Patent GB-815231-A (GB)
Title: New silicon-containing compounds and the use thereof
Inventor: GARDEN WILLIAM DAVID
IPC: C08G77/04
Filed: 1955-11-07
Abstract: Lubricating compositions, particularly for use under "kinetic boundary" conditions, comprise a phosphonated polysiloxane, preferably containing 2 to 22 silicon atoms per molecule, either alone or in admixture with another such compound or with another liquid polysiloxane.  The phosphonate groups are linked to silicon atoms through divalent hydrocarbon groups and the organic ester radicals contain not more than 8 carbon atoms and no aliphatic unsaturation; the remaining silicon valencies are satisfied by alkyl, aryl, alkaryl, aralkyl, haloalkyl or haloaryl groups.  The number of phosphonate groups is preferably 1 or 2 per molecule, and if 2, preferably on each terminal silicon atom.  The composition may also contain anti-oxidants, metallic soaps and thickeners such as finely divided silica, asbestos floats, carbon black, aryl ureas and phthalocyanines to form greases.  A table is given comparing the lubricating power of a number of phosphonated di- and higher siloxanes (see Group IV (a)) including 1 and 3 per cent solutions of these compounds in liquid methyl and methyl phenyl polysiloxanes.ALSO:The invention comprises phosphonated polysiloxanes in which the phosphonate groups are linked to silicon atoms through divalent hydrocarbon groups, the organic radicals in the phosphonate groups containing not more than 8 carbon atoms and no aliphatic unsaturation; the remaining silicon valencies being satisfied by alkyl or haloalkyl groups of not more than 6 carbon atoms or by aryl, alkaryl, aralkyl or haloaryl groups of not more than 12 carbon atoms. The preferred compounds contain 2 to 22 silicon atoms per molecule and are particularly useful as lubricating fluids.  The number of phosphonate groups is preferably 1 or 2 per molecule, and if 2, preferably on each terminal silicon atom.  They may be prepared by (1) reacting a Grignard reagent, prepared from a haloalkyl or haloaryl siloxane, with a dialkyl or diaryl phosphorochloridate, or (2) reacting the sodio-derivative of a dialkyl or diaryl phosphite with a haloalkyl siloxane.  The higher polysiloxane may be prepared from the phosphonated disiloxanes by equilibrating with polysiloxanes. The compounds may be used with other liquid polysiloxanes, e.g. in the form of a 1 or 3 per cent solution, and other ingredients may be added including anti-oxidants, metallic soaps and thickeners such as finely divided silica, asbestos floats, carbon black, aryl ureas and phthalocyanines to make the compositions into greases. The examples describe the preparation of (1) diphenyl p-pentamethyldisiloxanyl phenylphosphonate; (2) diethylpentamethyldisiloxanyl methyl phosphonate; (3) diphenyl pentamethyl disiloxanyl methyl phosphonate; (4) di-n-butyl pentamethyl disiloxanyl methyl phosphonate; (5) diphenyl p-(1,1,3,3 - tetramethyl - 3 - phenyldisiloxanyl) phenyl phosphonate; (6) 1,3-bis-(diethyl phosphonomethyl) tetramethyl disiloxane; (7), (8) and (9): <FORM:0815231/IV (a)/1> the average value of n being 20, 10 and 4 respectively; (10 1,3-bis-(diphenyl p-phosphonophenyl) tetramethyldisiloxane; (11) dicyclohexyl pentamethyldisiloxanyl methyl phosphonate.  The preparation of the intermediates, p - bromophenyl pentamethyl disiloxane and 1-p - bromophenyl - 3 - phenyl tetra methyldisiloxane is also described.