JPS5914943A - Vinyl chloride resin coated steel plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin-coated steel plate in which a coating layer of vinyl chloride resin is formed on the surface of an aluminum-zinc alloy plated steel plate as a substrate. As such, a vinyl chloride resin coated steel sheet is provided, which is a steel sheet or a galvanized steel sheet with a coating film of vinyl chloride resin formed on the surface. For those with a coating layer of pinyluryl chloride formed on the surface of galvanized steel sheets, after the surface of the four galvanized button plates has been chemically treated with zinc ricinate or chromic acid, etc., the surface of the chemical conversion treatment layer is It is formed by applying adhesive and baking it, then applying chlorinated vinyl vine on the surface of the adhesive layer and baking it.
Corrosion resistance and weather resistance are improved by galvanizing, chemical conversion treatment, and a coating layer on the surface. Adhesives to be used include strontium chromate, calcium chromate, barium chromate, zinc chromate, etc.; 5 to 10% by weight of K (the sum of all pigments) is used, and zinc? The corrosion resistance of steel plates has been further improved.

By the way, it is known that an aluminum-zinc alloy coated steel sheet, in which an aluminum-zinc alloy plating layer is formed on the surface of the copper sheet, has better corrosion resistance than the galvanized steel sheet used above. Friend zinc aluminum coated product disclosed in the official gazette, Special Publication No. 53-2
Corrosion-resistant aluminum-zinc coating and method for producing the same disclosed in Publication No. 2528'8, Japanese Patent Publication No. 54-8335-53-
A method for treating iron strands by hot-dip coating disclosed in Japanese Patent Publication No. 46-3644, Corrosion-resistant zinc alloy coated iron metal article and method for manufacturing the same, disclosed in Japanese Patent Publication No. 1983-3644,
According to the iron substrate product having a coating and its manufacturing method disclosed in Japanese Patent Publication No. 44143, and the improved treatment method for iron stracid by hot-dip coating disclosed in Japanese Patent Publication No. 57-11390, aluminum It is said that 6-zinc alloy coated steel sheets have two to six times higher corrosion resistance than galvanized steel sheets. However, when a polyvinyl chloride resin-coated copper plate is formed using this aluminum-zinc alloy plated steel plate as a substrate by the above method, if it is used in a corrosive atmosphere, the coating layer of vinyl chloride formed on the surface of the plated steel plate will deteriorate. It has the disadvantage of peeling off and blistering from the end face (cut edge of the punched steel sheet), and this blistering and peeling is significantly inferior to those using a galvanized steel sheet as a substrate. A vinyl chloride resin drawing machine steel plate is formed using an aluminum-zinc alloy plated steel plate as a substrate, and there are areas where lead is not uniformly dispersed and aluminum is present in a larger amount than zinc (aluminum-rich phase), and conversely where zinc is more abundant than aluminum. It is unevenly distributed in the part where it is abundant (zinc-rich phase), and the zinc-rich phase is intertwined with the aluminum-rich phase in three dimensions like an ant's nest. It is thought that in the atmosphere, the zinc-rich phase corrodes and disappears in preference to the aluminum-rich phase, and the resulting hydrogen gas and corrosion products push up the vinyl chloride resin coating layer formed on the surface. In other words, a battery is formed between the aluminum-rich phase and the iron on the end surface, and the zinc-rich phase and the iron on the end surface of the aluminum-zinc alloy plated steel sheet. The phase corrodes first.

The present invention has been made in view of the above points, and even when an aluminum-zinc alloy plated copper plate is formed as a substrate, the dinylyuryl chloride coating layer formed on the surface may peel off or swell. PVC resin coating with excellent corrosion resistance that will not cause corrosion a! The purpose is to provide steel plates.

That is, the present invention provides a surface K of an aluminum-zinc alloy-plated steel sheet (2) on which an aluminum-zinc alloy plating layer (1) is formed by a hot-dip plating method, and a chemical conversion treatment layer (2) obtained by chemically treating the aluminum-zinc alloy plating layer f1+. 3), and on the surface of this chemical conversion treatment layer (3), strontium oxide or lucium oxide η=*t↓=beak is 20 to 70% by weight relative to the non-volatile content of the adhesive. The above object has been achieved by a steel plate coated with a vinyl chloride resin, which is characterized in that a coating layer (5) of pinyluryl chloride is formed through an adhesive (4) in which the amount of the vinyl chloride resin is mixed.

