JP6719965B2 - Painting condition setting method and program - Google Patents

Description

The present invention relates to a method and a program for setting, by simulation, optimum conditions for a film thickness of a coating film and a base color when a paint containing a pigment and a bright material is applied on the base.

For example, in the manufacturing process of automobile exterior parts, first, the coating color (hereinafter, target color) of the part is determined at the design stage, and a paint for obtaining this target color is prototyped. Then, the trial paint is applied on the base to form a trial product, and it is verified whether or not the coating color of the trial product matches the target color.

However, paints often do not have a sufficient degree of hiding the color of the base (hiding power). In particular, metallic paints and pearl paints, which are often applied to paints for automobile exteriors, include aluminum flakes and coherent glitters. Since such a bright material is included, the hiding power greatly changes depending on the illumination direction and the observation direction with respect to the coated surface. For this reason, the target color decided at the design stage often does not match the appearance color of the actually painted prototype.

In this case, a trial product is prepared by changing the film thickness of the coating film and the color of the base, and adjustment is performed so as to match the target color. However, if a large number of prototypes are manufactured, the man-hour will increase and the cost will increase. In addition, if it is difficult to match the paint color of the prototype with the target color even after adjusting the film thickness or base color, it is necessary to readjust the components of the trial paint or reconsider the target color. Occurs. In this case, not only is the man-hour increased, but the degree of freedom in design is reduced.

Therefore, so-called computer color matching, in which the composition of a coating material (mixing ratio of a pigment and a glittering material) for obtaining a target color is calculated by computer simulation, has been studied (for example, see Patent Document 1).

JP, 10-310727, A

However, even when a paint having a composition calculated by the above computer color matching is used, a desired appearance color may not be obtained. For example, the film thickness of the coating film may fluctuate due to fluctuations in the coating conditions for each product, which may cause the coating color to fluctuate for each product and be different from the target color. Also, the film thickness of the coating film of each product may vary slightly depending on the site due to changes in the coating conditions during coating of each product, spray stability, and spray pattern, causing uneven coating color (painting unevenness). There is. In particular, when a coating material containing a pigment and a glittering material is used, the hiding power greatly changes depending on the illumination direction and the observation direction with respect to the coated surface as described above, so that the coating color tends to vary from product to product or from site to site.

For example, when the film thickness of the coating film is increased, the hiding power is increased, so that the variation of the coating color due to the minute variation of the film thickness can be suppressed and the coating color can be stabilized. However, if the film thickness is increased, the cost will increase due to an increase in the amount of paint used, an increase in coating time, an increase in drying time, an increase in drying energy, etc., and a deterioration in the appearance quality due to a paint pool at the edges of the coated surface. And so on. Therefore, it is better to make the film thickness as thin as possible, but a method for obtaining the minimum film thickness that matches the target color and that can prevent paint spots and the corresponding background color by simulation has been established. Instead, the reality is that many prototypes have to be produced as described above.

In view of the above-mentioned circumstances, the present invention has an object to obtain the minimum film thickness that is consistent with the target color and obtains a uniform coating color and the corresponding base color by simulation.

In order to solve the above problems, the present invention is a method for setting the optimum conditions of the film thickness and the base color of a coating film by simulation when coating a trial paint containing a pigment and a bright material on the base. Then, the step of calculating the variation of the coating color when the film thickness is slightly changed in an arbitrary film thickness and an arbitrary background color, and the film thickness and the background color of which the variation of the coating color is within a predetermined range. Setting coating conditions including a step of setting a range and a step of setting a minimum film thickness within the range of the film thickness and the base color and a base color corresponding thereto as an optimum value of the film thickness and the base color. Provide a way.

Further, the present invention is a program for causing a computer to set the optimum conditions of the film thickness of the coating film and the base color when the trial paint containing the pigment and the luster color material is applied on the base. A step of calculating a change in coating color when the film thickness and an arbitrary base color are slightly changed, and a step of setting a range of the film thickness and the base color in which the change of the coating color is within a predetermined range. And a step of setting the minimum film thickness within the range of the film thickness and the background color and the background color corresponding thereto as the optimum value of the film thickness and the background color. To do.

As described above, in the present invention, the variation of the coating color when the thickness is slightly changed is calculated by the simulation in the arbitrary thickness and the arbitrary base color, and the variation of the coating color is within the predetermined range. The thickness of the coating film and the range of the base color are set so that Then, the minimum film thickness within the range of the film thickness and the background color and the corresponding background color are set as the optimum values of the film thickness and the background color. As described above, it is possible to acquire the minimum film thickness capable of suppressing the fluctuation of the coating color caused by the minute fluctuation of the film thickness within the predetermined range, and the base color corresponding to the minimum film thickness.

The optimization of the film thickness and the base color as described above is repeated by using the reproduction calculation means by constructing a reproduction calculation means (program) for reproducing the coating color of the coating film with the arbitrary film thickness and the arbitrary base color. It is done by calculating. However, since the pigment and the luster material have completely different optical models, it is extremely difficult to construct a reproduction calculation means for reproducing the coating color of the coating film containing both of them.

Therefore, the above-mentioned coating condition setting method includes a plurality of types of coating films containing various pigments alone, a scattering coefficient and an absorption coefficient at an arbitrary film thickness and an arbitrary base color, and a plurality of types of glittering materials containing a single type. A step of creating a material database including a film thickness and an angle-varying spectral reflectance coefficient in an arbitrary background color of a coating film, and a pigment included in the trial paint from the material database and the composition of the trial paint And a step of calculating a gonio-spectral reflectance coefficient resulting from the above, and a gonio-spectral reflectance coefficient resulting from the glittering material included in the trial paint, and a gonio spectral reflectance due to the pigment included in the trial paint. A step of constructing a reproduction calculation means for reproducing a coating color with an arbitrary film thickness and an arbitrary base color by synthesizing a coefficient and a variable angle spectral reflectance coefficient due to the glittering material contained in the trial paint. It is preferable to obtain the optimum values of the film thickness and the background color by performing the iterative calculation using the reproduction calculation means.

As described above, based on the material database and the composition of the trial paint, the gonio-spectral reflectance coefficient due to the pigment contained in the trial paint and the gonio-spectral reflectance coefficient due to the luster material included in the trial paint. Is calculated separately. Thereby, the gonio spectral reflectance coefficient due to the pigment can be calculated based on the optical model of the pigment, and the gonio spectral reflectance coefficient due to the luster material is calculated based on the optical model of the luster material. Therefore, by combining these gonio-spectral reflectance coefficients, it is possible to construct a reproduction calculation unit that accurately reproduces a coating color with an arbitrary film thickness and an arbitrary background color.

For example, the composition of the trial paint can be quantified from the goniospectral reflectance coefficient of the coating film of various pigments and various luster materials contained in the material database and the goniospectral reflectance coefficient of the coating film of the trial paint. .. Specifically, included in the material database, the gonio-spectral reflectance coefficient of a plurality of types of coating films containing various pigments alone, and the gonio-spectral reflectance of a plurality of types of coating films containing various luster materials alone. From the coefficient and the gonio-spectral reflectance coefficient of the coating film of the trial paint, it is possible to calculate the types and blending ratios of the pigment and the luster material contained in the trial paint.

As described above, according to the present invention, it is possible to obtain the minimum film thickness that matches the target color and obtains a uniform coating color and the corresponding base color by simulation.

It is a schematic diagram of the coating condition setting device which concerns on one Embodiment of this invention. It is a flowchart which shows the creation procedure of a material database in the coating condition setting method which concerns on one Embodiment of this invention. It is a figure which shows an example of a material database. It is a flowchart which shows the calculation procedure of the coating color by the reproduction calculation means in the said coating condition setting method. It is a flowchart which shows the procedure of the optimization calculation of a film thickness and a base color in the said coating condition setting method. It is a figure which shows an example of the screen of the display part of the said coating condition setting apparatus.

The coating condition setting device 1 according to an embodiment of the present invention includes a measuring unit 2 and a computer 3, as shown in FIG.

The measuring unit 2 measures a gonio-spectral reflectance coefficient in a visible light region of an object to be measured (coating film or the like). The gonio-spectral reflectance coefficient is a coefficient of reflectance for each wavelength in a plurality of directions having different light receiving angles with respect to the irradiation direction, when the reflectance of the perfect diffusion surface of barium sulfate is 100. As the measuring unit 2, a commercially available goniospectrophotometer can be used. The measurement unit 2 emits light from a direction inclined by a predetermined angle with respect to a direction perpendicular to the surface to be measured, and receives reflected light at a plurality of different angles with the specular reflection direction of the irradiation direction as a starting point. To do. Specifically, the light receiving angle when the specular reflection direction is the starting point and the irradiation direction side is positive is six directions within a range of -15° to 110°C (for example, -15°, +15°, +25°). , +45°, +75°, +110°) to receive the reflected light. Then, the reflectance at each predetermined wavelength (for example, every 10 nm) between the wavelengths (400 to 700 nm) in the visible light region is measured from the received light amount at each light receiving angle θ.

The computer 3 has an input unit 4, a storage unit 5, a calculation unit 6, and a display unit 7. The input unit 4 is for inputting data and the like of the measurement unit 2, and includes, for example, a terminal that enables data communication with the measurement unit 2, a keyboard for manually inputting data, and the like. The storage unit 5 stores the data input from the input unit 4, the calculation result of the calculation unit 6, and the like. The arithmetic unit 6 performs an arithmetic operation using the data input from the input unit 4 and the data stored in the storage unit 5 according to a predetermined program. The specific function of the arithmetic unit 6 will be described later. The display unit 7 is, for example, a monitor, and displays the data input from the input unit 4, the calculation result by the calculation unit 6, and the like.

Next, a method of setting the coating conditions using the coating condition setting device 1 will be described. This coating condition setting method includes a step of creating a material database, a step of constructing a reproduction calculation means, and a step of optimizing a film thickness and a base color.

[Creation of material database]
The material database is information on the optical characteristics of a coating film containing various pigments or various luster pigments alone. The material database is created through the procedure shown in FIG. Hereinafter, each procedure will be described in detail.

(Step S1)
First, a plurality of bases having different brightness are prepared, and the measuring unit 2 measures the gonio-spectral reflectance coefficient of the surface of each base. In the present embodiment, the goniospectral reflectance coefficients R _W and R _B of the surfaces of a white background (hereinafter, white background W) and a black background (hereinafter, black background B) are measured. The white base W and the black base B are rectangular flat plates as shown in FIG. 1, for example. In the illustrated example, the white base W and the black base B are integrated, but they may be provided separately.

(Step S2)
Next, a plurality of types of paints containing various pigments alone are applied on the white base W and the black base B to form a coating film. Pigments are generally fine particles dispersed in a paint in order to impart colors such as red, blue, yellow, black and white. In the present embodiment, first, a coating material containing each of the pigments P1, P2, P3,... At a predetermined concentration is applied onto the white background W and the black background B in a predetermined film thickness (for example, 15 μm). Since the surface of the coating film lacks gloss and scattering of the surface may adversely affect the subsequent measurement of reflectance, for example, even if a clear coat is applied with a predetermined film thickness (for example, several tens of μm). Good. Then, by the measuring unit 2, the goniospectral reflectance coefficients (R _P1,W , R _P1,B ) of the surface of the coating film containing the various pigments P1, P2,... (R _{P2, W} , R _{P2, B} ), and the film thicknesses X _P1 , X _P2, ... Of the coating film are measured.

(Step S3)
Next, a plurality of types of paints containing various glitters alone are applied on the white base W and the black base B to form a coating film. The glitter material is roughly classified into a metallic glitter material included in the metallic paint and an interference glitter material included in the pearl paint. The metallic luster color material is generally a flake of a metal such as aluminum, has a scaly shape, and has an average diameter of about several μm to 100 μm. Metallic luster does not transmit light. On the other hand, the coherent luster material is a material exhibiting a pearl color, and is one in which metal oxides having different refractive indexes are coated on the surface of finely pulverized mica (mica) in one to multiple layers. Fresnel reflection occurs at the interface between multiple layers with different refractive indices, and the interference of light caused by this causes a pearl color (hue differs depending on the angle of illumination and light reception).

In the present embodiment, first, the white base material W and the black base material B are each coated with a coating material containing each of the glittering materials E1, E2,... at a predetermined concentration by a predetermined thickness (for example, 15 μm). The surface of the coating film may be coated with a clear coat in a predetermined film thickness (for example, several tens of μm). Then, by the measuring unit 2, the gonio-spectral reflectance coefficient (R _E1,W , R _E1,B ) of the surface of the coating film containing the various bright materials E1, E2,... , (R _{E2, W} , R _{E2, B} ), and the film thicknesses X _E1 , X _E2, ... Of the coating film are measured.

(Step S4)
Next, each base W, variable angle spectroscopic reflectance factor _R W of B, _{R B,} variable angle spectroscopic reflectance factor of the coating film having only pigment _{P1 (R P1, W, R} P1, B) and a thickness X _{From P1} , the scattering coefficient S _P1 and the absorption coefficient K _P1 are calculated for each light receiving angle θ and each wavelength λ in the coating film having only the pigment P1 in the arbitrary film thickness and the arbitrary background color (brightness). The scattering coefficient S _P1 and the absorption coefficient K _P1 can be calculated based on the optical model of pigment (Kuberka-Munk theory). The calculation of the scattering coefficient S _P1 and the absorption coefficient K _P1 is performed by a calculation unit (not shown) built in the measurement unit 2 or the calculation unit 6 of the computer 3. Similarly, the scattering coefficients S _P2 and S _P3 for each light receiving angle θ and each wavelength λ of each coating film containing the pigments P2, P3,... .. and absorption coefficients K _P2 , K _P3, ... The measured goniospectral reflectance coefficient may be affected by specular reflection on the surface and internal specular reflection caused by Fresnel reflection generated at the interface between the clear layer on the surface and air. Therefore, the measured gonio-spectral reflectance coefficient may be corrected to an ideal reflection state that is not affected by the specular reflection by the Saunderson correction method or the like.

(Step S5)
Next, the gonio-spectral reflectance coefficients R _W and RB of the bases _W and _B , the gonio-spectral reflectance coefficients (R _E1,W , R _E1,B ) and the film thickness of the coating film having only the glitter material E1. From X _E1 , the coverage P _E1 of the coating film having only the glitter material _E1 is calculated. Based on this coverage P _E1 , the goniospectral reflectance coefficient R _E1 for each light receiving angle θ and each wavelength λ in an arbitrary film thickness and an arbitrary base color (brightness) is calculated. The calculation of the coverage P _E1 and the gonio-spectral reflectance coefficient R _E1 is performed by a calculation unit (not shown) built in the measurement unit 2 or the calculation unit 6 of the computer 3. Similarly, the coverage P _E2 , P _E3, ... Of each coating film containing the glittering materials E2, E3,... Independently, and for each light receiving angle θ at any film thickness and any background color (brightness) , And the goniospectral reflectance coefficients R _E2 , R _E3 ... For each wavelength λ.

(Step S6)
Each data obtained in the above steps S1 to S5 is transmitted to the storage unit 5 of the computer 3 via the input unit 4 and stored as a material database (see FIG. 3). Each data may be transferred to the storage unit 5 of the computer 3 immediately after measurement or calculation, or may be temporarily stored in the memory in the measurement unit 2 and then collectively transferred to the storage unit 5.

[Construction of reproduction calculation means]
Next, a reproduction calculation means for reproducing the paint color is constructed through the procedure shown in FIG. 4, and this reproduction calculation means is installed in the computer 3. Hereinafter, each procedure for calculating the paint color will be described in detail.

(Step S7)
First, in the design stage of an object to be coated (for example, a car body), the coating color of the object to be coated is determined, and a trial paint for producing the coating color is prepared. Then, a trial paint is applied on the white base W and the black base B with a predetermined film thickness (for example, 15 μm) to form a coating film. The surface of the coating film may be coated with a clear coat in a predetermined film thickness (for example, several tens of μm). Then, the measuring unit 2 measures the gonio-spectral reflectance coefficients R _C,W , R _C,B of the surface of the coating film of the trial paint formed on the white base W and the black base B, and the coating film concerned. The film thickness X _{C of} is measured.

(Step S8)
Next, the composition of the trial paint is quantified. Specifically, the composition of the trial paint is determined from the variable angle spectral reflectance coefficients R _C,W , R _C,B of the coating film of the trial paint measured in step S7 and the material database stored in the storage unit 5. Quantify. Specifically, the gonio-spectral reflectance coefficients R _{C, W} , R _{C, B} of the coating film of the trial paint and the gonio-angles of the various pigments P1, P2,... Spectral reflectance coefficients (R _P1,W , R _P1,B ), (R _P2,W , R _P2,B )... And various eccentric spectral reflectance coefficients (R _E1,W , R _E1,B ), (R _E2,W , R _E2,B )... are compared to calculate the types and blending ratios of the pigment and the luster color material contained in the trial paint. If the composition of the trial material is known in advance, step S7 (application of the trial paint on the white base W and the black base B, and measurement of the goniospectral reflectance coefficients R _C,W , R _C,B ) ) And step S8 (quantity of trial paint) can be omitted.

(Step S9)
Next, the scattering coefficient and the absorption coefficient due to the pigment contained in the coating film of the trial paint are calculated. Specifically, in the material database, the scattering coefficients S _P1 and S _P3 of the pigments (for example, P1 and P3) contained in the trial paint are multiplied by the compounding ratio of each pigment in the trial paint, and then these are synthesized. By doing so, the scattering coefficient S _P due to the pigment contained in the trial paint is calculated. Similarly, the absorption coefficients K _P1 and K _P3 of the selected pigments P1 and P3 are multiplied by the compounding ratio of each pigment in the trial paint, and these are synthesized to obtain the absorption caused by the pigment contained in the trial paint. The coefficient K _P is calculated. From the scattering coefficient S _P and the absorption coefficient K _P thus obtained, the gonio-spectral reflectance coefficient R _P due to the pigment contained in the trial paint in an arbitrary film thickness and an arbitrary base color is calculated. When the gonio-spectral reflectance coefficient in the ideal state is corrected in step S4, the inverse function may be used to correct the gonio-spectral reflectance coefficient in the actual state.

(Step S10)
Next, the goniospectral reflectance coefficient due to the glittering material contained in the coating film of the trial paint is calculated. Specifically, in the material database, the goniospectral reflectance coefficients R _E2 and R _E4 of the luster pigments (for example, E2 and E4) contained in the trial paint were multiplied by the compounding ratio of each luster _pigment in the trial paint. By synthesizing the above, the goniospectral reflectance coefficient R _E due to the glittering material contained in the trial paint is calculated for an arbitrary film thickness and an arbitrary base color.

(Step S11)
Then, obtained in step S9, the variable angle spectroscopic reflectance factor R _P due to pigment contained in the prototype coating was determined in step S10, variable angle spectroscopic reflectance factor due to the luminous material contained in the prototype paint By combining with R _E , the gonio-spectral reflectance coefficient R of the coating film of the trial paint in an arbitrary film thickness and an arbitrary base color is calculated. Then, based on the gonio-spectral reflectance coefficient R, the coating color (for example, tristimulus value XYZ or L ^* a ^* b ^* value) of the coating film of the trial paint at an arbitrary film thickness and an arbitrary base color is determined. calculate. Reproduction calculation means (program) that reproduces the coating color of the coating film using the trial paint by the above steps S8 to S11 is installed in advance in the calculation unit 6 of the computer 3.

[Optimization of film thickness and base color]
(Step S12)
Next, the calculation unit 6 in which the reproduction calculation means is installed sets the optimum values of the film thickness and the background color. Specifically, as shown in FIG. 5, first, the reproduction calculation means is used to repeatedly perform the calculation while varying the film thickness and the base color (for example, the brightness L ^* ), and an arbitrary film within the set range is calculated. With respect to the thickness and an arbitrary base color, the fluctuation of the coating color when the film thickness of the coating film is slightly changed is calculated. For example, the variation of the coating color when the film thickness is changed by ±1 μm is calculated for all the film thicknesses and the lightness of the base in which the film thickness is 10 to 20 μm and the base lightness L ^* is in the range of 2 to 90.

FIG. 6 is a graph showing fluctuations in the coating color due to minute fluctuations in the film thickness for arbitrary film thicknesses and base colors. The graph in the figure shows the variation of the coating color when the film thickness is slightly changed for each light receiving angle θ (−15°, +15°, +25°, +45°, +75°, +110°) as a shade of color. It is a representation. The darker the color, the smaller the variation in the coating color, and the lighter the color, the greater the variation in the coating color. The horizontal axis of each graph is the film thickness (μm), and the vertical axis is the lightness L ^* of the base.

(Step S13)
Next, the allowable range of the film thickness and the base color is set so that the fluctuation of the coating color when the film thickness is slightly changed is within a predetermined range. As a result, if the film thickness and base color are within this allowable range, even if the film thickness slightly changes for each product or part due to changes in coating conditions, etc. By suppressing, it is possible to obtain a uniform paint color that matches the target color. In the graph of FIG. 6, in all the light receiving angles θ, the region where the variation of the coating color is equal to or less than a predetermined value (the region where the color is darker than a predetermined amount, the region surrounded by the dots in the figure) is the film thickness and the base The color is within the allowable range.

(Step S14)
Within the range of the film thickness and the background color set above, the minimum film thickness and the corresponding background color are the optimum values of the film thickness and the background color. In FIG. 6, the film thickness and the base color at the point where the film thickness is the minimum (x mark) in the allowable range surrounded by the scattered points are the optimum values.

As described above, it is possible to acquire the minimum film thickness necessary for keeping the variation of the coating color due to the slight variation of the film thickness to be equal to or less than the predetermined value, and the corresponding background color (brightness of the background) as the optimum value. As a result, it is possible to obtain a uniform coating color that matches the target color by suppressing the variation in the coating color for each product or part, and to reduce the film thickness as much as possible to reduce the amount of paint used. , Reduction of coating time, reduction of drying time, reduction of drying energy to reduce cost, and reduction of paint accumulation at the end of the coated surface to improve appearance quality.

The optimum values of the film thickness and the base color calculated in this way are output to the display unit 7. In addition, the display unit 7 displays a graph showing the allowable range and the optimum value of the film thickness and the base color shown in FIG. 6, the composition of the trial paint, the actual color of the paint color calculated by the reproduction calculation means, and the like. Good.

From the above, if the program for executing the above steps S8 to S14 is installed in the computer 3 in which the material database is stored, the variable angle spectral reflectance coefficient R _C, of the coating film of the trial paint measured in step S7 _, Only by inputting _W , R _{C, B} and the film thickness X _C into the computer 3, the minimum film thickness that matches the target color and obtains a uniform coating color and the background color corresponding thereto are automatically obtained. You can ask.

The present invention is not limited to the above embodiment. Hereinafter, other embodiments of the present invention will be described, but the description of the points overlapping the above embodiments will be omitted.

For example, in the above-described embodiment, the allowable range of the film thickness and the base color is set based on the change of the coating color when the film thickness of the coating film is slightly changed, but in addition to this, it is based on the hiding power. The allowable range of film thickness and base color may be set. Specifically, for example, the reproduction calculation means calculates an arbitrary film thickness based on the goniospectral reflectance coefficients R _C,W , R _C,B of the coating film of the trial paint on the white background W and the black background B. Also, the hiding power of the trial paint in the base color can be calculated, and the allowable range of the film thickness and the base color can be set so that the hiding power of a predetermined range can be obtained. Then, the minimum film thickness of the overlapping portion of the film thickness and the base color permissible range based on the variation of the coating color due to the slight fluctuation of the film thickness and the film thickness and the base color permissible range based on the hiding power. And the base color corresponding to this becomes the optimum value.

Further, in the above embodiment, the case where the paint itself for obtaining the target color is used as the trial paint in steps S7 and S8 is shown, but the present invention is not limited to this. For example, a first trial paint containing only a pigment having the same concentration as the pigment contained in the paint for obtaining the target color, and a first trial paint containing only the glitter material having the same concentration as the glittering material contained in the paint for obtaining the target color. Two trial paints may be used. In this case, the first trial paint and the second trial paint are applied on the white base W and the black base B, respectively, and the goniospectral reflectance coefficient of each coating is measured. Then, the gonio-spectral reflectance coefficient of the first trial paint and the gonio-spectral reflectance coefficients (R _P1,W , R _P1,B ) of the various pigments on the bases W and B included in the material database. , (R _{P2, W} , R _{P2, B} ) _, the type and blending ratio of the pigment contained in the trial paint are calculated. In addition, the gonio-spectral reflectance coefficients of the second trial paint and the gonio-spectral reflectance coefficients (R _E1,W , R _E1,B ), (R _E2,W ) of various luster materials included in the material database. , R _{E2, B} ), and the like, the type and mixing ratio of the glittering material contained in the trial paint are calculated. In this way, the composition of the trial paint can be quantified more accurately by measuring the gonio-spectral reflectance coefficient separately for the first trial paint containing only the pigment and the second trial paint containing only the luster color material. It becomes possible.

Further, in the above embodiment, the case where the base material to which the trial paint is applied is white and black is shown, but the present invention is not limited to this, and a base material of a plurality of colors having at least a difference in lightness may be used. However, the combination of black and white is the most preferable because the difference in brightness is the largest and the effect of the underlying color on the coating color (hiding power etc.) is likely to appear. Further, the base material to which the trial paint is applied is not limited to two colors and may be three or more colors.

Further, in the above-described embodiment, the case where the coating film thickness of the trial paint is one level is shown, but the present invention is not limited to this, and a plurality of levels (for example, three levels) of coating film are prepared and The goniospectral reflectance coefficient may be measured.

The coating condition setting method of the present invention can be applied not only to coating of automobiles but also to coating of any product using a coating material containing a pigment and a luster color material.

1 coating condition setting device 2 measuring unit 3 computer 4 input unit 5 storage unit 6 computing unit 7 display unit W white background B black background

Claims (3)

A method for setting the optimum conditions of the film thickness of the coating film and the base color by simulation when coating a trial paint containing a pigment and a bright material on the base,
A step of calculating a change in the coating color when the film thickness is slightly changed in an arbitrary film thickness and an arbitrary base color,
A step of setting the range of the film thickness and the base color in which the variation of the coating color is within a predetermined range,
A coating condition setting method comprising the steps of setting a minimum film thickness within the range of the film thickness and the base color and a base color corresponding thereto as an optimum value of the film thickness and the base color. Scattering coefficient and absorption coefficient in arbitrary film thickness and arbitrary background color of plural kinds of coating film containing various pigments alone, and arbitrary film thickness and arbitrary of plural kinds of coating film containing various luster pigments alone Creating a material database including the goniospectral reflectance coefficient in the background color of
From the material database and the composition of the trial paint, the goniospectral reflectance coefficient due to the pigment contained in the trial paint and the goniospectral reflectance coefficient due to the glitter material contained in the trial paint are calculated. The process of
By combining the gonio-spectral reflectance coefficient due to the pigment contained in the trial paint and the gonio spectral reflectance coefficient due to the luster material contained in the trial paint, an arbitrary film thickness and an arbitrary substrate are obtained. And a step of constructing a reproduction calculation means for reproducing the paint color in the color,
The coating condition setting method according to claim 1, wherein the optimum values of the film thickness and the base color are obtained by performing repeated calculations using the reproduction calculation means. A program for causing a computer to set optimum conditions of a film thickness and a base color of a coating film when a trial paint containing a pigment and a luster color material is coated on the base,
A step of calculating a change in the coating color when the film thickness is slightly changed in an arbitrary film thickness and an arbitrary base color,
A step of setting the range of the film thickness and the base color in which the variation of the coating color is within a predetermined range,
A program for causing a computer to execute a step of setting a minimum film thickness within the range of the film thickness and the background color and a background color corresponding thereto as an optimum value of the film thickness and the background color.