Patent GB-864848-A (GB)
Title: Improvements in or relating to fluorinated organosilicon compounds
IPC: C07F7/18
Filed: 1959-11-04
Abstract: The invention comprises fluoro-organosilanes of the formula:-  (CF3)2 CH CH2 Si H Rn X2-n where R is a monovalent hydrocarbon radical free from aliphatic unsaturation, X is hydrogen or an alkoxy or aryloxy radical, and n is 0, 1 or 2, and also comprises siloxanes derived from these silanes, the siloxanes being homo- or co-polymeric and being p  completely condensed or containing some silanol or alkoxy or aryloxy groups.  The silanes in which n is O and X is hydrogen are prepared by reacting hexafluoroisobutylene, (CF3)2C=CH2, with HSiCl3 in the presence o chloroplatinic acid to produce (CF3)2 CH CH2 SiCL3, followed by reaction with LiAlH4 to replace all the Si-bonded chlorine with hydrogen.  Reaction with one or two equivalents of an alcohol or phenol, preferably again using chloroplatinic acid as catalyst, converts the compounds to those in which one or both of the X radicals are alkoxy or aryloxy.  The catalyst is preferably used in the form of a solution of the hexahydrate in a solvent such as dimethyl carbitol.  Compounds containing one or two R radicals are prepared by reacting a Grignard reagent with the mono- or di-alkoxy compounds.  The siloxanes are prepared in the usual manner, using conventional components for the copolymers, including unsaturated radicals. The siloxanes may be cyclic or linear, and the copolymers may additionally be cross-linked.  The polymers are particularly useful for coating surfaces to render them oil-repellent, especially the polymers of unit formula [(CF3)2 CH CH2] H Si O; their curing may be catalysed by the use of such agents as salts of carboxylic acids, alkanolamine titanates and zirconates, water-soluble zirconium salts and zirconium and titanium esters of aliphatic alcohols.  The disiloxanes containing one R group per silicon atom and the silanes containing two R groups per silicon atom are useful as lubricant films on articles such as ceramics, glass and glass fibres.  The copolymers can be made in liquid, resinous or rubbery form.  All the compounds may be reacted with ethylenically, unsaturated compounds such as vinyl or alkyl silanes or siloxanes, styrene, ethyl acrylates and methyl methacrylate.  Catalysts for these reactions include peroxides, ionizing radiation, platinum on charcoal and chloroplatinic acid.  A number of examples are given.ALSO:Fluorinated organic compounds are prepared in the following sequence of reactions:-  <FORM:0864848/IV (b)/1> <FORM:0864848/IV (b)/2> <FORM:0864848/IV (b)/3> <FORM:0864848/IV (b)/4> <FORM:0864848/IV (b)/5> <FORM:0864848/IV (b)/6> <FORM:0864848/IV (b)/7>ALSO:Glass fibres are provided with oil-repelling, lubricating films by coating with a fluoro-organosilicon compound of the formula:-(CF3)2CH CH2 Si H Rn X2-n or a polysiloxane derived therefrom, where R is a monovalent hydrocarbon radical free from aliphatic unsaturation, X is hydrogen or an alkoxy or aryloxy radical and n is 0, 1 or 2.  The preferred compounds are silanes having two R groups, and disiloxanes of the formula:-[(CF3)2 CH CH2 Si H R]2O.ALSO:Oil-repellent coatings or lubricating films are provided on surfaces by coating with a fluoro-organosilane of the formula (CF3)2 CHCH2SiHRnX2-n, or with a polysiloxane derived therefrom, where R is a monovalent hydrocarbon radical free from aliphatic unsaturation, X is hydrogen or an alkoxy or aryloxy radical and n is 0, 1 or 2. Specified base members are glass, ceramics, metal, wood, leather paper and natural and synthetic textiles.  The compounds can be applied as such or in the form of solutions or aqueous emulsions, by dipping, spraying or brushing. The preferred compounds for providing oil-repellent coatings are polysiloxanes of unit formula [(CF3)2 CHCH2]HSiO.  These may contain curing catalysts and curing may be effected at room temperature or by heating, e.g. up to 150 DEG C.