JP2004017337A - Resin-coated steel pipe for backfill and joint thereof - Google Patents
Resin-coated steel pipe for backfill and joint thereof Download PDFInfo
- Publication number
- JP2004017337A JP2004017337A JP2002172238A JP2002172238A JP2004017337A JP 2004017337 A JP2004017337 A JP 2004017337A JP 2002172238 A JP2002172238 A JP 2002172238A JP 2002172238 A JP2002172238 A JP 2002172238A JP 2004017337 A JP2004017337 A JP 2004017337A
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- layer
- resin
- adhesive layer
- ethylene
- 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.)
- Pending
Links
Images
Landscapes
- Rigid Pipes And Flexible Pipes (AREA)
- Laminated Bodies (AREA)
Abstract
Description
【０００１】
【発明の属する技術分野】
本発明は、土中などに埋設する樹脂被覆鋼管およびその継手に関する。
【０００２】
【従来の技術】
ガス、上下水道などの配管や通信、電力ケーブルなどの管路材としてポリエチレン被覆鋼管が多用されてきているが、埋設工事の際、従来のポリエチレン被覆鋼管は石やレキなどによる貫通疵（被覆した樹脂を貫通する疵）を回避するため、鋼管の周囲を砂で埋めていた。そのため、ポリエチレン被覆鋼管に貫通疵を発生するレキを含む恐れのある掘り出した土砂の全てあるいは大部分が産業廃棄物として処理されてきた。ポリエチレン被覆の外側にポリプロピレン被覆をほどこした二重被覆鋼管は例えば特開昭５８−４２４４９号公報などで提供されてはいるが、具体的に掘り出した土砂で埋め戻す工事に耐えるための検討はされていなかった。
【０００３】
【発明が解決しようとする課題】
近年の世界的な環境問題の高まりから、ポリエチレン被覆鋼管を埋設する際、掘り出した土砂で埋め戻しを行い、産業廃棄物となる土砂を無くすもしくは可能な限り少量にできる貫通疵防止機能を持った樹脂被覆鋼管が望まれていた。
【０００４】
【課題を解決するための手段】
本発明者らは、上記の問題を解決すべく鋭意検討した。まず、掘り出した土砂に含まれるレキで埋め戻す際、レキの重量や落下する高さにより鋼管がどの程度偏平するか調査した。具体的には重機にて石を掴み、鋼管の上からで自然落下させ、その衝撃エネルギーと石が衝突した位置の鋼管の偏平率との関係を求める落石試験を実施した。使用した鋼管はＪＩＳ Ｇ ３４５２に準拠した８０Ａ鋼管であった。
【０００５】
使用した石はＪＩＳ Ａ ５００６に準拠した割ぐり石１号（１０ｋｇ）、２号（２０ｋｇ）、３号（３０ｋｇ）の硬石であった。石の下面と鋼管の上面の距離を高さとし、０．５ｍ、０．７５ｍ、１ｍ、１．５ｍ、２ｍと変化させた。石の重量と高さを掛け合わせた位置エネルギーを衝撃エネルギーとした。石が衝突した位置で鋼管を切断し、その位置の外径を測定し、試験前に測定した平均外径から下記の式により偏平率を求めた。
（偏平率）＝（衝突した位置の外径）／（試験前に測定した平均外径）×１００％
【０００６】
結果を図１に示す。この結果、本発明者らは、衝撃エネルギー２０ｋｇｆ・ｍ付近でＪＩＳ Ｇ ３４５２記載の８０Ａ鋼管の公差±１％を越えることを知見した。従って、掘り出した土砂に含まれるレキで埋め戻す際、鋼管の偏平を±１％未満にするために、鋼管に加わる衝撃エネルギーを２０ｋｇｆ・ｍ未満とする対策が必要である。以上の調査結果から、２０ｋｇｆ・ｍの衝撃エネルギーで被覆に貫通疵が発生しない貫通疵防止機能を持った樹脂被覆鋼管および樹脂被覆継手であれば、鋼管に加わる衝撃エネルギーを２０ｋｇｆ・ｍ未満とする対策を取ったレキの含まれる土砂を埋め戻し埋設工事に使用できる。
【０００７】
その要旨とするところは、
（１）鋼管の外面に接着層を有し、更にその外側に膜厚３．５ｍｍ以上のポリプロピレン層を有したことを特徴とする埋め戻し用樹脂被覆鋼管。
（２）鋼管の外面に接着層を有し、その外側に膜厚１．５ｍｍ以上のポリオレフィン層を有し、更にその外側に膜厚２．０ｍｍ以上のポリプロピレン層を有したことを特徴とする埋め戻し用樹脂被覆鋼管。
【０００８】
（３）前記接着層が、合成ゴム、あるいは無水マレイン酸変性ポリオレフィン、エチレン・無水マレイン酸共重合体、エチレン・無水マレイン酸・アクリル酸共重合体、エチレン・無水マレイン酸・アクリル酸エステル共重合体、エチレン・アクリル酸共重合体、エチレン・アクリル酸エステル共重合体、エチレン・メタクリル酸共重合体、エチレン・酢酸ビニル共重合体、アイオノマーのうち１つまたは２つ以上よりなることを特徴とする前記（１）乃至（２）記載の埋め戻し用樹脂被覆鋼管。
【０００９】
（４）前記鋼管と前記接着層との間にクロメート処理あるいはリン酸塩処理などを施した化成処理層を有したことを特徴とする前記（１）乃至（３）記載の埋め戻し用樹脂被覆鋼管。
（５）前記鋼管と前記接着層との間に、あるいは前記化成処理層と前記接着層との間にエポキシプライマー層を有したことを特徴とする前記（１）乃至（４）記載の埋め戻し用樹脂被覆鋼管。
【００１０】
（６）鋼管の内面にめっき層を有したことを特徴とする前記（１）乃至（５）記載の埋め戻し用樹脂被覆鋼管。
（７）鋼管の内面に液状エポキシ塗装、粉体エポキシ塗装、粉体ポリエステル塗装のいずれかを施したことを特徴とする前記（１）乃至（５）記載の埋め戻し用樹脂被覆鋼管。
（８）鋼管の内面にクロメート処理あるいはリン酸塩処理などを施した化成処理層を有し、更にその内側に粉体ポリオレフィン塗装を施したことを特徴とする前記（１）乃至（５）記載の埋め戻し用樹脂被覆鋼管。
【００１１】
（９）鋼管の内面に接着層を有し、更にその内側に成形ポリオレフィン層を有したことを特徴とする前記（１）乃至（５）記載の埋め戻し用樹脂被覆鋼管。
（１０）前記接着層が合成ゴム、あるいは無水マレイン酸変性ポリオレフィン、エチレン・無水マレイン酸共重合体、エチレン・無水マレイン酸・アクリル酸共重合体、エチレン・無水マレイン酸・アクリル酸エステル共重合体、エチレン・アクリル酸共重合体、エチレン・アクリル酸エステル共重合体、エチレン・メタクリル酸共重合体、エチレン・酢酸ビニル共重合体、アイオノマーのうち１つまたは２つ以上よりなることを特徴とする前記（９）記載の埋め戻し用樹脂被覆鋼管。
【００１２】
（１１）前記鋼管と前記接着層との間にクロメート処理あるいはリン酸塩処理などを施した化成処理層を有したことを特徴とする前記（９）乃至（１０）記載の埋め戻し用樹脂被覆鋼管。
（１２）前記鋼管と前記接着層との間に、あるいは前記化成処理層と前記接着層との間 にエポキシプライマー層を有したことを特徴とする前記（８）乃至（１１）記載の埋め戻し用樹脂被覆鋼管。
【００１３】
（１３）前記（１）乃至（１２）記載の樹脂被覆鋼管同士を接続する継ぎ手が、外面に膜厚３．５ｍｍ以上のポリプロピレン層を有したことを特徴とする埋め戻し用樹脂被覆鋼管継ぎ手。
（１４）前記（１）乃至（１２）記載の樹脂被覆鋼管同士を接続する継ぎ手が、外面に接着層を有し、その外側に膜厚１．５ｍｍ以上のプラスチック層を有し、更にその外側に膜厚２．０ｍｍ以上のをポリプロピレン層を有したことを特徴とする埋め戻し用樹脂被覆鋼管継ぎ手。
【００１４】
（１５）前記樹脂被覆鋼管継ぎ手の鋼部直外面にクロメート処理あるいはリン酸塩処理などを施した化成処理層を有したことを特徴とする前記（１３）乃至（１４）記載の埋め戻し用樹脂被覆鋼管継ぎ手。
（１６）前記化成処理層の直外面に更にエポキシプライマー層を有したことを特徴とする前記（１５）記載の埋め戻し用樹脂被覆鋼管継ぎ手。
（１７）前記樹脂被覆鋼管継ぎ手の内面にクロメート処理あるいはリン酸塩処理などを施した化成処理層を有し、更にその内面にエポキシ層を有したことを特徴とする前記（１４）乃至（１６）記載の埋め戻し用樹脂被覆鋼管継ぎ手。
【００１５】
【発明の実施の形態】
本発明の樹脂被覆鋼管は、まず、鋼管内面を脱脂し、ブラスト処理や酸洗して清浄にする。鋼管内面に亜鉛めっき、液状エポキシ塗装、粉体エポキシ塗装、粉体ポリエステル塗装を施したものでも良い。また、鋼管内面にクロメートやりん酸亜鉛カルシウムなどの化成処理やエポキシプライマーのいずれかあるいは両方を施したのち、粉体ポリエチレン塗装を施したものでもよい。更には、鋼管内面にクロメートや、外面に接着層を持ち予めパイプ状に成形した架橋あるいは非架橋ポリエチレンパイプをりん酸亜鉛カルシウムなどの化成処理やエポキシプライマーのいずれかあるいは両方を施したのち鋼管に挿入し、縮径加工し、鋼管を加熱し、接着層を溶融接着させても良い。
【００１６】
前記接着層としては合成ゴム、あるいは無水マレイン酸変性ポリオレフィン、エチレン・無水マレイン酸共重合体、エチレン・無水マレイン酸・アクリル酸共重合体、エチレン・無水マレイン酸・アクリル酸エステル共重合体、エチレン・アクリル酸共重合体、エチレン・アクリル酸エステル共重合体、エチレン・メタクリル酸共重合体、エチレン・酢酸ビニル共重合体、アイオノマーのうち１つまたは２つ以上の混合品が良い。
上記のような鋼管内面に防蝕処理を施した鋼管外面を脱脂し、ブラスト処理や酸洗して清浄にする。接着層、厚み３．５ｍｍ以上のポリプロピレン層を順じ被覆させる。または、接着層、厚み１．５ｍｍ以上のポリエチレン層、さらに、厚み２ｍｍ以上のポリプロピレン層を順じ被覆させる。
【００１７】
前記接着層としては合成ゴム、あるいは無水マレイン酸変性ポリオレフィン、エチレン・無水マレイン酸共重合体、エチレン・無水マレイン酸・アクリル酸共重合体、エチレン・無水マレイン酸・アクリル酸エステル共重合体、エチレン・アクリル酸共重合体、エチレン・アクリル酸エステル共重合体、エチレン・メタクリル酸共重合体、エチレン・酢酸ビニル共重合体、アイオノマーのうち１つまたは２つ以上の混合品が良い。加熱溶融させた合成ゴムを鋼管外面に滴下し、ゴムヘラなどでしごくのがよい。また、無水マレイン酸変性ポリオレフィン、エチレン・無水マレイン酸共重合体、エチレン・無水マレイン酸・アクリル酸共重合体、エチレン・無水マレイン酸・アクリル酸エステル共重合体、エチレン・アクリル酸共重合体、エチレン・アクリル酸エステル共重合体、エチレン・メタクリル酸共重合体、エチレン・酢酸ビニル共重合体、アイオノマーなどの接着剤やポリエチレンやポリプロピレンなどは押出機で加熱溶融し、丸ダイスやＴダイスを用いて鋼管外面に押出被覆する。
【００１８】
前記ポリエチレンやポリプロピレンなどには必要に応じて酸化防止剤、紫外線吸収剤、難燃剤、顔料、充填剤、滑剤、帯電防止剤などの添加剤およびその他の樹脂を混合しても良い。接着層を被覆する前にクロメートやりん酸亜鉛カルシウムなどの化成処理あるいはエポキシプライマーをいずれかあるいは両方を施すこともできる。上記前記樹脂被覆鋼管に使用する本発明の継ぎ手は、まず、継手内面を脱脂し、ブラスト処理や酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、射出成形法により厚さ３．５ｍｍ以上のポリプロピレン単層を、または、厚さ１．５ｍｍ以上のポリエチレン層、厚さ２．０ｍｍ以上のポリプロピレン層の２層被覆する。ブラスト処理や酸洗して清浄にした後、射出成形前にりん酸亜鉛処理、エポキシ電着塗装のいずれかあるいは両方を施してもよい。
【００１９】
【実施例】
（実施例１）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍの無水マレイン酸ポリプロピレン、厚み３．５ｍｍのポリプロピレン層を順じ被覆した。
【００２０】
（実施例２）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２１】
（実施例３）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのエチレン・無水マレイン酸共重合体、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２２】
（実施例４）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのエチレン・無水マレイン酸・アクリル酸共重合体、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２３】
（実施例５）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのエチレン・アクリル酸共重合体、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２４】
（実施例６）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのエチレン・メタクリル酸共重合体、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２５】
（実施例７）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのエチレン・エチレン酢酸ビニル共重合体、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２６】
（実施例８）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み２００μｍのアイオノマー、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２７】
（実施例９）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、接着層として厚み３００μｍの合成ゴム、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００２８】
（実施例１０）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリプロピレン、厚み３．５ｍｍのポリプロピレン層を順じ被覆した。
【００２９】
（実施例１１）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、りん酸亜鉛カルシウム処理、接着層として厚み２００μｍの無水マレイン酸ポリプロピレン、厚み３．５ｍｍのポリプロピレン層を順じ被覆した。
【００３０】
（実施例１２）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３１】
（実施例１３）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、りん酸亜鉛カルシウム処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３２】
（実施例１４）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、エポキシプライマー層、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３３】
（実施例１５）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、エポキシプライマー層、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３４】
（実施例１６）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３５】
（実施例１７）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、酸洗処理で清浄にした後、溶融亜鉛めっきを施した。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３６】
（実施例１８）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、粉体エポキシ塗装を施した。エポキシ塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３７】
（実施例１９）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、粉体ポリエステル塗装を施した。ポリエステル塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３８】
（実施例２０）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００３９】
（実施例２１）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、クロメート処理後、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４０】
（実施例２２）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、りん酸亜鉛カルシウム処理後、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４１】
（実施例２３）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、りん酸亜鉛カルシウム処理後、エポキシプライマー塗装、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４２】
（実施例２４）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、クロメート処理後、エポキシプライマー塗装、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４３】
（実施例２５）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、エポキシプライマー塗装、粉体ポリエチレン塗装を施した。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４４】
（実施例２６）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、外面に無水マレイン酸変性ポリエチレンの接着層を持ち予めパイプ状に成形したポリエチレンパイプを鋼管に挿入し、縮径加工し、鋼管を加熱し、接着層を溶融接着させた。接着層は厚み２００μｍ、ポリエチレンパイプの厚みは１．５ｍｍであった。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４５】
（実施例２７）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、りん酸亜鉛カルシウム処理後、外面に無水マレイン酸変性ポリエチレンの接着層を持ち予めパイプ状に成形したポリエチレンパイプを鋼管に挿入し、縮径加工し、鋼管を加熱し、接着層を溶融接着させた。接着層は厚み２００μｍ、ポリエチレンパイプの厚みは１．５ｍｍであった。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４６】
（実施例２８）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、りん酸亜鉛カルシウム処理後、エポキシプライマー塗装後、外面に無水マレイン酸変性ポリエチレンの接着層を持ち予めパイプ状に成形したポリエチレンパイプを鋼管に挿入し、縮径加工し、鋼管を加熱し、接着層を溶融接着させた。接着層は厚み２００μｍ、ポリエチレンパイプの厚みは１．５ｍｍであった。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４７】
（実施例２９）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、エポキシプライマー塗装後、外面に無水マレイン酸変性ポリエチレンの接着層を持ち予めパイプ状に成形したポリエチレンパイプを鋼管に挿入し、縮径加工し、鋼管を加熱し、接着層を溶融接着させた。接着層は厚み２００μｍ、ポリエチレンパイプの厚みは１．５ｍｍであった。ポリエチレン塗膜は４００μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み２ｍｍのポリプロピレン層を順じ被覆した。
【００４８】
（比較例１）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリプロピレン、厚み３．０ｍｍのポリプロピレン層を順じ被覆した。
【００４９】
（比較例２）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．５ｍｍのポリエチレン層、厚み１．５ｍｍのポリプロピレン層を順じ被覆した。
【００５０】
（比較例３）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み１．０ｍｍのポリエチレン層、厚み１．５ｍｍのポリプロピレン層を順じ被覆した。
【００５１】
（比較例４）
外径８０Ａ、厚さ４．２ｍｍ、長さ４ｍの鋼管内面を脱脂し、ブラスト処理で清浄にした後、液状エポキシ塗装を施した。エポキシ塗膜は５０μｍであった。さらに鋼管外面を脱脂し、ブラスト処理で清浄した後、クロメート処理、接着層として厚み２００μｍの無水マレイン酸ポリエチレン、厚み５．０ｍｍのポリエチレン層を順じ被覆した。
【００５２】
（実施例３０）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、射出成形法により厚さ３．５ｍｍのポリプロピレン単層被覆した。
【００５３】
（実施例３１）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、射出成形法により厚さ１．５ｍｍのポリエチレン層、厚さ２．０ｍｍのポリプロピレン層の２層被覆した。
【００５４】
（実施例３２）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、射出成形法により厚さ３．５ｍｍのポリプロピレン単層被覆した。
【００５５】
（実施例３３）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、射出成形法により厚さ１．５ｍｍのポリエチレン層、厚さ２．０ｍｍのポリプロピレン層の２層被覆した。
【００５６】
（実施例３４）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ１．５ｍｍのポリエチレン層、厚さ２．０ｍｍのポリプロピレン層の２層被覆した。
【００５７】
（実施例３５）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ３．５ｍｍのポリプロピレン単層被覆した。
【００５８】
（実施例３６）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、エポキシ電着塗装後、射出成形法により厚さ１．５ｍｍのポリエチレン層、厚さ２．０ｍｍのポリプロピレン層の２層被覆した。
【００５９】
（比較例５）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ３．０ｍｍのポリプロピレン単層被覆した。
【００６０】
（比較例６）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ１．５ｍｍのポリエチレン層、厚さ１．５ｍｍのポリプロピレン層の２層被覆した。
【００６１】
（比較例７）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ１ｍｍのポリエチレン層、厚さ２ｍｍのポリプロピレン層の２層被覆した。
【００６２】
（比較例８）
前記外径８０Ａ樹脂被覆鋼管に使用する継手内面を脱脂し、酸洗して清浄にする。りん酸亜鉛処理、エポキシ電着塗装を順じ施す。継手外面は継手内面を脱脂し、ブラスト処理や酸洗して清浄にした後、りん酸亜鉛処理後、エポキシ電着塗装後、射出成形法により厚さ５ｍｍのポリエチレン被覆した。
【００６３】
（落石試験とピンホール検査）
使用した石はＪＩＳ Ａ ５００６に準拠した割ぐり、２号（２０ｋｇ）の硬石であった。石の下面と鋼管の上面の距離を高さとし、高さは１ｍとし、外面被覆に加える衝撃エネルギーが２０ｋｇｆ・ｍになるように樹脂被覆鋼管およびその継手に自然落下させた。ポンホール検査はサンコウ電子研究所製ＴＲＳ−１１０を用いて、検査電圧１２ＫＶで検査した。結果を表１〜表５に示す。
【００６４】
その結果、実施例１〜３６は、▲１▼鋼管およ継手の外面に接着層を有し、その外側に膜厚３．５ｍｍ以上のポリプロピレン層を有している被覆仕様、▲２▼鋼管および継手の外面に接着層を有し、その外側に膜厚１．５ｍｍ以上のポリオレフィン層を有し、更にその外側に膜厚２．０ｍｍ以上のポリプロピレン層を有している被覆仕様、のいずれかの仕様であり、外面被覆に加える衝撃エネルギーが２０ｋｇｆ・ｍで外面被覆に貫通疵なしであった。一方、比較例１〜８は外面被覆に加える衝撃エネルギーが２０ｋｇｆ・ｍで外面被覆に貫通発生した。耐衝撃性劣ることがわかる。
【００６５】
【表１】
【表２】
【表３】
【表４】
【表５】
【発明の効果】
以上述べたように、本発明により、ポリエチレン被覆鋼管を埋設する際、掘り出した土砂で埋め戻しを行い、産業廃棄物となる土砂を無くすもしくは可能な限り少量にできるので産業廃棄物を少なくし、環境工場に貢献できる。
【図面の簡単な説明】
【図１】樹脂被覆鋼管の受ける衝撃値と鋼管の扁平率との関係を示した図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin-coated steel pipe buried in soil or the like and a joint thereof.
[0002]
[Prior art]
Polyethylene-coated steel pipes have been widely used as pipe materials for gas, water and sewage systems, communication, and power cables. In order to avoid flaws penetrating the resin, the periphery of the steel pipe was filled with sand. For this reason, all or most of the excavated earth and sand that may contain rubs that cause penetration flaws in the polyethylene-coated steel pipe has been treated as industrial waste. Although a double-coated steel pipe coated with a polypropylene coating on the outside of a polyethylene coating is provided, for example, in Japanese Patent Application Laid-Open No. 58-42449, it has been specifically studied to withstand the work of backfilling with excavated earth and sand. I didn't.
[0003]
[Problems to be solved by the invention]
Due to the growing global environmental problems in recent years, when burying polyethylene-coated steel pipes, it has a back-filling function with excavated earth and sand to prevent or reduce as much as possible the earth and sand that become industrial waste. A resin-coated steel pipe has been desired.
[0004]
[Means for Solving the Problems]
The present inventors have intensively studied to solve the above problem. First, when backfilling with rubble contained in the excavated earth and sand, we investigated how flat the steel pipe would be depending on the weight of the rubble and the height at which it fell. Concretely, a rock was grabbed by a heavy machine, dropped naturally from above the steel pipe, and a rock fall test was performed to determine the relationship between the impact energy and the flatness of the steel pipe at the position where the stone collided. The steel pipe used was an 80A steel pipe based on JIS G 3452.
[0005]
The stones used were hard stones of No. 1 (10 kg), No. 2 (20 kg) and No. 3 (30 kg) according to JIS A 5006. The distance between the lower surface of the stone and the upper surface of the steel pipe was set to a height, and varied from 0.5 m, 0.75 m, 1 m, 1.5 m, and 2 m. The potential energy obtained by multiplying the weight and height of the stone was defined as the impact energy. The steel pipe was cut at the position where the stone collided, the outer diameter at that position was measured, and the flatness was determined from the average outer diameter measured before the test by the following formula.
(Flatness) = (outer diameter at collision position) / (average outer diameter measured before test) × 100%
[0006]
The results are shown in FIG. As a result, the present inventors have found that the tolerance of the 80A steel pipe described in JIS G 3452 exceeds ± 1% at an impact energy of about 20 kgfm. Therefore, when backfilling with excavated earth and sand, it is necessary to take measures to reduce the impact energy applied to the steel pipe to less than 20 kgfm in order to make the flatness of the steel pipe less than ± 1%. From the above investigation results, in the case of a resin-coated steel pipe and a resin-coated joint having a penetrating flaw preventing function in which no penetrating flaw is generated in the coating with an impact energy of 20 kgf · m, the impact energy applied to the steel pipe is set to less than 20 kgf · m. It can be used for backfilling the earth and sand containing the remedies that have taken measures.
[0007]
The point of the summary is,
(1) A resin-filled steel pipe for backfill, which has an adhesive layer on the outer surface of the steel pipe, and further has a polypropylene layer having a thickness of 3.5 mm or more on the outside thereof.
(2) The steel pipe has an adhesive layer on the outer surface, a polyolefin layer having a thickness of 1.5 mm or more on the outside, and a polypropylene layer having a thickness of 2.0 mm or more on the outside. Resin-coated steel pipe for backfill.
[0008]
(3) The adhesive layer is made of synthetic rubber or maleic anhydride-modified polyolefin, ethylene / maleic anhydride copolymer, ethylene / maleic anhydride / acrylic acid copolymer, ethylene / maleic anhydride / acrylic ester copolymer Coalescent, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, one or more of ionomers, The resin-coated steel pipe for backfill according to the above (1) or (2).
[0009]
(4) The resin coating for backfill according to (1) to (3), further comprising a chemical conversion treatment layer subjected to chromate treatment or phosphate treatment between the steel pipe and the adhesive layer. Steel pipe.
(5) The backfill according to (1) to (4), wherein an epoxy primer layer is provided between the steel pipe and the adhesive layer or between the chemical conversion treatment layer and the adhesive layer. For resin coated steel pipe.
[0010]
(6) The resin-filled steel pipe for backfill according to (1) to (5), wherein the steel pipe has a plating layer on an inner surface.
(7) The resin-filled steel pipe for backfill according to any one of (1) to (5), wherein the inner surface of the steel pipe is coated with any one of liquid epoxy coating, powder epoxy coating, and powder polyester coating.
(8) The above (1) to (5), wherein the inner surface of the steel pipe has a chemical conversion treatment layer subjected to a chromate treatment or a phosphate treatment and the inside thereof is further subjected to powder polyolefin coating. Resin coated steel pipe for backfill.
[0011]
(9) The resin-filled steel pipe for backfill according to any of (1) to (5), wherein the steel pipe has an adhesive layer on an inner surface thereof and further has a molded polyolefin layer on the inner side thereof.
(10) The adhesive layer is a synthetic rubber or a maleic anhydride-modified polyolefin, an ethylene / maleic anhydride copolymer, an ethylene / maleic anhydride / acrylic acid copolymer, an ethylene / maleic anhydride / acrylic acid ester copolymer Characterized in that it comprises one or more of ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid copolymer, ethylene / vinyl acetate copolymer and ionomer The resin-coated steel pipe for backfill according to (9).
[0012]
(11) The resin coating for backfill according to (9) or (10), further comprising a chemical conversion treatment layer subjected to chromate treatment or phosphate treatment between the steel pipe and the adhesive layer. Steel pipe.
(12) The backfill according to (8) to (11), wherein an epoxy primer layer is provided between the steel pipe and the adhesive layer or between the chemical conversion treatment layer and the adhesive layer. For resin coated steel pipe.
[0013]
(13) A resin-filled steel pipe joint for backfilling, wherein the joint for connecting the resin-coated steel pipes according to (1) to (12) has a polypropylene layer having a thickness of 3.5 mm or more on an outer surface.
(14) The joint for connecting the resin-coated steel pipes according to (1) to (12) above has an adhesive layer on the outer surface, a plastic layer having a thickness of 1.5 mm or more on the outer side, and further has an outer side. A resin-coated steel pipe joint for backfilling, comprising a polypropylene layer having a thickness of 2.0 mm or more.
[0014]
(15) The resin for backfill according to any one of (13) to (14), wherein the resin-coated steel pipe joint has a chemical conversion treatment layer on the outer surface of a steel portion directly subjected to chromate treatment or phosphate treatment. Coated steel pipe joint.
(16) The resin-filled steel pipe joint for backfill according to the above (15), further comprising an epoxy primer layer directly on the outer surface of the chemical conversion treatment layer.
(17) The above (14) to (16), wherein the inner surface of the resin-coated steel pipe joint has a chemical conversion treatment layer subjected to chromate treatment or phosphate treatment, and further has an epoxy layer on the inner surface. ) The resin-coated steel pipe joint for backfill described in the above.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
In the resin-coated steel pipe of the present invention, first, the inner surface of the steel pipe is degreased, and is cleaned by blasting or pickling. The inner surface of the steel pipe may be subjected to zinc plating, liquid epoxy coating, powder epoxy coating, or powder polyester coating. Alternatively, the inner surface of the steel pipe may be subjected to a chemical conversion treatment such as chromate or zinc calcium phosphate and / or an epoxy primer, followed by powdered polyethylene coating. Further, a crosslinked or non-crosslinked polyethylene pipe having a chromate on the inner surface of the steel pipe or an adhesive layer on the outer surface and previously formed into a pipe shape is subjected to a chemical conversion treatment such as zinc calcium phosphate and / or an epoxy primer, and then to the steel pipe. It is also possible to insert, reduce the diameter, heat the steel pipe, and melt-bond the adhesive layer.
[0016]
As the adhesive layer, synthetic rubber, or maleic anhydride-modified polyolefin, ethylene / maleic anhydride copolymer, ethylene / maleic anhydride / acrylic acid copolymer, ethylene / maleic anhydride / acrylic ester copolymer, ethylene -Acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid copolymer, ethylene / vinyl acetate copolymer, ionomer, or a mixture of two or more thereof is preferred.
The outer surface of the steel pipe whose inner surface has been subjected to the anticorrosion treatment as described above is degreased and cleaned by blasting or pickling. An adhesive layer and a polypropylene layer having a thickness of 3.5 mm or more are sequentially covered. Alternatively, an adhesive layer, a polyethylene layer having a thickness of 1.5 mm or more, and a polypropylene layer having a thickness of 2 mm or more are sequentially coated.
[0017]
As the adhesive layer, synthetic rubber, or maleic anhydride-modified polyolefin, ethylene / maleic anhydride copolymer, ethylene / maleic anhydride / acrylic acid copolymer, ethylene / maleic anhydride / acrylic ester copolymer, ethylene -Acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid copolymer, ethylene / vinyl acetate copolymer, ionomer, or a mixture of two or more thereof is preferred. It is preferable to drop the synthetic rubber that has been heated and melted on the outer surface of the steel pipe and squeeze it with a rubber spatula. Also, maleic anhydride-modified polyolefin, ethylene / maleic anhydride copolymer, ethylene / maleic anhydride / acrylic acid copolymer, ethylene / maleic anhydride / acrylic acid ester copolymer, ethylene / acrylic acid copolymer, Adhesives such as ethylene / acrylate copolymers, ethylene / methacrylic acid copolymers, ethylene / vinyl acetate copolymers, ionomers, and polyethylene and polypropylene are heated and melted by an extruder, and round and T dies are used. Extrusion coating on the outer surface of the steel pipe.
[0018]
If necessary, additives such as an antioxidant, an ultraviolet absorber, a flame retardant, a pigment, a filler, a lubricant, an antistatic agent, and other resins may be mixed with the polyethylene, polypropylene, or the like. Before coating the adhesive layer, one or both of a chemical conversion treatment such as chromate and zinc calcium phosphate and an epoxy primer can be applied. In the joint of the present invention used for the above resin-coated steel pipe, first, the inner surface of the joint is degreased and cleaned by blasting or pickling. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, and is cleaned by blasting or pickling, and then a single layer of polypropylene having a thickness of 3.5 mm or more or a polyethylene layer having a thickness of 1.5 mm or more is formed by injection molding. Two layers of a polypropylene layer having a thickness of 2.0 mm or more are coated. After cleaning by blasting or pickling, one or both of zinc phosphate treatment and epoxy electrodeposition may be applied before injection molding.
[0019]
【Example】
(Example 1)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blast treatment, a maleic anhydride polypropylene having a thickness of 200 μm and a polypropylene layer having a thickness of 3.5 mm were sequentially coated as an adhesive layer.
[0020]
(Example 2)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, an adhesive layer was sequentially coated with a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer.
[0021]
(Example 3)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blast treatment, an adhesive layer was sequentially coated with an ethylene / maleic anhydride copolymer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm.
[0022]
(Example 4)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blast treatment, an ethylene / maleic anhydride / acrylic acid copolymer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer. .
[0023]
(Example 5)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, an ethylene-acrylic acid copolymer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer.
[0024]
(Example 6)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, an ethylene-methacrylic acid copolymer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer.
[0025]
(Example 7)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, an ethylene / ethylene / vinyl acetate copolymer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer.
[0026]
(Example 8)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, an ionomer having a thickness of 200 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer.
[0027]
(Example 9)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, a synthetic rubber having a thickness of 300 μm, a polyethylene layer having a thickness of 1.5 mm, and a polypropylene layer having a thickness of 2 mm were sequentially coated as an adhesive layer.
[0028]
(Example 10)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, a chromate treatment and a 200 μm-thick maleic anhydride polypropylene and a 3.5 mm-thick polypropylene layer were sequentially coated as an adhesive layer.
[0029]
(Example 11)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was treated with zinc calcium phosphate, followed by coating with a 200 μm-thick maleic anhydride polypropylene and a 3.5 mm-thick polypropylene layer as an adhesive layer.
[0030]
(Example 12)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0031]
(Example 13)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was treated with zinc calcium phosphate and coated as a bonding layer with 200 μm-thick polyethylene maleate anhydride, 1.5 mm-thick polyethylene layer, and 2 mm-thick polypropylene layer in this order.
[0032]
(Example 14)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, a chromate treatment, an epoxy primer layer, a 200 μm-thick maleic anhydride polyethylene as an adhesive layer, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer were sequentially coated. .
[0033]
(Example 15)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, the outer surface of the steel pipe was degreased and cleaned by a blast treatment, and thereafter, an epoxy primer layer, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer were sequentially coated as an adhesive layer.
[0034]
(Example 16)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0035]
(Example 17)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by pickling, followed by galvanizing. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0036]
(Example 18)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blast treatment, and then subjected to powder epoxy coating. The epoxy coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0037]
(Example 19)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blast treatment, and then subjected to powder polyester coating. The polyester coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0038]
(Example 20)
The inner surface of a steel pipe having an outer diameter of 80A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blast treatment, and then subjected to powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0039]
(Example 21)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to chromate treatment, followed by powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0040]
(Example 22)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, treated with zinc calcium phosphate, and then subjected to powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0041]
(Example 23)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blasting, followed by zinc calcium phosphate treatment, followed by epoxy primer coating and powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0042]
(Example 24)
The inner surface of a steel pipe having an outer diameter of 80A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blasting, followed by chromate treatment, epoxy primer coating, and powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0043]
(Example 25)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased and cleaned by blast treatment, and then subjected to epoxy primer coating and powdered polyethylene coating. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0044]
(Example 26)
A steel pipe having an outer diameter of 80A, a thickness of 4.2 mm, and a length of 4 m is degreased and cleaned by blasting, and then has a maleic anhydride-modified polyethylene adhesive layer on the outer surface and is formed into a pipe shape in advance. And the diameter was reduced, the steel pipe was heated, and the adhesive layer was melt-bonded. The thickness of the adhesive layer was 200 μm, and the thickness of the polyethylene pipe was 1.5 mm. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0045]
(Example 27)
The inner surface of a steel pipe with an outer diameter of 80A, thickness of 4.2mm, and length of 4m is degreased, cleaned by blasting, treated with zinc calcium phosphate, and has an adhesive layer of maleic anhydride-modified polyethylene on the outer surface. The polyethylene pipe was inserted into a steel pipe, the diameter of the pipe was reduced, the steel pipe was heated, and the adhesive layer was melt-bonded. The thickness of the adhesive layer was 200 μm, and the thickness of the polyethylene pipe was 1.5 mm. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0046]
(Example 28)
80A outer diameter, 4.2mm thickness, 4m length, degrease the inner surface of steel pipe, clean by blasting, after zinc zinc phosphate treatment, epoxy primer coating, adhesive layer of maleic anhydride-modified polyethylene on outer surface Then, a polyethylene pipe previously formed into a pipe shape was inserted into a steel pipe, the diameter was reduced, the steel pipe was heated, and the adhesive layer was melt-bonded. The thickness of the adhesive layer was 200 μm, and the thickness of the polyethylene pipe was 1.5 mm. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0047]
(Example 29)
80A outer diameter, 4.2mm thickness, 4m length, degrease the inner surface of the steel pipe, clean it by blast treatment, apply epoxy primer, and form male-anhydride-modified polyethylene adhesive layer on the outer surface and form it into a pipe beforehand The polyethylene pipe thus obtained was inserted into a steel pipe, diameter-reduced, the steel pipe was heated, and the adhesive layer was melt-bonded. The thickness of the adhesive layer was 200 μm, and the thickness of the polyethylene pipe was 1.5 mm. The polyethylene coating was 400 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment, a 200 μm-thick maleic anhydride polyethylene, a 1.5 mm-thick polyethylene layer, and a 2 mm-thick polypropylene layer as an adhesive layer in this order.
[0048]
(Comparative Example 1)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, the outer surface of the steel pipe was degreased and cleaned by a blast treatment, and thereafter, a chromate treatment, and a 200-μm-thick maleic anhydride polypropylene and a 3.0-mm-thick polypropylene layer were sequentially coated as an adhesive layer.
[0049]
(Comparative Example 2)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was coated with a chromate treatment and a 200 μm-thick maleic anhydride polyethylene, a 1.5-mm-thick polyethylene layer, and a 1.5-mm-thick polypropylene layer as an adhesive layer in this order.
[0050]
(Comparative Example 3)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was chromate-treated, and a 200 μm-thick maleic anhydride polyethylene, a 1.0 mm-thick polyethylene layer and a 1.5 mm-thick polypropylene layer were sequentially coated as an adhesive layer.
[0051]
(Comparative Example 4)
The inner surface of a steel pipe having an outer diameter of 80 A, a thickness of 4.2 mm, and a length of 4 m was degreased, cleaned by blasting, and then subjected to liquid epoxy coating. The epoxy coating was 50 μm. Further, after the outer surface of the steel pipe was degreased and cleaned by blasting, it was chromate-treated, and a 200 μm-thick maleic anhydride polyethylene and a 5.0 mm-thick polyethylene layer were sequentially coated as an adhesive layer.
[0052]
(Example 30)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, and then coated with a 3.5-mm-thick polypropylene single layer by an injection molding method.
[0053]
(Example 31)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, and then coated with a 1.5-mm-thick polyethylene layer and a 2.0-mm-thick polypropylene layer by injection molding.
[0054]
(Example 32)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, then treated with zinc phosphate, and then coated with a 3.5 mm-thick polypropylene single layer by an injection molding method.
[0055]
(Example 33)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, and then subjected to injection molding to form a polyethylene layer having a thickness of 1.5 mm and a polypropylene layer having a thickness of 2.0 mm. Layer coated.
[0056]
(Example 34)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, coated with an epoxy electrodeposition coating, and subjected to injection molding to form a polyethylene layer having a thickness of 1.5 mm. Two layers of 0 mm polypropylene layer were coated.
[0057]
(Example 35)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, coated with epoxy electrodeposition, and coated with a 3.5 mm-thick polypropylene single layer by injection molding.
[0058]
(Example 36)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, cleaned by blasting or pickling, and is coated with an epoxy electrodeposition coating. Then, a polyethylene layer having a thickness of 1.5 mm and a polypropylene layer having a thickness of 2.0 mm are formed by injection molding. Layer coated.
[0059]
(Comparative Example 5)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, coated with epoxy electrodeposition, and coated with a single layer of polypropylene having a thickness of 3.0 mm by an injection molding method.
[0060]
(Comparative Example 6)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, coated with epoxy electrodeposition, and then subjected to injection molding to form a polyethylene layer having a thickness of 1.5 mm. Two 5 mm polypropylene layers were coated.
[0061]
(Comparative Example 7)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint is degreased from the inner surface of the joint, cleaned by blasting or pickling, treated with zinc phosphate, coated with epoxy electrodeposition, polyethylene layer with a thickness of 1 mm by injection molding, and polypropylene layer with a thickness of 2 mm. In two layers.
[0062]
(Comparative Example 8)
The inner surface of the joint used for the outer diameter 80A resin-coated steel pipe is degreased, pickled and cleaned. Apply zinc phosphate treatment and epoxy electrodeposition coating in order. The outer surface of the joint was degreased from the inner surface of the joint, cleaned by blasting or pickling, cleaned with zinc phosphate, coated with epoxy electrodeposition, and coated with a 5 mm-thick polyethylene by injection molding.
[0063]
(Falling stone test and pinhole inspection)
The stone used was a crushed No. 2 (20 kg) hard stone based on JIS A 5006. The distance between the lower surface of the stone and the upper surface of the steel pipe was set to a height, and the height was set to 1 m. The resin was naturally dropped on the resin-coated steel pipe and its joints so that the impact energy applied to the outer surface coating became 20 kgfm. Pomhole inspection was performed at an inspection voltage of 12 KV using TRS-110 manufactured by Sanko Electronics Research Laboratory. The results are shown in Tables 1 to 5.
[0064]
As a result, Examples 1 to 36 were (1) a coating specification having an adhesive layer on the outer surface of the steel pipe and the joint, and having a polypropylene layer having a thickness of 3.5 mm or more on the outer side. And a coating specification having an adhesive layer on the outer surface of the joint, having a polyolefin layer having a thickness of 1.5 mm or more outside thereof, and further having a polypropylene layer having a thickness of 2.0 mm or more outside thereof. The impact energy applied to the outer surface coating was 20 kgf · m, and the outer surface coating had no penetration flaw. On the other hand, in Comparative Examples 1 to 8, the impact energy applied to the outer surface coating was 20 kgf · m, and penetrated the outer surface coating. It can be seen that the impact resistance is poor.
[0065]
[Table 1]
[Table 2]
[Table 3]
[Table 4]
[Table 5]
【The invention's effect】
As described above, according to the present invention, when burying a polyethylene-coated steel pipe, it is backfilled with excavated earth and sand, so that the earth and sand that becomes industrial waste can be eliminated or reduced as much as possible, thereby reducing industrial waste. Can contribute to environmental factories.
[Brief description of the drawings]
FIG. 1 is a diagram showing a relationship between an impact value received by a resin-coated steel pipe and an oblateness of the steel pipe.
Claims (17)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002172238A JP2004017337A (en) | 2002-06-13 | 2002-06-13 | Resin-coated steel pipe for backfill and joint thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002172238A JP2004017337A (en) | 2002-06-13 | 2002-06-13 | Resin-coated steel pipe for backfill and joint thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2004017337A true JP2004017337A (en) | 2004-01-22 |
Family
ID=31171856
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002172238A Pending JP2004017337A (en) | 2002-06-13 | 2002-06-13 | Resin-coated steel pipe for backfill and joint thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2004017337A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014111978A1 (en) * | 2013-01-18 | 2014-07-24 | 日新製鋼株式会社 | Shaped and coated metallic material, composite, and method for manufacturing shaped and coated metallic material and composite |
| WO2016199339A1 (en) * | 2015-06-12 | 2016-12-15 | 日本軽金属株式会社 | Metal resin composite molded body and method for producing same |
| JP2017001378A (en) * | 2015-06-12 | 2017-01-05 | 日本軽金属株式会社 | Metal resin composite molded body and method for producing the same |
-
2002
- 2002-06-13 JP JP2002172238A patent/JP2004017337A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014111978A1 (en) * | 2013-01-18 | 2014-07-24 | 日新製鋼株式会社 | Shaped and coated metallic material, composite, and method for manufacturing shaped and coated metallic material and composite |
| EA023554B1 (en) * | 2013-01-18 | 2016-06-30 | Ниссин Стил Ко., Лтд. | Shaped and coated metallic material, composite, and method for manufacturing shaped and coated metallic material and composite |
| WO2016199339A1 (en) * | 2015-06-12 | 2016-12-15 | 日本軽金属株式会社 | Metal resin composite molded body and method for producing same |
| JP2017001378A (en) * | 2015-06-12 | 2017-01-05 | 日本軽金属株式会社 | Metal resin composite molded body and method for producing the same |
| CN107709002A (en) * | 2015-06-12 | 2018-02-16 | 日本轻金属株式会社 | Metal-resin composite shaped body and its manufacture method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8454773B2 (en) | Induction welded waterproofing | |
| CN107060796A (en) | One kind uses Slurry Balanced Pipe Jacking Construction technique | |
| US20090173441A1 (en) | Method for joining piping systems and piping to equipment, fixtures, devices, structures, and appliances | |
| DE3581305D1 (en) | A FILLING, COATING AND FIXING MATERIAL CONTAINING A HYDRAULIC AND A LATENT HYDRAULIC BINDING AGENT. | |
| CN103372534B (en) | The metal objects of coating | |
| UA103007C2 (en) | Method for application of coating to metal pipeline, and pipeline produced by this method | |
| KR102075320B1 (en) | Immersion Tube for repairing pipeline using hot-melt and Method for manufacturing the immersion tube | |
| CN108867712B (en) | Side slope, pit bottom and substrate seepage prevention method based on tailing composite seepage prevention material | |
| JP2004017337A (en) | Resin-coated steel pipe for backfill and joint thereof | |
| JP4691229B2 (en) | Pipe coating method and stretched resin pipe manufacturing method | |
| JP2000190422A (en) | Polyolefin-coated steel material | |
| JP2019166815A (en) | Anticorrosive sheet and method for protecting concrete structure | |
| JP3193983B2 (en) | How to reuse excavated soil | |
| JPH10159495A (en) | Lining method of inside wall of tunnel and lining structure | |
| JPS5829916A (en) | Corrosion resistance processing method for ocean structure | |
| CN210179075U (en) | PE pipeline and geomembrane butt-joint structure | |
| JP4825711B2 (en) | Repair method of water shielding sheet made of thermoplastic resin | |
| JP2001056090A (en) | Protection method of propulsion pipe | |
| JPH08296227A (en) | Driven member made of coated steel | |
| JP2006177533A (en) | Polyolefin pipe with protective layer | |
| JP2005054001A (en) | Resin composition for floor material-welding bar | |
| GB2389560B (en) | Waterproofing material | |
| JPH0248430Y2 (en) | ||
| JPH10311494A (en) | Anticorrosive covering method of anticorrosive cover steel pipe joint | |
| RU63482U1 (en) | PIPELINE LOADER |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20041217 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061122 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20061205 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20070403 |