JP2008030474A - Coated metal substrate, active energy ray-curable coating composition, and method for producing coated metal substrate - Google Patents

Abstract

[PROBLEMS] To provide a coated metal substrate having a coating film excellent in various properties such as adhesion to a metal substrate, molding processability and solvent resistance, and in particular, having both excellent molding processability and wear resistance. An active energy ray-curable coating composition suitable for production thereof, a coated metal substrate obtained using the active energy ray-curable coating composition, and a method for producing the same.
A phosphoric acid ester compound (A) represented by a specific chemical formula, and at least one selected from a phosphoric acid ester derivative (A ^* ) formed by bonding (A) with another atom or atomic group A polyurethane resin (B ^* ) having a group capable of forming a salt and a terminal ethylenic double bond group, and a polyurethane resin derivative (B ^** ) formed by bonding (B ^* ) to another atom or atomic group A coated metal substrate in which at least a part of the surface of the metal substrate is coated with a coating film containing at least one selected from the group consisting of silica particles (C ^* ) and alumina particles (D).
[Selection figure] None

Description

  The present invention relates to a coated metal substrate in which at least a part of the surface of the metal substrate is coated with a coating film, an active energy ray-curable coating composition suitably used for producing the coated metal substrate, and the active energy The present invention relates to a coated metal substrate having a coating film formed using a wire curable coating composition, and a method for producing a coated metal substrate using the active energy beam curable coating composition.

In order to modify the surface of a metal substrate such as a metal plate such as aluminum, copper or iron, or a plated steel plate, a surface treatment is performed to form a coating film on the surface of the metal substrate using various coating compositions. Has been done. The main purpose of the surface treatment is to improve fingerprint trace adhesion prevention, molding processability, corrosion resistance and the like.
For example, in the past, when processing and forming a metal substrate as described above, a lubricating oil was applied to the surface of the metal substrate, the forming process was performed, and then a degreasing process was performed. It is cumbersome to apply lubricating oil and degrease after processing, and there is a strong demand to simplify the process of applying lubricating oil and the process of degreasing. Therefore, a coating film is provided on the surface of the metal base material in order to provide lubrication in place of the lubricating oil, and further to provide various functions such as rust prevention and the ability to repeatedly coat other paints. Things have been done.

The formation of the coating film is mainly performed by coating a coating composition containing an organic resin (binder resin) on the surface of the metal substrate to form an organic coating film.
In addition, before forming such an organic coating film, the surface of the metal substrate is subjected to inorganic treatment by performing chromate treatment, zinc phosphate treatment, etc. for the purpose of improving corrosion resistance, solvent resistance, etc. Two-coat coating is generally performed in which a base undercoat layer is formed and an organic coating film is formed thereon. In particular, the chromate treatment is often performed because it is effective for improving the corrosion resistance and the adhesion between the metal surface and the coating film.
However, it has been reported that the chromate treatment agent and hexavalent chromium contained in the base treatment layer formed using the same are toxic. For this reason, there is a demand for a treatment method using a non-toxic treatment agent instead of the chromate treatment agent, but it is difficult to develop a treatment agent that is non-toxic and can secure adhesion comparable to that of the chromate treatment agent. No treatment agent for metal surfaces that can provide adhesion is obtained.
Therefore, a paint that can form a coating film having good adhesion to a metal substrate regardless of the presence or absence of a chromate treatment, that is, good adhesion even with a one-coat coating that is applied directly to the surface of a metal substrate. There is a need for a coating material that can form a coating film having the following.

On the other hand, in the fields of conventional paints, coating agents, inks, etc., in order to obtain a paint viscosity suitable for coating and printing, a solvent type in which a binder resin is diluted with a solvent is the mainstream. However, the use of organic solvents has problems in terms of safety and health and work environment.
Solvent-free paints that do not use organic solvents do not need to consider problems due to organic solvents, but the paint viscosity is too high at room temperature, and it is necessary to heat the paint to obtain a paint viscosity suitable for coating There is. Moreover, when it is going to reduce a viscosity by adding a monomer, there exists a problem like a solvent type, such as there exists skin toxicity, an odor, etc. in the diluted monomer to add. In particular, when a high molecular weight binder resin is used to improve the physical properties of the coating film, it is difficult to use a high molecular weight binder resin because the viscosity of the coating becomes too high, and thus an excellent coating film. It is difficult to obtain physical properties.

In order to solve these problems, research and development of water-based paints that can easily adjust the viscosity of paints using safe and harmless water as a solvent have been actively conducted in recent years.
For example, Patent Documents 1 to 4 propose active energy ray-curable water-based polyurethane resin compositions as means for retaining required coating film properties and solving all safety and environmental problems.
Any of these active energy ray-curable aqueous polyurethane resin compositions contains an aqueous polyurethane resin having both an active energy ray-curable ethylenically unsaturated double bond and a group capable of forming a salt in the molecule. The coating film is cured by active energy rays, and the higher the acryloyl group concentration and the higher the degree of crosslinking, the higher the solvent resistance.
Such an active energy ray-curable aqueous polyurethane resin composition is excellent in adhesion to any organic material such as plastic film, wooden building materials, and decorative paper for building materials, and inorganic materials such as metal materials and glass, and has good solvent resistance. In addition, it is used for applications such as paints, coating agents, and inks.
However, in these active energy ray-curable aqueous polyurethane resin compositions, it is necessary to introduce a group capable of forming a salt or a polar group into the resin in order to make it water-based. It tends to be difficult to obtain solvent properties. If the degree of cross-linking of the binder resin is extremely increased in order to obtain solvent resistance, the coating film becomes brittle, and the adhesion and the processability associated therewith tend to be reduced. A metal substrate having such a coating film cannot be used for applications that require a high degree of workability and adhesion to withstand drawing and the like.

Patent Document 5 discloses a composition having excellent emulsion stability and good adhesion to a substrate, having a polymerizable double bond, and having a carboxyl group, a phosphate group, a carboxylate group, and a phosphate ester. An active energy ray-curable emulsion containing an active energy ray-curable emulsifier containing an anionic hydrophilic group such as a base is disclosed.
However, the emulsion-type composition obtained is difficult to homogenize when forming a coating film, and is inferior in solvent resistance and chemical resistance as well as physical properties of the coating film surface such as surface smoothness and gloss.
Furthermore, since the emulsion composition exhibits non-Newtonian flow, it is inferior in coating suitability, such as roll coating, when used as a paint, compared to a homogeneous water-soluble type.
This defect of not homogenizing at the time of forming the coating film is prominent in a thin cured coating film of several microns, which results in poor solvent resistance, adhesion to the substrate and workability of the coating film.

In order to solve such a problem, the applicants of Patent Document 6 have a phosphoric ester compound having an ethylenically unsaturated double bond, an ethylenically unsaturated double bond, and a group capable of forming a salt. An active energy ray-curable aqueous coating composition containing an aqueous polyurethane resin and colloidal silica is proposed.
JP-A-8-259888 JP-A-9-31150 Japanese Patent Laid-Open No. 10-251360 Japanese Patent Laid-Open No. 10-251361 JP-A-10-298213 International Publication No. 03/008507 Pamphlet

According to the active energy ray-curable aqueous coating composition described in Patent Document 6, various functions such as adhesion to metal surfaces, molding processability, corrosion resistance, and solvent resistance (chemicals) can be used without performing chromate treatment. A coating film having excellent properties can be obtained.
However, the coating film obtained by using such a composition has a relatively superior wear resistance compared to the previous one, but it is sufficient that, for example, scratches or abrasion occurs due to contact with paper or the like. Rather, there is a need for further improvements.
Therefore, the object of the present invention is to provide a coating film that is excellent in various properties such as adhesion to a metal substrate, molding processability and solvent resistance, and in particular, has excellent molding processability and wear resistance. Coated metal base material, active energy ray curable coating composition suitable for production of the coated metal base material, and coated metal base material having a coating film formed using the active energy ray curable paint composition And providing a method for producing a coated metal substrate using the active energy ray-curable coating composition.

As a result of intensive studies, the present inventors have found that a metal group is formed with a coating film containing a specific phosphate ester compound and / or derivative thereof, a specific polyurethane resin and / or derivative thereof, silica particles, and alumina particles. The present inventors have found that a coated metal substrate on which at least a part of the surface of the material is coated solves the above-mentioned problems, and has reached the present invention.
That is, the first aspect of the present invention is a coated metal substrate in which at least a part of the surface of the metal substrate is coated with a coating film,
The phosphoric acid ester compound (A) represented by the following general formula (1) or (2), and the phosphoric acid ester derivative (A) formed by bonding the phosphoric acid ester compound (A) with another atom or atomic group ^* At least one selected from the group consisting of
A polyurethane resin having a group capable of forming a salt and a terminal ethylenic double bond group (B ^* ), And the polyurethane resin (B ^* ) And other atoms or atomic groups bonded to a polyurethane resin derivative (B ^** At least one selected from the group consisting of
Silica particles (C ^* )When,
A coated metal substrate comprising alumina particles (D).

（式中、Ｒ^１はメチル基又は水素原子を示し、Ｒ^２は水素原子又は炭素数１〜４のアルキル基を示し、ｓは２〜１２の整数を示し、ｍは０〜５の整数を示し、ａは１〜３の整数を示し、ｂは０〜２の整数を示し、ｃは０〜２の整数を示し、かつａ＋ｂ＋ｃ＝３である。
）

(In the formula, R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, s represents an integer of 2 to 12, and m represents an integer of 0 to 5) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

（式中、Ｒ^１はメチル基又は水素原子を示し、Ｒ^２は水素原子又は炭素数１〜４のアルキル基を示し、ｔは２〜４の整数を示し、ｎは１〜１０の整数を示し、ａは１〜３の整数を示し、ｂは０〜２の整数を示し、ｃは０〜２の整数を示し、かつａ＋ｂ＋ｃ＝３である。
）

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, t represents an integer of 2 to 4, and n represents an integer of 1 to 10) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

  The second aspect of the present invention is an aqueous polyurethane resin having a phosphate-forming ester compound (A) represented by the following general formula (1) or (2), a group capable of forming a salt and a terminal ethylenic double bond group ( An active energy ray-curable coating composition comprising B), colloidal silica (C), and alumina particles (D).

（式中、Ｒ^１はメチル基又は水素原子を示し、Ｒ^２は水素原子又は炭素数１〜４のアルキル基を示し、ｓは２〜１２の整数を示し、ｍは０〜５の整数を示し、ａは１〜３の整数を示し、ｂは０〜２の整数を示し、ｃは０〜２の整数を示し、かつａ＋ｂ＋ｃ＝３である。
）

(In the formula, R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, s represents an integer of 2 to 12, and m represents an integer of 0 to 5) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

（式中、Ｒ^１はメチル基又は水素原子を示し、Ｒ^２は水素原子又は炭素数１〜４のアルキル基を示し、ｔは２〜４の整数を示し、ｎは１〜１０の整数を示し、ａは１〜３の整数を示し、ｂは０〜２の整数を示し、ｃは０〜２の整数を示し、かつａ＋ｂ＋ｃ＝３である。
）

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, t represents an integer of 2 to 4, and n represents an integer of 1 to 10) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

The third aspect of the present invention is to have a coating film formed by curing the active energy ray-curable coating composition of the second aspect with active energy rays on at least a part of the surface of the metal substrate. It is the coated metal base material characterized.
According to a fourth aspect of the present invention, an aqueous paint containing the active energy ray-curable coating composition of the second aspect is applied to at least a part of the surface of a metal substrate to form a paint film. A method for producing a coated metal substrate, comprising irradiating an active energy ray to form a coating film.

  According to the present invention, a coated metal substrate having a coating film excellent in various properties such as adhesion to a metal substrate, molding processability and solvent resistance, and in particular, having both excellent molding processability and wear resistance. Material, active energy ray-curable coating composition suitable for producing the coated metal substrate, coated metal substrate having a coating film formed using the active energy ray-curable coating composition, and the activity A method for producing a coated metal substrate using the energy ray-curable coating composition can be provided.

≪Coated metal substrate≫
The coated metal substrate of the present invention has at least one surface selected from the group consisting of a phosphate ester compound (A) and a phosphate ester derivative (A ^* ) (hereinafter, these are summarized). (A / A ^* ) component) and at least one selected from the group consisting of a polyurethane resin (B ^* ) and a polyurethane resin derivative (B ^** ) (hereinafter these are collectively represented by (B ^* / B ^** ) component)), silica particles (C ^* ), and alumina particles (D).

<Coating film>
The coating film contains at least (A / A ^* ) component, (B ^* / B ^** ) component, silica particles (C ^* ) and alumina particles (D).

[(A / A ^* ) component] (phosphate ester compound (A))
The phosphoric ester compound (A) is a compound represented by the general formula (1) or (2).
These are phosphate ester compounds containing at least one (meth) acryloyl group, and are common in that they have at least one ethylenically unsaturated double bond at the molecular end.

In general formula (1), R ¹ is a methyl group or a hydrogen atom.
R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom.
s is an integer of 2 to 12, preferably 2 to 4.
m is an integer of 0 to 5, preferably 1 to 5, and more preferably 1 to 3.
a is an integer of 1 to 3, b is an integer of 0 to 2, c is an integer of 0 to 2, and a + b + c = 3.
a is preferably 1 or 2.
b is preferably 0.
c is preferably 1 or 2.

  Examples of the compound represented by the general formula (1) (hereinafter sometimes referred to as the compound (1)) include compounds obtained by dehydration condensation of phosphoric acid, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, 2 A representative example is a dehydration condensate of phosphoric acid with a compound obtained by ring-opening addition of ε-caprolactone to -hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.

In the general formula ^{(2), R 1, R} 2, a, b, c are the same as the general formula (1) of ^{R 1, R 2, a,} b, c.
t is an integer of 2-4.
n is an integer of 1-20, preferably 3-20.

  Examples of the compound represented by the general formula (2) (hereinafter sometimes referred to as the compound (2)) include ethylene oxide such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and propylene. A representative example is a compound obtained by dehydration condensation of an adduct such as oxide or tetrahydrofuran and phosphoric acid.

  The phosphate ester compound (A) is preferably neutralized with a basic compound. Thereby, the phosphate ester compound (A) can be dissolved or uniformly dispersed in water. Therefore, when the coated metal substrate of the present invention is produced, when the phosphate ester compound (A) is dissolved or dispersed in an aqueous medium such as water to form an aqueous paint, storage stability without cloudiness or precipitation is obtained. A water-based paint with good properties can be obtained.

(Phosphate ester derivative (A ^* ))
The phosphate ester derivative (A ^* ) is formed by bonding the phosphate ester compound (A) with another atom or atomic group.
Here, in the present specification and claims, “another atom or atomic group” means an atom or atomic group other than the atom or atomic group in the molecule of the compound.
As other atoms or atomic groups to which the phosphate ester compound (A) is bonded, other components contained in the coating film (polyurethane resin (B ^* ), silica particles (C ^* ), alumina particles (D), etc.) Examples thereof include a solvent contained in the paint, an atom or an atomic group derived from the metal substrate and plating on the surface thereof.
“The phosphoric acid ester compound (A) is bonded to another atom or atomic group” means that the phosphoric acid ester compound (A) is bonded to another atom or atomic group (covalent bond, ionic bond, hydrogen bond, Other atoms or atomic groups to which the phosphate ester compound (A) is bonded are not included in the phosphate ester derivative (A ^* ).

Examples of the phosphoric acid ester derivative (A ^* ) include those in which part or all of the reactive active site of the phosphoric acid ester compound (A) is bonded to another atom or atomic group.
The reactive active site of the phosphate ester compound (A) includes at least a terminal ethylenically unsaturated double bond group and a bond group derived from a phosphate group.
The terminal ethylenically unsaturated double bond group represents H ₂ C═C <in the group H ₂ C═C (R ¹ ) — in the general formula (1) or (2).
The bonding group derived from the phosphoric acid group includes a hydroxyl group (—OH) and a phosphate ester bonding group derived from the group —P (═O) (OR ² ) _b (OH) _c in the general formula (1) or (2) ( ≧ P-OR ² ).
In the terminal ethylenically unsaturated double bond group, the double bond is usually cleaved to become —CH—C <, and other atoms or atomic groups (for example, (B ^* / B ^** ) component, silica particles ( C), atoms or atomic groups of alumina particles (D), etc.).
Hydroxyl group, usually, -O ^- become, or ionically bonded to another atom or group (e.g. a metal atom of the metal substrate), or other atom or group (e.g. metal oxides) in the hydrogen bonding Conceivable.
In the phosphate ester bonding group, R ² is usually substituted with an atom or an atomic group derived from an aqueous medium used when forming an aqueous paint (for example, a hydrogen atom derived from water, a hydrocarbon group R ³ derived from alcohol). ≧ P—O—H, ≧ P—O—R ^{3 and the} like.

The coating film contains an (A / A ^* ) component (at least one selected from the group consisting of the phosphoric acid ester compound (A) and the phosphoric acid ester derivative (A ^* )).
Coating film, both may contain only phosphoric acid ester compound (A), may contain only phosphoric acid ester derivative (A ^*), phosphate compound (A) and phosphoric acid ester derivatives (A ^*) May be contained.
In the present invention, it is preferable to contain at least a phosphate ester derivative (A ^* ), particularly considering the adhesion of the coating film to the metal substrate.
In the coating film, the content of the component (A / A ^* ) is preferably 1 to 30% by mass and more preferably 5 to 15% by mass with respect to the total mass of the coating film. . When it is within the above range, adhesion to a metal substrate is particularly improved.

The phosphate ester derivative (A ^* ) is usually formed by irradiating the phosphate ester compound (A) with active energy rays such as ultraviolet rays in the presence of other atoms or atomic groups.

[(B ^* / B ^** ) component] (polyurethane resin (B ^* ))
The polyurethane resin (B ^* ) is a polyurethane resin having a salt-forming group and a terminal ethylenic double bond group.
Here, in the present specification and claims, the “polyurethane resin” is a resin having a urethane bond (—NH—CO—O—) in the main chain, and has at least a polyisocyanate component and a polyol component.
The “component” in the polyurethane resin means a repeating unit constituting the resin, and the polyisocyanate component is derived from a polyisocyanate compound (B1) having two or more isocyanate groups (—NCO). The polyol component is derived from the polyol compound (B2) having two or more hydroxyl groups (—OH).
The “group capable of forming a salt” is an acidic group that forms a salt with a base to form a salt group, or a basic group that forms a salt with an acid to form a salt group.
The “terminal ethylenic double bond group” is a group having a carbon-carbon double bond at the terminal of the group, and examples thereof include a group represented by H ₂ C═C <. Examples of the terminal ethylenic double bond group include a vinyl group (H ₂ C═CH—) and a group in which part or all of the hydrogen atoms of the vinyl group are substituted with a substituent (such as an alkyl group).

Since the polyurethane resin (B ^* ) has a group capable of forming a salt, it can be stably dissolved or dispersed in water. When the coated metal substrate of the present invention is produced, the polyurethane resin (B ^* ) Can be dissolved or dispersed in an aqueous medium such as water to form an aqueous paint, which can be suitably used for producing the coated metal substrate of the present invention. Moreover, by having a terminal ethylenic double bond group, the said coating film can be formed by active energy ray irradiation. That is, when the coating film is formed, when irradiated with active energy rays, the terminal ethylenically unsaturated double bonds are polymerized to form a crosslinked structure, thereby forming a cured film.

The polyurethane resin (B ^* ) has, for example, two or more functional groups having a group capable of forming a salt with the polyisocyanate compound (B1), the polyol compound (B2), and having reactivity with the isocyanate group. It can be obtained by reacting the compound (B3) having (hereinafter abbreviated as compound (B3)). These compounds include, for example, an active energy ray-curable compound (B4) (hereinafter abbreviated as compound (B4)) having one hydroxyl group and one or more unsaturated double bonds at the terminal, and a crosslinking agent (B5). ) Or the like.

"Polyisocyanate compound (B1)"
As the polyisocyanate compound (B1), for example,
Aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate;
Aliphatic polyisocyanates such as trimers of aliphatic diisocyanates, adducts of low molecular triols and aliphatic diisocyanates;
Cycloaliphatic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, hydrogenated tolylene diisocyanate, methylcyclohexylene diisocyanate, isopropylidenecyclohexyl-4,4′-diisocyanate, norbornene diisocyanate;
An alicyclic polyisocyanate such as a trimer of the alicyclic diisocyanate, an adduct of a low-molecular triol and the alicyclic diisocyanate;
Aromatic aliphatic diisocyanates such as xylylene diisocyanate;
Aroaliphatic polyisocyanates such as adducts of xylylene diisocyanate trimers, low molecular triols and the above aromatic aliphatic diisocyanates; aromatic diisocyanates such as diphenylmethane-4,4′-diisocyanate, tolylene diisocyanate;
Trifunctional or higher polyisocyanates such as triphenylmethane triisocyanate, trimers of the above aromatic diisocyanates, aromatic polyisocyanates such as adducts of low molecular triols and aromatic diisocyanates, and polymethylene polyphenyl isocyanate;
Cosmonate LL (Mitsui Chemicals, Inc .: a mixture of carbodiimidized diphenylmethane-4,4′-diisocyanate and diphenylmethane-4,4′-diisocyanate);
And polyisocyanate compounds having a carbodiimide group such as Carbodilite V-05 (Nisshinbo Co., Ltd .: terminal aliphatic polyisocyanate compound having a carbodiimide group).
Any of these polyisocyanate compounds may be used alone, or two or more kinds may be mixed and used.
Among these, alicyclic diisocyanates are preferable and dicyclohexylmethane-4,4′-diisocyanate is particularly preferable because a cured coating film excellent in solvent resistance can be obtained.

"Polyol compound (B2)"
As the polyol compound (B2), for example, glycols, polymer polyols and the like can be used.
Examples of glycols include ethylene glycol, propylene glycol, diethylene glycol, cyclohexane-1,4-dimethanol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,6-hexanediol, 3 -Methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 1,9 -Nonanediol, cyclohexyldimethanol, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, castor oil-modified diol, and the like.
Furthermore, triols such as glycerin and trimethylolpropane, tetraols such as pentaerythritol, castor oil-modified polyol and the like can be mentioned.

The molecular weight of the polymer polyol is preferably a number average molecular weight (Mn) in the range of 500 to 5,000.
Examples of the polymer polyol include polyester polyol, polycarbonate polyol, and polyether polyol.
Examples of the polyester polyol include alkyl monoglycidyl ethers such as ethyl glycidyl ether, methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, decyl glycidyl ether and stearyl glycidyl ether, or alkyl glycidyl esters (product names). One or more monoepoxy compounds selected from Cardura E10 (manufactured by Shell Japan) and the like, aliphatic dibasic acids such as adipic acid, azelaic acid, sebacic acid and dimer acid, or phthalic anhydride, isophthalic acid, terephthalic acid, From aromatic polybasic acid such as trimellitic anhydride or its anhydride, or alicyclic polybasic acid such as hydrophthalic anhydride or dimethyl-1,4-cyclohexanedicarboxylic acid or its anhydride, etc. Polyester polyols obtained by addition reaction and / or condensation reaction of one or more polybasic acids or acid anhydrides barrel like. Furthermore, the polyester polyol obtained by the ring-opening polymerization of a polyol and (epsilon) -caprolactone and (beta) -methyl-delta-valerolactone is mentioned.
As the polycarbonate polyol, hexamethylene-based polycarbonate polyol using 1,6-hexanediol as a raw material, polycarbonate diol using 1,4-butylene glycol, polycarbonate diol using neopentyl glycol, 3-methyl-1,5 Examples thereof include polycarbonate diols using pentanediol and polycarbonate diols using 1,9-nonanediol.
Examples of the polyether polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

“Compound (B3)”
The compound (B3) is a compound having a group capable of forming a salt and having two or more functional groups having reactivity with an isocyanate group.
In the present invention, the “group capable of forming a salt” is, as described above, an acidic group that forms a salt with a base to form a salt group, or a salt group that forms a salt with an acid. Basic group.

The group of acidic and form salts with bases underlying salt, a carboxyl group, a phosphoric acid group, such as sulfonic acid group (-SO 3 _H) can be exemplified.
Examples of the phosphoric acid group include groups represented by the following formula (g1) or (g2).

In the above formula (g2), R represents a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group and an aryl group.
The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and specific examples include a methyl group, an ethyl group, a propyl group, and a butyl group.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and specific examples include a phenyl group and a naphthyl group.

When the group capable of forming a salt is an acidic group that forms a salt with a base to form a salt group, the group capable of forming a salt has excellent reactivity with a metal atom, and the coating film One or more selected from the group consisting of a carboxy group, a phosphoric acid group, and a sulfonic acid group is preferable because of its excellent adhesion to the metal substrate and the affinity of the polyurethane resin in the paint for water. That is, the group capable of forming a salt of the polyurethane resin (B ^* ) is preferably one or more selected from the group consisting of a carboxy group, a phosphoric acid group, and a sulfonic acid group.
As group which can form this salt, it may contain individually by 1 type and may contain 2 or more types.
Among these, a carboxy group is particularly preferable because it is easy to balance in various respects.

Examples of the basic group that forms a salt with an acid to form a salt group include an amino group (—NH ₂ ), a secondary amino group, and a tertiary amino group.
Here, the secondary amino group is an N-substituted amino group in which one of the hydrogen atoms of the amino group is substituted with a hydrocarbon group, and is represented by the following formula (g3).
The tertiary amino group is an N, N-disubstituted amino group in which two hydrogen atoms of the amino group are substituted with a hydrocarbon group, and is represented by the following formula (g4-1) or (g4-2).

In the above formulas (g3), (g4-1) and (g4-2), R each independently represents a hydrocarbon group. Examples of the hydrocarbon group include the same groups as those exemplified as the hydrocarbon group for R in the above formula (g2).
Two R in the formula (g4-1) may be the same or different.

When the group capable of forming a salt is a basic group which forms a salt group by forming a salt with an acid, the group capable of forming a salt is preferably a tertiary amino group. That is, the group capable of forming a salt of the polyurethane resin (B ^* ) is preferably a tertiary amino group.
As group which can form this salt, it may contain individually by 1 type and may contain 2 or more types.

Examples of the functional group having reactivity with an isocyanate group include a hydroxyl group and an amino group.
Examples of the compound having two or more functional groups having reactivity with an isocyanate group include diols and diamines.

  Specific examples of the compound (B3) include trimethylolpropane monophosphate; trimethylolpropane monosulfate; polyester diol in which at least a part of the dibasic acid component is sodium sulfosuccinic acid or sodium sulfoisophthalic acid; N -Methyldiethanolamine; for example, diaminocarboxylic acids such as lysine and cystine; 2,6-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxyethyl) ) Dihydroxyalkylalkanoic acids such as propionic acid, 2,2-bis (hydroxypropyl) propionic acid, bis (hydroxymethyl) acetic acid, 2,2-bis (hydroxymethyl) butanoic acid; bis (4-hydroxyphenyl) acetic acid; 2, 2 Bis (4-hydroxyphenyl) pentanoic acid; tartaric acid; N, N-dihydroxyethylglycine; N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide; or dihydroxyalkylalkanoic acid and ε-caprolactone, etc. Carboxyl group-containing polycaprolactone diol to which the lactone compound is added.

The required amount of the group capable of forming a salt, that is, the amount of the compound (B3) used can be appropriately determined according to the type and composition ratio of the compounding components.
For example, when a compound having an acidic group that forms a salt with a base, such as a carboxy group, is used as the compound (B3), the compound (B3) is obtained from the polyurethane resin (B ^* ) obtained. It is preferable to use an amount in which the acid value is in the range of 20 to 100 KOH mg / g, and it is more preferable to use an amount in the range of 20 to 60 KOH mg / g. When the acid value of the polyurethane resin (B ^* ) is within the above range, the polyurethane resin (B ^* ) is excellent in storage stability when dissolved or dispersed in an aqueous medium to obtain a solution or dispersion of the aqueous polyurethane resin. .

"Active energy ray-curable compound (B4)"
The active energy ray-curable compound (B4) has one hydroxyl group and one or more unsaturated double bonds at the terminal.
Specific examples of the active energy ray-curable compound (B4) include monohydroxy mono (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and the like. Or monohydroxy di (meth) acrylate such as glycerin di (meth) acrylate and light ester G-201P (manufactured by Kyoeisha Chemical); monohydroxy triacrylate such as pentaerythritol triacrylate; monohydroxy such as dipentaerythritol pentaacrylate Pentaacrylates; dihydroxy mono (meth) acrylates such as glycerin mono (meth) acrylate; and these include ethylene oxide, propylene oxide, tetrahydrofuran Compounds obtained by addition polymerization of ε-caprolactone.

