Wax and wax blends
OwnerDirk Jacobus Pretoriusinventor
Life of this patent
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Abstract
Wax powders of improved hardness and/or free-flowing properties are produced from blends containing a high content (e.g. 20 - 80%) of soft wax and a harder or higher melting wax component. The molten blend is sprayed and chilled in the form of droplets predominantly between 0.2 and 1 mm in diameter, to solidify rapidly while in suspension. The harder, higher melting components selectively solidify in the outermost region of the particles. The wax powder so obtained is superior to powders obtained by casting the blend into blocks, followed by milling. Typical powders are useful for candle extrusion and chipboard manufacture and as internal and external lubricants for plastics, e.g. polyvinylchloride.
Claims30
Process for producing a particulate wax composition improved in respect of at least one of the properties:
- free flowing ability and particle hardness, as compared with conventional blends of the same over-all composition, which comprises:
- a. preparing a melt essentially composed of a substantial content of low melting point, soft wax having a congealing point between about 20.degree. C. and 80.degree. C. and a penetration greater than 80 measured at 25.degree. C., 10.sup.-.sup.1 mm, and another wax superior thereto in respect of at least one of the properties:
- melting point and hardness;
- b. converting the melt into droplets, having a size corresponding to the particle size of the particulate wax composition being produced;
- c. suspending the droplets in a cooling medium;
- d. whilst thus suspended, over a period of between about 7 and 20 seconds, causing said droplets to solidify progressively from the outside inwardly by the chilling action of the cooling medium;
- and
- e. collecting as said particulate wax composition a free flowing powdered product consisting of the said droplets in externally solidified form, the wax superoir in respect of melting point and/or hardness being concentrated in the outer region of the droplets.
A hydrocarbon wax powder which is free flowing 25.degree. C. composed of solidified droplets of a blend essentially consisting of
- a. between 20% and 80% by weight of wax having a congealing point between 20 and 80.degree. C. and a penetration greater than 90, measured at 25.degree. C., 10.sup.-.sup.1 mm;
- and
- b. between 80% and 20% by weight of wax having a congealing point from 80.degree. C. upwards and a penetration, measured at 25.degree. C., 10.sup.-.sup.1 mm of at the most 5,
- the overall composition of each entire solidified droplet being substantially identical to that of the blend, the Components (a) and (b) in the soidified droplet being heterogeneously redistributed so that each solidified droplet consists of a hard outer shell, wherein component (a) is enriched relative to said overall composition and a softer core in which component (b) is enriched relative to said overall composition.
A process for manufacturing plastic comprising the step of mixing the hydrocarbon wax powder defined in clain 25 into the plastic component mix as an internal/external lubricant.
Dependencies are inferred from the claim text.