JP3580845B2 - Water-soluble rust preventive oil composition - Google Patents

Description

Ｒ_１ は水素原子または炭素数１〜３のアルキル基
Ｒ_２ は炭素数１〜３のアルキル基
で表されるアルキルアルカノールアミン１０〜２５重量％と、
脂環式アミン５〜２０重量％と、
ポリグリセリン脂肪酸エステル１〜１０重量％と、
アルキルアミノスルホネート１〜１０重量％と、
鉱油５〜２０重量％と、
水５〜１０重量％とを必須成分として含有することを特徴とするものである。
【０００８】
【作用】
上記の構成において、炭素数１２以上の高級脂肪酸はアルキルアルカノールアミンと反応して脂肪酸アミン塩となり、その脂肪酸アミン塩が鉱油の乳化剤として作用する。かつ、脂肪酸アミン塩と鉱油とが共に潤滑剤としても作用して、これらの潤滑効果によって軸受の音響性を向上させる。
【０００９】
また、炭素数１２以上の高級脂肪酸と炭素数８の脂肪酸とを併用することにより特に優れた防錆性が得られることが実験的に確認された。
以下に、本発明を詳細に説明する。
本発明者らは、軸受用の水溶性防錆油剤組成物における音響性の向上について研究を重ね、その結果次のような知見が得られた。
（イ）使用する界面活性剤（アニオン界面活性剤）をアルカリ塩ではなくアミン塩にすると音響性が向上する。
（ロ）アミンは、通常使用されるアルカノールアミンではなくジアルキルアルカノールアミンを使用すれば耐酸化劣化性が改良され、これによって音響性は向上する。
（ハ）非イオン界面活性剤である多価アルコール脂肪酸エステルの代わりにポリグリセリン脂肪酸エステルを使用すると音響性は向上する。この事実はやや以外な結果であったが、ポリグリセリン脂肪酸エステルにも耐酸化劣化性を向上させる作用があり、そのために音響性が向上したと考えられる。
（ニ）水溶性防錆油剤の分散状態について、エマルジョン状態の場合と分散性がより高いソリューブル状態の場合とを、軸受を処理して形成した被覆防錆油膜の水分蒸発性の比較で検討した。結果は、ソリューブル状態の方が蒸発性が良くて水分残存量が少なく、音響性も良好であった。
（ホ）アニオン界面活性剤の脂肪酸アミン塩を用いた場合、脂肪酸に炭素数１２以上の高級脂肪酸と炭素数８の脂肪酸とを併用すると、意外にも防錆性が著しく向上する。
【００１０】
本発明は、以上の知見に基づいてなされたものである。
本発明に用いる高級脂肪酸は、その炭素数を１２以上とする。炭素数１２未満では、得られる水溶性防錆油剤組成物の潤滑性，音響性の効果が少なくて不適当である。炭素数１２以上であれば良く、例えば炭素数３６または５４の重合脂肪酸も効果があることから炭素数に上限を設ける必要はないが、重合脂肪酸を除けば炭素数２４位までが実用上好ましい範囲である。具体的には、ラウリン酸，ミリスチン酸，パルミチン酸，ステアリン酸，アラキン酸，ベヘン酸，リグノセリン酸，オレイン酸，エルカ酸，リノール酸，リシノール酸等が適当な範囲であり、なかでもラウリン酸，オレイン酸，リシノール酸はそのアミン塩が乳化性良好で、潤滑性，音響性も優れており最も好ましい。
【００１１】
添加量は１０重量％未満では効果がなく、２５重量％を越えると組成物のバランスが失われて著しく粘ちょうになり好ましくない。
本発明にあっては、更に他の脂肪酸として炭素数８のカプリル酸が上記高級脂肪酸と併用される。両者を併用することによって防錆性が特に優れた水溶性防錆油剤組成物が得られるという事実が実験的に確認されたものである。その理由は明白になっていないが、次のような可能性は十分考えられる。すなわち、炭素数１２以上の高級脂肪酸塩分子が金属表面に配列して被覆膜を形成する際、特に、ラウリン酸，オレイン酸，リシノール酸等の塩分子のように鎖長に長短があるものを混合して使用すると分子間に空隙が生じ易い。また、オレイン酸のように二重結合を持ち折れ曲がり易い分子とか、リシノール酸のように水酸基をもち立体障害を有する分子が混在する場合にはその傾向が助長される。その空隙に炭素数の少ない脂肪酸の小さい分子が入り込み分子膜の密な充填が得られ、その結果として優れた防錆被覆膜が形成される。
【００１２】
したがって、被覆膜を形成する高級脂肪酸塩分子間の空隙を緻密に充填するには、添加する脂肪酸の分子の大きさが小さいことが必要であり、その炭素数を８とする。また、その添加量については、１重量％未満では上記空隙充填効果が認められない。一方、１０重量％を越えると過剰になって、このアミン塩が浸透剤として作用する結果、折角形成された高級脂肪酸塩被覆膜の分子を破壊するに至るという副作用を生じる。
【００１３】
本発明に用いるアルキルアルカノールアミンは、前記炭素数１２以上の高級脂肪酸と反応して脂肪酸アミン塩となり、乳化剤および潤滑剤として機能する。この脂肪酸アミン塩は、軸受表面を被覆した防錆膜が酸化劣化しても固化することがない（因みに、通常の防錆油剤に使用するアルカノールアミン塩の場合は、防錆膜が酸化すると固化する）。固化しないため、軸受に使用して優れた音響性が得られることが実験的に見いだされた。上記アルキルアルカノールアミンの具体例としては、Ｎ−メチルジエタノールアミン、Ｎ，Ｎ−ジメチルモノエタノールアミン等を挙げることができる。その添加量は１０〜２５重量％の範囲であり、１０重量％未満では効果がなく、一方、２５重量％を越えると組成のバランスを崩して分離するおそれがあり、いずれも適当でない。
【００１４】
本発明に用いる脂環式アミンの具体例はシクロヘキシルアミン，ジシクロヘキシルアミン等であり、防錆性の向上および組成のバランスの作用を行う成分である。その添加量は５〜２０重量％が適当な範囲であって、５重量％未満では効果がなく、一方、２０重量％を越えるとバランスの作用がなくなり分離等の障害を起こすこととなって不適当である。
【００１５】
本発明に用いるポリグリセリン脂肪酸エステルは、軸受表面に形成された防錆膜の酸化劣化を防止する作用があることが本発明者等により見出され、かかる作用のないソルビタンモノオレエート，ペンタエリスリトールジオレエート等の多価アルコール脂肪酸エステルに代えて使用するものである。多価アルコール脂肪酸エステルはまた、防錆膜を乾燥する際に膜中に水分を微細に分散して乾燥を遅延させる作用があり、その分散水分が原因となって音響性を低下させるという欠点を有しているが、このポリグリセリン脂肪酸エステルにはかような欠点はないので、この点からも本発明の水溶性防錆油剤組成物の成分として適当である。
【００１６】
ポリグリセリン脂肪酸エステルは分子式