"Crosslinking agent (B5)"
Examples of the crosslinking agent (B5) include ethylenediamine, piperazine, N-aminoethylpiperazine, hexamethylenediamine, hydrazine, diethyltriamine, triethyltetramine, aliphatic amines such as tetraethylenepentamine, cyclohexylenediamine, isophoronediamine, Alicyclic amines such as norbornanediaminomethyl, tolylenediamine, xylenediamine, phenylenediamine, tris (2-aminoethyl) amine, aromatic amines such as 2,6-diaminopyridine, γ-aminopropyltrimethoxysilane, γ Aminosilanes such as -diaminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, or N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane; It is.
Further, examples of ketimine compounds include ketimine compounds dehydrated between primary amines such as the above-exemplified diamines and triamines and isobutyl ketone.

A typical production method of the polyurethane resin (B ^* ) is shown below.
First, in a reaction solvent (an organic solvent that does not react with an isocyanate group), the polyisocyanate compound (B1), the polyol compound (B2), and the compound (B3) are combined with the hydroxyl group of the polyol compound (B2) and the compound (B3). A polyurethane having an isocyanate group at the terminal and having a group capable of forming a salt (hereinafter referred to as an isocyanate group terminal) A polyurethane prepolymer).

The reaction between the hydroxyl group and the isocyanate group can be carried out in the range of 20 to 120 ° C. without solvent or in the reaction solvent.
As the reaction solvent, an organic solvent inert to an isocyanate group is preferable. Examples of such an organic solvent include acetone, methyl ethyl ketone, ethyl acetate, dioxane, acetonitrile, tetrahydrofuran, benzene, toluene, xylene, monoglyme, diglyme, Examples include dimethyl sulfoxide and N-methylpyrrolidone. These can be used alone or in combination.
At this time, an appropriate amount of a known polymerization inhibitor and reaction catalyst can be arbitrarily added.
Examples of the polymerization inhibitor include hydroquinone, tertiary butyl hydroquinone, and methoquinone.
Examples of the reaction catalyst include urethanization catalysts such as dibutyltin dilaurate, stannous octylate, triethylamine, N, N-dimethylbenzylamine, sodium hydroxide, and diethylzinc tetra (n-butoxy) titanium.

  Next, this isocyanate group-terminated polyurethane prepolymer is reacted with an active energy ray-curable compound (B4) having one hydroxyl group and one or more unsaturated double bonds at the ends, and unsaturated double bonds are formed at the molecular chain ends. A polyurethane having a bond and a group capable of forming a salt (hereinafter referred to as an ethylenically unsaturated double bond-containing polyurethane prepolymer) is obtained.

  At this time, when reacting the active energy ray-curable compound (B4), or during other reactions after reacting the active energy ray-curable compound (B4), hydroquinone, tertiary butylhydroquin, methoquinone, etc. It is desirable to use a polymerization inhibitor.

  Next, the polyurethane prepolymer containing ethylenically unsaturated double bonds is neutralized at 50 ° C. or less, and an ionized neutralization solution (prepolymer neutralization solution) is dispersed in water, whereby the polyurethane prepolymer is dispersed in an aqueous phase. To prepare a water / organic solvent mixed solution.

At this time, neutralization of a group capable of forming a salt can be performed by a conventionally known method. For example, if a group capable of forming a salt is an acidic group, a basic compound is added to form a salt. If the group that can be obtained is a basic group, it can be neutralized by adding an acidic compound.
Specific examples of the basic compound that neutralizes an acidic group such as a carboxy group and a phosphoric acid group exemplified as a group capable of forming a salt include trialkylamines such as trimethylamine and triethylamine; Examples include alkyl alkanolamines such as monoethanolamine, diethylethanolamine, and diethanolmonomethylamine; and basic vinyl monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate.
Examples of acidic compounds that neutralize basic groups such as tertiary amino groups mentioned as examples of groups capable of forming salts include formic acid, acetic acid, propionic acid, succinic acid, butyric acid, glutaric acid, lactic acid, and citric acid Organic acids such as acrylic acid, methacrylic acid, cinnamic acid, etc., organic sulfonic acids such as sulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, Examples include inorganic acids such as phosphoric acid. In order to improve the affinity for water, all or part of the tertiary amino group (the group represented by the above formula (g4-1) or (g4-2)) is replaced with a known quaternizing agent. You may make it quaternized by using. Examples of the quaternized tertiary amino group include a group represented by the following formula (g5).
_{^{-N + (R) 2 (R}} ') X - (g5)
In the above formula (g5), R is the same as R in the formula (g4-1) or (g4-2). R ′ is a group derived from a quaternizing agent, and examples of R ′ include a methyl group.
Examples of X ⁻ include an ion represented by the following formula (g6).
_{CH 3 -O-S (= O} ) 2 -O - (g6)
Examples of the quaternizing agent for quaternizing the tertiary amine include, for example, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, and alkyl or aryl sulfonates such as methyl methanesulfonate and methyl paratoluenesulfonate, Epoxys such as ethylene oxide, propylene oxide, butyl glycidyl ether, and glycidyl methacrylate can be used.

Thereafter, if necessary, a crosslinking agent (B5) dissolved in water or an organic solvent is added to the water / organic solvent mixed solution at 30 ° C. or lower. At this time, the crosslinking agent (B5) reacts with the ethylenically unsaturated double bond-containing polyurethane prepolymer to crosslink the ethylenically unsaturated double bond-containing polyurethane prepolymer or extend the polymer chain.
Here, as another method of crosslinking or extending the polymer chain using the crosslinking agent (B5), the crosslinking agent (B5) is previously dissolved in the aqueous phase, and then ionized into the aqueous phase in the same manner as described above. There is a method of preparing a water / organic solvent mixed solution by dispersing the prepolymer neutralized solution.
In the water / organic solvent mixed solution thus obtained, the polyurethane resin (B ^* ) is dissolved or dispersed.

The polyurethane resin (B ^* ) thus obtained contains a polyisocyanate component derived from the polyisocyanate compound (B1) and a polyol component derived from the polyol compound (B2).
In the present invention, the polyurethane resin (B ^* ) preferably has 10 to 40 mol% of a component derived from a polyol compound having three or more hydroxyl groups in the polyol component, that is, three or more hydroxyl groups. Thereby, the degree of branching of the polymer chain of the polyurethane resin (B ^* ) can be increased. When the degree of branching of the polymer chain is increased, the cohesive force of the polyurethane resin (B ^* ) is increased, and the wear resistance of the coating film is improved.
Examples of the polyol compound having three or more hydroxyl groups include castor oil, trimethylolpropane, trimethylolpropane EO adduct, trimethylolethane, glycerin, pentaerythritol, and the like, or polyester polyol ester-bonded to these compounds. .

In addition, when the polyol component has 10 to 40 mol% of a triol or higher component, the polyurethane resin (B ^* ) has a terminal ethylenically unsaturated double bond at a concentration of 1.0 to 6.0 equivalents / kg. It is preferable to have. Thereby, sclerosis | hardenability improves and a coating film shows the outstanding abrasion resistance.
The concentration of the ethylenically unsaturated double bond can be adjusted by the number of ethylenically unsaturated double bonds contained in the active energy ray-curable compound (B4), for example, the ethylenically unsaturated double bond of the active energy ray-curable compound (B4). The greater the number of saturated double bonds, the higher the concentration of ethylenically unsaturated double bonds.
In order to set the concentration of the terminal ethylenically unsaturated double bond in the polyurethane resin (B ^* ) to 1.0 equivalent / kg or more, the ethylenically unsaturated double contained in the active energy ray-curable compound (B4) The number of bonds is preferably 2 or more per molecule.
In particular, as the active energy ray-curable compound (B4), 1 to 40% by mass of an active energy ray-curable compound having a hydroxyl group and having 3 or more ethylenically unsaturated double bonds per molecule is converted to water. By introducing it at a stage prior to the application, a coating film exhibiting excellent wear resistance can be obtained.
As the active energy ray-curable compound (B6) having 3 or more ethylenically unsaturated double bonds per molecule, monomers and / or oligomers such as ditrimethylolpropane triacrylate and pentaerthritol tetraacrylate, or These monomers and / or oligomers include ethylene oxide (EO) and / or propylene oxide (PO) adducts.

Moreover, the stage before phase-inverting 1-40 mass% of active energy ray hardening compounds (B6) which have a 3 or more ethylenically unsaturated double bond per molecule in a polyurethane resin (B *) to water. Introducing (encapsulated in urethane resin), a coating film exhibiting excellent wear resistance can be obtained.
Examples of the active energy ray-curable compound (B6) having 3 or more ethylenically unsaturated double bonds per molecule include trimethylolpropane triacrylate, glycerin triacrylate, ditrimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, Monomers and / or oligomers such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, or ethylene oxide (EO) and / or propylene oxide (PO) of these monomers and / or oligomers ) Additives or polyfunctional urea such as isocyanuric acid EO-modified triacrylate, 15-functional urethane acrylate (for example, New Frontier R-1150; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Examples include active energy ray-curable monomers and oligomers such as tan acrylate.

  In order to maintain the dispersion stability in water of the water-based urethane resin (B) containing the active energy ray-curable compound (B6) having 3 or more ethylenically unsaturated double bonds per molecule, it is nonionic. The structure of the polyalkylene ether may be introduced by a known method. An active energy ray-curable water-containing resin composition using polyalkylene glycol monoalkyl ethers containing one hydroxyl group as an active energy ray-curable aqueous urethane resin composition of polyalkylene ether (for example, Japanese Patent No. 2590682) And active energy ray-curable water-containing resin compositions in which polyalkylene glycol is introduced into the side chain in a pendant manner (see, for example, JP-A-2007-023177 and JP-A-2007-023178).

The above effect is particularly remarkable when the number average molecular weight (Mn) of the polyurethane resin (B ^* ) is 1000 or more.
Accordingly, the polyurethane resin (B ^* ) has 10 to 40 mol% of a triol or higher component in the polyol component, 1.0 to 6.0 equivalents / kg of terminal ethylenically unsaturated double bonds, and Mn Is preferably a polyurethane resin of 1000 or more.
Mn of the polyurethane resin (B ^* ) is more preferably 1000 to 500,000, and further preferably 1000 to 100,000.

In the polyurethane resin (B ^* ), part or all of the polyisocyanate component is preferably dicyclohexylmethane-4,4′-diisocyanate (hereinafter referred to as hydrogenated MDI). That is, it is preferable that the polyurethane resin (B ^* ) is produced using hydrogenated MDI as the polyisocyanate compound (B1). Such a polyurethane resin is particularly preferably used because of its excellent solvent resistance.
The blending ratio of hydrogenated MDI in the total polyisocyanate compound (B1) is preferably 25% by mass or more.

(Polyurethane resin derivative (B ^** ))
The polyurethane resin derivative (B ^** ) is formed by bonding the polyurethane resin (B ^* ) with another atom or atomic group.
As other atoms or atomic groups to which the polyurethane resin (B ^* ) is bonded, other components contained in the coating film (phosphate ester compound (A), silica particles (C ^* ), alumina particles (D), etc.) And atoms or atomic groups derived from the metal substrate and plating on the surface thereof.
“Polyurethane resin (B ^* ) and another atom or atomic group are bonded” means that polyurethane resin (B ^* ) is bonded to another atom or atomic group (covalent bond, ionic bond, hydrogen bond, Other atoms or atomic groups to which the polyurethane resin (B ^* ) is bonded are not included in the polyurethane resin derivative (B ^** ).

Examples of the polyurethane resin derivative (B ^** ) include those in which a part or all of the reactive active sites of the polyurethane resin (B ^* ) are bonded to other atoms or atomic groups.
The reactive active site of the polyurethane resin (B ^* ) includes at least a group capable of forming the salt and a terminal ethylenically unsaturated double bond group.
In the terminal ethylenically unsaturated double bond group, the double bond is usually cleaved to become —CH—C <, and other atoms or atomic groups (for example, (A / A ^* ) component, silica particles (C) It is considered that they are covalently bonded to an alumina particle (D) atom or atomic group.

A group capable of forming a salt is usually considered to ionize and ionically bond to another atom or atomic group (for example, a metal atom of a metal substrate).
In the present invention, as described above, the group capable of forming a salt in the polyurethane resin (B ^* ) is preferably at least one selected from the group consisting of a carboxy group, a phosphoric acid group, and a sulfonic acid group. Therefore, in the polyurethane resin derivative (B ^** ), the group capable of forming a salt is preferably at least one selected from the group consisting of a carboxy group, a phosphoric acid group, and a sulfonic acid group.
In this case, in the polyurethane resin derivative (B ^** ), it is preferable that some or all of the groups capable of forming these salts are bonded to a metal atom. These groups capable of forming salts are excellent in reactivity with metal atoms, and are usually considered to be anionized and ionically bonded to metal atoms such as a metal substrate.

In the present invention, as described above, the group capable of forming a salt in the polyurethane resin (B ^* ) is preferably a tertiary amino group. Therefore, in the polyurethane resin derivative (B ^** ), The group capable of forming a salt is preferably a tertiary amino group.
In this case, in the polyurethane resin derivative (B ^** ), part or all of the group capable of forming a salt is another atom or atomic group bonded to a metal atom and / or another atom bonded to a metal oxide or It is preferably bonded to an atomic group. Tertiary amino groups are usually cations such as —N (R) ₃ ^+, and ionic bonds to other atoms or atomic groups bonded to metal atoms such as metal substrates and metal oxides such as silica and alumina. For example, silicic acid can be cited as another atom or atomic group bonded to silica.

The coating film contains a component (B ^* / B ^** ) (at least one selected from the group consisting of the polyurethane resin (B ^* ) and the polyurethane resin derivative (B ^** )).
Coating may contain only polyurethane resin ^{(B *)} may contain only the polyurethane resin derivative ^{(B **),} polyurethane resin ^{(B *)} and a polyurethane resin derivative ^{(B **)} Both of them may be contained.
In the present invention, it is preferable to contain at least a polyurethane resin derivative (B ^** ), particularly considering the adhesion of the coating film to the metal substrate.
In the coating film, the content of the component (B ^* / B ^** ) is preferably 30 to 90% by mass, and preferably 40 to 80% by mass with respect to the total mass of the coating film. More preferred. Within the above range, the wear resistance is particularly good.

The polyurethane resin derivative (B ^** ) is usually formed by irradiating the polyurethane resin (B ^* ) with active energy rays such as ultraviolet rays in the presence of other atoms or atomic groups.
Whether or not the polyurethane resin derivative (B ^** ) is contained in the coating film can be confirmed by analyzing the coating film with an infrared spectrometer or the like.

[Silica particles (C ^* )]
As the silica particles (C ^* ), particularly when the coating film is formed, the silica particles can stably exist as colloids (colloidal silica) in the aqueous paint (excellent colloidal particle stability), so that the aluminum compound What was surface-treated with is preferable. Preferred examples of such silica particles (C ^* ) include silica particles contained in Snowtex C (manufactured by Nissan Chemical Industries, Ltd.).
The compounding amount of the silica particles (C ^* ) is preferably 3 to 60% by mass with respect to the total mass of the coating film in terms of enhancing solvent resistance, and in particular, chemical resistance against chemicals such as a degreasing liquid. In view of the properties, the content is more preferably 5 to 25% by mass.

[Alumina particles (D)]
The alumina particles (D) are particles composed of alumina.
The average particle diameter (d) of the alumina particles (D) is not particularly limited, and generally commercially available alumina particles can be used. In general, alumina particles having an average particle diameter of about 20 to 40 nm to several tens of μm are commercially available.
In the present invention, in particular, the average particle diameter (d) of the alumina particles (D) and the thickness (t) of the coating film formed using the coating composition containing the alumina particles (D) , D ≦ (2t / 3) is preferable because excellent wear resistance can be obtained. When the average particle diameter is d> (2t / 3), a part of the alumina particles may protrude on the coating film. The alumina particles protruding on the coating film are likely to be missing from the coating film during wear, and the missing alumina particles may act as a wear agent, and may be more easily worn than a film containing no alumina particles. .

  The shape of the alumina particles (D) is preferably spherical in order to give good results in wear resistance. When the alumina particles (D) have a leaf shape or an indefinite shape, a part of the alumina particles (D) protrudes from the surface of the film when the coating film is formed, so that the particles are easily missing from the coating film during wear. The prepared alumina particles act as an abrasion agent and may be more easily worn than a film containing no alumina particles.

The content of the alumina particles (D) in the coating film is preferably 1 to 20% by mass and more preferably 1 to 15% by mass with respect to the total mass of the coating film. When it is 1% by mass or more, excellent wear resistance can be obtained. Moreover, the balance with another component is favorable in it being 20 mass% or less, and it is excellent in the effect of this invention. For example, the lower the content of alumina particles (D), the higher the proportion of polyurethane resin (B ^* ), and the concentration in the coating composition of ethylenically unsaturated double bonds capable of crosslinking reaction is sufficiently high. A film having excellent surface hardness is formed by irradiation with active energy rays, and as a result, wear resistance is improved.

[Others]
The coating film may contain components other than those described above as optional components.
As components other than those described above, components listed as optional components in the active energy ray-curable coating composition of the second aspect of the present invention to be described later, and those formed by bonding these components to other atoms or atomic groups. Can be mentioned.
Specifically, as a component formed by bonding with another atom or atomic group, for example, a silane coupling agent, an organic material (for example, a phosphoric ester compound (A), a polyurethane resin (B ^* ), etc.) or an inorganic material ( For example, colloidal silica (C), alumina particles (D), metal substrate, etc.); active energy ray-curable monomers and / or oligomers that are dissolved or easily dispersed in water are other atoms or atomic groups Examples thereof include reaction products formed by bonding to (for example, the reactive active site of the polyurethane resin (B ^* ) described above).

  The coating film should just be formed in at least one part of the metal base material according to the objective. In other words, it should be formed at least in a site where wear resistance, scratch resistance, etc. are required, may be formed on a part of the metal substrate, or formed on the entire surface of the metal substrate. Also good.

The thickness of the coating film is not particularly limited and may be determined according to the purpose. For example, when it is desired to provide fingerprint resistance and lubricity, a film thickness of about 1 to 3 μm is usually preferable, and when it is necessary to ensure conductivity such as grounding, the thickness is about 0.5 to 1 μm. Film thickness is preferred.
As described above, the average particle diameter (d) of the alumina particles (D) and the thickness (t) of the coating film preferably satisfy the relationship d ≦ (2t / 3).

The adhesion amount of the coating film is not particularly limited and may be determined according to the thickness of the target coating film, but is preferably in the range of 0.2 to 5.0 g / m ² . More preferably, it is in the range of 5 to 3.0 g / m ² . When the adhesion amount is 0.2 g / m ² or more, the thickness of the coating film as a whole can provide sufficient wear resistance and scratch resistance. When it is 5.0 g / m ² or less, sufficient wear resistance and scratch resistance can be obtained, and the material cost is low, which is practical.

When the coating amount of the coating film is in the range of 0.2 to 5.0 g / m ² , the coating film is subjected to a ball-on-disk test (10 mm diameter stainless steel sphere made of SUS440C is pressed onto the test surface with a mass of 1 kg. Slid on the circumference of 70 mm in diameter at 60 rpm) is the number of sliding circumferences until the coating film of the part subjected to sliding wears down to 1/4 of the original film thickness? Or, the total sliding distance is preferably 100 m or more.

Moreover, when the adhesion amount of the coating film is in the range of 0.2 to 5.0 g / m ² , the coating film is a paper abrasion resistance evaluation test (high quality paper described in JIS-P-0001 is attached to the outer periphery. A wear ring having a diameter of 50 mm and a width of 12 mm is pressed onto the test surface with a mass of 500 g and reciprocally slid with a stroke of 30 mm). It is preferable that the number of times of sliding until is 3000 reciprocations or more.
Such a paper wear resistance evaluation test can be performed using, for example, a Suga type abrasion tester manufactured by Suga Test Instruments Co., Ltd.

Further, when the coating film adhesion amount is in the range of 0.2 to 5.0 g / m ² , the coating film has a steel wool wear test evaluation test (steel wool # 0000 is applied at a load of 0.98 N / cm ² . The test surface is pushed down and reciprocated at a stroke of 50 mm at a reciprocating speed of 40 reciprocations / minute). Preferably there is.
Such a steel wool abrasion evaluation test can be performed using, for example, a rubbing tester type I manufactured by Taihei Rika Kogyo Co., Ltd.

<Metal base material>
In the present invention, the type of metal constituting the metal substrate is not particularly limited, and any metal substrate can be applied.
Specifically, for example, metals such as iron, aluminum, titanium, zinc, copper, and nickel; two or more kinds of the above metals are mixed, or different metal elements or non-metallic elements such as carbon and silicon are added to the metal. An alloy etc. are mentioned.
Examples of the different metal element include cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, antimony, tin, copper, cadmium, and arsenic.
As an alloy containing iron, steel, that is, an iron-carbon alloy having a carbon concentration of 0.02 to about 2% by mass is preferable. Even ordinary steel (carbon steel) containing alloy steel (special steel) in which one or more elements other than carbon are added to ordinary steel, for example, chromium-containing steels such as stainless steel and chromium molybdenum steel, nickel steel, manganese Steel or the like may be used.
In the present invention, the metal substrate is preferably a metal substrate (M1) composed of any one of ordinary steel, alloy steel, aluminum, aluminum-based alloy, titanium, and titanium-based alloy.

Further, the metal substrate may be a plated metal substrate in which at least a part of its surface is coated with plating.
The type of plating is not particularly limited, but plating composed of any one metal element of zinc, aluminum, cobalt, tin and nickel, or at least two of the metal elements, or at least one of the metal elements Alloy plating containing a metal element other than the metal element and / or a non-metal element is preferable. Furthermore, for these plating, as a small amount of different elements, one or two of cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, antimony, tin, copper, cadmium, arsenic, etc. It may be one containing more than seeds or one in which an inorganic substance such as silica, alumina, titania or the like is dispersed.
In the present invention, the plating may be multilayer plating in combination with the above plating and other types of plating, such as iron plating, iron-phosphorus plating, and the like.
The adhesion amount of the plating on the surface of the metal base material is not particularly limited, but considering the expression of effects such as improvement of the corrosion resistance and coating adhesion of the metal base material by plating, and improvement of appearance and decoration, 1 g / m ² to preferably in the range of 500 g / ^{m 2,} more preferably in the range of ^{3g / m 2 ~250g / m 2} .

The method for forming the plating is not particularly limited, and for example, electroplating, electroless plating, hot dipping, vapor phase plating, or the like can be used.
The treatment method for forming the plating may be either a continuous type or a batch type. For example, in hot dipping, the continuous type is mainly used for thin plate materials and wire rods, and the batch type plating uses a metal substrate. By forming into final shapes such as pipe materials, rolled materials, processed products, bolts / nuts, cast forged products, etc., and then immersing them in a hot dipping bath (so-called post-plating).
Also, for plated metal substrates, as post-plating treatment, zero spangle treatment, which is uniform appearance after hot dipping, annealing treatment, which is a modification treatment of the plating layer, for surface condition and material adjustment The temper rolling may be performed.

  In the present invention, the metal substrate is the metal substrate (M1) or a plated metal substrate (M2) in which at least a part of the surface of the metal substrate (M1) is coated with plating. preferable.

The roughness of the surface of the metal substrate is not particularly limited and may be determined according to the purpose, but is preferably determined in consideration of the amount of coating film attached.
For example, when the adhesion amount of the coating film is in the range of 0.2 to 5.0 g / m ² described above, the metal substrate is 3.0 μm or less at least in the coating portion coated with the coating film. It preferably has an arithmetic average roughness, and particularly preferably 2.0 μm or less.
Here, the arithmetic average roughness in the present invention is the arithmetic average roughness Ra defined in JIS-B0601 (definition and display of surface roughness). The arithmetic average roughness Ra can be easily measured using an apparatus (commercially available surface roughness measuring machine) that measures the surface shape by tracing the test surface with a stylus type pickup.

Hereinafter, the reason why it is preferable that the arithmetic average roughness of the surface of the coated portion of the metal substrate is 3.0 μm or less when the amount of coating film attached is in the range of 0.2 to 5.0 g / m ^2. explain.
As will be described later, a typical method for producing the coated metal substrate of the present invention is to apply an aqueous paint containing the active energy ray-curable coating composition of the present invention to at least a part of the surface of the metal substrate, and then apply water. This is a method of forming a coating film by irradiating ultraviolet rays after evaporating and drying main volatile components.
In such a method for producing a coated metal base material, the coating material applied to the surface of the metal base material fills the concave portions of the micro undulations on the surface of the metal base material, so that more paint stays in the concave portion than the convex portions.
If the roughness level of the surface of the metal substrate is not significantly different from the average film thickness of the paint film (uncured film) formed after drying the paint, or greater than the average film thickness, Although there are some differences depending on wettability, drying conditions, etc., the film thickness covering the convex part on the surface of the metal substrate becomes particularly thin, or at least part of the convex part on the surface of the metal substrate is exposed and the entire film is covered. The rate tends to be low.
In particular, when the arithmetic average roughness of the surface of the original metal substrate exceeds 3.0 μm, the amount of the coating film on the substrate is in the range of 0.2 to 5.0 g / m ² , The film part covering the convex part on the surface of the metal base becomes an extremely thin film, or in some cases, a part of the convex part on the surface of the metal base is exposed without being covered with the film, and the wear resistance of the part, Other necessary characteristics such as scratch resistance and rust prevention may be insufficient.

  Any method may be used to control the arithmetic average roughness of the surface of the metal substrate used in the present invention. For example, a method of transferring unevenness (arithmetic average roughness of 3.0 μm or less) on the surface of a rolling roll to a metal substrate by rolling a solid metal, and unevenness (arithmetic average roughness of 3) on a mold surface during metal casting. 1.0 μm or less) to a cast material, a method of chemically etching the surface of a metal substrate with an acid, an alkaline solution or an electrolytic solution, mechanically grinding with a blast or water jet, and the arithmetic average roughness is Examples thereof include a method of imparting irregularities of 3.0 μm or less.

The shape of the metal substrate is not particularly limited, and various shapes can be used depending on the purpose. However, a plate material, a strip material, a rod material, a shape material (for example, a three-dimensional metal substrate such as H steel), a pipe material, and the like. Wires are preferred.
The method for producing the metal substrate is not particularly limited, and a conventionally known production method can be used. For example, as a final process of production, a production method in which rolling such as cold rolling and hot rolling, casting, forging, extrusion, drawing, etc. is performed.

In the present invention, a surface treatment layer may be provided on the surface of the metal substrate. In other words, before the coating film is formed, the metal substrate surface is subjected to a base treatment such as phosphate treatment or chromate treatment, and a base treatment layer such as a chromate film is provided, thereby providing a metal base material for the coating film. Adhesion to the surface and corrosion resistance are further improved.
However, in the present invention, in consideration of safety, environmental influences, and the like, the metal substrate is preferably a metal substrate that has not been subjected to chromate treatment.

As the chromate treatment, any of electrolytic chromate, reactive chromate and coating chromate may be used.
The chromate film is preferably obtained by applying and drying a chromate solution containing one or more of silica, phosphoric acid and hydrophilic resin to partially reduced chromic acid.
The adhesion amount of the chromate in the chromate treatment is preferably 5 to 150 mg / ^{m 2} reckoned as metal chromium, 10 to 50 mg / ^{m 2} is more preferable. Excellent adhesion and corrosion resistance can be obtained when it is 5 mg / m ² or more. If the adhesion amount exceeds 150 mg / m ² , the chromate film may cohesively break when subjected to sliding or during molding, which may reduce wear resistance and workability.
In the phosphate treatment, the amount of phosphate adhered is preferably in the range of 0.5 to 3.5 g / m ² as the phosphate.

  Depending on the purpose, the surface of the metal substrate may further be subjected to pickling treatment, alkali treatment, electrolytic reduction treatment, cobalt flash treatment, silane coupling agent treatment, inorganic silicate treatment, and the like.

The coated metal substrate of the present invention can be produced, for example, by applying an aqueous paint containing each of the above components to at least a part of the surface of the metal substrate and curing it.
As the aqueous paint used for the production of the coated metal substrate of the present invention, the active energy ray-curable coating composition of the second aspect of the present invention described below is preferably used.
For the production of the coated metal substrate of the present invention, the following method for producing a coated metal substrate of the fourth aspect of the present invention is preferably used.

