JPS60251971A - Masking method used in painting - Google Patents

Abstract

PURPOSE:To facilitate masking and to certainly perform the covering and fixation of a sheet material, by a method wherein a non-painting part is covered with the sheet material and the side part of the sheet material is allowed to position at a parting line forming part and stuck thereto by a thermosetting resin having initial tacking strength. CONSTITUTION:The non-painting part M of an article W to be painted is covered by using a sheet material 1. In this case, the sheet material 1 is stuck so that the thermosetting resin 2 having initial tacking strength applied to one side part of the sheet material is positioned at the boundary line between the non- painting part M and a part C to be painted. When the spraying of a paint by a painting gun and the baking thereof in a drying oven are performed in this state, the thermosetting resin 2 is cured by the heat in the oven and, therefore, the resin 2 is peeled off from the article W to be painted along with the sheet material 1 to form the parting line of the paint at a desired position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Prior Art) The present invention relates to a masking method for coating a part to be painted when only a part of the part to be painted is coated, and in particular, it relates to a masking method for coating a part to be painted, and in particular to a masking method for coating a part to be painted. It is useful when painting etc.

(Prior art) When painting only a portion of the surface of various products such as metal products or resin products, only a portion of the surface of the object to be coated is exposed during the painting process, and other unpainted portions are exposed. need to be covered. In addition, when applying multiple types of paint with different colors to the surface of these products, first, when painting with paint of a certain color, only the part of the object to be coated that is to be painted with that color is exposed. It is necessary to cover other areas where paint of a different color is applied.

In such cases, in order to cover the non-painted parts, workers manually remove the parts to be painted from the non-painted parts in order to obtain a boundary line between the surface of the painted part and the surface of the non-painted part, that is, a parting line. Adhesive tape was attached to the area close to the area, and a masking material covering the non-painted area was fixed to the object using the adhesive tape.

However, when a masking material is attached to an object to be coated using a tape in this manner, the adhesive of the tape remains on the object to be coated, which causes problems in terms of appearance.

(Object of the invention) The present invention can easily attach a sheet material to the non-painted part of the object to be coated to mask this, and the spraying during painting can be caused by wind pressure or paint baking (warm air during spraying). To reliably fix a sheet material so that it does not come off an object to be coated due to wind pressure.

(Structure of the Invention) To achieve the above object, the present invention provides that when painting the painted part of an article having a non-painted part and a painted part, the unpainted part is coated. In the painting masking material for painting the part to be painted, the non-painted part is covered with a sheet material, and the side part of the sheet material is located at the boundary between the non-painted part and the part to be painted. The side portions were adhered with a thermosetting resin having initial adhesive strength, and under this condition, a paint was applied to the part to be painted and the paint was baked, and then the sheet material was removed from the part to be painted hX. The masking method for painting is characterized in that the baking is performed so that the resin can be peeled off from the object to be coated together with the sheet material by curing the resin.

(Example) Hereinafter, the masking method of the present invention will be explained based on the drawings.

FIGS. 1A to 1D each show an automobile bumper as an object to be coated. Modern car bumpers are now mainly made of synthetic resin, which is more elastic than metal and absorbs shock, in order to improve the car's body protection function in the event of a collision and increase the degree of freedom in shaping. Figure 1 (Δ) ~ (
The automobile bumpers shown in D) are each molded from synthetic resin.

As shown in Figure 1 (△), the front surface of the automobile bumper W is almost flat, and only the upper side is painted with the central part of this surface as the boundary, or the upper and lower sides are colored differently. Painting is performed using paints of different colors. The automobile bumper W shown in FIG. 1(B) has a groove G formed along the longitudinal direction in the central part of its surface.
Either only the lower side of the groove G is painted, or the upper and lower sides are painted with separate paints of different colors. The automobile bumper W shown in FIG. 1(C) has two parallel grooves G formed in the center of its surface, and for example, the upper and lower sides other than the area between the grooves G are painted respectively. will be carried out. The automobile bumper W shown in FIG. 1(D) has loop-shaped grooves G formed at both end corners of its surface, and the parts other than those surrounded by these loop-shaped grooves G are painted. will be carried out.

For example, for the object W to be painted shown in FIG. A case in which the coating masking method of the present invention is applied for this purpose will be described.

First, as shown in FIG.
The object W to be coated shown in A> is placed. Next, using the sheet material 1 not shown in FIG.
This sheet material 1 is formed into a substantially rectangular shape larger than the area of the non-coated portion M, and a thermosetting resin 2 having initial adhesive strength is applied to one side of this sheet material 1.

Then, attach this sheet material 1 to the object W to be coated.
The thermosetting resin 2 coated on the - side of this is the non-coated part M
The sheet material 1 is attached so as to be located on the boundary line between the area C and the area C to be painted.

