Patent GB-603076-A (GB)
Title: Improvements in organo-siloxanes and methods of making them
IPC: C08G77/06
Filed: 1944-02-28
Abstract: Organo-siloxane compositions are made by mixing silicon tetrachloride or a tetra-alkoxy silicon with at least one mono-silane having from one to three monovalent hydrocarbon radicals which need not be the same, but which are selected from the group of alkyl, aryl and alkaryl radicals, attached to each silicon atom through carbon-silicon linkages, the remaining valencies of the silicon atoms being satisfied by chlorine or ethoxy radicals, hydrolysing the mixture by the gradual addition of water and if necessary heating the hydrolysis product.  In the hydrolysis of the above mixture it is preferred to add the water dissolved in from one to four volumes of a common solvent such as alcohol, dioxane, acetic acid or acetone. Hydrocarbon radicals mentioned as suitable substituents for the mono-silanes referred to above include methyl and ethyl, propyl, butyl, isobutyl, amyl, hexyl, heptyl to octadecyl, phenyl, tolyl, xylyl, mesityl, mono-, di- and tri-ethyl and propyl phenyls, naphthyl, mono-and poly-naphthyls and anthracyl.  If the mixture contains halogens, the preferred solvent is dioxane.  After removal of the solvent and excess of water, the hydrolysis products are viscous water - immiscible liquids which are capable of further polymerization by heating.  The amount of further polymerization is regulated by the use to which the products are to be put.  In examples: (1) silicon tetrachloride and phenyl triethoxy silane are treated dropwise with aqueous alcohol; (2) silicon tetrachloride and diethyl silicon dichloride is treated with dry alcohol and the ester so formed hydrolysed with aqueous alcohol; (3) moist air is passed through a solution of silicon tetrachloride and diphenyl silicon dichloride for 18 hours; (4) silicon tetrachloride and diphenyl silicon dichloride is treated first with dry methyl alcohol and then with aqueous acetone; (5), (6) and (7) tetra-ethoxysilicon and dimethyl silicon diethoxide are treated with aqueous hydrochloric acid; (8) tetra-ethoxy silicon and phenyl methyl silicon di-ethoxide are warmed with alcoholic HCl and then diluted with aqueous HCl; (9) silicon tetrachloride and phenyl di-methyl silicon chloride is treated with dioxane and then with aqueous acetic acid; (10) tetra-ethoxy silicon and phenyl dimethyl silicon ethoxide is treated with aqueous alcohol containing a trace of HCl followed by excess of water; (11) tetra-ethoxy silicon and trimethyl silicon ethoxide is treated with aqueous alcohol; (12) tetra-ethoxy silicon methyl silicon tri-ethoxide and dimethyl silicon diethoxide are treated with aqueous alcohol; (13) equi-molecular proportions of ethyl orthosilicate phenyl silicon trichloride and phenylmethyl silicon dichloride are treated with aqueous dioxane; (14) a mixture of phenyl silicon trichloride, dimethyl silicon diethoxide, methyl silicon tri-ethoxide and ethyl orthosilicate in the molar ratio of 4 : 2 : 1 : 1 is treated with aqueous alcohol, and the product heated for one hour at 250 DEG  C.; (15) silicon tetrachloride, ethyl silicon trichloride and phenyl ethyl silicon dichloride in the molar ratio 1 : 3 : 2.25 are treated in ether and glacial acetic acid solution with water and heated to 250 DEG  C.; (16) a mixture of phenylmethyl silicon diethoxide, methyl silicon triethoxide and ethyl orthosilicate in the molar ratio 2 : 1 : 1 is treated with twice the theoretical amount of water at 60-80 DEG  C. in the presence of a small amount of hydrochloric acid; (17) phenylethyl silicon dichloride, ethyl orthosilicate and ethyl silicon trichloride are treated in alcohol-ether solution with water and the product heated to 80 DEG  to 300 DEG  C.  