Patent GB-802688-A (GB)
Title: Improvements in or relating to organo-silicon compounds
IPC: C08G77/00
Filed: 1955-06-09
Abstract: A mixture of block copolymers having the general formula R1[(R2SiO)y]a[(CnH2nO)x] bR11, wherein R is a monovalent hydrocarbon radical, R1 and R11 are monovalent hydrocarbon or hydrocarbonoxy radicals, n is 2, 3 or 4, y is an integer of at least 2, x is an integer of at least 5, a and b are together equal to 2 or 3 (see Group IV (a)), is used generally as a lubricant. The water=soluble copolymers are used as antifoam agents, and together with water-soluble polyoxyethylene - polyoxypropylene diols, monoethers and diethers form useful lubricants; by themselves or in conjunction with the above diols, &c., or with ethylene or propylene glycols they form useful ingredients of lubricants having a water base (commonly called hydrolubes).ALSO:A mixture of block copolymers having the general formula <FORM:0802688/IV (a)/1> wherein R is a monovalent hydrocarbon radical, R1 and R11 are monovalent hydrocarbon or hydrocarbonoxy radicals, n is 2, 3 or 4, y is an integer of at least 2, x is an integer of at least 5, and a and b are together equal to 2 or 3, may be made by heating a mono- or di-hydroxy polyoxyalkylene compound having at least 5 oxyalkylene groups with an alkoxy terminated polysiloxane of the formula R111O(R2SiO)yR111 or R1(R2SiO)yR111, where R111 is an alkyl radical, and removing the alkanol formed from the reaction mixture.  The Si-bonded radicals may differ from unit to unit throughout the siloxane block, and the oxyalkylene chain or block may comprise groups of differing molecular weights.  The reaction may be effected in a solvent, e.g. toluene or xylene, and in the presence of a condensation catalyst, e.g. trifluoroacetic, perfluorobutyric, perfluoroglutaric, monochloroacetic and acetic acids, and potassium silanolate, which are subsequently removed. As starting materials the alkoxy-terminated linear siloxanes may be made by reacting a low molecular weight cyclic polysiloxane with a mono- or dialkoxysiloxane; polyoxyalkylene ethers containing both oxyethylene and oxypropylene groups may be made by the sequential addition of ethylene and propylene oxides to a monohydric alcohol; polyoxyalkylene glycols and mono-ol polymers are well-known.  In a typical example, a mixture of polyoxyethylene diol monomethylether (mol. wt. 750), an ethoxy terminated dimethylpolysiloxane (mol. wt. 1036), toluene and trifluoroacetic acid was refluxed at 120 DEG  C. for 4 hours, during which the ethanol formed was removed.  The reaction mixture was cooled and the catalyst neutralized by addition of triethanolamine.  Removal of the toluene left a water-soluble low melting soft solid which readily emulsified toluene and water.  Uses.-The products generally find use as lubricants and hydraulic fluids, but the watersoluble products find use as antifoam agents, rubber lubricants, e.g. in tyre moulds, and textile lubricants, and together with watersoluble polyoxyethylene - polyoxypropylene diols, monoethers and diethers form useful lubricants and hydraulic fluids; by themselves or in conjunction with the above diols &c., or with ethylene or propylene glycol, the block copolymers form useful ingredients of lubricants having a water base (commonly called hydrolubes).  The water-soluble copolymers also possess emulsifying properties for such systems as benzene-water, organosilane-water and polysiloxane-water mixtures.