JP5908770B2 - Method for producing pretreated stainless steel plate, pretreated stainless steel plate obtained thereby, and painted stainless steel plate - Google Patents

Description

  The present invention relates to a method for producing a chemical conversion treated stainless steel plate and a chemical conversion treated stainless steel plate obtained thereby. Moreover, this invention relates to the coated stainless steel plate containing the said chemical conversion treatment steel plate.

  2. Description of the Related Art Conventionally, a coated metal plate having a coating film formed on the surface of a metal plate has been used for building roof materials, exterior materials, home appliances, automobiles, and the like. The coated metal plate has a step of cleaning the surface of the metal plate, a step of forming a chemical conversion treatment film on the surface of the cleaned metal plate using a chemical conversion treatment liquid, and a coating film on the surface of the chemical conversion treatment film. It can be manufactured by a process. The coated metal plate is produced by appropriately selecting the type of metal plate and the composition of the coating film according to the application.

  Patent Document 1 describes a coated metal plate manufactured using a chemical conversion treatment solution containing a silane coupling agent. The coated metal plate of Patent Document 1 is manufactured by washing oil stains adhering to the surface of the metal plate with an alkaline degreasing agent or the like, forming a chemical conversion treatment film using a chemical conversion treatment liquid, and then forming a coating film. The Moreover, in the manufacturing method of the coating metal plate of patent document 1, it wash | cleans with water so that an alkali degreasing agent may not remain on the surface of a metal plate as much as possible.

JP 2009-275287 A

  In the painted metal plate of patent document 1, it is described that various metal plates can be used as a coating original plate. However, since the surface state of the metal plate is different for each metal plate, the adhesion of the chemical conversion film is different for each metal plate. In particular, when the metal plate is a stainless steel plate, even if only alkaline degreasing is performed, the adhesion of the chemical conversion film may not be sufficient.

  This invention is made | formed in view of this point, and provides the manufacturing method of the chemical conversion treatment stainless steel plate which can form stably the chemical conversion treatment film which is excellent in adhesiveness, and the chemical conversion treatment stainless steel plate obtained by it. For the purpose. Another object of the present invention is to provide a coated stainless steel sheet including the chemical conversion treated stainless steel sheet.

  The present inventors have found that the above-mentioned problems can be solved by precipitating a predetermined amount of silicate on the surface of a stainless steel plate, and have further studied and completed the present invention.

That is, this invention relates to the manufacturing method of the following chemical conversion treatment stainless steel plates.
[1] A step of depositing 0.1 to 100 mg / m ^{2 of} silicate in terms of Si on the surface of a stainless steel plate, and a silane coupling agent and organic on the surface of the stainless steel plate on which the silicate is deposited Applying a chemical conversion treatment solution containing a resin to form a chemical conversion treatment film.
[2] The step of precipitating the silicate contains 0.5 to 10 g / L silicate in terms of Si on the surface of the stainless steel plate, and has a pH of 9 to 14 and a liquid temperature of 40 to 40. The step of bringing the first treatment liquid at 80 ° C. into contact with the surface of the stainless steel plate treated with the first treatment liquid contains 0.01 to 0.5 g / L silicate in terms of Si, and the liquid temperature Including a step of bringing a second treatment liquid at 40 to 80 ° C. into contact with the chemical conversion treated stainless steel sheet according to [1].
[3] After the step of precipitating the silicate and before the step of forming the chemical conversion coating, the surface of the stainless steel plate has a silicate concentration of less than 0.01 g / L in terms of Si. The method for producing a chemical conversion treated stainless steel sheet according to [1] or [2], further comprising a step of washing with a third treatment liquid.

Moreover, this invention relates to the following chemical conversion treatment stainless steel plates.
[4] A stainless steel plate, a silicate layer in which 0.1 to 100 mg / m ^{2 of} silicate is deposited on the surface of the stainless steel plate, and a silane formed on the silicate layer A chemical conversion treatment stainless steel sheet, comprising: a chemical conversion treatment film containing a coupling agent and an organic resin.

