JPH0768538B2 - Metal working oil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metal working oil, and more specifically, as a base oil for an aqueous metal working oil such as a cutting oil, a drawing oil, a rolling oil, and a press oil. It relates to an ester suitable for use.

[Conventional technology]

Water-based metalworking oils such as cutting oils, drawing oils, rolling oils, and press oils generally use animal and vegetable oils and mineral oils as base oils, and when improving oiliness, extreme pressure additives, rust preventives, antioxidants, It is used as an emulsion of 1 to 30% by adding an emulsifier and the like. The properties required of the water-based metalworking oil are, in addition to good lubricity, stable emulsion state, good antioxidant property, good rust preventive property, and preferably microbial growth. There is no deterioration due to.

In order to improve lubricity, higher fatty acids have been conventionally used as an oiliness improver. Typical examples thereof include unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid and erucic acid. It is generally known that the chain length of fatty acids increases and the lubricity improves.
However, since the melting point of fatty acids increases with the chain length, which is not desirable, higher fatty acids having unsaturated bonds as described above have become the mainstream for applications in aqueous metal working oils. On the other hand, the unsaturated bond has a drawback that it is essentially susceptible to oxidation.

Also, higher fatty acid monoalkyl esters and the like are used as oiliness improvers. However, in order to obtain a stable emulsified state, it is not only necessary to add a large amount of a surfactant, but also if this surfactant remains on the metal surface, oil stains are likely to occur. Further, it is difficult to control the concentration of the surfactant at a constant level in the actual use condition.

Regarding rust resistance, nitrite and alkanolamine cannot be used in combination due to public health problems of nitrosamine, and now inorganic salts other than nitrite such as phosphate, borate and molypdenate, Alkanolamines and organic inhibitors are mainly used. However, it is difficult to say that the effect of adding these is sufficient.

In the case of water-based metal working oils, especially water-based cutting oils, the life of the working oil is often determined by the spoilage phenomenon. The spoilage phenomenon is caused by the growth of microorganisms, and as a result, problems such as a decrease in pH, a decrease in rust-preventing property, and the generation of a spoiled odor occur. In order to prevent this, the current situation is to carry out complicated management such as selection of dilution water, maintenance of an appropriate concentration, maintenance of pH, and regular addition of preservatives.

There is a demand for a water-based metalworking oil that not only has excellent lubricity and emulsion stability, but also sufficiently satisfies various properties such as antioxidative property, rust preventive property and antiseptic property.

[Problems to be solved by the invention]

The present invention intends to obtain an aqueous metalworking oil excellent in lubricity and emulsion stability, as well as in antioxidant property, rust preventive property and antiseptic property, by using a specific base oil. .

[Means for solving problems]

The present inventors have conducted extensive studies to obtain an aqueous metalworking oil satisfying good lubricity, excellent emulsion stability, antioxidant property, rust preventive property and antiseptic property, and as a result, a specific compound is used as a base oil. The inventors have found that they are excellent and have completed the present invention.

That is, the present invention relates to a hydroxyaryl fatty acid and a general formula (I) HOAnR (I) Ester with alcohol represented by or its alkylene oxide adduct (addition mole number m is 1 to 50, n and m
Of 50 or less) is contained in the metalworking oil.

The hydroxyaryl fatty acid used in the present invention is an aryl fatty acid containing a phenolic hydroxyl group in the molecule. In particular, in terms of the effect of achieving the purpose, the general formula Hydroxyaryl fatty acids represented by are suitable.
Specific examples of this hydroxyaryl fatty acid include:
Hydroxyphenylmyristic acid, hydroxyphenylpalmitic acid, hydroxyphenylstearic acid, hydroxyphenyloleic acid, hydroxyphenylbehenic acid, dihydroxyphenylpalmitic acid, trihydroxyphenylstearic acid, hydroxymethylphenylstearin Acids, hydroxynonylphenylstearic acid, hydroxydimethylphenylstearic acid, hydroxymethoxyphenylpalmitic acid, hydroxymethoxyphenylstearic acid and the like.

The alcohol used as the raw material of the ester used in the present invention has the general formula (I) HOAnR (I) And a monohydric alcohol having 1 to 28 carbon atoms or an alkylene oxide such as ethylene oxide, propylene oxide or butylene oxide added to the monohydric alcohol. Specific examples of the monohydric alcohol having 1 to 28 carbon atoms include natural alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, heptyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol, and oleyl alcohol, and reducing alcohols and petrochemicals. Alkyl phenols such as synthetic higher alcohols, nonylphenol and octylphenol. When the number of carbon atoms is more than 28, a large amount of surfactant is required to bring the derived compound into a stable emulsified state, which is not preferable. When the alkylene oxide is added to the monohydric alcohol, one kind or two or more kinds of the alkylene oxide can be used. When two or more kinds of alkylene oxides are used, block addition or random addition may be used, but block addition is preferable. The number of moles of alkylene oxide added is
When it exceeds 50, the lubricity is deteriorated, which is not preferable.
An alcohol having an addition mole number of 6 to 40 and 50% by weight or more of the addition alkylene oxide weight being ethylene oxide is preferable because an ester with a hydroxyaryl fatty acid has self-emulsifying property. When it is not self-emulsifying, a small amount of surfactant is required to obtain a stable emulsified state.

The esterification reaction of the hydroxyaryl fatty acid and the alcohol represented by the general formula (I) can be carried out by an acid catalyst or a non-catalytic reaction in the same manner as a usual esterification reaction. The reaction molar ratio of the hydroxyaryl fatty acid and the alcohol is not particularly specified, but a reaction molar ratio of forming a monoester is desirable. The esterification reaction may be stopped when the unreacted hydroxyaryl fatty acid remains.

The alkylene oxide adduct of an ester of a hydroxyaryl fatty acid and an alcohol represented by the general formula (I) can be obtained by adding an alkylene oxide to an ester in the same manner as a usual alkylene oxide addition reaction. Examples of the alkylene oxide to be added include ethylene oxide, propylene oxide and butylene oxide, and one or more of these can be used. When two or more alkylene oxides are used, block-like addition or random-like addition may be performed.
Block addition is preferred. If the number of moles of alkylene oxide added is more than 50, the lubricity decreases, which is not preferable. An adduct having an addition mole number of 6 to 40 and 50% by weight or more of the weight of the added alkylene oxide being ethylene oxide is preferable because it has self-emulsifying property.

When an alkylene oxide adduct is used as the alcohol represented by the general formula (I), the total number of moles of alkylene oxide adducts of the alkylene oxide adduct of the ester of the hydroxyaryl fatty acid and the alcohol represented by the general formula (I) (alcohol If the sum of the number of moles of alkylene oxide added to and the number of moles of alkylene oxide added to the ester) is more than 50, the lubricity decreases, which is not preferable. An adduct in which the total number of added moles is 10 to 40 and 50% by weight or more of the weight of the added alkylene oxide is ethylene oxide is preferable because it has self-emulsifying property.

Hydroxyaryl fatty acids are generally liquid at room temperature and are known to have antioxidative properties, antirust properties and antibacterial properties. Therefore, when this hydroxyaryl fatty acid is used, a derivative having excellent antioxidative property, anticorrosive property and antibacterial property can be obtained.

The ester of the hydroxyaryl fatty acid and the alcohol represented by the general formula (I) or the alkylene oxide adduct thereof of the present invention can be used not only as a base oil of an aqueous metalworking oil, but also as a natural animal and vegetable oil or a synthetic ester oil. , And mixed with mineral oil.

〔The invention's effect〕

By using the ester of the present invention or its alkylene oxide adduct, not only excellent lubricity and emulsion stability, but also sufficient performance in terms of oxidation stability, rust prevention and antibacterial property You can get oil.

The aqueous metal working oil containing the ester of the present invention or its alkylene oxide adduct can be widely used as a cutting oil, a drawing oil, a rolling oil, a press oil, and the like.

〔Example〕

 The present invention will be described with reference to examples.

The hydroxyaryl fatty acids used in the examples are shown in Table 1. These hydroxyaryl fatty acids were synthesized according to the previous patent application (Japanese Patent Application No. 60-149250).

The ester of hydroxyaryl fatty acid and alcohol was synthesized according to the following method.

Esterification: Equimolar amounts of hydroxyaryl fatty acid and alcohol were placed in a 1-necked flask and the total weight was adjusted to 0.3
Para-toluenesulfonic acid (wt%) was added, the temperature was raised to 160 ° C. while nitrogen gas was passed through, and the esterification reaction was carried out for 4 hours. If the esterification reaction is allowed to proceed sufficiently, 50
The reaction was further performed at mmHg for several hours.

The addition of alkylene oxide to the ester was performed according to the following method.

Addition reaction: 1.5% by weight of potassium hydroxide was added to the ester of hydroxyaryl fatty acid and dehydrated at 70 ± 5 ° C. and 20 mmHg for 0.5 hours, and then a predetermined amount of alkylene oxide was added dropwise at 120 ° C. under normal pressure or pressure. The reaction was carried out at ˜130 ° C. for 3 to 6 hours. After completion of the dropping, the reaction was completed by holding at 120 ° C. for 1 hour. Then, dealkylene oxide is added to 80
It was performed at ± 5 ° C. and 100 mmHg for 0.5 hours. Then, the alkali was neutralized with 5 to 15% hydrochloric acid, dehydrated at 100 ± 5 ° C. and 20 mmHg for 1 hour, and then passed.

Example 1. Various esters consisting of hydroxyaryl fatty acid and alcohol and alkylene oxide adducts thereof (Table-
2, test numbers 1-27) were evaluated for emulsification and lubricity.

Emulsification test: Performed according to JIS K-2520 Lubricating oil anti-emulsification test method. That is, a sample container containing 4 ml of ester and 76 ml of water was placed in a constant temperature bath at 54 ± 1 ° C and kept at a constant temperature, then 1500 ± 15
The mixture was emulsified by mixing for 5 minutes with a sample stirrer rotating at RPM. This emulsion was left standing in a thermostatic chamber at 20 ° C., and the emulsified state after one week was observed.

The results are summarized in Table 2 when the emulsion was in a stable emulsified state and in the case of phase separation or uniform dissolution as x.

Lubricity test: The emulsion was tested under the following conditions using a Ciel type high-speed four-ball tester, and the lubricity was evaluated by the size of the wear diameter (mm).

Rotational speed: 1,500 RPM Load: 50 Kg / cm ² Hour: 30 minutes The results obtained are summarized in Table-2.

Example 2. Emulsification and lubricity of an emulsion obtained by emulsifying an ester of hydroxyaryl resin acid and alcohol and its alkylene oxide adduct with a surfactant were evaluated.

Polyoxyethylene (20 mol) sorbitan monooleate as a surfactant, 4 ml of ester or adduct and water 7
0.2 g was used for a total volume of 6 ml. Otherwise, Example 1
The results obtained are shown in Table 3 together.

Example 3. Emulsification and lubricity were evaluated when the ester of hydroxyaryl fatty acid and alcohol of the present invention and its alkylene oxide adduct were used as a mixture with other oils.

The procedure was as in Example 2 except that 2 ml of the ester or adduct of the invention and 2 ml of another oil were used. The obtained results are summarized in Table-4.

Table 4 also shows the results obtained with 2 ml of the comparative ester and 2 ml of the other oil and with 4 ml of 60 spindle oil only.

As is clear from the results of Tables 2 to 4, the ester of hydroxyaryl fatty acid and alcohol of the present invention and its alkylene oxide adduct can be in a stable emulsified state alone, and if necessary, a small amount of surface active A stable emulsified state can be obtained by using the agent. Furthermore, even if it is used in combination with other oils, a stable emulsified state can be obtained.

Further, it is understood that the ester of the present invention and its alkylene oxide adduct are excellent in lubricity either alone or in combination with other oils.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C10N 30:12 40:22 40:24 Z

Claims (1)

[Claims] 1. A hydroxyaryl fatty acid and a general formula (I) HOAnR (I) Ester with alcohol represented by or its alkylene oxide adduct (addition mole number m is 1 to 50, n and m
Is 50 or less).