JPH0626082B2 - Method for manufacturing conductive tape-shaped sealing material - Google Patents

Description

Detailed Description of the Invention

[Industrial applications]

The present invention relates to a method for manufacturing a conductive tape-shaped sealing material capable of spot welding or electrostatic shielding.

[Prior art]

Conventionally, when two or more metal plates are spot-welded, a small gap is generated between the metal plates due to the thermal stress of the welded portion, and this gap is easily corroded, lacks airtightness such as water leakage, and easily vibrates. . Therefore, in order to waterproof / corrosion / vibrate the spot-welded part, apply adhesive to the part avoiding the spot-welded part before welding, or attach adhesive tape,
A sealing agent such as putty was applied after welding. However, since the former avoids the welded part, it is not completely waterproof and anticorrosive, and the workability is poor.The latter is one in which the sealing agent is applied from the outside of the welded part, and in the case of a complicated shape. Particularly, it is not easy for an operator to apply the sealing agent uniformly, and there has been a problem that cracks and pinholes are generated in the sealing agent due to shrinkage of the metal and the sealing agent over time. Therefore, in order to solve the above problem, a conductive seal material capable of spot welding has been developed. For example, as disclosed in Japanese Utility Model Publication No. 57-24456, it is a sheet-shaped sealing material in which conductive metal fine powder is mixed with a rubber-like elastic body to give conductivity, such as urethane rubber and chlorinated polyethylene. Fine powder of gold, silver, copper, aluminum, iron, etc. or conductive substance particles such as conductive carbon black are uniformly mixed in the rubber-like elastic body of, and the metal fine powder is applied by pressure during spot welding. There is one in which spot welding is made possible by bringing them into contact with each other.

[Problems to be Solved by the Invention]

As a material for the conventional sheet-like sealing material for spot welding, general rubber or plastic such as urethane or polyethylene is used, and these materials are continuously 10-2.
We manufacture 0m sheets, but in the case of foamed rubber, 1
There is no continuous sheet of 0 to 20m, and generally 1
It is about m × 1 m. Further, generally, spot welded portions are arranged in a row with a predetermined interval, and it is rare that many spots are spotted on a large area. Therefore, when using a conventional sheet, it is necessary to cut the tape into a tape having a required size, for example, a width of about 15 mm, depending on the joint between two or more metal plates. It was causing a situation of decline. In particular, the foamed rubber has, for example, a length of 150 to 200 m.
There is no such long tape-shaped one, and the manufacturing method for the tape-shaped sealing material itself has not been developed. Further, since the purpose of foaming the foamed rubber is to impart elasticity to the material, the foaming step has been performed within the range of this purpose. Therefore, there is a drawback that gas is generated from the sealing material due to heating during spot welding and a so-called blistering phenomenon occurs at the joint. In addition, the sealing material whose electric resistance is equal to or lower than the value capable of spot welding during spot welding pressurization has a drawback that stable spot welding cannot be performed such as variation in electric resistance including contact resistance and flashing from the nugget. there were. INDUSTRIAL APPLICABILITY The present invention has conductive, waterproof, vibration-proof, and adhesive properties, enables stable spot welding, and is suitable for electrostatic shield, and is a long-use conductive tape-shaped sealing material in a roll shape that is easy to use. It is an object of the present invention to provide a manufacturing method of.

[Means for Solving the Problems]

