DE1022225B - Process for the preparation of substituted silanes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN / Mmm < PATENT OFFICE

kl. 12 ο 26/03

INTERNAT. KL. C 07 f

EXPLORATION PAPER 1022 225

D 16329 IVb / 12 ο REGISTRATION DATE: NOVEMBER 11, 1953

ANNOUNCEMENT DEK REGISTRATION AND ISSUE OF THE EDITING LETTER:

JANUARY 9, 1958

The good heat resistance of organosiloxanes in which the organic groups represent methyl and / or phenyl radicals is known. It is also known that fluorocarbon compounds in which all or some of the hydrogen is replaced by fluorine are extremely stable. It has therefore been considered useful to combine fluorocarbon compounds with silicon in order to obtain fluorocarbon-substituted silanes and siloxanes. The previous production of such compounds was limited to the production of substances in which the fluorine was bonded to the alkyl group of a phenyl ring, such as. B. F ₃ CC ₆ H ₄ SiCl ₃ and other compounds of this type, or on those substances in which the fluorine was bonded to carbon atoms which were 2 to 4 atoms away from the silicon. However, such compounds do not have the high heat resistance that is often desired.

It has already been proposed to use silicon compounds which have hydrogen bonded to the silicon atom To implement tetrafluoroethylene at temperatures above 150 ° and under increased pressure. You get a Addition of the Si-H group to the ethylene bond. That is why one comes to unsaturated compounds this reaction only if one starts from acetylene compounds. Perhalogenated in the organic residue Organosilicon compounds are not accessible by this process.

It has now been found that when silanes are reacted, the hydrogen is bonded to the silicon atom wear, with unsaturated aliphatic organofluorine compounds at a temperature of 400 to 600 ° and a substitution reaction takes place at normal pressure with elimination of hydrogen halide. This is how you get there to silanes which have perhalogenated, fluorine-containing, unsaturated organic radicals.

According to the invention, chlorotrifluoroethylene, tetrafluoroethylene, perfluoropropylene, perfluorobutadiene, perfluorobutylene, Dichlorodifluoroethylene, dichlorohexafluorocyclopentene or dichloroctafluorocyclohexene or mixtures of these fluorocarbons with a silane or a mixture of silanes of the formula

R xsiy Si Ql ^ -xy Process for the preparation of substituted silanes

Applicant:

Dow Corning Corporation, Midland, Mich. (V. St. A.)

Representative: L. F. Drissl, lawyer, Munich 23, Clemensstr. 26th

Claimed priority: V. St. v. America dated November 17, 1952 and August 14, 1953

Loren Andrew Haluska, Midland, Mich. (V. St. A.), has been named as the inventor

The silanes thus obtained have the general formula

R »R m Si Cl ₁ -Ji- (B,

where R is a trifluorovinyl (CF ₃ = CF-), chlorodifluorovinyl (C F Cl = CF -), chlorohexafluorocyclopentenyl-

F ₂
C.

F ₂ C

F ₉ C-

C -

Ii

-CCl

or a chlorooctafluorocyclohexenyl radical

F ₉ C

F ₂ C CCl

where R 'is a monovalent hydrocarbon radical , χ a \ '

Value of 0, 1, 2 or 3 and y a value of 1 or 2 ς,

has implemented. ρ

According to a further embodiment of the erfmdungs- ²

According to the process, the resulting reaction is 50, R 'represents a monovalent hydrocarbon radical, product reacted further with a Grignard reagent η - 1 or 2, m - 0, 1, 2 or 3 and (m + n) no longer

as 4 mean.

The silanes obtained according to the invention contain either one or two of the fluorine-containing compounds described

70 »848/342

p gg g

be to any amount of the chlorine atoms attached to the silicon by a corresponding organic To replace the rest.

