WO2003027354A1

WO2003027354A1 - Precoated metal sheet with excellent press formability and process for producing the same

Info

Publication number: WO2003027354A1
Application number: PCT/JP2002/009583
Authority: WO
Inventors: Kouhei Ueda; Hiroshi Kanai; Yoshio Kimata
Original assignee: Nippon Steel Corporation
Priority date: 2001-09-19
Filing date: 2002-09-18
Publication date: 2003-04-03
Also published as: JP2003166079A; CN1304639C; TW591118B; KR20040044944A; MY144027A; JP3950370B2; CN1556873A

Abstract

A precoated metal sheet with excellent press formability which has on one or each side thereof a chemical-treatment coating layer comprising as solid components at least either of tannin and tannic acid, a silane coupling agent, and finely particulate silica and a resin coating layer formed on the chemical-treatment coating layer and comprising 100 parts by weight of a resin on a solid basis and 1 to 140 parts by weight of an aluminum phosphate pigment. The chemical-treatment coating layer preferably further contains a polyester resin, and the resin coating layer preferably further contains an anticorrosive pigment. Aluminum dihydrogen tripolyphosphate is optimal as the aluminum phosphate pigment. Calcium ion-exchangeable silica is optimal as the anticorrosive pigment.

Description

TECHNICAL FIELD The present invention relates to a precoated metal sheet excellent in press formability and a method for producing the same.

The present invention relates to a surface-treated metal material excellent in press formability and corrosion resistance, and is used for home appliances, building materials, civil engineering, machinery, automobiles, and furniture.

For containers, etc., it is characterized by exhibiting coating film adhesion and press-proofing effect at the time of press molding without using hexavalent foam, which is considered to be particularly environmentally problematic. Background art

Pre-painted metal coated with a colored resin coating has come to be used for home appliances, building materials, automobiles, etc., instead of the conventionally painted post-processed products. This metal plate is obtained by coating a metal plate that has been subjected to a pretreatment for metal with a resin paint, and is generally used after being coated with the resin paint and cut and press-molded. For this reason, the corrosion resistance of the cut end surface where the metal not covered with the resin coating is exposed and the peeling of the resin coating during press working have been problems for the pre-coated metal plate. These problems have been solved by performing chromate treatment and including a hexavalent chromium-based anti-pigment pigment in the resin coating, and are now widely used.

However, due to the environmental problems of chromate treatment and hexavalent chromium, which may be eluted from paint films containing hexavalent chromium-based anti-pigment pigments, recently, non-chromate conversion treatment that does not contain hexavalent chromium, The demand for non-chromate resin paint films is increasing. In Japanese Patent Application Laid-Open No. 2001-88968, tannin and ta There is disclosed a technique for providing a pre-coated metal sheet having excellent workability adhesion and corrosion resistance by using a chemical treatment simultaneously containing carboxylic acid, a silane coupling agent, and fine silica. On the other hand, in Japanese Patent Application Laid-Open No. 9-112931, a polyester series and a polyester series using a phosphoric acid-based pigment and a ion-exchanged silica-based pigment in place of the hexavalent pigment-based pigment are used. A technique for providing a pre-coated metal plate having excellent corrosion resistance at the cut end face portion by using an epoxy resin paint is disclosed in Japanese Patent Application Laid-Open No. H11-157,086.

The chemical conversion treatment technology disclosed in Japanese Patent Application Laid-Open No. 2001-899686 has excellent adhesion to a processed part in an Erichsen test or a T-bend test, but a press represented by deep drawing. The moldability had a disadvantage that the coating film was easily bitten by a press die and peeled off compared to a precoated metal plate subjected to a chromate treatment. On the other hand, in the technology disclosed in Japanese Patent Application Laid-Open No. 9-112931, a zinc phosphate treatment is used for the chemical conversion treatment. However, it was insufficient compared with a precoated metal plate that had been subjected to press forming, and had the disadvantage that, when subjected to press forming, the coating film was liable to be peeled off by the press die.

An object of the present invention is to solve the above-mentioned problems in the prior art, to provide a pre-coated metal plate having excellent corrosion resistance even without containing hexavalent chromium, and further having excellent press formability, and a method for producing the same. Is the challenge

Disclosure of the invention

The present inventors formed a chemical conversion treatment coating layer containing at least one of tanyun or tannic acid, a silane coupling agent, and a fine silicic acid simultaneously, and further contained an aluminum phosphate-based pigment thereon. By forming a resin coating layer, not only corrosion resistance, but also pressing We have found that a composite film with extremely good formability can be obtained. The present invention has been completed based on such knowledge, and the gist thereof is as follows.

(1) On one or both sides of the metal plate, there is a chemical conversion coating layer containing at least one of tannin or tannic acid as a solid content, a silane coupling agent, and fine silica at the same time. A precoated metal sheet excellent in press moldability, further comprising a resin coating layer containing 1 to 140 parts by mass of an aluminum phosphate pigment based on 100 parts by mass of the resin solid content. .

(2) The precoated metal sheet having excellent press moldability according to (1), wherein the chemical conversion coating layer further contains a polyester resin as a solid content.

(3) The press according to the above (1) or (2), wherein the aluminum phosphate-based pigment contained in the resin coating layer is aluminum trihydrogen triphosphate. Pre-coated metal sheet with excellent formability.

(4) The resin coating layer further contains a water-proof pigment, and the total content of the water-proof pigment and the aluminum phosphate pigment is 140 parts by mass with respect to 100 parts by mass of the resin solid content. The precoated metal sheet excellent in press formability according to any one of the above (1) to (3), which is characterized by the following.

