JPH06126888A - Colored polyurethane-coated steel material - Google Patents

Abstract

PURPOSE:To provide a colored polyurethane-coated steel material which has excellent corrosion prevention in the coating, is harmonized with an environment with various colors and prevents fading and chalking. CONSTITUTION:A colored polyurethane-coated steel material is obtained by ground-treating a surface necessary for beauty of the material 1 and sequentially laminating an urethane primer layer 2, a black polyurethane layer 3 containing carbon black, and a colored polyurethane layer 4 containing coloring pigment made of oxide of one or more elements selected from Co, Al, Cr, Fe, Ti, Zn, Mn Sb, Ni, Mg or single or mixture of composite oxide, light stabilizer with a hindered amine base, and an isocyanate curable fluororesin primer layer 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to steel structure members such as steel sheet piles, H-section steels, section steels for connecting walls, steel pipe piles, square steel pipe piles, steel pipe sheet piles and steel plates used in the ocean, rivers and harbors. The present invention relates to a polyurethane-coated steel material, and more particularly to a colored polyurethane-coated steel material which is colored in various colors and has excellent weather resistance that simultaneously prevents fading due to light, especially ultraviolet rays.

[0002]

2. Description of the Related Art As a conventional polyurethane-coated steel material, a black polyurethane coating prepared by adding a black pigment such as carbon black having excellent weather resistance to the polyurethane proposed in JP-A-57-21463 is used.

However, due to the recent increasing market needs for the aesthetic appearance of steel structures in cityscapes, rivers and harbors, the development of polyurethane-coated steel materials that are colored in various colors, are in harmony with the environment, and have excellent corrosion resistance. Is desired.

To meet such needs, as a method of adding various color pigments to the conventional polyurethane, Japanese Patent Application No.
There is one disclosed in Japanese Patent Publication No. 99802.

[0005]

However, in a steel material coated with such a conventional colored polyurethane, the colored polyurethane coating discolors and fades when exposed to ultraviolet rays for a long period of time, and the aesthetic appearance is impaired.

[0006] In order to prevent the fading of the surface, it has been proposed to add various hindered amine-based weathering agents, but if these weathering additives are simply added, for example, in an outdoor exposure test for about 5 years, the surface of It is not possible to prevent film thickness reduction due to fading and chalking. As described above, it has been difficult to prevent fading of the surface with the conventional technology.

[0007]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a black polyurethane layer containing carbon black, Co, Al, Cr, Fe, Ti, Zn, Mn,
A colored polyurethane layer having a color pigment consisting of an oxide or a composite oxide of one or more elements selected from Sb, Ni, and Mg and a hindered amine light stabilizer, and an isocyanate-curable fluororesin primer. It has been found that the above problems can be solved by laminating layers, and the present invention has been completed.

That is, according to the present invention, for example, as shown in FIGS. 1 to 8, the surface of a steel material 1 such as a steel plate, a steel sheet pile, an H-section steel, a wall section steel, a steel pipe pile, a square steel pipe pile, and a steel pipe sheet pile is blasted. The scale is removed by a treatment, and the urethane primer layer 2 is coated and cured to apply a base treatment, and the black polyurethane layer 3 to which carbon black is added is coated and cured, and then Co, Al, Cr, Fe, Ti. , Zn, Mn, Sb, N
i, a colored polyurethane layer 4 containing a hindered amine light stabilizer and a coloring pigment consisting of a single or a mixture of oxides or complex oxides of one or more elements selected from Mg and Mg, and its surface. It is a colored polyurethane-coated steel material, characterized in that an isocyanate-curable fluororesin primer layer 5 is applied to the above, cured and laminated. Hereinafter, the present invention will be described in detail.

The steel materials used in the present invention are steel sheets made of alloy steel such as carbon steel and stainless steel, steel sheet piles, H-section steels, section steels for connecting walls, steel pipe piles, square steel pipe piles and steel pipe sheet piles.

Further, for the purpose of improving the corrosion resistance of the steel material, the surface is plated with zinc, aluminum, chromium or the like, zinc-
It is also possible to use an alloy plating of aluminum, zinc-nickel or the like, or a plating obtained by subjecting the plating or alloy plating to dispersion plating in which inorganic fine particles such as silica or titanium oxide are dispersed.

When the colored polyurethane-coated steel material of the present invention is manufactured, the surface treatment of the steel material is performed by blasting the surface of the steel material with grit blast, sand blast or the like to remove rust, and then the urethane primer layer 2 is applied and cured. And apply the base treatment.

As the urethane primer, for example, a mixture obtained by adding an inorganic pigment to an isocyanate-terminated urethane prepolymer obtained by reacting a polyol with a polyisocyanate compound can be used.

In this case, polyether polyol or polyolefin polyol is used as the polyol.

As the polyether polyol, propylene glycol, butanediol, neopentyl glycol, hexanediol, glycerin, trimethylolpropane and the like are added with alkylene oxide such as propylene oxide, ethylene oxide or butylene oxide in the presence of an alkali catalyst and the like. A polyalkylene polyol having 2-3 active hydrogen groups (hydroxyl groups) in the molecule obtained by weighting is used.

Examples of these polyalkylene polyols include commercially available hydroxyl values of 50 to 150 mg-K.
OH / g of polypropylene glycol or the like can be used.

The polyolefin polyol has 2-3 active hydrogen groups (hydroxyl groups) in the molecule obtained by addition-polymerizing an alkylene oxide such as ethylene oxide or propylene oxide to a diene compound such as butadiene or isoprene. Polydiene polyol is used.

These polydiene polyols include
For example, a commercially available hydroxyl value is 50 to 150 mg-KOH
Polybutadiene polyol of about / g can be used.

As the polyisocyanate, a polyisocyanate compound containing two or more isocyanate groups in the molecule, such as crude diphenylmethane diisocyanate (crude MDI) and tolylene diisocyanate (TDI), is used.

The above-mentioned polyol and polyisocyanate are subjected to an addition reaction to form an isocyanate-terminated urethane prepolymer. At this time, the ratio of the isocyanate group (-NCO) of the polyisocyanate to the hydroxyl group (OH) of the polyol, that is, NCO / OH is weighted. The reaction is carried out so that the ratio is within the range of 1.6 to 3.

When the NCO / OH weight ratio is 1.6 or more than 3 and exceeds 3, the black polyurethane layer is peeled off when a dipping test or the like is carried out, and the water-resistant adhesion is deteriorated. For the urethane primer, an inorganic pigment is added to the above isocyanate-terminated urethane prepolymer.

As the inorganic pigment, use is made of silicon oxide obtained by crushing minerals such as clay and perlite, aluminum silicate obtained by crushing kaolin, kaolin clay, montmorillonite, talc, alumina, calcium carbonate and the like.

These inorganic pigments are contained in an amount of 20 to 20 with respect to 100 parts by weight of the isocyanate-terminated urethane prepolymer.
Add in the range of 0 parts by weight. If the addition amount is less than 20 parts by weight or more than 200 parts by weight, the water-resistant adhesiveness becomes poor.

As the black polyurethane layer 3, for example, polyurethane composed of polyolefin polyol, aromatic amine polyol, polyisocyanate and inorganic pigment can be used, and carbon black is added to this polyurethane before use.

In this case, as the polyolefin polyol, 2-3 active hydrogen groups (hydroxyl groups) are obtained in the molecule obtained by addition-polymerizing an alkylene oxide such as ethylene oxide or propylene oxide to a diene compound such as butadiene or isoprene. A polydiene polyol having is used.

Examples of the polydiene polyol include Poly bdR-45HT and Pol manufactured by Idemitsu Petrochemical Co., Ltd.
y bd R-45, Poly bd CS-15, Nisso PBG-2000, Nisso PBG-30 manufactured by Nippon Soda Co., Ltd.
A commercially available liquid polybutadiene polyol such as 00 can be used.

As the aromatic amine polyol, bis (2-
Hydroxypropyl) aniline, methylenebis (-O-
An aromatic amine polyol obtained by adding an alkylene oxide such as propylene oxide to an aniline compound such as chloroaniline (MOCA) is used.

Examples of these aromatic amine polyols include poly hardener PA40 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
0, Polyhardener PA300, etc. can be used.

The amount of these aromatic amine polyols is 30 per 100 parts by weight of the above-mentioned polyolefin polyol.
To 100 parts by weight.

The amount of the aromatic amine polyol added to the polyolefin polyol is less than 30 parts by weight and 10 or less.
If the amount exceeds 0 parts by weight, discoloration of the upper colored polyurethane layer 4 cannot be prevented.

As the polyisocyanate, 2 in the molecule
An isocyanate compound such as crude diphenylmethane diisocyanate (crude MDI) or tolylene diisocyanate (TDI) containing one or more isocyanate groups is used.

These polyisocyanates have a ratio of isocyanate groups (—NCO) of polyisocyanate to hydroxyl groups (OH) of the above-mentioned mixture of polyolefin polyol and aromatic polyol, that is, NCO / OH in a weight ratio of 0.85 to 1. Used in the range of 5.

When the NCO / OH ratio is less than 0.85 and exceeds 1.5, it is impossible to prevent fading of the upper colored polyurethane layer 4.

As the inorganic pigment, powders of crushed minerals such as clay and perlite such as silicon oxide, kaolin, kaolin clay, montmorillonite and the like, such as aluminum silicate, talc, alumina and calcium carbonate, may be used alone or in combination.

The mixing ratio of these inorganic pigments may be arbitrary, but the total amount of the inorganic pigments is in the range of 5 to 200 parts by weight with respect to 100 parts by weight of the polyolefin polyol.

If the blending amount of the inorganic pigment is less than 5 parts by weight or more than 200 parts by weight, fading of the upper colored polyurethane layer 4 cannot be prevented.

To the black polyurethane 3, in particular, 1 to 30 parts by weight of carbon black is added to the above-mentioned polyolefin polyol in order to prevent fading of the upper colored polyurethane layer 4 due to ultraviolet rays.

If the amount of the carbon black added is less than 1 part by weight or more than 30 parts by weight, the discoloration of the upper colored polyurethane layer 4 cannot be prevented.

The colored polyurethane layer 4 is made of acrylic polyol, aliphatic isocyanate terminated urethane prepolymer and Co, Al, Cr, Fe, Ti, Zn, Mn, Sb, N.
i, a coloring pigment composed of an oxide or complex oxide of one or more elements selected from Mg, or a mixture thereof, and a hindered amine light stabilizer.

As the acrylic polyol, a methacrylate monomer such as methyl methacrylate or ethyl methacrylate or an acrylic ester such as methyl acrylate or ethyl acrylate, and a hydroxyl group such as hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate or hydroxypropyl acrylate are contained. A copolymer obtained by copolymerizing with an ethylenically unsaturated monomer by a known method is used.

As these acrylic polyols, for example, commercially available acrylic polyols such as Takelac UA-702, Takelac UA-902, and Takelac UA-905 manufactured by Takeda Pharmaceutical Co., Ltd. can be used.

As the aliphatic isocyanate terminated urethane prepolymer, a compound obtained by addition reaction of polyether polyol and aliphatic isocyanate is used.

As the polyether polyol, propylene oxide, butanediol, neopentyl glycol, hexanediol, glycerin, trimethylolpropane, etc. are added to an alkylene oxide such as propylene oxide, ethylene oxide or butylene oxide in the presence of an alkali catalyst. A polyalkylene polyol having 2 to 3 active hydrogen groups (hydroxyl groups) in the molecule obtained by polymerization is used, and hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), or xylylene diisocyanate (XDI) is used. An aliphatic isocyanate-terminated urethane prepolymer obtained by addition reaction of an aliphatic isocyanate such as

Examples of these aliphatic isocyanate terminated urethane prepolymers include Takenate D-160N manufactured by Takeda Pharmaceutical Co., Ltd. in which hexamethylene diisocyanate is added to alkylene polyol, and Takenate D manufactured by Takeda Pharmaceutical Co., Ltd. in which isophorone diisocyanate is added.
-140, Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd. to which xylylene diisocyanate is added, etc. can be used.

The acrylic polyol and the aliphatic isocyanate terminated urethane prepolymer are the NCO / OH of the mixture.
Mix so that the ratio is in the range of 0.5-2.

In order to prevent discoloration due to ultraviolet rays, these mixtures contain Co, Al, Cr, Fe, Ti,
A coloring pigment composed of an oxide or a complex oxide of one or more elements selected from Zn, Mn, Sb, Ni, and Mg alone or as a mixture is added.

Co, Al, Cr, Fe, Ti, Zn, M
Coloring pigments composed of oxides or complex oxides of one or more elements selected from n, Sb, Ni, and Mg alone or in a mixture include, for example, a single oxide of Ti (titanium oxide / white), Shepherd Color. Company
Oxide Co manufactured by Co. Ltd. (CONCORD BLUE #
92 / purple), a single oxide of Mn (MANGANO V
IORET # 11 / purple), Co-Al composite oxide (ARCTIC BLUE # 3 / blue, ENSIGN
BLUE # 214 / blue), CO-Cr-Al composite oxide (TOPAZBLUE # 9 / blue, OLYMPIC
BLUE # 190 / blue, KINGFISHER B
LUE # 211 / blue), Fe-Ti composite oxide (R
USSET BROWN # 8 / Brown, Fe-Al-Ti
Complex oxide (GOLDEN BLOWN # 19 / brown), Fe-Zn-Ti complex oxide (AUTUMN
BROWN # 156 / Brown), Fe-Cr-Zn-Ti
Complex oxide (WALNUTBROWN # 10 / brown,
COCOA BROWN # 157 / Brown), Fe-Cr
-Mn-Ti composite oxide (CHOCOLATE BR
OWN # 20 / brown), Mn-Cr-Sb-Ti complex oxide (IRONSTONE BROWN # 39 / brown), Cr-Ni-Cu-Sb-Ti complex oxide (B
UCKSKINBROWN # 47 / brown), Mn-Sb
-Ti composite oxide (URBAN BROWN # 153
/ Brown, INDIAN BROWN # 221 / brown),
Ni-Sb-Ti composite oxide (SUNFLOWER
YELLOW # 14 / Yellow, MAPLE YELLOW
# 25 / Yellow, PRIMROSE YELLOW # 19
5 / Yellow), Cr-Sb-Ti composite oxide (HONE
Y YELLOW # 29 / orange, HONEY G
OLD YELLOW # 193 / orange), Ni-
Sb-Ti composite oxide (COLONIAL YELL
OW # 182 / Orange, MARIGOLD YEL
LOW # 196 / orange), Ni-Co-Zn-T
i complex oxide (SHAMLOCK GREEN # 22
3 / Green), Co-Zn-Ti-Cr composite oxide (C
AMOFLAGE GREEN # 179 / green), Ni
-Co-Zn-Sb-Ti composite oxide (JADE G
REEN # 4 / green, SHERWOOD GREEN #
5 / green), Co-Cr-Mg-Al-Zn composite oxide (TEAL GREEN # 201 / green), etc., alone or in the form of a mixture of powders of these single-color calcined pigments. .

The type and proportion of the powder to be mixed can be arbitrarily determined from the viewpoint of aesthetics, but in order to prevent the fading of the coating, the powder of the monochromatic calcined pigment or the mixture of the powders of the monochromatic calcined pigment is used as described above. 1 to 30 parts by weight relative to 100 parts by weight of the acrylic polyol.

