Rubber formulation processing oils

Oil that serves as a temporary or permanent component of a manufactured product. Aromatic process oils have good solvency characteristics their applications include proprietary chemical formulations, ink oils, and extenders in synthetic rubbers. Naphthenic process oils are characterized by low pour points and good solvency properties their applications include rubber compounding, printing inks, textile conditioning, leather tanning. 

A typical formula would consist of 18-28 parts of SBS rubber, 50-60 parts of an aliphatic/aromatic tackifier with about 15-30% aromaticity (for long open time), and 15-30 parts of a white oil or a very clean process oil. Formulations are designed to maximize open time, while maintaining adequate heat resi.stance (maintenance of bond strength upon aging at 40-55 C — warehouse conditions). 

Rubber blends with cure rate mismatch is a burning issue for elastomer sandwich products. For example, in a conveyor belt composite structure there is always a combination of two to three special purpose rubbers and, depending on the rubber composition, the curatives are different. Hence, those composite rubber formulations need special processing and formulation to avoid a gross dissimilarity in their cure rate. Recent research in this area indicated that the modification of one or more rubbers with the same cure sites would be a possible solution. Thus, chlorosulfonated polyethylene (CSP) rubber was modified in laboratory scale with 10 wt% of 93% active meta-phenylene bismaleimide (BMI) and 0.5 wt% of dimethyl-di-(/ r/-butyl-peroxy) hexane (catalyst). Mixing was carried out in an oil heated Banbury-type mixer at 150-160°C. The addition of a catalyst was very critical. After 2 min high-shear dispersive melt mix-... 

J. McAndless, Defense Research, Ottawa The C-13 NMR technique seems quite good for identifying the major component in the rubber formulations, namely the rubber itself. Is the technique sufficiently sensitive to pick out the antioxidants and the processing oils without having to go through the normal separation techniques ... 

Processing oils in a rubber formulation serve primarily as a processing aid. Oils fall into one of three primary categories paraffinic, naphthenic, and aromatic. The proper selection of oils for inclusion in a formulation is important. If the oil is incompatible with the polymer, it will migrate out of the compound with consequent loss in required physical properties, loss in rubber component surface properties, and deterioration in component-to-component adhesion, as in a tire. The compatibility of an oil with a polymer system is a function of... 

Rubber systems normally include a processing oil which provides a variety of benefits. Among them is reduced cost. In the fire-retarded formulation, the oil is a chlorinated paraffin (40% chlorine). The oil aids in making the rubber resilient, tough, and compatible with the filler. 

Lower cost general purpose bagasse-rubber composite formulations are identical to those for the fire-retarded formulation, except that a non-chlorinated rubber processing oil (e.g., Sun-dex 790) is substituted for the chlorinated paraffin oil, no... 

MagChem 40 is well suited for many rubber formulations, particularly neoprene. It finds wide use as a filler, anti-caking agent, cuid pigment extender. MagChem 40 is extremely efficient in chemical processes where ease of conversion is a factor. It is also used in the production of oil additives ald the desilic-ation of water. 

Rubbers. Plasticizers have been used in mbber processing and formulations for many years (8), although phthaHc and adipic esters have found Htde use since cheaper alternatives, eg, heavy petroleum oils, coal tars, and other predominandy hydrocarbon products, are available for many types of mbber. Esters, eg, DOA, DOP, and DOS, can be used with latex mbber to produce large reductions in T. It has been noted (9) that the more polar elastomers such as nitrile mbber and chloroprene are insufficiendy compatible with hydrocarbons and requite a more specialized type of plasticizer, eg, a phthalate or adipate ester. Approximately 50% of nitrile mbber used in Western Europe is plasticized at 10—15 phr (a total of 5000—6000 t/yr), and 25% of chloroprene at ca 10 phr (ca 2000 t/yr) is plasticized. Usage in other elastomers is very low although may increase due to toxicological concerns over polynuclear aromatic compounds (9). 

Other polymers used in the PSA industry include synthetic polyisoprenes and polybutadienes, styrene-butadiene rubbers, butadiene-acrylonitrile rubbers, polychloroprenes, and some polyisobutylenes. With the exception of pure polyisobutylenes, these polymer backbones retain some unsaturation, which makes them susceptible to oxidation and UV degradation. The rubbers require compounding with tackifiers and, if desired, plasticizers or oils to make them tacky. To improve performance and to make them more processible, diene-based polymers are typically compounded with additional stabilizers, chemical crosslinkers, and solvents for coating. Emulsion polymerized styrene butadiene rubbers (SBRs) are a common basis for PSA formulation [121]. The tackified SBR PSAs show improved cohesive strength as the Mooney viscosity and percent bound styrene in the rubber increases. The peel performance typically is best with 24—40% bound styrene in the rubber. To increase adhesion to polar surfaces, carboxylated SBRs have been used for PSA formulation. Blends of SBR and natural rubber are commonly used to improve long-term stability of the adhesives. 

The octylphenol condensate is used as an additive to lubricating oils and surface-active agents. Other uses of dimer are amination to octylamine and octyldiphenylamine, used in rubber processing hydroformylation to nonyl alcohol for phthalate production and carboxylation via Koch synthesis to yield acids in formulating paint driers (see Drying). 

This scries of robbers includes monomer ratios up to about 50% styrene. The addition of more than 50% styrene makes the materials more like plastic than robber. The most commonly used SBR rubbers contain about 25% styrene, which is polymerized in emulsion systems at 5-l0°C. Most SBR goes into tires, but the type for the tread differs from that of the sidewall or carcass. SBRs for adhesives, shoe soles, and other products also differ. The formulation permits vast varieties of end products. Among the processing variables that can be manipulated tu provide different end characteristics are temperature, viscusily. use of different emulsifiers and solvents, use of different antioxidants for stabilization, different oils, carbon blacks, and coagulation techniques. 

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