で表され、Ｒ_１ は炭素数１２〜２４のアルキル基，アルケニル基，同縮合基，ヒドロキシアルケニル基，同縮合基，ｎは１〜９である。その好ましい具体例には、テトラグリセリン縮合リシノール酸エステル，デカグリセリンモノオレイン酸エステルが挙げられる。添加量は１〜１０重量％が適当な範囲であり、１重量％未満では効果がない。一方、１０重量％を越えると希釈液の分離の原因となりまた潤滑性も低下するため不適当である。
【００１７】
本発明に用いるアルキルアミノスルホネートは防錆剤であり、更に乳化分散の効果をも有している。添加量は１〜１０重量％が適当な範囲であり、１重量％未満では効果がなく、１０重量％を越えても効果は特に増大せずにコストが増大し、いずれも適当でない。
本発明に用いる鉱油は、潤滑性付与剤および防錆膜基剤として作用するものであって、前記炭素数１２以上の高級脂肪酸および炭素数８の脂肪酸と共に防錆膜を主として構成する。パラフィン形潤滑油（ＶＧ５〜６８）が適当なものである。添加量は５〜２０重量％が適当な範囲であり、５重量％未満では防錆膜基剤として不足で潤滑，防錆の効果が認められない。一方、２０重量％を越えると組成のバランスを失い分離等の障害を起こすことから適当でない。
【００１８】
本発明に用いる水は、防錆油剤の性能上は必要な成分といえないが、上記の成分と共にバランスして均一で安定な油剤を形成するのに必要な成分であって、添加量は５〜１０重量％が適当な範囲であり、５重量％未満でもまた１０重量％を越えても、いずれもバランスを失い均一な油剤が得られず適当でない。
本発明の水溶性防錆油剤組成物にあっては、以上の各成分の他に必要に応じてオレイン酸ジエタノールアミド等の防錆剤，防腐剤，防黴剤，非鉄金属防食剤を併用添加することも好ましい。
【００１９】
以上の各成分を均一に混合溶解すれば、本発明の防錆油剤の原液が得られる。その混合の順序は特定する必要がないが、鉱油に炭素数１２以上の高級脂肪酸と炭素数８の脂肪酸とを加えて混合溶解し、次いでアルキルアルカノールアミンを加え攪拌して反応せしめ、次に脂環式アミン、ポリグリセリン脂肪酸エステル，アルキルアミノスルホネートの順に加えて攪拌し、最後に水を加えて攪拌して均一な油剤にするのが好ましい。
【００２０】
このようにして得られた油剤が本発明の原液であって、使用に当たっては通常１〜２０重量％の水分散液として用いる。なお、水分散液の状態は透明ないし半透明のソリューブル状になる。
【００２１】
【実施例】
以下、本発明を実施例及び比較例によって具体的に説明する。
（Ａ）試料の調整：
炭素数１２以上の高級脂肪酸（以下、脂肪酸Ａとする）としてオレイン酸（ Ｃ_１７Ｈ_３３ＣＯＯＨ），リシノレイン酸〔Ｃ_１７Ｈ_３２（ＯＨ）ＣＯＯＨ〕，ラウリン酸（Ｃ_１１Ｈ_２３ＣＯＯＨ）を単独または併用で使用し、炭素数８の脂肪酸（以下、脂肪酸Ｂという）としてはカプリル酸（Ｃ_７ Ｈ_１３ＣＯＯＨ）を使用し、アルキルアルカノールアミンとしてはＮ−メチルジエタノールアミン