If the amount added is less than 1 part by weight or more than 30 parts by weight, fading of the coating after the exposure test cannot be prevented.

When an organic pigment is used, the coated surface is discolored in a long-term outdoor exposure test.

Further, in the colored polyurethane layer, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 8-benzyl-7,
7,9,9-Tetramethyl-3-octyl 1,3,8-
A hindered amine light stabilizer such as triazaspiro [4,5] undecane-2,4-dione is added.

As bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, Sanol LS-292 and Sanol LS-765 manufactured by Sankyosha Co., Ltd. are bis (2,2,6,6-tetradecane). As methyl-4-piperidyl) sebacate, Sanol LS-770 manufactured by Sankyo Co.,
As 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, Sankyo LS manufactured by Sankyosha Co., Ltd.
1114 etc. can be used.

These hindered amine light stabilizers are
0.5 based on 100 parts by weight of the acrylic polyol
It is added in the range of 10 to 10 parts by weight.

If the amount of the hindered amine light stabilizer added is less than 0.5 parts by weight or more than 10 parts by weight, fading of the colored polyurethane layer 4 after the exposure test cannot be prevented.

The isocyanate-curable fluororesin primer used in the present invention is a mixture obtained by adding an ultraviolet absorber to a liquid fluororesin, and further mixing an aliphatic isocyanate terminated urethane prepolymer with a solvent.

A mixture of a liquid fluororesin and an ultraviolet absorber is, for example, Lumiflon LF manufactured by Asahi Glass Co., Ltd.
A general commercially available liquid fluororesin varnish such as 100 and Lumiflon LF200 is used.

As the aliphatic isocyanate-terminated urethane prepolymer, the same one used for forming the colored polyurethane layer 4 is used. For example, Takenate D-160N, Takenate D-140N, Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd. Etc. can be used.

Next, the method for producing the colored polyurethane-coated steel material of the present invention will be described by taking a steel sheet pile as an example.

The crests or troughs of the steel sheet pile are grit blasted, and the urethane primer 2 is spray-coated and cured.

Black polyurethane 3 is spray-painted on the surface to cure, and colored polyurethane 4 is further applied on the surface.
Spray paint and cure.

Then, an isocyanate-curable fluororesin primer is spray-coated on the surface of the sheet to produce the colored polyurethane-coated steel sheet pile of the present invention shown in FIG. 2 or 3.

As the method for applying the urethane primer 2, the black polyurethane 3, the colored polyurethane 4 and the isocyanate-curable fluororesin primer 5, conventionally known methods such as spray coating and ironing with a rubber ring or a rubber spatula can be used. .

The colored polyurethane-coated H-section steel of the present invention shown in FIG. 4 is obtained by sandblasting the entire surface of the H-section steel 1.
Urethane primer 2 is spray coated and cured.

Next, black polyurethane 3 is spray-coated on the surface and cured, and colored polyurethane 4 is spray-coated on the surface and cured.

Further, an isocyanate-curable fluororesin primer 5 is applied on the surface and cured to obtain the colored polyurethane-coated H-section steel of the present invention.

In the colored polyurethane-coated section steel for a wall of the present invention shown in FIG. 5, the entire surface of the section steel 1 for a wall is sandblasted, and a urethane primer 2 is spray-coated and cured.

Next, black polyurethane 3 is spray-coated on the surface and cured, and colored polyurethane 4 is spray-coated on the surface and cured.

Further, an isocyanate-curable fluororesin primer 5 is applied to the surface of the primer and cured to obtain the colored polyurethane-coated shaped steel for wall connection according to the present invention.

In the colored polyurethane-coated steel pipe pile of the present invention shown in FIG. 6, the outer surface of the steel pipe 1 is grit blasted while the steel pipe 1 is rotated in a spiral manner, and the urethane primer 2 is spray-coated and cured.

Next, black polyurethane 3 is spray-coated on the surface and cured, and colored polyurethane 4 is spray-coated on the surface and cured.

Further, an isocyanate-curable fluororesin primer 5 is applied on the surface and cured to obtain a colored polyurethane-coated steel pipe pile according to the present invention.

In the colored polyurethane-coated square steel pipe pile according to the present invention shown in FIG. 7, the outer surface is grit blasted and the urethane primer 2 is spray-coated and cured while the square steel pipe 1 is transported and transported by the transport table.

Next, black polyurethane 3 is spray-coated on the surface and cured, and colored polyurethane 4 is spray-coated on the surface and cured.

Further, an isocyanate-curable fluororesin primer 5 is applied on the surface and cured to obtain a colored polyurethane-coated steel pipe pile according to the present invention.

In the colored polyurethane-coated steel pipe sheet pile according to the present invention shown in FIG. 8, the outer surface of the steel pipe sheet pile 1 is sandblasted, and the urethane primer 2 is spray-coated and cured.

Next, black polyurethane 3 is spray-coated on the surface and cured, and colored polyurethane 4 is spray-coated on the surface and cured.

Further, an isocyanate-curable fluororesin primer 5 is applied on the surface and cured to obtain the colored polyurethane steel pipe sheet pile according to the present invention.

The colored polyurethane coated steel material of the present invention is shown in FIG.
~ As shown in Fig. 8, the surface of the steel material 1 such as steel plate, steel sheet pile, H-section steel, section steel for connecting wall, steel pipe pile, square steel pipe pile, and steel pipe sheet pile is removed by blasting or the like to remove scale and the like, and urethane primer Layer 2 is coated and cured to give a base treatment, carbon black added black polyurethane layer 3 is coated and cured, then Co, Al, Cr, Fe, Ti, Z
A colored polyurethane layer 4 containing a color pigment consisting of an oxide or a complex oxide of one or more elements selected from n, Mn, Sb, Ni and Mg, alone or in a mixture, and a hindered amine light stabilizer is applied. It is a colored polyurethane-coated steel material which is characterized in that it is cured by curing and is further laminated with an isocyanate-curable fluororesin primer 5 in order.

The urethane primer layer 2 has a thickness of 20 to 15
0 μm thickness, black polyurethane layer 3 is 0.5 to 15 m
m, the colored polyurethane layer 4 has a thickness of 0.3 to 10 mm, and the isocyanate-curable fluororesin primer layer 5
Has a thickness of 30 to 900 μm, good results can be obtained.

The present invention will be described below based on examples.

[0080]

【Example】

[0081]

[Example 1]

[0082]

[Preparation Example of Urethane Primer 1 of the Present Invention] First, polypropylene glycol, crude MDI and a solvent were put in a glass flask and heated at 90 ° C. to react to obtain an isocyanate-terminated urethane prepolymer.

Preparation: Polypropylene glycol: 20
0 parts by weight (hydroxyl value: 150 mg-KOH / g, molecular weight: 700) Crude MDI (isocyanate group content: 31%): 14
5 parts by weight

Obtained isocyanate-terminated urethane prepolymer: NCO / OH (weight ratio): 2 Isocyanate group content: 6.3%

20% by weight of fine clay powder as an inorganic pigment and 20% by weight of solvent were added to the above-mentioned isocyanate-terminated urethane prepolymer to prepare the urethane primer 1 of the present invention.
Got

[0086]

[Formulation Example of Black Polyurethane Paint 1 of the Present Invention] The following components were mixed to obtain a black polyurethane paint 1 of the present invention.

Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co.,
Hydroxyl value: 46.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine clay powder): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0088]

[Preparation of Colored Polyurethane Coating Material 1 of the Present Invention] The following components were blended to prepare the colored polyurethane coating material of the present invention.

Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value:
50 mg-KOH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5 parts by weight (Sankyo LS-292 manufactured by Sankyosha) Solvent: 30% by weight NCO / OH (weight ratio) of the above coating material: 0.5

[0090]

[Preparation example of isocyanate-curable fluororesin primer 1 of the present invention] The following components were mixed to obtain an isocyanate-curable fluororesin primer 1 of the present invention.