The present invention will be explained in detail below. As shown in the attached diagram, the aluminum-zinc alloy plating layer (1) is formed on the surface of the aluminum-zinc alloy-plated steel sheet (2) by hot dipping.
is formed. This aluminum zinc alloy plating layer (
As mentioned above, 1) is divided into an aluminum-rich phase (6) in which aluminum is contained more than zinc, and a zinc-rich phase (7) in which zinc is also contained in a larger amount. The structure is such that the phase (7) is intertwined with the aluminum-rich phase (6) like an ant nest. The components of the aluminum-zinc alloy plating layer (1) are not limited in any way, but for example, M is 4 to 75% by weight, most of the rest is zinc, and St, Mg, Ce'1, Sn
It is possible to use a product containing a small amount of a third component such as
AA-Zn-8r alloy, AI! -Zn-Mg alloy, An-Zn-C@gold alloy M-Zn-1Sn alloy, etc., is used for plating, and in particular, M is 55% by weight, Zn is 43.4% by weight, and Si is 1.5% by weight. It is preferable to use one containing 6% by weight. A chemical conversion treatment layer (3) is formed on the surface of this aluminum-zinc alloy plating layer (it) by applying chemical conversion treatment such as chromic acid type or zinc phosphate type. The chemical conversion treatment can be carried out by spraying, dipping, roll coating, or the like. Next, the surface of the chemical conversion treatment layer (3) is coated with strontium chromate or calcium chromate, and then baked at a temperature of 180 to 230°C. It is something to attach. Here, the adhesives (4) used include acrylic, epoxy-based 1, acrylic/phenol-based 1, acrylic/epoxy/phenol-based, hardening type uretashi-based, anhydrous machining acid-modified poly-D fillet-based , modified polyester-based adhesives can be used, but acrylic and other adhesives can be used.
Preferably, Eboshi adhesives and acrylic/phenolic adhesives are used. Strontium chromate and calcium chromate do not have the effect of improving the blistering of the anti-rust paint layer (5), and if the amount exceeds 70% by weight, the adhesive (4) and the paint layer (5) The adhesion is impaired.

Further, the adhesive (4) may be prepared by appropriately blending extender pigments such as titanium oxide and various antirust pigments shown in the conventional examples.

Therefore, the vinyl chloride resin-covered steel sheet formed in this way was used as a substrate for an aluminum-zinc alloy plated steel sheet (
By using 2), the aluminum-zinc alloy plating layer (1) on the surface can improve the corrosion resistance compared to the conventional galvanized steel sheet substrate. The coating layer (5) can prevent penetration of water and the like and transmission of light, and can improve corrosion resistance, weather resistance, and water resistance. Furthermore, the adhesive (4) interposed between the aluminum-zinc alloy plated steel sheet (2) and the coating layer (5) contains 20 to 70% of the nonvolatile component.
By incorporating wt% of chromate or calcium chromate, corrosion of the aluminum-zinc alloy plating layer (1) is prevented, and the zinc ritte phase (7) of the aluminum-zinc alloy plating layer (1) is corroded. It is something that can be suppressed.

In addition, in the above example, the adhesive (4) containing strontium oxide and calcium phosphate was applied to the chemical conversion treatment layer (
I tried to apply only one layer on the surface of 3), but the adhesive (
4) may be applied in two or more times to form a plurality of adhesive layers. In that case, for example, the adhesive (4) for undercoating should be 50 to 50% of the non-volatile content of the adhesive.
The adhesive (4) containing 70% by weight of strontium chromate or calcium chromate is used to increase the anti-rust effect, and the adhesive (4) for the top coat of the skin uses the non-volatile content of the adhesive. The coating layer (
5) improves the adhesion with.

As described above, in the present invention, strotium chromate or calcium chromate is added to the surface of the chemical conversion treatment layer of an aluminum-zinc alloy plated steel sheet at a rate of 20% relative to the non-volatile content of the adhesive.
Since a coating layer of pinyluryl chloride was formed through an adhesive containing ~70% by weight, it was possible to increase the corrosion resistance of the vinyl chloride resin-coated steel sheet by attaching the aluminum-zinc alloy plated steel sheet to the substrate. Adhesives containing strontium or calcium chloride can reduce the corrosion of the zinc-rich phase of the aluminum-zinc alloy plating layer, and even in corrosive atmospheres, the adhesive can prevent corrosion of the zinc-rich phase of the aluminum-zinc alloy plating layer. It is possible to prevent the formed pinyluryl chloride coating layer from blistering or peeling.

The present invention will be specifically explained below using examples.