Furthermore, this invention relates to the following coated stainless steel plates.
[5] A coated stainless steel sheet comprising the chemical conversion treated stainless steel sheet according to [4] and a coating film formed on the chemical conversion film.

  ADVANTAGE OF THE INVENTION According to this invention, the chemical conversion treatment stainless steel plate and coated stainless steel plate which are excellent in the adhesiveness of a chemical conversion treatment film can be provided stably.

1. The manufacturing method of a chemical conversion treatment stainless steel plate The manufacturing method of the chemical conversion treatment stainless steel plate of this invention has the process of depositing a silicate on the surface of a stainless steel plate, and the process of forming a chemical conversion treatment film on the surface of a stainless steel plate. Moreover, after depositing a silicate, you may have the process of wash | cleaning the surface of a stainless steel plate before forming a chemical conversion treatment film. Hereinafter, each step will be described in detail.

(1) 1st process In a 1st process, 0.1-100 mg / m < ² > of silicate is deposited by the Si conversion adhesion amount on the surface of a stainless steel plate. For example, the first step includes a step of bringing an aqueous solution (first treatment liquid) containing a high concentration silicate into contact with the surface of a stainless steel plate, and a low concentration silica on the surface of the stainless steel plate treated with the first treatment solution. And an aqueous solution containing an acid salt (second treatment liquid).

  The kind of stainless steel plate is not particularly limited. Examples of stainless steel sheets include ferritic stainless steel sheets such as SUS430, high purity ferritic stainless steels added with Ti and Nb such as SUS430LX, austenitic stainless steel sheets such as SUS304, martensitic stainless steel sheets such as SUS410, These duplex stainless steel sheets are included. The stainless steel plate may be surface-finished. Examples of surface finishing of stainless steel sheets include No. 2D, no. 2B, no. 4, no. 8, HL, BA, dull finish, emboss finish, etc. are included. The stainless steel plate may be a soft high-strength stainless steel such as an annealed material or a work-hardened high-tensile material. Furthermore, the surface of the stainless steel plate may be pickled. Examples of the pickling treatment solution used include hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, or a mixed solution thereof.

  When the silicate is precipitated on the surface of the stainless steel plate using the first treatment liquid and the second treatment liquid, the silicate may be precipitated in two stages of the following step A and step B.

[Step A]
In step A, the first treatment liquid is brought into contact with the surface of the stainless steel plate to degrease the surface of the stainless steel plate to remove dirt, and silicate is deposited on the surface of the stainless steel plate.

  The first treatment liquid is an alkaline silicate aqueous solution. The first treatment liquid may further contain a surfactant. Further, the first treatment liquid may contain an alkali builder such as phosphate, condensed phosphate, carbonate, caustic alkali (sodium hydroxide, potassium hydroxide) as necessary.

  Examples of the silicate compounded in the first treatment liquid include an alkali metal salt of orthosilicate such as sodium orthosilicate, an alkali metal salt of metasilicate such as sodium metasilicate, and an alkali metal sesquisilicate such as sodium sesquisilicate. It is. These silicates may be used alone or in combination of two or more.

  The silicate concentration in the first treatment liquid is preferably in the range of 0.5 to 10 g / L in terms of Si. When the Si equivalent concentration of the silicate is less than 0.5 g / L, the silicate may not be sufficiently precipitated. On the other hand, when the Si equivalent concentration of the silicate is more than 10 g / L, it may be difficult to control the precipitation amount of the silicate. The Si equivalent concentration of the silicate in the first treatment liquid can be quantified by ICP analysis.

  The pH of the first treatment liquid is preferably in the range of 9-14. By adjusting the pH of the first treatment liquid within a predetermined range, the number of hydroxyl groups on the surface of the stainless steel plate is increased to improve the adhesion between the stainless steel plate and the silicate, or the stainless steel plate and the chemical conversion coating. be able to. On the other hand, when the pH is less than 9, the surface of the stainless steel plate may not be sufficiently degreased.

