JP2818905B2 - Heat and water resistant heat retention heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a method for keeping a compressor crankcase warm.
The present invention relates to a heater used for heat retention requiring relatively high wattage, such as prevention of freezing of a refrigerator drain or the like.

(Prior Art) Conventionally, as a heater used for heat retention requiring relatively high wattage, a cord-shaped heater using a silicone rubber as a coating material and a silicone rubber-coated lead wire are connected,
One in which the entire connection portion is further molded with silicone rubber has been used.

However, in recent years, in order to reduce the size, improve the performance, and improve the safety of equipment, more heat generation and higher flame retardancy are required. To meet these demands, silicone rubber has limited improvement and new materials are needed.

On the other hand, Japanese Patent Application Publication No. 62-2407 discloses that a fluoroelastomer can be applied to an insulated wire to produce a wire having excellent heat resistance and flexibility.

(Problems to be Solved by the Present Invention) If a fluoroelastomer is applied to an insulating material of a cord-shaped heater, the heat resistance of the insulating material can be improved, the calorific value can be increased, and high flame retardancy can be achieved.

However, since the silicone rubber and the fluoroelastomer do not usually adhere to each other, there is a problem in how to maintain good water resistance at the connection with the lead wire. Therefore, if the fluoroelastomer insulated wire is used for the lead wire and the material of the mold is the same fluoroelastomer, it is thought that water resistance can be ensured. However, fluoroelastomer is generally more expensive than silicone rubber at a price per volume of 4 times or more. And, as a result, become too expensive to be practical.

The present inventors have conducted various searches to develop an insulated heater having an increased heating value, flame retardancy, and water resistance using a fluoroelastomer insulated cord-shaped heater and minimizing the increase in cost. As a result, the present invention has been achieved.

(Means for Solving the Problems) That is, a heat and water resistant and heat insulating heater of the present invention comprises a cord-shaped heater using a fluoroelastomer as an insulating coating, a lead wire using silicone rubber as an insulating coating, and the cord-shaped heater. In a heat retention heater having a connection terminal for electrically connecting a heater and the cord wire and a mold rubber for insulating the connection terminal as essential elements, a silicone rubber is used as a mold rubber, and the cord shape is used. The heater has been subjected to an adhesive treatment.

As the fluoroelastomer, a vinylidene fluoride copolymer rubber and a tetrafluoroethylene-propylene copolymer rubber are known, and both of them can be used. Preferably, a tetrafluoroethylene-propylene copolymer rubber excellent in flexibility and insulating properties is used. Both are generally commercially available, and in order to actually use them as an insulator, as shown in Japanese Patent Application Publication No. 62-2407, a compound is prepared by kneading a filler, a heat resistance improver, a crosslinking agent, and the like. After that, it is used after crosslinking.

The cord-shaped heater is made of nylon, polyester, glass fiber, aramid fiber, aromatic polyester fiber, etc. as it is, or is coated or impregnated with rubber, thermosetting resin, etc., and bundled to form a core material. A wire is wound and coated with an insulation, or a resistance wire is directly or twisted and an insulation coating is applied immediately above. The final shape of the cord-shaped heater is not particularly limited. In addition to a normal round shape, a flat shape, an elliptical shape,
Examples include a belt shape and a flat ribbon shape.

The silicone rubber used for the mold may be a so-called millable silicone rubber or a liquid silicone rubber, and any commercially available silicone rubber may be used without any particular limitation. Further, other rubbers such as fluoroelastomers or resins may be mixed as long as they are mainly composed of silicone rubber.

In the present invention, a silicone rubber mold material,
It is essential that the fluoroelastomer coating of the cord-shaped heater is adhered, and an adhesion treatment is performed. Here, the adhesive treatment includes, for example, a method in which a commercially available adhesive treatment agent of an alkoxysilane-based or alkoxytitanium-based compound is applied to the surface of the cord-shaped heater. As the adhesive treatment agent, for example, r-methacryloxypropyltriethoxysilane,
Examples include vinyl tri (2-ethoxyethoxy) silane or a mixture of tetra-n-butyl titanate and methyl hydrogen polysiloxane, and used as such or in solution.

Further, as another means, the heat and water resistant heat insulating heater of the present invention comprises a cord-shaped heater using a fluoroelastomer as an insulating coating, a lead wire using a silicone rubber as an insulating coating, the cord-shaped heater and the lead wire. A connection terminal that electrically connects the terminal and a mold rubber that insulates the connection terminal,
A mixture of a fluoroelastomer and silicone rubber is used as a mold rubber.

The fluoroelastomer is preferably of the same type as that used for the insulating coating material of the cord-shaped heater in order to increase the affinity between the cord-shaped heater and the mold rubber.

(Operation) According to the present invention, the fluoroelastomer insulated cord-shaped heater and the silicone rubber mold material, which are originally not bonded, are firmly bonded, so that watertightness is maintained. Also,
By using a mixture of a fluoroelastomer and silicone rubber as the cord heater, it is possible to maintain water tightness between the fluoroelastomer insulated cord heater and the mold rubber material and between the silicone rubber insulated lead wire and the mold rubber material, respectively.

(Example) Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is an explanatory view of a partially cut-away structure showing an embodiment of a heat-resistant water-resistant heat insulating heater according to the present invention, and FIG. 2 is a partially cut-away perspective view showing an example of a cord-shaped heater used in the present invention.