(5) The precoated metal sheet having excellent press formability according to the above (4), wherein the water-proof pigment contained in the resin coating layer is a calcium ion exchangeable silica.

(6) The pre-coated metal sheet having excellent press formability according to any one of the above (1) to (5), wherein the metal sheet is a metal sheet having a plating layer on one side or both sides.

(7) At least one of tannin or tannic acid, silane coupling agent and fine silica are simultaneously contained on one or both sides of the metal plate The coating solution is applied and dried to form a chemical conversion coating layer.

Excellent press moldability, characterized by applying a resin paint containing 1 to 140 parts by mass of an aluminum phosphate pigment to 100 parts by mass of resin solid content, and drying and curing. A method for manufacturing a pre-coated metal plate.

(8) The method for producing a precoated metal sheet having excellent press formability according to the above (7), wherein the chemical conversion treatment solution further contains a polyester resin.

(9) The resin coating further contains a water-proof pigment, and the total content of the water-proof pigment and the aluminum phosphate-based pigment is 140 parts by mass or less based on 100 parts by mass of the resin solid content. The method for producing a precoated metal sheet excellent in press formability according to the above (7) or (8), wherein

(10) A precoated metal plate press-formed product, wherein the precoated metal plate of the pressed product is the precoated metal plate according to any one of (1) to (6). Press molded products. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional view of a press-formed product of a pre-coated metal plate of the present invention. In FIG. 1, on one side of a metal plate 1, a chemical conversion coating 2 containing at least one of tannin or tannic acid, a silane coupling agent, and fine silica at the same time 2, a resin coating 3 containing an aluminum phosphate pigment , And an optional overcoat layer 4 are formed. On both surfaces of the metal plate 1, a chemical conversion coating 2, a resin coating 3, and an optional top coating layer 4 may be formed. Embodiment of the Invention

The present invention relates to a method for producing a metal plate or a plated metal plate, wherein one or both of tannin and tannic acid as solids A chemical conversion treatment film layer containing both an encapsulating agent and fine-grained sily is formed, and a resin film layer containing 1 to 140 parts by mass of an aluminum phosphate pigment is formed thereon. Achieved by It is more preferable that the aluminum phosphate pigment is aluminum trihydrogen diphosphate because the coating film is less likely to be kinked during press molding. Further, if the chemical conversion coating layer applied to the prepreg metal sheet of the present invention further contains a polyester resin as a solid content, the adhesion of the coating film is improved, and the coating film is less likely to be galling during press molding. More suitable.

It is preferable that the resin coating layer formed on the prepreg metal plate of the present invention contains an anti-reflection pigment in addition to the phosphoric acid-based pigment, because the corrosion resistance of the prepreg metal plate is improved. The amount of these pigments added is preferably such that the total content of the aluminum phosphate-based pigment and the water-proof pigment is 140 parts by mass or less based on 100 parts by mass of the resin solid content. Further, it is preferable that the anti-reflection pigment has calcium ion-exchangeable silicic acid, since the corrosion resistance is further improved.

The chemical conversion coating layer formed on the precoated metal sheet of the present invention may be a processing solution containing at least one of tannic acid and tannic acid, a silane coupling agent, and a fine-grained silicide force, or in addition to this. It is more preferable that the precoated metal sheet of the present invention can be manufactured more efficiently by applying and drying a treatment liquid containing a polyester resin. Further, the resin coating layer formed on the pre-coated metal plate of the present invention is formed by applying an aluminum phosphate-based pigment, or a resin paint containing an aluminum phosphate-based pigment and a water-proof pigment simultaneously, followed by drying and curing. It is more preferable to form the precoated metal sheet of the present invention because the precoated metal sheet of the present invention can be manufactured more efficiently.

The present inventors have conducted various studies on a non-chromate precoated metal sheet whose coating is difficult to be galled by a press mold when press-formed. As a result, the tannin and / or Ma Alternatively, a chemical conversion coating layer containing tannic acid, a silane coupling agent, and fine silica at the same time is formed, and a resin coating layer containing an aluminum phosphate-based pigment is further formed thereon. It has been found that the phenomenon that the coating film is peeled off by the mold is dramatically improved. The phenomenon in which the paint film is bitten by the press die during press molding and peels off is that the paint film on the prepote metal plate is rubbed with a high load by the press die and acts on the paint film at this time. This is probably due to the shearing force. Therefore, the following two methods can be considered to improve this problem. The first is to increase the adhesion between the coating and the metal. Second, it is difficult for the shearing force acting on the coating film to be transmitted to the interface between the coating film and the original metal plate, which is the coating film peeling surface. Although the details of the cause of the difficulty of the coating film being galled on the press mold when the precoated metal sheet of the present invention is press-formed are not known, tannin and / or tannic acid having excellent adhesion and the silane coupling agent and the fine-grained silica are used. By combining the chemical conversion coating layer and the coating layer containing the aluminum phosphate pigment at the same time, the adhesion of the coating is dramatically improved due to the synergistic effect, and the unique properties of the aluminum phosphate pigment This is presumed to be due to the fact that the shear stress generated in the coating film during press forming is less likely to be transmitted to the interface between the coating film and the metal plate due to the mechanical properties of the metal.

