Patent GB-919459-A (GB)
Title: Reaction products of aminoorgano-siloxanes and alkali metal silicates
IPC: C08G77/00
Filed: 1959-12-01
Abstract: The invention comprises the reaction product of (1) from 1 to 99 parts (by weight) of a siloxane containing at least 1 unit of the formula <FORM:0919459/III/1> wherein each Z is H or a monovalent hydrocarbon group with or without amino or hydroxy substituents, R is a divalent hydrocarbon radical of at least 3 C atoms, the Z2N- group being attached to at least the third C atom removed from Si, each R1 is a monovalent hydrocarbon radical and a is 0, 1 or 2, and optionally at least 1 conventional siloxane unit, and (2) from 1 to 99 parts of an alkali metal silicate, the parts (by weight) being based on 100 parts of the siloxane and silicate.  The reactants are merely mixed together and maintained, e.g. at 20 DEG  to 150 DEG C., to give the desired product.  Preferably the starting siloxane is formed in situ by hydrolysing the corresponding alkoxysilane(s).  In typical examples (1) g -aminopropyltriethoxy silane was added to aqueous potassium silicate and the resulting solution was heated to boiling with subsequent distillation of water-alcohol mixture to yield a clear aqueous solution of the reaction product; (5) g -aminopropyl (methyl) siloxane and Na3SiO3 were dissolved in water and heated at 102 DEG C. for 8 hours to give the desired reaction product.  Uses: as corrosion inhibitors for aqueous systems, particularly aqueous alcohol systems used for heat transfer purposes, as described and claimed in Specification 919,460.  Specifications 882,051 and 882,052 also are referred to.ALSO:The invention comprises the reaction product of (1) from 1 to 99 parts (by wt.) of a siloxane containing at least 1 unit of the formula <FORM:0919459/IV(a)/1> and optionally at least 1 unit of the formula <FORM:0919459/IV(a)/2> wherein each Z is H, a monovalent hydrocarbon or an amino- or hydroxy-substituted monovalent hydrocarbon group, R is a divalent hydrocarbon radical of at least 3 C atoms, the Z2N- group being attached to at least the third C atom removed from the Si atom, each R1 and each R2 is a monovalent hydrocarbon radical (saturated or unsaturated), a is 0, 1 or 2 and c is 1, 2 or 3, and (2) from 1 to 99 parts of an alkali metal silicate, the parts by weight being based on 100 parts of the siloxane and silicate.  The reactants are merely mixed together and maintained, e.g. at 20 DEG  to 150 DEG C., to give the desired product. Preferably the starting siloxane is formed in situ by hydrolysing the corresponding alkoxysilane(s).  In typical examples (1) g -aminopropyltriethoxy silane was added to aqueous potassium silicate and the resulting solution was heated with subsequent distillation of water-alcohol mixture to yield a clear aqueous solution of the reaction product; (5) g -aminopropyl(methyl) siloxane and Na3SiO3 were dissolved in water and heated at 102 DEG C. for 8 hours to give the desired reaction product.  Uses: As corrosion inhibitors for aqueous systems, particularly aqueous alcohol systems used for heat transfer purposes, as described and claimed in Specification 919,460.  Specifications 882,051 and 882,052 also are referred to.