Aqueous systems containing silanes for rendering masonry surfaces water repellant

Abstract

There is provided an aqueous emulsion of (a) a hydrolyzable silane having the general formula: R.sub.n --Si--(R').sub.4-n wherein R is a hydrocarbyl group containing from 1 to 20 carbon atoms, R' is a hydrolyzable group and n is 1 or 2, and oligomers thereof, e.g., dimers and trimers, and other oligomers, (b) an emulsifying agent having an HLB value of from 4 to 15, and (c) water.

What is claimed is: 
     
       1. An aqueous silane emulsion composition useful to render a .[.porous ceramic.]. .Iadd.masonry .Iaddend.material water repellant which consists essentially of (a) from 1% to 40% by weight of hydrolyzable silane having a molecular weight up to about 500 and the general formula:   R.sub.n --Si--(R').sub.4-n     wherein R is a C 1  -C 20  hydrocarbyl or halogenated hydrocarbyl group, R' is C 1  -C 3  alkoxy or halide or amino or carboxyl group, and n is 1 or 2, or oligomers thereof, (b) from 0.5 to 50% by weight of the silane component of an emulsifier having an HLB value of from 4-15, and (c) water.   
     
     
       2. An aqueous silane emulsion as defined in claim 1 wherein the silane is an alkylalkoxysilane. 
     
     
       3. An aqueous silane emulsion as defined in claim 1 wherein the silane is an alkyltrialkoxysilane. 
     
     
       4. An aqueous silane emulsion as defined in claim 1 wherein R is a C 1  -C 10  alkyl group, R' is a C 1  -C 3  alkoxy group and n is 1. 
     
     
       5. An aqueous silane emulsion as defined in claim 1 wherein R is a C 4  -C 10  alkyl group. 
     
     
       6. An aqueous silane emulsion as defined in claim 1 wherein the silane is octyltriethoxysilane. 
     
     
       7. An aqueous silane emulsion as defined in claim 1 wherein the concentration of the silane is from 10% to 20% by weight. 
     
     
       8. An aqueous silane emulsion as defined in claim 1 wherein the emulsifier is a nonionic emulsifying agent. 
     
     
       9. An aqueous silane emulsion as defined in claim 1 wherein the emulsifier is a nonionic polyhydroxy compound. 
     
     
       10. An aqueous silane emulsion as defined in claim 1 wherein the emulsifier is a sorbitan fatty acid ester. 
     
     
       11. An aqueous silane emulsion as defined in claim 1 wherein the emulsifier is a polyoxyethylene sorbitan fatty acid ester. 
     
     
       12. An aqueous silane emulsion as defined in claim 1 wherein the silane is isobutyltrimethoxysilane. 
     
     
       13. An aqueous silane emulsion as defined in claim 1 wherein the silane is octadecyltriethoxysilane. 
     
     
       14. An aqueous silane emulsion as defined in claim 1 wherein the silane is 4R-triethoxysilylmenthene-1. 
     
     
       15. A process for increasing the resistance to penetration by aqueous media of masonry which comprises applying to the surface thereof an aqueous silane emulsion which consists essentially of (a) from 1% to 40% by weight of hydrolyzable silane having a molecular weight up to about 500 and the general formula:   R.sub.n --Si--(R').sub.4-n     wherein R is a C 1  -C 20  hydrocarbyl or halogenated hydrocarbyl group, R' is C 1  -C 3  alkoxy, halide, amino, carboxylate, and n is 1 or 2, or oligomers thereof, (b) from 0.5 to 50% by weight of the silane component of an emulsifier having an HLB value of from 4-15, and (c) water. .Iadd.   
     
     
       16.  An aqueous silane emulsion composition useful to render a masonry material water repellant which consists essentially of (a) from 1% to 40% by weight of hydrolyzable silane having a molecular weight up to about 500 and the general formula:   R.sub.n --Si--(R').sub.4-n     wherein R is a C 8  -C 20  hydrocarbyl or halogenated hydrocarbyl group, R' is a C 1  -C 3  alkoxy or amino or carboxylate group, and n is 1 or 2, or oligomers thereof, (b) from about 1% to 50% by weight of the silane component of an emulsifier having an HLB value of from 4-15, and (c) water, said aqueous silane emulsion composition having stability against phase separation. .Iaddend. .Iadd.17. An aqueous silane emulsion as defined in claim 16 wherein the silane is an alkylalkoxysilane. .Iaddend. .Iadd.18. An aqueous silane emulsion as defined in claim 16 wherein the silane is an alkyltrialkoxysilane. .Iaddend. .Iadd.19. An aqueous silane emulsion as defined in claim 16 wherein the silane is an   
     
     
        octyltriethoxysilane. .Iaddend. .Iadd.20.  An aqueous silane emulsion as defined in claim 16 wherein the concentration of the silane is from 10% to 20% by weight. .Iaddend. .Iadd.21. An aqueous silane emulsion as defined in claim 16 wherein the emulsifier is a nonionic emulsifying agent. .Iaddend. .Iadd.22. An aqueous silane emulsion as defined in claim 16 wherein the emulsifier is a nonionic polyhydroxy compound. .Iaddend. .Iadd.23. An aqueous silane emulsion as defined in claim 16 wherein the emulsifier is a sorbitan fatty acid ester. .Iaddend. .Iadd.24. An aqueous silane emulsion as defined in claim 16 wherein the emulsifier is a polyoxyethylene sorbitan fatty acid ester. .Iaddend. .Iadd.25. An aqueous silane emulsion as defined in claim 16 wherein the silane is octadecyltriethoxysilane. .Iaddend. .Iadd.26. An aqueous silane emulsion as defined in claim 16 wherein the silane is 4R-triethoxysilylmenthene-1. 
     
     
        .Iaddend. .Iadd.27.  A process for increasing the resistance to penetration by aqueous media of masonry which comprises applying to the surface thereof an aqueous silane emulsion which consists essentially of (a) from 1% to 40% by weight of hydrolyzable silane having a molecular weight up to about 500 and the general formula:   R.sub.n --Si--(R').sub.4-n     wherein R is a C 8  -C 20  hydrocarbyl or halogenated hydrocarbyl group, R' is a C 1  -C 3  alkoxy or amino or carboxylate group, and n is 1 or 2, or oligomers thereof, (b) from about 1% to 50% by weight of the silane component of an emulsifier having an HLB value of from 4-15, and (c) water, said aqueous silane emulsion having stability against phase separation. .Iaddend.