JPH10202186A - Method for repairing defect of glittering coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a glittering coating film to be repaired more simply and easily. SOLUTION: In a repairing method for repairing a defect of a glittering coating film in which after the defect portion of the glittering coating film including a glittering agent-containing coating film containing a metallic pigment and/or a mica pigment as a glittering pigment, and a clear coating film formed thereon is sanding-heated, the glittering agent-containing coating for repairing containing a metallic pigment and/or the mica pigment as the glittering pigment is applied and then the clear coating is applied, the defect of the glittering coating film is repaired by the glittering agent-containing coating for repairing including a small amount of a white pigment besides the glittering pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repairing method for repairing a defective portion of a glittering coating film applied to, for example, an automobile body or parts, without the necessity of performing complicated toning. The present invention relates to a method for repairing a defect of a glittering coating film, which can effectively improve a color difference from a non-repair painted surface.

[0002]

2. Description of the Related Art For example, in order to form a thick and glossy metallic glossy glossy coating film on an automobile body, a coating film composed of a paint containing a metallic pigment or a mica pigment has been frequently used. ing. As shown in FIG. 1, the coating to be repaired generally has an undercoat coating 2 on a substrate 1.
A luster comprising applying a paint containing a metallic pigment and / or a mica pigment to the coating surface on which the intermediate coating film 3 is formed to form a metallic base coating film 4, and further applying a clear coating film 5. It is a multi-layer coating film.

[0003] In the case of such a glittering coating film, if coating defects such as sagging or dents occur in the process of a car body painting line, or local peeling of the coating film caused by missing attached dust, etc. It is necessary to repair the defective or peeled portion until the color tone becomes visually the same. Conventionally, for paint repair, a method of sanding the repaired part, applying a paint that has been color-matched so as to have the same color as the glittering paint film multiple times with an air spray gun, and then applying a clear paint is used. ing. However, in the case of this kind of partial repair means, the repair work for obtaining the same color tone and the color tone work of the paint require extremely skilled skills, and even a skilled repair worker has individual differences. It was difficult to always obtain the same color because of the relationship.

[0004] As a repair coating technique for a glittering coating intended to solve such a problem, a color base paint having a predetermined coloring pigment is applied to the surface of an object to be coated, and a mica base paint having a diffuse reflection material such as mica pieces is used. In a pearl coating obtained by applying and applying a clear coating, a repair paint for a pearl coating having at least a coloring pigment contained in the color base paint and a resin contained in a mica base paint, and a repair method using the same (Japanese Patent Laid-Open No.
-202961). Further, as another method, in a coating structure in which a color base coating containing a color pigment, a mica base coating and a clear coating are sequentially laminated, the color base coating and the mica base coating are made of the same resin-based coating, Japanese Patent Application Laid-Open No. 1-245882 discloses a pearl mica partial repair paint structure in which a toning coating film formed of a coloring paint mixture of a color base coating material and a mica base coating material is interposed between the color base coating film and the mica base coating film. ) Or when repairing a painted surface on which a glossy base containing mica and / or metallic pigments is formed on the color base, the mist of the color base paint diluted into a portion including the boundary between the polished color base portion and the outer portion thereof And then applying a glossy base paint to the portion including the mist-coated portion (Japanese Patent Laid-Open No. 4-274).
No. 5) has been proposed. However, none of these techniques sufficiently satisfies the repair accuracy of the same color tone, and it is difficult to obtain the same color difference in a light-colored system, particularly in a glitter coating film.

[0005] The visual discomfort often observed when repairing a light-colored glittering coating film is such that the hue of the repaired painted surface relative to the non-repaired painted surface is a highlight portion (the angle of vision is close to a right angle to the painted surface). Is a phenomenon that looks black at a shade portion (an angle at which vision is nearly parallel to the coating film). The cause of this difference in hue is that when a glittering coating is electrostatically applied on a production line, the amount of paint discharged is large and there is no glittering pigment piece in the coating formed due to the influence of static electricity. Orientation is random in the direction, but at the time of repair painting painted with an air spray gun, the amount of paint discharged is extremely small (about one-fourth the amount at the time of electrostatic painting). Arranged parallel to the painted surface in the paint film, so flip-flop property (brightness difference by angle) and color flop property (hue difference by angle) with non-maintenance painted surface
It is thought that there is a great difference in The present inventors have added a specific surface conditioner to the repair paint to orient the glitter pigment pieces in the coating film in a non-directional random state, so that a flip-flop property and a color flop property with the non-repair paint face are obtained. A method for improving the above was found, and a patent application was filed (see JP-A-7-228807). However, in this method, the difference in brightness between the unrepaired part and the repaired part, the color change in color between the highlight part and the shade part, and the color change in color due to the film thickness difference in the part to be repaired are each sufficiently small. I couldn't. This seems to be due to the fact that control of the orientation of the pigment cannot sufficiently respond to changes in the coating conditions.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, further enhance the advantages of the above-mentioned methods, and provide a method for repairing a glitter-containing coating film more simply and easily. To provide.

[0007]

SUMMARY OF THE INVENTION The present invention provides a glittering coating comprising a glittering coating containing a metallic pigment and / or a mica pigment as a glittering pigment and a clear coating formed thereon. After applying a sanding treatment to the defective portion of the above, a repairing brightener-containing paint containing a metallic pigment and / or a mica pigment as a bright pigment is applied, and then a clear paint is applied. The present invention relates to a method for repairing a defect of a glittering coating film, characterized in that the glitter-containing paint for repair contains a small amount of a white pigment in addition to the glitter pigment. Particularly, in the present invention, in the unrepaired part and the repaired part of the film of the glittering paint, the thickness of the base coating film of the repaired part is 3 μm and 10 μm.
The lightness (L) measured by a gonio colorimeter at the highlight portion (the angle of 15 ° from the reflected light reflected at 90 ° with respect to the incident angle of 45 ° and returned to the incident light side by 15 °) for the portion having And the same measured value at the unrepaired part (thickness 0 μm)

[0008]

(Equation 4)

The thickness of the base coating film of the repaired part is expressed as 3
The lightness (L) of the portion having the μm and 10 μm measured by the gonio-colorimeter was measured at the shade portion (90 ° for an incident angle of 45 °)
The difference between the value measured at 110 ° from the reflected light reflected back to the incident light side) and the same measured value at the unrepaired part (0 μm)

[0010]

(Equation 5)

When expressed as:

(Equation 6) The present invention also relates to a method for repairing a defect using a paint having the following.

In the method of the present invention, all of the lightness (L) are measured using a gonio colorimeter by using Hunter's L, a,
The colorimetry is performed based on the b color system (L is lightness, and a and b are variables related to the tristimulus system) (that is, lightness (L) is actually measured).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The repair target of the present invention is a glittering coating film having a defective portion. Here, schematically shown in the cross-sectional view of FIG. 2A, the undercoating film 2 and the intermediate coating film 3 formed on the base material 1 contain a metallic pigment and / or a mica pigment. A glittering multi-layer coating film formed by applying a paint to form a metallic base coating film 4 and further applying a clear coating film 5, wherein the metallic base coating film 4 and the clear coating film 5 have defective portions 8. Things. In the repairing method of the present invention, specifically, in a glittering coating film requiring such repairing, first, the repaired portion is sanded by a conventionally known technique (FIG. 2B), and then the glittering coating is applied. A brightener-containing paint for repair containing a small amount of a white pigment in addition to the pigment is applied by an air spray gun or the like, and a clear paint is applied thereon (FIG. 2C).

As described above, in the prior art, the difference in color tone between the repaired portion and the unrepaired portion in the application of the repair paint (that is, the color difference of the entire coating film including the repaired portion and the unrepaired portion) is visually checked by an engineer. Was done only dependent on. However, the present invention regulates the color tone of the entire coating film by defining the absolute value of the difference in lightness due to the film thickness at each angle (the light receiving portion of the gonio colorimeter) in each of the repaired portion and the unrepaired portion. It is not necessary to perform fine toning by blending a white or black pigment or the like depending on only visual evaluation as in the prior art, thereby providing a method in which human error hardly occurs in the color tone. be able to.

As the base of the brightener-containing paint for repairing used in the method of the present invention, a paint similar to the metallic pigment and / or mica pigment-containing brightener-forming coating-forming paint commonly used in automobile bodies and the like can be used. . Basically, a paint with exactly the same composition as the brightener-containing paint used at the time of non-repair,
Although it is optimal to add an effective amount of a white pigment, the difference in the paint resin components is not an essential problem in the present invention. As long as it is within the allowable range, the concentration of the brightener other than the white pigment to be added may be changed.

The above repair coating composition suitable for use in the method of the present invention comprises a combination of a film-forming resin and a crosslinking agent, and pigments known to those skilled in the art as metallic and / or mica-based pigments. A brightener-containing paint with a small amount of white pigment added. Examples of the film-forming resin include an acrylic resin, a polyester resin, an alkyd resin, a fluororesin, a cellulose acetobutyrate resin, and the like. As a crosslinking agent combined therewith, for example, an amino resin and / or a block polyisocyanate compound And the like. Examples of pigments known to those skilled in the art as metallic pigments and / or mica pigments include aluminum foil, bronze foil, tin foil, silver foil, titanium metal foil, stainless steel foil, nickel-
Examples include metal fine pieces such as copper foil, mica pieces such as pearl mica, white mica, interference mica, and colored mica. As a white pigment that can be added to the brightener-containing paint,
For example, titanium oxide and / or a mica-based pigment, for example, white mica, may be mentioned, and preferably titanium oxide and / or white mica.

In the above-mentioned repair paint, the content of the film-forming resin is generally 40 to the solid content in the paint composition.
The content of the crosslinking agent to be combined with the film-forming resin is preferably in the range of 15 to 65% by weight based on the solid content in the coating composition, and the content of the metallic pigment and / or the mica pigment was The amount is preferably in the range of 5 to 35% by weight based on the solid content in the coating composition.

The repair paint used in the present invention is preferably of a solution type. Such a bright coating film forming paint is an organic solvent type, aqueous (water-soluble,
(Water dispersibility, emulsion) and non-aqueous dispersion type. The solid content in the repair paint is 30 to 7 at the time of production.
0% by weight, at the time of application: in the range of 10 to 50% by weight (viscosity range: at the time of manufacture (measured with a Stormer viscometer)):
58 ku to 62 ku, at the time of application: 12.5 to 13 seconds / No.
(4FC / 20 ° C).

It is preferable that the white pigment to be added is uniformly mixed in the above-mentioned brightener-containing paint. Therefore, the white pigment may be added as it is, or may be added in the form of a paste containing the same film-forming component, solvent, and the like as the glitter-containing paint. The amount of the white pigment added to the repair paint is preferably 0.01 to 2.0% by weight, especially 0.1 to 1.0% by weight based on the solid content in the paint composition.
A weight percent range is suitable. When the amount of the white pigment added to the repair paint exceeds 2.0% by weight, the glitter in the highlight portion is reduced, and the coating film becomes blackish. It is not preferable because the effect of the method of the invention cannot be sufficiently obtained (that is, the repaired part becomes whitish with respect to the unrepaired part around the repaired part and the color tone cannot be unified).

In the method of the present invention, the white pigment to be added to the repair paint can be used alone or in combination of two or more. In particular, when titanium oxide and white mica are used in combination, More excellent repair performance can be provided. When two or more types of white pigments are used, the total amount of all the added white pigments is preferably within the above range.

Depending on the purpose, the repair coating composition may contain known auxiliaries and / or additives for the body of an automobile, such as conventionally known additives such as a curing catalyst, an ultraviolet absorber and an antioxidant, and various kinds of surfaces. You may contain a regulator etc.

In the second aspect of the present invention, the method for repairing a glittering coating film comprises measuring a deflection angle of a portion having a thickness of 3 μm and 10 μm in an unrepaired portion and a repaired portion of the glittering coating film. The difference between the lightness (L) measured by the color meter at the highlighted part and the same measured value at the unrepaired part (thickness 0 μm) was calculated.

[0023]

(Equation 7) And the difference between the lightness (L) measured by the gonio colorimeter of the part having 3 μm and 10 μm of the repaired part in the shade part and the same measurement value in the unrepaired part (0 μm) is respectively shown.

[0024]

(Equation 8) When expressed as:

[0025]

(Equation 9) It is characterized by having.

Here, as shown in FIG. 3, the unrepaired portion of the glittering coating film and the highlight portion of the repaired portion are only 15 ° from the reflected light reflected at 90 ° with respect to the incident angle of 45 °. The angle returned to the incident light side, and the shade part is 45 °
110 ° from the reflected light reflected at 90 ° to the incident angle of
Means the angle returned to the incident light side.

The lightness (L) and the difference in lightness of the bright coating film after the repair using the gonio colorimeter are measured / calculated in the following procedure; first, the measuring procedure in the highlight portion will be described. . FIG. 4A shows that the unrepaired portion (0 μm thick) and the thickness of the base coating film of the repair coating film based on the unrepaired portion are 3
The lightness of each of the μm-thick part and the 10 μm-thick part was measured using a gonio colorimeter:

(Equation 10) Is measured. Next, the difference between the brightness measured at the thickness of 3 μm and the thickness of 10 μm and the brightness at the unrepaired portion (thickness of 0 μm) was respectively determined.

[0028]

[Equation 11] [However, in the difference in brightness represented by the above formulas I and II, the numerical values on the right side of the formulas I and II are 4.0, respectively.
And 6.0, but changes depending on the hue of the hue of the coating film to be repaired. In a part having a thickness of 3 μm, in the case of a dark hue (for example, dark green), the numerical value on the right side of the above formula I is 4.00 (preferably 3.80), and a medium hue (for example, blue) , The value on the right side of Equation I is also 3.50 (preferably 3.00), and for light hues (eg, light gray),
The numerical value on the right side of Expression I is 3.00 (preferably 2.50). Similarly, for a portion having a thickness of 10 μm, in the case of a dark hue, the value on the right side of Expression II is 6.00.
(Preferably 5.80) and for medium hues,
The numerical value on the right side of Expression II is 5.00, and for a light hue, the numerical value on the right side of Expression II is 4.00. ] And the absolute value of their difference

[0029]

(Equation 12) [However, the absolute value of the difference of the above formula V (the value on the right side) is also
Similarly to the above lightness difference value, the value on the right side is generally 7.
Although it is 0, it changes depending on the hue of the hue of the coating film to be repaired. That is, in the case of a dark hue (for example, dark green), the numerical value on the right side of the above equation is 2.80,
For medium hues (eg, blue), the value on the right side of the above equation is 5.50 (preferably 4.50), and for light hues (eg, light gray),
The numerical value on the right side of the above equation is 7.00 (preferably 6.00)
It is. (Hereinafter, the above value will be referred to as a “color change color difference” due to the difference in film thickness of the repaired portion.) The method of the present invention comprises:
By performing preparation of the repairing brightener-containing paint and adjusting the coating conditions so as to satisfy the above-mentioned formulas I, II and V, the results of the visual evaluation of the repaired coating film no longer vary. The color tone of the whole film can be unified.

FIG. 4 also shows the shade portion.
From (b), the lightness at each point as well as the highlight part

(Equation 13) Then, the difference between the lightness measured at the thickness of 3 μm and 10 μm and the lightness at the unrepaired portion (thickness 0 μm) was respectively determined.

[0031]

[Equation 14] [However, in the difference between the lightness represented by the formulas III and IV, similarly to the description of the shade portion,
In general, the numerical values on the right side of Equations III and IV are
It is 1.5 and 2.0, but changes depending on the shade of the hue of the coating film to be repaired. That is, in the case of a dark hue (for example, dark green) in a portion having a thickness of 3 μm, the numerical value on the right side of the above formula III is 1.00 (preferably 0.50).
It is. ) For a medium hue (eg, blue), the value on the right side of Equation III above is 1.30 (preferably 1.00), and a light hue (eg,
Light gray), the numerical value on the right side of the above formula III is 1.
50 (preferably 1.20). Also, 1
Even in a portion having a thickness of 0 μm, in the case of a dark hue,
The numerical value on the right side of the IV is 1.00 (preferably 0.50), and for a medium hue, the numerical value on the right side of the above formula IV is 1.80 (preferably 1.50). , And in the case of a light hue, the numerical value on the right side of Expression IV is 2.00. And the absolute value of their difference

[0032]

(Equation 15) [However, the absolute value of the difference of the above formula VI (the value on the right side)
Is generally 1.2, but varies depending on the shade of hue of the coating film to be repaired. That is, for dark hues,
The numerical value on the right side of the above equation is 0.80 (preferably 0.60), and for a medium hue, the numerical value on the right side of the above equation is 1.00 (preferably 0.70). , And for a light hue, the numerical value on the right side of the above equation is 1.20 (preferably 1.00). (Hereinafter, the numerical value on the right side of Expression 15 above is referred to as a “color change color difference” due to the difference in film thickness of the repaired portion.) The absolute value of the difference in brightness measured in this way is calculated by the above-mentioned formulas III, IV and VI.
By satisfying the values described for each right side,
The color tone in the shade portion can be unified.

