Antioxidants, primary, adhesives

Aromatic amines are the most effective primary antioxidants (Fig. 34) but they are discolouring and can only be used where the darker colours are acceptable (for instance in rubber adhesive formulations containing carbon blacks as fillers). The... 

Process 4, conversion of peroxy radicals to hydroperoxides can be interrupted by traditional primary antioxidants (see Fig. 16). The fastest reacting primary antioxidants are the aromatic amines (e.g. Naugard 445). However, these materials yellow upon exposure to UV light which restricts their applieations. More common in adhesives are the hindered phenol types of which numerous types are available, with Irganox 1010 the most common choice for adhesives. 

CAS 6683-19-8 EINECS/ELINCS 229-722-6 Uses Primary antioxidant, stabilizer for plastics, styrenics, polyolefins, PVC, urethanes, acrylics, adhesives, elastomers, coatings, food-grade polymers food pkg. adhesives... 

For hot melt adhesives there are other considerations as well in choosing an antioxidant. Primary among these are volatility and solubility. Low molecular weight antioxidants (MW <400) should be avoided, for example BHT, as these... 

ZDEC is used in the following applications as a fast primary or secondary vulcanization accelerator in NR, SBR, IIR, EPDM and for natural and synthetic latex a stabilizer in butyl, butadiene, and urethane rubbers an antioxidant in rubber-based adhesive systems a stabilizer in cement a heat stabilizer for polyethylene. 

Uses Antioxidant, metal deactivator for polymers, PP, HDPE, LDPE, some thermoplastic elastomers used as primary insulation in wire/cable applies., EPDM, peroxide- and radiation-crosslinked PE, nylon, polyacetal, polybutene, PU, styrenic copolymers, unsat. rubber, PVC, PVB, hot-melt and sol n. adhesives, powd. coatings, metal coatings, rubber/plas-tic gaskets, plastic fabricated parts in contact with catalytic metals, oils/ lubricants in contact with metals, food pkg. 

Formulation-designed hot melt adhesives use a number of materials as the base polymer for the formulation. The most widely used material for this type of adhesive is polyethylene-co-vinyl acetate (EVA). Other materials used are polyethylene (low density), block copolymers (styrene-iso-prene-styrene), phenoxy resins, polypropylene, and paraffin waxes. Paraffin, the oldest hot melt adhesive, was used as a sealing wax. As with PSAs, tackifiers are also added to hot melt adhesives to lower their melt viscosity as well as to provide tack during the resolidification of the adhesive. If one examines some hot melt adhesive formulations, one finds that the tackifier is a primary component of the adhesive sometimes used to the same level or possibly in excess of the hase polymer. Another component is the addition of a wax. The wax is added not only to decrease the melt viscosity of the adhesive but also to aid in the recrystallization process. As one might be able to recount from statements made above about heat stability, an antioxidant is an important additive to hot melt adhesive formulations. Final additives indude colorants and fillers. 

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