JP2020027765A - Tape-like heater - Google Patents

Abstract

To provide a tape-like heater which can be used under a relatively high temperature of 100 °C or more and can prevent damage due to cracking of a coated layer.SOLUTION: A tape-like heater 100 comprises: first and second power supply wires 11 and 12; a plurality of heat generation bodies 13 having a positive temperature coefficient characteristic connected in parallel to the first and second power supply wires 11 and 12; and a coating layer 20 coating the plurality of power generation bodies 13 and the first and second power supply wires 11 and 12. A raw material of the coating layer 20 is a silicon rubber of 145% or more in a cutting extension by a tensile test using a dumbbell-shaped No. 3 test piece defined in JIS K 6251.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a tape-shaped heater.

  BACKGROUND ART Conventionally, an invention related to a linear PTC (Positive Temperature Coefficient) heater wire having a positive temperature coefficient characteristic has been known (see Patent Document 1 below). The linear PTC heater wire described in Patent Document 1 has a rectangular shape having first and second linear power supply lines and a plurality of positive temperature coefficient characteristics connected in parallel between the power supply lines. It includes a planar heating element, a first coating layer that covers the power supply line and the planar heating element, and a second coating layer that covers the first coating layer. reference.).

  In this conventional linear PTC heater wire, the outer surface of the first coating layer and the inner surface of the second coating layer are in close contact with each other at the area of the planar heating element. On the other hand, between the planar heating elements adjacent to each other in the longitudinal direction of the linear PTC heater wire, a gap is formed between the outer surface of the first coating layer and the inner surface of the second coating layer. have.

This conventional linear PTC heater wire is characterized by satisfying the following two conditions.
Condition 1: 10% ≦ (t / a) × 100 ≦ 50%
Condition 2: 3A ≦ B ≦ 10A

  In the above conditions 1 and 2, a is the thickness between the planar heating elements adjacent in the longitudinal direction of the linear PTC heater wire, and t is the center of the horizontal width of the linear PTC heater wire. Is the thickness of the gap in the portion, A is the length in the longitudinal direction of the linear PTC heater wire of the planar heating element, and B is the distance between the planar heating elements adjacent in the longitudinal direction. Is the distance.

  In the above-mentioned conventional linear PTC heater wire, even when laid along the object to be heated with a small radius of curvature, a wrinkle having a size that hinders the adhesion to the inner surface of the second coating layer that is inside the bend. Can be avoided. Therefore, the adhesion between the linear PTC heater wire and the object to be heated at the bent portion is sufficiently ensured without paying special attention to the construction (see the same document, paragraph 0014, etc.). ).

  Further, the temperature difference in the longitudinal direction of the conventional linear PTC heater wire can be kept within a small range. Thus, when the conventional linear PTC heater wire is used, desired heat transfer performance can be secured in the entire heating region including the curvature portion, and high thermal efficiency can be achieved.

JP 2018-018713 A

  A tape-shaped heater such as the conventional linear PTC heater wire may require a relatively high temperature of, for example, 100 ° C. or more. However, for example, when the material of the first coating layer and the second coating layer is a vinyl chloride resin as in the conventional linear PTC heater wire (see Patent Document 1, paragraph 0011, etc.). It is not suitable for such relatively high-temperature heat generation.

  A tape-like heater such as the conventional linear PTC heater wire may be used by being wound around a pipe for the purpose of, for example, keeping heat or preventing freezing. Generally, when a tape-shaped heater wound around a pipe is used and the coating layer is damaged by, for example, a burr or a corner of a flange left at a welding portion of an elbow of the pipe, the scratch is used as a starting point. There is a risk of tearing. Such damage due to tearing of the coating layer may impair the electrical insulation of the power supply line, and must be prevented from the viewpoint of the durability and safety of the tape heater.

  The present disclosure provides a tape-shaped heater that can be used at a relatively high temperature of 100 ° C. or higher and that can prevent damage due to tearing of a coating layer.