The properties of the products of the invention can be adjusted by varying the oxygen to silicon ratio. When this ratio is between 0.5 and 1.0, the products remain liquid with little tendency to polymerization, with a ratio greater than 1.0 the products form thermosetting compositions; the former class of materials are suitable for electrical filling media for transformers, circuit-breakers, cables and condensers, and the latter class for moulding compounds, film-forming coatings, varnishes and impregnating agents.ALSO:Organo-siloxane compositions are made by mixing silicon tetrachloride or a tetra-alkoxy silicon with at least one mono-silane having from one to three monovalent hydrocarbon radicals which need not be the same, but which are selected from the group of alkyl, aryl, and alkaryl radicals attached to each silicon atom through carbon-silicon linkages, the remaining valencies of the silicon atoms being satisfied by chlorine or ethoxy radicals, hydrolysing the mixture by the gradual addition of water and, if necessary, heating the hydrolysis product.  In the hydrolysis of the above mixture, it is preferred to add the water dissolved in from one to four volumes of a common solvent such as alcohol dioxane, acetic acid or acetone. Hydrocarbon radicals mentioned as suitable substituents for the mono-silanes referred to above include methyl and ethyl, propyl, butyl, isobutyl, amyl, hexyl, heptyl to octadecyl, phenyl, tolyl, xylyl, mesityl, mono-, di- and tri-ethyl and propyl phenyls, naphthyl, mono-and poly-naphthyls and anthracyl.  If the mixture contains halogens, the preferred solvent is dioxane.  After removal of the solvent and excess of water, the hydrolysis products are viscous water-immiscible liquids which are capable of further polymerization by heating.  The amount of further polymerization is regulated by the use to which the products are to be put.  In examples: (1) silicon tetrachloride and phenyl triethoxy silane are treated dropwise with aqueous alcohol; (2) silicon tetrachloride and diethyl silicon dichloride is treated with dry alcohol and the ester so formed hydrolysed with aqueous alcohol; (3) moist air is passed through a solution of silicon tetrachloride and diphenyl silicon dichloride for 18 hours; (4) silicon tetrachloride and diphenyl silicon dichloride is treated first with dry methyl alcohol and then with aqueous acetone; (5), (6) and (7) tetra-ethoxysilicon and dimethyl silicon diethoxide are treated with aqueous hydrochloric acid; (8) tetra-ethoxy silicon and phenyl methyl silicon di-ethoxide were warmed with alcoholic HCl and then diluted with aqueous HCl acid; (9) silicon tetrachloride and phenyl di-methyl silicon chloride is treated with dioxane and then with aqueous acetic acid; (10) tetra-ethoxy silicon and phenyl dimethyl silicon ethoxide is treated with aqueous alcohol containing a trace of HCl followed by excess of water; (11) tetra-ethoxy silicon and trimethyl silicon ethoxide is treated with aqueous alcohol; (12) tetra-ethoxy silicon methyl silicon triethoxide, and dimethyl silicon diethoxide are treated with aqueous alcohol; (13) equimolecular proportions of ethyl orthosilicate phenyl silicon trichloride and phenylmethyl silicon dichloride are treated with aqueous dioxane; (14) a mixture of phenyl silicon trichloride, dimethyl silicon diethoxide, methyl silicon tri-ethoxide and ethyl orthosilicate in the molar ratio of 4 : 2 : 1 : 1 is treated with aqueous alcohol, and the product heated for one hour at 250 DEG  C.; (15) silicon tetrachloride, ethyl silicon trichloride and phenyl ethyl silicon dichloride in the p  molar ratio 1 : 3 : 2.25 are treated in ether and glacial acetic acid solution with water and heated to 250 DEG  C.; (16) a mixture of phenylmethyl silicon diethoxide, methyl silicon triethoxide and ethyl orthosilicate in the molar ratio 2 : 1 : 1 is treated with twice the theoretical amount of water at 60-80 DEG  C. in the presence of a small amount of hydrochloric acid; (17) phenylethyl silicon dichloride, ethyl orthosilicate, and ethyl silicon trichloride are treated in alcohol-ether solution with water and the product heated to 80 DEG  to 300 DEG  C.  The properties of the products of the invention can be adjusted by varying the oxygen to silicon ratio. When this ratio is between 0.5 and 1.0, the products remain liquid with little tendency to polymerization, with a ratio greater than 1.0 the products form thermosetting composition.  The former class of materials are suitable for electrical filling media for transformers, circuit-breakers, cables and condensers, and the latter class for moulding compounds, film-forming coatings, varnishes and impregnating agents.