JP3464652B2 - Non-chromate type surface-treated metal sheet excellent in press galling resistance and coil deformation resistance, and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weldable non-chromate type surface-treated metal sheet having excellent press galling resistance, coil deformation resistance, and corrosion resistance. Especially cars,
The present invention relates to a surface treatment field using a zinc-based plated steel sheet, which is widely used in home appliances, building material products, and the like.

[0002]

2. Description of the Related Art Heretofore, galvanized steel sheets or galvanized steel sheets have been found to have a white rust on the surface and significantly impair the appearance in an atmosphere containing salt such as seawater or in a hot and humid atmosphere. Although the anticorrosive power may be reduced, a chromate-based anticorrosive treatment agent has been conventionally used to prevent the white rust. For example, JP-A-3-1313 is used.
No. 70 discloses a resin-based treatment agent in which an olefin-α, β-ethylenically unsaturated carboxylic acid copolymer resin dispersion contains a water-dispersible chromium compound and water-dispersible silica.

On the other hand, in recent years, particularly in the home electric appliance industry, from the viewpoint of process saving and cost saving, the number of products applied without coating is increasing. Not only corrosion resistance and coating adhesion but also galling resistance, fingerprint resistance, The required level of various performances such as unevenness of dew condensation on the surface appearance quality of steel sheets is increasing.
In order to meet such performance demands of customers, a coated metal sheet has been developed in which an organic composite film based on a special resin is formed on a chromate-treated plated steel sheet. For example, in Japanese Examined Patent Publication No. 14191/1992, an organic composite film in which a colloidal sol having a specific fine particle size is additionally adjusted is formed on a water-based organic resin on a plated steel sheet that has been subjected to a chromate treatment, and performances such as corrosion resistance and fingerprint resistance are obtained. A method for manufacturing an improved surface-treated steel sheet is disclosed.

Further, Japanese Patent Laid-Open No. 3-39485 discloses that
After applying chromate treatment on zinc-based plated steel sheet,
A dry weight of a coating material prepared by dispersing silica and a wax having a glass transition point (Tg point) of 40 ° C. or higher in an aqueous resin is 0.3.
To 3.0 g / m ² obtained by coating are disclosed. Further, in JP-A-3-28380, a coating comprising a carboxylated polyethylene resin and a Teflon (trademark) lubricant after a chromate treatment on an electrogalvanized steel sheet is used as a dry weight of 0.5 to 4 Lubricated steel sheets coated with 0.0 g / m ² are disclosed. Furthermore, in order to meet the demands of customers who require severe galling resistance such as deep drawing workability, a surface treated steel sheet was developed in which a solid lubricant was added to the organic coating to improve lubricity. . For example, Japanese Patent Application Laid-Open No. 6-173037 discloses a steel sheet having a lubricating coating in which silica and polyolefin wax are added to an ether / ester type urethane resin and an epoxy resin.

Japanese Patent Publication No. 14191/1992 discloses a surface-treated steel sheet having an excellent performance balance such as corrosion resistance, coating adhesion, fingerprint resistance and dew condensation resistance, which is one of the main products for home appliances at present. Is used as. Further, when importance is attached to galling resistance during pressing, scratch resistance during handling, abrasion resistance during transportation, etc., it is disclosed in JP-A-3-39485 and JP-A-3-28380. Such techniques are widely used.
Furthermore, in the case of molding under extremely severe pressing conditions such as deep drawing and strong ironing, the technique disclosed in Japanese Patent Laid-Open No. 6-173037 is used. However, JP-A-3-39485 and JP-A-3-2838
The surface of the steel sheet manufactured by the techniques disclosed in Japanese Patent Laid-Open No. 0 and Japanese Patent Application Laid-Open No. 6-173037 is slippery, and problems such as coil crushing due to loose winding and load collapse during cutting plate piling occur. Therefore, in order to avoid these problems, measures such as increasing the tension at the time of winding the coil and increasing the number of bands to prevent loosening of the coil after packaging are currently taken.

A surface-treated steel sheet having such a chromate-treated coating or a surface-treated steel sheet having an organic composite coating on the chromate-treated coating has the best corrosion resistance among known surface-treated steel sheets. Is recognized as However, the chromate-based treatment film contains hexavalent chromium, which is known to be a harmful element, and therefore there is an increasing demand for a surface-treated metal plate that does not contain hexavalent chromium. In addition, in order to improve the adhesion and corrosion resistance of the upper organic composite film, well-known electrolytic chromate and reactive chromate mainly containing trivalent chromium are often used as a coating base treatment. It may contain chromium and may be difficult to use in the future. As described above, chromate treatment is used as a primary rust preventive treatment for steel sheets and plated steel sheets, and as a base treatment for coating and coating. Is desired.

As a surface treatment technique containing no chromium,
There is a phosphate treatment such as zinc phosphate treatment. However, phosphate treatment is somewhat inferior to chromate treatment in terms of corrosion resistance as a primary rust preventive treatment, and chromium sealing is necessary to ensure corrosion resistance even as a coating base.As an alternative technique to chromate treatment, Is insufficient. In order to solve these problems, in JP-A-5-195244 or JP-A-7-145486,
Although a treatment method for forming a coating layer that does not contain chromium has been proposed, both have achieved the same performance as that of the conventional chromate-based treatment, that is, the same corrosion resistance and coating adhesion as chromate-based treatment. Not in.

Further, JP-A-11-106945 discloses a non-chromate type anticorrosive treatment agent containing a water-soluble polymer, phosphoric acid and a silane coupling agent, and a treatment method for forming a treatment film on a metal surface by a single layer treatment. Although it has been disclosed, it has not yet satisfied the corrosion resistance of the processed part equivalent to that of chromate-treated one, the press galling resistance equivalent to the above-mentioned organic composite film-coated steel sheet mainly composed of organic resin and silica. .

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a metal plate such as a zinc or zinc alloy plated steel sheet, which has corrosion resistance equal to or higher than that of a chromate-based treatment. An object of the present invention is to provide an inexpensive and weldable non-chromate type rustproof metal plate. In addition, not only corrosion resistance including the processed part but also coating adhesion, as well as galling resistance, fingerprint resistance, dew condensation resistance, etc. Welding at a low cost that can meet various performance requirements for steel sheet surface appearance quality. An object of the present invention is to provide a non-chromate type anticorrosion treated metal plate that can be used. Furthermore, in order to improve problems such as coil crushing due to winding looseness and load collapse during cutting plate piling while maintaining press galling resistance, the film composition, the dynamic friction coefficient of the film surface and the static friction coefficient are controlled at low cost. An object of the present invention is to provide a non-chromate type rustproof metal plate that can be welded.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that not only corrosion resistance and paint adhesion but also galling resistance, fingerprint resistance, and condensation resistance It has been found that it is effective to apply a coating composed of organic resin, finely divided silica and polyolefin wax dispersion to the upper layer in order to improve various performances with respect to the surface appearance quality of the steel sheet. It is possible to improve the adhesion between the upper coating and the metal plate such as zinc or zinc alloy plated steel plate by performing the base treatment combining the ring agent and the phosphoric acid component. It has been found that the corrosion resistance including the processed portion equal to or higher than the chromate treatment can be satisfied without using any agent. Furthermore, by controlling the molecular weight of the polyolefin wax dispersion contained in the upper layer coating to 6000 to 15000, the dynamic friction coefficient of the metal plate surface was controlled to 0.07 to 0.15, and the static friction coefficient was controlled to 0.10 or more. The inventors have found that a surface-treated metal sheet excellent in press galling resistance and coil deformation resistance can be obtained, and have invented the following technique.

That is, the non-chromate type rust-preventive treated metal plate of the present invention has a coating layer containing an aqueous resin, a silane coupling agent and a phosphoric acid component as an undercoating layer, and an upper layer having a solid content of 100. 1 to 50 parts by weight of organic resin
Parts by weight of finely divided silica and 1 to 30 parts by weight of a molecular weight of 600
It is characterized by having 0.1 to 5 g / m ^{2 of} an upper layer coating containing a polyolefin wax dispersion of 0 to 15,000.

The base treatment layer contains 0.1 part of a silane coupling agent based on 100 parts by weight of an aqueous resin as a solid content.
˜3000 parts by weight and a phosphoric acid component (as a P-containing anion component) in an amount of 0.01 to 100 parts by weight are preferable. The base treatment layer further contains, in terms of solid content, at least one of 1 to 2000 parts by weight of finely divided silica and 0.1 to 1000 parts by weight of an etchable fluoride based on 100 parts by weight of the aqueous resin. can do.

The silane coupling agent contained in the undercoat layer preferably has a glycidyl ether group. The amount of adhesion of the undercoat layer is preferably 5 to 500 mg / m ² . The polyolefin wax dispersion contained in the upper layer film has a molecular weight of 6000 to 15000 and a particle size of 0.1 to 1 which does not substantially contain a polar group.
It is preferable that at least one kind selected from a polyolefin wax dispersion of 5.0 μm, a modified polyolefin wax dispersion having a molecular weight of 6,000 to 15,000, an acid value of 40 or less, and a particle size of 0.1 to 5.0 μm.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. The present invention, without using a chromate-based treatment agent, corrosion resistance including a processed portion of chromate-treated or more, excellent coating adhesion, galling resistance during pressing, fingerprint resistance, condensation resistance unevenness, etc. It has succeeded in meeting the needs for high surface appearance quality. Furthermore, by adjusting the molecular weight of the polyolefin wax dispersion contained in the upper layer film to an appropriate value, it has succeeded in achieving both press galling resistance and coil deformation resistance.

Metal plates such as zinc or zinc alloy-plated steel sheets have not only corrosion resistance including the processed portion and coating adhesion but also galling resistance during pressing, fingerprint resistance, uneven condensation resistance, etc.
It has been reported many times that a coating composed of an organic resin, finely divided silica and a polyolefin wax dispersion is effective for improving various performances on the surface appearance quality of a steel sheet. It was premised that it had a chromate treatment and ensured the adhesion between the upper film and the metal plate.

Conventionally, a method of adding a silane coupling agent or a phosphoric acid component to a treatment agent for forming a film has been reported in order to further improve the adhesion to a base metal by further treatment. However, there is a problem in life such as gelation, workability due to the film becoming hard and brittle, corrosion resistance, and in particular, deterioration in performance such as corrosion resistance of the processed portion. Also, with this method, it is extremely difficult to ensure a high degree of adhesion with the underlying metal, which is equivalent to the case where there is a chromate treatment on the substrate, and development to higher quality such as corrosion resistance and press galling resistance. There is a limit to sex.

