Polymers and lubricating compositions containing polymers
A polymer having the structure (I): L is a linking group, R is a hydrocarbon group or a substituted-hydrocarbon group, and x is 2 or more, preferably from 2 to 100, more preferably from 2 to 50. Each {Q} is (a) an identical polymer block composed of 3 or more monomer units, or (b) contains a plurality of polymer blocks, each polymer block being composed of 3 or more monomer units, such that the moiety {Q}-L-{Q} has the structure {P n . . . P 2 P 1 }-L-{P 1 P 2 . . . P n } where each P n is an individual polymer block, the number of polymer blocks n in each {Q} being the same; wherein for each value of n the polymer blocks are identical; and wherein n is an integer of 2 or more, preferably from 2 to 100, more preferably from 2 to 50.
1. A polymer having the structure (I):
wherein L is a linking group, R is a hydrocarbon group or a substituted-hydrocarbon group, and x is 2 or more; and wherein each {Q}
contains a plurality of polymer blocks, each polymer block being composed of 3 or more monomer units, such that the moiety {Q}-L-{Q} has the structure {P n . . . P 2 P 1 }-L-{P 1 P 2 . . . P n } where each P n is an individual polymer block, the number of polymer blocks n in each {Q} being the same; wherein for each value of n the polymer blocks are identical; and wherein n is an integer of 2 or more, and wherein each polymer block is a homopolymer block and has the structure (II):
wherein m is an integer of at least 3; wherein R 1 is hydrogen or methyl; wherein X is a hydrocarbon group having from 1 to 50 carbon atoms, a substituted-hydrocarbon group having from 1 to 50 carbon atoms, COOR 2 , COSR 2 or CONR 2 R 3 , OCOR 2 , CONHR 2 , CN, COSiR 2 R 3 R 4 or CI wherein R 2 , R 3 and R 4 are independently hydrogen, a hydrocarbon group having from 1 to 50 carbon atoms, or a substituted-hydrocarbon group having from 1 to 50 carbon atoms; and wherein in each block having structure (II), each R 1 and each X and each m may be the same or different across polymer blocks.
2. A polymer according to claim 1 , wherein each X is COOR 2 ,
where each R 2 is a straight-chain or branched alkyl group.
3. A polymer according to claim 1 , wherein each X is COOR 2 , where each R 2 is a polyalkylene glycol residue of the formula —[(CR 5 H) y O] z OR 6 , where y is an integer from 2 to 4, and z is from 2 to 100, R 5 is hydrogen or an alkyl, and R 6 is hydrogen, an alkyl group or an aryl group.
4. A polymer according to claim 1 , wherein each {Q} is composed of a plurality of copolymer blocks of structure (II) such that the moiety {Q} {Q} has the structure (III):
wherein each m 1 , m 2 . . . m n is independently an integer of at least 3 and wherein each X 1 , X 2 . . . X n is independently a hydrocarbon group having from 1 to 50 carbon atoms, a substituted-hydrocarbon group having from 1 to 50 carbon atoms, COOR 2 , COSR 2 or CONR 2 R 3 , OCOR 2 , CONHR 2 , CN, COSiR 2 , R 3 R 4 or Cl wherein R 2 and R 3 , and R 4 are independently hydrogen, a hydrocarbon group having from 1 to 50 carbon atoms, or a substituted-hydrocarbon group having from 1 to 50 carbon atoms.
5. A polymer according to claim 4 , wherein each X 1 , X 2 . . . X n COOR 2 , where in each instance a, R 2 is a straight-chain or branched alkyl group.
6. A polymer according to claim 4 , wherein each X 1 , X 2 . . . X n is COOR 2 , where in each instance n, each R 2 is a polyalkylene glycol residue of the formula —[(CR 5 H) y O] z OR 6 , where y is an integer from 2 to 4, and z is from 2 to 100, R 5 is hydrogen or an alkyl group and R 6 is hydrogen, an alkyl group or an aryl group.
7. A polymer according to claim 4 , wherein each X 1 , X 2 . . . X n is COOR 2 and n is at least 2: wherein in at least one instance n, R 2 , is a straight-chain or branched alkyl group; and wherein in at least one other instance n, R 2 , is a polyalkylene glycol residue of the formula —[(CR 5 H) y O] z OR 6 , where y is an integer from 2 to 4, and z is from 2 to 100, R 5 is hydrogen or an alkyl group and R 6 is hydrogen, an alkyl group or an aryl group.
8. A polymer according to claim 1 , wherein each R 1 is hydrogen.
9. A polymer according to claim 4 , wherein each X 1 , X 2 . . . X n is COOR 2 and n is 2; wherein in one instance n, R 2 is a branched alkyl group and in the other instance n, R 2 is a polyalkylene glycol residue of the formula —[(CR 5 H) y O] z OR 6 where y is an integer from 2, to 4, and z is from 2 to 100, R 5 is hydrogen or an alkyl group, and R 6 , is hydrogen, an alkyl group or an aryl group.
10. A polymer according to claim 9 , wherein the branched alkyl group is 2 ethylhexyl, and the polyalkylene glycol residue is of the formula —[(CH 2 ) y O] z OMe where y is 2.
11. A polymer according to claim 10 , wherein the branched alkyl group is 2-ethylhexyl, and the polyalkylene glycol residue is of the formula —[(CH 2 ) y O] z OMe where y is 2 and z is an average value of 7 to 8.
12. A polymer according to claim 4 , wherein each X 1 , X 2 . . . X n is COOR 2 and n is 3; wherein in one instance n, R 2 is a branched alkyl group and in the other two instances n, R 2 is a polyalkylene glycol residue of the formula —[(CR 5 H) y O] z OR 6 where y is an integer from 2 to 4, and z is from 2 to 100, R 5 is hydrogen or an alkyl group, and R 6 is hydrogen, an alkyl group or an aryl group.
13. A polymer according to claim 12 , wherein the branched alkyl group is 2 ethylhexyl and each polyalkylene glycol residue is the same and of the formula —[(CH 2 ) y O] z OMe where y is 2.
14. A polymer according to claim 13 , whereto the branched alkyl group is 2-ethylhexyl, and each polyalkylene glycol residue is the same and of the formula —[(CH 2 ) y O] z OMe where y is 2 and z is an average value of 7 to 8.
15. A polymer according to claim 1 , wherein L is the residue of a di-functional initiator molecule which is effective to initiate polymerisation of the monomers used to form the polymer blocks.
16. A polymer according to claim 1 , wherein L has the structure:
where *indicates the points of attachment to the remainder of the polymer, and where a is an integer from 1 to 100.
17. A polymer according to claim 1 , wherein R has the structure:
where *indicates the points of attachment to the remainder of the polymer.
18. A lubricating composition comprising a major amount of a base lubricant, and a minor amount of a polymer according to claim 1 .
19. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity, a minor amount of a polymer according to claim 1 , and a minor amount of one or more of a phosphorus-containing compound, and oxidation inhibitor, a dispersant, a metal detergent, and anti-wear agent, a friction modifier and a viscosity modifier.
20. A method of reducing the friction between contacting surfaces of a mechanical device the method comprising lubricating the surfaces with a lubricating oil composition according to claim 18 .
21. A method of reducing the friction between contacting surfaces of a mechanical device, the method comprising lubricating the surfaces with a lubricating oil composition according to claim 19 .
22. The method according to claim 21 , wherein the mechanical device is a spark-ignited or compression ignited internal combustion engine.