JPH05200863A - Heat recoverable article - Google Patents

Abstract

PURPOSE:To provide a heat recoverable article applying insulating shield to the connection part or terminal part of an electric wire or cable. CONSTITUTION:A preliminarily crosslinked tubular molded article 1 is stretched under heating to impart heat recovery properties to the tubular article 1 and a metal wire braded layer 2 or a metal foil longitudinally applied layer 4 is provided to the outer periphery of the tubular article 1 and, further, a resin outer layer 3 is applied to the outer periphery of the layer 2 or 4. The cylindrical heat recoverable article thus obtained is longitudinally split at one place in the longitudinal direction thereof. Therefore, the insulating shield effect of an electrical noise generated part is large. Especially, the longitudinally split article is improved in workability because it is unnecessary to pass an electric wire through the article before connection and the article provided with a hot-melt adhesive layer 5 as the innermost layer is prevented from the penetration of water and has excellent insulating and waterproof shield effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-recoverable article for insulating and shielding a connecting portion such as an electric wire / cable or a terminal portion.

[0002]

2. Description of the Related Art Conventionally, as a method of insulating a connecting portion or a terminal portion of an electric wire / cable, etc., a method of covering a tubular insulating sleeve, a method of wrapping an adhesive tape on the connecting portion, or a heat recovery of a split mold is used. A method of covering and shrinking the sexual article has been used.

As a split type heat-recoverable article, Japanese Patent Laid-Open No. 47-47
Those described in JP-A-4437, JP-A-52-119686 and the like are known. However, these articles are only insulating and have no electrical shielding.

For this reason, in order to have a shielding property,
A metal foil tape was wrapped around the insulating layer or covered with a metal wire braided tube for shielding. Heretofore, there has been no heat-recoverable article that has both insulating properties and shielding properties and can be coated at the same time.

[0005]

The number of lines of communication wires and cables has increased, and when used in a high frequency region, many shielded wires have come to be used because the communication lines are disturbed. However, since the shield wire is stripped off at the connecting portion and the terminal portion and the shielding effect is lost, it is desired that the insulating shield can be easily performed after connecting the conductors.

As a result of various studies on the above problems, the present invention provides
The inventors have found that the above-mentioned problems can be solved by integrally covering an insulating layer and a metal shield layer on a connection part or a terminal part of a shielded wire, and shrinking the insulation to protect the shielded wire, thereby completing the present invention. Came to do.

[0007]

Means for Solving the Problems That is, the present invention is as follows: (1) A pre-crosslinked tubular molded article is heat-stretched to impart heat recoverability, and a metal wire braid layer or a metal foil is vertically attached to the outer periphery thereof. A heat-recoverable article in which a layer is provided and the outer periphery of which is covered with a resin, and (2) the cylindrical heat-recoverable article is longitudinally split in only one place, which is characterized in (1) It is a heat-recoverable article.

Furthermore, the present invention also includes the following embodiments. Pre-crosslinked tubular molding is polyethylene,
Characterized in that ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer and the like are kneaded one or more kinds, molded, and cross-linked by ionizing radiation. The heat-recoverable article according to (1) above.

A copper wire or an aluminum wire having a wire diameter of 0.05 to 0.2 mm or a copper foil or an aluminum foil having a thickness of 15 to 40 μm is braided or longitudinally attached on a tubular molded article and integrated by heat fusion. The heat-recoverable article according to (1) above. The outer side of a metal layer made of a metal braided wire or a metal foil is covered with a resin having a higher melting point than the melting point of the constituent material of the tubular shaped product, and is integrated with the metal layer. 1) The heat-recoverable article as described above.

According to the heat-recoverable article of the present invention, in particular, the end portion of the tube molded article is brought into contact with the shield wire at the time of heat shrinkage with a little shorter length than the metal wire or the metal foil, and grounded, so that the shield effect is sufficient. Is what you get.

