Patent GB-856374-A (GB)
Title: Thermally stable viscous solutions
IPC: C08K5/02
Filed: 1958-03-06
Abstract: A solution, stated to be homogeneous, thermally stable and viscous, comprises, as the major component, at least one chlorofluorinated or bromo-fluorohalogenated alkane oil, and, dissolved therein, a normally solid polymer (preferably 0,2 to about 30wt. per cent) having a DSV between 0,2 and 3, the DSV being defined in the Specification as the viscosity in centistokes of a 0,75 wt. per cent solution of the polymer in 2:5-dichlorobenzotrifluoride at 266 DEG F. The polymer is preferably a chlorotrifluoroethylene-vinylidene fluoride copolymer containing 10-50, preferably 15-35, mol. per cent of vinylidene fluoride, but also specified are silicone rubber gums and polyisobutene, as well as polymethacrylate, polyvinyl chloride, polystyrene, polydichlorostyrene, vinyl chloride-acetate copolymer, vinyl chlorideacrylonitrile copolymer, chlorated rubbers, ethyl cellulose, cellulose acetate butyrate, cellulose nitrate and polyvinyl butyral.  The chlorofluoriated oil contains 4-22 carbon atoms and has a minimum density at 140 DEG F. of about 1,7 grs./c.c., e.g. a polychlorotrifluoroethylene mixture of molecular weight about 300-1,000, 1:1:3:5:6-pentachlorononafluorohexane and 1:1:3:5:7:8-hexachlorododecafluorooctane; the bromofluorohalogenated oil contains 4-12 carbon atoms and is preferably more than half halogenated, e.g. b -hydroperbromofluorinated as well as -perbromofluorochlorinated oils; thus, 1:2:3:4-tetrabromohexafluorobutane, 1:2-dibromo-4:4-dichlorohexafluorobutane and 1:2:8:9-tetrabromo-4:6-dichlorotetradecafluorononane, as well as p the mixture of oils obtained from bromination of chlorotrifluoroethylene pyrolysis products may be used.  The Specification lists a large number of other suitable halogenated alkanes.  The solution may also contain a carboxylic ester or silicone of 5-50 carbon atoms, particularly di (2-ethylhexyl) phthalate but also, e.g., dioctyl-phthalate,-azelate and succinate, didecylazelate, dihexylsebacate or dibutyl glutarate. Specifications 742,907, 744,256 and U.S.A.  Specification 2,742,510 are referred to.ALSO:Polychlorotrifluoroethylenes of formula :  Y(CF2CFCI)xZ (1) are described, in which x is an integer between 3 and 9 and Y and Z are groups derived from an alkyl telogen completely halogenated with chlorine and/or fluorine, such as CCIF3, C2CI3F3 and C3CI5F3.  In the perchlorofluoroalkanes (2), (3) and (4) CI(CF2-CFCI)m-CF2-CFCI-CF2CI (2) F(CF2)n-CFCI-CF2CI (3) CF2CI-CFCI-(CF2)p-CFCI-CF2CI (4) m is in integer between 1 and 9, n between 2 and 20 and p between 0 and 18; such compounds are obtained by chlorinating perfluoro-olefins giving (3) and (4) or by chlorinating perchlorofluorochlorinated olefins giving (2) Chlorination with molecular chlorine is effected at about 20-150 DEG C. for about 0,5-24 hours.  By the decarboxylation of R-CFCI-CF2-CO2H is obtained R-CF = CF2, wherein R is CI(CF2-CFCI)m-CF2- and m is an integer between 2 and 9 ; this olefin is also prepared by thermal cracking of polychlorotrifluoroethylene in presence of steam at about 100-500 DEG C.  b -hydrochlorofluorinated alkanes are prepared by hydrochlorination at about 50-300 DEG C. of the previously mentioned olefins and of CF2 = CF-(CF2-CFCI)x CI wherein x is on integer between 2 and 9, the latter being also produced by the aforementioned thermal cracking. Bromofluorohalogenated alkanes of the formulae : <FORM:0856374/IV(b)/1> and <FORM:0856374/IV(b)/2> wherein m is an integer between 0 and 3, y is bromine or chlorine, and n is an integer between 0 and 4, are prepared by reacting the corresponding olefins with bromine at about 20-100 DEG C., or with active (e.g. ultra-violet) light and removing the brominated product by distillation or for example by removing excess bromine with chlorotrifluoroethylene, aqueous sodium bisulphite or ethylene, followed by fractionation of the mixture.  