Polysiloxane hydraulic fluids

Abstract

The present disclosure relates to polysiloxanes, processes for preparing polysiloxanes, and hydraulic fluids comprising polysiloxanes. This disclosure also relates to hydraulic fluids comprising one or more polysiloxane compounds and diphosphonate compounds, and to the use of diphosphonate compounds in hydraulic fluids or as additives or components in various compositions, for example to provide fire retardant properties to a fluid or composition. This disclosure also relates to use of the compositions as hydraulic fluids, which may be used in various machines, vehicles and craft, including aircraft.

Claims

1. A hydraulic fluid composition comprising a polysiloxane compound and a non-halogenated diphosphonate compound, wherein the polysiloxane compound is represented by a compound Formula 1 ##STR00069## wherein y is an integer selected from 1 to 40; R.sup.1, R.sup.2, R.sup.3, and R.sup.4, are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.5 and each R.sup.6 are independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and at least one of R.sup.1 to R.sup.4, or at least one of R.sup.5 and R.sup.6 from at least one of the y units, is C.sub.1-10alkylaryl, wherein the polysiloxane compound has a mol % of aryl moieties of about 15 mol % to about 35 mol %, relative to silicon, wherein the polysiloxane compound is present in the composition at a polydispersity of about 1 to about 5, and wherein the non-halogenated diphosphonate compound is represented by a compound of Formula 2: ##STR00070## wherein: X is selected from a group consisting of an aryl, C.sub.1-20alkylaryl, and C.sub.1-20dialkylaryl; and R.sup.11, R.sup.12, R.sup.13, and R.sup.14 are each independently selected from a group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

2. The hydraulic fluid composition of claim 1, wherein the polysiloxane compound of Formula 1 is represented by a compound of Formula 1a: ##STR00071## wherein x is an integer selected from 0 to 10; y is an integer selected from 1 to 20; z is an integer selected from 0 to 10; R.sup.1, R.sup.2, R.sup.3, and R.sup.4, are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.5 and each R.sup.6 are independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and each R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is independently selected from C.sub.1-10alkyl.

3. The hydraulic fluid composition of claim 2, wherein each R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is methyl and x and z are integers each independently selected from 1 to 3.

4. The hydraulic fluid composition of claim 2, wherein y is an integer selected from 2 to 16 or the sum of x, y and z, is an integer selected from 2 to 16.

5. The hydraulic fluid composition of claim 2, wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is C.sub.1-4alkyl; and wherein each R.sup.6 and y is selected to provide the polysiloxane compound of Formula 1a with between 1 to 6 optional substituents independently selected from the group consisting of aryl and C.sub.1-10alkylaryl and any other substituents for each R.sup.6 is independently selected from C.sub.1-4alkyl.

6. The hydraulic fluid composition of claim 5, wherein each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is methyl, and each R.sup.6 is independently selected from the group consisting of methyl, aryl, and C.sub.1-10alkylaryl.

7. The hydraulic fluid composition of claim 1, wherein at least one or both of R.sup.1 and R.sup.2 are selected from the group consisting of aryl and C.sub.1-10alkylaryl.

8. The hydraulic fluid composition of claim 1, wherein the C.sub.1-10alkylaryl is a C.sub.1-6alkylphenyl.

9. The hydraulic fluid composition of claim 1, wherein the composition comprises a mixture of at least two polysiloxane compounds of Formula 1.

10. The hydraulic fluid composition of claim 9, wherein the polysiloxane mixture comprises a series of different polysiloxane compounds of Formula 1 each having a different y value or a number of siloxane repeat units (Si—O) selected from and including each integer from 6 to 17.

11. The hydraulic fluid composition of claim 9, wherein the polysiloxane mixture comprises at least four polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 9 to 12 repeat units.

12. The hydraulic fluid composition of claim 1, wherein the diphosphonate compound is represented by a compound of Formula 2(a)(i): ##STR00072## wherein m is an integer selected from 1 to 10; R.sup.11, R.sup.12, R.sup.13, and R.sup.14, are each independently selected from the group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl; and each R.sup.15 and R.sup.16 is independently selected from the group consisting of hydrogen, C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

13. The hydraulic fluid composition of claim 12, wherein m of Formula 2(a)(i) is an integer selected from 1 to 6; R.sup.11, R.sup.12, R.sup.13, and R.sup.14, are each independently selected from the group consisting of C.sub.1-10alkyl and C.sub.1-10alkylaryl; and each R.sup.15 and R.sup.16 of Forumla 2(a)(i) is independently selected from the group consisting of hydrogen and methyl.

14. The hydraulic fluid composition of claim 12, wherein m of Formula 2(a)(i) is an integer selected from 1 to 6; R.sup.11, R.sup.12, R.sup.13, and R.sup.14 of Formula 2(a)(i) are each independently selected from C.sub.2-10alkyl; and each R.sup.15 and R.sup.16 of Formula 2(a)(i) is hydrogen.

15. The hydraulic fluid composition of claim 1, wherein the composition further comprises a phosphonate compound represented by a compound of Formula 3: ##STR00073## wherein R.sup.17, R.sup.18, and R.sup.19, are each independently selected from the group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

16. The hydraulic fluid composition of claim 15, wherein R.sup.17, R.sup.18, and R.sup.19, are each independently selected from the group consisting of C.sub.1-10alkyl and C.sub.1-10alkylaryl.

17. The hydraulic fluid composition of claim 1, wherein the amount of polysiloxane compound, based on weight % of the composition, is provided at between about 10 and 90%.

18. The hydraulic fluid composition of claim 1, wherein the volume ratio of the polysiloxane compound to the diphosphonate compound in the composition is provided at a volume ratio between about 4:1 and 1:4.

19. The hydraulic fluid composition of claim 1, wherein the composition further comprises or consists of an additive selected from the group consisting of an acid scavenger, an anti-erosion additive, a viscosity index improver, an antifoaming agent, an antioxidant, an anti-corrosion additive, and any combinations thereof.

20. The hydraulic fluid composition of claim 19, wherein the composition further comprises or consists of an additive selected from the group consisting of an acid scavenger, an antifoaming agent, an antioxidant, and any combinations thereof.

21. The hydraulic fluid composition of claim 19, wherein the acid scavenger is selected from the group consisting of a phenylglycidyl ether, pinene oxide, styrene oxide, glycidyl cyclohexyl ether, glycidyl epoxycyclohexyl ether, diglycidyl ether, glycidyl isopropyl ether, butadiene dioxide cyclohexylene oxide, bis-epoxycyclohexyl adipate, 3,4-epoxycyclohexylcarboylate and 3,4-epoxycyclohexane, and any combinations thereof.

