Lubrication method and compositions for use therein

• US 4,857,218 A
• Filed: 08/22/1985
• Issued: 08/15/1989
• Est. Priority Date: 08/17/1984
• Status: Expired due to Fees

• Current Assignee: Union Carbide Corporation Old Ridgebury Road Danbury CT 06817
• Original Assignee: Union Carbide Corporation (Dow, Inc.)
• Inventors: Hoy, Kenneth L., Meschke, Debra J.
• Primary Examiner(s): Howard, Jacqueline V.
• Application Number:
  US06/768,473
• Time in Patent Office: 1,454 Days
• Field of Search: 252/49.3, 252/49.5, 252/52 A, 568/620, 568/623, 568/624, 568/625
• US Class Current: 508/223
• CPC Class Codes: C08G 65/04 from cyclic ethers only
• CPC Class Codes: C08G 85/00 General processes for preparing compounds provided for in this subclass

Abstract

Lubricant compositions having good dilution viscosity characteristics and high viscosity/pressure coefficients can be produced using a connected branch copolymer having a core segment, non-crosslinked branched polymer segments connected to the core segment and a group of linear polymer segments connected to the branched polymer segments and bearing terminal groups capable of effecting hydrogen bonding. These connected branch copolymers are used in aqueous lubricant compositions, which may include a co-solvent such as ethylene or diethylene glycol.

Claims

1. In a method of reducing friction between two articles moving relative to, and closely adjacent, one another by disposing between adjacent surfaces of the two articles a lubricant composition comprising water and a polymer dissolved therein, the improvement which comprises using as the polymer a connected branch copolymer comprising:

(A) a core segment having a valence of v, wherein v is an integer, and having correspondingly v terminal bonds each connected to one of a group of;

(B) v polyvalent, non-crosslinked branched polymer segments each having an average of t terminal bonds, wherein t is greater than about two, one of said terminal bonds being connected to said core segment, and each of said branched polymer segments being connected via its remaining (t-1) terminal bonds to;

(C) a set of linear polymer segments, with an average of (t-1) linear polymer segments per set, to provide a group of about v(t-1) linear polymer segments wherein the linear polymer segments have substantially similar chain lengths and composition within the group, the connected branch copolymer having a group of terminal linear polymer segments bearing terminal groups capable of hydrogen bonding.

2. A method according to claim 1 wherein the lubricant composition comprises from about 5 to about 40 percent by weight of the connected branch copolymer and from about 95 to about 60 percent by weight of water.

3. A method according to claim 1 wherein the lubricant composition further comprises an alkylene glycol.

4. A method according to claim 3 wherein the lubricant composition comprises at least about 40 percent by weight of water, from about 5 to about 55 percent by weight of the alkylene glycol and from about 2 to about 40 percent by weight of the connected branch copolymer, the polymer being dissolved in the water/alkylene glycol mixture.

5. A method according to claim 4 wherein the lubricant composition comprises about 45 to about 70 percent by weight of water, from about 25 to about 50 percent by weight of the alkylene glycol and from about 5 to about 25 percent by weight of the connected branch copolymer.

6. A method according to claim 3 wherein the alkylene glycol is ethylene or diethylene glycol.

7. A method according to claim 1 wherein the lubricant composition has a viscosity of at least about 30cSt. at 40°

C.

8. A method according to claim 1 wherein the lubricant composition has a viscosity pressure coefficient of at least about 2.8×

10^-4 atm^-1 at 25°

C.

9. A method according to claim 1 wherein, in the connected branch copolymer, the linear polymer segments are divalent containing bonds connected to a second set of about v(t-1) branched polymer segments each having an average of t'"'"' terminal bonds, each of the branched polymer segments in the second set in turn being connected to a second set of linear polymer segments, with an average of t'"'"'-1 linear polymer segments per set, wherein t'"'"' is greater than about two, providing a second group of about (t'"'"'-1) [v(t-1)] linear polymer segments, and wherein the linear polymer segments have substantially similar chain lengths and compositions within the second group.

10. A method according to claim 9 wherein the connected branch copolymer has only two groups of linear polymer segments so that the second group of linear polymer segments bear terminal groups capable of effecting hydrogen bonding.

11. A method according to claim 9 wherein, in the connected branch copolymer, there are at least three groups of alternating branched polymer segments and linear polymer segments extending away from the core segment, the last, terminal group of linear polymer segments extending furthest from the core bearing terminal groups capable of effecting hydrogen bonding.

12. A method according to claim 1 wherein, in the connected branch copolymer, the core, branched and linear segments provide separate hydrophobic and hydrophilic portions of the polymer.

