Painting method and masking member

Abstract

To provide a coating method which can simplify a series of coating process while securing appearance quality when coating materials of a plurality of colors are coated onto mutually adjacent regions, and a masking member for the same.SOLUTION: When a first color area 21 and a second color area 22 are formed so as to be adjacent to each other in a parting 20, a first coating material is coated onto a coated object 10 and a first color coating layer 11 in a semi-dry state is formed, the partial first color coating layer 11 is coated along the parting 20 by a masking sheet 13a peelably contacting the first color coating layer 11 and is installed in the coated object 10 by a magnetic force of a magnet part 13b, a second coating material is coated onto the other part of the first color coating layer 11 and a second color coating layer 12 is formed, and the first color coating layer 11 and the second color coating layer 12 are cured.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a coating method for forming a first color region and a second color region adjacent to each other with a parting line therebetween, and to a masking member used in this coating method. [Background technology]

[0002] Conventionally, when painting a part of a surface with a different color, such as in two-tone painting, a masking member is placed along the parting line and then painted to prevent the paint from spilling out. As a painting method using such a masking member, for example, Patent Document 1 proposes a method using a masking jig that has a magnetic material on the front side and a standing wall on the back side. In this document, the masking jig is attached along the parting line, and paint is sprayed onto the painted surface while preventing the paint from splashing or spilling out onto the non-painted surface, thereby making the parting line clear and painting only the area on one side.

[0003] Patent Document 2 proposes a method of using a masking sheet fixture made of a magnetic flexible elongated body of a specific shape to cover non-painted areas with a masking sheet such as newspaper when repairing an automobile, etc. In this document, a masking sheet fixture of a specific shape is used to reduce the step that occurs at the boundary between the painted area and the non-painted area.

[0004] To apply two-tone painting to an automobile body or the like using a conventional masking member, the first paint was generally applied to the object to be painted to form a first color coating layer, this first color coating layer was then cured, and then a masking member was placed on the first color coating layer along the parting to cover it, and in this state a second paint was applied to form a second color coating layer, which was then cured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2596967 [Patent Document 2] JP 2020-121243 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in such a conventional coating method using a masking member, when forming areas of different colors adjacent to each other with a parting line, if the masking member is installed before the first color coating layer has hardened, there is a risk that the first color coating layer will adhere to the masking member and peel off or become damaged when the masking member is removed after the formation of the second color coating layer. Therefore, the masking member could not be installed along the parting line unless the first color coating layer has hardened. As a result, a hardening process must be performed after painting the first color and after painting the second color, which requires time and effort such as passing through a drying oven multiple times in a series of coating processes, and has a significant impact on productivity.

[0007] The first object of the present invention is to provide a painting method that can simplify a series of painting steps while ensuring appearance quality when applying multiple colors of paint to adjacent areas to perform multiple color painting, and the second object of the present invention is to provide a masking member that can be suitably used to realize this painting method. [Means for solving the problem]

[0008] In order to achieve the first object, the present invention provides a coating method for forming a first color region formed by hardening a first paint and a second color region formed by hardening a second paint adjacent to each other with a parting line, comprising the steps of: applying a first paint to an object to be coated to form a first color coating layer in a semi-dried state; covering a part of the first color coating layer along the parting line with a masking sheet that is in peelable contact with the first color coating layer; The coating machine includes a main body that is disposed along the surface of the object to be coated, and a rear portion having an inclined surface on the opposite side of the main body from the parting line, the rear portion being spaced apart from the object to be coated as the position of the rear portion becomes larger as the position of the rear portion becomes larger as the parting line. In this method, the magnet is attached to the object to be coated using the magnetic force of the magnet, a second paint is applied to the other part of the first color coating layer to form a second color coating layer, and the first color coating layer and the second color coating layer are then cured.

