Oils, White

This term refers to highly refined lubricating oils for which dearomatization, in particular, has been pushed to the extreme. These products are sometimes designated by the expression liquid petrolatum . 

There are two categories of white oils technical white oils and medicinal white oils. The technical white oils, which are already highly dearomatized, are used for specialized lubricants, particularly in the textile industry, and also as components in cosmetics, as plasticizers in the rubber or plastics industries, or as emulsion bases for certain pulverized agriculture products. The medicinal white oils, whose dearomatization is pushed further still, are used in pharmaceuticals, or in the food industry, wherever residual oils might be in contact with food. 

These white oils are subject to specifications from various organizations Codex in France, British Pharmacopoeia (BP) in the United Kingdom, and National Formulary (NF) in the USA. 

White oils can be characterized by their physical properties as base oils density, viscosity, flash point, etc. 

For medicinal or food grade white oils, a very high purity is required. This is controlled by tests analogous to food-grade paraffins  

FDA UV Absorbance Limits for Technical Grade White Oils 

Source Indirect Food Additives Adjuvants, Production Aids and Sanitizers. Mineral Oil, 21 CFR 178.3620. With permission. 

Food/medicinal grade specifications (21 CFR 172.878) are designed such that products meeting these specifications can be safely used in food and pharmaceuticals.6 The specifications control PNA levels by the UV absorption limits given in Table 11.2 and by the carbonizable substances test (ASTM D565). These are discussed in more detail later in the chapter, and these are the difficult specifications to meet. 

Food/medicinal oils are frequently referred to as meeting United States Pharmacopeia (USP) or National Formulary (NF) specifications, usually written as meets USP/NF specifications. USP and NF specifications differ only in specific gravity and viscosity. USP oils must have specific gravities between 0.845 and 0.905 at 25°C and have viscosities greater than 34.5 cSt at 40°C. NF oils must have viscosities less than 33.5 cSt at 40°C and must have densities between 0.818 and 0.880 at 25°C. Further details on specifications are provided later. 

In addition, food grade white oils must satisfy the following  

---

Sulfonic acids can come from the sulfonation of oil cuts from white oil production by sulfuric acid treatment. Sodium salts of alkylaromatic sulfonic acids are compounds whose aliphatic chains contain around 20 carbon atoms. The aromatic ring compounds are mixtures of benzene and naphthalene rings. 

To convert m to U.S. gal, multiply by 264. Does not include all production of white oils. 

Petroleum Oils. When satisfactorily stable kerosene—soap—water emulsions were produced in 1874, dormant (winter) oil sprays became widely used to control scale insects and mites (1). The first commercial emulsion or miscible oil was marketed in 1904 and by 1930 highly refined neutral or white oils, free from unsaturated hydrocarbons, acids, and highly volatile elements, were found to be safe when appHed to plant foHage, thus gready enlarging the area of usefulness of oil sprays (see Petroleum). 

Sodium Dispersions. Sodium is easily dispersed in inert hydrocarbons (qv), eg, white oil or kerosene, by agitation, or using a homogenizing device. Addition of oleic acid and other long-chain fatty acids, higher alcohols and esters, and some finely divided soHds, eg, carbon or bentonite, accelerate dispersion and produce finer (1—20 -lm) particles. Above 98°C the sodium is present as Hquid spheres. On cooling to lower temperatures, soHd spheres of sodium remain dispersed in the hydrocarbon and present an extended surface for reaction. Dispersions may contain as much as 50 wt % sodium. Sodium in this form is easily handled and reacts rapidly. For some purposes the presence of the inert hydrocarbon is a disadvantage. 

Typically, the oil is subjected to several successive oleum contacts ("treats") at ca 60—65°C. This charge ratio of feedstock oleum is generally empirically determined, but depends in part on the degree of aromatic removal required for the product. In the case of white oil manufacture, 100 parts of... 

Sulfonation With Oleum vs SOy The use of oleum has been compared to that of SO3 for the batch sulfonation of eight feedstocks for the manufacture of white oils (142). The averaged results were as follows ... 

The illustrated unit can be used to study vapor-phase reforming of kerosene fractions to high octane gasoline, or hydrogenation of benzene, neat or in gasoline mixtures to cyclohexane and methylcyclopentane. In liquid phase experiments hydrotreating of distillate fractions can be studied. The so-called Solvent Methanol Process was studied in the liquid phase, where the liquid feed was a solvent only, a white oil fraction. 

Oils other than white oil, or of entirely animal or vegetable origin or entirely of mixed animal and vegetable origin... 

Paraffinic white oils from the same source but varying in molecular weight as indicated by their viscosity differences. 

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). 

Chemical and Other Specialty Manufacture A wide variety of products may be derived from petroleum feed stocks, including such diverse materials as alcohols, butyl rubber, sulfur, additives, and resins. Other specialties such as solvent naphthas, white oils, Isopars, Varsol, may also be produced. As indicated previously the respective chemical affiliate usually has responsibility for products broadly classified as petrochemicals. 

The method has been cuticised by H. G. Hattling/ who stales that a pure white oil from diies, which contained no cineol,... 

The method has been criticised by H. G. Harding, who states that a pure white oil from Eucalyptus dives, which contained no cineol, showed an absorption of 32 per cent, by the resorcinol test. Rectifying the oil and applying the test to the portion distilling between 170° and 190° does not entirely remove the difficulty, as the results are always slightly high. 

Lubricating oils Bearings do not normally fail due to corrosion, but where this has occurred it has been associated with the acidity of white oils, the peroxide content and the presence of air. Peroxides are the controlling factor, but corrosion is reduced in the absence of air. The corrosion product consists of a basic lead salt of two or more organic acids " see Section 2.11). 

Fig. 20—Film thickness with slide ratio. Lubricant White oil No. 1-h5 % nonionic acid. Temperature 20°C, Relative humid 76 %, Ball diameter 25.4 mm. Load 2 N.

---