| 摘要 |
PROBLEM TO BE SOLVED: To provide a recycling method of aqueous cleaning liquid, with which the aqueous cleaning liquid is recycled from a waste cleaning liquid produced after cleaning of water-based coatings with the aqueous cleaning liquid. SOLUTION: In the method, the aqueous cleaning liquid is recycled from the waste cleaning liquid produced after spraying the water-based coatings to an automobile as a base coating with a coating machine, washing the coating machine with the aqueous cleaning liquid at least containing butyl cellosolve, an alcohol, an amine, and water and with a pH of 10-12, and further washing the coating machine with a hydrophobic cleaning liquid. In the method, a filtration step and an adjustment step are conducted. In the filtration step the waste cleaning liquid is passed through an ultrafiltration membrane so as to obtain a filtrate. Further in the adjustment step, at least one species selected from butyl cellosolve, the alcohol and the amine is added to the filtrate, and the filtrate is adjusted so as to have a pH of 9-12. COPYRIGHT: (C)2009,JPO&INPIT
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