Lubricants additives for

The development of a line of lubricant additives is an expensive and slow undertaking the market for these products —on the order of 10 billion dollars in 1992— is very large and is dominated by a few companies. 

One can distinguish three important additive classes according to their modes of action  

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Additives for lubrication under extreme conditions fatty esters, fatty acids, etc. 

This chapter is divided in two parts additives for motor fuels and additives for lubricants. Concerning additives for gasoline, one will find here in Chapter 9 some useful complements to Chapter 5, especially regarding the synthesis of additives and their modes of action. 

The third family (c. in Figure 9.1) less widespread, derived from the alkylphenols, offers as with the succinimides several possibilities of modification to the ratio of hydrophilic and lipophilic groups. Mannich s reaction of the alkyl-phenols also provides additives for lubricating oils. 

The introduction of monomers containing polar groups such as tertiary amines, imidazoles, pyrrolidones, pyridines, etc., gives the polymer dispersant properties that will be discussed in the article on dispersant additives for lubricants. 

Polymer-type antioxidants have been prepared by Eriedel-Crafts reaction of -cresol andp- and/or y -chloromethylstyrene in the presence of boron trifluoride-etherate (198). The oligomeric product resulting from the alkylation of phenyl-a-naphthylamine using C12—15 propylene oligomer in the presence of AlCl or activated white clays is used as an antioxidant additive for lubricating oils (199). 

In the other market areas, lead naphthenates are used on a limited basis in extreme pressure additives for lubricating oils and greases. Sodium and potassium naphthenates are used in emulsiftable oils, where they have the advantage over fatty acid soaps of having improved disinfectant properties. Catalyst uses include cobalt naphthenate as a cross-linking catalyst in adhesives (52) and manganese naphthenate as an oxidation catalyst (35). Metal naphthenates are also being used in the hydroconversion of heavy petroleum fractions (53,54) and bitumens (55). 

In the lightening of petroleum hydrocarbon oil, esters of mercaptocarboxyhc acids can modify radical behavior during the distillation step (58). Thioesters of dialkanol and trialkanolamine have been found to be effective multihinctional antiwear additives for lubricants and fuels (59). Alkanolamine salts of dithiodipropionic acid [1119-62-6] are available as water-soluble extreme pressure additives in lubricants (60). 

Minor and potential new uses include flue-gas desulfurization (44,45), silver-cleaning formulations (46), thermal-energy storage (47), cyanide antidote (48), cement additive (49), aluminum-etching solutions (50), removal of nitrogen dioxide from flue gas (51), concrete-set accelerator (52), stabilizer for acrylamide polymers (53), extreme pressure additives for lubricants (54), multiple-use heating pads (55), in soap and shampoo compositions (56), and as a flame retardant in polycarbonate compositions (57). Moreover, precious metals can be recovered from difficult ores using thiosulfates (58). Use of thiosulfates avoids the environmentally hazardous cyanides. 

Additives for lubricating oils providing a combination of viscosity index improvement (VII) and dispersancy have also been reported. These additives are prepared from ethyleneamines by reaction with various Vll-type polymers that have been chlorinated or modified in some other way to provide an ethyleneamine reaction site. Antimst additives for lubricating oils have been prepared by reaction of polyamines with fatty acids followed by reaction with polyalkylenesuccinic anhydrides (178,179). 

Moreover, stable liquid systems made up of nanoparticles coated with a surfactant monolayer and dispersed in an apolar medium could be employed to catalyze reactions involving both apolar substrates (solubilized in the bulk solvent) and polar and amphiphilic substrates (preferentially encapsulated within the reversed micelles or located at the surfactant palisade layer) or could be used as antiwear additives for lubricants. For example, monodisperse nickel boride catalysts were prepared in water/CTAB/hexanol microemulsions and used directly as the catalysts of styrene hydrogenation [215]. 

Thiadiazole derivatives have been found to be useful as additives for lubricating greases and as vulcanization agents <1996CHEC-II(4)307>. No new applications of this type have been reported since the publication of CHEC-11(1996). 

The product is obtained in 85% yield by treatment with aqueous NaOH followed by distillation (36GEP663891). 2-Aminopyridine is used in the manufacture of several chemotherapeutics, dyes for acrylic fibers, and as an additive for lubricants (71MI1). Monomeric cyanamide reacts with acetylene in the presence of the Tj -borininato cobalt catalyst to give 2-aminopyridine [Eq.(27)]. For experimental details see Bonnemann and Brijoux (84MI7). 

C.S. Liu, C.A. Migdal, N.R. Crawford, and R.I. Yamamota, Polyisobutylene succinimide and ethylene-propylene succinimide synergistic additives for lubricating oils compositions, US Patent 6117 825, assigned to Ethyl Corporation (Richmond, VA), September 12, 2000. 

C.K. Esche, Jr., C.A. Migdal, J.R. Sanderson, and A.L. Ippolito, Polyisobutylene succinimide, ethylene-propylene succinimide and an alkylated phenothiazine additive for lubricating oil compositions, US Patent 5 614124, assigned to Ethyl Additives Corporation (Richmond, VA), March 25,1997. 

Among the butylenes, isobutylene has become one of the important starting materials for the manufacture of polymers and chemicals. There are many patents that describe the use of isobutylene or its derivatives to produce insecticides, antioxidants, elastomers, additives for lubricating oils, adhesives, sealants, and caulking compounds. Table 9 shows the use pattern of butylenes in the United States. 

POUR POINT DEPRESSANT. An additive for lubricating and automotive oils that lowers the pour point (or increases the flow point) by 11.0°C. The agents now generally used are polymerized higher esters of acrylic add derivatives. They are most effective with low-viscosity oils. See also Petroleum. 

The principal uses of tungsten compounds lie outside the scope of this chapter (e.g. catalysts for oil refining). WS2 is an effective additive for lubricating oils.41 CaW04 is used as a phosphor for X-ray screens.42 W03 is almost as effective as Mo03 as a flame retardant for poly(vinyl chloride).5... 

Damrath, J.G., Jr., A.G. Papay, in Additive fur Schmierstoffe und Arbeitsflussigkeiten (Additives for Lubricants and Operational Fluids), Ed., W.J. Bartz, Technische Akademie, Esslingen, Germany, 1986 pp. 4/2/1-4/2/8 (5th International Colloquium, January 14th -16th, 1986, Esslingen). 

Shpenkov, G.P. and S. Sagatowski, A Method for the Manufacture of an Additive for Lubricants, Cooling Liquids and Fuels, and Additive for Lubricants. Summary of the Patent Applications, Reg. No.233400", Bulletin of the Patent Department, Warsaw, Poland, No. 15 (485) 1992 p. 26. 

Similarly to bis(octylphenoxy)dithiophosphate, one can obtain other bis(alkylphenoxy)derivatives of dithiophosphoric acid. As mentioned above, these ethers are veiy efficient additives for lubricant oils used in intensive operation engines. An addition of 1-5% of these substances greatly increases thermal oxidative stability and anticorrosion properties of lubricant oils and reduce varnish formation in engines. 

As indicated above, the new applications of organolead have been fostered largely through the interest of ILZRO. The most promising new applications are in the fields of marine antifouling paints, marine borer repellants for wood, antiwear additives for lubricants, polyurethan foam catalysts, and molluscicides for bilharzia control in tropical areas. 

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