# US 5,334,255 A · Method for removing and reclaiming excess paint from a paint spray booth > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,334,255 A - Document ID: US5334255A - Status: Granted - Kind: A - Application number: 07/915,041 - Filed: 1992-07-15 - Granted: 1994-08-02 - Earliest claimed: 1989-12-04 - Assignees: BASF SE - Inventors: Lawrence E. James; William C. Walsh - Web page: https://patentgrep.com/patent/US5334255A ## CPC - C08J 11/00: Recovery or working-up of waste materials (recovery of plastics B29B17/00; polymerisation processes involving purification or recycling of waste polymers or their depolymerisation products C08B, C08C, C08F, C08G, C08H) - C09D 7/71: {Paint detackifiers or coagulants, e.g. for the treatment of oversprays in paint spraying installations (chemical paint removers C09D9/00)} - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract Methods for removing and reclaiming excess paint from a paint spray booth includes entraining over-sprayed paint particles in a stream of air passing though the pain spray booth and causing the entrained over sprayed paint particles to come into contact with a flowing flood sheet within the paint spray booth such that a substantial portion of the paint particles are solubilized within the flowing aqueous flood sheet and are thereby removed from the stream of air. The solubilized paint particles are then separated and collected from the aqueous flood sheet so as to be reclaimed for future use, whereas the aqueous flood sheet is then recycled to the paint spray booth after the paint particles have been separated therefrom. To permit the reclamation of paint particles, the flood sheet includes an aqueous paint carrier having at least one of an aprotic heterocyclic oxygenate, a C.sub.4 -C.sub.6, lactone or a cyclic carbonate together with at least one organic solvent. ## Claims ### Claim 1 A method for removing and reclaiming excess paint from a paint spray booth comprising the steps of: i). entraining over-sprayed paint particles in a stream of air passing through the paint spray booth; ii). causing the entrained over-sprayed paint particles to come into contact with a flowing aqueous flood sheet within the paint spray booth such that a substantial portion of said paint particles are solubilized within said flowing aqueous flood sheet and thereby removed from said stream of air, and wherein said flowing aqueous flood sheet consists essentially of an aqueous paint carder which includes; A. between about 16 to about 45 percent by weight of at least one aprotic heterocyclic oxygenate selected the group consisting of N-methyl pyrrolidone, N-ethyl pyrrolidone, 1,5-dimethyl-2-pyrrolidone; B. between about 14 to 52 percent by weight of at least one organic solvent; and C. the balance being water; iii). separating and collecting said solubilized paint particles from said aqueous flood sheet, whereby said paint particles are reclaimed; and iv). recycling said aqueous flood sheet after separation of said paint particles therefrom according to step iii) to the paint spray booth. ### Claim 2 (depends on 1) The method as in claim 1, wherein the over-sprayed paint includes a system comprised of paint particles and an organic paint carrier, and wherein said step iii) is practiced by distilling said aqueous flood sheet so as to separate said system of paint particles and said organic paint carrier therefrom. ### Claim 3 (depends on 2) The method as in claim 2, wherein said separated system of paint particles and organic paint carder is reused in paint formulations sprayed within the paint spray booth. ### Claim 4 (depends on 1) The method as in claim 1, wherein said aprotic heterocyclic oxygenate consists of N-methyl pyrrolidone. ### Claim 5 (depends on 1) The method as in claim 1, wherein the organic solvent includes at least one glycol component selected from the group consisting of dibasic esters, propylene glycols, polypropylene glycol oligomers, and monoalkyl or monophenyl ether derivatives of propylene glycol and polypropylene glycol oligomers. ### Claim 6 (depends on 5) The method as in claim 5, wherein said organic solvent includes between about 4 to about 20 percent by weight of said at least one glycol component. ### Claim 7 (depends on 5, 6) The method as in claim 5 or 6, wherein the organic solvent is at least one selected from the group consisting of tripropylene glycol monomethyl ether, 2-butoxy ethanol, triethylene glycol monomethyl ether, propylene-glycol N-butyl ether, ethylene glycol phenyl butyl ether, propylene glycol phenyl butyl ether, dipropylene glycol N-butyl ether, and dipropylene glycol monomethyl ether. ### Claim 8 (depends on 1) The method as in claim 1, wherein the organic solvent is a at least one dibasic ester selected from C.sub.1 -C.sub.4 dialkyl ester of at least one C.sub.2 -C.sub.6 aliphatic dibasic acid. ### Claim 9 (depends on 8) The method as in claim 8, wherein a portion of the dibasic ester is replaced by ethyl-3-ethoxy propionate. ### Claim 10 (depends on 1) The method as in claim 1, wherein the organic solvent is a mixture of 2-butoxy ethanol, dipropylene glycol monomethyl ether and a dibasic ester. ### Claim 11 (depends on 1) The method as in claim 1, wherein the heterocyclic oxygenate is present in an amount between about 30 to about 45 percent by weight. ### Claim 12 A method for removing and reclaiming excess paint from a paint spray booth comprising the steps of: i). entraining over-sprayed paint particles in a stream of air passing through the paint spray booth; ii). causing the entrained over-sprayed paint particles to come into contact with a flowing aqueous flood sheet within the paint spray booth such that a substantial portion of said paint particles are solubilized within said flowing