GB865858A - Fluorinated compounds and process for making such compounds - Google Patents

Abstract

Perfluoropropyl-methyl iodide is telomerized with acrylic acid by heating in a sealed autoclave for 20 hours at 140 DEG C. in the presence of di-t butyl peroxide to give a telomer of the formula C3 F7.CH2(CH2 CH.COOH)60 I. Perfluoropropyl-methyl iodide is similarly reacted with vinyl methyl dichlorosilane to give a 1 : 1 adduct of the formula C3 F7. CH2(CH2 CH.Si CH3 Cl2) I and a 1 : 3 adduct of the formula C3F7.CH2(CH2CH.SiCH3Cl2)3\t I. Other olefinic silanes such as vinyl methyl diethoxy-, vinyl triethoxy-, vinyl trichloro-, 4-cyclo-hexenyl-trichloro-and 4-cyclohexenyl-methyl dichloro-silane may be similarly reacted with perfluoro-propyl-methyl iodide or other polyfluoroalkyl-iodides.ALSO:The invention comprises compounds of the formula: <FORM:0865858/IV (b)/1> wherein the remaining valencies of the ethylenic carbon atoms of the olefin monomer unit are satisfied by a combination of monovalent radicals, the algebraic sum of the Hammett sigma (para) parameter values of which is not greater than +0,2, Y is a hydrogen or fluorine atom and m and n are integers whose ratio m : n is not less than 1 : 20. The invention comprises also a process for the preparation of addition products which comprises reacting in the presence of an active source of free radicals a polyfluoroalkyl methyl iodide Y (CF2)mCH2I with an ethylenically unsaturated aliphatic compound having at least one hydrogen atom attached to a carbon atom of the ethylenic linkage, the remaining valencies of the ethylenic carbon atoms being satisfied by a combination of monovalent radicals the algebraic sum of the Hammett sigma (para) parameter of which is not greater than +0,2. The concept of the Hammett sigma parameter is explained in Chemical Reviews 53 (1953) pps. 191-261 and numerical values are given there for a large number of substituents. The reaction may be carried out in the presence of u.v. light, benzoyl peroxide, di-tertiary butyl peroxide or a , a -azo-di-isobutyronitrile and the olefin is preferably added to the iodide at a sufficiently slow rate so that the iodide is always present in molecular excess in the reaction mixture and adducts containing no more than three olefin monomer units are obtained. When highly reactive olefins such as acrylic acid are used, polymerisation of the olefin may first occur and a telogen adduct containing for example 60 olefin monomer units may be obtained. A list of suitable olefins is given which includes ethylene and its homologues, allyl halides, unsaturated acids, esters, ethers, thioethers and amides, cyclic olefins and olefinic silanes. Vinylidene chloride, maleic anhydride and methacrylonitrile are said to be inoperatable for the process. In examples iodides and olefines are heated in sealed pressure vessels, e.g. 16-20 hours at 145 DEG C. to give the following adducts: (1) C3F7,CH2 (CH2CH.C6H13).I, (2) C3F7.CH2 (CH2CH.COOH) 60I, (3) C3F7CH2(CH2CH.(CH2)8COOH)I, (4) C3F7CH2 (CH2CH.CH2NHCOCH3)3I, (5) C3F7CH2(CH.SICH3Cl2)I and some 1 : 3 adduct, and irriadiated at room temperature in an open vessel to give (6) H(CF2)4CH2(CH2CH,C6H13)I and (7) C3F7CH2(CH2CH,C6H13)I. The compounds of the invention may be coated on to a substrate to form a surface which is both water and oil repellent.ALSO:A monolayer film of H(CF2)8CH2.CH2CHI (CH2)8COOH is deposited on platinum from hexane solution to provide a surface which is repellent to water and various organic liquids.