13. A method according to claim 1 wherein the connected branch copolymer is an organic polymer comprising only the elements carbon, hydrogen, oxygen, nitrogen, phosphorus and silicon.

14. A method according to claim 13 wherein the connected branch copolymer comprises only the elements carbon, hydrogen, oxygen and nitrogen.

15. A method according to claim 1 wherein, in the connected branch copolymer, the core segment has a linear or star structure.

16. A method according to claim 15 wherein the connected branch copolymer has a divalent linear core segment connecting two polyvalent, non-crosslinked, branched polymer segments, which are in turn connected to two sets of linear polymer segments.

17. A method according to claim 15 wherein, in the connected branch copolymer, the linear core segment comprises a polysiloxane, polyoxyalkylene, polyphosphazine, polyalkylene, polyester, polyamide, polyurethane or an alkyl ether.

18. A method according to claim 17 wherein, in the connected branch copolymer, the linear core segment comprises an oxyalkylene homopolymer, or a random or block copolymer of an oxyalkylene.

19. A method according to claim 18 wherein, in the connected branch copolymer, the linear core segment further comprises a glycidyl polyether derived from methyl glycidyl ether.

20. A method according to claim 18 wherein, in the connected branch copolymer, the linear core segment is an ethylene oxide/propylene oxide copolymer.

21. A method according to claim 18 wherein, in the connected branch copolymer, the core segment has a number average molecular weight in the range of about 2000 to about 10000.

22. A method according to claim 15 wherein, in the connected branch copolymer, the star core segment comprises a polyether derived from reacting an alkylene oxide with glycerol, pentaerythritol, dipentaerythritol or trimethylolpropane.

23. A method according to claim 1 wherein the core segment of the connected branch copolymer comprises at least one unit identical with a monomeric unit of the branched segments providing a complex branched, core segment.

24. A method according to claim 23 wherein, in the connected branch copolymer, the complex branched, core segment comprises a glycidyl polyether polymerized onto an ethylene oxide/propylene oxide core reactant.

25. A method according to claim 24 wherein, in the connected branch copolymer, the glycidyl polyether is derived from glycidol.

26. A method according to claim 1 wherein, in the connected branch copolymer, at least one branched polymer segment comprises a polyether or polyamine.

27. A method according to claim 1 wherein, in the connected branch copolymer, at least one branched polymer segment comprises residues of a monomer of the formula:

##STR11## wherein X is nitrogen, oxygen, or sulfur;

Y is alkyl, alkylamine or hydroxyalkyl;

R is hydrogen or lower alkyl;

R¹ and R³ are each hydrogen, alkyl, aryl or aralkyl;

R² is (1) an alkyl, aryl or aralkyl group which may be connected to R¹ to form a cyclic ring or (2) hydrogen when n is 0;

R⁴ is hydrogen or lower alkyl;

m is (1) 0 when X is oxygen or sulfur or (2) 1 when X is nitrogen;

n is 0 or 1 provided that n is 1 when X is oxygen or sulfur.

28. A method according to claim 27 wherein, in the connected branch copolymer, at least one branched polymer segment comprises a glycidyl polyether.

29. A method according to claim 28 wherein, in the connected branch copolymer branched polymer segment, the glycidyl polyether is derived from glycidol.

30. A method according to claim 1 wherein, in the connected branch copolymer, at least one branched polymer segment comprises a polyimine derived from aziridine.

31. A method according to claim 1 wherein, in the connected branch copolymer, at least one of the branched polymer segments has a reduced branching density due to the presence of linear polymer segments within the branched polymer segment.

32. A method according to claim 1 wherein, in the connected branch copolymer, the terminal groups capable of effecting hydrogen bonding comprise carboxylic acid groups, esters, salts or amides of carboxylic acid groups, amino groups, phosphate groups, esters, salts or amides of phosphate groups, or hydroxyl groups.

33. A method according to claim 32 wherein the terminal groups capable of effecting hydrogen bonding are hydroxyl groups.

34. A method according to claim 33 wherein the terminal linear polymer segments comprise hydroxyl-terminated polyoxyalkylene linear polymer segments.

35. A method according to claim 34 wherein, in the connected branch copolymer, the polyoxyalkylene linear polymer segments comprise copolymers of ethylene and propylene oxides.

36. A method according to claim 34 wherein, in the connected branch copolymer, at least one polyoxyalkylene linear polymer segment further comprises a glycidyl polyether derived from methyl glycidyl ether.

