JP6424980B2 - Precoated metal plate - Google Patents

Description

The present invention relates to a precoated metal sheet.
Priority is claimed on Japanese Patent Application No. 2016-56852, filed March 22, 2016, the content of which is incorporated herein by reference.

Metal sheets used in the fields of home appliances, construction materials, automobiles, etc. were often painted after processing. On the other hand, in recent years, the surface of a metal plate may be coated with a pre-colored coating film (colored coating film) and processed in a state in which the coating film is coated. A metal plate to which a coating is applied after processing may be referred to as a post-coated metal plate, and a metal plate to be processed in a state of covering a colored coating may be referred to as a pre-coated metal plate.
In recent years, high-level design is required for a precoated metal sheet reflecting the increase in interior preference and the like, and designs for applying a metallic coating to the surface of the precoated metal sheet are widely used. Consumers' requirements for paint color are diversified, and metallic paint with a small difference in color tone and brightness change depending on the viewing direction is one of them.

  The precoated metal plate to which metallic coating has been applied may be referred to simply as a precoated metal plate or may be referred to as a metallic precoated metal plate. Similarly, a post-coated metal plate to which metallic coating has been applied may be simply referred to as a post-coated metal plate, or as a metallic post-coated metal plate. In addition, changes in color tone and brightness depending on the viewing direction may be referred to as flip flop property. The large flip-flop property means that the color tone and the glitter property largely change depending on the sight line direction, and the small flip-flop property means that the color tone and the glitter property hardly change depending on the sight line direction.

Most of the techniques relating to conventional metallic precoated metal sheets have an issue of obtaining a colored coating film having a strong metallic feeling.
For example, in Patent Document 1, in order to form a coating film excellent in whiteness and metallic gloss and having a large flip-flop property, aluminum flakes are oriented parallel to the coated surface, and an uncured base paint is used. A water dispersion of aluminum flakes is applied to the coated surface of
In Patent Documents 2 and 3, a scale-like aluminum pigment which is a bright pigment or an aluminum powder having a high aspect ratio is used to manufacture a metallic coating film having a large flip-flop property and a thermoplastic resin composition for a molded product having a metallic feeling. In the above, there is described a technique of adding scale-like graphite pigment and interference pearl mica.

Patent Document 4 describes titanium dioxide pigments, pigment-carrying scale-like aluminum pigments, and titanium dioxide as metallic paint compositions excellent in base opacifying properties that express pearly opalescence and iris feeling with suppressed blackish color tone. Disclosed is a metallic paint composition comprising a color pigment, a pearl pigment and a film-forming resin as composition components.
Patent Document 5 discloses a mica-like iron oxide powder containing 60% by weight or more of α-iron oxide with or without a primer coating on a metal plate, as a method for producing a metallic finish having a metallic luster with a bright feeling. Discloses a method of applying an organic solvent-type paint containing a film-forming resin and a color pigment.

Patent Document 6 includes a vehicle, a metal oxide-coated alumina flake pigment (A), and an aluminum flake pigment or a fine particle titanium dioxide pigment (B-1), and is characterized by having a concealing property. Have been disclosed.
Patent Document 7 includes (1) aluminum flake pigment, (2) interference mica pigment having a dark area, (3) interference bright pigment other than interference mica pigment having the dark area of the above (2), and (4) Disclosed is a bright paint composition containing a vehicle.

Patent Document 8 is a fatty acid-modified polyester having a number average molecular weight of 5,000 to 30,000, a hydroxyl value of 5 to 100 mg KOH / g, and an oil length of 3 to 30% as a coating composition capable of forming a coating film excellent in chemical resistance and weatherability. A polyester resin component (A) containing 50 to 100 mass% of a resin (A1), a melamine resin component (B) containing 50 to 100 mass% of a butyl etherified melamine resin (B1), and a luster pigment component (C) A paint composition is disclosed.
Patent document 9 does not have the hue change by the mixed layer of a metallic base coating film and a clear coating film when it coats by 2 coat 1 bake coating method, it is excellent in transparency, has fine brightness, and has flip-flop property. As a strong coating film, a solvent type metallic base paint composition containing urea modified acrylic resin (A), urethane modified polyester resin (B), curing agent (C), luster pigment (D) and inorganic fine particles (E) It is disclosed.