In step A, the first treatment liquid is brought into contact with the surface of the stainless steel plate for 1 to 30 seconds. The method for bringing the first treatment liquid into contact with the surface of the stainless steel plate is not particularly limited, and may be appropriately selected from known methods. Examples of such a contact method include a roll coating method, a curtain flow method, a spin coating method, a spray method, and a dip pulling method. It is preferable that the temperature of a 1st process liquid exists in the range of 40-80 degreeC. When the temperature of the first treatment liquid is less than 40 ° C., there is a possibility that silicate cannot be sufficiently precipitated. Moreover, even if it is a case where surfactant is mix | blended, there exists a possibility that the surface of a stainless steel plate cannot fully be degreased. On the other hand, when the temperature of the first treatment liquid is higher than 80 ° C., when the surfactant is blended, the micelles may collapse and the fat may flow out. By performing step A, the surface of the stainless steel plate is degreased to remove dirt, and 1 to 500 mg / m ² of silicate can be deposited (attached) on the surface of the stainless steel plate in terms of Si. .

[Step B]
In step B, the second treatment liquid is brought into contact with the surface of the stainless steel plate contacted with the first treatment liquid to remove silicate having insufficient adhesion to the surface of the stainless steel sheet, and the surface of the stainless steel plate is removed. Silicate is deposited on the portion where silicate is not deposited.

  The second treatment liquid is a silicate aqueous solution containing 0.01 to 0.5 g / L silicate in terms of Si. As the silicate compounded in the second treatment liquid, the same salt as the silicate compounded in the first process liquid can be used. The Si equivalent concentration of the silicate in the second treatment liquid can be quantified by ICP analysis.

  In step B, the second treatment liquid is brought into contact with the surface of the stainless steel plate in contact with the first treatment liquid for 2 to 30 seconds, and then dried. The method for bringing the second treatment liquid into contact with the surface of the stainless steel plate is not particularly limited, and may be appropriately selected from known methods. Examples of such a contact method include a roll coating method, a curtain flow method, a spin coating method, a spray method, and a dip pulling method. It is preferable that the temperature of a 2nd process liquid exists in the range of 40-80 degreeC. When the temperature of the 2nd processing liquid is less than 40 ° C, there is a possibility that silicate with insufficient adhesion cannot be removed. On the other hand, when the temperature of the second processing liquid is higher than 80 ° C., the amount of evaporation increases, and it may be difficult to control the concentration of silicate in the second processing liquid.

By the A process and the B process, only a silicate having excellent adhesion to the surface of the stainless steel plate can be deposited in layers or islands with an adhesion amount of 0.1 to 100 mg / m ^{2 in} terms of Si. . The adhesion amount of silicate is more preferably in the range of 0.5 to 50 mg / m ^{2 in} terms of Si. The amount of silicate deposited on the surface of the stainless steel plate in terms of Si can be quantified by fluorescent X-ray analysis.

  After finishing the A step and the B step, the surface of the stainless steel plate is drained with a rubber roll or the like. When not performing the 2nd process demonstrated next, the surface of a stainless steel plate is dried. The method for drying the stainless steel plate is not particularly limited, and may be room temperature drying, heat drying at 30 to 150 ° C., or blower drying.

(2) Second Step As described above, after depositing silicate on the surface of the stainless steel plate and before forming the chemical conversion film, the surface of the stainless steel plate is subjected to water or a low-concentration silicate aqueous solution (first (3 treatment liquids) may be included in the cleaning step.

  In the second step, the surface of the stainless steel plate is cleaned by bringing the third treatment liquid having a silicate concentration of less than 0.01 g / L in terms of Si into contact with the surface of the stainless steel plate.

  The third treatment liquid is water or an aqueous solution containing a silicate of less than 0.01 g / L in terms of Si. As the silicate compounded in the third processing liquid, the same salt as the silicate compounded in the first processing liquid can be used. The Si equivalent concentration of the silicate in the third treatment liquid can be quantified by ICP analysis.