The present invention will be described in more detail below with reference to the drawings. 1 to 5 are schematic views showing various specific examples of the heat recovery article of the present invention. FIG. 1 is a schematic view showing a heat-recoverable article provided with a metal wire braid layer, and FIG. 2 is a schematic view showing a heat-recoverable article provided with a metal foil vertical attachment layer. In FIGS. 1 and 2, each part A is a part showing a heat recovery property after being expanded by heating,
The parts indicate the parts that have shrunk after heating.

FIG. 3 is a schematic view showing a heat-recoverable article having a hot-melt adhesive layer 5 as the innermost layer and a metal foil vertical attachment layer. FIG. 4 is a schematic diagram showing a heat-recoverable article obtained by vertically dividing the heat-recoverable article of FIG. 3 in the longitudinal direction. Figure 5
The both ends of the inner layer of the heat-recoverable article provided with the metal wire braided layer 2 of FIG. 1 are peeled off, the length of the crosslinked tubular shaped article layer 1 is short, and the metal wire braided layer 2 and the resin outer layer 3 are long. FIG. 3 is a schematic diagram showing a metal wire braided layer exposure type heat recoverable article.

The structure of the heat-recoverable article shown in FIGS. 1 to 5 is properly used depending on the intended use. FIG. 6 is a cross-sectional view showing a state where the heat recovery article of FIG. 5 is heat-coated on the shielded wire connection portion.

In FIGS. 1 to 6, reference numerals 1 and 1'represent bridge bridge tubes, 2 and 2'and 12 metal braided wires, and
3'is an outer resin layer, 4 is a metal foil, and 5 is a hot melt adhesive layer. In FIG. 6, 11 and 11 ′ are jackets, 12 is a metal braided wire, 13 is an inner jacket, and 14 is a core wire.

The crosslinked tubular shaped article (crosslinked tube) constituting the inner layer in the present invention is one which is crosslinked by irradiation of ionizing radiation such as electron beam or γ ray, or an organic peroxide or a silane compound (water crosslinked type). It is possible to use a compound obtained by kneading the above) and the like, which is molded into a tube and then crosslinked by heating or humidification.

For example, preferably polyethylene (low density, high density, etc.), polypropylene, ethylene-propylene copolymer, ethylene-propylene-conjugated diene terpolymer, ethylene-vinyl acetate copolymer, ethylene- Along with one or more olefin resins such as ethyl acrylate copolymers and ethylene-methacrylate copolymers, various additives (for example, flame retardants, antioxidants, UV stabilizers, lubricants, etc.) as needed. , A processing aid, a filler, a colorant, etc. are added and kneaded. Particularly, in the case of 1) crosslinking by electron beam irradiation, a crosslinking aid composed of a polyfunctional allyl compound such as triallyl (iso) cyanurate is suitable. Is added in advance and then subjected to extrusion molding, followed by electron beam irradiation, or 2) in the case of chemical crosslinking, organic peroxide (dicumyl peroxide) Etc.), or a silane compound, if necessary kneaded added together with the cross-linking aid, a continuous tube obtained thermal crosslinking or humidified crosslinked to.

Further, in order to impart heat recoverability, the crosslinked tube is stretched (expanded) while applying an internal pressure to obtain a heat recoverable (heat shrinkable) tubular article.

As the outer layer resin, it is possible to use the same olefin resin, thermoplastic polyester resin, nylon elastomer and the like as those used for the crosslinked tubular molded article of the inner layer. Of course, the same various additives as those used for the crosslinked tubular molded product may be blended in the outer layer resin.

As the outer layer resin, it is preferable to use a material having a melting point slightly higher than the melting point of the resin for the crosslinked tube of the inner layer. The reason is that the inner layer recovers heat near the melting point (heat shrinkage).
This is because when this is attempted, the outer layer does not flow too much and is fixed integrally with the metal wire braided layer or the vertical attachment layer of the metal foil so that the inner layer can be uniformly heat-shrunk.