  In Patent Document 10, a coating film α (film thickness: 1.5 to 10 μm) containing a flake-like aluminum pigment C having an organic resin A as a film forming component and a surface inactivated on at least one surface of a metal plate Discloses a chromate-free coated metal sheet having a metallic appearance,

Japanese Patent Application Laid-Open No. 2000-000514 Japanese Patent Laid-Open Publication 2000-271536 Japanese Patent Application Laid-Open No. 2000-319521 Japanese Patent Application Laid-Open No. 6-299100 Japanese Patent Application Laid-Open No. 2-212564 Japanese Patent Laid-Open Publication 2000-86945 Japanese Patent Laid-Open Publication 2001-164191 Japanese Patent Application Laid-Open No. 2014-9288 Japanese Patent Application Laid-Open No. 2005-220289 International Publication WO 2013/065354

  In the case of a metallic post-coated metal sheet, in order to have a sufficient metallic feeling even in the corner portion where the coating tends to be thin, the film thickness of the coating film including the corner portion is required to be 30 to 100 μm. As for the drying time after coating, the time according to the film thickness of a coating film is needed.

On the other hand, since the metallic precoated metal sheet (in particular, the metallic precoated steel sheet) is manufactured in a continuous manufacturing line, the length of the heating and drying line after coating is limited, and it is necessary to complete the drying in a short time. Therefore, the film thickness of the coating film is 3 to 30 μm, which is thinner than the film thickness of the coating film of the metallic post-coated metal plate.
In addition, when the thick coating film is rapidly dried in a short time, the solvent in the coating film is bumped by heating and evaporating rapidly, and a defect called wax occurs frequently in the coating film, resulting in a metallic precoated metal sheet. The appearance of

  Since the coating film of the metallic pre-coated metal plate is thin, the flake-like (scale-like) luster pigment is strongly oriented, and the luster pigment is arranged in a state where the plane of the luster pigment is parallel to the coating surface. . As a result, the appearance of the metallic precoated metal sheet tends to have a strong metallic feeling when viewed from a certain direction, and a weak metallic feeling when viewed from another direction (that is, the flip-flop property is enhanced).

  Although the metallic precoated metal sheet has the appearance as described above, Patent Documents 1 to 10 aim to obtain a metallic precoated metal sheet having an improvement in the metallic feel of the metallic precoated metal sheet or a strong flip-flop property. That is, as in the present invention, there has been almost no prior art related to metallic precoated metal sheets having small changes in color tone and brightness depending on the viewing direction (that is, having weak flip-flop properties).

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a precoated metal plate (metallic precoated metal plate) having a small change in color tone and brightness depending on the viewing direction, that is, weak flipflop properties. To aim.

  The present invention adopts the following means in order to solve the above problems and achieve the above object.

(1) precoated metal sheet according to one embodiment of the present invention, a metal plate, provided on at least one surface of the metal plate, an average particle diameter of Ri 20~50μm der, luster pigments made of aluminum or mica ( However, when organic or inorganic color pigments are chemically adsorbed on the surface, the case where the surface is coated with a metal oxide and the case where it is a mica-like iron oxide powder) and the average particle diameter is 200 And a coating film having a thickness of 5 to 30 μm and containing a white pigment having a content of 0.5 to 4.0% by mass, wherein the white pigment is titanium oxide or zinc oxide. And at least one selected from the group consisting of barium sulfate, basic carbonates and silica, wherein the content of the bright pigment in the coating film is A in mass%, and the content of the white pigment is mass% B / A when B is in units The value of is 0.03 to 0.27.

(2) In the precoated metal plate described in (1), the average particle diameter of the white pigment may be 250 to 350 nm.

(3) In the precoated metal plate described in the above (1) or (2), the bright pigment may be aluminum flakes.

(4) In the precoated metal sheet according to any one of the above (1) to (3), the value of B / A may be 0.05 to 0.20.

(5) In the precoated metal plate according to any one of the above (1) to (4), light is incident on the surface at an incident angle of 45 °, and the angle at which the specularly reflected light of the light is emitted is 0 When the incident position of the light is 90 °, L15-L110, which is the difference between L15, which is the lightness at 15 ° measured using a variable-angle calorimeter, and L110, which is the lightness at 110 °, is It may be 70 or less.