[0009] In order to achieve the second object, the present invention provides a masking member for coating a first color coating layer formed by coating a first coating material on an object along a parting line and coating a second coating material, the masking member comprising a masking sheet that releasably contacts and covers the semi-dried first color coating layer, and a magnet portion that magnetically attaches the masking sheet to the object. The magnet portion includes a main body portion that is arranged along the surface of the object to be coated, and a rear portion having an inclined surface that is spaced apart from the object to be coated at a position on the opposite side to the parting of the main body portion so as to be spaced apart from the parting. . Effect of the Invention

[0011] According to the coating method of the present invention, after applying the first paint to the object to be coated to form a first color coating layer in a semi-dried state, a part of the first color coating layer is covered with a masking sheet along the parting line, and the second paint is applied to the other part of the first color coating layer to form a second color coating layer. At that time, the first color coating layer is covered with a masking sheet that is in peelable contact with the first color coating layer and is attached to the object to be coated by the magnetic force of the magnet part, so that even if the masking sheet is in contact with the first color coating layer in a semi-dried state, the first color coating layer can be prevented from adhering to the masking sheet or from being damaged by the masking sheet. Therefore, the second color coating layer can be formed without hardening the first color coating layer, and by hardening the first color coating layer and the second color coating layer thereafter, good appearance quality of the first color region and the second color region can be ensured. Therefore, when applying paint of different colors to adjacent regions, a coating method can be provided that can simplify a series of coating steps by omitting the hardening process while ensuring appearance quality.

[0012] According to the masking member of the present invention, the masking sheet covers the first color coating layer in a semi-dried state by being in peelable contact with the masking sheet, and the masking sheet can be attached to the object to be coated by the magnetic force of the magnet part, so that even if the first color coating layer formed by applying the first paint to the object to be coated is covered in a semi-dried state, it is possible to prevent the first color coating layer from adhering to the masking sheet or from being damaged. This makes it possible to form a second color coating layer by covering the first color coating layer along the parting line with the masking sheet without hardening the first color coating layer, and provides a masking member that can be suitably used in a coating method that omits hardening treatment while maintaining appearance quality when coating adjacent areas with different colors and performs a series of coating steps. [Brief description of the drawings]

[0013] [Figure 1] 1(a) to 1(f) are partial cross-sectional views illustrating the steps of a coating method according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a partial cross-sectional view showing a state in which a masking member according to one embodiment is placed on a first color coating layer. [Diagram 3] FIG. 4 is a diagram for explaining the conditions for establishing the viscosity of a first color coating layer and the peel strength due to the magnetic force of a masking member in a coating method according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a coating method using a masking member according to an embodiment of the present invention will be described in detail with reference to the drawings. The object to be coated is any of various components formed into a flat or three-dimensional shape from metal materials such as steel, and may be, for example, the body or exterior panel of an automobile or motorcycle, the exterior body of an electrical product, etc., but in this embodiment, an automobile body formed and joined into a three-dimensional shape from steel plates is taken as an example. This object to be coated has been coated with an undercoat and an undercoat, and by applying a topcoat using the coating method of this embodiment, a first color region formed by hardening the first paint and a second color region formed by hardening the second paint are formed adjacent to each other with a parting.

[0015] In this embodiment, to apply a topcoat to the workpiece 10, the following steps are sequentially performed: a first-color coating layer 11 formation step, in which a first paint is applied to the workpiece 10 to form a first-color coating layer 11 and the first-color coating layer 11 is semi-dried, as shown in FIG. 1(a); a masking step, in which a masking member 13 is placed at a predetermined position on the semi-dried first-color coating layer 11 to cover a portion of the first-color coating layer 11, as shown in FIG. 1(b); a second-color coating layer 12 formation step, in which a second paint is applied to the other portion of the first-color coating layer 11 that is not covered by the masking member 13, to form the second-color coating layer 12, as shown in FIG. 1(c); a clear layer 14 formation step, in which a clear paint is applied on the first-color coating layer 11 and the second-color coating layer 12 after removing the masking member 13, as shown in FIG. 1(d); and a curing step, in which the first-color coating layer 11, the second-color coating layer 12, and the clear layer 14 are entirely cured, as shown in FIG. 1(f).

