JPH0436003Y2

JPH0436003Y2 -

Info

Publication number: JPH0436003Y2
Application number: JP1986150646U
Authority: JP
Priority date: 1986-10-02
Filing date: 1986-10-02
Publication date: 1992-08-26
Also published as: JPS6358411U

Description

[Detailed explanation of the idea]

＜産業上の利用分野＞本考案は水密性に優れ、特に電線の外皮を剥い
て導線を露出させる際の剥離性に優れた水密型ビ
ニル絶縁電線に関するものである。〈従来の技術〉水密型屋外用ビニル絶縁電線（OW−Ｗ）は銅
線を軟質ポリ塩化ビニル（以下PVCと略称する）
の外皮で被覆し、銅線と外皮の間隙に水密充填剤
を充填している。この水密充填剤は疎水性である必要があること
は勿論であるが、絶縁外皮であるPVCとの密着
性が高く、かつ銅、あるいはアルミ等の金属との
密着力も大きいことが要求される。従来から、この要求性能を満足するものとして
エチレン／酢酸ビニル共重合体（以下EVAと略
称する）、特に酢酸ビニル含量の高いEVAが用い
られていた。〈考案が解決しようとする問題点〉このように、従来から水密型ビニル絶縁電線の
水密充填剤にはEVAが用いられてきたが、電線
の絶縁外皮である軟質PVCには必ずジオクチル
フタレート，ジイソデシルフタレート等の可塑剤
が混練されており、この可塑剤は酢酸ビニルとも
親和性があるため、PVCから隣接するEVAへ移
行するのである。この現象は特に酢酸ビニル成分の多いEVAに
おいて著しく、酢酸ビニルを40％以上共重合した
EVAにおいては極めて著しい。その結果、可塑剤がEVAを軟化させ、絶縁体
（水密充填剤と外皮）と金属導体との剥離性が悪
くなる。つまり、電線は端部接続部において、外
皮を剥いで銅線を露出させる必要があるが、この
とき、軟化したEVAが銅線の表面に残つてしま
うのである。また、可塑剤がEVA側に移行するため、PVC
中の可塑剤が減り、外皮にクラツクが入る等の欠
点があつた。更に、軟化したEVAは流動性を有し、電線の
端部から滲み出す不都合もあつた。本考案はかかる従来の水密型ビニル絶縁電線の
欠点を解消すべく検討の結果、得られたものであ
る。したがつて、本考案の目的はPVC中の可塑剤
が水密充填剤へ移行することを防ぎ、その結果、
剥離性、外皮の耐久性、水密性に優れた水密型ビ
ニル絶縁電線を提供することにある。〈問題点を解決するための手段〉上記目的を達成するため、本考案の水密型ビニ
ル絶縁電線は、金属線状導体とこれを被覆するポ
リ塩化ビニルの外皮との間に水密充填剤を充填し
た絶縁電線において、該水密充填剤として、Ａ酢酸ビニル単位含量40重量％以下のエチレ
ン／酢酸ビニル共重合体100重量部と、Ｂ −COOH，−SO₃Ｈ，−SH，＝Ｏ，−COOM
（Ｍは金属）から選ばれる少なくとも一種の極
性基を有するオレフイン系重合体または共重合
体（ただしエチレン／酢酸ビニル共重合体を除
く）５〜500重量部とを配合した混和物を用いたことを特徴とする。以下、図面を参照しつつ、本考案を具体的に説
明する。第１図および第２図は本考案の実施例を示す図
であり、第１図は斜視図、第２図は断面図であ
る。水密型ビニル絶縁電線１は金属撚線導体２を
PVCの外皮３で被覆し、その間隙に水密充填剤
４が充填されている。金属撚線導体２は通常、銅線であるがアルミ
線、あるいは他の電気伝導性金属線でも良い。外皮３は軟質PVCであり、PVCにはジオクチ
ルフタレート，ジイソデシルフタレート，ジー２
−エチルヘキシルフタレート，ジブチルフタレー
ト等のフタル酸系可塑剤、あるいはその他、脂肪
酸系，リン酸系，アジピン酸系等の可塑剤が含ま
れている。水密充填剤４はEVAと他の極性基含有重合体
との混和物であり、EVA中の酢酸ビニル共重合
量は40重量％以下、特に好ましくは35重量％以下
である。 EVA以外の極性基含有重合体は、−COOH，−
SO₃Ｈ，−OH，＝Ｏ，−COOM（Ｍは金属である
Zn，Na等を示す）等の極性基を有するモノマー
の重合体あるいは共重合体であり、たとえばアク
リル酸変性ポリオレフイン，無水マレイン酸変性
ポリオレフイン，アクリル酸金属塩変性ポリオレ
フイン（アイオノマー）等が好しい例である。 EVAと上記極性ポリマーとの混合割合は
EVA100重量部に対して極性ポリマ５〜50重量部
である。〈作用〉本考案における水密充填剤はEVAと他の極性
基含有重合体との混和物を用いている。 EVAは酢酸ビニルの存在により、金属とPVC
との両方に対して密着力を有しているが、PVC
からの可塑剤の移行が起こるので、この酢酸ビニ
ル量を減少させた。ただ、酢酸ビニルの量が減少すると金属および
PVCとの密着力が低下するので、これを補なう
ため、他の極性基を導入したものである。 EVA以外の極性ポリマーは、なぜ可塑剤を吸
収しないのかは定かでないが、そうすることによ
り、金属とPVCへの密着力を保持したまま、可
塑剤の移行を防止できるのである。〈実施例〉実施例１，２および比較例１水密充填剤として次の材料を用意した。（実施例１）Ａ：酢酸ビニル含有率28重量％，メルトフロー
レート（MFR）150g／10分のEVA（三井デユポ
ンポリケミカル社製、EV−220）80重量部とカル
ボン酸変性ポリエチレン系樹脂（同社製HPR
VR−101）20重量部との混和物。（実施例２）Ｂ：酢酸ビニル含有率33重量％，MFR＝31g／
10分のEVA（同社製EV−150）80重量部と上記
HPR VR−101 20重量部との配合物。（比較例１）Ｃ：酢酸ビニル含有率41重量％，MFR＝65g／
10分のEVA（同社製EV−40X）。これらＡ〜Ｃの充填剤を用いて次の試験を行な
つた。（密着性試験）第３図に示すように幅25mmの銅版５の上にシー
ト状充填剤６を重ね、その上に軟質PVCを重ね
て170°Cの電気プレスで圧着し、これを矢印Ａ方
向に剥離するときの力を測定した。（可塑剤移行率）断面60mm²の第１図及び第２図で示す水密型ビニ
ル絶縁電線に充填剤Ａ〜Ｃを使用し、60°Cで200
時間保持した。加熱前と後のPVC中の可塑剤の量を抽出する
ことにより可塑剤の減少率を求め、これを可塑剤
移行率とした。（電線剥離性）断面60mm²の第１図及び第２図で示す水密型ビニ
ル絶縁電線に充填剤Ａ〜Ｃを使用し、60°Cで200
時間保持した。加熱前と後の、電線皮剥ぎ器および電工ナイフ
で外皮を剥離したときの充填剤の導体上への残り
具合を調べた。これらの結果を第１表に示す。 <Industrial Field of Application> The present invention relates to a watertight vinyl insulated electric wire that is excellent in watertightness, particularly in peelability when peeling off the outer sheath of the electric wire to expose the conductor. <Conventional technology> Watertight outdoor vinyl insulated wire (OW-W) uses soft polyvinyl chloride (hereinafter abbreviated as PVC) instead of copper wire.