Therefore, in order to prevent the fluidity of the resin outer layer 3 to some extent, it is preferable that the polyolefin resin or the like having a relatively low melting point is slightly crosslinked to prevent the fluidity. However, it is not preferable that the outer layer resin has a too high melting point to make it difficult to flow or that it crosslinks too much to make it difficult to flow. The resin for the outer layer is preferably one that flows at a temperature higher than that of the resin for the inner layer by about 10 to 50 ° C., preferably about 20 to 40 ° C.

On the other hand, in order to integrate the resin constituting the outer layer and the metal wire braiding layer or the vertical attachment layer of the metal foil with the inner layer,
It is desirable to set in advance on the inner surface of the pipe made of a large metal or the like according to the expansion ratio for imparting the heat shrinkability of the crosslinked tube inner layer 1.

The inner surface of the outer layer resin is 0.05 to 0.2 m
A metal wire braiding layer 2 in which copper or aluminum wire having a wire diameter of about m is braided or an alloy wire thereof is provided, or 15
A metal layer 4 having a thickness of up to 30 μm, such as copper or aluminum, or a metal layer in which a metal composite foil obtained by vapor-depositing the above metals is vertically provided on one or both sides of a plastic tape is provided.

Instead of the above-mentioned metal braid layer, a horizontally wound layer of metal wire can be used equally. In this case, if the diameter of the metal wire is too thin, less than 0.05 mm, or if the thickness of the metal foil is too thin, less than 15 μm, the inner layer of the crosslinked tube may break or shift during heat recovery (heat shrinkage). This is not preferable, and the wire diameter of the metal wire is 0.
If the thickness exceeds 2 mm and is too thick, or if the metal foil exceeds 30 μm and is too thick, the heat recovery of the inner layer of the crosslinked tube is impaired, which is not preferable.

Since the outer layer resin 3 and the metal layers 2 and 4 do not have a memory effect, it is necessary to integrate them with the crosslinked tubular shaped article 1 which constitutes the inner layer. As a method of integrating, for example, in order to obtain a heat-recoverable article having a double diameter, first, the outer layer resin 3 and the metal foils 2 and 4 are set inside the metal pipe having twice the outer diameter of the cross-linked tubular molded product. .. Then, the cross-linked tubular shaped article 1 is loaded into the metal pipe while being heated to a temperature equal to or higher than the melting point, and internal pressure is applied to the tube to fuse the metal foil and the outer layer resin and cool them to integrate them.

The shrinkage ratio of the heat-recoverable article is determined by the ratio of the original size of the crosslinked tubular shaped product to the size of the metal pipe for integration, and the metal pipe must be thicker to increase the shrinkage. Just do it. However, in the present invention, it is not preferable that the expansion ratio is too large, and 3.0 times or less is preferable. The reason for this is that there is a limit to the deformation followability of the metal braided wire and the metal foil. The metal braided wire is pulled inward by the contraction of the inner layer of the crosslinked tube,
It exhibits the property of becoming longer in the length direction, and when the metal foil is pulled inward, wrinkles are formed in the length direction and the inner diameter is reduced. For this reason, the heat is recovered while keeping the metal layer.

The tubular heat-recoverable article obtained in the present invention can be used by longitudinally dividing it in the longitudinal direction. When the tubular heat-recoverable article cannot be previously passed through the wire connection portion or the like, the tube-like heat-recoverable article is cut in half along the length direction as shown in FIG. However, it is convenient to use a split type.

In the split mold, the inner layer side is shrunk by being fitted into the connecting portion later and shrinking by heating, so that the connecting portion is covered in a spiral shape. At this time, if the shrinkage ratio is set too large, the connecting portion will be exposed, so it is necessary to consider the size of the coating material and select a tube size that allows the wrap portion to remain even after complete shrinkage.

It is preferable that the length of the lap after the complete contraction is 1/4 or more of the tube diameter. This is necessary in terms of electrical insulation and waterproofness when an adhesive, particularly the hot melt adhesive layer 5, is applied to the innermost layer.

The heat-recoverable article of the present invention is useful not only as an insulating shield but also as a heat-recoverable article having a waterproof and anticorrosion function by providing a hot melt adhesive layer on the innermost layer.

