JPS58131177A - Manufacture of aluminum-plated steel plate coated with heat-resistant paint - Google Patents

Abstract

PURPOSE:To produce an aluminum-plated steel plate coated with paint excellent in adhesiveness for working and resistance to heat, by applying and baking metallic Al-contg. fluororesin paint through the filmy matter of amino silane to the surface of the aluminum-plated steel plate. CONSTITUTION:After a degreased aluminum-plated steel plate is treated by aqeous amino silane adjusted to pH 8-10, fluororesin paint contg. 10-20wt% metallic Al powder by 100 of resin is applied and baked onto said base material. Said aqueous amino silane is preferably the aqueous solution of aminopropyl trihydroxysilane, its concentration is preferably adjusted to 0.1-10wt%, and a period for the pretreatment is controlled at 10-20sec, to form the filmy matter of amino silane having proper thickness. The paint film is closely stuck to the base metal through the filmy matter of amino silane. In addition, the adhesiveness is enhanced by slightly etching the base metal in an alkali solution. The metallic Al powder is added to inhibit the deformation of the paint film at a high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a coated steel plate in which an aluminized steel plate is coated with a fluorine-based resin paint to improve heat resistance and workability.

Fluorine resin is a resin with excellent heat resistance and chemical resistance. As an application that takes advantage of the characteristics of fluorine-based resin, aluminum is coated with fluorine-based resin and used in cookers, frying pans, etc. When coating aluminum with fluorocarbon resin, sintering and etching methods, for example, have been conventionally used as bonding methods since fluorocarbon resin is difficult to adhere to metal. The sintering method involves applying fluorine resin, drying and baking at high temperatures for a long time.

In the etching method, irregularities are created on the aluminum surface by electrochemical means (for example, anodic treatment using a direct current in an aqueous solution containing an electrolyte such as ammonium chloride), and a fluorocarbon resin is applied thereon. A dry baking method is used. In the case of aluminized steel sheets, it is possible to obtain painted steel sheets coated with fluorocarbon resin using the method described above, but the sintering method requires many steps such as drying and baking at high temperatures for a long time, and In the etching method, there is a problem of pollution due to wastewater treatment such as etching solution.

Therefore, the present inventors performed a pre-painting treatment on aluminized steel sheets with aminosilane, which is water-based and has excellent long-term stability, to achieve excellent adhesion between the aluminized steel sheets and the paint, and to also act as a hardening agent for the paint at the interface with the paint. We have also found a method that is suitable from the perspective of preventing pollution.

The present invention proposes a technology developed for improving the heat-resistant adhesion and workability of coated steel sheets made by painting and baking, in which the base metal is an aluminized steel sheet.

That is, the present invention is characterized in that (1) the base metal is limited to an aluminized steel plate;

(2) Treatment with aqueous aminosilane.

(3) Adjust the pH of the aminosilane aqueous solution to be slightly alkaline within the range of 8 to 1o before use.

(4) Painting and baking a fluorine-based resin containing At powder on its upper surface.

The present invention relates to a method for manufacturing a painted aluminized steel sheet with excellent processing adhesion and heat-resistant adhesion, which has the following main components.

Next, these requirements will be explained in detail.

First, the aluminized steel plate used in the present invention is hot-dip plated,
It can be applied to all products manufactured by vapor deposition plating or any other method.

Fluorine-based resin paints are mainly used from the viewpoint of adhesion and heat resistance.

In the present invention, the paint system used is a polytetrafluoroethylene or trifluoroethylene paint that has excellent heat resistance, chemical resistance, etc., to which metallic At powder is added to prevent deformation at high temperatures.

The action mechanism of the silane coupling agent is well known, but when the Silane Cup IJ'7 coupling agent is expressed as RS i
+3HIIC)” R8i (OI()++ + 3H
X, which is adsorbed onto the surface of an inorganic substance and forms a film of oxane bonds, resulting in a dense water-resistant film. Furthermore, the organic functional group R contributes to the adhesion of the coating material to the polymer.

On the other hand, if a non-polluting water-based treatment can be used as a pre-painting treatment, it will be advantageous to carry out pollution treatment and radiation prevention installations.

However, in the past, pre-treatment for Cr loading of fluorine-based paints (~) was not very effective. That is, instead of the conventionally known method of adding a non-aqueous vehicle and a silane coupling agent to a pigment to serve as an anchor, the present invention uses an aqueous aminosilane between the coating film and the base metal 11. The feature is that the film-like material formed using the method is made into a valve.

Therefore, as the aminosilane, B-noprobil trihydroginla is suitable.

NH2CI(2Ck(2-CHsoS i, (OIDa
This compound is stable in aqueous solution due to hydrogen bonding and can be synthesized stably at any ratio in water.

There is no need to treat it as a dangerous substance during storage, and it is possible to store it diluted with water.

Moreover, it has the characteristic that a strong adhesion can be obtained to the paint due to the film of aminorane formed on the base metal.

The concentration of water-soluble aminopropyltrihydroxysilane, which is a type of water-based aminosilane used in the present invention, is related to the amount of film after coating and drying on an aluminized steel plate. The concentration of the treated aqueous solution should be controlled within the range of 0.1 to 10% by weight, and the processing time should be controlled within the range of 10 to 20 seconds, since the aminoran compound itself may be destroyed or the effect may be saturated. is desirable.

In particular, the pH of the treatment solution needs to be in the range of 8 to 10 in order to lightly alkali-etch the steel plate surface, and 10 to 20% by weight of metal A based on 100% resin is added to the fluorocarbon resin paint.
It is essential to contain 7 powders. The reason for limiting the concentration and pH of the treatment solution is that if it is less than 0.1 weight factor, a uniform and effective film cannot be obtained on the surface of the steel plate and the coating film adhesion to the steel plate cannot be obtained, and if it exceeds 10 weight factor, The film on the surface of the steel plate becomes thicker and the skin itself becomes hard.
This is because the adhesion of the coating film to the steel plate deteriorates as described above due to the presence of the J-cut. Also, the pH of the processing solution is less than 8iii'
! If the pH exceeds 110, a stable and uniform film can be obtained by melting the aluminized surface (g + ila) to -F). This is so that you will not be affected.

The reason for specifying the content of gold @HT powder is that if the content is less than 10%, the addition of At powder will sufficiently prevent the deformation of the coating at high temperatures, and thus the adhesion of the coating film. ,
This is to reduce the heat-resistant adhesion, and when the weight exceeds 20, the addition of At powder υ11 causes the coating to become hard. 'JllT property is poor, and even Le; l membrane tightness F-1
: It's no good if you let it go low.

Next, the present invention will be concretely explained with reference to embodiments, but the present invention is not limited to the following embodiments which do not exceed the gist of the invention.

Example 1 Plate if O15mm, plating 11ν or m] 8μ aluminum plated with alkali removal 11i mouth surface,
Aminopro”, “Lutrihydroquine silane 0.05
It was immersed for 10 seconds in each aqueous solution adjusted to pi-I of 7.5 to 12 at a loading rate of ~11.0%, and the excess water solution was squeezed out using a roll, and after drying, a coated base plate was obtained.

As a paint, apply ``tetrafluoride ethylene paint'' containing 8 to 25 weight percent of metal aluminum powder in resin 100% to each of the above-mentioned painting base plates. Painted steel plate.

Next, Comparative Examples 1 to 5 were prepared using paints that did not contain metal aluminum powder on painted base plates similar to the actual h''Q example.
．． Comparative Examples 6 to 8 were those that were coated with metal aluminum powder Hofu paint after normal chromate treatment, and the normal adhesion and heat-resistant adhesion of the paint film were tested in four trials. and are shown in Table 1.

Below is 1 of the white test.゛1 degree value, candy 1 mock metallurgy test was performed by Elixe 76mm extrusion processing (punch 1 also = 1 inch), Teyubon impact (dropping an Ikg weight from a height of 50C + n with a punch radius of 1/2 inch)・Bend 2t, 4t16t1 at 180°, apply cellophane tape with such force and quickly peel it off.If there is no peeling of the coating at all, mark it with ◎, and there is very little VC. , Those with paint film peeled off are marked with a circle, those with a fair amount of paint film peeled off are marked with a circle, those with a significantly uniform coating are marked with an X mark.

In addition, the normal 'I-? When such tests were conducted under normal conditions, 6Q p, l, 200°C (D n 1Ili %
7m Ii Medium K 100 hours retention 1. After that, the test was carried out and the heat resistant adhesion was evaluated as a.

