JPH0565232B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a repair coating method for a coating surface for repairing minute coating defects caused by adhesion of dust, oil droplets, etc. Conventional techniques and their problems For example, in the car body painting process of an automobile, the assembled car body is subjected to pre-painting treatments such as degreasing and rust removal, followed by primer electrodeposition and baking, intermediate coating and baking, polishing, top coating and They are sequentially transferred to processes such as baking, and if there are no problems in the subsequent visual inspection, they are sent to the next general assembly line. Conventionally, a vehicle body that has paint film defects and fails a visual inspection is sent to a separately provided repair processing line, and after the paint film defects are repaired, the vehicle body is sent to the visual inspection process again. Most of the paint film defects mentioned above are scattered minute defects such as recesses caused by paint and repelling due to adhesion of floating silicone oil droplets, etc., and convexities caused by dust trapped in the paint film. That's true. An example of the repair painting method for convex defects is shown in the first example.
Shown in Figure 4. FIG. 14a shows that an electrodeposited primer layer 53, an intermediate coat layer 54, and a top coat layer 55 are painted and baked on a steel plate 52 of a car body, and dust 56 is included in the top coat layer 55 and protrudes outward within a diameter X range. Paint film defect area 57
This figure shows an enlarged view of the situation where this occurs. In the conventional repair method, first, the coating film defect 57 and its surrounding area are removed using a grinder 58, as shown in FIG. 14b.
The dust 56 is completely removed by sanding using sandpaper or the like. If the defective part of the coating film is a recess caused by adhesion of silicone oil, etc., the adhesion of silicone oil, etc. is completely removed in the same manner. Next, the repair paint 6 is applied to the paint grinding part 60 using the spray gun 59.
4 is applied by spraying (see Fig. 14 c), dried or baked using a heat source 62 (see Fig. 14 d), and the repair coating part 6 is applied using a rotary buff 63 or the like.
1 (see Fig. 14e) and finished smooth as shown in Fig. 14f. The conventional repair method described above has the following problems. () Since the paint film defects and their surrounding areas are ground away using a grinder with a disk that is extremely large compared to the minute paint film defects, or sandpaper with a large area, the grinding area covers a wide area, and In some cases, the paint reaches the primer layer or the steel plate (subject to be coated), resulting in an increase in the area of the repaired paint film formed thereon, and the overall performance of the paint film deteriorates. () Spraying of repair paint using a spray gun requires a large amount of repair paint because it is applied to a wider area than the ground area, and the heat source used for dry baking must be distributed over a wide area. This consumes a large amount of energy. () Extensive grinding, painting, drying,
Because polishing, etc. is required, the total work time is, for example,
It takes more than 30 minutes, and therefore a separate repair painting line must be installed, resulting in high costs for both work and equipment. () Since the area to be coated with repair paint is large, skilled workers are required to apply uniform repair paint. These problems occur not only in car body painting, but also in general painting. The purpose of the present invention is to solve the above-mentioned problems, and to provide a coating surface that can easily repair defective coating parts without requiring much effort and time, and that causes almost no deterioration in the coating performance of the repaired area. The purpose of the present invention is to provide a repair painting method. Means for Solving the Problems The above-mentioned object of the present invention is to remove dust, oil droplets, etc. and paint film parts from minute paint film defects caused by adhesion of dust, oil droplets, etc. form a recess and then
On one side of a sheet having a surface tension of 10 dyn/cm or more and 60 dyn/cm or less, a solid coating material capable of forming a coating film, which is adhered in a lump and removable manner, is transferred by pressure to the minute depressions, and the transfer coating is further applied. This is achieved by a method of refinishing a painted surface, which is characterized by curing the material. In the present invention, it is effective to remove the minute coating film defects by using a laser irradiation or a cutting machine, but the present invention is not limited to this as long as minute recesses can be formed. It is preferable to make the size and depth of the minute recesses as small as possible in order to protect the paint film and to facilitate repair painting of the paint film. The above-mentioned "capable of forming a coating film" means that the resin in the coating material can be cured to form a coating film that is integrated with the existing coating film on the surrounding surface. Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, an example will be described in which the removal of minute coating film defects is performed by forming minute depressions on the coating surface based on laser irradiation. FIG. 1a shows a top coat layer 4 of a coating film consisting of an electrodeposited primer layer 2, an intermediate coat layer 3 and a top coat layer 4 on a steel plate 1 of a car body, similar to that shown in FIG. 14a.
The dust 5 is included in the convex minute coating film defects 6.
This figure shows an enlarged view of the situation where this occurs. First, as shown in FIG. 1b, a processing laser 7 whose beam cross section approximately corresponds to the defective part 6 is irradiated perpendicularly to the defective part 6, and the defective part 6 containing the dust 5 is sublimated. The portion 6 is removed to form a minute recess 8 on the coating surface. laser 7
An example of a laser beam processing machine for emitting light is shown in FIG. The laser processing machine 41 uses a visible laser for positioning such as a He-Ne laser, a carbon dioxide laser, and a YAG laser.
A laser oscillator 42 that oscillates a processing laser 7 such as a laser, a control section 44 that is connected to a power source 43 and controls the output and oscillation time of the laser 7, and an operation section 45 that operates the control section 44. We are prepared. The laser processing machine 41 configured in this way is
First, a visible laser is used to position the coating film defect 6, and then a processing laser is irradiated with the output adjusted. As a result, the paint film defect 6 that requires repair can be adjusted to a required depth, for example, the depth of the top coat layer 4, the depth up to the intermediate coat layer 3, or the top coat layer 4 is a colored paint film and the transparency on the colored paint film is Sublimation and removal can be performed to any desired depth, such as the depth of a transparent paint film when it is formed with a paint film, and the minimum necessary micro-recesses 8 can be formed. In forming the minute recesses 8, a laser oscillator 42' shown in FIG. 3 can also be used. The laser oscillator 42' is the laser oscillator 42 described above.
Similarly, a visible laser oscillator 46 that oscillates a visible laser 7', a processing laser oscillator 47 that oscillates a processing laser 7, and a housing 50 that has a cylindrical emission part 51 and accommodates both oscillators 46 and 47. It is equipped with The visible laser 7' for positioning emitted from the oscillator 46 is reflected by the prism 48 in a direction perpendicular to its irradiation angle, further reflected by the zinc selenium coating mirror 49, passes through the cylindrical emission part 51, and is reflected by the prism 48 in a direction perpendicular to the irradiation angle. Irradiation is applied to areas that require alignment. The processing laser 7 passes through the zinc selenium coating mirror 49, passes through the cylindrical emission part 51 along the same path as the visible laser 7', and is irradiated onto the above-mentioned region. This laser oscillator 42' is
Inert gas N such as nitrogen gas is fed into the housing 50. The inert gas N filling the housing 50 is blown through the cylindrical discharge part 51 to the area requiring the above-mentioned alignment, that is, the above-mentioned coating film defect part 6 and its surrounding area, and is blown to the defect part 6 and the surrounding area thereof. The surrounding area is placed under an inert gas N atmosphere. This suppresses discoloration (due to deterioration such as carbonization of the resin) of the coating surface around the coating film defect portion 6 caused by the heat of the processing laser 7. Further, the inert gas N circulates within the housing 50, and the visible laser and processing laser oscillators 46,
47 is discharged while being cooled. Therefore, regardless of the usage time of both oscillators 46, 47, the laser 7, which outputs stable output from both oscillators 46, 47,
There is also the advantage that 7' can be obtained. Next, an example of a method for removing minute coating film defects using a cutting machine will be described. Here, “cutting machine”
The term is used in a broad sense to include drilling machines and cutting processes that can form the minute recesses, such as small-diameter rotary drills, rotary files,
An ultrasonic processing machine or the like can be used. FIG. 4a shows that, similarly to the case shown in FIG.
This is an enlarged view of a state in which a convex minute coating film defect 6 is generated by being included. In FIG. 4b, when removing the dust 5 of the defective part 6 and the coating film covering the dust 5 using a cutting machine, in this embodiment, a rotary drill 9 is used as the cutting machine. However, it is not limited to this. The depth of the paint film to be cut and removed can be arbitrarily selected based on the state of the paint film defect. For example, the depth of the top coat layer 4, the depth up to the intermediate coat layer 3, or the depth of the top coat layer 4 between the colored paint film and the paint film. The depth can be set to any desired depth, such as the depth of the transparent coating when it is formed with a transparent coating on the membrane, and it is possible to remove the coating to a size and depth according to the purpose. , the above-mentioned minute recess 8 can be formed. Next, the coating material to be press-transferred to the formed minute recesses will be explained. Figure 5 shows an example of the coating material, which has a surface tension of 10 dyn/cm or more and 60 dyn/cm or less,
A solid coating material 1 capable of forming a coating film, which is adhered in a lump-like and removable manner to one side of a sheet 15, preferably having a surface tension of 20 dyn/cm or more and 40 dyn/cm or less.
