Patent claim: A lubricating oil composition comprising A an oil of lubricating viscosity in a major amount B an oilsoluble or oildispersible additive component in a minor amount obtainable by reacting b1 an aliphatic polyamine having at least two carbon atoms and at least two nitrogen atoms with at least one of the nitrogen atoms present in the form of a primary amine group and at least one of the remaining nitrogen atoms present in the form of a primary or secondary amine group and b2 an aliphatic hydrocarbyl mono acid or derivative thereof of formula Iwherein R1 represents a C9 to C29 aliphatic hydrocarbyl group and X represents OH or a suitable leaving group in a compound of formula I said reaction being conducted in a manner and under conditions sufficient to react at least one amine group of the aliphatic polyamine b1 with the aliphatic hydrocarbyl mono acid or derivative thereof b2 of formula I to form at least one amide andor imidazoline group and C an oilsoluble or oil dispersible additive component in a minor amount of a primary amide of formula R6CONH2 wherein R6 represents a C9 to C29 aliphatic hydrocarbyl group.

Related passage: The present invention will next be described in more detail by way of examples which should not be construed as limiting the invention thereto.Measurement of friction coefficient an immersion test iron and copper and an oxidation stability test wereperformed through the following procedures.1 Measurement of friction coefficients of rubber samples Tester Boundentype reciprocal kinetic friction tester Test conditionsload 9.8 N stroke 10 mm speed 3.3 mms temperature 60C friction operation 30 times upper friction member rubber A727 lower friction member chromiumplated sheet 5010005 mm.The rubber member was made of a circular rubber piece diameter 15 mm.In the friction test a few drops of a sample oil were fed onto the surface of the lower friction member and the rubber piece was pressed against the lower friction member by means of a ball diameter 12.7 mm under a friction load.2 Immersion test iron and copper pieces in watercontaining oil In a glass bottle capacity 500 mL a sample oil 100 mL and distilled water 2 mL were placed.The mixture was stirred by means of a homogenizer for one minute at 2000 rpm.Subsequently a copper piece pure copper for copper plate corrosion test and an iron piece bearing race WS1730 were put into the oil sample.The bottle was capped with aluminum foil and left to stand in a thermostatic bath at 100C for 48hours.At the end of the test the copper piece and the iron piece were visually observed.The loss in mass of the copper piece was measured.Discoloration of the copper piece was measured in accordance with JIS 2513 with ratings of 1a no discoloration gt1bgt4c considerable discoloration.Thereafter the oil sample was left to stand at room temperature for 20 hours and presence of sludge was checked before and after washing with hexane.In the washing with hexane hexane 50 mL was fed to the 500mL glass bottle and the oil sample was washed with hexane under slight stirring.Then hexane was removed.3 Oxidation stability test The oxidation stability test was performed in accordance with the method stipulated in CEC L48A00B.Specifically air was caused to blow through a test oil sample 100 mL at 160C and 5.0 Lh for 96 hours and the inner wall of the glass bottle was checked for presence of deposits.The npentaneinsoluble matter was determined through the method A.