<Examples 1 to 4, Comparative Examples 1 to 4> A955 weight section with plate thickness of 0.4 k, Zn4 g, 4 ply f
t%, Si 1.6% by weight aluminum-zinc alloy plated steel sheet (plating area 150y/lff' (both sides), plating thickness 20 microns on one side) was treated with chromic acid-based chemical conversion treatment liquid Bosidilite 1415A (manufactured by Nippon Bar Power Ijinta Co., Ltd.). Roll coating was applied so that the coating amount was 150 to 200 .mu./m' (dry state) and dried at 40 to 50°C. Next, in the formed chemical conversion treatment tank, 20 parts by weight of acrylic copolymer, 10 parts by weight of phenol resin, 20 parts by weight of normal-butanol, and Toluene? , 50 parts by weight of an adhesive containing strontium chloride in the amount shown in the following table based on the nonvolatile content of an acrylic/phenolic adhesive 9 to IIy/9
72” (dry state) and then at a temperature of 220
Baked for 60 seconds at 200°C, immediately thereafter applied vinyl chloride nor paint for exterior use (manufactured by Nippon Paint, brown color) to the top surface of the adhesive layer to a film thickness of 200 microns (dry state), and baked at 200°C for 75 seconds. After baking for a few seconds, a coating layer is formed on the surface. : Obtained vinyl chloride resin grade steel plate.

<Example 5.6> A vinyl chloride resin coating was prepared in the same manner as in Example 1 except that calcium chromate was added in the amount shown in the following table to the nonvolatile content of the acrylic phenolic adhesive and the following adhesive was used. Obtained steel plate.

<Conventional example> PVC resin was coated in the same manner as in Example 1, except that an acrylic/phenol adhesive containing no anti-rust pigment was applied to the surface of a galvanized iron plate (Z-25) with a thickness of 0.4 tw+. Obtained steel plate.

Next, the adhesion of the vinyl chloride resin coated steel plates obtained in Examples 1 to 6, Comparative Examples 1 to 4, and Conventional Example and the blistering of the coating film on the end surface were measured. In addition, evaluation of adhesion and splay of the paint film on the edge surface was performed as follows. did.

In the cold and hot cross-strike method, incisions are made in the coating layer with a knife at 5-bath intervals, and after 7 seconds of pressing, the temperature is 135°C x 1.
This is a forced peel test with one cycle of immersion in room temperature water for 23 hours, and a boiling water cross-cut test.
After extrusion processing, the adhesiveness was evaluated by forced peeling (Im test) after 5 cycles, one cycle being immersion in boiling water for 8 hours and immersion in room temperature water for 16 hours. Then score these results out of 5 [5 points (excellent) - 1 point (poor)]
] Deya J decided and followed, ◎...all 5 points, ○・
...There are 4 items in 1 part, Δ...There are 2 to 3 items in 1 part, ×...
・Displayed as 1 part 1 point.

Coating and film on the edge! No. 7?Do not seal the edges of the vinyl monochloride resin-coated steel plate on all sides, but seal the back side with polyester 31/tape7? -50mX 100II
A vinyl chloride resin-coated steel plate of I++ size was exposed to a salt spray tester (JIS-5400, 7, 8) to evaluate blistering and peeling from unsealed edges (hereinafter referred to as edge creep). Next. The evaluation of edge creases was expressed by the maximum bulge width at the edges, diagonal cross cuts were made with a knife in the coating layer, and the number and maximum bulges at these scratched areas were expressed. The results are shown in the table below.

From the results in the table above, it can be seen that the adhesive solution is mixed and the acid strike is 0.0%.
It can be seen that the adhesion and edge crease resistance of the coating film vary greatly depending on the amount of lithium, lithium, or calcium phosphate. Comparative Examples 1 to 3 contain a small amount of strontium chromate, but these have good adhesion but have large blisters, and Comparative Examples 4 and K, which contain a large amount of strontium chromate, It can be seen that the adhesion is reduced in some cases. On the other hand, the products of the examples were satisfactory in terms of adhesion and swelling, and were superior to those of the conventional examples.

[Brief explanation of drawings]

The attached drawing is a partially cutaway enlarged sectional view of one embodiment of the present invention,
(1) is an aluminum zinc alloy plating layer, (2) is an aluminum zinc alloy plating steel sheet, (3) is a chemical agent patent attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) A chemical conversion treatment layer is formed by chemical conversion treatment of the aluminum zinc alloy plating layer on the surface of an aluminum zinc alloy plated steel sheet on which an aluminum zinc alloy plating layer is formed by hot-dip plating. A coating layer of vinyl dichloride is formed on the surface via an adhesive containing 20 to 70% by weight of strontium chromate or calcium chromate based on the nonvolatile content of the adhesive. PVC resin coated steel plate.