초록 ▼

A process is provided for impregnating porous mineral substrates by a spray technique in which use is made of a gas-supported spraying assembly to apply liquid impregnating agent in a controlled manner to the substrate surface, the amount consumed being markedly less than the amount consumed in a co

A process is provided for impregnating porous mineral substrates by a spray technique in which use is made of a gas-supported spraying assembly to apply liquid impregnating agent in a controlled manner to the substrate surface, the amount consumed being markedly less than the amount consumed in a conventional method of application by a flow-coating process.

대표청구항 ▼

What is claimed is: 1. A process comprising impregnating a porous mineral substrate with a liquid impregnating agent, wherein the impregnating comprises spraying the liquid impregnating agent and a gas from a gas-supported spraying assembly; and the liquid impregnating agent is sprayed from the gas

What is claimed is: 1. A process comprising impregnating a porous mineral substrate with a liquid impregnating agent, wherein the impregnating comprises spraying the liquid impregnating agent and a gas from a gas-supported spraying assembly; and the liquid impregnating agent is sprayed from the gas-supported spraying assembly at a pressure of at most 2 bar gauge, wherein the gas-supported spraying assembly comprises a nozzle system comprising one or more nozzles; the liquid impregnating agent and the gas are fed into each of the one or more nozzles at a pressure of at most 2 bar gauge; and the gas atomizes the liquid impregnating agent in each of the one or more nozzles, wherein the liquid impregnating agent is substantially free of solvent. 2. The process as claimed in claim 1, wherein the gas comprises air. 3. The process as claimed in claim 1, wherein the gas-supported spraying assembly further comprises a gas-compression unit; a storage unit for storing the liquid impregnating agent; a connection from the gas-compression unit to the nozzle system for conveying the gas to the nozzle system; and a connection from the storage unit to the nozzle system for supplying the liquid impregnating agent to the nozzle system. 4. The process as claimed in claim 3, wherein the gas-supported spraying assembly further comprises, attached to the gas-compression unit, a gas regulating unit to control a pressure or an amount of the gas conveyed to the nozzle system. 5. The process as claimed in claim 4, wherein the gas regulating unit comprises a regulating valve. 6. The process as claimed in claim 3, wherein the gas-supported spraying assembly further comprises, attached to the storage unit, a liquid regulating unit to control an amount of the liquid impregnating agent supplied to the nozzle system. 7. The process as claimed in claim 6, wherein the liquid regulating unit comprises a regulating valve. 8. The process as claimed in claim 3, wherein the one or more nozzles each has a diameter of at most 4 mm. 9. The process as claimed in claim 3, wherein the gas comprises air. 10. The process as claimed in claim 9, wherein the spraying comprises feeding the air and the liquid impregnating agent into the nozzle system to generate a spray jet. 11. The process as claimed in claim 9, wherein the gas-compression unit generates a constant supply of compressed air. 12. The process as claimed in claim 9, wherein the gas-compression unit generates a variable supply of compressed air. 13. The process as claimed in claim 9, wherein the gas-compression unit generates an air supply, at room temperature and atmospheric pressure, of at least 100 l/min. 14. The process as claimed in claim 9, wherein the gas-compression unit generates an air supply, at room temperature and atmospheric pressure, of at least 100 l/min from each of the one or more nozzles. 15. The process as claimed in claim 3, wherein the spraying comprises guiding the nozzle system automatically over the porous mineral substrate. 16. The process as claimed in claim 1, wherein the liquid impregnating agent comprises at least one of a hydrophobicizing agent and an oleophobicizing agent. 17. The process as claimed in claim 1, wherein the liquid impregnating agent comprises at least one organosilicon compound. 18. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises at least one monomeric silane of the general formula I R1--Si(R2)a(OR3)3-a (I), where R1 and R2 are identical or different, and each is a linear or branched alkyl group having from 1 to 20 carbon atoms, optionally with partial or complete halogen substitution, an aryl group, or an aralkyl group having a linear or branched alkyl chain; R3 is a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl group; and a is 0, 1 or 2. 19. The process as claimed in claim 18, wherein the organosilicon compound comprises one or more selected from the group consisting of n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, isohexyltrimethoxysilane, isohexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, chloropropyltrimethoxy-silane, chloropropyltriethoxysilane, 1,1,2,2-tetrahydrotridecafluorooctyltrimethoxy-silane, and 1,1,2,2-tetrahydrotridecafluorooctyl-triethoxysilane. 20. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises at least one siloxane produced by a process comprising hydrolysis and condensation of at least one monomeric silane of the general formula I R1--Si(R2)a(OR3)3-a (I), where R1 and R2 are identical or different, and each is a linear or branched alkyl group having from 1 to 20 carbon atoms, optionally with partial or complete halogen substitution, an aryl group, or an aralkyl group having a linear or branched alkyl chain; R3 is a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl group; and a is 0, 1 or 2. 21. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises at least one selected from the group consisting of silanes, siloxanes and silicones. 22. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises at least one selected from the group consisting of silanes and siloxanes. 23. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises a silicone. 24. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises at least one of a siloxane and a monomeric silane of the general formula I R1--Si(R2)a(OR3)3-a (I), where R1 and R2 are identical or different, and each is a linear or branched alkyl group having from 1 to 20 carbon atoms, optionally with partial or complete halogen substitution, an aryl group, or an aralkyl group having a linear or branched alkyl chain; R3 is a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl group; and a is 0, 1 or 2. 25. The process as claimed in claim 17, wherein the at least one organosilicon compound comprises an antigraffiti impregnating agent. 26. The process as claimed in claim 25, wherein the antigraffiti impregnating agent comprises at least one fluoropolymer. 27. The process as claimed in claim 26, wherein the at least one fluoropolymer comprises reactive groups capable of bonding with the porous mineral substrate. 28. The process as claimed in claim 1, wherein the porous mineral substrate is selected from the group consisting of fiber-filled concrete, concrete, sandstone, limestone, natural stone, glass wool items, mineral wool items, bricks, artificial stone, mortar, render, terracotta, ceramic, calcium silicate brick, cement-bound construction materials and clay-bound construction materials. 29. The process as claimed in claim 1, wherein the porous mineral substrate, when dried and then immersed in water for 5 seconds, absorbs more than 200 g of water per square meter of the porous mineral substrate. 30. The process as claimed in claim 1, wherein the impregnating comprises spraying the liquid impregnating agent on the porous mineral substrate in one or more application passes. 31. The process as claimed in claim 30, wherein 1 to 200 g of the liquid impregnating agent per square meter of the porous mineral substrate is sprayed on the porous mineral substrate in each application pass. 32. The process as claimed in claim 1, wherein the impregnating comprises spraying on the porous mineral substrate in a first application pass 10 to 300 g of the liquid impregnating agent per square meter of the porous mineral substrate; and then spraying on the porous mineral substrate in each subsequent application pass 1 to 150 g of the liquid impregnating agent per square meter of the porous mineral substrate. 33. The process as claimed in claim 1, wherein the impregnating comprises spraying on the porous mineral substrate in a first application pass 10 to 200 g of the liquid impregnating agent per square meter of the porous mineral substrate; and then spraying on the porous mineral substrate in each subsequent application pass 1 to 100 g of the liquid impregnating agent per square meter of the porous mineral substrate. 34. The process as claimed in claim 30, wherein the one or more application passes comprises a first application pass and a subsequent second application pass; and during the second application pass the porous mineral substrate is wet with the liquid impregnating agent sprayed in the first application pass. 35. The process as claimed in claim 30, further comprising, after each of the one or more application passes, drying the porous mineral substrate. 36. The process as claimed in claim 1, wherein the porous mineral substrate is part of a building. 37. The process as shown in claim 25, wherein the antigraffiti impregnating agent comprises at least one triamino-and fluoroalkyl-functional organosiloxane. 38. The process as claimed in claim 37, wherein the organosiloxane has at least one [NHx(CH2)aNHy(CH2 )bNHz]--(I) wherein the group is bonded to at least one silicon atom via at least one N-bonded alkylene group having 1 to 4 C atoms, a and b are identical or different and are an integer ranging from 1to 6, x is 0 or 1 or 2, y is 0 or 1, z is 0 or 1 or 2, with the proviso that (x+y+z)≦4, and at least one Si--C bonded fluoroalkyl group of formula II: F3C(CF2)r(CH2)s-- (II) wherein r is 0 or an integer ranging from 1 to 18 and s is 0 or 2. 39. The process as claimed in claim 37, wherein the organosiloxane is a condensate of N-[N'-(2-aminoethyl)-2-aminoethyl]-3-aminopropyltrimethoxysilane and tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxy-silane. 40. The process as claimed in claim 1, wherein the nozzle system comprises two or more nozzles.