Patent GB-959741-A (GB)
Title: Process for preparing silicon isocyanates
IPC: D06M15/653
Filed: 1962-01-10
Abstract: Silicon isocyanates, e.g. tetraisocyanate and chlorotriisocyanate, are prepared by reacting together, in the liquid phase at a temperature of -85 DEG  to +150 DEG  C. isocyanic acid and a silicon tetrahalide, in the presence of a nitrogen-containing compound having the structure <FORM:0959741/C1/1> or a mixture of the two, wherein R1 is a monovalent hydrocarbon radical, R2, R3, R4 and R5 are either a monovalent hydrocarbon radical or hydrogen, one or two of R3, R4 and R5 being a monovalent aromatic radical, but not more than one being hydrogen. Specified nitrogen-containing compounds are dimethyl acetamide, dimethyl formamide, diethyl acetamide,/methyl ethyl acetamide, dimethyl butyramide, methy phenyl acetamide, ethyl phenyl acetamide, methyl ethyl acetamide, methyl benzyl acetamide, diphenylamine, dimethyl aniline, diethyl aniline, methyl ethyl aniline, methyl phenyl aniline, ethyl phenyl aniline, and phenyl naphthyl amine.  The preferred nitrogen-containing compounds are lower alkyl and phenyl substituted compounds.  The reaction temperature is preferably 20-80 DEG  C. Example 5 describes the preparation of Si(NCO)4 from 4 mols. of isocyanic acid and 1 mol. of SiCl4 in benzene and ether using dimethyl acetamide.ALSO:Silicon isocyanates of the general formula XpRy Si(NCO)z wherein p is 0 or 1, y is 0-3, z is 1-4, y+z=4, X is halogen and R is a monovalent hydrocarbon, alkoxy, or aryloxy radical, which may be substituted, are prepared by reacting together, in the liquid phase at a temperature of -85 DEG C. to +150 DEG C., isocyanic acid and a silicon halide of the general formula RySiXz in the presence of a nitrogen-containing compound having the structure: <FORM:0959741/C3/1> <FORM:0959741/C3/2> or a mixture of the two, wherein R1 is a monovalent hydrocarbon radical, R2, R3, R4 and R5 are either a monovalent hydrocarbon radical or hydrogen, one or two of R3, R4 and R5 being a monovalent aromatic radical, but not more than one being hydrogen. In the silicon halide, RySiXz, each R should preferably contain less than 7 carbon atoms. Specified R groups are alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkaryl, alkoxy, acyloxy, and substituted derivatives thereof, specified substituents being halo, nitro and sulpho, these substituents being inert to the reactants. The R1, R2, R3, R4 and R5 radicals may be those listed for R. Specified nitrogen-containing compounds are dimethylacetamide, dimethylformamide, diethylacetamide, methyl ethyl acetamide, dimethylbutyramide, methyl phenyl acetamide, ethyl phenyl acetamide, methyl ethenyl acetamide, methyl benzyl acetamide, diphenylamine, dimethylaniline, diethylaniline, methyl ethyl aniline, methyl phenyl aniline, ethyl phenyl aniline, and phenyl naphthyl amine. The preferred nitrogen-containing compounds are lower alkyl and phenyl substituted compounds.  The reaction temperature is preferably 20-80 DEG C. The reaction may be carried out in the presence of an inert solvent, those specified being diethyl ether, benzene, toluene, xylene, and petroleum ether, The examples describe the preparation of: (1), (7) and (9) Dimethyl diisocyanatosilane; (2) diethoxydiisocyanatosilane; (3) Diphenoxydiisocyanatosilane; (4) diphenyl diisocyanatosilane; (5) tetraisocyanatosilane; (6) di-n-butyl diisocyanatosilane; (8) phenyltriisocyanatosilane.  Uses: Imparting water repellency to textiles, preparation of sealings and coatings, and in the preparation of polymeric resins.