JPS6145329B2 - - Google Patents
Info
- Publication number
- JPS6145329B2 JPS6145329B2 JP13472482A JP13472482A JPS6145329B2 JP S6145329 B2 JPS6145329 B2 JP S6145329B2 JP 13472482 A JP13472482 A JP 13472482A JP 13472482 A JP13472482 A JP 13472482A JP S6145329 B2 JPS6145329 B2 JP S6145329B2
- Authority
- JP
- Japan
- Prior art keywords
- paper
- kraft
- polypropylene
- strength
- insulating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000000123 paper Substances 0.000 claims description 51
- 239000002655 kraft paper Substances 0.000 claims description 31
- 239000004743 Polypropylene Substances 0.000 claims description 28
- -1 polypropylene Polymers 0.000 claims description 28
- 229920001155 polypropylene Polymers 0.000 claims description 28
- 230000001070 adhesive effect Effects 0.000 claims description 11
- 239000000853 adhesive Substances 0.000 claims description 10
- 239000011347 resin Substances 0.000 claims description 10
- 229920005989 resin Polymers 0.000 claims description 10
- 239000011230 binding agent Substances 0.000 claims description 4
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 11
- 238000010292 electrical insulation Methods 0.000 description 7
- 239000000835 fiber Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000001125 extrusion Methods 0.000 description 5
- 229920000098 polyolefin Polymers 0.000 description 5
- 238000010009 beating Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 239000011810 insulating material Substances 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000000576 coating method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Laminated Bodies (AREA)
- Paper (AREA)
- Insulating Bodies (AREA)
Description
本発明は誘電特性、耐電圧特性および機械的特
性、とりわけ接着強度のすぐれた電気絶縁用ポリ
プロピレンラミネート紙に関するものである。
最近、電力需要の増大により電力機器は益々高
電圧化の趨勢にある。そしてそれに応ずる絶縁材
料としてポリプロピレンの溶融押出しによつて複
数枚の絶縁紙を複合一体化させた電気絶縁用ポリ
プロピレンラミネート紙が実用化されつつある。
この電気絶縁用ラミネート紙には繊維紙として
機械的強度のすぐれたクラフト絶縁紙が一般に使
用されている。しかしながら、クラフト絶縁紙は
熱可溶性ではないため、ポリプロピレン樹脂を溶
融押出しした時の温度では融合せず、また化学接
着性もない。そのためクラフト絶縁紙層との接着
は高温度でのポリプロピレン樹脂が紙表面の微細
な凹部に侵入したことによる、いわゆるアンカー
効果で保持されているにすぎない。そのためにケ
ーブル等に利用される過程で剥離現象を生じトラ
ブルの原因になりやすい。
そこでその剥離現象を防止するために、包装材
料等で提案されているイソシアネートのようなア
ンカーコート剤をクラフト紙表面に塗工する技術
の利用が考えられる。しかしこのアンカーコート
剤は極性物質であるため電気絶縁用ラミネート紙
の誘電特性を悪化させる欠点があり、低誘電正接
を要求される高電圧機器用絶縁材料としては不適
当である。この点特開昭55−60215で提案されて
いるポリオレフイン繊維とクラフトパルプとの混
抄紙とポリオレフインフイルムとを熱融着させて
電気絶縁用ラミネート紙を形成する方法は、前記
アンカーコート剤を使用する場合のように誘電特
性を悪化させることなく接着強度を向上させるこ
とができる点ですぐれた方法といえる。しかし、
この方法はポリオレフイン繊維50重量％までの混
合を許容する混抄紙と別途作成したポリオレフイ
ンフイルムとを熱カレンダー等により熱融着させ
ることに要点が置かれていることから、ポリオレ
フイン繊維の融点以上の温度下で熱圧加工が行わ
れ、そのためクラフトパルプから熱分解ガスが発
生し、そのガスが軟化したフイルム中に圧入され
てボイドを生じ耐圧が極端に低下する恐れがあ
る。一方、ポリプロピレン樹脂の溶融押出しによ
り、繊維紙同志を複合一体化させる電気絶縁用ラ
ミネート紙においては、すでに100％ポリプロピ
レン繊維紙（不織布）を使用することが提案され
ている（特公昭52−39932）。この場合は熱圧加工
法と比較して過酷でなく、またクラフト絶縁紙同
志を貼り合わせたものと比較して誘電特性が向上
するだけでなく剥離強度も強いことが認められ
る。しかしポリプロピレン繊維紙が多孔質である
ことに基因してインパルス破壊強度の低下をもた
らすと共に引張り強さやヤング率などの機械的特
性をも低下させる難点がある。
本発明者らは、上記先例に鑑みてポリプロピレ
ン樹脂の溶触押出し法によりクラフト絶縁紙をラ
ミネートした場合、該クラフト絶縁紙の気密度を
従来のものよりも低下させることにより、実用上
充分な接着強度を有するポリプロピレンラミネー
ト紙が得られることを見出した。またこの気密度
をある程度以上に保つことにより、インパルス破
壊強度あるいは機械的な強度も、従来の高気密度
のクラフト絶縁紙を使用したものと比較して全く
低下しないことを知見した。本発明はこの知見に
基づくものであり、すぐれた電気特性と実用上要
求される機械的特性を充足させた電気絶縁ポリプ
ロピレンラミネート紙を提供するものである。
すなわち、本発明は複数枚のクラフト絶縁紙を
ポリプロピレン樹脂を結合剤として押出機で溶融
押出ししながら一体化させてなる電気絶縁用ポリ
プロピレンラミネート紙において、前記クラフト
絶縁紙の気密度が、ガーレー秒単位で20以上4000
以下とすることを特徴とする。
本発明においてクラフト絶縁紙に使用するクラ
フトパルプは市販の電気絶縁用クラフトパルプ
（JIS Ｃ 2307）で差しつかえないが、充分に純
水洗滌して用いることが望ましい。
気密度の下限を20ガーレー秒と規定したのは、
この数値以下になると、目的とする接着強度は向
上するが、インパルス破壊強度の低下が著しくな
る為である。また気密度の上限を400ガーレー秒
としたのは、これ以上になると、目的とする接着
強度の向上が望めないためである。公知のよう
に、クラフト絶縁紙の場合には、気密度とインパ
ルス破壊強度の間には密接な関係があり、したが
つて、クラフト絶縁紙単体の場合には、超高圧ケ
ーブル絶縁用に使用するためには気密度を出来る
だけ上げて3000ガーレー秒以上にすることが望し
い。しかしながら、本発明者らは、ポリプロピレ
ンラミネート紙の場合には電気的ストレスに対す
る耐性が、クラフト絶縁紙層間に含まれるポリプ
ロピレンフイルム層によつてある程度カバーされ
るために気密度をかなり低下させても、ラミネー
ト紙全体のインパルス破壊強度は余り低下しない
ことを見出した。
本発明の如く、低気密度のクラフト絶縁紙を得
るためには、従来のポリプロピレンラミネート紙
用電気絶縁クラフト紙にくらべて叩解度を低めて
抄紙すれば良い。
以下、実施例について説明する。
実施例および比較例
長網多筒式抄紙機により電導度３μS/cmのイ
オン交換水を用い、絶縁紙用クラフトパルプの叩
解度を変化させることにより、電気密度を変化さ
せた坪量約40ｇ/m2のクラフト絶縁紙を抄紙し
た。
次にこれらクラフト絶縁紙をポリプロピレンエ
クストルージヨンプロセスにより第１図に示す如
く、溶融ポリプロピレンを結合剤としてラミネー
トした。この時の結合剤となるポリプロピレン層
は約100μｍになるように調製し、ラミネート後
の厚さが170μｍになるようにした。第１表にそ
の結果を示した。
The present invention relates to polypropylene laminated paper for electrical insulation, which has excellent dielectric properties, dielectric strength properties, and mechanical properties, especially adhesive strength. Recently, due to the increase in demand for electric power, there has been a trend toward higher voltage power equipment. As an insulating material corresponding to this, polypropylene laminate paper for electrical insulation, which is made by compositely integrating a plurality of sheets of insulating paper by melt extrusion of polypropylene, is being put into practical use. Kraft insulating paper, which has excellent mechanical strength, is generally used as fiber paper for this electrically insulating laminated paper. However, since kraft insulating paper is not thermosoluble, it does not fuse at the temperature at which polypropylene resin is melt extruded, and it does not have chemical adhesive properties. Therefore, the adhesion to the kraft insulating paper layer is maintained only by the so-called anchor effect, which is caused by the polypropylene resin entering the minute recesses on the paper surface at high temperatures. Therefore, during the process of being used in cables, etc., peeling occurs, which tends to cause trouble. Therefore, in order to prevent this peeling phenomenon, it is possible to use a technique of coating the surface of kraft paper with an anchor coating agent such as isocyanate, which has been proposed for packaging materials. However, since this anchor coating agent is a polar substance, it has the disadvantage of deteriorating the dielectric properties of electrically insulating laminated paper, making it unsuitable as an insulating material for high-voltage equipment that requires a low dielectric loss tangent. In this regard, the method proposed in JP-A-55-60215 for forming electrically insulating laminated paper by heat-sealing a mixed paper of polyolefin fibers and kraft pulp and a polyolefin film uses the anchor coating agent described above. This method can be said to be excellent in that it can improve adhesive strength without deteriorating dielectric properties as would be the case. but,