As shown in FIGS. 1 and 2, the heater of the present invention is a cord-shaped heater in which a resistance wire 2 is wound around a core material 1 and a fluoroelastomer 3 is insulated and coated directly above the core wire. 4 , a silicone rubber lead 5, a connection terminal 6, and a mold rubber 7.

The ends of the cord-shaped heater 4 and the lead wire 5 are stripped, and the conductors (tin-plated copper wire) of the resistance wire 2 and the lead wire 5 are caulked and connected by connection terminals 6 made of brass.

An adhesive 8 is applied to the surface of the cord-shaped heater to be molded, and the cord-shaped heater 4 and the molding rubber 7 are firmly adhered.

Table 1 shows the evaluation of the heat and water resistant heat insulation heaters according to the present invention.
Comparative tests were performed on samples using the materials listed in No. 1.

As the insulating coating material of the cord-shaped heater, a vinylidene fluoride-based fluoroelastomer or a tetrafluoroethylene-α-olefin-based fluorolastomer was used.

As the adhesive treatment agent, an isopropanol solution of r-methacryloxypropyltriethoxysilane, vinyltri (2-ethoxyethoxy) silane, or a heptane solution of a mixture of tetra n-butyl titanate and methyl hydrogen polysiloxane was used.

As the mold rubber, peroxide-curable millable silicone rubber, two-part liquid silicone rubber, or a mixture of silicone rubber and fluoroelastomer was used. As the silicone rubber peroxide-curable millable silicone rubber, NM7551 manufactured by Rhone Poulin Co., Ltd., and as the two-part liquid silicone rubber, KE1915 manufactured by Shin-Etsu Chemical Co., Ltd. was used.
As the mixture of the silicone rubber and the fluoroelastomer, a 1: 1 (weight) mixture of the NM7551 silicone rubber and the tetrafluoroethylene-propylene copolymer rubber was used.

First, in the peeling test, the mold part of the cord-shaped heater was fixed, and 0.5 kgf
When the tension was continuously applied for 5 seconds, the presence or absence of peeling was visually checked. Next, as an insulation resistance test, the sample subjected to the peeling test was immersed in boiling water for 1 hour, and then immersed in ice water for 5 hours.
The operation of soaking for one minute was defined as one cycle, and after repeating a total of five cycles, the insulation resistance in salt water was measured.

 Table 1 also shows the test results of various samples.

As can be seen from the table, the adhesive-treated product or the product obtained by using a mixture of silicone rubber and fluoroelastomer for the mold rubber does not peel off and has excellent insulation performance. On the other hand, those that have not been glued
Peeling occurred and insulation performance was poor. This indicates that the heat retention heater of the present invention has excellent water resistance.

(Effects of the Invention) According to the present invention, the waterproofness is excellent by strengthening the adhesion between the cord-shaped heater and the mold rubber, which makes use of the flame retardancy and heat resistance, which are the characteristics of the fluoroelastomer-insulated corded heater. Inexpensive heat retaining heater can be obtained. Since the heat retention heater achieves a larger amount of heat generation and a high degree of flame retardancy, it can contribute to downsizing, high performance, and improved safety of equipment, which is industrially beneficial.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a partially cut-away structure showing an embodiment of a heat-resistant water-resistant heat insulating heater according to the present invention, and FIG. 2 is a partially cut-away perspective view showing an example of a cord-shaped heater used in the present invention. 1 ... core material, 2 ... resistance wire, 3 ... fluoroelastomer,
4 …… Cord heater, 5 …… Silicon rubber lead wire, 6
…… Connection terminal, 7 …… Mold rubber, 8 …… Adhesive treatment

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-13103 (JP, A) JP-A-57-179565 (JP, A) JP-A-62-58588 (JP, A) JP-A 55-17985 60208 (JP, A) JP-A-58-209083 (JP, A) JP-A-62-66603 (JP, A) JP-A-1-211883 (JP, A) Japanese Utility Model Laid-open No. 52-67660 (JP, U) Japanese Utility Model Showa 55-105298 (JP, U) Japanese Utility Model Showa 52-103786 (JP, U) Japanese Utility Model Showa 56-57496 (JP, U) Japanese Utility Model Showa 57-195794 (JP, U) Japanese Utility Model Showa 59-80990 (JP, U) JP-A 63-33594 (JP, U) JP-B 62-2407 (JP, B2) JP-B 36-7275 (JP, Y1) JP-B 50-20339 (JP, Y1) JP 474-231 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05B 3/56 H05B 3/04

Claims (3)

(57) [Claims] 1. A cord-like heater using a fluoroelastomer as an insulating covering material, a lead wire using a silicone rubber as an insulating covering material, a connection terminal for electrically connecting the cord-like heater and the lead wire, In a heat insulation heater comprising, as an essential element, a mold rubber for insulating the connection terminals, a silicone rubber is used as a mold rubber, and the cord-shaped heater is subjected to an adhesive treatment. Water resistant warming heater. 2. The method according to claim 1, wherein said bonding treatment is performed by applying an adhesive treatment agent containing at least an alkoxysilane-based or alkoxytitanium-based compound to the surface of the cord-shaped heater. The heat-resistant water-resistant warming heater described. 3. A cord-shaped heater using a fluoroelastomer as an insulating covering material, a lead wire using a silicone rubber as an insulating covering material, a connection terminal for electrically connecting the cord-shaped heater and the lead wire, A heat and water resistant heat insulating heater, wherein a mixture of a fluoroelastomer and a silicone rubber is used as a mold rubber in a heat insulating heater comprising a mold rubber for insulating the connection terminals as an essential element.