[0016] The first and second paints used in this coating method are generally any type of paint that can be used as a color base for topcoats, and contain a film-forming resin component, a hardener, a pigment, a solvent, and various additives that are added as needed.

[0017] The resin component may be any of various resins commonly used as resin components for paints, such as at least one resin selected from acrylic resins, vinyl resins, polyester resins, alkyd resins, and urethane resins, and having, as functional groups, hydroxyl groups, carboxyl groups, silicon-containing groups, epoxy groups, and optionally blocked isocyanate groups.

[0018] Examples of the curing agent include melamine resins, urea resins, polyisocyanate compounds which may be blocked, carboxyl group-containing compounds, and epoxy group-containing compounds which react with the functional groups in the resin component.

[0019] Examples of pigments include black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, black iron oxide (iron tetroxide), black titanium oxide, copper manganese black, copper chrome black, cobalt black, cyanine black, and aniline black; blue pigments such as phthalocyanine-based, indanthrone-based, and indigo-based pigments; and red pigments such as azo-based, diketopyrrolopyrrole-based, perylene-based, perinone-based, and iron oxide. In this embodiment, the first paint and the second paint have different colors.

[0020] Examples of the solvent include aqueous liquids such as water, aromatic solvents such as xylene, aliphatic solvents such as mineral spirits, ester solvents such as ethyl acetate, butyl acetate, propyl propionate, butyl propionate, 1-methoxy-2-propyl acetate, 2-ethoxyethyl propionate, 3-methoxybutyl acetate, ethylene glycol ethyl ether acetate, and propylene glycol methyl ether acetate, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone, and alcohol solvents such as isopropanol, n-butanol, isobutanol, and 2-ethylhexanol. As additional components that are added as necessary, various additives such as a viscosity imparting agent, a flow control agent, a light stabilizer, an ultraviolet absorber, a body pigment, and a pigment dispersant may be blended.

[0021] The second paint used in this coating method may be the same as the first paint, which is usually made of various paints that can be used as a color base for the top coat, but it may also be a colored clear paint colored by adding pigments to a clear paint.

[0022] As the colored clear coating material, any known coating material can be used as appropriate. For example, a coating material in which an acrylic resin, a polyester resin, an alkyd resin, a urethane resin, an epoxy resin, or the like, a crosslinking agent such as a blocked polyisocyanate, a melamine resin, or a urea resin, a pigment, and other additives are dissolved or dispersed in an organic solvent may be used.

[0023] As the clear coating material, any known coating material can be used as appropriate. For example, a coating material in which an acrylic resin, a polyester resin, an alkyd resin, a urethane resin, an epoxy resin, or the like, a crosslinking agent such as a blocked polyisocyanate, a melamine resin, or a urea resin, and other additives are dissolved or dispersed in an organic solvent may be used.

[0024] 1(a), a first paint is applied to the cured surface of the workpiece 10 after the undercoat, and then dried to a semi-dry state to form the first color coating layer 11. The area in which the first color coating layer 11 is formed includes at least the area where the first color region 21 will be formed after painting, but in this embodiment, the first color coating layer 11 is formed over the entire surface of the workpiece 10.

[0025] The first paint can be applied by spraying in a paint booth where the temperature and humidity are controlled, for example, to form the first color coating layer 11. After application, the first color coating layer 11 is dried to a semi-dried state. To semi-dry the first color coating layer 11, for example, the first paint does not harden but the volatile components contained therein, such as water and solvents, can be evaporated by placing it in a simple oven at a low temperature of about 80°C for an extremely short time, or hot air can be applied to semi-dry it.