3 4

Residues on silicon. If there are two such radicals, compounds and fluorinated by decarboxylation

so these can be the same or different. It can be carboxylic acids. Perfluorobutylene (CF ₃ CF ₂ CF

therefore according to the invention z. B. both silanes of the type = CF ₂ ) by heating the sodium salt CF ₂ CF ₂ CF ₂

of bis-trifluorovinyldichlorosilane as well as of the type of CF ₂ COONa at 225 to 375 °, wherein

Trifluorovinyloctafluorobutyldichlorosilane can be obtained. 5 sodium fluoride and CO _{2 are} split off.

Silanes which only contain fluorine-containing radicals on the silicon. The silanes obtained according to the invention are not used most expediently made by making the change in the fluorocarbon radical hydrolyzable and corresponding unsaturated fluorocarbon compounds produce valuable siloxanes of the structural dung with water (e.g. chlorotrifluoroethylene, octafluorobutylene, etc.) unit

with trichlorosilane or dichlorosilane or mixtures io R _n R ', SiO ₄ _, " ₊ .,,

converts these substances. Should only a fluorocarbon "- T" ~~~ ' group are brought to the silicon, so one leaves

Trichlorosilane with the unsaturated fluorocarbon in which R, R 'and η have the above meaning and ζ

connection respond. If, on the other hand, two fluorocarbons should have a value of 0 to 2. This is surprising because

substance groups are bonded to the silicon, it is known that a silicon-bonded trifluorine

one applies dichlorosilane. Should two different methyl radicals (CF ₃ ) not be resistant to hydrolysis,

If fluorine-containing residues come into contact with the silicon, one sets.

a mixture of two different unsaturated examples

Fluorocarbon compounds with dichlorosilane. An equimolar mixture of symm. Dichlorodifluorine

The compounds of the invention can besides the 20 ethylene and methyldichlorosilane with a gen

The above-mentioned fluorinated residues can be extracted into a tube at any speed of 0.68 ecm per minute

contain valuable hydrocarbon residues. Such silanes stainless steel, which is heated to a temperature of 450 to

are obtained when starting materials of the formula 500 ° was heated, given. The rate of addition

was dimensioned so that the contact time of the vapors was

K! ^ M ^ j BIU, _{25 which is e} g i3 _enes temperature was 67.5 seconds,

be used in which χ has a value of at least The escaping vapors have been condensed and

1 has. Silanes of this type can be further obtained by distilling, with / 3-chlorodifluorovinylmethyldichlorosilane

be that one HSiCl ₃ or H ₂ SiCl ₃ as starting materials (ClFC = CF) -CH ₃ SiCl ₂ with a boiling point of 121 °

and the fluorinated reaction products were obtained at 740.8 mm.

a Grignard reagent of the general formula 30_. ,,

Example 2

Mg - ^ - A mixture of 1.1 moles symm. Difluorodichloro

are reacted, where R "is any organic, ethylene to the Grignard and 1.1 mole of trichlorosilane was in a time more capable formation radical and X is chlorine or bromine loading space of 1 ¹ J ₂ hours indicated in a heated tube at 450 °. Given by adjusting the ratio of chlorine to stainless steel, the contact time of the steam silane to the Grignard reagent can be one to three mixtures in the tube was 41.5 seconds, the divalent hydrocarbon residues attached to the silicon, softening vapors were condensed and distilled By using a mixture of two or more wherein / 3-chlorodifluorovinyltrichlorosilane (ClFC = CFSiCl ₃ ) Grignard reagents, two or more different residues with a boiling point of 116 to 117 ° at 746.5 mm can be bonded to the silicon Way 40 was obtained, for example, trifluorovinyltrichlorosilane by reacting Example 3

with phenyl and methyl Grignard reagents in tri

fluorovinylphenyhnethylchlorosilane. A mixture of 1 mole l ^ -Dichloro-S.S ^^ - S.S-hexa-