22. The hydraulic fluid composition of claim 19, wherein the antifoaming agent is selected from the group consisting of a silicone oil, polyvinyl alcohol, polyether, and any combinations thereof.

23. The hydraulic fluid composition of claim 19, wherein the antioxidant is selected from the group consisting of a 2,6-di-tert-butyl-p-cresol, phenyl-α-napthylamine, di(octylphenyl)amine, 6-methyl-2,4-bis(octylthio)-methyl-phenol, tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)], and any combinations thereof.

24. The hydraulic fluid composition of claim 1, wherein the composition is substantially free of fluorinated anti-erosion additives.

25. The hydraulic fluid composition of claim 24, wherein the composition is substantially free of any perfluorinated anionic surfactant.

26. The hydraulic fluid composition of claim 1, wherein the composition is substantially free of any one or more additional viscosity index improver selected from the group consisting of poly(alkyl acrylate), poly(alkyl methacrylate), poly(alkyl methacrylate) esters, polycyclic polymers, polyurethanes, polyalkylene oxides, and polyesters.

27. The hydraulic fluid composition of claim 1, wherein the flash point of the composition is between 160 and 300° C. when measured using flash point testing method of ASTM D4206 of 2-4 ml volumes with a Stanhope Seta Open Cup Apparatus.

28. The hydraulic fluid composition of claim 1, wherein the density (gcm.sup.−3 at 298K) of the composition is less than 1.5.

29. The hydraulic fluid composition of claim 1, wherein the composition exhibits a viscosity between about 5 and about 25 centipoises at about 100° F. and between about 500 and about 3500 centipoises at −65° F.

30. The hydraulic fluid composition claim 1, wherein the composition is effective for use as a fire resistant hydraulic fluid.

31. The hydraulic fluid composition of claim 30, wherein the composition is effective for use as a hydraulic fluid in aircraft.

32. A process for preparing a hydraulic fluid composition comprising adding together in a composition, in any order, the polysiloxane compound of Formula 1 and diphosphonate compound as defined in claim 1.

33. The process of claim 32, whereby the hydraulic fluid composition is prepared by adding into the composition, in any order, at least one of a phosphonate compound or additive.

34. A hydraulic fluid composition comprising: a polysiloxane compound of Formula 1: ##STR00074## wherein y is an integer selected from 4 to 40; R.sup.1, R.sup.2, R.sup.3, and R.sup.4, are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.5 and each R.sup.6 is independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and wherein at least one of R.sup.1 to R.sup.4, or at least one R.sup.5 and R.sup.6 from at least one of the y units, is C.sub.1-10alkylaryl, wherein the polysiloxane compound has a mol % of aryl moieties of about 20 mol % to about 30 mol %, relative to silicon, wherein the polysiloxane compound is present in the composition at a polydispersity of about 1 to about 5; and a non-halogenated diphosphonate compound represented by a compound of Formula 2: ##STR00075## wherein: X is selected from a group consisting of an aryl, C.sub.1-20alkylaryl, and C.sub.1-20dialkylaryl; and R.sup.11, R.sup.12, R.sup.13, and R.sup.14 are each independently selected from a group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

35. The hydraulic fluid composition of claim 34, wherein the polysiloxane compound of Formula 1 is represented by a compound of Formula 1a: ##STR00076## wherein x is an integer selected from 0 to 10; y is an integer selected from 4 to 20; z is an integer selected from 0 to 10; R.sup.1, R.sup.2, R.sup.3, and R.sup.4, are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.5 and each R.sup.6 are independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and each R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is independently selected from C.sub.1-10alkyl; and wherein at least one of R.sup.1 to R.sup.4, or at least one of R.sup.5 to R.sup.10 from at least one of the x, y or z units, is C.sub.1-10alkylaryl.

36. The hydraulic fluid composition of claim 35, wherein each R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is methyl and x and z are integers each independently selected from 1 to 3.

37. The hydraulic fluid composition of claim 34, wherein y is an integer selected from 4 to 16 or the sum of x, y and z, is an integer selected from 4 to 16.

38. The hydraulic fluid composition of claim 34, wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is C.sub.1-4alkyl; and wherein each R.sup.6 and y is selected to provide the polysiloxane compound of Formula 1a with between 1 to 6 optional substituents independently selected from the group consisting of aryl and C.sub.1-10alkylaryl and any other substituents for each R.sup.8 is independently selected from C.sub.1-4alkyl.

39. The hydraulic fluid composition of claim 38, wherein each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.10, is methyl, and each R.sup.6 is independently selected from the group consisting of methyl, aryl, and C.sub.1-10alkylaryl.

40. The hydraulic fluid composition of claim 34, wherein at least one of R.sup.1 and R.sup.2 is C.sub.1-10alkylaryl.

41. The hydraulic fluid composition of claim 34, wherein the C.sub.1-10alkylaryl is a C.sub.1-6alkylphenyl.

42. The hydraulic fluid composition of claim 34, wherein the composition comprises a mixture of at least two polysiloxane compounds of the Formula 1.

43. The hydraulic fluid composition of claim 42, wherein the polysiloxane mixture comprises a series of different polysiloxane compounds of Formula 1 each having a different y value or a number of siloxane repeat units (Si—O) selected from and including each integer from 6 to 17.

44. The hydraulic fluid composition of claim 43, wherein the polysiloxane mixture comprises at least four polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 8 to 13 repeat units.

45. The hydraulic fluid composition of claim 34, wherein the composition further comprises a phosphonate compound of Formula 3: ##STR00077## wherein R.sup.17, R.sup.18, and R.sup.19, are each independently selected from the group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

46. The hydraulic fluid composition of claim 45, wherein R.sup.17, R.sup.18, and R.sup.19, are each independently selected from the group consisting of C.sub.1-10alkyl and C.sub.1-10alkylaryl.

47. The hydraulic fluid composition of claim 34, wherein the amount of polysiloxane compound, based on weight % of the composition, is provided at between about 10 and 90%.

48. The hydraulic fluid composition of claim 34, wherein the composition further comprises or consists of an additive selected from the group consisting of an acid scavenger, an anti-erosion additive, a viscosity index improver, an antifoaming agent, an antioxidant, anti-corrosion additive, and any combinations thereof.