とを単独または併用で使用し、脂環式アミンとしてジシクロヘキシルアミンを使用し、ポリグリセリン脂肪酸エステルとしてはテトラグリセリン縮合リシノレイン酸エステル及びデカグリセリンモノオレイン酸エステルを単独または併用で使用し、鉱油はＰ系，ＶＧ１０を使用し、更に有機防錆剤兼界面活性剤としてアミノスルホネート，オレイン酸ジエタノールアミン，カプリル酸ジエタノールアミドを単独または併用で使用し、これら各成分を表に示す配合（重量％）に従って水中に均一に分散せしめて表１に示す実施例１〜７の試料原液を作成した。
【００２２】
一方、比較のために、上記実施例におけるアルキルアルカノールアミンの代わりにアルカノールアミン

を使用すると共に、ポリグリセリン脂肪酸エステルか多価アルコールエステルのいずれかを選択的に使用して、各成分を表２に示す配合（重量％）に従って水中に均一に分散せしめて比較例８〜１３試料原液を作成した。また、市販の防錆油（ＮＰ−７タイプ）を比較例１４とした。
【００２３】
【表１】

【００２４】
【表２】

【００２５】
上記の各試料原液の３重量％水分散液について以下の性能試験を実施した。
（Ｂ）試験内容：
（１）外観
蒸留水３重量％希釈液をガラス製見本瓶に入れて外観を肉眼で観察した。
Ｓ：透明ないし半透明
Ｅ：乳白色エマルション
分離：二層に分離
（２）防錆性試験（軸受湿潤試験）
▲１▼ 玉軸受（外径２２ｍｍ）１０個を超音波洗浄器（ＢＲＡＮＳＯＮ ２２００， 商品名）を用いてｎ−ヘキサン，アセトン，温メタノールの順で各１分間洗浄し乾燥させる。
【００２６】
▲２▼ これを試料原液の３重量％希釈液中に１分間浸漬して浸漬溶液から取り出し、６０℃，１０Ｔｏｒｒ以下の減圧乾燥器で１０分間乾燥させる。
▲３▼ この玉軸受を温度４０℃，相対湿度９０％の恒温恒湿槽に入れて１週間放置する。その後、玉軸受を取り出し顕微鏡で観察して錆の発生した個数を測定する。
【００２７】
結果の判定は次の通りとする。（錆発生個数／テスト個数）
○：０／１０
□：１〜 ３／１０
△：４〜 ５／１０
×：６〜１０／１０
（３）音響性試験（アンデロン試験）
▲１▼ 玉軸受（内径８ｍｍ、外径２２ｍｍ、シールなし）を超音波洗浄器を用いてｎ−ヘキサン，アセトン，温メタノールの順で十分に洗浄し、５０℃×５分間乾燥する。 ▲２▼ これを試料原液の３重量％希釈液中に１分間浸漬して浸漬溶液から取り出し、６０℃，１０Ｔｏｒｒ以下の減圧乾燥器で１０分間乾燥させる。
【００２８】
▲３▼ 次いで、この玉軸受に市販の精密グリース（マルテンプＳＲＬ，商品名）を精密注射器を用いて０．２ ｇ注入し、アンデロン試験機（菅原研究所製）により音響試験（１８００ｒｐｍ，２分間）を行い、ノイズの発生状況をオシログラフに記録して（アンデロン値を測定）、音響性の良否を判定する。
結果の判定は次の通りとする。
【００２９】
○：１．２ アンデロン以下
×：１．２ アンデロン以上
（４）酸化劣化試験（軸受固化試験）
本試験はＪＩＳ Ｋ２２５０グリース類酸化安定性試験に準ずる。
▲１▼ 玉軸受（外径２２ｍｍ）を超音波洗浄器を用いてｎ−ヘキサン，アセトン，温メタノールの順で十分に洗浄し、５０℃×５分間乾燥する。
【００３０】
▲２▼ これを試料原液の３重量％希釈液中に１分間浸漬して浸漬溶液から取り出し、６０℃，１０Ｔｏｒｒ以下の減圧乾燥器で１０分間完全に乾燥させる。なお、この乾燥玉軸受は１試料当たり３個作成する。
▲３▼ 次いで、同一試料毎に３個の乾燥玉軸受を上下３段に重ねてポリエチレンシートで包んだ後、包装材の所々に小さな孔を開ける。
【００３１】
▲４▼ この包みをグリース類安定度試験機用ボンベ（ＪＩＳ Ｋ２２２０）に入れて、酸素封入圧７．７ ｋｇｆ／ｃｍ^２ ，試験温度１００℃，試験時間１９２時間で酸化試験（玉軸受表面被膜固化試験）を行う。
▲５▼ １９２時間経過後ボンベより包みを取り出し、室温まで放冷してから玉軸受を包みから取り出して、防錆被膜（試料油剤の乾燥被膜）の状態，玉軸受の回転状態（手回し），重ね面の腐食の状態を測定した。
【００３２】
結果の判定は次の通りとする。
○：被膜の固化なし、玉軸受回転は円滑、玉軸受の重ね面腐食なし
×：被膜固化、玉軸受回転しない、重ね面腐食あり
（５）水分蒸発試験（水分残存量の測定）
▲１▼ 玉軸受（外径２２ｍｍ）を超音波洗浄器を用いてｎ−ヘキサン，アセトン，温メタノールの順で十分に洗浄し、５０℃×５分間乾燥してから重量を精秤する。
【００３３】
▲２▼ この玉軸受を試料原液の３重量％希釈液中に１分間浸漬してから取り出し、６０℃，１０Ｔｏｒｒ以下の減圧乾燥器で３０秒間乾燥させ、その後速やかに精秤する。
▲３▼ ついで、この玉軸受を電量滴定式水分測定器（カールフィッシャー法，三菱化成ＣＡ−ＯＣ，商品名）により玉軸受表面被膜（試料油剤被膜）中の水分を測定し、下記式より水分残存量（ｐｐｍ）を計算する。
【００３４】
水分残存量＝〔Ｘ_１ ／（Ｗ_２ −Ｗ_１ ）〕−Ｘ_２ ／Ｗ_３
Ｘ_１ ：試料３重量％希釈液浸漬乾燥後の玉軸受の水分量
Ｘ_２ ：ブランク玉軸受の水分量
Ｗ_１ ：洗浄乾燥後の玉軸受の重量
Ｗ_２ ：試料３重量％希釈液浸漬乾燥後の玉軸受の重量
Ｗ_３ ：ブランク玉軸受の重量
結果の判定は次の通りとする。
【００３５】
○：水分残存量〜１０００ｐｐｍ以下
×：水分残存量〜１０００ｐｐｍ以上
以上の試験の結果を表１，２に示す。
【００３６】
【発明の効果】
以上説明したように、本発明によれば、特許請求の範囲に示される８種の成分を必須成分として特定量含有するものとしたことにより、従来一般的に使用されてきたＪＩＳ Ｋ２２４６に規定される溶剤希釈形さび止め油および潤滑油形さび止め油に相当する防錆油と同等またはそれ以上の優れた防錆性が得られるという効果を奏する。しかも、耐酸化劣化性および水分蒸発性が改善された結果、従来の水溶性防錆油剤にあって弱点とされていた音響性についても良好な成績が得られるという効果を奏する。
【００３７】
更に、本発明の水溶性防錆油剤組成物は水分散液として使用するもので石油系溶剤を使用しないから、環境を破壊するおそれもない。[0001]
[Industrial applications]
The present invention relates to a water-soluble material used for rust prevention in an intermediate process of manufacturing and assembling and assembling grease in the outer ring, inner ring, rolling elements and cages in the rolling bearing manufacturing process. The present invention relates to a rust-preventive oil composition, in particular, has excellent rust-preventive power and oxidative stability despite being water-soluble, and does not impair various properties such as vibration characteristics and acoustic characteristics of a rolling bearing. The present invention relates to a water-soluble rust preventive oil composition.
[0002]
[Prior art]