Liquid fluororesin varnish: 100 parts by weight (Lumiflon LF100 manufactured by Asahi Glass Co., containing UV absorber) Aliphatic isocyanate terminated urethane prepolymer: 1
7 parts by weight (Takenate D-110 manufactured by Takeda Pharmaceutical Co., Ltd.
N) Curing acceleration catalyst (dibutyltin dilaurate): 0.00
5 parts by weight Solvent: 100 parts by weight

[0092]

Preparation Example of Conventional Comparative Colored Polyurethane Paint 1 The following components were blended to obtain a conventional colored polyurethane paint 1.

Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd.,
Hydroxyl value: 46.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Phthalocyanine blue (color tone: blue): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0094]

[Production Example of Coated Steel Sheet Pile] As shown in FIG.
(SPIII type × 5 m) mountain surface is subjected to grit blast treatment to remove rust, and the urethane primer of the present invention is spray-coated on the surface to a film thickness of 30 μm and cured to form a urethane primer layer 2. The base treatment was applied.

Next, the above-mentioned black polyurethane coating material of the present invention was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a black polyurethane layer 3.

Then, the colored polyurethane coating material of the present invention was spray coated on the surface so that the film thickness was 1 mm, and the colored polyurethane layer 4 was laminated.

Further, the above-mentioned isocyanate-curable fluororesin primer 1 of the present invention having a film thickness of 30 μm is formed on the surface thereof.
To form the isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet pile No. Got 1.

As a comparative example, a steel sheet pile (FSPIII type ×
5 m) mountain surface is subjected to grit blast treatment to remove rust, and the urethane primer of the present invention is applied to the surface to a film thickness of 30
A urethane primer layer was formed by spray coating and curing so as to have a thickness of μm, and a base treatment was performed.

Next, a conventional colored polyurethane coating material 1 was spray-coated on the surface so as to have a film thickness of 3 mm and cured, and a conventional colored polyurethane layer was laminated to form a colored polyurethane coated steel sheet pile No. I got 44.

These coated steel sheet piles were cut to a length of 1 m,
Table 1 shows the results of measuring the color difference on the surface of the colored polyurethane layer after the exposure test to the river for 7 years.

From the results shown in Table 1, the coated steel sheet pile in which the black polyurethane layer, the colored polyurethane layer and the isocyanate-curable fluororesin primer layer of the present invention were laminated was compared with the conventional coated steel sheet pile coated with the colored polyurethane layer. hand,
Almost no fading on the surface and almost no chalking, and excellent weather resistance.

[0102]

Example 2 The amount of the aromatic amine polyol compounded in the black polyurethane coating used for forming the black polyurethane layer was changed to 50 parts by weight and 100 parts by weight based on 100 parts by weight of polybutadiene polyol. Black polyurethane paints 2 and 3 were prepared.

As comparative examples, the following comparative black polyurethane paints 1 and 2 were prepared by changing the blending amount of the aromatic amine polyol to 29 parts by weight and 101 parts by weight.

[0104]

[Black polyurethane paint 2 of the present invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 50 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m)
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
52.6 parts by weight Inorganic pigment (fine clay powder): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0105]

[Black polyurethane paint 3 of the present invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 100 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420)
mg-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
95.8 parts by weight Inorganic pigment (fine clay powder): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0106]

[Comparative Black Polyurethane Paint 1] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 29 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
34.5 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0107]

[Comparative Black Polyurethane Paint 2] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 101 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420)
mg-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
96.5 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

Next, as shown in FIG. 3, steel sheet pile (FSP)
III type × 5 m length) 1 valley surface is sandblasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated to a film thickness of 50 μm and cured to form a urethane primer layer 2. It was formed and subjected to a base treatment.

Next, the above-mentioned black polyurethane coating material 2 or 3 of the present invention was spray-coated so as to have a film thickness of 2.5 mm and cured to laminate a black polyurethane layer 3.

Further, the colored polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 1.5 mm and cured to laminate a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 was applied to the surface to a thickness of 2
It is spray-coated so as to have a thickness of 0 μm and cured to laminate an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet pile No. 2 and 3 were produced.

As a comparative example, instead of the black polyurethane paint of the present invention, the above comparative black polyurethane paint 1 or 2 was applied to produce colored polyurethane coated steel sheet pile No. 45
And 46 were manufactured.

These coated steel sheet piles were cut into a length of 1 m,
Table 1 shows the results of measuring the color difference on the surface of the colored polyurethane layer after the exposure test to the river for 7 years.

From the results shown in Table 1, the colored polyurethane-coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1), the black polyurethane layer of the present invention contains an aromatic amine polyol and a polyolefin polyol 1.
Only when 30 to 100 parts by weight with respect to 00 parts by weight is blended, there is no fading on the surface of the colored polyurethane layer after the river exposure test and the weather resistance is excellent.

[0115]

Example 3 Polyisocyanate (Coarse M) to be blended in a black polyurethane coating used for forming a black polyurethane layer.
The amount of DI) is 1.0 and 1.5 in NCO / OH weight ratio.
The following black polyurethane coatings 4 and 5 of the present invention, which were changed to

As a comparative example, the amount of the crude MDI compounded was N.
The following comparative black polyurethane paints 3 and 4 were prepared with the CO / OH weight ratio changed to 0.7 and 1.6.

[0117]

[Formulation Example of Black Polyurethane Paint 4 of the Present Invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
41.7 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.0

[0118]

[Preparation example of black polyurethane paint 5 of the present invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
62.7 parts by weight Inorganic pigment (fine clay powder): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.5

[0119]

[Comparative example of comparative black polyurethane paint 3] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
29.2 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.7

[0120]

[Comparative Example of Comparative Black Polyurethane Paint 4] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
66.7 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.6

Next, as shown in FIG.
(mm × 125 mm, maximum thickness: 9 mm, length 5 m) 1 surface is sandblasted to remove rust, and the urethane primer 1 of the present invention of Example 1 has a thickness of 40 μm on the surface.
Spray paint so that the urethane primer layer 2
Was formed and subjected to a base treatment.

Next, the above-mentioned black polyurethane coating material 4 or 5 of the present invention was spray-coated on the surface so as to have a film thickness of 3 mm and cured to laminate a black polyurethane layer 3.

Then, on the surface thereof, the colored polyurethane coating material 1 of the present invention of Example 1 was spray-coated so as to have a film thickness of 1.5 mm and cured to laminate a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 having a film thickness of 5 was formed on the surface.
It is spray-coated so as to have a thickness of 0 μm and cured to form an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated H-section steel No. 4 and 5 were produced respectively.

As a comparative example, a colored polyurethane-coated H-section steel No. No. No. 1 coated with the above comparative black polyurethane paint 3 or 4 instead of the black polyurethane paint of the present invention was applied. 47
And 48 were manufactured respectively.

[0126] These coated H-section steels were cut to a length of 1 m,
Table 1 shows the results of measuring the color difference on the surface of the colored polyurethane layer after the exposure test to the river for 7 years.

From the results shown in Table 1, the colored polyurethane coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1) together, polyisocyanate was added to the mixture of polyolefin polyol and aromatic amine polyol in the black polyurethane layer of the present invention in an NCO / OH weight ratio of 0. Only in the range of 85 to 1.5, the surface of the colored polyurethane layer after the river exposure test is not discolored and the weather resistance is excellent.

[0128]

Example 4 The following black polyurethane of the present invention was prepared by changing the blending amount of the inorganic pigment blended in the black polyurethane coating used for forming the black polyurethane layer to 100 parts by weight and 200 parts by weight with respect to 100 parts by weight of the polyolefin polyol. Paints 6 and 7 were formulated.

