STABLE SILANOL COMPOSITIONS

1358350 Stable silanol solutions; polymerization of bis-methacrylates LEE PHARMACEUTICALS 24 May 1972 [24 May 1971] 24439/72 Headings C3S and C3P Stable solutions of silanols of the formula (HO) 3 Si(CH 2 ) n Y, wherein Y denotes an organofunctional group and n is 0 or an integer of from 1 to 3, are prepared by hydrolysing a silane of the formula X 3 Si(CH 2 ) n Y, wherein X denotes a hydrolysable group, and extracting the resulting silanol from the aqueous solution with a non-polar water-immiscible organic solvent in which the silanol is soluble. Suitable starting silanes are vinyl tris(2-methoxyethoxy)- silane, gamma-methacryloxypropyltrimethoxysilane, beta - (3,4 - epoxy - cyclohexyl)ethyltrimethoxysilane, gamma - glycidoxypropyltrimethoxysilane, gamma - mercaptopropyltrimethoxysilane, gamma - aminopropyltriethoxysilane, and N-beta-(aminoethyl)-gammaaminopropyltrimethoxysilane. Hydrolysis may be carried out with an acid or a base and the solvent solution is preferably neutralized after extraction. Suitable extraction solvents are ethyl ether, chloroform and methylene chloride. Uses.-For improvement of bonding of organic resins to mineral surfaces. Thus quartz, soda lime and glass bead fillers treated with the silanol solutions and subsequently with benzoyl peroxide give improved results when mixed with resin compositions based on a mixture of bisphenol - A - bis - (3 - methacrylate - 2 - hydroxypropyl)ether, triethylene glycol dimethacrylate ester, N - 4 - tolyl - diethanolamine and butylated hydroxytoluene. The above resin composition may also be applied to teeth previously treated successively with the silanol solutions and benzoyl peroxide.