[0026] The semi-dry state of the first color coating layer 11 refers to a state in which the volatile components such as water and solvent contained in the first paint have evaporated, the curing components of the first paint are uncured or have not cured sufficiently, and the viscosity of the first paint does not allow the first paint to adhere to the surface of the masking sheet 13a described below. For example, the viscosity of the first color coating layer 11 may be in the range of 2 kPa·S or more. By putting the first color coating layer 11 in a semi-cured state, even if a masking sheet 13a of a masking member 13 is pressed against the surface of the first color coating layer 11, the first color coating layer 11 is prevented from adhering to the masking sheet 13a, thereby preventing the first color coating layer 11 from being left with a mark or being scratched.

[0027] Next, in the masking process, as shown in FIG. 1(b), a masking member 13 is placed on the semi-dried first color coating layer 11 to define the area to which the second paint is to be applied in the next process of forming the second color coating layer.

[0028] The masking member 13 in this embodiment covers a part of the first color coating layer 11 in a semi-dried state along the parting line 20, and exposes the other part of the first color coating layer 11 as an area to be coated with the second paint. As shown in Fig. 2, this masking member 13 is equipped with a masking sheet 13a that releasably contacts and covers a part of the first color coating layer 11, and a magnet part 13b that magnetically attaches the masking sheet 13a to the workpiece 10.

[0029] The masking sheet 13a is a smooth sheet material that can be peelably brought into contact with the semi-dried first color coating layer 11, such as a release paper on which a coating of a silicone-based release agent or a non-silicone-based release agent is provided as a release layer on the surface of the substrate. The masking sheet 13a is attached to the side of the magnet portion 13b that faces the workpiece 10, for example, with double-sided tape. The masking sheet 13a has a front edge 13c that is arranged along the parting 20, and is attached so that the front edge 13c protrudes from the magnet portion 13b when the first color coating layer 11 is covered.

[0030] The magnet section 13b has flexibility allowing it to deform in accordance with the surface shape of the workpiece 10, and is formed in a continuous band shape from a material such as a rubber magnet that can be attached to the workpiece 10 by magnetic force. As shown in Fig. 2, the magnet section 13b is equipped with a main body section 13d that is arranged along the surface shape of the workpiece 10, and a rear section 13e that is provided on the opposite side of the main body section 13d from the parting edge 20 and has an inclined surface that is inclined so as to move away from the workpiece 10 the further away it is from the parting edge 20. The inclined surface is formed in a curved shape that continues from the main body section 13d.

[0031] In the masking process, such a masking member 13 is placed on the first color coating layer 11 along the parting 20 between the first color region 21 and the second color region 22. In detail, the front end edge 13c of the masking sheet 13a, which protrudes forward from the magnet portion 13b, is placed in close contact with the first color coating layer 11 along the parting 20, and is attached to the workpiece 10 on the first color coating layer 11 near the parting 20 by the magnetic force of the magnet portion 13b.

[0032] At this time, the masking sheet 13a is brought into contact with the surface of the semi-dried first color coating layer 11 with a pressure corresponding to the magnetic force of the magnet portion 13b. In this embodiment, a suitable condition for covering the semi-dried first color coating layer 11 with the masking member 13 may be set by combining the magnetic force of the magnet portion 13b, for example, the peel strength measured by the force required to peel the masking member 13 attached by the magnetic force of the magnet portion 13b from the workpiece 10 against the magnetic force, with the viscosity of the first color coating layer 11 in the semi-dried state. By covering the first color coating layer 11 with the masking member 13 within such a range of acceptable conditions, it is possible to stably cover a specified area without causing any contact marks with the masking member 13, such as peeling or scratches, on the first color coating layer 11 in a semi-dried state.

