JPS606990B2 - metal working oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-soluble metalworking oil that is non-corrosive and has a long life.

BACKGROUND ART Conventionally, as a method of preventing metalworking oil from spoiling, a disinfectant, particularly an organic disinfectant, has been added to the metalworking oil.

However, even if this organic disinfectant has a good anti-corrosion effect against a specific type of microorganism, it may not be sufficiently effective against other types of microorganisms. Therefore, when using a sterilizing agent, it is necessary to select an appropriate sterilizing agent in consideration of the target microorganisms, which results in a lack of versatility. Furthermore, - some organic disinfectants are themselves easily degraded by microorganisms, and such disinfectants necessarily have a short-lasting anti-septic effect;
This method has the drawback of requiring frequent addition of disinfectants, which requires a lot of effort and cost. Another sterilization method is to heat metalworking oil that has been used for a predetermined period of time to a relatively high temperature to sterilize anaerobic bacteria in the metalworking oil, and to replenish various additives that have disappeared through this process. is also known. However, like the above method, this method also requires a large amount of cost and is difficult to obtain sufficient effects. The present inventor has already proposed a method for preventing corrosion by bringing metal working oil into contact with metallic cobalt (Japanese Patent Application Laid-Open No. 141297).
However, this method requires specific equipment. The inventor of the present invention subsequently continued his research and found that such problems could be solved and that an excellent sterilizing effect could be obtained with a simple means, leading to the completion of the present invention.

The present invention provides a water-soluble metal working oil containing cobalt carboxyl salt.

In the present invention, the carboxylic acid cobalt salt acts as a spoilage inhibitor for lagoon metalworking oil. Here, the carboxylic acid is preferably a saturated carboxylic acid. Preferred specific examples of cobalt carboxylic acid salts include cobalt naphthenate and cobalt octylate. In addition, only cobalt salts are effective as metal salts of carboxylic acids; other metal salts,
For example, tin salts, copper salts, nickel salts, iron salts, etc. cannot provide the desired effects of the present invention. Furthermore, examples of water-based metalworking oils include cutting oils, rolling oils, heat treatment oils, and the like.

There are two types of cutting oil: emulsion type, which mainly consists of key oil, surfactant, rust preventive, and water, and soluble type, which mainly consists of large amount of surfactant, small amount of tin oil, rust preventive, and water. Some oils are in the form of emulsions.
Furthermore, examples of the heat-treated oil include those made of polyethylene glycol and water. These water-soluble metalworking oils are diluted at an appropriate dilution ratio, generally 5 to 1.
It is usually diluted 10 to 50 times with water, stored in a tank, etc., and used by circulating between the tank and the equipment used.

The above-mentioned cobalt carboxylic acid salt may be added during the production of the oil agent, or may be added at an appropriate time before or after diluting the water-droppable metal working oil with water.

The amount added is from 0.1 to 10% by weight, preferably from 0.2 to 5% by weight, based on the raw metalworking oil solution. The water-soluble metal working oil containing cobalt carboxylate salt obtained in this manner has a corrosion-preventing effect not limited to specific microorganisms, but inhibits the growth of a wide variety of microorganisms, and is free from spoilage and has a long life.

Moreover, not only is there no environmental pollution due to the generation of bad odors, but it is also highly safe for the human body. Furthermore, one of the features of the present invention is that the carboxylic acid cobatate salt can be directly added to the metal working oil before dilution, and no special equipment is required. Therefore, the present invention is extremely advantageous in the field of metal processing. Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 9 and Comparative Examples 1 to 7 Two samples of fresh metal working oil solution diluted 20 times with tap water were collected in test tubes, and 0.1 min of chips and oil ( Added 0.1 ml of rotten oil and 0.1 ml of spoiled oil of the former metal processing oil.

Next, a predetermined amount of the additive shown in Table 2 was added to this, and the culture was statically cultured at 3000 °C without adding any additive.
The number of viable bacteria (cells/wing) was measured at regular intervals. Note that sliding surface oil is mixed into metal processing oil such as cutting oil during metal processing, and has the property of promoting the decomposition effect by microorganisms. In addition, chips are metal powder produced by cutting during metal processing, and are mixed into metal processing oil. When measuring the number of viable bacteria, the following culture medium is used for each type of bacteria.

'1' Aerobic bacteria (agar plate method) Medium composition: Meat extract 0.5%, Beptone 1.0%, Sodium chloride 0.5%, Agar 1.5% (pH 7-〇) '2
1 Anaerobic bacteria (modified method V basic medium) soil composition: bepton 1.0%, yeast extract 0.5%, heart extract 0.1
4%, glucose 0.2%, potassium dihydrogen phosphate 0.0
45% Potassium monohydrogen phosphate 0.045%, ammonium sulfate 0.09%, sodium chloride 0.09%, magnesium sulfate (anhydrous salt) 0.009%, calcium chloride (anhydrous salt) 0.09%, agar 1 .5%, cysteine hydrochloride 0
．． 03%, sodium hydroxide 0.4% (pH 7'3) Sulfate-reducing bacteria Starkey medium (American type).

Culture. Collection 12th edition, 331 pages (197
6 years)) with 1.5% agar added. Oil agents A to C in the following examples have the following meanings. Oil agent A: Emulsion type cutting oil Oil agent B: Soluble type cutting oil Oil agent C: Emulsion type rolling oil Viable number of aerobic bacteria, anaerobic bacteria, and sulfate-reducing bacteria in each metalworking oil before adding disinfectant ) are shown in Table 1.

Table 1 Table 2 shows the measurement results of the number of viable bacteria when each fungicide was added.

Table 2

Claims (1)

[Claims] 1. A water-soluble metal working oil containing a cobalt carboxylic acid salt. 2. The metalworking oil according to claim 1, wherein the cobalt carboxylic acid salt is cobalt naphthenate or cobalt octylate.