≪Second aspect≫
The active energy ray-curable coating composition of the second aspect of the present invention (hereinafter sometimes abbreviated as “coating composition”) comprises a phosphoric ester compound (A), an aqueous polyurethane resin (B), colloidal silica (C ) And alumina particles (D).
Here, in the present specification and claims, the “active energy ray” refers to an energy ray such as ultraviolet ray, visible light, electron beam, X-ray.
The active energy ray-curable coating composition of the present invention has active energy curability that is cured by irradiation with active energy rays, and is active on a coating film formed using such an active energy ray-curable coating composition. By irradiating energy, the coating film is cured and a coating film is formed.
The coating film thus formed has excellent adhesion to the surface of the metal substrate. This is because, by irradiation with active energy rays, the terminal ethylenically unsaturated double bond of the phosphate ester compound (A) and the terminal ethylenically unsaturated double bond of the aqueous polyurethane resin (B) are polymerized to form a crosslinked structure. This is probably because the phosphate ester bonding group (≧ P-OR ² ) derived from the phosphate ester compound (A) has affinity or chemical binding to the metal substrate surface.

[Phosphate ester compound (A)]
Examples of the phosphoric acid ester compound (A) include those similar to the phosphoric acid ester compound (A) exemplified in the coated metal substrate of the first aspect of the present invention.

  The phosphate ester compound (A) is preferably neutralized with a basic compound. Thereby, the phosphoric acid ester compound (A) is dissolved or uniformly dispersed in water, and an active energy curable coating composition having good storage stability free from white turbidity and precipitation is obtained.

  In the coating composition of the present invention, the amount of the phosphate ester compound (A) is preferably 1 to 30% by mass, and 5 to 15% by mass with respect to the total solid content of the coating composition. Is more preferable. When it is within the above range, adhesion to a metal substrate is particularly improved.

[Aqueous polyurethane resin (B)]
The aqueous polyurethane resin (B) is obtained by dissolving or dispersing a polyurethane resin having a group capable of forming a salt group and a terminal ethylenically unsaturated double bond in an aqueous medium.
Any aqueous medium (solvent or dispersion medium) may be used as long as it is based on water. Here, “basic on the water” means a solvent composed of water alone or containing water and an organic solvent that dissolves in, mixes with, or suspends in water and does not separate from water.
The aqueous polyurethane resin (B) has a group capable of forming a salt group, so that it is stably dissolved or dispersed in an aqueous medium. When the aqueous polyurethane resin (B) is irradiated with active energy rays, the ethylenically unsaturated double bonds are polymerized to form a crosslinked structure, thereby forming a cured film.

Examples of the aqueous polyurethane resin (B) include those obtained by dissolving or dispersing the polyurethane resin (B ^* ) exemplified in the coated metal substrate of the first aspect of the present invention in water.
A preferred embodiment of the aqueous polyurethane resin (B) is the same as the polyurethane resin (B ^* ) except that it is dissolved or dispersed in water.
Aqueous polyurethane resin (B), for example, as described above, in the production of polyurethane resin (B ^*), After preparing the water-organic solvent mixed solution containing the polyurethane resin (B ^*), water, organic It can be obtained by distilling off part or all of the organic solvent from the solvent mixed solution under reduced pressure.

  In the coating composition of the present invention, the blending amount of the aqueous polyurethane resin (B) is preferably 30 to 90% by mass, and 40 to 80% by mass with respect to the total solid content of the coating composition. Is more preferable. Within the above range, the wear resistance is particularly good.

[Colloidal silica (C)]
The colloidal silica (C) used in the present invention is a colloidal form in which negatively charged amorphous silica particles are dispersed in water.
Colloidal silica (C) may be sol-stabilized by adding amine or the like for particle stabilization.
As the colloidal silica (C), colloidal silica surface-treated with an aluminum compound is particularly preferable because of its excellent colloidal particle stability. A preferable example of such colloidal silica is Snowtex C (manufactured by Nissan Chemical Industries, Ltd.).
The blending amount of the colloidal silica (C) is preferably 3 to 60% by mass with respect to the total solid content of the active energy ray-curable coating composition from the viewpoint of improving solvent resistance, and in particular, a degreasing solution or the like. Considering the chemical resistance to chemicals, it is more preferably 5 to 25% by mass.

[Alumina particles (D)]
Examples of the alumina particles (D) include those similar to the alumina particles (D) exemplified in the coated metal substrate of the first aspect of the present invention.
The blending amount of the alumina particles (D) in the coating composition is preferably 1 to 20% by mass and more preferably 1 to 15% by mass with respect to the total solid content of the coating composition. When the amount is 1 mass or more, excellent wear resistance can be obtained. Moreover, the balance with another component is favorable in it being 20 mass% or less, and it is excellent in the effect of this invention. For example, the smaller the content of alumina particles (D), the higher the proportion of the aqueous polyurethane resin (B), and the concentration in the coating composition of ethylenically unsaturated double bonds capable of crosslinking reaction is sufficiently high. A film having excellent surface hardness is formed by irradiation with active energy rays, and as a result, wear resistance is improved.

[Optional ingredients]
The coating composition of this invention may contain components other than the said phosphate ester compound (A), aqueous polyurethane resin (B), colloidal silica (C), and an alumina particle (D) as arbitrary components.
In particular, the coating composition of the present invention preferably contains a silane coupling agent. Thereby, high boiling resistance can be obtained.
As the silane coupling agent, a functional group or molecular unit having affinity or reactivity with an organic material (for example, a phosphate ester compound (A), an aqueous polyurethane resin (B), etc.) and an inorganic material (for example, A silane coupling agent having an alkoxysilane group having affinity and reactivity with colloidal silica (C), alumina particles (D), metal base material, and the like is preferable.
Specific examples of such silane coupling agents include vinyl silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, γ- (methacryloloxypropyl) trimethoxysilane, γ -(Meth) acryloylsilane such as (methacryloloxypropyl) methyldimethoxysilane, β (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane Such as epoxy silane, γ-anilinopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and other aminosilanes, γ-mercaptopropyltrimethoxysilane, isobutyltrimethoxysilane, n-decyltrimethoxysilane Alkyl silane can be mentioned, such as n- octadecyl trimethoxysilane.
Any one of these silane coupling agents may be used alone, and two or more of these may be mixed in advance or added separately. For example, aminosilane and epoxysilane can be premixed and added.
As the silane coupling agent, (meth) acryloylsilane is preferable and γ- (methacryloloxypropyl) trimethoxysilane is most preferable because it is particularly excellent in boiling resistance.
Although the compounding quantity of a silane coupling agent can be selected arbitrarily, since it is excellent in boiling resistance, about 0.1-20 mass% is preferable with respect to the total solid of this coating composition.

The coating composition of the present invention requires an active energy ray-curable monomer or oligomer that dissolves or easily disperses in water in order to advance the crosslinking reaction by active energy rays of the water-based urethane resin and further improve the wear resistance. Can be added accordingly.
Specific examples of active energy ray-curable monomers include polyfunctional acrylates modified with polyalkylene ether of EO-added trimethylolpropane triacrylate and PO-added trimethylolpropane triacrylate, and polyfunctional monomers having an OH group of pentaerythritol triacrylate. , An amine neutralized product of polybasic acid-modified polyfunctional acrylate (for example, Aronix TO-756 manufactured by Toagosei Co., Ltd.) obtained by reacting an anhydride with a polyfunctional monomer having an OH group of pentaerythritol triacrylate, or Examples include glycerin triacrylate.
Moreover, as a typical example of an active energy ray hardening-type oligomer, polyfunctional oligomers, such as purple light UV101 by Nippon Gosei Co., Ltd., are mentioned.
These compounds can be added preferably in an amount of 1 to 40% by mass. However, if the amount added is increased, the coating film becomes brittle and the wear resistance deteriorates.

Moreover, in order to advance the crosslinking reaction by the active energy ray of aqueous | water-based urethane resin, and to further improve abrasion resistance, the active energy ray hardening-type compound (B6) which has three or more ethylenically unsaturated double bonds per molecule 1-40 mass% can be introduce | transduced in the step before phase-shifting to the water of water-based urethane resin (B) (inclusive in a urethane resin).
Examples of the active energy ray-curable compound (B6) having 3 or more ethylenically unsaturated double bonds per molecule include trimethylolpropane triacrylate, glycerin triacrylate, ditrimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, Monomers and / or oligomers such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, or ethylene oxide (EO) and / or propylene oxide (PO) of these monomers and / or oligomers ) Additives, or polyfunctional compounds such as isocyanuric acid EO-modified triacrylate, 15-functional urethane acrylate (for example, New Frontier R-1150; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Examples include active energy ray-curable monomers and oligomers such as ethane acrylate.
In order to maintain the dispersion stability of the active energy ray-curable compound (B6) having 3 or more ethylenically unsaturated double bonds per molecule in water, the aqueous urethane resin (B) has a nonionic property. The structure of the polyalkylene ether may be introduced by a known method. An example in which an active energy ray-curable aqueous urethane resin is introduced into the structure of a polyalkylene ether is an active energy ray-curable water-containing resin composition using a polyalkylene glycol monoalkyl ether containing one hydroxyl group (for example, a patent) No. 2590682), active energy ray-curable water-containing resin composition in which polyalkylene glycol is introduced into the side chain in a pendant form (for example, see JP 2007-023177, JP 2007-023178), etc. Is mentioned.

The coating composition of the present invention is a phosphoric acid ester compound (A) having one or more ethylenically unsaturated double bonds in one molecule other than the phosphoric acid ester compound (A) as long as the effects of the present invention are not impaired. ') May be contained.
Examples of the phosphoric acid ester compound (A ′) include a reaction product of the phosphoric monoester compound or phosphoric diester compound in the compound (1) with an alkyl monoglycidyl ether, an alkyl glycidyl ester or a polyepoxy compound; glycidyl methacrylate, etc. And a reaction product of a compound having both an epoxy group and an unsaturated double bond with phosphoric acid, a phosphoric acid monoester compound, a phosphoric acid diester compound, or the like.

The coating composition of the present invention may further contain known additives such as active energy ray polymerizable monomers, active energy ray polymerizable oligomers, active energy ray curing polymerization initiators, resin compositions, aminoplasts, if necessary. , Diluents, surfactants, plasticizers, waxes, hydrolysis inhibitors, emulsifiers, leveling agents, antifoaming agents, antioxidants, antibacterial agents, silica powders and other inorganic powders, dyes, pigments and other colorants, You may contain a rust pigment, a rust preventive agent, etc.
In particular, when ultraviolet rays are used as active energy rays, it is preferable to add a photopolymerization initiator. The kind of photopolymerization initiator can be arbitrarily selected from known materials. The addition amount of the photopolymerization initiator can also be arbitrarily selected, and is preferably in the range of 0.2 to 20% by mass, for example, 0.5 to 10% by mass with respect to the total solid content of the coating composition. Is more preferable.
In addition, when hardening a coating film using an electron beam as an active energy ray, a polymerization initiator is not especially required.

[Method for preparing active energy ray-curable coating composition]
The active energy ray-curable coating composition of this embodiment is obtained by dissolving or dispersing the above-described phosphate ester compound (A), aqueous polyurethane resin (B), colloidal silica (C), and alumina particles (D) in an aqueous medium. Can be prepared. For example, a mixture of an aqueous polyurethane composition (B), colloidal silica (C) and alumina particles (D) dissolved or dispersed in water or retaining water dilutability, and a phosphate ester compound (A) are mixed. It is preferable to prepare it. In addition, the alumina particles (D) are preliminarily dispersed in water with an anionic surfactant, a nonionic surfactant, an aqueous dispersant or a wax in consideration of storage stability in an aqueous medium. It is good to use.
At this time, the phosphoric acid ester compound (A) is neutralized with a basic compound before mixing with other components in order to obtain an active energy ray-curable coating composition that is free from cloudiness and precipitation and has good storage stability. It is preferable.

As described above, the aqueous medium (solvent or dispersion medium) may be based on water. In addition to water, the phosphoric ester compound (A), the aqueous polyurethane resin (B), colloidal silica (C ) And alumina particles (D) may be contained in an amount that can be dissolved or dispersed, and an organic solvent that can be used for the water-based paint may be included.
Examples of the organic solvent include alcohols such as ethanol and isopropyl alcohol; glycol derivatives such as propylcellosolve, butylcellosolve, and butyldiglycol ether; and nitrogen-containing water-soluble solvents such as N-methylpyrrolidone and dimethylformamide. In some cases, a nonaqueous solvent such as butanol or hexanol may be added in order to improve the dispersion stability of the paint.
The content of the organic solvent is preferably 5% by mass or less based on the total mass of the aqueous medium from the viewpoint of safety, hygiene, or environmental pollution.

      In addition, when the additive as described above is blended, the additive can be added during the preparation of the coating composition, but as disclosed in JP-A-8-259888, an aqueous solution is used. When the polyurethane resin (B) is prepared, it can be introduced at a stage before phase inversion into water. In this case, even if the additive is a water-insoluble compound, it can be easily mixed, which is preferable. In this case, the mixing of these additives is preferably performed after the reaction between the hydroxyl group and the isocyanate group is completed.

≪Third aspect≫
According to a third aspect of the present invention, there is provided a coating film obtained by curing the active energy ray-curable coating composition according to the second aspect of the present invention with active energy rays on at least a part of the surface of a metal substrate. It is the covering metal substrate which has.
The coating film obtained by curing the active energy ray-curable coating composition of the second aspect of the present invention with active energy rays is the same as the coating film of the coated metal substrate of the first aspect of the present invention. It is excellent in various properties such as adhesion to a metal substrate, molding processability, solvent resistance, etc., and in particular, excellent molding processability and wear resistance are compatible.

      The coating film should just be formed in at least one part of the metal base material according to the objective. In other words, it should be formed at least in a site where wear resistance, scratch resistance, etc. are required, may be formed on a part of the metal substrate, or formed on the entire surface of the metal substrate. Also good.

The thickness of the coating film is not particularly limited and may be determined according to the purpose. For example, when it is desired to provide fingerprint resistance and lubricity, a film thickness of about 1 to 3 μm is usually preferable, and when it is necessary to ensure conductivity such as grounding, the thickness is about 0.5 to 1 μm. Film thickness is preferred.
The average particle diameter (d) of the alumina particles (D) and the thickness (t) of the coating film are as follows: d ≦ (2t) / 3) is preferably satisfied.

The adhesion amount of the coating film is not particularly limited and may be determined according to the thickness of the target coating film, but is preferably in the range of 0.2 to 5.0 g / m ² . More preferably, it is in the range of 5 to 3.0 g / m ² . When the adhesion amount is 0.2 g / m ² or more, the thickness of the coating film as a whole can provide sufficient wear resistance and scratch resistance. When it is 5.0 g / m ² or less, sufficient wear resistance and scratch resistance can be obtained, and the material cost is low, which is practical.

When the coating amount of the coating film is in the range of 0.2 to 5.0 g / m ² , the coating film is subjected to a ball-on-disk test (10 mm diameter stainless steel sphere made of SUS440C is pressed onto the test surface with a mass of 1 kg. Slid on the circumference of 70 mm in diameter at 60 rpm) is the number of sliding circumferences until the coating film of the part subjected to sliding wears down to 1/4 of the original film thickness? Or, the total sliding distance is preferably 100 m or more.

Moreover, when the adhesion amount of the coating film is in the range of 0.2 to 5.0 g / m ² , the coating film is a paper abrasion resistance evaluation test (high quality paper described in JIS-P-0001 is attached to the outer periphery. A wear ring having a diameter of 50 mm and a width of 12 mm is pressed onto the test surface with a mass of 500 g and reciprocally slid with a stroke of 30 mm). It is preferable that the number of times of sliding until is 3000 reciprocations or more.
Such a paper wear resistance evaluation test can be performed using, for example, a Suga type abrasion tester manufactured by Suga Test Instruments Co., Ltd.

Further, when the coating film adhesion amount is in the range of 0.2 to 5.0 g / m ² , the coating film is a steel wool abrasion test evaluation test (steel wool # 0000 is applied at a load of 0.98 N / cm ² . Press the test surface and reciprocate at a stroke of 50 mm at a reciprocating speed of 40 reciprocations / minute). Preferably there is.
Such a steel wool abrasion evaluation test can be performed using, for example, a rubbing tester type I manufactured by Taihei Rika Kogyo Co., Ltd.

[Metal base]
In the present invention, the type of metal constituting the metal substrate is not particularly limited, and any metal substrate can be applied.
Specifically, in the coated metal base material of the first aspect of the present invention, the same metal base materials as mentioned above can be mentioned.

  The coated metal substrate of this embodiment can be produced by the method for producing a coated metal substrate of the fourth embodiment of the present invention described below.

≪Fourth aspect≫
Next, the manufacturing method of the covering metal base material of the 4th aspect of this invention is demonstrated.
In the method for producing a coated metal substrate according to this aspect, a coating film is formed by coating an aqueous paint containing the active energy ray-curable coating composition according to the second aspect of the present invention on at least a part of the surface of the metal substrate. Then, the coating film is formed by irradiating the coating film with active energy rays.

The method for producing a coated metal substrate usually includes one or more of the following steps.
(1) A process for removing dirt on the surface of a metal substrate and improving the wettability and adhesion of the coating composition, such as alkali degreasing, pickling, sand blasting, shot blasting, water washing, hot water washing, solvent washing, Known processes such as polishing, (2) Pretreatment processes for further improving the wettability and adhesion of the coating composition, such as chromate treatment, zinc phosphate treatment, iron phosphate treatment, other phosphate treatments, composites Known treatments such as oxide film treatment, substitution deposition treatment of Ni, Co, etc., and treatment steps combining these treatments, (3) step of applying or adhering the coating composition to the surface of the metal substrate, 4) a step of volatilizing the solvent in the coating composition on the surface of the metal substrate to form a coating film, (5) a heating step for promoting the curing reaction of the coating film, and (6) a curing reaction of the coating film. Irradiation of active energy rays to promote Extent, (7) the above-mentioned (4) and / or step to preheat the pre-metal substrate to facilitate the step (5) or the like.

In the active energy ray-curable coating composition of the second aspect of the present invention, since the curing reaction of the composition proceeds by active energy rays, for example, the step (3), the step (4), and (6) By performing the above process as an indispensable process and performing other processes in combination as appropriate, a coating film can be formed on the surface of the metal substrate.
The order of these steps is not particularly limited, and may be appropriately selected and determined in accordance with the purpose and the type of treatment chemical.
Moreover, these processes can be performed by a conventionally well-known method, for example, the application | coating process of (3) is based on well-known methods, such as a roll coater, a curtain coater, dip coating, spraying, brush coating, electrostatic coating etc., for example. be able to.
The solvent volatilization step (4) can be performed by a known method such as air drying, hot air heating, induction heating, irradiation with energy rays such as near infrared rays and far infrared rays, and ultrasonic vibration.
The step (5) can be performed by, for example, a method of heating the metal material used in the step (4).

  The step (6) is an active energy ray irradiation step, and the coating film of the active energy ray-curable coating composition is cured by irradiating active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. A cured coating film (coating film) is formed. Curing of the coating film is considered to be because a part or all of each component in the coating film reacts with other atoms or atomic groups to form bonds by irradiation with active energy rays. Examples of the reaction that occurs at this time include cross-linking between molecules of the aqueous polyurethane resin (B); the aqueous polyurethane resin (B) and the phosphoric ester compound (A), colloidal silica (C), alumina particles (D), and metal base material. Reaction with a phosphoric ester compound (A) and colloidal silica (C), alumina particles (D), a metal substrate, etc. are considered.

Examples of the active energy rays include ultraviolet rays, visible light, electron beams, X-rays, etc. Among them, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable because facility costs and running costs are relatively low.
Irradiation with active energy rays can be performed in an atmosphere containing oxygen such as air or in an inert gas atmosphere.
In particular, when the active energy ray is ultraviolet light, the wear resistance is further improved, and therefore, it is preferable to irradiate the coating film with ultraviolet light in an inert gas atmosphere. By irradiating ultraviolet rays in an inert gas atmosphere, radical consumption due to oxygen in the atmosphere is suppressed, and a crosslinking reaction of ethylenically unsaturated bonds can be promoted. As a result, the degree of crosslinking of the coating film is improved and the wear resistance is improved.
Examples of the inert gas include nitrogen gas, carbon dioxide gas, argon gas, and a gas containing at least one of these. The oxygen concentration in these inert gases is preferably 0 to 10%.

When the coating film is cured by irradiating with ultraviolet rays, the ultraviolet rays can be irradiated by using, for example, a mercury lamp or a xenon lamp as a light source.
When the coating is irradiated with an electron beam and cured, an electron beam irradiation device with an acceleration voltage of 20 to 2000 KeV, preferably 150 to 300 KeV is used, and a small amount of oxygen is contained in an inert gas atmosphere. Irradiation is preferably performed so that the irradiation dose is 5 to 200 kGy, preferably 10 to 100 kGy.

  The step (7) can be performed by the method for heating the metal substrate described in (4) and (5). What is necessary is just to select suitably about the specific conditions of each process.

Hereinafter, the present invention will be specifically described by way of examples. In the following, unless otherwise specified, parts represent parts by mass and% represents mass%. In the following text, viscosity represents Gardner viscosity. The Gardner viscosity is a value generally measured using a Gardner bubble viscometer used at the time of resin synthesis, and represents the viscosity by comparing the reference viscosity 菅 with the rate at which the bubbles rise. The Gardner viscosity is expressed in alphabets as U-V or the like, and the notation of U-V means an intermediate viscosity between the “reference viscosity tube U” and “V”.
First, synthesis examples 1 to 6 show synthesis examples of the water-based polyurethane resin (B), which will be specifically described.

Synthesis Example 1 [Synthesis of aqueous polyurethane resin a]
In a reactor equipped with a stirrer equipped with a reflux condenser, a nitrogen inlet tube and a thermometer, 234 parts of polyoxyethylene glycol (Mn = 1000), 102 parts of 2,2-bis (hydroxymethyl) propionic acid, castor oil LM-R (Toyoku Oil Co., Ltd.) 113 parts, hydrogenated MDI (dicyclohexylmethane-4,4′-diisocyanate) 390 parts, methyl ethyl ketone 839 parts, dibutyltin laurate 0.02 part was added and stirred to 70 ° C. The temperature was raised in 5 hours and reacted at 70 to 75 ° C. for 3 hours.
To this, 0.05 part of tert-butylhydroquinone, 161 parts of light ester G-201P (manufactured by Kyoeisha Chemical Co., Ltd.), and 384 parts of methyl ethyl ketone were added, and the nitrogen introduction tube was replaced with an air introduction tube, again at 70 to 75 ° C. Then, the reaction was carried out for 10 hours while adding 0.04 part of tert-butylhydroquinone every 4 hours to obtain a polyurethane resin solution.
To this solution, 70 parts of triethylamine and 2609 parts of pure water are gradually added. After maintaining at 30 ° C. for 2 hours, 0.5 part of Surfynol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.) is added and methyl ethyl ketone is added at 50 ° C. Was distilled off under reduced pressure to obtain a transparent liquid aqueous polyurethane resin a.
The aqueous polyurethane resin a has a solid content concentration of 29.3%, an acid value of 38.7 KOH mg / g, a viscosity of U-V, a triol content in the polyol component: 12 mol%, and a terminal ethylenically unsaturated double. The bond concentration was 1.4 equivalent / kg, the number average molecular weight (Mn) was 3000, and had active energy ray curability.

Synthesis Example 2 [Synthesis of aqueous polyurethane resin b]
In a reactor equipped with a stirrer equipped with a reflux condenser, a nitrogen inlet tube and a thermometer, 37 parts of polyoxyethylene glycol (Mn = 600), 69 parts of 2,2-bis (hydroxymethyl) propionic acid, 28 trimethylolpropane Parts, 315 parts of hydrogenated MDI (dicyclohexylmethane-4,4′-diisocyanate), 28 parts of hexamethylene diisocyanate, 498 parts of methyl ethyl ketone, 0.02 part of dibutyltin laurate and stirring to 70 ° C. in 0.5 hours The temperature was raised and reacted at 70 to 75 ° C. for 3 hours.
To this, 0.05 part of tert-butylhydroquinone, 741 parts of Aronix M-403 (manufactured by Toa Gosei Co., Ltd.) and 743 parts of methyl ethyl ketone were added, and the nitrogen introduction tube was replaced with an air introduction tube, and again at 70 to 75 ° C. Reaction was performed for 6 hours while adding 0.04 part of tert-butylhydroquinone every 4 hours to obtain a polyurethane resin solution.
After adding 52 parts of triethylamine to this solution, a solution consisting of 2922 parts of pure water and 21 parts of anhydrous piperazine was gradually added over 30 minutes, followed by stirring and mixing at 40 ° C. for 1 hour. To this, 0.5 part of Surfynol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.) was added, and methyl ethyl ketone was distilled off under reduced pressure at 50 ° C. to obtain an aqueous polyurethane resin b of milky white water dispersion.
The aqueous polyurethane resin b has a solid content concentration of 30.3%, an acid value of 29.1 KOH mg / g, a viscosity of 100 cp, a triol content in the polyol component: 36 mol%, and a terminal ethylenically unsaturated double bond. Concentration: 3.7 equivalent / kg, Mn: 2700, and had active energy ray curability.

Synthesis Example 3 [Synthesis of aqueous polyurethane resin c]
In a reactor equipped with a stirrer equipped with a reflux condenser, a nitrogen inlet tube and a thermometer, 249 parts of polyoxyethylene glycol (Mn = 1000), 109 parts of 2,2-bis (hydroxymethyl) propionic acid, castor oil LM-R (Toyoku Oil Co., Ltd.) 54 parts, hydrogenated MDI (dicyclohexylmethane-4,4′-diisocyanate) 416 parts, methyl ethyl ketone 828 parts, dibutyltin laurate 0.02 part was added and stirred to 70 ° C. with stirring. The temperature was raised in 5 hours, and the reaction was carried out at 70 to 75 ° C. for 3 hours.
To this, 0.05 part of tert-butylhydroquinone, 172 parts of light ester G-201P (manufactured by Kyoeisha Chemical Co., Ltd.) and 394 parts of methyl ethyl ketone were added, and the nitrogen introduction tube was changed to an air introduction tube, again at 70 to 75 ° C. Then, the reaction was carried out for 9 hours while adding 0.04 part of tert-butylhydroquinone every 4 hours to obtain a polyurethane resin solution.
To this solution, 74 parts of triethylamine and 2598 parts of pure water are gradually added. After maintaining at 30 ° C. for 2 hours, 0.5 part of Surfynol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.) is added and methyl ethyl ketone is added at 50 ° C. Was distilled off under reduced pressure to obtain a transparent liquid aqueous polyurethane resin c.
The aqueous polyurethane resin c has a solid content concentration of 30.1%, an acid value of 41.3 KOH mg / g, a viscosity of S, a triol content in the polyol component: 6 mol%, and a terminal ethylenically unsaturated double bond. Concentration: 1.4 equivalent / kg, Mn: 2000, and had active energy ray curability.

Synthesis Example 4 [Synthesis of aqueous polyurethane resin d]
In a reactor equipped with a stirrer equipped with a reflux condenser, a nitrogen inlet tube and a thermometer, 264 parts of polyoxyethylene glycol (Mn = 1000), 127 parts of 2,2-bis (hydroxymethyl) propionic acid, castor oil LM-R (Toyoku Oil Co., Ltd.) 127 parts, hydrogenated MDI (dicyclohexylmethane-4,4′-diisocyanate) 415 parts, methyl ethyl ketone 918 parts, dibutyltin laurate 0.02 part was added and stirred to 70 ° C. with stirring. The temperature was raised in 5 hours and reacted at 70 to 75 ° C. for 3 hours.
To this, 0.05 part of tert-butyl hydroquinone, 82 parts of hydroxyethyl acrylate and 303 parts of methyl ethyl ketone were added, and the nitrogen introduction tube was replaced with an air introduction tube, and again at 70 to 75 ° C. every 4 hours. The reaction was carried out for 10 hours while adding 0.04 part to obtain a polyurethane resin solution.
To this solution, 76 parts of triethylamine and 2591 parts of pure water are gradually added, held at 30 ° C. for 2 hours, 0.5 part of Surfynol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.) is added, and methyl ethyl ketone is added at 50 ° C. Was distilled off under reduced pressure to obtain a transparent liquid aqueous polyurethane resin d.
The aqueous polyurethane resin d has a solid content concentration of 29.7%, an acid value of 42.2 KOH mg / g, a viscosity of V, a triol content in the polyol component: 12 mol%, and a terminal ethylenically unsaturated double bond. Concentration: 0.7 equivalent / kg, Mn: 3000, and had active energy ray curability.

Synthesis Example 5 [Synthesis of aqueous polyurethane resin e]
In a 1 liter four-necked round bottom flask equipped with a nitrogen inlet tube, a condenser for cooling, a thermometer, and a stirrer, 65 parts of polytetramethylene ether glycol (PTMG) with a molecular weight of 1000, 17 parts of trimethylolpropane, 2,2-bis 54 parts of (hydroxymethyl) propionic acid, 632 parts of methyl ethyl ketone (MEK) as a solvent and 285 parts of hydrogenated MDI (dicyclohexylmethane-4,4 ′ diisocyanate) were charged, reacted at 70 to 75 ° C. for 2 hours, and then urethanized. As a catalyst, 0.13 part of stannous octylate was added and reacted for another 3 hours. After all the hydroxyl groups in the reaction solution have been replaced with NCO, the nitrogen inlet tube is replaced with an air inlet tube, and 276 parts of Aronics M-305 (manufactured by Toagosei Co., Ltd.), 413 parts of MEK, 0.28 parts of methoxyquinone and 0.28 part of tert-butyl hydroquinone was added. After heating again to 70-75 degreeC and making it react for 1 hour, stannous octoate 0.21 part was added and it was made to react for 8 hours, and the polyurethane resin solution was obtained. To this solution, 77 parts of trimethylolpropane triacrylate was added, and after further adding 41 parts of triethylamine and neutralizing, a solution consisting of 2211 parts of pure water and 17 parts of anhydrous piperazine was gradually added over 30 minutes, and then at 40 ° C. for 1 hour. Stir and mix. After adding 2 parts of Surfinol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.), methyl ethyl ketone was distilled off under reduced pressure at 50 ° C., nonvolatile content: 31.0%, solid content acid value 29 (KOHmg / g), An aqueous polyurethane resin (e) of an active energy ray-curable polyurethane resin having a viscosity of 19 cp, a triol content of 29 mol% in the polyol component, an unsaturated group concentration of 3.1 equivalent / kg, and a number average molecular weight of 4000 was obtained.

Synthesis Example 6 [Synthesis of aqueous polyurethane resin f]
An example of preparation of the diol compound 1 having a polyalkylene ether chain in a pendant form in order to introduce the polyalkylene ether into an aqueous urethane resin will be described.
Methoxypoly (oxyethylene / oxypropylene) -2-propyl previously heated to 50 ° C. and melted in a 1-liter four-necked round bottom flask equipped with a nitrogen inlet tube, a condenser for cooling, a thermometer, and a stirrer Amine (EO / PO = 9/1 molar ratio, molecular weight = 1000) and 500 g (0.5 mol) were added and stirred. Then, 72 g (0.5 mol) of 4-hydroxybutyl acrylate was added in about 30 minutes while maintaining the internal temperature at 45 to 50 ° C. Then, it stirred for 5 hours, keeping internal temperature at 30-40 degreeC. Next, 65.5 g (0.25 mol) of hydrogenated MDI was added over about 30 minutes while maintaining the internal temperature at 30 to 40 ° C. It stirred for 1 hour, keeping internal temperature at 30-40 degreeC after throwing in. An infrared spectrophotometer was used to confirm that there was no isocyanate group peak, and the sample was taken out. The obtained diol compound was almost colorless at 40 ° C. and solidified into a wax at room temperature. It was confirmed by high performance liquid chromatography (Tosoh 8020) that it had a single peak and was a high purity product. The measured value of the hydroxyl value is almost equal to 44.2 with respect to the calculated value of the hydroxyl value of 44.0, and it was confirmed that the hydroxyl group and the hydrogenated MDI did not react during the dimerization with the hydrogenated MDI. .
Next, a synthesis example of the aqueous urethane resin f is shown. A 1-liter four-necked round bottom flask equipped with a nitrogen inlet tube, a condenser for cooling, a thermometer and a stirrer is pendant with 81 parts of polytetramethylene ether glycol (PTMG) having a molecular weight of 1000 and the polyalkylene ether chain obtained above. 1, 31 parts of diol compound, 21 parts of trimethylolpropane, 38 parts of 2,2-bis (hydroxymethyl) propionic acid, 703 parts of methyl ethyl ketone (MEK) as a solvent, hydrogenated MDI (dicyclohexylmethane-4,4 ′ 298 parts of diisocyanate) were charged and reacted at 70 to 75 ° C. for 2 hours. Then, 0.14 part of stannous octylate was added as a urethanization catalyst and further reacted for 3 hours. After all the hydroxyl groups in the reaction solution have been replaced with NCO, the nitrogen inlet tube is replaced with an air inlet tube, 206 parts of Aronics M-305 (manufactured by Toagosei Co., Ltd.), 390 parts of MEK, 0.30 parts of methoxyquinone and 0.30 part of tert-butyl hydroquinone was added. The temperature was raised again to 70 to 75 ° C. and reacted for 1 hour, and then 0.22 part of stannous octylate was added and reacted for 8 hours to obtain a polyurethane resin solution. To this solution, 81 parts of dipentaerythritol hexaacrylate was added, and after further neutralizing by adding 28 parts of triethylamine, a solution consisting of 2211 parts of pure water and 28 parts of anhydrous piperazine was gradually added over 30 minutes, and then at 40 ° C. for 1 hour. Stir and mix. After adding 2 parts of Surfynol AK02 (manufactured by Nissin Chemical Industry Co., Ltd.), methyl ethyl ketone was distilled off under reduced pressure at 50 ° C., nonvolatile content: 31.5%, solid content acid value 19 (KOHmg / g), An aqueous polyurethane resin (f) of active energy ray-curable polyurethane resin having a viscosity of 19 cp, a triol content of 27 mol% in the polyol component, an unsaturated group concentration of 3.1 equivalent / kg, and a number average molecular weight of 6000 was obtained.

Formulation Examples 1-14
Using the aqueous polyurethane resins a to f obtained in Synthesis Examples 1 to 6, active energy ray-curable coating compositions were prepared according to Tables 1 and 2.

The numerical values in Tables 1 and 2 all represent parts by mass except for%.
The aqueous polyurethane resins a to f described in Tables 1 and 2 are the aqueous polyurethane resins a to f obtained in Synthesis Examples 1 to 6.
Moreover, each compounding component other than these is as follows, respectively.
-Kayamar PM21: manufactured by Nippon Kayaku Co., Ltd., a phosphate ester compound having a methacryloyloxy group [in the above general formula (1), R ¹ is a methyl group, s is 2, and m is 1 or 2 (average 1.5), a is 1 or 2 (average 1.5), b is 0, c is 1 or 2 (average 1.5), and a + c is 3 . ].
Irgacure 184: manufactured by Ciba Specialty Chemicals, 1-hydroxycyclohexyl phenyl ketone (photopolymerization initiator).
Snowtex C: Represents an aluminum-treated colloidal silica manufactured by Nissan Chemical Co., Ltd.
-NUC-silicon A-174: Toray Dow Corning Co., Ltd., represents γ-methacryloyloxypropyltrimethoxysilane (silane coupling agent).
-Aquacer 515: manufactured by Big Chemie Co., Ltd., represents a water-dispersed olefin wax.
FZ-3153: Toray Dow Corning Co., Ltd., represents a silicone emulsion.
-Al-1: The product made by Big Chemie Co., Ltd., NANOBOYK3600 (spherical alumina particles having a particle size of 40 nm).
-Al-2: Sumitomo Chemical Co., Ltd. product, Sumiko Random AA-03 (spherical alumina particles having a particle size of 0.3 μm) is represented.
-Al-3: Sumitomo Chemical Co., Ltd. product, Sumiko Random AA-07 (spherical alumina particles having a particle size of 0.7 μm) is represented.
-Al-4: Sumitomo Chemical Co., Ltd. make, Sumicorundum AA-2 (spherical alumina particle with a particle size of 2 micrometers) is represented.

Test Examples 1-35
Using the active energy ray-curable coating compositions prepared in Formulation Examples 1 to 14, coating films were formed on the metal substrates shown in Tables 3 to 5 by the method shown below.
In Tables 3-5, metal base material M-1 to M-9 shows the following, respectively. Moreover, the antirust oil film on the surface of each metal substrate was removed with methyl ethyl ketone (MEK) before forming the coating film.
M-1: electrogalvanized steel sheet not subjected to chromate treatment (plate thickness: 0.8 mm, plating thickness: about 2.8 μm, arithmetic average roughness: 1.5 μm) M-2: electrogalvanized steel sheet ( Plate thickness: 0.8 mm, plating thickness: about 6.0 μm, arithmetic average roughness: 3.8 μm) M-3: Ferritic stainless steel plate containing 18% by mass of Cr (plate thickness: 0.8 mm, arithmetic average) (Roughness: 1.2 μm) M-4: Hot-dip galvanized steel sheet not subjected to chromate treatment (plate thickness: 0.8 mm, plating thickness: about 7.0 μm, arithmetic average roughness: 1.3 μm) M- 5: Aluminum alloy plate containing 4.5% by mass of Mg (plate thickness: 0.8 mm, arithmetic average roughness: 1.4 μm) M-6: O containing 18% by mass of Cr and 8% by mass of Ni -Stainless steel plate (thickness: 0.8 mm, arithmetic average roughness: 1.0 μm) M-7: Martensitic stainless steel plate containing 13% by mass of Cr (plate thickness: 0.8 mm, arithmetic average roughness: 1.1 μm) M-8: Electrical Zn—Ni alloy plated steel plate (Plate thickness: 0.8 mm, plating thickness: about 2.8 μm, arithmetic average roughness: 1.8 μm) M-9: Molten Zn-11% Al-3% Mg-0.2% Si alloy-plated steel sheet ( (Plate thickness: 0.8 mm, plating thickness: about 6 μm, arithmetic average roughness: 2.5 μm)

[Method for producing coated metal substrate]
Adjust the active energy ray-curable coating composition so that the solid content concentration is 20%, and this. Using DDR (draw down rod) # 2 or # 5, the coating amount of the coating film shown in Tables 3 to 5 (about 1 g / m ² or 2 g / m ² ) on each metal substrate having a thickness of 0.8 mm. ) To form a coating film, and the coating film is dried at 80 ° C. for 20 minutes with a blow dryer, and 120 W high-pressure mercury lamp-conveyor speed of 10 m / min (irradiation) with a nitrogen gas purge UV irradiation device. A coated metal base material having a coating film formed on the surface of the metal base material was cured by curing at a quantity of 260 mJ / cm ² ).
At this time, nitrogen was used as the inert gas, and the oxygen concentration in the UV irradiation apparatus was adjusted to 5 to 10%.
The adhesion amount (g / m ² ) of the coating film and the thickness of the coating film are shown in Tables 3 to 5.

Ball-on-disk test, paper wear test, steel wool wear test, solvent resistance test (mechanical rubbing test), adhesion test (cross-cut cellophane adhesive test) Detachment test), workability test I (cross cut Eriksen workability test), and workability test II (vise bending test) were performed in the following procedure. The results are shown in Tables 3-5.
The ball-on-disk test, the paper abrasion test, and the steel wool abrasion test are wear resistance, the solvent resistance test is solvent resistance, the adhesion test is adhesion to a metal substrate, and the workability tests I and II are This is a test for evaluating molding processability.

[Ball-on-disk test]
A test piece of 100 × 100 mm was prepared, and a 10 mm diameter SUS440C stainless steel ball was pressed onto the test surface (coating film) with a mass of 1 kg using a friction and wear tester FR-2100 (manufactured by Resuka Co., Ltd.). Then, it was slid at 60 rpm on a circumference having a diameter of 70 mm, and the number of sliding circumferences until the coating film of the part subjected to the sliding was abraded 1/4 of the original film thickness was measured. Film thickness measurement relied on fluorescent X-ray analysis of silicon atoms in the coating.

[Paper abrasion evaluation test]
A test piece of 5 × 5 cm is prepared, and a high-quality paper described in JIS-P-0001 is wrapped around the outer periphery of a wear wheel (diameter 50 mm, width 12 mm) of Suga Abrasion Tester NUS-ISO 3 (Suga Test Instruments Co., Ltd.) The wear ring was pressed onto the test surface (coating film) with a mass of 500 g and slid back and forth with a stroke of 30 mm. At this time, the quality paper was replaced with a new one every time the wear wheel made one rotation, and was always slid with the new quality paper.
The determination was made by measuring the number of sliding times until the coating film of the part subjected to sliding wears down to 1/4 of the original film thickness. Film thickness measurement relied on fluorescent X-ray analysis of silicon atoms in the coating.

[Steel wool wear test]
A test piece of 5 × 13 cm is prepared, and steel wool (# 0000) is attached to the head of a rubbing tester: I type (manufactured by Taihei Rika Kogyo Co., Ltd.), and a specified number of times is applied with a load of 0.98 N / cm ^2. (5, 10, 20, 50, 100 times) Rubbing (sliding distance 50 mm, reciprocating speed 40 reciprocations / min), the number of rubbing until the metal substrate was exposed was visually determined.

[Solvent resistance test (mechanical rubbing test)]
A test piece of 5 × 13 cm was prepared and attached to a rubbing tester: type I head (manufactured by Taihei Rika Kogyo Co., Ltd.) so that 0.8 g of absorbent cotton was wrapped in gauze of 4.5 × 3.5 cm, and a solvent ( Ethanol or MEK) was included, rubbed for a specified number of times (10, 20, 50, 60 times) with a load of 300 g, and whether or not the ground was exposed was determined.
A: There is no exposed part and rubbing marks are not noticeable.
○: There is no exposed part, but there is a rubbing trace.
Δ: There is a portion reaching the ground to the extent of traces.
X: The coating film was peeled off and the base was exposed.
In Tables 3-5, ethanol resistance is a test using reagent primary ethanol as a solvent for the solvent resistance test, and MEK resistance is a test using reagent primary methyl ethyl ketone as a solvent for the solvent resistance test. is there.

[Adhesion test (cross cellophane adhesive tape test)]
A test piece of 100 × 100 mm was prepared, and 11 parallel lines penetrating the coating film were drawn at 1 mm intervals in the center of the test piece on the coating film side at intervals of 1 mm. 100 square grids were provided in cm. Next, a cellophane adhesive tape was pressure-bonded on the grid and peeled off rapidly, and the number X of grids remaining on the grid was determined.

[Processability Test I (Boiling-Crosscutter Ericksen Processability Test (JIS-Z-2247))]
Make a grid on the coating film in the same way as the grid pattern creation method above in the center of 3cm from the end of a 50x150mm test piece boiled for 3 hours in advance. Squeezed (extruded). In the same manner as described above, the grids were peeled off with a cellophane adhesive tape, and the number X of grids remaining on the grids was determined.

