Additives for Rubber

Unlike natural rubber, filled synthetic rubber compounds (e.g., styrene butadiene rubber (SBR), ethylene propylene diene rubber (EPDM)) exhibit inherent low tack. The tack property is very important for tyre applications where multiple layers must adhere to each other. The lack of adequate tack may lead to failure of the final product. Long-chain and branched alkyl phenol-based novolac resins have been recommended as tackifier. 

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Other kinds of rubber chemicals are blowing agents, peptizers, and retarders. The total market for all chemical additives for rubber is over 250 million Ib/yr. 

Polyterpenes, coumarone-indene resins, and so-called petroleum resins are produced commercially using cationic polymerization. These are used as additives for rubber, coatings, floor coverings, and adhesives. 

Additionally for rubber compounds, the differences in polarity and unsaturation of the various polymers cause different affinities for fillers and curing additives. In blends of different rubber polymers, the reinforcing filler carbon black for instance locates itself preferentially in the phase with the higher unsaturation and/or polarity, leaving the lower unsaturation or nonpolar phase unreinforced. The affinity for carbon black decreases in the following order of polymers [2] ... 

Processing oil is a well-known additive for rubbers and is commonly employed in PP/EPDM TPVs [10-12]. It lowers the hardness and improves the processability. The oil, in most cases paraffinic oil, can be considered as a low molecular weight olefin. The difference in polarity between the three components is small, and the oil is present in both the PP and in the elastomer phases [67]. In order to understand the mechanical and the rheological properties of olefinic thermoplastic elastomers (OTPEs), the concentration of oil in each phase must be known. 

Zinc complexes are important as additives for rubber polymers. Dithiocarbamate complexes are most commonly used here, but bis(8-hydroxyquinolinato)zinc inhibits the thermal decomposition of poly[(trifluoroethoxy)(octafluoropentoxy)phosphazene]. The zinc is thought to complex residual P—OH groups in the polymer chain, which would otherwise lead to rearrangement and chain scission.126... 

Although Monsanto can rely on only two of its own raw materials, tertbutylamine and p-nitrochlorobenzene, for its range of additives, it is regarded as an efficient producer and a pioneer in antiozonants based on p-phenylenediamine and prevulcanization inhibitors. It has one of the most complete ranges of additives for rubber and the most modern units to manufacture them. 

Inorganic additives for rubber compounds also include materials that enhance performance under various accelerated stress conditions. Zinc oxide is an effective heat stabilizer for some types of elastomers. Iron oxide, lead compounds, barium salts, and specially treated clays, such as kaolinite, add performance margin in wet aging conditions. 

Interannual changes in production of total chlorinated paraffins (CPs) reported by the Flame Retardant Chemicals Association of Japan (FRCJ) [2] are shown in Fig. 2. FRCJ also reported the production and shipment of SCCPs, medium-chain chlorinated paraffins (MCCPs), and long-chain chlorinated paraffins (LCCPs) in 2001 [2] as shown in Table 1. It indicates that 500 tons per year of SCCPs were shipped, suggesting that SCCPs were not used for polyrvinyl chloride. In the Kanto region, 500 tons per year of SCCPs were mainly used in oil fluids. In contrast, nearly 200 tons of SCCPs were shipped to the Kansai region for other uses including flame retardant additives and lipid additives for rubber, paint, and adhesives. As shown in Table 1, approximately half of SCCPs were used in oil fluids and the other half for other products. 

Alphaflex . [Aliriiaflex] PIPE and molybdenum disulfide reinforcing agent fricdon-ieducmg additive for rubber. 

Vistanex . [Exxon] Polyisobutylene polymeric additive for rubber processing, in molded and extruded pt. and coated materials. 

This overview of applications for benzene shows that the three most important products from benzene are used in the manufacture of plastics in the form of polystyrene, phenolic resins and polyamide fibers. Other uses for benzene, of lesser importance in terms of quantity but still extremely versatile, are halogen and nitrogen derivatives for the chemistry of dyestuffs, production of plant protection agents and additives for rubber and plastics processing, as well as for the manufacture of pharmaceuticals. 

Dyneon, a wholly owned subsidiary of 3M set up in 1996, is one of the world s leading fluoropolymer producers with operations or representation in more than 50 countries. It sells process aids to the plastics industry, particularly polyolefins. Other products include fluoroelastomers, PTFE and speciality additives for rubbers. Among fluoropolymers, there are additives to prevent dripping in burning plastics. 

Masterbatch concentrates of antioxidant thiols as additives for rubbers... 

Fluoroethylene Fluorine-containing oligomers Daikin Kogyo Lubricating oils Additives for rubber... 

Linear low-molecular-weight a-olefins have become very important industrial intermediates during the past decades. This is partly due to recent developments in homogeneous catalysis such as the Oxo and Wacker processes, and partly to increased demand for biodegradable detergents and for plasticizers and additives for rubber or gasoline. 

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