JP3228830B2 - Method for producing foamed polyethylene clad tube - Google Patents
Method for producing foamed polyethylene clad tubeInfo
- Publication number
- JP3228830B2 JP3228830B2 JP26762293A JP26762293A JP3228830B2 JP 3228830 B2 JP3228830 B2 JP 3228830B2 JP 26762293 A JP26762293 A JP 26762293A JP 26762293 A JP26762293 A JP 26762293A JP 3228830 B2 JP3228830 B2 JP 3228830B2
- Authority
- JP
- Japan
- Prior art keywords
- foamed polyethylene
- foamed
- polyethylene
- coated
- tube
- 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 - Fee Related
Links
Landscapes
- Rigid Pipes And Flexible Pipes (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Molding Of Porous Articles (AREA)
- Thermal Insulation (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、発泡ポリエチレン被覆
管の製造方法に係り、特に、押出機にスパイラルダイを
装着し、金属管の周囲に発泡性ポリエチレン樹脂組成物
を押出発泡成形し被覆してなる発泡ポリエチレン被覆管
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foamed polyethylene-coated tube, and more particularly, to a method in which a spiral die is mounted on an extruder, and a foamable polyethylene resin composition is extruded by foaming and formed around a metal tube. And a method for producing a foamed polyethylene coated tube.
【０００２】[0002]
【従来の技術】金属管を給湯や冷媒の移送等に使用する
場合、前記金属管の表面における結露防止や保温性向上
のため、従来より発泡ポリエチレン被覆管が多く採用さ
れている。これは、前記金属管の周囲に、ポリエチレン
樹脂を１．２〜２．０倍の発泡倍率で押出発泡成形し被
覆したもので、前記金属管としては、曲げ易さや、ロウ
付けによる接着の容易さから、主に銅管が使用される。2. Description of the Related Art When a metal tube is used for supplying hot water or transferring a refrigerant, a foamed polyethylene coated tube has been conventionally employed in many cases in order to prevent dew condensation on the surface of the metal tube and to improve heat retention. This is made by extruding and forming a polyethylene resin around the metal tube at an expansion ratio of 1.2 to 2.0 times by extrusion foaming. The metal tube is easy to bend and easy to bond by brazing. Therefore, mainly copper tubes are used.
【０００３】また、前記金属管の周囲にポリエチレン樹
脂を押出発泡成形し被覆する際には、押出機の本体に、
ダイのマンドレルを前記本体に固定するための支えが溶
融樹脂の流路に設けられたスパイダーダイを取り付け、
このダイ内を通過する前記金属管に、前記ダイの円スリ
ットより、溶融ポリエチレン樹脂を、温度１３０〜１７
０℃、圧力１００〜２００ｋｇ／ｃｍ2程度で押出発泡
成形する方法が採用されている。[0003] When extruding and foaming a polyethylene resin around the metal tube by means of extrusion foaming, the extruder body is provided with:
Attach a spider die provided with a support for fixing the mandrel of the die to the main body in the flow path of the molten resin,
The molten polyethylene resin was passed through the metal tube passing through the die through the circular slit of the die, at a temperature of 130-17.
A method of extrusion foaming at 0 ° C. and a pressure of about 100 to 200 kg / cm 2 is employed.
【０００４】[0004]
【発明が解決しようとする課題】ところで、上記従来の
発泡ポリエチレン被覆管に使用されている発泡ポリエチ
レンは、発泡倍率が低いため非常に硬質となっている。
その結果、上記従来の発泡ポリエチレン被覆管は、配管
の施工等の際に曲げにくく、かつ前記金属管をロウ付け
するためナイフ等を用いて発泡ポリエチレン被覆を取り
除く際、前記ポリエチレン被覆が切断しにくい等の欠点
を有している。The foamed polyethylene used in the above-mentioned conventional foamed polyethylene coated pipe is very hard because of a low expansion ratio.
As a result, the above-mentioned conventional foamed polyethylene coated pipe is difficult to bend at the time of piping construction, and when the foamed polyethylene coating is removed using a knife or the like to braze the metal pipe, the polyethylene coating is hard to cut. And the like.
