Patent GB-663770-A (GB)
Title: Preparation of silicon-containing heteropolymers
IPC: C07F7/12
Filed: 1948-09-20
Abstract: A polymerizable composition comprises maleic anhydride or an ester of maleic or fumaric acid in which the alcohol radical is allyl, methallyl, 1-chloro-2-propyl, 2-chloro-ethyl, benzyl, tetrahydrofurfuryl, cyclohexyl, phenyl, cresyl or an alkyl radical having from one to eight carbon atoms and having at least one hydrogen atom attached to the same carbon atom as the oxygen atom, and a silane whose molecule consists of a silicon atom attached to four monovalent radicals, at least one of which is an alkoxy radical having from one to four carbon atoms and having at least one hydrogen atom attached to the same carbon atom as the oxygen atom, and the remainder of which are hydrocarbon radicals including at least one allyl or methallyl radical.  The hydrocarbon radicals other than allyl or methallyl may be benzyl, alkyl radicals having from one to eight carbon atoms and having at least one hydrogen atom attached to the same carbon atom as the free valency, monovalent hydrocarbon radicals of the benzene series having the free valency attached to the nucleus, having from six to twenty-one carbon atoms and having not more than three side chains consisting of alkyl radicals of not more than five carbon atoms, monovalent cycloaliphatic hydrocarbon radicals having a single nucleus containing from five to six carbon atoms one of which is connected to the free valency and to a hydrogen atom, another of which, adjacent the first, is connected to two hydrogen atoms, and the rest of which are each connected to at least one hydrogen atom, having from five to sixteen carbon atoms and having not more than two side chains consisting of alkyl radicals of not more than five carbon atoms, or a monovalent hydrocarbon radical of the naphthalene series having the free valency attached to a nucleus having from ten to twenty-five carbon atoms and having not more than three side chains consisting of alkyl radicals of not more than five carbon atoms.  Where a naphthalene hydrocarbon radical is present all the other radicals in the silane are allyl, methallyl or ethoxy.  In the preferred silanes all the radicals attached to the silicon atom are allyl, methallyl, or ethoxy.  Polymerization takes place when the silane and the anhydride or ester are brought together in any ratio with a catalyst, preferably an organic peroxide such as benzoyl peroxide, or an ozonide, with or without a solvent, such as methyl ethyl ketone or dioxane, and is expedited by heating.  The amount of catalyst normally employed may vary from 0.05 to 5 per cent, preferably 0.1 to 3 per cent, by weight of the reaction mixture, and the polymerization is normally conducted at 50-75 DEG C.  When a silane containing only one allyl or methallyl radical is polymerized with an ester containing only one olefinic double bond, the resultant polymer may be hydrolysed to convert the alkoxy radicals to hydroxy radicals, which then are condensed with one another, thus producing siloxanes.  The hydrolysis may be carried out by adding the polymerized silane to a solution of an inorganic acid, preferably hydrochloric acid, in water or, preferably, in a solvent such as dioxane, acetone, methyl ethyl ketone, methyl alcohol or ethyl alcohol which is capable of maintaining a mutual solution of the water, the acid, and the polymerized silane.ALSO:The Specification relates to the production of silanes containing at least one allyl or methallyl radical and at least one alkoxy radical directly attached to the silicon atom, the remainder of the radicals attached to the silicon atom being monovalent hydrocarbon radicals. Allylalkoxysilanes and methallylalkoxysilanes are prepared by reacting an allyl or methallyl magnesium halide with an alkyl orthosilicate, and further substitutions are made by reacting these alkoxy silanes with Grignard reagents.  Examples describe the introduction of the following radicals into the silane molecule: allyl, methallyl, ethoxy, n-butyl, phenyl, cyclohexyl, cyclopentyl, 4-tertiary-amyl cyclohexyl, and benzyl.