[Workability test II (vise bending test)]
Prepare a 50 x 150 mm test piece, prepare a T setting plate with the same thickness as the test piece with the coating film side facing out, and bend 180 degrees with 0 to multiple T setting plates in between Squeezed and bent with a vise. The number of sandwiched sheets is 0T, 1T is 1T, 2T is 2T, and 3T is 3T. It was reported that the bent part was peeled off with a cellophane adhesive tape in the same manner as described above and did not peel off.

Tables 3 to 5 show the test results. Formulation Example 1-1, 1-2, 1-3, 1-5, Formulation Example 2, 3, 4, 11 or Formulation Example 13-1 having the same composition except that the blending amount of the alumina particles (D) is different. , 13-2, 13-3, Test Example 1-1, 1-2, 1-3, 1-5, Test Example 2, 3, 4, 13, or Test Example 23, 24, 25 and 27 were compared.
(1) Test Examples 1-1 and 1-2, Test Examples 2 and 3, and Test Examples 23 and 24 in which the blending amount of the alumina particles (D) is within the range of 1 to 20% by mass of the total solid content The test results were also good. Particularly, the wear resistance was very good in the ball-on-disk test, the paper wear test, and the steel wool wear test.
(2) On the other hand, Test Example 1-3, Test Example 4, and Test Example 25 using a coating composition containing 30% by mass of alumina particles (D) had low wear resistance and workability. Moreover, the abrasion resistance was low in Test Example 1-5, Test Example 13, and Test Example 27 using the coating composition in which the alumina particles (D) were not blended.

Comparing Test Example 6 and Test Example 7, both the ball-on-disk test, the paper wear resistance evaluation test, and the steel wool wear test were tested regardless of whether the same coating composition of Formulation Example 6 was used. Example 7 was markedly better. This uses alumina particles (D) having an average particle diameter d of 0.7 μm. In Test Example 6, a coating layer having a film thickness t of 1 μm is formed, and in Test Example 7, the film thickness t is 2 μm. A coating layer is formed, and it is considered that Test Example 7 satisfies d ≦ (2t / 3).
Similarly, when Test Example 7 and Test Example 8 are compared, a coating film having the same film thickness is formed, but alumina particles (D) having an average particle diameter d of 2 μm are used, and d ≦ (2t / 3 Test Example 8 that does not satisfy () has lower wear resistance.

    In Test Example 12 using the coating composition of Formulation Example 10 in which the phosphoric acid ester compound (A) was not blended, all the test results of wear resistance, solvent resistance, adhesion, and workability were very bad.

Comparing Test Examples 1-1, 2, 10, and 11 using the coating compositions of Formulation Examples 1-1, 2, 8, and 9 having the same composition except for the type of the aqueous polyurethane resin (B), Test Example 1-1 using aqueous polyurethane resins a and b having 10 to 40 mol% of triol or higher components and 1.0 to 6.0 equivalents / kg of terminal ethylenically unsaturated double bonds No. 2 was good in any test results, and in particular, the wear resistance was very good in the ball-on-disk test, paper wear evaluation test, and steel wool wear test.
On the other hand, Test Examples 10 and 11 had slightly low wear resistance and solvent resistance.

    A comparison between Test Example 2 and Test Example 9 shows that test example 2 was cured by UV irradiation (UV curing) in a nitrogen gas atmosphere even though the coating composition of the same formulation example 2 was used. However, the results of the ball-on-disk test were good and the wear resistance was excellent.

    Comparing Test Examples 3, 14-21, 23, 28-35 using the coating compositions of Formulation Examples 3 and 13-1 and M-1 to M-9 as metal substrates, respectively, 3.0 μm or less Test Examples 3, 15 to 21, and 29 to 35 using a metal base material having an arithmetic average roughness of 5 are good in any test results. Particularly, the wear resistance is a ball-on-disk test, a paper wear evaluation. Both the test and the steel wool wear test were very good results. However, Test Examples 14 and 28 using M-2 having a surface roughness of 3.8 μm were slightly inferior in wear resistance.

Moreover, Test Examples 15 and 18 to 21 using the coating composition of Formulation Example 3 and using M-3, M-6, M-7, M-8, and M-9, each having a hard metal substrate surface, Compared to Test Example 3 using M-1 whose metal substrate surface was softer than those, the results were good in abrasion resistance. Test Examples 29 and 32-35 using the coating composition of Formulation Example 13-1 and using M-3, M-6, M-7, M-8, and M-9, each having a hard metal substrate surface, Compared with Test Example 23 using M-1 whose metal substrate surface was softer than those, a difference due to the hardness of the metal substrate surface could not be confirmed. It is considered that Formulation Example 13-1 includes the UV-reactive oligomer in the aqueous polyurethane resin, and the coating film thereby becomes harder than the coating film according to Formulation Example 3.
Comparing Test Examples 3 and 23 using the coating compositions of Formulation Examples 3 and 13-1 and M-1 as a metal substrate, respectively, an aqueous polyurethane resin f containing a UV-reactive oligomer in an aqueous polyurethane resin f The test result of Test Example 23 using was better.

The coated metal substrate of the present invention has a coating film that is excellent in various properties such as adhesion to the metal substrate surface, molding processability, and solvent resistance, and particularly excellent in wear resistance.
In the coated metal substrate of the present invention, the coating film on the surface is, for example, from various viewpoints such as fingerprint mark adhesion prevention use, lubricating steel plate use, primer use, and coating use that does not require top coating. It can be provided on the surface of the metal substrate for various purposes such as surface protection. Therefore, the coated metal substrate of the present invention can be used for various applications.
The active energy ray-curable coating composition of the present invention is suitable for the production of the coated metal substrate of the present invention, and has various adhesive properties such as adhesion to the metal substrate surface, moldability, and solvent resistance. It is possible to form a coating film having excellent characteristics and particularly excellent wear resistance. For this reason, it can be used for both 2-coat and 1-coat coatings. In particular, since one-coat coating is possible, there is no need to use organic solvents or chromate treatment during work, etc., safety and work environment. Is good.
Therefore, the active energy ray-curable coating composition of the present invention is useful for applications such as paints, coating agents, inks, primer coatings, anchor agents, etc., as water-based paints that have high safety and can improve the working environment. be able to.
The method for producing a coated metal substrate of the present invention using the active energy ray-curable coating composition of the present invention can be suitably used for producing the coated metal substrate of the present invention.

Claims (30)

A coated metal substrate in which at least a part of the surface of the metal substrate is coated with a coating film, wherein the coating film is
The phosphoric acid ester compound (A) represented by the following general formula (1) or (2), and the phosphoric acid ester compound (A ^* ) formed by bonding the phosphoric acid ester compound (A) with another atom or atomic group. At least one selected from the group;
A polyurethane resin (B ^* ) having a salt-forming group and a terminal ethylenic double bond group, and a polyurethane resin derivative (B ^* ) formed by bonding the polyurethane resin (B ^* ) to another atom or atomic group ^* ) At least one selected from the group consisting of:
Silica particles (C ^* ),
A coated metal substrate comprising alumina particles (D).

(In the formula, R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, s represents an integer of 2 to 12, and m represents an integer of 0 to 5) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, t represents an integer of 2 to 4, and n represents an integer of 1 to 10) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
) The phosphate ester derivative (A ^* ) is formed by bonding a part or all of the reactive active site of the phosphate ester compound (A) with another atom or atomic group, and the phosphate ester compound (A The coated metal substrate according to claim 1, wherein the reactive active site of () includes at least a terminal ethylenically unsaturated double bond group and a bond group derived from a phosphate group. The polyurethane resin derivative (B ^** ) is formed by bonding a part or all of the reactive active sites of the polyurethane resin (B ^* ) to another atom or atomic group, and the polyurethane resin (B The coated metal substrate according to claim 1 or 2, wherein the reactive active site of ^* ) includes at least a group capable of forming the salt and the terminal ethylenic double bond. The group capable of forming a salt of the polyurethane resin (B ^* ) and / or the polyurethane resin derivative (B ^** ) is at least one selected from the group consisting of a carboxy group, a phosphoric acid group, and a sulfonic acid group, The coated metal substrate according to any one of claims 1 to 3, wherein in the polyurethane resin derivative (B ^** ), part or all of the group capable of forming the salt is bonded to a metal atom. A group capable of forming a salt of the polyurethane resin (B ^* ) and / or the polyurethane resin derivative (B ^** ) is a tertiary amino group, and in the polyurethane resin derivative (B ^** ), the salt is formed. The part or all of the possible groups are bonded to other atoms or atomic groups bonded to metal atoms and / or to other atoms or atomic groups bonded to metal oxides. Coated metal substrate. The polyurethane resin (B ^* ) and / or the polyurethane resin derivative (B ^** ) is a polyurethane resin having 10 to 40 mol% of a triol or higher component in a polyol component. Coated metal substrate. A part or all of the polyisocyanate component of the polyurethane resin (B ^* ) and / or the polyurethane resin derivative (B ^** ) is dicyclohexylmethane-4,4'-diisocyanate. The coated metal substrate as described.   The coated metal substrate according to any one of claims 1 to 7, wherein the alumina particles (D) are spherical.   The content of the said alumina particle (D) is 1-20 mass% with respect to the total solid of the said coating film, The coated metal base material in any one of Claims 1-8. The coated metal substrate according to any one of claims 1 to 9, wherein the silica particles (C ^* ) are surface-treated with an aluminum compound.   The average particle diameter (d) of the alumina particles (D) and the thickness (t) of the coating film satisfy a relationship of d ≦ (2t / 3). Coated metal substrate. The coated metal substrate according to claim 1, wherein the coating film has an adhesion amount of 0.2 to 5.0 g / m ² .   The coated metal substrate according to claim 12, wherein the surface of the metal substrate has an arithmetic average roughness of 3.0 μm or less at least at a coating portion coated with the coating film.   In the ball-on-disk test of the coating film (a stainless steel ball made of SUS440C having a diameter of 10 mm is pressed onto the test surface with a mass of 1 kg and slid on a circumference of 70 mm in diameter at 60 rpm), The coated metal substrate according to claim 12 or 13, wherein the coating film has a sliding circumference of 500 times or more until it wears down to 1/4 of the original film thickness, or the total sliding distance is 100 m or more. Wood.   Paper wear resistance evaluation test of the coating film (A 50 mm diameter, 12 mm wide wear ring with a high quality paper affixed to the outer periphery described in JIS-P-0001 was pressed onto the test surface with a mass of 500 g, and reciprocated with a stroke of 30 mm. 15. The coated metal according to any one of claims 12 to 14, wherein the coating film of the portion subjected to sliding is 3,000 reciprocations or more until the coating film is worn by 1/4 of the original film thickness. Base material. Steel abrasion test of the coating film (5 × 13 cm test piece was prepared, steel wool (# 0000) was pressed onto the test surface with a load of 0.98 N / cm ² , a stroke of 50 mm, a reciprocating speed of 40 In the reciprocating sliding at a reciprocating / minute), the coating film of the portion subjected to the sliding has a sliding frequency of 20 reciprocations or more until the metal base material is exposed. Coated metal substrate.       The metal substrate is composed of any one of ordinary steel, additive element-containing steel, alloy steel, aluminum, additive element-containing aluminum, aluminum-based alloy, titanium, additive element-containing titanium, and titanium-based alloy. The coated metal substrate according to any one of claims 1 to 16, which is (M1) or a plated metal substrate (M2) in which at least a part of the surface of the metal substrate (M1) is coated with plating.       The plating is made of any one metal element of zinc, aluminum, cobalt, tin and nickel, or at least two of the metal elements, or at least one of the metal elements, and other than the metal elements The coated metal substrate according to claim 17, which is an alloy plating containing a metal element and / or a non-metal element.       The coated metal substrate according to any one of claims 1 to 18, wherein the metal substrate is a metal substrate that has not been subjected to chromate treatment.       The said metal base material is a board | plate material, a strip | belt material, a bar material, a shape material, a pipe material, or a wire, The coated metal base material in any one of Claims 1-19. The phosphoric ester compound (A) represented by the following general formula (1) or (2), an aqueous polyurethane resin (B) having a group capable of forming a salt and a terminal ethylenic double bond group, and colloidal silica (C) And an active energy ray-curable coating composition comprising alumina particles (D).

(In the formula, R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, s represents an integer of 2 to 12, and m represents an integer of 0 to 5) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, t represents an integer of 2 to 4, and n represents an integer of 1 to 10) A represents an integer of 1 to 3, b represents an integer of 0 to 2, c represents an integer of 0 to 2, and a + b + c = 3.
)       The water-based polyurethane resin (B) has 10 to 40 mol% of a triol or higher component in the polyol component, and 1.0 to 6.0 equivalents / kg of a terminal ethylenically unsaturated double bond group. The active energy ray-curable coating composition according to claim 21, which is 1000 or more water-based polyurethane resin.   The active energy ray curable type according to claim 21 or 22, wherein the aqueous polyurethane resin (B) is an aqueous polyurethane resin having a number average molecular weight of 1000 or more including an oligomer containing 3 or more terminal ethylenically unsaturated double bond groups. Paint composition.       The active energy ray-curable coating composition according to claim 21, wherein a part or all of the polyisocyanate component of the aqueous polyurethane resin (B) is dicyclohexylmethane-4,4′-diisocyanate.       The active energy ray-curable coating composition according to any one of claims 21 to 24, wherein the alumina particles (D) are spherical.       26. The active energy ray-curable type according to any one of claims 21 to 25, wherein the content of the alumina particles (D) is 1 to 20% by mass with respect to the total solid content of the active energy ray-curable coating composition. Paint composition.       27. The active energy ray-curable coating composition according to claim 21, wherein the colloidal silica (C) is surface-treated with an aluminum compound.       A coating comprising a coating film obtained by curing the active energy ray-curable coating composition according to any one of claims 21 to 27 with an active energy ray on at least a part of a surface of a metal substrate. Metal substrate.       An aqueous coating material containing the active energy ray-curable coating composition according to any one of claims 21 to 27 is applied to at least a part of a metal substrate surface to form a coating film, and then the active energy beam is applied to the coating film. A method for producing a coated metal substrate, wherein a coating film is formed by irradiation with       30. The method for producing a coated metal substrate according to claim 29, wherein the active energy ray is an ultraviolet ray, and the coating film is irradiated with the ultraviolet ray in an inert gas atmosphere.