Diesel fuel and lubricating oil antifoams and methods of use

Abstract

The present invention relates to diesel fuel and lubrication oil defoaming agents, and crude oil demulsifiers, as well as methods for using same. In particular, the defoaming agents and demulsifiers are comprised of copolymers which have structures constituting a backbone of polysiloxane onto which is grafted an organic group. These structures comprise a polymer of the formula MD.sub.xD'.sub.yD".sub.zM, where M is O.sub.0.5Si(CH.sub.3).sub.3, D is a OSi(CH.sub.3).sub.2, D' is OSi(CH.sub.3)R, D" is OSi(CH.sub.3)R', R is a polyhydric C.sub.6-C.sub.28 organic group, R' is a phenol derivative or a long chain aliphatic group or polyethers, z is between 0 and 80, x+y+z is between 10-200, x / z is .gtoreq.1, and x / (y+z) is between about 1 and about 5, or formula M'D.sub.aM' where M' is O.sub.0.5Si(CH.sub.3).sub.2R, a is between 4-10, and R and D are the same as defined above.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to defoaming agents for petroleum products (such as diesel fuel and lubricating oils) and crude oil demulsifying agents, and methods for using them.

[0003] 2. Description of Related Art

[0004] Diesel fuel is a mixture of a variety of hydrocarbons. Most of the hydrocarbons are aliphatic, but aromatics may be present at up to twenty to twenty-five weight percent of the fuel. The mixture can also include kerosine or gas oil. Diesel fuel is commonly used in motor vehicles, and has a tendency to foam profusely when it is poured into the fuel tank of a motor vehicle. It is therefore desirable to reduce such foaming, which can be accomplished by the addition of a defoamer.

[0005] Oil companies treat diesel fuel with organic additives,-such as detergents, cetane improvers, viscosity breakers and occasionally perfumes (collectively referred to as "DAP"). Each oil company has its own preferred DAP which it t...