49. The hydraulic fluid composition of claim 48, wherein the composition further comprises or consists of an additive selected from the group consisting of an acid scavenger, an antifoaming agent, an antioxidant, and any combinations thereof.

50. The hydraulic fluid composition of claim 34, wherein the composition is substantially free of fluorinated anti-erosion additives.

51. The hydraulic fluid composition of claim 34, wherein the composition is substantially free of any one or more additional viscosity index improver selected from the group consisting of poly(alkyl acrylate), poly(alkyl methacrylate), poly(alkyl methacrylate) esters, polycyclic polymers, polyurethanes, polyalkylene oxides, and polyesters.

52. The hydraulic fluid composition of claim 34, wherein the flash point of the composition is between 160 and 300° C. when measured using flash point testing method of ASTM D4206 of 2-4 ml volumes with a Stanhope Seta Open Cup Apparatus.

53. The hydraulic fluid composition of claim 34, wherein the density (gcm.sup.3 at 298K) of the composition is less than 1.5.

54. The hydraulic fluid composition of claim 34, wherein the composition exhibits a viscosity between about 5 and about 25 centipoises at about 100° F. and between about 500 and about 3500 centipoises at −65° F.

55. The hydraulic fluid composition of claim 34, wherein the composition is effective for use as a fire resistant hydraulic fluid or a hydraulic fluid in aircraft.

56. A process for preparing a hydraulic fluid composition comprising combining together in a composition, in any order, the polysiloxane compound of Formula 1 and one or more additional compounds and additives, wherein each of the one or more polysiloxane compounds of Formula 1, one or more additional compounds including phosphonate compounds of Formula 3, and one or more additional additives, are as defined according to claim 34.

57. A hydraulic fluid composition comprising: a polysiloxane compound of Formula 1: ##STR00078## wherein y is an integer selected from 4 to 25; each R.sup.3 and R.sup.4 are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and each R.sup.5 and each R.sup.6 is independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and each R.sup.1 and R.sup.2 is independently C.sub.1-10alkylaryl, wherein the polysiloxane compound has a mol % of aryl moieties of about 15 mol % to about 35 mol %, relative to silicon, and a non-halogenated diphosphonate compound represented by a compound of Formula 2: ##STR00079## wherein: X is selected from a group consisting of an aryl, C.sub.1-20alkylaryl, and C.sub.1-20dialkylaryl; and R.sup.11, R.sup.12, R.sup.13, and R.sup.14 are each independently selected from a group consisting of C.sub.1-20alkyl, aryl, and C.sub.1-20alkylaryl.

58. The hydraulic fluid composition of claim 57, wherein the polysiloxane compound of Formula 1 is represented by a compound of Formula 1a: ##STR00080## wherein x is an integer selected from 0 to 10; y is an integer selected from 4 to 20; z is an integer selected from 0 to 10; each R.sup.1 and R.sup.2 is independently C.sub.1-10alkylaryl; each R.sup.3 and R.sup.4 are each independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; each R.sup.5 and each R.sup.6 are independently selected from the group consisting of C.sub.1-10alkyl, aryl, and C.sub.1-10alkylaryl; and each R.sup.7, R.sup.8, R.sup.9, and R.sup.10 is independently selected from C.sub.1-10alkyl.

59. The hydraulic fluid composition of claim 58, wherein each R.sup.7, R.sup.8, R.sup.9, and R.sup.1 is methyl and x and z are integers each independently selected from 1 to 3.

60. The hydraulic fluid composition of claim 57, wherein y is an integer selected from 4 to 16 or the sum of x, y and z is an integer selected from 4 to 16.

61. The hydraulic fluid composition of claim 57, wherein each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.1 is C.sub.1-4alkyl; and wherein each R.sup.6 and y is selected to provide the polysiloxane compound with between 1 to 6 additional substituents independently selected from the group consisting of aryl and C.sub.1-10alkylaryl and any other substituents for each R.sup.6 is independently selected from C.sub.1-4alkyl.

62. The hydraulic fluid composition of claim 61, wherein each R.sup.3, R.sup.4, R.sup.5, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 is methyl, and each R.sup.6 is independently selected from the group consisting of methyl, aryl, and C.sub.1-10alkylaryl.

63. The hydraulic fluid composition of claim 57, wherein each R.sup.1 and R.sup.2 is independently C.sub.1-6alkylphenyl.

64. The hydraulic fluid composition of claim 57, wherein the composition comprises a mixture of at least two polysiloxane compounds of Formula 1.

65. The hydraulic fluid composition of claim 64, wherein the polysiloxane mixture comprises a series of different polysiloxane compounds of Formula 1 each having a different y value or a number of siloxane repeat units (Si—O) selected from and including each integer from 6 to 17.

66. The hydraulic fluid composition of claim 64, wherein the polysiloxane mixture comprises at least four polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 9 to 12 repeat units.

67. The hydraulic fluid composition of claim 57, wherein the composition is effective for use as a fire resistant hydraulic fluid or a hydraulic fluid in aircraft.

68. A process for preparing a hydraulic fluid composition comprising combining together in a composition, in any order, the polysiloxane compound of Formula 1 according to claim 57 with one or more additional compounds and/or additives.

69. The hydraulic fluid composition of claim 10, wherein the polysiloxane mixture comprises at least six polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 8 to 13 repeat units.

70. The hydraulic fluid composition of claim 43, wherein the polysiloxane mixture comprises at least four polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 9 to 12 repeat units.

71. The hydraulic fluid composition of claim 64, wherein the polysiloxane mixture comprises at least six polysiloxane compounds each having a different number of siloxane repeat units (Si—O) selected from 8 to 13 repeat units.

72. The hydraulic fluid composition of claim 1, wherein the polysiloxane compound is present in the composition at a polydispersity of about 1 to about 3.

73. The hydraulic fluid composition of claim 34, wherein the polysiloxane compound is present in the composition at a polydispersity of about 1 to about 3.

74. The hydraulic fluid composition of claim 1, wherein the polysiloxane compound has a mol % of aryl moieties of about 20 mol % to about 30 mol %, relative to silicon.

75. The hydraulic fluid composition of claim 57, wherein the polysiloxane compound has a mol % of aryl moieties of about 20 mol % to about 30 mol %, relative to silicon.