aqueous flood sheet and thereby removed from said stream of air, and wherein said flowing aqueous flood sheet consists essentially of an aqueous paint career which includes; A. between about 16 to about 45 percent by weight of at least one C.sub.4 -C.sub.6 lactone selected from the group consisting of o-butyrolactone and valerlactone; B. between about 14 to 52 percent by weight of at least one organic solvent; and C. the balance being water; iii). separating and collecting said solubilized paint particles from said aqueous flood sheet, whereby said paint particles are reclaimed; and iv). recycling said aqueous flood sheet after separation of said paint particles therefrom according to step iii), to the paint spray booth. ### Claim 13 (depends on 12) The method as in claim 12, wherein the over-sprayed paint includes a system comprised of paint particles and an organic paint carrier, and wherein said step iii) is practiced by distilling said aqueous flood sheet so as to separate said system of paint particles and said organic paint carrier therefrom. ### Claim 14 (depends on 13) The method as in claim 13, wherein said separated system of paint particles and organic paint carrier is reused in paint formulations sprayed within the paint spray booth. ### Claim 15 (depends on 12) The method as in claim 12, wherein the organic solvent includes at least one glycol component selected from the group consisting of dibasic esters, propylene glycols, polypropylene glycol oligomers, and monoalkyl or monophenyl ether derivatives of propylene glycol and polypropylene glycol oligomers. ### Claim 16 (depends on 15) The method as in claim 15, wherein said organic solvent includes between about 4 to about 20 percent by weight of said at least one glycol component. ### Claim 17 (depends on 15, 16) The method as in claim 15 or 16, wherein the organic solvent is at least one selected from the group consisting of tripropylene glycol monomethyl ether, 2-butoxy ethanol, triethylene glycol monomethyl ether, propylene-glycol N-butyl ether, ethylene glycol phenyl butyl ether, propylene glycol phenyl butyl ether, dipropylene glycol N-butyl ether, and dipropylene glycol monomethyl ether. ### Claim 18 (depends on 12) The method as in claim 12, wherein the organic solvent is a at least one dibasic ester selected from C.sub.1 -C.sub.4 dialkyl ester of at least one C.sub.2 -C.sub.6 aliphatic dibasic acid. ### Claim 19 (depends on 18) The method as in claim 18, wherein a portion of the dibasic ester is replaced by ethyl-3-ethoxy propionate. ### Claim 20 (depends on 12) The method as in claim 12, wherein the organic solvent is a mixture of 2-butoxy ethanol, dipropylene glycol monomethyl ether and a dibasic ester. ### Claim 21 A method for removing and reclaiming excess paint from a paint spray booth comprising the steps of: i). entraining over-sprayed paint particles in a stream of air passing through the paint spray booth; ii). causing the entrained over-sprayed paint particles to come into contact with a flowing aqueous flood sheet within the paint spray booth such that a substantial portion of said paint particles are solubilized within said flowing aqueous flood sheet and thereby removed from said stream of air, and wherein said flowing aqueous flood sheet consists essentially of an aqueous paint career which includes; A between about 16 to about 45 percent by weight of a cyclic carbonate; B. between about 14 to 52 percent by weight of at least one organic solvent; and C. the balance being water; iii). separating and collecting said solubilized paint particles from said aqueous flood sheet, whereby said paint particles are reclaimed; and iv). recycling said aqueous flood sheet after separation of said paint particles therefrom according to step iii), to the paint spray booth. ### Claim 22 (depends on 21) The method as in claim 21, wherein the over-sprayed paint includes a system comprised of paint particles and an organic paint carrier, and wherein said step iii) is practiced by distilling said aqueous flood sheet so as to separate said system of paint particles and said organic paint carrier therefrom. ### Claim 23 (depends on 22) The method as in claim 22, wherein said separated system of paint particles and organic paint carrier is reused in paint formulations sprayed within the paint spray booth. ### Claim 24 (depends on 21) The method as in claim 21, wherein the organic solvent includes at least one glycol component selected from the group consisting of dibasic esters, propylene glycols, polypropylene glycol oligomers, and monoalkyl or monophenyl ether derivatives of propylene glycol and polypropylene glycol oligomers. ### Claim 25 (depends on 24) The method as in claim 24, wherein said organic solvent includes between about 4 to about 20 percent by weight of said at least one glycol component. ### Claim 26 (depends on 24, 25) The method as in claim 24 or 25, wherein the organic solvent is at least one selected from the group consisting of tripropylene glycol monomethyl ether, 2-butoxy ethanol, triethylene glycol monomethyl ether, propylene-glycol N-butyl ether, ethylene glycol phenyl butyl ether, propylene glycol phenyl butyl ether, dipropylene glycol N-butyl ether, and dipropylene glycol monomethyl ether. ### Claim 27 (depends on 21) The method as in claim 21, wherein the organic solvent is a at least one dibasic ester selected from C.sub.1 -C.sub.4 dialkyl ester of at least one C.sub.2 -C.sub.6 aliphatic dibasic acid. ### Claim 28 (depends on 27) The method as in claim 27, wherein a portion of the dibasic ester is replaced by ethyl-3-ethoxy propionate. ### Claim 29 (depends on 21) The method as in claim 21, wherein the organic solvent is a mixture of 2-butoxy ethanol, dipropylene glycol monomethyl ether and a dibasic ester.