JP5571971B2 - Metalworking oil composition - Google Patents

Description

  The present invention relates to a metalworking oil composition, and more particularly to a metalworking oil composition that is used for cutting or grinding, and that is particularly lubricious and excellent in rust prevention.

  When metal is machined or ground, a machining fluid is used for the purpose of improving machining accuracy and extending tool life. Metalworking oil contains lubricants, extreme pressure additives, metal corrosion inhibitors, rust inhibitors, preservatives, antifoaming agents, etc., and their types and blending ratios depend on the desired processing material and finish. Various formulations are made depending on differences in accuracy or processing conditions. Water-insoluble metal processing oils containing mineral oil as a main component lead to ignition hazards due to higher processing speeds and higher feed rates, and environmental deterioration due to oil smoke and mist. Water-soluble metalworking oil is frequently used for economic reasons such as improvement of these dangers and environmental deterioration, or reduction of total cost. Among them, water-soluble metalworking oils mainly composed of water that is particularly excellent in cooling properties and not flammable are often used.

  However, since the water-soluble metal processing oil is further diluted with water and used, it has excellent cooling properties, but it also causes rust in processed products and processing machines. In order to solve this problem, nitrite has long been used, but nitrite produces nitrosamine by reaction with alkanolamine, and there is a concern of carcinogenicity. As an alternative to these, according to Patent Document 1, a mixture of a fatty acid, a dibasic acid and an alkanolamine or a cyclic amine is used, but it is superior in rust prevention as compared with a combination of a nitrite and an alkanolamine. Is currently not on the market.

According to Patent Document 2, polyethyleneimine is used as a rust preventive, but when polyethyleneimine and fatty acid are mixed, polyethyleneimine and fatty acid react to produce a component insoluble in water. There is a problem that leads to contamination of the machine.
Japanese Patent Laid-Open No. 11-209774 JP 2005-15617 A

  In consideration of the above problems, the present invention provides a metalworking oil composition that does not contain nitrite and has an anti-rust and anti-rust agent that is practically satisfactory by selecting an optimal anti-lubricating agent, and further has lubricity. Is to provide.

  As a result of repeated studies to solve the above problems, the present inventors have found a metalworking oil composition that is optimal for the above problems, and have completed the present invention. That is, the present invention comprises a compound obtained by adding 0.1 to 30 alkylene oxides per active hydrogen bonded to the nitrogen atom to polyethyleneimine having a molecular weight of 300 to 30,000. A metalworking oil composition.

  Since the water-soluble metalworking oil composition of the present invention is excellent in rust prevention and lubricity, it prevents the occurrence of rust on the workpiece and processing machine in metalworking, and also has excellent lubricity. It also provides practically satisfactory effects in an environment related to waste reduction, such as stable production, reduction of processing machine load, and reduction of processing tool consumption.

Hereinafter, the present invention will be described in detail.
The polyethyleneimine used in the present invention is a polymer of ethyleneimine, and includes those having a branched structure containing primary, secondary, and tertiary amines in addition to linear polymers. The molecular weight is in the range of 300 to 30,000, but is preferably 1,000 to 15,000 in terms of rust prevention. In addition, the number of active hydrogen couple | bonded with the nitrogen atom in the polyethyleneimine mentioned later can be calculated from the amine ratio by ¹³ C-NMR, for example.

  Examples of the alkylene oxide added to the polyethyleneimine include alkylene oxides having 2 to 4 carbon atoms, specifically ethylene oxide, propylene oxide, and butylene oxide. Propylene oxide or The combined use of ethylene oxide and propylene oxide is preferred. When a plurality of types of alkylene oxide are added, the addition form may be block addition or random addition. The number of added moles of alkylene oxide is 0.1-30, preferably 1-20, more preferably 1.5-15, per active hydrogen bonded to the nitrogen atom of the polyethyleneimine.

  Addition of alkylene oxide to polyethyleneimine may be by any method. Usually, when the number of added moles of alkylene oxide per active hydrogen of polyethyleneimine is 1.0 or less, alkylene oxide is added without a catalyst. When the added mole number of alkylene oxide is more than 1.0, 1.0 mole of alkylene oxide is added without a catalyst, and then alkylene oxide is appropriately added under a basic catalyst.

  The alkylene oxide adduct of polyethyleneimine according to the present invention can be used alone or in admixture of two or more, and the blending ratio is 0.1 to 0.1% when the total amount of the metalworking oil composition is 100% by mass. 30% by mass, preferably 0.5-20% by mass, more preferably 1-10% by mass. When the amount is less than 0.1% by mass, the rust prevention property is deteriorated, and when the amount is more than 30% by mass, a further effect cannot be obtained.

  The metalworking oil composition of the present invention contains the above-mentioned compound as an essential component, but usually contains several types of surfactants, among which anionic surfactants and nonionic surfactants are often used. . The composition of the present invention can also be used in combination with the surfactants listed below to obtain a composition with more excellent rust prevention and lubricity.