76. The hydraulic fluid composition of claim 1, wherein each R.sup.1 and R.sup.2 is independently C.sub.1-10alkylaryl.

77. The hydraulic fluid composition of claim 76, wherein the polysiloxane compound comprises a compound selected from the group consisting of: ##STR00081## ##STR00082##

78. The hydraulic fluid composition of claim 34, wherein each R.sup.1 and R.sup.2 is independently C.sub.1-10alkylaryl.

79. The hydraulic fluid composition of claim 78, wherein the polysiloxane compound comprises a compound selected from the group consisting of: ##STR00083## ##STR00084##

80. The polysiloxane compound of claim 57, wherein the polysiloxane compound is selected from the group consisting of: ##STR00085## ##STR00086##

81. The hydraulic fluid composition of claim 1, wherein X is C.sub.1-20dialkylaryl.

82. The hydraulic fluid composition of claim 1, wherein X is aryl.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the examples, reference will be made to the accompanying drawings, in which:

(2) FIG. 1 shows a schematic representation of liquid chromatography for a polysiloxane mixture according to one example of the present disclosure where an amount of a specific polysiloxane compound is provided in a vertical axis and the polysiloxane compound defined by number of silane (Si) groups is provided along the horizontal axis;

(3) FIG. 2 shows GC data for the first step of the preparation of EB-D8-EB according to one example of the present disclosure showing the distribution of oligomers which are volatile in the GC;

(4) FIG. 3 shows a Proton NMR for the first step of the preparation of EB-D8-EB according to one example of the present disclosure showing the chain extension having taken place with terminal Si—H groups evident (peak at ˜4.65) and the methyl groups associated with Si (peak ˜0.15 is terminal Si and peak 0.05 with backbone Si);

(5) FIG. 4 shows GC data in relation to the second step (hydosilylation) of the preparation of EB-D8-EB according to one example of the present disclosure showing the distribution of oligomers which are volatile in the GC;

(6) FIG. 5 shows a Proton NMR of the second reaction step for the preparation of EB-D8-EB according to one example of the present disclosure;

(7) FIG. 6 shows an HPLC of EB-D8-EB showing the low molecular weight oligomers according to one example of the present disclosure;

(8) FIG. 7 shows an HPLC of EB-D8-EB showing the full distribution of oligomers according to one example of the present disclosure;

(9) FIG. 8 shows GC data of EB-D8-EB according to one example of the present disclosure before distillation/WFE; and

(10) FIG. 9 shows GC data of EB-D8-EB according to one example of the present disclosure after distillation/WFE.

EXAMPLES

(11) The present disclosure is further described by the following examples. It is to be understood that the following description is for the purpose of describing particular examples only and is not intended to be limiting with respect to the above description.

A. Hydraulic Fluid Compositions

(12) Hydraulic fluid compositions were prepared and various properties determined. A range of examples of fluid compositions are shown in Tables 4 and 5 below. For Table 4, polysiloxanes were provided in compositions with diphosphonates in ratios of 50:50 to 95:5 respectively. The suitable miscibility of polysiloxanes with a monophosphonate, diphosphonate and an aviation industry hydraulic fluid of Skydrol® (LD4) was also evaluated. Currently used aviation hydraulic fluids are monophosphate based fluids, such as Skydrol® (LD4). Another hydraulic fluid currently in use is Skydrol® 5, which is a monophosphate based hydraulic fluid that also contains a perfluorinated surfactant as an anti-erosion additive. It will be appreciated that the monophosphate compounds (i.e. P(═O)(OR).sub.3) used in current aviation hydraulic fluids are structurally distinguished from phosphonates containing a hydrocarbon group directly attached to the phosphorus atom and not via an oxygen atom (i.e. RP(═O)(OR).sub.2), for example the monophosphonates or diphosphonates as described herein. Table 5 also provides a range of further examples of fluid compositions comprising alkyl phosphonates by themselves and in combination with a “F9 Mix” that is a combination mixture of a polysiloxane and diphosphonate. Fluid compositions were also prepared and tested covering a range of additional additives, for example including acid scavengers and antioxidants.

(13) TABLE-US-00004 TABLE 4 Hydraulic fluid compositions EB-D8-EB EB-D8-EB EB-D8-EB EB-D8-EB EB-D12(EB)-EB EB-D8-EB Tetrabutyl Tetrabutyl Tetrabutyl Tetrabutyl Tetrabutyl SAE Dibutyl EB-D8-EB EB-D8-EB propane propane propane propane propane AS1241 hexyl Skydrol ® Skydrol ® disphos- disphos- disphos- disphos- disphos- specification phosphonate LD4 LD4 phonate phonate phonate phonate phonate Weight 50:50 50:50 75:25 95:5 90:10 75:25 50:50 50:50 Ratio Density   1.02 N/A N/A N/A N/A N/A    0.986   1.01 N/A (g/cm.sup.3, 25° C.) Viscosity Nil 6.75 ± 0.02 10.35 ± 0.01  10.18 ± 0.02  11.63 ± 0.01  11.64 ± 0.39  12.81 ± 0.04  14.29 ± 0.01  N/A @ 65° F. (cP) Viscosity   9 < 12.5 5.01 ± 0.01 8.49 ± 0.01 7.77 ± 0.01 8.87 ± 0.01 8.93 ± 0.01 9.39 ± 0.02 9.96 ± 0.02 N/A @ 100° F. (cP) Viscosity 2000 < 2600 387 ± 2  436 ± 4  326.3 ± 0.5  340 ± 4  417 ± 3  786 ± 3  2027 ± 11  5764 ± 32  @ −65° F. (cP)s Flash >160    155  155  155  >200    >200    >200    >200    >200 point (° C.) Fire point >176    >200    >200    >200    >200    >200    >200    >200    >200 (° C.) Wick >25    >320    >320    >320    >320    >320    >320    >320    >320 (cycles) O-ring 0-18 (14)     17.5   12.4   12.2   9.8  10.5   9.4   8.5 11.4% swell (%) Kapco O-ring 0-18 (14.5)   26.0   17.7   18.1  15.1  14.9  14.5  13.9  6.9% swell (%) Parker Paint 2B 3B* 3B* 2B* 3B* 2B   2B   3B hardness >3H 5H F* F* 4H* 4H* 5H >6H >6H @ 20° C., 28 day.sup.1 or ultimate.sup.2 .sup.1,2Minimum pencil hardness required in .sup.1“pencil push” test to scratch paint and .sup.2ultimate test *Tested at 60° C.

(14) TABLE-US-00005 TABLE 5 Hydraulic fluid compositions Room Temp (25 C.) 38 C. −54 C. Viscosity Viscosity Viscosity (cP) (cP) (cP) Skydrol LD4 16.18 ± 0.07 10.34 ± 0.01  964.90 ± 4.87 (F9 Mix) EB-D8-EB [50:50] tetraButyl 17.28 ± 0.03 11.87 ± 0.02  2618.0 ± 9.0  Propane diPhosphonate DiEthyl Octane Phosphonate (AP26)  4.64 ± 0.01 3.39 ± 0.01 Frozen 6 hr DiEthyl Octane Phosphonate (AP26) [20:80] + 12.43 ± 0.02 8.65 ± 0.03 1507.0 ± 14.1 F9 mix DiEthyl Decane Phosphonate (AP28)  7.02 ± 0.04 4.89 ± 0.01 Frozen <3 hr DiEthyl Decane Phosphonate (AP28) [20:80] + 13.57 ± 0.04 9.26 ± 0.04 1586.3 ± 27.5 F9 mix DiButyl Octane Phosphonate (AP30)  5.83 ± 0.01 4.16 ± 0.01 510.1 ± 6.3 DiButyl Octane Phosphonate (AP30) [20:80] + 12.50 ± 0.01 8.66 ± 0.01 1727.3 ± 4.1  F9 mix DiButyl Decane Phosphonate (AP32)  6.97 ± 001 4.91 ± 0.01 706.2 ± 5.4 DiButyl Decane Phosphonate (AP32) [20:80] + 12.90 ± 0.01 8.91 ± 0.01 1728.1 ± 27.1 F9 mix
Product Analysis

(15) Polysiloxane products were analysed either by GC, proton NMR and/or HPLC. The analysis data presented below is for EB-D8-EB and provides an illustration of the analysis approach for polysiloxanes other than EB-D8-EB. The analysis data presented here is associated with the first reaction step i.e. ring opening polymerisation to form the polysiloxane backbone (GC and NMR), the second reaction step i.e. the end capping by hydrosilylation (GC and NMR) as well as the distribution of oligomers in the final product (HPLC). Additionally presented is a typical GC trace of the distilled/WFE product where low molecular weight volatiles have been removed.

(16) Analysis data for EB-D8-EB

(17) GC data is shown in FIG. 2 for the first step of the preparation of EB-D8-EB showing the distribution of oligomers which are volatile in the GC. At this stage of the process oligomers to 19 silicon chain length are observed in the GC (see FIG. 2). The GC results, which are also provided below in Table 6 show the formation of the polysiloxane backbone with a number average/weight average (NiWi) close to the targeted D8.

(18) TABLE-US-00006 TABLE 6 GC Results Ret Species/ Time Time (h) n 0  1  NiWi 2  NiWi 3.632 TMDS or 0.08% 0.10% 0.11% Acetone 4.77 TMDS or 1.74% 5.21% 5.25% Acetone 5.995 TMDS or 1.35% 1.70% 1.73% Acetone 9.867 H-Si3-H 3 7.11% 0.213 7.13% 0.214 10.167 D4 95.35% 5.73% 4.90% 13.232 D5 2.85% 2.95% 13.406 H-Si4-H 4 7.89% 0.315 7.89% 0.316 16.058 D6 0.82% 0.85% 16.141 H-Si5-H 5 8.57% 0.429 8.19% 0.410 18.467 H-Si6-H 6 8.01% 0.480 8.08% 0.485 20.522 H-Si7-H 7 7.73% 0.541 7.80% 0.546 22.372 H-Si8-H 8 7.35% 0.588 7.41% 0.593 24.053 H-Si9-H 9 6.86% 0.618 6.94% 0.624 25.592 H-Si10-H 10 6.30% 0.630 6.38% 0.638 27.012 H-Si11-H 11 5.72% 0.629 5.81% 0.639 28.329 H-Si12-H 12 5.15% 0.618 5.25% 0.630 29.554 H-Si13-H 13 4.35% 0.565 4.44% 0.578 30.734 H-Si14-H 14 3.17% 0.444 3.25% 0.456 32.009 H-Si15-H 15 1.75% 0.262 1.80% 0.270 33.488 H-Si16-H 16 0.79% 0.126 0.81% 0.130 35.298 H-Si17-H 17 0.54% 0.092 0.56% 0.095 37.61 H-Si18-H 18 0.46% 0.082 0.47% 0.085 40.629 H-Si19-H 19 0.36% 0.068 0.37% 0.071 187 82.08% 6.70  82.59% 6.78  Average Chain 2.00 .sup.  8.16  8.21  Length

(19) Proton NMR is provided in FIG. 3 in relation to the first step of the preparation of EB-D8-EB showing the chain extension having taken place with terminal Si—H groups evident (peak at ˜4.65) and the methyl groups associated with Si (peak ˜0.15 is terminal Si and peak 0.05 with backbone Si).

(20) GC data is provided in FIG. 4 in relation to the second step (hydosilylation) of the preparation of EB-D8-EB showing the distribution of oligomers which are volatile in the GC. At this stage of the process oligomers to 11 silicon chain lengths are observed as a consequence of hydrosilylation having taken place. It will be noted that longer chain oligomers do not appear in the GC such that the average chain length appears smaller than it actually is. The GC data is also provided below in Table 7.

(21) TABLE-US-00007 TABLE 7 Hydrosilylated Product Ret Species/Time Time (h) n 1 NiWi 5.995 Acetone 4.77% impurity 7.29 Styrene 9.07% 10.095 D4 4.10% 13.328 D5 2.51% 16.054 D6 0.74% 25.673 EB-Si2-EB 2 12.77% 0.255 27.294 EB-Si3-EB 3 14.33% 0.430 28.85 EB-Si4-EB 4 13.71% 0.548 29.689 EB-Si5-EB 5 12.43% 0.621 31.847 EB-Si6-EB 6 9.79% 0.587 33.584 EB-Si7-EB 7 6.50% 0.455 35.706 EB-Si8-EB 8 3.56% 0.285 38.427 EB-Si9-EB 9 1.98% 0.178 42.015 EB-Si10-EB 10 1.37% 0.137 46.808 EB-Si11-EB 11 1.09% 0.120 65.00 77.52% 3.62 Average Chain Length 4.67

(22) Proton NMR as shown in FIG. 5 of the second reaction step for the preparation of EB-D8-EB indicates that none of the starting H-D8-H (peak at ˜4.65 in the Proton NMR above is not evident) is seen at the completion of the process.