The metal sheet used for the pre-coated metal sheet of the present invention is a cold-rolled steel sheet, a hot-rolled steel sheet, a hot-dip galvanized steel sheet, an electro-zinc-plated steel sheet, a hot-dip galvanized steel sheet, an aluminum-plated steel sheet, an aluminum-zinc alloy Commonly known metal plates and plated plates such as plated steel plates, aluminum-magnesium-zinc plated steel plates, aluminum-magnesium-silicon-zinc plated steel plates, stainless steel plates, and aluminum plates can be applied. These metal plates may be used after being subjected to ordinary treatment such as hot water washing and alkali degreasing before the chemical conversion treatment.

The chemical conversion coating layer applied to the precoated metal plate of the present invention is a tandem coating. And tannic acid, silane coupling agent, and fine silica.

The tannin or tannic acid used may be a tannin which can be hydrolyzed or a condensed tannin, or a partially decomposed tannin may be used. The tannins and tannic acids are not particularly limited, such as hamame tannins, quintuple tannins, gallic tannins, milanolan tannins, Jibijibi tannins, Anogaro villa tannins, Ronnie tannins, and catechins. The use of “tanyunic acid: AL” (manufactured by Fuji Chemical Co., Ltd.) particularly improves the processing adhesion of the coating film. The addition amount of at least one of tannin and tannic acid is not particularly specified, but the content in the chemical conversion solution applied to a metal plate to form this is 2 to 80 g / l. If so, it is more suitable. If at least one of tannin or tannic acid is less than 2 g / 1, the protective effect and coating adhesion may not be ensured, while the protective effect may exceed 80 g / l. Or the adhesion of the coating film may be reduced, or it may not be dissolved in the aqueous solution.

Confuse.

Examples of the silane coupling agent to be used include γ- (2-aminoethyl) aminoprovirtrimethoxysilane, y- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoaminoethyl) amine Minopropyl triethoxysilane, y- (2-aminoethyl) aminopropylmethyl ethoxysilane, y- (2 -aminonoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ —Methacryloxypropylmethyl dimethoxysilane, -methacryloxypropyl built-triethoxysilane, y —Methacryloxypropylmethylmethylethoxysilane, N-i3

-(N-vinylbenzylaminoethyl) -γ-aminopropyl Methoxysilane, N— / 3— (N—vinylbenzylaminoethyl) -V—Aminopropylmethyldimethoxysilane, N— / 3— (N-vinylbenzylaminoethyl) -γ—Aminoprobioltriethoxysilane, N _ jS — (N-bierbenzylaminoethyl) _ τ / — aminop Methyl pyrmethyl ethoxysilane, _γ — glycidoxypropyl methyl methoxysilane, γ — glycidoxypropyl methyl dimethoxysilane, γ — glycidoxypropyl methyl ethoxysilane, γ —Glycidoxypropylmethylmethoxysilane, γ —Mercaptopropyltrimethoxysilane, γ —Mercaptopropylmethyldimethoxysilane, γ —Mercaptopropyltriethoxysilane, γ —Mercaptopyl mouth Emissions, methyl Application Benefits main Tokishishiran, dimethyl Chirujime Tokishishiran, Mechiruto Li et Tokishishiran, dimethyl Jefferies Tokishishiran, Biniruto Re § Se Tokishishiran, .gamma. click throat propyl Application Benefits main Tokishishiran, gamma - click port opening pro Pirumechirujime Tokishishiran, _gamma - Black mouth propyl pyritriethoxysilane, _γ — Black mouth propylinolemethyl yl ethoxysilane, hexamethyldisilazane, γ —anilinov bu Tokishishiran, _Upsilon - Aniri Nopuro Pirumechiruje Tokishishiran, vinyl Application Benefits main Tokishishiran, vinyl methylate Roh regime Tokishishiran, Byuruto Li et Tokishishiran, vinyl Rumechiruje Tokishishiran, Okuta Sildimethyl [3 — (trimethoxysilyl) propyl] ammonium chloride, octadecyl dimethyl [3_ (methyldimethoxysilyl) propyl] ammonium chloride, octadecyl dimethyl [3 _ (triethoxysilinole) propyl] Ammonium chloride, octadecyl dimethyl [31- (methyl ethoxysilyl) propyl] Ammonium chloride, ^ oku Mouth mouth propyl methyl dimethoxysilane, γ- Menolecap top Mouth Pyrmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, etc., can be mentioned, but those having a daricidyl ether group are -glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyl When ethoxysilane is used, the processing adhesion of the coating film is particularly improved. Furthermore, the use of a triethoxy-type silane coupling agent can improve the storage stability of the base treatment material. This is presumably because triethoxysilane is relatively stable in aqueous solution and the polymerization rate is slow.

The amount of the silane coupling agent to be added is not particularly specified, but it is more preferable that the content in the chemical conversion solution applied to the metal plate to form the chemical conversion coating layer is 2 to 80 g / 1. It is. If it is less than 2 g Zl, sufficient coating film adhesion may not be obtained during processing, and the corrosion resistance may not be sufficient. If it exceeds 80 g / l, the adhesion of the coating film may be reduced.

The fine silica used in the present invention is a generic term for silica capable of stably maintaining a water-dispersed state when dispersed in water to have a fine particle size. Examples of the finely divided silica include “Snowtex N”, “Snowtex C”, “Snowtex UP”, ΓSnowtex PS ”(all manufactured by Nissan Chemical Industries), and“ Adelate AT-120Q ”. Commercially available silica gel such as “Asahi Denka Kogyo” or powdered silica such as Aerosil # 300 (Nippon Aerosil) can be used. The fine silica may be appropriately selected depending on the required performance. The use of fine-grained silica such as “Snowtex C” that can stably disperse even at a pH of 4 or more can improve the storage stability of the base treating agent. This is because the pH of the chemical solution can be adjusted to 4 or more, and the pH is low and the reactivity is high. This is probably because the reaction of the coupling agent can be suppressed. The addition amount of the fine silicic acid is not particularly specified, but the content in the chemical conversion treatment liquid applied to the metal plate to form the chemical conversion coating layer is limited.

