Patent ID: 7534309

Claim:
An aqueous aluminum brazing composition comprising a K—Zn—F-type zinc fluoride flux, an organic binder comprising a (meth)acrylate copolymer containing at least one carboxyl group-containing monomer, a (meth)acrylic acid/(meth)acrylate copolymer emulsion added as a precipitation inhibitor in an amount of 0.003-1.50 wt. %, based on 100 wt. % of the brazing composition, and an amino alcohol having a boiling point of 120-200° C. as a reaction inhibitor for inhibiting a reaction between zinc contained in the flux and a carboxyl group contained in the organic binder or the precipitation inhibitor, wherein the numerical value of the weight-average molecular weight of the copolymer in the emulsion used as the precipitation inhibitor is more than ten times greater than that of the copolymer of the organic binder and the brazing composition has a thixotropic index of 1.01-1.20.