A process for the reduction of wear in the fuel system of a diesel engine, which comprises contacting said engine fuel system with a fuel having a reduced sulfur and aromatics content and comprising an effective anti-wear amount of a product obtainable by reacting components a), b) and c), where component a) is a compound of the formula I or a mixture of compounds of the formula I, component b) is a compound of the formula II or a mixture of compounds of the formula II and component c) is a compound of the formula III or a mixture of compounds of the formula III,
- in which, in the compound of the formula I,
- the radicals Y independently of one another are OH, (HOCH2CH2)2N— or —HNR1 and
- the radicals R1 are hydrogen, C1-C18alkyl, C5-C12cycloalkyl,
- C3-C6alkenyl, C7-C9phenylalkyl, phenyl, or phenyl which is substituted by 1 to 3 radicals A1, the radicals A1 independently of one another being C1-C12alkyl, halogen, hydroxyl, methoxy or ethoxy, in which
- R2 is hydrogen, C1-C8alkyl, O., OH, NO, —CH2CN, C1-C18alkoxy, C5-C12cycloalkoxy, C3-C6alkenyl, C7-C9phenylalkyl or C7-C9phenylalkyl which is mono-, di- or trisubstituted on the phenyl ring by C1-C4alkyl, or R2 is furthermore C1-C8acyl or HOCH2CH2—, and
- a is the number 1, 2, 3, 4 or 6, where,
- if Y is OH and a is 1,
- X is C1-C45alkyl, C3-C18alkenyl, —CH2CH2T1(CH2CH2O)bR4 or
- in which R2 is as defined above, and
- T1 is oxygen, sulfur or
- R4 is C1-C20alkyl,
- b is an integer ranging from 0 to 10 and
- R5 is hydrogen, C1-C18alkyl or phenyl, or,
- if Y is OH and a is 2,
- X is —CH2CH2T2(CH2CH2O)bCH2CH2—, in which b is as defined above,
- in which
- T2 is oxygen, sulfur,
- and R5 is as defined above,
- R6 is hydrogen, C1-C18alkyl or phenyl,
- c is an integer ranging from 2 to 10,
- d is an integer ranging from 2 to 6 and
- R7 and R8 independently of one another are hydrogen, C1-C18alkyl or phenyl, or R7 and R8 together with the C atom to which they are bonded form a C5-C12cycloalkyl ring, or
- if a is 3,
- X is C3-C10alkanetriyl or N(CH2CH2—)3, or,
- if Y is OH and a is 4,
- X is C4-C10alkanetetrayl,
- in which
- R9 is C1-C4alkyl, or,
- if Y is OH and a is 6,
- X is
- or C6-C10alkanehexayl, or,
- if Y is HNR1 and a is 1,
- X is C1-C18alkyl, C3-C18alkenyl, C5-C12cycloalkyl, C7-C9phenylalkyl, phenyl,
- in which R2 is as defined above or X is furthermore
- or X together with R1 is a group of the formula —CH2CH2CH2CH2CH2— or
- —CH2CH2OCH2CH2—, in which
- R10 is hydrogen or methyl and
- e is 2 or 3, or,
- if Y is —HNR1 and a is 2,
- X is —CfH2f—,
- in which
- f is an integer ranging from 2 to 10 and
- g is an integer ranging from 1 to 6, and,
- in the compound of the formula II,
- the radicals Z are hydrogen or a group of the formula
- and
- k is an integer ranging from 0 to 6, in which
- h is 2or 3,
- i is an integer ranging from 0 to 12 and
- R11 is C1-C30alkyl, C8-C30alkenyl, C5-C12cycloalkyl, phenyl or C7-C9phenylalkyl, with
- the proviso that the compound of the formula II has a group
- in the compound of the formula III,
- R12 is C1-C18alkyl, C5-C12cycloalkyl, phenyl or C7-C9phenylalkyl,
- R15 is hydrogen, C1-C18alkyl, C5-C12cycloalkyl, phenyl or C7-C9phenylalkyl,
- s is 0, 1 or 2,
- Q is —CmH2m—,
- in which R15 is as defined above,
- m is an integer ranging from 0 to 3,
- R16 is C1-C8alkyl and
- n is an integer ranging from 1 to 6, where,
- if n is 1,
- R17 is hydrogen, C1-C45alkyl, C5-C12cycloalkyl, C2-C18alkenyl, a monovalent radical of a hexose, a monovalent radical of a hexitol,
- in which
- R2 is as defined above, or furthermore R17 is —CH2CH2—T3—R19 or
- in which
- T3 is oxygen, sulfur or
- R19 is
- in which R12 and R15 are as defined above, or R19 is furthermore hydrogen, C1-C24alkyl, phenyl, C5-C12cycloalkyl or
- which
- p is an integ ging from 2 to 4,
- q is an integer ranging from 2 to 20,
- R22 is C1-C18alkyl, phenyl or phenyl which is substituted by 1 to 3 radicals A1, in which the radicals A1 independently of one another are C1-C12alkyl, halogen, hydroxyl, methoxy or ethoxy, or R22 is furthermore C5-C8cycloalkyl,
- R23 and R24 independently of one another are hydrogen or methyl, with the proviso that
- R23 and R24 are not simultaneously methyl;
- R25 is hydrogen or C1-C24alkyl, or,
- if n is 2,
- R17 is a divalent radical of a hexose, a divalent radical of a hexitol,
- in which p and q are as defined above, —CH2CH2—T4—CH2CH2—, —CH2—CH═CH—CH2—, —CH2—C≡C—CH2—,
- in which
- R18 and R20 independently of one another are hydrogen or C1-C12alkyl or together are the radical —CH2CH2CH2CH2CH2—,
- r is an integer ranging from 2 to 10,
- T4 is sulfur,
- in which R7 and R8 are as defined above, and
- R26 is hydrogen, C1-C18alkyl, phenyl or phenyl which is substituted by 1 to 3 radicals A1,
- in which the radicals A1 are as defined above in formula I, or R26 is furthermore
- C5-C8cycloalkyl or
- in which R2 is as defined above, or,
- if n is 3,
- R17 is a trivalent radical of a hexose, a trivalent radical of a hexitol,
- in which
- R27 is hydrogen, CH2OH, C1-C4alkyl, C1-C18alkylamido or
- in which Q, R12 and R15 are as defined above, or,
- if n is 4,
- R17 is a tetravalent radical of a hexose, a tetravalent radical of a hexitol,
- C4-C10alkanetetrayl,
- or,
- if n is 5,
- R17 is a pentavalent radical of a hexose or a pentavalent radical of a hexitol, or,
- if n is 6,
- R17 is a hexavalent radical of a hexitol or