JPH04202298A - Water soluble cutting oil - Google Patents

Abstract

PURPOSE:To provide the title oil improved in the prevention of foaming, rust proofness and storage stability by using an alkali metal salt and/or amine salt of a specific condensed fatty acid. CONSTITUTION:A condensed fatty acid with an acid value of 55-130 is prepared by subjecting a monohydroxy fatty acid (e.g. 12-hydroxy-9-octadecenoic acid) or a mixture thereof with 60wt.% or less of a dihydroxy fatty acid to a dehydration condensation at 100-200 deg.C for 30min to 8hr in an inert gas atmosphere. The condensed fatty acid is neutralized with an alkali metal hydroxide (e.g. NaOH) or an amine compound (e.g. ammonia) to obtain an alkali metal salt or amine salt of the condensed fatty acid. The title cutting oil is prepared by dissolving 0.1-50wt.% of the obtained salt in water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a water-soluble cutting fluid. More specifically, the present invention relates to a water-soluble cutting fluid that has low foaming properties and excellent rust prevention properties and is used in metal processing such as cutting and grinding.

[Prior Art] Conventionally, water-soluble cutting fluids have been widely used for metal processing such as cutting and grinding, as they have excellent cutting performance and grinding performance, and have good cooling efficiency. These water-soluble cutting fluids are mainly composed of alkali metal salts or amine salts of naphthenic acids, rosin acids, fatty acids, etc. - They tend to foam during boat fishing, especially alkali metal salts of fatty acids. The workability is reduced due to the bubbles produced, and there is also the disadvantage that the processed materials may become rusty or corroded.

Water-soluble cutting fluids have been reported that improve these drawbacks and have low foaming and rust prevention properties.

For example, water-soluble cutting fluids using epoxidized fatty acids or salts of polyhydroxylated fatty acids obtained by hydrating them (Japanese Patent Application Laid-open No. 88096/1983), alkali metal salts of ricinoleic acid polycondensates, or amine salts. Water-soluble cutting fluids (Japanese Patent Publication No. 2-5799) and the like are known.

[Problems to be Solved by the Invention] However, these conventionally known water-soluble cutting fluids do not exhibit sufficient effects when used in cutting and grinding.

For example, when using epoxidized fatty acids for a long period of time in an aqueous solution state, the epoxy groups gradually become hydrated and become hydroxyl groups, resulting in low stability over time, and those using polyhydroxylated fatty acid salts Although it has excellent water solubility, it has the problem of insufficient lubricity during cutting. In addition, methods using alkali metal salts or amine salts of ricinoleic acid polymers contain a large amount of double bonds in the molecule and polymerize during use, making the solution unstable and causing problems such as separation and metal surfaces. However, there were disadvantages such as generation of sludge or increase in viscosity.

The present invention was developed in view of the above-mentioned problems, and when used as a water-soluble cutting fluid, it exhibits excellent cutting performance and grinding performance, has excellent rust prevention properties, storage stability, and has low foaming properties. The purpose of the present invention is to provide a certain water-soluble cutting fluid.

[Means for Solving the Problems] As a result of intensive research to solve the above problems, the present inventors have developed a specific compound that is a polycondensate of hydroxy compounds and has a hydroxyl group in its side chain. In order to complete the present invention, we have found a water-soluble cutting fluid that has excellent cutting performance and grinding performance, has excellent rust prevention properties, excellent storage stability, and has low foaming properties by using it as a water-soluble cutting fluid. It's arrived.

That is, one of the gist of the present invention is a water-soluble cutting fluid that uses an alkali metal salt and/or amine salt of a condensed fatty acid obtained by dehydration condensation of a dihydroxy fatty acid, and another gist is a water-soluble cutting fluid that uses a dihydroxy fatty acid and a monohydroxy fatty acid. This is a water-soluble cutting fluid that uses alkali metal salts and/or amine salts of condensed fatty acids obtained by dehydration condensation of these fatty acids individually or in combination.

Examples of monohydroxy fatty acids used in the present invention include monohydroxy fatty acids obtained by hydrolyzing and refining vegetable oils, waxes, etc. by conventional methods, and examples of dihydroxy fatty acids include dihydroxy fatty acids obtained from unsaturated fatty acids. The former monohydroxy fatty acid includes 12-hydroxy-9-octadecenoic acid obtained from castor oil, and the latter dihydroxy fatty acid is produced by using unsaturated fatty acids as raw materials and introducing hydroxyl groups into their unsaturated bonds. Dihydroxy fatty acids obtained are mentioned.