(6) In the precoated metal sheet according to any one of the above (1) to (5), the surface of the coating may further have a clear coating.

  According to the above aspect, it is possible to provide a precoated metal plate in which the change in color tone and brightness due to the direction of the line of sight is small.

It is a figure which shows the measurement principle of the lightness L by a variable angle color difference meter. It is a schematic diagram which shows the cross-section of the postcoat metal plate which concerns on a prior art. It is a schematic diagram which shows the cross-section of the precoat metal plate which concerns on a prior art. It is a schematic diagram which shows the cross-section of the precoat metal plate which concerns on this embodiment. It is a schematic diagram which shows the structure of the precoat metal plate which concerns on this embodiment. It is a schematic diagram which shows the structure of the precoat metal plate which concerns on this embodiment.

First, the knowledge that has led to the present invention will be described.
MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the present inventors investigated the difference in the property of a coating film in a postcoat metal plate and a precoat metal plate first.
As a result of the survey, in the post-coated metal plate, the film thickness of the coating film is relatively large with respect to the thickness of the luster pigment, so the degree of freedom in the orientation of the luster pigment is high in the coating film. It was found that incident light tends to be diffusely reflected.

  On the other hand, the present inventors have found the following points regarding the precoated metal sheet. That is, since the film thickness of the coating film is relatively smaller than the thickness of the luster pigment, the plane of the luster pigment is oriented parallel to the coating surface in the coating film. As a result, the light incident on the precoated metal plate is often specularly reflected, which makes the difference between the color tone and the glitter according to the viewing direction large (that is, the flip-flop property increases).

  The present inventors have found that it is possible to reduce the flip-flop property by mixing an appropriate amount of fine white pigment in the coating film in order to reduce the flip-flop property in the precoated metal plate, according to the present invention. It reached.

  Next, the inventors investigated the cause of the difference in flip-flop properties in the post-coated metal plate according to the prior art, the pre-coated metal plate according to the prior art, and the pre-coated metal plate according to the present embodiment.

  FIG. 1 is a view showing the principle of color tone measurement using a variable-angle color difference meter. In FIG. 1, an incident light beam is applied from the direction of 45 ° to the upper left with respect to the measurement surface (painted surface), and the direction of 45 ° to the right corresponding to regular reflection is the reference angle (0 °) (ie, light Light intensity L etc. by placing the light receivers in the directions of 15 °, 25 °, 45 ° (vertically upward), 75 ° and 110 ° on the incident light beam side with the incident position of 90 °) Is shown.

Generally, human vision can be expressed in Lab (sometimes expressed as L * a * b) space, where a is in the red direction, -a is in the green direction, b is in the yellow direction, -b Represents the blue direction, and L represents the lightness (brightness).
The inventors of the present invention found that among the above-mentioned indices, the difference in flip-flop property of the metallic coating is mainly due to the difference in L value representing lightness.
That is, the present inventors have found that the flip-flop property is large when the difference in L value is large depending on the angle, and the flip-flop property is small when the difference in L value depending on the angle is small.

  As a result of measuring the L value by arranging the light receiver at each angle by the present inventors, if the difference ΔL between the L value at 15 ° and the L value at 110 ° is 70 or less, even in the precoated metal plate, It has been found that flip-flop properties similar to post-coated metal plates can be realized.

FIG. 2A is a schematic view showing a cross-sectional structure of a post-coated metal plate according to the prior art. FIG. 2B is a schematic view showing a cross-sectional structure of a precoated metal sheet according to the prior art. FIG. 2C is a schematic view showing the cross-sectional structure of the precoated metal sheet according to the present embodiment.
As shown in FIG. 2A, in the post-coated metal plate according to the prior art, the film thickness of the coating film is relatively thick at 30 to 100 μm, so the orientation of the bright pigment 5 in the coated film is small, that is, bright The pigment 5 is present in various directions. As a result of the light rays incident from the upper left side being reflected by the plane of the luster pigment 5 directed in various directions, the reflected light travels in various directions. Thereby, the flip-flop property is small on the surface of the post-coated metal plate.

  As shown in FIG. 2B, in the precoated metal plate according to the prior art, since the film thickness of the coating film is relatively small (about 3 to 30 μm), the bright pigment 5 is substantially parallel to the coating film surface in the coating film. Orient at an angle. As a result, the light incident on the precoated metal plate has a high probability of regular reflection, and the flip-flop property is increased.

As shown in FIG. 2C, in the precoated metal plate according to the present embodiment, an appropriate amount of fine white pigment 7 is mixed in the coating film. The white pigment 7 diffuses an incident light beam before reaching the bright pigment 5 and a reflected light beam reflected by the bright pigment 5. As a result, although the orientation of the bright pigment 5 is high, the flip-flop property is smaller than that of the conventional precoated metal plate.
In addition, in FIG. 2C, the diameter of the white pigment 7 is enlarged and displayed rather than actual.

  Therefore, the precoated metal sheet according to the present embodiment can reduce the change in color tone and brightness (flip flop property) due to the direction of the line of sight by including an appropriate amount of the fine white pigment 7 in the coating film.

Hereinafter, a precoated metal sheet according to an embodiment will be described with reference to the drawings.
(Pre-coated metal plate 10)
First, the precoated metal plate 10 will be described.
FIGS. 3 and 4 are schematic views showing the configuration of the precoated metal plate 10.

  As shown in FIGS. 3 and 4, the precoated metal plate 10 is provided on the surface of at least one of the metal plate 1 and the metal plate 1, and the luster pigment 5 has an average particle diameter of 200 to 400 nm and a content of 0. And the coating film 3 having a film thickness of 5 to 30 μm, containing the white pigment 7 of 5 to 4.0% by mass. The white pigment 7 is any one or more selected from the group consisting of titanium oxide, zinc oxide, barium sulfate, basic carbonate and silica.

<Metal plate 1>
The precoated metal plate 10 includes the metal plate 1 as a base material. The metal plate 1 is not particularly limited, and a known metal plate can be used, and it may be made of an alloy material. As an example of such a metal plate 1, a steel plate, a stainless steel plate, an aluminum plate, an aluminum alloy plate, a titanium plate, a copper plate etc. are mentioned.
The metal plate 1 may be plated on the surface. Types of plating include zinc plating, aluminum plating, copper plating, nickel plating and the like. It may be alloy plating of these. In the case of steel plates, generally known steel plates and plated steel plates such as hot-dip galvanized steel plate, electro-galvanized steel plate, zinc-nickel alloy plated steel plate, hot-dip alloyed galvanized steel plate, aluminum-plated steel plate, aluminum-zinc alloyed plated steel plate, etc. It can be used.

<Coating film 3>
The precoated metal plate 10 is provided on at least one surface of the metal plate 1, and contains a luster pigment 5 and a white pigment 7 having an average particle diameter of 200 to 400 nm and a content of 0.5 to 4.0% by mass. And the coating film 3 having a film thickness of 5 to 30 μm.
The coating film 3 may be provided on one side of the metal plate 1 as shown in FIG. 3, or may be provided on both sides of the metal plate 1 as shown in FIG.

<Bright pigment 5>
The coating 3 has a bright pigment 5. Here, the luster pigment 5 is a generic term for pigments having luster such as pearl pigment, glass flake pigment, metallic pigment and the like.
Specifically, as a pearl pigment, generally known pearl pigments such as mica and synthetic mica can be used, and commercially available pigments may be used.

The glass flake pigment is a glass powder in the form of flakes, and may be coated on the surface with a metal or a metal oxide. As a glass flake pigment, you may use a commercially available thing.
As the metallic pigment, for example, fine particles of a metal such as aluminum or silver or fine particles in the form of flakes can be used.
The luster pigment 5 is preferably a metallic pigment capable of obtaining a suitable metallic appearance, particularly preferably aluminum flakes.

However, as the luster pigment 5, a pigment-supported scale-like aluminum pigment described in Patent Document 4 (a metallic pigment in which an organic or inorganic color pigment is chemically adsorbed on the surface of a scale-like aluminum pigment), Patent Document Use of the mica-like iron oxide powder described in 5 or the metal oxide-coated alumina flake pigment described in Patent Document 6 is not preferable because a suitable flip-flop property can not be obtained.
The reason for this is not clear, but when the above-mentioned pigment is added to the coating film 3, some kind of interaction works between the above-mentioned pigment and the white pigment 7 described later, and a suitable flip-flop property is not obtained. It is considered to be.

The form of the luster pigment 5 is not particularly limited, but in order to suitably reflect light, it is preferably in the form of flakes. Here, flake-like means that the aspect ratio (average particle size D50 (cumulative weight 50% particle size) / thickness ratio) is generally 5 to 20.
The size of the bright pigment 5 is also not particularly limited, but in order to obtain suitable flip-flop properties, the average particle size (D50 (cumulative weight 50% particle size)) is preferably 20 to 50 μm, and the thickness is 0. It is preferable that it is 5-5.0 micrometers.

<White pigment 7>
The coating film 3 contains a white pigment 7 having an average particle diameter of 200 to 400 nm and a content of 0.5 to 4.0% by mass.
Depending on the type, particle size, and addition amount of the white pigment 7, the function as the white pigment 7 is expressed, and the coating film 3 becomes cloudy or loses gloss, or the color tone becomes blue gray, so the white pigment 7 It is necessary to appropriately select the type, particle size and addition amount of

  The white pigment 7 is at least one selected from the group consisting of titanium oxide, zinc oxide, barium sulfate, basic carbonate and silica. It is preferable that the white pigment 7 contained in the coating film 3 is any one or more of the above-mentioned compounds, since a suitable flip-flop property can be obtained.

The average particle size of the white pigment 7 is 200 to 400 nm.
When the average particle diameter of the white pigment 7 is 200 nm or less, it is not preferable because a sufficient diffuse reflection function can not be obtained. In addition, when the average particle diameter of the white pigment 7 is more than 400 nm, the action as a white pigment is expressed, for example, the color tone becomes blue gray tone, and the metallic feeling is unfavorably lost. The average particle size of the white pigment 7 is preferably 250 to 350 nm.

The coating film 3 contains 0.5 to 4.0% by mass of the white pigment 7.
When the content of the white pigment 7 is less than 0.5% by mass, it is not preferable because a suitable flip-flop property can not be obtained. When the content of the white pigment 7 is more than 4% by mass, the transparency of the coating film 3 is lowered, and the metallic feeling may be lost, which is not preferable.
The coating film 3 preferably contains the white pigment 7 in an amount of 1.0 to 3.0% by mass, and more preferably 1.5 to 2.5% by mass.

  By making content of the white pigment 7 of the coating film 3 into 0.5-4.0 mass%, the light which irradiated the surface of the precoat metal plate 10 is reflected suitably. The light irradiated to the precoated metal plate 10 is reflected in a mode close to diffuse reflection, but unlike so-called diffuse reflection, diffuse reflection of a very small amount of white pigment 7 reflects in a mode that raises the metallic feeling other than regular reflection.

In the prior art, when a white pigment is added to a coating film to form a white coating film, for example, in WO 2014/175420, 30 to 60% by mass of titanium oxide which is a white pigment in the coating film It is added.
On the other hand, in the present embodiment, the white pigment 7 is not added to form a white coating film, but the white pigment 7 is added because the coating film 3 has a suitable flip-flop property. Therefore, compared with the prior art, the addition amount of the white pigment 7 to the coating film 3 is significantly less, and is 0.5 to 4.0% by mass.

The resin which is the main component of the coating 3 is not particularly limited. As the resin of the coating film 3, polyethylene, polyester, acrylic and the like are preferable because of high transparency.
As in the case of the conventional metallic coating, a coloring agent (dye) and various additives can be mixed in the coating 3, and a clear coating (not shown) may be formed on the surface. As a coloring agent (dye) to be added to the coating film 3, known ones such as azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes, phthalocyanine dyes, diphenylmethane and triphenylmethane dyes, other nitro dyes, acridine dyes, etc. are used. .

<About the content ratio of the luster pigment 5 and the white pigment 7 in the coating film 3>
As described above, the coating film 3 contains the luster pigment 5 and the white pigment 7. However, in order to provide a suitable flip-flop property, the content (unit: mass%) of the luster pigment 5 in the coating film 3 is When the content (unit: mass%) of the white pigment 7 in the coating A 3 and the coating film 3 is B, the value B / A needs to be 0.03 to 0.27. Preferably, the value of B / A is 0.05 to 0.20, more preferably 0.06 to 0.18.

  Various additives which can be added to the coating film 3 include additives such as antifoaming agents, leveling agents, dispersion aids, etc., and organic wax components such as polyethylene, polypropylene, ester, paraffin and fluorine. And an inorganic wax component such as molybdenum disulfide, a diluent for lowering the viscosity of the paint, a solvent, water and the like.

(Method of manufacturing precoated metal plate 10)
Next, a method of manufacturing the precoated metal plate 10 will be described.

  The precoated metal plate 10 can be manufactured by appropriately selecting the necessary treatment and performing the selected treatment using a general continuous coating line and a coating line for cuttings. As a typical manufacturing process of a coating line, it is performed in order of washing | cleaning, drying, chemical conversion treatment, drying, painting, drying and baking, cooling, and drying. However, the manufacturing process of the precoat metal plate 10 in this embodiment is not limited to this.

  When a clear coat film (not shown) is formed on the surface of the coating film 3, the coating film 3 is dried and baked, and then a paint for clear coat film (hereinafter referred to as "clear paint") is applied It may be dried and baked and cured. Alternatively, after the clear paint is applied by a wet on wet or multi-layer simultaneous application method together with a paint for coating, the laminated two layers may be simultaneously dried and baked and cured. The wet on wet or multilayer simultaneous application method is more preferable because the manufacturing process is further omitted.

  In addition, when the metal plate 1 is a zinc-based plated steel plate, it is a line having a wet on wet coating facility or a simultaneous multilayer coating facility after the plating process in a continuous electroplating steel plate facility or a continuous hot dip galvanized steel plate facility. By manufacturing it, it can apply | coat before the oxide film of a plating metal surface is formed, and the appearance defect by an oxide film can be prevented.

  Here, in the multilayer simultaneous coating, a plurality of coating liquids can be applied by an apparatus capable of discharging different layers of paint from two or more parallel slits such as a slot die coater or a slide hopper curtain coater. At the same time, it is applied to a substrate in a state of being laminated at the same time, and this laminated coating solution is simultaneously dried and baked.

  Wet-on-wet coating is a multi-layer coating liquid in which another coating liquid is further applied on the base material in a wet state before the coating liquid is dried after the coating liquid has been coated on the substrate. Simultaneously drying and baking. Specifically, as a wet on wet coating method, for example, one coating layer is applied by a coating method such as roll coating, dip coating, curtain flow coating, roller curtain coating, and then this coating layer is dried. Before baking, after applying a second layer of a coating on the substrate by curtain flow coating, roller curtain coating, slide hopper type curtain coating, slot die coating, etc. by a method that can be applied without contact with the substrate, There is a method of simultaneously drying and baking the laminated multilayer coating film in a wet state.

  In the present embodiment, as a method for simultaneously drying and baking a coating which is simultaneously coated with multiple layers or wet-on-wet coated, generally known paint baking ovens such as a hot air drying furnace, a direct heating furnace, induction heating A furnace, an infrared heating furnace, or a heating furnace using these in combination can be used.

  As described above, by stacking and simultaneously applying the undried coating solution, the drying step conventionally performed for each layer is collectively performed, which is also advantageous in terms of productivity and manufacturing cost, There is also an advantage that the drying equipment can be reduced.

Example 1
Polyester was used as resin which forms a coating film. The composition of the coating film was changed as described in the table to make a paint base, and a coating film having the film thickness described in the table was formed on a galvanized steel sheet to obtain a sample. For each sample, the flip flop property (ΔL), metallic feel and appearance were evaluated by the method described later.

<Flip-flop property (ΔL)>
The flip-flop properties of each sample were measured as follows. First, L15 which is L value in 15 degrees, and L110 which is L values in 110 degrees were measured using variable angle color difference meter MA-68II made from X-RITE. Next, ΔL represented by the equation L15−L110 = ΔL was calculated, and ΔL was used as an indicator of flip flop property.

The flip flop property was evaluated as follows by the value of ΔL.
Very Good: ΔL ≦ 60
Good: 60 <ΔL ≦ 65
Fair: 65 <ΔL ≦ 70
Bad: 70 <ΔL
Those evaluated as Very Good, Good, and Fair in the above four-level evaluation were regarded as pass.

<Metallic feel>
The metallic feel was evaluated as follows.
Eight evaluators who were skilled in the evaluation of the metallic effect of the precoated metal sheet evaluated the metallic effect of the precoated metal sheet under natural daylight in the following three stages.
3 points: There is metallic feeling 2 points: Low metallic feeling 1 point: There is no metallic feeling By the total score by eight persons, the metallic feeling was evaluated in the following 4 steps.
Very Good: 20 or more and 24 or less Good: 16 or more and less than 20 points Fair: 12 or more and less than 16 points Bad: 8 or more and less than 12 points Those evaluated as Very Good, Good, and Fair in the above four-step evaluation I passed.

<Appearance>
The appearance was evaluated as follows.
One evaluator who was skilled in the evaluation of the appearance of the precoated metal sheet observed the appearance of the precoated metal sheet in natural daylight.
The appearance was evaluated in the following two steps.
Good: When no defect was found Bad: When a defect of 1 mmφ or more was recognized In the above two-stage evaluation, those that were evaluated as Good were regarded as pass.

  The conditions and evaluation results of each example and comparative example are shown in Tables 1 to 5.

As shown in Tables 1 to 3, in the examples satisfying the conditions of the present invention, all the evaluations of the flip-flop property, the metallic feeling and the appearance were suitable.
On the other hand, as shown in Tables 4 and 5, in the comparative example which does not satisfy the conditions of the present invention, either evaluation of flip flop property, metallic feeling or appearance was unsuitable.

Example 2
Next, without changing the conditions for the luster pigment and the white pigment, the kind of resin in the coating film was changed, and the flip flop property, the metallic feeling and the appearance were examined in the same manner as in Example 1.
The evaluation results are shown in Table 6.

As shown in Table 6, even when any resin was used, a suitable evaluation result could be obtained.
In Tables 1 to 6, aluminum used as a luster pigment refers to aluminum flakes.

  According to the above-described embodiment, it is possible to provide a precoated metal plate in which the change in color tone and brightness due to the direction of the line of sight is small.

1 metal plate 3 coating film 5 luster pigment 7 white pigment 10 precoated metal plate

Claims (6)

With metal plates;
Provided on at least one surface of the metal plate, an average particle diameter of Ri 20~50μm der glitter pigment (however made of aluminum or mica and chemically adsorb colored pigments of an organic or inorganic to the surface In the case where the surface is coated with a metal oxide and the case where it is a mica-like iron oxide powder) and white having an average particle diameter of 200 to 400 nm and a content of 0.5 to 4.0% by mass A film containing a pigment and having a film thickness of 5 to 30 μm;
Equipped with
The white pigment is at least one selected from the group consisting of titanium oxide, zinc oxide, barium sulfate, basic carbonate and silica,
When the content of the luster pigment in the coating film is A in mass% and the content of the white pigment is B in mass%, the value of B / A is 0.03 to 0.27. A precoated metal plate characterized by being The precoated metal sheet according to claim 1, wherein the average particle size of the white pigment is 250 to 350 nm. The pre-coated metal sheet according to claim 1 or 2, wherein the bright pigment is an aluminum flake. The value of said B / A is 0.05-0.20, The precoat metal plate in any one of Claims 1-3 characterized by the above-mentioned. When light is made incident at an incident angle of 45 ° to the surface, the angle at which the specularly reflected light of the light is emitted is 0 °, and the incident position of the light is 90 °, measurement was performed using a variable-angle colorimeter The precoat according to any one of claims 1 to 4, wherein L15-L110 which is the difference between L15 which is the lightness at 15 ° and L110 which is the lightness at 110 ° is 70 or less. Metal plate. The precoated metal sheet according to any one of claims 1 to 5, further comprising a clear coating film on the surface of the coating film.

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