WO2003074760A1

WO2003074760A1 - Surface treated steel sheet and method for production thereof

Info

Publication number: WO2003074760A1
Application number: PCT/JP2002/002052
Authority: WO
Inventors: Tatsuya Miyoshi; Satoru Ando; Akira Matsuzaki; Naoto Yoshimi; Takahiro Kubata; Masaaki Yamashita
Original assignee: Jfe Steel Corporation
Priority date: 2000-09-07
Filing date: 2002-03-06
Publication date: 2003-09-12
Also published as: KR100608137B1; KR20040016893A; CN1524133A; EP1482074A4; EP1482074A1

Abstract

A surface treated steel sheet which comprises a zinc based metal plated steel sheet, a composite oxide film formed on the steel sheet, and a straight silicone resin film formed on the oxide film, wherein the composite oxide film comprises (α) fine oxide particles and (β) phosphoric acid and /or a derivative of phosphoric acid as a constituent.

Description

Specification

Surface treatment plate and its! ¾i¾ method

Translation field

TECHNICAL FIELD The present invention relates to a surface-treated steel sheet having excellent heat resistance and scratch resistance, which can be used for various parts of automobiles, home appliances, and building materials, and a method for producing the same. Background leakage

From the standpoint of durability and economy, dumbbell-plated steel sheets are used in a wide range of fields, such as automobiles, home appliances, and building materials. Conventionally, for the purpose of imparting functions such as corrosion resistance and paintability, a zinc-based plated steel sheet is subjected to chromate treatment, and a thin resin coating with a thickness of several meters is further formed on the surface. Is being done.

However, such zinc-coated steel sheets do not have heat resistance, and when exposed to high-temperature environments such as around the engine room of automobiles, shrink bands of stoves, microwave ovens, CRT tubes of televisions, and the vicinity of welded parts, the calorie may deteriorate. There were problems such as discoloration and fuming due to heat, and deterioration of corrosion resistance. In the case of only chromate treatment, discoloration during heating is suppressed to some extent due to the absence of organic components.However, since the film is extremely thin, it is scratched during processing, deteriorating the appearance, and There was a problem when corrosion resistance deteriorated.

As a method for solving such a problem, for example, (1) Japanese Patent Application Laid-Open No. 4-33844, (2) Japanese Patent Application Laid-Open No. 6-179981, and (3) Japanese Patent Application Laid-Open No. 7-278837 have been proposed. ing.

As a technique using a silicone resin, (4) JP-A-63-102929 and JP-A-2000-15741 have been proposed.

Chromate treatment uses hexavalent chromium, which is a pollution control substance, and this hexavalent chromium is treated in a closed system in the treatment process, and is completely reduced and recovered, and is not released to nature. Sealing with organic composite film Since the elution from the chromate film can be reduced to almost zero by the action, the environment and human body are not substantially polluted by hexavalent chromium. However, recent global environmental issues have led to a growing trend to voluntarily reduce the use of heavy metals, including hexavalent chromium. In addition, in order to prevent the environment from being polluted when dumping shredder dust from waste products, there has been a move to reduce or eliminate heavy metals in products as much as possible.

For this reason, a number of pollution-free treatment techniques that do not rely on chromate treatment have been proposed to prevent the occurrence of white spots on zinc-based plated steel sheets. Among them, several methods using an organic compound or an organic resin have been proposed. For example, the following methods can be mentioned.

(1) Method using tannic acid (for example, JP-A-51-71233)

(2) An anonymous paint in which an epoxy resin is mixed with an amino acid and tannic acid (for example, JP-A-63-90581)

(3) A method using a mixture of tannic acid such as a method using a mixed product of an aqueous resin and ^ fffiphenol carboxylic acid (for example, JP-A-8-325760).

(4) A surface treatment method of applying an aqueous solution of a hydrazine derivative to the surface of a tin or zinc iron plate (for example, JP-B-53-27694, JP-B-56-10386)

(5) A fungicide containing an amine addition salt obtained by adding an amine to a mixture of acylsarcosin and benzotria pool (JP-A-58-130284)

(6) A treating agent in which a heterocyclic compound such as a benzothiazole compound is mixed with pernic acid (JP-A-57-198267).

(7) A composition for surface treatment comprising an organic resin containing a monomer containing a 7-acid-monomer as a copolymerization component and a phosphoric acid compound of phosphoric acid or metal (JP-A-9-208859, JP-A-9-241856) )

And the like.

In the above prior arts (1) and (2), a chromate treatment was performed on a plated steel sheet, and a treatment liquid (water glass) based on silicic acid and water-soluble with an alkali metal oxide was applied to the upper layer and dried. However, since alkali metal components remain in the upper film, There is a problem that it is inferior in water solubility and consequently inferior in corrosion resistance. In addition, the prior art of (2) has a disadvantage that it is poor in lubricity and consequently inferior in scratch resistance at the time of processing because it is composed only of inorganic components. (3) shows the formation of a chromate film with silica added to the Zn-Ni alloy plating. However, the addition of silica makes it difficult to suppress discoloration due to heating, and has the disadvantage of poor scratch resistance during processing. There is.

In addition, the conventional technology of (4) uses a ladder type silicone resin formed on a zinc-plated steel sheet with a chemical conversion coating, but has a cross-linked structure called a ladder type. As a result, the cured film became too thick, resulting in poor scratch resistance during processing and poor adhesion of the film during processing. The conventional technology of (5) had both heat resistance and scratch resistance. However, in order to improve corrosion resistance, chromate

(Including hexavalent chromium), it is difficult to say that it is a non-polluting material.

In the techniques (1) to (7), which do not use chromate, since the organic components are mainly used, if heated to a high temperature, the organic components are thermally decomposed and only sufficient corrosion resistance cannot be obtained. The surface turned black and could not be used for heat-resistant applications. As described above, there has been no zinc-based plated steel sheet having excellent heat resistance and scratch resistance at high temperatures and excellent corrosion resistance without using chromium in the prior art. Disclosure of the invention

An object of the present invention is to provide a surface-treated steel sheet which is excellent in both heat resistance and flaw resistance at high temperatures, does not use chromium in the treatment step, is safe and has excellent corrosion resistance, and a method for producing the same. Is to do.

The present inventors have developed a composite oxide film composed of oxide fine particles and a phosphate compound as a first layer on a zinc-based plated steel sheet surface, and a resin film mainly composed of a specific straight silicone resin as a second layer. A new zinc-coated steel sheet with excellent heat discoloration resistance, smoke emission when heated, corrosion resistance after heating and scratch resistance has been newly discovered.

The present invention has been made based on such findings, and the features thereof are as follows. [1] On the surface of the dumbbell-coated steel sheet, a composite oxide film containing (a) oxide fine particles and (] 3) phosphoric acid and Z or a phosphoric acid compound as constituent elements as the first layer is formed by the above-mentioned component ( shed) and P ₂ 0 ₅ the above ingredients () total amount of adhered and formed so that Do and 5~4000mg / m ² of at the exchange, 0 straight silicone resin film with Si0 ₂ calculated as the second layer of the upper layer .:! Surface-treated steel sheet, characterized in that the ~ 3 g / m ² formed.

[2] The composite oxide film further contains (a) one or more of Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, and Ce as components, and wherein the One composite oxide fine particles (the P ₂ 0 ₅ above components in terms of oxide film in (3), the total deposition amount of the metal conversion calculated mass of the component (§) is 5～4000Mgm ² The surface-treated steel sheet according to [1].

[3] The surface-treated steel sheet according to [2.], wherein the metal of the component (r) contained in the composite oxide film is Mn, Z, or A1.

[4] The surface-treated steel sheet according to any one of [1] to [: 3], wherein the component (α) contained in the composite oxide film is silicon dioxide.

[5] components contained in the composite oxide film (alpha) is silicon dioxide and in an amount ranging adhesion of. 5 to 95 wt% as a mass ratio to the total deposition amount of the composite oxide film at the Si0 ₂ in terms of The surface-treated steel sheet according to any one of the above [1] to [3], wherein:

C6] One or more components (a) of Mg, Ca, Sr, li, Mn, Fe, Co> Ni, Zn, Al, La, Ce contained in the composite oxide film, and a component ( in terms of metal amount of P ₂ 0 ₅ in terms of weight and Ingredient (§) 3) (molar ratio of the metal that the sum of respective terms of a metal amount in the case of two or more) (P ₂ 0 ₅ ZME) is lZ2~ The surface-treated steel sheet according to any one of [2] to [5], which is 2Zl.

C7] The surface-treated steel sheet according to any one of [1] to [6], wherein the organic group contained in the straight silicone resin film is a methyl group.

[8], wherein the Si0 ₂ component of the straight silicone resin film is not higher than 60% of the total coating weight, the surface treated steel sheet according to any one of [1] to [7].

[9] 20 parts by mass of a crystalline lubricant based on 100 parts by mass of the straight silicone resin The surface-treated steel sheet according to any one of [1] to [8], wherein the steel sheet contains not more than 1 part by weight.

[10] The organic resin composition according to any of [1] to [8], wherein an organic lubricant having a softening point of 70 ° C or more is contained in an amount of 20 parts by mass or less based on 100 parts by mass of the straight silicone resin. Surface-treated steel sheet according to any of the above.

[1 1] At least one surface of the zinc-based plated steel sheet

(A) Oxide fine particles 0.001 to 3.0 mol / l

The (mouth) phosphoric acid and / or phosphoric acid compound is treated with an aqueous solution containing 0.001～6.0Mol / l in P ₂ 0 ₅ in terms of weight, by heating and drying thereafter, as the first layer coating on the plated steel sheet surface ,

() Oxide fine particles

() Phosphate and 'κ or phosphate compounds

By a complex oxide film containing as a component is formed at a coverage of 5~4000mg m ^2, the following Ide coating composition mainly comprising a straight silicone resin thereon is coated, heating and drying the, Si0 ₂ 0.:! A method for producing a surface-treated steel sheet, characterized in that a second layer coating of up to 3 g / m ² is formed.

[12] As an additional component in the aqueous solution for forming a composite oxide film,

(C) The metal ions of Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, and Ce, and the compound containing at least one of the metal ions is the total of the metal equivalents of the metal. By treating with an aqueous solution containing 0.001 to 3.0 moll, and then drying.

() Oxide fine particles

(/ 3) phosphoric acid and / or phosphate compound

(A) 5 to 4000 mg / g of a composite oxide film containing one or more components of Mg, Ca, Sr, Ii, Mn, FeCo, Ni, Zn, Al, La, and Ce as components. formed at a coverage of m ^2, and then the coating composition was applied mainly of straight silicone resin thereon, by heating and drying, to the formation of the second layer coating Ai～3gm ² in Si0 ₂ in terms of A method for producing a surface-treated steel sheet, characterized in that: BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic front view of a testing machine for evaluating the scratch resistance of a test material. Embodiment of the Invention

In the surface-treated steel sheet of the present invention, a composite oxide film is formed as a first layer on the surface of a zinc-coated steel sheet. The composite oxide film containing silicon dioxide of the present invention as a component is

Li ₂ 0 and Si0 Unlike all Ku the Arukarishirike Ichito treatment film typified by ₂ treatment composition comprising, contains as components the (alpha) oxide particles and (j3) phosphoric acid and / or phosphorous Xie匕合product And, if necessary, further contain (r) one or more of Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, and Ce as constituents. Features.

(Ii) As the oxide fine particles, which is one of the constituent elements of the composite oxide film, silicon dioxide is preferable, and colloidal silica, for example, Snowtex 0, OS, OXS, OUP, AK manufactured by Nissan Chemical Industries, Ltd. :, 040, O and OZL (more acidic solution), Snowtex XS, S, XS, NS, N, QAS-25, LSS-35, LSS-45, LSS-75 (more alkaline solution) etc. can be applied. In addition, Catalyst Chemicals Co., Ltd. Cataloid S, SI-350, SI-40, SA (above alkaline solution) Cataloid SN (above acidic solution), Asahi Denka Kogyo Co., Ltd. Adelite AT-20-50, AT- 20N, AT-300, AT-300S (more alkaline solution), Adelite AT20Q (more acidic solution), etc. can be applied.

Among them, those having a particle size of 14 nm or less, and particularly those having a particle size of 8 nm or less are preferable from the viewpoint of corrosion resistance. Further, a material obtained by dispersing dry-type fine particles in a coating composition solution may be used. As the fumed silica, AEROS1L 200, 300, 300CF, 380, etc., manufactured by Nippon Aerosil Co., Ltd. can be used. Among them, those having a particle diameter of 12 nm or less, preferably 7 nm or less are preferable.

In addition to the above, as the oxide fine particles, a colloid solution or a fine powder of aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, antimony oxide, or the like can be used.

(] 3) Phosphoric acid and Z or phosphate compound For example, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, and the like, and metal salts and compounds thereof can be added to a film composition to be combined as a film component. Among them, the first phosphate is preferred from the viewpoint of the stability of the coating composition solution. Further, when ammonium primary phosphate, ammonium secondary phosphate, and ammonium phosphate tertiary were added to the coating composition solution as phosphates, a tendency was observed to improve the corrosion resistance. The reason for this is not clear, but when these ammonium salts are used, the gel does not gelate even if the pH of the skin solution is increased. In general, metal salts become insoluble in an alkaline region, so that when formed from a composition solution having a high pH, it is considered that a more sparingly soluble compound is generated in the drying process.

The presence state of phosphoric acid and Z or a phosphoric acid compound in the film is not particularly limited, and may be crystalline or non-crystalline. The ionicity and solubility of phosphoric acid and Z or a phosphoric acid compound in the film are not particularly limited.

The components contained as needed in the film (a) Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, Ce are not particularly limited in the state of existence in the film. Presumably exist as a metal, or as a compound such as an oxide, 7jC oxide, hydrated oxide, or phosphate compound, or as a complex compound or a metal. The ionicity, solubility, and the like of these compounds, hydroxides, hydrated oxides, and phosphate compounds are not particularly limited.

Among the components (r), Mn and A1 have better corrosion resistance than the other components (a). The reason for this is not clear, but hydroxides are likely to be formed in the corrosive environment, neutral pH, and form a network for complexation with phosphate compounds, silica, etc., resulting in a dense film. It is thought that it is.

The method of introducing the component ( _r ) into the film is not particularly limited, but Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, Ce phosphate, nitrate, It may be added to the coating composition solution as a sulfate, chloride, or the like.

Adhesion of the composite Sani匕物coating, the components in the oxide particles (a) and P ₂ 0 ₅ in terms of (beta)., Further wherein if the component (§) is present, as the sum of the metal mass in terms is suitably 5~ 4000mg / m ^2. Preferably from 50: L000mg / m ² , more preferably from 100 to 500 mg / m ^2, further preferably 200 to 400 mg / m ^2. If the adhesion amount is less than 5 mg / m ² , the corrosion resistance is not sufficient, while if it exceeds 4000 mg / m ² , the appearance of the coating and the appearance after heating are deteriorated, and the conductivity is further reduced. to degrade.

In order to obtain particularly good corrosion resistance, a composite oxide ^^ components of the medium (but silicon dioxide, total adhesion of the composite Sani匕物coating adhesion amount is defined above in the Si0 ₂ in terms of silicon dioxide It is desirable that the mass ratio be in the range of 5 to 95 wt%, preferably 10 to 60 wt%.

When silicon dioxide is in the above range, the reason why particularly excellent corrosion resistance is obtained is not clear, but the barrier property that cannot be obtained only with silicon dioxide is complemented by the phosphoric acid component, and a dense film is formed. It is considered that excellent corrosion resistance was realized due to the synergistic effect of the corrosion inhibitory action of each of the phosphoric acid component and the silicon dioxide.

From The same viewpoint, the proportion of the metal component is a phosphoric acid and / or phosphoric acid compound and a component which is a component of the composite oxide (3) (§), and [rho ₂ 0 ₅ in terms of component (beta) in terms of metal amount of Ingredient (§) if (metal in the case of two or more respective sum of terms of a metal amount) is 1 Bruno 2-2 1 molar ratio (P ₂ 0 ₅ ZME) and A better corrosion resistance can be obtained.

The reason why particularly excellent corrosion resistance is obtained when the ratio of the phosphoric acid component and the metal component is in the above range is not clear, but since the solubility of the phosphoric acid component varies depending on the ratio of the phosphoric acid and the metal. However, when the solubility of the coating is within the above range, it is particularly hardly soluble, and it is considered that the barrier property of the coating is higher.

In the first layer coating, additives such as polyphosphate, phosphate (eg, zinc phosphate, aluminum dihydrogen phosphate, zinc phosphite, etc.), molybdate, and phosphorus are further added as additives for further suppressing corrosion resistance. Molybdate (such as aluminum phosphomolybdate), organic phosphoric acid and its salts (phytic acid, phytate, phosphonic acid, phosphonate and their metal salts, alkali metal ^), organic inhibitors (eg hydrazine derivatives , Thiol compounds, dithiol rubamates, etc.) may be added to the coating composition. Further, as other additives, coupling agents (for example, silane coupling agents, titanium coupling agents, etc.) can be added. However, organic resin Any addition is not preferable because it causes smoke and appearance deterioration after heating at a high temperature.

The plated steel sheet of the present invention has a film formed by applying and baking a treatment liquid mainly containing a specific straight silicone resin as a second layer on the surface of the first layer. Silicone is a general term for materials that have a siloxane (one Si—0—Si—) portion. Trees J !, oil, rubber, etc. are used.

Thus, the straight silicone resin used in the present invention will be described. Siloxane (one Si—0 to Si—) is used as a skeleton, and a hydroxyl group (—OH) and an alkoxyl group

(One OR: R is an organic group) or an organic group bonded to the material, which has both organic and inorganic properties, and is characterized by not being modified with other organic resins. In addition, the film is flexible because it does not have a bridge structure, and is characterized by excellent scratch resistance. The organic group bonded with silicofluoride atom, a methyl group (- CH _3), Echiru group (one C ₂ ¾), phenyl group (an C ₆ H _5), a vinyl group (- CH = C¾), butyl Group (-QH ₇ ) and the like. The straight silicone resin used may contain these organic groups alone or may contain two or more different organic groups. It is not preferable to use a modified silicone resin other than the straight silicone resin, because the modified organic resin component is thermally decomposed during heating, causing discoloration and smoking.

Further, among the organic groups, those having a methyl group having a small number of carbon atoms are more preferable from the viewpoint of preventing smoke caused by ^^ of the organic component due to heating.

_S i0 ₂ component contained in the straight silicone resin is preferably 60% or more of the total film weight. This other Si0 ₂ component of the straight silicone resin are the water acid group or an organic group, smoke with an organic group is increased in order to Retsui spoon. The reason why the organic lubricant is added to the silicone resin film is that the organic lubricant has an effect of more effectively preventing the resin film and the adhered surface from being scratched and galling due to roll forming and press molding. Because it has. The reason for using an organic lubricant having a softening point of 70 ° C. or higher is not preferable if the temperature is lower than 70 ° C. because organic components are easily decomposed and smoke is inferior. Examples of organic lubricants having a softening point of 70 ° C or higher include: Microcrossing phosphorus wax (softening point 70 to 90 ° C), polyethylene (softening point 90 to 140 ° C), and polypropylene (softening point 140 to 170 ° C). C), tetrafluoroethylene (softening point 320 ° C), etc. I can do it. The above-mentioned lubricants may be added alone, or two or more different lubricants may be used in combination. Further, the acid phosphorus value of the micro phosphorus phosphorus wax, polyethylene, and polypropylene may be 0 or more than 0, or a combination thereof. Since the silicone resin is of a solvent type, it is preferably added in the form of powder or in a state of being dispersed in a solvent in advance, and the particle size is preferably 20 m or less from the viewpoint of scratch resistance.

In addition to the above organic lubricants, crystalline lubricants include inorganic lubricants such as graphite, boron nitride, and molybdenum disulfide. Such a lubricant can be preferably used when fuming is important, but it may be slightly inferior in scratch resistance as compared with organic ones. You can do it.

The organic lubricant is preferably added in an amount of 20 parts by mass or less based on 100 parts by mass of the silicone resin. If the amount is more than 20 parts by mass, the amount of organic components increases, and the smoke emission during heating is inferior. A more preferable addition amount is 10 parts by mass or less from the viewpoint of fuming properties. In the case of an inorganic lubricant, if the addition amount exceeds 20 parts by mass, the flaw resistance deteriorates, which is not preferable.

0 adhesion amount of straight silicone resin in the Si0 ₂ terms.:! It is preferable to the ~ 3g / m ^2. If the amount of adhesion is less than O.lg m ² , the scratch resistance during roll forming / press molding is poor, and if it exceeds 3 g / m ² , smoke generation during heating and adhesion during bending are inferior.

A coating mainly composed of a straight silicone resin as described above is applied to the surface of a zinc-based steel plate, heated and dried to form a film.

The coated steel sheets that form the above-mentioned coatings include galvanized steel sheets manufactured by electroplating, hot-dip plating, and vapor deposition, zinc, as well as nickel, iron, aluminum, cobalt, and molybdenum. A zinc alloy-plated steel sheet containing at least one of the following components, and a dispersion-plated steel sheet containing silica, alumina, and the like in a plating film. More preferably, from the viewpoint of heat resistance, a zinc-nickel alloy-coated steel sheet and a zinc-55% aluminum alloy-coated steel sheet having a high melting point of the plated metal. In addition, hot-rolled aluminized steel sheet without zinc plating, cold-rolled steel sheet without Steel plates can also be used.

The steel sheet used as the base of the zinc-based plated steel sheet is not particularly limited, and various compositions, surface roughness, and rolling methods can be used.

The formation of the composite oxide film and the resin film on the surface of the zinc-based plated steel sheet is performed as follows. That is, the treatment solution for the composite oxide film composition described above is applied to the surface of the zinc-based plated steel sheet by a known method such as a roll coater, a force flow coater, or spray coating, and the hot air stove or induction heater is applied. A predetermined amount of the coating film is formed by applying the above-mentioned paint mainly composed of the straight silicone resin similarly to the surface of the composite oxide film formed by drying by a known method such as a heating furnace. To form Next, the zinc-coated steel sheet coated with the paint was heated using a hot air stove or induction heating device.

By heating to a temperature of 80 to 300 ° C or lower and baking, the solvent in the paint is volatilized to form a resin film.

Note that the concentration of the processing solution is limited to the above range for the following reason. Was or phosphoric acid and Z Rinsani匕合product is fried unfavorable such secured a predetermined coating weight is less than O.OOlmoVl with P ₂ 0 ₅ in terms of weight, poor processing solution stability at 6.0 mol / l greater Therefore, it is not preferable. If the oxidized fine particles are less than O.OOlmol / 1, it is not preferable because a predetermined amount of the particles cannot be secured, and if it is more than 3.0mol / l, the stability of the treatment liquid is inferior. Also, for metal ions of Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, Ce, and compounds containing at least one of the metal ions, the metal conversion amount of the metal If the total is less than O.OOlmoW, the effect of adding metal ions is not obtained, which is not preferable. If the total is more than 3.0 mol / l, the stability of the treatment liquid is inferior.

The baking temperature of the above-mentioned resin film should be in the range of 80 to 300 ° C. If the baking temperature is lower than 80 ° C, the resin film is not sufficiently cured, and the scratch resistance during processing is poor. On the other hand, if the temperature exceeds 300 ° C., the curing of the resin film proceeds excessively, and the organic groups in the straight silicone resin are decomposed and volatilized, which is not preferable because of poor scratch resistance. An example

The treatment liquids (film compositions) for forming the first layer film shown in Tables 1 and 2 were prepared. The adjusted second layer film forming treatment solution shown in Table 3-5 (the coating composition) _£

Oxide fine particles (α) Phosphoric acid / phosphate compound () Metal component (r)

(Component 1) (Component 2) Primary particles of the present invention (mol / l) (mol / l) Molar ratio; Tatsuna Total composition Condition suitability Type Trade name Diameter (nm) * 1 type * 2 (β) Λτ) Type (mol / l) Type (mol / l) Mole amount * 3

1 Silicon dioxide Nissan Chemical Industries 6 ~ 8 0.33 Orthophosphoric acid 0.30 1.00 U 0.30 ― One 0.30 4.3 o Snowtex OS

ι Silicon dioxide Nissan Chemical Industry 6 ~ 8 0.33 Orthophosphoric acid 0.06 1.50 Mn 0.04 ― ― 0.04 2.6 〇

Snowpack OS

珪素 Silicon dioxide 6-8 0.40 Orthophosphoric acid manufactured by Nissan Chemical Industries. 0.13 1.30 Fe 0.10 ― 0.10 0.8 o Snowtex OS