Here, the absolute value of the difference between the measured lightness of the highlight part and the lightness measured in the unrepaired part is calculated from the numerical values defined above (the numerical values on the right side of the above formulas I and II). Is also smaller, the glitter is reduced, the coating becomes darker, and conversely, if it is larger than the above value,
The repaired part becomes whitish with respect to the unrepaired part around the repaired part,
It is not preferable because the color tone cannot be unified. Furthermore, if the color change due to the difference in film thickness of the repaired portion with respect to the highlight portion is smaller than the value specified for the right side of the above formula V, the glittering feeling is reduced, and the coating film becomes blackish. Exceeding the numerical value on the right side of the above formula V is not preferable because the repaired part becomes whitish as compared with the unrepaired part around the repaired part and the color tone cannot be unified.

In the shade part, the absolute value of the difference between each measured lightness and the lightness measured in the unrepaired part is:
If the value is smaller than the value defined above (the value on the right side of the above formula VI), the repaired portion becomes whitish with respect to the unrepaired portion around the repaired portion, so that the color tone cannot be unified and the value on the right side of the above formula VI Exceeding the range is not preferred because the glitter is reduced and the coating film becomes dark.

The repairing method of the present invention can be applied irrespective of the hue of the glittering coating film to be repaired, and particularly, the glittering property of a thin hue (for example, a coating color having an L value of 20 or more, especially 40 or more). Application to a coating film is effective.

The repairing method of the present invention includes, for example, a wet-on-wet method according to the performance requirement of a coating film that has not been repaired, according to the performance requirement of a coating film that has not been repaired, for example, in a repaired portion after sanding a defective portion of the glittering coating film. This is completed by applying a clear coating film forming paint to form a clear coating film.

In the method of the present invention, the dry film thickness of the repair coating film is preferably in the range of 5 to 20 μm, and the dry film thickness of the clear coating film applied thereon is preferably 30 to 60 μm.
The range of m is preferred. The baking procedure and conditions after application (painting) of each paint can be performed by a conventionally known method.

[0038]

The present invention will be described below with reference to examples.
The present invention is not limited to the following examples. Example 1 : First, an electrostatic painted plate is prepared. Nippon Paint Co., Ltd. cationic electrodeposition paint (V-20) with a dry film thickness of 20μ
m steel plate (dimensions: 8 × 30
cm) on four sheets under the following coating conditions under the intermediate coating (paint:
After applying Nippon Paint's OTOH850 gray),
A light gray-colored glitter paint (paint composition A1) was electrostatically applied, and a clear paint (paint composition C) was manually sprayed thereon (film thickness: 30 ± 5 μm) to prepare a repair original plate.

The paint formulations A1 (light gray metallic; metallic color) Ingredient wt% Al paste MH9901 (Toyo Aluminum Co., Ltd., solid content 65%) 2.5 Alpaste MC707 (manufactured by Asahi Chemical Industry Co., Ltd., solid content 65%) 3.0 Shinkasha Magenta RT343D (manufactured by Ciba Geigy) 0.2 Shanin Blue 5206 (manufactured by Dainichi Seika) 0.2 Monarch 1400 (manufactured by Cabot) 0.2 Thermosetting acrylic resin A (manufactured by Nippon Paint Co., hydroxyl value 45) , 23.0, acid value 15, number average molecular weight 18,000, solid content 50%) Dianal HR2048 (manufactured by Mitsubishi Rayon Co., Ltd., thermosetting acrylic 21.0 resin, solid content 55%) Uban 20N60 (manufactured by Mitsui Cytec, butyl) Melamine resin, 16.5 solid content 60%) Crosslinked resin particles (Nippon Paint Co., Ltd., solid content 20) %) 15.0 Disparone KS273N (Kusumoto Kasei Co., Ltd., surface conditioner) 0.2 n-butanol 0.2 Xylol 6.0 Toluene 6.0 Total 96.9

Electrostatic coating conditions Item Bright paint coating discharge amount 1 stage 2 stage 380 cc 330 cc Atomization pressure 3.5 kg / cm ³ 3.5 kg / cm ³ (gun source) (gun source) Pattern pressure 3.0 kg / cm ³ 3.0 kg / cm ³ (gun source) (gun source) Voltage -90 kV Linear speed 60 m / min Conveyor speed 2.6 m / min Interval time 1 stage / 2 stages 2 stages / clear coating 1.5 minutes 7 2.0 minutes Setting time 10 minutes Baking conditions 140 ° C x 20 minutes

The paint formulation C: clear paint; 2C1B for Ingredient wt% thermosetting acrylic resin A (Nippon Paint Co., Ltd., hydroxyl value 70, 63.6 acid number 20, number average molecular weight 7300, 55% solids) Dia NARL HR554 (Mitsubishi Rayon Co., Ltd., thermosetting acrylic resin 58.3, solid content 60%) Uban 20N60 (Mitsui Cytec Co., Ltd., butylated melamine resin, 50.0 solid content 60%) Crosslinked resin particles (Nippon Paint Co., Ltd.) 1.0, Tinuvin 900 (manufactured by Ciba Geigy, ultraviolet absorber) 2.0 Sanol LS292 (manufactured by Mitsui Organic Synthesis, antioxidant) 1.0 n-Butanol 3.0 Solvesso 100 5.0 0 total 192.9

One of the above repaired original sheets was stored as a correction original sheet, and the other was used as a repaired coated plate sample and was subjected to water polishing using # 1000 water polishing paper.

Next, a titanium oxide paste (paint B1) was added to the above paint A1 in an amount of 0.3, 0.6, and 1.0% by weight to prepare repair paints. The repair paint and the clear paint were applied to the repair coating plate obtained by the above-mentioned water polishing under the following hand-blown coating conditions under a film thickness gradient coating (film thickness of repair paint film: about 15).
μm to dust (1 to 3 μm); clear coating film thickness: 3
0 ± 5 μm).

The coating formulations B1: adding titanium oxide paste Ingredient wt% titanium R820 (manufactured by Ishihara Sangyo Kaisha, Ltd.) 20.0 thermosetting acrylic resin A (Nippon Paint Co., Ltd., hydroxyl value 45, 72.0 acid number 15, Number average molecular weight 18,000, solid content 50%) Uban 20N60 (manufactured by Mitsui Cytec Co., Ltd., butylated melamine resin, 15.0 solid content 60%) n-butanol 3.0 xylol 6.0 toluene 4.0 total 120.0

Hand-blown coating conditions (frame blowing) Item conditions Hand-blown gun Meiji F-75 Caliber 1.5 Discharge amount 2 rotations Pattern width 1 rotation Air pressure 0.25 rotations Gun distance 25cm Base coating / clear coating interval 3-5 Minutes Setting time 10 minutes Baking conditions 140 ° C x 20 minutes

With respect to the repaired coated plate and the correction original plate (corresponding to the repaired portion and the unrepaired portion, respectively), the highlight portion and the shade portion, and the thin film repaired portion (repair portion thickness: 3 μm portion) and the thickness of the repaired coated plate, respectively. The difference in lightness in the film repaired part (repair part thickness: 10 μm portion) was measured by a variable-angle color difference meter (manufactured by Minolta, Model CR-354), and also visually evaluated. The results are summarized in Table 1. The criteria for the visual evaluation are as follows.

○: excellent and excellent ●: good but slightly different Δ: slightly different □: considerably different ×: different

[0048]

[Table 1]

From Table 1, it can be seen that, by applying a repair paint to which a titanium oxide paste is added, the difference in brightness (color difference) between the thick-film repair portion and the thin-film repair portion in both the highlight portion and the shade portion. Is smaller.
Similar results were obtained from visual evaluation. In particular, in the visual evaluation of the shade portion, by adding the titanium oxide paste to the repair paint, the blackness disappeared, and the difference from the unrepaired portion disappeared. However, from Table 1, it can be seen that when 1.0% of the titanium oxide paste was added, the glitter in the highlight portion was slightly reduced and the portion became blackish.

EXAMPLE 2 In the repair paint formulation, the following A2 was used in place of the paint formulation A1, and B1 was added at 0%, 0.3% and 0.6% by weight based on the bright paint formulation A2. %, And 1.
A repair coating plate and a correction original plate were prepared in the same manner as in Example 1 except that the repair paint was prepared by adding 0% by weight. In each of the repair coating plate and the correction original plate (corresponding to the repaired portion and the unrepaired portion, respectively), the highlight portion and the shade portion, and the thin film repair portion (repair portion thickness: 3 μm portion) and the thick film repair portion of the repair coating plate ( Repair part thickness: 10μ
The difference in lightness in the (m part) was measured by a gonio colorimeter, and was also visually evaluated. The results are summarized in Table 2.

The paint formulations A2 (dark green; mica color) Ingredient% by weight Exterior Marlin Super Gold (manufactured by Mahr) 0.5 Exterior Marlin highlight green (manufactured by Mahr) 2.0 Rio Nord Green 6YKPN (Toyo Ink Mfg. Co., Ltd. 0.2 Titanium R820 (Ishihara Sangyo) 0.2 Monarch 1300 (Cabot) 0.8 Thermosetting acrylic resin A (Nippon Paint Co., Ltd., hydroxyl value 45, 23.0 acid value 15, number) Average molecular weight of 18000, solid content of 50%) Dianal HR2048 (manufactured by Mitsubishi Rayon Co., Ltd., thermosetting acrylic 21.0 resin, solid content of 55%) Uban 20N60 (manufactured by Mitsui Cytec, butylated melamine resin, 16.5 solid content) 60%) Crosslinked resin particles (Nippon Paint Co., Ltd., solid content 20%) 8.0 Dispalon KS273N (Kusumoto Kasei Co., Ltd., surface conditioner) 0.2 n-butanol 3.0 xylol 6.0 toluene 6.0 total 87.4

[0052]

[Table 2]

Table 2 shows that the addition of the titanium oxide paste reduces the difference in brightness (color difference) between the thick-film repaired portion and the thin-film repaired portion in both the highlight portion and the shade portion. . Similar results were obtained from visual evaluation. In particular, in the visual evaluation of the shade portion, by adding the titanium oxide paste to the repair paint, the blackness disappeared, and the difference from the unrepaired portion disappeared.

Example 3 The following A3 was used in place of the paint formulation A1, and the following B3 was used in place of the additive paste B1 in an amount of 0, 1.0, 2.0, 4.0% by weight based on the paint formulation A3. Other than using it,
In the same manner as in Example 1, four repair coated plates and one correction original plate were prepared. Here, in a system containing 2.0% by weight of the additive paste B3 with respect to the paint composition A3, 0.3% by weight of a titanium paste (: additive composition B1) was also added. ) Was prepared. For the repaired painted plate and repaired original plate (corresponding to the repaired portion and the unrepaired portion, respectively), the highlight portion and the shade portion, the thin film repaired portion (repaired portion thickness: 3 μm portion) and the thick film repaired portion (repaired portion thickness) : 10 μm portion) was measured with a variable-angle color difference meter, and a visual evaluation was performed at the same time. The results are summarized in Table 3.

[0055] Paint formulations A3 (blue metallic; metallic color) Ingredient wt% Al paste 94-0642 (Toyo Aluminum Co., Ltd., solid content 65%) 0.8 Alpaste 7580 (Toyo Aluminum Co., Ltd., 65% solids) 0.8 First Gen Super Violet RBL (Dainippon Ink) 0.3 Shanin Blue 5206 (Dainichi Seika) 1.8 Carbon FW200P (Degsa) 0.4 Thermosetting acrylic resin A (Nippon Paint) (Manufactured by Mitsubishi Rayon Co., Ltd., thermosetting acrylic 21.0 resin, solid content 55%) Yuban 20N60 (hydroxyl value 45, 23.0 acid value 15, number average molecular weight 21,000, solid content 55%) Cross-linked resin particles (Nippon Paint Co., Ltd., manufactured by Mitsui Cytec, butylated melamine resin, 16.5 solid content 60%) 15.0 Dispalon KS273N (Kusumoto Kasei Co., Ltd., surface conditioner) 0.2 n-butanol 3.0 Xylol 6.0 Toluene 6.0 Total 94.8

[0056] Paint formulations B3 (additive white mica paste) Ingredient wt% Iriodin 111W-2 (Merck) 20.0 thermosetting acrylic resin A (Nippon Paint Co., Ltd., hydroxyl value 45, 72.0 acid number 15, number average molecular weight 18,000, solid content 50%) Uban 20N60 (manufactured by Mitsui Cytec Co., Ltd., butylated melamine resin, 15.0 solid content 60%) n-butanol 3.0 xylol 6.0 toluene 4.0 total 120 .0

[0057]

[Table 3]

From Table 3, it can be seen that, by applying the repair paint to which white mica paste was added, the thick film repair portion was obtained in both the highlight portion and the shade portion, similarly to the system to which titanium oxide paste was added. It can be seen that the difference in brightness (color difference) from the thin film repaired part is small. Similar results were obtained from visual evaluation. In particular, in the visual evaluation of the shade portion, by adding the white mica paste to the repair paint, the blackness disappeared and the difference from the unrepaired portion disappeared. Furthermore, it was also found from the evaluation results that the use of the titanium oxide paste in the repair paint enables more excellent repair. However, it was found that when 4.0% of the white mica paste was added, the glitter of the highlight portion was slightly reduced and the portion became blackish.

[0059]

According to the present invention, a glossy coating film is repaired by defining the angle-changed color difference in a highlight portion and a shade portion of the glittering coating film and adjusting the effective addition amount of a white pigment and / or a mica pigment so as to satisfy the conditions. By applying the paint for repair to the repair site, the unification of the color tone can be determined not only by visual evaluation but also by calculation of the repair factor in the equipment measurement (that is, the measurement of the gonio color difference). Human error in the process hardly occurs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a bright coating film to be repaired.

FIG. 2 is a process chart schematically illustrating the method of the present invention.

FIG. 3 is a schematic diagram showing a light receiving position when measuring a variable angle color difference in the method of the present invention.

FIG. 4 is a conceptual diagram showing a lightness measurement position in the method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Undercoat, 3 ... Intermediate coat, 4 ... Metallic base coat, 5, 5 ', 35 ... Clear coat, 8
... Defect part, 9 ... Sanding treatment part, 10 ... Glitter coating to be repaired, 20 ... Repair glitter coating, 21, 34
... Film containing brightener for repair.

Claims (4)

[Claims] 1. After sanding treatment of a defective portion of a glittering coating film comprising a glitter coating film containing a metallic pigment and / or a mica pigment as a glitter pigment and a clear coating film formed thereon. A method of applying a repairing brightener-containing paint containing a metallic pigment and / or a mica pigment as a bright pigment, and then applying a clear paint to repair defects in the bright coating film,
A method for repairing a defect in a glittering coating film, wherein the glitter-containing paint for repair contains a small amount of a white pigment in addition to the glitter pigment. 2. The method according to claim 1, wherein the white pigment is titanium oxide or white mica. 3. The defect of a glittering coating film according to claim 1, wherein the white pigment is added in an amount of 0.01 to 2.0% by weight based on the solid content of the glittering paint containing the repairing agent. Method. 4. In the unrepaired part and the repaired part of the brilliant coating film, the lightness (L) of the part having a thickness of 3 μm and 10 μm of the repaired part measured by a gonio colorimeter is changed to a highlight part (45 °).
The difference between the value measured at 15 ° from the reflected light reflected at 90 ° to the incident angle with respect to the incident angle) and the same measured value at the unrepaired portion (thickness 0 μm) is expressed by Equation 1 And the lightness (L) of the repaired portion having 3 μm and 10 μm measured by a gonio colorimeter was measured at the shade portion (45 °).
110 ° from the reflected light reflected at 90 ° to the incident angle of
The difference between the measured value at the angle just returned to the incident light side) and the same measured value at the unrepaired part (0 μm) is given by When expressed as, the following relationship: The method for repairing a defect of a glittering coating film according to claim 1, comprising: