Microcrystalline waxes, composition

Base-plate wax compositions are generally regarded as trade secrets. A substantial percentage of paraffin is usually present, probably 50—80 wt %. Beeswax [8012-89-3] camauba wax [8015-86-9] ceresin, microcrystalline waxes, Acrawax C (Glyco Products Co. Inc.), mastic gum, rosin [8050-09-7] and synthetic resins may make up the balance of the formulation. Base-plate waxes are generally sold in sheet form about 1.3 mm thick, 75 mm wide, and 140 mm long. 

The compositions of sheet and shape waxes are also trade secrets. However, they are blends of various proportions of paraffin, microcrystalline waxes, camauba wax, ceresin, beeswax, gum dammar, mastic gum, and possibly other resins. Sheet waxes are marketed in square sheets approximately 80 by 90 mm. Various thicknesses are available from 32 gauge (0.5 mm) to 14 gauge (1.63 mm). 

J.J. Rocchio J.O. Doall, Analysis of Microcrystalline Waxes Used as Desensitizers in Composition B , BRL Memo Rept 123... 

Petrolatum comprises a complex hydrocarbon mixture that is about 60 to 70% mineral oil, the remainder consisting primarily of paraffin and microcrystalline wax. Despite this composition, the effect of petrolatum on outer SC lipids is distinct from that of mineral oil. As shown in Figure 28.6(a), neat petrolatum forms lamellar-like streamers in the intercellular space, as seen previously.44 The streamers appear to be suspended in a nonstaining or empty intercellular medium,... 

The most widely used thermoplastic polymer is the ethylene—vinyl acetate copolymer, which is obtainable in a wide range of molecular weights as well as in a variety of compositions. Often flexibilizers or plasticizers are added in order to improve both the mechanical shock resistance and the thermal properties of the adhesive. Polybutenes, phthalates, and tricresyl phosphate have been used as plasticizers. Tackifying agents can also be added. Because hot-melt adhesives are frequendy ethylene-based, they are subject to oxidation if, as in a typical situation, the adhesive sits in an applicator for long periods before use. Thus, antioxidants such as hindered phenols are often used, as are fillers. Fillers are added to opacify or to modify the adhesive s flow characteristics, as well as to reduce cost. Wax is also a very important component. Wax alters surface characteristics by decreasing both the liquid adhesive s surface tension and its viscosity in the melt. Upon solidification, however, the wax acts to increase the strength of the adhesive. Both paraffin and microcrystalline wax are used (see Waxes). 

These compositional changes are reflected in the physical properties of waxes. Paraffinic waxes, which are mainly linear C18 to C40, form large crystals and are known as macrocrystalline or hard waxes intermediate waxes have increased branching and range from C25 to C60 (there s obviously considerable overlap), while microcrystalline waxes have, as their name indicates, very small crystals and higher melting points, and possess very complex structures in the C25 to C85 range.11 It can be surmised that many of the structures in microcrystalline waxes... 

GP-090, -094. [Georgia-Pacific] Paraf-fin/microcrystalline wax aq. emulsion sizing agents for composition board, gypsum board prods. 

For small production runs of ceramics, extrusion free-forming through fine nozzles is useful In a pilot study Grida et. al. used a microcrystalline wax and stearic acid as a surfactant [Gri 03] The ceramic performs produced can be used as scaffolds in tissue and bone engineering, or for metal matrix composites. 

There is very little published information on the thermal decomposition process for liquid gold films. Deram et al. recently published their work on the thermal decomposition and thin-film formation of a commercial thermoplastic liquid gold ink [50]. The exact composition of the formulation studied was not determined, but it was believed to consist of a gold mercaptide containing aryl or ester functional groups in combination with resins and microcrystalline paraffin wax. 

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