JPH05147097A - Method for coloring drawings - Google Patents

Abstract

PURPOSE:To provide a method for uniformly giving various colors to drawings, such as a container, obtained by drawing a laminate of a dyeable crystalline thermoplastic resin layer, such as a polyamide resin (nylon-6, nylon-66, or the like) and a polyester resin (PET or the like), applied on the surface of a metal plate. CONSTITUTION:A laminate obtained by coating the surface of a metal plate with a dyeable crystalline thermoplastic resin layer is molded by drawing. In a temperature range from a melt initiation temperature of the applied thermoplastic resin up to and including [an endothermic peak (Tm) -5 deg.C in a differential thermal analysis], the drawings are thermally treated and, thereafter, colored with a dye. In this manner, the surface of the drawings can be uniformly dyed and easily provided with various colors, and the tone can be changed without labor. Because of these merits, this invention can be used for producing electronic component parts and various types of containers requiring a good appearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated plate having a metal plate surface coated with a dyeable crystalline thermoplastic resin layer of polyamide resin (nylon-6, nylon-66, etc.), polyester resin (PET, etc.). The present invention relates to a coloring method in which a drawn product such as a container obtained by drawing can be uniformly colored in various colors.

[0002]

2. Description of the Related Art Laminated plates in which a synthetic resin layer is coated on the surface of a metal plate such as a steel plate or an aluminum plate are formed by drawing into various shapes, and in the field of electric products and building materials,
The surface of the molded product is colored in various colors for the purpose of imparting decorativeness and distinctiveness. As a coloring method, usually, a film before being laminated on a metal plate is colored, and a method of forming a film after mixing a colorant such as a pigment before forming the film, or a film dyed with a dye is used. There is a method of stacking by using. In such a method of using a film colored before lamination, there is a problem that the film is discolored due to heat history when laminated on a metal plate or partial variation of coating thickness, or uneven color is generated, or the color tone is changed. There was a problem that it took time to do.

Therefore, there is a method of dyeing a drawn product obtained by drawing using the above laminated plate with a dye and coloring the molded product itself. The film is made of a crystalline thermoplastic resin such as polyamide resin or polyester resin. In the case of a film formed from a resin, when deep drawing with a large drawing ratio or bending at an acute angle is performed in the cold, the crystallographic orientation is locally increased, and the dyeability deteriorates. Then, there was a problem that color unevenness occurs in that portion.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been found to solve the above-mentioned problems by heat-treating a draw-formed product in a specific temperature range and then dyeing it. A laminated plate coated with a crystalline thermoplastic resin layer that can be dyed with a dye is drawn on the surface of a metal plate, and the melting start temperature of the coated thermoplastic resin or more is exceeded [[Endothermic peak (Tm) of differential thermal analysis] -5 ° C] or less, after heat treatment, the molded product is dyed with a dye.

Hereinafter, the method of the present invention will be described in detail. Examples of the metal plate used in the present invention include a steel plate, an aluminum plate, a stainless plate, and a copper plate, but are not limited to these. The resin material of the crystalline thermoplastic resin layer covering the metal plate is a crystalline and dyeable resin, for example, nylon-6, nylon-6.
6, polyamide resins such as nylon-6 / 66 copolymer, and polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin.

Various methods can be applied to coat the above-mentioned metal plate with the crystalline thermoplastic resin layer. After applying various adhesives to the metal plate and baking it, the synthetic resin film is melt extruded by an extruder. The method of laminating is preferable because of good productivity. Next, the laminated plate obtained by these methods is used to draw into various shaped containers and the like. As a draw forming method, a sequential feeding die with a lance slit is used, and finally, multi-stage draw forming can be carried out at a draw ratio and an ironing ratio required for a container shape and the like. The drawing may be further bent if necessary.

In the present invention, it is necessary to heat-treat a drawn product such as a container obtained by the above method in a specific range, and the melting start temperature of the coated resin to [the endothermic peak (Tm) -5 of the differential thermal analysis]. [° C]. here,
The melting start temperature and endothermic peak (Tm) of the resin may be measured by a differential scanning calorimeter (DSC). If the heat treatment temperature is lower than the melting start temperature of the resin, uniform dyeing cannot be performed, and the endothermic peak ( There is a problem that the coated resin is discolored at a processing temperature exceeding Tm) −5 ° C. The heat treatment may be carried out by an ordinary heating means such as a heater, and the heating time may be determined in consideration of the thickness of the resin, the draw ratio and the like.

The molded article which has been subjected to the above heat treatment is dyed with a dye, and as the dye, one having excellent dyeability with respect to the resin layer to be used may be selected, and examples thereof include a direct dye, an acid dye and a basic dye. , Mordant dye, acidic mordant dye,
Sulfur dyes, sulfur vat dyes, soluble vat dyes, disperse dyes,
Examples thereof include reactive dyes. As a method of dyeing, a method of immersing the molded product as it is in a dye bath having a constant concentration is suitable.

[0009]

EXAMPLE A laminated plate in which a film (thickness 20 μm) made of nylon-6 was coated on an aluminum plate (thickness 300 μm) was drawn so that the resin layer was on the outside, and the diameter was 6.3 mm and the height was 5 mm. A bottomed cylindrical container of 0.11 mm was obtained. Using the obtained container, the heat treatment conditions were changed, and the effect on the dyeability was confirmed. (The melting start temperature of the nylon-6 used here is 210 ° C., and the endothermic peak (Tm) is 225.
It was ℃. ) A container obtained by the above-mentioned drawing was heat-treated at 220 ° C. for 5 seconds and then immersed in an acid dye (navy blue) solution to dye the resin layer. As a result, uniform dyeing was performed without uneven color on the surface. On the other hand, color unevenness was observed in the case where the heat treatment temperature was 207 ° C. and the case where the heat treatment was not performed using the above container, and the resin layer on the surface was discolored in the case where the heat treatment temperature was 230 ° C.

[0010]

As described above, according to the method of the present invention, it is possible to uniformly dye the surface of the drawn product, easily apply various colors, and it is easy to change the color tone. There are advantages.

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Claims (1)

[Claims] 1. A laminated plate in which a crystalline thermoplastic resin layer capable of being dyed with a dye is coated on the surface of a metal plate by drawing,
The molded article is dyed with a dye after being heat-treated in a temperature range not lower than the melting start temperature of the coated thermoplastic resin and not higher than [the endothermic peak (Tm) -5 ° C of differential thermal analysis]. Method of coloring drawn products.