  Examples of the anionic surfactant include amine salts and alkali metal salts of carboxylic acids, and alkali metal salts of sulfonic acids. As carboxylic acids, those having about 8 to 30 carbon atoms are generally used, and caprylic acid, 2-ethylhexanoic acid, pelargonic acid, 3,5,5-trimethylhexanoic acid, isononanoic acid, lauric acid, myristic acid, palmitic acid. , Stearic acid, behenic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, adipic acid, sebacic acid, dodecanedioic acid, alkenyl succinic acid and the like. Examples of amines include monoethanolamine, diethanolamine, triethanolamine, propanolamine, isopropanolamine, diisopropanolamine, 2-amino-2-methylpropanol, n-butanolamine, isobutanolamine, t-butanolamine, and n-butyl. Ethanolamine, isobutylethanolamine, t-butylethanolamine, n-butyldiethanolamine, isobutyldiethanolamine, t-butyldiethanolamine, diglycolamine, morpholine, methylmorpholine, ethylmorpholine, cyclohexylamine, dicyclohexylamine, ethylenediamine, diethylenetriamine, tri Ethylenehexamine, hexaethylenepentamine, pentaethylenehexamine and alkylenes of these amines There is Kisaido adduct is sodium, potassium or the like alkali metal. As a more preferable combination, sebacic acid, dodecanedioic acid, octylic acid, and 3,5,5-trimethylhexanoic acid are used as the carboxylic acid. Examples of the amine include monoethanolamine, monoisopropanolamine, 2-amino-2-methylpropanol, n-butylethanolamine, diglycolamine, and triethanolamine.

  Examples of the nonionic surfactant include alkylene glycol, polyoxyalkylene glycol, polyoxyalkylene alkyl ether, sorbitan fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, and polyoxyalkylene glycol fatty acid ester. In addition to the above, there are various surfactants generally used in metalworking oils, but there is no particular limitation in the present invention, and these surfactants can be used alone or in combination of two or more. Can also be used.

  In addition to the above components, the metalworking oil of the invention may be blended with mineral oil and extreme pressure additives to improve processability, taking into consideration secondary performance aspects, metal corrosion inhibitors, preservatives, Although a foaming agent etc. are mix | blended, it is possible to mix | blend suitably also according to the objective also about the composition of this invention. In addition, when using about the composition of this invention, it dilutes in water normally, but the dilution density | concentration at that time is 1-25 mass%, and is suitably adjusted with processing conditions etc.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these.
Synthesis example
In order to obtain a compound obtained by adding 2 moles of propylene oxide per active hydrogen of polyethyleneimine, first, propylene per mole of Epomin SP-200 (manufactured by Nippon Shokubai; active hydrogen number of about 244) is a polyethyleneimine having a nominal molecular weight of about 10,000. The oxide was reacted at about 244 mol under a temperature range of 120 to 160 ° C. and a pressure of 0.7 MPa or less. Subsequently, potassium hydroxide was added as a catalyst, and after dehydration, about 244 mol of propylene oxide was further added under a temperature range of 120 to 160 ° C. and a pressure of 0.7 MPa or less to obtain the target compound. A compound in which the number of added moles of alkylene oxide was changed was synthesized in the same manner.

  As Examples 1 to 7 and Comparative Examples 1 to 5, metal working oil compositions blended at the ratios shown in Table 1 were prepared, and the results of the following tests on the compositions are shown in Table 1.

(1) Dilution stability test: The stability of the dilution was observed when the compositions of Examples and Comparative Examples were diluted 20 times with water and allowed to stand at room temperature for 7 days.
Judgment criteria: ○ ··· No separation of diluent
× ··· Separation of diluted solution (2) Rust prevention test: SCR440 (chromium steel) having a diameter of 0.5 mm and a length of 10 cm of 30 ml of the compositions of Examples and Comparative Examples diluted 20 times with water ) To remove excess liquid, and stored for 2 days in an environment of a temperature of 40 ° C. and a humidity of 98%.
Judgment criteria: ◎ ····· No rust observed
○ ... Slight rusting is observed
X: Generation of rust observed on the entire surface (3) Lubricity test: traverse plane in SUS304 under the following conditions for the compositions of Examples and Comparative Examples diluted 20 times with water The dressing time value of the grindstone during grinding was measured.
Grinding tool: WA80M
Evaluation conditions Grinding speed: 1100m / min
Feeding: 12m / min
Cutting depth: 0.004mm / 1 traverse

Evaluation Method The traverse process was repeated, and the lubricity of the metal oil agent was evaluated from the total processing depth when the surface roughness Ra of the processed surface exceeded 0.36 μm according to the following criteria.
Judgment criteria: ○ ・ ・ ・ ・ 1.0mm or more
× ... less than 1.0mm

  From the above results, the metalworking fluid composition according to the present invention obtained practically satisfactory results in all aspects of dilution stability, rust prevention and lubricity. In particular, when compared with Comparative Examples 1, 4 and 5, good performance was obtained in rust prevention. Therefore, the composition of the present invention obtained better performance than the example using polyethyleneimine, nitrite and cyclic amine. In addition, this invention can be used according to the objective and application not only in the said Example.

Claims (1)

A compound obtained by adding 1 to 5 alkylene oxides per active hydrogen bonded to the nitrogen atom to polyethyleneimine having a molecular weight of 300 to 30,000, and an amine salt or alkali of a carboxylic acid having 8 to 30 carbon atoms A water-soluble cutting / grinding oil composition comprising a metal salt .