Patent GB-991037-A (GB)
Title: Cyclic silanes, their preparation and hydrolysis
IPC: C08G77/26
Filed: 1962-09-26
Abstract: The invention comprises cyclic silanes of general formula <FORM:0991037/C3/1> and also siloxanes and copolymeric siloxanes thereof, wherein R is a monovalent substituent which is hydrogen, a hydrocarbon radical, a hydrocarbon radical containing oxygen in the form of an ether linkage, an amino-alkyl, aminophenyl, halogenophenyl or an organosilyl radical of general formula (XR1)Y2Si-, wherein each Y is a monovalent hydrocarbon radical and X is a chlorine, bromine, iodine or hydrogen atom, each R1 is a divalent saturated aliphatic hydrocarbon radical wherein the silicon atom is attached to a carbon atom which is at least the third and not more than the sixth carbon atom away from the other substituent attached to R1 and each R11 is a monovalent substituent which is a hydrocarbon radical, a hydrocarbon radical containing oxygen in the form of ether linkages, an alkoxy radical, an aliphatic saturated radical bonded to silicon through a C-O-Si linkage containing oxygen in the form of ether linkages or a phenoxy radical. R may be hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkaryl, ethoxymethyl, ethoxyethyl, methoxyphenyl, aminomethyl, aminoethyl, aminohexyl, aminooctyl, aminophenyl, p-chlorophenyl and m-bromophenyl. R1 may be radicals containing 3 to 6 methylene groups which may be substituted by methyl or ethyl groups.  R11 may be methoxy, ethoxy, butoxy, -OCH2CH2OCH3, -OCH2 CH2CH2OCH2CH3, OCH2OCH2CH3 or phenoxy. Preferably, the nitrogen atom is attached to a carbon atom which is the third carbon atom away from the silicon atom.  They are prepared by (1) reacting a compound <FORM:0991037/C3/2> with a compound of formula RNH2 and when R=H intermediate compounds of formula HN[Si(R11)2(R1X)]2 are formed.  The reaction proceeds in presence of either a large excess of amine, e.g. 7 to 10 mols. per mol. of the silane or in presence of tributylamine, pyridine and quinoline as hydrogen halide acceptors; the symbols XR1 and R11 have the values given above; (2) heating above 100 DEG C. a compound of general formula (RNHR1 -Si(R11)a(OZ)3-a, wherein R1 and R are defined as above but R cannot be (XR1)-SiY2-; Z is phenyl, alkyl or an alkyl group containing ether linkages; and a is 0, 1 or 2.  The invention further comprises (a) siloxanes of general unit formula <FORM:0991037/C3/3> They are prepared by hydrolysing compounds of formula <FORM:0991037/C3/4> the symbols R, R1, R11 and a having the values given above.  When the cyclic silane contains no alkoxy or phenoxy radicals disiloxanes are produced; (b) end blocked diorganosiloxanes of general formula <FORM:0991037/C3/5> where x is at least 1. They are prepared by reacting hydroxy and blocked diorganosiloxanes with the above cyclic silanes. R111 is a monovalent hydrocarbon radical which may be halogenated, e.g. chloromethyl or 3,3,3-trifluoropropyl, and (c) copolymer siloxanes containing the units (RNHR1) R11SiO and R111 2SiO wherein the symbols R, R1, R11, R111 are as defined above.  These polymers may be end blocked by hydrogen, monovalent hydrocarbon radicals which may be substituted. They are prepared by cyclic silanes of the invention wherein R11 is alkoxy or phenoxy with one or more hydroxyl containing silanes or siloxanes.  Many examples are given which include <FORM:0991037/C3/6>