GB684597A - Improvements in or relating to the preparation of organo silicon derivatives from unsaturated compounds - Google Patents

Abstract

Silicon-containing polymers are obtained by heating an organo-silicon vinyl monomer (see Group IV (b)), particularly under super-atmospheric pressures and in the presence or absence of catalysts. Silicones are obtained by the hydrolysis of hydrolysable organo-silicon compounds (see Group IV (b)), e.g. organo-silicon halides are hydrolysed by treatment with water. In particular halogen containing vinyl silicon compounds such as the olefinyl silicon chlorides may be hydrolysed with water to produce silicones and silicols which may be cured by heat treatment. The halogen containing vinyl silicon compounds which are hydrolysable may be of the general formula R1xR2yM4-x-y-z Si(CR4=CHR5)z, wherein R1, R2, R4 and R5 represent hydrogen or hydrocarbon radicals or substituted amino or oxy radicals, M represents a halogen of atomic weight less than 90, the sum of x + y is from 0 to 2, z is from 3 to 1 and x + y + z is not greater than 3. The hydrolysis may be carried out in an ether solution by pouring on to ice or an ice water mixture. A ketone solvent may be used in the hydrolysis, e.g. methylethyl-, dimethyl-, methylpropyl- or methylisopropyl ketone. The hydrolysed products may be dissolved in aliphatic or aromatic hydrocarbon solvents, e.g. hexane, benzene, or toluene, ether solvents, e.g. dimethyl, diethyl, diisopropyl or dibutyl ether, or cyclic ethers such as dioxan, or diethers such as diethyl ether of ethylene glycol, or mixed ethers, ester solvents, e.g. ethyl, butyl or amyl acetates, propionates or butyrates. Any of the above solvents may be added prior to the hydrolysis step. Fillers which may be added to liquid polymers may be inorganic or organic fillers, e.g. mica, clays, asbestos, and cellulose products and fibres such as wood, wood fibres and paper. Other components which may be blended with the polymers include natural resins such as rosins, copal or shellac, and synthetic resins such as the urea aldehyde resins, e.g. urea formaldehyde, phenol aldehyde, melamine aldehyde and acetone formaldehyde resins, alkyd, cumaronindene, vinyl allyl dibasic acid, acrylate and methacrylate resins, and various cellulose derivatives including the ethers and esters such as nitrocellulose and cellulose acetate. In the examples: (1) trichlorosilane and allyl chloride are heated in a bomb, unreacted trichlorosilane is removed by distillation, and the residue is diluted with ether and poured on to ice, and the ether layer yields a hard film when the ether evaporates; (2) pentine-1 and trichlorosilane are heated in a bomb and a portion of the product is treated as in (1) while the remainder is fractionated to leave a residue of alkyl silicon chloride polymers; (3) hexine-1 and trichlorosilane are reacted as in (2).ALSO:Organo-silicon compounds are prepared by heating a silicon compound having at least one hydrogen atom directly attached to silicon with an organic compound containing an acetylenic linkage or with a halogenated hydrocarbon containing an ethylenic linkage. Mixtures of one or both reactants may also be used, e.g. a mixture containing silane and/or one or more chlorosilanes such as mono-, di-, tri- and tetrachlorosilane. The preferred reaction temperature is from 50 DEG to 450 DEG C., and the reaction may be effected in a closed vessel or in the presence of ultra-violet irradiation. The reaction may be carried out in at least two separate stages and either or both reactants may be introduced at each stage, particularly where the reaction is not completed at the first stage, and the temperature and/or pressure conditions can be varied at each stage. The silicon compound reactant may contain halogen directly attached to the silicon atom. The reaction product can be fractionated to recover a liquid organo-silicon compound. When an acetylenic reactant is employed, the reaction may be effected in the presence of an organic peroxide, e.g. acetyl or benzoyl peroxide, peracetic or perbenzoic acid. Inert gases, e.g. nitrogen or ethane, or inert liquids volatile at the reaction temperature, e.g. cyclohexane or pentane, may be introduced into the reaction chamber to increase the pressure. The reaction may also be carried out using an ethylenic or acetylenic reactant in the presence of a salt or compound of an element of Group IB, IIB, IIIA or IVA of the Periodic Table. When a halosilicon compound is employed in the reaction, the product may be hydrolysed with water. By employing reaction temperatures and pressures favourable for the decomposition of the products, it is possible to isolate derivatives having a substituent organic group of lower carbon content than the unsaturated reactant. The silicon compound reactant may be a mono- or poly-silicon compound and may be an inorganic compound containing, for example, halogen-particularly fluorine, chlorine or bromine, and the polysilicon compounds