As comparative examples, the following comparative black polyurethane paints 5 and 6 were prepared, in which the blending amount of the inorganic pigment was changed to 4 parts by weight and 210 parts by weight with respect to 100 parts by weight of the polyolefin polyol.

[0130]

[Preparation example of black polyurethane paint 6 of the present invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine powder of clay): 100 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 40% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0131]

[Preparation example of black polyurethane paint 7 of the present invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine clay powder): 200 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 50% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0132]

[Comparative example of comparative black polyurethane paint 5] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine clay powder): 4 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 50% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0133]

[Comparative Example of Comparative Black Polyurethane Paint 6] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine powder of clay): 210 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 50% by weight NCO / OH (weight ratio) of the above paint: 0.85

Next, as shown in FIG. 5, the section steel for connecting walls (total width 750 mm, beam weir 350 mm, flange plate thickness 9 m)
m, length 5 m) 1 surface is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a film thickness of 45 μm and cured to form a urethane primer layer. 1 was formed and a base treatment was performed.

Next, the above-mentioned black polyurethane coating 6 or 7 of the present invention was spray-coated on the surface so as to have a film thickness of 3 mm and cured to form a black polyurethane layer 2.

Next, the colored polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 was applied to the surface to a thickness of 7
It is spray-coated so as to have a thickness of 0 .mu.m and is cured to laminate an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel for connecting wall of the present invention No. 6 and 7 were produced respectively.

As a comparative example, instead of the black polyurethane paint of the present invention, the above comparative black polyurethane paint 5 or 6 was used to form a colored polyurethane-coated wall section steel No. Four
9 and 50 were produced respectively.

Table 1 shows the results of measuring the color difference of the surface of the colored polyurethane layer by cutting the coated steel for coated wall to a length of 1 m and subjecting it to a river exposure test for 7 years.

From the results shown in Table 1, the colored polyurethane-coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1), the black polyurethane layer of the present invention can be used only when the inorganic pigment is added in the range of 5 to 200 parts by weight to 100 parts by weight of polyolefin polyol. The surface of the colored polyurethane layer after the exposure test is not discolored and has excellent weather resistance.

[0141]

[Example 5] The amount of carbon black compounded in the black polyurethane coating used for forming the black polyurethane layer was 10 per 100 parts by weight of the polyolefin polyol.
The following black polyurethane coatings 8 and 9 of the present invention were prepared by changing to 30 parts by weight and 30 parts by weight.

Further, as comparative examples, comparative black polyurethane paints 7 and 8 were prepared in which the blending amount of the carbon black was changed to 0 part and 31 parts by weight with respect to 100 parts by weight of the polyolefin polyol.

[0143]

[Formulation Example of Black Polyurethane Paint 8 of the Present Invention] The following components were mixed to obtain a black polyurethane paint 1 of the present invention.

Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd.,
Hydroxyl value: 46.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 10 parts by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0145]

[Formulation Example of Black Polyurethane Paint 9 of the Present Invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 30 parts by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0146]

[Comparative example of comparative black polyurethane paint 7] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine powder of clay): 5 parts by weight Carbon black (fine powder): 0 parts by weight (without addition) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

[0147]

[Comparative Example of Comparative Black Polyurethane Paint 8] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
37.9 parts by weight Inorganic pigment (fine clay powder): 5 parts by weight Carbon black (fine powder): 31 parts by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.85

Next, as shown in FIG. 6, the steel pipe pile (SGP
The outer surface of 200 A × 5 m length × 6 mm thickness) 1 is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated to a film thickness of 50 μm and the urethane primer layer 2 is formed. Was formed and subjected to a base treatment.

Then, the above-mentioned black polyurethane coating material 8 or 9 of the present invention was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a black polyurethane layer 3.

Then, the colored polyurethane coating material 1 of the present invention of Example 1 was spray coated on the surface so as to have a film thickness of 1 mm and cured to laminate a colored polyurethane layer 4.

Further, on the surface thereof, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 having a film thickness of 1 was formed.
It is spray-coated so as to have a thickness of 00 μm and is cured, and an isocyanate-curable fluororesin primer layer 5 is laminated on the colored polyurethane-coated steel pipe pile No. 8 and 9 were produced respectively.

As a comparative example, the comparative polyurethane paint 7 or 8 described above was used instead of the black polyurethane paint of the present invention.
Colored polyurethane-coated steel pipe pile No. 51 and 52
Were manufactured respectively.

These coated steel pipe piles were cut to a length of 1 m,
Table 1 shows the results of measuring the color difference on the surface of the colored polyurethane layer after the exposure test to the river for 7 years.

From the results shown in Table 1, the colored polyurethane-coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1) as well, the black polyurethane layer of the present invention is used only when carbon black is added in the range of 1 to 30 parts by weight based on 100 parts by weight of the polyolefin polyol. The surface of the colored polyurethane layer after the exposure test is not discolored and has excellent weather resistance.

[0155]

Example 6 The following black polyurethane paints 10 and 11 of the present invention were prepared by changing the kinds of inorganic pigments to be mixed in the black polyurethane paint used for forming the black polyurethane layer.

[0156]

[Preparation Example of Black Polyurethane Paint 10 of the Present Invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m)
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
41.7 parts by weight Inorganic pigment (Kaolin clay fine powder): 20 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.0

[0157]

[Formulation Example of Black Polyurethane Paint 11 of the Present Invention] Polyolefin polyol: 100 parts by weight (Polybd R-45HT manufactured by Idemitsu Petrochemical Co., Ltd., hydroxyl value: 4
6.5 mg-KOH / g) Aromatic amine polyol: 30 parts by weight (Polyhardener PA400 manufactured by Dai-ichi Kogyo Seiyaku Co., hydroxyl value: 420 m
g-KOH / g) Crude MDI (isocyanate group content: 31% by weight):
41.7 parts by weight Inorganic pigment (calcium carbonate fine powder): 20 parts by weight Carbon black (fine powder): 1 part by weight Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.0

Next, as shown in FIG. 7, square steel pipe piles (20
(0 mm × 200 mm × 9 mm thickness × 5 m length) 1 surface is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a film thickness of 35 μm. After curing, a urethane primer layer 2 was formed and a base treatment was performed.

Next, the above-mentioned black polyurethane coating 10 or 11 of the present invention was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a black polyurethane layer 3.

Next, the colored polyurethane coating material 1 of the present invention of Example 1 was spray coated on the surface so as to have a film thickness of 1 mm and cured to laminate a colored polyurethane layer 4.

Further, on the surface thereof, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 having a film thickness of 2 was formed.
Spray-painted to a thickness of 00 μm and cured to laminate an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated square steel pipe pile No. 10 and 11 were produced respectively.

Table 1 shows the results of measuring the color difference of the surface of the colored polyurethane layer by cutting these coated square steel pipe piles to a length of 1 m and subjecting them to a river exposure test for 7 years.

From the results shown in Table 1, even if the type of the inorganic pigment of the black polyurethane layer of the present invention is changed, the surface of the colored polyurethane layer after the river exposure test does not fade and the weather resistance is excellent.

[0164]

Example 7 The following colored polyurethane paints 2 and 3 of the present invention were prepared by changing the kind of acrylic polyol compounded in the colored polyurethane paint used for forming the colored polyurethane layer.

[0165]

[Preparation of Colored Polyurethane Paint 2 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-902 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 17.5 mg
-KOH / g) Aliphatic isocyanate terminated urethane prepolymer:
5.2 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (SANOL LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0166]

[Preparation of Colored Polyurethane Paint 3 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-905 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 40 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
1.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (SANOL LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.5

Next, as shown in FIG. 8, the outer surface of the steel pipe sheet pile was sandblasted to remove rust, and the urethane primer 1 of the present invention of Example 1 was spray coated to a film thickness of 30 μm. After curing, a urethane primer layer 2 was formed and a base treatment was applied.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 3 mm and cured to form a black polyurethane layer 3.

Next, the colored polyurethane coating composition 2 or 3 of the present invention was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a colored polyurethane layer 4.

Next, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 was spray-coated to a film thickness of 700 μm and cured, and an isocyanate-curable fluororesin primer layer 5 was laminated to form the present invention. Colored polyurethane coated steel pipe sheet pile No. 12 and 13 were produced respectively.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these coated steel pipe sheet piles to a length of 1 m and subjecting them to a river exposure test for 7 years.

From the results shown in Table 1, even if the type of the acrylic polyol of the colored polyurethane layer of the present invention is changed, the surface of the colored polyurethane layer after the river exposure test is free from fading and chalking and is excellent in weather resistance.

[0173]

[Example 8] In the same manner as in Example 1, the following colored polyurethane coatings 4 and 5 of the present invention were prepared by changing the kind of the aliphatic isocyanate-terminated urethane prepolymer compounded in the colored polyurethane coating used for forming the colored polyurethane layer. By using the colored polyurethane coated steel sheet pile No. of the present invention. 12
And 13 were manufactured respectively.

[0174]

[Preparation of Colored Polyurethane Paint 4 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
7.8 parts by weight (Takenate D-14 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 10.5% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5 parts by weight (Sankyo LS-292 manufactured by Sankyosha) Solvent: 30% by weight NCO / OH (weight ratio) of the above coating material: 0.5

[0175]

[Preparation of Colored Polyurethane Paint 5 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
6.3 parts by weight (Takenate D-11 manufactured by Takeda Pharmaceutical Company Limited)
0N, isocyanate group content: 11.5% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5 parts by weight (Sankyo LS-292 manufactured by Sankyosha) Solvent: 30% by weight NCO / OH (weight ratio) of the above coating material: 0.5

These coated steel sheet piles were cut to a length of 1 m,
Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer after a 7-year river exposure test.

From the results shown in Table 1, even if the type of the aliphatic isocyanate-terminated urethane prepolymer of the colored polyurethane layer of the present invention was changed, the surface of the colored polyurethane layer after the river exposure test was not faded or chalked and was excellent in weather resistance. .

[0178]

Example 9 The amount of the aliphatic isocyanate-terminated urethane prepolymer compounded in the colored polyurethane coating used for forming the colored polyurethane layer was adjusted to the weight ratio (NCO / OH) of the isocyanate group (NCO) to the hydroxyl group (OH) of the acrylic polyol. The following colored polyurethane coatings 6 and 7 of the present invention were changed to 1.0 and 2.0.

As a comparative example, the NCO / OH ratio was 0.4.
The following comparative colored polyurethane paints 2 and 3 were prepared, which were changed to 2.1 and 2.1.

[0180]

[Preparation of Colored Polyurethane Paint 6 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 2
9.7 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 1.0

[0181]

[Preparation of Colored Polyurethane Paint 7 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 5
9.4 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292, manufactured by Sankyosha) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 2.0

[0182]

[Preparation of Comparative Colored Polyurethane Paint 2] The following components were mixed to prepare the colored polyurethane paint of the present invention.

Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value:
50 mg-KOH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
1.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.4

[0184]

[Preparation of Comparative Colored Polyurethane Paint 3] The following components were mixed to prepare the colored polyurethane paint of the present invention.

Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value:
50 mg-KOH / g) Aliphatic isocyanate terminated urethane prepolymer: 6
2.4 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
Parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 2.1

Next, as shown in FIG. 1, a steel plate (200 m
The surface (m width × 9 mm thickness × 5 m length) is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a thickness of 150 μm and cured. The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray coated on the surface so as to have a film thickness of 15 mm and cured, and a black polyurethane layer 3 was laminated.

Then, the colored polyurethane coating material 6 or 7 of the present invention was spray-coated on the surface so that the film thickness was 10 mm to form a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer of the present invention of Example 1 was applied to the surface to a thickness of 90.
Spray-painted to a thickness of 0 μm and cured to form an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet No. 14 and 15 were produced respectively.

As a comparative example, a colored polyurethane-coated steel sheet No. 3 using the above comparative colored polyurethane coating 2 or 3 instead of the colored polyurethane coating of the present invention was used. 53 and 5
4 were each manufactured.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, the colored polyurethane coated steel sheet pile No. Considering also the results of 1 (1 in Table 1, Example 1), in the colored polyurethane layer of the present invention, the aliphatic isocyanate-terminated urethane prepolymer is added to the hydroxyl group (OH) of the acrylic polyol in weight of the isocyanate group (NCO). Ratio NCO / OH 0.5-2.0
Only when the range is set, fading and chalking on the surface of the colored polyurethane layer after the river exposure test can be prevented.

[0193]

Example 10 The following colored polyurethane coatings 8 to 27 of the present invention were prepared by changing the kinds of the coloring pigments mixed in the colored polyurethane coating used for forming the colored polyurethane layer.

As a comparative example, the following comparative colored polyurethane paint 4 using an organic pigment other than the present invention as the coloring pigment
~ 7 was compounded.

[0195]

Preparation of Colored Polyurethane Paints 8 to 27 of the Present Invention Each paint was prepared by changing only the color pigment of the colored polyurethane paint 6 of the present invention as follows.

[0196]

[Colored polyurethane paint 8 of the present invention] Pigment: Co alone oxide (10 parts by weight) Color tone: Purple

[0197]

[Colored polyurethane paint 9 of the present invention] Pigment: Mn single oxide (10 parts by weight) Color tone: Purple

[0198]

[Colored polyurethane coating material 10 of the present invention] Pigment: Co-Cr-Al composite oxide (10 parts by weight) Color tone: Blue

[0199]

[Colored polyurethane paint 11 of the present invention] Pigment: Fe-Ti composite oxide (10 parts by weight) Color tone: brown

[0200]

[Colored polyurethane paint 12 of the present invention] Pigment: Fe-Al-Ti composite oxide (10 parts by weight) Color tone: brown

[0201]

[Colored polyurethane paint 13 of the present invention] Pigment: Fe-Zn-Ti composite oxide (10 parts by weight) Color tone: brown

[0202]

[Colored polyurethane paint 14 of the present invention] Pigment: Fe-Cr-Zn-Ti composite oxide (10 parts by weight) Color tone: brown

[0203]

[Colored polyurethane paint 15 of the present invention] Pigment: Fe-Cr-Mn-Ti composite oxide (10 parts by weight) Color tone: brown

[0204]

[Colored polyurethane paint 16 of the present invention] Pigment: Mn-Cr-Sb-Ti composite oxide (10 parts by weight) Color tone: brown

[0205]

[Colored polyurethane paint 17 of the present invention] Pigment: Cr-Ni-Cu-Sb-Ti composite oxide (10
Weight part) Color: Brown

[0206]

[Colored polyurethane paint 18 of the present invention] Pigment: Mn-Sb-Ti composite oxide (10 parts by weight) Color tone: brown

[0207]

[Colored polyurethane paint 19 of the present invention] Pigment: Ni-Sb-Ti composite oxide (10 parts by weight) Color tone: yellow

[0208]

[Colored polyurethane paint 20 of the present invention] Pigment: Cr-Sb-Ti composite oxide (10 parts by weight) Color tone: orange

[0209]

[Colored polyurethane paint 21 of the present invention] Pigment: Ni-Sb-Ti composite oxide (10 parts by weight) Color tone: orange

[0210]

[Colored polyurethane paint 22 of the present invention] Pigment: Ni-Co-Zn-Ti composite oxide (10 parts by weight) Color tone: green

[0211]

[Colored polyurethane paint 23 of the present invention] Pigment: Co-Zn-Ti-Cr complex oxide (10 parts by weight) Color tone: green

[0212]

[Colored polyurethane paint 24 of the present invention] Pigment: Ni-Co-Zn-Sb-Ti composite oxide (10
Weight part) Color: Green

[0213]

[Colored Polyurethane Paint 25 of the Present Invention] Pigment: Co-Cr-Mg-Al-Zn complex oxide (10
Weight part) Color: Green

[0214]

[Colored polyurethane paint 26 of the present invention] Pigment: Co-Cr-Mg-Al-Zn composite oxide (5 parts by weight), titanium oxide (5 parts by weight) Color tone: light green

[0215]

[Colored polyurethane paint 27 of the present invention] Pigment: Co-Cr-Mg-Al-Zn composite oxide (5 parts by weight), Ni-Sb-Ti composite oxide (3 parts by weight), titanium oxide (2 parts by weight) Color: Yellow-green

[0216]

[Preparation of Comparative Colored Polyurethane Paints 4 to 7] Each paint was prepared by changing only the color pigment of the colored polyurethane paint 6 of the present invention as follows.

[0217]

[Comparative colored polyurethane paint 4] Pigment: Phthalocyanine blue (10 parts by weight) Color tone: Blue

[0218]

[Comparative colored polyurethane paint 5] Pigment: isoindolinone yellow (10 parts by weight) Color tone: yellow

[0219]

[Comparative colored polyurethane paint 6] Pigment: isoindolinone yellow (5 parts by weight), quinacridone red (5 parts by weight) Color tone: orange

[0220]

[Comparative colored polyurethane paint 7] Pigment: Phthalocyanine green (10 parts by weight) Color tone: Green

Next, as shown in FIG. 1, a steel plate (200 m
(m width × 1 mm thickness × 5 m length) surface is pickled to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated and cured to a film thickness of 20 μm, The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 0.5 mm and cured to laminate a black polyurethane layer 3.

Next, the colored polyurethane coating materials 8 to 27 of the present invention were spray-coated on the surface so that the film thickness was 0.3 mm to form a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 was applied to the surface to a thickness of 1
Spray-painted to a thickness of 00 μm and cured to form an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet No. 16-35 were produced respectively.

As a comparative example, the above comparative colored polyurethane paints 4 to 7 were used instead of the colored polyurethane paint of the present invention.
Colored polyurethane coated steel sheet No. 55-58 were each manufactured.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, the colored polyurethane layer of the present invention was coated with Co, Al, Cr, Fe, Ti, Zn and M.
Discoloration and chalking of the surface of the colored polyurethane layer after the river exposure test only when a coloring pigment consisting of an oxide or a complex oxide of one or more elements selected from n, Sb, Ni, and Mg is used. Can be prevented.

[0228]

Example 11 The amount of the color pigment added to the colored polyurethane coating used for forming the colored polyurethane layer was 20 parts by weight and 30 parts by weight based on 100 parts by weight of the acrylic polyol.
The following colored polyurethane coating material 2 of the present invention, which is used in parts by weight,
8 and 29 were compounded.

As a comparative example, the amount of the color pigment added was 0.5 parts by weight and 3 parts by weight based on 100 parts by weight of the acrylic polyol.
Comparative colored polyurethane paints 8 and 9 were mixed in an amount of 1 part by weight.

[0230]

[Preparation of Colored Polyurethane Paint 28 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 2
0 parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co.) Solvent: 35% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0231]

[Preparation of Colored Polyurethane Paint 29 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 3
0 parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 40% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0232]

[Preparation of comparative colored polyurethane paint 8] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]):
0.5 parts by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyo Co.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0233]

[Preparation of comparative colored polyurethane paint 9] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 3
1 part by weight Hindered amine light stabilizer: 0.5% by weight (Sankyo LS-292 manufactured by Sankyosha) Solvent: 35% by weight NCO / OH (weight ratio) of the above coating: 0.5

Next, as shown in FIG. 1, a steel plate (200 m
The surface (m width × 10 mm thickness × 5 m length) is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a film thickness of 50 μm and cured. The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 3 mm and cured to laminate a black polyurethane layer 3.

Next, the colored polyurethane coating material 28 or 29 of the present invention was spray coated on the surface so that the film thickness was 1 mm to form a colored polyurethane layer 4.

Then, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 was applied to the surface to a thickness of 1
Spray-painted to a thickness of 00 μm and cured to laminate an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet No. 36 and 37 were produced respectively.

As a comparative example, the colored polyurethane-coated steel sheet No. No. 1 using the above comparative colored polyurethane coating 8 or 9 instead of the colored polyurethane coating of the present invention was used. 59 and 6
0 were produced respectively.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, the colored polyurethane-coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1) as well, the coloring polyurethane layer of the present invention contains 1% of the coloring pigment per 100 parts by weight of the acrylic polyol.
Discoloration on the surface of the colored polyurethane layer after the river exposure test can be prevented only when added in the range of -30 parts by weight.

[0241]

Example 12 The present invention described below in which the addition amount of the hindered amine light stabilizer compounded in the colored polyurethane coating used for forming the colored polyurethane layer was changed to 5 parts by weight and 10 parts by weight with respect to 100 parts by weight of the acrylic polyol. Pigmented polyurethane paints 30 and 31 were prepared.

As a comparative example, the amount of the color pigment added was 0.1 part by weight based on 100 parts by weight of acrylic polyol.
Comparative colored polyurethane paints 10 and 11 changed to 1 part by weight
Was prepared.

[0243]

[Preparation of Colored Polyurethane Paint 30 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 2
0 parts by weight Hindered amine light stabilizer: 5% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 35% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0244]

[Preparation of Colored Polyurethane Paint 31 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 3
0 parts by weight Hindered amine light stabilizer: 10% by weight (Sankyo LS-292 manufactured by Sankyosha) Solvent: 40% by weight NCO / OH (weight ratio) of the above coating material: 0.5

[0245]

[Preparation of Comparative Colored Polyurethane Paint 10] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]):
0.5 parts by weight Hindered amine light stabilizer: 0.1% by weight (Sankyo LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 30% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0246]

[Preparation of comparative colored polyurethane paint 11] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 3
1 part by weight Hindered amine light stabilizer: 11% by weight (SANOL LS-292 manufactured by Sankyo Co., Ltd.) Solvent: 35% by weight NCO / OH (weight ratio) of the above paint: 0.5

Next, as shown in FIG. 1, a steel plate (200 m
The surface (m width x 8 mm thickness x 5 m length) is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a film thickness of 30 µm and cured. The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a black polyurethane layer 3.

Next, the colored polyurethane coating material 30 or 31 of the present invention was spray-coated on the surface so that the film thickness was 1 mm to form a colored polyurethane layer 4.

Further, on the surface thereof, the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 having a film thickness of 5 was formed.
Spray coating is applied so as to have a thickness of 0 μm, and the coating is cured to laminate an isocyanate-curable fluororesin primer layer 5. 38 and 39 were produced respectively.

As a comparative example, a colored polyurethane-coated steel sheet No. 10 using the above comparative colored polyurethane paint 10 or 11 instead of the colored polyurethane paint of the present invention was used. 61
And 62 were manufactured respectively.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, the colored polyurethane-coated steel sheet pile No. Considering the results of No. 1 (No. 1 in Table 1, Example 1), the hindered amine light stabilizer was added to the acrylic polyol 10 in the colored polyurethane layer of the present invention.
Discoloration and chalking on the surface of the colored polyurethane layer after the river exposure test can be prevented only by adding in the range of 0.5 to 10 parts by weight with respect to 0 parts by weight.

[0254]

Example 13 The following colored polyurethane coatings 32 and 33 of the present invention were prepared by changing the kind of the hindered amine light stabilizer compounded in the colored polyurethane coating used for forming the colored polyurethane layer.

[0255]

[Preparation of Colored Polyurethane Paint 32 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
0 parts by weight Hindered amine light stabilizer: 1% by weight (Sankyo LS-765 manufactured by Sankyo Co.) Solvent: 35% by weight NCO / OH (weight ratio) of the above paint: 0.5

[0256]

[Preparation of Colored Polyurethane Paint 33 of the Present Invention] Acrylic polyol: 100 parts by weight (Takelac UA-702 manufactured by Takeda Pharmaceutical Co., Ltd., hydroxyl value: 50 mg-K
OH / g) Aliphatic isocyanate terminated urethane prepolymer: 1
4.9 parts by weight (Takenate D-16 manufactured by Takeda Pharmaceutical Co., Ltd.
0N, isocyanate group content: 12.6% by weight) Coloring pigment (Co-Al composite oxide [color tone: blue]): 1
0 parts by weight Hindered amine light stabilizer: 1% by weight (SANOL LS-1114 manufactured by Sankyosha) Solvent: 35% by weight NCO / OH (weight ratio) of the above coating: 0.5

Next, as shown in FIG. 1, a steel plate (200 m
The surface (m width × 7 mm thickness × 5 m length) is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface so as to have a film thickness of 30 μm and cured. The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 2 mm and cured to laminate a black polyurethane layer 3.

Next, the colored polyurethane coating material 32 or 33 of the present invention was spray coated on the surface so that the film thickness was 1 mm to form a colored polyurethane layer 4.

[0260] Further, the surface of the surface is coated with the isocyanate-curable fluororesin primer 1 of the present invention of Example 1 in a film thickness of 1
Spray-painted to a thickness of 00 μm and cured to laminate an isocyanate-curable fluororesin primer layer 5, and the colored polyurethane-coated steel sheet No. 40 and 41 were produced respectively.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, discoloration and chalking of the surface of the colored polyurethane layer after the river exposure test can be prevented even if the kind of the hindered amine light stabilizer is changed in the colored polyurethane layer of the present invention.

[0263]

Example 14 The following isocyanate-curable fluororesin primers 2 and 3 of the present invention were prepared by changing the type of the aliphatic isocyanate-terminated urethane prepolymer used for forming the isocyanate-curable fluororesin primer layer.

[0264]

[Preparation of isocyanate-curable fluororesin primer 2 of the present invention] Liquid fluororesin varnish: 100 parts by weight (Lumiflon LF-100 manufactured by Asahi Glass Co., Ltd.) Aliphatic isocyanate-terminated urethane prepolymer: 1
7 parts by weight (Takenate D-140 manufactured by Takeda Pharmaceutical Co., Ltd.
N) Curing acceleration catalyst (dibutyltin dilaurate): 0.00
5 parts by weight Solvent: 100 parts by weight

[0265]

[Preparation of isocyanate-curable fluororesin primer 3 of the present invention] Liquid fluororesin varnish: 100 parts by weight (Lumiflon LF-100 manufactured by Asahi Glass Co., Ltd.) Aliphatic isocyanate terminated urethane prepolymer: 1
7 parts by weight (Takenate D-160 manufactured by Takeda Pharmaceutical Co., Ltd.
N) Curing acceleration catalyst (dibutyltin dilaurate): 0.00
5 parts by weight Solvent: 100 parts by weight

Next, as shown in FIG. 1, a steel plate (200 m
The surface (m width x 12 mm thickness x 5 m length) is grit blasted to remove rust, and the urethane primer 1 of the present invention of Example 1 is spray-coated on the surface to a film thickness of 50 μm and cured. The urethane primer layer 2 was formed.

Next, the black polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so as to have a film thickness of 3 mm and cured to laminate a black polyurethane layer 3.

Then, the colored polyurethane coating material 1 of the present invention of Example 1 was spray-coated on the surface so that the film thickness was 1 mm to form a colored polyurethane layer 4.

Further, the above-mentioned isocyanate-curable fluororesin primer 2 or 3 of the present invention is spray-coated on the surface so as to have a film thickness of 100 μm and cured, and an isocyanate-curable fluororesin primer layer 5 is laminated to form a book. Inventive colored polyurethane coated steel sheet No. 42 and 43 were manufactured respectively.

Table 1 shows the results of measuring the color difference and the amount of chalking on the surface of the colored polyurethane layer by subjecting these colored polyurethane-coated steel sheets to a river exposure test for 7 years.

From the results shown in Table 1, discoloration and chalking of the surface of the colored polyurethane layer after the river exposure test can be prevented even if the type of the aliphatic isocyanate-terminated urethane prepolymer of the isocyanate-curable fluororesin primer layer of the present invention is changed. .

[0272]

[Table 1]

[0273]

[Table 2]

[0274]

[Table 3]

[0275]

[Table 4]

[0276]

As is apparent from the above examples, the colored polyurethane-coated steel material of the present invention has a black polyurethane layer containing carbon black, Co, Al, Cr, and Fe, Ti, Zn, Mn,
A colored polyurethane layer containing a colored pigment consisting of an oxide or a composite oxide of one or more elements selected from Sb, Ni, and Mg, and a hindered amine light stabilizer, and an isocyanate-curable fluororesin primer. Since it has a layer, it has an excellent aesthetic appearance, and has excellent weather resistance as compared to conventional colored polyurethane-coated steel materials without surface color difference and chalking even after 7 years of river exposure test.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a steel sheet having a surface on which a black polyurethane layer, a colored polyurethane layer and an isocyanate-curable fluororesin primer layer are laminated.

FIG. 2 is a cross-sectional view showing a steel sheet pile in which a black polyurethane layer, a colored polyurethane layer and an isocyanate-curable fluororesin primer layer are laminated on the mountain surface.

FIG. 3 is a cross-sectional view showing a steel sheet pile in which a black polyurethane layer, a colored polyurethane layer and an isocyanate curing type fluororesin primer layer are laminated on the valley surface.

FIG. 4 is a cross-sectional view showing an H-section steel in which a black polyurethane layer, a colored polyurethane layer and an isocyanate-curable fluororesin primer layer are laminated on the surface.

FIG. 5 is a cross-sectional view showing a continuous wall shaped steel having a black polyurethane layer, a colored polyurethane layer, and an isocyanate-curable fluororesin primer layer laminated on the surface.

FIG. 6 is a cross-sectional view showing a steel pipe having a black polyurethane layer, a colored polyurethane layer and an isocyanate-curable fluororesin primer layer laminated on the outer surface.

FIG. 7 is a cross-sectional view showing a square steel pipe having a black polyurethane layer, a colored polyurethane layer, and an isocyanate-curable fluororesin primer layer laminated on the outer surface.

FIG. 8 is a cross-sectional view showing a steel pipe pile in which a black polyurethane layer, a colored polyurethane layer and an isocyanate curing type fluororesin primer layer are laminated on the outer surface.

[Explanation of symbols]

1 Steel materials such as blasted steel plate, steel sheet pile, H-section steel, shaped steel for wall, steel pipe pile, square steel pipe pile, steel pipe sheet pile 2 Urethane primer layer 3 Black polyurethane layer containing carbon black 4 Co, Al , Cr, Fe, Ti, Zn, Mn, S
Colored polyurethane layer containing a colored pigment consisting of an oxide or a complex oxide of one or more elements selected from b, Ni, and Mg and a hindered amine light stabilizer 5 Isocyanate-curable fluororesin primer layer

Claims (1)

[Claims] 1. A black polyurethane layer containing carbon black and Co, A on the surface of a steel material subjected to a base treatment.
1, Cr, Fe, Ti, Zn, Mn, Sb, Ni, Mg
A colored polyurethane layer containing a colored pigment consisting of an oxide or a complex oxide of one or more elements selected from the above, alone or in a mixture, and a hindered amine light stabilizer, and an isocyanate-curable fluororesin primer layer were sequentially laminated. A colored polyurethane-coated steel material characterized by the above.