The said olefins yielding compounds (6) have the formula :  CF2 = CF(CF2-CFCI)n-CF2-CFCI2 (7) wherein n is an integer from 0 to 4 ; they may be prepared by dechlorinating the corresponding perchlorofluorinated alkanes, or by pyrolysis of chlorotrifluoroethylene polymer, e.g. at about 100-500 DEG C. in presence of steam.  The monoolefin (7) and the diolefin. CF2 = CF-(CF2-CFCI)n-CF2-CF = CF2 (8 wherein n is an integer from 0 to 3 can be obtained from the thermal cracking of a chlorotrifluoroethylene polymer.  By the decarboxylation of R1-CFCI-CF2-CO2H is obtained R1-CF = CF2 (wherein R1 is the same as R, above, except that m is an integer between 1 and 4); the latter on bromination gives compound (5), wherein y is chlorine, or it may be dechlorinated with zinc to give compound (8).  Bromination of (8) gives compound (5) wherein y is bromine.  Other perbromofluorohalogenated compounds may be prepared thus : (a) decarboxylation of F(CF2)n CF2-CF2-CO2H and CO2H-CF2-CF2(CF2)m CF2-CF2-CO2H giving respectively F(CF2)nCF = CF2 and CF2 = CF(CF2)mCF = CF2, wherein n is a integer between 2 and 10 and m is an integer between 0 and 8, which olefins may be brominated ; (b) decarboxylation of CF2CI-CFCI-(CF2-CFCI)m-CF2-CFCI-CF2, CO2H giving CF2CI-CFCI-(CF2-CFCI)m-CF2-CCI = CF2 or CF2 = CF-(CF2-CFCI)mCF2-CCI = CF2 by subsequent dechlorination, wherein m is an integer between 0 and 3, both of which olefins may be brominated ; (c) bromochlorinating the double bonds of any of the above-mentioned olefins with at least a stoichiometric amount of bromine chloride at about 20-100 DEG C. ; (d) hydrobromination of any of the preceding olefins with HBr at about 50-300 DEG C. to give usually, a b -hydro-compound.  The Specification lists a large number of specific chlorofluorinated and bromofluorohalogenated alkanes prepared by the above methods.  Specifications 742,907, 744,256 and U.S.A. Specification 2,742,510 are referred to.ALSO:A lubricant or hydraulic fluid comprises as the major component at least one chlorofluorinated or bromofluorohalogenated alkane oil and, dissolved therein a normally solid polymer having a D.S.V. between 0.2 and 3, the D.S.V. being defined in the Specification as the viscosity in centistokes of a 0.75% wt. solution of the polymer in 2 : 5-dichlorobenzotrifluoride at 266 DEG F.  The polymer is preferably a chlorotrifluoroethylene - vinylidene fluoride copolymer containing 10-50, preferably 15-35% mol of vinylidene fluoride, but also specified are silicone rubber gums and polyisobutene, as well as polymethacrylate, polyvinyl chloride, polystyrene, polydichlorostyrene, vinyl chloride - acetate and vinyl chloride-acrylonitrile copolymers, chlorinated rubbers; ethylcellulose, cellulose nitrate, cellulose acetate/butyrate and polyvinylbutyral.  The Specification list a large number of suitable chlorofluorinated and bromofluorohalogenated alkanes.  An optional ingredient is a carboxylic ester or silicone of 5-50 carbon atoms, e.g. di(2-ethylhexyl)phthalate, dibutyl glutarate, dihexylsebacate, didecylarylate or dioctyl-phthalate, -azelate or -succinate. Specifications 742,907, 744,256 and U.S.A.  Specification 2,742,510 are referred to.