37. A method according to claim 1 wherein the average number of terminal linear polymer segments in each molecule of the connected branch copolymer is from about 8 to about 30.

38. A method according to claim 1 wherein the number average molecular weight of the terminal linear polymer segments is at least about 4000.

39. A method according to claim 1 wherein the connected branch copolymer is of the formula:

##STR12## wherein A is a core segment having a valence of z+1;

B and B'"'"' are non-crosslinked, branched polymer segments having valences of m+1 and n+1, respectively;

C and C'"'"' are linear polymer segments having substantially similar chain lengths and composition within each group of x or y segments;

m is greater than 1 and may vary between each set of linear polymer segments;

n is (1) greater than 1 or (2) may be 0 when y is greater than 0;

x is (1) 1 when y is 0 or (2) m when y is 1 and the product of all m values when y is greater than 1;

y and z are each integers greater than or equal to 0;

provided that y is at least 1 when z is 0.

40. A method according to claim 39 wherein the structure of the connected branch copolymer is such that in said formula y is 0 and z is 1, the connected branch copolymer thus being of the formula:

space="preserve" listing-type="equation">(C'"'"').sub.n B'"'"'-A-B'"'"'-C'"'"').sub.n

wherein A, B'"'"', C'"'"' and n are as defined in claim 39.

41. A method according to claim 1 wherein the lubricant composition further comprises at least one of an anti-oxidant, an anti-wear, an anti-corrosion and an extreme pressure additive.

42. In a method of reducing friction between two articles moving relative to, and closely adjacent to one another, by disposing between adjacent surfaces of the two articles a lubricant composition comprising water, an alkylene glycol and a polymer dissolved in the water/alkylene glycol mixture, the improvement which comprises using as the lubricant composition a composition comprising:

from about 45 to about 70 percent by weight of water;

from about 25 to about 50 percent by weight of an alkylene glycol; and

from about 5 to about 25 percent by weight of a connected branch copolymer comprising;

(A) a core segment comprising a linear polyether connected to;

(B) two polyvalent, non-crosslinked branched polymer segments each having an average of t terminal bonds, wherein t is greater than about 2, one of the branched polymer segments being connected, via one of its t terminal bonds, to each end of the linear core segment, and each of the branched polymer segments being connected to;

(C) a set of linear, hydroxyl-terminated polyoxyalkylene polymer segments, with an average of (t-1) linear polymer segments per set, to provide a group of about 2(t-1) linear polymer segments wherein the linear polymer segments have substantially similar chain lengths and composition within the group,

the lubricant composition having a viscosity of at least about 30cSt at 40°

C. and a viscosity pressure coefficient of at least about 2.8×

10^-4 atm^-1 at 25°

C.

43. A lubricant composition comprising:

at least about 40 percent by weight of water;

from about 5 to about 55 percent by weight of an alkylene glycol; and

from about 2 to about 40 percent by weight of a connected branch copolymer comprising;

(A) a core segment having a valence of v, wherein v is an integer, and having correspondingly v terminal bonds each connected to one of a group of;

(B) v polyvalent, non-crosslinked branched polymer segments each having an average of t terminal bonds, wherein t is greater than about two, one of said terminal bonds being connected to said core segment and each of said branched polymer segments being connected via its remaining (t-1) terminal bonds to;

(C) a set of linear polymer segments, with an average of (t-1) linear polymer segments per set, to provide a group of about v(t-1) linear polymer segments wherein the linear polymer segments have substantially similar chain lengths and composition within the group, the connected branch copolymer having a group of terminal linear polymer segments bearing terminal groups capable of effecting hydrogen bonding.

44. A lubricant composition according to claim 43 comprising from about 45 to about 70 percent by weight of water, from about 25 to about 50 percent by weight of the alkylene glycol and from about 5 to about 25 percent by weight of the connected branch copolymer;

the connected branch copolymer being dissolved in the water/alkylene glycol mixture.

45. A lubricant composition according to claim 43 wherein the alkylene glycol is ethylene or diethylene glycol.

46. A lubricant composition according to claim 43 having a viscosity of at least about 30cSt at 40°

C.

47. A lubricant composition according to claim 43 having a viscosity pressure coefficient of at least about 2.8×

10^-4 atm^-1 at 25°

C.

48. A lubricant composition according to claim 43 wherein, in the connected branch copolymer, the core, branched and linear segments provide separate hydrophobic and hydrophilic portions of the polymer.

49. A lubricant composition according to claim 43 wherein the connected branch copolymer is an organic polymer comprising only the elements carbon, hydrogen, oxygen, nitrogen, phosphorus and silicon.

50. A lubricant composition according to claim 49 wherein the connected branch copolymer comprises only the elements carbon, hydrogen, oxygen and nitrogen.

51. A lubricant composition according to claim 43 wherein, in the connected branch copolymer, the core segment has a linear or star structure.

52. A lubricant composition according to claim 51 wherein the connected branch copolymer has a divalent linear core segment connecting two polyvalent, non-crosslinked, branched polymer segments, which are in turn connected to two sets of linear polymer segments.

53. A lubricant composition according to claim 51 wherein, in the connected branch copolymer, the linear core segment comprises an oxyalkylene homopolymer, or a random or block copolymer of an oxyalkylene.

54. A lubricant composition according to claim 53 wherein, in the connected branch copolymer, the linear core segment is an ethylene oxide/propylene oxide copolymer.

55. A lubricant composition according to claim 53 wherein, in the connected branch copolymer, the core segment has a number average molecular weight in the range of about 4000 to about 16000.

56. A lubricant composition according to claim 43 wherein, in the connected branch copolymer, the terminal groups capable of effecting hydrogen bonding comprise carboxylic acid groups, esters, salts or amides of carboxylic acid groups, amino groups, phosphate groups, esters, salts or amides of phosphate groups, or hydroxyl groups.

57. A lubricant composition according to claim 56 wherein the terminal groups capable of effecting hydrogen bonding are hydroxyl groups.

58. A lubricant composition according to claim 57 wherein the terminal linear polymer segments comprise hydroxyl-terminated polyoxyalkylene linear polymer segments.

59. A lubricant composition according to claim 58 wherein, in the connected branch copolymer, the terminal polyoxyalkylene linear polymer segments comprise copolymers of ethylene and propylene oxides.

60. A lubricant composition according to claim 43 wherein the average number of terminal linear polymer segments in each molecule of the connected branch copolymer is from about 8 to about 30.

61. A lubricant composition according to claim 43 wherein the average molecular weight of the terminal linear polymer segments is at least about 4000.

62. A lubricant composition comprising from 80 to 98 percent by weight of water and from 20 to 2 percent by weight of a connected branch copolymer dissolved in the water, the copolymer comprising:

(A) a core segment having a valence of v, wherein v is an integer, and having correspondingly v terminal bonds each connected to one of a group of;

(B) v polyvalent, non-crosslinked branched polymer segments each having an average of t terminal bonds, wherein t is greater than about two, one of said terminal bonds being connected to said core segment, and each of said branched polymer segments being connected via its remaining (t-1) terminal bonds to;

(C) a set of linear polymer segments, with an average of (t-1) linear polymer segments per set, to provide a group of about v(t-1) linear polymer segments wherein the linear polymer segments have substantially similar chain lengths and composition within the group, the connected branch copolymer having a group of terminal linear polymer segments bearing terminal groups capable of effecting hydrogen bonding.

63. A lubricant composition according to claim 62 comprising at least about 5 percent by weight of the connected branch copolymer.

64. A lubricant composition according to claim 62 having a viscosity of at least about 30cSt at 40°

C.

65. A lubricant composition according to claim 62 having a viscosity pressure coefficient of at least about 2.8×

10^-4 atm^-1 at 25°

C.

66. A lubricant composition according to claim 62 wherein, in the connected branch copolymer, the core segment comprises an oxyalkylene homopolymer or a random or block copolymer of an oxyalkylene.

67. A lubricant composition according to claim 62 wherein the connected branch copolymer is an organic polymer comprising only the elements carbon, hydrogen, oxygen, nitrogen, phosphorus and silicon.

68. A lubricant composition according to claim 67 wherein the connected branch copolymer comprises only the elements carbon, hydrogen, oxygen and nitrogen.

69. A lubricant composition according to claim 62 wherein, in the connected branch copolymer, the terminal groups capable of effecting hydrogen bonding comprise carboxylic acid groups, esters, salts or amides of carboxylic acid groups, amino groups, phosphate groups, esters, salts or amides of phosphate groups, or hydroxyl groups.

70. A lubricant composition according to claim 69 wherein the terminal groups capable of effecting hydrogen bonding are hydroxyl groups.

71. A lubricant composition according to claim 70 wherein the terminal linear polymer segments comprise hydroxyl-terminated polyoxyalkylene linear polymer segments.

72. A lubricant composition according to claim 62, wherein the average number of terminal linear polymer segments in each molecule of the connected branch copolymer is from about 8 to about 30.

73. A lubricant composition according to claim 62 wherein the average molecular weight of the terminal linear polymer segments is at least about 4000.