Rubber processing aids

Akrochem Peptizer. [Akrochem] Pqxizing agents for rubber processing aid ftvcfaloraprene. 

Chem. Descrip. Polyethylene wax CAS 9002-88-4 EINECS/ELINCS 200-815-3 Uses Rubber processing aid mold release agent for thermosetting plastics pigment cone, for plastics... 

Uses Rubber processing aid, extender absorbent for min. oils and other liq. plasticizers improves ozone resist. natural colorant in foods Manuf./Distrib. St. Lawrence Trade Names Akrofax AS-LG... 

Table 1. Oils and Processing Aids for Reclaiming Rubber...

Natural rubber displays the phenomenon known as natural tack. When two clean surfaces of masticated rubber (rubber whose molecular weight has been reduced by mechanical shearing) are brought into contact the two surfaces become strongly attached to each other. This is a consequence of interpenetration of molecular ends followed by crystallisation. Amorphous rubbers such as SBR do not exhibit such tack and it is necessary to add tackifiers such as rosin derivatives and polyterpenes. Several other miscellaneous materials such as factice, pine tar, coumarone-indene resins (see Chapter 17) and bitumens (see Chapter 30) are also used as processing aids. 

Another common device used in the rubber industry is the thin film evaporator. This device is very often used in the manufacture of ultra-low molecular weight elastomers that are used in sealant applications or specialty coatings, and as processing aids in conventional rubber compounding processes. The thin film evaporator described earlier, has found a multitude of other industry applications, including food processing operations. 

Anorin-38 has also shown an interesting effect as a multifunctional additive (a single additive to replace many of the conventional additives) for natural rubber (NR). It showed excellent blending behavior and compatibility with NR. Aorin-38 enhances the tensile properties and percent elongation, decreases fatigue, acts as an antioxidant and antiozonant, and positively affects many of the other properties, apart from acting as a process aid and a cure enhancer [183-186]. 

The curing properties were determined with the aid of a rubber process analyzer (RPA 2000, Alpha Technologies) at a temperature of 160°C. The compounds were cured in a laboratory press at 160°C and 100 bar at a time corresponding to the fgo of the specific compound. 

In the rubber field it is not only the polymer that determines the properties of an elastomer, but many accompanying substances, like fillers, pigments, plasticisers, curing agents, antioxidants, stabilisers and processing aids (cf. Table 2.2). With rubbers the possible compositional permutations are numerous. In fact, already within the additive group of CBs there are more than 30 different possible products. 

Municipal waste (MW) Always relevant except intermediates only use in processing aids Articles waste for recycling (RW -solid) Relevant if substance is induded in aifides of glass, paper, plastics, rubber, metal, construction material or in specific articles (cars. EEE etc ) Hazardous waste (HW) Substances as such or in chemical products, liquid wastes for recycling... 

Processing aid-80, a masterbatch in the form of pressed crumb consisting of an 80 20 blend of crosslinked to ordinary natural rubber. The correct proportions of vulcanised latex and field latex are blended, coagulated and the resulting crumb pressed into 100 lb bales. The use of PA 80 confers Superior Processing properties on any natural or styrene-butadiene rubber with which it may be mixed. See Superior Processing Rubber. 

A compounding ingredient which enhances the surface tack of uncured rubber compounds. Tackifiers, exemplified by pine tar are classed under softeners and processing aids . 

Rubber reclaiming, 27 473 476, 784—785. See also Rubber recycling oils and processing aids for, 27 472t Rubber recycling, 27 461—480, 784—785. See also Rubber reclaiming asphalt modification, 27 467—469 civil engineering market for,... 

A typical tire rubber formulation for tire tread will contain various rubbers, mainly styrene-butadiene (50%) and cA-polybutadiene (12%), various processing aids (2%), softeners (3%), vulcanizing agent (mainly sulfur 1%), accelerators, and reinforcing filler (namely carbon black 30%) so that by bulk, carbon black is the second most used material. 

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