JP2005028360A - Light irradiation device, touch-up painting method and application for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light irradiation device used for both of coating film light setting/coating film color evaluation. <P>SOLUTION: The light irradiation device is equipped with an irradiation instrument provided with a lamp for emitting light having ≤5000K correlated color temperature and a filter arranged in front of the irradiation instrument in the light irradiation direction and attached detachably. The light intensity of the light emitted from the lamp is 1-5 mW/cm<SP>2</SP>in 365 nm wavelength and 20 cm irradiation distance and the light intensity in 800 nm wave length and 10 cm irradiation distance is 80-250 mW/cm<SP>2</SP>. The light irradiation device is used for both methods of the setting of a photosetting composition and the detecting of a coating film color determination. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention uses a light irradiating device that can cure a photocurable composition and can be used for determining the color tone of a coating film, and also for photocuring / coating color determination, and the light irradiation device. The repair coating method.

  In recent years, in the automotive repair coating industry, it has been widely practiced to apply or fill a photo-curable paint to a damaged part of an automobile and to irradiate the repair part with a light irradiation device to cure the paint. Yes. Conventionally, an ultraviolet irradiation device using a metal halide lamp, a high-pressure mercury lamp, or the like as a light source has been used as such a light irradiation device, but there is a problem that ultraviolet rays and ozone harmful to the human body are generated. Therefore, various repair coating methods using a photocurable composition that is cured by light in the wavelength range of light (visible light to infrared light) having an emission spectrum at a wavelength of 300 nm or more with almost no generation of ultraviolet rays or ozone have been proposed. Yes.

  For example, Patent Document 1 describes a light irradiation apparatus including a specific auxiliary tool. According to this apparatus, it is possible to irradiate light constantly within a target range, which is useful for repair coating. Patent Document 2 describes a light irradiation method using an irradiation apparatus in which a heat ray cut filter is mounted in the irradiation direction of a lamp. According to this method, the photocurable composition applied to the object to be coated can be cured without causing deformation or discoloration of the object to be coated. Patent Document 3 describes a light irradiation device in which a support column supporting a lamp can be raised and lowered. According to this light irradiation apparatus, the photocurable composition applied to the surface of the object having a complicated shape can be efficiently photocured.

  By the way, in the field of automobile repair coating, a specific light irradiation device is used to evaluate the color tone of the coating film after the repair coating. As such a light irradiation apparatus for coating color tone evaluation, an artificial solar lamp having a light source that emits a light beam having a correlated color temperature of 6500K to 6800K or a lamp having a spectral distribution equivalent to that of sunlight is used as irradiation light. It is common sense in the paint industry.

Actually, the light irradiation device for use in curing the photocurable composition is used for the finished appearance evaluation after repair, that is, the judgment of the coating color tone, for example, the colorimetric work for comparing the repair coating and the color sample. Then, for reasons such as the amount of light is too strong, accurate evaluation can not be performed, on the other hand, even if the photocurable composition is irradiated with the light beam of the light irradiation device for coating color tone evaluation, the light amount is insufficient, It is generally known that the curing reaction does not proceed sufficiently. Therefore, there are methods in which two types of light curing device for photo-curing and light irradiation device for coating film color determination are always provided at the work site, or coating film color determination is performed in outdoor direct sunlight. Is the current situation.
Japanese Patent Laid-Open No. 10-40703 JP 2001-259511 A Utility Model Registration No. 3085776

  An object of the present invention is to provide a light curing device for photocuring / color tone determination, and a repair coating method using the same, capable of photocuring the coating film and determining the color tone of the formed coating film. And providing its use.

As a result of diligent research to solve the above-described problems, the present inventors have determined that a light irradiation apparatus including a lamp that emits a light beam having a specific range of correlated color temperature and light intensity depends on whether or not a filter is mounted. The present inventors have found that switching between photocuring and coating color tone evaluation is possible, and the present invention has been completed.
That is, the present invention provides: An irradiator including a lamp that emits a light beam having a correlated color temperature of 5000 K or less, and a detachable filter disposed in front of the irradiator in a light irradiation direction, and the light beam emitted from the lamp is The light intensity at an irradiation distance of 20 cm at a wavelength of 365 nm is in the range of 1 to 5 mW / cm ² , and the light intensity at an irradiation distance of 10 cm at a wavelength of 800 nm is in the range of 80 to 250 mW / cm ^2. Light irradiation device,
2. The lamp is a double-tube type lamp composed of a ceramic arc tube in which a luminescent material is enclosed and an outer tube covering the arc tube, and the outer tube is 50% or more in a light beam of 180 nm. 2. The light irradiation device according to item 1, comprising a fused silica glass having a transmittance of 80% or more for light at 220 nm and a transmittance of 90% or more for light at 300 nm.
3. The photocurable composition is applied to the damaged part, and the photocurable composition is cured by irradiating the coating film surface with light using the light irradiation device described in Item 1 or 2. Repair painting method,
4). After applying the photocurable composition to the damaged part and irradiating the coating film surface with light using the light irradiation device according to item 1 or 2, the photocurable composition is cured. Next, a top coat is applied and dried on the coated surface to form a top coated film, and the surface of the top coated film is irradiated with light through a filter using the light irradiation device described in item 1 or 2. A repair coating method characterized by determining the color tone of the top coat film by
5. The repair coating method according to item 4, wherein the top coat film contains a pigment having glitter as a part of the component, and the light irradiation device according to item 6.1 or 2, the photocurable composition Use of the light irradiation device for both curing and coating color tone determination,
About.

  The light irradiation apparatus of the present invention is capable of sufficiently curing a photocurable composition by light irradiation for a short time, and is not only a simple color determination but also a bright pigment that has been difficult to determine conventionally by mounting a filter. The orientation, denseness, flip-flop properties, etc. of the glitter pigment containing can be easily visually confirmed. When the light irradiation device of the present invention is applied to a repair coating application such as an automobile, the colorimetric work for comparing the repair coating portion and the sample card can be performed more accurately. It becomes easy to obtain a color tone equivalent to that of the normal part. Since it can be applied to both photocuring and coating color tone determination in this way, by providing this light irradiation device at the work site, it is possible to perform both curing of the coating film and color tone determination. Have.

  The light irradiation apparatus of the present invention is used for both photocuring / coating color tone determination, and an irradiator including a lamp having a correlated color temperature of radiated light of 5000 K or less, preferably 3000 to 4900 K, and light irradiation of the irradiator It is desirable to provide a filter that can be attached and detached in the direction, and the irradiator preferably includes a reflector and a lens. Here, “mounting / removing” means “mounting and demounting”.

In the present invention, the color tone of the coating film means the overall finish of the appearance of the coating film formed by paints, inks, cosmetics, etc., in addition to the color, gloss, transparency, orientation of the pigment, It can be confirmed mainly by visual observation, including the denseness of the pigment, flip-flop properties (glittering), pearly luster, jetness and the like.
The color temperature is a kind of index that generally represents the chromaticity of the emitted light. Generally, the light having a higher color temperature tends to be blue, and the light having a lower color temperature tends to be red. The color temperature is expressed by the temperature (K) of an ideal body called a black body. When the color of the light beam is not on the black body locus which is the color locus and the color locus on the chromaticity diagram, the color temperature of the light beam can be approximately expressed as a correlated color temperature. That is, the correlated color temperature is the temperature of the closest black body that does not match completely when the color of the light ray is not on the black body locus. In the present invention, when the correlated color temperature exceeds 5000K, in the coating color tone evaluation, for example, a unique color development such as a metallic feeling or a pearly feeling (pearly luster feeling) of the coating film containing the glitter pigment can be captured. Since it may not be possible, it is not preferable.

The correlated color temperature in the present invention is determined by the color temperature measuring device when the color temperature of the emitted light becomes substantially constant after, for example, about 3 minutes since the light irradiation device is turned on. The measured value.
Further, the emitted light beam preferably has a certain amount of light in the light absorption wavelength region of the photopolymerization initiator contained in the composition in order to cure the photocurable composition, for example, a wavelength of 365 nm The light intensity at an irradiation distance of 20 cm is 1 to 5 mW / cm ² , preferably ² to 4 mW / cm ² , and at a wavelength of 800 nm, the light intensity at an irradiation distance of 10 cm is 80 to 250 mW / cm ^2. , Preferably 100-200mW
/ Cm ² is desirable.

Further, the illuminance of the emitted light is desirably in the range of 2000 to 5000 lx, preferably 2500 to 4500 lx.
The light intensity is obtained by measuring the center of the emitted light with a light meter at the predetermined distance. As a light meter used for measuring the light intensity with a wavelength of 365 nm, for example, “UNIMETER”
UIT-150 TYPE UIT-150A "(trade name, manufactured by Ushio Denki Co., Ltd.), and as a light meter used for measuring the light intensity at a wavelength of 800 nm, for example," MODEL I400A "(trade name, INTERNATIONAL LIGHT INC. Manufactured). The illuminance is a value obtained by measuring the center of the emitted light with “MINOLTA T-10” (trade name, manufactured by Minolta, Inc., illuminometer) at an irradiation distance of 1 m.

  As a lamp provided in an irradiator for irradiating a light beam having the above color temperature and light intensity, a conventionally known lamp can be used without limitation, such as a metal halide lamp, a ceramic metal halide lamp, a halogen lamp, a xenon lamp, a krypton lamp, Examples include fluorescent lamps, semiconductor lasers, and light emitting diodes. Among these, ceramic metal halide lamps in which the arc tube is made of ceramic are suitable.

As a ceramic metal halide lamp suitable for the light irradiation apparatus of the present invention, for example, it is desirable to have a structure having a double tube structure in which an outer tube is covered so as to cover a luminous tube in which a luminescent material is sealed. A lamp in which nitrogen gas is sealed and sealed is suitable for the space between the outer tube and the outer tube.
In this way, the ceramic metal halide lamp has a double tube structure, and by using ceramic as the arc tube, the luminescent material in the arc tube can be prevented from escaping to the outside. This is because the correlated color temperature can be prevented from changing, and the arc tube is covered with an outer tube, thereby improving the heat retention of the arc tube and keeping the temperature of the luminescent gas in the arc tube constant during lighting. It is preferable that the correlated color temperature of the light emitted from the lamp does not change during lighting.

As a result, it is possible to determine a luminescent material that satisfies the three conditions of correlated color temperature, 365 nm ultraviolet light intensity, and 800 nm infrared light intensity, which are suitable for photocuring and coating color tone determination. is there.
In the ceramic metal halide lamp, a fused quartz glass can be used as a material for the outer tube for satisfactorily transmitting the ultraviolet rays emitted from the arc tube. The fused silica glass is preferably made of a material that transmits ultraviolet light having a wavelength of 365 nm or less. Specifically, it has a transmittance of 50% to 70%, preferably 50 to 60% for 180 nm light, 80 to 90% for 220 nm light, preferably 80 to 85%, and 90% for 300 nm light. % Or more, preferably 90 to 95% of the characteristic fused silica glass. By using an outer tube made of fused silica glass with such characteristics, the photocurable composition can be cured, and color tone judgment can be easily performed even in the colorimetric work of a glittering coating film. It becomes.

  In this specification, the light transmittance with respect to fused silica glass is calculated using a spectroscopic measurement method. Using a standard light source whose spectral distribution is known in advance, the fused silica glass is irradiated with light emitted from the light source, and the spectral distribution of the light transmitted through the glass is measured. Next, the spectral distribution of the light transmitted through the glass is calculated as the light transmittance by comparing with the spectral distribution of the standard light source.

Specifically, for example, mercury, which is a luminescent substance that mainly emits ultraviolet rays, and sodium, which is a luminescent substance that mainly emits infrared rays, can be selected as the luminescent substance. Further, dysprosium and cerium may be added to the light-emitting substance. Thereby, light with good color rendering properties can be emitted, and the color tone of the coating film can be accurately determined.
In the light irradiation device of the present invention, as a filter that is attached to and detached from the front surface of the light irradiation direction lens of the irradiator, for example, a heat-absorbing plate glass colored by adding a trace amount of metal such as iron, nickel, cobalt, selenium, etc. A heat ray reflecting plate glass in which a metal oxide film having a high reflectance is coated on the surface of the float plate glass, frosted glass in which sand as an abrasive is blown onto the glass surface with compressed air, and the like can be used.

In the present invention, it is possible to suppress the scattering of the light irradiated by the light irradiation device equipped with the filter, to make the illuminance to the irradiated object uniform, and to more accurately evaluate the color tone of the coating film. It is.
In the present invention, it is desirable that the illuminance of the light ray through the filter is in the range of 100 to 3000 lx, preferably 1500 to 2500 lx.

The above irradiators may be used alone, or a plurality of the irradiators may be appropriately arranged and used. Further, it may be one that is mounted on a support column or one that is held and operated by hand. It is desirable that the support column is telescopic, and a support wheel may be attached to the bottom.
The method of the present invention is a repair coating method in which a photocurable composition is applied to a surface to be coated, and the photocurable composition is cured by irradiating the coating film surface with light using the light irradiation device. is there.

As the photocurable composition, any conventional photocurable putty composition or photocurable primer composition may be used as long as it contains a photopolymerization initiator activated by irradiation of light and a photopolymerizable resin composition. Things can be used without restriction.
There is no restriction | limiting in particular as a to-be-coated surface, For example, the coating-film surface formed on base materials, such as a metal surface, a plastic surface, an inorganic base material surface, and this base material is mentioned.

In the present invention, when the light irradiation device is used for photocuring, it is desirable that the filter is in a detached state, but a filter may be attached if necessary. Moreover, although the said irradiation conditions can be suitably adjusted according to the kind of photocurable composition, a film thickness, etc., as an irradiation distance from a lamp | ramp to a coating film, for example, generally 50 cm or less, Preferably it is 10-30 cm. The irradiation time is in the range of 60 to 180 seconds, preferably 100 to 150.
A range of seconds is preferred.

  In addition, the method of the present invention is to apply a photocurable composition to the damaged part and to cure the photocurable composition by irradiating the coating film surface with light using the light irradiation device. Next, a top coating is applied on the coated surface, and the color of the top coated film is irradiated on the surface of the top coated film by irradiating light having a correlated color temperature of 5000 K or less through a filter using the light irradiation device. This is a repair coating method for judging

As a method for judging the color tone of the top coat film surface in the presence of light rays by the light irradiation device, there are a method by visual observation, a method for color-coordinating the color sample and the paint film surface, a method using a measuring instrument, etc. Can be mentioned. The irradiation distance from the lamp to the top coat film surface is desirably 10 cm or more, and preferably about 30 to 200 cm, and can be appropriately adjusted according to the type of the film.
The top coat film surface to which the method of the present invention is applied is not particularly limited, but enamel paints such as metallic paints, pearl paints and solid color paints usually used for top coat painting; Can do. Moreover, the multilayer coating film by 2 or more types of coating materials chosen from these top coating materials can also be included. Conventionally known methods can be used for applying and drying the top coat, and there is no particular limitation.

In the method of the present invention, even when the top coat surface contains a glitter pigment as a part of the component, the effect can be sufficiently exhibited. Examples of the glitter pigment include aluminum pigment, glitter mica pigment obtained by thinly coating the surface of mica powder with metal oxide such as titanium oxide and iron oxide, copper powder, gold powder, brass powder and the like.
The light irradiation device of the present invention can be used for each application because it can cure the photocurable composition and can also be used for color tone determination of the above-mentioned top coat film, etc. The present invention is suitably applied to repair applications using paint, for example, repair applications such as a coating film provided on an automobile body.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1
FIG. 1 is a schematic view showing a side surface of the light irradiation apparatus of the present invention.
FIG. 2 is a schematic view showing a lamp provided in the light irradiation apparatus of the present invention.
1, the light irradiation device 1 has a structure in which an irradiator 5 having a lamp 2, a mirror 3 and a lens 4 is mounted on a movable support column 6 so as to be movable up and down. Lamp 2 is a correlated color temperature 4300K, the light intensity in the irradiation distance 20cm in 365nm wavelength is about 3 mW / cm ^2, still at a wavelength of 800 nm, the light intensity in the irradiation distance 10cm is, 150 mW / cm ² of about This is a ceramic metal halide lamp that emits a light beam. The glass filter 7 subjected to double-side frosting is attached to the front surface of the lens 4 and is detachable, and can be installed so as to cover the light emitting surface from the irradiator 5.

In FIG. 2, the lamp 2 has a double tube structure in which an outer tube 22 is covered so as to cover the arc tube 21. The arc tube 21 is made of ceramic, and a predetermined luminescent substance such as mercury or sodium is enclosed in the arc tube 21, and sealing tubes are formed at both ends following the arc tube 21.
The outer tube 22 is made of fused silica glass having 55% transmittance for 180 nm light, 83% transmittance for 220 nm light, and 93% transmittance for 300 nm light, and covers the arc tube 21. The sealing portion 23 is formed at one end of the outer tube 22, and the arc tube 21 is disposed in a sealed state in the outer tube 22. Further, the space between the outer tube 22 and the arc tube 21 is filled with nitrogen.

From the sealing tube that follows the arc tube 22, an external lead rod that protrudes to the outside is connected to the internal lead 24 in the outer tube 22.
Further, a ceramic base 25 is fixed to the seal portion 23 of the outer tube 22 by an adhesive, and a power supply pin 26 electrically connected to the internal lead 24 is provided on the base 25.

Example 2 of coating and color tone evaluation
The light irradiation apparatus 1 described in Example 1 was used to irradiate the steel sheet coated with “OPTRAC” (manufactured by Kansai Paint Co., Ltd., photocurable putty) to a thickness of 1 mm. The curability was evaluated.

  Next, three sheets of light-cured coating plates were prepared using the light irradiation device 1, and each of the top coating films of silver metallic (Note 1), 3 coat pearl (Note 2) and blue solid (Note 3) was formed. Test coating plates for color tone judgment were prepared. Next, for each test coating plate, a color sample corresponding to each coating color is arranged in the vicinity of each test coating plate, and each test coating plate and each color sample corresponding to the test coating plate are simultaneously mounted with a filter at an irradiation distance of 100 cm. The film was irradiated with light, and the color tone of the coating film was evaluated.

Examples 3-4 and Comparative Examples 1-2
In Example 2, each test coating plate was prepared in the same manner as in Example 2 except that the light irradiation conditions in the photocuring and coating color tone determination were as shown in Table 1, and the curability and the color tone of the test coating plate were prepared. Was judged. The results are also shown in Table 1. The light intensity in Table 1 is a value measured under the condition of no filter.

(Note 1) Silver metallic: Silver metallic coating ("Letane PG Hybrid III metallic white", manufactured by Kansai Paint Co., Ltd., trade name, coating with paint containing aluminum pigment) and clear coating ("Letane PG Multi Clear Hx (Q) base) "(Trade name, manufactured by Kansai Paint Co., Ltd.) 100 parts by weight," Letane PG Multiclear Hx Standard Curing Agent "(trade name, manufactured by Kansai Paint Co., Ltd.) 50 parts by weight and" PG Hybrid Thinner 20 "(trade name, Kansai Paint Co., Ltd.) (Manufactured) A multilayer coating film in which 20 parts by weight of a clear coating film mixed immediately before use is sequentially formed.
(Note 2) 3-Coated Pearl: Colored base coating (“Letane PG Hybrid White”, trade name, manufactured by Kansai Paint Co., Ltd., coating with white pigment-containing paint), Pearl coating (“Letane PG217L Pearl Liquid White”, product Name, manufactured by Kansai Paint Co., Ltd., paint film with mica pigment-containing paint), clear coating film ("Letan PG Multi Clear Hx (Q) Base" (trade name, manufactured by Kansai Paint Co., Ltd.) 100 parts by weight, "Letan PG Multi Clear Hx""Standard curing agent" (trade name, manufactured by Kansai Paint Co., Ltd.) 50 parts by weight and "PG Hybrid Thinner 20" (trade name, manufactured by Kansai Paint Co., Ltd.) 20 parts by weight are sequentially formed. A multilayer coating film.

(Note 3) Blue solid: Blue-based colored base coating (“Letane PG Hybrid G38 Deep Blue”, trade name, manufactured by Kansai Paint Co., Ltd., coating with blue pigment-containing paint), Clear coating (“Letane PG Multi-Clear” 100 parts by weight of “Hx (Q) base” (trade name, manufactured by Kansai Paint), 50 parts by weight of “Letane PG Multiclear Hx Standard Curing Agent” (trade name, manufactured by Kansai Paint) and “PG Hybrid Thinner 20” (product) (Name, manufactured by Kansai Paint Co., Ltd.) A multilayer coating film formed by sequentially forming a coating film (clear coating mixed with 20 parts by weight immediately before use).
Evaluation item (* 1) Curability: The curability of the photocurable composition was examined by touch.

◎: Very good, ○: Good, ×: Poor curing (* 2) Aluminum orientation: “ABI II” (trade name, color sample, manufactured by Kansai Paint Co., Ltd.) The above-mentioned silver metallic test coating plate and the color sample were visually compared with respect to the size and direction of the aluminum pigment.
◎: About the size and orientation of the aluminum pigment, the difference between the test coating plate and the color sample is very easy to understand, and visual evaluation is very easy. ○: About the size and direction of the aluminum pigment, there is a difference between the test coating plate and the color sample. Easy to understand and easy to visually evaluate. ○ △: The size and orientation of the aluminum pigment can be confirmed by the difference between the test coating plate and the color sample, and visual evaluation is possible. △: About the size and orientation of the aluminum pigment. The difference between the coated plate and the color sample is difficult to understand, and the visual evaluation is slightly difficult. X: Regarding the size and orientation of the aluminum pigment, a difference between the coated plate and the color sample cannot be visually evaluated.

(* 3) Pearl feeling: Using paint color number Toyota051 of “ABI II” (trade name, color sample, manufactured by Kansai Paint Co., Ltd.) as a sample of 3-coat pearl, depending on the size of pearl pigment and changes in light irradiation direction Regarding the change in color, the test coat plate of 3 coat pearl and the color sample were compared visually.
A: The change in color due to the change in the size of the pearl pigment and the direction of light irradiation is very easy to see the difference between the test coating plate and the color sample, and the visual evaluation is very easy. ○: The size of the pearl pigment and the direction of light irradiation Regarding the change in color due to the change in color, the difference between the test coating plate and the color sample is easy to understand and easy to visually evaluate. ○ △: About the change in color due to the change in the size of the pearl pigment and the direction of light irradiation Differences can be confirmed with the color swatches, and visual evaluation is possible. △: Regarding the change in color due to changes in the size of the pearl pigment and the direction of light irradiation, it is difficult to see the difference between the test coating plate and the color swatches. Slightly difficult, x: Regarding the change in color due to the change in the size of the pearl pigment and the light irradiation direction, the difference between the test coating plate and the color sample cannot be determined by visual evaluation.

(* 4) Transparency: Blue solid color sample “ABI II” (trade name, color sample, manufactured by Kansai Paint Co., Ltd.) is used as paint color number Toyota 082. The color sample was visually compared.
A: Regarding transparency, the difference between the test coated plate and the color sample is very easy to understand, and visual evaluation is very easy. ○: Regarding transparency, the difference between the test coating plate and the color sample is easy to understand, and visual evaluation is easy. Δ: Regarding transparency, the difference between the test coating plate and the color sample is slightly difficult to understand, and visual evaluation is difficult. × : Regarding the transparency, a difference between the test coating plate and the color sample cannot be made by visual evaluation.

  For example, the present invention can be applied to repair coating applications that use both a photocurable composition and a top coating, such as automotive repair coating.

FIG. 1 is a schematic diagram illustrating the configuration of the light irradiation apparatus of the present invention. FIG. 2 is a schematic diagram illustrating the configuration of the lamp of the light irradiation apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light irradiation apparatus 2 Lamp 21 Light emission tube 22 Outer tube 23 Seal part 24 Lead 25 Base 26 Feeding pin 3 Mirror 4 Lens 5 Irradiator 6 Supporting support 7 Filter

Claims (6)

An irradiator including a lamp that emits a light beam having a correlated color temperature of 5000 K or less, and a detachable filter disposed in front of the irradiator in a light irradiation direction, and the light beam emitted from the lamp is The light intensity at an irradiation distance of 20 cm at a wavelength of 365 nm is in the range of 1 to 5 mW / cm ² , and the light intensity at an irradiation distance of 10 cm at a wavelength of 800 nm is in the range of 80 to 250 mW / cm ^2. A light irradiation device characterized.   The lamp is a double-tube type lamp composed of a ceramic arc tube in which a luminescent material is enclosed and an outer tube covering the arc tube, and the outer tube is 50% or more in a light beam of 180 nm. The light irradiation device according to claim 1, wherein the light irradiation device is made of fused silica glass having a transmittance of 80% or more for light of 220 nm and a transmittance of 90% or more for light of 300 nm.   A photocurable composition is applied to the damaged part, and the photocurable composition is cured by irradiating the coating film surface with light using the light irradiation device according to claim 1. Repair painting method.   After applying the photocurable composition to the damaged part and irradiating the coating film surface with light using the light irradiation device according to claim 1 or 2, the photocurable composition is cured. Next, a top coat is applied to the coated surface and dried to form a top coated film, and the surface of the top coated film is irradiated with light using a light irradiation device according to claim 1 or 2. A repair coating method characterized by determining the color tone of the top coat film.   The repair coating method according to claim 4, wherein the top coat film contains a pigment having glitter as part of its components.   Use of this light irradiation apparatus which uses the light irradiation apparatus of Claim 1 or 2 for both methods of hardening of a photocurable composition, and a coating-film color tone determination.

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