JP4165773B2 - Lubricating oil composition - Google Patents

Description

【００４４】
一般式（１）中、Ｒ¹ 、Ｒ² 、Ｒ³ およびＲ⁴ は、別個に、炭素数１〜１８の炭化水素基を示し、そうした炭化水素基としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、直鎖または分枝のペンチル基、直鎖または分枝のヘキシル基、直鎖または分枝のヘプチル基、直鎖または分枝のオクチル基、直鎖または分枝のノニル基、直鎖または分枝のデシル基、直鎖または分枝のウンデシル基、直鎖または分枝のドデシル基、直鎖または分枝のトリデシル基、直鎖または分枝のテトラデシル基、直鎖または分枝のペンタデシル基、直鎖または分枝のヘキサデシル基、直鎖または分枝のヘプタデシル基、直鎖または分枝のオクタデシル基などの炭素数１〜１８のアルキル基；直鎖または分枝のブテニル基、直鎖または分枝のペンテニル基、直鎖または分枝のヘキセニル基、直鎖または分枝のヘプテニル基、直鎖または分枝のオクテニル基、直鎖または分枝のノネニル基、直鎖または分枝のデセニル基、直鎖または分枝のウンデセニル基、直鎖または分枝のドデセニル基、直鎖または分枝のトリデセニル基、直鎖または分枝のテトラデセニル基、直鎖または分枝のペンタデセニル基、直鎖または分枝のヘキサデセニル基、直鎖または分枝のヘプタデセニル基、直鎖または分枝のオクタデセニル基などの炭素数４〜１８のアルケニル基；シクロペンチル基、シクロヘキシル基、シクロヘプチル基などの炭素数５〜７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（全ての構造異性体を含む）、メチルエチルシクロペンチル基（全ての構造異性体を含む）、ジエチルシクロペンチル基（全ての構造異性体を含む）、メチルシクロヘキシル基、ジメチルシクロヘキシル基（全ての構造異性体を含む）、メチルエチルシクロヘキシル基（全ての構造異性体を含む）、ジエチルシクロヘキシル基（全ての構造異性体を含む）、メチルシクロヘプチル基、ジメチルシクロヘプチル基（全ての構造異性体を含む）、メチルエチルシクロヘプチル基（全ての構造異性体を含む）、ジエチルシクロヘプチル基（全ての構造異性体を含む）などの炭素数６〜１１のアルキルシクロアルキル基；フェニル基、ナフチル基などのアリール基：トリル基（全ての構造異性体を含む）、キシリル基（全ての構造異性体を含む）、エチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のプロピルフェニル基（全ての構造異性体を含む）、直鎖または分枝のブチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のペンチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘキシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘプチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のオクチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のノニルフェニル基（全ての構造異性体を含む）、直鎖または分枝のデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のウンデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のドデシルフェニル基（全ての構造異性体を含む）などの炭素数７〜１８の各アルキルアリール基；ベンシル基、フェニルエチル基、フェニルプロピル基（プロピル基の異性体を含む）、フェニルブチル基（ブチル基の異性体を含む）、フェニルペンチル基（ペンチル基の異性体を含む）、フェニルヘキシル基（ヘキシル基の異性体を含む）などの炭素数７〜１２の各アリールアルキル基などが挙げられる。
【００４５】
なお、上記のアルキル基やアルケニル基は、酸素に結合する部分の炭素原子が第１級炭素である、いわゆるプライマリーのアルキル基やアルケニル基でもよく、当該炭素原子が第２級である、いわゆるセカンダリーのアルキル基やアルケニル基でもよく、さらに当該炭素原子が第３級である、いわゆるターシャリーのアルキル基やアルケニル基でもよい。
【００４６】
一般式（１）で表される化合物の中でも、Ｒ¹ 、Ｒ² 、Ｒ³ およびＲ⁴ が個別に直鎖状または分枝状の炭素数１〜１８のアルキル基であるジアルキルジチオリン酸亜鉛は、特に酸化防止性に優れた潤滑油組成物を与える点で好ましい。
本発明においては、一般式（１）に包含される２種以上のジヒドロカルビルジチオリン酸亜鉛を任意の混合で割合してジヒドロカルビルジチオリン酸亜鉛として使用することもできる。
【００４７】
ジヒドロカルビルジチオリン酸亜鉛の具体例としてはジエチルジチオリン酸亜鉛、ジｎ−プロピルジチオリン酸亜鉛、ジイソプロピルジチオリン酸亜鉛、ジｎ−ブチ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ｔｅｒｔ−ブチルジチオリン酸亜鉛、ジ（直鎖または分枝ペンチル）ジチオリン酸亜鉛、ジ（直鎖または分枝ヘキシル）ジチオリン酸亜鉛、ジ（直鎖または分枝ヘプチル）ジチオリン酸亜鉛、ジ（直鎖または分枝オクチル）ジチオリン酸亜鉛、ジ（直鎖または分枝ノニル）ジチオリン酸亜鉛、ジ（直鎖または分枝デシル）ジチオリン酸亜鉛、ジ（直鎖または分枝ウンデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝ドデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝トリデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝テトラデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝ペンタデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝ヘキサデシル）ジチオリン酸亜鉛、ジ（直鎖または分枝オクタデシル）ジチオリン酸亜鉛、ジフェニルジチオリン酸亜鉛、ジエチルフェニルジチオリン酸亜鉛、ジプロピルフェニルジチオリン酸亜鉛、ジイソプロピルフェニルジチオリン酸亜鉛、ジブチルフェニルジチオリン酸亜鉛、ジペンチルフェニルジチオリン酸亜鉛、ジヘキシルフェニルジチオリン酸亜鉛、ジヘプチルフェニルジチオリン酸亜鉛、ジオクチルフェニルジチオリン酸亜鉛、ジ２−エチルヘキシルフェニルジチオリン酸亜鉛、ジノニルフェニルジチオリン酸亜鉛、ジデシルフェニルジチオリン酸亜鉛、ジウンデシルフェニルジチオリン酸亜鉛、ジドデシルフェニルジチオリン酸亜鉛、ジトリデシルフェニルジチオリン酸亜鉛、ジテトラデシルフェニルジチオリン酸亜鉛、ジペンタデシルフェニルジチオリン酸亜鉛、ジヘキサデシルフェニルジチオリン酸亜鉛、ジヘプタデシルフェニルジチオリン酸亜鉛、ジオクタデシルフェニルジチオリン酸亜鉛またはこれらの混合物を挙げることができる。
【００４８】
また成分（３）の他の好適な例であるジヒドロカルビルジチオカルバミン酸亜鉛としては以下の一般式（２）で表されるものが挙げられる。
【００４９】
【化２】

【００５０】
上記一般式（２）中、Ｒ⁵ 、Ｒ⁶ 、Ｒ⁷ およびＲ⁸ は別個に、炭素数１〜１８の炭化水素基を示し、そうした炭化水素基としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、直鎖または分枝のペンチル基、直鎖または分枝のヘキシル基、直鎖または分枝のヘプチル基、直鎖または分枝のオクチル基、直鎖または分枝のノニル基、直鎖または分枝のデシル基、直鎖または分枝のウンデシル基、直鎖または分枝のドデシル基、直鎖または分枝のトリデシル基、直鎖または分枝のテトラデシル基、直鎖または分枝のペンタデシル基、直鎖または分枝のヘキサデシル基、直鎖または分枝のヘプタデシル基、直鎖または分枝のオクタデシル基などの炭素数１〜１８のアルキル基；直鎖または分枝のブテニル基、直鎖または分枝のペンテニル基、直鎖または分枝のヘキセニル基、直鎖または分枝のヘプテニル基、直鎖または分枝のオクテニル基、直鎖または分枝のノネニル基、直鎖または分枝のデセニル基、直鎖または分枝のウンデセニル基、直鎖または分枝のドデセニル基、直鎖または分枝のトリデセニル基、直鎖または分枝のテトラデセニル基、直鎖または分枝のペンタデセニル基、直鎖または分枝のヘキサデセニル基、直鎖または分枝のヘプタデセニル基、直鎖または分枝のオクタデセニル基などの炭素数４〜１８のアルケニル基；シクロペンチル基、シクロヘキシル基、シクロヘプチル基などの炭素数５〜７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（全ての構造異性体を含む）、メチルエチルシクロペンチル基（全ての構造異性体を含む）、ジエチルシクロペンチル基（全ての構造異性体を含む）、メチルシクロヘキシル基、ジメチルシクロヘキシル基（全ての構造異性体を含む）、メチルエチルシクロヘキシル基（全ての構造異性体を含む）、ジエチルシクロヘキシル基（全ての構造異性体を含む）、メチルシクロヘプチル基、ジメチルシクロヘプチル基（全ての構造異性体を含む）、メチルエチルシクロヘプチル基（全ての構造異性体を含む）、ジエチルシクロヘプチル基（全ての構造異性体を含む）などの炭素数６〜１１のアルキルシクロアルキル基；フェニル基、ナフチル基などのアリール基；トリル基（全ての構造異性体を含む）、キシリル基（全ての構造異性体を含む）、エチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のプロピルフェニル基（全ての構造異性体を含む）、直鎖または分枝のブチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のペンチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘキシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘプチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のオクチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のノニルフェニル基（全ての構造異性体を含む）、直鎖または分枝のデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のウンデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のドデシルフェニル基（全ての構造異性体を含む）などの炭素数７〜１８の各アルキルアリール基；ベンシル基、フェニルエチル基、フェニルプロピル基（プロピル基の異性体を含む）、フェニルブチル基（ブチル基の異性体を含む）、フェニルペンチル基（ペンチル基の異性体を含む）、フェニルヘキシル基（ヘキシル基の異性体を含む）などの炭素数７〜１２の各アリールアルキル基などが挙げられる。
【００５１】
なお、上記のアルキル基やアルケニル基は、窒素原子に結合する部分の炭素原子が第１級炭素である、いわゆるプライマリーのアルキル基やアルケニル基でもよく、当該炭素原子が第２級である、いわゆるセカンダリーのアルキル基やアルケニル基でもよく、さらに当該炭素原子が第３級である、いわゆるターシャリーのアルキル基やアルケニル基でもよい。
【００５２】
一般式（２）で表される化合物の中でも、Ｒ⁵ 、Ｒ⁶ 、Ｒ⁷ およびＲ⁸ が別個に炭素数４〜１３のアルキル基であるジアルキルジチオカルバミン酸亜鉛は、酸化安定性の高い潤滑油組成物を与える点で特に好ましい。
【００５３】
ジヒドロカルビルジチオカルバミン酸亜鉛として特に好ましい具体例を摘記すると、例えば、ジ（直鎖または分枝）ブチルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ペンチルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ヘキシルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ヘプチルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）オクチルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ノニルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）デシルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ウンデシルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）ドデシルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）トリデシルジチオカルバミン酸亜鉛、ジ（直鎖または分枝）、およびこれらの混合物などを挙げることができる。
【００５４】
また成分（３）の他の好適な例であるジアルキルジチオカルバミン酸モリブデンとしては以下の一般式（３）で表されるものが挙げられる。
【００５５】
【化３】

【００５６】
上記一般式（３）中、Ｒ⁹ 、Ｒ¹⁰、Ｒ¹¹およびＲ¹²は、別個に、炭素数１〜１８の炭化水素基を示し、そうした炭化水素基としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、直鎖または分枝のペンチル基、直鎖または分枝のヘキシル基、直鎖または分枝のヘプチル基、直鎖または分枝のオクチル基、直鎖または分枝のノニル基、直鎖または分枝のデシル基、直鎖または分枝のウンデシル基、直鎖または分枝のドデシル基、直鎖または分枝のトリデシル基、直鎖または分枝のテトラデシル基、直鎖または分枝のペンタデシル基、直鎖または分枝のヘキサデシル基、直鎖または分枝のヘプタデシル基、直鎖または分枝のオクタデシル基などの炭素数１〜１８のアルキル基；直鎖または分枝のブテニル基、直鎖または分枝のペンテニル基、直鎖または分枝のヘキセニル基、直鎖または分枝のヘプテニル基、直鎖または分枝のオクテニル基、直鎖または分枝のノネニル基、直鎖または分枝のデセニル基、直鎖または分枝のウンデセニル基、直鎖または分枝のドデセニル基、直鎖または分枝のトリデセニル基、直鎖または分枝のテトラデセニル基、直鎖または分枝のペンタデセニル基、直鎖または分枝のヘキサデセニル基、直鎖または分枝のヘプタデセニル基、直鎖または分枝のオクタデセニル基などの炭素数４〜１８のアルケニル基；シクロペンチル基、シクロヘキシル基、シクロヘプチル基などの炭素数５〜７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（全ての構造異性体を含む）、メチルエチルシクロペンチル基（全ての構造異性体を含む）、ジエチルシクロペンチル基（全ての構造異性体を含む）、メチルシクロヘキシル基、ジメチルシクロヘキシル基（全ての構造異性体を含む）、メチルエチルシクロヘキシル基（全ての構造異性体を含む）、ジエチルシクロヘキシル基（全ての構造異性体を含む）、メチルシクロヘプチル基、ジメチルシクロヘプチル基（全ての構造異性体を含む）、メチルエチルシクロヘプチル基（全ての構造異性体を含む）、ジエチルシクロヘプチル基（全ての構造異性体を含む）などの炭素数６〜１１のアルキルシクロアルキル基；フェニル基、ナフチル基などのアリール基；トリル基（全ての構造異性体を含む）、キシリル基（全ての構造異性体を含む）、エチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のプロピルフェニル基（全ての構造異性体を含む）、直鎖または分枝のブチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のペンチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘキシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のヘプチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のオクチルフェニル基（全ての構造異性体を含む）、直鎖または分枝のノニルフェニル基（全ての構造異性体を含む）、直鎖または分枝のデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のウンデシルフェニル基（全ての構造異性体を含む）、直鎖または分枝のドデシルフェニル基（全ての構造異性体を含む）などの炭素数７〜１８の各アルキルアリール基；ベンシル基、フェニルエチル基、フェニルプロピル基（プロピル基の異性体を含む）、フェニルブチル基（ブチル基の異性体を含む）、フェニルペンチル基（ペンチル基の異性体を含む）、フェニルヘキシル基（ヘキシル基の異性体を含む）などの炭素数７〜１２の各アリールアルキル基などが挙げられる。
【００５７】
なお、上記のアルキル基やアルケニル基は、窒素原子に結合する部分の炭素原子が第１級炭素である、いわゆるプライマリーのアルキル基やアルケニル基でもよく、当該炭素原子が第２級である、いわゆるセカンダリーのアルキル基やアルケニル基でもよく、さらに当該炭素原子が第３級である、いわゆるターシャリーのアルキル基やアルケニル基でもよい。
【００５８】
一般式（３）で表される化合物の中でも、Ｒ⁹ 、Ｒ¹¹、Ｒ¹¹およびＲ¹²が別個に炭素数４〜１３のアルキル基であるジアルキルジチオカルバミン酸モリブデンは、酸化安定性の高い潤滑油組成物を与える点で特に好ましい。
【００５９】
上記一般式（３）におけるＸ¹ 、Ｘ² 、Ｘ³ およびＸ⁴ は、別個に、硫黄原子または酸素原子を示しているが、高い酸化安定性を得るためＸ¹ 、Ｘ² 、Ｘ³ およびＸ⁴ の少なくとも１個は硫黄原子であることが好ましい。
【００６０】
本発明においては、一般式（３）に包含されるジアルキルジチオカルバミン酸モリブデンの２種以上を任意の割合で混合して使用することもできる。そしてこの場合には、一般式（３）中の下記に示す原子団（Ａ）の平均構造を−Ｍｏ₂ ＳａＯ（ｘ−ａ）−で表した場合に、ａが好ましくは１〜３、より好ましくは１．５〜２．５であるジアルキルジチオカルバミン酸モリブデン混合物を使用することが、酸化安定性および軸受の腐食に対する安定性の点で好ましい。
【００６１】
【化４】

【００６２】
上記原子団（Ａ）中のＸ¹ 、Ｘ² 、Ｘ³ およびＸ⁴ は、一般式（３）におけるＸ¹ 、Ｘ² 、Ｘ³ およびＸ⁴ をそれぞれ示す。
【００６３】
ジヒドロカルビルジチオカルバミン酸モリブデンとして特に好ましい具体例を摘記すると、例えば、ジ（直鎖または分枝）ブチルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ペンチルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ヘキシルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ヘプチルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）オクチルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ノニルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）デシルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ウンデシルジチオカルバミン酸硫化モリブデン、ジ（直鎖または分枝）ドデシルジチオカルバミン酸モリブデン、ジ（直鎖または分枝）トリデシルジチオカルバミン酸モリブデン、ジ（直鎖または分枝）ブチルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ペンチルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ヘキシルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ヘプチルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）オクチルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ノニルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）デシルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ウンデシルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）ドデシルジチオカルバミン酸硫化オキシモリブデン、ジ（直鎖または分枝）トリデシルジチオカルバミン酸硫化オキシモリブデン、およびこれらの混合物などを挙げることができる。
【００６４】
また成分（３）の他の好適な例であるサルファイド類としては、具体的には例えば、以下の一般式（４）で表されるジヒドロカルビルポリサルファイドが挙げられる。
【００６５】
Ｒ¹³−Ｓ_g −Ｒ¹⁴ 一般式（４）
【００６６】
式中、Ｒ¹³およびＲ¹⁴は同一でも異なっていてもよく、それぞれ炭素数１〜２２の直鎖状または分枝状のアルキル基、炭素数６〜２０のアリール基、炭素数７〜２０のアルキルアリール基、または炭素数７〜２０のアリールアルキル基を示し、ｇは１〜５、好ましくは１〜２、さらに好ましくは２を示す。
【００６７】
Ｒ¹³およびＲ¹⁴の具体例としてはメチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、直鎖または分枝ペンチル基、直鎖または分枝ヘキシル基、シクロヘキシル基、直鎖または分枝ヘプチル基、直鎖または分枝オクチル基（ｔｅｒｔ−オクチル基等）、直鎖または分枝ノニル基、直鎖または分枝デシル基、直鎖または分枝ウンデシル基、直鎖または分枝ドデシル基（ｔｅｒｔ−ドデシル基等）、直鎖または分枝トリデシル基、直鎖または分枝テトラデシル基、直鎖または分枝ペンタデシル基、直鎖または分枝ヘキサデシル基（２−メチルペンタデシル基、ｔｅｒｔ−ヘキサデシル基等）、直鎖または分枝ヘプタデシル基、直鎖または分枝オクタデシル基、直鎖または分枝ノナデシル基、直鎖または分枝イコシル基、直鎖または分枝ヘンイコシル基、直鎖または分枝ドコシル基などのアルキル基；プロペニル基、ブテニル基などのアルケニル基；フェニル基、ナフチル基（全ての異性体を含む）などのアリール基；トリル基、エチルフェニル基、プロピルフェニル基、ブチルフェニル基、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、キシリル基、エチルメチルフェニル基、ジエチルフェニル基、ジプロピルフェニル基、ジブチルフェニル基、メチルナフチル基、エチルナフチル基、プロピルナフチル基、ブチルナフチル基、ジメチルナフチル基、エチルメチルナフチル基、ジエチルナフチル基、ジプロピルナフチル基、ジブチルナフチル基などのアルキルアリール基（これらアルキルアリール基のアルキル部分は直鎖でも分枝でもよく、アルキル部分のアリール基上の置換位置は任意である。）；およびベンジル基、フェネチル基、フェニルプロピル基などのアリールアルキル基（これらアリールアルキル基のアルキル部分は直鎖でも分枝でもよく、アリール部分の置換位置は任意である。）を挙げることができる。
【００６８】
これらＲ¹³およびＲ¹⁴の具体例として挙げたもののうち、プロピレンまたはイソブテンから誘導された炭素数３〜１８のアルキル基；炭素数６〜８のアリール基；炭素数７〜８のアルキルアリール基；あるいは炭素数７〜８のアリールアルキル基が好ましい。これらの基としては例えば、イソプロピル基、プロピレン２量体から誘導される分枝状ヘキシル基、プロピレン３量体から誘導される分枝状ノニル基、プロピレン４量体から誘導される分枝状ドデシル基、プロピレン５量体から誘導される分枝状ペンタデシル基、プロピレン６量体から誘導される分枝状オクタデシル基、ｔｅｒｔ−ブチル基、イソブテン２量体から誘導される分枝状オクチル基、イソブテン３量体から誘導される分枝状ドデシル基、イソブテン４量体から誘導される分枝状ヘキサデシル基などのアルキル基（これらのアルキル基は全ての分枝異性体を含む。）；プロペニル基、ブテニル基などのアルケニル基；フェニル基、トリル基、エチルフェニル基、キシリル基などのアルキルアリール基（これらアルキルアリール基のアルキル部分は直鎖でも分枝でもよく、アルキル部分のアリール基上の置換位置は任意である。）；およびベンジル基、フェニルエチル基（フェニル基の置換位置は任意である。）などのアリールアルキル基が挙げられる。これらのうちプロピレンまたはイソブテンから誘導された炭素数３〜１８、特に６〜１５のアルキル基が特に好ましい。
【００６９】
ジヒドロカルビルポリサルファイドの具体例としてはジメチルモノサルファイド、ジメチルジサルファイド等のジメチルポリサルファイド；ジエチルモノサルファイド、ジエチルジサルファイド等のジエチルポリサルファイド；ジｎ−プロピルモノサルファイド、ジｎ−プロピルジサルファイド等のジｎ−プロピルポリサルファイド；ジイソプロピルモノサルファイド、ジイソプロピルジサルファイド等のジイソプロピルポリサルファイド；ジ−ｎ−ブチルモノサルファイド、ジ−ｎ−ブチルジサルファイド等のジ−ｎ−ブチルポリサルファイド；ジイソブチルモノサルファイド、ジイソブチルジサルファイド等のジイソブチルポリサルファイド；ジｓｅｃ−ブチルモノサルファイド、ジｓｅｃ−ブチルジサルファイド等のジｓｅｃ−ブチルポリサルファイド；ジｔｅｒｔ−ブチルモノサルファイド、ジｔｅｒｔ−ブチルジサルファイド等のジｔｅｒｔ−ブチルポリサルファイド；ジ（直鎖または分枝ペンチル）モノサルファイド、ジ（直鎖または分枝ペンチル）ジサルファイド等のジ（直鎖または分枝ペンチル）ポリサルファイド；ジ（直鎖または分枝ヘキシル）モノサルファイド、ジ（直鎖または分枝ヘキシル）ジサルファイド等のジ（直鎖または分枝ヘキシル）ポリサルファイド；ジシクロヘキシルモノサルファイド、ジシクロヘキシルジサルファイド等のジシクロヘキシルポリサルファイド；ジ（直鎖または分枝ヘプチル）モノサルファイド、ジ（直鎖または分枝ヘプチル）ジサルファイド等のジ（直鎖または分枝ヘプチル）ポリサルファイド；ジｔｅｒｔ−オクチルモノサルファイド、ジｔｅｒｔ−オクチルジサルファイド等のジｔｅｒｔ−オクチルポリサルファイド；ジ（直鎖または分枝オクチル）モノサルファイド、ジ（直鎖または分枝オクチル）ジサルファイド等のジ（直鎖または分枝オクチル）ポリサルファイド；ジ（直鎖または分枝ノニル）モノサルファイド、ジ（直鎖または分枝ノニル）ジサルファイド等のジ（直鎖または分枝ノニル）ポリサルファイド；ジ（直鎖または分枝デシル）モノサルファイド、ジ（直鎖または分枝デシル）ジサルファイド等のジ（直鎖または分枝デシル）ポリサルファイド；ジ（直鎖または分枝ウンデシル）モノサルファイド、ジ（直鎖または分枝ウンデシル）ジサルファイド等のジ（直鎖または分枝ウンデシル）ポリサルファイド；ジｔｅｒｔ−ドデシルモノサルファイド、ジｔｅｒｔ−ドデシルジサルファイド等のジｔｅｒｔ−ドデシルポリサルファイド；ジ（直鎖または分枝ドデシル）モノサルファイド、ジ（直鎖または分枝ドデシル）ジサルファイド等のジ（直鎖または分枝ドデシル）ポリサルファイド；ジ（直鎖または分枝トリデシル）モノサルファイド、ジ（直鎖または分枝トリデシル）ジサルファイド等のジ（直鎖または分枝トリデシル）ポリサルファイド；ジ（直鎖または分枝テトラデシル）モノサルファイド、ジ（直鎖または分枝テトラデシル）ジサルファイド等のジ（直鎖または分枝テトラデシル）ポリサルファイド；ジ（直鎖または分枝ペンタデシル）モノサルファイド、ジ（直鎖または分枝ペンタデシル）ジサルファイド等のジ（直鎖または分枝ペンタデシル）ポリサルファイド；ジ２−メチルペンタデシルモノサルファイド、ジ２−メチルペンタデシルジサルファイド等のジ２−メチルペンタデシルポリサルファイド；ジｔｅｒｔ−ヘキサデシルモノサルファイド、ジｔｅｒｔ−ヘキサデシルジサルファイド等のジｔｅｒｔ−ヘキサデシルポリサルファイド；ジ（直鎖または分枝ヘキサデシル）モノサルファイド、ジ（直鎖または分枝ヘキサデシル）ジサルファイド等のジ（直鎖または分枝ヘキサデシル）ポリサルファイド；ジ（直鎖または分枝ヘプタデシル）モノサルファイド、ジ（直鎖または分枝ヘプタデシル）ジサルファイド等のジ（直鎖または分枝ヘプタデシル）ポリサルファイド；ジ（直鎖または分枝オクタデシル）モノサルファイド、ジ（直鎖または分枝オクタデシル）ジサルファイド等のジ（直鎖または分枝オクタデシル）ポリサルファイド；ジ（直鎖または分枝ノナデシル）モノサルファイド、ジ（直鎖または分枝ノナデシル）ジサルファイド等のジ（直鎖または分枝ノナデシル）ポリサルファイド；ジ（直鎖または分枝イコシル）モノサルファイド、ジ（直鎖または分枝イコシル）ジサルファイド等のジ（直鎖または分枝イコシル）ポリサルファイド；ジ（直鎖または分枝ヘンイコシル）モノサルファイド、ジ（直鎖または分枝ヘンイコシル）ジサルファイド等のジ（直鎖または分枝ヘンイコシル）ポリサルファイド；ジ（直鎖または分枝ドコシル）モノサルファイド、ジ（直鎖または分枝ドコシル）ジサルファイド等のジ（直鎖または分枝ドコシル）ポリサルファイド；ジプロペニルモノサルファイド、ジプロペニルジサルファイド等のジプロペニルポリサルファイド；ジブテニルモノサルファイド、ジブテニルジサルファイド等のジブテニルポリサルファイド；ジフェニルモノサルファイド、ジフェニルジサルファイド等のジフェニルポリサルファイド；ジナフチルモノサルファイド、ジナフチルジサルファイド等のジナフチルポリサルファイド；ジトリルモノサルファイド、ジトリルジサルファイド等のジトリルポリサルファイド；ジエチルフェニルモノサルファイド、ジエチルフェニルジサルファイド等のジエチルフェニルポリサルファイド；ジプロピルフェニルモノサルファイド、ジプロピルフェニルジサルファイド等のジプロピルフェニルポリサルファイド；ジブチルフェニルモノサルファイド、ジブチルフェニルジサルファイド等のジブチルフェニルポリサルファイド；ジペンチルフェニルモノサルファイド、ジペンチルフェニルジサルファイド等のジペンチルフェニルポリサルファイド；ジヘキシルフェニルモノサルファイド、ジヘキシルフェニルジサルファイド等のジヘキシルフェニルポリサルファイド；ジヘプチルフェニルモノサルファイド、ジヘプチルフェニルジサルファイド等のジヘプチルフェニルポリサルファイド；ジオクチルフェニルモノサルファイド、ジオクチルフェニルジサルファイド等のジオクチルフェニルポリサルファイド；ジノニルフェニルモノサルファイド、ジノニルフェニルジサルファイド等のジノニルフェニルポリサルファイド；ジデシルフェニルモノサルファイド、ジデシルフェニルジサルファイド等のジデシルフェニルポリサルファイド；ジウンデシルフェニルモノサルファイド、ジウンデシルフェニルジサルファイド等のジウンデシルフェニルポリサルファイド；ジドデシルフェニルモノサルファイド、ジドデシルフェニルジサルファイド等のジドデシルフェニルポリサルファイド；ジキシリルモノサルファイド、ジキシリルジサルファイド等のジキシリルポリサルファイド；ジエチルメチルフェニルモノサルファイド、ジエチルメチルフェニルジサルファイド等のジエチルメチルフェニルポリサルファイド；ジ（ジエチルフェニル）モノサルファイド、ジ（ジエチルフェニル）ジサルファイド等のジ（ジエチルフェニル）ポリサルファイド；ジ（ジプロピルフェニル）モノサルファイド、ジ（ジプロピルフェニル）ジサルファイド等のジ（ジプロピルフェニル）ポリサルファイド；ジ（ジブチルフェニル）モノサルファイド、ジ（ジブチルフェニル）ジサルファイド等のジ（ジブチルフェニル）ポリサルファイド；ジメチルナフチルモノサルファイド、ジメチルナフチルジサルファイド等のジメチルナフチルポリサルファイド；ジエチルナフチルモノサルファイド、ジエチルナフチルジサルファイド等のジエチルナフチルポリサルファイド；ジプロピルナフチルモノサルファイド、ジプロピルナフチルジサルファイド等のジプロピルナフチルポリサルファイド；ジブチルナフチルモノサルファイド、ジブチルナフチルジサルファイド等のジブチルナフチルポリサルファイド；ジベンジルモノサルファイド、ジベンジルジサルファイド等のジベンジルポリサルファイド；ジフェネチルモノサルファイド、ジフェネチルジサルファイド等のジフェネチルポリサルファイド；ジフェニルプロピルモノサルファイド、ジフェニルプロピルジサルファイド等のジフェニルプロピルポリサルファイドおよびこれらの混合物などが挙げられる。
【００７０】
サルファイド類の他の化合物としては、以下の一般式（５）で表されるジエステルポリサルファイドが挙げられる。
【００７１】
Ｒ¹⁵ＯＣＯ（ＣＨ₂ ）_h Ｓ_j （ＣＨ₂ ）_k ＣＯＯＲ¹⁶ 一般式（５）
【００７２】
式中、Ｒ¹⁵およびＲ¹⁶は同一でも異なっていてもよく、それぞれ炭素数２〜２０、好ましくは４〜２０の直鎖状または分枝状のアルキル基を、ｈおよびｋは同一でも異なっていてもよく、それぞれ２〜５、好ましくは２を、ｊは１〜２、好ましくは１を示す。
【００７３】
Ｒ¹⁵およびＲ¹⁶の具体例としてはエチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、直鎖または分枝ペンチル基、直鎖または分枝ヘキシル基、直鎖または分枝ヘプチル基、直鎖または分枝オクチル基、直鎖または分枝ノニル基、直鎖または分枝デシル基、直鎖または分枝ウンデシル基、直鎖または分枝ドデシル基、直鎖または分枝トリデシル基、直鎖または分枝テトラデシル基、直鎖または分枝ペンタデシル基、直鎖または分枝ヘキサデシル基、直鎖または分枝ヘプタデシル基、直鎖または分枝オクタデシル基、直鎖または分枝ノナデシル基、直鎖または分枝イコシル基を挙げることができる。
【００７４】
ジエステルポリサルファイドの具体例としては
Ｃ₄ Ｈ₉ ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₄ Ｈ₉ 、
Ｃ₄ Ｈ₉ ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₄ Ｈ₉ 、
Ｃ₅ Ｈ₁₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₅ Ｈ₁₁、
Ｃ₅ Ｈ₁₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₅ Ｈ₁₁、
Ｃ₆ Ｈ₁₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₆ Ｈ₁₃、
Ｃ₆ Ｈ₁₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₆ Ｈ₁₃、
Ｃ₇ Ｈ₁₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₇ Ｈ₁₅、
Ｃ₇ Ｈ₁₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₇ Ｈ₁₅、
Ｃ₈ Ｈ₁₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₈ Ｈ₁₇、
Ｃ₈ Ｈ₁₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₈ Ｈ₁₇、
Ｃ₉ Ｈ₁₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₉ Ｈ₁₉、
Ｃ₉ Ｈ₁₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₉ Ｈ₁₉、
Ｃ₁₀Ｈ₂₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₀Ｈ₂₁、
Ｃ₁₀Ｈ₂₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₀Ｈ₂₁、
Ｃ₁₁Ｈ₂₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₁Ｈ₂₃、
Ｃ₁₁Ｈ₂₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₁Ｈ₂₃、
Ｃ₁₂Ｈ₂₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₂Ｈ₂₅、
Ｃ₁₂Ｈ₂₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₂Ｈ₂₅、
Ｃ₁₃Ｈ₂₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₃Ｈ₂₇、
Ｃ₁₃Ｈ₂₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₃Ｈ₂₇、
Ｃ₁₄Ｈ₂₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₄Ｈ₂₉、
Ｃ₁₄Ｈ₂₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₄Ｈ₂₉、
Ｃ₁₅Ｈ₃₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₅Ｈ₃₁、
Ｃ₁₅Ｈ₃₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₅Ｈ₃₁、
Ｃ₁₆Ｈ₃₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₆Ｈ₃₃、
Ｃ₁₆Ｈ₃₃ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₆Ｈ₃₃、
Ｃ₁₇Ｈ₃₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₇Ｈ₃₅、
Ｃ₁₇Ｈ₃₅ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₇Ｈ₃₅、
Ｃ₁₈Ｈ₃₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₈Ｈ₃₇、
Ｃ₁₈Ｈ₃₇ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₈Ｈ₃₇、
Ｃ₁₉Ｈ₃₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₁₉Ｈ₃₉、
Ｃ₁₉Ｈ₃₉ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₁₉Ｈ₃₉、
Ｃ₂₀Ｈ₄₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ（ＣＨ₂ ）₂ ＣＯＯＣ₂₀Ｈ₄₁、
Ｃ₂₀Ｈ₄₁ＯＣＯ（ＣＨ₂ ）₂ Ｓ₂ （ＣＨ₂ ）₂ ＣＯＯＣ₂₀Ｈ₄₁
またはこれらの混合物が挙げられる。
【００７５】
サルファイド類の他の化合物としては、以下の一般式（６）で表されるテトラエステルテトラサルファイドが挙げられる。
【００７６】
（Ｒ¹⁷ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ 一般式（６）
【００７７】
式中、Ｒ¹⁷は炭素数８〜２０、好ましくは１０〜１８の直鎖状または分枝状のアルキル基を示す。Ｒ¹⁷の具体例としては直鎖または分枝オクチル基、直鎖または分枝ノニル基、直鎖または分枝デシル基、直鎖または分枝ウンデシル基、直鎖または分枝ドデシル基、直鎖または分枝トリデシル基、直鎖または分枝テトラデシル基、直鎖または分枝ペンタデシル基、直鎖または分枝ヘキサデシル基、直鎖または分枝ヘプタデシル基、直鎖または分枝オクタデシル基、直鎖または分枝ノナデシル基、直鎖または分枝イコシル基を挙げることができ、特に直鎖または分枝ドデシル基、直鎖または分枝トリデシル基が好ましい。
【００７８】
テトラエステルテトラサルファイドの具体例としては
（Ｃ₈ Ｈ₁₇ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₉ Ｈ₁₉ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₀Ｈ₂₁ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₁Ｈ₂₃ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₂Ｈ₂₅ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₃Ｈ₂₇ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₄Ｈ₂₉ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₅Ｈ₃₁ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₆Ｈ₃₃ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₇Ｈ₃₅ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₈Ｈ₃₇ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₁₉Ｈ₃₉ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃ、
（Ｃ₂₀Ｈ₄₁ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃまたはこれらの混合物が挙げられ、特に
（Ｃ₁₂Ｈ₂₅ＳＣＨ₂ ＣＨ₂ ＣＯＯＣＨ₂ ）₄ Ｃが好ましい。
【００７９】
本発明において成分（３）は基油１００重量部に対し、０．０１重量部以上、好ましくは０．１重量部以上であり、かつ１０重量部以下、好ましくは５重量部以下の範囲で配合する。成分（３）の配合量が上記０．０１重量部未満である場合は十分な酸化防止効果が得られないため好ましくなく、また成分（３）の配合量が上記１０重量部を超える場合は摩耗が発生するおそれがあるため好ましくない。
【００８０】
本発明の潤滑油組成物は、それ自体でも優れた酸化安定性を備えるが、これらの各種性能をさらに高める目的で、公知の潤滑油添加剤を単独で、または数種類組み合わせた形で、本発明の潤滑油組成物に配合することができる。
【００８１】
配合可能な公知の添加剤としては、例えば、中性、塩基性、炭酸カルシウム過塩基性、ホウ酸カルシウム過塩基性のアルカリ土類金属スルホネート、アルカリ土類金属サリシレート、アルカリ土類金属フェネートなどの清浄剤；有機リン酸エステル、有機亜リン酸エステル、脂肪酸、脂肪酸エステル、脂肪族アルコールなどの摩耗防止剤；ポリブテニルコハク酸イミド、長鎖アルキルポリアミン、長鎖脂肪酸とポリアミンのアミドまたはこれらのホウ素化物などの無灰分散剤；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、ジアルキルジフェニルアミンなどのアミン系酸化防止剤；フェノール系無灰酸化防止剤；モリブデンジチオホスフェート、二硫化モリブデン、長鎖脂肪族アミン、長鎖脂肪酸、長鎖脂肪酸エステル、長鎖脂肪族アルコールなどの摩擦低減剤；石油スルホネート、アルキルベンゼンスルホネート、ジノニルナフタレンスルホネート、アルケニルコハク酸エステル、多価アルコールエステルなどの防錆剤；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などのポリアルキレングリコール系非イオン系界面活性剤に代表される抗乳化剤；イミダゾリン、ピリミジン誘導体、アルキルチアジアゾール、メルカプトベンゾチアゾール、ベンゾトリアゾールまたはその誘導体、１，３，４−チアジアゾールポリスルフィド、１，３，４−チアジアゾリル−２，５−ビスジアルキルジチオカーバメート、２−（アルキルジチオ）ベンゾイミダゾール、β−（ｏ−カルボキシベンジルチオ）プロピオンニトリルなどの金属不活性化剤；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などの消泡剤；ポリメタクリレート、オレフィンコポリマーまたはその水素化物などの粘度指数向上剤が挙げられる。
【００８２】
これらの添加剤を本発明の潤滑油組成物に添加する場合には、その添加量は潤滑油組成物１００重量部に対し、消泡剤では０．０００５〜１重量部、金属不活性化剤では０．００５〜１重量部、その他の添加剤ではそれぞれ０．１〜１５重量部の範囲で通常選ばれる。
【００８３】
本発明の潤滑油組成物は２輪車、４輪車などのガソリンエンジン、陸用ディーゼルエンジン、舶用ディーゼルエンジンなどの内燃機関用潤滑油として特に好ましく使用できるが、その他、自動変速機油、手動変速機油、デファレンシャル油などの自動車用ギヤ油；工業用ギヤ油；油圧作動油；圧縮機油；冷凍機油；切削油；圧延油、プレス油、鍛造油、絞り加工油、引き抜き油、打ち抜き油などの塑性加工油；熱処理油、放電加工油などの金属加工油；すべり案内面油；軸受け油；錆止め油；熱媒体油など、各種用途に使用することができる。
【００８４】
【実施例】
以下、本発明の内容を実施例および比較例によりさらに具体的に説明するが、本発明はこれらによりなんら限定されるものではない。
使用した基油および添加剤を以下に示す。
【００８５】
１．成分（１）
（１）デセントリマー水素化物
ＡＳＴＭ Ｄ ２５４９による全芳香族含有量０質量％。
４０℃における動粘度１７．２５ｍｍ² ／ｓ。
数平均分子量４２２。
（２）ワックス異性化物
ＡＳＴＭ Ｄ ２５４９による全芳香族含有量０．５質量％。前述したＡｎａｌｙｔｉｃａｌ Ｃｈｅｍｉｓｔｒｙ 第４４巻の方法による飽和炭化水素成分９８．６質量％、芳香族炭化水素成分０．７質量％、極性化合物０．７質量％。４０℃における動粘度１６．５ｍｍ² ／ｓ。１００℃における動粘度４ｍｍ² ／ｓ。粘度指数１４４。流動点−１７．５℃。
【００８６】
２．成分（２）
（１）モノエイコシルテトラリン
４０℃における動粘度４０．２７ｍｍ² ／ｓ。
【００８７】
３．成分（３）
（１）ジアルキルジチオリン酸亜鉛
アルキル基はｓｅｃ−ブチル基とｓｅｃ−ヘキシル基の混合アルキル基。有効濃度１００質量％。
（２）モリブデンジオクチルジチオカーバメート
鉱油で希釈されている。有効濃度３０質量％。
（３）ジベンジルジスルフィド
（４）ジラウリルチオジプロピオネート
【００８８】
４．その他
（１）溶剤精製鉱油
ＡＳＴＭ Ｄ ２５４９による全芳香族含有量２６質量％。４０℃における動粘度２２．７ｍｍ² ／ｓ。１００℃における動粘度４．４ｍｍ² ／ｓ。粘度指数１０１。流動点−１２．５℃。
（２）添加剤パッケージ
金属清浄剤、無灰分散剤、フェノール系酸化防止剤、腐食防止剤および摩擦調整剤を含む。
【００８９】
（実施例１〜４）
表１に示す組成を有する混合物を、温度８０℃で２時間加熱撹拌し、本発明の潤滑油組成物を得た。
高圧示差熱分析計を用いて温度２００℃、酸素圧２ＭＰａの条件下で酸化寿命を測定した。結果を表１に示す。
【００９０】
（比較例１〜５）
実施例と同様にして、表１に示す組成を有する比較のための潤滑油組成物を得た。実施例と同様にして酸化寿命を測定した。結果を表１に示す。
【００９１】
【表１】

【００９２】
表１から判るように実施例１〜４の潤滑油組成物はいずれも優れた酸化安定性を示した。
それに対して、成分（１）の替わりに溶剤精製鉱油を使用した比較例１、成分（１）と成分（２）の配合割合が本発明の範囲からはずれた比較例２および比較例３、成分（２）を添加しなかった比較例４、および、成分（３）を添加しなかった比較例５の酸化安定性は十分なものではなかった。
このように、本発明の潤滑油組成物は各構成要素の一つが本発明の範囲から外れても十分な酸化安定性を得られないものであり、これらの構成要素を全て満たすことが重要である。
【００９３】
【発明の効果】
本発明の潤滑油組成物は高い酸化安定性を達成したものであり、従来の潤滑油よりも過酷な条件において使用することができる。
本発明の潤滑油組成物は２輪車、４輪車などのガソリンエンジン、陸用ディーゼルエンジン、舶用ディーゼルエンジンなどの内燃機関用潤滑油として特に好ましく使用できるが、その他、自動変速機油、手動変速機油、デファレンシャル油などの自動車用ギヤ油；工業用ギヤ油；油圧作動油；圧縮機油；冷凍機油；切削油；圧延油、プレス油、鍛造油、絞り加工油、引き抜き油、打ち抜き油などの塑性加工油；熱処理油、放電加工油などの金属加工油；すべり案内面油；軸受け油；錆止め油；熱媒体油など、各種用途に使用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition having excellent oxidative stability and particularly suitable for use in an internal combustion engine.
[0002]
[Prior art]
Generally, lubricating oil in an internal combustion engine is exposed to a high temperature portion such as between a piston and a cylinder, and deteriorates due to a reaction with air or combustion gas.
[0003]
On the other hand, recently, an increasing number of automobiles are equipped with a three-way catalyst as a countermeasure for exhaust gas regulations, and it is allowed to operate an internal combustion engine more severely. Further, from the viewpoint of energy saving, the weight reduction of the automobile body has been promoted for the purpose of improving fuel efficiency, and accordingly, the crankcase has been reduced in size and the amount of crankcase oil has been reduced. As a result, the lubricating oil is used under more severe conditions.
In addition, in recent years, gas engines that use a gas such as natural gas, LPG, or cracked gas are frequently used. In this gas engine, the operating temperature of the lubricating oil is further increased.
For these reasons, the oxidative stability of lubricating oils has become increasingly important in recent years, compared to zinc dithiophosphates, hindered phenols, and aromatic amines compared to mineral or synthetic base oils. It was dealt with by adding antioxidants such as, but it was not enough.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to further improve the oxidation stability of a lubricating oil and provide a lubricating oil composition for an internal combustion engine having a high oxidation stability.
[0005]
[Means for Solving the Problems]
That is, the present invention relates to (1) 70 to 97% by mass of a synthetic oil having a total aromatic content of 5% by mass or less (hereinafter referred to as “component (1)”) and (2) a naphthenic aroma containing one benzene ring. (3) Sulfur-containing antioxidant (hereinafter referred to as “component (3)”) with respect to 100 parts by weight of a base oil containing 3 to 30% by mass of a group component (hereinafter referred to as “component (2)”). A lubricating oil composition comprising 0.01 to 10 parts by weight is provided. When a specific additive is combined with a base oil having such a specific composition, each is used alone Thus, it was possible to obtain excellent oxidation stability that cannot be obtained.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the contents of the present invention will be described in detail.
It is important that the synthetic oil having a total aromatic content of 5% by mass or less of the component (1) in the present invention has a total aromatic content of 5% by mass or less, preferably 3% by mass or less. is there. When the total aromatic content exceeds 5% by mass, a synergistic effect with the component (2) and the component (3) is not obtained so much and there is a possibility that excellent antioxidant properties and sludge generation preventing properties may not be exhibited. It is not preferable.
[0007]
The total aromatic content in the present invention refers to “Standard Test Method for Separation of Reproducible Aromatics and Nonaromatics Fraction of High-OilOb in accordance with ASTM D 2549”. The aromatic fraction content, and usually this aromatic fraction contains alkylbenzene, alkylnaphthalene, anthracene, phenanthrene, and alkylated products thereof, compounds in which four or more benzene rings are condensed, or Has heteroaromatics such as pyridines, quinolines, phenols, naphthols And compounds are included.
[0008]
The viscosity of component (1) is not particularly limited, but the kinematic viscosity at 40 ° C. is 5 mm.² / S or more, preferably 10 mm² / S or more and 200 mm² / S or less, preferably 100 mm² / S or less is desirable. The kinematic viscosity at 40 ° C. of component (1) is 5 mm.² / S or more is preferable because oil film formation is sufficient, lubricity is excellent, and evaporation loss of the base oil under high temperature conditions can be reduced. On the other hand, the kinematic viscosity at 40 ° C. of component (1) is 200 mm.² / S or less is preferable because the fluid resistance becomes small and the frictional resistance at the lubrication point becomes small.
[0009]
Specific examples of component (1) in the present invention include wax isomerized oil, olefin polymer or hydride thereof; ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl Diesters such as sebacate; polyol esters such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate; polyesters such as trimellitic acid ester, alkylbenzene, alkylnaphthalene, Polyoxyalkylene glycols, dialkyl diphenyl ethers, polyphenyl ethers, and the like. Among these, wax isomerized oils and olefin polymers are also included. Its hydride are preferred.
[0010]
These base oils may be used alone or in combination of two or more at any ratio as long as the condition that the total aromatic content is 5% by mass or less is satisfied. Therefore, for example, even if a synthetic oil containing an aromatic group such as alkylbenzene or alkylnaphthalene is used in combination with another synthetic oil, it is within the scope of the present invention if the total aromatic content of the base oil is 5% by mass or less. included.
[0011]
The constitution of the wax isomerized oil, which is one of suitable examples of the component (1), is not particularly limited, but is usually 95 to 99.5% by mass of a saturated hydrocarbon component, and an aromatic hydrocarbon component of 0. 1 to 5% by mass and 0.01 to 1% by mass of a polar compound are contained.
The content of each component here is as follows: Analytical Chemistry Vol. 44 No. 6 (1972) pp. 915-919 “Separation of High-Boiling Petroleum Displaced Glue-Deled Amount of Aging” In this method, however, silica gel is loaded below, alumina gel is loaded on top, n-heptane is used for elution of saturated hydrocarbon components, and aromatic hydrocarbon components are used for elution. By using benzene and methanol for elution of polar compounds, the aromatic hydrocarbon components and polar compounds in the sample can be separated. Measured.
[0012]
Although there is no restriction | limiting in particular about the property of wax isomerized oil, Usually, it has the property as enumerated below.
Kinematic viscosity at 40 ° C .; 10 to 25 mm² / S, preferably 10-20 mm² / S.
Kinematic viscosity at 100 ° C; 1 to 10 mm² / S, preferably 2-6mm² / S.
Viscosity index; 130-150, preferably 140-150.
Pour point: -25 to -10 ° C, preferably -25 to -15 ° C.
[0013]
Although there is no restriction | limiting in particular about the manufacturing method of wax isomerized oil, If the example is given, the method of hydrocracking a wax under an isomerization catalyst and isomerizing to an isoparaffin will be mentioned. As the wax used as a raw material, slack wax obtained from solvent dewaxing, hydrogen and carbon monoxide obtained by gasification process (partial oxidation) of natural gas, and heavy linear paraffin by Fischer-Tropsch synthesis The thing which was done is mentioned.
[0014]
Further, as an isomerization catalyst, for example, a catalyst composed of a Group VIb metal and a Group VIII iron group metal is supported on a support composed of an oxide or composite oxide of Group III, Group IV and Group V elements. And what was finally made into sulfide is mentioned. The catalyst may further support a fluorine-containing compound as necessary.
Group VIb metals include tungsten and molybdenum, and Group VIII iron group metals include nickel, cobalt, and iron.
[0015]
Supports oxides such as silica, alumina, zirconia, titania, magnesia; silica alumina, silica zirconia, silica titania, silica magnesia, silica alumina zirconia, silica alumina titania, silica alumina magnesia, crystalline silica alumina (zeolite), crystals And composite oxides such as crystalline alumina phosphate and crystalline silica alumina phosphate. Among these, alumina and silica alumina are preferable.
[0016]
The hydrocracked oil thus obtained can be used as it is as a wax isomerized oil, but depending on the properties of the raw material and the properties of the wax isomerized oil to be obtained, the light component may be removed, Further, a dewaxing process such as solvent dewaxing or contact dewaxing may be performed.
[0017]
It is desirable that the olefin constituting the olefin polymer or hydride thereof, which is one of the preferred examples of component (1), is an olefin having 2 to 16 carbon atoms, preferably 2 to 12 carbon atoms. It may be a so-called α-olefin having a double bond at the terminal or a so-called internal olefin having the double bond inside. Further, it may be a linear olefin or a branched olefin.
[0018]
Examples of such olefins include ethylene, propylene, 1-butene, 2-butene, isobutene, linear or branched pentene (including α-olefin and internal olefin), linear or branched. Hexene (α-olefin, including internal olefin), linear or branched heptene (α-olefin, including internal olefin), linear or branched octene (α-olefin, including internal olefin) Linear) or branched nonene (including α-olefin and internal olefin), linear or branched decene (including α-olefin and internal olefin), linear or branched Undecene (alpha-olefin, including internal olefin), linear or branched dodecene (alpha-olefin, including internal olefin), linear or branched Tridecene (α-olefin, including internal olefin), linear or branched tetradecene (α-olefin, including internal olefin), linear or branched pentadecene (α-olefin, including internal olefin) ), Linear or branched hexadecene (including α-olefins, internal olefins), and mixtures thereof, including ethylene, propylene, 1-butene, 2-butene, isobutene, 1- Octene, 1-decene, 1-dodecene and mixtures thereof are preferably used.
[0019]
The olefin polymer includes not only a homopolymer of one olefin but also a copolymer such as a random copolymer, an alternating copolymer, and a block copolymer of two or more olefins.
[0020]
The olefin polymer usually contains a double bond, but it is preferable to use an olefin polymer obtained by hydrogenating the double bond from the viewpoint of excellent thermal and oxidation stability.
[0021]
The production method of the olefin polymer is arbitrary and is not limited at all. Generally, it is an organic peroxide catalyst such as benzoyl peroxide by a non-catalytic thermal reaction; aluminum chloride, aluminum chloride-polyhydric alcohol system. Friedel-Crafts type catalysts such as aluminum chloride-titanium tetrachloride type, aluminum chloride-alkyltin halide type, boron fluoride; Ziegler type catalysts such as organic aluminum chloride-titanium tetrachloride type, organic aluminum-titanium tetrachloride type; Using known catalyst systems such as metallocene catalysts such as aluminoxane-zirconocene and ionic compounds-zirconocene; Lewis acid complex catalysts such as aluminum chloride-base and boron fluoride-base, Obtained by homopolymerization or copolymerization That.
[0022]
The method for obtaining the hydride of the olefin polymer is optional, for example, by hydrogenating the olefin polymer with hydrogen in the presence of a known hydrogenation catalyst and saturating the double bonds present in the olefin polymer. can get. Some catalysts can perform olefin polymerization and hydrogenation of double bonds existing in the polymer in one step without going through the two steps of olefin polymerization and hydrogenation of the resulting polymer. is there.
[0023]
As the olefin polymer, ethylene-propylene copolymer, polybutene [butane-butene (1-butene produced as a by-product during naphtha pyrolysis) is excellent in terms of heat / oxidation stability, viscosity-temperature characteristics, and low-temperature fluidity. , A mixture of 2-butene and isobutene) a copolymer obtained by polymerization of a fraction], a 1-octene oligomer, a 1-decene oligomer, a 1-dodecene oligomer, a hydride thereof, and a mixture thereof are more preferable. The ethylene-propylene copolymer hydride, polybutene hydride, 1-octene oligomer hydride, 1-decene oligomer hydride, 1-dodecene oligomer hydride, and mixtures thereof are particularly preferably used.
[0024]
In addition, synthetic oils such as ethylene-propylene copolymers, polybutenes, and poly-α-olefins that are currently commercially available for lubricating base oils are usually those whose double bonds are already hydrogenated. In the present invention, these commercially available products can also be preferably used.
[0025]
The number average molecular weight of the olefin polymer or hydride thereof is 250 or more, preferably 350 or more, and is 4000 or less, preferably 3000 or less, more preferably 1500 or less. By setting the number average molecular weight to 250 or more, it is preferable because oil film formation is sufficient, excellent lubricity can be obtained, and evaporation loss of the base oil under high temperature conditions is reduced. On the other hand, when the number average molecular weight is 4000 or less, the fluid resistance is reduced, and therefore, the frictional resistance at the lubrication point is preferably reduced.
[0026]
The content ratio of the component (1) in the base oil referred to in the present invention is 70% by mass or more, preferably 77% by mass or more, and 97% by mass or less, preferably 88% by mass or less. When the content ratio of the component (1) is less than 70% by mass, problems such as an increase in viscosity and a decrease in lubricating performance are not preferable. Moreover, when the said ratio exceeds 97 mass%, since there exists a possibility that malfunctions, such as a viscosity increasing and lubrication performance may fall, it is unpreferable.
[0027]
The naphthenoaromatic component containing one benzene ring as component (2) of the present invention contains one benzene ring and one or more naphthene rings in the molecule. These benzene ring and naphthene ring All condense to form polycyclic compounds. The number of naphthene rings contained in the molecule is 1 to 15, preferably 1 to 10.
The naphthene ring mentioned here includes a 5-membered ring, a 6-membered ring and a 7-membered ring, and mainly a 5-membered ring and a 6-membered ring. Further, an arbitrary number of hydrogen atoms in the benzene ring and / or naphthene ring in the molecule may be substituted with an alkyl group. The carbon number of the alkyl group is usually 1 to 50, and the total carbon number of the substituted alkyl group is usually about 1 to 50.
[0028]
Specific examples of such component (2) include tetralin, indane, 1,2,7,8-tetrahydro-as-indacene, 1,2,5,6-tetrahydro-s-indacene, 1,2,3, 4,5,6-hexahydroacenaphthylene, 1,2,3,4-tetrahydrofluorene, 2,3,3a, 4,5,6-hexahydrophenalene, 1,2,3,4,4a, 9,10,10a-octahydrophenanthrene, 1,2,3,4,5,6,7,8-octahydrophenanthrene, 1,2,3,4,4a, 9,9a, 10-octahydroanthracene, 1,2,3,4,5,6,7,8-octahydroanthracene, alkyltetralin, alkylindane, alkyl-1,2,7,8-tetrahydro-as-indacene, alkyl-1,2,5 6- Torahydro-s-indacene, alkyl-1,2,3,4,5,6-hexahydroacenaphthylene, alkyl-1,2,3,4-tetrahydrofluorene, alkyl-2,3,3a, 4,5 , 6-hexahydrophenalene, alkyl-1,2,3,4,4a, 9,10,10a-octahydrophenanthrene, alkyl-1,2,3,4,5,6,7,8-octahydro Phenanthrene, alkyl-1,2,3,4,4a, 9,9a, 10-octahydroanthracene, alkyl-1,2,3,4,5,6,7,8-octahydroanthracene, or mixtures thereof Among these, alkyltetralin is particularly preferable.
[0029]
Alkyltetralin, which is a suitable example of component (2), has 1 to 4 alkyl groups having 1 to 40 carbon atoms, and has excellent alkyl group, from the viewpoint of excellent thermal and oxidation stability and availability. Is preferably an alkyltetralin having 6 to 40 carbon atoms, 1 to 4 alkyl groups having 1 to 40 carbon atoms, and an alkyltetralin having 12 to 40 carbon atoms in total. It is more preferable that the alkyl tetralin has 1 to 4 alkyl groups having 1 to 30 carbon atoms and the total carbon number of the alkyl groups is 15 to 30.
Use of alkyltetralin having an alkyl group with a total carbon number of 6 or more is preferable because oil film formation is sufficient, excellent lubricity is obtained, and evaporation loss of the base oil under high temperature conditions is reduced. On the other hand, it is preferable to use alkyltetralin having an alkyl group with a total carbon number of 40 or less because the fluid resistance is reduced and the frictional resistance at the lubrication point is reduced.
[0030]
The alkyl group having 1 to 40 carbon atoms in relation to the alkyltetralin may be linear or branched, and specific examples of such alkyl groups include methyl, ethyl, propyl, Isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear Or a branched heptyl group, a linear or branched octyl group, a linear or branched nonyl group, a linear or branched decyl group, a linear or branched undecyl group, a linear or branched dodecyl group Group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, linear Or a branched octadecyl group, a linear or branched nonadecyl group, a linear or branched icosyl group, a linear or branched heicosyl group, a linear or branched docosyl group, a linear or branched Tricosyl group, linear or branched tetracosyl group, linear or branched pentacosyl group, linear or branched hexacosyl group, linear or branched heptacosyl group, linear or branched octacosyl group, linear Or a branched nonacosyl group, a linear or branched triacontyl group, a linear or branched hentriacontyl group, a linear or branched dotriacontyl group, a linear or branched tritriacontyl group, a linear or Branched tetratriacontyl group, straight chain or branched pentatriacontyl group, straight chain or branched hexatriacontyl group, straight chain or branched heptatriacontyl group Group, straight or branched oct triacontyl group, straight or branched nonadecyl triacontyl group, straight or branched tetracontyl group.
[0031]
The alkyl group of the alkyl tetralin is particularly preferably an alkyl group derived from an ethylene oligomer.
[0032]
The number of alkyl groups in the alkyltetralin can be selected in the range of 1 to 4, but from the viewpoint of thermal / oxidative stability and availability, an alkyltetralin having one or two alkyl groups, ie, mono Alkyltetralin, dialkyltetralin or mixtures thereof are most preferred as alkyltetralin.
[0033]
Needless to say, an alkyltetralin is a single structure alkyltetralin as long as it has 1 to 4 alkyl groups having 1 to 40 carbon atoms and the total number of carbon atoms in the alkyl groups is 6 to 40. Alternatively, a mixture of alkyltetralins having different structures may be used.
[0034]
The production method of alkyltetralin is arbitrary and is not limited at all, but in general, it can be produced by the synthesis method shown below.
[0035]
Examples of the aromatic compound used as a raw material include tetralin, naphthalene, and mixtures thereof. When naphthalene is used as a raw material, alkyltetralin can be obtained by alkylation followed by partial nuclear hydrogenation.
Examples of the alkylating agent include lower monoolefins such as ethylene, propylene, butene, and isobutylene, preferably ethylene or linear or branched olefins having 6 to 40 carbon atoms obtained by polymerization of propylene; wax, heavy Linear or branched olefins having 6 to 40 carbon atoms obtained by pyrolysis of petroleum oil, petroleum fractions, polyethylene, polypropylene, etc .; n-paraffins are separated from petroleum fractions such as kerosene, diesel oil, etc. A linear olefin having 6 to 40 carbon atoms obtained by olefination with a catalyst; and a mixture thereof can be used.
[0036]
As the alkylation catalyst in the alkylation, known catalysts such as Friedel-Crafts type catalysts such as aluminum chloride and zinc chloride; acidic catalysts such as sulfuric acid, phosphoric acid, silicotungstic acid, hydrofluoric acid and activated clay; Is used.
[0037]
In addition, although the conditions of partial nuclear hydrogenation here are arbitrary, normally reaction in the presence of a hydrogenation catalyst, such as total pressure of 1-15 MPa, temperature of 100-200 degreeC, LHSV0.1-2.0hr-1. Under the conditions, hydrocracking conditions are adopted so that the cracking rate is 30 to 70% by mass.
Any hydrogenation catalyst can be used, but usually, for example, molybdenum, chromium, tungsten, vanadium, platinum, nickel, copper, iron, cobalt, oxides and / or sulfides thereof, or mixtures thereof, etc. Is used.
These catalysts may be used as they are, or may be used in a form supported on a carrier such as silica-alumina, activated alumina, zeolite, diatomaceous earth and the like.
[0038]
The viscosity of component (2) is not particularly limited, but the kinematic viscosity at 40 ° C. is 5 mm.² / S or more, preferably 10 mm² / S or more and 200 mm² / S or less, preferably 100 mm² / S or less is desirable. The kinematic viscosity at 40 ° C. of component (2) is 5 mm.² / S or more is preferable because oil film formation is sufficient, lubricity is excellent, and evaporation loss of the base oil under high temperature conditions can be reduced. On the other hand, the kinematic viscosity at 40 ° C. of component (2) is 200 mm.² / S or less is preferable because the fluid resistance becomes small and the frictional resistance at the lubrication point becomes small.
[0039]
The content ratio of the component (2) in the base oil in the present invention is 3% by mass or more, preferably 12% by mass or more, and 30% by mass or less, preferably 23% by mass or less. When the content ratio of the component (2) is less than 3% by mass or more than 30% by mass, the ability to prevent oxidative deterioration associated with the use of the lubricating oil is not sufficient, and the lubricating performance increases the viscosity of the lubricating oil. This is not preferable because of problems such as falling.
[0040]
The base oil used in the present invention contains the component (1) and the component (2), and the viscosity is not particularly limited, but generally the kinematic viscosity at 40 ° C. is 5 mm.² / S or more, preferably 10 mm² / S or more and 200 mm² / S or less, preferably 100 mm² / S or less is desirable. The kinematic viscosity of the base oil at 40 ° C is 5 mm.² / S or more is preferable because oil film formation is sufficient, lubricity is excellent, and evaporation loss of the base oil under high temperature conditions can be reduced. On the other hand, the kinematic viscosity at 40 ° C. of the base oil is 200 mm.² / S or less is preferable because the fluid resistance becomes small and the frictional resistance at the lubrication point becomes small.
[0041]
The sulfur-containing antioxidant that is component (3) in the present invention includes metal dihydrocarbyl dithiophosphates such as zinc dihydrocarbyl dithiophosphate and molybdenum dihydrocarbyl dithiophosphate; zinc dihydrocarbyl dithiocarbamate, molybdenum dihydrocarbyl dithiocarbamate, di Metal dithiocarbamates such as copper hydrocarbyl dithiocarbamate; sulfides and mixtures thereof may be mentioned, among which zinc dihydrocarbyl dithiophosphate, zinc dihydrocarbyl dithiocarbamate, molybdenum dihydrocarbyl dithiocarbamate, sulfides and the like are preferred.
[0042]
As a suitable example of component (3), zinc dihydrocarbyl dithiophosphate includes a compound represented by the following general formula (1).
[0043]
[Chemical 1]

[0044]
In general formula (1), R¹ , R² , R^Three And R^Four Each independently represents a hydrocarbon group having 1 to 18 carbon atoms. Examples of such hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec- Butyl, tert-butyl, linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl, linear or branched Nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear Or an alkyl group having 1 to 18 carbon atoms such as a branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, a linear or branched octadecyl group; a linear or branched Buteni Group, linear or branched pentenyl group, linear or branched hexenyl group, linear or branched heptenyl group, linear or branched octenyl group, linear or branched nonenyl group, linear or Branched decenyl group, linear or branched undecenyl group, linear or branched dodecenyl group, linear or branched tridecenyl group, linear or branched tetradecenyl group, linear or branched pentadecenyl group An alkenyl group having 4 to 18 carbon atoms such as a linear or branched hexadecenyl group, a linear or branched heptadecenyl group, a linear or branched octadecenyl group; a carbon such as a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group A cycloalkyl group of 5 to 7; methylcyclopentyl group, dimethylcyclopentyl group (including all structural isomers), methylethylcyclope Til group (including all structural isomers), diethylcyclopentyl group (including all structural isomers), methylcyclohexyl group, dimethylcyclohexyl group (including all structural isomers), methylethylcyclohexyl group (all structures) Isomers), diethylcyclohexyl group (including all structural isomers), methylcycloheptyl group, dimethylcycloheptyl group (including all structural isomers), methylethylcycloheptyl group (including all structural isomers) Alkyl group having 6 to 11 carbon atoms such as diethylcycloheptyl group (including all structural isomers); aryl group such as phenyl group and naphthyl group: tolyl group (including all structural isomers) , Xylyl group (including all structural isomers), ethylphenyl group (including all structural isomers), linear or Is a branched propylphenyl group (including all structural isomers), a linear or branched butylphenyl group (including all structural isomers), a linear or branched pentylphenyl group (all structural isomers) Straight chain or branched hexylphenyl group (including all structural isomers), straight chain or branched heptylphenyl group (including all structural isomers), straight chain or branched octyl Phenyl group (including all structural isomers), linear or branched nonylphenyl group (including all structural isomers), linear or branched decylphenyl group (including all structural isomers), Each alkylaryl group having 7 to 18 carbon atoms such as a linear or branched undecylphenyl group (including all structural isomers) and a linear or branched dodecylphenyl group (including all structural isomers) Benzyl group, Fe Ruethyl group, phenylpropyl group (including isomer of propyl group), phenylbutyl group (including isomer of butyl group), phenylpentyl group (including isomer of pentyl group), phenylhexyl group (isomer of hexyl group) Each arylalkyl group having 7 to 12 carbon atoms and the like.
[0045]
The alkyl group or alkenyl group may be a so-called primary alkyl group or alkenyl group in which the carbon atom bonded to oxygen is a primary carbon, or a so-called secondary in which the carbon atom is secondary. Or a so-called tertiary alkyl group or alkenyl group in which the carbon atom is tertiary.
[0046]
Among the compounds represented by the general formula (1), R¹ , R² , R^Three And R^Four Is a linear or branched alkyl group having 1 to 18 carbon atoms, which is particularly preferable in terms of providing a lubricating oil composition excellent in antioxidant properties.
In the present invention, two or more kinds of zinc dihydrocarbyl dithiophosphates included in the general formula (1) may be used in the form of any mixture and used as zinc dihydrocarbyl dithiophosphates.
[0047]
Specific examples of zinc dihydrocarbyl dithiophosphate include zinc diethyldithiophosphate, zinc din-propyldithiophosphate, zinc diisopropyldithiophosphate, zinc din-butyldithiophosphate, zinc diisobutyldithiophosphate, zinc disec-butyldithiophosphate, di zinc tert-butyldithiophosphate, zinc di (linear or branched pentyl) dithiophosphate, zinc di (linear or branched hexyl) dithiophosphate, zinc di (linear or branched heptyl) dithiophosphate, di (linear) Or branched octyl) zinc dithiophosphate, di (straight or branched nonyl) zinc dithiophosphate, di (straight or branched decyl) zinc dithiophosphate, di (straight or branched undecyl) zinc dithiophosphate, di ( Linear or branched dodecyl) zinc dithiophosphate, di (linear or branched tridecyl) di Zinc oleate, zinc di (linear or branched tetradecyl) dithiophosphate, zinc di (linear or branched pentadecyl) dithiophosphate, zinc di (linear or branched hexadecyl) dithiophosphate, di (linear or branched) Octadecyl) zinc dithiophosphate, zinc diphenyldithiophosphate, zinc diethylphenyldithiophosphate, zinc dipropylphenyldithiophosphate, zinc diisopropylphenyldithiophosphate, zinc dibutylphenyldithiophosphate, zinc dipentylphenyldithiophosphate, zinc dihexylphenyldithiophosphate, diheptyl Zinc phenyldithiophosphate, zinc dioctylphenyldithiophosphate, zinc di2-ethylhexylphenyldithiophosphate, zinc dinonylphenyldithiophosphate, zinc didecylphenyldithiophosphate, diundecylphenyl Zinc thiophosphate, zinc didodecylphenyl dithiophosphate, zinc ditridecylphenyl dithiophosphate, zinc ditetradecylphenyl dithiophosphate, zinc dipentadecylphenyl dithiophosphate, zinc dihexadecylphenyl dithiophosphate, zinc diheptadecylphenyl dithiophosphate, Mention may be made of zinc dioctadecylphenyldithiophosphate or mixtures thereof.
[0048]
Moreover, what is represented by the following general formula (2) as another suitable example of the component (3) zinc dihydrocarbyl dithiocarbamate is mentioned.
[0049]
[Chemical 2]

[0050]
In the general formula (2), R^Five , R⁶ , R⁷ And R⁸ Is a hydrocarbon group having 1 to 18 carbon atoms, and examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a sec-butyl group. Group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl Group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or Alkyl groups having 1 to 18 carbon atoms such as branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, linear or branched octadecyl group; linear or branched butenyl Linear or branched pentenyl group, linear or branched hexenyl group, linear or branched heptenyl group, linear or branched octenyl group, linear or branched nonenyl group, linear or branched A branched decenyl group, a linear or branched undecenyl group, a linear or branched dodecenyl group, a linear or branched tridecenyl group, a linear or branched tetradecenyl group, a linear or branched pentadecenyl group, C4-C18 alkenyl groups such as linear or branched hexadecenyl group, linear or branched heptadecenyl group, linear or branched octadecenyl group; carbon numbers such as cyclopentyl group, cyclohexyl group and cycloheptyl group 5-7 cycloalkyl groups; methylcyclopentyl group, dimethylcyclopentyl group (including all structural isomers), methylethylcyclopente Group (including all structural isomers), diethylcyclopentyl group (including all structural isomers), methylcyclohexyl group, dimethylcyclohexyl group (including all structural isomers), methylethylcyclohexyl group (all structures) Isomers), diethylcyclohexyl group (including all structural isomers), methylcycloheptyl group, dimethylcycloheptyl group (including all structural isomers), methylethylcycloheptyl group (including all structural isomers) Alkyl cycloalkyl group having 6 to 11 carbon atoms such as diethylcycloheptyl group (including all structural isomers); aryl group such as phenyl group and naphthyl group; tolyl group (including all structural isomers) Xylyl group (including all structural isomers), ethylphenyl group (including all structural isomers), linear or Branched propylphenyl group (including all structural isomers), linear or branched butylphenyl group (including all structural isomers), linear or branched pentylphenyl group (all structural isomers) Straight chain or branched hexylphenyl group (including all structural isomers), straight chain or branched heptylphenyl group (including all structural isomers), straight chain or branched octylphenyl Groups (including all structural isomers), linear or branched nonylphenyl groups (including all structural isomers), linear or branched decylphenyl groups (including all structural isomers), straight Each alkylaryl group having 7 to 18 carbon atoms such as a chain or branched undecylphenyl group (including all structural isomers), a linear or branched dodecylphenyl group (including all structural isomers); Benzyl group, phenyl Ethyl group, phenylpropyl group (including isomer of propyl group), phenylbutyl group (including isomer of butyl group), phenylpentyl group (including isomer of pentyl group), phenylhexyl group (isomer of hexyl group) Each arylalkyl group having 7 to 12 carbon atoms and the like.
[0051]
The alkyl group or alkenyl group may be a so-called primary alkyl group or alkenyl group in which the carbon atom bonded to the nitrogen atom is a primary carbon, and the carbon atom is secondary, It may be a secondary alkyl group or alkenyl group, and may be a so-called tertiary alkyl group or alkenyl group in which the carbon atom is tertiary.
[0052]
Among the compounds represented by the general formula (2), R^Five , R⁶ , R⁷ And R⁸ Is a dialkyldithiocarbamate zinc, which is independently an alkyl group having 4 to 13 carbon atoms, from the viewpoint of providing a lubricating oil composition having high oxidation stability.
[0053]
Specific examples of particularly preferred zinc dihydrocarbyl dithiocarbamate include, for example, zinc di (linear or branched) butyl dithiocarbamate, zinc di (linear or branched) pentyldithiocarbamate, di (linear or branched) Zinc hexyl dithiocarbamate, zinc di (straight or branched) zinc heptyl dithiocarbamate, zinc di (straight or branched) octyl dithiocarbamate, zinc di (straight or branched) nonyldithiocarbamate, di (linear or branched) Branch) zinc decyl dithiocarbamate, zinc di (straight or branched) zinc undecyl dithiocarbamate, zinc di (straight or branched) zinc dodecyldithiocarbamate, zinc di (straight or branched) zinc tridecyldithiocarbamate, di ( Linear or branched), and mixtures thereof. .
[0054]
Moreover, what is represented by the following general formula (3) is mentioned as another suitable example of the component (3) molybdenum dialkyldithiocarbamate.
[0055]
[Chemical 3]

[0056]
In the general formula (3), R⁹ , R^Ten, R¹¹And R¹²Each independently represents a hydrocarbon group having 1 to 18 carbon atoms. Examples of such hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec- Butyl, tert-butyl, linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl, linear or branched Nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear Or an alkyl group having 1 to 18 carbon atoms such as a branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, a linear or branched octadecyl group; a linear or branched Buteni Group, linear or branched pentenyl group, linear or branched hexenyl group, linear or branched heptenyl group, linear or branched octenyl group, linear or branched nonenyl group, linear or Branched decenyl group, linear or branched undecenyl group, linear or branched dodecenyl group, linear or branched tridecenyl group, linear or branched tetradecenyl group, linear or branched pentadecenyl group An alkenyl group having 4 to 18 carbon atoms such as a linear or branched hexadecenyl group, a linear or branched heptadecenyl group, a linear or branched octadecenyl group; a carbon such as a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group A cycloalkyl group of 5 to 7; methylcyclopentyl group, dimethylcyclopentyl group (including all structural isomers), methylethylcyclope Til group (including all structural isomers), diethylcyclopentyl group (including all structural isomers), methylcyclohexyl group, dimethylcyclohexyl group (including all structural isomers), methylethylcyclohexyl group (all structures) Isomers), diethylcyclohexyl group (including all structural isomers), methylcycloheptyl group, dimethylcycloheptyl group (including all structural isomers), methylethylcycloheptyl group (including all structural isomers) Alkyl cycloalkyl group having 6 to 11 carbon atoms such as diethylcycloheptyl group (including all structural isomers); aryl group such as phenyl group and naphthyl group; tolyl group (including all structural isomers) , Xylyl group (including all structural isomers), ethylphenyl group (including all structural isomers), linear or Is a branched propylphenyl group (including all structural isomers), a linear or branched butylphenyl group (including all structural isomers), a linear or branched pentylphenyl group (all structural isomers) Straight chain or branched hexylphenyl group (including all structural isomers), straight chain or branched heptylphenyl group (including all structural isomers), straight chain or branched octyl Phenyl group (including all structural isomers), linear or branched nonylphenyl group (including all structural isomers), linear or branched decylphenyl group (including all structural isomers), Each alkylaryl group having 7 to 18 carbon atoms such as a linear or branched undecylphenyl group (including all structural isomers) and a linear or branched dodecylphenyl group (including all structural isomers) Benzyl group, Fe Ruethyl group, phenylpropyl group (including isomer of propyl group), phenylbutyl group (including isomer of butyl group), phenylpentyl group (including isomer of pentyl group), phenylhexyl group (isomer of hexyl group) Each arylalkyl group having 7 to 12 carbon atoms and the like.
[0057]
The alkyl group or alkenyl group may be a so-called primary alkyl group or alkenyl group in which the carbon atom bonded to the nitrogen atom is a primary carbon, and the carbon atom is secondary, It may be a secondary alkyl group or alkenyl group, and may be a so-called tertiary alkyl group or alkenyl group in which the carbon atom is tertiary.
[0058]
Among the compounds represented by the general formula (3), R⁹ , R¹¹, R¹¹And R¹²In particular, molybdenum dialkyldithiocarbamate, which is an alkyl group having 4 to 13 carbon atoms, is particularly preferable in terms of providing a lubricating oil composition having high oxidation stability.
[0059]
X in the general formula (3)¹ , X² , X^Three And X^Four Independently represents a sulfur atom or an oxygen atom, but in order to obtain high oxidative stability, X¹ , X² , X^Three And X^Four It is preferable that at least one of is a sulfur atom.
[0060]
In the present invention, two or more kinds of molybdenum dialkyldithiocarbamates included in the general formula (3) may be mixed and used at an arbitrary ratio. In this case, the average structure of the atomic group (A) shown below in the general formula (3) is represented by -Mo.₂ When represented by SaO (xa)-, it is possible to use a molybdenum dialkyldithiocarbamate mixture in which a is preferably 1 to 3, more preferably 1.5 to 2.5. It is preferable in terms of stability against corrosion.
[0061]
[Formula 4]

[0062]
X in the above atomic group (A)¹ , X² , X^Three And X^Four X in general formula (3)¹ , X² , X^Three And X^Four Respectively.
[0063]
Specific examples of particularly preferred molybdenums for dihydrocarbyl dithiocarbamate include, for example, molybdenum disulfide di (straight or branched) butyl dithiocarbamate, molybdenum disulfide di (straight or branched) pentyldithiocarbamate, di (linear or branched). Branch) Molybdenum sulfide hexyl dithiocarbamate, Molybdenum disulfide di (straight or branched) Molybdenum disulfide, Di (straight or branched) octyldithiocarbamate sulfide, Di (straight or branched) nonyldithiocarbamate molybdenum sulfide, Di (linear or branched) decyl dithiocarbamate molybdenum sulfide, di (straight or branched) undecyl dithiocarbamate molybdenum sulfide, di (straight or branched) molybdenum dodecyl dithiocarbamate, di (straight or branched) Toride Molybdenum didicarbamate, di (straight or branched) butyldithiocarbamate oxymolybdenum sulfide, di (straight or branched) pentyldithiocarbamate oxymolybdenum sulfide, di (straight or branched) hexyldithiocarbamate oxymolybdenum sulfide, Di (straight or branched) heptyl dithiocarbamate oxymolybdenum sulfide, di (straight or branched) octyl dithiocarbamate oxymolybdenum sulfide, di (straight or branched) nonyldithiocarbamate oxymolybdenum oxysulfide, di (straight or straight) Branched) Decyldithiocarbamate oxymolybdenum sulfide, di (straight or branched) undecyldithiocarbamate oxymolybdenum sulfide, di (straight or branched) dodecyldithiocarbamate oxymolybdenum sulfide, di (straight or branched) tri Sill oxymolybdenum sulfide, and the like, and mixtures thereof.
[0064]
Specific examples of the sulfides that are other suitable examples of the component (3) include dihydrocarbyl polysulfides represented by the following general formula (4).
[0065]
R¹³-S_g -R¹⁴              General formula (4)
[0066]
Where R¹³And R¹⁴May be the same or different and each is a linear or branched alkyl group having 1 to 22 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or 7 carbon atoms. To 20 arylalkyl groups, and g represents 1 to 5, preferably 1 to 2, and more preferably 2.
[0067]
R¹³And R¹⁴Specific examples of methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group, linear or branched Hexyl group, cyclohexyl group, linear or branched heptyl group, linear or branched octyl group (such as tert-octyl group), linear or branched nonyl group, linear or branched decyl group, linear or branched Undecyl group, linear or branched dodecyl group (such as tert-dodecyl group), linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group ( 2-methylpentadecyl group, tert-hexadecyl group, etc.), linear or branched heptadecyl group, linear or branched octadecyl group, linear or branched nonadecyl Group, alkyl group such as linear or branched icosyl group, linear or branched heicosyl group, linear or branched docosyl group; alkenyl group such as propenyl group and butenyl group; phenyl group, naphthyl group (all isomers) Aryl group such as tolyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group Group, dodecylphenyl group, xylyl group, ethylmethylphenyl group, diethylphenyl group, dipropylphenyl group, dibutylphenyl group, methylnaphthyl group, ethylnaphthyl group, propylnaphthyl group, butylnaphthyl group, dimethylnaphthyl group, ethylmethylnaphthyl group Group, diethylnaphthyl , Alkylpropyl groups such as dipropylnaphthyl group and dibutylnaphthyl group (the alkyl part of these alkylaryl groups may be linear or branched, and the substitution position on the aryl group of the alkyl part is arbitrary); and the benzyl group And arylalkyl groups such as a phenethyl group and a phenylpropyl group (the alkyl part of these arylalkyl groups may be linear or branched, and the substitution position of the aryl part is arbitrary).
[0068]
These R¹³And R¹⁴Among those listed as specific examples, an alkyl group having 3 to 18 carbon atoms derived from propylene or isobutene; an aryl group having 6 to 8 carbon atoms; an alkylaryl group having 7 to 8 carbon atoms; or 7 to 8 carbon atoms Are preferred. Examples of these groups include isopropyl group, branched hexyl group derived from propylene dimer, branched nonyl group derived from propylene trimer, and branched dodecyl derived from propylene tetramer. Group, branched pentadecyl group derived from propylene pentamer, branched octadecyl group derived from propylene hexamer, tert-butyl group, branched octyl group derived from isobutene dimer, isobutene Alkyl groups such as branched dodecyl groups derived from trimers, branched hexadecyl groups derived from isobutene tetramers (these alkyl groups include all branched isomers); propenyl groups, Alkenyl groups such as butenyl groups; alkylaryl groups such as phenyl groups, tolyl groups, ethylphenyl groups, xylyl groups (of these alkylaryl groups) The alkyl moiety may be linear or branched, and the substitution position on the aryl group of the alkyl moiety is arbitrary.); And arylalkyl such as benzyl group and phenylethyl group (the substitution position of the phenyl group is arbitrary) Groups. Of these, an alkyl group having 3 to 18 carbon atoms, particularly 6 to 15 carbon atoms, derived from propylene or isobutene is particularly preferable.
[0069]
Specific examples of the dihydrocarbyl polysulfide include dimethyl polysulfide such as dimethyl monosulfide and dimethyl disulfide; diethyl polysulfide such as diethyl monosulfide and diethyl disulfide; di-n-propyl disulfide such as di-n-propyl monosulfide and di-n-propyl disulfide Propyl polysulfide; diisopropyl polysulfide such as diisopropyl monosulfide and diisopropyl disulfide; di-n-butyl polysulfide such as di-n-butyl monosulfide and di-n-butyl disulfide; diisobutyl polysulfide such as diisobutyl monosulfide and diisobutyl disulfide Disec-butyl such as disec-butyl monosulfide and disec-butyl disulfide Disulfide; ditert-butyl polysulfide such as ditert-butyl monosulfide and ditert-butyl disulfide; di (linear or branched pentyl) monosulfide, di (linear or branched pentyl) disulfide and the like (Linear or branched pentyl) polysulfide; di (linear or branched hexyl) monosulfide, di (straight or branched hexyl) disulfide such as disulfide; dicyclohexyl monosulfide, Dicyclohexyl polysulfide such as dicyclohexyl disulfide; di (straight or branched heptyl) monosulfide, di (straight or branched heptyl) disulfide such as disulfide; ditert-octylmono Di-tert-octyl polysulfide such as disulfide, di-tert-octyl disulfide; di (linear or branched octyl) disulfide such as di (linear or branched octyl) monosulfide, di (linear or branched octyl) disulfide Poly (sulfide); di (straight or branched nonyl) monosulfide, di (straight or branched nonyl) disulfide such as disulfide; di (straight or branched nonyl) monosulfide; Di (linear or branched undecyl) polysulfide such as di (linear or branched undecyl) disulfide; Di (linear or branched undecyl) monosulfide, di (linear or branched undecyl) disulfide and the like (Linear or branched undecyl) polysulfide; di-tert-dodecyl monosulfur Id, di tert-dodecyl disulfide such as di tert-dodecyl disulfide; di (straight or branched dodecyl) monosulfide, di (linear or branched dodecyl) disulfide such as disulfide Poly (sulfide); di (linear or branched tridecyl) monosulfide, di (linear or branched tridecyl) disulfide such as disulfide; di (linear or branched tridecyl) monosulfide; Di (linear or branched tetradecyl) disulfide such as di (linear or branched tetradecyl) disulfide; Di (linear or branched pentadecyl) monosulfide, di (linear or branched pentadecyl) disulfide and the like (Linear or branched pentadecyl) polysulfide; di Di-methylpentadecyl polysulfide such as methylpentadecyl monosulfide and di2-methylpentadecyl disulfide; ditert-hexadecyl polysulfide such as ditert-hexadecyl monosulfide and ditert-hexadecyl disulfide; Di (linear or branched hexadecyl) polysulfide such as (linear or branched hexadecyl) monosulfide, di (linear or branched hexadecyl) disulfide; di (linear or branched heptadecyl) monosulfide, di (direct Di (linear or branched heptadecyl) polysulfide such as chain or branched heptadecyl) disulfide; Di (linear or branched octadecyl) disulfide such as di (linear or branched octadecyl) monosulfide Or minutes Octadecyl) polysulfide; di (straight or branched nonadecyl) monosulfide, di (straight or branched nonadecyl) disulfide and the like di (straight or branched nonadecyl) polysulfide; di (straight or branched icosyl) mono Di (linear or branched icosyl) polysulfide such as sulfide, di (straight or branched icosyl) disulfide; Di (straight or branched hencosyl) monosulfide, di (linear or branched hemicosyl) disulfide, etc. Di (linear or branched docosyl) polysulfide; di (linear or branched docosyl) monosulfide, di (linear or branched docosyl) disulfide and the like; dipropenyl Monosulfide, dipropenyl disulfide, etc. Diphenyl sulfite; dibutenyl monosulfide such as dibutenyl monosulfide; dibutenyl disulfide; diphenyl polysulfide such as diphenyl monosulfide and diphenyl disulfide; dinaphthyl polysulfide such as dinaphthyl monosulfide and dinaphthyl disulfide; Ditolyl polysulfide such as ditolyl disulfide; Diethylphenyl polysulfide such as diethylphenyl monosulfide and diethylphenyl disulfide; Dipropylphenyl polysulfide such as dipropylphenyl monosulfide and dipropylphenyl disulfide; Dibutylphenyl monosulfide and dibutylphenyl disulfide Dibutylphenyl polysulfide such as sulfide Dipentylphenyl polysulfide such as dipentylphenyl monosulfide and dipentylphenyl disulfide; Dihexylphenyl polysulfide such as dihexylphenyl monosulfide and dihexylphenyl disulfide; Diheptylphenyl polysulfide such as diheptylphenyl monosulfide and diheptylphenyl disulfide; Dioctylphenyl Disulfyl phenyl polysulfide such as monosulfide and dioctylphenyl disulfide; Dinonylphenyl polysulfide such as dinonylphenyl monosulfide and dinonylphenyl disulfide; Didecylphenyl polysulfide such as didecylphenyl monosulfide and didecylphenyl disulfide; Decylphenyl monosal Diundecylphenyl polysulfide such as diidodecylphenyl disulfide; didodecylphenyl monosulfide, didodecylphenyl polysulfide such as didodecylphenyl disulfide; dixylylpolysulfide such as dixylyl monosulfide, dixylyl disulfide; diethylmethylphenyl Dimethyldiphenylpolysulfide such as monosulfide and diethylmethylphenyldisulfide; Di (diethylphenyl) polysulfide such as di (diethylphenyl) monosulfide and di (diethylphenyl) disulfide; Di (dipropylphenyl) monosulfide, di ( Di (dipropylphenyl) polysulfide such as dipropylphenyl) disulfide; Di (dibutylphenyl) polysulfide such as nosulfide and di (dibutylphenyl) disulfide; Dimethylnaphthylpolysulfide such as dimethylnaphthylmonosulfide and dimethylnaphthyldisulfide; Diethylnaphthylpolysulfide such as diethylnaphthylmonosulfide and diethylnaphthyldisulfide; Dipropyl naphthyl polysulfide such as propyl naphthyl monosulfide and dipropyl naphthyl disulfide; Dibutyl naphthyl polysulfide such as dibutyl naphthyl monosulfide and dibutyl naphthyl disulfide; Dibenzyl polysulfide such as dibenzyl monosulfide and dibenzyl disulfide; Diphenethyl monosulfide Diphenethyl such as sulfide and diphenethyl disulfide Risarufaido; diphenyl-propyl monosulfide, diphenyl propyl polysulfide, and mixtures thereof, such as diphenyl-propyl disulfide and the like.
[0070]
Examples of other compounds of the sulfides include diester polysulfides represented by the following general formula (5).
[0071]
R¹⁵OCO (CH₂ )_h S_j (CH₂ )_k COOR¹⁶      General formula (5)
[0072]
Where R¹⁵And R¹⁶May be the same or different and each represents a linear or branched alkyl group having 2 to 20 carbon atoms, preferably 4 to 20 carbon atoms, h and k may be the same or different, and each may be 2 to 5 , Preferably 2, j is 1-2, preferably 1.
[0073]
R¹⁵And R¹⁶Specific examples of these include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, Linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear Or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, linear or branched octadecyl group, linear or branched Mention may be made of branched nonadecyl groups, straight-chain or branched icosyl groups.
[0074]
Specific examples of diester polysulfide
C_Four H₉ OCO (CH₂ )₂ S (CH₂ )₂ COOC_Four H₉ ,
C_Four H₉ OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC_Four H₉ ,
C_Five H₁₁OCO (CH₂ )₂ S (CH₂ )₂ COOC_Five H₁₁,
C_Five H₁₁OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC_Five H₁₁,
C₆ H₁₃OCO (CH₂ )₂ S (CH₂ )₂ COOC₆ H₁₃,
C₆ H₁₃OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₆ H₁₃,
C₇ H₁₅OCO (CH₂ )₂ S (CH₂ )₂ COOC₇ H₁₅,
C₇ H₁₅OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₇ H₁₅,
C₈ H₁₇OCO (CH₂ )₂ S (CH₂ )₂ COOC₈ H₁₇,
C₈ H₁₇OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₈ H₁₇,
C₉ H₁₉OCO (CH₂ )₂ S (CH₂ )₂ COOC₉ H₁₉,
C₉ H₁₉OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₉ H₁₉,
C_TenH_{twenty one}OCO (CH₂ )₂ S (CH₂ )₂ COOC_TenH_{twenty one},
C_TenH_{twenty one}OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC_TenH_{twenty one},
C₁₁H_{twenty three}OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₁H_{twenty three},
C₁₁H_{twenty three}OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₁H_{twenty three},
C₁₂H_{twenty five}OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₂H_{twenty five},
C₁₂H_{twenty five}OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₂H_{twenty five},
C₁₃H₂₇OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₃H₂₇,
C₁₃H₂₇OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₃H₂₇,
C₁₄H₂₉OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₄H₂₉,
C₁₄H₂₉OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₄H₂₉,
C₁₅H₃₁OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₅H₃₁,
C₁₅H₃₁OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₅H₃₁,
C₁₆H₃₃OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₆H₃₃,
C₁₆H₃₃OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₆H₃₃,
C₁₇H₃₅OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₇H₃₅,
C₁₇H₃₅OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₇H₃₅,
C₁₈H₃₇OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₈H₃₇,
C₁₈H₃₇OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₈H₃₇,
C₁₉H₃₉OCO (CH₂ )₂ S (CH₂ )₂ COOC₁₉H₃₉,
C₁₉H₃₉OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₁₉H₃₉,
C₂₀H₄₁OCO (CH₂ )₂ S (CH₂ )₂ COOC₂₀H₄₁,
C₂₀H₄₁OCO (CH₂ )₂ S₂ (CH₂ )₂ COOC₂₀H₄₁
Or a mixture thereof.
[0075]
Examples of other compounds of the sulfides include tetraester tetrasulfide represented by the following general formula (6).
[0076]
(R¹⁷SCH₂ CH₂ COOCH₂ )_Four C General formula (6)
[0077]
Where R¹⁷Represents a linear or branched alkyl group having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms. R¹⁷Specific examples of such include linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched Tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, linear or branched octadecyl group, linear or branched nonadecyl group , A straight chain or branched icosyl group can be mentioned, and a straight chain or branched dodecyl group or a straight chain or branched tridecyl group is particularly preferable.
[0078]
Specific examples of tetraester tetrasulfide
(C₈ H₁₇SCH₂ CH₂ COOCH₂ )_Four C,
(C₉ H₁₉SCH₂ CH₂ COOCH₂ )_Four C,
(C_TenH_{twenty one}SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₁H_{twenty three}SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₂H_{twenty five}SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₃H₂₇SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₄H₂₉SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₅H₃₁SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₆H₃₃SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₇H₃₅SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₈H₃₇SCH₂ CH₂ COOCH₂ )_Four C,
(C₁₉H₃₉SCH₂ CH₂ COOCH₂ )_Four C,
(C₂₀H₄₁SCH₂ CH₂ COOCH₂ )_Four C or a mixture thereof, in particular
(C₁₂H_{twenty five}SCH₂ CH₂ COOCH₂ )_Four C is preferred.
[0079]
In the present invention, the component (3) is 0.01 parts by weight or more, preferably 0.1 parts by weight or more, and 10 parts by weight or less, preferably 5 parts by weight or less with respect to 100 parts by weight of the base oil. To do. When the blending amount of component (3) is less than 0.01 parts by weight, it is not preferable because sufficient antioxidant effect cannot be obtained. When the blending amount of component (3) exceeds 10 parts by weight, abrasion occurs. This is not preferable because there is a risk of the occurrence of water.
[0080]
The lubricating oil composition of the present invention itself has excellent oxidation stability. However, for the purpose of further enhancing these various performances, the lubricating oil composition of the present invention may be used alone or in combination with several kinds of lubricating oil additives. It can mix | blend with the following lubricating oil composition.
[0081]
Known additives that can be blended include, for example, neutral, basic, calcium carbonate overbased, calcium borate overbased alkaline earth metal sulfonates, alkaline earth metal salicylates, alkaline earth metal phenates, etc. Detergents; anti-wear agents such as organophosphates, organophosphites, fatty acids, fatty acid esters, aliphatic alcohols; polybutenyl succinimides, long chain alkyl polyamines, long chain fatty acids and polyamine amides or these Ashless dispersants such as boride; amine-based antioxidants such as phenyl-α-naphthylamine, alkylphenyl-α-naphthylamine, dialkyldiphenylamine; phenol-based ashless antioxidants; molybdenum dithiophosphate, molybdenum disulfide, long chain fat Group amines, long chain fatty acids, long chain fatty acids Friction reducing agents such as tellurium and long-chain aliphatic alcohols; antirust agents such as petroleum sulfonates, alkylbenzene sulfonates, dinonylnaphthalene sulfonates, alkenyl succinic acid esters, polyhydric alcohol esters; polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyls Demulsifiers typified by polyalkylene glycol-based nonionic surfactants such as ethers and polyoxyethylene alkyl naphthyl ethers; imidazolines, pyrimidine derivatives, alkylthiadiazoles, mercaptobenzothiazoles, benzotriazoles or their derivatives, 1,3,4 -Thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bisdialkyldithiocarbamate, 2- (alkyldithio) benzimidazole, β- (o Carboxybenzyl thio) metal deactivators, such as propionitrile; silicone, fluorosilicone, antifoaming agents such as fluoroalkyl ether; polymethacrylates include viscosity index improvers such as olefin copolymers or their hydrides.
[0082]
When these additives are added to the lubricating oil composition of the present invention, the amount added is 0.0005 to 1 part by weight for the antifoaming agent and 100% by weight for the metal deactivator. Is usually selected in the range of 0.005 to 1 part by weight, and other additives in the range of 0.1 to 15 parts by weight.
[0083]
The lubricating oil composition of the present invention can be particularly preferably used as a lubricating oil for internal combustion engines such as gasoline engines such as motorcycles and four-wheeled vehicles, land diesel engines, and marine diesel engines. Automotive gear oil such as machine oil and differential oil; industrial gear oil; hydraulic fluid; compressor oil; refrigeration oil; cutting oil; rolling oil, press oil, forging oil, drawing oil, drawing oil, punching oil, etc. Processing oil; Metal processing oil such as heat treatment oil, electric discharge machining oil; slip guide surface oil; bearing oil; rust prevention oil;
[0084]
【Example】
Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
The base oil and additives used are shown below.
[0085]
1. Ingredient (1)
(1) Descent Rimmer hydride
Total aromatic content 0% by weight according to ASTM D 2549.
Kinematic viscosity at 40 ° C 17.25 mm² / S.
Number average molecular weight 422.
(2) Wax isomerate
Total aromatic content 0.5% by weight according to ASTM D 2549. 98.6% by mass of saturated hydrocarbon component, 0.7% by mass of aromatic hydrocarbon component, and 0.7% by mass of polar compound by the method of Analytical Chemistry Vol. 44 described above. Kinematic viscosity at 40 ° C 16.5mm² / S. Kinematic viscosity at 100 ° C 4mm² / S. Viscosity index 144. Pour point -17.5 ° C.
[0086]
2. Ingredient (2)
(1) Monoeicosyltetralin
Kinematic viscosity at 40 ° C. 40.27 mm² / S.
[0087]
3. Ingredient (3)
(1) Zinc dialkyldithiophosphate
The alkyl group is a mixed alkyl group of sec-butyl group and sec-hexyl group. Effective concentration 100% by mass.
(2) Molybdenum dioctyl dithiocarbamate
Diluted with mineral oil. Effective concentration 30% by mass.
(3) Dibenzyl disulfide
(4) Dilauryl thiodipropionate
[0088]
4). Other
(1) Solvent refined mineral oil
Total aromatic content 26% by weight according to ASTM D 2549. Kinematic viscosity at 40 ° C. 22.7 mm² / S. Kinematic viscosity at 100 ° C 4.4 mm² / S. Viscosity index 101. Pour point -12.5 ° C.
(2) Additive package
Includes metal detergents, ashless dispersants, phenolic antioxidants, corrosion inhibitors and friction modifiers.
[0089]
(Examples 1-4)
The mixture having the composition shown in Table 1 was heated and stirred at a temperature of 80 ° C. for 2 hours to obtain the lubricating oil composition of the present invention.
The oxidation life was measured under the conditions of a temperature of 200 ° C. and an oxygen pressure of 2 MPa using a high-pressure differential thermal analyzer. The results are shown in Table 1.
[0090]
(Comparative Examples 1-5)
In the same manner as in the examples, a comparative lubricating oil composition having the composition shown in Table 1 was obtained. The oxidation lifetime was measured in the same manner as in the examples. The results are shown in Table 1.
[0091]
[Table 1]

[0092]
As can be seen from Table 1, all of the lubricating oil compositions of Examples 1 to 4 exhibited excellent oxidation stability.
In contrast, Comparative Example 1 using solvent refined mineral oil instead of Component (1), Comparative Example 2 and Comparative Example 3 in which the blending ratio of Component (1) and Component (2) deviated from the scope of the present invention, Component The oxidation stability of Comparative Example 4 in which (2) was not added and Comparative Example 5 in which component (3) was not added was not sufficient.
As described above, the lubricating oil composition of the present invention cannot obtain sufficient oxidative stability even if one of the components falls outside the scope of the present invention, and it is important to satisfy all of these components. is there.
[0093]
【The invention's effect】
The lubricating oil composition of the present invention achieves high oxidative stability and can be used under severer conditions than conventional lubricating oils.
The lubricating oil composition of the present invention can be particularly preferably used as a lubricating oil for internal combustion engines such as gasoline engines such as motorcycles and four-wheeled vehicles, land diesel engines, and marine diesel engines. Automotive gear oil such as machine oil and differential oil; industrial gear oil; hydraulic fluid; compressor oil; refrigeration oil; cutting oil; rolling oil, press oil, forging oil, drawing oil, drawing oil, punching oil, etc. Processing oil; Metal processing oil such as heat treatment oil, electric discharge machining oil; slip guide surface oil; bearing oil; rust prevention oil;

Claims (5)

(1) 70 to 97% by mass of synthetic oil having a total aromatic content of 5% by mass or less and (2) having 1 to 50 carbon atoms in the molecule, one benzene ring and one naphthene ring Or (3) with respect to 100 parts by weight of a base oil containing 3 to 30% by weight of a naphthenoaromatic component containing two or more and having a structure in which all of these benzene rings and naphthene rings are condensed to form a polycyclic compound A lubricating oil composition comprising 0.01 to 10 parts by weight of a sulfur-containing antioxidant. (1) in the total aromatic content is 5 mass% or less of the wax isomerized oil 70 to 97 mass% and (2) molecules, having an alkyl group having 1 to 50 carbon atoms, one and naphthenic benzene ring 100 parts by weight of a base oil containing 3 to 30% by weight of a naphthenoaromatic component containing one or two or more rings and having a structure in which all of these benzene rings and naphthene rings are condensed to form a polycyclic compound, (3) A lubricating oil composition comprising 0.01 to 10 parts by weight of a sulfur-containing antioxidant. The lubricating oil composition according to claim 1, wherein the component (2) is an alkyltetralin having an alkyl group having 1 to 50 carbon atoms. The lubricating oil composition according to any one of claims 1 to 3, wherein the component (3) comprises at least one selected from metal dihydrocarbyl dithiophosphates, metal dithiocarbamic acid metal salts, and sulfide. The lubricating oil composition according to any one of claims 1 to 3, wherein as the component (3), at least one selected from metal dithiocarbamate metal salts, dihydrocarbyl polysulfide, diester polysulfide, and tetraester polysulfide is blended.