JPS61277187A - Electrically heating carpet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electric carpet in which a surface material, a planar heating element, and a back material are bonded together using a low melting point polyamide hot melt adhesive.

(Conventional technology) Conventionally, electric carpets are made by disposing heat generation wires and temperature detection wires on a backing material made of a heat insulating material such as felt or urethane foam, and then bonding a surface material on top of the backing material through a heat dissipation plate. What has been done is known.

(Utility Model Publication No. 55-18943 @ Publication) Conventionally, ethylene-based hot melt adhesives such as polyethylene and ethylene/vinyl acetate copolymer were used to bond these surface materials, heat sinks, heating elements, and back materials. Heat and pressure bonding using a plate has been used.

Until now, hard materials such as needle punch felt and French pile with relatively smooth surfaces and no cushioning properties were often used for surface layer materials, but in recent years, raised-type materials with good cushioning properties have become desirable. As a result, improvements have been made to the bonding method.

For example, JP-A-58-78382 proposes using a two-component reactive adhesive such as polyurethane, epoxy resin, or polyacrylate as the adhesive to avoid the wear and tear of the nap caused by pressure bonding.

(Problems to be Solved by the Invention) In order to obtain high adhesive strength with conventionally used olefin hot melt adhesives, it is necessary to use high temperature and high pressure bonding conditions. Therefore, even when a hard type surface material is used, there is a drawback that the heating wire may be deformed during bonding, or may be damaged in some cases, resulting in a significant drop in withstand voltage. At the same time, the temperature detection wire is also deformed, the impedance of the temperature detection wire increases, and the controlled temperature becomes higher than the set temperature, resulting in overheating.

Therefore, it was necessary to create grooves in the felt using a press or the like beforehand, and to arrange heating wires and temperature detection wires along these grooves to prevent damage during pressing. In particular, when urethane foam is used as the backing material for the purpose of softening and reducing the weight of electric heating carpets, it is difficult to process grooves, so hot melt adhesion using olefin hot melt adhesives that have been used up until now cannot be used. Adhesion has been performed using urethane-based liquid adhesives.

In order to improve these drawbacks of olefin hot melt adhesives, ethylene/vinyl acetate copolymers are added to lower the melting point. Generates a sour odor,
This significantly reduces the product value.

On the other hand, when adhesives such as polyurethane, epoxy resins, and polyacrylates are used, the adhesive adheres to the surrounding area during application, contaminating the work environment and the product, reducing the commercial value of the finished electric heating carpet. This causes a decrease in the amount of water. In addition, these adhesives remain in a liquid or highly viscous state until they are heated and cured after being applied, so a heat-pressing process must follow after the adhesive is applied, and the adhesive application process and bonding process are separated. The drawback was that it was not possible to streamline the process. Furthermore, since the urethane adhesive contains a solvent, it also has the drawback of requiring measures for sanitary work environment and fire prevention.

The present invention provides an electric heating carpet that solves these technical problems of the conventional carpet.

(Means for Solving the Problems) That is, the present invention provides an electric heating carpet formed by bonding a surface material, a sheet heating element, and a backing material. This electrically heated carpet is characterized in that one or both of the carpets are hot-melt bonded with a low melting point polyamide resin.

Surface materials in the present invention include nonwoven fabrics such as needle punch felt, French pile, etc., as well as raised knits, jagged, tufted, loop, etc. on the urethane foam surface.
A material made of moquette or other raised epidermis pasted together is used. Various types of sheet heating elements can be used, such as metal foil heaters in which heating wires and temperature detection wires are bonded to metal foil such as aluminum foil, and conductor-polymer composite sheet heating elements. . Further, as the backing material, a heat insulating material such as felt or urethane foam, or a lining bonded to these materials is used.

The low melting point polyamide resin of the present invention is a multicomponent polymer containing lauryl lactam and caprolactam as basic units, and further containing one or more polyamide forming components other than these, and has a flow initiation temperature in the range of 60 to 90°C. and has a melt viscosity of 50 to 2.5 at 120°C.
00 Pas, and has a lower melting point and a much lower melt viscosity than hot-melt multi-component copolyamide resins conventionally widely used for adhesive interlining for clothing.

Such a low melting point polyamide resin is disclosed in, for example, JP-A-59
-According to the method disclosed in Publication No. 136370,
It can be produced by condensing ε-caprolactam, ω-lauryllactam, a salt of hexamethylene diamine and dodecanoic acid, and a salt of methylpentamethylene diamine and azelaic acid.

The low melting point polyamide resin used in the present invention having a flow start temperature of 90° C. or higher is not preferable because a high temperature is required for adhesion. On the other hand, if the flow start temperature is 60° C. or lower, the adhesive strength will decrease due to the heat generated during use of the electric heating carpet, and it cannot be used. Further, a low melting point polyamide resin having a melt viscosity of 2.500 pas or more at 120° C. requires high temperature for adhesion, whereas a low melting point polyamide resin having a melt viscosity of 50 Pas or less does not provide sufficient adhesive strength.

The low melting point diamide hot melt adhesive of the present invention may be used in any of the form of sheet, net, powder, base, and solution, but from the viewpoint of the work process, it is cost effective to reduce the amount of adhesive used. From this point of view, it is desirable to use it in powder form.

In the present invention, the following various methods can be used to hot-melt bond the surface layer material, planar heating element, and back surface material using a low melting point polyamide resin.

That is, (1) the above-mentioned low melting point polyamide resin in the form of a sheet, net, powder, or solution is placed between the surface layer material and the sheet heating element and between the sheet heating element and the back surface material, and heated from above and below. A method of bonding three parts by heating and pressurizing them at once using a plate. (2) Either one of the surface material and the sheet heating element or the sheet heating element and the back surface material is hot-melted with a low melting point polyamide resin, and then the other is hot melted with a low melting point polyamide resin. How to melt glue. (3)
A method in which low-melting point polyamide resin is laminated or coated on one side of the surface material and the back material in advance, and a sheet heating element is sandwiched between the surfaces and bonded by heating and applying pressure. (4) Either one of the surface material and the planar heating element or the planar heating element and the back material is hot-melt bonded with a low-melting point polyamide resin, and the other is hot-melt bonded with a material other than the low-melting point polyamide resin. Various embodiments may be employed, such as bonding with a polyurethane adhesive, an epoxy adhesive, or a polyacrylate adhesive.

Furthermore, the present invention provides a heat equalizing plate or an insulating film between the surface material and the surface of the sheet heating element, or between the sheet heating element and the back surface material.
This includes cases where cushioning materials such as foamed polyurethane are sandwiched, and hot-melt adhesives using low-melting point polyamide resin are used to bond between these heating plates, insulating films, cushioning materials and surface materials, planar heating elements, and backing materials. Needless to say, it also includes gluing.

Embodiments of the present invention will be described below based on the drawings.

Examples 1 to 4, Comparative Examples 1 to 3 In Fig. 1, a represents urethane foam 1 and raised knit 2.
This is a surface material whose outer material is frame laminated. b
is a backing material in which a lining 4 is frame laminated to a urethane foam 3. A commercially available low melting point polyamide resin powder was sprinkled on one side of the surface material and the back material in advance and melted and fixed to create a hot melt adhesive layer C, and a heating wire 6 and a temperature detection wire 7 were arranged on the aluminum foil 5. Table 1 shows the results of heating and pressing the sheet heating element d under various bonding conditions.

The low melting point polyamide resin used was a copolymer obtained by condensing ε-caprolactam, ω-laurinlactam, a salt of hexamethylene diamine and dodecanedioic acid, and a salt of methylpentamethylene diamine and azelaic acid, and was Using an orifice of 1.0 jamφ and a load of 50 g, the temperature at the start of flow was 73° C. as measured by a temperature increase method of 3° C./min, and the melt viscosity at 120° C. was 450 Pas. For comparison, Table 1 shows the results of adhesion using commercially available polyolefin hot melt adhesive A and EVA-modified polyolefin hot melt adhesive.

It can be seen from the table that when a low melting point polyamide resin is used, high adhesive strength can be obtained under mild adhesive conditions, and an electric heating carpet with excellent performance can be obtained.

With the conventional polyolefin hot melt adhesive layer in the comparative example, sufficient adhesive strength could not be obtained unless high temperature and high pressure adhesive conditions were used, and under such adhesive conditions the temperature detection wire would be damaged and the temperature control performance and The withstand voltage becomes poor. When an EVA-modified modified polyolefin hot melt adhesive was used, the adhesive strength was low, and moreover, it gave off a sour odor when used on an electric heating carpet.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of a representative example of the electric heating carpet of the present invention used in Examples. FIG. 2 shows a cross-sectional view when needle punch felt is used as the surface layer material. a... Surface material b... Back material C... Hot melt adhesive layer d... Planar heating element 1... Urethane foam 2... Raised knit 3... Urethane foam 4...・Lining 5...Aluminum foil 6...Heating wire 7...Temperature detection wire

Claims (1)

[Claims] 1. In an electric heating carpet formed by bonding a surface material, a sheet heating element, and a backing material, one or both of the surface layer material, the sheet heating element, and the sheet heating element and the backing material are made of a low melting point polyamide. Electrically heated carpet characterized by hot melt adhesive bonding with resin. 2. The low melting point polyamide resin is a multi-component copolymer containing lauryl lactam and caprolactam as basic units and further containing one or more types of polyamide forming components other than these, and the flow start temperature is in the range of 60 to 90 ° C. Yes, and the melt viscosity at 120°C is 50 to 2,500
The electrically heated carpet according to claim 1 in the range of Pas.