disilane and disiloxane. The silanes, halogen substituted silanes, disilanes and disiloxanes may also contain substituent organic groups, or organo substituted silanes containing no inorganic substituents may be employed. In any of these compounds the organic group present may be one or more aliphatic, carbocyclic, alicyclic or heterocyclic groups. Thus alkyl and aryl substituted silanes the alkyl or aryl groups of which may or may not also include halogens such as fluorine, chlorine or bromine may be used, e.g. butyldichlorosilanes, diethylchlorosilane, trimethylsilane or tributylsilanes may be used. The silicon compound reactant may contain oxygen or halogen and oxygen, and the thio derivatives of these compounds may also be used, e.g. alkoxy-, thio-alkoxy-aryloxy- and thio-aryloxy-silanes such as triethoxysilane and trithiophenoxysilane may be used. The oxygen containing silicon compounds may be an acyloxysilane, particularly those derived from the fatty acids, e.g. triacetoxysilane and diacetoxysilane. The silicon compound reactant may contain nitrogen which may be present in a silicon-nitrogen link, e.g. in an amino, imino, substituted amino or substituted imino group linked to silicon or a silazane such as N-diethylamino-dimethylsilane and sym.-diethyldisilazane, and such compounds may be substituted further by halogen and oxygen containing groups. The organic compound reactant may be an acetylene, a halogen-substituted acetylene, or a halogen-substituted olefin or diolefin, particularly where the substituting halogen is fluorine, chlorine or bromine. Alkyl or other aliphatic groups, aryl or other carbocyclic groups, unsaturated alicyclic groups such as the cyclo-olefins and other types of substituent groups, for example, nitrile or nitro groups, may be present in the organic compound. The halogen substituted olefin may be, for example, a halogen-substituted styrene, allyl chloride, vinyl chloride, vinylidine chloride or tetra - fluoroethylene. Acetylenic compounds that may be used for the process include acetylene, vinyl acetylene, pentine-1, hexine-1, ethylpropyl acetylene and phenyl acetylene, and other substituted acetylenes, wherein the substituent groups may be aliphatic, olefinyl, alkylene, carbocyclic or oxy groups. When using an acetylene compound for the reaction, the initial addition product which is formed and may be isolated may be of the general formula R1xR2yR34-y-xSi(CR4= CHR5)z, wherein R1, R2 and R3 may be halogen of atomic weight less than 90, hydrogen or a hydrocarbon radical, e.g. aliphatic radicals including alkyl and olefinyl radicals, carbocyclic radicals including aryl, alkaryl and aralkyl radicals, or a cycloaliphatic radical, e.g. the cyclohexyl radical, or a substituted oxy group such as OR or a substituted amino group, e.g. NHR or NH2, wherein R may represent any of the radicals just mentioned above, or an acyl radical, R4 and R5 may represent hydrogen or a hydrocarbon radical, or a substituted amino group or substituted oxy group of the type just mentioned above, the sum of x and y is from 0 to 3, z is from 4 to 1 and the sum of x, y and z must not exceed 4. Thus compounds can be produced wherein R1 is chlorine and x is 3 and R5 is a hydrocarbon radical, wherein R1 is chlorine and x and z are 2 and at least one R5 is a hydrocarbon radical, and wherein R1 is ethyl, x is 3, z is 1 and R5 is a hydrocarbon radical. Compounds formed having a single vinyl group may be of the formula R1R2R3Si-CR4=CHR5, where each R group has the above significance, compounds having hydrogen remaining attached to silicon may be of the general formula R1xR2yH4-x-y-zSi(CR4= CHR5), wherein each R group has the above significance, the sum of x and y is from 0 to 2 and z is from 3 to 1 and the sum of x, y and z must not exceed 3. Compounds formed from a mono-substituted acetylene may be of the general formula R1xR2yR34-x-y-zSi(CH= CHR5)z, where each R group has the above significance and the sum of x and y is from 0 to 3, z is from 4 to 1, and the sum of x, y and z must not exceed 4, e.g. in the case of silicochloroform and a mono-substituted acetylene, the initial compound formed has the general formula Cl3Si-CH= CHR5, where R5 has the above significance. Specific compounds that may be prepared employing an acetylenic reactant are vinyl dichlorosilane, vinyl monochlorosilane, divinyl monochlorosilane, divinyl dichlorosilane, trivinyl chlorosilane, methyl ethyl vinyl chlorosilane (obtainable from methyl ethyl chlorosilane and acetylene), vinyl triethyl silane, pentenyl trichlorosilanes, hexenyl trichlorosilanes, dipentenyl propyl ethoxy silanes (obtainable from propyl ethoxy silane and two mols. of 1-pentine), beta-styryl diethyl N-diethylaminosilane (obtainable from N-dimethylaminosilane and phenyl acetylene), the specific compounds referred to above where bromine or fluorine replaces chlorine in entirety or partially, where other alkyl or other aliphatic groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl