JPH0578646A - Sealing material - Google Patents

Abstract

PURPOSE:To obtain a sealing material having excellent adhesivity to superimposed part of panel member compatible with hardness of surface and moldability of external shape and improved operation efficiency and qualities, comprising plural layers of thermoplastic resins having different softening points and melting points. CONSTITUTION:For example, a first layer comprises a thermoplastic resin having 40-120 deg.C softening point and 80-140 deg.C melting point, a second layer (part to be brought into contact with a superimposing part of panel member) is composed of a thermoplastic resin having 30-100 deg.C softening point and 70-l30 deg.C melting point, the surface of the second layer is provided with an adhesive layer and the surface of the first layer is equipped with a treating layer having high adhesion of coating compound to give the objective sheet-like sealing material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing material, and more particularly to a sheet-shaped sealing material for covering a portion where panel members are superposed and joined.

[0002]

2. Description of the Related Art For example, for articles such as automobile bodies, refrigerators, and washing machines, first, a metal plate such as a thin iron plate or an aluminum plate is punched by a press to form panel members for respective parts, and then those panel members are removed. They are assembled on top of each other by spot welding, tacking, screwing, etc. As the overlapping portion of such panel members, for example, as shown in FIG. 6A, a joint portion 22 when a protective member 21 for protecting the edge of the panel member 20 is attached, 6 (b), a portion 24 in which the end edge of the panel member 23 is wound up is tightened, and as shown in FIG. 6 (c), a portion 26 in which the end edge of the panel member 25 is folded back and overlapped, FIG. 6 (d). ), The two panel members 27 and 28 are superposed, and the end 29 of one panel member 28 is folded back, as shown in FIG. 6E, the surface of one panel member 30. In addition, there may be mentioned a portion 32 in which the edge of the other panel member 31 is superposed. At these overlapping portions, a step or the like in which the edge of the panel member is exposed is formed. Such a superposed portion not only deteriorates the appearance quality of the article, but also has a disadvantage that rust is easily generated from the exposed edge.

Therefore, for example, in an automobile body or the like, a vinyl chloride-based compound for a sealer is applied to a step or the like of the overlapped portion to seal and flatten the appearance, thereby improving the appearance quality. Prevents rust.

However, the coating operation of the compound is
A method of adhering a compound extruded by air pressure to the overlapping portion is used, but it requires skill and is time-consuming because it requires rust prevention and aesthetics. It was

Therefore, it has been conventionally known to cover the overlapping portion with a sheet-like sealing material made of a thermoplastic resin, as disclosed in Japanese Patent Laid-Open No. 2-131173.

The sealing material is formed of ethylene vinyl acetate based prepolymer resin in a sheet form. When the overlapping portion of the panel member is sealed by the sealing material, first, as shown in FIG. 7A, the sealing material 36 is superposed on the overlapping portion 35 of the panel members 33 and 34, and then, The sealing material 36 is softened by the heat of baking and drying during the coating of the panel members 33 and 34. This baking drying is carried out by a drying furnace (not shown), and the baking drying is carried out at a temperature of about 150 ° C. for about 20 minutes. The sealing material 36 softened by this heat is
As shown in FIG. 7B, the overlapping portions 35 of the panel members 33 and 34 are softened and flown into close contact with each other, and the overlapping portions 35 are sealed.

With the sealing material 36, the panel member 3
Not only the work of covering the superposed portions 35 of 3, 34 becomes easy, but also a smooth appearance can be obtained.

However, as shown in FIG. 7B, a space may be generated in the narrow portion 37 of the overlapping portion 35 of the panel members 33 and 34. As a result, water or the like may enter the space and corrode. Therefore, it is conceivable to use a resin having a low softening point and a low melting point as the material of the sealing material 36 to enhance the fluidity at the time of heating, but in such a case, the sealing material 36 is quickly softened and surely adheres along the overlapping portion 35. On the other hand, the hardness of the sealing material 36 after curing is low,
Since it easily flows at high temperatures, it is difficult to make the shape of the sealed portion constant. In this way, the sealing material 36 is
There is a disadvantage that the adhesion to the overlapping portion 35 and the hardness and the outer formability cannot be achieved at the same time.

The sealing material 36 is the panel member 3
When they are superposed on the overlapping portions 35 of 3, 34, they are not in close contact with each other. For this reason, in order to prevent the sealing material 36 from falling off when it is superposed on the overlapping portion 35, the panel members 33, 3 are not sealed during the sealing work by the sealing material 36.
4 must always be maintained in a horizontal state. For example, when the overlapping section 35 exists in a vertical position, the overlapping section 35 must be in a horizontal state for sealing work. Therefore, there is a disadvantage that the work efficiency is lowered.

Further, since the sealing material 36 is a synthetic resin containing polyethylene, the adhesion of the coating material is low, and the coating material applied to the surface of the sealing material 36 is easily peeled off. Could be lowered.

[0011]

In order to solve the above inconvenience, the present invention makes the adhesion of the panel member to the overlapping portion compatible with the hardness of the surface and the outer formability of the panel member. Improves work efficiency when sealing, and
An object is to provide a sealing material that can improve quality.

[0012]

In order to achieve the above object, the present invention is a sheet-like sealing material made of a thermoplastic resin, which seals a superposed portion of a panel member by heating. And a second layer provided below the first layer and in contact with the overlapping portion of the panel member and having a softening point and a melting point lower than those of the first layer.

The softening point of the first layer is 40.degree.
The melting point is 0 ° C., the melting point is 80 ° C. to 140 ° C., the softening point of the second layer is 30 ° C. to 100 ° C., and the melting point is 70 ° C. to 130 ° C.

A pressure-sensitive adhesive layer is provided on the surface of the second layer.

Further, the invention is characterized in that a treatment layer having a high adhesiveness of the paint is provided on the surface layer of the first layer.

[0016]

When the overlapping portion of the panel member is sealed by the sealing material of the present invention, first, the sealing material is installed along the overlapping portion and heating is performed. At this time, the second
The layer is placed in contact with the overlapping portion of the panel member.

Since the second layer has a lower softening point and a lower melting point than the first layer, the second layer is in a fluidized state prior to the first layer and flows along the shape of the overlapping portion. Ensures close contact without creating a space. Thereafter, as the heating temperature rises, the first layer becomes semi-fluid and the surface has a smooth appearance. Further, the first layer can use a synthetic resin having a higher softening point and melting point as compared with conventional ones, and can improve its hardness and outer formability.

As described above, the sealing material is composed of a plurality of layers of the first layer and the second layer having different softening points and melting points to improve the adhesiveness to the overlapping portion and the surface hardness. It is possible to improve and form a desired outer shape.

Further, the sealing material, specifically, has a softening point of 30 ° C. to 100 ° C. and a melting point of 70 ° C. to 1 of the second layer.
At 30 ° C., the second layer is softened and melted prior to the first layer, and the softening point of the first layer is 40 ° C. to 120 ° C.
With a melting point of 80 ° C to 140 ° C, as the temperature increases,
Soften the first layer.

Further, by providing a pressure-sensitive adhesive layer on the surface layer of the second layer, it is possible to attach the adhesive layer to the overlapping portion and perform the sealing work without keeping the overlapping portion of the panel member in a horizontal state. And

Further, by providing a treatment layer having high paint adhesion on the surface layer of the first layer, the adhesion of the paint when applying the paint to the overlapping portion sealed by the sealing material is improved.

[0022]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing the structure of the sealing material of this embodiment, and FIGS. 2 (a) and 2 (b) are explanatory views showing the steps of the sealing operation by the sealing material of this embodiment.

As shown in FIG. 1, the sealing material 1 of the present embodiment.
Are formed in a multi-layer structure in which the first layer 2 and the second layer 3 are laminated and are formed in a sheet shape.

The first layer 2 is made of a synthetic resin film such as an ethylene / methacrylic acid copolymer film (for example, Yucaron-EMA-XG400 manufactured by Mitsubishi Petrochemical Co., Ltd.) and has a thickness of 100 to It is formed to 300 μ. The softening point of the first layer 2 is 62 ° C. and the melting point is 8
It is set at 5 ° C.

The second layer 3 is a polybutadiene film (for example, JSR-RB manufactured by Japan Synthetic Rubber Co., Ltd.).
820) and other synthetic resin films as materials, and the thickness dimension thereof is 80 to 120 μm. The second layer 3 has a softening point of 52 ° C and a melting point of 80 ° C.

Although not shown, the first layer 2 and the second layer 3 are adhered to each other by pressure bonding with a hot roll or the like, or they are either the first layer 2 or the second layer 3. The other film is directly laminated on the above film by a so-called extrusion lamination method to be integrated.

Using the sealing material 1 thus constructed, the sealing operation is performed according to the following procedure.

First, as shown in FIG. 2A, the edge 5 of the panel member 4 and the edge 7 of the panel member 6 are superposed on each other and joined by spot welding. As a result, the sealing material 1 is installed on the overlapping portion 8 formed with a step. At this time, the sealing material 1 is
The layer 3 is installed so as to contact the step of the overlapping portion 8.

Next, the panel members 4 and 6 with the sealing material 1 installed are heated by a drying furnace (not shown). The temperature of the drying furnace is set to about 170 ° C., and the baking and drying time is about 20 minutes. At this time, since the softening point and the melting point of the second layer 3 are lower than those of the first layer 2, the second layer 3 is in a fluidized state prior to the first layer 2. As a result, as shown in FIG. 2B, the second layer 3
Flows along the shape of the overlapping portion 8 and surely adheres to the overlapping portion 8 without forming a space.

After that, as the heating temperature rises, the first
Layer 2 becomes semi-fluid. This gives the surface a smooth appearance.

As described above, since the sealing material 1 is composed of the plural layers of the first layer 2 and the second layer 3 having different softening points and melting points, the adhesion to the overlapping portion 8 is improved, It is possible to achieve both improvement in hardness and outer formability.

Further, in the present embodiment, the first layer 2
Is made of a synthetic resin film such as a low-density polyethylene film (for example, LD180 manufactured by Tosoh Corporation) and has a thickness dimension of 100 to 300 μm, and the second layer 3 is an adhesive polymer film ( For example, synthetic resin film such as Tohso Corp.'s Mersen P, J-125) is used as a material, and its thickness dimension is 80 to
It may be formed to 120 μ. As a result, the softening point of the first layer 2 is 93 ° C. and the melting point thereof is 110 ° C., and the softening point of the second layer 3 is 88 ° C. and the melting point is 122 ° C., so that the same effect as that of the above-described embodiment is obtained. be able to.

Next, another embodiment will be described.

FIG. 3 is an explanatory sectional view showing the structure of a sheet material of another embodiment, and FIGS. 4 (a) and 4 (b) are explanatory views showing the steps of the sealing work by the sheet material of this embodiment.

As shown in FIG. 3, the sealing material 9 of this embodiment
Is a sheet having a multi-layer structure in which a first layer 10 and a second layer 11 are laminated, and a treatment layer 12 is provided on the surface of the first layer 10 and an adhesive layer 13 is provided on the surface of the second layer 11. Is formed in.

The first layer 10 is an ethylene / vinyl acetate copolymer film (for example, Ultrasen 630F manufactured by Tosoh Corporation), and is made of a synthetic resin film having a thickness of 150 μ, and its softening point is 63 ° C. The melting point is set to 85 ° C.

The second layer 11 is made of an adhesive polymer film (for example, Tohso Corp. Mersen M505).
0A) made of a synthetic resin film having a thickness of 100 μ, the softening point is 40 ° C., and the melting point is 81 ° C.

The treatment layer 12 is formed by coating a vinyl chloride-based paint (eg, VG series medium manufactured by Teikoku Ink Co., Ltd.) with a kiss coater to a thickness of 5 to 6 .mu.m and drying it. It should be noted that the surface of the first layer 10 is subjected to corona treatment prior to applying the treatment layer 12, and the adhesion of the coating material can be improved by only the corona treatment. The layer subjected to corona treatment may be treated layer 12. In this embodiment, the treatment layer 12 is reliably attached to the surface of the corona-treated first layer 10 to prevent the treatment layer 12 from peeling off.

Further, the pressure-sensitive adhesive layer 13 is formed by applying a pressure-sensitive adhesive (N-10 manufactured by Nippon Tack Industries Co., Ltd.) to a thickness of 30 μm. The pressure-sensitive adhesive layer 13 may be applied on the entire surface of the second layer 11, but it may be applied in the form of stripes or dots to form the second layer 1
The adhesive force after melting may be increased when 1 is brought into direct contact with the panel members 4 and 6.

Using the sealing material 9 thus constructed, the sealing operation is carried out by the following procedure.

First, as shown in FIG. 4A, the edge 5 of the panel member 4 and the edge 7 of the panel member 6 are superposed on each other and joined by spot welding or the like. As a result, the sealing material 9 is installed on the overlapping portion 8 formed with a step. At this time, the sealing material 9 is placed on the overlapping portion 8 by the pressure-sensitive adhesive layer 13 by installing the second layer 3 so as to contact the step of the overlapping portion 8. Therefore, the panel members 4,
The sealing material 9 is prevented from falling off even when the work is performed with the 6 being in the vertical state as shown in FIG.

Next, the panel members 4 and 6 with the sealing material 9 installed are heated by a drying furnace (not shown). The temperature of the drying furnace is set to about 170 ° C., and the baking and drying time is about 20 minutes. At this time, since the second layer 11 has a lower softening point and a lower melting point than the first layer 10, the second layer 11 is in a fluidized state prior to the first layer 10. As a result, as shown in FIG. 4B, the second layer 11 flows along the shape of the overlapping portion 8 and surely adheres to the overlapping portion 8 without forming a space.

After that, as the heating temperature rises, the first
The layer 10 becomes semi-fluid. As a result, the surface has a smooth appearance, and the adhesion of the paint when the paint is applied by the treatment layer 12 is improved.

As described above, since the sealing material 1 is composed of a plurality of layers of the first layer 10 and the second layer 11 having different softening points and melting points, the adhesion to the overlapping portion 8 is improved, The hardness and the outer formability can be improved at the same time, and since the pressure-sensitive adhesive layer 13 can perform the sealing work without maintaining the overlapping portion 8 in a horizontal state, the work efficiency is improved. Further, the treatment layer 12 improves the adhesiveness of the paint, so that peeling of the paint and the like can be prevented.

Further, as shown in FIG. 5, in each of the above-described embodiments, an adhesive (for example, N-19 manufactured by Nippon Tuck Industries Co., Ltd.) or the like is used as a material between the first layer 14 and the second layer 15. The adhesive layer 16 may be provided. Thereby, the first layer 14 and the second layer 15 can be prevented from separating from each other, and the multilayer structure can be reliably maintained.

In each of the above-described embodiments, the panel members are superposed and joined by spot welding. However, it is needless to say that the present invention is not limited to spot welding. Of course, they may be joined by a joining method.

[0047]

As is apparent from the above, the sheet material of the present invention has a multi-layer structure having the first layer and the second layer having different softening points and melting points, and therefore, is softer than the first layer. Since the second layer having a lower point and a lower melting point is surely adhered to the overlapping portion of the panel member, and the outer shape can be formed in a desired shape by the first layer having a higher softening point and a higher melting point than the second layer,
It is possible to achieve both high adhesion and high outer formability.

Further, since the pressure-sensitive adhesive layer is provided on the surface layer of the second layer, by sticking the pressure-sensitive adhesive layer to the overlapping portion of the panel member, it is possible to seal the overlapping portion without maintaining the horizontal state. You can do the work. As a result, the work efficiency in sealing the overlapping portion can be improved.

Further, since the treatment layer is provided on the surface layer of the first layer to improve the adhesion of the coating material, the coating quality can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing the structure of a sheet material of this example.

FIG. 2 is an explanatory diagram showing the steps of a sealing operation.

FIG. 3 is an explanatory sectional view showing the structure of a sheet material of another embodiment.

FIG. 4 is an explanatory view showing the steps of the sealing work.

FIG. 5 is an explanatory sectional view showing the structure of a sheet material of another embodiment,

FIG. 6 is an explanatory diagram showing an overlapping portion.

FIG. 7 is an explanatory diagram showing a conventional sealing operation process using a sheet material.

[Explanation of symbols]

1, 9 ... Sealing material, 2, 10, 14 ... First layer, 3, 1
1, 15 ... Second layer, 4, 6 ... Panel member, 8 ... Overlapping part, 13 ... Adhesive layer, 12 ... Treatment layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Hirano 27-33 Matsukaze-cho, Hiratsuka-shi, Kanagawa Prefecture (72) Inventor Katsuo Ito 2764-39 Kimmase, Sekijuku-cho, Higashi-Katsushika-gun, Chiba Prefecture

Claims (4)

[Claims] 1. A sheet-like sealing material made of a thermoplastic resin for sealing an overlapping portion of panel members by heating, the first layer being provided on a lower layer of the first layer, and the panel member being overlaid. A sealing material comprising a second layer which is in contact with the mating portion and has a softening point and a melting point lower than those of the first layer. 2. The softening point of the first layer is 40 ° C. to 120 ° C.,
The melting point is 80 ° C. to 140 ° C., and the softening point of the second layer is 3
The sealing material according to claim 1, wherein the sealing material has a melting point of 0 ° C to 100 ° C and a melting point of 70 ° C to 130 ° C. 3. The sealing material according to claim 1, wherein a pressure-sensitive adhesive layer is provided on the surface layer of the second layer. 4. The sealing material according to claim 1, wherein the surface layer of the first layer is provided with a treatment layer having high adhesiveness of paint.