An example of the surface-treated metal plate in the present invention is shown in FIG.
Shown in. In FIG. 1, the present invention comprises a metal plate 4, an undercoating layer 3 in which an aqueous resin, a silane coupling agent, and a phosphoric acid component are combined, an organic resin, fine silica particles, and an upper layer film 2 containing a polyolefin wax dispersion 1. It is characterized by being composed of two layers. By simultaneously combining the water-based resin, the silane coupling agent, and the phosphoric acid component, it is possible to dramatically improve the adhesion between the underlying metal and the upper layer film. The guarantee of strong adhesion also contributes to the improvement of corrosion resistance due to the shielding effect of corrosion factors. The phosphoric acid component has the effect of etching the surface of the base metal,
It also has a great effect on stabilizing performance.

Further, an upper layer film 2 containing an organic resin, finely divided silica and a polyolefin wax dispersion 1
Synergistically with, it is possible to improve not only corrosion resistance and paint adhesion, but also various performances such as press galling resistance, fingerprint resistance, and dew condensation resistance with respect to the surface appearance quality of the steel sheet.
By adjusting the molecular weight of the wax to an appropriate value, the wax is made to exist in a granular form on the coating surface, and at the same time, the hardness of the wax and the affinity of the coating surface are controlled. As a result, not only it has good corrosion resistance and adhesion, but also has a dynamic friction coefficient of 0.
It is possible to obtain a surface-treated metal sheet having an excellent resistance to press galling and excellent resistance to coil deformation, which is controlled to have a coefficient of static friction of 0.10 or more and a coefficient of static friction of 07 to 0.15.

By separating the functions by the two-layer treatment, the problems of the treating agent life and the performance deterioration described above can be easily solved. Furthermore, it is possible to expect the possibility of higher quality. Hereinafter, embodiments of the present invention will be described in detail. The base metal plate applicable in the present invention includes iron, iron-based alloys, aluminum, aluminum-based alloys, copper, and copper-based alloys. It is also possible to optionally use a plated metal plate plated on a metal plate. Examples of the plated metal plate include a zinc-plated metal plate and a zinc-metal plate.
Nickel plated metal plate, zinc-iron plated metal plate, zinc-
Zinc-based electroplating such as chrome-plated metal plate, zinc-aluminum-plated metal plate, zinc-titanium-plated metal plate, zinc-magnesium-plated metal plate, zinc-manganese-plated metal plate, hot dip plating, vapor deposition plated steel plate, aluminum or aluminum Alloy-plated metal plate, lead or lead alloy-plated metal plate, tin or tin alloy-plated metal plate, and cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum as a small amount of different metal elements or impurities in these plated layers. Those containing manganese, iron, magnesium, lead, antimony, tin, copper, cadmium, arsenic, etc. and / or those containing dispersed inorganic substances such as silica, alumina, titania, etc. are included.
Further, it is also applicable to multi-layer plating in which the above plating and other types of plating are combined, such as iron plating and iron-phosphorus plating. The plating method is not particularly limited, and any known method such as electroplating method, hot dipping method, vapor deposition plating method, dispersion plating method, and vacuum plating method may be used. Further, these metal plates can be subjected to usual treatments such as washing with hot water and degreasing with alkali before the base treatment.

The base treatment used in the present invention is characterized in that a chemical solution containing an aqueous resin, a silane coupling agent and a phosphoric acid component is applied and dried. As the water-based resin used for the base treatment, in addition to water-soluble resin, water-insoluble resin that can be in a state of being finely dispersed in water such as emulsion or suspension (water-dispersible resin) is used. Include it. The resin that can be used as such a water-based resin is not particularly limited, but a polyolefin resin, an acrylic olefin resin, a polyurethane resin, an acrylic resin, a polycarbonate resin, an epoxy resin, a polyester resin, an alkyd resin. , Phenolic resins, and other heat-curable resins can be exemplified, and crosslinking is more preferable. The organic resins may be used as a mixture of two or more or by copolymerization. Among these, especially the wettability with the upper layer film,
In consideration of adhesion, it is desirable to select a resin having a high acid value and / or hydroxyl value.

Examples of the silane coupling agent used for the surface treatment include γ- (2-aminoethyl) aminopropyltrimethoxysilane and γ- (2-aminoethyl).
Aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ-
(2-aminoethyl) aminopropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane,
γ-methacryloxypropylmethyldiethoxysilane,
N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (N-vinyl Benzylaminoethyl) -γ-aminopropyltriethoxysilane,
N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltriethoxy Silane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane,
γ-mercaptopropylmethyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane,
Vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltriethoxysilane, γ-
Chloropropylmethyldiethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ
-Anilinopropyltriethoxysilane, γ-anilinopropylmethyldiethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl ] Ammonium chloride, octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride, octadecyldimethyl [3- (triethoxysilyl) propyl] ammonium chloride, octadecyldimethyl [3- (methyldiethoxysilyl)]
Propyl] ammonium chloride, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane and the like can be mentioned, but γ-glycidoxypropyltrimethoxysilane having a glycidyl ether group, or γ-glycidoxypropyltriethoxysilane and the like. When used, the adhesion with the upper layer film is further improved.

The content of the silane coupling agent is 0.1 to 300 in terms of solid content, based on 100 parts by weight of the aqueous resin.
It is preferably 0 part by weight. If the amount is less than 0.1 part by weight, sufficient adhesion to the underlying metal and the upper coating cannot be obtained, and the corrosion resistance is also insufficient. If it exceeds 3000 parts by weight, the processability and corrosion resistance, especially the corrosion resistance of the processed part may deteriorate, and the resin may gel in the state of the treating agent to cause a problem.

As the phosphoric acid component used for the surface treatment,
Orthophosphoric acid (H ₃ PO _4), hypophosphorous acid (H ₃ PO _2), phosphorous acid (H ₃ PO _3), pyrophosphoric acid _{(H 4 P 2 O 7)} , tripolyphosphate (H ₅ P ₃ O ₁₀ ) and the chemical formula is H _{X + 2} P _X O
All the acids of condensed phosphoric acid of _{3X + 1} (where X is an integer of 3 or more) and salts thereof are included. Particularly, orthophosphate, phosphite, hypophosphite, and pyrophosphate are preferable because they are economical.

Phosphoric acid component (as P-containing anion component)
The content of is preferably 0.01 to 100 parts by weight in terms of solid content with respect to 100 parts by weight of the aqueous resin.
If it is less than 0.01 part by weight, sufficient adhesion to the underlying metal and the upper layer coating cannot be obtained, and the corrosion resistance is also insufficient. 100
If it exceeds the weight part, the processability and corrosion resistance, especially the corrosion resistance of the processed part may deteriorate, and the resin may gel in the state of the treating agent to cause a problem.

The surface treatment in the present invention may contain finely divided silica. When the base treatment contains fine silica,
Improves adhesion to upper coating and corrosion resistance. As the finely divided silica used for the base treatment, any of spherical, linear, or beaded silica in which branched spherical silica is bonded may be used. In the case of spherical silica, the particle size is 5-5
0 nm, in the case of linear silica 5-50 nm in diameter and length /
In the case of beaded silica having a thickness ratio of 1 to 5 chemically bonded or having beaded branches, the ratio of [length of bonded body / average particle diameter of spherical silica] is 4 or more and 1 or more Those having branching are preferable. If the primary particle size exceeds 50 nm, it may be difficult to form a dense film, and the adhesion to the upper film and the corrosion resistance may deteriorate. As the type of fine silica, water dispersible silica, fine powder silica and the like can be used. The water-dispersible silica is a generic term for silica having a characteristic that it can maintain a water-dispersed state when dispersed in water because it has a fine particle size and that sedimentation is not observed semipermanently. As water-dispersible silica,
From the viewpoint of corrosion resistance, those containing less impurities such as sodium are preferable. For example, "Snowtex N", "Snowtex C", "Snowtex UP", "Snowtex PS" (all manufactured by Nissan Chemical Industries, Ltd.), "Adelite AT"
Commercially available silica gel such as “-20Q” and “Adelite AT-20N” (all manufactured by Asahi Denka Co., Ltd.) can be used. The fine silica powder is generally called dry silica, and fine powder silica such as "Aerosil # 300" (manufactured by Nippon Aerosil) can be used. The fine silica particles may be appropriately selected according to the required performance.

The content of the finely divided silica is preferably 1 to 2000 parts by weight in terms of solid content, based on 100 parts by weight of the aqueous resin. If it is less than 1 part by weight, the effect of addition is small, and if it exceeds 2000 parts by weight, the effect of improving the corrosion resistance is saturated and it is uneconomical, and the treated film becomes too hard and cracks occur in the film, resulting in corrosion resistance and an upper layer. The adhesion to the film may be reduced.

Further, the base treatment in the present invention may contain an etching fluoride. When the base treatment contains an etching fluoride, the adhesion with the upper layer film is improved and stabilized. In the present invention, as the etching fluoride, zinc fluoride tetrahydrate, zinc hexafluorosilicate hexahydrate, zircon hydrofluoric acid, titanium hydrofluoric acid, hydrosilicofluoric acid or the like can be used. .
The content of the etching fluoride is preferably 0.1 to 1000 parts by weight based on 100 parts by weight of the aqueous resin in terms of solid content. If it is less than 0.1 parts by weight, the effect of addition is small, and if it exceeds 1000 parts by weight, the effect of improving corrosion resistance is saturated and it is uneconomical.

To form an undercoating layer on a metal plate, the above-mentioned undercoating agent is applied to the metal plate and heated and dried. The amount of these surface treatment layers deposited is 5 to 500 mg in terms of solid content.
/ M ² is preferable. If it is less than 5 mg / m ² , sufficient effects may not be obtained, and the adhesion to the underlying metal or the upper layer coating and the corrosion resistance may be reduced. Even if it exceeds 500 mg / m ² , the adhesion to the underlying metal or the upper layer coating may be deteriorated.

As a coating method for forming these undercoating layers, any method such as spraying, curtain, flow coater, roll coater, bar coater, brush coating, dipping and air knife squeezing may be used.
The ultimate heating temperature is preferably 50 to 250 ° C.
If the temperature is lower than 50 ° C, sufficient film formability cannot be obtained, so that the adhesion to the underlying metal or the upper layer film and the corrosion resistance are reduced, or the appearance is uneven. On the other hand, when the temperature exceeds 250 ° C, the resin which is an organic substance or the alkyl portion of the silane coupling agent undergoes modification such as thermal decomposition or the treated film becomes too hard, resulting in poor adhesion or corrosion resistance to the underlying metal or the upper layer film. descend. 70-160 degreeC is more preferable.

The drying equipment is not particularly limited, but a method using hot air blowing, an indirect heating method using a heater, an infrared ray method, an induction heating method, or a combination of these methods can be employed. Further, depending on the type of aqueous resin used, it can be cured by energy rays such as ultraviolet rays and electron rays.

The upper layer film used in the present invention is characterized in that a chemical solution containing an organic resin and finely divided silica is applied to the upper layer of a metal plate which has been subjected to a base treatment, followed by baking and drying. A water-based resin is preferable as the organic resin used for the upper layer film. The water-based resin referred to here includes not only water-soluble resins but also water-insoluble resins that are originally water-insoluble but can be in a state of being finely dispersed in water, such as emulsions and suspensions (water-dispersible resins). . The resin that can be used as the water-based resin is not particularly limited, but a polyolefin-based resin, an acrylic olefin-based resin, a polyurethane-based resin,
Acrylic resins, polycarbonate resins, epoxy resins, polyester resins, alkyd resins, phenol resins, other heat-curable resins, etc. can be exemplified,
More preferably, it is crosslinkable. The organic resins may be used as a mixture of two or more or by copolymerization. If necessary, various crosslinking agents such as melamine resins and amino resins may be added. Of these, acrylic olefin resins, especially when considering both performance and cost
It is preferable to use an acrylic resin. Further, when severe deep drawing is required, it is preferable to use a urethane resin having both hardness and elongation.

The finely divided silica used for the upper coating is
Any of spherical, linear, or beaded silica in which spherical silica having branches is bonded may be used. In the case of spherical silica, the particle size is 5 to 50 nm, and in the case of linear silica,
In the case of beaded silica having a diameter of 5 to 50 nm and a length / thickness ratio of 1 to 5 chemically bonded, or a beaded silica having a branch, the ratio of [length of bonded body / average particle diameter of spherical silica] is Those having 4 or more and 1 or more branches are preferable. If the primary particle size exceeds 50 nm, it may be difficult to form a dense film and the corrosion resistance may deteriorate. As the type of fine silica, water dispersible silica, fine powder silica and the like can be used. The water-dispersible silica is a general term for silica which has a characteristic that it can maintain a water-dispersed state when dispersed in water because it has a fine particle size, and that sedimentation is not observed semipermanently. As the water-dispersible silica, those having less impurities such as sodium are preferable from the viewpoint of corrosion resistance. For example, "Snowtex N",
Commercially available silica gel such as "Snowtex C", "Snowtex UP", "Snowtex PS" (above Nissan Chemical Industries), "Adelite AT-20Q", "Adelite AT-20N" (above Asahi Denka Kogyo) Can be used. The fine silica powder is generally called dry silica, and fine powder silica such as "Aerosil # 300" (manufactured by Nippon Aerosil) can be used. The fine silica particles may be appropriately selected depending on the dispersion form of the resin in the treatment agent and the required performance.

As the polyolefin wax dispersion, a polyethylene wax, a polypropylene wax, or a polybutylene wax in which an emulsifier concentration is 5% or less, preferably dispersed in water or an aqueous solution without using an emulsifier is used. As the modified polyolefin wax dispersion, a polyethylene wax, polypropylene wax, or polybutylene wax similarly used is one having an emulsifier concentration of 5% or less, preferably dispersed in water or an aqueous solution without using an emulsifier. The polar group, in the presence of a catalyst, oxygen, oxidized polyolefin wax obtained by oxidizing the polyolefin wax with an oxidizing agent such as ozone or nitric acid, or acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, It is obtained by dissolving an ethylenically unsaturated carboxylic acid monomer such as itaconic acid and a polyolefin wax with benzene or the like, heating with a polymerization initiator (peroxide, redox, heavy metal catalyst, etc.) in a nitrogen stream and grafting.

The mass average particle diameter of the polyolefin wax dispersion and the modified polyolefin wax dispersion is preferably 0.1 to 5.0 μm, more preferably 1.0 to 4.0 μm. If the mass average particle diameter is less than 0.1 μm, aggregation is likely to occur and stability is poor, which is not preferable. The mass average particle size is 5.
If it exceeds 0 μm, the dispersion stability becomes poor, which is not preferable.
Further, the ratio of the mass average particle diameter to the number average particle diameter is preferably within the range of mass average particle diameter / number average particle diameter <3.

The range of the weight average molecular weight of the polyolefin wax dispersion and the modified polyolefin wax dispersion is 6,000 to 15,000.
Are preferred. When the mass average molecular weight is less than 6000, the coil deformation resistance deteriorates, which is not preferable. If the mass average molecular weight exceeds 15,000, the press galling resistance is deteriorated, which is not preferable.

