Aqueous aluminum brazing composition, aluminum material coated with the brazing composition, brazing method using the aluminum material, and automotive heat exchanger manufactured by using the brazing method
US7534309B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 16, 2003 |
| Grant date | May 19, 2009 |
| Priority date | — |
| Expiry date | Feb 5, 2024 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF28F1/126
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An aqueous aluminum brazing composition containing an organic binder and a zinc-based flux which prevents the precipitation of the zinc-based flux having a large specific gravity while securing an excellent brazeability. The thixotropic index of the brazing composition is adjusted to 1.01-1.20 by adding a (meth)acrylic acid/(meth)acrylate copolymer emulsion to the brazing composition as a precipitation inhibitor in an amount of 0.03-1.50 wt % of 100 wt % of the brazing composition. Since the (meth)acrylic acid/(meth)acrylate copolymer emulsion is used as the precipitation inhibitor in a specific amount instead of other types of compounds used for a powder-containing paint, such as ultrafine particle silica, poly(meth)acrylate, or polyvinyl alcohol, the precipitation of the zinc-based flux can be prevented without impairing the brazeability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.