The Grignard process is then expediently anfluorocyclopent-1-ene and 1.5 moles of methyldichlorosilane if unsaturated aliphatic radicals are introduced 45 in a period of 6 hours in a to 470 to 500 ° should be. given heated stainless steel tube. Contact in the formula starting silanes with the vapors in the tube was 86 seconds. the

_, _w ".". escaping vapors were condensed and distilled

R sHj / biCW ,,, _{Hertj where} 2-chloro-3,3-4,4-5,5-hexafluorcyclopent-l-enyl-

üi the χ has a value of 1, 2 or 3, R 'can be a 50 methyldichlorosilane with a boiling point of 153.5 ° with any monovalent hydrocarbon radical. At 737.7 mm was obtained, those silanes are best in which R 'is an ali- _.

phatic hydrocarbon or an aryl hydrocarbon example 4

Substance remainder is, such as R'HSiCl ₂ , R ' ₂ HSiCl, R' ₃ SiH, a mixture of 3.54 moles of methyldichlorosilane and

R'H ₂ SiCl, R'HgSi and R ' ₂ SiH ₂ . Suitable silanes 55 3.3 mol of chlorotrifluoroethylene were mentioned for a period of time: ethyldichlorosilane, ethylpropylchlorosilane, placed in a quartz tube heated to 438 to 448 ° trimethylsilane, phenylmonochlorosilane, vinyl monochloro for 8 hours and 27 minutes. The contact time of the silane, dicyclohexylsilane, tolyldichlorosilane, benzyl mono-vapors at the specified temperature was 34 seconds of six-chlorosilane, xenyldichlorosilane and cyclohexenyldichloro-. The escaping vapors were condensed silane. 60 and distilled, with trifluorovinylmethyldichlorosilane

The reaction between the fluorocarbons and the [(F ₂ C = CF) CH ₃ SiCl ₂ ] with a boiling point of 88 to silanes proceeds easily and smoothly in the absence of 90 ° at 774 mm. Catalysts. If necessary, however, catalysis. .

are used. Suitable substances here- example

for are boron trifluoride and boron trichloride. 65 A mixture of 3.27 moles of chlorotrifluoroethylene and

The fluorocarbon 5.11 mol of trichlorosilane used for the reaction was for 3 hours and compounds are commercially available, known substances. 44 minutes in a quartz tube heated to 462 to 508 ° can be given obtained by a variety of procedures. The contact time of the vapors when z. B. by exchange reaction between antigen temperature was 35 seconds. The Entmonpentafluorid and the corresponding chlorinated vapors were condensed and distilled,

being trifluorovinyltrichlorosilane with a boiling point from 74 to 76 ° at 746.3 mm.

Example 6

An equimolar mixture of 1,2-dichloro-3,3-4,4-5,5-6,6-octafluorocyclohex-1-ene was obtained and phenyldichlorosilane reacted according to the procedure of Example 1, wherein 2-chloro-3,3-4,4-5,5-6,6-octafluorcyclohex-1-enylphenyldichlorosilane was obtained.

Claims (1)

PATENT CLAIM: Process for the preparation of silanes containing aliphatic unsaturated fluorocarbon radicals, characterized in that one a) chlorotrifluoroethylene, tetrafluoroethylene, perfluoropropylene, Perfluorobutadiene, perfluorobutylene, dichlorodifluoroethylene, Dichlorohexafluorocyclopentene or Dichloroctafluorcyclohexene or mixtures of these fluorocarbon compounds with b) a silane or a mixture of silanes of the formula R x -x-y, wherein R 'is a monovalent hydrocarbon radical, χ has a value of 0, 1, 2 or 3 and y has a value of 1 or 2, reacts at a temperature of 400 to 600 ° and at normal pressure and c) if appropriate, the reaction product with a Grignard reagent of the formula R "Mg X, in which R "is a hydrocarbon radical and X is chlorine or bromine. Considered publications:
French Patent No. 961 878. © 709 848/342 12.