  When performing a 2nd process, after performing a 1st process, it is made to dry, after making the 3rd process liquid contact the surface of a stainless steel plate for 0.5 to 3 seconds. If the contact time of the third treatment liquid is too long, the amount of silicate deposited on the surface of the stainless steel plate will decrease, so the contact time is adjusted so that the amount of silicate deposited is within the preferred range . The method for bringing the third treatment liquid into contact with the surface of the stainless steel plate is not particularly limited, and may be appropriately selected from known methods. Examples of such a contact method include a roll coating method, a curtain flow method, a spin coating method, a spray method, and a dip pulling method. The temperature of the third treatment liquid is preferably in the range of 40 to 80 ° C. When the temperature of the 3rd processing liquid is less than 40 ° C, there is a possibility that silicate with insufficient adhesion to the surface of a stainless steel plate cannot be removed. On the other hand, when the temperature of the third treatment liquid is higher than 80 ° C., the amount of evaporation increases, and it may be difficult to control the concentration of silicate in the third treatment liquid. And what is necessary is just to drain and dry like the said B process. Thereby, the silicate with insufficient adhesion to the surface of the stainless steel plate can be removed.

(3) Third Step In the third step, a chemical conversion treatment film containing a silane coupling agent and an organic resin is applied to the surface of the stainless steel plate on which the silicate is deposited to form a chemical conversion treatment film.

  The chemical conversion treatment liquid is an aqueous treatment liquid (aqueous solution) containing a silane coupling agent and an organic resin. The chemical conversion treatment liquid may contain a diisocyanate compound having an aromatic ring, an aliphatic diisocyanate compound, or a polycarbodiimide compound. In addition to water, a small amount of alcohol, ketone, cellosolve-based water-soluble organic solvent, or the like may be used in combination as a solvent for the chemical conversion treatment solution.

  Although the kind of silane coupling agent is not specifically limited, It is preferable to have a primary amino group. When a polycarbodiimide compound is blended in the chemical conversion treatment liquid, the silane coupling agent having a primary amino group is crosslinked with the polycarbodiimide compound to form a dense chemical conversion treatment film having a high barrier property. Examples of silane coupling agents include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (2-aminoethyl) aminopropyltrimethoxysilane, N- (2-aminoethyl) aminopropylmethyl. Examples include dimethoxysilane, N- (2-aminoethyl) aminopropyltriethoxysilane, N- (2-aminoethyl) aminopropylmethyldiethoxysilane, N- (2-aminoethyl) aminopropylmethyldimethoxysilane, and the like.

  Although the kind of organic resin is not specifically limited, Water based resins, such as a urethane resin and a phenol resin, are used. Aqueous resins such as urethane resins and phenol resins are preferable from the viewpoint of improving adhesion because they have polar groups.

  The number average molecular weight of the organic resin is preferably in the range of 1000 to 1000000. When the number average molecular weight is less than 1000, the chemical conversion film may be insufficiently formed. On the other hand, when the number average molecular weight is more than 1,000,000, the stability of the chemical conversion solution may be lowered.

  The glass transition temperature (Tg) of the organic resin is preferably in the range of 0 to 100 ° C. When the glass transition temperature is less than 0 ° C., galling of the coating film is likely to occur during molding. On the other hand, when the glass transition temperature is higher than 100 ° C., the cohesive force of the organic resin is increased, and the adhesion during molding may be reduced.

  It is preferable that the solid content concentration of a chemical conversion liquid is in the range of 0.1 to 40% by mass. When solid content concentration is less than 0.1 mass%, there exists a possibility that a chemical conversion treatment film may not function. On the other hand, when solid content concentration exceeds 40 mass%, there exists a possibility that the storage stability of a chemical conversion liquid may fall. Moreover, it is preferable that pH of a chemical conversion liquid is adjusted in the range of 3-12.

The prepared chemical conversion solution (pH = 3 to 12) is applied to the surface of the stainless steel plate by a roll coating method, a spray method, or the like, and dried at room temperature without washing with water. It is preferable that the coating amount of the chemical conversion treatment liquid is adjusted so that the amount of the chemical conversion coating after drying is in the range of 1 to 500 mg / m ² . When the adhesion amount of a chemical conversion treatment film is less than 1 mg / m < ² >, there exists a possibility that adhesiveness with a coating film may fall. On the other hand, when the adhesion amount of the chemical conversion film exceeds 500 mg / m ² , it is not preferable from the viewpoint of cost. As described above, it is possible to form the chemical conversion film by drying at room temperature. However, considering continuous operation, it is preferable to shorten the drying time at a temperature of 50 ° C. or higher. However, when the drying temperature exceeds 200 ° C., the organic components contained in the chemical conversion film may be thermally decomposed, which is not preferable.

By the above procedure, a stainless steel plate, a silicate layer in which 0.1 to 100 mg / m ^{2 of} silicate is deposited on the surface of the stainless steel plate, and a chemical conversion coating formed on the silicate layer And the chemical conversion treatment stainless steel plate of this invention which has these can be manufactured.

  Since the chemical conversion treated stainless steel sheet of the present invention has a predetermined amount of silicate deposited on the surface of the stainless steel sheet, regardless of the surface state of the stainless steel sheet, the chemical treatment film on the stainless steel sheet is applied by the anchor effect of the silicate. High adhesion. Therefore, the manufacturing method of the chemical conversion treatment stainless steel plate of this invention can manufacture stably the chemical conversion treatment stainless steel plate which is excellent in the adhesiveness of a chemical conversion treatment film.

2. Manufacturing method of a coated stainless steel plate After producing a chemical conversion treatment stainless steel plate as mentioned above, a coated stainless steel plate may be manufactured through the process of forming a coating film on the surface of a chemical conversion treatment stainless steel plate.

(4) 4th process In a 4th process, a coating material is apply | coated to the surface of the chemical conversion treatment film after a 3rd process, and a coating film is formed.

  The kind of resin used as the base of the paint is not particularly limited, and may be appropriately selected from known organic resins. Examples of organic resins include urethane resins, epoxy resins, polyethylene resins, polypropylene resins, olefin resins such as ethylene-acrylic acid copolymers, styrene resins such as polystyrene, polyester resins, copolymers or modifications thereof. Products, acrylic resins, fluorine resins, and the like.

  You may mix | blend a rust preventive pigment further with a coating material. As the rust preventive pigment, porous silica particles (modified silica) bonded with calcium ions by ion exchange are used. Further, in addition to the modified silica, a polyphosphate may be used as necessary. Examples of polyphosphates include aluminum pyrophosphate, aluminum metaphosphate, aluminum dihydrogen tripolyphosphate, and the like.

  The method for forming the coating film on the surface of the chemical conversion coating is not particularly limited. For example, the paint may be applied to the surface of the chemical conversion film by a method such as roll coating or curtain coating, and baked. What is necessary is just to adjust baking temperature suitably in the range of 180-500 degreeC according to the organic resin used as a base. The coating film may have a multilayer structure.

  The coated stainless steel plate of this invention which has the chemical conversion treatment stainless steel plate of this invention and the coating film formed on the chemical conversion treatment stainless steel film by the above procedure can be manufactured.

  Since the coated stainless steel plate of the present invention has a predetermined amount of silicate deposited on the surface of the stainless steel plate, the adhesion of the chemical conversion film and the coating film to the stainless steel plate is high regardless of the surface state of the stainless steel plate.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited by these Examples.

  In this example, the adhesion of the chemical conversion film to the stainless steel plate was examined by examining the adhesion of the coated stainless steel plate.

1. Production of coated stainless steel plate (1) Stainless steel plate SUS430 having a thickness of 0.5 mm was prepared as a stainless steel plate (coating raw plate).