The material of the sheet material 1 is natural rubber, polyurethane,
It is possible to use rubber mixtures or synthetic resin mixtures such as polyvinyl chloride and polyethylene, and it is also possible to use aluminum foil or rubber mixtures or synthetic resins (such as aluminum powder coated on the surface of the H-finger mild material). The object W to be coated is an automobile bumper manufactured by Plus Deck, and the base material is poly7-, which has a non-polar molecular structure such as a polypropylene mixture. If a material with a polar molecular structure such as polyurethane, nylon, or polybutylene terephthalate is used as the base material, any material may be used as the material for the sheet material 1. When masking a damaged car bumper, it is better not to use a sheet material that contains a plasticizer with a polar molecular structure, such as a soft polyvinyl chloride mixture. When the paint dries, the plastic material with a polar molecular structure contained in the sheet material may migrate into the material of the automobile bumper W, and the surface of the bumper W, which is the object to be painted, may be attacked. Therefore, when used for masking an automobile bumper W containing such a material, it is desirable to use a material that does not contain a plasticizer with a polar molecular structure such as polyethylene or polypropylene as the sheet material. .

Examples of thermosetting resins having initial adhesive strength include phenol resins, urea resins, melamine resins, epoxy resins, silicone resins, diallyl phthalate resins, polyurethane resins, unsaturated polynisder resins, and polyimide resins. Furthermore, a mixture with a weight ratio of 20% natural rubber, 50% polyisoprene (average molecular weight 47,000), 30% polybutylene (average molecular weight @ 60000), 100% clay, 2% sulfur, and tetramethylthiuram disulfide (TMT>1) is used. Of these, it is possible to
Polyisoprene and polybutylene are the tackifiers, natural rubber and polyisoprene are the crosslinking reactive polymers,
Sulfur and MT are crosslinking agents C', and polybutylene is a non-crosslinking polymer, which is used because it remains a little sticky after the crosslinking reaction.

As shown in FIG. 4, the sheet material 1 is made of thermosetting resin 2.
With the material adhered to the object W to be coated, the movable trolley 11 is transported into a painting booth (not shown) and the paint is sprayed with a painting gun (after the spraying, the movable trolley 11 is transported into a hot air drying oven). Then, perform paint baking +j.

Next, when the sheet material 1 is removed from the object W to be coated, the thermosetting resin 2 is turned into - by the heat in the hot air drying oven, so the resin 2 is peeled off from the object W together with the sheet material 1. The thermosetting resin 2 does not remain on the surface of the object W to be coated, and a parting line of the paint is formed at the position indicated by the symbol P in FIG.

In the illustrated embodiment, the thermosetting resin 2 is applied to the side part of the sheet material 1 in advance, but the thermosetting resin 2 is applied to the boundary between the painted part C and the non-painted part M of the test object W. The resin 2 may be applied in advance, and the sheet material 1 may be adhered to the resin 2 when covering the non-painted portion M.

In addition, as shown in FIGS. 1B to 1D, when masking the non-painted area M using the groove G formed in the object W as a boundary, a resin 2 is placed in the groove G in advance. After coating, the non-painted area M is covered with sheet material 1, and this sheet material 1
The side part of the sheet material 1 is adhered to the resin 2, or the sheet material 1 is pushed into the groove G when the resin 2 coated on the sheet material 1 is used to cover the part M to be coated with the sheet material 1. Install. In this case as well, when the sheet material 1 is removed from the object W after painting baking, the resin 2 hardens and is peeled off from the object W.

(Effects of the Invention) As described above, according to the present invention, the non-painted part is covered with a sheet material, and the side part of the sheet material is located at the boundary between the non-painted part and the painted part. Then, the side portions are adhered with a thermosetting resin having initial adhesive strength, and under this condition, the paint is applied to the painted portion, and after the coating 1 is baked, the sheet material is attached to the coated portion. When removed from the object, the resin is cured during baking so that the resin can be peeled off from the object together with the sheet material, so the adhesive of the masking jig does not remain on the surface of the object. It does not spoil the appearance.

[Brief explanation of drawings]

Figures 1 (A) to (D) are perspective views showing an automobile bumper as the object to be coated, Figure 2 is a perspective view of the non-painted part of the object covered with Seamil material, and Figure 3 4 is a perspective view showing a state in which the thermosetting resin is applied to the sides of the sheet material, and FIG. 4 is a sectional view showing the state in which masking of the non-painted parts is completed. 1... Sheet material, 2...Thermosetting resin, W...To be coated C...To be coated part, M...Unpainted part, G...Groove.Patent applicant Nissan Motor Co., Ltd. Agent Patent attorney 8 1) Diagram 4

Claims (1)

[Claims] In a painting masking material for painting the to-be-painted part while covering the un-to-be-painted part when painting the to-be-painted part of an article having a non-to-be-painted part and a to-be-painted part, the non-to-be-painted part is coated. covering the part with a sheet material, and positioning the side part of the sheet material at the boundary between the non-painted part and the painted part, and adhering the side part with a thermosetting resin having initial adhesive strength, Under this condition, after applying the paint to the object to be painted and baking the paint, when the sheet material is removed from the object to be painted, the resin hardens during the baking process and the resin is removed together with the sheet material. A masking method for painting, characterized in that it can be peeled off from an object to be painted.