【０００５】そこで、本発明者らは、発泡ポリエチレン
被覆管の曲げ易さと切断し易さとを改良する目的で、ポ
リエチレン樹脂にα−オレフィン系共重合体ゴムをポリ
エチレン樹脂１００重量部に対し３〜４０重量部配合し
た発泡性ポリエチレン樹脂組成物を、金属管の表面に溶
融被覆させる方法を提案した（特願平４−２５１６２２
号）。しかしながら、この発泡性ポリエチレン樹脂組成
物を、上記従来の方法を用いて前記金属管の周囲に押出
発泡成形し被覆すると、前記組成物が前記金属管の周方
向に均一に発泡しにくいばかりではなく、その発泡倍率
が１．５倍以上になりにくい等の問題があることがわか
った。Accordingly, the present inventors have proposed that an α-olefin copolymer rubber is added to a polyethylene resin in an amount of 3 to 100 parts by weight based on 100 parts by weight of the polyethylene resin in order to improve the ease of bending and the ease of cutting the foamed polyethylene coated tube. A method was proposed in which 40 parts by weight of a foamable polyethylene resin composition was melt-coated on the surface of a metal tube (Japanese Patent Application No. 4-251622).
issue). However, when this expandable polyethylene resin composition is extrusion-foamed and coated around the metal tube using the above-mentioned conventional method, not only is the composition difficult to foam uniformly in the circumferential direction of the metal tube, but also It was found that there was a problem that the expansion ratio was difficult to be 1.5 times or more.
【０００６】本発明は、上記事情に鑑みてなされたもの
で、ポリエチレン樹脂にα−オレフィン共重合体ゴムを
ポリエチレン樹脂１００重量部に対し３〜４０重量部配
合した発泡性ポリエチレン樹脂組成物を金属管の表面に
発泡押出成形し被覆してなる発泡ポリエチレン被覆管の
製造方法であって、前記金属管の周囲が、周方向に均一
に発泡し、かつ発泡倍率が１．２倍以上である発泡ポリ
エチレンで均一に被覆された発泡ポリエチレン被覆管の
製造方法を提供することをその目的としている。The present invention has been made in view of the above circumstances, and provides a foamable polyethylene resin composition comprising a polyethylene resin and 3 to 40 parts by weight of an α-olefin copolymer rubber mixed with 100 parts by weight of the polyethylene resin. What is claimed is: 1. A method for producing a foamed polyethylene-coated tube in which the surface of the tube is foamed and extruded and coated, wherein the periphery of the metal tube is uniformly foamed in a circumferential direction and a foaming ratio is 1.2 times or more. It is an object of the present invention to provide a method for producing a foamed polyethylene coated tube uniformly coated with polyethylene.
【０００７】[0007]
【課題を解決するための手段】本発明は、ポリエチレン
樹脂にα−オレフィン系共重合体ゴムを前記ポリエチレ
ン樹脂１００重量部に対し３〜４０重量部配合した発泡
性ポリエチレン樹脂組成物を、押出機を用いて溶融、混
練し、スパイラルダイを用いて、金属管の表面に１．２
〜３．５倍の発泡倍率で押出発泡成形し被覆した後、冷
媒液を用いて冷却固化してなる発泡ポリエチレン被覆管
の製造方法である。According to the present invention, there is provided an extruder comprising a foamable polyethylene resin composition obtained by mixing a polyethylene resin with an α-olefin copolymer rubber in an amount of 3 to 40 parts by weight based on 100 parts by weight of the polyethylene resin. Is melted and kneaded using a spiral die.
This is a method for producing a foamed polyethylene coated tube formed by extrusion foaming molding at a foaming ratio of up to 3.5 times, coating, and then cooling and solidifying using a refrigerant liquid.
【０００８】ここで、本発明で用いられるポリエチレン
樹脂は、密度（ＪＩＳ Ｋ６７６０−１９７７）が０．
９１５〜０．９３０g／ｃｍ3程度であり、更にメルトイ
ンデックス（ＪＩＳ Ｋ７２１０−１９７６、以下ＭＩ
と記す。）が０．０５〜４．０ｇ／１０分、より好まし
くは０．１〜２．０ｇ／１０分の範囲にあるものから選
択される。これは、ＭＩが０．０５ｇ／１０分未満であ
ると押出成形が困難となり、一方、ＭＩが４．０ｇ／１
０分を超えると高倍率（発泡倍率１．５倍以上）の発泡
体が得にくくなるためである。The polyethylene resin used in the present invention has a density (JIS K6760-1977) of 0.1.
It is about 915 to 0.930 g / cm 3 and further has a melt index (JIS K7210-1976, hereinafter MI)
It is written. ) Is in the range of 0.05 to 4.0 g / 10 min, more preferably 0.1 to 2.0 g / 10 min. This means that if the MI is less than 0.05 g / 10 minutes, extrusion molding becomes difficult, while the MI is 4.0 g / 1.
If the time exceeds 0 minutes, it is difficult to obtain a foam having a high magnification (expansion ratio of 1.5 or more).
【０００９】更に、前記発泡性ポリエチレン樹脂組成物
に含まれる発泡剤としては、アゾジカルボンアミド、ジ
ニトロソペンタメチレンテトラミン、４，４´−オキシ
ビスベンゼンスルホニルヒドラジッド、或は炭酸水素ナ
トリウムとクエン酸アルカリ塩の混合物等の化学発泡剤
が好ましい。また、その配合割合は、前記ポリエチレン
樹脂１００重量部に対し、前記化学発泡剤を０．２〜
２．５重量部、好ましくは０．５〜１．５重量部とす
る。これは、配合割合を０．２重量部未満とすると高倍
率の発泡ポリエチレンが得にくくなり、一方、配合割合
が２．５重量部を越えると、高倍率の発泡ポリエチレン
が得られる半面、形成された発泡ポリエチレン被覆表面
の平滑性が低下しやすくなるためである。Further, as the blowing agent contained in the foamable polyethylene resin composition, azodicarbonamide, dinitrosopentamethylenetetramine, 4,4'-oxybisbenzenesulfonylhydrazide, or sodium bicarbonate and citric acid Chemical blowing agents, such as mixtures of alkali salts, are preferred. The compounding ratio of the chemical blowing agent is 0.2 to 100 parts by weight of the polyethylene resin.
2.5 parts by weight, preferably 0.5 to 1.5 parts by weight. This is because if the blending ratio is less than 0.2 parts by weight, it is difficult to obtain a high-magnification foamed polyethylene, while if the blending ratio exceeds 2.5 parts by weight, a high-magnification foamed polyethylene can be obtained, but it is formed. This is because the smoothness of the foamed polyethylene-coated surface tends to decrease.
【００１０】また、本発明で用いられるα−オレフィン
系共重合体ゴムとしては、エチレン・プロピレン、エチ
レン・ブテン、エチレン・プロピレン・ブテンの各共重
合体等が挙げられる。ここで、これらα−オレフィン系
共重合体ゴムのＭＩは、２３０℃、２．１６ｋｇ荷重で
０．１〜５．０ｇ／１０分、好ましくは０．２〜１．０
ｇ／１０分とし、その配合割合は、前記ポリエチレン樹
脂１００重量部に対し、３〜４０重量部、好ましくは５
〜３０重量部とする。The α-olefin copolymer rubber used in the present invention includes ethylene / propylene, ethylene / butene, and ethylene / propylene / butene copolymers. Here, MI of these α-olefin-based copolymer rubbers is 0.1 to 5.0 g / 10 minutes at 230 ° C. and a load of 2.16 kg, preferably 0.2 to 1.0 g.
g / 10 minutes, and the compounding ratio is 3 to 40 parts by weight, preferably 5 to 100 parts by weight of the polyethylene resin.
To 30 parts by weight.
【００１１】これは、配合割合を３重量部未満とする
と、形成された発泡ポリエチレン被覆が切断しにくい等
の欠点が生じ、一方、配合割合が４０重量部を越える
と、成形安定性が著しく低下するためである。また、金
属管としては、例えば外径１０〜３０ｍｍ程度、肉厚
０．６〜１．５ｍｍ程度のものが用いられ、材質には銅
等が使用される。[0011] If the compounding ratio is less than 3 parts by weight, the formed foamed polyethylene coating has disadvantages such as difficulty in cutting. On the other hand, if the compounding ratio exceeds 40 parts by weight, the molding stability is remarkably deteriorated. To do that. As the metal tube, for example, one having an outer diameter of about 10 to 30 mm and a thickness of about 0.6 to 1.5 mm is used, and a material such as copper is used.