(2) Pre-painting treatment Preparation of each treatment solution (A) Preparation of first treatment solution The first treatment solution is prepared by dissolving various salts (silicate or sodium hydroxide) shown in Table 1 to a predetermined concentration in water. It adjusted by adjusting pH according to. In addition to the silicate, a surfactant (DKS NL-60; polyoxyethylene alkyl ether; Daiichi Kogyo Seiyaku Co., Ltd.) was added to the C treatment solution shown in Table 1 at a concentration of 2 g / L. . In addition to sodium hydroxide, a surfactant (DKS NL-60) was further added to the F treatment solution shown in Table 1 at a concentration of 10 g / L.

(B) Preparation of second treatment liquid The same salt as the first treatment liquid was dissolved in water to a predetermined concentration to prepare second treatment liquids shown in Tables 2 and 3.

(C) Preparation of third treatment liquid As shown in Table 2 and Table 3, as the third treatment liquid, water or an aqueous solution in which the same salt as the first treatment liquid is dissolved in water to have a predetermined concentration is used. Got ready.

B. Precipitation of silicate The 1st process liquid was apply | coated to the surface of the stainless steel plate by the spray method on the conditions shown in Table 2 and Table 3 (1st process). Subsequently, the 2nd process liquid was apply | coated to the surface of the stainless steel plate by the spray method on the conditions shown in Table 2 and Table 3 (2nd process). Finally, the third treatment solution was applied to the surface of the stainless steel plate under the conditions shown in Tables 2 and 3 by spraying to wash the surface of the stainless steel plate (third step), drained with a rubber roll, and at room temperature. Blower drying was performed.

  The Si equivalent amount of silicate deposited on the surface of each stainless steel plate was measured using a fluorescent X-ray analyzer (RIX3000; Rigaku Corporation).

(3) Chemical conversion treatment Preparation of chemical conversion treatment solution A mixture of N- (2-aminoethyl) aminopropyltriethoxysilane and cationic urethane resin (mass ratio 6: 4) is added to water, and the chemical conversion treatment has a solid content concentration of 5% by mass. A liquid was prepared. The cationic urethane resin was prepared by the following procedure. 160 parts by mass of polyether polyol, 5 parts by mass of trimethylolpropane, 25 parts by mass of N-methyl-N, N-diethanolamine, 95 parts by mass of isophorone diisocyanate and 130 parts by mass of methyl ethyl ketone are placed in a reaction vessel and heated at 75 ° C. for 30 minutes. A urethane prepolymer was obtained by heating. Subsequently, 18 mass parts of dimethyl sulfate was mix | blended with the urethane prepolymer, and it heated at 55 degreeC for 40 minute (s), and obtained the cationic urethane prepolymer. Next, 600 parts by mass of water was added to the cationic urethane prepolymer and uniformly emulsified, and then methyl ethyl ketone was recovered to prepare a cationic urethane resin.

B. Formation of Chemical Conversion Treatment Film The prepared chemical conversion treatment solution was applied to the surface of each stainless steel plate by a roll coating method and dried at 80 ° C. to form a chemical conversion treatment film with a coating amount of 100 mg / m ² .

(4) Coating A polyester-based undercoat paint was applied onto the chemical conversion film and baked at a reaching plate temperature of 200 ° C. to form an undercoat film having a thickness of 5 μm. Next, a polyester-based top coat was applied to the surface of the undercoat film and baked at a reaching plate temperature of 230 ° C. to form a top coat film having a thickness of 15 μm.

2. Evaluation of Adhesion of Chemical Conversion Coating (1) Adhesion Test The adhesion of the chemical conversion coating was evaluated based on the remaining rate of the coating after bending the coated stainless steel plate by 180 degrees. Specifically, the coated stainless steel plate was subjected to 180-degree close folding so that the coating film was on the outside. Subsequently, the cellophane tape was affixed to the bending ridge line part, the cellophane tape was peeled off in the direction perpendicular to the bending ridge line, and the residual ratio of the coating film was measured. If the residual rate of the coating film is 90% or more, it is “Excellent” that the processing adhesion is extremely excellent, and if the residual rate of the coating film is 70% or more and less than 90%, it is “Excellent” that the processing adhesion is excellent. When the residual ratio of the coating film was less than 70%, it was evaluated as “x” because no improvement was observed in the processing adhesion.

