丁基胶塞简介

Rubber StopperRubber Stopper IElastomersElastomer(Rubber) IButyl rubber(IIR, copolymer of isobutylene with isoprene)•Butyl rubbers are produced via a cationic polymerizationin a methyl chloride diluent at temperatures less than ‐90C •Chemical inertness•Impermeability to gases•Resistance to heat and oxidation•Weatherability(Aging Stability)Elastomer(Rubber) IIHalobutyl rubber(Bromobutyl(BIIR), Chlorobutyl(CIIR))Most Abundant Halobutyl Isomer Minor Halobutyl Isomers•The majority of the isoprenyl units are in the trans‐configuration•Faster cure rate than BR and cocured more readily with other elastomers •Bromobutyl rubber–Faster cure rate than CIIR (Greater reactivity of the C‐Br bond than C‐Cl)–Higher crosslink density per mole of halogen in the polymer–Cure systems are more effective with bromobutyl(Peroxide, Zinc free cure systems based on sulfur or sulfur donors)–Disadvantage is shorter scorch times compared to chlorobutylElastomer(Rubber) IIISilicon rubber•High Temperature Resistance•Flexibility•Good BiocompatabilityEthylene‐Propylene‐Diene rubber(EPDM Rubber)•High Temperature ResistanceElastomer(Rubber) IVFluorocarbon rubber ‐CH 2‐CF 2‐CF 3‐CF ‐CF 2‐Brominated isobutylene ‐co ‐para ‐methylstyrene elastomer (BIMSM) Rubber•Expensive•High Temperature Resistance•Very Clean•Need low level curatives•Alternative to coated stopperRubber Stopper IIManufacturing Process ICompoundingType of Rubber StopperRubber Formula IngredientsVulcanization(Curing) I•Vulcanization(Curing)–Chains are linked together to form a network –Elastomer is basically HMW liquid with lowelasticity and strength and curingtransforms a viscous material to a tough elastic solidVulcanization(Curing) II•Sulfur Curing System–Elastomer must contain double bonds with allylic hydrogens–Soluble(Rhombic crystals of S8rings), Insoluble (amorphous, polymeric sulfur)–Sulfur cross‐links have limited stability at sustained high temperature –Crosslinking with sulfur alone is quite inefficient and requires several hours•Sulfur vulcanization is often inefficient to butyl rubber curing•Requires aggressive accelerators such as thiuram or thiocarbamates. •Resin Cure System–Resin cure systems (commonly using alkyl phenol‐formaldehyde derivatives) provide for carbon‐carbon cross‐links and more stablecompoundsVulcanization(Curing) III•Peroxide curing system–C‐C double bonds are not required and used to crosslinksaturated elastomers•Ethylene‐Propylene Rubber (EPDM)•Silicone Rubber–Butyl rubber cannot be cured with peroxides•Metal Oxide curing system–Crosslinking occurs via allylic halogens–Mixture of ZnO and MgO are generally used–Zinc oxide is commonly used to cross‐link halobutyl rubber •Bromobutyl is faster curing than chlorobutyl and has betteradhesion to high unsaturation rubbers.Vulcanization(Curing) IV •Accelerators–Type and rate of sulfur crosslinking–Guanidines, Thiazoles, Dithiocarbanates,Xanthates, Thiurams•Activator–Efficiency of sulfur crosslinking–Zinc Oxide, Stearic acid•Retarder–Calcium StearateVulcanization(Curing) V•Antioxidant/Antiozonants–Oxygen and ozone can react with elastomers and alter network structure by causing chain scissionand/or crosslinking.–Butylatedhydroxytoluene(BHT)–Amine Antioxidants•PAN(Phenyl‐α‐naphthylamine), IPPD, 6PPD, DPPD,TMQ•Anti‐isomerization agent–ESBO (Epoxidized soybean oil)Vulcanization(Curing) VI•Process Aid–Physical Plasticizer•Soften a compound by reducing entanglements anddecreasing internal friction•Oils, Fatty acids, esters, pine tar, liquid polymers, rosin –Chemical peptizers•Reduce MW by increasing oxidative chain scission•Sulfonic acids, pentachlorothiophenolVulcanization(Curing) VII•Fillers–Particulate fillers (less than 1㎛) can increase the strength of an amorphous rubber more than 10‐fold–Carbon black filler–Non‐carbon black filler•Calcium carbonate, Baryte(Barium sulfate), Silica,Kaolin clay, talc, TiO2, Aluminium trihydrate..Modern Rubber FormulationHigh Purity Formulation•UltraPure(by Stelmi)–Ultrapure®6900•Chlorobutyl‐based, zinc‐free high purity formulation –Ultrapure®6950•BIMS Based formulationRubber Stopper IIIManufacturing Process IIOverview of Manufacturing Process IMixing (Compounding) IMixing (Compounding) IIDimensioningDimensioning ‐CalenderMolding IMolding IITrimming ITrimming IIWashing/Siliconization/Drying IWashing/Siliconization/Drying II DryingPackaging IPackaging II。