The methods and conditions for analyzing the mass average molecular weight of these polyolefin wax dispersions and modified polyolefin wax dispersions are shown below, but the molecular weight analysis is not limited to this method. -Analysis method: GPC for high temperature (gel permeation chromatography) -Column: PS (polystyrene) gel mixed type (2-4 serial connection) -Solvent: o-dichlorobenzene (ODCB), trichlorobenzene (TCB), etc.-Measurement temperature: 130 to 140 ° C.-Detector: Differential refractometer (RI) or infrared detector-Preparation of calibration curve: Conversion to each molecular weight using a commercially available monodisperse PS.

The modified polyolefin wax dispersion has an acid value (KO) specified by JIS K5902.
The range of Hmg / g) is preferably 40 or less.
If the acid value exceeds 40, the lubricant becomes hard and sufficient lubricity cannot be obtained. Further, the density of these polyolefin wax dispersions and modified polyolefin wax dispersions defined by JIS K 6760 is 950 to 1000 kg / m ³ , and
The hardness (penetration) defined by 2207 is 0.2 mm or less, the crystallinity determined by X-ray diffraction is 80% or more, and the melting point is preferably 110 to 150 ° C.

At least one selected from these polyolefin wax dispersions and modified polyolefin wax dispersions is contained in the upper layer film in a solid content of 1 to 30 parts by weight. If it is less than 1 part by weight, sufficient press galling resistance cannot be obtained, and if it exceeds 30 parts by weight, the coating adhesion is deteriorated, which is not preferable. Further, a surfactant, an anticorrosive inhibitor, an antifoaming agent and the like may be added to these upper layer films, if necessary.

The range of adhesion of these upper layer coatings is 0.1 to 5 g / m ² as dry weight. More preferably, it is 0.3 to 3.0 g / m ² . Adhesion amount is 0.1g / m ²
If it is less than 5.0 g, the corrosion resistance is poor, and if it exceeds 5.0 g / m ² , the weldability becomes difficult, which is not preferable. As a coating method for forming these upper layer films, any method such as spraying, curtain, flow coater, roll coater, bar coater, brush coating, dipping and air knife squeezing may be used.

The ultimate baking temperature is 80 to 250 ° C.
Is desirable. If the temperature is lower than 80 ° C, it is difficult to completely evaporate the water in the paint, and the corrosion resistance is reduced. If the temperature exceeds 250 ° C, the alkyl part of the resin, which is an organic substance, may undergo thermal decomposition and other modifications, or the film may harden excessively. It is not preferable because the corrosion resistance and the workability are deteriorated. 70-160 degreeC is more preferable.

Although the drying equipment is not particularly limited, a method of blowing hot air, an indirect heating method with a heater, an infrared method, an induction heating method, or a combination of these methods can be used. Further, depending on the type of organic resin used, it can be cured by energy rays such as ultraviolet rays and electron rays.

[0042]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. (1) Kind of metal plate The metal plate shown in Table 1 was used.

[0043]

[Table 1]

(2) Types of base treatment chemicals Table 2 shows a list of the base treatment chemicals used in the examples.

[0045]

[Table 2]

(3) Preparation of base treatment chemicals Aqueous resins, silane coupling agents, phosphoric acid components, fine silica particles and etching fluorides shown in Table 1 were blended in the ratios shown in Tables 5, 6 and 9 to prepare the base treatment chemicals. Was adjusted. (4) Method of applying / drying the base treatment chemicals Roll on the plated metal plate shown in (1) so that the dry weight of the aqueous organic-inorganic composite coating prepared in (3) becomes the values shown in Tables 5, 6, and 9. Apply with a coater and heat with a hot air stove
Samples for evaluation were prepared by baking and drying at the ultimate plate temperatures shown in Nos. 6 and 9. In addition, the adhesion amount of the base treatment film is shown in Table 5,
6 and 9. (5) Types of Upper Layer Coating Agents Table 3 shows a list of upper layer coating agents used in the examples.

[0047]

[Table 3]

(6) Preparation of Upper Layer Coating Agent The organic resin, fine silica and polyolefin dispersion shown in Table 3 were mixed in the ratios shown in Tables 5, 6 and 9 to prepare the upper layer coating agent. (7) Applying the primer to the plated metal plate that has been subjected to the primer treatment shown in (4).
The dry weight of the upper layer film chemical prepared in Step 5 is shown in Tables 5, 6, and 9.
Was coated with a roll coater so as to have the value shown in, and baked and dried at the ultimate plate temperature shown in Tables 5, 6, and 9 in a hot air oven to prepare an evaluation sample. Further, the amounts of the upper layer coatings are shown in Tables 5, 6 and 9. (8) Performance evaluation item 1) JISK5 was applied to the evaluation sample manufactured with the adhesion of the upper layer film (7).
An Erichsen tester specified by 400 was used to extrude 7 mm so that the upper layer film to be tested was a convex portion, and an adhesive tape (Nichiban Co., Ltd .: trade name Cellotape) was attached to the extruded portion. The pressure-sensitive adhesive tape was quickly pulled in the direction of an angle of 45 °, and the appearance of the extruded portion was visually judged.
If it is difficult to evaluate visually, use methyl violet 3
% Acetone solution, the film was present in the dyed part and the film was not present in the undyed part, and the adhesion was judged. The judgment criteria are as follows, and ⊚ and ◯ were judged to be good.