Examples of the hot-melt adhesive include polyolefin-based hot-melt adhesives such as ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer; and tackifiers such as butyl rubber and styrene-isoprene copolymer rubber. A polyester-based or polyamide-based hot melt adhesive or the like may be used. Further, various compounding agents such as a lubricant, an antioxidant and a flame retardant can be added to the hot melt adhesive.

The hot-melt adhesive layer 5 is formed by means such as normal application or spraying or lamination of sheet-like hot-melt adhesives so as to have a thickness of about 0.2 to 2.0 mm depending on its application. The application of the hot-melt adhesive layer 5 to the heat-recoverable article can be carried out at the same time as the integration of the resin inner layer, the metal layer and the resin outer layer or after that, as appropriate.

After producing a long product as the heat-recoverable article of the present invention, it may be cut into several centimeters to several tens of centimeters, if necessary. In this case, it is convenient to solder the copper stranded wire to the metal foil or the metal braided wire after cutting in order to easily ground the metal layer. The heat-recoverable article of the present invention is
(EN) Provided is a heat-recoverable article having an unprecedented electric shield effect, electric insulation, waterproof / corrosion-proof, and connection workability by a split mold.

[0033]

EXAMPLES The present invention will be specifically described by the following examples, which do not limit the scope of the present invention. (Example 1) A low-density polyethylene tube having a wall thickness of 0.3 mm (outer diameter 14 mm, inner diameter 13.4 mm) was inserted into an aluminum metal pipe having an inner diameter of 15 mm, and then a punch hole having a diameter of 2 mm was punched in an aluminum foil having a thickness of 20 mm. 10
Those opened at mm intervals are vertically attached to the inner surface of the tube.

Separately, an ethylene-vinyl acetate copolymer having a wall thickness of 2.0 mm was formed into a tube shape having an outer diameter of 9 mm and an inner diameter of 5 mm, and this was irradiated with an electron beam of 12 Mrad to form a crosslinked tube having a crosslinked gel fraction of 55%. A shaped article is obtained. This is inserted into the inside of the aluminum foil and pressurized and expanded while feeding heated high pressure air into the crosslinked ethylene-vinyl acetate copolymer tube, and fused and integrated with the aluminum foil and the low density polyethylene tube. At this time, the temperature and the pressure were 150 ° C. and 2.0 kg / cm ² , respectively, and they were completely integrated, and then pressure-cooled as it was to obtain a heat-recoverable article.

(Example 2) A 0.5 mm thick thermoplastic polyurethane resin tube (outer diameter 14 mm, inner diameter 13 mm) was inserted into an aluminum metal pipe having an inner diameter of 15 mm, and thereafter. A braided tube formed by braiding 12 mm copper wire is vertically attached to the inner surface of the tube.

Separately, a high-density polyethylene having a wall thickness of 2.0 mm and an ethylene-methyl methacrylate copolymer were mixed with each other.
9: O.D., 5: O.D.
18mm for electron beam
Ad irradiation is performed to obtain a crosslinked tubular shaped product having a crosslinked gel fraction of 58%.

This is inserted into the copper braided tube, pressurized and expanded while feeding heated high pressure air into the crosslinked tubular shaped article, and fused and integrated with the copper braided tube and the polyurethane resin tube. The temperature and the pressure at this time were 170 ° C. and 3.0 kg / cm ² , respectively, and they were completely integrated, and then pressure-cooled as it was to obtain a heat-recoverable article.

In the same manner, the combination of various materials shown in Tables 1 and 2 was carried out to obtain a heat recoverable article. The obtained heat-recoverable article was heat-shrinked at the connection portion of the polyethylene insulated shield wire having a sheath outer diameter of 9 mm, and the shield property was evaluated.

After the conductor is connected to the shielded wire, the end of the shielded wire is bent to the outside of the shield, and the heat-recoverable article obtained in the example is cut into a length of 60 mm. Each of them was stripped by 10 mm and connected to a ground wire so that it could come into contact with the wire shield wire. The heat-recoverable article was heated and shrunk by a hot-air dryer to simultaneously insulate the conductor connecting portion and connect the shield wire.