4 Silicon dioxide Nissan Chemical Industries 6 ~ 8 0.30 Orthophosphoric acid 0.22 1.22 Co 0.18 ― ― 0.18 1.3 o Snowtex OS

5 Silicon dioxide Nissan Chemical Industries 6 ~ 8 0.33 Orthophosphoric acid 0.15 1.25 Ni 0.12 ― ― 0.12 3.0 〇

Snowpack OS

6 Silicon dioxide Nissan Chemical Industries 6-8 0.33 Orthophosphoric acid 0.22 1.10 Zn 0.20 ― 0.20 2.4 o Snowtex OS

7 Silicon dioxide Made by Sansan Chemical Industry 6 ~ 8 0.33 Orthophosphoric acid 0.15 1.50 Al 0.10 ― 0.10 2.1 o

Snowpack OS

8 Silicon dioxide Nissan Chemical Industries 6-8 0.33 Orthophosphoric acid 0.09 1.80 s a 0.05 1-1 0.05 1.5 o Snow os OS

9 Silicon dioxide 6 ~ 8 0.33 Orthophosphoric acid 0.09 1.80 Ce 0.05 ― 1 0.05 2.0 〇

AEROSIL200

10 Silicon dioxide Japan 7: Made in Japan 12 0.50 Orthophosphoric acid 0.15 1.50 Mn 0.10 0.1 — 0.10 2.6 o

AEROSIL200

1 1 Silicon dioxide Nippon IQV 12 12 0.50 Orthophosphoric acid 0.10 1.20 Ni 0.08 0.08 3.0 o

AEROSIL200

12 Silicon dioxide Nippon Aye O-Sil 12 0.33 Orthophosphoric acid 0.10 1.20 Co 0.08 0.08 2.8 o

AEROSIL200

13 Silicon dioxide Nippon Steel 12 0.33 Orthophosphoric acid 0.12 1.50 Al 0.08 0.08 2.9 〇

Snowtex OUP

14 Silicon dioxide Nissan Chemical Industries 12- 14 0.20 Orthophosphoric acid 0.12 1.20 Mn 0.10 0.10 1.5 o Snow tous OUP

15 Silicon dioxide Nissan Chemical Industries 12-14 0.20 Orthophosphoric acid 0.12 1.20 Al 0.10 0.10 2.0 o

Alumina sol 200

16 Aluminum oxide ::: Nissan Chemical Industries * 4 0.33 Orthophosphoric acid 0.10 1.00 Mn 0.10 0 10 3.1 〇

* 1) Si02 equivalent, * 2) Ρ20δ equivalent, * 3) Meet the requirements of this project: 〇, Not met: X * 4) Feathery particles

Table 2

* D Si02 equivalent, * 2) P205 equivalent, * 3) Meets the requirements of this project: 0, Not met: X, * 4) Feathery particles

Table 3

* 1) UZ: Electric zinc plated steel sheet, EZN: Zinc-nickel alloy plated steel sheet, GI: Hot dip galvanized steel sheet, GA: Alloyed hot dipped galvanized steel sheet,

GF: molten zinc-5% aluminum; steel alloy coated steel sheet, GL: molten zinc-55% aluminum alloy coated steel sheet,

* 2) No. described in Table 1 ...

* 3) Weight ratio to total weight of first layer (composite oxide film)

* 4) (r) The ratio of the molar value of the total value of the metal in terms molar amount of components, P ₂ 0 ₅ reduced mass in the (beta) phosphoric acid and / or phosphoric acid compound

* 5) The total coating weight = (oxide particles mass + () 8) [rho ₂ 0 ₅ reduced mass in the (y3) phosphoric acid and / or phosphoric acid compound ten (r) components of the metal equivalent weight

Table 4

* 1) UZ: Electric zinc plated steel sheet, 、: Zinc-nickel alloy plated steel sheet, GI: Hot dip galvanized steel sheet, GA: Alloyed hot dipped galvanized steel sheet,

GF: Hot-dip zinc-5% aluminum alloy coated steel sheet, GL: Hot-dip zinc-55 '/. Aluminum alloy plated steel sheet,

* 2) No. described in Table 1

* 3) The mass ratio to the total mass of the first layer (composite oxide film).

* 4) (r) The ratio of the molar value of the total value of the metal in terms molar amount of components, P ₂ 0 ₅ reduced mass in the () phosphoric acid and / or phosphoric acid compound

* 5) The total coating weight = ( «) oxide particles mass + (js) p ₂ o ₅ reduced mass in the (beta) phosphoric acid and / or phosphoric acid compound + (r) components of the metal equivalent weight

Table 5

* 1) UZ: Electro-galvanized steel sheet, EZN: Sub-nickel alloy-plated steel sheet, GI: Hot-dip galvanized steel sheet, GA: Alloyed hot-dip galvanized steel sheet,

GF: Fused zinc-5% aluminum alloy coated steel sheet, GL: Fused zinc-55% aluminum alloy coated steel sheet,

* 2) No. described in Table 1

* 3) Weight ratio to total weight of first layer (composite oxide film)

* 4) (r) The ratio of the molar value of the total value of the metal in terms molar amount of components, P ₂ 0 ₅ reduced mass in the (S) phosphoric acid and / or phosphoric acid compound

* 5) The total coating weight = oxide particles mass + (jS) P ₂ 0 ₅ in terms of mass (/ 3) phosphoric acid and / or phosphoric acid compound + _(r) components of the metal equivalent weight

After washing both sides of the following zinc-coated steel sheet with alkaline degreasing water, apply the treatment solution for forming the first layer film shown in Tables 1 and 2 on the surface of the plating with a roll coater all over the surface. Was adjusted and dried by heating to form a first layer film. Then, the coating composition mainly composed of the straight silicone resin shown in Tables 3 to 5 was applied by a roll coating method (adhesion amount was adjusted by wet application amount), and this was applied to an induction heating furnace. The test material was prepared by baking at an ultimate plate temperature of 60 to 400 ° C.

(1) Electro-galvanized steel sheet (sheet thickness 0.8 mm, coating weight 20 gm ² )

(2) Zinc-nickel alloy plated steel plate (¾j? 0.8mm, coating weight 20g / m ² )

(3) Hot-dip galvanized steel sheet (sheet thickness 0.8 mm, coating weight 90 g / m ² )

(4) Alloyed hot-dip galvanized steel sheet (sheet thickness 0.8 mm, coating weight 45 g / m ² )

(5) Hot-dip galvanized steel sheet with 5% aluminum alloy (sheet thickness 0.8 nm, coating weight 90 g / m ")

(6) Steel sheet with hot-dip zinc-55% aluminum alloy (sheet thickness 0.8 mm, coating weight 70 g / m ² )

Tables 3 to 5 show the amount of composite oxide attached to the first layer and the amount of resin film attached to the second layer of each sample.

The prepared test materials were evaluated for heat discoloration resistance, smoke generation, pre-calo heating, post-heating corrosion resistance, and scratch resistance. The results are shown in Tables 6-8.

The performance evaluation method is described below.

[Performance basket]

(1) Heat discoloration resistance

After the specimen reached a plate temperature of 600 ° C, it was heat-treated for 1 hour, and the discoloration of the specimen surface was measured with a colorimeter. The i¾B criteria are as follows.

◎: AE≤2

〇: 2 <ΔΕ≤5

Room: 5 <ΔΕ ^ 10

X: ΔΕ> 10

(2) Smoke emission The smoke generation status of each specimen was evaluated visually until the plate temperature reached 600 ° C. The evaluation criteria are as follows.

◎: No smoke

〇: Smoke is slightly observed

Rum: smoke is clearly visible

X: remarkably smoke

(3) Corrosion resistance before heat

A plurality of test pieces of 70 mm × 150 mm were cut out from the test material, and the test pieces were subjected to a salt spray test specified in JIS Z 2371, and the whitening area after 500 hours was visually determined. The evaluation criteria are as follows.

◎: White 鲭 No occurrence

〇 +: White 鑌 generated area 5% or less

〇: White 錡 Occurrence area More than 5% and 10% or less

△: White △ Occurrence area More than 10% 30% or less

X: White area generation area more than 30%

(4) Corrosion resistance after heating

After reaching the plate temperature of 600 ° C, the test material was heat-treated for 1 hour, and several 70mm x 150mm test pieces were cut out and subjected to salt spray test specified in JIS Z 2371. The test was carried out, and the reddish area after 500 hours was visually determined. The evaluation criteria are as follows.

：: Red 鑌 No occurrence

〇: Red 鲭 Occurrence area 5% or less

△: Red △ Occurrence area more than 5% 30% or less

X: Red area more than 30%

(5) Scratch resistance

The test machine shown in the schematic front view in FIG. 1 was used. The tester includes a female die 1 having a flat surface fixed to one side 2a of a box-shaped frame 2 as shown in FIG. 1, and a substantially horizontal protrusion having a predetermined height facing the female die 1. Male dice 4 with Article 3 and male dice 4 And a hydraulic cylinder 5 fixed to the other side 2b of the frame 2 for horizontally moving the male die 4 toward the female die 1. The male die 4 is fixed to a rod 5 a of a hydraulic cylinder 5 via a load cell 6. The width of the ridge 3 of the male die 4 is 10 mm, and the length of its tip is lmm.

The test material is inserted vertically into the gap between the female die 1 and the male die 4, and the hydraulic cylinder 5 is actuated, so that the test material 7 is 50 kgf (500 kg ^ cm) by the female die 1 and the male die 4. ² ) Pressed with pressure. Next, the test material 7 was pulled upward at a speed of 500 mm / min, as indicated by the arrow, and the coating and the adhesion damage of the portion slid at that time were visually evaluated. The evaluation criteria are as follows.

◎: No scratch

〇: Slight damage to coating, but no plating damage

△: The coating is damaged and plating damage is small

X: The coating is damaged, and plating damage is large

Table 6

Table 7

t

Table 8

As is evident from Tables 3 to 5 and Tables 6 to 8, the zinc-coated steel sheets on which the coating according to the present invention is formed are all resistant to heat discoloration, smoke, corrosion resistance before and after caro heat, and scratch resistance. Is also excellent. On the other hand, the comparative examples are inferior in heat discoloration resistance, smoke generation, corrosion resistance before or after heating, and scratch resistance.

