Polyalkyl (meth)acrylate copolymers having outstanding properties

1. A copolymer obtainable by polymerizing at least one monomer composition which consists of

a) from 0 to 40% by weight of at least one ethylenically unsaturated ester compound of the formula (I)

in which R is hydrogen or methyl, R 1 is a linear or branched alkyl radical having from 1 to 5 carbon atoms, R 2 and R 3 are each independently hydrogen or a group of the formula —COOR′ in which R′ is hydrogen or an alkyl group having from 1 to 5 carbon atoms,

b) from 10 to 99.9% by weight of at least one ethylenically unsaturated ester compound of the formula (II)

in which R is hydrogen or methyl, R 4 is a linear or branched alkyl radical having from 6 to 15 carbon atoms, R 5 and R 6 are each independently hydrogen or a group of the formula —COOR″ in which R″ is hydrogen or an alkyl group having from 6 to 15 carbon atoms,

c) from 0 to 80% by weight of at least one ethylenically unsaturated ester compound of the formula (III)

in which R is hydrogen or methyl, R 7 is a linear or branched alkyl radical having from 16 to 30 carbon atoms, R 8 and R 9 are each independently hydrogen or a group of the formula —COOR′″ in which R′″ is hydrogen or an alkyl group having from 16 to 30 carbon atoms,

d) from 0.1 to 30% by weight of at least one ethylenically unsaturated, polar ester compound of the formula (IV)

in which R is hydrogen or methyl, X is oxygen, sulfur or an amino group of the formula —NH— or

—NR a — in which R a is an alkyl radical having from 1 to 40 carbon atoms, R 10 is a radical which comprises from 2 to 1000 carbon atoms and has at least 2 heteroatoms, R 11 and R 12 are each independently hydrogen or a group of the formula

—COX′R 10 ′ in which X′ is oxygen or an amino group of the formula —NH— or —NR a′ — in which R a′ is an alkyl radical having from 1 to 40 carbon atoms, and R 10′ is a radical comprising from 1 to 100 carbon atoms,

wherein said compound (d) of formula (IV) comprises at least one ester compound of the formula (XIV)

e) from 0 to 50% by weight of comonomer, wherein said comonomer is

(i) a hydroxyalkyl (meth)acrylate selected from 3-hydroxypropyl methacrylate, 3,4-dihydroxybutyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,5-dimethyl-1,6-hexanediol (meth)acrylate and 1,10-decanediol (meth)acrylate, or

(ii) styrene or substituted styrenes selected from alpha-methylstyrene and alpha-ethylstyrene, vinyltoluene and p-methylstyrene, monochlorostyrenes, dichlorostyrenes, tribromostyrenes and tetrabromostyrenes;

based in each case on the total weight of the ethylenically unsaturated monomers;

wherein said compound of the formula (IV) comprises at least one group of the formula —CO— which is a carbonyl group of a ketone, an aldehyde, a urea group containing (meth)acrylate or mixtures thereof;

wherein the R 10 radical in at least one of the ester compounds of the formula (IV) comprises at least one group of the formula —CO— and at least one nitrogen atom; and

wherein the R 10 radical in at least one of the ester compounds of the formula (IV) comprises at least one urea group.

2. The copolymer as claimed in claim 1 , wherein the copolymer has a specific viscosity η sp/c , measured in chloroform at 25° C., in the range from 8 to 74 ml/g.

3. The copolymer as claimed in claim 1 , wherein the copolymer has a polydispersity M w /M n in the range from 1.05 to 4.0.

4. A lubricant oil composition comprising at least one copolymer as claimed in claim 1 .

5. The lubricant oil composition as claimed in claim 4 , wherein the lubricant oil composition comprises at least one mineral oil and/or a synthetic oil.