:2.7,the steel wire pull-out force of the vulcanized rubber reached the highest,and had more amount of coating.The formation of the bonding resin increased the cross-linking density of the rubber,increased the steel wire pull-out force and the amount of rubber coating,and improved the heat-resistant aging performance.The adhesive performance increased first and then decreased with the increase of the amount of bonding resin and HMMM before and after aging.