  One aspect of the present disclosure is directed to a first and second power supply lines, a plurality of heating elements having a positive temperature coefficient characteristic connected in parallel to the first and second power supply lines, and the plurality of heating elements. And a coating layer covering the first and second power supply lines, wherein a dumbbell-shaped No. 3 test piece specified in JIS K6251 is used as a material of the coating layer. A tape-shaped heater characterized in that it is a silicone rubber having an elongation at break of 145% or more in a tensile test.

  Since the tape-shaped heater of the above aspect is made of silicone rubber as the material of the coating layer, it can be used at a relatively high temperature of, for example, 150 ° C. or more for a long period of time. Further, in the tape-shaped heater of the above aspect, the material of the coating layer is a silicone rubber having an elongation at break of 145% or more in a tensile test using a dumbbell-shaped No. 3 test piece specified in JIS K6251. Even if the coating layer is damaged, damage due to tearing of the coating layer can be prevented.

  In the tape-shaped heater of the above aspect, the elongation at the time of cutting of the silicone rubber may be 619% or less. In this case, for example, the coating layer does not become extremely flexible, and the handling of the tape-shaped heater can be facilitated.

  In the tape-shaped heater of the above aspect, the elongation at the time of cutting of the silicone rubber may be 170% or more and 272% or less. In this case, the coating layer can have appropriate rigidity, and the handling of the tape heater can be improved.

  In the tape-shaped heater of the above aspect, the material of the coating layer may be a silicone rubber having a tear strength of 170 N / cm or more and 390 N / cm or less according to a tear strength test method specified in JIS K 7128-3. . With this configuration, even when the coating layer is damaged, damage due to tearing of the coating layer can be more reliably prevented.

  In the tape-shaped heater of the above aspect, the tear strength of the silicone rubber may be 186 N / cm or more and 232 N / cm or less. With this configuration, even when the coating layer is damaged, damage due to tearing of the coating layer can be more reliably prevented.

  In the tape-shaped heater according to the above aspect, the covering layer includes a first covering layer covering the plurality of heating elements and the first and second power supply lines, and a second covering layer covering the first covering layer. And a shield formed by a metal braided wire may be interposed between the first coating layer and the second coating layer.

  With this configuration, the effect of external electromagnetic noise on the current flowing through the power supply line can be reduced, and the effect of the current flowing through the power supply line on the external environment can be reduced. Further, the mechanical strength of the tape-shaped heater can be improved.

  According to the present disclosure, it is possible to provide a tape-shaped heater that can be used at a relatively high temperature of 100 ° C. or higher and that can be prevented from being damaged by tearing of a coating layer.

FIG. 2 is a perspective view of a part of the tape-shaped heater according to the embodiment of the present disclosure. FIG. 2 is a perspective view of a power supply line and a heating element of the tape-shaped heater shown in FIG. 1. FIG. 3 is a sectional view of the tape-shaped heater shown in FIG. 1 along the line III-III. Sectional drawing which follows the IV-IV line of the tape-shaped heater shown in FIG. FIG. 2 is a perspective view showing a test method of a material forming a coating layer of the tape-shaped heater shown in FIG. 4 is a graph illustrating a relationship between elongation at break and tear strength of a coating layer of a tape-shaped heater according to examples and comparative examples of the present disclosure.

  Hereinafter, an embodiment of a tape-shaped heater of the present disclosure will be described with reference to the drawings.

  FIG. 1 is a perspective view in which a part of a tape-shaped heater 100 according to an embodiment of the present disclosure is cut. FIG. 2 is a perspective view of the power supply lines 11 and 12 and the heating element 13 that constitute the heating section 10 of the tape-shaped heater 100 shown in FIG. FIG. 3 is a cross-sectional view of the tape-shaped heater 100 shown in FIG. 1 along the line III-III. FIG. 4 is a cross-sectional view of the tape-shaped heater 100 shown in FIG. 1 along the line IV-IV.

  Although the details will be described later, the tape-shaped heater 100 according to the present embodiment is characterized by having the following configuration. The tape-shaped heater 100 includes first and second power supply lines 11 and 12 and a plurality of heating elements 13 having a positive temperature coefficient characteristic and connected in parallel to the first and second power supply lines 11 and 12. And a coating layer 20 that covers the plurality of heating elements 13 and the first and second power supply lines 11 and 12. The material of the coating layer 20 is silicone rubber having an elongation at break of 145% or more in a tensile test using a dumbbell-shaped No. 3 test piece specified in JIS K6251.