The gap between the copper wire and the sheath is filled with a watertight filler. Of course, this watertight filler needs to be hydrophobic, but it is also required to have high adhesion to PVC, which is the insulating outer cover, and also high adhesion to metals such as copper or aluminum. Conventionally, ethylene/vinyl acetate copolymer (hereinafter abbreviated as EVA), particularly EVA with a high vinyl acetate content, has been used as a material that satisfies this required performance. <Problems to be solved by the invention> As described above, EVA has traditionally been used as the watertight filler for watertight vinyl-insulated wires, but the soft PVC that is the insulation sheath of the wires always contains dioctyl phthalate and diisodecyl. A plasticizer such as phthalate is mixed in, and this plasticizer has an affinity for vinyl acetate, so it migrates from PVC to the adjacent EVA. This phenomenon is particularly noticeable in EVA, which has a high vinyl acetate content, and is particularly noticeable in EVA that contains more than 40% vinyl acetate.
It is extremely noticeable in EVA. As a result, the plasticizer softens the EVA, making it difficult to separate the insulator (watertight filler and outer skin) from the metal conductor. In other words, it is necessary to peel off the outer sheath to expose the copper wire at the end connection part of the wire, but at this time, softened EVA remains on the surface of the copper wire. In addition, since the plasticizer migrates to the EVA side, PVC
There were disadvantages such as the amount of plasticizer inside decreased and cracks appearing on the outer shell. Furthermore, the softened EVA has fluidity and has the disadvantage of seeping out from the ends of the wires. The present invention was developed as a result of studies aimed at eliminating the drawbacks of such conventional watertight vinyl insulated wires. Therefore, the purpose of the present invention is to prevent the plasticizer in PVC from migrating to the watertight filler, and as a result,
The purpose of the present invention is to provide a watertight vinyl insulated electric wire with excellent peelability, durability of the outer sheath, and watertightness. <Means for solving the problem> In order to achieve the above object, the watertight vinyl insulated electric wire of the present invention has a watertight filler filled between the metal wire conductor and the polyvinyl chloride sheath covering it. In the insulated wire, the watertight filler contains A. 100 parts by weight of an ethylene/vinyl acetate copolymer having a vinyl acetate unit content of 40% by weight or less; B -COOH, -SO ₃ H, -SH, =O, -COOM
A mixture containing 5 to 500 parts by weight of an olefinic polymer or copolymer (excluding ethylene/vinyl acetate copolymer) having at least one polar group selected from (M is a metal) is used. It is characterized by Hereinafter, the present invention will be specifically explained with reference to the drawings. 1 and 2 are views showing an embodiment of the present invention, with FIG. 1 being a perspective view and FIG. 2 being a sectional view. Watertight vinyl insulated wire 1 has metal stranded conductor 2
It is covered with a PVC outer skin 3, and the gap therebetween is filled with a watertight filler 4. The stranded metal conductor 2 is typically a copper wire, but may also be an aluminum wire or other electrically conductive metal wire. The outer skin 3 is soft PVC, and the PVC contains dioctyl phthalate, diisodecyl phthalate, and di-2.
- Contains phthalic acid plasticizers such as ethylhexyl phthalate and dibutyl phthalate, and other plasticizers such as fatty acid, phosphoric acid, and adipic acid. The watertight filler 4 is a mixture of EVA and another polar group-containing polymer, and the amount of vinyl acetate copolymerized in EVA is 40% by weight or less, particularly preferably 35% by weight or less. Polar group-containing polymers other than EVA are -COOH, -
SO ₃ H, -OH, =O, -COOM (M is metal
It is a polymer or copolymer of a monomer having a polar group such as Zn, Na, etc.), and preferable examples include acrylic acid-modified polyolefin, maleic anhydride-modified polyolefin, and acrylic acid metal salt-modified polyolefin (ionomer). It is. The mixing ratio of EVA and the above polar polymer is
The amount of polar polymer is 5 to 50 parts by weight per 100 parts by weight of EVA. <Function> The watertight filler in the present invention uses a mixture of EVA and other polar group-containing polymers. EVA is metal and PVC due to the presence of vinyl acetate.
It has adhesion to both PVC and PVC.
The amount of vinyl acetate was reduced because migration of plasticizer from the plasticizer occurred. However, when the amount of vinyl acetate decreases, metals and
Since the adhesive strength with PVC decreases, other polar groups are introduced to compensate for this. It is unclear why polar polymers other than EVA do not absorb plasticizers, but by doing so, they can prevent plasticizer migration while maintaining adhesion to metal and PVC. <Example> Examples 1 and 2 and Comparative Example 1 The following materials were prepared as watertight fillers. (Example 1) A: 80 parts by weight of EVA (manufactured by Mitsui DuPont Polychemicals, EV-220) with a vinyl acetate content of 28% by weight and a melt flow rate (MFR) of 150g/10 minutes and a carboxylic acid-modified polyethylene resin ( HPR manufactured by the company
VR-101) 20 parts by weight. (Example 2) B: Vinyl acetate content 33% by weight, MFR = 31g/
80 parts by weight of 10-minute EVA (EV-150 manufactured by the same company) and the above
Blend with 20 parts by weight of HPR VR-101. (Comparative example 1) C: Vinyl acetate content 41% by weight, MFR = 65g/
10 minute EVA (EV-40X made by the company). The following tests were conducted using these fillers A to C. (Adhesion test) As shown in Fig. 3, a sheet-like filler 6 is layered on a copper plate 5 with a width of 25 mm, and soft PVC is layered on top of it and crimped with an electric press at 170°C. The force when peeling in the direction was measured. (Plasticizer migration rate) Fillers A to C were used in watertight vinyl insulated wires with a cross section of 60 mm ² as shown in Figures 1 and 2, and
Holds time. The reduction rate of plasticizer was determined by extracting the amount of plasticizer in PVC before and after heating, and this was taken as the plasticizer transfer rate. (Wire peelability) Fillers A to C were used on watertight vinyl insulated wires with a cross section of 60 mm ² as shown in Figures 1 and 2, and the wires were peeled for 200 min at 60°C.
Holds time. The degree to which the filler remained on the conductor was examined before and after heating, when the outer sheath was peeled off using a wire stripper and an electrician's knife. These results are shown in Table 1.

【表】〈考案の効果〉本考案の水密型ビニル絶縁電線は次の効果を発
揮する。 (1) 可塑剤が外皮から充填剤へ移行して、充填剤
が軟化しないので、電線の絶縁体剥離性が永久
的に良好である。 (2) 外皮中の可塑剤が減少しないので、永久的に
物性低下が起こらない。 (3) 充填剤が軟化して、端部から滲み出ることが
ない。[Table] <Effects of the invention> The watertight vinyl insulated electric wire of the invention exhibits the following effects. (1) Since the plasticizer migrates from the outer sheath to the filler and the filler does not soften, the wire's insulation removability is permanently good. (2) Since the plasticizer in the outer skin does not decrease, there is no permanent deterioration of physical properties. (3) The filler will not soften and ooze out from the edges.

[Brief explanation of drawings]

第１図および第２図は本考案の実施例を示し、
第１図は斜視図、第２図は断面図であり、第３図
は密着力試験を説明する説明図である。１……水密型ビニル絶縁電線、２……導体、３
……外皮、４……水密充填剤。 1 and 2 show an embodiment of the present invention,
FIG. 1 is a perspective view, FIG. 2 is a sectional view, and FIG. 3 is an explanatory diagram for explaining an adhesion test. 1...Watertight vinyl insulated wire, 2...Conductor, 3
...Outer skin, 4...Watertight filler.

Claims

[Scope of Claim for Utility Model Registration] In an insulated wire in which a watertight filler is filled between a metal wire conductor and a polyvinyl chloride sheath covering it, as the watertight filler, A. Vinyl acetate unit content: 40% by weight 100 parts by weight of the following ethylene/vinyl acetate copolymer and B -COOH, -SO ₃ H, -SH, =O, -COOM
A mixture containing 5 to 50 parts by weight of an olefinic polymer or copolymer (excluding ethylene/vinyl acetate copolymer) having at least one polar group selected from (M is metal) is used. A watertight vinyl insulated wire featuring: