JPS6259868B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a planar heating element used as a heating element for electric carpets, etc., in which an anchor coat 2 of thermoplastic resin is applied to one side of a metal foil 1, and On the other side, an ink 3 made of the same type of resin as the anchor coat 2 is printed in the shape of a heat generating circuit, and an insulating film 5 is applied to the anchor coat 2 side of the metal foil 1 via an adhesive resin layer 4 made of the same type of thermoplastic resin as the anchor coat 2. After attaching the metal foil 1, remove the part of the metal foil 1 other than the ink 3 by etching, and then remove the metal foil 1.
This relates to a method for producing a planar heating element characterized in that an insulating film 7 is attached to the opposite surface of the anchor coat 2 via an adhesive resin layer 6 made of the same type of thermoplastic resin as the ink 3.

In this type of sheet heating element, the heating circuit is created by printing ink on metal foil in the circuit shape and etching it to remove the metal foil other than the ink. Conventionally, thermosetting epoxy inks, thermoplastic polyurethane inks, and polyester inks have been used. On the other hand, polyethylene, polyester, etc. are used as insulating films that are attached to both sides of metal foil for insulation, and because the ink and this insulating film have poor adhesion, an anchor coating agent is applied between the two. It is necessary to improve adhesion. However, if an anchor coating agent is used in this way, it becomes difficult to peel off the insulating film and the metal foil, and it becomes impossible to peel off the insulating film from the terminal part of the metal foil and connect the wire. This requires methods such as applying a mold release agent, which increases the number of work steps. In addition, urethane-based or titanium-based hardening type anchor coating agents are used, but these have the problem that it is difficult to set heat treatment conditions. It is also used on the opposite side, but if you apply an anchor coating agent to the ink side after etching and removing unnecessary metal foil, it will coat the already hardened ink and the anchor coat on the opposite side. The anchor coat had to be applied again, and there was also the problem of poor adhesion between the hardened anchor coat and the new anchor coat.

The present invention has been made in view of the above points, and is capable of adhering an insulating film to the ink well without the need to apply an anchor coat to the ink, and furthermore, the insulating film can be easily peeled off to connect the terminal portion. The object of the present invention is to provide a method for manufacturing a planar heating element that is easy to work with.

The present invention will be explained in detail below with reference to Examples. An anchor coat 2 mainly composed of an ethylene copolymer such as ethylene-ethyl acrylate copolymer (EEA) is applied to one side of a metal foil 1 such as aluminum foil, and an anchor coat 2 is applied to the other side of the metal foil 1. coat 2
Similarly, ink 3 containing EEA as a main component is printed in the circuit shape by screen printing or the like. An insulating film 5 is bonded to the surface of the metal foil 1 on the anchor coat 2 side by melt-extruding and laminating an adhesive resin layer 4 made of the same type of resin as the anchor coat 2, such as polyethylene. The anchor coat 2 enhances the adhesion of the adhesive resin layer 4 to the metal foil 1, thereby improving the adhesion of the insulating film 5. Insulating film 5 is polyethylene 8
It is formed of multiple layers of polyester 9 and polyester 9, and its adhesion is improved with a urethane-based anchor coating agent 10. By passing this metal foil 1 through an etching bath and etching it, the portion other than the ink 3 is etched away to form a heat generating circuit. Next, after etching like this,
Anchor coat 2 on metal foil 1 and ink 3 on the other side
The insulating film 7 is bonded by melt-extruding and laminating an adhesive resin layer 6 made of the same type of resin, such as polyethylene. The insulating film 7 is formed of multiple layers of polyethylene 8 and polyester 9, and is coated with an undercoat agent 1 such as urethane.
At 0, the adhesion is improved. Here, since the adhesive resin layer 6 is of the same type as the ink 3, it is possible to bond the ink 3 and the adhesive resin layer 6 without using an anchor coating agent. In addition, in the above example, EEA is used as anchor coat 2 and ink 3.
We used ethylene-vinyl acetate copolymer (EVA), which is based on ethylene copolymer, and ethylene-acrylic acid copolymer (EAA), which uses ethylene copolymer as main component. You may also use Since these ethylene copolymers have polar groups, they easily adhere to the metal foil 1. In addition, the melting points of these ethylene copolymers are slightly lower than, but almost close to, the melting point of the polyethylene of the adhesive resin layers 4 and 6 (EEA: mP around 85°C, low density polyethylene: mP around 100°C). Adhesion between the adhesive resin layers 4 and 6 and the anchor coat 2 and ink 3 is caused by the melt extrusion and post-heating of 6. Also, if a crosslinking agent or curing agent is added to the ethylene copolymer, the melting point will rise slightly and become closer to ethylene, and heat can also be applied by applying heat with a hot press or using a sheet heating element. By doing so, crosslinking and curing progress, and the adhesiveness can be further improved. Furthermore, when the insulating film 7 on the terminal portion of the metal foil 1 is peeled off to connect lead wires, etc., the insulating film 7 can be easily peeled off to prevent the anchor coating agent from interposing between the insulating film 7 and the ink 3. can be done. In particular, as in the above embodiment, the anchor coat 2 and ink 3 have lower melting points than the adhesive resin layers 4 and 6, so heating the terminal part of the lead wire connection will melt the anchor coat 2 and ink 3 parts. This allows for easier peeling.
Furthermore, even if the ink 3 remains on the peeled part of the metal foil 1, if solder is used to connect the lead wires,
The ink 3 melts and allows connection of lead wires without any interference.

As described above, according to the present invention, the insulating film can be well adhered to the ink without the need to apply an anchor coat to the ink, and furthermore, the insulating film can be easily peeled off and the connection work of the terminal portion can be easily performed. It is.

[Brief explanation of the drawing]

The attached drawing is a sectional view showing an enlarged thickness of a planar heating element manufactured according to the present invention. 1 is a metal foil, 2 is an anchor coat, 3 is an ink, 4 is an adhesive resin layer, 5 is an insulating film, 6 is an adhesive resin layer, and 7 is an insulating film.

Claims (1)

[Claims] 1 An ink made of the same type of resin as the anchor coat of thermoplastic resin is printed in the shape of a heating circuit on one side of the metal foil, and an insulating film is applied to the anchor coated side of the metal foil via an adhesive resin layer of the same type of thermoplastic resin as the anchor coat. The feature is that the non-ink part of the metal foil is removed by etching, and then an insulating film is pasted on the opposite side of the metal foil to the anchor coat via an adhesive resin layer made of the same type of thermoplastic resin as the ink. A method for manufacturing a sheet heating element.