| abstract |
The invention relates to polyalkyl (meth)acrylates suitable for improving the viscosity index for use as oil additives having an improved dispersing and detergent action in diesel engines and spark-ignition engines, the polyalkyl (meth)acrylates being copolymers of 80 - 99.5 parts by weight of alkyl (meth)acrylates of the formula n<IMAGE>n in whichn R is hydrogen or methyl and R1 is an alkyl radical having 6 to 24 carbon atoms, preferably 8 to 20 carbon atoms,n together with 0.5 - 20 parts by weight of at least one functionalised alkyl methacrylate of the formula II n<IMAGE>n in whichn R' is hydrogen or methyl and R2 is an alkyl radical having 2 to 6 carbon atoms and substituted by at least one OH group or is a poly-alkoxylated radical n<IMAGE>n in whichn R3 and R4 are hydrogen or methyl, R5 is an alkyl radical having 1 to 40 carbon atoms and n is an integer from 1 to 60,n the total of the monomers of the formulae (I) and (II) being 100 parts by weight,n and, if appropriate, 0 - 20 parts by weight of one or more monomers of the formula III n<IMAGE>n in which n n R'' is hydrogen or methyl and n R6 is an alkyl radical having 1 to 5 carbon atoms |