◎: No peeling of film ○: Peeling of less than 20% of area Δ: Peeling of less than 50% of area ×: Peeling of more than 50% of area 2) A sample for evaluation prepared with flat plate corrosion resistance (7) JISZ237 as it is as a flat plate (sealing the end surface and back surface of the steel plate as cut)
The salt spray test described in 1 was performed, and the white rust generation rate after 72 hours was measured. In the following evaluation, ⊚ and ◯ were judged to be good.

◎: White rust is not generated ○: White rust occurrence rate is less than 10% △: White rust occurrence rate is 10% or more and less than 50% ×: White rust occurrence rate is 50% or more 3) Processed part corrosion resistance (7) Regarding the evaluated sample according to JISK54
With an Erichsen tester specified in No. 00, 6 mm is extruded so that the upper layer film to be tested becomes a convex part (the end face part and the back face part of the steel plate extruded by 6 mm with the Erichsen tester are sealed), and it is described in JISZ2371. A salt spray test was conducted to measure the white rust occurrence rate at the extruded portion after 48 hours. In the following evaluation, ⊚ and ◯ were judged to be good.

◎: White rust is not generated ○: White rust occurrence rate is less than 5% △: White rust occurrence rate is 5% or more and less than 20% ×: White rust occurrence rate is 20% or more 4) Paint adhesion (7) Using a bar coater, a melamine alkyd resin paint (Kansai Paint Co., Ltd., Amylak # 1000) was applied to the sample for evaluation having a dry film thickness of 20.
The coating was applied so as to have a thickness of μm and baked at a furnace temperature of 130 ° C. for 20 minutes. Next, after leaving it for one night, the ones soaked in boiling water for 30 minutes and those not soaked were subjected to 7 mm Erichsen processing, and adhesive tape (Nichiban Co., Ltd .: trade name Cellotape) was attached to the Eriksen processed part of the test piece. It was The adhesive tape was quickly pulled in the direction of an angle of 45 °, and the appearance of the Erichsen processed portion was visually evaluated. In the following evaluation, ⊚ and ◯ were judged to be good.

◎: No peeling ○: Peeling area ratio less than 5% △: Peeling area ratio 5% or more, less than 50% ×: Peeling area ratio 50% or more 5) Samples produced with continuous weldability (7) are shown in Table 4 A continuous spot welding test was performed under the conditions shown in (1) to determine the number of points at which a nugget diameter of 3 mmφ or more could be stably formed.

[0053]

[Table 4]

In the following evaluations, ⊚ and ◯ were judged to be good. ◎: 5,000 points or more ○: 2,500 points or more and less than 5,000 △: 1,000 points or more and less than 2,500 ×: points less than 1000 6) A square cylinder crank press test was performed on a sample prepared with press galling resistance (7) . The conditions of the square cylinder crank press test were that a sample (0.8 × 220 × 180 mm) was molded to 65 × 115 mm and a height of 30 mm with a wrinkle pressing pressure of 4 tons, and the sliding surface after molding was visually evaluated. . In the following evaluations, ⊚ and ◯ were judged to be good.

◎: No blackening ○: Less than 50% of the sliding area is blackened and has a sliding flaw △: 50% or more of the sliding area is blackened and has a sliding flaw ×: Base metal 7) Exposed and scuffed 7) Fingerprint resistance The sample prepared in (7) was subjected to a fingerprint resistance test. In the fingerprint resistance test, an actual finger was pressed against the sample for 3 seconds, and the degree of conspicuousness of the fingerprint mark was visually evaluated. With the following evaluation ◎
And were evaluated as good.

◎: Fingerprint traces are not known ○: Fingerprint traces can be seen by careful observation △: Fingerprint traces are slightly conspicuous ×: Fingerprint traces are very noticeable 8) Static friction coefficient Shinto Kagaku 10D HEIDON static friction Using a coefficient measuring device, a sample with an area of 25 cm ² excluding burrs prepared in (8) was attached to a plane indenter at a rate of 0.5 ° / sec. The static friction coefficient was measured. 9) Dynamic Friction Coefficient The dynamic friction coefficient of the sample prepared in (7) was measured with a 14S HEIDON dynamic friction coefficient measuring device manufactured by Shinto Kagaku under the conditions of 10 mmφ stainless steel ball sliding, load 100 g, and sliding speed 150 mm / min. 10) Coil deformation resistance 10t with an inner diameter of 508mm and a thickness of 1mm and different friction coefficients
After manufacturing several types of coils and lifting and lowering these coils three times with a crane, the deviation (distance) at the outermost end of the coil winding direction (longitudinal direction) caused by the looseness of the outermost winding was measured, and the dynamic friction coefficient, The relationship with the coefficient of static friction was investigated.
As a result, the dynamic friction coefficient, the static friction coefficient, and the deviation (distance) at the end of the coil winding direction (longitudinal direction) caused by winding slack
When the dynamic friction coefficient is less than 0.07 and the static friction coefficient is less than 0.10, the deviation of the coil outermost end due to looseness of winding is 50 mm or more, but the dynamic friction coefficient is 0.07 or more. By setting the coefficient of static friction to 0.10 or more, it was possible to suppress the deviation of the coil outermost end due to looseness of winding to 30 mm or less. Therefore, in the laboratory test, the dynamic friction coefficient and the static friction coefficient measured in 8) and 9) were used as indexes of the coil deformation resistance. In the following evaluation, ◯ was judged to be good.