In order to achieve the above object, as a method for producing the conductive tape-shaped sealing material 10 of the present invention, first, a conductive rubber powder 16 or the like is stirred and mixed into synthetic rubber to form a rectangular shape by heating. At least the surface layers of the two opposite side surfaces of the block sheet except for the front and rear sides having the smallest area are cut and removed, and the block sheet 20 of the foamed rubber in which the fine powder of the conductive material is uniformly mixed is provided. 0.8-1
A large number of conductive foamed rubber sheets 23 are formed by equally thinly slicing to 0.0 mm, and the conductive end faces of the large number of conductive foamed rubber sheets 23 are abutted, and each abutting portion 24.
Of the adjacent conductive foamed rubber sheet 23, a base material 26 having a predetermined width coated with the conductive adhesive 25 is attached to one surface of the upper and lower surfaces of the conductive foamed rubber sheet 23 to cover the abutting portion, and the foamed rubber of any length. The sheet 30 is formed, and then the conductive adhesive 12 is applied to one side of the foamed rubber sheet 30 and one side of the double-sided release paper 14.
Is adhered to form a single-sided adhesive rubber sheet 36, which is wound into a roll, and further, a conductive adhesive 13 is applied to the release surface formed on at least one side of the release paper 15, and the roll is then rolled. The one-sided adhesive rubber sheet 36 is fed out, and the one-sided adhesive rubber sheet 36 has the foamed rubber sheet 30.
The conductive adhesive 13 is transferred and applied to the surface to form a long conductive sheet-shaped sealing material, and the conductive sheet-shaped sealing material is cut into a tape having an arbitrary width to have a length of 150 to 200 m.
It is a manufacturing method in which it is wound into a roll.

[Action]

By the method for producing the conductive tape-shaped sealing material 10 of the present invention, the conductive foamed rubber sheet 23 is processed into a tape shape having an arbitrary length, and is rolled into a double-sided release paper, which is stable regardless of the site. The tape-shaped sealing material with conductivity is
It can be obtained as a general double-sided pressure-sensitive adhesive tape, and can be used by taking out a required length according to the welding location and cutting it to remove the release paper. Further, the conductive tape-shaped sealing material 10 produced by the manufacturing method of the present invention is wound up in a roll shape by the double-sided release paper 14 and can be easily pulled out. When sealing between the metal surfaces, the conductive tape-like sealing material 10 is pre-clamped on one of the metal surfaces located at the joining portion between the metal surfaces, and the conductive tape-like sealing material 10 is cut into a required length to be easily attached by the conductive adhesive 13. After pasting, the double-sided release paper 14 is wrapped around and the other metal surface is coated with the conductive adhesive 12.
When it is pressed against, it can be easily temporarily fixed, and further, without applying unnecessary pressure from the outside of the metal plate at the joint between the metal surfaces to which the tape-shaped sealing material 10 having conductivity in the normal state is attached. Stable spot welding can be performed. When spot welding is performed, the conductive tape-shaped seal material 10 is melted and contracted by welding heat only at the welding point, joining both metal plates, and re-expansion of the sealing material at the weld area is extremely small, and even in the vicinity of the weld area, blisters occur. Is not observed, and the other parts retain the foamy shield effect without being affected by heat, and stable corrosion protection, waterproofing, dustproofing, and vibration damping effects can be obtained at the joints between the metal surfaces. Further, the conductive tape-shaped sealing material 10 may be used for shielding without performing spot welding at the joint portion between the metal surfaces to which the conductive tape-shaped sealing material 10 is attached. Since it is conductive in the normal state, it is effective as a conductive putty for preventing metal corrosion due to a potential difference, that is, as an electrostatic shield.

【Example】

An embodiment will be described with reference to the drawings. In FIG. 1, 10 shows a conductive tape-shaped sealing material according to the present invention. The conductive tape-shaped sealing material 10 is made of conductive carbon black or gold, silver, A large number of, for example, a large number of foamed rubber sheets 23 having conductivity in a normal state of about 10 mm, which are made by uniformly mixing 16 such as powders of a conductive material having a length of about 30 μ, such as copper, iron, and aluminum. Then, the conductive foamed rubber sheets 23 adjacent to each other in each abutting portion 24
A conductive adhesive such as aluminum or a resin obtained by uniformly mixing 16 of the conductive material powder or the like through a conductive adhesive 25 in which the conductive material powder 16 or the like is uniformly mixed. By cutting and adhering the tape-shaped base material 26 to a predetermined width and length for covering the abutting portion, a large number of foamed rubber sheets 23 are continuously formed into a series of arbitrary length, for example, 20 m. A sheet 30 of conductive foamed rubber is formed, and a double-sided release paper 14 is attached to one surface of the series of conductive foamed rubber sheets via a pressure sensitive adhesive 12 having conductivity similar to the conductive pressure sensitive adhesive 25, Further, a conductive adhesive 13 similar to the conductive adhesive 12 is attached to the other surface and cut and formed into a tape shape having a width of 15 mm. The conductive tape-like sealing material 10 can be wound up in a roll shape via the double-sided release paper 14 and easily peeled off at the time of use. Between the two or more metal surfaces using the conductive tape-like sealing material 10. When sealing the sheet, the conductive tape-shaped sealing material 10 is pre-squeezed on one metal surface located at the joining portion between the metal surfaces, cut to a required length, and simply attached, and then the double-sided release paper 14 is attached. If you remove it and press the other metal surface in place, you can easily temporarily fix it,
Furthermore, stable spot welding can be performed from the outside of the metal plate at the joint between the metal surfaces to which the conductive tape-like sealing material 10 is attached. Block Sheet of Foamed Rubber Next, a method of manufacturing the conductive tape-shaped sealing material 10 will be described. First, synthetic rubber (CR, BR, NBR).
Etc.) at about 120 ° C. to 170 ° C. and the powder 16 of the conductive material is uniformly mixed by stirring and the like, and the volume is 2 to 2 by expansion foaming by utilizing gas generation.
When it is expanded 15 times, as shown in FIGS. 2A to 2C, a rectangular foam rubber block sheet 20 is manufactured. The above synthetic rubber is a material suitable for the present invention in that it has good airtightness because it becomes closed cells by foaming and other synthetic resins become open cells by foaming. Excision of surface layer of block sheet This block sheet 20 has, for example, an upper surface size of 1 m.
² with a thickness of about 30 mm, the entire surface, that is, upper and lower,
In some cases, the conductive material is dispersed and solidified in a very depopulated state on all the front and rear surface layers, and the non-conductive foamed rubber layer 21 having an extremely high electric resistance may be generated. Becomes the conductive foamed rubber layer 22 in which is uniformly mixed. Therefore, each of the two opposite sides of the block sheet 20 is excluded except at least the front and rear sides having the smallest area.
The surface layer on the side surface, that is, the upper, lower, left and right non-conductive foamed rubber layers 21 are cut (lines AA to DD in FIG. 2A) and eliminated. The non-conductive foamed rubber layer 21 on the entire surface may be eliminated. Conductive Foamed Rubber Sheet Next, the conductive foamed rubber 22 layer after the non-conductive foamed rubber layer 21 is removed is placed between the upper and lower parts (A- in FIG. 2 (A)) as shown in FIG. 2 (C). A conductive foamed rubber sheet 23 is manufactured by equally thinly slicing between A and BB) to a thickness of about 0.8 mm with a slicer. In this case, stable slicing to 0.8 mm or less is difficult, but since it is a foamed rubber with a closed-cell sponge inside, it is crushed by elasticity when pressed and 0.08 mm or less become. Therefore, by selecting the thickness of the conductive foam rubber sheet 23 and the elasticity against pressure, the thickness of the conductive tape-like sealing material 10 described later can be adjusted to a thickness according to the application, for example, 0.8 to 10 mm. The range can be arbitrarily limited. Abutting portion connection Next, the conductive end faces of the large number of conductive foamed rubber sheets 23 thus formed, that is, FIG. 2 (A).
At least one surface (upper surface in this embodiment) of the upper and lower surfaces of the conductive foamed rubber sheet 23 adjacent to each other of the abutting portions 24 is made by continuously abutting the cut surfaces of the C-C line and the D-D line. In addition, an adhesive tape made of a conductive base material 26 having an appropriate width and having a conductive adhesive 25 formed by uniformly mixing the conductive material powder 16 and the like in a length for covering the abutting portion 24. The cut pieces are attached and the abutting portions 24 are connected to each other to form a continuous continuous strip-shaped conductive foamed rubber sheet 30 having a length of 150 to 200 m and wound into a roll. The base material 26 may be a conductive aluminum plate or a resin obtained by uniformly mixing the conductive material powder 16 or the like. In the case of an aluminum plate, a single-sided adhesive tape is used as shown in FIG. 3 (B). In the case of resin, a double-sided adhesive tape having a release paper 27 attached to the outside as shown in FIG. 3 (C) may be used. In this case, the release paper 27 is peeled off when the conductive adhesive 12 or 13 is applied in a later step. Even when the base material is coarse paper or non-woven fabric, the adhesive 25 impregnates the conductive material without impairing the conductivity. Single-sided Adhesive Rubber Sheet Next, as shown in FIG. 4 (A), the powder 16 of the conductive material and the adhesive are put into the adhesive tray 29, and the powder 32 of the conductive material 16 is rotated by the rotation of the roller 32. Is evenly stirred and mixed in the adhesive, and the adhesive 12 having conductivity is uniformly applied by the roller 32 to one surface of the double-sided release paper 14 sent between the roller 32 and the roller 31. That is, also in this coating step, the roller 32 mixes the powder 16 of the conductive material with the adhesive and mixes them uniformly, so that the adhesive 12 has a normal conductivity. The double-sided release paper 14 coated with the conductive adhesive 12 is dried in the drying chamber 33 and sent between the press rollers 34 and 35. On the other hand, the continuous series of long conductive foam rubber sheets 30 is sent between the press rollers 34, 35, and here, the conductive adhesive 12 side of the double-sided release paper 14 and the long conductive foams. One surface of the rubber 30 on the side of the base material 26 is pressed and bonded to produce a single-sided adhesive rubber sheet 36 as shown in FIG. 4 (B). Conductive foamed rubber sheet Next, as shown in FIG. 5, the conductive material powder 16 and the like and the adhesive are put into the adhesive receiving tray 29, and the roller 32 is rotated so that the conductive material powder 16 and the like are inside the adhesive. Conductive adhesive 13 that is uniformly stirred and mixed in the
Is applied to the release surface of the release paper 15 having at least one release surface fed between the rollers 32 and 31 and the roller 32.
Is applied evenly. In this step as well, in the coating step, the powder of the conductive material, etc.
6 is mixed with the pressure-sensitive adhesive and uniformly mixed, and the normal conductivity of the pressure-sensitive adhesive 13 is secured. Conductive sheet-shaped sealing material The release paper 15 coated with the conductive adhesive 13 is a drying chamber 33.
And then sent between the press rollers 34 and 35. On the other hand, the one-sided adhesive rubber sheet 36 composed of a long conductive foamed rubber sheet 30 is sent between the press rollers 34 and 35. Here, the one-sided adhesive rubber side of the release paper 15 and the conductive adhesive 13 side are fed. The continuous conductive foam rubber sheet 30 (11) surface of the sheet 36 is press-bonded, and the conductive adhesive 13 of the release paper 15 is a continuous continuous conductive foam rubber sheet of the single-sided adhesive rubber sheet 36. The conductive sheet-shaped sealing material is formed by transfer onto 30 surfaces. On the other hand, the release paper 15 on which the conductive adhesive 13 has been transferred is peeled off from the conductive adhesive 13 and discarded. Tape-shaped cutting The conductive sheet-shaped sealing material 10 is formed by cutting the conductive sheet-shaped sealing material into a tape shape by a cutter 37 with a width of about 15 mm and winding it into a roll. The electrical resistance of the above conductive tape-like sealing material having a thickness of 0.8 mm, a width of 15 mm and a length of 100 mm is 1 in the thickness direction and in the normal state.
0 ⁴ Ω or less, 9 at spot welding pressure (160 kg / cm ² )
Ω or less.

【The invention's effect】

Since the present invention is configured as described above, it has the effects described below. For the first time, the method for producing a tape-shaped sealing material according to the present invention makes it possible to process the foamed material into a wide tape thickness range of, for example, 0.8 to 10 mm, and a long tape shape of 150 to 200 m, and has a wide range of applications. It has been possible to provide a conductive tape-like sealing material that can be easily attached even between metal surfaces having a complicated shape. Further, since the conductive tape-like sealing material produced by the manufacturing method of the present invention is cut into a required length and simply attached to the inner surface of two or more metals to be spot-welded, the portions can be spot-welded. Therefore, workability can be improved. Furthermore, when electricity is applied, the sealing material has electrical conductivity in the normal state, so that it is instantly melted by heat only at the welding point without shrinking, and shrinks, the part is melt-bonded, and other parts are exposed to heat. Stable spot welding can be performed without being affected by the current shield effect. That is, the conductive tape-like sealing material of the present invention has conductivity in a normal state, and since the electric resistance is small, during energization of spot welding,
Excessive Joule heat is not generated, the flash is scattered from the nugget and the strength is reduced, and indentation does not occur because it is not necessary to pressurize spot welding excessively.
It is possible to obtain stable and attractive welding. In addition, since the conductive tape-shaped sealing material is conductive in the normal state, it is also effective as a conductive putty for preventing metal corrosion due to the potential difference, and in each case stable corrosion protection is achieved on the inner surface of the joint of two or more metals. Waterproof, dustproof and antivibration effects can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a conductive tape-like sealing material produced by the manufacturing method of the present invention, FIG. 2 (A) is a perspective view of a foam rubber block sheet, and FIG. 2 (B) is FIG. 2 (A). 2C is a state view in which the conductive foamed rubber of the block sheet is sliced, FIG. 3A is a perspective view of a series of conductive foamed rubber sheets, and FIG. B) and (C) are enlarged cross-sectional views of the main part of the abutting part, FIG. 4 (A) is a schematic view showing the manufacturing process of the single-sided adhesive rubber sheet, and FIG. 4 (B) is a perspective view of the single-sided adhesive rubber sheet. FIG. 5 is a schematic view showing a manufacturing process of the conductive tape-shaped sealing material. 10 ... Conductive tape-like sealing material, 11 ... Conductive foam rubber, 12, 13 ... Conductive adhesive, 14 ... Double-sided release paper, 15 ... Release paper, 16 ... Conductive material powder, etc. , 20 ... Block sheet, 21 ... Non-conductive foamed rubber layer, 22 ... Conductive foamed rubber layer, 23 ... Conductive foamed rubber sheet, 24 ... Abutting part, 25
...... Conductive adhesive, 26 …… Base material, 27 …… Release paper, 2
9 ... Adhesive saucer, 30 ... Long conductive foam rubber, 3
1, 32 ... Roller, 33 ... Drying chamber, 34, 35 ... Press roller, 36 ... Single-sided adhesive rubber sheet, 37 ... Cutter

Claims (2)

[Claims] 1. A synthetic rubber containing fine powder of a conductive material, etc., and heated to form a rectangular foamed rubber block sheet, and at least the side surface having the smallest area among the opposite side surfaces of the block sheet is removed. The surface layer on each of the two side surfaces is cut and removed, and the foamed rubber block sheet in which the fine powder of the conductive material or the like is uniformly mixed is evenly thinly sliced to form a large number of conductive foamed rubber sheets. While continuously abutting the conductive end faces of the foamed rubber sheet,
On the upper and lower surfaces of the foamed rubber sheet adjacent to each abutting part,
Fine powder of a conductive material is uniformly mixed, and a base material having a predetermined width coated with an adhesive having conductivity in a normal state is adhered to cover the abutting portion, and adjacent abutting foams of the abutting portions are provided. Rubber sheets are sequentially connected to form a foamed rubber sheet of an arbitrary length, and then the conductive adhesive of double-sided release paper coated with the conductive adhesive on one side is attached to one side of the foamed rubber sheet. To form a single-sided adhesive rubber sheet, which is wound into a roll shape, and further, the conductive adhesive is transferred and applied to the release surface of the release paper, at least one side of which is the release surface, and then made into the roll shape. A single-sided adhesive rubber sheet is fed out to form a long conductive sheet-like sealing material by applying the conductive adhesive agent of the release paper to the foamed rubber sheet surface of this adhesive rubber sheet, and then the release paper is discarded, Further, the conductive sheet-like sheet Method for producing a conductive tape-like sealing material, characterized in that as cut the wood into a tape of any width wound into a roll. 2. The foamed rubber block sheet is 0.8 mm
Claim 1 which slices evenly to -10.0 mm
The method for producing a conductive tape-shaped sealing material according to item.