JPH09221622A - Coating composition excellent in abrasion resistance and coated metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating composition expressing excellent abrasion resistance, flaw resistance and corrosion resistance and to suppress abrasion of a forming roll, a shearing blade, etc., in a forming or a cutting process. SOLUTION: This coating composition excellent in abrasion resistance comprises a resin composition consisting of a polyvinylidene fluoride resin and an acrylic resin as a main component, each 1-20wt.% of powdery silicon carbide and glass beads based on the total solid in the coating composition as an inorganic aggregate, 1-40wt.% of acrylic polymer beads having a specific composition and 1-20wt.% of powdery tetrafluoroethylene resin based on the total solid of the coating composition as an organic aggregate to be 10-50wt.% of the sum of the inorganic and the organic aggregate and 10-70wt.% of the inorganic aggregate in the total aggregates. The coated metal plate has a coated film made by coating and baking the coating composition at least on one side of the metal plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition having excellent abrasion resistance and a coated metal plate coated with this coating composition, and handling scratches, processing and assembly of the coated metal plate during processing and transportation. The present invention relates to a coating composition that is less likely to be scratched at the time of scratching, scratches due to wind and sand after construction, and a coated metal plate coated with the coating composition.

[0002]

2. Description of the Related Art In recent years, the demands on the market for painted metal sheets used for building exterior materials such as roofs and exterior wall materials have become increasingly severe, and maintenance-free long-term durability is required. It has come to be. Fluororesin-based paints containing at least 70% by weight of polyvinylidene fluoride resin have been developed as paints for painted metal sheets to meet such demands. Has become the mainstream of building exterior materials that require However, this coated steel sheet has the advantage that it has excellent weather resistance and is extremely superior in workability as compared with general outdoor coated steel sheets, while it has a low coating film hardness, so it can be used in the environment during and after construction. There was a drawback that the coating film was easily scratched.

[0003]

Generally, by adding a hard additive to an organic coating film to apparently increase the hardness of the coating film, it is possible to impart abrasion resistance and scratch resistance to the coating film. Japanese Patent Application Laid-Open No. 61-236869 discloses a coating material in which glass fiber is blended with a fluororesin-based coating material to improve the strength and hardness of the coating film and to improve the scratch resistance and abrasion resistance. Have been. However, since this paint uses hard fiber-based aggregates, the forming rolls may be worn during the forming process of the coated metal plate on which the coating film is formed, or the shearing blade may be worn when cutting. In addition, there is a problem that the excellent workability, which is an advantage of the fluororesin coating film, is deteriorated, and the overall properties have never been satisfactory.

[0004] To deal with such a problem, Japanese Patent Publication No. 6-88
In Japanese Patent Publication No. 371, a fluororesin fine particle is added to a coating film, and in Japanese Patent Publication No. 7-65016, an acrylic resin fine particle having a specific composition is added to a coating film. A coated metal plate has been disclosed in which abrasion resistance is improved while suppressing abrasion of a forming roll and a shearing blade at the time. However, the level of wear resistance of these coated metal sheets is not always satisfactory. Therefore, an object of the present invention is to provide a coating composition having excellent abrasion resistance and capable of appropriately suppressing abrasion of a molding roll, a shearing blade, or the like during molding or cutting, and a coating composition of this coating composition. It is to provide a painted metal plate.

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, in a coating composition containing a resin component composed of a polyvinylidene fluoride resin and an acrylic resin as a main component. In addition, by adding silicon carbide powder and glass beads as the inorganic aggregate, and acrylic polymer beads and tetrafluoroethylene resin powder having a specific composition as the organic aggregate in specific proportions, respectively, excellent wear resistance can be obtained. It has been found that a coating film having a property can be obtained, and further, a coated metal plate on which this coating film is formed is less likely to cause abrasion of a forming roll or a shearing blade during forming or cutting. The present invention has been made based on such knowledge, and the characteristic configuration thereof is as follows.

(1) A resin component composed of a polyvinylidene fluoride resin and an acrylic resin is used as a main component, and silicon carbide powder [A] and glass beads [B] as inorganic aggregates are added to the entire coating composition. [A] in the proportion of solid content: 1 to 20% by weight,
[B]: 1 to 20% by weight, further as an organic aggregate,
Acrylic polymer beads [C] containing 49 to 69% by weight of methyl methacrylate, 1 to 21% by weight of a monomer copolymerizable with methyl methacrylate and 30 to 50% by weight of a crosslinkable monomer, and tetrafluoroethylene resin powder [D] ]
A coating composition containing [C]: 1 to 40% by weight and [D]: 1 to 20% by weight in the total solid content of the coating composition. A coating composition with excellent wear resistance, characterized in that the total content of the inorganic aggregate and the organic aggregate is 10 to 50% by weight, and the proportion of the inorganic aggregate in the total aggregate is 10 to 70% by weight. Stuff. (2) The crosslinkable monomer has at least one acryloyl group or methacryloyl group in one molecule and is capable of being crosslinked with at least one of an acryloyl group, a methacryloyl group, acrylic acid or methacrylic acid. A coating composition having excellent abrasion resistance, which is an acrylate and / or a methacrylate having 1 or more of

(3) On at least one surface of the metal plate, the above
A coated metal plate having excellent wear resistance, which has a coating film obtained by applying and baking the coating composition according to (1) or (2). (4) On at least one surface of the metal plate, having a chemical conversion treatment film, having an undercoat coating film containing a rust-preventive pigment or a rust-preventive pigment and an aggregate in the upper layer, further above it (1 ) Or
A coated metal plate having excellent wear resistance, which has a coating film obtained by applying and baking the coating composition according to (2).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The coating composition of the present invention contains a resin component composed of a polyvinylidene fluoride resin and an acrylic resin as a main component, and has a very hard inorganic aggregate and an appropriate hardness and elasticity and It is characterized in that the organic aggregate having lubricity is added in combination at a specific ratio. In the coating composition of the present invention, the mixture of the polyvinylidene fluoride resin and the acrylic resin as the main components of the resin is used because the crystallinity of the polyvinylidene fluoride resin is reduced by the good compatibility of the acrylic resin. Improve durability,
In addition, it is to improve paintability and adhesiveness by blending the acrylic resin. The polyvinylidene fluoride resin has a weight average molecular weight of 150,000 or more and a melting point of 15
Those of 0 to 180 ° C. are particularly preferable. As such a polyvinylidene fluoride resin, for example, Kainer 500 (weight average molecular weight: 350) manufactured by Nippon Penwald Co., Ltd.
000, melting point: 160 to 165 ° C.) and the like.

As the acrylic resin, 70% by weight or more of the constituent monomer units are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n.propyl acrylate, n.propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, The number of carbon atoms of the alkyl group such as n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, t-butyl acrylate, and t-butyl methacrylate is 1 to 8 It is preferable to use at least one monomer selected from the acrylic acid alkyl ester monomers or the methacrylic acid alkyl ester monomers. The reason why such an acrylic acid alkyl ester monomer or a methacrylic acid alkyl ester monomer is suitable is that it has excellent compatibility with the polyvinylidene fluoride resin and also has excellent weather resistance.

On the other hand, the remaining 3 units of the acrylic resin structural unit
As the monomer forming 0% by weight or less, those copolymerizable with the acrylic acid alkyl ester monomer or the methacrylic acid alkyl ester monomer, for example, acrylic acid, methacrylic acid, styrene, vinyltoluene, acrylonitrile, methacrylonitrile, acryl Examples thereof include acid amide, methacrylic acid amide, and vinyl chloride. The acrylic resin has a weight average molecular weight of 50.
Those in the range of 000 to 200,000 are particularly preferable. When the weight average molecular weight is less than 50,000, the physical properties of the resin coating film, for example, the processability are significantly reduced, which is not preferable. On the other hand, when the weight average molecular weight exceeds 200,000, the thixotropy of the coating increases, and the coating operation is undesirably reduced.

The weight ratio of polyvinylidene fluoride resin and acrylic resin is preferably in the range of 90:10 to 40:60.
When the weight ratio of the polyvinylidene fluoride resin to the acrylic resin exceeds 90:10, the thixotropy increases,
It is not preferable because it becomes difficult to make a paint. On the other hand, when the weight ratio of polyvinylidene fluoride resin to acrylic resin is 4
If the ratio is less than 0:60, the processability and weather resistance of the coating film are significantly reduced, which is not preferable. Silicon carbide powder and glass beads are added as inorganic aggregates, and acrylic polymer beads and tetrafluoroethylene resin powder are added as organic aggregates to the above resin components.

By adding silicon carbide powder and glass beads as the inorganic aggregate, the following effects can be obtained. That is, since the silicon carbide powder and the glass beads are extremely hard, they have the effect of increasing the hardness of the entire coating film and improving the wear resistance, and since the glass beads have a lubricating effect, they are molded. It has the effect of suppressing the wear of the forming roll and the shearing blade during processing and cutting, but by adding silicon carbide powder and glass beads, which are different in particle shape, together, a high packing density of the aggregate can be obtained. As a result, the wear resistance of each aggregate is maximized, and wear scratches that reach the base material can be significantly suppressed.

The following effects can be obtained by adding acrylic polymer beads and tetrafluoroethylene resin powder as an organic aggregate. That is, since the acrylic polymer beads and the tetrafluoroethylene resin powder each have an appropriate hardness, the hardness of the entire coating film is appropriately increased by the addition of the acrylic polymer beads and the forming roll during forming or cutting. Has the effect of improving the abrasion resistance of the coating film and the hardness of the coating film while suppressing the wear of the steel and the shearing blade, and at the same time, these organic aggregates have an appropriate elasticity and impart elasticity to the entire coating film Therefore, it is considered that the hard inorganic aggregate contained in the coating film is prevented from biting into the forming roll at the time of roll forming, thereby contributing to the prevention of abrasion of the forming roll. In addition, acrylic polymer beads increase the abrasion resistance and coating hardness of the coating film because the surface layer slightly melts due to the baking treatment during coating film formation and strengthens the integrity with the resin component in the coating. Since the progress of cracks in the coating film is suppressed, the occurrence of cracks during processing can be suppressed. On the other hand, since the tetrafluoroethylene resin powder is chemically inert, the interaction with the wear object is reduced, which contributes to the improvement of the wear resistance and the scratch resistance of the coating film.

The effect is that the addition of acrylic polymer beads increases the hardness of the coating film and reduces the abrasion of the coating film, so that the tetrafluoroethylene resin powder is prevented from falling off, while the tetrafluoroethylene resin resin is prevented. Excellent wear resistance due to the synergistic action of acrylic polymer beads and tetrafluoroethylene resin powder, such as the wear of acrylic polymer beads is reduced by the addition of powder to reduce the friction at the contact part with the worn object. And it is considered that scratch resistance can be obtained.

In the present invention, the inorganic aggregate and the organic aggregate as described above are added in combination, so that the surface aggregate of the coating film and the abrasion of the forming roll and the like reach the base metal and reach the base metal. Such severe damage and abrasion can be protected by the inorganic aggregate, and extremely excellent scratch resistance and abrasion resistance which cannot be obtained by the conventional coated metal plate can be obtained. The blending amounts of the silicon carbide powder and the glass beads are each 1 to 20% by weight in the total solid content of the coating composition. If the blending amount of these is less than 1% by weight, the abrasion resistance is insufficient, while if over 20% by weight, the coating workability is deteriorated, which is not preferable. From these viewpoints, the more preferable blending amount of the silicon carbide powder and the glass beads is 2.5 to 5, respectively.
It is 10% by weight.

As the acrylic polymer beads,
It is necessary to maintain appropriate hardness and elasticity, and not to impair the excellent properties of the coating composition or coating film. Specifically, it must not dissolve in the solvent of the coating, and the storage of the coating. It is required that there is no alteration or sedimentation and solidification inside, stability does not decrease, and that it has an affinity with the acrylic resin in the paint. Such acrylic polymer beads include 49 to 69% by weight of methyl methacrylate and 1 to 21 of a monomer copolymerizable with methyl methacrylate.
It is optimal to contain 30% to 50% by weight and a crosslinking monomer.

Examples of monomers copolymerizable with methyl methacrylate include methyl acrylate, ethyl acrylate, ethyl methacrylate, n.propyl acrylate, n.propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n.
Butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate,
sec.butyl acrylate, sec.butyl methacrylate, t.butyl acrylate, t.butyl methacrylate, acrylic acid, methacrylic acid, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, bornyl acrylate, bornyl metha Acrylate, isobornyl acrylate, isobornyl methacrylate, allyl acrylate, allyl methacrylate, styrene, vinyltoluene, acrylonitrile, methacrylonitrile, 2-dimethylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl acrylate , 2-diethylaminoethyl methacrylate, 2-t.butylaminoethyl acrylate, 2-t.butyl Aminoethyl methacrylate, vinyl chloride, and the like.

The amount of these monomers blended is 1 to 21% by weight.
If the blending amount is less than 1% by weight, the acrylic polymer beads are hard and brittle, so that the scratch resistance is poor, while if over 21% by weight, the hardness of the acrylic polymer beads is insufficient and Performances such as solvent properties are significantly reduced.

The crosslinkable monomer has at least one acryloyl group or methacryloyl group in one molecule and can be crosslinked with at least one of an acryloyl group, a methacryloyl group, acrylic acid or methacrylic acid. Acrylates and / or methacrylates having one or more such functional groups are preferred. For example, it is a monomer having two or more acryloyl groups or methacryloyl groups or a monomer having a functional group such as a hydroxyl group or an epoxy group in the molecule. The so-called crosslinkable monomer containing such a reactive group increases the crosslinking density of the acrylic polymer as the addition amount increases, but the addition amount is optimally in the range of 30 to 50% by weight. The reason is that if the amount added is less than 30% by weight, the hardness of the acrylic polymer beads is insufficient, while
This is because if it exceeds 50% by weight, the crosslink density becomes too high and it becomes brittle.

As the crosslinkable monomer, an acrylate monomer or a methacrylate monomer having a hydroxyl group in the molecule, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, glycerol acrylate, glycerol methacrylate,
4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 3,4-dihydroxybutyl acrylate, 3,4-dihydroxybutyl methacrylate, trimethylolpropane acrylate, trimethylolpropane methacrylate, trimethylolpropane diacrylate, trimethylolpropane There are dimethacrylate and the like, and as the acrylate monomer or methacrylate monomer having an epoxy group in the molecule, for example, glycidyl acrylate, glycidyl methacrylate, bis-glycidyl acrylate, bis.
There are glycidyl methacrylate and the like, and further, as an acrylate monomer or a methacrylate monomer containing two or more acryloyl groups or methacryloyl groups in the molecule, for example, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1 ，
3-butanediol diacrylate, 1,3-butanediol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimetha Acrylate, neopentyl glycol diacrylate,
Neopentyl glycol dimethacrylate, 1,6-
There are hexanediol diacrylate, 1,6-hexanediol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and the like.

The content of the acrylic polymer beads is 1 to 40% by weight based on the total solid content of the coating composition. If the blending amount of the acrylic polymer beads is less than 1% by weight, the abrasion resistance is not sufficient, and the effect of preventing the forming roll from being damaged by the hard inorganic aggregate during roll forming is undesirably reduced. On the other hand, if the blending amount exceeds 40% by weight, the long-term stability of the coating composition is deteriorated, which is not preferable.
From these viewpoints, the more preferable blending amount of the acrylic polymer beads is 2.5 to 30% by weight.

The content of the tetrafluoroethylene resin powder is 1 to 20% by weight based on the total solid content of the coating composition.
If the blending amount of the tetrafluoroethylene resin powder is less than 1% by weight, abrasion resistance is insufficient, while if it exceeds 20% by weight, coating workability is deteriorated, which is not preferable. Further, from these viewpoints, the more preferable blending amount of the tetrafluoroethylene resin powder is 2.5 to 10% by weight. Along with this tetrafluoroethylene resin powder, another similar fluororesin powder, for example, a fine powder such as a copolymer of ethylene tetrafluoride and propylene hexafluoride or a copolymer of ethylene tetrafluoride and ethylene is used. You may use together.

The total content of the inorganic aggregate and the organic aggregate in the total solid content of the coating composition is 10 to 50% by weight. If the total content of the organic aggregate and the inorganic aggregate is less than 10% by weight, the hardness of the entire coating film is insufficient and desired wear resistance cannot be obtained. on the other hand,
If the total content exceeds 50% by weight, the coating film becomes too hard, the elongation is remarkably reduced, and the bending workability and the forming roll wear property are deteriorated. From these viewpoints, a more preferable range of the total content of the organic aggregate and the inorganic aggregate is 20 to 40% by weight. The proportion of the inorganic aggregate in the total aggregate is 10 to 70% by weight. If the proportion of the inorganic aggregate in the total aggregate is less than 10% by weight, the hardness of the entire coating film is insufficient and desired wear resistance cannot be obtained. On the other hand, if it exceeds 70% by weight, the coating film becomes too hard and the abrasion resistance of the forming roll deteriorates.

There is no particular restriction on the particle size of each aggregate, but from the viewpoint of the quality characteristics of the coated metal plate including wear resistance,
The average particle size is 5 to 20 μm for silicon carbide powder and glass beads, and 10 to 50 μm for acrylic polymer beads.
m, tetrafluoroethylene resin powder is preferably in the range of 1 to 5 μm. Generally, the average particle size of each aggregate is less than the lower limit of the above wear resistance, while the average particle size of each aggregate exceeds the above upper limit, the coating film defects are likely to occur during coating. However, the workability is significantly reduced.

Silicon carbide powder, glass beads, which is an aggregate,
Acrylic polymer beads and ethylene tetrafluoride resin powder may be mixed in the paint as it is. However, in order to improve affinity and dispersibility in the paint and prevent sedimentation of the aggregate, coupling is performed before mixing. It is preferable to perform agent treatment.
As the coupling agent, silane-based, aluminum-based,
There are titanium, chromium and the like, and it is desirable to mix them well with the coupling agent after they are well mixed. Examples of the silane-based coupling agent include γ-glycoxyoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like, and examples of the aluminum-based coupling agent include acetoalkoxyaluminum diisopropylate. be able to. As a specific method of adding the aggregate to the paint, a coupling agent equivalent to 3% by weight of the total weight of the aggregate is dissolved in a solvent such as isophorone, and the aggregate may be added to the solvent. What is necessary is just to make it contact, add it to the paint which is slowly stirred, and mix it uniformly.

In the coating composition of the present invention, a coloring pigment, an extender pigment, a solvent, an additive and the like can be blended, if necessary, in addition to the above-mentioned essential components. Examples of color pigments include titanium oxide, carbon black, iron oxide,
Examples include lead chromate, metal powder, calcined pigment, pearl pigment and the like. Examples of the extender include calcium carbonate, clay, talc, antimony trioxide, barium sulfate, kaolin and the like. Examples of additives include an antifoaming agent,
Examples include a pigment dispersant, an anti-sagging agent, and an anti-scratch agent. As the solvent, for example, toluene, xylene,
Examples include ethyl acetate, butyl acetate, cellosolve solvents, methyl isobutyl ketone, methyl ethyl ketone, diisobutyl ketone, isophorone, cyclohexanone, and the like.

Next, a coated metal plate coated with the above-mentioned coating composition will be described. There is no particular limitation on the coated metal sheet used in the coated metal sheet of the present invention. For example, a galvanized steel sheet, a zinc-5% aluminum alloy-coated steel sheet, a zinc-coated steel sheet manufactured by a hot-dip plating method or an electrolytic plating method or the like.
A zinc-based plated steel sheet such as a 55% aluminum alloy plated steel sheet, an aluminum plated steel sheet, a stainless steel sheet, an aluminum sheet, a cold rolled steel sheet, or the like can be used. The above-mentioned metal plate is usually subjected to degreasing treatment before coating, and in some cases, further subjected to pickling, and then subjected to chemical conversion treatment such as chromate treatment or phosphate treatment.

The coating composition can be directly coated on the above-mentioned chemical conversion treatment film, but in order to improve the performance such as corrosion resistance and adhesion, an undercoating paint usually used for coated metal plates. That is, it is desirable that a so-called primer is applied, baked and then applied. Further, it is preferable that the undercoat coating film contains a rust preventive pigment or a rust preventive pigment + aggregate in order to improve corrosion resistance and abrasion resistance. There is no particular limitation on the coating method, and a coating method such as a roll coater method, a curtain flow coater method, a spray coating, a brushing method, etc. which are conventionally generally performed can be applied. The most common. The dry coating thickness of the coating composition is usually 5 to 40 μm. If the thickness of the coating film is less than 5 μm, it is difficult to hold the aggregate in the coating film, and the weather resistance of the coating film is reduced (UV transmittance is increased), which is not preferable. On the other hand, if the thickness exceeds 40 μm, the coating workability is deteriorated, the appearance of the coating film is deteriorated, and the cost is increased, which is not preferable.

The baking treatment after applying the coating composition is 3
Heating is performed for 0 to 180 seconds to reach a metal plate temperature of 200 ° C. or higher. If the baking time is less than 30 seconds, the resin component is insufficiently melt-cured.
If it exceeds 2 seconds, thermal degradation including the undercoat paint component starts,
In either case, the original performance of the paint is not exhibited, which is not preferable. There is no particular limitation on the heating method at the time of baking, and hot air heating method, high frequency heating method and the like can be applied.

[0030]

【Example】

[Example 1] A coating type chromate treatment was applied to a metal plate so that the adhered amount was 30 mg / m ² in terms of metal chromium, and then an epoxy resin type coating was applied as an undercoating coating so that the dry coating film thickness was 5 μm. After that, it is baked at about 200 ° C. for 60 seconds, and then the coating composition prepared as follows as a top coating is applied so that the dry film thickness becomes 25 μm, and then baked at about 250 ° C. for 60 seconds to obtain a coated metal plate obtained. Was subjected to the following various tests. The results are shown in Tables 1 to 4 together with the composition and amount of the aggregate added to the top coat.

(Coating composition) A coating containing polyvinylidene fluoride resin: acrylic resin = 80: 20 (weight ratio) was used as a base coating, and the amount of the aggregates shown in Tables 1 and 2 was added thereto. A coating composition was obtained. The aggregate is added to the base paint by dissolving 3% by weight of the total weight of the aggregate in an aluminum-based coupling agent in isophorone, adding the aggregate therein, and contacting it well. It was carried out by adding to the agitated base paint and mixing it uniformly.

(Coated metal plate) As the coated metal plate,
Hot-dip galvanized steel sheet (abbreviated as GI in the table), zinc-5%
Aluminum alloy plated steel sheets (abbreviated as GF in the table) and zinc-55% aluminum-1.6% silicon alloy plated steel sheets (abbreviated as GL in the table) were used. All thicknesses are 0.
6 mm, and the coating weight was 130 g / m ² per side for zinc-galvanized steel sheet and zinc-5% aluminum alloy-plated steel sheet, and zinc-55% aluminum-1.
100% per side for 6% silicon alloy plated steel sheet
g / m ² .

