GB689400A - Aqueous colloidal dispersions of polymers - Google Patents

Abstract

Colloidal dispersions of polymeric ethylenically unsaturated organic compounds are prepared by polymerizing in an aqueous p medium which contains a water-soluble initiator, as dispersing agent, a fluoralkyl compound of general formula B(CF2)n(CH2)mA, where B is hydrogen or fluorine, n is at least 5, m is 0 or 1, m+n is at least 6 and A is an ionic hydrophilic group, and, optionally, a saturated hydrocarbon having more than 16 carbon atoms as stabilizer. Suitable monomers are those of general formula <FORM:0689400/IV (a)/1> where A and B are hydrogen or halogen, D and E are hydrogen, halogen, alkyl, alkenyl, cycloalkenyl, aryl, aralkyl, aralkenyl, haloalkenyl, cyano, carboxy, carbalkoxy, acyloxy, aldehyde, ketone, amido, imido and ether groups, e.g. vinyl chloride, fluoride, bromide, and iodide, 1,1-difluoro- or dichloroethylene, tetrafluoroethylene, chlorotrifluoroethylene, 1,1-dichloro - 2,2 - difluoroethylene; ethylene, propylene, isobutylene, vinylcyclohexene, vinyl naphthalene, propenylbenzene; 1,3-butadiene, chloroprene, 1-phenyl and 2-phenyl-1,3-butadienes, 2-fluoro-1,3-butadiene, 2-3-dichloro-1,3-butadiene, 2-iodo-1,3-butadiene, 2-phenoxy-1,3-butadiene; acrylic, methacrylic, and a -chloroacrylic acids, ethyl acrylate, methyl, butyl, methoxymethyl, chlorethyl, and b -diethylaminoethyl methacrylates, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide; vinyl formate, acetate, chloroacetate, butyrate, and laurate; acrolein, methacrolein; methyl vinyl ketone, N-vinylphthalimide and succinimide; vinyl ethyl and vinyl isobutyl ethers, vinylpyridine, N-vinylcaprolactam, N-vinylbutyrolactam; and dimethyl and diethyl fumarates and maleates and allyl glycidyl ether, which form copolymers, may also be present. The dispersing agents may be alkali metal, ammonium or amine salts of polyfluoroalkanoic acids, B(CF2)nCOOH, where n is 6 to 20 and B is hydrogen or fluorine; phosphoric acid esters, B(CF2)nCH2OPO(OM)2, or diesters (B(CF2)nCH2O)2PO(OM), where n is 5 to 10 and M is hydrogen, alkali-metal, ammonium or amine; sulphuric acid esters B(CF2)nCH2OSO3M; polyfluoroalkylphosphoric acids or their salts, H(CF2)nPO(OM)2, where n is an even integer from 6 to 12; and polyfluoroalkyl amine salts, <FORM:0689400/IV (a)/2> where n is 5 to 12 and R is hydrogen or an alkyl group of 1 to 4 carbon atoms. The polymerization, which may be effected under increased temperature and pressure, may be initiated by ammonium or alkali-metal persulphates, perborates and percarbonates, hydrogen peroxide, di-succinic acid peroxide, azo compounds, e.g. disodium g -g 1-azobis (g -cyanovalerate) or a -a 1-azobis (diisobutyramidine) hydrochloride, or ultra-violet light may be used in the presence of uranyl nitrate and benzoin. Promotors such as sodium sulphite, bisulphite, thiosulphate and hydrosulphite, ferrous sulphate and ferrous ammonium sulphate; buffers, e.g. borax, disodium hydrogen phosphate, ammonium carbonate, sodium acetate and silver nitrate; fillers, e.g. alumina, titanium dioxide and silica; and stabilizers such as an eicosane, tetracosane, tetracontane, hexacontane, white mineral oil and paraffin waxes may be included. Polytetrafluorethylene dispersions may be extruded and coagulated to form filaments which are sintered and cold drawn; cast to form unsupported films or coatings for wood, metal, wire-screens, ceramics or textiles; coated on to wires; or used to impregnate cotton, wool, silk, glass fibres, asbestos and paper by coagulating and drying in situ. Specifications 572,265, 574,688, 583,874, 626,155 and 631,570 are referred to.ALSO:Salts of polyfluoroalkanoic acids of general formula B(CF2)nCOOH, where B is H or F, and n is 6 to 20, prepared by the permanganate oxidation of polyfluoralkanols obtained by heating methanol and tetrafluorethylene in the presence of a free radicle producing catalyst, are used as dispersing agents in the polymerization of aqueous dispersions of ethylenically unsaturated compounds. Examples are (1) the sodium, potassium, lithium, ammonium, alkylamine or tetraethyl ammonium hydroxide salts of dodecafluoroheptanoic, pentadecafluoro-octanoic, hexa- or heptadecafluorononanoic, eicosafluoroundecanoic, and tetracosafluorotridecanoic acids; (2) mono- or di-fluoroalkyl phosphates B(CF2)nCH2OPO(OM)2, where n is 5-10 and M is hydrogen, alkali metal, ammonium, saturated alkylamine or quaternary ammonium group, prepared by treating polyfluoroalkanol with phosphorus pentoxide or oxychloride, e.g. ammonium dodecafluoroheptyl or hexadecafluorononyl phosphates, dodecafluoroheptyl or hexadecafluorononyl dihydrogen phosphate; sodium heptadecafluorononyl and potassium nonadecafluorodecyl phosphates, ammonium di (tetrafluoropropyl) phosphate, ammonium di (heptafluorobutyl, phosphate, and sodium di-(octafluoroamyl) phosphate; (3) polyfluoroalkyl sulphates B(CF2)nCH2OSO3M, prepared by treating polyfluoroalkanols with chlorosulphonic acid or concentrated sulphuric acid and sulphuric anhydride, e.g. ammonium hexadecafluorononyl, potassium dodecafluoroheptyl, sodium heptadecafluorononyl and ammonium nonadecafluorodecyl sulphates; (4) polyfluoroalkylphosphonic acids and their salts prepared by reacting tetrafluoroethylene with dialkyl phosphite in the presence of a catalyst, and hydrolysing the reaction product by concentrated sulphuric or hydrochloric acid, e.g. dodecafluorohexylphosphonic acid, ammonium hexadecafluoro-octyl phosphonate, and sodium eicosafluorodecylphosphonic acid; (5) polyfluoroalkylamine salts, <FORM:0689400/IV (b)/1> where n is 5 to 12 and R is hydrogen or a lower alkyl group. The primary amines may be prepared by the reduction of the amides, which are prepared from acid chlorides with lithium aluminium hydride in absolute ether, and in cases where the amino group is tertiary, by the reaction of tetrafluoroethylene with a tertiary amine in the presence of a free radical producing catalyst, e.g. dodecafluoroheptylamine hydrochloride, hexadecafluorononylamine sulphate, pentadecafluoro-octylamine phosphate, N,N-dimethyl hexadecafluorononylamine hydrochloride. Specifications 572,265, 574,688, 583,874, 626,155 and 631,570, [both in Group IV (a)], are referred to.