◯: Dynamic friction coefficient: 0.07 or more, static friction coefficient: 0.
1 or more ×: dynamic friction coefficient: less than 0.07, static friction coefficient: 0.
The evaluation results of less than 1 are shown in Tables 7, 8 and 10. As is clear from these results, according to the technique of the present invention, various properties such as corrosion resistance, adhesion, and weldability are excellent, and the dynamic friction coefficient is controlled to 0.07 to 0.15 and the static friction coefficient is controlled to 0.1 or more. In addition, it is possible to obtain an inexpensive non-chromate type surface-treated metal plate which is excellent in press galling resistance and coil deformation resistance.

[0058]

[Table 5]

[0059]

[Table 6]

[0060]

[Table 7]

[0061]

[Table 8]

[0062]

[Table 9]

[0063]

[Table 10]

[0064]

EFFECTS OF THE INVENTION According to the present invention, the surface appearance of a steel sheet such as not only corrosion resistance and coating adhesion but also fingerprint resistance, dew condensation resistance, etc. is not contained in the treated film, which does not contain harmful chromium such as hexavalent chromium. The coating composition and dynamic friction coefficient of the coating surface are excellent in terms of various performances with respect to quality, and in addition, while maintaining press galling resistance, to improve problems such as coil crush due to loose winding and load collapse during cutting plate piling. It becomes possible to provide an inexpensive and weldable non-chromate type rust-preventive treated metal plate whose static friction coefficient is controlled, and it is particularly suitable as a material for the fields of automobiles, home appliances and building materials. Therefore, it can be said that the present invention has an extremely high industrial value.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a surface-treated metal plate of the present invention.

[Explanation of symbols]

1 ... Polyolefin wax dispersion 2 ... Upper layer film 3 ... Undercoat layer 4 ... Metal plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C10M 107/02 C10M 107/02 107/18 107/18 107/28 107/28 125/26 125/26 143/00 143/00 145/14 145/14 145/20 145/20 145/22 145/22 149/18 149/18 173/02 173/02 C23C 22/36 C23C 22/36 28/00 28/00 C // C10N 20: 00 C10N 20:00 Z 20:04 20:04 20:06 20:06 Z 30:06 30:06 30:12 30:12 50:02 50:02 50:08 50:08 80:00 80:00 ( 72) Inventor Akira Takahashi 1st Kimitsu, Kimitsu-shi, Chiba Nippon Steel Co., Ltd. Inside Kimitsu Works (56) References JP-A-7-228828 (JP, A) JP-2000-319787 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 22/07 B05D 7/24 301 B32B 15/08 C09K 3/00 C10M 107/02 C10M 107/18 C10M 107/28 C10M 125/26 C10M 145/14 C10M 145/20 C10M 145/22 C10M 149/18 C10M 173/02 C23C 22/36 C23C 28/00 C 10N 20:00 C10N 20:04 C10N 30:06 C10N 30:12 C10N 50:02 C10N 50:08 C10N 80:00

Claims (7)

(57) [Claims] 1. An undercoating layer having a coating layer containing an aqueous resin, a silane coupling agent and a phosphoric acid component, and an organic resin of 100 parts by weight as a solid content and 1 to 5 as an overlying layer.
0 parts by weight of finely divided silica and 1 to 30 parts by weight of a molecular weight of 60
A surface-treated metal plate having an upper layer film containing 0.1 to 5 g / m ² containing a polyolefin wax dispersion of 0 to 15,000. 2. The base treatment layer comprises a silane coupling agent of 0.1 part by weight based on 100 parts by weight of an aqueous resin as a solid content.
The surface-treated metal plate according to claim 1, which contains 1 to 3000 parts by weight and 0.01 to 100 parts by weight of a phosphoric acid component. 3. The base treatment layer comprises, in terms of solid content, 1 to 2000 parts by weight of finely divided silica and 0.1 to 1000 parts by weight of an etchable fluoride based on 100 parts by weight of the aqueous resin. The surface-treated metal plate according to claim 1 or 2, further comprising at least one kind. 4. The surface-treated metal plate according to claim 1, wherein the silane coupling agent contained in the undercoating layer has a glycidyl ether group. 5. The amount of adhesion of the undercoat layer is calculated in terms of solid content.
5 to 500 mg / m ²2. The method according to claim 1, wherein
The surface-treated metal plate according to any one of 4 to 4. 6. The polyolefin wax dispersion contained in the upper layer film has a molecular weight of 6000 to 15000 and a particle size of 0.1 to 5.0, which is substantially free of polar groups.
μm polyolefin wax dispersion with a molecular weight of 6000 to 15000, acid value of 40 or less, particle size of 0.1
The surface-treated metal plate according to claim 1, wherein the surface-treated metal plate is at least one selected from modified polyolefin wax dispersions having a thickness of 5.0 μm. 7. The coefficient of dynamic friction of the surface is 0.07 to 0.1.
5. The surface-treated metal plate according to any one of claims 1 to 6, wherein the coefficient of static friction is 0.10 or more.