JP5386831B2 - Coating film polishing method - Google Patents

Description

  The present invention relates to a coating film polishing apparatus and a coating film polishing method using the same.

  In automobile manufacturing, the surface of a vehicle body is painted for the purpose of providing rust prevention and aesthetics. In general, paint is a single material that cannot satisfy all the required performance, and several materials can be used properly and applied several times to satisfy various performances as a total coating film. ing. For example, the coating of the outer plate of an automobile body is generally a coating of a steel plate substrate (pre-treatment, electrodeposition coating, intermediate coating, and top coating in order). Rust prevention, intermediate coating is used to adjust the surface to improve the finished appearance, and top coating is responsible for coating performance, with the finished appearance and durability as the main components.

At the time of top coating, fine convex coating defects (dust, blisters, flow, sagging) occur, but such coating defects need to be removed from the viewpoint of aesthetics. In the coating defect removal step (sanding), foreign matters are physically removed using a polishing machine equipped with a polishing film (see, for example, Patent Document 1). There are various types of polishing films having different roughness, and various types are used depending on the foreign matter and in the polishing process.
JP 2001-179590 A

  The roughness of the polishing film is usually uniform, and when the polishing film having a different roughness is used, the polishing film is changed or the tool is changed. For this reason, when polishing in-line, the work efficiency is poor and it is difficult to repair in the tact.

  Accordingly, an object of the present invention is to provide a coating film polishing apparatus and a coating film polishing method that have high work efficiency and efficiently remove coating defects.

As a result of earnestly examining the above problems, the present inventors have provided a polishing material on the entire surface, and have two concentric regions with different roughness of the polishing material, and a region with a rough roughness on the inner side. The polishing film in which the region having a fine roughness is arranged on the outer side is located on the convex curved surface of the polishing pad so that the region having the coarse roughness of the polishing film is located on the top of the convex curved surface. The polishing pad is used when the coating film is polished in a region where the roughness of the polishing film is fine compared to when the coating film is polished in a region where the roughness of the polishing film is rough. It has been found that the above problems can be solved by tilting .

  According to the present invention, the efficiency of the in-line polishing operation is improved, and the convex defects on the coating film can be easily repaired within the tact.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a coating film polishing apparatus according to an embodiment of the present invention (first embodiment).

  The coating film polishing apparatus 1 of FIG. 1 is attached to the pad body 4 (corresponding to a polishing pad) attached to the tool main body part composed of the head part 2 and the body part 3, the tip of the head part, and the pad 4. A polishing film 5 is provided. The head unit 2 includes a drive source 6, a rotation shaft 7, and a support unit 8. The body unit 3 includes an operation unit 9. The drive shaft 6 rotates the rotating shaft 7, the support portion 8, and the pad 4 to polish the polished surface of the coating film. Here, the rotation is a concept including not only a motion that continuously rotates in one direction but also an orbital motion as disclosed in Patent Document 1. The operation unit 9 is a part that supplies / blocks the compressed air supplied to the coating film apparatus 1 to / from the driving source 6. The drive source 6 may be an electric motor in addition to air.

  As a tool main-body part, the tool normally used in the case of grinding | polishing can be used, As a commercial item, the 3125 butter removal sander by Three M company is mentioned, for example.

  The pad 4 has a convex curved surface shape toward the coating film (FIG. 4). The polishing film 5 having a curved surface makes it difficult for the polishing films 5 having different roughnesses to interfere with each other, and the polishing operation using two polishing materials having different roughnesses with one polishing film 5. Work efficiency is improved. In addition, since it is possible to selectively polish only foreign matters, unnecessary dents around the foreign matters can be reduced.

  The pad 4 is not particularly limited, and a known polishing pad can be used, but an elastic material body such as a sponge is preferable from the viewpoint of moldability.

  In the polishing pad 4, the longest distance (L in FIG. 5) in the vertical direction with respect to the coating film of the convex portion to which the polishing film 5 is attached is about 5 mm. In general, the distance L is preferably 1 to 3 mm. When a curved surface is provided on the polishing pad in such a range, polishing work can be performed without interference of abrasives having different roughness, and work efficiency is improved.

  The polishing film 5 is circular before being attached to the pad 4, and has two concentric areas (11, 12) as shown in FIG. Roughness varies. The region 11 near the center is made of an abrasive that is rougher than the region 12. By adopting such a configuration, first, after removing the convex coating defect portion in the rough region, it is possible to polish a range wider than the defect portion removal range in the fine roughness region.

  The abrasive in the region 11 is not particularly limited, but is preferably 3000 or less, more preferably 1000 to 2500 (for example, a scallop disc 401Q manufactured by Three M Co.). is there. In addition, the abrasive in the region 12 is not particularly limited, but preferably more than 3000, more preferably 3500 to 5000 (for example, a 3M trizacto (registered) Trademark) disk 466LA).

  The ratio of the diameter of the circle of the region 11 (a in FIG. 2) and the diameter of the circle of the region 12 (b in FIG. 3) is not particularly limited, but a: b = 1: 1.5 to 1: It is preferably 10, more preferably 1: 2 to 1: 5, and still more preferably 1: 3. This is because the region 11 which is a rougher polishing portion than the region 12 is intended to remove the convex coating defect portion, and is therefore polished with a smaller range than the fine polishing portion.

  Thus, by making the roughness of the area | region 11 and the area | region 12 different, it is not necessary to replace the polishing film 5, the time for replacing the polishing film or the time for changing the tool becomes unnecessary, and the working time can be shortened. it can.

  Next, the coating film polishing method of the present invention will be described with reference to FIG.

  This is a method of using the coating film polishing apparatus when removing fine convex coating defects (dust, blisters, flow, sagging) 21 generated during top coating.

  In addition, this invention is not limited to the following embodiment, The method of removing the coating defect which arose in the electrodeposition process or the intermediate coating process is also included.

  In the present embodiment, a steel plate automobile body 22 is used as an object to be coated, and an electrodeposition coating film 23 and an intermediate coating film 24 as a base coating film, and a base coating film 25 and a clear coating film 26 as top coating films. Polishing is performed on the laminated coating film formed by the coating system.

  However, the coating film polishing method of the present invention is not limited to the material and application of the object to be coated, the material and structure of the base coating film, and the material and structure of the top coating film. For example, the present invention can be applied to an object formed from aluminum other than a steel plate, an aluminum alloy, or plastic. In addition to the two layers of the electrodeposition coating film and the intermediate coating film, the foundation coating film may be composed of any one layer or three or more layers. Further, the top coat film may be applied to a solid coat film containing no glitter pigment, or a top coat film containing a glitter pigment other than the two coat one bake system, in addition to the so-called two coat one bake coating system. it can.

<Laminated coating film configuration>
The electrodeposition coating film 23 has an electrophoretic action by immersing an object to be coated in a cation type electrodeposition paint or an anion type electrodeposition paint and applying a predetermined voltage between the object to be coated 22 and the electrodeposition paint. Thus, an uncured coating film is formed on the surface of the article 1 to be coated, and a cured coating film is formed by baking the coating film at 160 ° C. to 180 ° C. for 15 minutes to 30 minutes, for example. The film thickness of the electrodeposition coating film 22 is, for example, 10 to 40 μm, although it varies depending on the type and purpose of the article 1.

  The intermediate coating film 24 is mainly composed of a polyester resin, an acrylic resin, a vinyl chloride vinyl acetate copolymer resin, a urethane resin, a cellulose resin, or the like, and a thermosetting paint or a colorant or additive added thereto. If it is a room-temperature curable paint or a two-component curable paint, which is diluted with a solvent, is applied to the surface of the electrodeposition coating using a spraying gun or other coating machine. For example, it is formed by baking at 80 to 160 ° C. for 10 to 60 minutes. The thickness of the intermediate coating film is, for example, 15 to 45 μm, although it varies depending on the type and purpose of the object to be coated.

  The intermediate coating film 24 can be omitted depending on the type and purpose of the object to be coated. Alternatively, the electrodeposition coating film can be omitted, and the intermediate coating film can be formed directly on the surface of the object to be coated.

  The base coating film 25 is mainly composed of a polyester resin, an acrylic resin, a vinyl chloride vinyl acetate copolymer resin, a urethane resin, a cellulose resin, and the like, and a coloring material, a bright material, and additives as necessary are added thereto. A thermosetting paint, a room temperature curable paint or a two-component curable paint, which is diluted with a solvent, is applied to the surface of the intermediate coating film 3 using a coating machine such as a spray coating gun, If it is a thermosetting paint, it is formed by baking at 80 to 160 ° C. for 10 to 60 minutes, for example. In addition, it paints with the clear coating film 5 mentioned later and wet-on-wet, and is simultaneously baked on this baking conditions.

  Examples of additives include waxes such as polyethylene wax and polypropylene wax, and dispersants. Examples of solvents include water, aromatic hydrocarbon solvents or hydrocarbon solvents (ester solvents, ketone solvents). Examples thereof include solvents and alcohol-based solvents.

  The clear coating film 26 is a thermosetting paint or a room temperature curable paint comprising, as a main component, a polyester resin, an acrylic resin, a vinyl chloride vinyl acetate copolymer resin, a urethane resin, a cellulose resin, or the like, and an additive added thereto. Alternatively, a two-component curable paint, which is obtained by diluting the paint with a solvent, is applied to the surface of an uncured base coating film using a spraying gun or other coating machine. It is formed by baking at 80 to 160 ° C. for 10 to 60 minutes.

  Examples of additives include waxes such as polyethylene wax and polypropylene wax, and dispersants. Examples of solvents include water, aromatic hydrocarbon solvents or hydrocarbon solvents (ester solvents, ketone solvents). Examples thereof include solvents and alcohol-based solvents.

  In particular, the clear coating film 26 of the present embodiment is a scratch-resistant coating film having a high breaking energy with a breaking energy of 0.07 to 1.2 J (joules) in order to prevent scratches caused by a car wash machine or dry wiping. The scratch-resistant coating film softens the coating film and increases the breaking strength in order to absorb impacts that lead to scratches. Therefore, it is necessary to use a polishing film having a different roughness depending on the foreign matter and finish it to an appropriate surface, and the polishing method using the coating film polishing apparatus of the present invention is very suitable.

<Polishing method>
Polishing is performed using the polishing apparatus 1 after the overcoating step.

  First, the coating defect 21 generated in the clear coating film 26 is removed by using the region 11 on the polishing film 5 (FIG. 4, polishing step 1). Here, it is desirable to remove the coating defects in a minimum range so that the size after the removal becomes as small as possible.

  When the coating defect 21 is a foreign matter such as dust or crumbs, the protruding portion may be removed by sanding using the polishing film 5 after removing the foreign matter using a sharp tool (knife or the like). . The coating defect removal range is substantially circular in plan view.

  Next, the polished surface is finished using the region 12 on the polishing film 5. The polishing range is wider than the coating defect removal range (FIG. 6, polishing step 2).

  As described above, the method for polishing a coating film according to the present invention uses a polishing apparatus provided with a polishing film having two regions with different roughnesses, so that it is easy to selectively polish foreign matter, Since unnecessary dents around the foreign matter can be reduced, a uniform coating surface can be obtained.

It is a side view showing the coat polish device which is a 1st embodiment of the present invention. It is a top view of the polishing film attached to the apparatus of 1st Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view schematically showing an embodiment of a coating film configuration having an abnormal site polished by the coating film polishing method of the present invention. It is a figure which represents typically the grinding | polishing process 1 in the grinding | polishing method of the coating film of this invention. It is a figure which shows the longest distance of the perpendicular direction with respect to the coating film of the convex part to which an abrasive film is attached. It is a figure which represents typically the grinding | polishing process 2 in the grinding | polishing method of the coating film of this invention.

Explanation of symbols

1 coating film polishing equipment,
2 head,
3 Body part,
4 pad (polishing pad),
5 Abrasive film,
6 Drive source,
7 rotation axis,
8 support part,
9 Operation part,
11 Rough area on the abrasive film,
12 Fine areas on the abrasive film,
21 painting defects,
22
23 Electrodeposition coating film,
24 Intermediate coating film,
25 Base coating,
26 Clear coating.

Claims (2)

Abrasive material is provided on the entire surface, and there are two concentric areas where the roughness of the abrasive material is different. A rough area is arranged on the inner side, and a fine area is arranged on the outer side. The roughness of the polishing film is mounted in a state where the polishing film is mounted on the convex curved surface of the polishing pad so that the roughness of the polishing film is located on the top of the convex curved surface. A method of polishing a coating film , wherein the polishing pad is tilted when the coating film is polished in a region where the roughness of the polishing film is fine compared to when the coating film is polished in a region where the roughness is rough .   The method for polishing a coating film according to claim 1, wherein polishing is performed in a region where the roughness of the abrasive of the film is fine, and then polishing is performed in a region where the roughness of the abrasive of the film is fine.

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