  Hereinafter, the configuration of the tape-shaped heater 100 according to the present embodiment will be described in more detail. The tape-shaped heater 100 includes, for example, a heating unit 10 and a coating layer 20 that covers the heating unit 10. The heat generating unit 10 includes, for example, a metal terminal 14 and an electrode 15 in addition to the first power supply line 11, the second power supply line 12, and the heat generating body 13 described above. The coating layer 20 includes, for example, a first coating layer 21, a second coating layer 22 that covers the first coating layer 21, and a portion between the first coating layer 21 and the second coating layer 22. And a shield 23 interposed therebetween.

  The first and second power supply lines 11 and 12 are, for example, flexible stranded wires or flat knitted wires made of a plurality of copper wires, are arranged substantially in parallel at predetermined intervals, and are tape-like heaters. It extends generally parallel in the length direction of 100. One end of each of the first and second power supply lines 11 and 12 is connected to, for example, a power cable having a plug. The first and second power supply lines 11 and 12 are configured such that an AC current is supplied by inserting a plug of a power cable into a power supply outlet, for example.

  The heating element 13 is a PTC (Positive Temperature Coefficient) heater having a positive temperature coefficient characteristic, and is obtained, for example, by adding a trace amount of a rare earth element to barium titanate. The heating element 13 is, for example, a rectangular flat sheet-like heating element. The size of the heating element 13 is not particularly limited. For example, the thickness is about 1.5 mm to 2.0 mm, and the width transverse to the first and second power supply lines 11 and 12 is about 8 mm to 9 mm. The length along the length direction of the tape-shaped heater 100 is about 5.5 mm to 6.5 mm.

  The plurality of heating elements 13 are arranged at predetermined intervals in the length direction of the tape-shaped heater 100, one end in the width direction is connected to the first power supply line 11, and the other end in the width direction is the second power supply line. It is connected to the electric wire 12.

  The metal terminal 14 is made of, for example, a conductive metal such as copper, phosphor bronze, iron, iron nickel alloy, gold, silver, or aluminum, and the heating element 13 is connected to the first and second power supply lines 11, 12 is electrically connected. The metal terminals 14 are fixed via electrodes 15 at one end and the other end in the width direction of the heating element 13. The metal terminal 14 is fixed to the heating element 13 and the first power supply line 11 or the second power supply line 12 by being plastically deformed and caulked so as to sandwich them. As described above, by electrically and mechanically connecting the individual heating elements 13 to the first and second power supply lines 11 and 12 by the pair of metal terminals 14, the plurality of heating elements 13 are connected in parallel. I have.

  The electrode 15 is interposed between the heating element 13 and the metal terminal 14 to conduct electricity between the heating element 13 made of the barium titanate-based PTC and the metal terminal 14. The electrode 15 is formed by applying and baking a paste-like electrode material to the surface of the heating element 13 at one end and the other end in the width direction of the heating element 13, and the surface of the heating element 13 made of barium titanate-based PTC is formed. Established in

  The coating layer 20 includes, for example, a first coating layer 21 that covers the plurality of heating elements 13 and the first and second power supply lines 11 and 12, and a first coating layer 21 that covers the first coating layer 21, as described above. 2 coating layers 22. As described above, the material of the first coating layer 21 and the second coating layer 22 is silicone having an elongation at break of 145% or more in a tensile test using a dumbbell-shaped No. 3 test piece specified in JIS K6251. It is rubber. Further, the first coating layer 21 and the second coating layer 22, that is, the elongation at the time of cutting of the silicone rubber which is the material of the coating layer 20 is, for example, 619% or less.

  FIG. 5 is a perspective view showing an example of a method for testing a material constituting the coating layer 20 of the tape-shaped heater 100 shown in FIG. The lower limit and the upper limit of the elongation at break of the silicone rubber as the material of the coating layer 20 by the above tensile test can be determined, for example, as follows. First, a plurality of silicone rubbers having different characteristics are prepared, and test pieces TP of each silicone rubber are prepared. The test piece TP is formed into, for example, a strip having a width of about 10 mm and a thickness of about 1 mm. Next, a minute flaw C is formed in the center of the test piece TP by, for example, a blade. Next, a winding test is performed in which the test piece TP is wound while applying tension in the circumferential direction of the cylindrical straight pipe SP having an outer diameter of 25 mm. At this time, a test piece TP that has a crack extending from the scratch C and finally breaks is rejected, and a test piece TP that has not cracked from the scratch C and did not break is passed.

  Next, for each silicone rubber that has passed the above winding test, the elongation at break is measured by the above tensile test. Next, a standard deviation σa of elongation at break is calculated for each silicone rubber. Further, for each silicone rubber, the average value of the elongation at break μa is calculated to obtain μa ± 3σa. The minimum value of μa−3σa of the plurality of silicone rubbers is defined as the lower limit of the elongation at break of the silicone rubber as the material of the coating layer 20, and the maximum value of μa + 3σa of the plurality of silicone rubbers is the material of the coating layer 20. The upper limit of the elongation at break of the silicone rubber can be set.

  The lower limit and the upper limit of the elongation at break of the silicone rubber, which is the material of the coating layer 20, may be, for example, μa ± 2σa of the elongation at break of the silicone rubber that has passed the winding test. In this case, the elongation at break of the silicone rubber as the material of the coating layer 20 by the above-described tensile test is, for example, 170% or more and 272% or less.

  The material of the coating layer 20, that is, the first and second coating layers 21 and 22 has, for example, a tear strength of 170 N / cm or more and 390 N / cm or less according to a tear strength test method specified in JIS K 7128-3. Silicone rubber. The lower limit and the upper limit of the tear strength of the silicone rubber as the material of the coating layer 20 according to the above-described tear strength test method can be determined, for example, as follows.

  The tear strength of each silicone rubber that has passed the above winding test is measured by the above-described tear strength test method. Next, the standard deviation σb of the tear strength is calculated for each silicone rubber. Further, for each silicone rubber, the average value μb of the tear strength is calculated to obtain μb ± 3σb. The minimum value of μb−3σb of the plurality of silicone rubbers is defined as the lower limit of the tear strength of the silicone rubber that is the material of the coating layer 20, and the maximum value of μ + 3σ of the plurality of silicone rubbers is the material of the coating layer 20. The upper limit of the tear strength of the silicone rubber can be set.

  The lower limit and the upper limit of the tear strength of the silicone rubber as the material of the coating layer 20 may be, for example, the narrowest range of μb ± 3σb among μb ± 3σb of a plurality of silicone rubbers. In this case, the tear strength of the silicone rubber as the material of the coating layer 20 according to the above-described tear strength test method can be, for example, 186 N / cm or more and 232 N / cm or less.

  The covering layer 20 has, for example, a shield 23 made of a metal braided wire between the first covering layer 21 and the second covering layer 22. The shield 23 is, for example, a braided tin-plated soft copper wire. The shield 23 covers, for example, 50 to 90% of the surface of the first coating layer 21. Note that the coating layer 20 may not have the shield 23.

  The tape-shaped heater 100 can be manufactured, for example, as follows. First, a plurality of heating elements 13 are connected between the first and second power supply lines 11 and 12 via a plurality of metal terminals 14 and electrodes 15. Next, the first coating layer 21 is formed by extruding silicone rubber around the heat generating portion 10. At this time, silicone rubber is extruded so that no gap is formed between the first coating layer 21 and the heat generating portion 10.

  Next, the first covering layer 21 is covered with the shield 23. Next, the second covering layer 22 is formed by extruding silicone rubber around the first covering layer 21 covered by the shield 23. At this time, silicone rubber is extruded so that no gap is formed between the first coating layer 21 and the second coating layer 22. Finally, the first and second power supply lines 11 and 12 are connected to a power supply cable (not shown), and the power supply cable is fixed around the second coating layer 22 so that the tape-shaped heater 100 can be used. Is manufactured.

  The tape-shaped heater 100 has a flat cross-sectional shape as shown in FIGS. 3 and 4, for example. More specifically, the tape-shaped heater 100 has a pair of generally flat surfaces at both ends in the thickness direction, and an oval cross-sectional shape having a pair of semi-cylindrical curved surfaces at both ends in the width direction. Have. The thickness T of the tape-shaped heater 100 is, for example, about 10 mm, the thickness t1 of the first coating layer 21 is, for example, about 6 mm to about 7 mm, and the thickness t2 of the second coating layer 22 is , For example, about 2 mm. The width W of the tape-shaped heater 100 is, for example, about 20 mm. The tape-shaped heater 100 has, for example, a width W that is twice or more the thickness T.

  Hereinafter, the operation of the tape-shaped heater 100 of the present embodiment will be described.

  The tape-shaped heater 100 is wound around an object to be kept warm, such as a pipe that needs to be kept warm, and a plug of a power cable (not shown) is inserted into a power supply outlet. Then, an alternating current is supplied to the first and second power supply lines 11 and 12 of the heat generating unit 10, and the heat generating body 13, which is a PTC heater, generates heat in a predetermined temperature range, and heats the heat insulating target via the coating layer 20. Is transmitted. As a result, the temperature of the object to be kept warm is maintained by the tape-shaped heater 100.

  Here, as described above, the tape-shaped heater 100 has the first and second power supply lines 11 and 12 and the positive temperature coefficient characteristics connected in parallel to the first and second power supply lines 11 and 12. A plurality of heating elements 13 are provided, and a coating layer 20 that covers the plurality of heating elements 13 and the first and second power supply lines 11 and 12. The material of the coating layer 20 is a silicone rubber having an elongation at break of 145% or more in a tensile test using a dumbbell-shaped No. 3 test piece specified in JIS K6251.

  Thus, the tape-shaped heater 100 can be used for a long period of time at a relatively high temperature of, for example, 150 ° C. or more, since the material of the coating layer 20 is silicone rubber. Further, in the tape-shaped heater 100, even when the coating layer 20 is damaged by the fact that the material of the coating layer 20 is silicone rubber having an elongation at break of 145% or more in the tensile test, the coating layer 20 is torn. Damage can be prevented.

  Further, in the tape-shaped heater 100 of the present embodiment, the elongation at break of the silicone rubber as the material of the coating layer 20 by the above tensile test is 619% or less. Thereby, the coating layer 20 does not become extremely flexible, it is possible to provide the tape-shaped heater 100 with appropriate rigidity, and the handling of the tape-shaped heater 100 can be facilitated.

  In the tape-shaped heater 100 of the present embodiment, the elongation at break of the silicone rubber, which is the material of the coating layer 20, is 170% or more and 272% or less by the tensile test. Thereby, the tear of the coating layer 20 can be more reliably prevented, the coating layer 20 can have higher rigidity, and the handling of the tape-shaped heater 100 can be further improved.

  Further, in the tape-shaped heater 100 of the present embodiment, the material of the coating layer 20 is a silicone rubber having a tear strength of 170 N / cm or more and 390 N / cm or less according to a tear strength test method specified in JIS K 7128-3. is there. With this configuration, even if the coating layer 20 is damaged, damage due to tearing of the coating layer 20 can be more reliably prevented.

  Moreover, in the tape-shaped heater 100 of the present embodiment, the tear strength of the silicone rubber as the material of the coating layer 20 according to the tear strength test method is 186 N / cm or more and 232 N / cm or less. With this configuration, even if the coating layer 20 is damaged, damage due to tearing of the coating layer 20 can be more reliably prevented.

  Moreover, in the tape-shaped heater 100 of the present embodiment, the coating layer 20 includes the first coating layer 21 that covers the plurality of heating elements 13 and the first and second power supply lines 11 and 12, and the first coating layer 21. A second coating layer 22 that covers the layer 21. In addition, a shield 23 made of a metal braid is interposed between the first coating layer 21 and the second coating layer 22.

  With this configuration, the influence of external electromagnetic noise on the current flowing through the power supply lines 11 and 12 can be reduced, and the influence of the current flowing through the power supply lines 11 and 12 on the external environment can be reduced. Further, the mechanical strength of the tape-shaped heater 100 can be improved. Therefore, damage due to tearing of the coating layer 20 can be prevented.

  As described above, according to the present embodiment, there is provided a tape-shaped heater 100 that can be used at a relatively high temperature of 100 ° C. or more and that can prevent damage due to tearing of the coating layer 20. can do.

  As described above, the embodiment of the tape-shaped heater according to the present disclosure has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design change may be made without departing from the gist of the present disclosure. And the like, if any, are included in the present disclosure.

[Example]
Hereinafter, examples of the silicone rubber constituting the coating layer of the tape-shaped heater according to the present disclosure will be described. First, the silicone rubber of Example 1 having moderate rigidity and the silicone rubber of Example 2 which is more flexible than the silicone rubber of Example 1 were prepared, and a dumbbell-shaped No. 3 test piece specified in JIS K6251 was used. A tensile test was performed to measure the elongation at break of each silicone rubber. Further, the silicone rubbers of Examples 1 and 2 were subjected to a tear strength test specified in JIS K 7128-3 to measure the tear strength of each silicone rubber.

  Next, each of the silicone rubbers of Examples 1 and 2 was processed into a strip shape having a thickness of 1 mm and a width of 10 mm, and a small wound was made at the center in the width direction with a blade to prepare a test piece for a winding test. The scratch was about 2 mm long in the width direction of the test piece, and was formed by penetrating the test piece. Next, a winding test was performed using the silicone rubber test piece of Example 1 and the silicone rubber test piece of Example 2. Specifically, a test piece of each silicone rubber was wound around the circumference of a metal straight pipe having an outer diameter of 25 mm. As a result, in each of the test pieces, no crack was extended from the scratch, and each test piece did not break.

[Comparative example]
Next, using the silicone rubber of Comparative Example 1 which is harder than the silicone rubber of Example 1, a tensile test and a tear strength test were performed in the same manner as in Example 1 and Example 2, and elongation at break and tear strength were performed. Was measured. Next, a winding test was performed using the silicone rubber of Comparative Example 1 in the same manner as in Example 1 and Example 2. As a result, a crack was extended from a scratch on the test piece, and finally the test piece was broken.

  The results of the tensile test and the tear strength test of Examples 1 and 2 and Comparative Example 1 are shown in Tables 1 and 2 below, respectively. FIG. 6 shows the relationship between the average value of elongation at break and the average value of tear strength in Example 1, Example 2, and Comparative Example 1. In FIG. 6, points A1, A2, and Z1 indicate the average values of the results of Example 1, Example 2, and Comparative Example 1, respectively.

  As described above, the silicone rubber of Example 1 has an elongation at break shown in Table 1 of 200% or more and 206% or less, and a tear strength shown in Table 2 of 200 N / cm or more. 219 [N / cm] or less, and there was no crack extension or breakage in the winding test. Further, the silicone rubber of Example 2 has an elongation at break of 405 [%] or more and 517 [%] or less shown in Table 1, and a tear strength shown in Table 2 of 230 [N / cm] or more and 318 [N]. / Cm] or less, and there was no crack extension or breakage in the winding test.

  On the other hand, the silicone rubber of Comparative Example 1 has an elongation at break shown in Table 1 of 67% or more and 76% or less, and a tear strength shown in Table 2 of 165 N / cm or more and 182 N / Cm] or less, and the crack extended and fractured in the winding test.

  The silicone rubber of Example 1 had a standard deviation σa of elongation at break of 25.2 [%] and a standard deviation σb of tear strength of 7.4 [N / cm]. In the silicone rubber of Example 2, the standard deviation σa of elongation at break was 48.5 [%], and the standard deviation σb of tear strength was 36.4 [N / cm].

  Assuming that the average value of the elongation at break of the silicone rubber of Example 1 is μa, the elongation at break μa−3σa and μa + 3σa are about 145 [%] and about 297 [%], respectively. Assuming that the average value of elongation at break of the silicone rubber of Example 2 is μa, μa−3σa and μa + 3σa of elongation at break are about 327% and about 619%, respectively. In this case, the range of elongation at the time of cutting of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than the minimum value of μa−3σa and not more than the maximum value of μa + 3σa, that is, about 145 [%] or more and about 619 [%]. It can be:

  The range of the elongation at break of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than about 170 [%], which is the range of the elongation at break of the silicone rubber of Example 1 ± 2 σa, and is about 272 [%]. ] It may be as follows. The range of the elongation at break of the silicone rubber constituting the coating layer of the tape-shaped heater is about 375 [%] or more, which is the range of μa ± 2σa of the elongation at break of the silicone rubber of Example 2, and about 570 [%]. ] It may be as follows.