As described above, the surface-treated steel sheet of the present invention has excellent thermochromic properties and smoke generating properties in an environment exposed to high temperatures, and has excellent corrosion resistance before and after heating without using chromium. Have. Furthermore, it has excellent properties such as scratching of the coating and plating surface when processing as a part and adhesion of the coating.

Claims

The scope of the claims

1. zinc-coated steel sheet,

Wherein formed on the surface of the zinc-based plated steel sheet, (containing as a component an oxide microparticles and (] 3) phosphoric acid and / or phosphoric acid compound, the component (a) and at P ₂ 0 ₅ in terms A composite oxide film having a total adhesion amount of the component (iS) of 5 to 4000 mgm ² ,

Formed on said composite oxide film has a Si0 ₂ component, and the stress one preparative silicone resin film having a deposition amount of 0.1～3Gm ² layers with Si0 ₂ in terms of,

Surface treated steel sheet having.

2. The composite oxide film further comprises (A) at least one or more components selected from the group consisting of Mg, Ca, Sr, Li, MnFe, Co, Ni, Zn, Al, La, and Ce; and oxide particles (with P ₂ 0 ₅ above components in terms of the double focus oxide film in (beta), the component

^{2. The} surface-treated steel sheet according to claim 1, wherein the total adhesion amount of the metal equivalent mass of (r) is 5 to 4000 mg / m ² .

3. The surface-treated steel sheet according to claim 2, wherein at least one or more components (r) contained in the composite oxide film are Mn, Z, or A1.

4. The surface-treated steel sheet according to any one of claims 1 to 3, wherein the oxide fine particles (a) contained in the composite oxide film are silicon dioxide.

5. surface-treated steel sheet according to claim 4, wherein the amount deposited is in the range of 5 to 95 wt% in mass ratio to the total deposition amount of the composite oxide film on the Si0 ₂ in terms of silicon dioxide.

6. Mg, Ca, Sr, Li, Mn, Fe, Co, Ni, Zn, Al,

At least one component (r) and component (/ 3) selected from the group of La and Ce The molar ratio (P ₂₀ Me Me) between the p ₂ o ₅ conversion amount of the component (r) and the metal conversion amount of the component (r) (the sum of the metal conversion amounts for metals of 2 or more in the case of more than two species) is 1/2 to The surface-treated steel sheet according to any one of claims 2 to 5, which is 2/1.

7. The surface-treated steel sheet according to any one of claims 1 to 6, wherein the straight silicone resin film has a methyl group as an organic group.

8. Surface-treated steel sheet according to any one of the straight silicone Ichin Si0 ₂ component of the resin film in the range 1 to 7 according to at least 60% of the total film weight.

9. The surface-treated steel sheet according to any one of claims 1 to 8, wherein the straight silicone resin film contains 20 parts by mass or less of a crystalline lubricant sealed in 100 parts by mass of the straight silicone resin.

10. The surface treatment according to any one of claims 1 to 8, wherein the straight silicone resin film contains 20 parts by mass or less of an organic lubricant having a softening point of 70 or more based on 100 parts by mass of the straight silicone resin. steel sheet.

1 1. The method for producing a surface-treated steel sheet has the following steps:

At least one surface of (a) zinc plated steel sheet, the (I) oxide fine particles 0.001~3.0mol / l and (mouth) phosphate and down or phosphoric acid compound P ₂ 0 ₅ equivalent amount from 0.001 to 6.0 treating with an aqueous solution containing mol / l;

(b) As a first layer film on the surface of the coated steel sheet, heat-drying of the steel sheet treated with an aqueous solution is used as a first layer film (contains oxide fine particles and (β) phosphoric acid and / or a phosphate compound as constituent elements Forming a composite oxide film with an adhesion amount of 5 to 4000 mg m ² ;

(C) a coating composition composed mainly of straight silicone resin in an upper layer of the composite Sani匕物coating was applied, dried by heating, forming the second layer coating 0.1 to 3 g / m ² in Si0 ₂ in terms of Process.

1 2. The method for producing a surface-treated steel sheet has the following steps:

At least one surface of (a) zinc plated steel sheet, the (I) oxide fine particles 0.001～3.0Mol / l and (mouth) phosphoric acid and / or phosphoric acid compound with P ₂ 0 ₅ equivalent amount from 0.001 to 6.0 mol / l and (c) a compound containing at least one of metal ions of Mg, Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, and Ce. Treating with an aqueous solution containing a total of 0.001 to 3.0 mol / l;

(b) Heat treatment and drying of the steel sheet treated with the τ solution to form a first layer coating on the surface of the plated steel sheet. (Particulate oxide and (3) phosphoric acid and / or phosphate compound and (a) Mg , Ca, Sr, Ii, Mn, Fe, Co, Ni, Zn, Al, La, Ce A complex oxide film containing at least one component selected from the group consisting of 5-4000 mg / forming with an adhesion amount of m ² ;

(C) composite oxide film of the straight silicone resin and applying a coating composition based on an upper layer of, by heating and drying, the step of forming the second layer coating of 0.1 to 3 g m ² with Si0 ₂ conversion.