【００１２】本発明においては、前記組成物を押出機を
用いて溶融、混練する際、押出機のシリンダーの加熱お
よびスクリュの混練摩擦熱により、前記組成物の温度を
１７０〜２３０℃、より好ましくは１９０〜２２０℃と
して前記組成物の溶融、混練を行うことが望ましい。In the present invention, when the composition is melted and kneaded using an extruder, the temperature of the composition is preferably 170 to 230 ° C., more preferably, by heating the cylinder of the extruder and kneading frictional heat of the screw. It is preferable to perform melting and kneading of the composition at 190 to 220 ° C.
【００１３】この場合、前記組成物の温度を１７０℃未
満とすると、高倍率の発泡ポリエチレンが得られにくく
なる。また、前記組成物の温度が２３０℃を越えると、
前記組成物の溶融張力が低下し、その結果、発泡剤によ
り形成された気泡室の樹脂壁を突き破って発泡ガスが抜
け出てしまい、前記気泡室を維持・拡大できず、高倍率
の発泡ポリエチレンが得られにくくなる。In this case, if the temperature of the composition is lower than 170 ° C., it becomes difficult to obtain a high-magnification foamed polyethylene. When the temperature of the composition exceeds 230 ° C.,
The melt tension of the composition is reduced, and as a result, the foaming gas escapes by breaking through the resin wall of the cell chamber formed by the foaming agent, and the cell chamber cannot be maintained or expanded, and the high-magnification foamed polyethylene is formed. It is difficult to obtain.
【００１４】更に、押出機のメタリングゾーンおよびダ
イ内における前記組成物の樹脂圧力は、２００〜３５０
ｋｇ／ｃｍ2とするのが望ましい。前記温度下で、前記
組成物をこの樹脂圧力範囲に維持すると、発泡剤が前記
組成物の細部にまで均一微細に拡散し、その結果、微細
な気泡が均一に形成された高倍率の発泡ポリエチレンが
得られる。この場合、樹脂圧力を２００ｋｇ／ｃｍ2未
満とすると、得られた気泡が粗いうえ、高倍率の発泡ポ
リエチレンが得られにくくなる。また、樹脂圧力が３５
０ｋｇ／ｃｍ2を越えると、ダイの出口でメルトフラク
チュアと呼ばれる現象が発生しやすく、形成された発泡
ポリエチレン被覆表面の平滑性が得られにくくなる。Further, the resin pressure of the composition in the metering zone and the die of the extruder is 200 to 350.
kg / cm 2 is desirable. When the composition is maintained in the resin pressure range under the temperature, the foaming agent diffuses uniformly and finely to the details of the composition, and as a result, high-density foamed polyethylene in which fine bubbles are uniformly formed. Is obtained. In this case, if the resin pressure is less than 200 kg / cm 2 , the obtained bubbles are coarse, and it becomes difficult to obtain high-magnification foamed polyethylene. When the resin pressure is 35
If it exceeds 0 kg / cm 2 , a phenomenon called melt fracture tends to occur at the exit of the die, and it becomes difficult to obtain smoothness of the foamed polyethylene-coated surface formed.
【００１５】溶融、混練後の前記組成物は、ダイを用い
て前記金属管の表面に押出発泡成形される。しかしなが
ら、上記樹脂温度と樹脂圧力の条件下であっても、従来
のスパイダーダイ等で押出発泡成形した場合には、前記
金属管の周方向に均一な発泡ポリエチレンを得ることは
困難である。これは、スパイダーダイ等には、ダイのマ
ンドレルを本体に固定するための支えが、溶融樹脂の流
路に設けられていることに起因する。すなわち、溶融樹
脂が前記支えの設置箇所を通過しなければならないこと
により、前記支えの設置箇所を通過した樹脂と周囲の樹
脂との間に温度差が生じ、その結果、円周方向に発泡倍
率ムラが発生して発泡ポリエチレンの表面に凹凸を生じ
るためである。The composition after melting and kneading is extruded and foamed on the surface of the metal tube using a die. However, even under the conditions of the resin temperature and the resin pressure, it is difficult to obtain uniform foamed polyethylene in the circumferential direction of the metal tube when extrusion foaming is performed using a conventional spider die or the like. This is because a spider die or the like is provided with a support for fixing the mandrel of the die to the main body in the flow path of the molten resin. That is, since the molten resin must pass through the support installation location, a temperature difference occurs between the resin that has passed through the support installation location and the surrounding resin, and as a result, the expansion ratio in the circumferential direction is increased. This is because unevenness occurs to cause irregularities on the surface of the foamed polyethylene.
【００１６】本発明者らは、種々の構造を有するダイに
ついて検討を行い、その結果、上記傾向は多かれ少なか
れほとんどのダイ構造において見られるが、スパイラル
ダイを用いた場合には均一な押出発泡が可能であること
を見出した。スパイラルダイとは、樹脂がダイの軸線回
りに螺設されたスパイラル状をなす流路内を流れながら
順次押出し方向の流れに変換される構造をしているもの
で、流路内に障害物は存在しない。The present inventors have studied dies having various structures. As a result, the above tendency can be seen more or less in most die structures. However, when a spiral die is used, uniform extrusion foaming is achieved. I found that it is possible. A spiral die has a structure in which resin is sequentially converted into a flow in the extrusion direction while flowing in a spiral flow path that is screwed around the axis of the die. not exist.
【００１７】また、一般ダイのような流路内における樹
脂の合流箇所（ウエルドマーク）も存在しないので、樹
脂は、円周方向に均一な温度で押出される。従って、本
発明に係る発泡ポリエチレン被覆管の製造方法におい
て、金属管の周方向に均一な発泡ポリエチレンを得るた
めには、スパイラルダイの使用が不可欠な要件となる。Further, since there is no joining point (weld mark) of the resin in the flow path as in a general die, the resin is extruded at a uniform temperature in the circumferential direction. Therefore, in the method for producing a foamed polyethylene coated tube according to the present invention, the use of a spiral die is an essential requirement in order to obtain a uniform foamed polyethylene in the circumferential direction of the metal tube.
【００１８】更に、本発明における押出発泡成形時の発
泡倍率は、１．２〜３．５倍、望ましくは１．５〜３．
５倍とする。これは、発泡倍率が１．２倍未満のものは
被覆管を曲げたとき金属管が座屈しやすくなり、一方、
発泡倍率が３．５倍を越えると、発泡ポリエチレンの押
出成形性が不良となるためである。Further, the expansion ratio at the time of extrusion foam molding in the present invention is 1.2 to 3.5 times, preferably 1.5 to 3 times.
5 times. This is because, when the foaming ratio is less than 1.2 times, the metal tube tends to buckle when the cladding tube is bent,
If the expansion ratio exceeds 3.5 times, the extrusion moldability of the expanded polyethylene becomes poor.
【００１９】押出発泡成形の結果得られた発泡ポリエチ
レンは更に冷却固化され、発泡ポリエチレン被覆が形成
されるが、本発明においては、前記発泡ポリエチレン
を、温度５０〜１００℃の冷媒液（具体的には冷却水
等）を用いて冷却するのが望ましい。この場合、温度５
０℃未満の冷媒液で冷却すると、発泡ポリエチレン被覆
の表面に凹凸が発生しやすくなる。また、前記冷媒液の
温度が１００℃を越えることは、冷却効率の点から好ま
しくない。更に、該温度での冷却時間は、前記発泡ポリ
エチレン被覆の厚みにも依るが、通常の厚み、すなわち
厚みが１〜５ｍｍの場合、２秒以上が好ましい。これ
は、少なくとも該温度で発泡ポリエチレン被覆の表面が
固化する時間である。The foamed polyethylene obtained as a result of the extrusion foam molding is further cooled and solidified to form a foamed polyethylene coating. In the present invention, the foamed polyethylene is treated with a refrigerant liquid at a temperature of 50 to 100 ° C. (specifically, Is desirably cooled using cooling water or the like. In this case, the temperature 5
When cooled with a refrigerant liquid of less than 0 ° C., irregularities are likely to be generated on the surface of the foamed polyethylene coating. Further, it is not preferable that the temperature of the refrigerant liquid exceeds 100 ° C. in terms of cooling efficiency. Furthermore, the cooling time at this temperature depends on the thickness of the foamed polyethylene coating, but is preferably 2 seconds or more when the thickness is normal, that is, 1 to 5 mm. This is the time at which the surface of the foamed polyethylene coating solidifies at least at that temperature.
【００２０】そして、上記の手順を踏むことにより、前
記金属管の周囲に、前記組成物が、１．２〜３．５倍、
望ましくは１．５〜３．５倍の発泡倍率で均一に被覆さ
れた発泡ポリエチレン被覆管を得ることができる。[0020] Then, by following the above procedure, the composition becomes 1.2 to 3.5 times around the metal tube.
Desirably, a foamed polyethylene coated tube uniformly coated at a foaming ratio of 1.5 to 3.5 times can be obtained.
【００２１】なお、前記金属管の周囲に形成された発泡
ポリエチレン被覆の表面に無発泡ポリエチレン樹脂層を
形成する目的で、発泡ポリエチレン被覆の形成と同時、
または、発泡ポリエチレン被覆の形成後に、更に無発泡
ポリエチレン樹脂を押出積層被覆することももちろん可
能である。また、その場合の無発泡ポリエチレン樹脂の
厚みは、０．２〜１．５ｍｍ程度とする。Incidentally, in order to form a non-foamed polyethylene resin layer on the surface of the foamed polyethylene coating formed around the metal tube, simultaneously with the formation of the foamed polyethylene coating,
Alternatively, after forming the foamed polyethylene coating, a non-foamed polyethylene resin may be further subjected to extrusion lamination coating. In this case, the thickness of the non-foamed polyethylene resin is about 0.2 to 1.5 mm.
【００２２】[0022]
【実施例】以下に実施例を示し、本発明の効果について
説明する。ポリエチレン樹脂（密度＝０．９２５g／ｃ
ｍ3 ＭＩ＝０．３ｇ／１０分）１００重量部に対し
て、エチレン・プロピレン共重合体ゴム（ＭＩ＝０．７
ｇ／１０分）を１０重量部配合して得たポリエチレン樹
脂組成物に、発泡剤として炭酸水素ナトリウムとクエン
酸アルカリ塩（三菱油化製、商品名ファインセロール）
を１．２重量部配合した発泡性ポリエチレン樹脂組成物
を、以下の表１に記載した条件で、鋼管の表面に、それ
ぞれ肉厚が２．０ｍｍとなるよう押出発泡成形し被覆し
た後冷却した。EXAMPLES Examples will be shown below to explain the effects of the present invention. Polyethylene resin (density = 0.925 g / c
m 3 MI = 0.3 g / 10 min.) 100 parts by weight of ethylene / propylene copolymer rubber (MI = 0.7 g)
g / 10 min.) in a polyethylene resin composition obtained by blending 10 parts by weight with sodium bicarbonate and alkali citrate (Finecelol, trade name, manufactured by Mitsubishi Yuka) as blowing agents.
Was added to 1.2 parts by weight of a foamable polyethylene resin composition, extruded and foamed on the surface of a steel pipe so as to have a wall thickness of 2.0 mm under the conditions described in Table 1 below, and then cooled. .
【００２３】更に、そのそれぞれについて、外層として
ポリエチレン樹脂（密度＝０．９２０g／ｃｍ3 ＭＩ＝
２．０ｇ／１０分）を肉厚が０．５ｍｍになるように押
出被覆し、外径２７ｍｍの発泡ポリエチレン被覆鋼管を
製造した。それぞれの発泡ポリエチレン被覆鋼管の製造
条件を表１に、また、その結果得られた発泡ポリエチレ
ン被覆の発泡倍率およびその表面状態を表２に示す。Further, in each case, a polyethylene resin (density = 0.920 g / cm 3 MI =
(2.0 g / 10 min) by extrusion coating to a wall thickness of 0.5 mm to produce a foamed polyethylene-coated steel pipe having an outer diameter of 27 mm. Table 1 shows the production conditions of the foamed polyethylene-coated steel pipes, and Table 2 shows the expansion ratio and the surface state of the resulting foamed polyethylene coating.
【００２４】[0024]
【表１】 [Table 1]
【００２５】[0025]
【表２】 [Table 2]
【００２６】表１および表２から明かなように、本発明
に係る製造条件の結果得られた発泡ポリエチレン被覆の
表面はいずれも平滑であった。また、本発明の請求項２
〜４に基づく製造条件の結果得られた発泡ポリエチレン
被覆（実施例１〜４）は、その表面平滑性が特に優れる
とともに、１．５倍以上の高い発泡倍率を示した。As is clear from Tables 1 and 2, the surfaces of the foamed polyethylene coating obtained as a result of the production conditions according to the present invention were all smooth. Further, claim 2 of the present invention
The foamed polyethylene coating (Examples 1 to 4) obtained as a result of the production conditions based on Nos. To 4 exhibited particularly excellent surface smoothness and exhibited a high expansion ratio of 1.5 times or more.
【００２７】[0027]
【発明の効果】以上説明したように、本発明によれば、
ポリエチレン樹脂にα−オレフィン系共重合体ゴムを前
記ポリエチレン樹脂１００重量部に対し、３〜４０重量
部配合した発泡性ポリエチレン樹脂組成物から成形され
た発泡ポリエチレン被覆であって、特に、１．２倍以上
の高発泡倍率を有し、かつ表面の平滑な発泡ポリエチレ
ン被覆を有する被覆管を得ることができる。As described above, according to the present invention,
A foamed polyethylene coating molded from a foamable polyethylene resin composition in which an α-olefin copolymer rubber is mixed with a polyethylene resin in an amount of 3 to 40 parts by weight based on 100 parts by weight of the polyethylene resin, It is possible to obtain a coated tube having a high expansion ratio of at least twice and having a foamed polyethylene coating with a smooth surface.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 田口 昌利 埼玉県北本市下石戸上1975番地２ 三菱 マテリアル株式会社 北本製作所内 (72)発明者 吉田 憲治 埼玉県北本市下石戸上1975番地２ 三菱 マテリアル株式会社 北本製作所内 (56)参考文献 特開 昭48−81076（ＪＰ，Ａ) 特開 昭49−22577（ＪＰ，Ａ) 特開 昭52−117961（ＪＰ，Ａ) 特開 昭52−91072（ＪＰ，Ａ) 特開 昭55−129685（ＪＰ，Ａ) 特開 昭58−84831（ＪＰ，Ａ) 特開 昭60−225741（ＪＰ，Ａ) 特開 平３−207639（ＪＰ，Ａ) 特開 平３−197020（ＪＰ，Ａ) 特開 平４−174914（ＪＰ，Ａ) 特開 平６−101785（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B29C 47/02 B29C 47/20 F16L 9/14 F16L 59/147 C08J 9/06 B29D 23/00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masatoshi Taguchi 1975-2 Shimoishitogami, Kitamoto City, Saitama Prefecture Mitsubishi Materials Corporation Kitamoto Works (72) Inventor Kenji Yoshida 1975-2 Shimoishitogami 2 Kitamoto City, Saitama Mitsubishi Materials (56) References JP-A-48-81076 (JP, A) JP-A-49-22577 (JP, A) JP-A-52-117961 (JP, A) JP-A-52-91072 (JP, A) JP, A) JP-A-55-129685 (JP, A) JP-A-58-84831 (JP, A) JP-A-60-225741 (JP, A) JP-A-3-207639 (JP, A) JP JP-A-3-197020 (JP, A) JP-A-4-174914 (JP, A) JP-A-6-101785 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) B29C 47 / 02 B29C 47/20 F16L 9/14 F16L 59/147 C08J 9/06 B29D 23/00
Claims (5)
重合体ゴムを前記ポリエチレン樹脂１００重量部に対し
３〜４０重量部配合した発泡性ポリエチレン樹脂組成物
を、押出機を用いて溶融、混練し、スパイラルダイを用
いて、金属管の表面に１．２〜３．５倍の発泡倍率で押
出発泡成形して該表面を被覆した後、冷媒液を用いて冷
却固化することを特徴とする発泡ポリエチレン被覆管の
製造方法。An extrudable polyethylene resin composition comprising a polyethylene resin and 3 to 40 parts by weight of an α-olefin copolymer rubber mixed with 100 parts by weight of the polyethylene resin is melted and kneaded using an extruder. A foamed polyethylene, characterized in that the surface of a metal tube is extruded and foamed at a foaming ratio of 1.2 to 3.5 times using a spiral die to cover the surface, and then cooled and solidified using a refrigerant liquid. A method of manufacturing a cladding tube.
前記組成物の温度を、１７０〜２３０℃とすることを特
徴とする請求項１記載の発泡ポリエチレン被覆管の製造
方法。2. The method according to claim 1, wherein the temperature of the composition at the time of melting and kneading using the extruder is 170 to 230 ° C.
ラルダイより押出発泡成形する際の押出圧力を、２００
〜３５０ｋｇ／ｃｍ2とすることを特徴とする請求項１
記載の発泡ポリエチレン被覆管の製造方法。3. An extrusion pressure at the time of extruding and foaming the composition from a spiral die using the extruder is 200.
2. The pressure is set to 350 kg / cm 2.
A method for producing a foamed polyethylene-coated tube according to the above.
エチレンを前記冷媒液を用いて冷却固化する際の前記冷
媒液の温度を、５０〜１００℃とすることを特徴とする
請求項１記載の発泡ポリエチレン被覆管の製造方法。4. The temperature of the refrigerant liquid when the foamed polyethylene coated on the surface of the metal tube is cooled and solidified by using the refrigerant liquid is set to 50 to 100 ° C. The method for producing a foamed polyethylene coated tube of the above.
エチレンの表面を更に無発泡ポリエチレン樹脂で押出被
覆することを特徴とする請求項１，２，３または４記載
の発泡ポリエチレン被覆管の製造方法。5. The foamed polyethylene coated tube according to claim 1, wherein the surface of the foamed polyethylene coated on the surface of the metal tube is further extrusion-coated with a non-foamed polyethylene resin. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26762293A JP3228830B2 (en) | 1993-10-26 | 1993-10-26 | Method for producing foamed polyethylene clad tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26762293A JP3228830B2 (en) | 1993-10-26 | 1993-10-26 | Method for producing foamed polyethylene clad tube |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07117096A JPH07117096A (en) | 1995-05-09 |
| JP3228830B2 true JP3228830B2 (en) | 2001-11-12 |
Family
ID=17447250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26762293A Expired - Fee Related JP3228830B2 (en) | 1993-10-26 | 1993-10-26 | Method for producing foamed polyethylene clad tube |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3228830B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3544899B2 (en) * | 1999-09-02 | 2004-07-21 | 住友軽金属工業株式会社 | Method of suppressing or avoiding corrosion and discoloration in foamed copper tube |
| JP2002156074A (en) * | 2000-11-20 | 2002-05-31 | Sekisui Chem Co Ltd | Covered pipe and manufacturing method therefor |
| DE102006014235A1 (en) * | 2006-03-28 | 2007-10-04 | Brugg Rohr Ag, Holding | Sheath for heat-insulated pipes |
| JP5529387B2 (en) * | 2007-04-06 | 2014-06-25 | 積水化学工業株式会社 | Composite tube and manufacturing method thereof |
| JP5671216B2 (en) * | 2009-05-18 | 2015-02-18 | 日鉄住金防蝕株式会社 | Insulated polyolefin coated steel pipe |
| CN112622138B (en) * | 2020-12-11 | 2023-09-22 | 义乌市大胜橡塑制品有限公司 | One-step compression molding process for polyethylene yoga column |
-
1993
- 1993-10-26 JP JP26762293A patent/JP3228830B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07117096A (en) | 1995-05-09 |
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