  Further, the range of the elongation at break of the silicone rubber constituting the coating layer of the tape-shaped heater is about 195 [%] or more, which is the range of the elongation at break of the silicone rubber of Example 1 ± a ± σa, and about 246 [%]. ] It may be as follows. The range of the elongation at break of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than about 424 [%], which is the range of μa ± σa of the elongation at break of the silicone rubber of Example 2, and about 522 [%]. ] It may be as follows.

  Further, in the silicone rubber of Example 1, assuming that the average value of the tear strength is μb, the tear strengths μb−3σb and μa + 3σb are about 186 [N / cm] and about 232 [N / cm], respectively. Assuming that the average value of the tear strength of the silicone rubber of Example 2 is μb, the tear strengths μb−3σb and μb + 3σb are about 170 [N / cm] and about 390 [N / cm], respectively. In this case, the range of the tear strength of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than the minimum value of μb−3σb and not more than the maximum value of μb + 3σb, ie, not less than about 170 [N / cm] and not more than about 390 [N / Cm] or less.

  Further, the range of the tear strength of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than about 194 [N / cm], which is the range of the tear strength of the silicone rubber of Example 1, which is ± b ± 2σb, and is not less than about 224 [N]. / Cm] or less. The range of the tear strength of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than about 206 [N / cm], which is the range of the tear strength of the silicone rubber of Example 2 ± b ± 2σb, and is about 353 [N]. / Cm] or less.

  The range of the tear strength of the silicone rubber constituting the coating layer of the tape-shaped heater is not less than about 201 [N / cm], which is the range of the tear strength of the silicone rubber of Example 1 ± b ± σb, and is about 217 [N]. / Cm] or less. Further, the range of the tear strength of the silicone rubber forming the coating layer of the tape-shaped heater is not less than about 243 [N / cm], which is the range of the tear strength of the silicone rubber of Example 2 ± b ± σb, and about 317 [N]. / Cm] or less.

  As described above, the elongation at break of the silicone rubber constituting the coating layer of the tape-shaped heater, or, by defining the range of the elongation at break and the tear strength based on the standard deviation of the experimental value, the coating layer tears A tape-shaped heater capable of preventing damage can be provided.

11 First power supply line 12 Second power supply line 13 Heating element 20 Coating layer 21 First coating layer 22 Second coating layer 23 Shield 100 Tape heater

Claims (6)

First and second power supply lines, a plurality of heating elements having a positive temperature coefficient characteristic connected in parallel to the first and second power supply lines, the plurality of heating elements, and the first and second heating elements. And a coating layer for covering the power supply line, a tape-shaped heater comprising:
A tape-shaped heater, wherein a material of the coating layer is a silicone rubber having an elongation at break of 145% or more in a tensile test using a dumbbell-shaped No. 3 test piece specified in JIS K6251.   The tape-like heater according to claim 1, wherein the elongation at the time of cutting of the silicone rubber is 619% or less.   The tape-like heater according to claim 2, wherein the elongation at the time of cutting of the silicone rubber is 170% or more and 272% or less.   The material of the coating layer is a silicone rubber having a tear strength of 170 N / cm or more and 390 N / cm or less according to a tear strength test method specified in JIS K 7128-3. 4. The tape-shaped heater according to any one of items 3.   The tape-shaped heater according to claim 4, wherein the tear strength of the silicone rubber is 186 N / cm or more and 232 N / cm or less. The covering layer has a first covering layer covering the plurality of heating elements and the first and second power supply lines, and a second covering layer covering the first covering layer,
The tape-shaped heater according to claim 1, wherein a shield constituted by a braided metal wire is interposed between the first coating layer and the second coating layer.

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