JPS61145436A - Method and apparatus for evaluating appearance property of film - Google Patents

Abstract

PURPOSE:To make it possible to simply evaluate the surface of a film having high appearance quality such as excellent glossiness or sharpness, by detecting only reflected light forming a definite angle to an incident direction in the reflected light from a surface to be measured. CONSTITUTION:Parallel luminous flux is vertically incident to a surface 14 to be measured and the reflected light thereof is taken out of the parallel luminous flux by a translucent mirror 15 to be converged to the focal surface of a lens by a condensing lens 16 while the light intensity distribution on the focal surface is detected by a photodiode array 18. When an ftheta lens is used as the condensing lens 16, only light reflected to the same direction is separated from the other reflected light and can be detected effectively. Then, the ratio of the light intensity of the component of reflected light forming an angle of almost zero to the incident direction of parallel luminous flux in the reflected light from the surface 14 to be measured and that of the component of reflected light forming an angle of 0.5-20 deg. to the incident direction of parallel luminous flux is calculated by an amplifying operation apparatus to enable the evaluation of the appearance properties of a film.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is a coating film appearance property evaluation method that quantitatively evaluates the appearance properties of a finished surface such as a paint film that has a high level of gloss and sharpness. METHODS AND APPARATUS.

Conventional technology> Conventionally, as a method for evaluating the appearance properties such as gloss and sharpness of paint films, there is, for example, the specular gloss measurement method specified in JIS Z 8741, and practical instruments using this method have been used. Many are widely used industrially. There is a method for measuring the specular gloss as shown in FIG. 6. In the specular gloss measurement method described above, light emitted from a light source 1 is converted into a parallel beam by an aperture 2 with an opening angle Sl force q ~ 3 degrees and a lens 4, and is made incident on a surface to be measured 5, and the light reflected from the surface to be measured 5 is The lens 6 creates an aperture 8 with an opening angle S2 of 1.8 to 12 degrees.
All of the light that has passed through the aperture 8 is received by the light receiver 9, and the integrated value of the received light intensity in this range is used as a measure of glossiness, as shown in Fig. 7. be.

<Problems to be Solved by the Invention> By the way, as described above, the opening angle S1 of the light source side ear opening 2 is 1 to 3 degrees, and the opening angle S2 of the receiver side ear opening 8 is 1.8 to 12 degrees.
Because the angle is wide open, the parallelism of the incident light is poor, and the reflected light also includes reflected light that deviates from the direction of specular reflection. Since it is detected as an integral value of the received light intensity in the range,
There is a problem in that the ability to inspect differences in glossiness on a high-gloss surface deteriorates, making it impossible to detect changes in the light-receiving pattern.

In particular, recent automotive paints and other high-light V'? ,
With the increasing demand for paint films with a high gloss finish, the importance of measuring the degree of pigment dispersion in the paint manufacturing process and evaluating the glossiness of the final finished paint film has increased, and as a result, the traditional mirror finish as described above has become increasingly important. Gloss alone is insufficient.

Therefore, an object of the present invention is to make it possible to evaluate finished surfaces such as paint films that have high-level appearance properties such as excellent gloss and sharpness.

Means for Solving the Problems In order to achieve the above object, the method for evaluating the appearance and properties of a coating film according to the present invention is such that a parallel light beam is perpendicularly incident on the surface to be measured, and the reflected light from the surface to be measured is separated. by means of a means to take out the parallel light beam a and converge it onto the focal plane of the lens by means of a lens;
It is characterized by detecting the light intensity distribution on the focal plane to evaluate the appearance and properties of the paint film.

Furthermore, the coating film appearance and property evaluation apparatus of the present invention includes a light source and a light beam Il! which converts the light from the light source into a parallel beam and irradiates the surface to be measured from a direction perpendicular to the surface to be measured. ! Adjustment means and luminous flux!
a beam separating means installed between the adjusting means and the surface to be measured and extracting the reflected light from the measuring surface to the outside of the parallel beam; a lens means converging the reflected light taken out from the beam separating means; It is characterized in that it includes a light intensity distribution detection means installed on the focal plane of the lens means, and a processing means for a light intensity distribution signal output from the light intensity detection means.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

Figure 1 is a block diagram of the coating film appearance and property evaluation device.
1 is a laser as a light source; 12 is a condenser lens, a pinhole, a collimator lens, etc. (not shown); and 14 is a light flux adjusting means for adjusting the laser beam from the laser 11 into a parallel light beam having a predetermined diameter; A reflecting surface to be measured 15 is interposed between the light flux adjustment means 12 and the surface to be measured 14 and directs a part of the light reflected by the surface to be measured 14 in a direction perpendicular to the optical axis of the incident light beam. A translucent mirror 16 serves as a beam separating means for separating the light beam into two beams, and a condenser lens 16 serves as a lens means for condensing a part of the beam reflected from the surface to be measured 14 onto the focal plane X-Y. Also, 1
8 is a diode array (7r) as a light intensity distribution detecting means having a concentric light receiving section that converts the light focused on the focal plane X-Y into an electric signal. Then, the distance of the condenser lens 16 from the surface to be measured 14, and the distance of the condenser lens 1
The distances between the six and seven otodiode arrays 18 are both equal to the focal length of the condenser lens 16. Further, 19 is an amplification calculation device for processing the light intensity distribution signal detected by the diode 7 ray 18, and 20 is a display device for displaying the results of the processing by the amplification calculation device 19r. The width arithmetic unit 19 and the display 20 constitute a calculation means 30 as a processing means.

In the coating film appearance and property evaluation apparatus having the above configuration, first, a light beam is emitted from the light source 11. The above luminous flux is not adjusted! ! The f-bow 212 adjusts the 1lTr round bundle of a predetermined 1-1 diameter. As shown in FIG.
The light is incident from a direction perpendicular to 4. The incident parallel light flux is
This reflected light beam is reflected by the surface of the surface to be measured 14, but this reflected light beam is affected by the refractive index of the coating film forming material, the surface shape of the surface to be measured 14, that is, the surface waviness and roughness, and the light scattering 6L contained inside. It has a certain strength and spread depending on the properties of the particles. Then, a part of the reflected light beam from the surface to be measured 14 is separated laterally by a semi-transparent mirror 15.

The separated reflected light flux is focused by a condenser lens X'16 onto the focal plane of a condenser lens 7:16. That is, of the light reflected from the surface to be measured 14, only the light reflected in the direction of the same angle θ with respect to the incident direction is all converged by the condenser lens 16 to the same position on the focal plane of the condenser lens 16. be done. At this time, when an fθ lens is used as the condenser lens Everything from the condenser lens 16 to the focus of the fθ lens,
On the focal plane a distance bm away from the optical axis
The light is focused at the position rθ1lIl. That is, only the light reflected in the same direction can be separated from other reflected light and can be effectively detected. The light condensed on the focal plane is detected by the amplification calculating device 19 shown in FIG. The ratio between the light intensity of the light component and the light intensity of the reflected light component whose angle with the incident direction of the parallel light beam is in the range of 0.5 to 20 degrees is calculated. Then, the result of the calculation is displayed on the display 20.

The results of various measurements made using such a coating film appearance property evaluation apparatus will be described below.

FIG. 3 shows an example of the measured light intensity distribution on the 7-Lie transform surface.

This uses a parallel beam of light from a helium neon laser with a beam diameter of 10 m+s as the incident light, and the surface to be measured is an automobile top coat.
The visual glossiness becomes better in the order of C. According to this, it is recognized that the reflection patterns differ within the range of θ of ±1 degree, and it can be seen that not only the intensity of the reflected light but also the pattern of the reflected light can be effective information. Further, as a metric for the reflected light pattern, the light intensity at 020 degrees, the light intensity at 021 degrees, the ratio of the light intensity at 020 degrees and the light intensity at 021 degrees, etc. can be used. In addition, in Figure @4, the horizontal axis shows the visual evaluation and ranking of various automotive top coats, including black glass plates, and the vertical axis shows 20 degree specular gloss and light intensity at 020 degrees. According to this, in an area close to a surface with high gloss and high sharpness, such as a black lath surface, 20 degree specular gloss has a low ability to detect differences. It is recognized that I(0°) has a sufficient ability to detect a difference, whereas the value of I(0°) becomes small.

In addition, in the PJ5 diagram, the horizontal axis shows the dispersion time in medium dispersion using glass beads as the dispersion medium, and the vertical axis shows the methods defined as methods for measuring dispersed particles of pigment in paint liquids, and the methods currently used in paints. Particle size data by method A using Gly/Dodeno specified in JIS K 5400, which is widely used in industry, and the ratio of light intensity at θ = 2 degrees and light intensity at θ = 0 degrees are shown. In this example, a quinacridone red pigment was dispersed in flukitovarnish at a pigment volume concentration of 9.4%, and the dispersion was applied to a glass plate with a doctor blade, which was used as the surface to be measured. According to the figure, the light intensity ratio I2°/IO' has a correlation with the particle size of the Grindogeno, and it is also possible to detect the degree of dispersion in a region that cannot be detected by the Grindogeno. is possible.

The present invention can be modified in design other than the embodiment described above, and in the embodiment shown in FIG. 1, the light source 11 can be not only a helium neon laser but also other lasers.
A xenon arc lamp, a tungsten lamp, etc. may be used, and a plurality of lasers with different oscillation wavelengths may be used to compensate for the decrease in the amount of reflected light due to the light absorption characteristics of the pigment.

The condensing lens 16 does not necessarily have to be an fθ lens, but may be a general lens, that is, an f tanθ lens. In 7r), a diode array with a concentric light-receiving surface was used, but it is also possible to use one photodetector for scanning, or a total of two photodetectors, one in the center and one in the periphery. You may also place a container.

<Effects of the Invention> As can be seen from the above description, the present invention allows a parallel light beam to enter the surface to be measured perpendicularly, and among the reflected light from the surface to be measured, only the reflected light whose angle with the incident direction is constant. Since it detects and measures light intensity, it is possible to easily and accurately evaluate painted surfaces with high quality appearance such as excellent gloss and sharpness.

Furthermore, it is particularly effective when used for evaluating pigment dispersion quality and coating film forming process.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
FIG. 3 shows the light intensity distribution of the reflected light measured by the apparatus configured as shown in FIG. 2. FIG. 4 shows the light intensity distribution of the reflected light measured by the embodiment of the present invention. FIG. 5 is a diagram showing the degree of pigment dispersion measured according to an example of the present invention, and FIG. 16 is a diagram showing a coating film appearance property evaluation apparatus for carrying out the conventional specular gloss measurement method. FIG. 7 is a diagram showing a light reception pattern by the apparatus of FIG. 6. 11... Light source, 12... Luminous flux adjustment means, 14...
Surface to be measured, 15... Semi-transparent mirror, 16... Condenser lens, 18... Light intensity distribution detection means, 19... Amplification calculation device, 20... Display device, 30... calculation means. Patent Applicant: Nippon Paint Co., Ltd. Attorney: Patent Attorney Aoyama Sogai (2) Figure 1 Figure 2 Figure 3 Figure 6

Claims (8)

[Claims] (1) A parallel beam of light is perpendicularly incident on the surface to be measured, the reflected light from the surface to be measured is taken out of the parallel beam by the beam separation means, and is converged on the focal plane of the lens by the lens means. A method for evaluating the appearance and properties of a paint film, characterized in that the appearance and properties of the paint film are evaluated by detecting the light intensity distribution of the light intensity distribution. (2) Among the reflected light from the surface to be measured, the light intensity of the component of the reflected light whose angle with the incident direction of the parallel light beam is approximately zero is detected. The coating film appearance and property evaluation method described in . (3) A patent claim characterized by detecting the light intensity of a component of the reflected light from the surface to be measured whose angle with the incident direction of the parallel light beam is in the range of 0.5 to 20 degrees. The method for evaluating the appearance and properties of a coating film according to item (1). (4) Among the reflected light from the surface to be measured, the light intensity of the component of the reflected light whose angle with the incident direction of the parallel light beam is approximately zero;
The method for evaluating the appearance and properties of a coating film according to claim 1, characterized in that the ratio of the light intensity of the component of the reflected light whose angle is in the range of 0.5 to 20 degrees is calculated. (5) a light source, and a light flux adjusting means that converts the light from the light source into a parallel light flux and irradiates the surface to be measured from a direction perpendicular to the surface to be measured;
A light beam separating means is installed between the light flux adjusting means and the surface to be measured, and extracts the reflected light from the surface to be measured out of the parallel light beam, and a lens means converges the reflected light extracted from the light beam separating means. and a light intensity distribution detection means installed on the focal plane of the lens means, and a processing means for a light intensity distribution signal output from the light intensity distribution detection means. . (6) The processing means for the light intensity distribution signal is a means for detecting the light intensity of a component of the reflected light from the surface to be measured whose angle with the incident direction of the parallel light beam is approximately zero. A coating film appearance property evaluation device according to claim (5). (7) The processing means for the light intensity distribution signal has an angle of 0.5 to 2 with the incident direction of the parallel light beam of the reflected light from the surface to be measured.
The coating film appearance and property evaluation apparatus according to claim (5), characterized in that the apparatus is a means for detecting the light intensity of a component of reflected light in a range of 0 degrees. (8) The light intensity distribution signal processing means calculates the light intensity of a component of the reflected light from the surface to be measured whose angle with the direction of incidence of the parallel light flux is approximately zero, and the direction of incidence of the parallel light flux. The coating film appearance property according to claim (5), characterized in that the method is a calculation means for calculating the ratio of the light intensity of the component of the reflected light whose angle formed by the angle is in the range of 0.5 to 20 degrees. Evaluation method.