In order to evaluate the shield characteristics of the obtained connection portion, a signal was passed through the signal line at 0 to 1,000 MHz and the amount of noise generated was examined. For comparison, a heat-recoverable article made of the same material as the example and containing no metal foil or metal wire was heat-shrinked, and the amount of noise generated was examined. The results are shown in Tables 1-2.
Shown in.

[0041]

[Table 1]

[0042]

[Table 2]

(Note) LD / PE: low density polyethylene (manufactured by Sumitomo Chemical Co., Ltd.,
Trade name Sumikasen L705) Polyurethane: Dainippon Ink and Co., Ltd., trade name Pandex T5169 Polyester: Toray Dupont Co., Ltd. Trade name Hytrel 4057 EVA: Ethylene-vinyl acetate copolymer (Sumitomo Chemical Co., Ltd., Trade name Evatate D3022) HD / PE: high-density polyethylene (manufactured by Showa Denko KK,
Product name: Shorex C4502)

EMA: Ethylene-methyl methacrylate copolymer (Sumitomo Chemical Co., Ltd., trade name Acryft
WD301) EEA: ethylene-ethyl acrylate copolymer (manufactured by Nippon Unica Co., Ltd., trade name 6182) * 1) Vertical split type

The heat-recoverable articles obtained by the present invention are 20 to 20.
A noise level reduction of 30 dB was observed, and it was found that the shield effect was very large. On the other hand, in the comparative example, even if the shielded wire is used as the electric wire, the connection part is not shielded, so that noise is almost always recognized at the same level as the unprocessed shielded wire due to noise generation from here. There wasn't.

[0046]

As described above, the heat-recoverable article of the present invention has a very large effect of insulating and shielding the electric noise-generating portion. In addition, as a result of performing the same test for the vertically-separated tubular heat-recoverable article and the heat-recoverable article provided with the adhesive layer in the innermost layer, the vertically-separated tubular heat-recoverable article is preliminarily connected before the wire connection. It has good workability without passing through it, and the heat-recoverable article with the hot-melt adhesive layer as the innermost layer does not have water ingress in the waterproof test after the shield test, and has insulation, waterproof, and shield effects. Was demonstrated.

[Brief description of drawings]

FIG. 1 is a schematic view showing a heat-recoverable article containing a metal wire braid according to the present invention.

FIG. 2 is a schematic view showing a heat-recoverable article containing a metal foil according to the present invention.

FIG. 3 is a schematic view showing a heat-recoverable article in which a hot melt adhesive layer 5 is applied to the innermost layer according to the present invention.

FIG. 4 is a schematic view showing a heat-recoverable article according to the present invention, which is longitudinally divided.

FIG. 5 is a schematic diagram showing a heat-recoverable article in which the cross-linked tubular shaped material layer 1 has a short length, and the metal layers 2, 4 and the resin outer layer 3 have a long length.

FIG. 6 shows a state diagram in which a heat recovery article according to the present invention is coated on a shielded electric wire.

[Explanation of symbols]

 1, 1'Crosslinked tube 2, 2 ', 12 Metal braided wire 3, 3'Resin outer layer 4 Metal foil 5 Hot melt adhesive layer 11, 11' Outer sheath 13 Inner sheath 14 Core wire

[Procedure amendment]

[Submission date] December 1, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Added

[Correction content]

[Figure 6]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H01R 4/72 4229-5E // H01B 17/64 8410-5G B29K 105: 02 B29L 9:00 4F 23:22 4F

Claims (2)

[Claims] 1. A preliminarily cross-linked tubular molded article is heat-stretched to impart heat recoverability, a metal wire braided layer or a vertical attachment layer of a metal foil is provided on the outer periphery thereof, and the outer periphery thereof is further coated with a resin. A heat-recoverable article characterized. 2. The heat-recoverable article according to claim 1, wherein the cylindrical heat-recoverable article is longitudinally split at only one location in the lengthwise direction.