The key point of this method is to heat-fuse a mixed paper that allows up to 50% by weight of polyolefin fibers and a separately prepared polyolefin film using a thermal calendar, etc. Therefore, the temperature is higher than the melting point of polyolefin fibers. As a result, thermal decomposition gas is generated from the kraft pulp, and this gas is forced into the softened film, creating voids and potentially reducing the pressure resistance extremely. On the other hand, the use of 100% polypropylene fiber paper (non-woven fabric) has already been proposed for electrical insulation laminated paper, which is made by combining fiber papers together into one composite piece by melt extrusion of polypropylene resin (Japanese Patent Publication No. 52-39932). . In this case, it is found that it is less harsh than the hot-pressure processing method, and that not only the dielectric properties are improved but also the peel strength is strong compared to the case where kraft insulating papers are bonded together. However, due to the porous nature of polypropylene fiber paper, there is a problem in that the impulse rupture strength is lowered and mechanical properties such as tensile strength and Young's modulus are also lowered. In view of the above precedent, the present inventors have discovered that when kraft insulating paper is laminated by the melt extrusion method of polypropylene resin, the airtightness of the kraft insulating paper is lower than that of conventional kraft insulating paper, thereby achieving a practically sufficient adhesive strength. It has been found that polypropylene laminated paper having the following properties can be obtained. It has also been found that by maintaining this airtightness above a certain level, the impulse breaking strength or mechanical strength does not decrease at all compared to those using conventional high airtightness kraft insulating paper. The present invention is based on this knowledge and provides an electrically insulating polypropylene laminate paper that satisfies excellent electrical properties and practically required mechanical properties. That is, the present invention provides a polypropylene laminated paper for electrical insulation, which is obtained by integrating a plurality of sheets of kraft insulating paper by melting and extruding them in an extruder using a polypropylene resin as a binder, wherein the airtightness of the kraft insulating paper is in units of Gurley seconds. in 20 or more 4000
It is characterized by the following. The kraft pulp used for the kraft insulating paper in the present invention may be commercially available kraft pulp for electrical insulation (JIS C 2307), but it is preferable to use it after thorough washing with pure water. The lower limit of airtightness was defined as 20 Gurley seconds.
If the value is below this value, the desired adhesive strength will be improved, but the impulse rupture strength will be significantly lowered. Furthermore, the reason why the upper limit of the airtightness is set to 400 Gurley seconds is that if it exceeds this, the desired improvement in adhesive strength cannot be expected. As is well known, in the case of kraft insulating paper, there is a close relationship between airtightness and impulse breakdown strength. In order to do this, it is desirable to increase the airtightness as much as possible to 3000 Gurley seconds or more. However, the present inventors found that in the case of polypropylene laminated paper, the resistance to electrical stress is covered to some extent by the polypropylene film layer included between the kraft insulating paper layers, even though the airtightness is considerably reduced. It was found that the impulse rupture strength of the entire laminated paper did not decrease much. In order to obtain a kraft insulating paper with a low airtight density as in the present invention, the paper may be made with a lower degree of beating than the conventional electrically insulating kraft paper for polypropylene laminated paper. Examples will be described below. Examples and Comparative Examples By using ion-exchanged water with an electrical conductivity of 3 μS/cm using a fourdrinier multi-tube paper machine and changing the beating degree of kraft pulp for insulating paper, the electrical density was changed to about 40 g/ m2 kraft insulating paper was made. These kraft insulating papers were then laminated by a polypropylene extrusion process using molten polypropylene as a binder, as shown in FIG. The polypropylene layer serving as the binder at this time was prepared to have a thickness of about 100 μm, and the thickness after lamination was 170 μm. Table 1 shows the results.
【表】
第１表に示す如く比較例１のように気密度を
7600ガーレー秒のように高くすると、インパルス
破壊強度はきわめて高いが、接着強度はかなり低
い。逆に気密度をあまり低めると、比較例２に示
したように接着度は比較例１のものにくらべて約
十数倍にも向上するが、インパルス破壊強度がき
わめて低下してしまい、超高圧ケーブル用絶縁材
料の性能を満足しなくなる。
すなわち、あまりにクラフト絶縁紙を高気密度
にするようにパルプの叩解を高めると、目的とす
る接着強度の向上は得られず、逆に叩解度を低め
てあまりに低気密度にすると接着強度は向上する
が、電気的な破壊強度が低下してしまう。
これに対して実施例１〜４の如く気密度が200
〜4000ガーレー秒の範囲であるとインパルス破壊
強度を高度に維持しながら接着強度を著しく増加
させることが出来る。さらに実施例５に示す如く
気密度が20ガーレー秒程度でも200KV/mm近くの
インパルス破壊強度の得られることが分る。そし
て引張り強さや引張りヤング率などもそれほど低
下させない。
以上の如く本発明により気密度を20〜4000ガー
レー秒、好ましくは200ガーレー秒以上4000ガー
レー秒以下に調整したクラフト絶縁紙の複数枚を
ポリプロピレン樹脂を溶融押出ししながら、これ
を接着剤として複合させた電気絶縁用ポリプロピ
レンラミネート紙は、クラフト絶縁紙層とポリプ
ロピレン樹脂層との層間の接着強度を顕著に増加
させ、しかも超高圧ケーブル用材料として充分な
インパルス破壊強度を有し、またケーブル作成時
などに必要とされる引張り強さや引張りヤング率
などの機械的特性もそれほど低下させないなど絶
縁用ポリプロピレンラミネート紙の性能を一層向
上させることが出来る。[Table] As shown in Table 1, the airtightness was determined as in Comparative Example 1.
At higher speeds, such as 7600 Gurley seconds, the impulse rupture strength is very high, but the bond strength is quite low. On the other hand, if the airtightness is too low, as shown in Comparative Example 2, the degree of adhesion is improved by about ten times as much as that of Comparative Example 1, but the impulse rupture strength is extremely reduced, and ultra-high pressure The performance of the insulating material for cables will no longer be satisfied. In other words, if the beating of the pulp is increased to make the kraft insulating paper too airtight, the desired improvement in adhesive strength will not be obtained, and on the other hand, if the beating degree is lowered to make the airtightness too low, the adhesive strength will improve. However, the electrical breakdown strength decreases. On the other hand, as in Examples 1 to 4, the airtightness is 200.
In the range of ~4000 Gurley seconds, it is possible to significantly increase the adhesive strength while maintaining a high level of impulse rupture strength. Furthermore, as shown in Example 5, it was found that even when the airtightness was approximately 20 Gurley seconds, an impulse rupture strength of nearly 200 KV/mm could be obtained. In addition, the tensile strength and tensile Young's modulus are not significantly reduced. As described above, according to the present invention, multiple sheets of kraft insulating paper whose airtightness is adjusted to 20 to 4000 Gurley seconds, preferably 200 Gurley seconds to 4000 Gurley seconds, are composited together as an adhesive while melt-extruding polypropylene resin. The polypropylene laminated paper for electrical insulation significantly increases the interlayer adhesion strength between the kraft insulating paper layer and the polypropylene resin layer, and has sufficient impulse rupture strength as a material for ultra-high voltage cables. It is possible to further improve the performance of polypropylene laminated paper for insulation without significantly reducing the mechanical properties such as tensile strength and tensile Young's modulus required for insulation.
第１図の本発明の実施例を示す電気絶縁用ラミ
ネート紙の断面図であり、第２図は該ラミネート
紙のクラフト絶縁紙層とポリプロピレン樹脂溶融
押出し層との層間剥離強度の測定法を説明するた
めの試験取付部の断面図である。
１……クラフト絶縁紙、２……ポリプロピレン
樹脂溶融押出し層、１０……試験片（電気絶縁用
ポリプロピレンラミネート紙）、１１……金属添
板、１２……上部クリツプ、１３……クラフト絶
縁紙層１を一部剥離した部分の残りの層。
FIG. 1 is a cross-sectional view of the electrically insulating laminated paper showing the embodiment of the present invention, and FIG. 2 illustrates a method for measuring the interlayer peel strength between the kraft insulating paper layer and the polypropylene resin melt-extruded layer of the laminated paper. FIG. 1... Kraft insulating paper, 2... Polypropylene resin melt extrusion layer, 10... Test piece (polypropylene laminated paper for electrical insulation), 11... Metal plate, 12... Upper clip, 13... Kraft insulating paper layer The remaining layer where part of 1 was peeled off.
Claims (1)
脂を結合剤として押出機で溶融押出ししながら一
体化させてなる電気絶縁用ラミネート紙におい
て、前記クラフト絶縁紙の気密度がガーレー秒単
位で20以上4000以下としたことを特徴とする、接
着強度を改善した絶縁用ポリプロピレンラミネー
ト紙。1. An electrically insulating laminated paper made by integrating multiple sheets of kraft insulating paper using polypropylene resin as a binder while melting and extruding it in an extruder, where the airtightness of the kraft insulating paper is 20 or more and 4000 or less in Gurley seconds. Insulating polypropylene laminated paper with improved adhesive strength.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13472482A JPS5925114A (en) | 1982-08-03 | 1982-08-03 | Insulating polyolefin laminated paper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13472482A JPS5925114A (en) | 1982-08-03 | 1982-08-03 | Insulating polyolefin laminated paper |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5925114A JPS5925114A (en) | 1984-02-09 |
| JPS6145329B2 true JPS6145329B2 (en) | 1986-10-07 |
Family
ID=15135114
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13472482A Granted JPS5925114A (en) | 1982-08-03 | 1982-08-03 | Insulating polyolefin laminated paper |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5925114A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62185232U (en) * | 1986-05-19 | 1987-11-25 | ||
| JPH0414363Y2 (en) * | 1986-10-03 | 1992-03-31 | ||
| JPH0542028Y2 (en) * | 1987-09-26 | 1993-10-22 |
-
1982
- 1982-08-03 JP JP13472482A patent/JPS5925114A/en active Granted
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62185232U (en) * | 1986-05-19 | 1987-11-25 | ||
| JPH0414363Y2 (en) * | 1986-10-03 | 1992-03-31 | ||
| JPH0542028Y2 (en) * | 1987-09-26 | 1993-10-22 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5925114A (en) | 1984-02-09 |
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