Patent GB-1014051-A (GB)
Title: Novel silanes and siloxanes
Inventor: OWEN WILLIAM JOHN
IPC: C07F9/02
Filed: 1961-08-11
Abstract: The invention comprises (a) silanes of general formula <FORM:1014051/C3/1> wherein R1 and R11 are monovalent hydrocarbon or halogenated monovalent hydrocarbon radicals, Q is a phosphorus atom or the groups ­P=O or ­P=S; Z is a divalent hydrocarbon radical of at least two carbon atoms and is free of aliphatic unsaturation; Y is a halogen, alkoxy or acyloxy group; X is 0 or 1 and b is 0, 1 or 2; and (b) their corresponding polysiloxanes and copolymers thereof with other silanes and siloxanes.  The silanes are prepared by reacting a compound R1PH2; <FORM:1014051/C3/2> wherein R1 is hydrogen, a monovalent hydrocarbon radical or halogenated monovalent hydrocarbon radical with a silane containing an olefinically unsaturated substituent and at least one hydrolysable group, e.g. halogen, alkoxy or acyloxy, the remaining valencies of the silicon atom being satisfied with monovalent hydrocarbon or halogenated monovalent hydrocarbon radicals.  The silanes used have the general formula Y3- bR11bSiB wherein Y and R11 are as defined above; B is a vinyl or allyl radical and b is 0, 1 or 2.  The reaction preferably takes place in the presence of a free radical source as catalyst, e.g. azobisisobutyronitrile or ultra-violet light.  R1 and R11 may be methyl, ethyl, propyl, phenyl and chlorophenyl radicals. Organosilanes used are vinyl dimethylchlorosilane, vinyl methyl dichlorosilane and allyltrichlorosilane.  In addition the trivalent phosphorus containing silanes may be oxidized to the corresponding pentavalent phosphorus compounds containing the groups ­P=O or ­P=S by reaction with an oxidizing agent, e.g. a peroxide or sulphur. Siloxane polymers of the unit general formula <FORM:1014051/C3/3> wherein R1, R11, Q, Z, b and X are as defined above and are prepared by hydrolysis of the corresponding tervalent or pentavalent silanes, preferably by adding a solution of the silane in benzene or toluene to water with cooling at 0-15 DEG  C.  The linear siloxanes may have hydroxy or alkoxy groups directly attached to the terminal silicon atoms, thus enabling further polymerization or cross-linking with silicates and polysilicates to occur.  Copolymers are obtained by reaction with linear or cyclic siloxanes of general formula <FORM:1014051/C3/4> wherein A is a monovalent hydrocarbon radical or substituted monovalent hydrocarbon radical and m has an average value of 1-3, e.g. linear or cyclic dimethylpolysiloxane; or alternatively by cohydrolysis of a phosphorus containing silane with an organosilicon compound, e.g. dimethyl dichlorosilane. Copolymerization may also take place with blocking agents containing the trimethylsiloxy group.  The examples describe (1) reaction of phenylphosphine and dimethylvinylchlorosilane in presence of azobisisobutyronitrile to give phenyl bis-(dimethylchlorosilylethyl)phosphine; (2) hydrolysis of the product in (1) to give <FORM:1014051/C3/5> ; (3) oxidation of the product of Example (2) to introduce the ­P=O group; (4) oxidation of the product of Example (2) to introduce the ­P=S group; (5) co-polymerization of the product of Example (3) with octamethyl cyclotetrasiloxane and hexamethyldisiloxane, and (6) the copolymerization of the product of Example (2) with octamethylcyclotetrasiloxane and hexamethyldisiloxane in presence of sulphur.