WO2002061175A1

WO2002061175A1 - Surface treating agent for metal material and method for treating surface

Info

Publication number: WO2002061175A1
Application number: PCT/JP2001/001500
Authority: WO
Inventors: Mitsuru Nakamura; Jenshun Fan; Osamu Furuyama
Original assignee: Nihon Parkerizing Co., Ltd
Priority date: 2001-01-31
Filing date: 2001-02-28
Publication date: 2002-08-08
Also published as: JPWO2002061175A1

Abstract

A surface treating agent for a metal material, characterized as comprising the following (A), and (B) and/or (C); (A): one or more phosphates of one or more metals selected from among Zn, Fe, Mn, Ni, Co, Ca, Mg and Al which have an average particle diameter of 5νm or less, (B): an inorganic binder selected from among a silicon compound, a phosphorus compound, a zirconium compound and a titanium compound, (C): one or more polymer components containing one or more polymers being represented by the following formula (1) and having an average polymerization degree of 2 to 50. The surface treating agent contains no chromium and is capable of imparting excellent corrosion resistance to a metal.

Description

Description Surface treatment agent for metal materials and surface treatment method

The present invention relates to a surface-treating agent for metal sheets, and to a surface-treated metal sheet having excellent end face corrosion resistance when it is applied to a metal sheet and used as a coating base, and in particular, does not contain toxic chromium. It is. Background art

Post-painted products that have been painted after conventional processing, such as for home appliances, building materials, and automobiles, are often pretreated with phosphates and the like. Instead of processing, pre-coated metal sheets coated with a colored organic coating have been used. This metal sheet is a metal sheet that has been subjected to a base treatment and a metal sheet coated with an organic film, and has the property of having good workability, good corrosion resistance, and good appearance. I have.

For example, Japanese Patent Application Laid-Open No. H08-1688723 discloses a technique for obtaining a pre-coated steel sheet having excellent workability, stain resistance, and hardness by defining the structure of a film. . On the other hand, Japanese Patent Application Laid-Open No. H03-1000180 discloses a precoated steel sheet having improved end face corrosion resistance by using a specific chromate treatment solution.

These pre-coated steel sheets have workability and paint adhesion, as well as corrosion resistance due to the combined effect of chromate treatment and organic coating, and omission of post-work coating to improve productivity and quality. Is widely used.

However, due to the toxicity of hexavalent chromium, which can be eluted from the chromate treatment and the organic film containing the chromium-based pigment, the demand for non-chromium-free treatment and non-chromium organic film has recently increased. Japanese Patent Application Laid-Open No. 53-92338 discloses that thiourea and tan W

2 A treatment technique using an aqueous solution containing nin or tannic acid is disclosed.However, when a pre-coated metal plate is manufactured using this protection method, if it is applied to home appliances or automobiles with severe processing shapes, processing There is a problem that the adhesion of the coating film in the part is greatly inferior.

Japanese Patent Application Laid-Open No. 59-116163 / 81 discloses a technique for improving the whiteness resistance and paint adhesion by treating the surface with an aqueous solution containing tannic acid and a silane coupling agent. Although disclosed, this method also cannot ensure the required processing adhesion of the precoated metal plate. For automobiles, phosphate treatment is still used as pre-treatment when painting after processing. However, this phosphate treatment requires surface conditioning before the treatment and complicates the process such as washing and drying after the treatment. Therefore, shortening of the process and cost reduction are required. Disclosure of the invention

In view of the above, an object of the present invention is to provide a surface-treated metal plate that is non-chromium-based and has excellent end face corrosion resistance when used as a coating base.

The present inventors have conducted intensive studies in order to solve the above problems of the prior art, and as a result, used a phosphate, a water-soluble polymer and / or a metal compound in combination as a metal surface treatment agent. By doing so, it has been found that the corrosion resistance of the metal material and the adhesion between the coating resin and the metal plate are dramatically improved, and that the above-mentioned problems can be solved. That is, the present invention is (1) a surface treating agent for a metal material, comprising water, the following (A), (B) and / or (C).

(A) a metal having an arithmetic mean particle size of 5 μηι or less and selected from divalent or trivalent Zn, Fe, Mn, Ni, Co, Ca, Mg, and A1 At least one selected from phosphates containing at least one of the following.

(B) An inorganic binder having at least one selected from a silicon compound, a phosphorus compound, a zirconium compound, and a titanium compound.

(C) One or more polymer components containing one or more polymers represented by the following general formula (1) at an average degree of polymerization of 2 to 50.