It is preferably from 1 to 40 g / 1. If it is less than 1 g / 1, the coating adhesiveness of the coating film may be poor, and if it exceeds 40 g / 1, the effects of processing adhesion and corrosion resistance are saturated, which is uneconomical.

It is more preferable that the chemical conversion coating layer further contains a polyester resin as a solid content because the processing adhesion is further improved. There is no particular restriction on the content of the polyester resin.However, if the content in the chemical conversion solution applied to the metal plate to form the chemical conversion coating layer is l to 60 g Zl, Processing adhesion is improved. If the amount is less than 1 g / l, the effect of the addition of the resin is not observed. If the amount exceeds 60 gZl, the adhesion to the coating film may be rather deteriorated. Examples of the polyester resin include “Finetex ES-650”, “Finetex ES-611J”, “Finetex ES-670J”,

Finetex ES—675 (all manufactured by Dainippon Ink and Chemicals), Byronal MD—1200, Pai-Narual MD—122, and Byronal MD— 1250 "," Bi-Naru MD-1-1100 "," Bi-Naru MD-133 "," Bi-Ronal MD-193 "(all manufactured by Toyobo Co., Ltd.), etc. Can be used.

An acid, an alkali, or the like may be added to the chemical conversion treatment solution applied to form the chemical conversion treatment film layer of the present invention for pH adjustment within a range where performance is not impaired.

In order to form a chemical conversion treatment layer on a metal plate, it is preferable to apply the above-mentioned chemical conversion treatment agent to a metal plate and bake and dry it, thereby improving production efficiency. The baking temperature is preferably 50 to 250 ° C. At temperatures below 50 ° C, water Since the evaporation rate of the minute is slow and sufficient film-forming property cannot be obtained, the protection is insufficient. On the other hand, when the temperature exceeds 250 ° C., the alkyl portion of tannin, a tannic acid-silane coupling agent, which is an organic substance, undergoes denaturation such as thermal decomposition, and the adhesion and corrosion resistance decrease. 70 to 160 ° C is more preferable. In hot air drying, drying for 1 second to 5 minutes improves the production efficiency, and is more preferable.

The coating method of the chemical conversion treatment liquid is not particularly limited, and a generally known coating method, for example, a roll coating, a Ringer's Nore coat, an air spray, an airless spray, an immersion, or the like can be adopted. Further, it is more preferable to apply the coating on a continuous coating line called a general coil coating line or sheet coating line, which is complete with these coating devices, because the coating work efficiency is high and mass production is possible.

The amount of the chemical conversion coating layer to be deposited is preferably 10 to 500 mg / m ² as a solid content. If it is less than 100 mg / m ² , sufficient working adhesion will not be ensured, and if it exceeds 500 mg / m ² , the working adhesion will rather decrease.

In the precoated metal sheet of the present invention, the resin of the resin coating layer formed on the chemical conversion coating layer may be of any type such as an aqueous type, a solvent type and a powder type. As the type of resin, generally known ones such as polyacrylic resin, polyolefin resin, polyurethane resin, epoxy resin, polyester resin, polybutylal resin, and melamine resin can be used. It can be used as it is or in combination. The resin coating layer of the precoated metal plate of the present invention needs to contain 1 to 140 parts by mass of an aluminum phosphate pigment based on 100 parts by mass of the resin solids. If the addition amount of the aluminum phosphate-based pigment is less than 1 part by mass, there is no effect on the galling of the coating film by the die during press molding, and this is unsuitable. The greater the amount of aluminum phosphate pigment added, the more the coating will seize during press molding. It is more effective and more suitable for steel, but if it exceeds 140 parts by mass, it is not suitable because the workability as a pre-coated metal plate is significantly poor.

As the aluminum phosphate-based pigment, generally known ones, for example, aluminum trihydrogen phosphate, aluminum metal methacrylate, and the like can be used, and aluminum trihydrogen phosphate is used. Are more readily available and more suitable. Commercially available aluminum trihydrogen diphosphate can be used, for example, “K—WHITE” manufactured by Tika.

In the resin coating layer of the prepreg metal plate of the present invention, it is preferable to add a water-proof pigment exhibiting a water-proof effect in addition to the aluminum phosphate-based pigment, because the corrosion resistance is improved. The larger the amount of the water-proof pigment is, the more effective it is. Therefore, the total content of the aluminum phosphate pigment and the water-proof pigment is preferably 140 to 100 parts by mass of the resin solid content. Less than parts by weight is preferred. If the total added amount of the aluminum phosphate pigment and the anti-reflective pigment exceeds 140 parts by mass, problems such as greatly deteriorated workability when the precoated metal plate is bent may occur, which is preferable. Not good.

As the anti-pigment added to the resin coating layer of the precoated metal sheet of the present invention, generally known anti-pigment pigments can be used. For example, (1) phosphoric acid-based pigments such as zinc phosphate and iron phosphate; and (2) molybdenum acid such as calcium molybdate, aluminum molybdate, and barrier molybdate. (3) vanadium-based pigments, such as vanadium oxide; (4) strontium chromate, zinc chromate, canolecium chromate, potassium chromate, and parium chromate Chromate-based anti-pigment pigments (5) Fine particles such as water-dispersible silica, fumed silica, and calcium ion-exchangeable silica can be used. However, the chromate prevention described in (4) 鲭 It is desirable not to use pigments due to environmental concerns. Furthermore,

Of the silica-based pigments described in (5), calcium ion-exchangeable silica is harmless to the environment and has a large protective effect. Therefore, if this is added as a protective pigment, the protective effect is more exhibited. It is suitable. As the calcium ion-exchangeable silica, “Shieldex” manufactured by Gracce can be used. Further, these anti-sun pigments may be added in combination of two or more kinds.

In the resin coating layer of the prepreg metal plate of the present invention, in addition to the aluminum phosphate-based pigment and the anti-reflective pigment, a known pigment generally called an extender or a coloring pigment for coloring is used in combination. Can be added. The extender pigment is a general term for pigments added to improve various properties required for resin coatings, such as the brittleness of the resin coating layer and the concealability after coating. Talc, which plays a role in the above, titanium white (titanium oxide) for improving the concealing property of the resin coating, and silica for improving the scratch resistance of the glossy resin coating of the resin coating. When these extenders are added, the above-mentioned properties are improved, which is preferable. Further, as the coloring pigment, titanium oxide (T i 0 _2), zinc oxide (Z n O), oxide Jirukoniumu (Z r O _2), carbonate Karushiumu (C a CO _3), sulfuric Paris um (B a SO _4), alumina (a l ₂ O _3), the force sediment tank laser, carbon black, and organic pigments such as iron oxide _{_{(F e 2 0 3, F}} e 3 〇 _4), commonly known coloring such as organic pigments Pigments can be used. It is more preferable to use a plurality of these extender pigments and color pigments having different effects in combination, because the effects are exhibited. When an extender pigment or a coloring pigment is added, the total amount of the total addition of the aluminum phosphate pigment, the anti-reflection pigment, and the extender coloring pigment is based on 100 parts by mass of the resin solid content in the resin paint. It is preferable that the amount be 140 parts by mass or less. If the amount of all pigments exceeds 140 parts by mass, In some cases, problems such as poor workability when bending a metal plate may occur.

The thickness of the resin coating containing the aluminum phosphate pigment of the precoated metal plate of the present invention is not particularly limited, but various properties of the resin coating vary depending on the film thickness. There is a need to.

In order to form the resin coating layer containing the aluminum phosphate pigment of the pre-coated metal plate of the present invention, a resin paint containing the amount of the face specified in the present invention with respect to the resin solid content in advance is used. It is more preferable to produce and apply it, and then to dry and cure it, because the production efficiency is improved. These resin coatings can be used in any form such as solvent-based coatings, water-based coatings, melt-type coatings, powder coatings, electrodeposition coatings, ultraviolet-curing coatings, and electron beam-curing coatings. These resin coating methods can be applied by generally known coating methods such as roll coating, curtain flow coating, roller curtain coating, die coating, air spray, airless spraying, electrodeposition coating, powder coating, and the like. It can be carried out by dipping, painting, brushing, or the like. However, if a continuous coating line called a general coil coating line or sheet coating line equipped with a roll coat, curtain flow coat, and roller curtain coat is used, coating work efficiency is high and mass production is possible. It is suitable. As a method for drying and curing the resin coating, a generally known drying and curing method such as a hot air oven, a direct fire oven, a far-infrared opening, and an induction heating oven can be used. In addition, when the resin coating is in the form of a UV-curable resin coating, a generally known ultraviolet irradiation device can be used. In the case of an electron beam-curable resin coating, a generally known electron beam irradiation device can be used. .

In the precoated metal sheet of the present invention, an overcoating resin coating layer may be further provided on the resin coating layer containing the aluminum phosphate-based pigment. this This is more preferable because the color tone appearance, the design appearance, and other resin film performance of the painted metal plate are improved. The top-coating resin coating layer can be formed by applying a generally known top-coat paint, drying and baking to cure. Generally known topcoats include, for example, polyester-based topcoats, epoxy-based topcoats, urethane-based topcoats, acrylic-based topcoats, and melamine-based topcoats. As the top coating, any form such as a solvent-based coating, a water-based coating, a powder coating, an electrodeposition coating, an ultraviolet curing coating, and an electron beam curing coating can be used. In the top coat, generally known coloring pigments and extenders such as titanium oxide (TiO ₂ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), calcium carbonate (Ca) CO _3), sulfuric Paris um (B a S 0 _4), alumina (A 1 ₂ O _3), Kaori Nkure, carbon black, iron oxide (F e ₂ O ₃

, F e 3 0 _4), it can be added talc, silica and the like. In addition, the top coat paint may be a well-known design paint, for example, a fuse skin paint, a fine paint, a hammer tone paint, a mat paint, a metallic paint, a pearl paint, a texture paint, etc. Can be used. The coating method of the top coat paint is a commonly known coating method, for example, Lono record, curtain flow coat, roller curtain coat, die coat, air spray, airless spray, electrodeposition coating, powder coating, It can be carried out by dipping, painting, brushing, etc. However, painting with a continuous coating line called a general coil coating line or sheet coating line equipped with a Lono Record, Curtain Flow Coat, and Roller Coat Coat makes painting work efficient and enables mass production. Therefore, it is more preferable. The method of drying and baking of the top coat paint is a commonly known drying and baking method such as a hot air oven, a direct fire oven, a far infrared oven, and an induction heating oven. Can be. When the top coat is an ultraviolet-curable resin coating, a generally known ultraviolet irradiation device can be used. When the top coating is an electron beam-curable resin coating, a generally known electron beam irradiation device can be used. Example

Hereinafter, the test materials used in the experiment will be described in detail.

