Precoated metal sheet, method for manufacturing precoated metal sheet, and continuous coating device

Abstract

To purpose of the present invention is to obtain high levels of both the adhesiveness between coatings and the glossiness in a multilayer precoated metal sheet produced on a continuous coating line. A precoated metal sheet having a plurality of coating layers on one or both sides of a metal sheet (10), wherein the coating layers include: a coloring coating layer (111) disposed on the metal sheet (10) side, the coloring coating layer (111) containing a coloring pigment; a pigment-enriched layer (123) formed on the coloring coating layer (111), the pigment-enriched layer (123) having a coloring pigment concentration higher than the average coloring pigment concentration in the coloring coating layer (111), and the coloring pigment concentration increasing towards the obverse layer side; a diffusion layer (122) formed on the pigment-enriched layer (123), the diffusion layer (122) having a coloring pigment concentration that decreases towards the obverse surface side; and a clear layer (121) formed on the diffusion layer (122), the clear layer (121) containing no coloring pigment. The ratio d1 / d2 between the thickness d1 of the clear layer (121) and the thickness d2 of the pigment-enriched layer (123) is 1.7<=d1 / d2<=4.7.

Description

technical field [0001] The present invention relates to a precoated metal sheet capable of achieving both high gloss and high adhesion between coating layers, a method for manufacturing the precoated metal sheet, and a continuous coating device. Background technique [0002] As coated metal sheets for various purposes such as home appliances, construction materials, civil engineering, machinery, automobiles, furniture, and containers, pre-coated metal sheets that have been pre-coated at ironworks, etc. are used. The precoated metal sheet is formed by coating the surface (one or both surfaces) of a metal sheet such as a steel sheet or a plated steel sheet with a single-layer or multi-layer coating film. For example, in a precoated steel sheet, a multi-layered coating film (for example, a primer coating film, a colored coating film, a varnish coating film, etc.) is coated on the surface of a plated steel sheet. [0003] Conventional continuous coating methods that continuousl...

AI Technical Summary

Problems solved by technology

However, there is a problem that when the upper layer is coated, it is difficult for the upper layer of varnish paint to fuse with the completely dried and hardened lower layer of the colored coating film, and the adhesion between the upper and lower layers is reduced, so it is easy to get stuck on the two-layer coating film. delamination at the interface

Images