JP4300021B2 - Lubricating oil composition for sliding guide surfaces - Google Patents

Description

【００３３】
【化２】

【００３４】
【化３】

［式（４）〜（６）中、Ｒ⁹及びＲ¹⁰は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜２０の炭化水素基を表し、ｃ及びｄは同一でも異なっていてもよく、それぞれ０〜８の整数を表す。］
このようなチアジアゾール化合物の具体例としては、２，５−ビス（ｎ−ヘキシルジチオ）−１，３，４−チアジアゾール、２，５−ビス（ｎ−オクチルジチオ）−１，３，４−チアジアゾール、２，５−ビス（ｎ−ノニルジチオ）−１，３，４−チアジアゾール、２，５−ビス（１，１，３，３−テトラメチルブチルジチオ）−１，３，４−チアジアゾール、３，５−ビス（ｎ−ヘキシルジチオ）−１，２，４−チアジアゾール、３，５−ビス（ｎ−オクチルジチオ）−１，２，４−チアジアゾール、３，５−ビス（ｎ−ノニルジチオ）−１，２，４−チアジアゾール、３，５−ビス（１，１，３，３−テトラメチルブチルジチオ）−１，２，４−チアジアゾール、４，５−ビス（ｎ−ヘキシルジチオ）−１，２，３−チアジアゾール、４，５−ビス（ｎ−オクチルジチオ）−１，２，３−チアジアゾール、４，５−ビス（ｎ−ノニルジチオ）−１，２，３−チアジアゾール、４，５−ビス（１，１，３，３−テトラメチルブチルジチオ）−１，２，３−チアジアゾール及びこれらの混合物などを好ましく挙げることができる。
【００３５】
アルキルチオカルバモイル化合物としては、例えば、下記一般式（７）：
【００３６】
【化４】

［式（７）中、Ｒ¹¹〜Ｒ¹⁴は同一でも異なっていてもよく、それぞれ炭素数１〜２０のアルキル基を表し、ｅは１〜８の整数を表す］
で表される化合物が挙げられる。このようなアルキルチオカルバモイル化合物の具体例としては、ビス（ジメチルチオカルバモイル）モノスルフィド、ビス（ジブチルチオカルバモイル）モノスルフィド、ビス（ジメチルチオカルバモイル）ジスルフィド、ビス（ジブチルチオカルバモイル）ジスルフィド、ビス（ジアミルチオカルバモイル）ジスルフィド、ビス（ジオクチルチオカルバモイル）ジスルフィド及びこれらの混合物などを好ましく挙げることができる。
【００３７】
アルキルチオカーバメート化合物としては、例えば、下記一般式（８）：
【００３８】
【化５】

［式中、Ｒ¹¹〜Ｒ¹⁴は同一でも異なっていてもよく、それぞれ炭素数１〜２０のアルキル基を表し、Ｒ¹⁵は炭素数１〜１０のアルキル基を表す］
で示される化合物が挙げられる。このようなアルキルチオカーバメート化合物の具体例としては、メチレンビス（ジブチルジチオカーバメート）、メチレンビス［ジ（２−エチルヘキシル）ジチオカーバメート］などを好ましく挙げることができる。
【００３９】
さらに、チオテルペン化合物としては、例えば、五硫化リンとピネンの反応物を、ジアルキルチオジプロピオネート化合物としては、例えば、ジラウリルチオジプロピオネート、ジステアリルチオジプロピオネート及びこれらの混合物などが挙げられる。
【００４０】
本発明のすべり案内面用潤滑油組成物において、（Ａ）成分としての硫黄化合物の含有量は任意であるが、得られる潤滑油組成物の摩擦特性の点から、組成物全量基準で０．１質量％以上であることが好ましく、０．５質量％以上であることがより好ましく、１質量％以上であることがさらにより好ましい。また、得られる潤滑油組成物が水溶性切削液との分離性により優れること、それ以上含有させてもさらなる摩擦特性の向上は期待できない場合があることなどから、（Ｂ）成分の含有量は組成物全量基準で２０質量％以下であることが好ましく、１０質量％以下であることがより好ましく、５質量％以下であることがさらにより好ましい。
【００４１】
本発明においては、（Ａ）成分としてリン化合物又は硫黄化合物のいずれか一方のみを用いてもよく、また、リン化合物及び硫黄化合物の双方を用いてもよいが、より潤滑特性に優れる点から、リン化合物と硫黄化合物とを併用することが好ましい。
【００４２】
本発明にかかる（Ｂ）成分は下記一般式（１）：
Ｒ¹Ｏ−（ＥＯ）_l−（Ｒ³Ｏ）_m−（ＥＯ）_n−Ｒ² （１）
［式（１）中、Ｒ¹及びＲ²は同一でも異なっていてもよく、それぞれ水素原子又は炭素数１〜６のアルキル基を表し、ＥＯはオキシエチレン基を表し、Ｒ³Ｏは炭素数３〜６のオキシアルキレン基を表し、ｌ、ｍ及びｎは同一でも異なっていてもよく、それぞれ１〜５０の整数を表す］
で表されるポリアルキレングリコール誘導体である。
【００４３】
一般式（１）中、Ｒ¹、Ｒ²としてのアルキル基は直鎖状、分岐鎖状、環状のいずれであってもよい。かかるアルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、各種ブチル基、各種ペンチル基、各種ヘキシル基、シクロペンチル基、シクロヘキシル基などが挙げられる。
【００４４】
また、一般式（１）中のＲＯは炭素数３〜６のオキシアルキレン基であり、繰り返し単位のオキシアルキレン器としては、オキシプロピレン基（ＰＯ）、オキシブチレン基、オキシペンチレン基、オキシへキシレン基などが挙げられる。これらの中でも、水溶性切削液との分離性により優れる点から、オキシプロピレン基が好ましい。
【００４５】
本発明にかかるポリアルキレングリコール誘導体は、ＥＯ、Ｒ³Ｏ、ＥＯの繰り返し数を表すｌ、ｍ、ｎがそれぞれ１〜５０の整数であることから明らかなように、オキシアルキレン鎖−（Ｒ³Ｏ）_m−の両端がオキシエチレン鎖（ＥＯ）_l及び（ＥＯ）_nと結合したブロック共重合体である。ｌ、ｍ、ｎのうちのいずれか１つが０であるポリアルキレングリコール誘導体を用いた場合には、水溶性切削液との分離性が不十分となる。また、ｌ、ｍ、ｎのそれぞれは、上述のように一般式（１）で表されるポリアルキレングリコール誘導体の平均分子量が５００〜５０００となるような値であることが好ましい。さらに、ｌ、ｍ、ｎの総和に対してｌ、ｎの和が占める割合（ｌ＋ｎ）／（ｌ＋ｍ＋ｎ）は、０．０５〜０．８であることが好ましく、０．０８〜０．７であることがより好ましく、０．０９〜０．５であることがさらに好ましい。（ｌ＋ｎ）／（ｌ＋ｍ＋ｎ）が上記の範囲内であると、水溶性切削液との分離性がより高められる傾向にある。
【００４６】
なお、ｍが２以上である場合、ｍ個のＲ³Ｏは同一でも異なっていてもよい。また、オキシアルキレン鎖（Ｒ³Ｏ）_mが２種以上のＲ³Ｏで構成される場合、当該オキシアルキレン鎖はブロック共重合鎖、ランダム共重合鎖のいずれであってもよい。
【００４７】
本発明において、上記（Ｂ）成分は、１種類を単独で用いてもよく、２種類以上を組み合わせて用いてもよい。また、その配合量は、組成物全量を基準として、０．０００１〜１質量％が好ましく、０．００１〜０．１質量％がより好ましい。
【００４８】
このように、本発明のすべり案内面用潤滑油組成物によれば、所定基油に（Ａ）、（Ｂ）成分を必須成分として含有せしめることで、摩擦特性、スティックスリップ防止性、並びに水溶性切削液に対する分離性の全てを高水準でバランスよく達成することが可能となる。また、本発明のすべり案内面用潤滑油組成物は、水溶性切削液と混合した際の水溶性切削液の劣化（切削性能の低下、腐敗の促進、鉱油寿命の短縮、廃液処理コストの上昇など）を抑制可能なものであり、水溶性切削液に対する安定性にも優れている。
【００４９】
また、本発明のすべり案内面用潤滑油組成物において、所定基油に、（Ａ）、（Ｂ）成分に加えて（Ｃ）炭素数６〜２４のモノアミン及び／又は炭素数６〜２４の脂肪酸をさらに含有せしめることで、摩擦特性、スティックスリップ防止性、をさらに向上させることができる。
【００５０】
本発明にかかるモノアミンの炭素数は、前述の通り６〜２４であり、好ましくは１２〜２４である。ここでいう炭素数とはモノアミンに含まれる総炭素数の意味であり、モノアミンが２個以上の炭化水素基を有する場合にはその合計炭素数を表す。
【００５１】
本発明にかかるモノアミンとしては、第１級モノアミン、第２級モノアミン、第３級モノアミンの何れもが使用可能であるが、得られる潤滑油組成物の潤滑特性の点から、第１級モノアミンが好ましい。
【００５２】
モノアミンの窒素原子に結合する炭化水素基としては、アルキル基、アルケニル基、シクロアルキル基、アルキルシクロアルキル基、アリール基、アルキルアリール基、アリールアルキル基等の何れもが使用可能であるが、得られる潤滑油組成物の潤滑特性の点から、アルキル基又はアルケニル基であることが好ましい。アルキル基、アルケニル基としては、直鎖状のものであっても分岐鎖状のものであっても良いが、得られる潤滑油組成物の潤滑特性の点から、直鎖状のものが好ましい。
【００５３】
本発明で用いられるモノアミンの好ましいものとしては、具体的には例えば、ヘキシルアミン（全ての異性体を含む）、ヘプチルアミン（全ての異性体を含む）、オクチルアミン（全ての異性体を含む）、ノニルアミン（全ての異性体を含む）、デシルアミン（全ての異性体を含む）、ウンデシルアミン（全ての異性体を含む）、ドデシルアミン（全ての異性体を含む）、トリデシルアミン（全ての異性体を含む）、テトラデシルアミン（全ての異性体を含む）、ペンタデシルアミン（全ての異性体を含む）、ヘキサデシルアミン（全ての異性体を含む）、ヘプタデシルアミン（全ての異性体を含む）、オクタデシルアミン（全ての異性体を含む）、ノナデシルアミン（全ての異性体を含む）、イコシルアミン（全ての異性体を含む）、ヘンイコシルアミン（全ての異性体を含む）、ドコシルアミン（全ての異性体を含む）、トリコシルアミン（全ての異性体を含む）、テトラコシルアミン（全ての異性体を含む）、オクタデセニルアミン（全ての異性体を含む）（オレイルアミン等を含む）及びこれらの２種以上の混合物などが挙げられる。これらの中でも、得られる潤滑油組成物の潤滑特性の点から、炭素数１２〜２４の第１級モノアミンが好ましく、炭素数１４〜２０の第１級モノアミンがより好ましく、炭素数１６〜１８の第１級モノアミンがさらに好ましい。
【００５４】
また、本発明にかかる（Ｃ）成分としての炭素数６〜２４の脂肪酸は、飽和の脂肪酸であっても不飽和の脂肪酸であっても良く、また、直鎖状の脂肪酸でも分岐鎖状の脂肪酸であっても良い。さらに、ヒドロキシ基を有するヒドロキシ脂肪酸であっても良い。
【００５５】
本発明にかかる脂肪酸の炭素数は、前述の通り６〜２４であり、好ましくは１２〜２４である。ここでいう脂肪酸の炭素数とは脂肪酸に含まれる総炭素数を意味し、脂肪酸が２個以上の炭化水素基を有する場合にはそれらの炭化水素基に含まれる炭素数とカルボキシル基に含まれる炭素数との合計炭素数を意味する。
【００５６】
本発明において好ましく用いられる脂肪酸としては、具体的には例えば、直鎖状又は分岐状のヘキサン酸、直鎖状又は分岐状のヘプタン酸、直鎖状又は分岐状のオクタン酸、直鎖状又は分岐状のノナン酸、直鎖状又は分岐状のデカン酸、直鎖状又は分岐状のウンデカン酸、直鎖状又は分岐状のヘキセン酸、直鎖状又は分岐状のヘプテン酸、直鎖状又は分岐状のオクテン酸、直鎖状又は分岐状のノネン酸、直鎖状又は分岐状のデセン酸、直鎖状又は分岐状のウンデセン酸等の不飽和脂肪酸、直鎖状又は分岐状のドデカン酸、直鎖状又は分岐状のトリデカン酸、直鎖状又は分岐状のテトラデカン酸、直鎖状又は分岐状のペンタデカン酸、直鎖状又は分岐状のヘキサデカン酸、直鎖状又は分岐状のヘプタデカン酸、直鎖状又は分岐状のオクタデカン酸、直鎖状又は分岐状のノナデカン酸、直鎖状又は分岐状のイコサン酸、直鎖状又は分岐状のヘンイコサン酸、直鎖状又は分岐状のドコサン酸、直鎖状又は分岐状のトリコサン酸、直鎖状又は分岐状のテトラコサン酸等の飽和脂肪酸；直鎖状又は分岐状のドデセン酸、直鎖状又は分岐状のトリデセン酸、直鎖状又は分岐状のテトラデセン酸、直鎖状又は分岐状のペンタデセン酸、直鎖状又は分岐状のヘキサデセン酸、直鎖状又は分岐状のヘプタデセン酸、直鎖状又は分岐状のオクタデセン酸、直鎖状又は分岐状のノナデセン酸、直鎖状又は分岐状のイコセン酸、直鎖状又は分岐状のヘンイコセン酸、直鎖状又は分岐状のドコセン酸、直鎖状又は分岐状のトリコセン酸、直鎖状又は分岐状のテトラコセン酸、リノール酸等の不飽和脂肪酸、及びこれらの混合物等が挙げられる。これらの中でも、得られる潤滑油組成物の潤滑特性の点から、炭素数１２〜２４の脂肪酸が好ましく、炭素数１４〜２０の脂肪酸がより好ましく、炭素数１６〜１８の脂肪酸がさらに好ましい。
【００５７】
本発明においては、（Ｃ）成分として、炭素数６〜２４のモノアミンと炭素数６〜２４の脂肪酸とを併用してもよく、また、いずれか一方を使用してもよいが、得られる潤滑油組成物が潤滑特性により優れかつ水溶性切削液との分離性により優れることから、炭素数１２〜２４のモノアミン及び／又は炭素数１２〜２４の脂肪酸を用いることが好ましく、炭素数１２〜２４のモノアミンを用いることがより好ましい。
【００５８】
本発明のすべり案内面用潤滑油組成物において、（Ｃ）成分の含有量は任意であるが、得られる潤滑油組成物の摩擦特性の点から、組成物全量基準で０．００１質量％以上であることが好ましく、０．０１質量％以上であることがより好ましく、０．１質量％以上であることがさらにより好ましい。また、得られる潤滑油組成物が水溶性切削液との分離性により優れること、並びにそれ以上含有させてもさらなる摩擦特性の向上は期待できない場合があることなどから、（Ｃ）成分の含有量は、組成物全量基準で１０質量％以下であることが好ましく、３質量％以下であることがより好ましく、１質量％以下であることがさらにより好ましい。
【００５９】
また、本発明のすべり案内面用潤滑油組成物においては、（Ｄ）アルカリ金属、アルカリ土類金属、亜鉛及び鉛の中から選ばれる少なくとも１種の金属の有機酸塩を含有せしめることで、すべり案内面用潤滑油としての特性を一層向上させることができる。
【００６０】
上記（Ｄ）成分のうち、アルカリ金属としてはナトリウム及びカリウム等が、また、アルカリ土類金属としてはマグネシウム、カルシウム及びバリウム等が挙げられ、本発明においてはアルカリ土類金属が好ましく用いられる。
【００６１】
また（Ｄ）成分のうち、有機酸塩としては、（Ｄ−１）スルフォネート、（Ｄ−２）フェネート、（Ｄ−３）サリシレート、ならびにこれらの混合物等が挙げられる。
【００６２】
（Ｄ−１）スルフォネートとしては、分子量１００〜１５００、好ましくは２００〜７００のアルキル芳香族化合物をスルホン化することによって得られるアルキル芳香族スルホン酸と、アルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）とを反応させて得られる、いわゆる中性スルフォネート；中性スルフォネートと、過剰のアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩や塩基（酸化物や水酸化物）を水の存在下で加熱することにより得られる、いわゆる塩基性スルフォネート；炭酸ガスの存在下で中性スルフォネートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）と反応させることにより得られる、いわゆる炭酸塩過塩基性（超塩基性）スルフォネート；中性スルフォネートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）ならびにホウ酸又は無水ホウ酸等のホウ酸化合物と反応させたり、又は炭酸塩過塩基性（超塩基性）スルフォネートとホウ酸又は無水ホウ酸等のホウ酸化合物を反応させることによって製造される、いわゆるホウ酸塩過塩基性（超塩基性）スルフォネート；及びこれらの混合物等が挙げられる。
【００６３】
また、上記アルキル芳香族スルホン酸としては、具体的にはいわゆる石油スルホン酸や合成スルホン酸等が挙げられる。ここでいう石油スルホン酸としては、一般に鉱油の潤滑油留分のアルキル芳香族化合物をスルホン化したものやホワイトオイル製造時に副生する、いわゆるマホガニー酸等が用いられる。また合成スルホン酸としては、例えば洗剤の原料となるアルキルベンゼン製造プラントから副生したり、ポリオレフィンをベンゼンにアルキル化することにより得られる、直鎖状や分枝状のアルキル基を有するアルキルベンゼンをスルホン化したもの、あるいはジノニルナフタレン等のアルキルナフタレンをスルホン化したもの等が用いられる。またこれらアルキル芳香族化合物をスルホン化する際のスルホン化剤としては特に制限はないが、通常、発煙硫酸や無水硫酸が用いられる。
【００６４】
（Ｄ−２）フェネートとしては、具体的には例えば、炭素数４〜２０のアルキル基を１〜２個有するアルキルフェノールと、元素イオウの存在下又は不存在下で、アルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）と反応させることにより得られる中性フェネート；中性フェネートと過剰のアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩や塩基（酸化物や水酸化物）を水の存在下で加熱することにより得られる、いわゆる塩基性フェネート；炭酸ガスの存在下で中性フェネートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）と反応させることにより得られる、いわゆる炭酸塩過塩基性（超塩基性）フェネート；中性フェネートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）ならびにホウ酸又は無水ホウ酸等のホウ酸化合物と反応させたり、又は炭酸塩過塩基性（超塩基性）フェネートとホウ酸又は無水ホウ酸等のホウ酸化合物を反応させることによって製造される、いわゆるホウ酸塩過塩基性（超塩基性）フェネート；及びこれらの混合物等が挙げられる。
【００６５】
（Ｄ−３）サリシレートとしては、具体的には例えば、炭素数４〜２０のアルキル基を１〜２個有するアルキルサリチル酸を、元素イオウの存在下又は不存在下で、アルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）と反応させることにより得られる中性サリシレート；中性サリシレートと、過剰のアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩や塩基（酸化物や水酸化物）を水の存在下で加熱することにより得られる、いわゆる塩基性サリシレート；炭酸ガスの存在下で中性サリシレートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）と反応させることにより得られる、いわゆる炭酸塩過塩基性（超塩基性）サリシレート；中性サリシレートをアルカリ金属、アルカリ土類金属、亜鉛又は鉛の塩基（酸化物や水酸化物）ならびにホウ酸又は無水ホウ酸等のホウ酸化合物と反応させたり、又は炭酸塩過塩基性（超塩基性）金属サリシレートとホウ酸又は無水ホウ酸等のホウ酸化合物を反応させることによって製造される、いわゆるホウ酸塩過塩基性（超塩基性）サリシレート；及びこれらの混合物等が挙げられる。
【００６６】
（Ｄ）成分の好ましい化合物の具体例としては、カルシウムスルホネート、マグネシウムスルホネート、炭酸カルシウム含有過塩基性カルシウムフェネート、炭酸カルシウム含有過塩基性カルシウムサリシレート、及びこれらの混合物が挙げられる。
【００６７】
（Ｄ）成分の全塩基価は任意であるが、通常、（Ｄ）成分としては、全塩基価が、好ましくは０〜５００ｍｇＫＯＨ／ｇ、より好ましくは０〜４５０ｍｇＫＯＨ／ｇのものが用いられる。なお、本発明でいう全塩基価とは、ＪＩＳ Ｋ ２５０１−１９９２「石油製品及び潤滑油−中和試験方法」に準拠して測定される塩酸法による全塩基価を意味している。（Ｄ）成分としては上記したような化合物の中から選ばれる１種のみを用いてもよく、また２種以上の混合物を用いてもよい。
【００６８】
本発明のすべり案内面用潤滑油組成物が（Ｄ）成分を含有する場合、（Ｄ）成分の含有量は任意であるが、通常、組成物全量基準で２０質量％以下であることが好ましい。
【００６９】
本発明のすべり案内面用潤滑油組成物においては、その優れた性質を高めるために、必要に応じて後述するその他の各種添加剤をさらに含有させてもよい。このような添加剤としては、ジ−ｔｅｒｔ−ブチル−ｐ−クレゾール、ビスフェノールＡ等のフェノール系化合物、フェニル−α−ナフチルアミン、Ｎ，Ｎ'−ジ（２−ナフチル）−ｐ−フェニレンジアミン等のアミン系化合物等の酸化防止剤；ベンゾトリアゾールやアルキルチアジアゾール等の金属不活性化剤；シリコーン油、フルオロシリコン油等の消泡剤；エチレンオキサイド、プロピレンオキサイドの縮合生成物等の抗乳化剤；ポリメタクリレート等の流動点降下剤；ポリメタクリレート、ポリブテン、ポリアルキルスチレン、オレフィンコポリマー、スチレン−ジエンコポリマー、スチレン−無水マレイン酸コポリマー等の粘度指数向上剤などが挙げられる。
【００７０】
本発明のすべり案内面用潤滑油組成物に、これら添加剤を配合する場合は、それぞれ単独で使用しても良く、また２種類以上組み合わせて使用してもよい。これら公知の添加剤を配合する場合の添加量は任意であるが、通常、これら公知の添加剤の合計量が組成物全量基準で２０質量％以下となるような量を添加するのが好ましい。
【００７１】
【実施例】
以下、実施例及び比較例に基づき本発明をさらに具体的に説明するが、本発明は以下の実施例に何ら限定されるものではない。
【００７２】
［実施例１〜６、比較例１〜３］
実施例１〜６及び比較例１〜３においては、以下に示す基油及び添加剤を用いて、表１に表す組成を有するすべり案内面用潤滑油組成物を調整した。
【００７３】
（基油）
Ｘ１：パラフィン系高度溶剤精製鉱油（４０℃における動粘度：６８．０ｍｍ² ／ｓ）。
【００７４】
（（Ａ）成分）
Ａ１：オレイルアシッドホスフェート
Ａ２：２−エチルヘキシルアシッドホスフェートのオレイルアミン塩
Ａ３：トリクレジルホスフェート
Ａ４：硫化エステル（硫黄含有率：１１．４質量％）
Ａ５：硫化ラード（硫黄含有率：１１．０質量％）。
【００７５】
（（Ｂ）成分）
Ｂ１：Ｈ−（ＥＯ）_l−（ＰＯ）_m−（ＥＯ）_n−Ｈ（平均分子量：３５００、（ｌ＋ｎ）／（ｌ＋ｍ＋ｎ）＝０．１）。
【００７６】
（（Ｃ）成分）
Ｃ１：オレイルアミン
Ｃ２：オレイン酸。
【００７７】
（（Ｄ）成分）
Ｄ１：カルシウムスルホネート（重量平均分子量４５０の石油スルホン酸カルシウム塩、全塩基価（塩酸法）０ｍｇＫＯＨ／ｇ、カルシウム含有量２．０質量％）。
【００７８】
（その他の成分）
Ｅ１：Ｈ−（ＥＯ）_l−（ＰＯ）_m−Ｈ（平均分子量：３５００、ｌ／（ｌ＋ｍ）＝０．１）。
【００７９】
次に、実施例１〜６及び比較例１〜３の各潤滑油組成物を用いて以下の試験を行った。
【００８０】
（摩擦特性評価試験）
図１は摩擦特性評価試験に用いた摩擦係数測定システムを示す概略構成図である。図１中、ベッド６上にはロードセル５を介して連結されたテーブル１及び可動治具４が配置されており、さらにテーブル１上には、加工工具の代用物としての重鎮９が配置されている。テーブル１及びベッド６はいずれも鋳鉄からなるものである。また、可動治具４は軸受部を有するもので、当該軸受部は送りネジ３を介してＡ／Ｃサーボモータ２に連結されている。Ａ／Ｃサーボメータ２により送りネジ３を動作させることで、可動治具４を送りネジ３の軸方向（図中の矢印方向）に往復運動させることができる。さらに、ロードセル５はコンピュータ７と、コンピュータ７及びＡ／Ｃサーボメータ２はそれぞれ制御板８と電気的に接続されており、これにより可動治具４の往復運動の制御及びテーブル１と可動治具４との間の荷重の測定を行うことができる。
【００８１】
このような摩擦係数測定システムにおいて、ベッド６の上面に潤滑油組成物を滴下し、テーブル重鎮９の選定によりテーブル１とベッド６との間を面圧２００ｋＰａに調整した後、送り速度１．２ｍｍ／ｍｉｎ、送り長さ１５ｍｍで可動治具４を往復運動させた。このときのテーブル１と可動治具４との間の荷重をロードセル５（荷重計）により測定し、得られた測定値に基づいて案内面（テーブル１／ベッド６＝鋳鉄／鋳鉄）の摩擦係数を求めた。なお、上記試験は慣らし運転を３回行った後に行った。各潤滑油組成物の摩擦係数を表１に示す。
【００８２】
（スティックスリップ防止性評価試験）
図２はスティックスリップ防止性評価装置（プリント アンド パートナーズ（ＰＬＩＮＴ ＆ ＰＡＲＴＮＥＲＳ）社製ＴＥ−７７試験機）を示す概略構成図である。図２に示した装置は、支持台１１０上に下側試験片１２、上側試験片１１、弾性体１０をこの順で積層し、所定荷重で試験片１１、１２同士を押し付けながら弾性体１０を支持台１１０の面に沿って往復動（すべり運動）させることにより、試験片１１、１２を摺動させるものである。そして、かかる摺動の際に試験片１１、１２に加えられる荷重を荷重検出器１３により測定することで、試験片１１、１２間の摩擦係数が求められる。図３は、上記操作で得られる摩擦係数と時間との相関の一例を示すグラフである。図中のΔμは摩擦係数の振幅を示している。
【００８３】
このような装置を用い、試験片及び条件をすべり案内面用潤滑油評価用に改良したこと以外は文献（トライボロジー学会トライボロジー会議予稿集 東京 １９９９−５ Ｄ１７）に示されている方法に準拠して、試験片１１、１２間に各潤滑油組成物を介在させたときのΔμを測定した。具体的には、試験片１１、１２のいずれもＪＩＳ Ｇ ４０５１ Ｓ４５Ｃを、弾性体１０にはクロロプレンゴムをそれぞれ用い、平均すべり速度０．３ｍｍ／ｓ、荷重２５０Ｎで試験を行った。Δμが０．０３未満の場合「スティックスリップなし」、振幅Δμが０．０３以上の場合「スティックスリップ有り」としてスティックスリップ防止性を評価した。得られた結果を表１に示す。
【００８４】
（水溶性切削液に対する分離性の評価試験）
潤滑油組成物２０ｍＬと水溶性切削液（エマルション型切削液、新日本石油（株）製、ＪＩＳ Ｋ ２２４１「切削油剤」のＷ１種１号相当品、希釈率１０倍）８０ｍＬとを１００ｍＬメスシリンダに採取した。このメスシリンダに栓をして室温で１分間振とうした後、０．５時間、１時間、３時間、６時間及び２４時間経過したときの分離状況を観察して分離性を評価した。分離性の評価は以下のようにして行った。
【００８５】
図４は振とう後所定時間経過したときのメスシリンダ１５内の分離状況の一例を示す説明図である。本試験においては、分離した各層の呼称を、栓１４から近い順に泡層（Ｆ層）１６、油層（Ｏ層）１７、クリーム層（Ｃ層）１８、乳化層（Ｅ層）１９と定め、各層の体積を測定した。得られた結果を表１に示す。表１に示した数値はＦ層−Ｏ層−Ｃ層−Ｅ層の体積を示すもので、例えば「０−１９−２−７９」はＦ層が０ｍｌ、Ｏ層が１９ｍｌ、Ｃ層が２ｍｌ、Ｅ層が７９ｍｌであったことを意味する。また、Ｃ層の体積が小さく、又はＣ層の体積が０ｍｌになるまでの時間が短いものほど分離性が良好であることを意味する。
【００８６】
【表１】

表１に示したように、実施例１〜６のすべり案内面用潤滑油組成物はいずれも、摩擦係数及びΔμが十分に小さい値を示し、また、短時間でクリーム層が消失するものであり、摩擦特性、スティックスリップ防止性、水溶性切削液との分離性の全てに優れるものであることが確認された。
【００８７】
【発明の効果】
以上説明した通り、本発明によれば、摩擦特性、スティックスリップ防止性、並びに水溶性切削液との分離性の全てを高水準でバランスよく達成可能なすべり案内面用潤滑油組成物が提供される。
【図面の簡単な説明】
【図１】実施例で用いた摩擦係数測定システムを示す概略構成図である。
【図２】実施例で用いたスティックスリップ防止性評価装置を示す概略構成図である。
【図３】図２の装置を用いて得られる摩擦係数と時間との相関の一例を示すグラフである。
【図４】水溶性切削液に対する分離性の評価試験における各層の分離状況を示す説明図である。
【符号の説明】
１…テーブル、２…Ａ／Ｃサーボメータ、３…送りネジ、４…可動治具、５…ロードセル、６…ベッド、７…コンピュータ、８…制御盤、９…重鎮、１０…弾性体、１１…上側試験片、１２…下側試験片、１３…荷重検出器、１１０…支持台、１４…栓、１５…メスシリンダ、１６…泡層（Ｆ層）、１７…油層（Ｏ層）、１８…クリーム層（Ｃ層）、１９…乳化層（Ｅ層）。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lubricating oil composition for a sliding guide surface used in a guide mechanism for sliding motions on two parallel planes of a machine tool.
[0002]
[Prior art]
When a stick-slip occurs on a sliding guide surface such as a machining table of a machine tool, the frictional vibration is transferred to the workpiece as it is, resulting in problems such as reduced machining accuracy or reduced tool life due to the vibration. Arise.
[0003]
Many of the machine tools have a structure in which the sliding guide surface lubricating oil can be mixed into the machining fluid of the workpiece. In particular, when a water-soluble cutting fluid is used as the machining fluid, the incorporation of the sliding guide surface lubricating oil deteriorates the water-soluble cutting fluid (decrease in cutting performance, acceleration of decay, shortening of mineral oil life, increase in waste liquid treatment cost, etc.) It has become one of the causes.
[0004]
Therefore, in order to avoid such a phenomenon, attempts have been made to improve the characteristics of the lubricating oil for sliding guide surfaces by adding various additives. As such a sliding guide surface lubricating oil, a base oil blended with a sulfur-based extreme pressure agent, a phosphate ester or its amine salt and an alkylene glycol derivative is known (for example, Patent Document 1). .
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-58783
[0006]
[Problems to be solved by the invention]
However, even with the above-mentioned conventional lubricating oil for the sliding guide surface, both the lubricating properties such as the friction characteristics and the anti-stick property on the sliding guide surface and the separability from the water-soluble cutting fluid are achieved at a high level. It is difficult.
[0007]
The present invention has been made in view of the above-described problems of the prior art, and a sliding guide surface that can achieve all of friction characteristics, stick-slip prevention properties, and separability from water-soluble cutting fluid at a high level in a well-balanced manner. It is an object to provide a lubricating oil composition.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors firstly described the above-mentioned lubricant required for a sliding guide surface in a combination of a phosphorus compound and / or a sulfur compound and a polyalkylene glycol derivative. It was found that the characteristics of the above depend significantly on the structure of the polyalkylene glycol derivative. As a result of further research based on such knowledge, by incorporating a polyalkylene glycol derivative having a specific structure into a specific base oil together with a phosphorus compound and / or a sulfur compound, friction characteristics, stick-slip prevention properties, and water-soluble cutting fluid are obtained. As a result, it was found that a lubricating oil for a sliding guide surface excellent in all separation properties was obtained, and the present invention was completed.
[0009]
That is, the lubricating oil composition for a sliding guide surface of the present invention comprises at least one base oil selected from mineral oils, fats and oils, at least one selected from phosphorus compounds and sulfur compounds, and the following general formula (1 ):
R ¹ O- (EO) _l -(R ^Three O) _m -(EO) _n -R ² (1)
[In formula (1), R ¹ And R ² May be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, R ^Three O represents an oxyalkylene group having 3 to 6 carbon atoms, and l, m and n may be the same or different and each represents an integer of 1 to 50. The ratio (l + n) / (l + m + n) of the sum of l and n to the sum of l, m and n is 0.05 to 0.5. ]
It is characterized by containing the polyalkylene glycol derivative represented by these.
[0010]
In the present invention, it is preferable that the sliding guide surface lubricating oil composition further contains at least one selected from amines having 6 to 24 carbon atoms and fatty acids having 6 to 24 carbon atoms.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail.
[0012]
In the lubricating oil composition for a sliding guide surface of the present invention, at least one selected from mineral oil, fats and oils and synthetic oils is used as the base oil.
[0013]
As mineral oil, lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil is solvent desorbed, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing In addition, paraffinic or naphthenic mineral oil obtained by appropriately combining one or two or more purification means such as white clay treatment may be used.
[0014]
Examples of fats and oils include beef tallow, lard, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, and hydrogenated products thereof.
[0015]
Synthetic oils include, for example, poly-α-olefins (ethylene-propylene copolymers, polybutenes, 1-octene oligomers, 1-decene oligomers and hydrides thereof), alkylbenzenes, alkylnaphthalenes, monoesters (butyl stearate). Rate, octyl laurate), diester (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sepacate, etc.), polyester (trimellitic acid ester, etc.), polyol ester ( Trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate), polyoxyalkylene Call, polyphenyl ether, dialkyl diphenyl ether, phosphate ester (tricresyl phosphate, etc.), fluorine-containing compound (perfluoropolyether, such as fluorinated polyolefins), such as silicone oil can be exemplified.
[0016]
In the present invention, the above base oils may be used alone or in combination of two or more.
[0017]
The kinematic viscosity at 40 ° C. of the base oil according to the present invention is 10 to 700 mm. ² / S is preferred, 15 to 500 mm ² / S is more preferable.
[0018]
Moreover, it is preferable that content of a base oil is 50-99.98 mass% on the composition whole quantity basis.
[0019]
In the present invention, the base oil includes (A) at least one selected from phosphorus compounds and sulfur compounds, and (B) the following general formula (1):
R ¹ O- (EO) _l -(R ^Three O) _m -(EO) _n -R ² (1)
[In formula (1), R ¹ And R ² May be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, R ^Three O represents an oxyalkylene group having 3 to 6 carbon atoms, and l, m and n may be the same or different and each represents an integer of 1 to 50]
And a polyalkylene glycol derivative represented by the formula:
[0020]
Among the component (A) according to the present invention, preferable examples of the phosphorus compound include phosphate ester, acidic phosphate ester, chlorinated phosphate ester, phosphite ester and phosphorothioate. These phosphorus compounds are esters of phosphoric acid, phosphorous acid or thiophosphoric acid with alkanols and polyether-type alcohols or derivatives thereof.
[0021]
Among the above phosphorous compounds, phosphate esters include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl Phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xyl Renyl diphenyl phosphate, etc .; Acid phosphate is monobutyl Cyd phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid, Monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl acid phosphate, dipentyl acid phosphate, dihexyl acid phosphate disulfate Fate, Dioctyl Acid Phosphate, Dinonyl Acid Phosphate, Didecyl Acid Phosphate, Diundecyl Acid Phosphate, Didodecyl Acid Phosphate, Ditridecyl Acid Phosphate, Ditetradecyl Acid Phosphate, Dipentadecyl Acid Phosphate, Dihexadecyl Acid Phosphate Heptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, etc .; chlorinated phosphates include tris dichloropropyl phosphate, tris chloroethyl phosphate, tris chlorophenyl phosphate, polyoxyalkylene bis [di (chloro Alkyl)] phosphate, etc .; as phosphite, dibutyl phosphite , Dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl phosphite, diphenyl phosphite, dicresyl phosphite Phyto, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite, tridodecyl phosphite, trioleyl phosphite Phyto, triphenyl phosphite, tricresyl phosphite, etc .; as phosphorothioate, tributyl phosphorothioate, tripentyl phosphorothione , Trihexyl phosphorothioate, triheptyl phosphorothioate, trioctyl phosphorothioate, trinonyl phosphorothionate, tridecyl phosphorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate , Tritridecyl phosphorothioate, tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, trihexadecyl phosphorothionate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphate Phorothionate, triphenyl phosphorothioate, tricresyl phosphorothionate, trixylenyl phosphorothionate, cresyl diphenyl phosphorothionate, xylenyl diphenyl phosphonate Phosphothionate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phosphorothionate, tris (n-butylphenyl) phosphorothionate, tris (isobutylphenyl) phosphorothionate, tris ( s-butylphenyl) phosphorothionate, tris (t-butylphenyl) phosphorothionate, and the like. Mixtures of these can also be used.
[0022]
In the lubricating oil composition for a sliding guide surface of the present invention, when a phosphorus compound is used as the component (A), the content thereof is arbitrary, but from the viewpoint of the friction characteristics of the resulting lubricating oil composition, the composition is based on the total amount. Is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more. In addition, since the obtained lubricating oil composition is excellent in separability from the water-soluble cutting fluid, and further improvement in friction characteristics may not be expected even if it is further contained, the content of the component (A) is It is preferably 10% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass or less based on the total amount of the composition.
[0023]
In addition, among the component (A) according to the present invention, the sulfur compound has a sulfur atom in the molecule and is dissolved or uniformly dispersed in the lubricating base oil, so that the lubricating oil composition has excellent extreme pressure and excellent Any material that can exhibit frictional properties may be used.
[0024]
Examples of such sulfur compounds include sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiadiazole compounds, alkylthiocarbamoyl compounds, thiocarbamate compounds, thioterpene compounds, dialkylthiodipropionate compounds, and the like. These sulfur compounds may be used alone or in a mixture of two or more.
[0025]
Sulfurized fats and oils are obtained by reacting sulfur and sulfur-containing compounds with fats and oils (lard oil, whale oil, vegetable oil, fish oil, etc.). The sulfur content of the sulfurized fat is not particularly limited, but generally 5 to 30% by mass is suitable. Specific examples thereof include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, sulfurized rice bran oil, and mixtures thereof.
[0026]
Examples of the sulfurized fatty acid include sulfurized oleic acid, and examples of the sulfurized ester include sulfurized methyl oleate, sulfurized rice bran fatty acid octyl, and mixtures thereof.
[0027]
Examples of the sulfurized olefin include the following general formula (2):
R ^Five -S _a -R ⁶ (2)
[In formula (2), R ^Five Is an alkenyl group having 2 to 15 carbon atoms, R ⁶ Represents an alkyl group having 2 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms, and a represents an integer of 1 to 8]. This compound is obtained by reacting an olefin having 2 to 15 carbon atoms or a dimer to tetramer thereof with a sulfurizing agent such as sulfur or sulfur chloride. As the olefin, propylene, isobutene, diisobutene and the like are preferable.
[0028]
Dihydrocarbyl polysulfide is represented by the following general formula (3):
R ⁷ -S _b -R ⁸ (3)
[In formula (3), R ⁷ And R ⁸ May be the same or different, each having an alkyl group having 1 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or a carbon number. Represents an arylalkyl group of 7 to 20, and b represents an integer of 1 to 8]
It is a compound represented by these. Where R ⁷ And R ⁸ A compound in which is an alkyl group is referred to as an alkyl sulfide.
[0029]
R in the general formula (3) ⁷ And R ⁸ Specific examples of the methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, Examples include various octyl groups, various nonyl groups, various decyl groups, various dodecyl groups, cyclohexyl groups, cyclooctyl groups, phenyl groups, naphthyl groups, tolyl groups, xylyl groups, benzyl groups, and phenethyl groups.
[0030]
Preferred examples of the dihydrocarbyl polysulfide include dibenzyl polysulfide, various dinonyl polysulfides, various didodecyl polysulfides, various dibutyl polysulfides, various dioctyl polysulfides, diphenyl polysulfide, dicyclohexyl polysulfide, and mixtures thereof.
[0031]
Examples of the thiadiazole compound include 1,3,4-thiadiazole represented by the following general formula (4), 1,2,4-thiadiazole compound represented by the following general formula (5), and the following general formula (6). 1,4,5-thiadiazole represented by the formula is preferably used.
[0032]
[Chemical 1]

[0033]
[Chemical formula 2]

[0034]
[Chemical 3]

[In the formulas (4) to (6), R ⁹ And R ^Ten May be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, c and d may be the same or different and each represents an integer of 0 to 8. ]
Specific examples of such thiadiazole compounds include 2,5-bis (n-hexyldithio) -1,3,4-thiadiazole, 2,5-bis (n-octyldithio) -1,3,4-thiadiazole. 2,5-bis (n-nonyldithio) -1,3,4-thiadiazole, 2,5-bis (1,1,3,3-tetramethylbutyldithio) -1,3,4-thiadiazole, 3, 5-bis (n-hexyldithio) -1,2,4-thiadiazole, 3,5-bis (n-octyldithio) -1,2,4-thiadiazole, 3,5-bis (n-nonyldithio) -1 , 2,4-thiadiazole, 3,5-bis (1,1,3,3-tetramethylbutyldithio) -1,2,4-thiadiazole, 4,5-bis (n-hexyldithio) -1,2 , 3-thiadiazole, 4 5-bis (n-octyldithio) -1,2,3-thiadiazole, 4,5-bis (n-nonyldithio) -1,2,3-thiadiazole, 4,5-bis (1,1,3,3) Preferred examples include -tetramethylbutyldithio) -1,2,3-thiadiazole and mixtures thereof.
[0035]
Examples of the alkylthiocarbamoyl compound include the following general formula (7):
[0036]
[Formula 4]

[In formula (7), R ¹¹ ~ R ¹⁴ May be the same or different and each represents an alkyl group having 1 to 20 carbon atoms, and e represents an integer of 1 to 8]
The compound represented by these is mentioned. Specific examples of such alkylthiocarbamoyl compounds include bis (dimethylthiocarbamoyl) monosulfide, bis (dibutylthiocarbamoyl) monosulfide, bis (dimethylthiocarbamoyl) disulfide, bis (dibutylthiocarbamoyl) disulfide, and bis (diamil). Preferable examples include thiocarbamoyl) disulfide, bis (dioctylthiocarbamoyl) disulfide, and mixtures thereof.
[0037]
Examples of the alkylthiocarbamate compound include the following general formula (8):
[0038]
[Chemical formula 5]

[Wherein R ¹¹ ~ R ¹⁴ May be the same or different and each represents an alkyl group having 1 to 20 carbon atoms; ¹⁵ Represents an alkyl group having 1 to 10 carbon atoms]
The compound shown by these is mentioned. Preferable examples of such alkylthiocarbamate compounds include methylenebis (dibutyldithiocarbamate), methylenebis [di (2-ethylhexyl) dithiocarbamate] and the like.
[0039]
Further, examples of the thioterpene compound include a reaction product of phosphorus pentasulfide and pinene, and examples of the dialkylthiodipropionate compound include dilauryl thiodipropionate, distearyl thiodipropionate, and a mixture thereof. It is done.
[0040]
In the lubricating oil composition for a sliding guide surface of the present invention, the content of the sulfur compound as the component (A) is arbitrary, but from the viewpoint of the frictional characteristics of the resulting lubricating oil composition, the total amount of the composition is 0.00. It is preferably 1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. In addition, since the obtained lubricating oil composition is more excellent in separability from the water-soluble cutting fluid, and further improvement in friction characteristics may not be expected even if it is further contained, the content of the component (B) is It is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less based on the total amount of the composition.
[0041]
In the present invention, only one of a phosphorus compound or a sulfur compound may be used as the component (A), and both a phosphorus compound and a sulfur compound may be used. It is preferable to use a phosphorus compound and a sulfur compound in combination.
[0042]
The component (B) according to the present invention is represented by the following general formula (1):
R ¹ O- (EO) _l -(R ^Three O) _m -(EO) _n -R ² (1)
[In formula (1), R ¹ And R ² May be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, R ^Three O represents an oxyalkylene group having 3 to 6 carbon atoms, and l, m and n may be the same or different and each represents an integer of 1 to 50]
It is a polyalkylene glycol derivative represented by these.
[0043]
In general formula (1), R ¹ , R ² The alkyl group as may be linear, branched or cyclic. Specific examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, cyclopentyl groups, and cyclohexyl groups.
[0044]
In addition, RO in the general formula (1) is an oxyalkylene group having 3 to 6 carbon atoms, and examples of the oxyalkylene unit of the repeating unit include an oxypropylene group (PO), an oxybutylene group, an oxypentylene group, and an oxyhexene group. Examples include xylene groups. Among these, an oxypropylene group is preferable because it is excellent in separability from a water-soluble cutting fluid.
[0045]
The polyalkylene glycol derivatives according to the present invention are EO, R ^Three As is clear from the fact that l, m and n representing the number of repetitions of O and EO are each an integer of 1 to 50, the oxyalkylene chain-(R ^Three O) _m -Both ends of oxyethylene chain (EO) _l And (EO) _n Is a block copolymer combined with When a polyalkylene glycol derivative in which any one of l, m, and n is 0, the separability from the water-soluble cutting fluid is insufficient. In addition, each of l, m, and n is preferably a value such that the average molecular weight of the polyalkylene glycol derivative represented by the general formula (1) is 500 to 5000 as described above. Further, the ratio (l + n) / (l + m + n) of the sum of l and n to the sum of l, m and n is preferably 0.05 to 0.8, and is 0.08 to 0.7. More preferably, it is more preferably 0.09 to 0.5. When (l + n) / (l + m + n) is within the above range, the separability from the water-soluble cutting fluid tends to be further improved.
[0046]
When m is 2 or more, m R ^Three O may be the same or different. In addition, an oxyalkylene chain (R ^Three O) _m 2 or more types of R ^Three When composed of O, the oxyalkylene chain may be a block copolymer chain or a random copolymer chain.
[0047]
In this invention, the said (B) component may be used individually by 1 type, and may be used in combination of 2 or more types. The blending amount is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.1% by mass, based on the total amount of the composition.
[0048]
As described above, according to the lubricating oil composition for a sliding guide surface of the present invention, by incorporating the components (A) and (B) as essential components into the predetermined base oil, friction characteristics, stick-slip prevention properties, and water solubility are achieved. It is possible to achieve a high level of well-balanced separability with respect to the cutting fluid. In addition, the lubricating oil composition for a sliding guide surface of the present invention deteriorates the water-soluble cutting fluid when mixed with the water-soluble cutting fluid (decrease in cutting performance, promotion of decay, shortening of the mineral oil life, increase in waste liquid treatment cost. Etc.) and is excellent in stability against water-soluble cutting fluid.
[0049]
Moreover, in the lubricating oil composition for a sliding guide surface of the present invention, in addition to the components (A) and (B), (C) a monoamine having 6 to 24 carbon atoms and / or 6 to 24 carbon atoms in addition to the components (A) and (B). By further containing a fatty acid, it is possible to further improve the friction characteristics and stick-slip prevention properties.
[0050]
As described above, the monoamine according to the present invention has 6 to 24 carbon atoms, preferably 12 to 24 carbon atoms. The carbon number here means the total number of carbon atoms contained in the monoamine. When the monoamine has two or more hydrocarbon groups, it represents the total number of carbon atoms.
[0051]
As the monoamine according to the present invention, any of a primary monoamine, a secondary monoamine, and a tertiary monoamine can be used. From the viewpoint of the lubricating properties of the resulting lubricating oil composition, the primary monoamine is preferable.
[0052]
As the hydrocarbon group bonded to the nitrogen atom of the monoamine, any of an alkyl group, an alkenyl group, a cycloalkyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, etc. can be used. From the viewpoint of lubricating properties of the resulting lubricating oil composition, an alkyl group or an alkenyl group is preferable. The alkyl group and alkenyl group may be linear or branched, but are preferably linear from the viewpoint of the lubricating properties of the resulting lubricating oil composition.
[0053]
Preferable monoamines used in the present invention include, for example, hexylamine (including all isomers), heptylamine (including all isomers), and octylamine (including all isomers). , Nonylamine (including all isomers), decylamine (including all isomers), undecylamine (including all isomers), dodecylamine (including all isomers), tridecylamine (all Including isomers), tetradecylamine (including all isomers), pentadecylamine (including all isomers), hexadecylamine (including all isomers), heptadecylamine (all isomers) ), Octadecylamine (including all isomers), nonadecylamine (including all isomers), icosylamine (including all isomers), hen Cosylamine (including all isomers), docosylamine (including all isomers), tricosylamine (including all isomers), tetracosylamine (including all isomers), octadecenylamine (all (Including isomers) (including oleylamine and the like) and mixtures of two or more thereof. Among these, from the viewpoint of lubricating properties of the resulting lubricating oil composition, primary monoamines having 12 to 24 carbon atoms are preferable, primary monoamines having 14 to 20 carbon atoms are more preferable, and those having 16 to 18 carbon atoms are preferred. Primary monoamines are more preferred.
[0054]
Further, the fatty acid having 6 to 24 carbon atoms as the component (C) according to the present invention may be a saturated fatty acid or an unsaturated fatty acid, and may be a linear fatty acid or a branched chain fatty acid. Fatty acids may be used. Further, it may be a hydroxy fatty acid having a hydroxy group.
[0055]
As described above, the fatty acid according to the present invention has 6 to 24 carbon atoms, preferably 12 to 24 carbon atoms. The number of carbon atoms of the fatty acid here means the total number of carbon atoms contained in the fatty acid. When the fatty acid has two or more hydrocarbon groups, the number of carbon atoms contained in those hydrocarbon groups and the carboxyl group are included. It means the total number of carbons with the number of carbons.
[0056]
Specific examples of fatty acids preferably used in the present invention include linear or branched hexanoic acid, linear or branched heptanoic acid, linear or branched octanoic acid, linear or Branched nonanoic acid, linear or branched decanoic acid, linear or branched undecanoic acid, linear or branched hexenoic acid, linear or branched heptenoic acid, linear or Unsaturated fatty acids such as branched octenoic acid, linear or branched nonenoic acid, linear or branched decenoic acid, linear or branched undecenoic acid, linear or branched dodecanoic acid , Linear or branched tridecanoic acid, linear or branched tetradecanoic acid, linear or branched pentadecanoic acid, linear or branched hexadecanoic acid, linear or branched heptadecanoic acid , Linear or branched octadecane , Linear or branched nonadecanoic acid, linear or branched icosanoic acid, linear or branched henicosanoic acid, linear or branched docosanoic acid, linear or branched tricosanoic acid , Saturated fatty acid such as linear or branched tetracosanoic acid; linear or branched dodecenoic acid, linear or branched tridecenoic acid, linear or branched tetradecenoic acid, linear or branched Pentadecenoic acid, linear or branched hexadecenoic acid, linear or branched heptadecenoic acid, linear or branched octadecenoic acid, linear or branched nonadecenoic acid, linear or branched Such as linear icosenoic acid, linear or branched henicosenoic acid, linear or branched docosenoic acid, linear or branched tricosenoic acid, linear or branched tetracosenoic acid, linoleic acid, etc. Saturated fatty acids, and Mixtures of these and the like. Among these, from the viewpoint of the lubricating properties of the resulting lubricating oil composition, fatty acids having 12 to 24 carbon atoms are preferable, fatty acids having 14 to 20 carbon atoms are more preferable, and fatty acids having 16 to 18 carbon atoms are more preferable.
[0057]
In the present invention, as the component (C), a monoamine having 6 to 24 carbon atoms and a fatty acid having 6 to 24 carbon atoms may be used in combination. Since the oil composition is excellent in lubrication characteristics and excellent in separability from a water-soluble cutting fluid, it is preferable to use a monoamine having 12 to 24 carbon atoms and / or a fatty acid having 12 to 24 carbon atoms, and 12 to 24 carbon atoms. It is more preferable to use the monoamine.
[0058]
In the lubricating oil composition for a sliding guide surface of the present invention, the content of the component (C) is arbitrary, but from the point of friction characteristics of the resulting lubricating oil composition, 0.001% by mass or more based on the total amount of the composition It is preferable that it is 0.01 mass% or more, and it is still more preferable that it is 0.1 mass% or more. In addition, since the obtained lubricating oil composition is more excellent in separability from the water-soluble cutting fluid, and further improvement in frictional characteristics may not be expected even if it is further contained, the content of the component (C) Is preferably 10% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass or less based on the total amount of the composition.
[0059]
Moreover, in the lubricating oil composition for a sliding guide surface of the present invention, (D) by containing an organic acid salt of at least one metal selected from alkali metals, alkaline earth metals, zinc and lead, The characteristics as the lubricating oil for the sliding guide surface can be further improved.
[0060]
Among the components (D), sodium and potassium are examples of the alkali metal, and magnesium, calcium and barium are examples of the alkaline earth metal. In the present invention, an alkaline earth metal is preferably used.
[0061]
Among the components (D), examples of the organic acid salt include (D-1) sulfonate, (D-2) phenate, (D-3) salicylate, and mixtures thereof.
[0062]
(D-1) As the sulfonate, an alkyl aromatic sulfonic acid obtained by sulfonating an alkyl aromatic compound having a molecular weight of 100 to 1500, preferably 200 to 700, an alkali metal, an alkaline earth metal, zinc or lead. So-called neutral sulfonates obtained by reacting bases (oxides and hydroxides) of the above; neutral sulfonates and excess alkali metal, alkaline earth metal, zinc or lead salts and bases (oxides and water) So-called basic sulfonates obtained by heating an oxide) in the presence of water; neutral sulfonates in the presence of carbon dioxide gas are converted to alkali metal, alkaline earth metal, zinc or lead bases (oxides or hydroxides). So called carbonate overbased (superbasic) sulfonates; neutral sulfonates Reaction with alkali metal, alkaline earth metal, zinc or lead bases (oxides and hydroxides) and boric acid compounds such as boric acid or boric anhydride, or carbonate overbased (superbasic) sulfonates And so-called borate overbased (superbasic) sulfonates produced by reacting boric acid compounds such as boric acid or boric anhydride, and mixtures thereof.
[0063]
Specific examples of the alkyl aromatic sulfonic acid include so-called petroleum sulfonic acid and synthetic sulfonic acid. As the petroleum sulfonic acid here, generally used are those obtained by sulfonating an alkyl aromatic compound in a lubricating oil fraction of mineral oil, or so-called mahoganic acid that is by-produced when white oil is produced. As synthetic sulfonic acids, for example, sulfonated alkylbenzenes having linear or branched alkyl groups, which are obtained as a by-product from an alkylbenzene production plant, which is a raw material for detergents, or are obtained by alkylating polyolefins to benzene. Or sulfonated alkylnaphthalene such as dinonylnaphthalene is used. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but usually fuming sulfuric acid or anhydrous sulfuric acid is used.
[0064]
(D-2) Specific examples of the phenate include, for example, an alkali metal and an alkaline earth metal in the presence or absence of an alkylphenol having 1 to 2 alkyl groups having 4 to 20 carbon atoms and elemental sulfur. Neutral phenates obtained by reacting with zinc or lead bases (oxides and hydroxides); neutral phenates and excess alkali metals, alkaline earth metals, zinc or lead salts and bases (oxides and hydroxides) So-called basic phenate obtained by heating (hydroxide) in the presence of water; neutral phenate in the presence of carbon dioxide gas, alkali metal, alkaline earth metal, zinc or lead base (oxide or water) So-called carbonate overbased (superbasic) phenates obtained by reacting with oxides); neutral phenates with alkali metal, alkaline earth metal, zinc or lead bases Oxides and hydroxides) and boric acid compounds such as boric acid or boric anhydride, or reacting borate compounds such as boric acid or boric anhydride with carbonate overbased (superbasic) phenate And so-called borate overbasic (superbasic) phenate, and a mixture thereof.
[0065]
(D-3) Specifically, for example, an alkyl salicylic acid having 1 to 2 alkyl groups having 4 to 20 carbon atoms in the presence or absence of elemental sulfur may be used as an alkali metal or alkaline earth. Neutral salicylates obtained by reacting with metals, zinc or lead bases (oxides and hydroxides); neutral salicylates and excess alkali metals, alkaline earth metals, zinc or lead salts and bases (oxidation) So-called basic salicylates obtained by heating materials and hydroxides in the presence of water; neutral salicylates in the presence of carbon dioxide gas, alkali metal, alkaline earth metal, zinc or lead bases (oxides) So-called carbonate overbased (superbasic) salicylates obtained by reacting them with hydroxides; neutral salicylates with alkali metals, alkaline earth metals, React with lead or lead base (oxide or hydroxide) and boric acid compounds such as boric acid or boric anhydride, or carbonate overbased (superbasic) metal salicylate and boric acid or boric anhydride And so-called borate overbased (superbasic) salicylates produced by reacting boric acid compounds such as, and the like, and mixtures thereof.
[0066]
Specific examples of preferred compounds of component (D) include calcium sulfonate, magnesium sulfonate, calcium carbonate-containing overbased calcium phenate, calcium carbonate-containing overbased calcium salicylate, and mixtures thereof.
[0067]
Although the total base number of (D) component is arbitrary, as (D) component, the total base number is preferably 0-500 mgKOH / g, more preferably 0-450 mgKOH / g. In addition, the total base number as used in the field of this invention means the total base number by the hydrochloric acid method measured based on JISK 2501-1992 "Petroleum products and lubricating oil-neutralization test method". As the component (D), only one kind selected from the compounds described above may be used, or a mixture of two or more kinds may be used.
[0068]
When the lubricating oil composition for a sliding guide surface of the present invention contains the component (D), the content of the component (D) is arbitrary, but is usually preferably 20% by mass or less based on the total amount of the composition. .
[0069]
In the lubricating oil composition for a sliding guide surface of the present invention, other various additives described later may be further contained as necessary in order to enhance the excellent properties. Examples of such additives include phenolic compounds such as di-tert-butyl-p-cresol and bisphenol A, phenyl-α-naphthylamine, N, N′-di (2-naphthyl) -p-phenylenediamine, and the like. Antioxidants such as amine compounds; metal deactivators such as benzotriazole and alkylthiadiazole; antifoaming agents such as silicone oil and fluorosilicone oil; demulsifiers such as condensation products of ethylene oxide and propylene oxide; polymethacrylate Pour point depressants such as polymethacrylates, polybutenes, polyalkylstyrenes, olefin copolymers, styrene-diene copolymers, styrene-maleic anhydride copolymers, and the like.
[0070]
When these additives are blended with the lubricating oil composition for a sliding guide surface of the present invention, they may be used alone or in combination of two or more. Although the addition amount in the case of mix | blending these well-known additives is arbitrary, It is preferable to add normally the quantity that the total amount of these known additives will be 20 mass% or less on the basis of the composition whole quantity.
[0071]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.
[0072]
[Examples 1-6, Comparative Examples 1-3]
In Examples 1 to 6 and Comparative Examples 1 to 3, a lubricating oil composition for a sliding guide surface having the composition shown in Table 1 was prepared using the following base oils and additives.
[0073]
(Base oil)
X1: Paraffin-based highly solvent refined mineral oil (kinematic viscosity at 40 ° C .: 68.0 mm ² / S).
[0074]
((A) component)
A1: Oleyl acid phosphate
A2: Oleylamine salt of 2-ethylhexyl acid phosphate
A3: tricresyl phosphate
A4: Sulfurized ester (sulfur content: 11.4% by mass)
A5: Sulfurized lard (sulfur content: 11.0% by mass).
[0075]
((B) component)
B1: H- (EO) _l -(PO) _m -(EO) _n -H (average molecular weight: 3500, (l + n) / (l + m + n) = 0.1).
[0076]
((C) component)
C1: oleylamine
C2: oleic acid.
[0077]
((D) component)
D1: Calcium sulfonate (petroleum sulfonic acid calcium salt having a weight average molecular weight of 450, total base number (hydrochloric acid method) 0 mgKOH / g, calcium content 2.0 mass%).
[0078]
(Other ingredients)
E1: H- (EO) _l -(PO) _m -H (average molecular weight: 3500, l / (l + m) = 0.1).
[0079]
Next, the following tests were conducted using the lubricating oil compositions of Examples 1 to 6 and Comparative Examples 1 to 3.
[0080]
(Frictional property evaluation test)
FIG. 1 is a schematic configuration diagram showing a friction coefficient measurement system used in a friction characteristic evaluation test. In FIG. 1, a table 1 and a movable jig 4 connected via a load cell 5 are arranged on a bed 6, and a heavyweight 9 as a substitute for a processing tool is arranged on the table 1. Yes. Both the table 1 and the bed 6 are made of cast iron. The movable jig 4 has a bearing portion, and the bearing portion is connected to the A / C servo motor 2 via the feed screw 3. By operating the feed screw 3 by the A / C servometer 2, the movable jig 4 can be reciprocated in the axial direction of the feed screw 3 (arrow direction in the figure). Further, the load cell 5 is electrically connected to the computer 7, and the computer 7 and the A / C servometer 2 are electrically connected to the control plate 8, thereby controlling the reciprocating motion of the movable jig 4 and the table 1 and the movable jig. The load between 4 can be measured.
[0081]
In such a friction coefficient measurement system, a lubricating oil composition is dropped on the upper surface of the bed 6, and after adjusting the surface pressure between the table 1 and the bed 6 to 200 kPa by selecting the table weight 9, the feed rate is 1.2 mm. The movable jig 4 was reciprocated with a feed length of 15 mm / min. The load between the table 1 and the movable jig 4 at this time is measured by a load cell 5 (load meter), and the friction coefficient of the guide surface (table 1 / bed 6 = cast iron / cast iron) based on the obtained measurement value. Asked. In addition, the said test was done after running in 3 times. Table 1 shows the friction coefficient of each lubricating oil composition.
[0082]
(Stick-slip prevention evaluation test)
FIG. 2 is a schematic configuration diagram showing a stick-slip prevention evaluation apparatus (TE-77 tester manufactured by Print & Partners). In the apparatus shown in FIG. 2, a lower test piece 12, an upper test piece 11, and an elastic body 10 are laminated in this order on a support base 110, and the elastic body 10 is pressed while pressing the test pieces 11 and 12 together with a predetermined load. The test pieces 11 and 12 are slid by reciprocating (sliding) along the surface of the support table 110. And the friction coefficient between the test pieces 11 and 12 is calculated | required by measuring the load added to the test pieces 11 and 12 by the load detector 13 in the case of this sliding. FIG. 3 is a graph showing an example of the correlation between the friction coefficient obtained by the above operation and time. Δμ in the figure indicates the amplitude of the friction coefficient.
[0083]
In accordance with the method described in the literature (Tribology Society Tribology Conference Proceedings Tokyo 1999-5 D17) except that the test piece and conditions were improved for the evaluation of the lubricating oil for the sliding guide surface using such an apparatus. Δμ when each lubricating oil composition was interposed between the test pieces 11 and 12 was measured. Specifically, JIS G 4051 S45C was used for each of the test pieces 11 and 12, chloroprene rubber was used for the elastic body 10, and the test was performed at an average sliding speed of 0.3 mm / s and a load of 250N. When Δμ was less than 0.03, “no stick-slip”, and when amplitude Δμ was 0.03 or more, “stick-slip” was evaluated. The obtained results are shown in Table 1.
[0084]
(Evaluation test of separability against water-soluble cutting fluid)
100 mL graduated cylinder with 20 mL of lubricating oil composition and 80 mL of water-soluble cutting fluid (emulsion-type cutting fluid, manufactured by Nippon Oil Corporation, JIS K2241 “Cutting fluid”, equivalent to W1 type 1 product, dilution factor 10 times) It was collected. The measuring cylinder was capped and shaken at room temperature for 1 minute, and then the separation state was observed after 0.5 hours, 1 hour, 3 hours, 6 hours, and 24 hours, and the separation was evaluated. Evaluation of separability was performed as follows.
[0085]
FIG. 4 is an explanatory diagram showing an example of a separation state in the graduated cylinder 15 when a predetermined time has elapsed after shaking. In this test, the names of the separated layers are defined as a foam layer (F layer) 16, an oil layer (O layer) 17, a cream layer (C layer) 18, and an emulsified layer (E layer) 19 in the order from the stopper 14. The volume of each layer was measured. The obtained results are shown in Table 1. The numerical values shown in Table 1 indicate the volume of F layer-O layer-C layer-E layer. For example, "0-19-2-79" is 0 ml for F layer, 19 ml for O layer, and 2 ml for C layer. , Which means that the E layer was 79 ml. In addition, the smaller the volume of the C layer or the shorter the time until the volume of the C layer becomes 0 ml, the better the separability.
[0086]
[Table 1]

As shown in Table 1, each of the sliding guide surface lubricating oil compositions of Examples 1 to 6 shows a sufficiently small coefficient of friction and Δμ, and the cream layer disappears in a short time. It was confirmed that it was excellent in all of friction characteristics, stick-slip prevention properties, and separability from water-soluble cutting fluid.
[0087]
【The invention's effect】
As described above, according to the present invention, there is provided a lubricating oil composition for a sliding guide surface that can achieve all of friction characteristics, stick-slip prevention properties, and separability from water-soluble cutting fluid at a high level and in a well-balanced manner. The
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a friction coefficient measurement system used in an example.
FIG. 2 is a schematic configuration diagram showing a stick-slip prevention evaluation apparatus used in Examples.
FIG. 3 is a graph showing an example of a correlation between a friction coefficient and time obtained using the apparatus of FIG. 2;
FIG. 4 is an explanatory diagram showing a separation state of each layer in a separation property evaluation test for a water-soluble cutting fluid.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Table, 2 ... A / C servo meter, 3 ... Feed screw, 4 ... Movable jig, 5 ... Load cell, 6 ... Bed, 7 ... Computer, 8 ... Control panel, 9 ... Heavyweight, 10 ... Elastic body, 11 ... Upper test piece, 12 ... Lower test piece, 13 ... Load detector, 110 ... Support base, 14 ... Plug, 15 ... Measuring cylinder, 16 ... Foam layer (F layer), 17 ... Oil layer (O layer), 18 ... Cream layer (C layer), 19 ... Emulsion layer (E layer).

Claims (2)

At least one base oil selected from mineral oils, fats and oils, and synthetic oils;
At least one selected from phosphorus compounds and sulfur compounds;
The following general formula (1):
R ¹ O— (EO) ₁ — (R ³ O) _m — (EO) _n —R ² (1)
[In Formula (1), R ¹ and R ² may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, and R ³ O represents a carbon number. It represents a 3-6 oxyalkylene group, l, m and n may be the same or different, and table an integer of 1 to 50, respectively, l, m, l based on the sum of n, the sum of n The ratio (l + n) / (l + m + n) is 0.05 to 0.5 ]
A lubricating oil composition for a sliding guide surface, comprising a polyalkylene glycol derivative represented by the formula:   The lubricating oil composition for a sliding guide surface according to claim 1, further comprising at least one selected from amines having 6 to 24 carbon atoms and fatty acids having 6 to 24 carbon atoms.

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