1. Metal plate

The following metal plates were used as test materials for the experiment.

Hot-dip galvanized steel sheet (GI):

0.6 mm thickness, 60 g / m ² per side of zinc coating (two sides next)

Electro-galvanized steel sheet (EG):

Sheet thickness 0.6 mm, zinc coating amount 20 g / m ² per side (next to both sides)

5 5% alloyed aluminum zinc plated steel plate (GL):

0.6 mm thickness, 90 g Zm ² per side in terms of zinc adhesion (double-sided)

Zn—11 1% aluminum-3% magnesium0.2% silicon-plated steel sheet (SD):

0.6 mm thickness, 60 g / m ² per side in terms of zinc weight (both sides plated)

Cold rolled steel plate (CR):

0.6 mm thickness

2. Chemical conversion solution

The following chemical conversion pretreatment liquids were prepared as the chemical conversion pretreatment liquids used for the test materials in the experiment (A): An aqueous solution containing 20 g of tannic acid, 40 g / l of a silane coupling agent, and 20 g of fine silica was prepared and used as a metal pretreatment agent. For tannic acid, use “Tannic acid AL” manufactured by Fuji Chemical Co., Ltd .; for silane coupling agents, γ-glycidoxypropyltrimethoxysilane; for fine silica, use “Snowtec Ichigo” manufactured by Nissan Chemical Co., Ltd. Using. Chemical conversion solution (Β):

An aqueous solution containing 20 g of tannic acid, 40 g of a silane coupling agent, 20 g / l of fine silica, and 20 g / 1 of a polyester resin was prepared as a metal pretreatment agent. Note that tannic acid ALj manufactured by Fuji Chemical Industry Co., Ltd., γ-daricidoxyprobuilt remethoxysilane manufactured by Fuji Chemical Industry Co., Ltd., and Nissan Chemical Co., Ltd. "Finetex ES-650 J" manufactured by Dainippon Ink Co., Ltd. was used as the polyester resin.

Chemical conversion solution (C):

As a comparison of the present invention, "ZM-130AN" manufactured by Nippon Parti Rising Co., Ltd., which is a commercially available coating mate treatment, was used.

Chemical conversion solution (D):

As a comparison of the present invention, “Pal Pond” manufactured by Nippon Parker Ising Co., Ltd., which is a commercially available zinc phosphate treatment, was used.

3. Resin paint containing aluminum phosphate pigment

A resin paint is added to a commercially available polyester-, urethane-, or epoxy-based clear paint that does not contain any pigment, by adding an aluminum phosphate-based pigment and, if necessary, an anti-reflective paint, followed by stirring. It was created. "K-I-G 105" manufactured by Tiriki Co., Ltd. was used as the aluminum phosphate pigment. As the anti-pigment, "NP-530" manufactured by Toho Pigment Co., Ltd. (described as "phosphoric acid Zn" in the table) is used as a zinc phosphate-based anti-pigment, and G is used as calcium ion exchange silica. Race company "S hieldex—C303" Was described as “C a — S i”), and commercially available stoichiometric chromate (described as “S r — C r” in the table) was used as the chromium-based anti-pigment pigment. Table 1 shows the amount of each pigment added. Also, if necessary, as a constitutional facial, “Aerosil 300” (manufactured by Nippon Aerosil Co., Ltd.) (“Silica” in the table) as a commercially available fine-grained silica, and an oxidized white pigment “CR-95” manufactured by Ishihara Sangyo Co., Ltd. (described as “Titanium White” in the table) was added as titanium. The amount of each pigment added is described in the table.

4. Top coating

A commercially available polyester-based top coat “FL100HQ” manufactured by Nippon Paint Co., Ltd. was used. The color used was white.

5. Back paint

A commercially available polyester-based top coat “FL100HQ” manufactured by Nippon Paint Co., Ltd. was used. The color used was gray.

6. Making a pre-coated metal plate

Various metal plates were degreased by immersing them in an aqueous solution of FC-364S (manufactured by Nippon Parkerizing) at a concentration of 2% by mass at a temperature of 60 ° C for 10 seconds, washed with water, and dried. Then, the chemical conversion treatment liquids (A), (B), (C), and (D) were applied to both sides of a metal plate with a roll coater, and dried in a hot-air drying oven to obtain a chemical conversion coating layer. In the case of the chemical conversion treatment liquids (A), (B) and (D), the chemical conversion treatment liquid was applied so that the total adhesion amount of the dry film was 200 mg / m ² . In the case of the chemical conversion treatment liquid (C), it was applied so that the amount of adhesion would be 50 mg / ² in terms of metal powder. For the test piece using the chemical conversion treatment liquid (E), a degreased metal plate was immersed in the chemical conversion treatment liquid (E) for 2 minutes, and dried in a hot-air drying oven to obtain a chemical conversion treatment coating layer. The chemical conversion treatment (E) was coated so that the amount of zinc phosphate attached was 2 g / m ² . The plate temperature reached during chemical conversion drying was 60 ° C. Next, a resin paint containing aluminum phosphate pigment on one side Paint with a roll coater so that the film thickness after drying is 5 / zm. On the other surface, apply the back paint with a single coater and apply the film thickness after drying.

The coating was applied to a thickness of 5 μm, and the coating was dried and cured in an induction heating furnace blown with hot air under conditions where the ultimate plate temperature of the metal plate was 210 ° C to obtain a resin coating layer. After drying and baking, the painted metal plate was sprayed with water using a spray and cooled with water. Furthermore, a top coat is applied on the resin coating layer containing the aluminum phosphate pigment so that the film thickness after drying is 15 // m using a mouth coater, and the coating is applied to an induction heating furnace blown with hot air. The temperature of the metal plate

Dry baking was performed at 230 ° C. After drying and baking, the painted metal plate was sprayed with water by spraying and cooled with water to obtain a pre-coated metal plate as a test material.

The following evaluation tests were carried out on the precoated metal sheets prepared in this manner. In each of the tests, the surface coated with a resin paint containing an aluminum phosphate-based pigment was used as the evaluation surface.

1. Coating process adhesion test

The prepared precoated metal plate was bent at 180 °, and the coating film of the processed portion was observed with a 20-power loupe to check for any cracks in the coating film. In the bending test, bending was performed so that the surface coated with the resin coating containing the aluminum phosphate-based pigment was on the outside. Further, an adhesive tape was stuck to the applied portion, and the remaining state of the coating film when the adhesive tape was vigorously peeled off was visually observed. In this test, the tape was peeled twice. The bending was performed at 20 ° C. in an atmosphere of 0 T.

The evaluation of coating film cracking is ◎ when there is no coating film cracking, 時 when there is about 1 to 3 small cracks in the coating film, 時 when there is very small cracking in the coating film, 塗膜In addition, X was evaluated when there was a clearly large crack visually observed on the entire processed part. In addition, the evaluation of the remaining state of the coating film after peeling off with a tape was evaluated as ◎ when the coating film was not peeled off and remained on the plated steel sheet, 〇 when the coating film was partially peeled slightly, and Was evaluated as “△” when the part was severely peeled off, and as “X” when peeling was observed over almost the entire bent portion.

Further, the precoated metal plate was subjected to 0 T processing (ECCA-T 7), immersed in boiling water for 1 hour, taken out and left for 24 hours, and then the coating film was subjected to tape peeling. The evaluation of the remaining state of the coating film was as follows: ◎: when the coating film remained on the steel plate without peeling at all; △: when the coating film partially peeled slightly; Peeling was evaluated as △, and peeling was evaluated as X when peeling was observed over almost the entire bent part.

2. Coating test with beads

A test method that reproduces the peeling of the coating film caused by the coating film of the pre-coated metal plate being pressed by the press mold when the pre-coated metal plate is press-formed. Test method ”(public technique 95-10778). First, the prepared precoated metal plate was cut into a test piece of 30 mm (width) x 300 mm (length), and this test piece was cut into a flat die and a die provided with a 3 mm radius bead. And sandwich it. At this time, the test piece was sandwiched between the surface coated with the resin paint containing aluminum phosphate pigment (evaluation surface) so that the bead of the die was pressed, and a 1 t load was applied to apply additional force to the die bead. The metal part was pressed against the evaluation surface of the pre-coated metal plate. In this state, the precoated metal plate was pulled out at a speed of 200 mm Z min, and the state of peeling of the coating film on the evaluation surface of the precoated metal plate rubbed with a bead was visually observed and evaluated.

The evaluation was ◎ when the coating film was not peeled at all, △ when the coating film was partially peeled, and about 20% as the area ratio of the part rubbed with the bead. The case where the above was peeled was marked as △, and the case where the entire surface was peeled was marked as X.

3. Corrosion resistance test

On the surface of the prepared pre-coated metal plate coated with the resin paint containing aluminum phosphate pigments, a power cutter was used to make a scratch that penetrated the coating film and penetrated to the metal plate. Then, the sample was cut so that the return at the time of cutting (Paris) was on the surface coated with the backside paint (so that it was the lower Paris), and a sample for corrosion resistance test was prepared. And J I S K 5

The salt spray test was carried out according to the method described in 4.0-9.1. The salt water was sprayed on the surface coated with the resin paint containing the aluminum phosphate pigment so as to wipe it. The test time was 120 h when the precoated metal sheet was a cold-rolled steel sheet, 240 h when it was an electro-galvanized steel sheet, hot-dip galvanized steel sheet, 55% alloyed aluminum. In the case of a zinc-plated steel sheet, Zn-l 1% aluminum-1 3% magnesium-1 0.2% silicon-plated steel sheet, the time was set at 360 h.

The evaluation method for the coating film at the cut part is as follows: ◎ when the maximum blister width on one side of the cut is less than 1 mm, 〇 when it is 2 mm or more and less than 3 mm, △ when it is 3 mm or more and less than 5 mm, X was evaluated when it was 5 mm or more.

In addition, the evaluation method of the cut end face part is ◎ when the swollen width from the end face is less than 2 mm, Δ when it is 2 mm or more and less than 3 mm, Δ when it is 3 mm or more and less than 5 mm, 5 mm. In the above cases, it was evaluated as X.