Table 1 shows that for Examples 19, 112-7 and 11-15, which are within the claimed scope of the present invention, amine/lane concentration 0.1-10% by weight + pH 8-10. +Metal aluminum powder 10-20 Even after 100 hours at heating temperature 1 200℃, peeling of coating 1 after 180 degree bending 2 was extremely (contrary to I + n 2), Invention a!, External Examples 1, 8-10 and 1.6.17
The two yarns are separated by q・11.

Comparative Examples 1 to 5 using paints containing no metallic aluminum powder. It can be seen that in Comparative Examples 6 to 8, in which paints containing metal aluminum powder were used in the ordinary Chronaut treatment, there was significant paint film separation after heating at 200° C. for 100 hours.

Implementation i3'l) 2 Using a coated steel plate obtained by processing and dry baking in the same manner as in Example 1, tests such as processing adhesion and post-processing heat-resistant adhesion were conducted.

In other words, in terms of processing adhesion, punch 1 ((A quality 5K) as shown in Fig.
DII) and)-Dice 2.2a (Material 5KI) 1.1
) and an upper die 3.3a (material: 5KDII), the painted steel plate A was drawn into a rectangular tube as shown in FIG. 2 to obtain a processed product 13. In the figure, 1v↓punch+2+2a indicates the lower die, and 3.3a indicates the upper die.

2nd grade processed product 13 Co-ner γlj j/C cello deep f After being applied, it is quickly peeled off, and the one with no peeling of the paint film is marked ◎, and the one with very slight peeling of the paint film is ρ0
The mark was marked Δ, the one in which one coat of Machinari coating had peeled off was marked as Δ, and the one in which one coat had peeled off significantly was marked with X. Regarding the heat-resistant adhesion after processing, the drawn product was held in an ambient temperature of 250° C. for 100 hours, and then a processing adhesion test was conducted and evaluated. Show the results to a second person.

Margin below Table 2 Amino Amino Aluminilla l, ll-Isu
Paint film density, ・1″11 cow sora/Nran powder filling Bocchi concentration Shoulder radius Ri11 King f+
[weight] (weight) pH (v)
ITIII j Power [1f ripe [11e KaIL shoulder? 1 table i 0.05 '7,5
8 6 (j △n 0,
10 8. ．． 0 10
6 (j) ↓′i,))＜
rl Rn Q I'l ]OR'
-As shown in Table 2, even if the coating film has good adhesion properties after processing, the coating film densities after processing and heating, which are the object of the present invention, are as good as those in Example]. It is H that shows the performance.

Therefore, the heat-resistant painted aluminized steel sheet according to the present invention has improved heat resistance, processing performance, and post-processing heat resistance due to the heat resistance unique to the aluminized steel sheet and the bonding effect of the present invention, and does not require conventional treatment. It has the same advantages as conventional coated aluminized steel sheets, as it eliminates the need for two coats of paint and does not require pollution treatment.
Its industrial value is enormous.

[Brief explanation of drawings]

Figure 1 shows the processing adhesion of Example 2 according to the present invention by ii+1
This shows the method of forming the fllI drum, where ■ is a punch, 2.2a is a lower die, 3.3a is an upper die, and A is a painted steel plate. FIG. 2 is a perspective view of a processed product which has been subjected to rectangular cylinder drawing using the forming die shown in FIG. B is a rectangular tube drawn double. 1"1 figure rice 2 figure

Claims (1)

[Claims] 1. A degreased aluminized steel plate is treated with aqueous aminosilane adjusted to pH 8 to 10, and a fluorine-based resin paint containing metal AA powder in an amount of 10 to 20 parts by weight per 100 parts of the resin is applied. A method for producing a heat-resistant painted aluminized steel sheet, comprising applying a baking coating to the base material. 2. The method for producing a heat-resistant painted aluminized steel sheet according to claim 1, wherein the aqueous aminosilane is an aqueous aminopropyltrihydroxysilane solution having a concentration of 0.1 to 10% by weight. 3. The method for producing a heat-resistant painted aluminized steel sheet according to claim 1 or 2, wherein the pretreatment time with aqueous aminosilane is 10 to 20 seconds.