(Test / Evaluation Method) (1) Workability The test piece was bent in a room at 20 ° C. by 180 ° and evaluated by the number of the smallest plate scissors without cracks. In this evaluation, 0
4T was passed, and 5T or more was rejected. (2) Forming roll abrasion A test piece having a width of 500 mm and a length of 1000 mm was formed by a roll forming machine, and the surface of a forming roll after forming 50 test pieces was observed and evaluated as follows. ◎: No abnormality at all ○: Slight scratching ×: Abnormal

(3) Taber Abrasion Test Using a wear wheel CS-10, a test was conducted by applying a load of 1 kg to the wear wheel, and evaluation was made by the number of rotations until the primer was exposed. In this evaluation, less than 2500 times was disqualified and 2500 times or more was regarded as passed. (4) Sand Falling Abrasion Test Based on ASTM-D968, No. 4 silica sand was dropped and tested, and the sand falling amount until the primer was exposed was evaluated. In this evaluation, less than 15 L was rejected, and 15 L or more was passed. (5) Corrosion resistance A salt spray test of JIS Z 2371 was performed, and the degree of rust after 2000 hours was visually observed and evaluated by the following. ◎: No rusting at all ○: Slight rusting ×: Significant rusting

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[Example 2] Except that a paint containing various chromates as rust preventive pigments and aluminum borate whiskers as an aggregate was used as a primer (undercoat paint) in a linear-polyester paint. A test material was prepared in the same manner as in Example 1 and tested and evaluated by the same method. The results are shown in Tables 5 to 7 together with the composition of the primer, the composition of the aggregate added to the top coat and the amount added.

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

[Table 7]

[0043]

According to the present invention described above, excellent abrasion resistance, scratch resistance and corrosion resistance are obtained, and further, abrasion of a forming roll or a shearing blade during forming or cutting is effectively suppressed. You can

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Claims (4)

[Claims] 1. A resin composition comprising a polyvinylidene fluoride resin and an acrylic resin as a main component, to which, as an inorganic aggregate, silicon carbide powder [A] and glass beads [B], a solid composition of a coating composition. [A]: 1-20% by weight,
[B]: 1 to 20% by weight, further as an organic aggregate,
Acrylic polymer beads [C] containing 49 to 69% by weight of methyl methacrylate, 1 to 21% by weight of a monomer copolymerizable with methyl methacrylate and 30 to 50% by weight of a crosslinkable monomer, and tetrafluoroethylene resin powder [D] ]
A coating composition containing [C]: 1 to 40% by weight and [D]: 1 to 20% by weight in the total solid content of the coating composition. A coating composition with excellent wear resistance, characterized in that the total content of the inorganic aggregate and the organic aggregate is 10 to 50% by weight, and the proportion of the inorganic aggregate in the total aggregate is 10 to 70% by weight. Stuff. 2. The crosslinkable monomer has at least one acryloyl group or methacryloyl group in one molecule, and is crosslinkable with at least one of an acryloyl group, a methacryloyl group, acrylic acid or methacrylic acid. The coating composition having excellent abrasion resistance according to claim 1, which is an acrylate and / or a methacrylate having one or more functional groups. 3. A coating excellent in wear resistance, which comprises a coating film obtained by applying and baking the coating composition according to claim 1 or 2 on at least one surface of a metal plate. Metal plate. 4. A metal plate having a chemical conversion treatment film on at least one surface thereof, and a rust preventive pigment or an undercoat paint film containing a rust preventive pigment and an aggregate as an upper layer thereof, and further as an upper layer thereof. A coated metal sheet having excellent wear resistance, which has a coating film obtained by applying and baking the coating composition according to Item 1 or 2.