Paint containing aluminum phosphate pigment

Ig ig FH anti-pigment

Phosphorous pigments

No. Metal plate

Eye IJ treatment Shelf / (shelf J j-nt g i solid eti-type re-dispersed Vi 100 mass parts Department

* M "parts by mass" "parts by mass"

1 G1 A e. Lyester 20 Ca-Si 50 Untranslated one 80

2 G1 B e. Riester 1 Unopened mouth ― Unopened mouth ― 1

3 G1 B e. Riester 10

4 G1 B ester 20 Unadvised b-unintroduced 20

5 G1 B e. Riester 50 Not added-Unchanged one 50

6 G1 B e. Riester 100 Unopened-Unworked One 100

7 G1 B e. Reester 140 Not added-Not recommended

8 G1 B e. Riester 20 Ca-Si 10 Unopened mouth-30

9 G1 B e. Riester 20 Ca-ii 20 Not recommended. Riester 20 Ca-ύΐ 50 Undecorated ― 70 rounds 11 G1 B e. Lyester 20 Ca-ύΐ 100 Not added ― 120 t

t light 12 G1 B ester 20 Ca-ύΐ 50 silica 10 80

Example 13 G1 B e. Lyester 20 Ca-ύί 100 Silica 40 160

14 G1 B e. Lyester 20 Ca-ύΐ 50 Titanium white 10 80

15 G1 B e. Reester 20 Phosphoric acid Zn 50 Not yet one way 70

16 G1 B e. Riester 20 Sr-Cr 50 Not added 1 70

17 G1 B Urethane 20 Ca-Si 50 Not added 1 70

18 G1 B Jeho. Pheasant 20 Ca-Si 50 Untranslated one 70

19 EG B Lyester 20 Ca-Si 50 Untranslated 70

20 GL B Ho. Lyester 20 Ca-Si 50 Untranslated 70

21 SD B Lyester 20 Ca-Si 50 Not 70

22 CR B Polyester 20 Ca-Si 50 Unmoved port 70

23 G1 B e. Riester Unexcited mouth Unmoved mouth Unreversed 0

24 G1 B e. Reester 0.5 not added b unmoved port 0.5 ratio 25 G1 B e. Reester 150 not yet, untranslated 150 comparison 26 G1 C Riester 20 Ca-Si 50 Not added 70 Example 27 G1 C Riester 20 Sr-Cr 50 Untransformed 70

28 G1 D e. Riester 20 Ca-i 50 Not included b 70

29 G1 E. Riester 20 Ca-bi 50 Untranslated 70

The details of the evaluation results will be described below.

Compared with (Comparative Example—No. 24), the coating film is suitable because it is less likely to peel off in the coating film galling test using beads. In addition, the precoated metal sheet of the present invention contains a polyester resin in the chemical conversion coating layer, thereby improving the processing adhesion of the coating film, and peeling off the coating film in a galling test of the coating film using a bead. This is more preferable because it is difficult to carry out (Example of the present invention—comparison between No. 1 and N 0.10). In the case where the resin coating was prepared by adding a water-proof pigment in addition to the aluminum phosphate-based pigment (Example 1 of the present invention, No. 8 to 22), the one not added (Example of the present invention—No. 2) Corrosion resistance is improved as compared to 7). In particular, when the pigment is a calcium ion-exchangeable silica (Example of the present invention—No. 1, 8 to: 14, 17 to 22), the corrosion resistance is further improved, and the conventional chromate. It is suitable because it has the same corrosion resistance as the one to which a systemic pigment is added (Example of the present invention—No. 16 and Comparative example 1 No. 26). Industrial applicability

Advantageous Effects of Invention According to the present invention, it is possible to provide a pre-coated metal sheet that is excellent in workability and corrosion resistance of a coating film and is very suitable for press molding without using hexavalent chromium, which is likely to affect the environment. It has become possible. Therefore, it can be said that the present invention is an invention having extremely high industrial value.

Claims

The scope of the claims

1. On one or both sides of the metal plate, there is a chemical conversion coating layer containing at least one of tannin or tannic acid as a solid, a silane coupling agent, and fine silica at the same time. A precoated metal plate having excellent press moldability, further comprising a resin coating layer containing 1 to 140 parts by mass of an aluminum phosphate pigment based on 100 parts by mass of a resin solid content. .

2. The precoated metal sheet according to claim 1, wherein the chemical conversion coating layer further contains a polyester resin as a solid content.

3. The prepreg having excellent press moldability according to claim 1 or 2, wherein the aluminum phosphate-based pigment contained in the resin coating layer is aluminum trihydrogen phosphate. One metal plate.

4. The resin coating layer further contains a water-proof pigment, and the total content of the water-proof pigment and the aluminum phosphate pigment is 140 parts by mass or less based on 100 parts by mass of the resin solid content. The precoated metal sheet excellent in press formability according to any one of claims 1 to 3, characterized in that:

5. The prepreg metal sheet having excellent press formability according to claim 4, wherein the water-proof pigment contained in the resin coating layer is calcium exchangeable silica.

6. The precoated metal sheet having excellent press formability according to any one of claims 1 to 5, wherein the metal sheet is a metal sheet having a plating layer on one side or both sides.

7. Apply a treatment liquid containing at least one of tannin or tannic acid, a silane coupling agent and a finely divided sily on one or both sides of the metal plate, and dry to form a chemical conversion coating layer. Further, a prepreg having excellent press moldability characterized by applying a resin paint containing 1 to 140 parts by mass of an aluminum phosphate pigment to 100 parts by mass of the resin solid content and drying and curing. A method for manufacturing a metal plate.

8. The method according to claim 7, wherein the chemical conversion treatment solution further contains a polyester resin.

9. The resin paint further contains a water-proof pigment, and the total content of the water-proof pigment and the aluminum phosphate-based pigment is 140 parts by mass or less based on 100 parts by mass of the resin solid content. 9. The method for producing a precoated metal sheet excellent in press formability according to claim 7 or 8, characterized in that:

10. A pre-coated metal sheet press-formed product, wherein the pre-coated metal sheet of the press-formed product is the pre-coated metal sheet according to any one of claims 1 to 6. Goods.