JPS6021545B2 - Thermoplastic resin coated metal plate with excellent corrosion resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal plate coated with a thermoplastic resin. ,zinc,
Addition of one or more oxides or hydroxides of aluminum, lead, tin, manganese, cobalt, nickel, copper (or chromium) greatly improves corrosion resistance without reducing resin properties or adhesive performance. This invention relates to a thermoplastic resin-coated metal plate that has been improved.

BACKGROUND ART Composite materials made by coating metal plates with thermoplastic resin have been widely used in fields such as building parts, home appliances, and can parts. Particularly in fields that require corrosion resistance, such as outdoor building materials or poor materials for cans, corrosion resistance varies greatly depending on the type of surface treatment of the base metal plate, so it is important to pay close attention to the surface treatment. That was the reality. Although these thermoplastic resin-coated metal sheets generally exhibit excellent corrosion resistance in the unprocessed state, when they are processed, they exhibit corrosion resistance, especially in the resin layer. If a clutch occurs,
Corrosion resistance deteriorated significantly, which became a problem in practical use. The present invention solves various problems as mentioned above, and
The object of the present invention is to provide a thermoplastic resin-coated metal plate that has significantly improved corrosion resistance after processing.

Hereinafter, the content of the present invention will be explained in detail.

First, thermoplastic resins include polyethylene resin, polypropylene resin, vinyl chloride resin, polyester resin,
Examples include one type or a mixture of two or more types selected from nylon resins, ionomer resins, pyrogenic resins, acrylic resins, vinyl acetate resins, urethane resins, and the like. Next, as the adhesive resin, one or two of acrylic resin, epoxy resin, nylon resin, urethane resin, vinyl resin, synthetic rubber resin, phenol resin, olefin resin, or ester resin is used. It includes more than one species.

Next, the metal powder added to the adhesive layer or thermoplastic resin layer is one of the oxides or hydroxides of zinc, aluminum, lead, tin, manganese, cobalt, nickel, copper, or chromium. Or two or more types,
When adding it to the adhesive layer, its particle size and blending amount are as follows:
The powder has a particle size of 10 mm or less and contains 10 to 10 parts by weight of the powder based on 10 parts by weight of the solid content of the adhesive resin.On the other hand, when added to a thermoplastic resin layer, the particle size 5
The above-mentioned powder having a particle size of 0 fm or less is contained in an amount of 10 to 300 parts by weight per 100 parts by weight of the solid content of the thermoplastic resin.

Add aluminum, zinc,
There are metal powders such as tin and lead. Rust-preventing pigments such as strontium acid may also be added. Here, if the amount of the powder added is less than 1 part by weight, the corrosion resistance will be extremely reduced. On the other hand, if the amount added to the adhesive layer is 10 parts by weight or more, the adhesion will decrease when coated with a thermoplastic resin. In addition, the amount added to the thermoplastic resin layer is
When the amount exceeds 300 parts by weight, the strength of the resin layer itself becomes brittle and cracks tend to occur when processed. In addition, the particle size of the powder is loAm when added to the adhesive layer.
The following is preferable; if it exceeds loAm, the uniformity of the adhesive layer will be reduced and the coverage of the thermoplastic resin of the upper layer will be deteriorated.

On the other hand, when the particle size of the powder when added to the thermoplastic resin layer is 50 m or more, not only the appearance of the resin layer deteriorates, but also the uniform dispersibility of the powder becomes poor.
The powder used in the present invention may also be used as a pigment, but it can be used for the purpose of the present invention even if it does not meet various strict conditions as a commercially available pigment.

Next, basic metal plates include mild steel plates, aluminum plates, alloy plates thereof, glazed tin plates, chromic acid-treated steel plates, chrome-plated steel plates, electrically or hot-dip galvanized steel plates, and alloy plates. Examples include cut plates or strip plates of surface-treated steel plates such as coated steel plates, nickel-plated steel plates, phosphate-treated steel plates, and chromate-treated steel plates.

Next, the thickness of the thermoplastic resin layer is generally 10 to 50 mm.
A value of 0 France m is useful; if it is less than loAm, the corrosion protection against metal plates will decrease, and if it is more than 500 m, it will be economically disadvantageous.

These thermoplastic resins are available in film or sheet form,
The metal slope can be coated in any form such as powder, pellet, or paste, but in consideration of workability, a film or sheet is preferred. Further, if necessary, a thermoplastic resin colorant, light or heat stabilizer, lubricant, antistatic agent, etc. may be added. On the other hand, the thickness of the adhesive layer is generally preferably in the range of 1 to 10 m, and lr
If the thickness is less than 10 m, the corrosion resistance will be extremely degraded, causing a practical problem, and if it is 101 m or more, it will be economically disadvantageous. Further, the adhesive may be in the form of a solution, powder, paste, film, or sheet. Now, an example of a method for obtaining a thermoplastic resin-coated metal plate of the present invention will be briefly described.

First, adhesive is applied to the surface of a cut plate or band-shaped metal plate using a coating equipment such as a Rofu coat, and then
Dry and cure at a temperature of 0.000C and then coated with thermoplastic resin.

After coating, if necessary, a reheating treatment is performed to improve adhesive properties, and then immediately cooled to obtain a thermoplastic resin-coated metal plate. Here, when using an adhesive containing the metal powder, the thermoplastic resin coated on the upper layer may cover either the resin layer containing the metal powder or the resin layer not containing the metal powder. .

In addition, when using an adhesive that does not contain the metal powder, the thermoplastic resin coated on the upper layer must cover the resin layer containing the metal powder. The thermoplastic resin-coated metal plate thus obtained has excellent properties such as processing adhesion, corrosion resistance, and chemical resistance, and has a beautiful surface, so it can be applied to various uses.

The effects of Examples will be explained in detail below.

Example 1 A polyester resin film (product name: Lumirror...
・A film (manufactured by Toray Industries, Inc., film thickness: 50 rm) was coated with the following adhesive using the following treatment method.

Adhesive urethane resin (solid content 51%) Product name: Adcode 7691 Manufactured by Toyo Morton Co., Ltd. 10 parts by weight Zinc oxide powder (particle size 1 to 6 rm) 1 part by weight Curing agent Product name: Catalyst F Manufactured by Toyo Morton Co., Ltd. 6 .5 parts by weight processing method: Apply the adhesive on one side of the steel plate by roll coating to a dry thickness of 5 mm, then heat-treat between sands at a temperature of 200 q0 in step 3, and evaporate the solvent component. The film was then coated and immediately quenched.

The obtained polyester resin-coated steel sheet exhibited excellent processing adhesion, with no delamination observed between the polyester resin and the steel sheet even when subjected to Igga Eriksen 8 side overhang processing.

In addition, almost no blisters or red rust were observed from the cross-cut portions during a 10-bait corrosion resistance test using a salt water mist tester specified in JISZ 2371.

On the other hand, when an adhesive with zinc oxide powder removed was used, a large amount of red rust was observed from the cross-cut portions after 4 gluing times in the salt water mist test. Example 2 A polypropylene resin film (wet tension of the surface in contact with the adhesive: 39 dyne/, film thickness: 60〃m) was placed on one side of a degreased electrolytically chromic acid-treated steel plate with a thickness of 0.5 mm using the adhesive shown below. It was coated using the same treatment method as in Example 1.

Adhesive urethane resin Product name: Adcode 7691 manufactured by Toyo Morton Co., Ltd. 10 parts by weight Zinc hydroxide powder (particle size 2-8 rm) 2 parts by weight Curing agent Product name: Catalyst F manufactured by Toyo Morton Co., Ltd. 6.5 parts by weight The polypropylene resin-coated steel sheet exhibited excellent processing adhesion in the same A-Xen peel test as in Example 1, and no delamination between the polypropylene resin and the steel sheet was observed.

In addition, almost no pristar or red rust was observed from the cross-cut portion during the 12-field corrosion resistance test using the same salt water mist tester as in Example 1. On the other hand, when using an adhesive with zinc hydroxide removed, a large amount of red rust was observed from the cross-cut portions in the salt water fog test at 7 hours. Example 3 A low-density polyethylene resin film (wetting tension of the surface in contact with the adhesive: 39.0 Dine/
An arc, film thickness 100 mm) was coated using the following adhesive in the same manner as in Example 1.

Adhesive urethane resin (solid content 50%) Product name: Adcode 7691 Manufactured by Toyo Morton Co., Ltd. 10 parts by weight Aluminum hydroxide powder (particle size 1 to 6 m) 4 parts by weight Curing agent Product name: Catalyst F Toyo Morton The obtained polyethylene resin-coated steel sheet (6.5 parts by weight) showed excellent processing adhesion in the same Eriksen peel test as in Example 1, and no delamination between the polyethylene resin and the steel sheet was observed.

Further, during a corrosion resistance test using the same salt spray tester as in Example 1 for 10 calm hours, almost no blisters or red rust were observed from the cross-cut portions. On the other hand, in the case of using a thermoplastic resin from which aluminum hydroxide powder was removed, a large amount of red rust was observed from the cross-cut portions after 4 hours of the salt water mist test. Example 4 30% of metallic chromium was applied to the surface of a clean galvanized steel plate with a thickness of 0.5 mm (amount of zinc deposited on one side: 10%/〆).
Chromate treatment is applied so that it becomes O/Me.

After applying an acrylic adhesive to one side using the same treatment method as in Example 1 and drying it, the following thermoplastic resin was applied to a thickness of 200 rm using normal roll coating. Sand heat treatment was carried out. Thermoplastic resin Polyvinyl chloride resin 10 parts by weight Dioctyl phthalate 5 parts by weight Calcium stearate 3 parts by weight Zinc oxide powder (particle size 10~
The resulting polyvinyl chloride resin-coated metal sheet showed excellent processing adhesion in the same Eriksen peel test as in Example 1, and showed no delamination between the vinyl chloride resin and the galvanized steel sheet. I was hooked. I couldn't admit it.

In addition, corrosion resistance test 20 using salt water lamp similar to Example 1
During the heating time, almost no blisters or red rust were observed from the cross-cut portion. On the other hand, those using thermoplastic resin with zinc oxide powder removed,
A large amount of red rust was observed from the cross-cut portion during the 7th period of the salt water mist test. Example 5 Clean surface thickness 0
．． Chromate treatment is applied to the surface of a zinc alloy-plated steel sheet with a thickness of 32 mm (zinc alloy coating amount on one side: 10 m/m), and the following thermoplastic resin film is applied to one side. , and coated with a urethane adhesive in the same manner as in Example 1.

Thermoplastic resin film (thickness: 100 mm) Polyethylene resin: 10 parts by weight Aluminum hydroxide powder (grain: 20-40 mm): 10
Parts by weight (character ≧ Meng; Yoshio Yoshio Yoshisan Miyoshi/Hada) The obtained polyethylene resin-coated metal plate showed excellent processing adhesion in the same Eriksen peel test as in Example 1, and was similar to the polyethylene resin film. No delamination was observed in the zinc alloy coated steel sheet.

Further, during the corrosion resistance test 20 using the same salt water fog as in Example 1, almost no occurrence of pristar or red rust was observed from the cross-cut portions. On the other hand, in a polyethylene resin-coated metal plate in which the polyethylene resin film does not contain aluminum hydroxide powder, a large amount of red rust was observed to occur from the cross-cut portions during the 7 minute salt water fog test.

Claims (1)

[Scope of Claims] 1. In a metal plate coated with a thermoplastic resin, urethane resin and zinc or aluminum oxide or hydroxide with a grain size of 10 μm are provided at the interface between the thermoplastic resin and the metal substrate.
A thermoplastic resin with excellent corrosion resistance, characterized in that an adhesive containing one or more of the following powders in an amount of 10 to 100 parts by weight per 100 parts by weight of the solid content of the resin is interposed: Coated metal plate. 2. Corrosion resistance according to claim 1, wherein the metal substrate is a thin steel plate, a tinned steel plate, an electrolytic chromic acid treated steel plate, a galvanized steel plate, a surface-treated steel plate similar to these, or an aluminum plate. Excellent thermoplastic resin coated metal plate. 3. In a metal plate coated with a thermoplastic resin, one or more powders of zinc or aluminum oxide or hydroxide with a particle size of 50 μm or less are added to the thermoplastic resin,
A thermoplastic resin-coated metal plate having excellent corrosion resistance, characterized in that 10 to 300 parts by weight of the powder is mixed with 100 parts by weight of the solid content of the thermoplastic resin. 4. Corrosion resistance according to claim 3, wherein the metal substrate is a thin steel plate, a tinned steel plate, an electrolytic chromic acid treated steel plate, a galvanized steel plate, a surface-treated steel plate similar to these, or an aluminum plate. Excellent thermoplastic resin coated metal plate.