1 to 0 6 parts by weight of copolymer produces greases which have good properties and consistently pass water resistance tests and therefore are preferred the base oil forming the major component of the grease composition may be any oil having lubricating characteristics any conventionally refined base stocks derived from paraffinic naphthenic and mixed mineral oil base crudes can be employed in general the naphthenic or paraffinic base oils or their blends will have saybolt universal viscosities in the range of from about 35 seconds to 300 seconds at 210 u00b0 f when a lubricating oil blend is employed in the grease making process the oils may be blended as they are being used or they may be blended separately beforehand the preferred mineral base oils are those having saybolt universal viscosities in the range of from about 67 seconds to about 87 seconds at 210 u00b0 f they may be blends of lighter or heavier oils in the lubricating oil viscosity range a grease kettle was charged with 14 0 lbs solvent neutral oil 600 600 saybolt 100 u00b0 f and 3 7 lbs diphenylmethane 4 4 39 diisocyanate after heating and mixing under a shear pressure of 100 110 psi 3 8 lbs octadecylamine and 0.