JPH0657328B2 - Masking jig for painting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a masking jig for coating for coating an unpainted portion of an object to be coated and coating only a part of the object to be coated. In particular, it is particularly useful when coating a resin-made article such as a resin automobile bumper.

(Prior Art) Painting work when only a part of the surface of an object to be coated such as a resin automobile bumper is to be painted, or when the surface of the object to be coated is of a plurality of different colors. At times, it is necessary to expose only a part of the object to be coated and to cover the non-painted part of the other part.

4 (A) to (D) respectively show a resin automobile bumper W as an article to be coated. In recent years, automobile bumpers are mainly made of synthetic resin, which is more elastic than metal and absorbs impact in order to improve the body protection function at the time of collision and increase the freedom of shaping. The automobile bumpers W shown in FIGS. 4A to 4D are each made of synthetic resin.

The automobile bumper W shown in FIG. 4 (A) has a substantially flat surface, with the central portion of the surface as a boundary.
Only the upper side B is coated, or the upper side B and the lower side A are coated with different paints having different colors.
The automobile bumper W shown in FIG. 4 (B) has a groove G formed in the central portion of the surface thereof along the longitudinal direction,
Only the lower side A is coated around the groove G, or the upper side B and the lower side A are coated with different paints having different colors. An automobile bumper W shown in FIG. 4 (C) has two parallel grooves G formed in the central portion of the surface thereof, for example, a space B between the grooves G and a portion A different from this.
Either one of them is painted, or these parts are painted with different colors from each other. Further, the automobile bumper W shown in FIG. 4 (D) has loop-shaped grooves G formed at both ends of the surface thereof, and a portion B surrounded by these loop-shaped grooves G and this portion. It is applied to one of the parts A other than the above, or is applied with paints having different colors.

Conventionally, for example, when a resin automobile bumper W as shown in FIG. 4 (B) is applied with different colors on the upper side B and the lower side A, first, as shown in FIG. ), The lower portion A is coated, and in order to dry and solidify the coating material applied to this portion A, the article W is conveyed to a drying oven (not shown) at a predetermined temperature atmosphere. When the lower portion A to which the paint is applied is first coated, the masking jig 1 may be used to cover the upper unpainted portion B where the coating is not performed. Then the upper part B
In order to paint, as shown in FIG. 2 (B), the masking jig 1 is used to mask only the lower part A, which is the non-painted part, to expose the upper part B. After the application of the coating material to the portion B is completed, the article W to be coated is conveyed to the same drying furnace.

The conventional masking jig 1 shown in FIGS.
It is composed of an adhesive tape 2 for forming a parting line L of the paint, and a film portion 3 which is integral with the adhesive tape 2 and covers a non-painted portion. The adhesive tape 2 has a base material made of paper or a polyester film, and an adhesive agent is applied to one surface thereof. Moreover, the film part 3 was formed of paper.

(Problems to be Solved by the Invention) Using the conventional coating masking jig 1 as described above,
In the case of applying two colors to the object W to be coated, particularly when the second color paint is applied to the upper surface B, the coating material applied to the upper surface B of the object to be coated is dried and solidified. To this end, when the object W to be coated is heated in a drying oven with the masking jig 1 attached to the object W, the film portion 3 made of paper is formed.
The masking jig 1 including the adhesive tape 2 made of polyester and polyester hardly expands or softens even when exposed to a heating atmosphere of about 120 ° C. for about 30 minutes in a drying oven, while the object to be coated W The automobile bumper, which is No. 2, is thermally expanded, and the coating material applied to the surface of the lower portion A, which has already been coated, is also softened by the heat.

As a result, as shown in FIG. 3 (A), before being carried into the drying oven, a gap S was formed between the surface of the article to be coated W and the film portion 3, whereas in the drying oven. During heating, as shown in FIG. 3 (B), the paper film portion 3 comes into contact with the surface of the lower side A on which the coating is completed. Then, there is a tendency that the film portion 3 adheres to the surface of the non-painted portion A, and the paint on the surface of the non-painted portion A on which the paint has been already applied has a coating defect such as a scratch or a touch mark of the film portion 3. There was a problem that it would occur.

Therefore, in order to form a high-quality coated surface, conventionally, after the coating on the upper surface B is completed, the object W to be coated is placed in the drying furnace.
The coating masking jig 1 had to be removed from the article W before it was transported. But like this,
In order to remove the masking jig 1 before drying and solidifying the paint, it is necessary to take great care because the paint on the upper surface B is undried, and this work takes time, and the surface B of the undried paint is required. However, there is a problem that the masking jig 1 may be touched and become defective.

The present invention has been made in view of the above-mentioned problems of the prior art, and after applying a coating material to a coating target portion of a resin coating target object, a masking jig is attached to the coating target object and dried. The purpose is to make it possible to dry and solidify the paint in a furnace so that a high quality paint can be achieved by a simple masking operation.

(Means for Solving Problems) The present invention for achieving the above-mentioned object, when coating the coating target portion of the resin-coated article having a non-coating portion and a coating target portion, While covering the unpainted portion,
In a masking jig for coating, which is placed in a heating and drying oven while being adhered to an object to be coated, expansion and contraction to form a parting line of the paint which is adhered to the non-coated area and applied to the surface of the object to be coated. Having an adhesive tape and a film portion whose end is adhered to the adhesive tape and covers the non-painted portion, and the film portion has a thermal expansion which is almost equal to that of the resin composition constituting the article to be coated. A masking jig for painting, characterized by using a resin film made of a resin composition to which an inorganic filler is added so as to have a specific ratio and a predetermined stiffness.

(Operation) According to the present invention, as the film portion of the masking jig for coating,
Using a resin film made of a resin composition having a coefficient of thermal expansion almost equal to that of the resin composition forming the article to be coated and having an inorganic filler so as to have a predetermined stiffness,
Moreover, since we use a stretchable adhesive tape to form the parting line of the paint on the surface of the part to be coated,
Adhesive tape for masking the painted part of the object can be applied with good followability. Also, the masked state is painted with the specified paint and the masking jig is attached to the object. Even if the resin coating object is heated in a heating / drying oven in a high temperature atmosphere in this state, the film part thermally expands in accordance with the thermal expansion of the coating object, and also has a predetermined stiffness. Therefore, the film portion itself does not adhere to the surface of the article to be coated. Therefore, when the coating masking jig is peeled off, scratches or the like do not occur on the surface of the portion masked by the coating masking jig itself. As a result, it is not necessary to remove the masking jig before the coating material dries and solidifies, and high-quality coating can be performed by a simple operation.

(Embodiment) Next, an embodiment of the present invention shown in FIG. 1 will be described.

FIG. 1 is a view showing a masking jig for painting according to an embodiment of the present invention. The masking jig for painting 1 is an adhesive tape 2 for forming a parting line of paint, as in the conventional one. And a film portion 3 which is adhered to and integrated with and covers the non-painted portion.

The adhesive tape 2 of the coating masking jig 1 of the present invention uses cotton C as its base material, and the back surface is coated with the adhesive 4.

In addition, as the film portion 3, an inorganic filler is added so as to have a coefficient of thermal expansion substantially equal to that of the resin composition forming the article W and to have a predetermined "stiffness" (so-called strain strength). A resin film formed by using the resin composition is used. As the resin film, for example, a polyethylene film is preferably used, and as the inorganic filler, for example, calcium carbonate D is preferably used.

By adding the inorganic filler to the resin composition in this way, the coefficient of thermal expansion and the stiffness of the resin composition can be adjusted, and as a result, the film portion 3 does not scratch the object W to be coated,
Since the inorganic filler can be easily peeled off, it can be said that the inorganic filler is a peeling and thermal expansion modifier for the film part 3.

The resin film thus mixed with calcium carbonate D is used as the film portion 3, the non-painted portion is covered and the coating material is sprayed, and then the article W is masked for coating to dry and solidify the coating material. Even if heated together with the jig 1, when the masking jig 1 is subsequently removed from the article W to be coated, the film portion 3 will be easily peeled from the surface of the non-painted portion.
It has been found that the content of this calcium carbonate D is about 30%, which is the best. Further, when the content of calcium carbonate as a peelability and thermal expansion modifier is about 30%, for example, by heating at a temperature of 150 ° C. in a drying oven for 1 hour, the already-painted coating is softened and the portion thereof is softened. Even if the gas is generated from the gas, the gas is satisfactorily released through the film portion 3, and the quality of the coating film surface already coated is maintained in a good condition. On the other hand, when the content is set to 30% or less, the gas does not escape well, and scratches are observed on the coated surface due to the gas. When the content is increased, the sheet base material as the film part 3 becomes weaker, and the masking work Workability is not good.

As the adhesive tape 2 which is integrated with the film portion 3, the one using cotton C as a base material is used, and the adhesive state to the surface of the article W can be surely maintained even in a heating atmosphere in a drying oven. Incidentally, as the material of the film portion 3, polypropylene can be used in addition to the above polyethylene. In this case, the heat resistant temperature is about 30 degrees higher than that of polyethylene. Moreover, you may use vinyl chloride, polyester, etc. as a material of the film part 3.

Next, the operation will be described. The coated object W shown in FIG. 4 (B) using the above-described coating masking jig 1 of the present invention.
First, the first paint of a predetermined color is applied to the lower surface A of the object W to be coated. After applying the coating material to the portion A, the article W is heated in a drying oven (not shown) to dry and solidify the coating material applied to the portion A.

Furthermore, in order to apply the paint on the second surface, which is different in color from the first paint, to the upper part B, the part A where the paint has already been applied is made a non-painted part and the adhesive tape 2 is applied to this part A.
To stick. Then, the side surface portion of the film portion 3 is sandwiched between the adhesive tape 2 and the object W to be coated, and the film portion 3 covers the unpainted portion A which has already been coated and exposes the portion B to be coated. In this state, the second coating material is applied to the part to be coated B, and the masking jig 1 for coating is the object W to be coated.
The object W to be coated is carried into the drying oven while being attached to the. Next, after the coating material is dried and solidified in the drying furnace, the coating masking jig 1 is peeled off from the article W to be coated. In this way, when the masking jig 1 is peeled from the article W after the coating material is dried and solidified, a predetermined inorganic filler is mixed in the film portion 3, so that the peeling operation is easy. .

In addition, when polyethylene is used alone as the film part 3, the coefficient of thermal expansion of the film part 3 made of polyethylene is higher than the coefficient of thermal expansion of the article W made of a resin such as polypropylene, polyurethane or polybutylene terephthalate. Not only becomes larger, but also because it is too soft, there is a greater tendency for the non-painted part and the film part 3 to come into contact, but polyethylene as the film part 3 has calcium carbonate D as a predetermined inorganic filler. When about 30% is mixed, the stiffness of the film part 3 becomes a desired stiffness, and the coefficient of thermal expansion of the film part 3 can be set similarly to the coefficient of thermal expansion of the resin of the article W to be coated, The film part 3 became difficult to adhere to the non-painted part during heating.

Therefore, even if the coating material in the unpainted portion A that has already been coated softens during the coating material drying step in the drying furnace, the film portion 3 thermally expands and is unlikely to adhere to the unpainted portion.
Since the film part 3 is easily peeled off even when the non-painted part A contacts the non-painted part A, a high quality coated surface can be obtained.

In the illustrated embodiment, the present invention has been described with reference to the case where two-color coating is performed on the article W shown in FIG. 4 (B), but FIGS. 4 (A) (C) (D) The present invention can be embodied in the case where any one of the coated objects W is coated in two colors, or except when two-color coating is performed, a part of the coated object is not coated. The present invention can be embodied even when coating is applied only to other portions.

(Effects of the Invention) As described above, according to the present invention, the non-painted portion is coated when the painted portion of the resin-made article having the non-painted portion and the painted portion is coated. A parting line of the coating material that is applied to the surface of the non-painted portion in a coating masking jig that is put into a heating and drying oven while being coated and adhered to the object to be coated. A stretchable pressure-sensitive adhesive tape which forms a film, and a film portion whose end is adhered to the pressure-sensitive adhesive tape and which covers the non-painted portion, and a resin composition which constitutes the article to be coated as the film portion, Since a resin film composed of a resin composition in which an inorganic filler is added so as to have a substantially equal coefficient of thermal expansion and a predetermined stiffness is used, when masking a coated portion of a coated object. Adhesive tape can be attached with good followability Also, even if the coating is applied in a masked state and the masking jig is attached to the object to be coated and the material is heated in a heating and drying oven, the film portion follows the thermal expansion of the object to be coated and has a predetermined stiffness. Therefore, the film itself does not adhere to the surface of the article to be coated. Therefore, the peeling operation can be easily performed, and the masking jig itself does not scratch the surface of the object to be coated during the peeling, and higher quality coating can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a coating masking jig according to an embodiment of the present invention, and FIG. 2 (A) is a perspective view showing an object to be coated in a state where the coating is partially completed. FIG. 2 (B) is a cross-sectional view showing a state in which a non-painted portion of an object to be coated has already been coated with a conventional masking jig for coating, and FIG. 3 (A) is FIG. 2 (B). ), FIG. 3 (B) is a vertical cross-sectional view of the coating object showing the state of the masking jig in the drying furnace, and FIGS. 4 (A) to (D) are examples of the coating object. It is a perspective view. 1 ... Masking jig for painting, 2 ... Adhesive tape, 3 ... Film part, A ... Non-painted part, B ... Part to be painted, C ... Cotton, D ... Peelability adjusting agent, W ... … To be coated

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Umeki 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. Showauchi (56) Reference JP-A-52-39776 (JP, A) Actually opened 57-35869 (JP, U) Actually opened 59-20876 (JP, U) Actually opened 52-34857 (JP, U) )

Claims (1)

[Claims] 1. A method of coating a non-painted portion of a resin-made article having a non-painted portion and a painted portion, and coating the non-painted portion with the article. In a masking jig for coating that is put into a heating and drying oven in the state, an elastic adhesive tape that forms a parting line of the paint that is adhered to the non-painted portion and is applied to the surface of the coated portion, The adhesive tape has an end portion adhered thereto and a film portion covering the non-painted portion, and the film portion has a thermal expansion coefficient substantially equal to that of the resin composition constituting the article to be coated and has a predetermined value. A masking jig for painting, characterized by using a resin film composed of a resin composition to which an inorganic filler is added so as to be stiff.