JPH0660024U - Heat recovery tube - Google Patents

Abstract

(57) [Summary] [Purpose] A heat recovery tube suitable for electromagnetic wave shielding of electric wires and cables. [Structure] At least two layers of (A) a shape memory alloy layer and (B) a heat-recoverable resin layer that follows the heat recovery of the shape memory alloy. It has at least two layers of (A) a shape memory alloy layer, and (C) an elastomer layer which has no melting point and is deformed to follow the heat recovery of the shape memory alloy.
Furthermore, a hot melt adhesive was provided on the innermost layer. [Effect] The good electromagnetic wave shielding effect and the characteristics of the shape memory alloy layer having excellent mechanical strength can be used as they are, and heat recovery can be performed without causing interfacial peeling.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a heat recovery tube suitable for applications such as electromagnetic wave shielding of electric wires and cables.

[0002]

[Prior art and problems]

 In recent years, electromagnetic wave shields have become necessary as electric and electronic devices have advanced. Electromagnetic wave shield heat recovery articles are used for electromagnetic wave shielding of electric wires, cables and connection parts.

For example, a heat recovery tube composed of two layers is known as a tube-shaped electromagnetic wave shielding material. In that case, the inner layer is a resin or metal layer highly filled with carbon, and the outer layer is a heat-recoverable resin layer.

Resins highly filled with carbon are inferior in electromagnetic wave shielding effect and are hardly used. Further, in the case where a metal layer such as aluminum is provided, when the heat is recovered, it is necessary to make the metal layer as thin as possible so that the heat can be recovered.

However, although the above heat recovery article recovers heat, the metal itself does not recover heat. For example, in the case of a tube shape, many wrinkles wavy in the length direction are observed, and the mechanical strength of the metal layer is increased. Is insufficient, cracks are likely to occur, and the metal layer and the heat recovery resin layer are easily separated.

[0006]

[Means for Solving the Problems]

 As a result of various studies on the above problems, the present inventor has found that a heat-recoverable resin layer that follows heat recovery for insulation or mechanical protection of a shape-recoverable shape memory alloy layer having an electromagnetic wave shield, or / And a heat recovery tube combined with an elastomer layer that has no melting point and is deformed to follow the heat recovery of the shape memory alloy. Since the layers follow and recover heat, it was found that the shape memory alloy layer and the resin layer or the elastomer layer are not easily peeled off, and the present invention has been completed.

That is, the present invention provides a heat recovery tube having at least two layers: (A) a shape memory alloy layer, and (B) a heat recovery resin layer that follows the heat recovery of the shape memory alloy. Further, there is provided a heat recovery tube having at least two layers of (A) a shape memory alloy layer, and (C) an elastomer layer which has a melting point and is deformed to follow the heat recovery of the shape memory alloy. Another feature is that a hot melt adhesive is provided on the innermost layer.

Hereinafter, the present invention will be described in detail. The heat recovery tube of the present invention is represented by, for example, the structure shown in FIG. FIG. 1 is a schematic diagram showing a heat recovery tube 3 having a shape memory alloy layer as an inner layer 1 and an inner shape memory alloy as a outer layer 2 and a heat recoverable resin layer having a similar heat recovery temperature. Instead of the second heat-recoverable resin layer, an elastomer layer which has no melting point and is deformed to follow the heat recovery of the shape memory alloy may be provided.

Examples of the heat-recoverable resin used in the present invention include those commonly used in heat-recoverable resin layers of heat-recoverable articles, such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene. -Ethyl acrylate copolymer, polyvinylidene fluoride and the like can be mentioned.

Further, as the elastomer having no melting point and deformed to follow the heat recovery of the shape memory alloy, ethylene-propylene rubber, ethylene-propylene-diene rubber, butyl rubber, styrene-butadiene copolymer rubber Examples include rubber and polynorbornene used in molded products such as transpolyisoprene, acrylic rubber, fluororubber, and polyurethane.

In the case of this elastomer layer, the elastomer has elasticity, and is stretched and extended following the alloy layer at the time of heat recovery of the shape memory alloy, and is covered so as to wrap the alloy layer. Excellent in close contact with the object.

As described above, in the heat recovery tube of the present invention, it suffices to heat the shape memory alloy 1 and the elastomer layer naturally follows, so that the heating operation is easy. The heat-recoverable resin layer and the elastomer layer of the present invention can be blended with ordinary flame retardants, flame retardant aids, fillers, antioxidants, light stabilizers, lubricants, carbon black, pigments, etc. according to the intended use. .

As the shape memory alloy used in the present invention, for example, Ag—Cd series, Au—Cd series, Cu—Zn series, Cu—Al—Ni series, Cu—Sn series, Ni—Al series, Ti— -Ni type etc. are mentioned. In order to manufacture the heat recovery tube 3 of the present invention, first, a tube is manufactured using a shape memory alloy, and then a heat recovery resin or elastomer is extruded and coated on the tube. In the case of a heat-recoverable resin, it is convenient to prepare a heat-recovery tube by electron beam cross-linking if necessary or by preliminarily blending a cross-linking agent such as dicumylper-oxide and heating and partially cross-linking.

Furthermore, a heat recovery tube can be obtained by enlarging the inner diameter in the state of a soft martensite phase below the transformation temperature of the shape memory alloy. In the heat recovery tube thus manufactured, the shape memory alloy layer and the heat recovery resin or elastomer layer are in close contact with each other, and the mechanical strength of the shape memory alloy layer is obtained as it is.

The electromagnetic wave shielding effect of the shape memory alloy layer constituting the heat recovery tube of the present invention was measured by the KEC method (by Kansai Electronics Industry Promotion Center), and the shielding effect was recognized in the range of 10 MHz to 1000 MHz. As a result, a shield effect of 1000 dB or more was confirmed with the electric field shield. FIG. 2 is a schematic diagram showing a heat recovery tube in which the innermost layer of FIG. 1 is provided with a hot-melt adhesive layer 4 that softens at a heat recovery temperature or lower.

As the hot melt adhesive used in the present invention, for example, a vinyl acetate hot melt adhesive, a polyester hot melt adhesive, a polyamide hot melt adhesive or the like can be used.

[0017]

[Effect of device]

 By using the heat recovery tube of the present invention, the good characteristics of the shape memory alloy layer with excellent electromagnetic wave shielding effect and mechanical strength can be utilized as they are, and heat recovery can be achieved without causing interfacial peeling, especially for electric wires and cables. It is suitable for insulation coating such as.

[Brief description of drawings]

FIG. 1 is a schematic view showing a structure of a heat recovery tube having a shape memory alloy layer as an inner layer according to the present invention.

FIG. 2 is a schematic view showing a heat recovery tube in which a hot melt adhesive layer 4 that softens at a heat recovery temperature or lower is provided in the innermost layer of FIG.

[Explanation of symbols]

 1 shape memory alloy layer 2 resin layer having heat recovery property 3 heat recovery tube 4 hot melt adhesive layer

Claims (3)

[Scope of utility model registration request] 1. A heat recovery tube comprising at least two layers of (A) a shape memory alloy layer and (B) a heat recovery resin layer that follows the heat recovery of the shape memory alloy. 2. At least two layers of (A) a shape memory alloy layer, and (C) an elastomer layer which has no melting point and is deformed so as to follow the heat recovery of the shape memory alloy. Heat recovery tube. 3. The heat recovery tube according to claim 1, further comprising a hot melt adhesive provided on the innermost layer.