JP2010003606A - Planar heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar heating element 10 which prevents formation of an air layer to inhibit thermal conduction between a heating object when attaching and pasting to the heating object such as a door mirror. <P>SOLUTION: A plurality of electrodes 11, 12 and an exothermic part 13 to generate heat by turning on electricity between the electrodes 11, 12 are arranged between an insulating layer 14 of sheet or film shape and an adhesive layer 15, and a required number of holes 10a penetrating in thickness direction are provided. When attaching and pasting the heating element to the heating object, even if air is enclosed between the adhesive layer 15 and the heating object, the air can be discharged easily through the holes 10a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a planar heating element that is attached to, for example, a vehicle door mirror to remove fogging or frost.

  The planar heating element is attached to, for example, the rear surface of a door mirror of a vehicle, and is used as a door mirror heating means for removing cloudiness and frost caused by condensation of water vapor in the air on the surface of the door mirror. FIG. 3 is a plan view showing an example of an electrode pattern in a conventional planar heating element, and FIG. 4 is a sectional view showing a part of the conventional planar heating element cut along line IV-IV in FIG. is there.

  As shown in FIG. 4, the planar heating element 100 includes a first electrode 101 and a second electrode 102, and heat generated so as to cover one side of the first electrode 101 and the second electrode 102. The portion 103 is integrally provided so as to be sandwiched between a base film 104 made of an electrically insulating material and an adhesive layer 105 made of a double-sided adhesive tape or the like.

  The first electrode 101 and the second electrode 102 are obtained by etching the copper foil joined to the heat generating portion 103 into a predetermined pattern such as a comb tooth shape as shown in FIG. A voltage is applied via the connection terminals 101a and 102a. The heating part 103 is a conductive thin film formed by printing or applying a PTC ink composition containing carbon particles or conductive metal particles in a polymer with a uniform layer thickness and drying. A current is generated between the comb teeth 101b and 102b of the electrodes 101 and 102 to generate heat.

That is, the planar heating element 100 having the above configuration is adhered to the back surface of a door mirror (not shown) by the adhesive layer 105, and heats the door mirror by heating with electricity to remove fog and frost on the surface. (See, for example, the following patent document).
Japanese Patent Laid-Open No. 9-13477 JP 2006-324164 A

  However, when this type of planar heating element 100 is attached to the back surface of the door mirror or the like by the adhesive layer 105, air is confined between the adhesive layer 105 and the back surface of the door mirror or the like to form an air layer. In such a case, since such an air layer has low thermal conductivity, heat transfer from the planar heating element 100 to the door mirror is hindered, and there is a problem that the efficiency of removing fog and frost on the surface of the door mirror is lowered. Therefore, it is necessary to pay close attention to the work of attaching the sheet heating element 100, and workability is poor.

  The present invention has been made in view of the above points, and the technical problem thereof is an air layer that hinders heat conduction between the object to be heated and pasted to the object to be heated such as a door mirror. Is to prevent the formation.

  As a means for effectively solving the technical problem described above, the planar heating element according to the present invention has a plurality of electrodes and a heating part that generates heat when energized between the plurality of electrodes, a sheet or a film. The required number of holes that are disposed between the insulating layer and the adhesive layer and penetrate in the thickness direction are opened.

  According to the planar heating element according to the present invention, even when air is trapped between the adhesive layer and the heating object when pasted to the heating object, the air is passed through the hole penetrating in the thickness direction. It can be easily discharged. Therefore, workability is improved. Moreover, an air layer can be prevented from being formed between the planar heating element and the heating object, and heat transfer to the heating object can be improved.

  Hereinafter, a planar heating element according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an example of an electrode pattern in a planar heating element according to the present invention. FIG. 2 is a sectional view of the planar heating element according to the present invention taken along line II-II in FIG. It is sectional drawing shown.

  As shown in FIG. 2, the planar heating element 10 according to the present invention covers the first electrode 11 and the second electrode 12 and one side of the first electrode 11 and the second electrode 12. It has a laminated structure in which the arranged resistance heating layer 13 is integrally provided so as to be sandwiched between the base film 14 and the adhesive layer 15.

  The first electrode 11 and the second electrode 12 are obtained by bonding a copper foil to the resistance heating layer 13 and etching the copper foil into a predetermined pattern such as a comb-like shape as shown in FIG. A voltage is applied via the connection terminals 11a and 12a, respectively.

  The resistance heating layer 13 corresponds to the heating portion according to claim 1, and is printed or coated with a uniform layer thickness of a PTC ink composition containing carbon particles or conductive metal particles in a polymer. In the conductive thin film formed by drying, the current flows between the comb teeth 11b and 12b of the first electrode 11 and the second electrode 12 in a direction perpendicular to the edges of the comb teeth 11b and 12b. It generates heat by flowing.

  The base film 14 corresponds to the insulating layer described in claim 1 and is made of a synthetic resin film having high electrical insulation and flexibility.

  As the adhesive layer 15, a double-sided adhesive tape made of a synthetic resin having high thermal conductivity is suitably employed.

  In the planar heating element 10 having the laminated structure as described above, a plurality of holes 10a penetrating in the thickness direction are formed at appropriate intervals. The first electrode 11 and the second electrode 12 are extended so as to avoid these holes 10a. In other words, the first electrode 11 and the second electrode 12 are provided around each hole 10a. And a circular region 10b in which the resistance heating layer 13 is not formed.

  The planar heating element 10 configured as described above is attached to the back surface of a door mirror (not shown) in the vehicle, for example, and is connected to the connection terminals 11a and 12a via the first electrode 11 and the second electrode. When a voltage is applied between the electrodes 12, the resistance heating layer 13 is energized to generate heat, and the heat is conducted to the door mirror to remove cloudiness and frost caused by condensation of water vapor in the air on the surface of the door mirror. To do.

  When the sheet heating element 10 is attached to the back surface of the object to be heated such as the door mirror by the adhesive layer 15, the residual air between the bonding layer 15 and the back surface of the door mirror or the like is the thickness of the sheet heating element 10. It is discharged from the hole 10a penetrating in the direction. In addition, even if the remaining air is trapped between the adhesive layer 15 and the back surface of the door mirror or the like, the remaining air is made to flow in a plurality of holes 10a by squeezing the surface of the base film 14 in an appropriate direction. It can be easily discharged from either of these.

  For this reason, the workability | operativity at the time of sticking the planar heating element 10 improves. Moreover, it can prevent that the air layer which inhibits heat transfer will be formed in the adhesion surface of the planar heating element 10, and can also prevent the fall of the heating efficiency with respect to heating objects, such as a door mirror.

It is a top view which shows an example of the electrode pattern in the planar heating element which concerns on this invention. It is sectional drawing which cuts and shows a part of planar heating element which concerns on this invention by the II-II line | wire of FIG. It is a top view which shows an example of the electrode pattern in the conventional planar heating element. FIG. 4 is a cross-sectional view showing a part of a conventional planar heating element cut along line IV-IV in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Planar heating element 10a Hole 11 1st electrode 12 2nd electrode 13 Resistance heating layer (heating part)
14 Base film (insulating layer)
15 Adhesive layer

Claims (1)

  A plurality of electrodes and a heat generating portion that generates heat when energized between the plurality of electrodes are disposed between the sheet or film-like insulating layer and the adhesive layer, and a required number of holes penetrating in the thickness direction are provided. A planar heating element characterized by being established.

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