Lubricant Additives

Ashless Phosphorus-Containing Lubricating Oil Additives 93

Test conditions: 40 kg, 100 rpm, 60 min, 121°C

Four-ball wear scar diameter (mm)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Nonyl phenolOleyl alcohol

Dodecyl phenolDinonyl phenolLauryl alcohol

Tricresyl phosphate (neutral)Base oil (100 s naphthenic)

(a)

(b)

Test conditions: 100 kg, 100 rpm, 60 min, 121°C

Four-ball wear scar diameter (mm)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Nonyl phenolOleyl alcohol

Dodecyl phenolDinonyl phenolLauryl alcohol

Base oil (100 s naphthenic)

FIGURE 3.13 Effect of hydrophobe on wear properties—four-ball wear scar diameter. Acid phosphate
esters based on nonionics containing 23–25% ethylene oxide.