Alkaline degreasing method using alkaline degreasing solution

摘要

The alkali silicate is contained in a concentration of 0.01 to 3 g / l, and the HLB value (= 20 × Mw / M, Mw: weight of the hydrophilic group portion, M: molecular weight of the surfactant) is 5 to 11, and the following general formula (I Alkali degreasing cleaning method using the alkali degreasing cleaning liquid which contains 0.01-10 g / L of nonionic surfactant which has a structure represented by), and whose pH value is 9.5 or more.;R-0-(EO) m (AO) n H ... (I);(Wherein R represents an alkyl group, EO represents an ethylene oxide group, AO represents an alkylene oxide group (propylene oxide group and / or butylene oxide group), m represents the number of moles of addition of EO and is an integer of 3 to 7, n Is the number of moles of AO added and is an integer from 1 to 6, and m and n satisfy the relationship of n m≤3n)