It is 6. Sheet 1 having such surface tension
5, the coating material 16 is likely to adhere to the sheet 15, and the coating material 16 can be shaped into small but thick dots. Moreover, the coating material 16 does not peel off even when subjected to impacts such as during manufacturing, transport, storage, etc., and when applied to the minute depressions 8 and pressed from the back surface of the sheet 15. , can be easily peeled off from the sheet 15. Therefore, the coating material 16 can be easily transferred to the minute depressions 8, and the coating material 16 can be easily transferred to the minute depressions 8.
can be easily repaired. If the surface tension of the sheet 15 exceeds the above range,
The coating material 16 on the sheet surface becomes difficult to peel off when necessary, and if it is less than the above range, the coating material 16
Not only does it become easier to fall off the sheet surface,
The coating material 16 cannot be made into lumps. The sheet 15 is preferably highly smooth, but may be mesh-like or cloth-like, and its thickness is preferably 20 μm to 1 mm, more preferably
It is 20 μm to 100 μm. The composition of the sheet 15 may be any component having a surface tension within the above-mentioned range, such as a synthetic resin sheet selected from fluorine resin, polyethylene, polypropylene, polyester, vinyl chloride resin, etc.
Nets, cloth, or other synthetic resin sheet nets,
Examples include sheets formed by impregnating, painting, or laminating cloth, paper, or the like with the synthetic resin, silicone resin, or the like. If the sheet is mesh-like, the size, shape, etc. of the mesh may be such that the coating material can stick in lumps.
It is sufficient that the amount is not easily desorbed. However, for ease of handling, these sheets are preferably transparent or translucent. The solid coating material 16 capable of forming a coating film is fixed in dots on the surface of the sheet 15, has little or no fluidity at room temperature, and does not form a cured coating film. It is necessary that you do not. Here, normal temperature refers to a temperature within the range of room temperature to 100°C. Further, the coating material 16 may have either adhesive or adhesive properties, and may be in a wet state containing an appropriate amount of an organic solvent, water, or a mixture thereof, or in a wet state containing almost no amount of these solvents. It may be in any dry state without containing it. However, in order to facilitate repair work and obtain excellent smoothness of the finished coating surface, the above coating material 16
is preferably non-tacky and dry. After being transferred (filled) into the minute recesses 8, the coating material 16 is left at room temperature, heated, or exposed to active energy, either as it is, or in a state where a part or all of it is moistened, softened, or dissolved with the above-mentioned solvent. It is cured by irradiation with a wire and forms a coating film. less than,
The coating material that is the main component of the above-mentioned solid coating material will be explained in detail. (1) Solid coating materials that harden and form a coating film when left at room temperature; (a) Two-component coatings...for example, polyol resin/
Polyisocyanate compound type, epoxy resin/amine type, unsaturated polyester resin/
Examples include a polymerizable monomer/polymerization initiator system. (b) Catalyst-curing paint...For example, an amino alkyd resin paint containing an acidic organic compound as a curing catalyst can be used. (c) Solvent-volatile paints: Paints that solidify simply by volatilizing the solvent, such as lacquers whose main component is thermoplastic acrylic resin, nitrocellulose lacquers, oil-based paints, dry oil-modified resin-based paints, etc. can be mentioned. Among these solid coating materials that harden when left at room temperature, for coating materials whose main component is solvent-volatile paint, it is necessary to put a solvent in advance into the minute depressions on the coating surface before filling these coating materials. , or after filling the coating material, it is preferable to use a solvent to moisten, soften, or dissolve the coating material. Furthermore, in the case of coating materials whose main components are the above-mentioned two-component paints or catalytically softened paints, a solvent is not necessarily required to form a coating film in the recesses, but these two paints can be used at room temperature due to crosslinking reactions. Since it hardens, it is preferable to fill the minute recesses on the surface of the coating film before curing progresses too much on the surface of the sheet. (2) Solid coating material that hardens by heating to form a coating film; (a) Thermosetting paint...For example, a paint that consists of a base resin and a crosslinking agent, and which crosslinks and hardens by reacting with both components when heated. can be mentioned. As the above-mentioned base resin, alkyd resin,