[0033] For example, as shown in FIG. 3, when the viscosity of the first color coating layer 11 is in the range of 2 kPa·S or more and the peel strength of the magnet part 13b attached to the workpiece 10 by magnetic force is 15 g / cm 2 More than 100g / cm 2 The following ranges may also be used: If the viscosity of the first color coating layer 11 is less than 2 kPa·S, the first color coating layer 11 will not be in a dry state well and will easily flow or deform when subjected to an external force. The higher the viscosity of the first color coating layer 11, the better, but hardening treatment of the first color coating layer 11 is not necessary. Furthermore, if the peel strength of the magnet portion 13b is excessively low, a part or all of the masking member 13 may come off from the surface of the workpiece 10 due to pressure such as wind pressure applied when the first paint is applied. On the other hand, if the peel strength of the magnet portion 13b is excessively high, a contact mark with the magnet portion 13b may remain on the first color coating layer 11 even when the masking member 13 is removed after the application of the second paint.

[0034] In the masking process, the masking member 13 is placed on the first color coating layer 11 to cover the formation area of ​​the first color region 21, which is a part of the first color coating layer 11, and to expose the formation area of ​​the second color region 22, which is the other part of the first color coating layer 11.

[0035] 1(c), a second paint is applied to the first color coating layer 11 in the formation range of the second color region 22 exposed from the masking member 13 in the same manner as for the first color coating layer 11 to form the second color coating layer 12. The second color coating layer 12 can be formed in the same manner as for a normal topcoat base, and does not require a process to bring it to a semi-dried state as in the case of the first color coating layer 11.

[0036] In the process of forming the clear layer 14 in this embodiment, first, as shown in Figure 1(d), the masking member 13 is removed together with the second paint adhering to the masking member 13, and then, as shown in Figure 1(e), clear paint is applied continuously to both surfaces of a portion of the first color coating layer 11 for forming the first color region 21 and the second color coating layer 12 adjacent to this first color coating layer 11 at the parting 20 to form a clear coating layer.

[0037] In the curing process of this embodiment, as shown in Figure 1 (f), the workpiece 10, in which the first color coating layer 11, the second color coating layer 12 and the clear layer are in an uncured or semi-cured state, is placed in a booth where the temperature, humidity, etc. are controlled to specified conditions, and heated to cure the first color coating layer 11, the second color coating layer 12 and the clear layer 14. This allows a two-tone coating to be applied to the object 10, in which a first color area 21 formed by hardening the first paint and a second color area 22 formed by hardening the second paint are adjacent to each other with a parting 20 therebetween.

[0038] According to the coating method using the masking member 13 described above, the masking sheet 13a of the masking member 13 can cover the semi-dried first color coating layer 11 in a peelable manner, and this masking sheet 13a can be attached to the workpiece 10 by magnetic force using the magnet part 13b. Therefore, even if the first color coating layer 11 formed by applying the first paint is covered with the masking member 13 in an uncured state, the first color coating layer 11 will not adhere to the masking sheet 13a or be damaged. This allows the first color coating layer 11 to be covered along the parting line 20 with the masking sheet 13a to form the second color coating layer 12 without hardening the first color coating layer 11, making it possible to form coating layers of different colors in areas adjacent to the parting line 20 without hardening while maintaining appearance quality, and this method can be suitably used when applying such coatings.

[0039] Furthermore, in the masking member 13 of this embodiment, the magnet portion 13b is provided with a main body portion 13d that is disposed along the surface of the workpiece 10, and a rear portion 13e that has an inclined surface on the opposite side of the main body portion 13d from the parting 20, the further away from the workpiece the further away from the parting 20. Therefore, even if the masking member 13 is disposed in contact with the semi-dried first color coating layer 11 to cover it, it is possible to further prevent the angular ends of the magnet portion 13b from coming into strong contact with the first color coating layer 11, which would cause the first color coating layer 11 to be dented or scratched.

[0040] In addition, in the masking member 13 of this embodiment, the masking sheet 13a has a front edge 13c that is arranged along the parting 20, and this front edge 13c is arranged to protrude further toward the parting 20 than the magnet portion 13b. Therefore, the thickness of the portion of the masking member 13 that is arranged on the parting 20 can be made thin, and when the second paint is applied, the second paint does not accumulate near the parting 20, and the occurrence of a step near the parting 20 can be prevented.