[Where X in the formula (1) is a hydrogen atom, a hydroxyl group, a C1-C5 alkyl group, a C1-C5 hydroxyalkyl group, and a C6-C12 aryl group. A pendyl group, a penzal group, an unsaturated hydrocarbone group condensed with the benzene ring to form a naphthalene ring, or a group represented by the following formula (2):

0 H

R1 and R2 in the formula (2) represent a hydrogen atom, a hydroxy group, a C1-C5 alkyl group or a C1-C10 hydroxyalkyl group, respectively, and the formulas (1) and (2) ), Y1 and Y2 bonded to the benzene ring are each independently a hydrogen atom or a Z group represented by the following formulas (3) and (4):

R3

C H2 — N (3)

R3, R4, R5, R6 and R7 in the above formulas (3) and (4) are each independently a hydrogen atom, <1 to 10 alkyl groups or 1 to 1; X, Y1, and Y2 bonded to each benzene ring in the polymer molecule represent 10 hydroxyalkyl groups, and X, Y1, and Y2 each bonded to another benzene ring. The average value of the number of substitution of the Z group in each benzene ring in the polymer molecule is from 0.2 to 1.0. ]. (2) The surface treatment agent for a metal material according to (I), wherein the solid content of the phosphate (A) is preferably in the range of 5% by weight to 95% by weight based on the total solid content. . (3) The surface treatment agent for a metal material described in (1) or (2) is applied to the surface of the metal material, dried and coated with 0.05 to 5 g / m ^{2 in} terms of phosphate (A). This is a surface treatment method for metal materials characterized by the following.

Hereinafter, the present invention will be described in detail.

Phosphate containing at least one metal selected from divalent or trivalent Zn, Fe, Mn, Ni, Co, Ca, Mg and A1 used in the present invention. (A) includes the following examples. Normally, phosphates of divalent or trivalent metals exist as hydrates such as dihydrate and tetrahydrate, but the number of water of hydration is not limited with respect to the effects of the present invention. Illustrated in the form of an anhydrous salt.

_{_{Zn 3 (P0 4) 2,}} Zn 2 Fe (P0 4) 2, Zn 2 Ni (P0 4) 2, Ni 3 (P0 4) 2, Zn 2 Mn (P0 4) 2, Mn 3 (PO4) 2, _{_{_{Mn 2 Fe (P0 4> 2}}} , Ca 3 (P0 4) 2, Zn 2 Ga (P0 4) 2, FeP0 4, AlP0 4, Co 3 (P0 4) 2, g 3 (P0 4) 2.

Regarding the particle size of the phosphate film crystals formed on the plating surface, considering the corrosion resistance and the adhesion of the coating film as an undercoat film, it is preferable to coat the plating surface uniformly and densely. However, it can be inferred that the smaller the particle size of the phosphate film, the better. In order to stably disperse in the processing solution, the arithmetic average particle size of the divalent or trivalent metal phosphate used in the present invention is 5 m or less. Is desirable.

Next, the inorganic binder (B) used in the present invention has at least one selected from a silicon compound, a phosphorus compound, a zirconium compound, and a titanium compound. Examples of such inorganic binders include, in the case of silicon compounds, alkali silicates such as sodium silicate, potassium silicate and lithium silicate, and polymer silica such as colloidal silica.

Examples of the phosphorus compound include phosphoric acid, aluminum phosphate, pyrophosphoric acid, and tripolyphosphoric acid. Examples of the zirconium compound include water-dispersible zirconium colloid, zirconium carbonate ammonium, zircon ammonium fluoride, zircon fluorination power, and sodium zirconium fluoride. Examples of the titanium compound include water-dispersible titanium colloid, water-soluble inorganic titanium compounds such as titanium sulfate, titanium oxysulfate, titanium hydrofluoric acid, titanium fluoride ammonium, and titanium alkoxide.

The polymer component (C) used in the present invention is an oligomer or a polymer containing 5 polymerized units represented by the formula (1), and the average polymerization degree of the polymerized unit of the formula (1) is 2 to 2.

50. In the formulas (1) and (2), Y 1 and Y 2 bonded to the benzene ring each independently have a hydrogen atom or a Z group represented by the formulas (3) and (4). R 3, R 4, R 5, R 6 and R 7 in the formulas (3) and (4) each independently represent a hydrogen atom, an alkyl group of C1 to G10 or a hydroxyalkyl group of G10 to C10. And the average value of the number of substitution of the Z group in each benzene ring in the polymer molecule is 0.2 to 1.0.

If the average value of the number of Z group substitutions is less than 0.2, the resulting polymer will have insufficient adhesion to the substrate surface, resulting in poor coatability. On the other hand, if it exceeds 1.0, the resulting polymer will have high hydrophilicity and the resulting steel sheet will have insufficient corrosion resistance. R3, R4, R5, R6 and R7 in the formulas (3) and (4) each independently represent a hydrogen atom, a C1-G10 alkyl group or a C1-C10 hydroxyalkyl. When the number of carbon atoms is 11 or more, the film forming property of the formed post-treatment agent is reduced, so that the corrosion resistance, coating property, workability, and the like become insufficient.

The content of the phosphate (A) in the surface treatment for a metal material of the present invention is based on the total solid content. It is preferably in the range of 5% by weight to 95% by weight. If the content is less than 5% by weight, the corrosion resistance after coating becomes insufficient due to the small amount of phosphate used as a corrosion inhibitor. If the content exceeds 95% by weight, the amount of phosphate in the film is excessive and the effect of the binder is insufficient, so that the adhesion is reduced. A more preferred range is 105 weight. /. 770% by weight.

The surface treatment agent for a metal material of the present invention is preferably applied to the surface of the metal material, dried, and coated in a range of 0.05 to 5 g Zm ^{2 in} terms of phosphate (A). If it is less than 0.05 g Zm ² , the corrosion resistance becomes insufficient because the amount of the film is small. On the other hand, if the coating amount exceeds 5 g / m ² , the adhesion after processing may be insufficient or the cost may be disadvantageous. _A more preferred range is 0.1 to ² g Zm ² .

The surface treatment of the present invention includes cold-rolled steel sheet, hot-rolled steel sheet, hot-dip galvanized steel sheet, electro-zinc-plated steel sheet, hot-dip galvanized steel sheet, aluminum-plated steel sheet, aluminum-zinc alloy-plated steel sheet, and stainless steel sheet The present invention can be applied to generally known metal materials such as an aluminum plate, a copper plate, a titanium plate, and a magnesium plate and a plating plate. These metals

Β Β Β 板処理処理前前処理前前前, Β 前処理板処理処理前前処理,,, 処理処理前. The surface treatment of the present invention is characterized in that a chemical solution containing phosphate fine particles, a water-soluble polymer and / or a metal compound, etc. is applied and dried. Phosphate has been used for a long time as a pretreatment agent for painting, but it has been confirmed that it has insulating properties and interfacial buffering effects. It is estimated to be 0. In addition, it is thought that since it is crystalline, fine irregularities are formed on the surface of the metal material, and the coating surface is improved by increasing the surface area. Conventionally, a phosphate film with high added value has been produced by contacting a metal material with a chemical containing zinc ions, phosphate ions, an accelerator, etc., depositing a zinc phosphate film, washing with water, and removing excess water. Although it has been manufactured as a phosphate-treated steel sheet except for ions, the surface treatment of the present invention uses inorganic and organic binders.6. It is characterized by being provided on the surface.

One of the inorganic and organic binders may be used, or both may be used in combination. The binder type must be non-corrosive to the steel sheet and one that does not adversely affect the topcoat paintability. Surface treatment of the present invention The agent can be applied by conventional coating methods, such as mouth coating, curtain flow coating, air spray, airless spraying, immersion, vacuum coating, brushing, and the like. Examples and comparative examples

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples of the present invention.

1. Preparation of test plate

1.1 Test materials

• Alloy-plated steel plate (GA)

Sheet thickness 0.6 mm, coating weight 45 g / m ² per side (plated on both sides) • Steel plate with zinc plating (GI)

0.6mm thick, 60gZm ² per side of zinc coating (both sides coated)

.Cold rolled steel plate (SPCC-SD)

0.6mm thick.

1.2 Pretreatment '' The test material was immersed in an aqueous solution with a concentration of 20 g / L and a temperature of 60 ° C for 10 seconds using an alkali degreasing agent CL—N364S (manufactured by Nippon Parkerizing) for 10 seconds. After washing with water, it was dried.

1.3 Surface treatment

Examples 1 to 11 and Comparative Examples 1 to 4

Using a surface treatment agent having the composition shown in Table 2, it was applied to a predetermined thickness using a mouth coater, and dried in a hot-air drying oven so that the plate temperature reached 80 ° C.

• Coating chromate treatment (Comparative Example 5)

Using a GI material and applying ZM-1300AN (manufactured by Nippon Pharma Co., Ltd.) as a coating chromating agent, apply it in a roll coater so that the Cr adhesion amount will be 4 Omg m ² , respectively. At 80 ° C. • Zinc phosphate treatment (Comparative Example 6)

Using GA material and S PCC material, spray-prepare Preparen ZN (manufactured by Nippon Pasco Rising) as a surface conditioner at room temperature for 20 seconds, and then apply zinc phosphate Was subjected to a zinc phosphate treatment by immersion treatment at 42 ° C for 120 seconds. Thereafter, it was washed with water and dried.

1.4 Top coating (GI material)

Paint: Amirac # 1 000 (Kansai Paint)

Painting method: Bar coating method

Baking: 1 40 ° C, 20 minutes

Film thickness: 25 tm.

1.5 Top coating (GA and SPCC)

The electrodeposition coating was performed under the following conditions.

Paint: GT—10 V (Kansai Paint cationic electrodeposition paint)

Painting method: Coulomb control slow start for 30 seconds

Baking: 1 75 C, 25 minutes

Film thickness: 20 melons.

2. Evaluation

2.1 Corrosion resistance 1 '

The salt spray test specified in JIS-Z2371 was performed for 120 hours on the test material that also used GI material. The whiteness resistance was visually measured and evaluated. The evaluation criteria are as follows. '

©: Whiteness less than 5%

〇: Whiteness occurrence rate 5% or more, less than 10%

Δ: Whiteness occurrence rate 10% or more, less than 50%

X: Whiteness rate 50% or more.

2.2 Corrosion resistance 2

For the test materials using GA and SPCC materials, insert the cuts diagonally on the painted surface with a single knife, immerse them in a 5% aqueous solution of sodium chloride, and leave them at 55 ° (at 24 hours for 24 hours. Then, a tape peeling test was performed on the cut portion, and the maximum peeling width on both sides was measured.

◎: Peeling width less than 3 mm

〇: 3 mm or more and less than 5 mm Δ: 5 mm or more and less than 20 mm

x: 20 mm or more.

2.2 Paint adhesion

2.2.1 Primary adhesion

For GI, GA, and SPCC materials, insert a lmm square grid on the painted surface with a knives knife and extrude 5 mm with an Erichsen tester so that the painted surface is convex. A tape peel test was performed. The method of inserting grids, the method of extruding Erichsen, and the method of peeling the tape were performed according to the methods described in JIS-K5400.8.2 and JIS-K5400.8.5. The evaluation was based on the number of peeled coating films. The evaluation criteria are shown below.

◎: No peeling

〇: 1 or more peeled, less than 10

△: Number of peeling 1 1 or more, less than 50

X: Number of peeled 5 1 or more.

2.2.2 Secondary adhesion

After the test plate was immersed in boiling water for 2 hours, a test similar to the “Next adhesion” was performed and evaluated. Table 1 Water-soluble polymers

Sato a b Functional group X Functional group Y 1 z Substitution number

(= Ζ) Average Polymer 15 H -CH ₂ N (CH ₃ ) 2 1.0 0 Polymer 25 -CH ₂ -C _e H4-0H -CH ₂ N (CH ₃ ) ₂ 0.50 Polymer 3 5-H _Z -C ₈ H4-0H -CH ₂ N (H ₃ ) 2 0.75 Polymer 4 5 11 -CH ₂ N (CH ₃ ) 2 0.30 Table 2 Compositions of surface treatment agents used in Examples and Comparative Examples

N o Phosphate compound <Λ) Inorganic Han Water-soluble 皮膜 Film amount Compound Arithmetic mean diameter Tar (15) No polymerization (A ') A + B + C (p

1 Ζη ₂ η (Ι DU Ita ΊResiri)! ; Nr, \ · π uηu

2 Ζη ₂ Μη (1 0.5 ill charcoal, di, eight, ル

3 1.5M in Si, Le :) Nium coloy ― 0.8 3.00

-

4 Zn ₂ Ni (P04) _z 0.5ΛΙ m Polymerization stop 1 0.6 2.00

5 Zn ₂ Ni (P0 0.5 ί m-no polymerization 2 0.5 0.50

6 0.jj.m 1 3! Closed 3 0.3 0.50

7 Ca _a (PC) 0.5 «m-polymerization break 4, 0.4 1.00

8 Ca _a (P04) O.jJL m Colloidal silica-0.2 0.50

9 Mn ₂ l ^r e (I ^> 04) ₂ O.Bju m Titanium: 0.2 2.00 for ilH

1 0 Zn ₂ Ca (r04) 0.5_um m-carbonate 0.5 2.00 mm

1 1 Zn ₂ Ca (P04) _z l.Oum ffi union 1 0.6 2.00

1 2 Zn ₂ Ni (P04) ₂ Ι.θ ί m 1.00

1 3 Carbonate

_{1 4 Zn 2 Ni (P04)} 2 0,5〃 m Polymer _{1 0.6 0.01 5 Zn 2 Hn (} P0 4) 2 O. ju m colloidal Γ Rushirika 0.5 0.01 Table 3 Results of evaluation test of implementation ① and comparison ②

Surface treatment 别 Material Adhesion Corrosion resistance 1 Corrosion resistance 2 o / \ ί¾ 1χϋ M 1

丄 or ◎ ◎ Example 2 No 2 GA ◎ .Example 3 No 3 SPC ◎ ◎ Example 4 No 4 SPC ◎ ◎ ◎

^ c / Jl! i I7 ₀ 7 (; Λ ◎

'Ν o 8 J ◎

1 w ©

N ϋ u ◎

¾ * fc ΛΛΙ c 1)

Ii Tari 1 1 M O 丄 1 1 丄 ◎

IN U ίϊΛ Comparatively cool 2 No 13 SPC 〇〇 X mm 3 No 14 Si Si Δ Δ Δ Comparative example 4 No 15 ϋ ΐ 〇〇 Δ Comparative example 5 Ζ-1300ΛΝ ϋ ◎ ◎ ◎ ◎ ◎

Comparative Example 6 PB-L30Z0 SPC ◎ 〇 As is evident from the results in Table 3, Examples 1 to 11 using the surface treatment agent of the present invention were excellent in coating adhesion and corrosion resistance, and the current coatings shown in Comparative Examples 5 and 6 The performance was equal to or better than that of mouth mate treatment or phosphate conversion treatment. However, Comparative Examples 1 to 4 had compositions outside the scope of the claims of the present invention, but had poor paint adhesion and poor corrosion resistance. , Industrial applicability

According to the present invention, it has become possible to provide a surface-treated steel sheet having excellent coating adhesion and corrosion resistance without using environmentally toxic chromium. Therefore, it can be said that the present invention is an invention having extremely high industrial value.

Claims

Scope of Claim (1) A surface treatment agent for metal materials, characterized by containing water and the following (A), (B) and / or (C). (A) at least a metal selected from among divalent or trivalent Zn, Fe, Mn, Ni, Co, Ca, Mg and Al having an arithmetic average particle size of 5 μπι or less and It has at least one kind selected from among phosphates containing one kind. (B) An inorganic binder having at least one selected from a silicon compound, a phosphorus compound, a zirconium compound, and a titanium compound. (C) One or more polymer components containing one or more polymers represented by the following general formula (1) at an average degree of polymerization of 2 to 50.

[However, in the formula (1), X bonded to the benzene ring is a hydrogen atom, a hydroxyl group, a C1-C5 alkyl group, a C1-C5 hydroxyalkyl group, a C6-C12 aryl group, or a penzyl group. A penzal group, an unsaturated hydroxycarbon group condensed to the benzene ring to form a naphthalene ring, or a group represented by the following formula (2):

0 H

Wherein R1 and R2 in the formula (2) are a hydrogen atom and a hydroxyl group, respectively. Or a C1-C5 alkyl group or a C1-C10 hydroxyalkyl group, and in the formulas (1) and (2), Y1 and Y2 bonded to the benzene ring are each independently a hydrogen atom, Or a Z group represented by the following formulas (3) and (4):

R3, R4, R5, R6 and R7 in the above formulas (3) and (4) each independently represent a hydrogen atom, a C1-C10 alkyl group or a C1-C10 hydroxyalkyl group. Each of X, Y1 and Y2 bonded to each benzene ring in the polymer molecule may be the same as each of X, Y1 and Y2 bonded to other benzene rings. Alternatively, they may be different from each other, and the average number of substitutions of the Z group in each benzene ring in the polymer molecule is 0.2 to 1.0. ]

(2) A surface treating agent for a metal material, wherein the solid content of the phosphate (A) according to claim 1 is in the range of 5 to 95% by weight based on the total solid content.

(3) and characterized in that the claim 1, wherein the metal material surface treatment agent is applied after Drying on the metal surface, is 0. 05 to 5 g / m ² coated with phosphate (A) in terms The surface treatment method for metal materials.