Polyester resins, alkyl resins, fluororesins, silicone resins, etc. can be used, and as the crosslinking agent, amino resin block polyisocyanate compounds, polyhydric carboxylic acid compounds, etc. can be used. Furthermore, a self-crosslinking resin that is crosslinked and cured by the base resin alone can be used. (b) Thermoplastic paint... Examples include paints whose main component is a thermoplastic resin such as vinyl resin or acrylic resin. (c) The paints exemplified in (1) above can also be cured by heating. Among these solid coating materials that cure by heating, coating materials whose main component is thermosetting coatings include coating materials that contain little or no solvent and are crosslinked and cured after being melted by heating after being filled, such as powder. Examples include coating materials whose main component is paint, and paints that are softened in the presence of a solvent before or after filling, and then cured by causing a crosslinking reaction by heating. In addition, after filling, thermoplastic paints form a coating film by either heating the thermoplastic resin, which is the main component, and then curing it, or softening and dissolving it in the presence of a solvent, and then vaporizing the solvent by heating. do. As a method of heating the coating material filled in the minute depressions on the coating surface, infrared rays, laser and electron beam irradiation, supply of hot air, electromagnetic induction, etc. can be employed, and in particular, laser which can heat only the minute depressions can be used. Irradiation is effective. (3) Coating materials that are cured by irradiation with active energy rays such as ultraviolet rays or electron beams to form a coating film; The main component is a resin containing polymerizable unsaturated bonds (e.g., acrylic resin, polyester resin, etc.) and Depending on the situation, a paint containing a polymerizable unsaturated monomer can be used. When filling the recesses with this paint, it is preferable to impart adhesiveness to the paint material in advance or to make a solvent present therein. Coating materials whose main components are the coatings exemplified in (1) to (3) above may include colored pigments, metallic pigments,
Extender pigments, pearl pigments, anti-sagging agents, plasticizers, etc. can be added. In addition, when the active energy irradiation in (3) is ultraviolet irradiation, it is preferable to add a photosensitizer to the coating material exemplified in (3), and it is preferable not to add a coloring agent such as the above-mentioned colored pigment. Thereby, the curing of the coating material containing the coating material as a main component can be accelerated. Next, a method for releasably adhering the coating material 16 in bulk to one side of the sheet 15 will be explained with reference to FIG. First, the components constituting the solid coating material are dissolved or dispersed in a solvent as necessary to form a liquid. The viscosity, nonvolatile content, etc. of this liquid material (hereinafter referred to as "liquid paint") can be arbitrarily selected depending on the size and shape of the material to be fixed to one side of the sheet. Next, the liquid coating material 10 is dropped onto one side of the sheet 15, and the solvent is evaporated to form a solid coating material 16 (see FIG. 5).
In addition, in the case of liquid paints whose main components are two-component paints and catalyst-curing paints that harden at room temperature through a crosslinking reaction, volatilization of the above-mentioned solvent is not required in principle. As shown in the figure, the sheet 15 is attached to the support plate 14.
It may be held by This makes handling of the coating material easier. 1 sheet of liquid paint 10
5 Dripping onto one side can be performed by using equipment 13 such as a syringe, dispenser, dropper, etc., and pushing out the liquid coating material 10 from these equipment 13, or by pouring and dropping using a needle, stick, etc. You can also do it. It is desirable to remove air bubbles that may be contained in the dropped coating material before the coating material solidifies. The solidification of the coating material dropped onto the sheet 15 due to solvent volatilization occurs to the extent that the sheet 15 is not softened by heat and the coating material is not completely cured, for example, a thermosetting coating material becomes solid but crosslinked and cured. This is carried out by heating to such an extent that most or all of the solvent contained in the coating material is volatilized, or by leaving it at room temperature and volatilizing the solvent in the same manner as above. The size and shape of the coating material 16 fixed to one side of the sheet 15 can be arbitrary depending on the size of the minute recesses 8 on the coating surface that require repair.
For example, the coating material 16 has a diameter of 0.1 mm to 20 mm and a height of 0.1 mm to 20 mm.
