FLUOROSILICON COMPOUNDS AND PREPARATION METHOD

Abstract: A fluorinated organosilicon compound is represented by formula (I).

Description: TITLE OF THE INVENTION: FLUOROSILICON COMPOUNDS AND PREPARATION METHOD BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to fluorosilicon compounds and to a preparation method. 2. DESCRIPTION OF THE PRIOR ART The majority of known fluorinated organosilicon compounds have structures in which a fluorine-containing groups such as perfluoroalkyl is bonded to a silicon atom through a dimethylene or trimethylene group. Synthesis of these compounds usually requires many stages, including a Grignard reaction and a reaction involving a precious metal catalyst, such as platinum (cf. USP 5,202,453; EP 0,538,061 A2) . Reactions for making fluorinated organosilicon compounds by way of a cyclization process between olefine derivatives of silicone and fluorine have also been described (cf. USP 2,596,967; UKP 760,201 and 802,358; Holbrook G.W.J. Am.Chem.Soc 82 825 (1960); Park J.D. J.Org.Chem. , 25, 1628 (1960). However, this reaction has been largely ignored over the past ten years. SUMMARY OF THE INVENTION According to the first aspect of the invention there is provided a fluorinated organosilicon compound represented by the formula:- -Si- CH / \ CH, CF . R F \ / CF 2 Preferably the compound is represented by the following formula: - R : R 2 R 3 SiO ( R SiO ) a SiR^R 3 I CHCH 2 CF 2 CF(OCF 2 CF 2 ) b (R 5 ) c R 6 (1) wherein R X ,R 2 ,R 3 and R 4 are independently selected from alkyl groups having 1 - 4 carbon atoms or independently selected from the above alkyl groups,the CF 3 CH 2 CH 2 - group, and the R 6 (R 5 ) c (CF 2 CF 2 0) b CFCF 2 CH 2 CH .group, where R 6 ,R 5 ,a,b and c are as hereinafter defined. R 5 is a bivalent group such as -0CF 2 -, -OCF 2 CF 2 - or -OCFCF(CF 3 )-. R 6 is a -OCF3- group or -F atom, a is an integer from 0 to 6, b is zero or 1, c is an integer between 2 and 6. Fluorinated organosilicon compounds in accordance with the invention have a wide operating temperature range and excellent chemical resistance; they are oil- and water- repellent and have outstanding dielectric properties. In addition, due to the phenomenon of "super-flexibility", the viscosity of these materials is much lower than their molecular weight would suggest. All these properties, together with their density, which can be arranged to be in the range 1.3 - 1.7 g/ml make these liquids very suitable for use as base liquids in Electro-Rheological (ER) Fluids as well as more general applications. The invention includes a cyclo butane ring of formula:- - CH-CH, I I - CF-CF, A preferrred formula being: Si-O I CH-CH 2 RF - CF-CF 2 According to a second aspect of the invention, there is provided a method of manufacturing a compound in accordance with the first aspect by reacting a vinyl siloxane of general formula:- R i R 2 R 3 SiO ( R 4 SiO ) a SiR x R 2 R 3 CH=CH 2 wherein R : ,R 2 ,R 3 ,and R 4 have the meanings defined above, with a perfluoro-olefin of the general formula:- CF 2 =CF(OCF 2 CF 2 ) b (R 5 ) C R 6 wherein R 5 , R 6 , b and c are as previously defined above, in the present of a free radical inhibitor. The compounds are produced by a reaction between vinyl siloxane and perfluoro-olefin in the presence of a free radical inhibitor at elevated temperature and pressure. Preferably, in the cyclization reaction of the vinylsiloxane and the perfluoro-olefin, the ratio of reactants is in the range 1-2 moles of perfluoro-olefin for each mole of vinyl siloxane, preferably between 1.1 and 1.6. The reaction temperature may be in the range 150-250°C and preferably between 180 and 230°C. The reaction time may be 5-100 hours, and typically between 10 and 70 hours. The reaction is preferably carried out at elevated pressure in an autoclave. Typical examples of fluorinated organosilicon compounds prepared by this method include:- CH 3 I (CH 3 ) 3 Si.O.Si.O.Si(CH 3 ) 3 I CH-CH 2 CF-CF 2 O.CF 2 .CF 2 .(OCF 2 ) 4 .OCF 3 (CH 3 ) 3 SiO[Si(CH3)0] 2 Si(CH 3 )3 CH.CH 2 .CF 2 .CF(OCF 2 ) 4 .F CF 3 .CH,.CH 2 .(CH 3 ) 2 .Si.O.Si. (CH 3 ).O.Si. (CH 3 ) 2 .CH,CH,CF CH.CH,.CF 2 .CF[OCF 2 .CF(CF 3 ) ] 3 F

Claims: CLAIMS 1. A fluorinated organosilicon compound represented by the formula -Si- CH / \ CH, CF . R F CF, 2.A compound including a cyclo butane ring of formula:- -CH-CH 2 I I -CF-CF 2 3 . compound as claimed in Claim 2 of formula : - -Si-O- CH-CH, R F - CF-CF 2 4. A compound as claimed in any preceding claim having the formula : - R : R 2 R 3 SiO ( R 4 SiO ) a SiR : R R 3 CHCH 2 CF 2 CF ( OCF 2 CF 2 ) b ( R° ) c R c ( 1 ) I I wherein R 1 ,R 2 ,R 3 and R 4 are independently selected from alkyl groups having 1 - 4 carbon atoms or independently selected from the above alkyl groups,the CF 3 CH 2 CH 2 - group, and the R 6 (R 5 ) c (CF 2 CF 2 0) b CFCF 2 CH 2 CH . group, where R 6 ,R 5 ,a,b and c are as hereinafter defined. R° is a bivalent group such as -OCF ; -, - OCF 2 CF 2 - or -OCF 2 CF(CF 3 )-. R 6 is a -OCF 3 - group or -F atom, a is an integer from 0 to 6, b is zero or 1, c is an integer between 2 and 6. 5. A compound as claimed in any preceding claim having the formula:- CH 3 I (CH 3 ) 3 Si.O.Si.O.Si(CH 3 ) 3 CH-CH 2 I I CF.CF 2 O.CF,.CF 2 .(OCF 2 ) 4 .OCF 3 (CH 3 )OSiOSi(CH 3 )OSi(CH 3 ) : 6. A compound as claimed in any preceding claim having the formula:- (CH 3 ) 3 SiO[Si(CH 3 )0] 2 Si(CH 3 ) 3 CH.CH,.CF 2 .CF(OCF,) 4 .F 7. A compound as claimed in any preceding claim having the formula :- CF 3 CH 2 CH 2 ( CH 3 ) 2 SiOSi ( CH 3 ) 2 CH 2 CH,CF 3 CHCH 2 CF 2 CF [ OCF 2 CF ( CF 3 ) 1 3 I I 8. A method of manufacturing a compound as defined above by reacting a vinyl siloxane of general formula :- R 1 R 2 R 3 SiO ( R 4 SiO ) a SiR^R 3 CH=CH wherein R 1 ,R 2 ,R 3 ,and R 4 are independently selected from alkyl groups having 1-4 carbon atoms or independently selected from the above alkyl groups, the vinyl group -CH=CH 2 , and the -CH 2 CH 2 CF 3 group, and a is an integer from 0 to 6, with a perfluoro-olefin of the general formula :- CF 2 =CF ( OCF 2 CF 2 ) b ( R ) c R ό ι; 7 wherein R 5 , R 6 , b and c are as previously defined above, in the present of a free radical inhibitor. 9. A method as claimed in Claim 8 wherein, the ratio of reactants is in the range 1-2 moles of perfluoro-olefin for each mole of vinyl siloxane, preferably between 1.1 and 1.6. 10. A method as claimed in any one of Claims 8 or 9 wherein the reaction is carried out at a temperature range 150-250°C and preferably between 180 and 230°C. 11. A method as claimed in any one of Claims 8 to 10 wherein the reaction is carried out over a time period of 5-100 hours, and preferably between 10 and 70 hours. 12. A method as claimed in any one of Claim 8 to 11, wherein the reaction is carried out at elevated pressure in an autoclave.

Inventors: MILESHKEVICH VLADIMIR, MILESHKEVICH, VLADIMIR
Applicants: FSO LIMITED, MILESHKEVICH VLADIMIR, MILESHKEVICH, VLADIMIR
Application year: 1996
Main classification: C07F7
IPC codes: C07F7, C08G77, C10M105, C10M171, C10N40