Rolling bearings are manufactured through processes such as processing individual components, assembling the processed parts, and filling grease into the assembled bearings. These processed parts are used for both cleaning and rust prevention. A rust inhibitor is applied. Conventionally, oil-based rust preventives such as NP-3 type rust preventive oil of solvent dilution type and NP-7 type rust preventive oil of lubricating oil type specified in JIS K2246 have been used as such rust preventive agents. Was. These oil-based rust preventives are generally obtained by adding a corrosion inhibitor to a petroleum base such as lubricating oil or petrolatum and dissolving or dispersing in a petroleum-based solvent. Form a film.
[0003]
[Problems to be solved by the invention]
However, if light hydrocarbons such as petroleum-based solvents are volatilized and released into the atmosphere, they will become one of the components of urban smog and cause environmental destruction. Regulations are becoming stricter. Therefore, as a countermeasure, it is conceivable to use a water-based water-soluble rust-preventive oil agent that does not contain light hydrocarbons, but in that case, the following various problems arise in terms of performance. ing.
[0004]
(1) The result of the acoustic test of the bearing after the grease is filled is inferior (the acoustic property is inferior).
That is, in the water-soluble rust preventive oil agent, a surfactant for emulsifying and dispersing the oil agent in water is an essential component. When an alkali metal compound such as an alkali salt of a fatty acid or an alkali salt of a sulfonic acid is used as the surfactant, the acoustic properties of the bearing deteriorate due to the influence of the alkali. Also, when a surfactant such as sorbitan monooleate or an amino compound such as alkanolamine is used, the rust-preventive oil film has poor oxidation resistance and tends to solidify, which results in deterioration of acoustic properties. In addition, there is also a tendency that if the residual amount of water in the rust-preventive oil film obtained by immersing the bearing in a water-soluble oil agent and drying is large, the acoustic properties are poor.
[0005]
(2) Rust prevention properties of the rust prevention oil film are poor.
That is, since the water-soluble rust-preventive oil agent contains a substance having a hydrophilic group such as a surfactant and an amine in the rust-preventive oil film, NP which is insoluble in high humidity conditions such as a wet test is used. Comparing the rust-preventive properties of an oil-based rust preventive such as -3, NP-7 and the like, and a water-soluble rust preventive oil, a tendency is observed that a water-soluble one is inferior to a water-insoluble one.
[0006]
Therefore, the present invention has been made in view of such a conventional problem, and has a water-soluble property which is superior to both oil-based rust preventives such as NP-3 and NP-7 in terms of both rust prevention and bearing acoustic properties. It is intended to provide a rust preventive oil composition.
[0007]
[Means for Solving the Problems]
The present invention that achieves the above objects,
10 to 25% by weight of higher fatty acids having 12 or more carbon atoms,
1 to 10% by weight of a fatty acid having 8 carbon atoms,
The general formula is

