JP4058618B2 - Coated optical fiber core, coated optical fiber core with connector, optical fiber cord, optical fiber cord with connector, and optical fiber cable - Google Patents

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【００７１】
【表２】

【００７２】
【表３】

【００７３】
【表４】

【００７４】
【表５】

【００７５】
表中の（Ｅ−１）〜（Ｅ−１３）、（Ｐ−１）〜（Ｐ−３）は以下の通りである。
なお、ＭＩは、メルトインデックス（Melt Index）の略称である。ＭＩは、シリンダーに樹脂組成物を詰め、１９０℃の温度下、シリンダーの上部からピストンを２．１６ｋｇの一定荷重で押す場合に、シリンダーの下部から流れ出る樹脂組成物の量を示す指標である。ＭＩが大きいほど、シリンダーから流れ出る樹脂組成物の量が多いことを示し、樹脂組成物の流動性が高いことを意味する。
ＯＩは、酸素指数（Oxygen Index）の略称であり、樹脂組成物が燃焼するために必要とする酸素の濃度指数である。ＯＩが大きいほど、樹脂組成物が燃焼するための酸素をより必要とするので、難燃性が高いことを意味する。
【００７６】
（Ｅ−１）
ＳＥＢＳ（スチレン含量１８％，引張り強さ１５ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝１．５，ＯＩ＝２１）
【００７７】
（Ｅ−２）
シンジオタクチック−１，２−ポリブタジエン（融点：１０５℃，引張り強さ：１２．７ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝０．２，ＯＩ＝２１）
【００７８】
（Ｅ−３）
ＳＥＰＳ（スチレン含量１３重量％，引張り強さ１０．８ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝２．０，ＯＩ＝２０）
【００７９】
（Ｅ−４）
ＳＥＢＣ（スチレン含量２０重量％，引張り強さ１７．０ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝３．０，ＯＩ＝２２）
【００８０】
（Ｅ−５）
ＳＥＢＳ（スチレン含量３０重量％，引張り強さ２１．６ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝２．０，ＯＩ＝２２）
【００８１】
（Ｅ−６）
ＳＢＳ（スチレン含量４０重量％，引張り強さ１４．０ＭＰａ）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝３．０，ＯＩ＝２３）
【００８２】
（Ｅ−７）
ＳＥＰＳ（スチレン含量１３重量％，引張り強さ１０．８ＭＰａ）の樹脂分のみ（難燃剤を含有しない）（ＭＩ＝２．５，ＯＩ＝１７）
【００８３】
（Ｅ−８）
シンジオタクチック−１，２−ポリブタジエン（融点：１０５℃，引張り強さ１２．７ＭＰａ）の樹脂分のみ（難燃剤を含有しない）（ＭＩ＝１．５，ＯＩ＝１７）
【００８４】
（Ｅ−９）
エチレン・ビニルアセテート樹脂（ＥＶＡ）（ビニルアセテート含量１３重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝２．０，ＯＩ＝２０）
【００８５】
（Ｅ−１０）
エチレン・ビニルアセテート樹脂（ＥＶＡ）（ビニルアセテート含量１９重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝４．０，ＯＩ＝２０）
【００８６】
（Ｅ−１１）
エチレン・ビニルアセテート樹脂（ＥＶＡ）（酢酸ビニル含量２８重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝５．０，ＯＩ＝２２）
【００８７】
（Ｅ−１２）
エチレン・ビニルアセテート樹脂（ＥＶＡ）（酢酸ビニル含量１７重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝７．５，ＯＩ＝２０）
【００８８】
（Ｅ−１３）
エチレン・エチルアクリレート樹脂（ＥＥＡ）（エチルアクリレート含量１９重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝４．０，ＯＩ＝２０）
【００８９】
（Ｐ−１）
ＨＩＰＳ（ブタジエン含量２３重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝１．０，ＯＩ＝２１）
【００９０】
（Ｐ−２）
ブロックＰＰ（融点：１６８℃）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝１．０，ＯＩ＝１９）
【００９１】
（Ｐ−３）
ＨＩＰＳ（ブタジエン含量２３重量％）を樹脂分とするノンハロゲン樹脂組成物（ＭＩ＝０．５，ＯＩ＝２１）
【００９２】
被覆光ファイバ心線に対する各種試験の方法は、以下のようにして行う。
【００９３】
［被覆除去性］
２５℃の下、実施例及び比較例の被覆光ファイバ心線の末端から長さ３０ｍｍの部分を図５に示す被覆除去具に対応する「被覆除去具ＪＲ−２２」（住友電気工業株式会社の商品名）を用いて、外部被覆を除去する。各被覆光ファイバ心線の対して被覆の除去を、３試行分、行う。３試行の全てにおいて、除去時の引き抜き力が２．０ｋｇ・ｆ以下であり、ガラスファイバの上に紫外線硬化型樹脂層が残留せず、ガラスファイバの破断が見られないものを合格とする。前記条件を満たさないものを不合格とする。なお、表中の引き抜き力は、３試行の平均値であり、比較例５及び比較例６においては、３試行の全てにおいて、ガラスファイバが破断する。
【００９４】
ここで、引き抜き力は、以下のようにして得られる値である。
引き抜き力：「被覆光ファイバ心線の末端から長さ３０ｍｍの部分を被覆除去具ＪＲ−２２の刃により挟み込んだ状態で固定し、引張り試験器を用いて引張り速度５００ｍｍ／分の条件で引張り試験を行う（被覆除去具と引張り試験器のチャックとの距離＝１００ｍｍ）時に要する力の最大値」
【００９５】
［機械特性（側圧特性）］
実施例及び比較例の被覆光ファイバ心線に対して、長手方向長さ１００ｍｍ当たり５００ｋｇの荷重を加え（Ｒ５のエッジを有する平滑な金属板に当該心線を挟んで、荷重を加えていく。）、伝送損失量（ｄＢ／１００ｍｍ）を測定する（荷重を加える前後の光の減衰量をマルチメータ（例えば、安藤電気製のＡＱ２１４０）で測定する。この値を側圧ロス（ｄＢ／１００ｍｍ）として表１〜表５に示す。側圧ロスが０．１ｄＢ／１００ｍｍ以下のものは、信頼性が高く、合格とする。
【００９６】
［環境適応特性（温度の変動によっても、光伝送特性を高次元で維持する特性）］
実施例及び比較例の被覆光ファイバ心線を、ＯＴＤＲ測定器（波長：１．３１μｍ）にて伝送損失量（ｄＢ）を測定し、単位長あたりの伝送損失を初期ロス（ｄＢ／ｋｍ）とする。初期ロスが１．０ｄＢ／ｋｍ以下のものは、信頼性が高く、合格とする。
次に、被覆光ファイバ心線に対して、−２０℃（６時間保持）〜６０℃（６時間保持）を３サイクル繰り返すヒートサイクル曝露試験を実施し、その試験中、連続モニター（波長：１．３１μｍ）にて伝送損失量（ｄＢ）を測定し、初期ロスとの差分の最大値を「温度変化ロス（ｄＢ／ｋｍ）］として表１〜表５に示す。温度変化ロスが、０．３ｄＢ／ｋｍ以下のものを合格とする。
【００９７】
［難燃性］
実施例及び比較例の被覆光ファイバ心線に対して、ＪＩＳ ３００５に準拠した水平燃焼試験を行い、自消性を示すものを合格とする。
【００９８】
［ハンドリング性］
実施例及び比較例の被覆光ファイバ心線の末端から長さ３０ｍｍの部分を図５に示す被覆除去具に対応する「被覆除去具ＪＲ−２２」（住友電気工業株式会社の商品名）を用いて、紫外線樹脂被覆層と外部被覆とを同時に除去する。次いで、ガラスファイバ露出部をフェルールの中空に収容し、被覆除去端面をフェルールの突き当て端面に当接させて被覆光ファイバ心線の末端にコネクタを取り付ける。
ガラスファイバ露出部をフェルールの中空に通す工程からコネクタ取り付けが完了するまでのハンドリング性において、被覆光ファイバ心線にこしが有り、フェルールの中空に通す工程で失敗することなく、通すことができ、コネクタ取り付けまでの工程で、被覆光ファイバ心線に曲げ癖がつかないものを、ハンドリング性良好と判定し、○とする。一方、被覆光ファイバ心線にこしが無く、フェルールの中空に通す工程で一回でも挿入ミスがあったり、あるいはコネクタ取り付けまでの工程で、被覆光ファイバ心線に曲げ癖がつくものを、ハンドリング性不良と判定し、×とする。
【００９９】
［耐熱性］
Telcordia規格（ＧＲ−３２６）に使用される８５℃×１６８時間の条件の耐熱性試験を行い、その試験中、連続モニター（波長：１．３１μｍ）にて伝送損失量（ｄＢ）を測定し、初期ロスとの差分の最大値を「耐熱ロス（ｄＢ／ｋｍ）］として表１〜表５に示す。耐熱ロスが、０．２ｄＢ／ｋｍ以下のものを合格とする。
また、上記耐熱性試験の前後における無偏肉率を測定し、８０％以上を信頼性が高く、合格とする。無偏肉率は、以下の式にて算出する。
無偏肉率（％）＝「外部被覆の厚さの最小値」／「外部被覆の厚さの最大値」×１００
【０１００】
実施例１〜５の被覆光ファイバ心線は、第一樹脂組成物及び第二樹脂組成物が共に難燃剤を含み、第一樹脂が、ポリスチレン系熱可塑性エラストマー、ポリブタジエン系熱可塑性エラストマーまたはエチレン−αオレフィン共重合体、第二樹脂が、ポリプロピレン系樹脂であり、第一被覆層のヤング率及び引張り強さ、第二被覆層のヤング率が本発明に規定する範囲内の被覆光ファイバ心線である。実施例の被覆光ファイバ心線は、初期ロスが少ないだけでなく、機械特性、環境適応特性、被覆除去性、難燃性、ハンドリング性及び耐熱性の全てに優れる。
【０１０１】
比較例１及び比較例２の被覆光ファイバ心線は、第一樹脂が、それぞれ、ポリスチレン系熱可塑性エラストマー及びポリブタジエン系熱可塑性エラストマーであり、第二樹脂が、それぞれ、ポリプロピレン系樹脂及びポリスチレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下ではあるものの、引張り強さが１０ＭＰａを超え、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。比較例１及び比較例２の被覆光ファイバ心線は、初期ロスが少なく、機械特性、環境適応特性、難燃性、ハンドリング性及び耐熱性に優れるが、被覆除去後に紫外線硬化型樹脂が残留し、被覆除去性に劣る。
【０１０２】
比較例３及び比較例４の被覆光ファイバ心線は、第一樹脂が、それぞれ、ポリスチレン系熱可塑性エラストマー及びポリブタジエン系熱可塑性エラストマーであり、第二樹脂がポリプロピレン系樹脂であり、第一被覆層のヤング率（７．５ＭＰａ）が１５０ＭＰａ以下ではあるものの、引張り強さが１０ＭＰａを超え、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。また、第一樹脂組成物は、金属酸化物や酸化防止剤などの配合物を一切添加しない樹脂単体である。比較例３及び比較例４の被覆光ファイバ心線は、初期ロスが少なく、機械特性、環境適応特性、ハンドリング性及び耐熱性に優れるが、難燃性に劣り、また、被覆除去後に紫外線硬化型樹脂が残留し、被覆除去性に劣る。
【０１０３】
比較例５の被覆光ファイバ心線は、第一被覆層が実施例１と同構成であり、第二樹脂がポリスチレン系樹脂であり、第二被覆層のヤング率が７００ＭＰａ未満の被覆光ファイバ心線である。比較例５の被覆光ファイバ心線は、初期ロスが少なく、環境適応特性、難燃性、ハンドリング性及び耐熱性に優れるが、機械特性に劣り、被覆除去時に第二被覆層の座屈によりガラスファイバが破断し、被覆除去性に劣る。
【０１０４】
比較例６の被覆光ファイバ心線は、第一樹脂がＥＶＡ（酢酸ビニル含量１４重量％）であり、第二被覆層が実施例１と同構成であり、第一被覆層のヤング率が１５０ＭＰａを超える被覆光ファイバ心線である。比較例６の被覆光ファイバ心線は、初期ロスが少なく、環境適応特性、難燃性、ハンドリング性及び耐熱性に優れるが、機械特性に劣り、被覆除去時に第二被覆層の座屈によりガラスファイバが破断し、被覆除去性に劣る。
【０１０５】
参考例１〜２の被覆光ファイバ心線は、第一樹脂が、それぞれ、ポリスチレン系熱可塑性エラストマー及びポリブタジエン系熱可塑性エラストマーであり、第二樹脂が、それぞれ、ポリスチレン系樹脂及びポリプロピレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下、引張強さが１０ＭＰａ以下、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。第一被覆層までの外径は０．８ｍｍφを超えている。参考例１〜２の被覆光ファイバ心線は、初期ロスが少なく、環境適応特性、被覆除去性、難燃性及び耐熱性に優れるが、機械特性及びハンドリング性に劣る。
【０１０６】
参考例３〜４の被覆光ファイバ心線は、第一樹脂が、それぞれ、ポリスチレン系熱可塑性エラストマー及びポリブタジエン系熱可塑性エラストマーであり、第二樹脂が、それぞれ、ポリプロピレン系樹脂及びポリスチレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下、引張強さが１０ＭＰａ以下、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。第一被覆層までの外径は０．３ｍｍφ未満である。参考例３〜４の被覆光ファイバ心線は、初期ロスが少なく、環境適応特性、被覆除去性、難燃性、ハンドリング性及び耐熱性に優れるが、機械特性に劣る。
【０１０７】
比較例７の被覆光ファイバ心線は、第一樹脂がＥＶＡ（酢酸ビニル含量１９重量％）であり、第二樹脂がポリスチレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下、引張強さが１０ＭＰａを超え、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。比較例７の被覆光ファイバ心線は、初期ロスが少なく、機械特性、環境適応特性、難燃性及びハンドリング性に優れるが、被覆除去後に紫外線硬化型樹脂が残留し、被覆除去性に劣る。また、Telcordia規格（ＧＲ−３２６）の耐熱性試験では、耐熱性試験後の無偏肉率が８０％未満となり、波長１．３１μｍの伝送損失量の最大値が０．２ｄＢ／ｋｍを超え、耐熱性に劣る。
【０１０８】
参考例５の被覆光ファイバ心線は、第一樹脂がＥＶＡ（酢酸ビニル含量２８重量％）であり、第二樹脂がポリプロピレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下、引張強さが１０ＭＰａ以下、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。参考例５の被覆光ファイバ心線は、初期ロスが少なく、機械特性、環境適応特性、被覆除去性、難燃性及びハンドリング性に優れるが、Telcordia規格（ＧＲ−３２６）の耐熱性試験では、耐熱性試験後の無偏肉率が８０％未満となり、波長１．３１μｍの伝送損失量の最大値が０．２ｄＢ／ｋｍを超え、耐熱性に劣る。
【０１０９】
比較例８の被覆光ファイバ心線は、第一樹脂がＥＶＡ（酢酸ビニル含量１９重量％）であり、第二樹脂がポリスチレン系樹脂であり、第一被覆層のヤング率が１５０ＭＰａ以下、引張強さが１０ＭＰａを超え、第二被覆層のヤング率が７００ＭＰａ以上の被覆光ファイバ心線である。第一被覆層までの外径は０．８ｍｍφを超えている。比較例８の被覆光ファイバ心線は、初期ロスが少なく、環境適応特性及び難燃性に優れるが、機械特性及びハンドリング性に劣り、また、被覆除去後に紫外線硬化型樹脂が残留し、被覆除去性に劣る。また、Telcordia規格（ＧＲ−３２６）の耐熱性試験では、耐熱性試験後の無偏肉率が８０％未満となり、波長１．３１μｍの伝送損失量の最大値が０．２ｄＢ／ｋｍを超え、耐熱性に劣る。
【０１１０】
なお、実施例、比較例及び参考例の被覆光ファイバ心線に使用した第一樹脂及び第二樹脂は、いずれも、ノンハロゲン樹脂から選択されている。
【０１１１】
【発明の効果】
本発明によれば、燃焼時に有毒ガスを発生しない特性、高い難燃性、高い環境適応特性、及び、高い機械特性を有するとともに、被覆除去をガラスファイバの破断を頻発させることなく容易に実施できる被覆光ファイバ心線、並びに、これを用いたコネクタ付被覆光ファイバ心線、光ファイバコード、コネクタ付光ファイバコード及び光ファイバケーブルを提供できる。
【図面の簡単な説明】
【図１】本発明の実施形態に係る被覆光ファイバ心線の模式断面図である。
【図２】本発明の実施形態に係る被覆光ファイバ心線の製造を説明する図である。
【図３】本発明の実施形態に係る被覆光ファイバ心線の被覆除去を説明する図である。
【図４】本発明の実施形態に係るコネクタ付被覆光ファイバ心線の製造を説明する図である。
【図５】被覆光ファイバ心線の被覆除去に使用する被覆除去具を示す図である。
【図６】本発明の実施形態に係る光ファイバケーブルの模式断面図である。
【図７】従来の被覆光ファイバ心線を説明する図である。
【符号の説明】
10，100 被覆光ファイバ心線
11，101 ガラスファイバ
11A ガラスファイバ露出部
11B ガラスファイバの先端面
13，103 光ファイバ心線
14 第一被覆層
15 第二被覆層
16，104 外部被覆
16A 被覆除去端面
17A 中空
17 フェルール
17B フェルールの突き当て端面
17C フェルールの開放端面
18 コネクタ
19 コネクタ付被覆光ファイバ心線
50 光ファイバケーブル
51 テンションメンバ
52 緩衝材
53 押え巻き層
54 樹脂層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coated optical fiber, a coated optical fiber with connector, an optical fiber cord, an optical fiber cord with connector, and an optical fiber cable.
[0002]
[Prior art]
An optical fiber core wire 103 having an outer diameter of 250 μm to 265 μm, in which the outer side of a glass fiber 101 having an outer diameter of 125 μm mainly composed of quartz glass is coated with an ultraviolet curable resin layer 102, is used for an optical cord or the like. Known as. Here, the optical cord is usually in the form of a coated optical fiber core 100 in which an outer coating 104 made of vinyl chloride or the like is provided on the outside of the optical fiber core 103, and is used for wiring of optical communication equipment or the like. (See the cross-sectional view of FIG. 7A).
On the other hand, as an optical cord, a coated optical fiber core (silicone / nylon core) in which a silicone resin and a nylon resin are sequentially provided as an outer coating on the outer periphery of a glass fiber having an outer diameter of 125 μm mainly composed of quartz glass. It has been known.
[0003]
When the coated optical fiber core 100 is used as an optical cord, a connector that can be connected to other optical communication devices is usually attached to the end of the coated optical fiber core 100. First, the coating of the coated optical fiber 100 (ultraviolet curable resin) is performed using a coating removal tool described later so that the glass fiber 101 at the end of the optical fiber is exposed at a predetermined distance (about 30 mm). 102 and the outer coating 104) need to be removed.
[0004]
5A and 5B are diagrams showing a coating removing tool used for coating removal of the coated optical fiber, wherein FIG. 5A is a side view of the coating removing tool, and FIG. 5B is a cross-sectional view in the X direction. It is.
The sheath removing tool 20 has two pairs of guide portions 23 and a pair of blades 22 inside the end portions on the opening and closing sides of the plate-like lever members 21a and 21b with one end pivotally connected. The plate-like lever members 21a and 21b are closed by sandwiching a portion about 30 mm away from the end of the coated optical fiber core wire 100, so that each V groove 23a of each of the two pairs of guide portions is fixed. The coated optical fiber core wire 100 is held therein, and the coating of the coated optical fiber core wire 100 is cut with a pair of blades 22. Since a semicircular recess (not shown) is formed at the blade tip of the blade 22 at a position where the coated optical fiber core wire 100 is disposed, the glass fiber in the coated optical fiber core wire 100 is not formed. The cutting edge does not reach the surface, and the glass fiber is not damaged.
[0005]
Next, with the plate lever members 21a and 21b closed, the sheath removal tool 20 is moved to the terminal side of the coated optical fiber core 100 so that the terminal side portion of the coated optical fiber core wire 100 is moved in the terminal direction. Drawing and exposing the glass fiber at the end of the coated optical fiber core 100 are exposed. At this time, since there is a slight gap between the surface of the glass fiber and the cutting edges and between the cutting edges, the covering of the gap portion is not cut by the cutting of the cutting edge but is torn by the movement of the cutting edge.
[0006]
Then, normally, a connector having a hollow ferrule capable of accommodating the exposed glass fiber is prepared, and the coating removal end face is brought into contact with the abutting end face of the ferrule while the glass fiber is accommodated in the hollow. A connector is attached to the end portion of the optical fiber core, and then processed so that the front end surface of the glass fiber and the open end surface of the ferrule have a predetermined shape.
[0007]
When the outer coating 104 of the coated optical fiber core 100 has a single layer structure, as a resin constituting the outer coating 104, a polyester-based thermoplastic elastomer (see JP-A-5-1554950 and JP-A-11-60285) ), A mixture of polypropylene and styrene-based thermoplastic elastomer in a predetermined ratio (see JP-A-9-33770), a mixture of polyamide 6 and an olefin-based thermoplastic elastomer in a predetermined ratio (see JP-A-11-241018) It has been known.
[0008]
When the outer coating 104 of the coated optical fiber 100 has a two-layer structure, the resin of the inner layer (first coating layer) is a resin having a low Young's modulus such as a thermosetting silicone resin, and the outer layer ( The resin of the second coating layer) is a thermoplastic resin such as high density polyethylene (see JP-A-53-123152), the resin of the inner layer is a thermoplastic elastomer, and the resin of the outer layer is a thermoplastic resin. Some (see JP 2001-159725 A) are known.
[0009]
The above-mentioned coated optical fiber cores have a single-layer structure or a two-layer structure, optical transmission characteristics, environmental adaptability characteristics (low temperature, high temperature, wet heat), mechanical strength, side pressure resistance characteristics, flame resistance The purpose is to balance various characteristics such as sex.
[0010]
In recent years, due to a demand for reducing the environmental load, it has been required to adopt a material that does not generate a harmful gas such as hydrogen chloride gas when the coated optical fiber is burned. Is a resin selected from a polyethylene-based resin having no halogen (hereinafter referred to as non-halogen), a non-halogen polystyrene-based resin, and a non-halogen polyester resin, and having an inner layer and an outer layer flame-retardant (JP 2000- 241676) is known.
[0011]
[Problems to be solved by the invention]
However, according to the study by the present inventors, the coated light obtained by further providing the outer coating 104 on the outer circumferential surface of the optical fiber core formed by coating the outer circumferential surface of the glass fiber 101 with the ultraviolet curable resin layer 102. The fiber core 100 is more difficult to remove than the silicone / nylon core. That is, even if the glass fiber is to be exposed using the coating removal tool, the glass fiber 101 is broken (see FIG. 7B) or the ultraviolet curable resin layer 102 remains on the glass fiber 101. Was found to occur frequently (see FIG. 7C). Since the silicone / nylon core does not have an ultraviolet curable resin layer outside the glass fiber, the ultraviolet curable resin layer does not remain on the glass fiber.
[0012]
The coated optical fiber core with connector is generally subjected to various environmental tests for reliability evaluation. Among these, for example, 85 ° C. × 168 hours used for Telcordia standard (GR-326). The heat resistance test under the above conditions is known as a particularly severe heat resistance test. Here, if the heat resistance of the outer sheath of the coated optical fiber core with connector is insufficient, the outer sheath creeps after the heat resistance test, so that the glass fiber is displaced from a predetermined position, or the outer sheath is deviated. The occurrence of flesh and the application of stress to the glass fiber may cause problems such as degradation of optical transmission characteristics. In particular, when the outer coating resin is a non-halogen resin and a coated optical fiber core wire is used, in the heat resistance test under the condition of 85 ° C. × 168 hours, the Telcordia standard (GR-326) is satisfied, It has been technically difficult to achieve both good coating removal properties.
[0013]
The present invention has been made in order to solve the above-described problems. The object of the present invention is to provide a characteristic that does not generate toxic gas at the time of combustion, and a high environmental adaptability (even if the environmental factors such as temperature and humidity vary). It has characteristics that maintain transmission characteristics at a high level) and high mechanical characteristics (characteristics that maintain optical transmission characteristics at a high level even when pressure is applied to the coated optical fiber core). It is an object to provide a coated optical fiber core that can be easily implemented without frequent occurrence, and a coated optical fiber core with connector, an optical fiber cord, an optical fiber cord with connector, and an optical fiber cable using the same.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problems, the present inventors have intensively studied, and as a result, the outer coating of the coated optical fiber core wire is made to consist of an inner layer (first coating layer) and an outer layer (second coating layer), The inventors have found that the object can be achieved by specifying the physical properties of the inner layer and the outer layer and the resin compositions constituting the inner layer and the outer layer, and thus the present invention has been completed. That is, the technical configuration and operational effects of the present invention are as follows. However, the action includes estimation, and the correctness of the action does not limit the present invention.
[0015]
The coated optical fiber core according to claim 1 further includes a first coating layer and a second coating on the outer peripheral surface of the optical fiber core in which one or more ultraviolet curable resin layers are provided on the outer peripheral surface of the glass fiber. A first resin contained in the first resin composition that constitutes the first coating layer, and a second resin composition that constitutes the second coating layer. Both of the second resins contained in the resin are resins having no halogen, and the first coating layer at 25 ° C. Tensile elasticity The rate is 150 MPa or less, the tensile strength of the first coating layer is 10 MPa or less, and the second coating layer at 25 ° C. Tensile elasticity The rate is 700 MPa or more.
[0016]
According to such a configuration, both the first resin and the second resin are resins that do not contain a halogen, so that the characteristics that do not generate a toxic gas during combustion are excellent.
[0017]
In addition, the second coating layer at 25 ° C. Tensile elasticity When the rate is 700 MPa or more, the outer layer can sufficiently absorb the side pressure received by the coated optical fiber core (pressure from the outside received from the outer peripheral surface of the coated optical fiber). The first coating layer at 25 ° C. Tensile elasticity When the rate is 150 MPa or less, the first coating layer is a softer layer than the second coating layer, which is the outer layer, so that the pressure cannot be completely absorbed by the second coating layer. Even if it exists, this pressure can be buffered by the 1st coating layer which is an inner layer. Therefore, optical transmission loss due to the glass fiber receiving pressure can be suppressed, and a coated optical fiber core having high mechanical characteristics can be obtained.
[0018]
In addition, the first coating layer at 25 ° C. Tensile elasticity The rate is 150 MPa or less, the tensile strength of the first coating layer is 10 MPa or less, and the second coating layer at 25 ° C. Tensile elasticity When the rate is 700 MPa or more, the UV curable resin layer can be used together with the outer coating (first coating layer and second coating layer) without breaking the glass fiber using the coating removal tool as described above. It can be set as the structure which can be removed easily. The first coating layer at 25 ° C. Tensile elasticity When the rate exceeds 150 MPa or the tensile strength of the first coating layer exceeds 10 MPa, the blade of the coating removal tool does not enter the ultraviolet curable resin layer, and the ultraviolet curable resin layer is placed on the glass fiber during coating removal. It is easy to cause a problem that the residue remains. The second coating layer at 25 ° C. Tensile elasticity When the rate is less than 700 MPa, the second coating layer buckles during coating removal, resistance is applied to the buckled portion, and the coating removal force becomes extremely large, so that the glass fiber frequently breaks.
[0019]
Claim 1 In the coated optical fiber core wire according to, both the first resin composition and the second resin composition contain a flame retardant. According to such a structure, it can be set as the coated optical fiber core wire which has high flame retardance.
[0020]
Claim 1 In the coated optical fiber core wire according to the present invention, the first resin composition and the second resin composition contain a metal hydroxide as a flame retardant. According to such a structure, it can be set as the coated optical fiber core wire which has high flame retardance especially.
[0021]
The present inventors set the first resin as one or more resins selected from the group consisting of an ethylene-α-olefin copolymer having a melting point of 85 ° C. or higher, a polystyrene-based thermoplastic elastomer, and a polybutadiene-based thermoplastic elastomer, Resin, Block polypropylene formed by block copolymerization of propylene and ethylene propylene rubber, and random polypropylene formed by random copolymerization of propylene and ethylene By making it 1 or more types of resin selected from the group which consists of 1st coating layer and 2nd coating layer Tensile elasticity It has been found that the rate and the tensile strength of the first coating layer can be easily set within the above-described range. Therefore, in the coated optical fiber core according to claim 1, the first resin is selected from the group consisting of an ethylene-α-olefin copolymer having a melting point of 85 ° C. or higher, a polystyrene-based thermoplastic elastomer, and a polybutadiene-based thermoplastic elastomer. One or more resins, the second resin is Block polypropylene formed by block copolymerization of propylene and ethylene propylene rubber, and random polypropylene formed by random copolymerization of propylene and ethylene It is characterized by being one or more kinds of resins selected from the group consisting of:
[0022]
Preferably The outer diameter to the first coating layer is 0.3 mm to 0.8 mm. When the outer diameter is less than 0.3 mm, mechanical characteristics (side pressure characteristics) tend to be lowered. When the outer diameter exceeds 0.8 mm, mechanical characteristics (side pressure characteristics are lowered, rigidity of the coated optical fiber core wire is lowered, and handling properties (handleability) tend to be lowered. This According to the configuration, a coated optical fiber core wire excellent in mechanical characteristics and mechanical characteristics can be obtained.
[0023]
Claim 2 The coated optical fiber core wire according to the present invention is configured such that the ultraviolet curable resin layer is provided with a first ultraviolet curable resin layer and a second ultraviolet curable resin layer in a direction away from the glass fiber, or A curable resin layer, a second ultraviolet curable resin layer, and a colored layer are provided, and the second ultraviolet curable resin layer has a tensile secant modulus of 5 MPa to 600 MPa. According to such a configuration, first, since the ultraviolet curable resin layer has at least the first ultraviolet curable resin layer and the second ultraviolet curable resin layer, the first ultraviolet curable resin layer is flexible. Layer, and the second UV curable resin layer as a solid layer, the lateral pressure received by the optical fiber core (pressure from the outside received from the outer peripheral surface of the optical fiber core, in particular, the optical fiber core The pressure is absorbed by the second ultraviolet curable resin layer, and the pressure is so large that the second ultraviolet curable resin layer cannot completely absorb the pressure. However, by adjusting the physical properties of the first UV curable resin layer and the second UV curable resin layer, such as buffering the pressure with the first UV curable resin layer, light generated by the glass fiber receiving pressure. Transmission loss can be reduced.
[0024]
In the above configuration, the tensile secant modulus of the second ultraviolet curable resin layer is 5 MPa to 600 MPa. When the tensile secant modulus is less than 5 MPa, in the case where the first ultraviolet curable resin layer is a softer layer than the second ultraviolet curable resin layer for the purpose described above, it is difficult to absorb pressure from the outside, It becomes easy to damage glass fiber. On the other hand, if the tensile secant modulus exceeds 600 MPa, the blade of the coating removal tool described above is difficult to enter the second ultraviolet curable resin layer, and the ultraviolet curable resin layer is difficult to separate from the coated optical fiber core. Therefore, the ultraviolet curable resin layer tends to remain on the glass fiber.
The ultraviolet curable resin layer often has the above-described colored layer for the purpose of identifying and visually recognizing the optical fiber core wire.
[0025]
Claim 3 The coated optical fiber core wire according to the present invention is configured such that the non-uniform wall thickness ratio after the heat resistance test under the condition of 85 ° C. × 168 hours is 80% or more. The heat resistance test under the condition of 85 ° C. × 168 hours is a particularly severe heat resistance test used in the Telcordia standard (GR-326). It is possible to reliably reduce the possibility that the optical transmission characteristics will be deteriorated due to displacement from the position or occurrence of uneven thickness of the outer coating and stress applied to the glass fiber. Therefore, it can be set as the coated optical fiber core which has especially high heat resistance (The characteristic which maintains an optical transmission characteristic in a high dimension even if a coated optical fiber core receives heat).
[0026]
Claim 4 The coated optical fiber core with connector according to the present invention includes a coated optical fiber core according to the present invention having a glass fiber exposed portion and a coated removal end surface by exposing the glass fiber at a predetermined length from the terminal, and the exposed glass fiber. And a connector incorporating a hollow ferrule capable of accommodating the portion is connected such that the exposed portion of the glass fiber is accommodated in the hollow and the coating removal end surface is in contact with the abutting end surface of the ferrule.
According to such a configuration, since the coated optical fiber core according to the present invention is used, the coated optical fiber with a connector has characteristics that do not generate toxic gas during combustion, high environmental adaptability, and high mechanical characteristics. It can be a cord.
[0027]
Claim 5 The optical fiber cord according to the present invention is provided with a protective layer for protecting the coated optical fiber core wire on the outer periphery of the coated optical fiber cable wire according to the present invention. According to such a configuration, since the coated optical fiber core wire according to the present invention is used, an optical fiber cord having characteristics that do not generate toxic gas at the time of combustion, high environmental adaptability characteristics, and high mechanical characteristics can be obtained. it can.
[0028]
Claim 6 The optical fiber cord with connector according to the present invention can accommodate the optical fiber cord according to the present invention having the glass fiber exposed portion and the coating removal end surface by exposing the glass fiber at a predetermined length from the terminal, and the glass fiber exposed portion. A connector incorporating a hollow ferrule is connected so that the exposed portion of the glass fiber is accommodated in the hollow and the coating removal end face abuts against the abutting end face of the ferrule. According to such a configuration, since the optical fiber cord according to the present invention is used, an optical fiber cord with a connector having characteristics that do not generate toxic gas during combustion, high environmental adaptability, and high mechanical characteristics can be obtained. it can.
[0029]
Claim 7 In the optical fiber cable according to the present invention, a plurality of coated optical fiber cores according to the present invention are disposed on the outer peripheral surface of the tension member, a buffer material is disposed outside the coated optical fiber core wire, and a presser winding layer is formed on the buffer material. It is provided on the outside, and the outer peripheral surface of the presser wound layer is covered with a resin layer. According to such a configuration, since the coated optical fiber core wire according to the present invention is used, an optical fiber cable having characteristics that do not generate toxic gas at the time of combustion, high environmental adaptability characteristics, and high mechanical characteristics can be obtained. it can.
[0030]
Claim 8 In the optical fiber cable according to the present invention, a plurality of the optical fiber cords according to the present invention are arranged on the outer peripheral surface of the tension member, a buffer material is arranged outside the optical fiber cord, and a presser winding layer is provided outside the buffer material. The outer circumferential surface of the presser wound layer is covered with a resin layer. According to such a configuration, since the optical fiber cord according to the present invention is used, it is possible to provide an optical fiber cable having characteristics that do not generate toxic gas during combustion, high environmental adaptability, and high mechanical characteristics.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in the schematic cross-sectional view of FIG. 1, the coated optical fiber core wire 10 according to the embodiment of the present invention further includes a first coating layer 14, a second coating layer 15, and an outer peripheral surface of the optical fiber core wire 13. Are provided in order in a direction away from the optical fiber core wire 13.
The Young's modulus (hereinafter also simply referred to as Young's modulus) at 25 ° C. of the first coating layer is 150 MPa or less, preferably 5 MPa to 100 MPa. The tensile strength of the first coating layer is 10 MPa or less, and preferably 0.5 MPa to 8 MPa. The Young's modulus (hereinafter also simply referred to as Young's modulus) at 25 ° C. of the second coating layer is 700 MPa or more, and preferably 750 MPa to 1600 MPa.
Here, the Young's modulus is a value obtained using a No. 2 type test piece according to JIS K7113.
[0032]
Therefore, since the first coating layer 14 is a layer that is more flexible than the second coating layer 15 that is the outer layer, the pressure from the outside that is received from the outer peripheral surface of the coated optical fiber core wire 10 is the second coating layer 15. Even if the force is so great that it cannot be completely absorbed, the pressure can be buffered by the first covering layer 14 as the inner layer. Therefore, optical transmission loss due to the glass fiber 11 receiving pressure can be suppressed.
[0033]
The first coating layer 14 and the second coating layer 15 are made of a resin composition. The Young's modulus and tensile strength of the first coating layer, and the Young's modulus of the second coating layer are adjusted by adjusting the type and content of the resin constituting the resin composition, the type of additive and the content thereof. , Preferably within the above range.
[0034]
Resin (hereinafter referred to as first resin) of a resin composition (hereinafter referred to as first resin composition) constituting first coating layer 14 and resin composition (hereinafter referred to as second resin composition) constituting second coating layer 15 The resin (hereinafter referred to as second resin) is a resin having no halogen (hereinafter referred to as non-halogen resin). Thereby, it has the characteristic which does not generate | occur | produce toxic gas at the time of combustion.
[0035]
The first resin is not particularly limited as long as the Young's modulus and tensile strength of the first coating layer 14 are non-halogen resins capable of satisfying the above conditions. However, polystyrene-based thermoplastic resin, polybutadiene-based thermoplastic elastomer, or heat resistant It is preferable to select from a high (= melting point of 85 ° C. or higher) ethylene-α-olefin copolymer.
[0036]
A polystyrene-based thermoplastic elastomer is a block copolymer containing polystyrene as a hard segment, diene polymers such as polybutadiene, hydrogenated polybutadiene, and polyisoprene, and ethylene propylene rubber as a soft segment, and the soft segment as a polybutadiene. Styrene block copolymer (SBS), styrene isoprene styrene block copolymer (SIS) whose soft segment is isoprene, styrene ethylene butylene styrene block copolymer (SEBS) hydrogenated with SBS, soft segment is ethylene propylene rubber Styrene ethylene propylene styrene block copolymer (SEPS). Further, a styrene ethylene butylene olefin crystal copolymer (SEBC), which is a block copolymer of polystyrene and crystalline polyolefin, can be exemplified.
[0037]
An example of the polybutadiene-based thermoplastic elastomer is syndiotactic 1,2-polybutadiene. The heat-resistant ethylene-α-olefin copolymer includes EVA (ethylene acetate) having a VA content (vinyl acetate) of 14 to 18% by weight, and EEA having an ethylene acrylate content of 10 to 20% by weight. (Ethylene-ethyl acrylate) can be exemplified.
[0038]
The second resin is not particularly limited as long as the Young's modulus of the second coating layer 15 is a non-halogen resin capable of satisfying the above conditions, but one or more resins selected from the group consisting of polystyrene resins and polypropylene resins are suitable. Can be illustrated.
[0039]
Examples of the polystyrene-based resin include styrene homopolymer, impact-resistant polystyrene (HIPS) formed by finely dispersing a rubber component such as styrene-butadiene rubber in the polystyrene.
Examples of polypropylene resins include propylene homopolymer, block polypropylene (block PP) formed by block copolymerization of propylene and ethylene propylene rubber, and random polypropylene (random PP) formed by random copolymerization of propylene and ethylene. it can.
[0040]
Moreover, it is preferable that the 1st resin composition and the 2nd resin composition contain a flame retardant. Known flame retardants can be used without limitation. Specifically, metal hydroxide flame retardants such as aluminum hydroxide and magnesium hydroxide, phosphorus flame retardants such as phosphate ester and red phosphorus, melamine Preferable examples include nitrogen-based flame retardants such as cyanurate. Magnesium hydroxide is preferable because it has a high flame-retarding effect and good extrudability when forming a coating layer.
[0041]
Each of the first resin composition and the second resin composition should contain a flame retardant in the resin (first resin in the case of the first resin composition, second resin in the case of the second resin composition). The flame retardant is preferably 30 parts by weight or more with respect to 100 parts by weight of the resin, and has high flame resistance (passes the horizontal combustion test). It can be set as the resin composition excellent in property.
[0042]
In addition, the first resin composition and the second resin composition are added with a light stabilizer (HALS), an antioxidant (such as a sulfur-based antioxidant), a lubricant, an anti-aging agent, etc., as necessary. You may contain a thing. As a light stabilizer, LA-52 (tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate: manufactured by Asahi Denka Co., Ltd.) Examples of sulfur-based antioxidants include Cynox 412S (pentaerythritol tetrakis (3-laurylthiopropionate)). Use of a light stabilizer and a sulfur-based antioxidant is preferable because light resistance and moist heat resistance are increased.
Further, by adding a compounding agent such as a known plasticizer, softener, rubber softener, process oil, extender oil, cross-linking agent as an additive, the Young's modulus and tensile strength of the first coating layer 14, The Young's modulus of the two coating layers 15 may be adjusted within the above range. Examples of the rubber softening agent include paraffinic oil and non-aromatic rubber softening agent.
[0043]
Each of the first resin composition and the second resin composition is preferably formed by mixing components constituting each resin composition, and known melting such as a Banbury mixer, a pressure kneader, a twin screw mixer, etc. It can mix using a mixing apparatus.
[0044]
The optical fiber core wire 13 used for the coated optical fiber core wire 10 according to the embodiment of the present invention is provided with an ultraviolet curable resin layer 12 on the outer peripheral surface of the glass fiber 11 as shown in FIG. Specifically, a known optical fiber core wire having an outer diameter (Di) of 0.250 mm to 0.260 mm in which a glass fiber 11 having an outer diameter of 0.125 mm is covered with an ultraviolet curable resin layer 12 can be preferably exemplified. The glass fiber 11 is mainly composed of quartz glass, and as the resin of the ultraviolet curable resin layer 12, a urethane acrylate resin or the like is widely known, and these can be used without limitation. The ultraviolet curable resin layer 12 is composed of an inner layer (first ultraviolet curable resin layer) and an outer layer (second ultraviolet curable resin layer) having different physical properties (two-layer structure), Those having a colored layer in the outer layer are also known, and these can also be used without limitation.
[0045]
The tensile secant modulus (also called Young's modulus) of the first UV curable resin layer is 0.5 MPa to 2 MPa, the tensile secant modulus of the second UV curable resin layer is 5 MPa to 1500 MPa, and the tensile secant modulus of the colored layer is The pressure is preferably set to 500 MPa to 1500 MPa.
In order to develop such a Young's modulus, in the production of the resin of the first UV curable resin layer, urethane acrylate and polymerizable unsaturated monomer obtained by reacting polyether diol, isophorone diisocyanate and hydroxyethyl acrylate. N-vinylcaprolactam, isobornyl acrylate, nonanediol acrylate, nonylphenol acrylate, photopolymerizable initiator Lucillin TPO (manufactured by BASF), and other additives tetrakis {methylene-3- (3-5-di) -T-Butyl-4-hydroxyphenyl) propionate} Methane, γ-mercaptopropyltrimethoxysilane and 2,2,6,6-tetramethyl-4-piperidyl alcohol are mixed and produced by irradiating with ultraviolet rays. The form is preferred.
[0046]
In the production of the resin of the second ultraviolet curable resin layer, urethane acrylate obtained by reacting polypropylene oxide glycol, toluene diisocyanate and hydroxyethyl acrylate, N-vinylcaprolactam and tricyclodecane dimethanol as polymerizable unsaturated monomers Diacrylate, Lucirin TPO (manufactured by BASF) and Irgacure 184 (manufactured by Ciba Specialty Chemicals) as photopolymerization initiators, and tetrakis {methylene-3- (3-5-di-t) as other additives -Butyl-4-hydroxyphenyl) propionate} methane is mixed, and this is preferably irradiated with ultraviolet rays.
[0047]
Furthermore, the colored layer is also usually in the form of an ultraviolet curable resin layer. In the production of the colored layer resin, epoxy acrylate obtained by reacting bisphenol A with 2hydroxybutyl (meth) acrylate and / or Or urethane acrylate obtained by reacting polypropylene oxide glycol, toluene diisocyanate and hydroxyethyl acrylate, bisphenol A ethylene oxide modified acrylate, trimethylolpropane trioxyethyl (meth) acrylate, silicon acrylate, photopolymerization as polymerizable unsaturated monomer Benzophenone, benzoin ether as a functional initiator, and tetrakis {methylene-3- (3-5-di-t-butyl-4-hydroxyphenyl) propionate as other additives } A form in which methane is mixed and irradiated with ultraviolet rays is preferable.
[0048]
In this way, the first UV curable resin layer is a flexible layer and the second UV curable resin layer is a rigid layer, so that the side pressure received by the optical fiber core 13 (the outer peripheral surface of the optical fiber core 13) The second ultraviolet curable resin layer absorbs the pressure with respect to the external pressure received from the outside, particularly the pressure received before the outer coating 16 is provided on the optical fiber core wire 13; Even if the pressure is such a large force that the second UV curable resin layer cannot absorb completely, the glass fiber 11 receives the pressure by buffering the pressure with the first UV curable resin layer, thereby transmitting light. Loss can be reduced.
[0049]
More preferably, the tensile secant modulus of the second ultraviolet curable resin layer is 5 MPa to 600 MPa. When the tensile secant modulus is less than 5 MPa, it is difficult to absorb pressure from the outside and the glass fiber is easily damaged. On the other hand, if the tensile secant modulus exceeds 600 MPa, the blade of the coating removal tool 20 is difficult to enter the second ultraviolet curable resin layer, and the ultraviolet curable resin layer is difficult to separate from the coated optical fiber core.
[0050]
Preferred dimensions of each layer constituting the optical fiber core wire 13 are shown below.
Glass fiber 11 outer diameter: 125 μm
Outer diameter to the first UV curable resin layer: 200 μm
Outer diameter to the second UV curable resin layer: 245 μm
Outer diameter to colored layer: 255 μm
[0051]
In the coated optical fiber core wire 10 according to the embodiment of the present invention, the diameter (Dp) to the first coating layer 14 is 0.3 mm to 0.8 mm, and the diameter (Ds) to the second coating layer 15 is 0.00. The form made into 85 mm-0.95 mm can be illustrated suitably.
In particular, when Dp is 0.3 mm to 0.8 mm, mechanical characteristics (side pressure characteristics) and handling properties (handleability) can be particularly improved.
[0052]
The coated optical fiber core 10 according to the embodiment of the present invention is preferably manufactured by applying a resin composition that constitutes the outer coating 16 of the optical fiber core wire 13 as follows.
That is, as shown in FIG. 2, the optical fiber core wire 13 is fed out from the supply reel 31 and supplied to the extruder 33 through the tension control device 32. Here, the extruder 33 includes a first housing part 33A in which the first resin composition is housed, a second housing part 33B in which the second resin composition is housed, the first resin composition, and the second resin composition. A cross head 33C capable of applying the outer coating 16 to the outer periphery of the optical fiber core wire 13 by sequentially pushing out the objects is provided. The first resin composition and the second resin composition are preferably applied to the outer periphery of the optical fiber core wire 13 in a molten state. Usually, the extruder 33 includes a heater (not shown) at a predetermined position. .
Next, the material extruded from the extruder 33 is guided to the cooling water tank 34 and cooled to cure the outer coating 16 to form the coated optical fiber core wire 10, which is wound around the take-up reel 36 through the tension controller 35. .
[0053]
Further, the coated optical fiber core wire 10 according to the embodiment of the present invention has an uneven thickness ratio of 80% or more after the heat resistance test under the condition of 85 ° C. × 168 hours used in the Telcordia standard (GR-326). It is preferable to be configured as follows.
For example, by using a resin having a melting point of 85 ° C. or higher as the first resin and the second resin, the uncoated wall thickness can be the coated optical fiber core wire 10 that satisfies the above conditions, but is not limited thereto. It is not a thing.
[0054]
Next, a method for manufacturing a coated optical fiber with connector according to an embodiment of the present invention will be described.
In order to manufacture the coated optical fiber core with connector, first, the end of the coated optical fiber core 10 is processed using the above-described coating removal tool 20 (see FIG. 5). That is, the coated optical fiber core wire 10 is held in the V-groove 23a of the sheath removal tool 20, and the plate lever members 21a and 21b are closed across a portion about 30 mm away from the end of the coated optical fiber core wire 10. Thus, as shown in FIG. 3A, the cutting is made so that the cutting edge 22A (the top of the cutting) of the blade 22 does not reach the glass fiber.
[0055]
Next, by separating the ultraviolet curable resin layer 12 and the outer coating 16 from the glass fiber 11 so as to be drawn in the terminal direction P of the coated optical fiber core wire 10, the ultraviolet curable resin layer 12 is shredded, The glass fiber 11 of the coated optical fiber core wire 10 is exposed (see FIG. 3B). Here, the Young's modulus of the first coating layer 14 is 150 MPa or less, the tensile strength of the first coating layer 14 is 10 MPa or less, and the Young's modulus of the second coating layer 15 is 700 MPa or more. The UV curable resin layer 12 and the outer coating 16 can be integrally removed without causing the UV curable resin layer 12 to remain on the glass fiber 11 frequently, and the glass fiber 11 can be easily exposed.
[0056]
Thus, the coated optical fiber core wire 10 having the glass fiber exposed portion 11A and the coating removal end face 16A produced by processing the end of the coated optical fiber core wire 10 using the coating removal tool 20, and the glass fiber exposure The connector-coated optical fiber core wire 19 according to the embodiment of the present invention is manufactured by connecting the connector 18 incorporating the ferrule 17 having the hollow 17A capable of accommodating the portion 11A (see FIG. 4). More specifically, while the glass fiber exposed portion 11A is housed in the hollow 17A in a state where no strain force is applied, the coating removal end surface 16A is brought into contact with the abutting end surface 17B of the ferrule, and is usually fixed to maintain this state. The coated optical fiber 10 and the connector 18 are connected by means (not shown).
[0057]
Next, the front end surface 11B of the glass fiber and the open end surface 17C of the ferrule are processed so as to have a desired shape by polishing. Incidentally, the surface constituted by the tip end surface 11B of the glass fiber and the open end surface 17C of the ferrule can include a flat surface, a spherical surface, a curved surface, and the like. According to the specifications of the coated optical fiber core wire 19 with a connector, Selected.
[0058]
Since the coated optical fiber core wire 19 with a connector uses the coated optical fiber core wire 10 according to the embodiment of the present invention, the characteristics that do not generate a toxic gas at the time of combustion, high flame retardancy, high environmental adaptability characteristics, and , Have high mechanical properties.
[0059]
The optical fiber cord according to the embodiment of the present invention is provided with a protective layer for protecting the coated optical fiber core wire 10 on the outer periphery of the coated optical fiber core wire 10 according to the embodiment of the present invention. Here, the protective layer can be preferably exemplified by a layer made of a known tensile strength fiber. Usually, a resin layer is provided on the outer periphery of the protective layer, and a polyethylene resin layer can be suitably exemplified as the resin layer. The outer diameter of the optical fiber cord is appropriately changed according to the application. However, when the dimension of the coated optical fiber core wire is within the above-described preferable range, the light whose outer diameter is 2.0 mmφ or 1.5 mmφ is used. A fiber cord can be suitably exemplified.
[0060]
An optical fiber cord with a connector according to an embodiment of the present invention includes an optical fiber cord according to an embodiment of the present invention having a glass fiber exposed portion and a coating removal end surface by exposing a glass fiber at a predetermined length from a terminal. And a connector having a hollow ferrule capable of accommodating the glass fiber exposed portion, and connected so that the glass fiber exposed portion is accommodated in the hollow and the coating removal end surface abuts against the abutting end surface of the ferrule. . According to such a configuration, since the optical fiber cord according to the embodiment of the present invention is used, it has characteristics that do not generate toxic gas at the time of combustion, high environmental adaptability characteristics, and high mechanical characteristics.
[0061]
As shown in the schematic cross-sectional view of FIG. 6, the optical fiber cable 50 according to the embodiment of the present invention includes a plurality of coated optical fiber core wires 10 according to the present invention on the outer peripheral surface of the tension member 51, The buffer material 52 is disposed outside the core wire 10, the presser wound layer 53 is provided outside the buffer material 52, and the outer peripheral surface of the presser wound layer 53 is covered with the resin layer 54. Here, the coated optical fiber core wire 10 may be disposed along the axial direction of the tension member 51 or may be disposed in the spiral direction of the tension member 51.
[0062]
As the tension member 51, a steel wire (single wire or twisted wire) covered with a polyethylene resin can be suitably exemplified, and as the cushioning material 52, a polypropylene defibrated yarn can be suitably exemplified. Further, the presser wound layer 53 is a layer formed by winding a polyethylene terephthalate or polyethylene film tape so that the coated optical fiber core wire 10 can be pressed against the tension member 51 via the buffer material 52. Is preferred. A suitable example of the resin layer 54 is a polyethylene resin layer.
[0063]
As described above, since the optical fiber cable 50 uses the coated optical fiber core wire 10 according to the embodiment of the present invention, the optical fiber cable 50 has characteristics that do not generate a toxic gas at the time of combustion, high environmental adaptability characteristics, and high mechanical characteristics. .
[0064]
Further, by replacing the coated optical fiber core wire 10 with the optical fiber cord according to the embodiment of the present invention, an optical fiber cable having characteristics that do not generate toxic gas during combustion, high environmental adaptability characteristics, and high mechanical characteristics is provided. It can also be produced.
[0065]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, these do not limit this invention.
[0066]
[Production of first resin composition and second resin composition]
Magnesium hydroxide as a flame retardant (average particle size: 0.7 μm, BET specific surface area: 8 m with respect to 100 parts by weight of resin) ² ) 80 parts by weight, 0.5 parts by weight of Icarganox 1010 (trade name of Ciba Specialty Chemicals) as an antioxidant, the Young's modulus and tensile strength of the first coating layer, and the second coating layer The Young's modulus was adjusted by a method of appropriately blending a rubber softener and the like. The resin composition is performed by a method of cutting a discharged strand into a pellet using a twin-screw mixer (screw outer diameter: 45 mmφ, L / D = 32).
[0067]
[Production of coated optical fiber core]
As the optical fiber core, an optical fiber core (outer diameter: 250 μm) in which an ultraviolet curable resin layer (urethane acrylate resin layer) is provided on the outer periphery of a glass fiber (outer diameter of 125 μm) mainly composed of quartz glass is used. . The ultraviolet curable resin layer has a three-layer structure including a first ultraviolet curable resin layer, a second ultraviolet curable resin layer, and a colored layer. The outer diameter to the first ultraviolet curable resin layer is 200 μm, and the second The outer diameter to the UV curable resin layer is 245 μm, the outer diameter to the colored layer is 255 μm, the Young's modulus of the first UV curable resin layer is 1 MPa (25 ° C.), and the Young's modulus of the second UV curable resin layer is 400 MPa. (25 ° C.), the Young's modulus of the colored layer is 1100 MPa (25 ° C.). By providing the first coating layer and the second coating layer in accordance with the above-described method on the outer periphery of the optical fiber core, Examples 1 to 5 , Reference Example 1 10 The coated optical fiber core wires of Comparative Examples 1 to 8 are produced. Here, as an extruder for coating the first coating layer and the second coating layer, a single-screw extruder (screw outer diameter: 45 mmφ, L / D = 24) is used, and each extruder is Are connected to a crosshead (corresponding to the crosshead 33C). Tables 1 to 5 show the types of the first resin and the second resin used in Examples, Reference Examples, and Comparative Examples, and the physical properties of the first coating layer and the second coating layer. In the table, Dp means the diameter up to the first coating layer, and Ds means the diameter up to the second coating layer. The Young's modulus (25 ° C.) and the tensile strength are measured according to JIS K 7113, more specifically as follows.
[0068]
(UV curable resin layer)
The mixture (film thickness: about 100 μm) for producing the ultraviolet curable resin layer corresponding to each example and each comparative example was irradiated with ultraviolet rays (irradiation light amount: 100 mJ / cm) under nitrogen. ² ) To produce a dumbbell-shaped No. 2 test piece (JIS K 7113 compliant). Using this test piece, a tensile test is performed under the conditions of a distance between marked lines of 25 mm and a tensile speed of 1 mm / min. The Young's modulus is the tensile secant modulus calculated by adopting the 2.5% secant method.
[0069]
(First coating layer, second coating layer)
The resin composition of the first resin composition and the second resin composition corresponding to each example and each comparative example, using a known apparatus composed of a twin-screw kneading extruder, a pressure kneader, a Banbury mixer, a roll, etc. By melt-kneading the product, a film-like product having a film thickness of about 300 μm is formed. Next, a dumbbell-shaped No. 2 test piece (JIS K 7113 compliant) is produced from this film-like material. Using this test piece, a tensile test is performed under the conditions of a distance between marked lines of 25 mm and a tensile speed of 1 mm / min. The Young's modulus is a tensile elastic modulus calculated using a tangential method.
[0070]
[Table 1]

[0071]
[Table 2]

[0072]
[Table 3]

[0073]
[Table 4]

[0074]
[Table 5]

[0075]
(E-1) to (E-13) and (P-1) to (P-3) in the table are as follows.
Note that MI is an abbreviation for Melt Index. MI is an index indicating the amount of the resin composition flowing out from the bottom of the cylinder when the cylinder is filled with the resin composition and the piston is pushed from the top of the cylinder at a constant load of 2.16 kg at a temperature of 190 ° C. A larger MI indicates that the amount of the resin composition flowing out from the cylinder is larger, which means that the fluidity of the resin composition is higher.
OI is an abbreviation for oxygen index (Oxygen Index) and is a concentration index of oxygen required for the resin composition to burn. The larger the OI, the higher the flame retardancy because the resin composition needs more oxygen for burning.
[0076]
(E-1)
Non-halogen resin composition having SEBS (styrene content 18%, tensile strength 15 MPa) as resin component (MI = 1.5, OI = 21)
[0077]
(E-2)
Non-halogen resin composition (MI = 0.2, OI = 21) containing syndiotactic-1,2-polybutadiene (melting point: 105 ° C., tensile strength: 12.7 MPa) as a resin component
[0078]
(E-3)
Non-halogen resin composition having SEPS (styrene content 13% by weight, tensile strength 10.8 MPa) as resin component (MI = 2.0, OI = 20)
[0079]
(E-4)
Non-halogen resin composition having SEBC (styrene content 20% by weight, tensile strength 17.0 MPa) as resin component (MI = 3.0, OI = 22)
[0080]
(E-5)
Non-halogen resin composition having SEBS (styrene content 30% by weight, tensile strength 21.6 MPa) as resin component (MI = 2.0, OI = 22)
[0081]
(E-6)
Non-halogen resin composition having SBS (styrene content 40% by weight, tensile strength 14.0 MPa) as resin component (MI = 3.0, OI = 23)
[0082]
(E-7)
Resin content of SEPS (styrene content 13% by weight, tensile strength 10.8 MPa) (no flame retardant) (MI = 2.5, OI = 17)
[0083]
(E-8)
Only resin content of syndiotactic-1,2-polybutadiene (melting point: 105 ° C., tensile strength 12.7 MPa) (does not contain flame retardant) (MI = 1.5, OI = 17)
[0084]
(E-9)
Non-halogen resin composition (MI = 2.0, OI = 20) containing ethylene vinyl acetate resin (EVA) (vinyl acetate content of 13% by weight) as a resin component
[0085]
(E-10)
Non-halogen resin composition (MI = 4.0, OI = 20) containing ethylene vinyl acetate resin (EVA) (vinyl acetate content 19% by weight) as a resin component
[0086]
(E-11)
Non-halogen resin composition containing ethylene / vinyl acetate resin (EVA) (vinyl acetate content 28% by weight) as a resin component (MI = 5.0, OI = 22)
[0087]
(E-12)
Non-halogen resin composition (MI = 7.5, OI = 20) containing ethylene vinyl acetate resin (EVA) (vinyl acetate content 17% by weight) as a resin component
[0088]
(E-13)
Non-halogen resin composition (MI = 4.0, OI = 20) containing ethylene / ethyl acrylate resin (EEA) (ethyl acrylate content 19% by weight) as a resin component
[0089]
(P-1)
Non-halogen resin composition having HIPS (butadiene content 23% by weight) as a resin component (MI = 1.0, OI = 21)
[0090]
(P-2)
Non-halogen resin composition having block PP (melting point: 168 ° C.) as a resin component (MI = 1.0, OI = 19)
[0091]
(P-3)
Non-halogen resin composition having HIPS (butadiene content 23% by weight) as a resin component (MI = 0.5, OI = 21)
[0092]
Various test methods for the coated optical fiber are performed as follows.
[0093]
[Coating removal]
Under 25 ° C., a portion having a length of 30 mm from the end of the coated optical fiber cores of Examples and Comparative Examples is “Coating Remover JR-22” (Sumitomo Electric Industries, Ltd.) corresponding to the coating removing tool shown in FIG. The outer coating is removed using the product name. The coating is removed from each coated optical fiber for three trials. In all three trials, the pulling force at the time of removal is 2.0 kg · f or less, the ultraviolet curable resin layer does not remain on the glass fiber, and the glass fiber is not broken. Those that do not satisfy the above conditions are rejected. The pulling force in the table is an average value of three trials, and in Comparative Example 5 and Comparative Example 6, the glass fiber breaks in all three trials.
[0094]
Here, the pulling force is a value obtained as follows.
Pull-out force: “A portion of 30 mm in length from the end of the coated optical fiber core is fixed in a state where it is sandwiched by the blade of the coating removal tool JR-22, and a tensile test is performed at a pulling speed of 500 mm / min using a tensile tester (Maximum value of force required when the coating remover and the chuck of the tensile tester = 100 mm)
[0095]
[Mechanical characteristics (side pressure characteristics)]
A load of 500 kg per 100 mm length in the longitudinal direction is applied to the coated optical fiber cores of the example and the comparative example (the core wire is sandwiched between smooth metal plates having R5 edges, and the load is applied. ), Measuring the transmission loss (dB / 100 mm) (Measure the attenuation of light before and after applying the load with a multimeter (for example, AQ2140 manufactured by Ando Electric Co., Ltd.) This value is used as the lateral pressure loss (dB / 100 mm). The results are shown in Tables 1 to 5. Those having a side pressure loss of 0.1 dB / 100 mm or less have high reliability and are considered acceptable.
[0096]
[Environmental adaptation characteristics (characteristics that maintain optical transmission characteristics at a high level even with temperature fluctuations)]
The coated optical fiber cores of Examples and Comparative Examples were measured for transmission loss (dB) with an OTDR measuring device (wavelength: 1.31 μm), and the transmission loss per unit length was defined as the initial loss (dB / km). To do. Those with an initial loss of 1.0 dB / km or less have high reliability and are accepted.
Next, a heat cycle exposure test in which −20 ° C. (held for 6 hours) to 60 ° C. (held for 6 hours) is repeated for 3 cycles is performed on the coated optical fiber. The transmission loss amount (dB) is measured at .31 μm), and the maximum value of the difference from the initial loss is shown as “temperature change loss (dB / km)” in Tables 1 to 5. The thing below 3 dB / km is set as a pass.
[0097]
[Flame retardance]
A horizontal burning test based on JIS 3005 is performed on the coated optical fiber cores of the examples and comparative examples, and the one showing self-extinguishing properties is regarded as acceptable.
[0098]
[Handling]
Using the “coating removal tool JR-22” (trade name of Sumitomo Electric Industries, Ltd.) corresponding to the coating removal tool shown in FIG. 5 for the portion 30 mm in length from the end of the coated optical fiber cores of Examples and Comparative Examples Then, the ultraviolet resin coating layer and the outer coating are simultaneously removed. Next, the exposed portion of the glass fiber is accommodated in the hollow of the ferrule, and the connector is attached to the end of the coated optical fiber core wire with the coating removal end face brought into contact with the abutting end face of the ferrule.
In handling from the process of passing the exposed portion of the glass fiber through the hollow of the ferrule to the completion of the connector mounting, the coated optical fiber core has a strain, and can be passed without failing in the process of passing through the hollow of the ferrule. If the coated optical fiber core wire does not have a bending flaw in the process up to the connector attachment, it is determined that the handling property is good and is marked as “good”. On the other hand, there is no strain on the coated optical fiber, and there is an insertion error even once in the process of passing through the hollow of the ferrule. It is determined that the defect is poor, and x is set.
[0099]
[Heat-resistant]
The heat resistance test under the condition of 85 ° C. × 168 hours used in the Telcordia standard (GR-326) is performed, and during that test, the transmission loss (dB) is measured with a continuous monitor (wavelength: 1.31 μm), The maximum difference from the initial loss is shown in Tables 1 to 5 as “heat resistance loss (dB / km).” A heat resistance loss of 0.2 dB / km or less is regarded as acceptable.
Moreover, the unbalanced wall thickness ratio before and after the heat resistance test is measured, and 80% or more is highly reliable and acceptable. The uneven thickness ratio is calculated by the following formula.
Uneven thickness ratio (%) = “Minimum value of outer coating thickness” / “Maximum value of outer coating thickness” × 100
[0100]
Example 1 5 In the coated optical fiber core, the first resin composition and the second resin composition both contain a flame retardant, and the first resin is a polystyrene-based thermoplastic elastomer, a polybutadiene-based thermoplastic elastomer, or an ethylene-α olefin copolymer. The second resin The It is a polypropylene resin, and is a coated optical fiber core wire in which the Young's modulus and tensile strength of the first coating layer and the Young's modulus of the second coating layer are within the ranges defined in the present invention. The coated optical fiber cores of the examples not only have a small initial loss, but are excellent in all of mechanical properties, environmental adaptability properties, coating removal properties, flame retardancy, handling properties, and heat resistance.
[0101]
In the coated optical fiber cores of Comparative Example 1 and Comparative Example 2, the first resin is a polystyrene-based thermoplastic elastomer and a polybutadiene-based thermoplastic elastomer, respectively, and the second resin is a polypropylene-based resin and a polystyrene-based resin, respectively. Although the Young's modulus of the first coating layer is 150 MPa or less, the coated optical fiber core has a tensile strength of more than 10 MPa and a Young's modulus of the second coating layer of 700 MPa or more. The coated optical fiber cores of Comparative Example 1 and Comparative Example 2 have little initial loss and excellent mechanical properties, environmental adaptability properties, flame retardancy, handling properties, and heat resistance, but UV curable resin remains after the coating is removed. Inferior coating removal property.
[0102]
In the coated optical fiber cores of Comparative Example 3 and Comparative Example 4, the first resin is a polystyrene-based thermoplastic elastomer and a polybutadiene-based thermoplastic elastomer, respectively, and the second resin is a polypropylene-based resin. Although the Young's modulus (7.5 MPa) is 150 MPa or less, it is a coated optical fiber having a tensile strength exceeding 10 MPa and a Young's modulus of the second coating layer of 700 MPa or more. The first resin composition is a resin simple substance to which no compound such as a metal oxide or an antioxidant is added. The coated optical fiber core wires of Comparative Example 3 and Comparative Example 4 have little initial loss and are excellent in mechanical properties, environmental adaptability properties, handling properties and heat resistance, but are inferior in flame retardancy, and are UV curable after coating removal Resin remains and is inferior in coating removal.
[0103]
In the coated optical fiber core of Comparative Example 5, the first coated layer has the same configuration as in Example 1, the second resin is a polystyrene resin, and the second coated layer has a Young's modulus of less than 700 MPa. Is a line. The coated optical fiber of Comparative Example 5 has little initial loss and is excellent in environmental adaptability, flame retardancy, handling properties and heat resistance, but is inferior in mechanical properties, and is glassy due to buckling of the second coating layer when the coating is removed. The fiber breaks and the coating removal property is poor.
[0104]
In the coated optical fiber core wire of Comparative Example 6, the first resin is EVA (vinyl acetate content 14% by weight), the second coating layer has the same configuration as in Example 1, and the Young's modulus of the first coating layer is 150 MPa. It is a coated optical fiber core wire exceeding. The coated optical fiber core wire of Comparative Example 6 has little initial loss and is excellent in environmental adaptability, flame retardancy, handling properties, and heat resistance, but is inferior in mechanical properties, and is glass due to buckling of the second coating layer when the coating is removed. The fiber breaks and the coating removal property is poor.
[0105]
In the coated optical fiber cores of Reference Examples 1 and 2, the first resin is a polystyrene-based thermoplastic elastomer and a polybutadiene-based thermoplastic elastomer, respectively, and the second resin is a polystyrene-based resin and a polypropylene-based resin, respectively. A coated optical fiber having a Young's modulus of the first coating layer of 150 MPa or less, a tensile strength of 10 MPa or less, and a Young's modulus of the second coating layer of 700 MPa or more. The outer diameter up to the first coating layer exceeds 0.8 mmφ. The coated optical fiber cores of Reference Examples 1 and 2 have little initial loss and are excellent in environmental adaptability, coating removal properties, flame retardancy, and heat resistance, but inferior in mechanical properties and handling properties.
[0106]
In the coated optical fiber cores of Reference Examples 3 to 4, the first resin is a polystyrene-based thermoplastic elastomer and a polybutadiene-based thermoplastic elastomer, respectively, and the second resin is a polypropylene-based resin and a polystyrene-based resin, respectively. A coated optical fiber having a Young's modulus of the first coating layer of 150 MPa or less, a tensile strength of 10 MPa or less, and a Young's modulus of the second coating layer of 700 MPa or more. The outer diameter to the first coating layer is less than 0.3 mmφ. The coated optical fiber cores of Reference Examples 3 to 4 have little initial loss and are excellent in environmental adaptability, coating removal, flame retardancy, handling properties, and heat resistance, but inferior in mechanical properties.
[0107]
In the coated optical fiber core wire of Comparative Example 7, the first resin is EVA (vinyl acetate content 19% by weight), the second resin is a polystyrene resin, the Young's modulus of the first coating layer is 150 MPa or less, and the tensile strength Is a coated optical fiber having a thickness exceeding 10 MPa and a Young's modulus of the second coating layer of 700 MPa or more. The coated optical fiber of Comparative Example 7 has little initial loss and is excellent in mechanical properties, environmental adaptability, flame retardancy, and handling properties. However, the ultraviolet curable resin remains after the coating is removed, and the coating removal properties are poor. Moreover, in the heat resistance test of the Telcordia standard (GR-326), the non-uniform wall thickness ratio after the heat resistance test is less than 80%, and the maximum value of the transmission loss at a wavelength of 1.31 μm exceeds 0.2 dB / km, Inferior in heat resistance.
[0108]
In the coated optical fiber core of Reference Example 5, the first resin is EVA (vinyl acetate content 28% by weight), the second resin is a polypropylene resin, the Young's modulus of the first coating layer is 150 MPa or less, and the tensile strength A coated optical fiber having a thickness of 10 MPa or less and a Young's modulus of the second coating layer of 700 MPa or more. The coated optical fiber core wire of Reference Example 5 has little initial loss and is excellent in mechanical properties, environmental adaptability properties, coating removal properties, flame retardancy, and handling properties. In the heat resistance test of Telcordia standard (GR-326), The uneven thickness ratio after the heat resistance test is less than 80%, the maximum value of the transmission loss at a wavelength of 1.31 μm exceeds 0.2 dB / km, and the heat resistance is poor.
[0109]
In the coated optical fiber core wire of Comparative Example 8, the first resin is EVA (vinyl acetate content 19% by weight), the second resin is a polystyrene resin, the Young's modulus of the first coating layer is 150 MPa or less, and the tensile strength Is a coated optical fiber having a thickness exceeding 10 MPa and a Young's modulus of the second coating layer of 700 MPa or more. The outer diameter up to the first coating layer exceeds 0.8 mmφ. The coated optical fiber of Comparative Example 8 has little initial loss and excellent environmental adaptability and flame retardancy, but is inferior in mechanical properties and handling properties, and UV curable resin remains after the coating is removed. Inferior to sex. Moreover, in the heat resistance test of the Telcordia standard (GR-326), the non-uniform wall thickness ratio after the heat resistance test is less than 80%, and the maximum value of the transmission loss at a wavelength of 1.31 μm exceeds 0.2 dB / km, Inferior in heat resistance.
[0110]
The first resin and the second resin used for the coated optical fiber cores of the examples, comparative examples, and reference examples are all selected from non-halogen resins.
[0111]
【The invention's effect】
According to the present invention, it has characteristics that do not generate toxic gas during combustion, high flame retardancy, high environmental adaptability, and high mechanical characteristics, and can easily perform coating removal without frequent breakage of the glass fiber. A coated optical fiber core, and a coated optical fiber core with connector, an optical fiber cord, an optical fiber cord with connector, and an optical fiber cable using the same can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a coated optical fiber core wire according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining the production of a coated optical fiber core wire according to an embodiment of the present invention.
FIG. 3 is a view for explaining coating removal of a coated optical fiber according to an embodiment of the present invention.
FIG. 4 is a diagram for explaining the manufacture of a coated optical fiber with connector according to an embodiment of the present invention.
FIG. 5 is a view showing a coating removal tool used for coating removal of a coated optical fiber.
FIG. 6 is a schematic cross-sectional view of an optical fiber cable according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a conventional coated optical fiber core wire.
[Explanation of symbols]
10,100 coated optical fiber core
11, 101 Glass fiber
11A Glass fiber exposed area
11B Glass fiber tip
13, 103 Optical fiber core
14 First coating layer
15 Second coating layer
16,104 Exterior covering
16A coating removal end face
17A hollow
17 Ferrule
17B Ferrule end face
Open end face of 17C ferrule
18 Connector
19 Coated optical fiber with connector
50 optical fiber cable
51 Tension member
52 cushioning material
53 Presser wound layer
54 Resin layer

Claims (8)

In the direction of separating the first coating layer and the second coating layer from the optical fiber core, further on the outer peripheral surface of the optical fiber core having one or more ultraviolet curable resin layers provided on the outer peripheral surface of the glass fiber. The first resin contained in the first resin composition constituting the first coating layer and the second resin contained in the second resin composition constituting the second coating layer, Both are resins having no halogen, and the first resin is one or more selected from the group consisting of an ethylene-α-olefin copolymer having a melting point of 85 ° C. or higher, a polystyrene-based thermoplastic elastomer, and a polybutadiene-based thermoplastic elastomer. of a resin, the second resin is selected from the group consisting of propylene and an ethylene propylene rubber and the block polypropylene and propylene by polymerizing a block copolymer and ethylene are random copolymerized That is one or more resins that are selected from the group consisting of random polypropylene, the tensile elastic modulus at 25 ° C. of the first coating layer is 150MPa or less, the tensile strength of the first coating layer is 10MPa or less, the second The coated optical fiber core wire whose tensile elastic modulus in 25 degreeC of a coating layer is 700 Mpa or more, and said 1st resin composition and said 2nd resin composition contain a metal hydroxide as a flame retardant. The ultraviolet curable resin layer is provided with a first ultraviolet curable resin layer and a second ultraviolet curable resin layer in a direction away from the glass fiber, or the first ultraviolet curable resin layer and the second ultraviolet ray. The coated optical fiber core wire according to claim 1, wherein a curable resin layer and a colored layer are provided, and the tensile secant modulus of the second ultraviolet curable resin layer is 5 MPa to 600 MPa. The coated optical fiber core wire according to any one of claims 1 and 2, wherein an unbalanced wall thickness ratio after a heat resistance test under a condition of 85 ° C x 168 hours is 80% or more. The coated optical fiber core wire according to any one of claims 1 to 3, wherein the glass fiber is exposed at a predetermined length from a terminal, and has a glass fiber exposed portion and a coating removal end surface. A connector with a built-in hollow ferrule that can be accommodated, and a sheath with a connector that is connected so that the exposed portion of the glass fiber is accommodated in the hollow and the end face of the sheath removal contacts the abutting end face of the ferrule Optical fiber core. The optical fiber cord which provides the protective layer which protects the said coated optical fiber core wire in the outer periphery of the coated optical fiber core wire in any one of Claims 1-3. The optical fiber cord according to claim 5, wherein the glass fiber is exposed at a predetermined length from the terminal to have a glass fiber exposed portion and a coating removal end face, and a hollow ferrule that can accommodate the glass fiber exposed portion. An optical fiber cord with a connector, which is connected so that the exposed portion of the glass fiber is accommodated in the hollow and the end surface of the coating removal comes into contact with the abutting end surface of the ferrule. A plurality of the coated optical fiber core wires according to any one of claims 1 to 3 are disposed on an outer peripheral surface of a tension member, a buffer material is disposed outside the coated optical fiber core wire, and a presser winding layer is disposed on the buffer material. An optical fiber cable which is provided on the outer side and is formed by covering the outer peripheral surface of the presser wound layer with a resin layer. A plurality of the optical fiber cords according to claim 5 are arranged on an outer peripheral surface of a tension member, a buffer material is arranged outside the optical fiber cord, a presser winding layer is provided outside the buffer material, and the presser winding layer An optical fiber cable formed by coating the outer peripheral surface of a resin layer with a resin layer.

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