Patent ID: 6800345
Filing Date: 2004-10-05
Classification: B23K,F28F,Y10T

Abstract:
An aluminum extruded multi-cavity flat tube having excellent brazing characteristics for use in automotive heat exchangers, wherein at least one of the flat surfaces of the tube is coated by roll-transfer printing with a brazing flux composition having a viscosity between 100 and 10,000 mPa-s and comprising brazing flux and a synthetic resin based, as its main constituent, on a methacrylate homopolymer or a methacrylate copolymer, the weight ratio of the brazing flux to the synthetic resin in the flux composition is in the range of from 9:1 to 7:3 and the coating with the brazing flux composition is formed by mixing brazing flux powders with an organic solvent, in which the synthetic resin is dissolved, having an atomic ratio of carbon to oxygen of from 2 to 3 in its molecular structure, and evaporating the organic solvent.