(23) HPLC of EB-D8-EB in FIG. 6 shows separation of the low molecular weight oligomers. The HPLC of EB-D8-EB in FIG. 7 shows the full distribution of oligomers.

(24) Analysis and integration of the combined HPLC data presented above showing the relative amounts of the oligomers present in the EB-D8-EB product, allowed determining the average chain length to be ˜8 (see FIG. 1).

(25) The GC data in FIG. 8 (before distillation/WFE) and FIG. 9 (after distillation/WFE) show the distribution following distillation/WFE clearly indicating the reduction in the presence of low molecular weight volatiles

(26) Additive Addition

(27) Where the acid number was outside of the specification it could be reduced by the use of activated alumina. The use of DCE 410 [7-Oxabicyclo[4.1.0]heptane-3-carboxylic acid, 2-ethylhexyl] is an antacid additive used in Skydrol® (LD4) for limiting acid levels in phosphate ester formulations was found to be effective after the acid number had been reduced.

B. Preparation of Polysiloxane Compounds of Formula 1 and 1a

Example 1: Preparation of α,ω-Diethylbenzyl Octasiloxane (EB-D8-EB)

(28) ##STR00058##

(29) TMDS (tetramethyl disiloxane; 671.6 g) was placed into a 5000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line and condenser. D4 (octamethylcyclotetrasiloxane; 2341.7 g) was added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (4.34 g) added with stirring. The temperature was raised to 50° C. for three hours, to produce a distribution of hydride-terminated siloxane chains of average length 8 repeat units. Next a large excess of sodium bicarbonate (6.08 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Karstedt's catalyst (2%, 1.00 g) was added to styrene (1066.9 g), and then that mixture was added to the hydride-terminated siloxane in three portions: 293 g, 352 g and 448 g; at intervals of about 1 hour. Shortly after each addition the temperature rose by about 40° C. then slowly declined. An hour after the last addition activated carbon (20 g) was added to adsorb the Karstedt's catalyst, and the mixture stirred for a further hour. Filter aid (Celite 542; 20 g) was then added and the mixture filtered through medium-speed paper. Volatiles (principally residual styrene and D4) were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 150° C., flow rate 4 ml/min on a 2″ unit). The final product was a white to pale yellow oil.

(30) The composition of the siloxane product was analysed by liquid chromatography and the siloxane oligomer mixture obtained is represented in the chart provided in FIG. 1 where an amount of a specific siloxane compound is provided in the vertical axis and the siloxane compound defined by number of silane (Si) groups is provided along the horizontal axis. The number average molar mass was determined to be 869, the weight average molar mass was determined to be 1044, and from these calculations the polydispersity (PD) was determined to be about 1.2. The composition of the mixture of siloxane oligomers essentially provides a number average siloxane oligomer corresponding to about 8 silane groups (i.e. EB-D8-EB). This siloxane product composition was shown to provide advantageous properties for use as a hydraulic fluid or component therein, which includes advantageous viscosity properties and various compatibility with other hydraulic fluids including various components and additives thereof.

Example 2: Preparation of α,ω-Diethylbenzyl Ethylbenzyl Dodecasiloxane (EB-D12EB-EB)

(31) ##STR00059##

(32) TMDS (tetramethyl disiloxane; 134.3 g) was placed into a 2000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 667.4 g) and “D4H” (tetramethylcyclotetrasiloxane; 60.1 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (1.72 g) was added with stirring. The temperature was raised to 50°-60° C. for three hours, to produce a distribution of hydride-terminated siloxane chains of average length 12 repeat units, with an average of 3 hydride units per chain. Next a large excess of sodium bicarbonate (3.65 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Karstedt's catalyst (2%, 1.50 g) was added to styrene (320.1 g), and then that mixture was added to the hydride-terminated siloxane in two portions of 160.0 g, with a delay of about 1 hour between additions. Shortly after each addition the temperature rose by about 50° C. then slowly declined. An hour after the last addition activated carbon (8.8 g) was added to adsorb the Karstedt's catalyst, and the mixture stirred for a further hour. Filter aid (Celite 542; 8.8 g) was then added and the mixture filtered through medium-speed paper. Volatiles (principally residual styrene and D4) were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 150° C., flow rate 4 ml/min on a 2″ unit). The final product was a white to pale yellow oil.

Example 3: Preparation of α,ω-Diethylbenzyl Diethyl Benzyl Hexadecasiloxane (EB-D16EB2-EB)

(33) ##STR00060##

(34) TMDS (tetramethyl disiloxane; 94.03 g) was placed into a 2000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 622.90 g) and “D4H” (tetramethylcyclotetrasiloxane; 84.18 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (1.602 g) was added with stirring. The temperature was raised to 60°-70° C. for four hours, to produce a distribution of hydride-terminated siloxane chains of average length 16 repeat units, with an average of 3 hydride units per chain. Next a large excess of sodium bicarbonate (5.66 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Karstedt's catalyst (2%, 0.8 g) was added to styrene (298.72 g), and then that mixture was added to the hydride-terminated siloxane. in two portions of 149.36 g, with a delay of about 40 minutes between additions. Shortly after each addition the temperature rose by about 70 and 40° C. respectively then slowly declined. An hour after the last addition activated carbon (8.2 g) was added to adsorb the Karstedt's catalyst, and the mixture stirred for a further 2-3 hours. Filter aid (Celite 542; 5.46 g) was then added and the mixture filtered through medium-speed paper. Volatiles (principally residual styrene and D4) were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 150° C., flow rate 4 m/min on a 2″ unit). The final product was a white to pale yellow oil.

Example 4: Preparation of α,ω-Diethylbenzyl Diphenyl Hexadecasiloxane (EB-D16(Ph2)-EB)

(35) ##STR00061##

(36) TMDS (tetramethyl disiloxane; 94.03 g) was placed into a 2000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 622.90 g) and “D3PH” (trimethyltriphenylcyclosiloxane; 190.72 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (1.43 g) was added with stirring. The mix was stirred at room temperature for four hours, to produce a distribution of hydride-terminated siloxane chains of average length 16 repeat units, with an average of 3 hydride units per chain. Next a large excess of sodium bicarbonate (4.01 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Karstedt's catalyst (2%, 0.234 g) was added to styrene (149.36 g), and then that mixture was added to the hydride-terminated siloxane. Shortly after the temperature rose by about 60° C. and then slowly declined. An hour after later activated carbon (11.04 g) was added to adsorb the Karstedt's catalyst, and the mixture stirred for a further 2-3 hours. Filter aid (Celite 542; 184.36 g) was then added and the mixture filtered through medium-speed paper. Volatiles (principally residual styrene and D4) were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 150° C., flow rate 4 ml/min on a 2″ unit).

