Patent GB-643489-A (GB)
Title: Improvements in or relating to petroleum oils and greases made therewith
IPC: C10G29/24
Filed: 1947-08-07
Abstract: Fusible resinous condensation products of an aldehyde and a phenol having at least one alkyl substituent, the total number of substituent carbon atoms of the phenol being in the range 10-20, or an ether of dihydrocardanol, are added to petroleum oils or to lubricating greases made therewith in a proportion of from 0.1 to 10 per cent by weight.  The petroleum oils may be crude or refined petroleum oils or fractions thereof having closed cup flash points not lower than 250 DEG  F.  The aldehydes which may be used include monomeric and polymeric aldehydes as well as compounds, such as the acetals and hexamethylene tetramine, capable of yielding aldehydes. Formaldehyde, paraldehyde, glyoxal and furfuraldehyde are particularly suitable and the mole. ratio of the substituted phenol to the aldehyde employed preferably lies between about 2 to 1 and 1 to 2.  The alkyl substituents of the phenols are saturated open-chain hydrocarbon substituents having primary, secondary, and/or tertiary carbon atoms and the phenols are unsubstituted at either the para or one of the ortho positions.  The substituted phenol may be dihydrocardanol, i.e. the hydrogenation product of cardanol or anacardanol.  Alternatively dihydrocardanol with a butyl or amyl substituent or a phenol having two separate tertiary amyl substituents may be used.  In place of the fusible resinous condensation products of an aldehyde and dihydrocardanol, metal derivatives in which one or more hydrogen atoms of the resin molecule are replaced by a metal, such as lead, barium, sodium, potassium, lithium, calcium, copper, tin or zinc, may be used. The metal derivative may be obtained by reacting the resin with the hydroxide of the metal.  In an example dihydrocardanol is refluxed with 37.5 per cent formaldehyde and 28 per cent ammonia and the reaction product is then dehydrated at 230-250 DEG  F.  The final product is dissolved in a transformer oil.  A lead derivative is also prepared from the final product by contacting it at 120-130 DEG  C. with freshly precipitated lead hydroxide.  The mass is then cooled, and extracted with benzene to dissolve out the lead derivative which, after recovery from the benzene, is dissolved in a transformer oil. In place of the phenol/aldehyde resinous condensation products described, ethers of dihydrocardanol in which the hydrogen atom of the hydroxy group is replaced with an aliphatic or aromatic radical (such as methyl, ethyl, amyl, benzyl, lauryl or tertiary butyl) may be used. Lubricating greases may be prepared from petroleum oils of the type defined by heat dissolving or dispersing a soap such as sodium or aluminium stearate in the oil together with 0.1-10 per cent by weight of the phenol/aldehyde resin, a metal derivative of dihydrocardanol/aldehyde resin, or an ether of dihydrocardanol. The mass is then cooled.  Data are given showing that the addition of the phenolic derivatives described reduces the sludging of a transformer oil and a motor oil on prolonged exposure to the air at 300 DEG  F. Specifications 594,960 and 603,987, [Group IV (b)], are referred to.