(2) Results Tables 2 and 3 show the results of the kind of treatment liquid used, the Si equivalent precipitation amount of silicate on the stainless steel plate surface, and the adhesion test for each coated stainless steel plate.

In the coated stainless steel sheet in which the coating film was peeled off, peeling occurred at the interface between the stainless steel sheet and the chemical conversion film. Painted stainless steel plate No. In 35-40 (comparative example), since the Si precipitation amount on the surface of the stainless steel plate was less than 0.1 mg / m ² , the adhesion of the chemical conversion film was poor. On the other hand, the painted stainless steel plate No. In 1-34 (Example), since the Si precipitation amount on the surface of the stainless steel plate was within a predetermined range, the adhesion of the chemical conversion film was good. In particular, painted stainless steel plate No. In 2 to 8, 12 to 18, 24 to 28, 31 and 32 (Examples), the amount of silicate deposited was within the range of 0.5 to 50 mg / m ^{2 in} terms of Si. The adhesion was even better.

Moreover, using SUS304 and SUS430LX having a plate thickness of 0.5 mm as the coating original plate, a coated stainless steel plate was produced under the conditions shown in Tables 2 and 3, and the adhesion of the chemical conversion treatment film was evaluated. As a result, in the case of a coated stainless steel sheet having a precipitation amount of silicate of 0.1 to 100 mg / m ^{2 in} terms of Si, the evaluation of adhesion is “◯” or “◎” as in the case of using SUS430 as a coating original sheet. "It was good.

  From the above results, it can be seen that the chemically treated stainless steel sheet produced by the production method of the present invention is excellent in the adhesion of the chemically treated film.

  Since the chemical conversion treated stainless steel plate produced by the production method of the present invention and the coated stainless steel plate having the same are excellent in the adhesion of the chemical conversion treatment film, materials such as building roofing materials, exterior materials, home appliances, and automobiles Useful as.

Claims (5)

A step of depositing 0.1 to 100 mg / m ² of silicate alone in terms of Si on the surface of the stainless steel plate;
The silicate only on the surface of the stainless steel plate which was precipitated, the treatment liquid is applied you contains a silane coupling agent and an organic resin, and forming a skin layer,
The a method of pretreatment stainless steel. The step of depositing only the silicate is:
A step of contacting a first treatment liquid containing 0.5 to 10 g / L silicate in terms of Si and having a pH of 9 to 14 and a liquid temperature of 40 to 80 ° C. on the surface of the stainless steel plate;
The surface of the stainless steel plate contacted with the first treatment liquid is contacted with a second treatment liquid containing 0.01 to 0.5 g / L silicate in terms of Si and having a liquid temperature of 40 to 80 ° C. A process of
including,
The manufacturing method of the pre- processing stainless steel plate of Claim 1. After the step of depositing only the silicate, and before the step of forming a pre-Symbol skin film, the surface of the stainless steel plate, a third concentration of the silicate is less than 0.01 g / L in terms of Si The manufacturing method of the pre- processed stainless steel plate of Claim 1 which further has the process of wash | cleaning with a process liquid. Stainless steel plate,
On the surface of the stainless steel plate, a silicate layer in which only 0.1 to 100 mg / m ^{2 of} silicate in terms of Si is deposited;
Wherein formed on the silicate layer, and peel film contains a silane coupling agent and an organic resin,
The a, pretreatment stainless steel. Preprocessing stainless steel sheet according to claim 4,
And a coating film which is formed on top of the previous Symbol skin membrane,
Having a painted stainless steel sheet.