Example 5: Preparation of α,ω-Tetraphenyl Octosiloxane (Ph2-D8-Ph2)

(37) ##STR00062##

(38) TPhTMTS (1,1,5,5-ttetraphenyl-1,3,3,5-tetramethyltrisiloxane, 24.24 g) was placed into a 100 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 18.54 g) was added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (0.11 g) was added stirring under nitrogen for 5 hours. An excess of sodium bicarbonate (0.76 g) and activated carbon (0.76 g) were added, and the mixture stirred for 6 hours. Filter aid (Celite) was then added and the mixture filtered through medium-speed paper. Volatiles were then removed from the filtered reaction mixture by rotary evaporation at ˜10 mBar, at 80° C. for 3-4 hours. A clear liquid was produced.

Example 6: Preparation of Tetraethylbenzyltetramethyltetracyclosiloxane

(39) ##STR00063##

(40) D4H (tetramethylcyclotetrasiloxane; 24.05 g) was placed into a 100 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. The mixture was degassed using nitrogen and vacuum, then Karstedt's catalyst (2%, 0.16 g) was added. Subsequently, the styrene (42.675 g) was added in four portions and the mixture allowed to cool before the next addition. Shortly after each addition the temperature rose by about 40-70° C. and then slowly declined. After the last addition, the mix was allowed to cool and activated carbon (0.66 g) was added to adsorb the Karstedt's catalyst. The mix was filtered through medium-speed paper and volatiles were then removed from the filtered reaction mixture by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 150° C., flow rate 4 ml/min on a 2″ unit). The final product was a viscous liquid.

Example 7: Preparation of α,ω-Diethylbenzylphenyldodecasiloxane (EB-D12(Ph)-EB)

(41) ##STR00064##

(42) TMDS (tetramethyl disiloxane; 6.72 g) was placed into a 250 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 33.37 g) and “D3Ph” (trimethyltriphenylcyclosiloxane: 6.81 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (0.10 g) was added with stirring. The mixture was stirred at room temperature for three hours. Sodium bicarbonate (0.35 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Styrene (10.67 g) was then added followed by Karstedt's catalyst (2%, 0.075 g) was added. Shortly after the addition the temperature rose by about 60° C. respectively then slowly declined. Activated carbon (0.6 g) was added to adsorb the Karstedt's catalyst. Volatiles were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), for two hours.

Example 8: Preparation of α,ω-Diethylbenzyldiphenyldodecasiloxane (EB-D12(Ph2)-EB)

(43) ##STR00065##

(44) TMDS (tetramethyl disiloxane; 6.72 g) was placed into a 250 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 29.66 g) and “D3Ph” (trimethyltriphenylcyclosiloxane: 13.62 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (0.09 g) was added with stirring. The mixture was stirred at room temperature for three hours. Sodium bicarbonate (0.15 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Styrene (10.67 g) was then added followed by Karstedt's catalyst (2%, 0.04 g) was added. Shortly after the addition the temperature rose by about 60° C. respectively then slowly declined. Activated carbon (0.6 g) was added to adsorb the Karstedt's catalyst. Volatiles were then removed from the filtered reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), for two hours.

Example 9: Preparation of α,ω-Diethylbenzylethylbenzyldodecasiloxane (EB-D12(EB)-EB)

(45) ##STR00066##

(46) TMDS (tetramethyl disiloxane; 2014.9 g) was placed into a 2000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 10010.8 g) and “D4H” (tetramethylcyclotetradiloxane; 901.9 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (25.85 g) was added with stirring. The mixture was stirred at 70° C. for four hours. Sodium bicarbonate (0.15 g) was added, and the mixture stirred for 30 minutes to ensure neutralization of the acid. Styrene (2400 g) was then added followed by Karstedt's catalyst (2%, 0.5 g) was added. An exotherm of ˜80° C. was observed and the reaction mix allowed to cool to ˜70° C. before a second portion of styrene (2400 g) with an ensuing exotherm of ˜40° C. The reaction was allowed to cool to ˜80° C. before activated carbon (132.1 g) was added to adsorb the Karstedt's catalyst. Celite (88 g) and MgSO.sub.4 (88 g) were added and the mix filtered. Volatiles were then removed from the filtered reaction mixture by distillation at reduced pressure (˜1 mBar, up to 160° C.), for two hours.

Example 10: Preparation of α,ω-Diethylbenzyldiethylbenzyldodecasloxane (EB-D12(EB2)-EB)

(47) ##STR00067##

(48) TMDS (tetramethyl disiloxane; 6.72 g) was placed into a 100 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 29.7 g) and “D4H” (tetramethylcyclotetradiloxane; 6.01 g) were added, the mixture degassed using nitrogen and vacuum, then trifluoromethanesulfonic acid (0.106 g) was added with stirring. The mixture was stirred at 50-60° C. for three hours. Sodium bicarbonate (0.18 g) was added, and the mixture stirred for 10-20 minutes to ensure neutralization of the acid. Styrene (21.3 g) was then added followed by Karstedt's catalyst (2%, 0.08 g) was added. An exotherm of ˜100° C. was observed. The reaction was allowed to cool to ambient before activated carbon (0.6 g) was added to adsorb the Karstedt's catalyst. The mix was filtered. Volatiles were then removed from the filtered reaction mixture by distillation at reduced pressure (˜1 mBar, up to 160° C.), for two hours.

Example 11: Preparation of Tetraphenylhexadecasiloxane (Ph2-D16-Ph2)

(49) ##STR00068##

(50) TPhTMTS (1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane, 9.7 g) was placed into a 100 ml round bottom flask equipped with a magnetic flea, nitrogen feed, vacuum line, condenser and temperature probe. D4 (octamethylcyclotetrasiloxane; 19.28 g) was added, the mixture degassed using nitrogen and vacuum, then siloxanolate (0.3 g) was added stirring under nitrogen overnight before heating to 150° C. for one hour.

C. Preparation of Diphosphonate Compounds of Formula 2

Example 7: Preparation of Tetraethyl Propane Diphosphonate

(51) 1,3-dibromopropane (60.6 g) and triethyl phosphite (100.0 g) were charged to a 250 ml round bottom flask equipped with a magnetic flea, nitrogen feed, condenser, receiver and temperature probe. A slow nitrogen feed was started, and the temperature raised towards 180° C. with stirring. At about 150° C. the mixture began to boil as the by-product ethyl bromide distilled over into the receiver, and the rate of temperature rise increased. The temperature peaked at about 185° C., after which the remaining triethyl phosphite (50.0 g) was slowly fed in. The mixture was held at 1700-180° C. for a further 2 hours to ensure complete reaction. The crude product was then cooled, and volatiles (principally unreacted triethyl phosphite and a side reaction by-product, diethyl ethyl phosphonate) were removed from the reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 160° C., flow rate 4 ml/min on a 2″ unit). The final product was a white oil.

Example 8: Preparation of Tetrabutyl Propane Diphosphonate

(52) 1,3-dibromopropane (888.3 g) and tributyl phosphite (2203 g) were charged to a 5000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, condenser, receiver and temperature probe. A slow nitrogen feed was started, and the temperature raised towards 180° C. with stirring. At about 150° C. the mixture began to boil as by-product butyl bromide distilled over into the receiver, and the rate of temperature rise increased. When the temperature reached 200° C. the remaining tributyl phosphite (881 g) was fed in at a sufficient rate to maintain the reaction temperature near 200° C. The mixture was held at 1700-190° C. for a further 2 hours to ensure complete reaction. The crude product was then cooled, and volatiles (principally unreacted tributyl phosphite and a side reaction by-product, dibutyl butane phosphonate) were removed from the reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 160° C., flow rate 4 ml/min on a 2″ unit). The final product was a white to pale yellow oil.

Example 9: Preparation of Diethyldibutyl Propane Diphosphonate

(53) 1,3-dibromopropane (504.72 g) and triethylphosphite (498.47 g) were charged to a 2000 ml round bottom flask equipped with a magnetic flea, nitrogen feed, condenser, receiver and temperature probe. A slow nitrogen feed was started, and the temperature raised towards 160° C. with stirring. At about 140° C. the mixture began to boil as by-product ethyl bromide distilled over into the receiver, and the rate of temperature rise increased. After the exotherm peaked and the by-product distilled off tributyl phosphite (625.8 g) was fed in at a sufficient rate to maintain the reaction temperature near 200° C. The mixture was held at 1700-180° C. for a further 2 hours to ensure complete reaction. The crude product was then cooled, and volatiles (principally unreacted triethyl and/or tributyl phosphite) were removed from the reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or by wiped film evaporation (˜5 mBar at 160° C., flow rate 4 ml/min on a 2″ unit). The final product was pale yellow oil and the colour removed using activated charcoal.

Example 10: Preparation of TetraButyl Xylyl Diphosphonate

(54) α,α′-DiChloroXylene (17.51 g) and tributylphosphite (150.19 g) were charged into a 250 ml round bottom flask equipped with a magnetic flea, nitrogen feed, condenser, receiver and temperature probe. A slow nitrogen feed was started, and the temperature raised towards 200° C. with stirring. The reaction mixture was cooled to about 160° C. the reaction and successive addition of sodium bromide (20.58 g) and sodium iodide (30 g. The crude product was then cooled, and volatiles (principally unreacted tributyl phosphite) removed from the reaction mixture, either by distillation at reduced pressure (˜1 mBar, up to 160° C.), or wiped film evap. (˜5 mBar at 160° C., flow rate 4 ml/min on a 2″ unit).

D. Preparation of Phosphonate Compounds of Formula 3

Example 11: Preparation of Diethyl Benzyl Phosphonate

(55) Benzyl bromide (171.0 g) and triethyl phosphite (28.5 g) were added to a 500 ml round bottom flask equipped with a distillation set-up, magnetic flea, and a 20 cm long Dufton fractionating column. The reaction was heated to 140° C. under agitation and the by-product ethyl bromide was distilled off and collected. Five more portions of triethyl phosphite (28.5 g) were added, at such a rate as to maintain the stillhead temperature at about 40° C. and the reactor temperature of at about 140° C. Once the distillation had ceased, NMR was used to confirm the reaction had gone to completion from the absence of the —CH.sub.2—Br signal in the proton NMR. The crude product was purified via high vacuum distillation to remove volatiles (principally unreacted triethyl phosphite and a side reaction by-product, diethyl ethyl phosphonate). The final product was a clear, pale yellow oil.

Example 12: Preparation of Dibutyl Hexane Phosphonate

(56) 1-bromohexane (194.8 g) and tributyl phosphite (443.1 g) were added to a round bottom flask with a distillation set-up and magnetic flea. The reactants were heated to 165-170° C. and the by-product, butyl bromide was distilled off and collected. Once the distillation had ceased, NMR was used to confirm the reaction had gone to completion from the absence of the —CH.sub.2—Br signal in the proton NMR, usually after about 2-3 hours. Generally, only about 50% of the theoretical amount of butyl bromide was collected due to its relatively high boiling point preventing rapid volatilization. The crude product was purified via high vacuum distillation to remove volatiles (principally unreacted tributyl phosphite and a side reaction by-product, dibutyl butane phosphonate). The final product was a clear, pale yellow oil.

Example 13: Preparation of Diethyl Octane Phosphonate

(57) BromoOctane (1931.3 g) and some of the total triethyl phosphite (1994 g) were added to a 5000 ml round bottom flask equipped with a distillation set-up, magnetic flea, and a 20 cm long Dufton fractionating column. The reaction mix was heated towards 200° C. A vigorous exotherm occurred as the temperature exceeded 160°-180° C. accompanied the by-product ethyl bromide being distilled off and collected. Slowly add the remaining TriEthyl Phosphite so as to keep distillate temperature below 100° C. As the exotherm declines and the reaction approaches completion maintain the temperature at 170° C.-180° C. for another 2 hours. Unreacted TriEthyl Phosphite and other volatiles DiEthylEthylPhosphate (DEEP) are removed by vacuum distillation. Once the distillation had ceased, NMR was used to confirm the reaction had gone to completion from the absence of the —CH.sub.2—Br signal in the proton NMR. The crude product was purified via high vacuum distillation to remove volatiles (principally unreacted triethyl phosphite and a side reaction by-product, diethyl ethyl phosphonate).