Matched coating for aluminium alloy base material

Abstract

The matched coating for aluminum alloy base material special to corrosion protection and decoration comprises: the primer with epoxy-amine addition system as double constituents, the middle painting as polyester / polyurethane system used polyester resin with acid number of as 8-10 and alternative soft and hard chain segments, and the top coat used polyester resin with acid number not more than 6 and main chain as hard segment and chain length and branching degree both more than the middle. Wherein, the polyamine on primer reacts with the epoxy resin to produce the secondary amine with more slow activity and enhance the adhesive force. This invention solves the aluminum alloy adhesion problem without smoke resistant material, and comes up to the first-level security standard.

Description

technical field [0001] The invention relates to a matching coating for aluminum alloy substrates, which is especially suitable for anticorrosion and decoration of various aluminum alloy train bodies. Background technique [0002] At present, domestic rail trains are speeding up in an all-round way. In order to reduce the weight of the car body, the train body is transitioning from a steel structure substrate to an aluminum alloy substrate. However, under natural conditions, the aluminum alloy reacts with oxygen in the air to easily form an oxide film, and this oxide film has a relatively high density, thus causing many existing coatings to fail to achieve good adhesion on the surface. The current means to solve this problem is to chemically treat the aluminum alloy surface, or to modify the coating itself so that it can achieve good adhesion on the difficult-to-adhesive aluminum alloy substrate, or to combine these methods. For example, U.S. Patent 6458898B1 introduces a tw...

AI Technical Summary

Problems solved by technology

However, this anti-corrosion effect is limited to the physical shielding effect of aluminum powder. The adhesion between the bottom layer and the aluminum alloy substrate still depends on the adhesion ability of the existing ordinary H04-1 epoxy enamel, and no special attention is paid to the bottom layer. The adhesion problem with the oxide layer on the aluminum alloy surface, the combination of the surface layer and the bottom layer also utilizes the compatibility between the existing S01-3 polyurethane varnish and the existing epoxy enamel paint. The problem of poor adhesion to aluminum alloy substrates