Can be within the range of 0.3mm to 10mm,
Furthermore, the shape can be, for example, a hemisphere, a rectangular parallelepiped, another polyhedron, a cone, a pyramid, or a combination thereof. The thickness of the support plate 14 is preferably the same as or greater than the height of the coating material fixed to the sheet 15, and the material of the support plate is, for example, vinyl chloride resin, Teflon, polyethylene, polypropylene. , polyester, paper, etc. can be used. The support plate 14 and the sheet 15 are attached by using an adhesive or an adhesive, or by heat fusion. A method for transferring and filling the lump-like solid coating material 16 configured in this way into the minute recesses 8 will be explained with reference to FIG. 7. First, as shown in FIG. 7a, microscopic coating film defects 6 existing in the coating film are removed by the above method to form microscopic depressions 8, and then a solvent 21 is poured into the microscopic depressions 8. The wall surface of the minute recess 8 is kept moist by dripping. Thereby, the affinity and adhesion between the coating material 16 and the wall surface (coating film) of the minute recess 8 can be improved. As the solvent 21, it is preferable to use a solvent having high affinity with the coating film and the coating material 16, such as hydrocarbon-based, alcohol-based, ester-based, ketone-based, ether-based organic solvents, water,
Or a mixture thereof can be used. However, if the repair coating material has high affinity and adhesion to the existing coating film, the above-mentioned dripping of the solvent can be omitted. Next, a block-like solid coating material 16 fixed to one side of the sheet 15 is applied to the micro-recess 8, and the coating material 16 is pressed from the back surface of the sheet 15 toward the micro-recess 8 (Fig. 7). b and c). As a result, the coating material 16 is peeled off from the sheet 15 and transferred and filled into the micro-recesses 8, and a part of the solvent 21 in the micro-recesses 8 is pushed out to the outside, and this overflowing solvent 21 causes Air bubbles are prevented from entering the micro-recesses 8. Furthermore, the surface of the coating material 16 is dissolved, swollen, or softened by the solvent, thereby improving the affinity and adhesion with the existing coating film. It is desirable that the size and shape of the coating material 16 be the same as or slightly larger than that of the minute recesses 8. In addition, these solvents are
It may be added after filling the coating material. Methods for curing the coating material 16 filled in the minute recesses 8 include leaving it at room temperature, heat treatment, irradiation with active energy, and the like. In this embodiment, the filling coating material 16
Further, the filling coating material 16 is heated and hardened by irradiating the laser 7 (see FIG. 7d). Even in the case of curing the filling part coating material 16, it is done under an inert gas N atmosphere using the laser oscillator 42' illustrated in FIG. This is preferable in terms of preventing. Furthermore, in curing the filler coating material 16, as shown in FIG. Preferably, the inert gas N passing through 51 is heated. As a result, not only high-temperature curing paints (those that can be cured by high-output laser irradiation) but also low-temperature curing paints (those that can be hardened by low-output laser irradiation) can be cured in a short time. Low-temperature curing paints require low-power laser irradiation, so
When the inert gas N is not heated, the influence of the heat dissipation effect of the highly thermally conductive car body steel plate 1 becomes large, and therefore it takes a particularly long time to cure the low temperature curing type paint. However, in a heated inert gas N atmosphere, the above-mentioned heat dissipation effect can be supplemented, and it becomes possible to harden in a short time. Note that the heating that supplements the heat dissipation effect is not limited to the heating of inert gas as described above, but various heating means such as heating by supplying hot air, induction heating, heating by infrared rays or far-infrared irradiation, etc. Can be adopted. After the coating material hardens, the filling portion coating material 16 is smoothed and finished using a grindstone, a small rotary buff 29, etc. (7th step)
(see figure e). In this way, in the repair coating method for defective parts of a paint film of the present invention, the minimum necessary number of defective parts is removed using laser irradiation or a cutting machine, and the necessary amount is filled in the recess after the defective part has been removed. Since the repair coating material is filled and only the filled part coating material is cured, the consumption of the repair coating material and energy is small, and the work does not require labor and time, and does not require a coating expert. Table 1 shows the repair work time by the method of the present invention in comparison with the repair work time by the conventional method.