R ₁ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms R ₂ represents 10 to 25% by weight of an alkyl alkanolamine represented by an alkyl group having 1 to 3 carbon atoms,
5 to 20% by weight of alicyclic amine;
1 to 10% by weight of polyglycerin fatty acid ester,
1 to 10% by weight of an alkylaminosulfonate;
5-20% by weight of mineral oil,
It is characterized by containing 5 to 10% by weight of water as an essential component.
[0008]
[Action]
In the above configuration, the higher fatty acid having 12 or more carbon atoms reacts with the alkyl alkanolamine to form a fatty acid amine salt, and the fatty acid amine salt acts as an emulsifier for mineral oil. In addition, the fatty acid amine salt and the mineral oil both act as a lubricant, and the lubrication effect improves the acoustic properties of the bearing.
[0009]
In addition, it was experimentally confirmed that particularly excellent rust preventive properties were obtained by using a higher fatty acid having 12 or more carbon atoms and a fatty acid having 8 carbon atoms in combination.
Hereinafter, the present invention will be described in detail.
The present inventors have repeated studies on the improvement of acoustic properties in a water-soluble rust-preventive oil composition for bearings, and as a result, the following findings have been obtained.
(A) When the surfactant (anionic surfactant) used is not an alkali salt but an amine salt, the acoustic properties are improved.
(Ii) The use of dialkylalkanolamines instead of the commonly used alkanolamines improves the oxidation-deterioration resistance, thereby improving the acoustic properties.
(C) When polyglycerol fatty acid ester is used in place of polyhydric alcohol fatty acid ester which is a nonionic surfactant, acoustic properties are improved. Although this fact was a result other than a little, it is considered that polyglycerol fatty acid ester also has an effect of improving the resistance to oxidation deterioration, and therefore, the acoustic properties have been improved.
(D) Regarding the dispersion state of the water-soluble rust-preventive oil agent, the case of the emulsion state and the case of the soluble state with higher dispersibility were examined by comparing the water evaporation property of the coated rust-preventive oil film formed by treating the bearing. . As a result, in the soluble state, the evaporability was better, the amount of remaining water was smaller, and the acousticity was better.
(E) In the case where a fatty acid amine salt of an anionic surfactant is used, when a fatty acid having 12 or more carbon atoms and a fatty acid having 8 carbon atoms are used in combination, the rust prevention is remarkably improved.
[0010]
The present invention has been made based on the above findings.
The higher fatty acid used in the present invention has 12 or more carbon atoms. If the number of carbon atoms is less than 12, the resulting water-soluble rust-preventive oil composition has poor lubricating and acoustic effects and is unsuitable. It is sufficient that the number of carbon atoms is 12 or more. For example, it is not necessary to provide an upper limit to the number of carbon atoms because a polymerized fatty acid having 36 or 54 carbon atoms is also effective. It is. Specifically, lauric acid, myristic acid, palmitic acid, stearic acid, arachiic acid, behenic acid, lignoceric acid, oleic acid, erucic acid, linoleic acid, ricinoleic acid, and the like are within an appropriate range. Oleic acid and ricinoleic acid are most preferable because their amine salts have good emulsifiability, lubricity and acoustic properties.
[0011]
If the amount is less than 10% by weight, there is no effect, and if it exceeds 25% by weight, the composition loses its balance and becomes extremely viscous, which is not preferable.
In the present invention, caprylic acid having 8 carbon atoms is used as another fatty acid in combination with the higher fatty acid. It has been experimentally confirmed that a water-soluble rust-preventive oil composition having particularly excellent rust-preventive properties can be obtained by using both of them. Although the reason is not clear, the following possibilities are quite possible. That is, when higher fatty acid salt molecules having 12 or more carbon atoms are arranged on a metal surface to form a coating film, particularly, those having a long or short chain, such as salt molecules such as lauric acid, oleic acid, and ricinoleic acid. When used as a mixture, voids tend to form between molecules. In addition, when a molecule having a double bond and easily bendable such as oleic acid or a molecule having a hydroxyl group and having steric hindrance such as ricinoleic acid is mixed, the tendency is promoted. Small molecules of a fatty acid having a small number of carbon atoms enter the voids, and dense packing of the molecular film is obtained. As a result, an excellent rust preventive coating film is formed.
[0012]
Therefore, in order to densely fill gaps between higher fatty acid salt molecules forming the coating film, it is necessary that the size of the fatty acid molecule to be added is small, and the number of carbon atoms is set to eight. If the amount of addition is less than 1% by weight, the above void filling effect is not recognized. On the other hand, if it exceeds 10% by weight, the amine salt becomes excessive and acts as a penetrant, resulting in the side effect of destroying the molecules of the higher fatty acid salt-coated membrane formed.
[0013]
The alkyl alkanolamine used in the present invention reacts with the higher fatty acid having 12 or more carbon atoms to form a fatty acid amine salt, and functions as an emulsifier and a lubricant. This fatty acid amine salt does not solidify even if the rust preventive film covering the bearing surface is oxidized and degraded. (By the way, in the case of the alkanolamine salt used in the normal rust preventive oil, the rust preventive film solidifies when oxidized. Do). It has been experimentally found that it does not solidify and can be used in bearings to provide excellent acoustic properties. Specific examples of the alkylalkanolamine include N-methyldiethanolamine and N, N-dimethylmonoethanolamine. The addition amount is in the range of 10 to 25% by weight, and if it is less than 10% by weight, there is no effect. On the other hand, if it exceeds 25% by weight, the composition may be out of balance and separation may occur.
[0014]
Specific examples of the alicyclic amine used in the present invention include cyclohexylamine, dicyclohexylamine, and the like, which are components that improve rust prevention and balance the composition. The appropriate amount of addition is 5 to 20% by weight, and if it is less than 5% by weight, there is no effect. On the other hand, if it exceeds 20% by weight, the effect of balance is lost and troubles such as separation are caused to cause trouble. Appropriate.
[0015]
It has been found by the present inventors that the polyglycerin fatty acid ester used in the present invention has an action of preventing oxidative deterioration of a rust preventive film formed on a bearing surface, and sorbitan monooleate and pentaerythritol having no such action. It is used in place of polyhydric alcohol fatty acid esters such as dioleate. Polyhydric alcohol fatty acid ester also has the effect of dispersing moisture finely in the film when drying the rust preventive film and delaying the drying. However, the polyglycerol fatty acid ester does not have such a drawback, and therefore is also suitable as a component of the water-soluble rust-preventive oil composition of the present invention.
[0016]
Polyglycerin fatty acid ester has the molecular formula

Wherein R ₁ is an alkyl group having 12 to 24 carbon atoms, an alkenyl group, a condensed group, a hydroxyalkenyl group, a condensed group, and n is 1 to 9. Preferred specific examples thereof include tetraglycerin condensed ricinoleate and decaglycerin monooleate. The appropriate amount of addition is 1 to 10% by weight, and less than 1% by weight has no effect. On the other hand, if it exceeds 10% by weight, it causes separation of the diluting liquid and also deteriorates lubricating property, which is not suitable.
[0017]
The alkylaminosulfonate used in the present invention is a rust preventive, and has an effect of emulsification and dispersion. The appropriate amount of addition is from 1 to 10% by weight. If it is less than 1% by weight, there is no effect, and if it exceeds 10% by weight, the effect is not particularly increased and the cost is increased.
The mineral oil used in the present invention acts as a lubricity-imparting agent and a rust preventive film base, and mainly constitutes a rust preventive film together with the higher fatty acid having 12 or more carbon atoms and the fatty acid having 8 carbon atoms. Paraffin type lubricating oils (VG5-68) are suitable. An appropriate addition amount is 5 to 20% by weight, and if it is less than 5% by weight, the lubrication and rust prevention effects are not recognized because the rust preventive film base is insufficient. On the other hand, if it exceeds 20% by weight, the composition will lose its balance and cause obstacles such as separation, which is not suitable.
[0018]
The water used in the present invention is not a necessary component in terms of the performance of the rust-preventive oil agent, but is a component necessary to form a uniform and stable oil agent in balance with the above components. An appropriate range is from 10 to 10% by weight, and if it is less than 5% by weight or exceeds 10% by weight, the balance is lost and a uniform oil agent cannot be obtained, which is not suitable.
In the water-soluble rust-preventive oil composition of the present invention, in addition to the above components, a rust preventive such as diethanolamide oleate, a preservative, a fungicide, and a non-ferrous metal anticorrosive may be added in combination, if necessary. It is also preferable to do so.
[0019]
If the above components are uniformly mixed and dissolved, a stock solution of the rust preventive oil agent of the present invention can be obtained. It is not necessary to specify the order of mixing, but a higher fatty acid having 12 or more carbon atoms and a fatty acid having 8 carbon atoms are added to the mineral oil, mixed and dissolved, and then an alkyl alkanolamine is added thereto, and the mixture is stirred and reacted. It is preferable to add a cyclic amine, a polyglycerin fatty acid ester, and an alkylaminosulfonate in this order and stir, and finally add water and stir to obtain a uniform oil.
[0020]
The oil agent thus obtained is the stock solution of the present invention and is usually used as an aqueous dispersion of 1 to 20% by weight in use. The state of the aqueous dispersion becomes a transparent or translucent solution.
[0021]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
(A) Sample preparation:
Oleic acid (C ₁₇ H ₃₃ COOH), ricinoleic acid [C ₁₇ H ₃₂ (OH) COOH], and lauric acid (C ₁₁ H ₂₃ COOH) alone are used as higher fatty acids having 12 or more carbon atoms (hereinafter referred to as “fatty acid A”). Or a combination thereof, caprylic acid (C ₇ H ₁₃ COOH) is used as the fatty acid having 8 carbon atoms (hereinafter referred to as “fatty acid B”), and N-methyldiethanolamine is used as the alkyl alkanolamine.

Are used alone or in combination, dicyclohexylamine is used as an alicyclic amine, tetraglycerin-condensed ricinoleate and decaglycerin monooleate are used alone or in combination as polyglycerin fatty acid ester, and mineral oil is P System, VG10, and furthermore, aminosulfonate, diethanolamine oleate, and diethanolamide caprylate are used alone or in combination as an organic rust inhibitor and a surfactant, and these components are added to water according to the formulation (% by weight) shown in the table. To obtain the sample stock solutions of Examples 1 to 7 shown in Table 1.
[0022]
On the other hand, for comparison, alkanolamine was used in place of the alkyl alkanolamine in the above examples.

And using either polyglycerin fatty acid ester or polyhydric alcohol ester selectively and dispersing each component uniformly in water according to the formulation (% by weight) shown in Table 2, Comparative Examples 8 to 13 A sample stock solution was prepared. A commercially available rust-preventive oil (NP-7 type) was used as Comparative Example 14.
[0023]
[Table 1]

[0024]
[Table 2]

[0025]
The following performance tests were carried out on the 3% by weight aqueous dispersions of the above sample stock solutions.
(B) Test content:
(1) Appearance A 3% by weight dilution of distilled water was placed in a glass sample bottle, and the appearance was visually observed.
S: Transparent or translucent E: Milky white emulsion Separation: Separation into two layers (2) Rust prevention test (bearing wetness test)
{Circle around (1)} Ten ball bearings (22 mm in outer diameter) are washed with an ultrasonic cleaner (BRANSON 2200, trade name) in the order of n-hexane, acetone and warm methanol for 1 minute each and dried.
[0026]
{Circle around (2)} This is immersed in a 3% by weight diluted solution of the sample stock solution for 1 minute, taken out of the immersion solution, and dried for 10 minutes in a vacuum dryer at 60 ° C. and 10 Torr or less.
{Circle around (3)} The ball bearing is placed in a thermo-hygrostat at a temperature of 40 ° C. and a relative humidity of 90% and left for one week. Thereafter, the ball bearing is taken out and observed with a microscope to measure the number of rusts.
[0027]
The result is determined as follows. (Rust generation number / test number)
○: 0/10
□: 1 to 3/10
Δ: 4 to 5/10
×: 6 to 10/10
(3) Acoustic test (Anderon test)
{Circle around (1)} A ball bearing (inner diameter 8 mm, outer diameter 22 mm, no seal) is sufficiently washed with an ultrasonic cleaner in the order of n-hexane, acetone and warm methanol, and dried at 50 ° C. × 5 minutes. {Circle around (2)} This is immersed in a 3% by weight diluted solution of the sample stock solution for 1 minute, taken out of the immersion solution, and dried for 10 minutes in a vacuum dryer at 60 ° C. and 10 Torr or less.
[0028]
{Circle around (3)} Then, 0.2 g of commercially available precision grease (Multemp SRL, trade name) was injected into the ball bearing using a precision syringe, and an acoustic test (1800 rpm, 2 minutes) was performed with an Anderon tester (manufactured by Sugawara Laboratories). ) To record the noise generation status on an oscillograph (measurement of the Anderon value) to judge the quality of the acoustic property.
The result is determined as follows.
[0029]
：: less than 1.2 anderon ×: more than 1.2 anderon (4) Oxidation deterioration test (bearing solidification test)
This test conforms to the JIS K2250 grease oxidation stability test.
{Circle around (1)} A ball bearing (outer diameter: 22 mm) is sufficiently washed with an ultrasonic cleaner in the order of n-hexane, acetone, and warm methanol, and dried at 50 ° C. for 5 minutes.
[0030]
{Circle around (2)} This is immersed in a 3% by weight diluted solution of the sample stock solution for 1 minute, taken out of the immersion solution, and completely dried for 10 minutes in a vacuum dryer at 60 ° C. and 10 Torr or less. In addition, three dry ball bearings are prepared for each sample.
{Circle around (3)} Next, three dry ball bearings are stacked on the upper and lower three stages for the same sample and wrapped with a polyethylene sheet, and small holes are made in places of the packing material.
[0031]
(4) Put this package in a cylinder (JIS K2220) for a grease stability tester, and perform an oxidation test (ball bearing surface coating) at an oxygen charging pressure of 7.7 kgf / cm ² , a test temperature of 100 ° C, and a test time of 192 hours. Solidification test).
(5) After lapse of 192 hours, the package is taken out of the cylinder, allowed to cool to room temperature, and then the ball bearing is taken out of the package, and the state of the rust-preventive film (dry film of the sample oil), the rotational state of the ball bearing (hand-operated), The state of corrosion of the overlapping surface was measured.
[0032]
The result is determined as follows.
：: No solidification of the coating, smooth rotation of the ball bearing, no corrosion of the overlapping surface of the ball bearings ×: Solidification of the coating, no rotation of the ball bearing, corrosion of the overlapping surface (5) Water evaporation test (measurement of residual moisture)
{Circle around (1)} A ball bearing (outer diameter: 22 mm) is sufficiently washed with an ultrasonic cleaner in the order of n-hexane, acetone and warm methanol, dried at 50 ° C. × 5 minutes, and then precisely weighed.
[0033]
{Circle around (2)} This ball bearing is immersed in a 3% by weight diluted solution of the sample stock solution for 1 minute, taken out, dried in a vacuum drier at 60 ° C. and 10 Torr or less for 30 seconds, and immediately weighed immediately.
{Circle around (3)} Then, the water content of the ball bearing surface coating (sample oil coating) was measured using a coulometric titration moisture meter (Karl Fischer method, Mitsubishi Kasei CA-OC, trade name). Calculate the residual amount (ppm).
[0034]
Moisture remaining amount = _{[X 1 / (W 2 -W 1} ) ] _- X 2 / _{W 3}
X ₁ : Water content of ball bearing after immersion and drying of sample 3% by weight diluted solution X ₂ : Water content of blank ball bearing W ₁ : Weight of ball bearing after washing and drying W ₂ : After immersion and drying of sample 3% by weight diluted solution The weight of the ball bearing W ₃ : The determination of the weight result of the blank ball bearing is as follows.
[0035]
：: Residual water content up to 1000 ppm or less X: Test results of residual water content up to 1000 ppm or more are shown in Tables 1 and 2.
[0036]
【The invention's effect】
As described above, according to the present invention, the eight kinds of components described in the claims are contained in a specific amount as an essential component, and thus are defined in JIS K2246 which has been generally used conventionally. This has the effect of providing excellent rust-preventive properties equivalent to or better than rust-preventive oils corresponding to solvent-diluted rust preventive oils and lubricating oil-type rust preventive oils. In addition, as a result of the improvement in resistance to oxidation deterioration and evaporation of water, there is an effect that good results can be obtained for acoustic properties which have been regarded as weak points in conventional water-soluble rust preventive oils.
[0037]
Furthermore, since the water-soluble rust-preventive oil composition of the present invention is used as an aqueous dispersion and does not use a petroleum-based solvent, there is no possibility of damaging the environment.

Claims (1)

10 to 25% by weight of higher fatty acids having 12 or more carbon atoms,
1 to 10% by weight of a fatty acid having 8 carbon atoms,
The general formula is

R ₁ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms R ₂ represents 10 to 25% by weight of an alkyl alkanolamine represented by an alkyl group having 1 to 3 carbon atoms,
5 to 20% by weight of alicyclic amine;
1 to 10% by weight of polyglycerin fatty acid ester,
1 to 10% by weight of an alkylaminosulfonate;
5-20% by weight of mineral oil,
A water-soluble rust-preventive oil composition comprising 5 to 10% by weight of water as an essential component.