JP4200841B2 - Chain guide or chain tensioner shoe - Google Patents

Description

【００３３】
【化２】

で表される化合物が挙げられる。これら一般式におけるＰＩＢは、ポリブテニル基を示し、高純度イソブテン又は１−ブテンとイソブテンの混合物をフッ化ホウ素系触媒又は塩化アルミニウム系触媒で重合させて得られる数平均分子量が９００〜３５００、望ましくは１０００〜２０００のポリブテンから得られる。上記数平均分子量が９００未満の場合は清浄性効果が劣り易く、３５００を超える場合は低温流動性に劣り易いため、望ましくない。
また、上記一般式におけるｎは、清浄性に優れる点から１〜５の整数、より望ましくは２〜４の整数であることがよい。更に、上記ポリブテンは、製造過程の触媒に起因して残留する微量のフッ素分や塩素分を吸着法や十分な水洗等の適切な方法により、５０ｐｐｍ以下、より望ましくは１０ｐｐｍ以下、特に望ましくは１ｐｐｍ以下まで除去してから用いることもよい。
【００３４】
更に、上記ポリブテニルコハク酸イミドの製造方法としては、特に限定はないが、例えば、上記ポリブテンの塩素化物又は塩素やフッ素が充分除去されたポリブテンと無水マレイン酸とを１００〜２００℃で反応させて得られるポリブテニルコハク酸を、ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ペンタエチレンヘキサミン等のポリアミンと反応させることにより得ることができる。
【００３５】
一方、上記ポリブテニルコハク酸イミドの誘導体としては、上記般式（１）又は（２）で表される化合物に、ホウ素化合物や含酸素有機化合物を作用させて、残存するアミノ基及び／又はイミノ基の一部又は全部を中和したり、アミド化した、いわゆるホウ素変性又は酸変性化合物を例示できる。その中でもホウ素含有ポリブテニルコハク酸イミド、特にホウ素含有ビスポリブテニルコハク酸イミドが最も好ましいものとして挙げられる。
【００３６】
上記ホウ素化合物としては、ホウ酸、ホウ酸塩、ホウ酸エステル等が挙げられる。具体的には、上記ホウ酸として、オルトホウ酸、メタホウ酸及びテトラホウ酸などが挙げられる。また、上記ホウ酸塩としては、アンモニウム塩等、具体的には、例えばメタホウ酸アンモニウム、四ホウ酸アンモニウム、五ホウ酸アンモニウム、八ホウ酸アンモニウム等のホウ酸アンモニウムが好適例として挙げられる。また、ホウ酸エステルとしては、ホウ酸と好ましくは炭素数１〜６のアルキルアルコールとのエステル、より具体的には例えば、ホウ酸モノメチル、ホウ酸ジメチル、ホウ酸トリメチル、ホウ酸モノエチル、ホウ酸ジエチル、ホウ酸トリエチル、ホウ酸モノプロピル、ホウ酸ジプロピル、ホウ酸トリププロピル、ホウ酸モノブチル、ホウ酸ジブチル、ホウ酸トリブチル等が好適例として挙げられる。なお、ホウ素含有ポリブテニルコハク酸イミドにおけるホウ素含有量Ｂと窒素含有量Ｎとの質量比「Ｂ／Ｎ」は、通常０．１〜３であり、好ましくは、０．２〜１である。
また、上記含酸素有機化合物としては、具体的には、例えばぎ酸、酢酸、グリコール酸、プロピオン酸、乳酸、酪酸、吉草酸、カプロン酸、エナント酸、カプリル酸、ペラルゴン酸、カプリン酸、ウンデシル酸、ラウリン酸、トリデカン酸、ミリスチン酸、ペンタデカン酸、パルミチン酸、マルガリン酸、ステアリン酸、オレイン酸、ノナデカン酸、エイコサン酸等の炭素数１〜３０のモノカルボン酸や、シュウ酸、フタル酸、トリメリット酸、ピロメリット酸等の炭素数２〜３０のポリカルポン酸並びにこれらの無水物、又はエステル化合物、炭素数２〜６のアルキレンオキサイド、ヒドロキシ（ポリ）オキシアルキレンカーボネート等が挙げられる
【００３７】
なお、本発明に用いる潤滑油において、ポリブテニルコハク酸イミド及び／又はその誘導体の含有量は特に制限されないが、０．１〜１５％が望ましく、より望ましくは１．０〜１２％であることが好ましい。０．１％未満では清浄性効果に乏しくなることがあり、１５％を超えると含有量に見合う清浄性効果が得られにくく、抗乳化性が悪化し易い。
【００３８】
更にまた、本発明に用いる潤滑油は、次の一般式（３）
【００３９】
【化３】

で表されるジチオリン酸亜鉛を含有することが好適である。
上記式（３）中のＲ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ別個に炭素数１〜２４の炭化水素基を示す。これら炭化水素基としては、炭素数１〜２４の直鎖状又は分枝状のアルキル基、炭素数３〜２４の直鎖状又は分枝状のアルケニル基、炭素数５〜１３のシクロアルキル基又は直鎖状若しくは分枝状のアルキルシクロアルキル基、炭素数６〜１８のアリール基又は直鎖状若しくは分枝状のアルキルアリール基、炭素数７〜１９のアリールアルキル基等のいずれかであることが望ましい。また、アルキル基やアルケニル基は、第１級、第２級及び第３級のいずれであってもよい。
【００４０】
上記Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７としては、具体的には、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、へキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、ノナデシル基、イコシル基、ヘンイコシル基、ドコシル基、トリコシル基、テトラコシル基等のアルキル基、プロペニル基、イソプロペニル基、ブテニル基、ブタジエニル基、ペンテニル基、ヘキセニル基、ヘプテニル基、オクテニル基、ノネニル基、デセニル基、ウンデセニル基、ドデセニル基、トリデセニル基、テトラデセニル基、ペンタデセニル基、ヘキサデセニル基、ヘプタデセニル基、オレイル基等のオクタデセニル基、ノナデセニル基、イコセニル基、ヘンイコセニル基、ドコセニル基、トリコセニル基、テトラコセニル基等のアルケニル基、シクロペンチル基、シクロへキシル基、シクロヘプチル基等のシクロアルキル基、メチルシクロペンチル基、ジメチルシクロペンチル基、エチルシクロペンチル基、プロピルシクロペンチル基、エチルメチルシクロペンチル基、トリメチルシクロペンチル基、ジエチルシクロペンチル基、エチルジメチルシクロペンチル基、プロピルメチルシクロペンチル基、プロピルエチルシクロペンチル基、ジ−プロピルシクロペンチル基、プロピルエチルメチルシクロペンチル基、メチルシクロへキシル基、ジメチルシクロへキシル基、エチルシクロへキシル基、プロピルシクロへキシル基、エチルメチルシクロへキシル基、トリメチルシクロへキシル基、ジエチルシクロヘキシル基、エチルジメチルシクロヘキシル基、プロピルメチルシクロヘキシル基、プロピルエチルシクロヘキシル基、ジ−プロピルシクロへキシル基、プロピルエチルメチルシクロヘキシル基、メチルシクロヘプチル基、ジメチルシクロヘプチル基、エチルシクロヘプチル基、プロピルシクロヘプチル基、エチルメチルシクロヘプチル基、トリメチルシクロヘプチル基、ジエチルシクロヘプチル基、エチルジメチルシクロヘプチル基、プロピルメチルシクロヘプチル基、プロピルエチルシクロヘプチル基、ジ−プロピルシクロヘプチル基、プロピルエチルメチルシクロヘプチル基等のアルキルシクロアルキル基、フェニル基、ナフチル基等のアリール基、トリル基、キシリル基、エチルフェニル基、プロピルフェニル基、エチルメチルフェニル基、トリメチルフェニル基、ブチルフェニル基、プロピルメチルフェニル基、ジエチルフェニル基、エチルジメチルフェニル基、テトラメチルフェニル基、ペンチルフェニル基、ヘキシルフェニル基、ヘプチルフェニル基、オクチルフェニル基、ノニルフェニル基、デシルフェニル基、ウンデシルフェニル基、ドデシルフェニル基等のアルキルアリール基、ベンジル基、メチルベンジル基、ジメチルベンジル基、フェネチル基、メチルフェネチル基、ジメチルフェネチル基等のアリールアルキル基、等が例示できる。
なお、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７がとり得る上記炭化水素基には、考えられる全ての直鎖状構造及び分枝状構造をが含まれ、また、アルケニル基の二重結合の位置、アルキル基のシクロアルキル基への結合位置、アルキル基のアリール基への結合位置、及びアリール基のアルキル基への結合位置は任意である。また、上記炭化水素基の中でも、その炭化水素基が、直鎖状又は分柱状の炭素数１〜１８のアルキル基である場合若しくは炭素数６〜１８のアリール基、又は直鎖状若しくは分枝状アルキルアリール基である場合が特に好ましい。
【００４１】
上記ジチオリン酸亜鉛の好適な具体例としては、例えば、ジイソプロピルジチオリン酸亜鉛、ジイソブチルジチオリン酸亜鉛、ジ−ｓｅｃ−ブチルジチオリン酸亜鉛、ジ−ｓｅｃ−ペンチルジチオリン酸亜鉛、ジ−ｎ−ヘキシルジチオリン酸亜鉛、ジ−ｓｅｃ−ヘキシルジチオリン酸亜鉛、ジ−オクチルジチオリン酸亜鉛、ジ−２−エチルヘキシルジチオリン酸亜鉛、ジ−ｎ−デシルジチオリン酸亜鉛、ジ−ｎ−ドデシルジチオリン酸亜鉛、ジイソトリデシルジチオリン酸亜鉛、及びこれらの任意の組合せに係る混合物等が挙げられる。
【００４２】
また、上記ジチオリン酸亜鉛の含有量は、特に制限されないが、より高い摩擦低減効果を発揮させる観点から、潤滑油全量基準且つリン元素換算量で、０．１％以下であることが好ましく、また０．０６％以下であることがより好ましく、更にはジチオリン酸亜鉛が含有されないことが特に好ましい。ジチオリン酸亜鉛の含有量がリン元素換算量で０．１％を超えると、ＤＬＣ部材と鉄基部材との摺動面における上記脂肪酸エステル系無灰摩擦調整剤や上記脂肪族アミン系無灰摩擦調整剤の優れた摩擦低減効果が阻害されるおそれがある。
【００４３】
上記ジチオリン酸亜鉛の製造方法としては、従来方法を任意に採用することができ、特に制限されないが、具体的には、例えば、上記Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７に対応する炭化水素基を持つアルコール又はフェノールを五二硫化りんと反応させてジチオリン酸とし、これを酸化亜鉛で中和させることにより合成することができる。なお、上記ジチオリン酸亜鉛の構造は、使用する原料アルコールによって異なることは言うまでもない。
本発明においては、上記一般式（３）に包含される２種以上のジチオリン酸亜鉛を任意の割合で混合して使用することもできる。
【００４４】
上述のように、本発明に用いる潤滑油は、ＤＬＣ薄膜とチェーンなど金属材料との摺動面に用いた場合に、極めて優れた低摩擦特性を示すものであるが、特に内燃機関用潤滑油として必要な性能を高める目的で、金属系清浄剤、酸化防止剤、粘度指数向上剤、他の無灰摩擦調整剤、他の無灰分散剤、磨耗防止剤若しくは極圧剤、防錆剤、非イオン系界面活性剤、抗乳化剤、金属不活性化剤、消泡剤等を単独で又は複数種を組合せて配合し、必要な性能を高めることができる。
【００４５】
上記金属系清浄剤としては、潤滑油用の金属系清浄剤として通常用いられる任意の化合物が使用できる。例えば、アルカリ金属又はアルカリ土類金属のスルホネート、フェネート、サリシレート、ナフテネート等を単独で又は複数種を組合せて使用できる。ここで、上記アルカリ金属としてはナトリウム（Ｎａ）やカリウム（Ｋ）等、上記アルカリ土類金属としてはカルシウム（Ｃａ）やマグネシウム（Ｍｇ）等が例示できる。また、具体的な好適例としては、Ｃａ又はＭｇのスルフォネート、フェネート及びサリシレートが挙げられる。
なお、これら金属系清浄剤の全塩基価及び添加量は、要求される潤滑油の性能に応じて任意に選択できる。通常、全塩基価は、過塩素酸法で０〜５００ｍｇＫＯＨ／ｇ、望ましくは１５０〜４００ｍｇＫＯＨ／ｇであり、その添加量は潤滑油全量基準で、通常０．１〜１０％である。
【００４６】
また、上記酸化防止剤としては、潤滑油用の酸化防止剤として通常用いられる任意の化合物を使用できる。例えば、４，４’−メチレンビス（２，６−ジ−ｔｅｒｔ−ブチルフェノール）、オクタデシル−３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート等のフェノール系酸化防止剤、フェニル−α−ナフチルアミン、アルキルフェニル−α−ナフチルアミン、アルキルジフェニルアミン等のアミン系酸化防止剤、並びにこれらの任意の組合せに係る混合物等が挙げられる。また、かかる酸化防止剤の添加量は、潤滑油全量基準で、通常０．０１〜５％である。
【００４７】
更に、上記粘度指数向上剤としては、具体的には、各種メタクリル酸エステルから選ばれる１種又は２種以上のモノマーの共重合体やその水添物等のいわゆる非分散型粘度指数向上剤、及び更に窒素化合物を含む各種メタクリル酸エステルを共重合させたいわゆる分散型粘度指数向上剤等が例示できる。また、他の粘度指数向上剤の具体例としては、非分散型又は分散型エチレン−α−オレフィン共重合体（α−オレフィンとしては、例えばプロピレン、１−ブテン、１−ペンテン等）及びその水素化物、ポリイソブチレン及びその水添物、スチレン−ジエン水素化共重合体、スチレン−無水マレイン酸エステル共重合体、並びにポリアルキルスチレン等も例示できる。
これら粘度指数向上剤の分子量は、せん断安定性を考慮して選定することが必要である。具体的には、粘度指数向上剤の数平均分子量は、例えば分散型及び非分散型ポリメタクリレートでは５０００〜１００００００、好ましくは１０００００〜８０００００がよく、ポリイソブチレン又はその水素化物では８００〜５０００、エチレン−α−オレフィン共重合体又はその水素化物では８００〜３０００００、好ましくは１００００〜２０００００がよい。また、かかる粘度指数向上剤は、単独で又は複数種を任意に組合せて含有させることができるが、通常その含有量は、潤滑油基準で０．１〜４０．０％であることが望ましい。
【００４８】
更にまた、他の無灰摩擦調整剤としては、ホウ酸エステル、高級アルコール、脂肪族エーテル等の無灰摩擦調整剤、ジチオリン酸モリブデン、ジチオカルバミン酸モリブデン、二硫化モリブデン等の金属系摩擦調整剤等が挙げられる。
また、他の無灰分散剤としては、数平均分子量が９００〜３５００のポリブテニル基を有するポリブテニルベンジルアミン、ポリブテニルアミン、数平均分子量が９００未満のポリブテニル基を有するポリブテニルコハク酸イミド等及びそれらの誘導体等が挙げられる。
更に、上記磨耗防止剤又は極圧剤としては、ジスルフィド、硫化油脂、硫化オレフィン、炭素数２〜２０の炭化水素基を１〜３個含有するリン酸エステル、チオリン酸エステル、亜リン酸エステル、チオ亜リン酸エステル及びこれらのアミン塩等が挙げられる。
更にまた、上記防錆剤としては、アルキルベンゼンスルフォネート、ジノニルナフタレンスルフォネート、アルケニルコハク酸エステル、多価アルコールエステル等が挙げられる。
また、上記非イオン系界面活性剤及び抗乳化剤としては、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルナフチルエーテル等のポリアルキレングリコール系非イオン系界面活性剤等が挙げられる。
更に、上記金属不活性化剤としては、イミダゾリン、ピリミジン誘導体、チアジアゾール、ベンゾトリアゾール、チアジアゾール等が挙げられる。
更にまた、上記消泡剤としては、シリコーン、フルオロシリコーン、フルオロアルキルエーテル等が挙げられる。
なお、これら添加剤を本発明に用いる潤滑油に含有させる場合には、その含有量は、潤滑油全量基準で、他の摩擦調整剤、他の無灰分散剤、磨耗防止剤又は極圧剤、防錆剤、及び抗乳化剤については０．０１〜５％、金属不活性剤については０．００５〜１％、消泡剤については０．０００５〜１％の範囲から適宜選択できる。
【００４９】
【実施例】
以下、本発明を実施例と比較例によって、更に具体的に説明するが、本発明は、これら実施例のみに限定されるものではない。
【００５０】
（試験片の作製）
〔１〕試験片Ａ
ポリアミド６６樹脂（デュポン社製 ザイテル４５ＨＳＢ、融点：２６５℃）のペレットを乾燥後、射出成型機を用いて図１に示す寸法・形状のリング試験片１に成型した。成型後、リング試験片１の側面を研磨して表面粗さをＲａ＝３μｍとした。
次に、プラズマＣＶＤ装置に上記リング試験片１を入れ、真空に引いたのち、Ｈ_２プラズマにより成膜面であるリング側面を洗浄した後、ＣＨ_４プラズマによりＤＬＣを成膜した。なおＤＬＣ薄膜の膜圧は０．７〜０．８μｍとした。
【００５１】
〔２〕試験片Ｂ
上記ポリアミド６６樹脂８０重量部に対し、炭素繊維（呉羽化学工業製 クレカチョップＭ−２００７Ｓ、繊維直径：１４．５μｍ、繊維長：９０μｍ）を２０重量部配合し、押し出し機を用いて混練・造粒した。そして、造粒したペレットを射出成型機を用いて、図１に示す寸法・形状のリング試験片に成型した。
。射出成型機を用いて造粒したペレットを同様のリング試験片に成型すると共に、上記同様の操作を繰り返して、リング試験片の側面を研磨した後、ＤＬＣ薄膜を成膜した。
【００５２】
〔３〕試験片Ｃ
上記試験片Ａと同一の材料を用いて、同様の寸法・形状のリング試験片に加工した後、その側面を研磨して表面粗さをＲａ＝３μｍとし、ＤＬＣ薄膜を成膜することなく試験片Ｃとした。
【００５３】
〔４〕試験片Ｄ
上記試験片Ｂと同一の材料を用いて、同様の寸法・形状のリング試験片に加工した後、その側面を研磨して表面粗さをＲａ＝３μｍとし、ＤＬＣ薄膜を成膜することなく試験片Ｄとした。
【００５４】
（潤滑油の調整）
〔１〕潤滑油Ａ
ベースオイルとしてのポリアルファオレフィン（１−オクテンオリゴマー）に、エステル系無灰摩擦調整剤としてグリセリンモノオレートを１．０％、無灰系分散剤としてポリブテニルコハク酸イミドを５．０％、その他の添加剤として粘度指数向上剤、酸化防止剤、防錆剤、抗乳化剤、非イオン系界面活性剤、金属不活性化剤、消泡剤等を合計量で７．０％それぞれ添加し、作動油Ａとした。
【００５５】
〔２〕潤滑油Ｂ
ベースオイルとしてのポリアルファオレフィン（１−オクテンオリゴマー）のみから成る潤滑油を調整し、これを潤滑油Ｂとした。
【００５６】
（性能評価）
本発明の摺動特性改善効果を確認するため、上記試験片Ａ〜Ｄの摩耗試験を上記潤滑油Ａ及びＢと組合わせて実施した。摺接する相手材としては一般的な炭素鋼（Ｓ５５Ｃ調質材 ＨＲＡ＝７０）を選定し（ＨＲＡは、ＪＩＳＺ２２４５に規定されるロックウェル硬さのＡスケール）、試験装置に取り付けるため、上記炭素鋼の形状を直径６０ｍｍ、厚さ１０ｍｍのディスク形状とし（後述するディスク１５）、上記試験片との摺接面の表面粗さをＲｚ（最大粗さ）＝５μｍ程度とした。
【００５７】
この摩耗試験に使用した縦型ピンオンディスク方式の摩擦摩耗試験機の概要を図２に示す。
当該試験機は、上部にリングホルダー１１を有し、このリングホルダー１１は、摺動時にリング試験片１の径方向の移動が生じないように、リング試験片１の内周面側に設置したスナップリング２２のバネ力によって、リング試験片１の外周面をリングホルダー１１の溝部に押し付けて固定するようになっている。
一方、当該試験機の下部には回転軸１３に結合されたディスクホルダー１４を備え、炭素鋼から成る上記ディスク１５をディスクホルダー１４にボルトで固定すると、ディスク１５はリング試験片１に対して回転自在となる。次に、リングホルダー１４を下降させることでリング試験片１とディスク１５を摺接関係とさせ、さらにリングホルダー１１の軸線方向から圧力Ｐを加えることによって、リング試験片１とディスク１５とが圧接することになる。この際、シールリング１０とディスク１５の摺接部は、エンジンオイルＯ（すなわち、潤滑油Ａ又はＢ）中に浸漬されている。なお、符号１６はロードセル、符号１７はトルク検出器を示す。
【００５８】
上記試験機を用いて、圧接面圧：２ＭＰａ、摩擦速度：７ｍ／秒、試験時間：６時間の試験条件で行った摩耗試験の結果を表１に示す。
【００５９】
【表１】

【００６０】
【発明の効果】
以上説明してきたように、本発明によれば、チェーンとの摺動表面がＤＬＣ薄膜によって被覆され、しかも脂肪酸エステル系無灰摩擦調整剤及び／又は脂肪族アミン系無灰摩擦調整剤を含有する潤滑油を介して上記チェーンと摺動するようにしているので、耐摩耗性と低摩擦抵抗を両立させたチェーンガイド及びチェーンテンショナーを提供することができ、例えば自動車用の内燃機関に搭載した場合には、当該機関の燃費改善に大きく寄与するものである。
【図面の簡単な説明】
【図１】本発明の実施例において摩耗試験に用いたリング試験片の形状を示す斜視図である。
【図２】本発明の実施例において摩耗試験に用いた縦型ピンオンディスク方式の摩擦摩耗試験機の概略図である。[0001]
BACKGROUND OF THE INVENTION
For example, in an internal combustion engine for an automobile, the present invention prevents a chain from being detached or vibrated by guiding a cam chain provided in a valve mechanism or applying tension to the cam chain. The present invention relates to a shoe used for a chain guide or a chain tensioner, and a chain system using such a shoe.
[0002]
[Prior art]
In recent years, the application of thermoplastic resin to sliding parts such as bearings, rollers, and gears has been progressing from the viewpoint of reducing noise associated with sliding, weight reduction, and non-lubrication of sliding parts. Due to demands for downsizing and the like, the usage environment (surface pressure, operating temperature) of resin sliding materials has become increasingly severe.
In particular, chain guides and chain tensioner shoe materials used in automobile internal combustion engines require heat resistance and oil resistance at 140 ° C or higher in addition to sliding characteristics. In this case, a polyamide resin excellent in heat resistance / oil resistance, mechanical strength and wear resistance is applied.
[0003]
However, although polyamide resin is excellent in the material properties as described above, there is a problem that the frictional resistance during sliding is high.
As a technique for reducing the sliding friction of polyamide resin, a method of adding a fluororesin such as polytetrafluoroethylene (for example, see Patent Document 1) or a solid lubricant such as molybdenum disulfide to polyamide is known.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-53761
[Problems to be solved by the invention]
However, in the method of adding the solid lubricant as described above to the polyamide, if the surface roughness of the sliding counterpart is large or the surface pressure and sliding speed during sliding are high, the solid lubricant Is removed from the polyamide resin, which is the base material, and pitching wear occurs starting from the drop-off part, or the solid lubricant existing part having poor wear resistance is partially worn away, resulting in a resin. There is a problem that wear of the entire composition is promoted.
In addition, in order to suppress wear of the resin composition, it is also common to add a fiber filler such as glass fiber in the composition, but depending on the sliding conditions, it dropped out of the composition. Since the fiber filler is sandwiched between the sliding surfaces and acts as an abrasive, there is a problem that wear may be promoted. The conventional chain guide made of polyamide resin can solve these problems. And problems with shoes for chain tensioners.
[0006]
The present invention has been made paying attention to the above-described problems in the prior art, and the object of the present invention is to have excellent wear resistance and low frictional resistance, and to reduce wear of the mating member. An object of the present invention is to provide a chain guide or chain tensioner shoe that can contribute to improving the performance of a mounted device, and a chain system using such a shoe.
[0007]
[Means for Solving the Problems]
The present inventors, as well as consider the sliding material including a surface coating to achieve the above object, the results of extensive acute meaning also studied the combination of sliding material and lubricating composition, the sliding surface of the shoe Was found to be able to achieve both wear resistance and low friction resistance by coating a diamond-like carbon (hereinafter referred to as “DLC”) thin film and adding a specific ashless friction modifier to the lubricating oil. The present invention has been completed.
[0008]
That is, the shoe for a chain guide or chain tensioner of the present invention slides with a chain in the presence of lubricating oil, and the lubricating oil is a fatty acid ester-based ashless friction modifier and / or an aliphatic amine-based shoe. In addition to containing an ashless friction modifier, the sliding surface of the shoe is coated with a DLC thin film.
[0009]
In the chain system of the present invention, the above-described chain guide shoe and / or chain tensioner shoe of the present invention is applied, and the sliding counterpart member of the shoe, that is, the surface of the metal chain is rough. The maximum roughness Rz is 5 μm or less.
[0010]
Furthermore, the manufacturing method of the shoe for chain guide or chain tensioner of the present invention is a method applied to manufacture of the above shoe of the present invention, and is a shoe base chain containing a thermoplastic resin such as polyamide , for example. A DLC film is formed on the sliding surface by a plasma CVD method.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail. In the present specification, “%” indicates mass percentage unless otherwise specified.
[0012]
In the chain guide or chain tensioner shoe of the present invention, since the coating made of the DLC thin film is applied to the sliding surface with the chain, the fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless Under the lubricating oil containing the friction modifier, wear resistance and low friction characteristics are exhibited, and the friction coefficient and the amount of wear are greatly reduced.
[0013]
Here, the DLC thin film is mainly composed of carbon atoms, and can be formed by, for example, a plasma CVD method.
This DLC material is amorphous, and the bonding form between carbons consists of both a diamond structure (SP ³ bond) and a graphite bond (SP ² bond). Specifically, aC (amorphous carbon) consisting only of carbon elements, aC: H (hydrogen amorphous carbon) containing hydrogen, and some metal elements such as titanium (Ti) and molybdenum (Mo). MeC contained in can be preferably used.
[0014]
In addition, as a base material (base material) for the chain guide or chain tensioner shoe of the present invention, it is desirable to use a material containing a thermoplastic resin having a melting point of 200 ° C. or higher, for example, a polyamide resin. Here, the reason why the melting point of the thermoplastic resin is set to 200 ° C. or more is that, in this type of shoe, the surface temperature on the sliding surface during operation may rise to nearly 200 ° C. When a resin having a melting point of is used as a base material, the risk of softening or erosion increases.
[0015]
For example, a solid lubricant such as polytetrafluoroethylene (PTFE) or molybdenum disulfide (MoS ₂ ), or glass fiber or carbon fiber as a fiber reinforcing material can be added to the resin. From the viewpoint of securing moldability / workability and wear resistance for obtaining a desired shape, it is desirable that the content of the thermoplastic resin having a melting point of 200 ° C. or higher is at least 40%.
[0016]
The shoe for a chain guide or chain tensioner according to the present invention can be suitably used for, for example, a valve operating mechanism of an internal combustion engine for an automobile, and maintains good friction characteristics with the cam chain, thereby improving the fuel efficiency of the internal combustion engine. It can contribute to improvement.
[0017]
The shoe for chain guide or chain tensioner of the present invention contains, for example, the thermoplastic resin as described above, and the DLC is formed on the sliding surface of the base material chain formed into a desired shoe shape by the plasma CVD method. Can be produced by forming a film.
In the chain system of the present invention, the above-described chain guide shoe and / or chain tensioner shoe of the present invention is used, and the surface roughness of the chain with which the shoe is slid is JIS B0601-2001. Since the maximum height roughness Rz specified is 5 μm or less, the wear between the chain and the shoe is minimized under the lubricating oil containing the friction modifier, and the sliding between the two A state will be maintained stably over a long period of time. In addition, the maximum height roughness Rz of the sliding surface with the chain shoe is set to 5 μm or less. When the maximum height roughness Rz exceeds 5 μm, the chain sliding surface acts as a stone and the shoe material This is because the DLC thin film coated on the surface is easily scraped off.
[0019]
Next, the composition of the lubricating oil used in the present invention will be described in detail.
As the lubricating oil, a lubricating base oil containing a fatty acid ester-based ashless friction modifier and / or an aliphatic amine-based ashless friction modifier is used.
[0020]
Here, the lubricating base oil is not particularly limited, and any type may be used as long as it is normally used as a base oil of a lubricating oil composition such as mineral oil, synthetic oil, fats and oils, and mixtures thereof. Can be used.
As mineral oil, specifically, a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation can be desolvated, solvent extraction, hydrocracking, solvent dewaxing, hydrorefining, sulfuric acid washing, clay Oils such as paraffinic or naphthenic oils or normal paraffins, etc., which are refined by appropriately combining purification treatments, etc., can be used. Solvent refining and hydrorefining treatments are generally used, but the aromatic content is further reduced. It is more preferable to use an advanced hydrocracking process that can be carried out or a GTL Wax (gas tow liquid wax) produced by isomerization.
[0021]
Specific examples of synthetic oils include poly-α-olefins (eg, 1-octene oligomers, 1-decene oligomers, ethylene-propylene oligomers), poly-α-olefin hydrides, isobutene oligomers, and isobutene oligomers. Hydride, isoparaffin, alkylbenzene, alkylnaphthalene, diester (eg, ditridecyl glutarate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, dioctyl sebacate, etc.), polyol ester (eg, trimethylolpropane caprylate, trimethylolpropane pelargol And trimethylolpropane esters such as trimethylolpropane isostearinate; pentaerythritol 2-ethylhexanoate, pentaerythritol Pentaerythritol esters such as largonate), polyoxyalkylene glycols, dialkyldiphenyl ethers, polyphenyl ethers and the like. Among them, preferred examples include poly-α-olefins such as 1-octene oligomers and 1-decene oligomers or hydrides thereof.
[0022]
The base oil in the lubricating oil used in the present invention is a mixture of two or more mineral base oils, or a mixture of two or more synthetic base oils, in addition to using a mineral base oil or a synthetic base oil alone or in combination. It doesn't matter. Further, the mixing ratio of two or more kinds of base oils in the above mixture is not particularly limited and can be arbitrarily selected.
[0023]
The sulfur content in the lubricating base oil is not particularly limited, but is preferably 0.2% or less, more preferably 0.1% or less, and even more preferably 0.05% or less, based on the total amount of the base oil. Preferably there is. In particular, since the sulfur content of hydrorefined mineral oil or synthetic base oil is 0.005% or less, or contains substantially no sulfur content (5 ppm or less), these are preferably used as the base oil.
[0024]
Also, the aromatic content in the lubricating base oil is not particularly limited, but the total aromatic content is 15% or less in order to maintain long-term low friction characteristics as a lubricating oil composition for internal combustion engines. More preferably, it is preferably 10% or less, more preferably 5% or less. That is, when the total aromatic content of the lubricating base oil exceeds 15%, the oxidation stability is inferior, which is not preferable.
In addition, the total aromatic content said here means the aromatic fraction content measured based on the method prescribed | regulated to ASTMD2549.
[0025]
The kinematic viscosity of the lubricating base oil is not particularly limited, but when used as a lubricating oil for an internal combustion engine, the kinematic viscosity at 100 ° C. is preferably 2 mm ² / s or more, more preferably 3 mm ^2. / S or more. On the other hand, the kinematic viscosity is preferably 20 mm ² / s or less, preferably 10 mm ² / s or less, and particularly preferably 8 mm ² / s or less. When the kinematic viscosity at 100 ° C. of the lubricating base oil is less than 2 mm ² / s, it is not preferable because sufficient abrasion resistance cannot be obtained and evaporation characteristics may be deteriorated. On the other hand, when the kinematic viscosity exceeds 20 mm ² / s, it is difficult to exhibit low friction performance, and low temperature performance may be deteriorated. In the present invention, a mixture of any two or more base oils selected from the above base oils can be used, and the base oil alone is used as long as the kinematic viscosity at 100 ° C. falls within the above preferred range. Even if the kinematic viscosity is other than the above, it can be used.
[0026]
Also, the viscosity index of the lubricating base oil is not particularly limited, but is preferably 80 or more, more preferably 100 or more, particularly when used as a lubricating oil for internal combustion engines. The above is preferable. By increasing the viscosity index of the lubricating base oil, it is possible to obtain a lubricating oil for an internal combustion engine that consumes less oil and has excellent low-temperature viscosity characteristics and fuel saving performance.
[0027]
The fatty acid ester ashless friction modifier and / or the aliphatic amine ashless friction modifier is a straight chain having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, and particularly preferably 10 to 20 carbon atoms. Or the fatty acid ester which has a branched hydrocarbon group, a fatty-acid amine compound, and these arbitrary mixtures can be mentioned. When the carbon number is outside the range of 6 to 30, there is a possibility that the friction reducing effect cannot be obtained sufficiently.
[0028]
Specific examples of the straight chain or branched hydrocarbon group having 6 to 30 carbon atoms include hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henocosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triaconyl group, etc. Alkyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icosenyl group, N'ikoseniru group include docosenyl, tricosenyl group, tetracosenyl group, Pentakoseniru group, Hekisakoseniru group, Heputakoseniru group, Okutakoseniru group, Nonakoseniru group, an alkenyl group such as tri container group.
The alkyl group and alkenyl group include all possible linear structures and branched structures, and the position of the double bond in the alkenyl group is arbitrary.
[0029]
Moreover, as said fatty acid ester, the ester of the fatty acid which has this C6-C30 hydrocarbon group, and aliphatic monohydric alcohol or aliphatic polyhydric alcohol etc. can be illustrated, Specifically, glycerol monooleate, Particularly preferred examples include glycerine diolate, sorbitan monooleate, sorbitan diolate, and the like.
Examples of the aliphatic amine compound include aliphatic monoamines or their alkylene oxide adducts, aliphatic polyamines, imidazoline compounds, and derivatives thereof. Specifically, fats such as laurylamine, lauryldiethylamine, lauryldiethanolamine, dodecyldipropanolamine, palmitylamine, stearylamine, stearyltetraethylenepentamine, oleylamine, oleylpropylenediamine, oleyldiethanolamine, N-hydroxyethyloleylimidazoline, etc. Amine alkylene compounds, amine alkylene oxide adducts such as N, N-dipolyoxyalkylene-N-alkyl (or alkenyl) (carbon number 6 to 28) of these aliphatic amine compounds, carbon numbers in these aliphatic amine compounds Residual amino group and / or imino by reacting 2-30 monocarboxylic acid (fatty acid, etc.) or polycarboxylic acid having 2-30 carbon atoms such as oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid, etc. Base Some or amidated or neutralize all, so-called acid-modified compounds, and the like. Preferable examples include N, N-dipolyoxyethylene-N-oleylamine.
[0030]
Further, the content of the fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless friction modifier contained in the lubricating oil used in the present invention is not particularly limited, but is 0. The content is preferably 05 to 3.0%, more preferably 0.1 to 2.0%, and particularly preferably 0.5 to 1.4%. If the content is less than 0.05%, the friction reducing effect tends to be small, and if it exceeds 3.0%, the solubility and storage stability in the lubricating oil are significantly deteriorated, and precipitates are likely to be generated. It is not preferable.
[0031]
On the other hand, the lubricating oil used in the present invention preferably contains polybutenyl succinimide and / or a derivative thereof.
Examples of the polybutenyl succinimide include the following general formulas (1) and (2)
[0032]
[Chemical 1]

[0033]
[Chemical 2]

The compound represented by these is mentioned. PIB in these general formulas represents a polybutenyl group, and the number average molecular weight obtained by polymerizing a high purity isobutene or a mixture of 1-butene and isobutene with a boron fluoride catalyst or an aluminum chloride catalyst is 900 to 3500, preferably Obtained from 1000-2000 polybutene. When the number average molecular weight is less than 900, the cleanability effect tends to be poor, and when it exceeds 3500, the low temperature fluidity tends to be poor.
Further, n in the above general formula is preferably an integer of 1 to 5, more preferably an integer of 2 to 4, from the viewpoint of excellent cleanliness. Further, the polybutene is used to remove a trace amount of fluorine and chlorine remaining due to the catalyst in the production process by an appropriate method such as an adsorption method or sufficient water washing, and is preferably 50 ppm or less, more preferably 10 ppm or less, and particularly preferably 1 ppm. It is also possible to use after removing to the following.
[0034]
Furthermore, the method for producing the polybutenyl succinimide is not particularly limited. For example, the polybutene chlorinated product or polybutene from which chlorine or fluorine is sufficiently removed and maleic anhydride are reacted at 100 to 200 ° C. The polybutenyl succinic acid thus obtained can be obtained by reacting with polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and the like.
[0035]
On the other hand, as a derivative of the polybutenyl succinimide, a boron compound or an oxygen-containing organic compound is allowed to act on the compound represented by the general formula (1) or (2), thereby remaining amino groups and / or Examples thereof include so-called boron-modified or acid-modified compounds in which part or all of the imino group is neutralized or amidated. Among them, boron-containing polybutenyl succinimide, particularly boron-containing bispolybutenyl succinimide is most preferable.
[0036]
Examples of the boron compound include boric acid, borates, and borate esters. Specifically, examples of the boric acid include orthoboric acid, metaboric acid, and tetraboric acid. Moreover, as said borate, ammonium borate, such as ammonium salt etc., specifically, for example, ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, etc. are mentioned as a suitable example. As the boric acid ester, an ester of boric acid and preferably an alkyl alcohol having 1 to 6 carbon atoms, more specifically, for example, monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate, boric acid Preferred examples include diethyl, triethyl borate, monopropyl borate, dipropyl borate, triplypropyl borate, monobutyl borate, dibutyl borate, tributyl borate and the like. In addition, the mass ratio “B / N” of the boron content B and the nitrogen content N in the boron-containing polybutenyl succinimide is usually 0.1 to 3, preferably 0.2 to 1. .
Specific examples of the oxygen-containing organic compound include formic acid, acetic acid, glycolic acid, propionic acid, lactic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl. C1-C30 monocarboxylic acids such as acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, nonadecanoic acid, eicosanoic acid, oxalic acid, phthalic acid, Examples thereof include C2-C30 polycarponic acids such as trimellitic acid and pyromellitic acid, and anhydrides or ester compounds thereof, alkylene oxides having 2 to 6 carbon atoms, and hydroxy (poly) oxyalkylene carbonate.
In the lubricating oil used in the present invention, the content of polybutenyl succinimide and / or its derivative is not particularly limited, but is preferably 0.1 to 15%, more preferably 1.0 to 12%. It is preferable. If it is less than 0.1%, the cleaning effect may be poor, and if it exceeds 15%, it is difficult to obtain a cleaning effect corresponding to the content, and the demulsibility tends to deteriorate.
[0038]
Furthermore, the lubricating oil used in the present invention has the following general formula (3):
[0039]
[Chemical 3]

It is preferable to contain the zinc dithiophosphate represented by these.
R ⁴ , R ⁵ , R ⁶ and R ⁷ in the above formula (3) each independently represent a hydrocarbon group having 1 to 24 carbon atoms. Examples of these hydrocarbon groups include linear or branched alkyl groups having 1 to 24 carbon atoms, linear or branched alkenyl groups having 3 to 24 carbon atoms, and cycloalkyl groups having 5 to 13 carbon atoms. Or a linear or branched alkylcycloalkyl group, an aryl group having 6 to 18 carbon atoms, a linear or branched alkylaryl group, an arylalkyl group having 7 to 19 carbon atoms, or the like. It is desirable. The alkyl group or alkenyl group may be any of primary, secondary, and tertiary.
[0040]
Specific examples of R ⁴ , R ⁵ , R ⁶ and R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group, tricosyl group, tetracosyl group, alkyl group, propenyl group, Isopropenyl group, butenyl group, butadienyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, oleyl Octadeseni Group, nonadecenyl group, icocenyl group, heicosenyl group, dococenyl group, tricocenyl group, tetracocenyl group and other alkenyl groups, cyclopentyl group, cyclohexyl group, cycloheptyl group and other cycloalkyl groups, methylcyclopentyl group, dimethylcyclopentyl group, ethyl Cyclopentyl group, propylcyclopentyl group, ethylmethylcyclopentyl group, trimethylcyclopentyl group, diethylcyclopentyl group, ethyldimethylcyclopentyl group, propylmethylcyclopentyl group, propylethylcyclopentyl group, di-propylcyclopentyl group, propylethylmethylcyclopentyl group, methylcyclohexyl Group, dimethylcyclohexyl group, ethylcyclohexyl group, propylcyclohexyl group, ethylmethylcyclohexyl , Trimethylcyclohexyl group, diethylcyclohexyl group, ethyldimethylcyclohexyl group, propylmethylcyclohexyl group, propylethylcyclohexyl group, di-propylcyclohexyl group, propylethylmethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, Ethylcycloheptyl group, propylcycloheptyl group, ethylmethylcycloheptyl group, trimethylcycloheptyl group, diethylcycloheptyl group, ethyldimethylcycloheptyl group, propylmethylcycloheptyl group, propylethylcycloheptyl group, di-propylcycloheptyl group Alkylcycloalkyl groups such as propylethylmethylcycloheptyl group, aryl groups such as phenyl group and naphthyl group, tolyl group, xylyl group, Nyl group, propylphenyl group, ethylmethylphenyl group, trimethylphenyl group, butylphenyl group, propylmethylphenyl group, diethylphenyl group, ethyldimethylphenyl group, tetramethylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group , Alkylaryl groups such as octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, benzyl group, methylbenzyl group, dimethylbenzyl group, phenethyl group, methylphenethyl group, dimethylphenethyl group, etc. An arylalkyl group etc. can be illustrated.
The hydrocarbon groups that R ⁴ , R ⁵ , R ^6, and R ⁷ can include all possible linear structures and branched structures, and also include double bonds of alkenyl groups. The position, the bonding position of the alkyl group to the cycloalkyl group, the bonding position of the alkyl group to the aryl group, and the bonding position of the aryl group to the alkyl group are arbitrary. Further, among the hydrocarbon groups, when the hydrocarbon group is a linear or branched alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a linear or branched group Particularly preferred is a linear alkylaryl group.
[0041]
Preferred examples of the zinc dithiophosphate include, for example, zinc diisopropyldithiophosphate, zinc diisobutyldithiophosphate, zinc di-sec-butyldithiophosphate, zinc di-sec-pentyldithiophosphate, zinc di-n-hexyldithiophosphate. , Zinc di-sec-hexyldithiophosphate, zinc di-octyldithiophosphate, zinc di-2-ethylhexyldithiophosphate, zinc di-n-decyldithiophosphate, zinc di-n-dodecyldithiophosphate, zinc diisotridecyldithiophosphate , And mixtures of these arbitrary combinations.
[0042]
Further, the content of the zinc dithiophosphate is not particularly limited, but from the viewpoint of exerting a higher friction reduction effect, it is preferably 0.1% or less in terms of the total amount of lubricating oil and in terms of phosphorus element, It is more preferable that it is 0.06% or less, and it is particularly preferable that zinc dithiophosphate is not contained. When the zinc dithiophosphate content exceeds 0.1% in terms of phosphorus element, the fatty acid ester-based ashless friction modifier and the aliphatic amine-based ashless friction on the sliding surface between the DLC member and the iron base member There exists a possibility that the outstanding friction reduction effect of a regulator may be inhibited.
[0043]
As a method for producing the zinc dithiophosphate, a conventional method can be arbitrarily adopted, and is not particularly limited. Specifically, for example, hydrocarbons corresponding to R ⁴ , R ⁵ , R ⁶ and R ⁷ are used. It can be synthesized by reacting a group-containing alcohol or phenol with phosphorus pentasulfide to dithiophosphoric acid and neutralizing it with zinc oxide. In addition, it cannot be overemphasized that the structure of the said zinc dithiophosphate changes with raw material alcohol to be used.
In the present invention, two or more kinds of zinc dithiophosphates included in the general formula (3) may be mixed and used at an arbitrary ratio.
[0044]
As described above, the lubricating oil used in the present invention exhibits extremely excellent low friction characteristics when used on a sliding surface between a DLC thin film and a metal material such as a chain. For the purpose of enhancing the required performance, metallic detergents, antioxidants, viscosity index improvers, other ashless friction modifiers, other ashless dispersants, antiwear or extreme pressure agents, rust preventives, non An ionic surfactant, a demulsifier, a metal deactivator, an antifoaming agent, etc. can be mix | blended individually or in combination of multiple types, and required performance can be improved.
[0045]
As said metallic detergent, the arbitrary compounds normally used as a metallic detergent for lubricating oil can be used. For example, alkali metal or alkaline earth metal sulfonates, phenates, salicylates, naphthenates, and the like can be used alone or in combination. Here, examples of the alkali metal include sodium (Na) and potassium (K), and examples of the alkaline earth metal include calcium (Ca) and magnesium (Mg). Specific preferred examples include Ca or Mg sulfonates, phenates and salicylates.
In addition, the total base number and addition amount of these metal detergents can be arbitrarily selected according to the required performance of the lubricating oil. Usually, the total base number is 0 to 500 mgKOH / g, preferably 150 to 400 mgKOH / g by the perchloric acid method, and the addition amount is usually 0.1 to 10% based on the total amount of the lubricating oil.
[0046]
Further, as the antioxidant, any compound usually used as an antioxidant for lubricating oil can be used. For example, phenolic antioxidants such as 4,4′-methylenebis (2,6-di-tert-butylphenol), octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, phenyl Examples thereof include amine-based antioxidants such as -α-naphthylamine, alkylphenyl-α-naphthylamine, and alkyldiphenylamine, as well as mixtures according to any combination thereof. Moreover, the addition amount of this antioxidant is 0.01 to 5% normally on the basis of the total amount of lubricating oil.
[0047]
Furthermore, as the above viscosity index improver, specifically, a so-called non-dispersion type viscosity index improver such as a copolymer of one or more monomers selected from various methacrylic acid esters and hydrogenated products thereof, Furthermore, a so-called dispersion type viscosity index improver obtained by copolymerizing various methacrylic acid esters containing a nitrogen compound can be exemplified. Specific examples of other viscosity index improvers include non-dispersed or dispersed ethylene-α-olefin copolymers (for example, propylene, 1-butene, 1-pentene and the like as α-olefins) and hydrogen thereof. Examples thereof include a compound, polyisobutylene and a hydrogenated product thereof, a styrene-diene hydrogenated copolymer, a styrene-maleic anhydride ester copolymer, and a polyalkylstyrene.
The molecular weight of these viscosity index improvers needs to be selected in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, 5,000 to 1,000,000, preferably 100,000 to 800,000 for dispersed and non-dispersed polymethacrylates, 800 to 5,000 for polyisobutylene or a hydride thereof, ethylene- In the case of an α-olefin copolymer or a hydride thereof, 800 to 300,000, preferably 10,000 to 200,000 is preferable. Moreover, although this viscosity index improver can be contained individually or in combination of multiple types, it is desirable that the content is usually 0.1 to 40.0% based on the lubricating oil.
[0048]
Furthermore, other ashless friction modifiers include ashless friction modifiers such as boric acid esters, higher alcohols, aliphatic ethers, metal friction modifiers such as molybdenum dithiophosphate, molybdenum dithiocarbamate, and molybdenum disulfide. Is mentioned.
Other ashless dispersants include polybutenylbenzylamine and polybutenylamine having a polybutenyl group having a number average molecular weight of 900 to 3500, and polybutenyl succinimide having a polybutenyl group having a number average molecular weight of less than 900. And derivatives thereof.
Furthermore, as the antiwear agent or extreme pressure agent, disulfide, sulfurized fat and oil, sulfurized olefin, phosphate ester containing 1 to 3 hydrocarbon groups having 2 to 20 carbon atoms, thiophosphate ester, phosphite ester, Examples thereof include thiophosphite esters and amine salts thereof.
Furthermore, examples of the rust preventive include alkylbenzene sulfonate, dinonyl naphthalene sulfonate, alkenyl succinate, polyhydric alcohol ester and the like.
Examples of the nonionic surfactant and demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl naphthyl ether, and the like. .
Furthermore, examples of the metal deactivator include imidazoline, pyrimidine derivatives, thiadiazole, benzotriazole, thiadiazole and the like.
Furthermore, examples of the antifoaming agent include silicone, fluorosilicone, and fluoroalkyl ether.
In addition, when these additives are contained in the lubricating oil used in the present invention, the content is based on the total amount of the lubricating oil, other friction modifiers, other ashless dispersants, antiwear agents or extreme pressure agents, The rust inhibitor and demulsifier can be appropriately selected from the range of 0.01 to 5%, the metal deactivator is 0.005 to 1%, and the antifoaming agent is 0.0005 to 1%.
[0049]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited only to these Examples.
[0050]
(Preparation of test piece)
[1] Test piece A
Pellets of polyamide 66 resin (DuPont Zytel 45HSB, melting point: 265 ° C.) were dried and molded into a ring test piece 1 having the dimensions and shape shown in FIG. 1 using an injection molding machine. After molding, the side surface of the ring test piece 1 was polished so that the surface roughness was Ra = 3 μm.
Next, the ring test piece 1 was put in a plasma CVD apparatus, and after evacuating, the ring side surface, which was the film formation surface, was washed with H ₂ plasma, and then a DLC film was formed with CH ₄ plasma. The film pressure of the DLC thin film was 0.7 to 0.8 μm.
[0051]
[2] Test piece B
20 parts by weight of carbon fiber (Kureha Chemical Industries Kureka Chop M-2007S, fiber diameter: 14.5 μm, fiber length: 90 μm) is blended with 80 parts by weight of the above polyamide 66 resin, and kneaded and manufactured using an extruder. Grained. And the granulated pellet was shape | molded into the ring test piece of the dimension and shape shown in FIG. 1 using the injection molding machine.
. The pellets granulated using an injection molding machine were molded into the same ring test piece, and the same operation was repeated to polish the side surface of the ring test piece, and then a DLC thin film was formed.
[0052]
[3] Specimen C
Using the same material as the above test piece A, after processing into a ring test piece of the same size and shape, the side surface is polished to a surface roughness of Ra = 3 μm, and the test is performed without forming a DLC thin film. It was set as the piece C.
[0053]
[4] Test piece D
Using the same material as the above test piece B, after processing into a ring test piece of the same size and shape, the side surface is polished to a surface roughness of Ra = 3 μm, and the test is performed without forming a DLC thin film. It was set as the piece D.
[0054]
(Adjustment of lubricating oil)
[1] Lubricating oil A
Polyalphaolefin (1-octene oligomer) as base oil, 1.0% glycerol monooleate as ester ashless friction modifier, 5.0% polybutenyl succinimide as ashless dispersant, etc. Add 7.0% of the total amount of viscosity index improver, antioxidant, rust inhibitor, demulsifier, nonionic surfactant, metal deactivator, antifoaming agent, etc. Oil A was designated.
[0055]
[2] Lubricant B
A lubricating oil consisting only of polyalphaolefin (1-octene oligomer) as a base oil was prepared, and this was designated as lubricating oil B.
[0056]
(Performance evaluation)
In order to confirm the sliding characteristic improvement effect of the present invention, the wear test of the test pieces A to D was performed in combination with the lubricating oils A and B. As the material to be slidably contacted, general carbon steel (S55C tempered material HRA = 70) is selected (HRA is Rockwell hardness A scale defined in JISZ2245), and the above carbon steel is attached to the test apparatus. The shape of the disc was a disc shape having a diameter of 60 mm and a thickness of 10 mm (disc 15 described later), and the surface roughness of the sliding contact surface with the test piece was about Rz (maximum roughness) = 5 μm.
[0057]
FIG. 2 shows an outline of a vertical pin-on-disk type friction wear tester used for this wear test.
The test machine has a ring holder 11 at the top, and this ring holder 11 is installed on the inner peripheral surface side of the ring test piece 1 so that the radial movement of the ring test piece 1 does not occur during sliding. With the spring force of the snap ring 22, the outer peripheral surface of the ring test piece 1 is pressed against the groove portion of the ring holder 11 and fixed.
On the other hand, a disk holder 14 coupled to a rotating shaft 13 is provided at the lower part of the test machine. When the disk 15 made of carbon steel is fixed to the disk holder 14 with a bolt, the disk 15 rotates with respect to the ring test piece 1. Be free. Next, the ring holder 14 is lowered to bring the ring test piece 1 and the disk 15 into a sliding contact relationship. Further, by applying a pressure P from the axial direction of the ring holder 11, the ring test piece 1 and the disk 15 are pressed against each other. Will do. At this time, the sliding contact portion between the seal ring 10 and the disk 15 is immersed in the engine oil O (that is, the lubricating oil A or B). Reference numeral 16 denotes a load cell, and reference numeral 17 denotes a torque detector.
[0058]
Table 1 shows the results of a wear test conducted using the above tester under the test conditions of pressure contact surface pressure: 2 MPa, friction speed: 7 m / sec, test time: 6 hours.
[0059]
[Table 1]

[0060]
【The invention's effect】
As described above, according to the present invention, the sliding surface with the chain is covered with the DLC thin film, and the fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless friction modifier is contained. Since it is made to slide with the chain via lubricating oil, it is possible to provide a chain guide and a chain tensioner that have both wear resistance and low frictional resistance. For example, when mounted on an internal combustion engine for automobiles This greatly contributes to improving the fuel consumption of the engine.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the shape of a ring test piece used in an abrasion test in an example of the present invention.
FIG. 2 is a schematic view of a vertical pin-on-disk friction and wear tester used for wear testing in an embodiment of the present invention.

Claims (11)

In the shoe used for the chain guide or chain tensioner that slides with the chain in the presence of lubricating oil and prevents the chain flapping,
The lubricating oil contains a fatty acid ester ashless friction modifier and / or an aliphatic amine ashless friction modifier, and the sliding surface of the shoe is covered with a diamond-like carbon thin film. Chain guide or chain tensioner shoe.   The fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless friction modifier has a hydrocarbon group having 6 to 30 carbon atoms, and 0.05 to 3. The chain guide or chain tensioner shoe according to claim 1, comprising 0%.   The shoe for a chain guide or chain tensioner according to claim 1 or 2, wherein the lubricating oil contains polybutenyl succinimide and / or a derivative thereof.   The chain guide or chain tensioner shoe according to claim 3, wherein the content of the polybutenyl succinimide and / or its derivative is 0.1 to 15% based on the total amount of the lubricating oil.   The said lubricating oil contains zinc dithiophosphate, and the content is 0.1% or less by the lubricating oil whole quantity reference | standard and phosphorus element conversion amount, The statement in any one of Claims 1-4 characterized by the above-mentioned. Chain guide or chain tensioner shoe as described. Chain guide or chain shoe for tensioner according to any one of claims 1-5, wherein said diamond-like carbon film is one that was formed by a plasma CVD method.   The chain guide or chain tensioner shoe according to any one of claims 1 to 6, wherein the base material contains a thermoplastic resin having a melting point of 200 ° C or higher.   The shoe for a chain guide or chain tensioner according to claim 7, wherein the thermoplastic resin is a polyamide resin.   The chain guide or chain tensioner shoe according to any one of claims 1 to 8, wherein the shoe is used for a valve mechanism of an internal combustion engine.   A chain system using the chain guide shoe and / or the chain tensioner shoe according to any one of claims 1 to 8, wherein the shoe has a metal chain having a surface roughness Rz = 5 μm or less and a sliding surface. A chain system characterized by movement. A chain guide shoe or a chain tensioner shoe manufacturing method according to any one of claims 1 to 9 , wherein plasma CVD is applied to a sliding surface of a shoe base material containing a thermoplastic resin with a chain. A method for producing a shoe for a chain guide or a chain tensioner, characterized in that a diamond-like carbon film is formed by a method.

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