[0041] According to the coating method of this embodiment using this masking member 13, after the first paint is applied to the object 10 to form the first color coating layer 11 in a semi-dried state, a part of the first color coating layer 11 is covered with the masking sheet 13a along the parting 20, and the second paint is applied to the other part of the first color coating layer 11 to form the second color coating layer 12. At this time, the first color coating layer 11 is covered with the masking sheet 13a that releasably contacts the first color coating layer 11 and is attached to the object 10 by the magnetic force of the magnet part 13b, so that even if the masking sheet 13a is brought into contact with the first color coating layer 11 in a semi-dried state, it is possible to prevent the first color coating layer 11 from adhering to the masking sheet 13a or the first color coating layer 11 from being damaged by the masking sheet 13a.

[0042] Therefore, the second color coating layer 12 can be formed without curing the first color coating layer 11, and by subsequently curing the first color coating layer 11 and the second color coating layer 12, good appearance quality can be ensured for the first color region 21 and the second color region 22. As a result, when coating adjacent regions with different colors, the series of coating steps can be simplified by omitting the curing process while ensuring appearance quality.

[0043] In addition, in the coating method of this embodiment, the front edge 13c of the masking sheet 13a protrudes beyond the magnet portion 13b and is disposed in close contact with the parting 20 between the first color region 21 and the second color region 22, so that only the front edge 13c of the masking sheet 13a can be disposed at the parting 20, and paint can be prevented from accumulating near the parting 20 during coating. In other words, when the magnet portion 13b is disposed at the front edge 13c of the masking sheet 13a, the magnet portion 13b, which is much thicker than the masking sheet 13a, is disposed at the front edge 13c of the masking sheet 13a, and paint is likely to accumulate in a position adjacent to the parting 20 when the second paint is applied, and a step or the like occurs at the parting 20 after hardening. However, if the front edge 13c of the masking sheet 13a is positioned so that it protrudes beyond the magnet portion 13b, only the thin front edge 13c of the masking sheet 13a can be positioned at the parting 20, making it difficult for paint to accumulate adjacent to the front edge 13c of the masking sheet 13a during application, and preventing the occurrence of a step near the parting 20.

[0044] The above embodiment can be modified as appropriate within the scope of the present invention. For example, in the above embodiment, an automobile body made of steel is described as an example of the object to be coated, but the object is not particularly limited, and the masking member 13 can be applied to various members that can be magnetically attached. [Explanation of symbols]

[0045] 10 Object to be painted 11 First color coating layer 12 Second color coating layer 13 Masking materials 13a Masking sheet 13b Magnet section 13c Front edge 13d Main body 13e Rear 14 Clear layer 20. Forget 21 1st color area 22 Second color area

Claims

1. A coating method for forming a first color region formed by hardening a first coating material and a second color region formed by hardening a second coating material adjacent to each other with a boundary therebetween, The first paint is applied to an object to be coated to form a first color coating layer in a semi-dried state; a masking sheet that is in peelable contact with the first color coating layer covers a portion of the first color coating layer along the parting line, and the masking sheet is attached to the workpiece by the magnetic force of a magnet portion that includes a main body portion that is arranged along the surface of the workpiece, and a rear portion that has an inclined surface that is spaced apart from the workpiece on the opposite side of the main body portion from the parting line as the position of the rear portion is spaced apart from the parting line; The second paint is applied to the other portion of the first color coating layer to form a second color coating layer; A coating method comprising curing the first color coating layer and the second color coating layer.

2. A masking member for coating a first color coating layer formed by coating a first coating material on an object to be coated along a parting line, and for coating a second coating material, a masking sheet that peelably contacts and covers the first color coating layer in a semi-dried state; A magnet portion that magnetically attaches the masking sheet to the object to be coated, A masking member, wherein the magnet portion comprises a main body portion that is arranged along the surface of the workpiece, and a rear portion having an inclined surface on the opposite side of the main body portion from the parting that moves away from the workpiece as the position moves away from the parting increases.

Images