A method for introducing a hydroxyl group into an unsaturated fatty acid is to react the unsaturated fatty acid with a peroxide such as peracetic acid or hydrogen peroxide, epoxidize the unsaturated bond, and then hydrolyze the epoxy group. h) A method of introducing a 0xyl group can be mentioned.

As the above reaction, the pure content of unsaturated fatty acids is 0.2 to 0.
．． Examples include adding 5% by weight of peroxide and reacting at 40 to 80°C for 1 to 5 hours in the presence of a catalyst such as formic acid, phosphoric acid, or sulfuric acid. is epoxidized, and the epoxy group is then hydrated to become a hydroxy group.

After the reaction is completed, the catalyst and excess peroxide are removed from the reaction mixture by washing with water, and the mixture is dehydrated at about 50 to 120°C to obtain dihydroxy fatty acids. Examples of the unsaturated fatty acids used here include lauroleic acid, myristioic acid, seamarinic acid, oleic acid, elaidic acid, linoleic acid, liluic acid, ricinoleic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, etc. The unsaturated fatty acids are
They can be used alone or in combination of two or more.

In addition, the unsaturated fatty acids mentioned above include soybean oil, olive oil, tall oil, lard, chicken oil, castor oil, cottonseed oil, bran oil,
Fatty acids obtained by decomposing and concentrating animal and vegetable oils such as rapeseed oil and fish oil according to a conventional method can be used, and it is preferable that the fatty acids of the oils and fats contain at least 80% by weight of unsaturated fatty acids.

The condensed fatty acid used in the present invention is obtained by dehydration condensation using the dihydroxy fatty acid, monohydroxy fatty acid, or mixed fatty acid of mono- and dihydroxy fatty acid according to a conventional method. Dehydration condensation can be carried out by reacting dihydroxy fatty acids, monohydroxy fatty acids, or mixed fatty acids of dihydroxy fatty acids and monohydroxy fatty acids at 100 to 200°C for 30 minutes to 8 hours under a stream of inert gas such as nitrogen gas. can.

In the condensation reaction, as the degree of condensation of the resulting condensed fatty acid increases, the acid value decreases; however, since the degree of condensation and the acid value are in an inversely proportional relationship, the degree of condensation can be determined by the acid value. The condensed fatty acids used in the present invention preferably have an acid value of 55 to 130. Condensed fatty acids with an acid value of less than 55 have low water solubility and high viscosity, making them difficult to handle, and condensed fatty acids with an acid value of over 130 have good water solubility, but tend to form scum. This is undesirable.

In addition, the condensed fatty acids mentioned above are polymerized compounds through ester groups in which hydroxyl groups and carboxyl groups in dihydroxy fatty acid molecules are condensed, and have a carboxyl group at the end and a hydroxyl group in the side chain. Because of these characteristics, it has better water solubility than ordinary polymer compounds. Furthermore, the amount of hydroxyl groups in the side chain can be adjusted by using monohydroxy fatty acid in combination with dihydroxy fatty acid, thereby adjusting the water solubility. When monohydroxy fatty acids are used together, the amount of monohydroxy fatty acids added is preferably 60% by weight or less based on the dihydroxy fatty acids. If the amount of monohydroxy fatty acid added exceeds 60% by weight, stability decreases. That is, monohydroxy fatty acids have unsaturated bonds in their molecules, and when they are present in large quantities, they undergo thermal polymerization during use, resulting in increased viscosity, decreased water solubility, and scum formation.

Next, the alkali metal salt and/or amine salt of the condensed fatty acid used in the present invention is obtained by neutralizing the condensed fatty acid with an alkali metal hydroxide and/or amine compound according to a conventional method. The alkali metal hydroxides used here include sodium hydroxide, potassium hydroxide, etc., and the amine compounds include ammonia, triethylamine,
Examples include monoethanolamine, jetanolamine, triethanolamine, and the like.

The alkali metal salt and/or amine salt of the condensed fatty acid is
It has excellent hydrophilicity and can be easily made into an aqueous solution or emulsion either as it is or in combination with a very small amount of an emulsifier, and the stability of the aqueous solution is also excellent.

The water-soluble cutting fluid of the present invention contains the alkali metal salt and/or amine salt of the condensed fatty acid as an aqueous solution or emulsion, and can be used as it is or optionally added with animal and vegetable oils, fatty acid esters, mineral oil, extreme pressure additives, and antioxidants. It can be used in metal processing such as cutting and grinding in combination with a surfactant, a rust preventive agent, an antifoaming agent, etc. The concentration of the condensed fatty acid salt when used in an aqueous solution or mixed with other compositions is 0.1 to
50% by weight is preferred.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto unless the gist thereof is exceeded.

[Example] - Preparation of hydroxylated fatty acids Into a four-eye flask equipped with a stirrer, a cooler, a thermometer, and a dropping funnel, 100 g of the unsaturated fatty acids shown in Table 1 and 2% of the total amount of formic acid were charged. , using a hydrogen peroxide solution with a concentration of 35% relative to the fatty acid, dropping 1.2 times the mole of hydrogen peroxide,
The mixture was heated and stirred at 70°C for 4 hours. After the reaction, the reaction mixture was washed twice with pure water at 30 mA each time, and then dehydrated at 120°C to obtain hydroxylated fatty acids (NO
, 1-3) were obtained. Table 1 shows the acid value (AV), iodine value (IV), and hydroxyl value (OH~') of the obtained hydroxylated fatty acid.

Table 1 ・Preparation of condensed fatty acids Using the hydroxylated fatty acids, ricinoleic acid, and 12-hydroxystearic acid in Table 1, heat at 200°C for a predetermined time under a nitrogen stream to perform a condensation reaction and use it in Examples and Comparative Examples. A condensed fatty acid was obtained.

Table 2 shows the acid value and hydroxyl value of the obtained condensed fatty acids.

Table 2 Examples 1 to 7, Comparative Examples 1 to 4 Condensed fats #N0.1 to 8 shown in Table 2 were neutralized with triethanolamine to prepare a water-soluble cutting fluid as a 5% aqueous solution. Using the obtained water-soluble cutting fluid, a load-bearing capacity test was carried out.
A defoaming test and a rust prevention test were conducted. The results obtained are shown in Table 3, and Table 3 of each test method is shown below.

- Load-bearing ability test The load-bearing ability was measured at a rotational speed of 600 rpm using a four-ball friction tester in accordance with JIS-2519.

・Anti-foaming test Pour 50 mfl of water-soluble cutting fluid diluted 60 times with tap water into a 100 mρ measuring cylinder with a stopper, and after sealing,
The measuring cylinder was shaken up and down 30 times at a liquid temperature of 30° C., then left to stand, and the foam volume (m Il, ) was measured after 0 seconds, 30 seconds, and 60 seconds.

- Rust prevention test A test piece prepared in accordance with J15-G-3141 was immersed in an aqueous solution of a water-soluble cutting fluid with a concentration of 1100 pp diluted with pure water, and the amount (%) of rust generated was measured.

Examples 8 to 9, Comparative Example 5 Table 4 shows triethanolamine salts of condensed fatty acids shown in Table 2.
A water-soluble cutting fluid was prepared by blending it into the composition shown below, and the cutting test shown below was conducted using this to evaluate the cutting performance (cutting resistance value). The results are shown in Table 4.

・Cutting test conditions Cutting 11: 3 ton vertical internal drawing broach machine Cutting tool: Maximum depth of cut per tooth 0.05 mm, width 7
mm, blade spacing 8 mm, material 5KH55 key approach tool Work material: S-45C Cutting speed: 2 m/min Table 4 [Effects of the Invention] As explained above, the present invention has been developed by dehydrating and condensing specific hydroxy fatty acids. This method uses an alkali metal salt and/or amine salt of a condensed fatty acid obtained by using a dihydroxy fatty acid or a dihydroxy fatty acid and a monohydroxy fatty acid to produce a condensed fatty acid with a carboxyl group at the end and a hydroxyl group in the side chain. Then,
Compared to conventional water-soluble cutting fluids, water-soluble cutting fluids using this salt have excellent cutting and grinding properties, have good rust prevention properties, do not cause rust on the workpiece, and have low corrosion resistance. Miyoshi Oil & Fat Co., Ltd. Patent applicant for features such as foaming properties and excellent workability

Claims (1)

[Scope of Claims] 1. A water-soluble cutting fluid characterized by using an alkali metal salt and/or amine salt of a condensed fatty acid obtained by dehydration condensation of a dihydroxy fatty acid. 2. A water-soluble cutting fluid characterized by using an alkali metal salt and/or amine salt of a condensed fatty acid obtained by dehydration condensation of dihydroxy fatty acids and monohydroxy fatty acids individually or in combination.