[Table] As shown in Table 1, the time required for repair work using the method of the present invention is approximately 1/9 to 1/18 shorter than the time required for repair work using the conventional method. It is now possible to repair defective parts of the paint film, and it is also possible to eliminate a separate repair line. In addition, in curing the filling part coating material 16,
Instead of irradiating with the laser 7, hot air may be supplied to the filling portion coating material 16, and the filling portion coating material may be heated and hardened by contact with the hot air. As the device for supplying the hot air, a hot air supply device 121 shown in FIG. 8 can be used. The hot air supply device 121 includes a coiled electric heater 124 connected to a power source 123, and a coiled electric heater 124 that is placed in a cylindrical body 122 having openings at both ends and a tapered opening at one end, and a coiled electric heater 124 that supplies air toward the electric heater 124. A blower 125 is disposed to discharge air heated by the electric heater 124 from the small diameter opening 126 of the cylindrical body 122. By using the hot air supply device 121 configured in this way, hot air can be supplied to the filling part coating material 1.
6 can be supplied intensively and can be rapidly cured. Hot air supply device 7 shown in FIG.
1 is a small diameter cylindrical body 72 having openings at both ends;
It is equipped with an electric heater 73 disposed inside the cylindrical body 72, and heats gas such as an inert gas supplied from an opening at one end of the cylindrical body 72, and discharges the heated gas from the opening at the other end. be. This hot air supply device 71
Also, the same effect as the hot air supply device 61 can be obtained, and when an inert gas is used, discoloration of the coating film (due to deterioration such as carbonization of the resin) can also be prevented. In addition, in curing the filling part coating material 16,
It can be cured by irradiating infrared rays or far infrared rays. It can also be cured by irradiating it with an electron beam.
Infrared rays or far infrared rays (hereinafter referred to as "infrared rays")
When irradiating, as shown in FIG. 10, for example, an infrared irradiation device 81 comprising an infrared irradiation lamp 82 and a hemispherical reflector 83 that reflects the infrared rays irradiated from the lamp 82 in a certain direction is used. be able to. In the case of electron beam irradiation, as shown in FIG.
An electron beam irradiation device 91 can be employed, which includes a controller 94 for controlling the high voltage generator 93. Furthermore, the filling portion coating material 16 may be dried at room temperature or cured based on a reaction such as a crosslinking reaction, and a portion of the car body steel plate 1 corresponding to the surrounding area may be induction heated by electromagnetic induction, thereby forming the filling portion coating material. 16 may be cured. As shown in FIG. 12, the induction heating device consists of a U-shaped core 103 wound around an induction coil 102 placed in a portal shape on the coating surface, and a U-shaped core 103 that is connected to a power source 104 and supplies current to the induction coil 102. The control unit 105 generates an eddy current in the steel plate 1, and the steel plate 1 is generated by the joule heat caused by the eddy current.
An induction heating device 101 for heating can be employed. This induction heating device 101 may be equipped with a temperature sensor (not shown) that detects the temperature of the steel plate 1 and sends a detection signal to the control unit 105. Thereby, the heating temperature of the steel plate 1 can be kept substantially constant. Furthermore, when using an ultraviolet curing type repair paint, for example, an ultraviolet irradiation device 11 shown in FIG.
The repair paint can be rapidly cured by ultraviolet irradiation using No. 1. Ultraviolet irradiation device 1
11 includes a small diameter optical fiber 113 connected to an ultraviolet generator 112, and the repair coating material 16
It is possible to perform ultraviolet irradiation in a concentrated manner. As the UV-curable repair coating material, a transparent coating material that can transmit ultraviolet light can be particularly advantageously employed. In the above example, a method for repairing convex paint film defects caused by dust trapped in the paint film was described in detail. Repair of paint film defects is also carried out in a similar manner. In this case, the deposits such as oil droplets are removed by laser irradiation or by a cutting machine such as a rotary drill. In addition, the top coat layer is composed of, for example, a colored paint film and a transparent paint film on top of the colored paint film, and the colored paint can be used as a repair coating material when dust is included in the top coat layer, resulting in minute paint film defects. Repair painting can also be performed using two types of solid coating materials: transparent and transparent. The repair coating material filling process using these solid colored coating materials and transparent coating materials and the process of curing the coating materials will be explained below. First, using a cutting machine, laser irradiation, etc., the colored coating film is removed to form minute recesses. After that, the colored coating material of the same color as the colored coating film is pressed onto the bottom of the microscopic depression so that it has the same thickness as the microscopic depression,
After transferring, the colored coating material is cured by the same method as described above, that is, by laser irradiation, hot air supply, infrared ray or electron beam irradiation, room temperature curing, induction heating, or ultraviolet irradiation. Next, the transparent coating material is transferred onto the cured colored coating material to fill the minute recesses with the coating material, and the transparent coating material in the recesses is further cured. The surface of the cured transparent paint is similar to the above example,
Polishing gives it a smooth finish. In this embodiment, the amount of colored coating material to be cured can be reduced by the amount of transparent coating material, and furthermore, metallic coating is used as the colored coating and a colorless transparent coating is coated on top of the metallic coating. It can be particularly advantageously used for repairs. In the above example, after the colored coating material was cured, the transparent coating material was filled and cured, but the colored coating material was put into the recess and then the transparent coating material was filled without curing. , by any of the methods described above, namely laser irradiation, supply of hot air, infrared ray or electron beam irradiation, room temperature curing, induction heating, infrared irradiation, or by using any of these methods in combination. may be cured. The method of the present invention can be applied not only to the above-mentioned car body painting, but also to a wide range of general painting. Effects of the Invention As is clear from the above, according to the method of the present invention, the following effects can be obtained. That is, microscopic coating film defects are removed in an extremely narrow range using a cutting machine, laser irradiation, etc., thereby forming microscopic depressions on the coating film surface, so that the repair coating that is filled into the microscopic depressions can be removed. Only a very small amount of material can be used, and the amount of energy consumed for curing the coating material can also be small. In addition, since the repair is a narrow area, there is almost no deterioration in the performance of the entire paint film, and it can be repaired in a short period of time.Furthermore, finishing is easy and does not require a particularly skilled person for repair painting. . If the above-mentioned repair coating material is filled into the micro-recesses and the filled repair coating material is cured in an inert gas atmosphere, discoloration of the coating surface can be prevented. Furthermore, since the coating material can be cured in various directions such as laser irradiation, hot air supply, infrared ray irradiation, electron beam irradiation, induction heating, room temperature curing, and ultraviolet irradiation, it can be used as a repair coating material from low temperature curing type to A wide variety of coating materials can be used, including high temperature curing types. Furthermore, as a result of the extremely short repair time as described above, repair painting can be performed within the main line, making it possible to omit a separate repair line.

[Brief explanation of the drawing]

Figures 1a and b are explanatory diagrams showing an example of the step of removing minute paint film defects in the method for repairing paint surfaces according to one embodiment of the present invention, and Figure 2 is a laser processing method used in the method of the present invention. Schematic diagram showing an example of the machine, Part 3
The figure is a longitudinal sectional front view showing an example of a laser oscillator.
Figures a and b are explanatory diagrams showing another example of the step of removing the minute coating film defects, and Figure 5 is a longitudinal side view showing one example of the solid coating material capable of forming a coating film used in the present invention.
FIG. 6 is a vertical side view showing an example of the manufacturing method;
7a to 7e are explanatory diagrams showing step-by-step the method for repairing a coating surface according to the above-described embodiment of the present invention; FIG. 8 is a longitudinal sectional front view schematically showing an example of a hot air supply device; FIG. 9 is a longitudinal front view schematically showing another example of a hot air supply device, FIG. 10 is a longitudinal front view schematically showing an example of an infrared irradiation device, and FIG. 11 is a longitudinal front view schematically showing an example of an electron beam irradiation device. FIG. 12 is a front view schematically showing an example of an induction heating device;
FIG. 3 is a front view schematically showing an example of an ultraviolet irradiation device, and FIGS. 14 a to 14 f are explanatory diagrams showing a repair process according to a conventional coating film surface repair method step by step using the coating film. . 1... Steel plate of car body, 4... Top coat layer, 5... Dust, 6... Minute coating film defect, 7... Laser for processing, 8... Minute recess, 9... Rotary drill, 15
... sheet, 16 ... solid coating material, 21 ... solvent.

Claims (1)

[Claims] 1. Remove the dust, oil droplets, etc. and the coating film from the microscopic coating film defects caused by the adhesion of dust, oil droplets, etc. to form microscopic depressions on the coating film surface, and then apply 10 dyn/cm or more.
On one side of a sheet having a surface tension of 60 dyn/cm or less, a solid coating material capable of forming a film, which is adhered in a lump-like manner and releasable, is transferred by pressure to the minute depressions, and the transferred coating material is further cured. A repair coating method for a painted surface, which is characterized by: