JPS6140720B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a water-soluble cutting fluid (hereinafter referred to as "mizukiri") used for cutting and grinding. More specifically, the present invention relates to an improved drainer with less microbial deterioration and less iron ion elution. (Technical background) Water drainers used for cutting and grinding metals are used to remove mineral oils, fats and oils, polar additives, surfactants, antifoaming agents, metal anticorrosives, antioxidants, preservatives, preservatives, etc. The composition is mixed as appropriate. Mizukiri is usually diluted 10 to 100 times with water. This diluted liquid is called coolant. Coolants are required to have performance that improves machinability (primary performance) and performance related to workability and others (secondary performance). Among these, secondary performance includes good rust prevention, resistance to deterioration, ease of management, harmlessness to the human body, and less foaming and odor. Although the emphasis differs depending on the purpose and conditions of use, a drainer must have a good balance of the above-mentioned performances. Preventing microbial deterioration of coolants is a very important issue. As coolant decay progresses, primary and secondary performance will deteriorate, and
Bad odors also make the work environment worse. If the frequency of coolant change due to spoilage is not high, it will be disadvantageous in terms of cost. Furthermore, if mold grows in the coolant, it not only reduces the primary performance and secondary performance, but also causes pipes in the circulation system to become clogged. In addition to the above, elution of iron ions is another cause of coolant deterioration. When metal processing is continued using a coolant, iron ions gradually elute into the coolant, which causes the coolant to turn reddish-brown and a reddish-brown substance to adhere to the surface of the workpiece.
spoil its appearance. Therefore, the operator must perform work to remove the colored substance. Further, when the material of the workpiece is an iron-based metal, the above-mentioned deposits may promote the formation of rust on the workpiece. (Prior Art) In order to prevent microbial deterioration of the coolant, various antibacterial substances are added to drainers, but the deterioration of the coolant cannot be prevented for a long period of time, and the situation is not satisfactory. In order to prevent the elution of iron ions, various studies have been conducted on the composition of cutting oil.
No effective means have been found. (Objective of the Invention) Among the above-mentioned properties, the present invention is particularly superior in that it is resistant to deterioration, more specifically in that it is resistant to microbial deterioration, that is, it is resistant to rotting, resistant to the growth of mold, and that there is little elution of iron ions. It provides a water drainer. As a result of extensive research, the present inventor discovered that by adding a special diamine, it is possible to significantly improve microbial deterioration resistance and reduce the elution of iron ions without impairing the performance of draining. We have arrived at the present invention. (Structure of the Invention) The present invention provides a diamine ( This drainer is characterized by containing D-amine (hereinafter referred to as D amine). However, R ₁ is a hydrogen atom or has a carbon number of 1 to 24
an alkyl group, alkenyl group, cycloalkyl group, alkylaryl group, aralkyl group or aryl group. R ₂ is an alkyl group, alkenyl group, cycloalkyl group, alkylaryl group, aralkyl group or aryl group having 1 to 24 carbon atoms. n
is 2 or an integer from 4 to 18. Components of the present invention will be explained in detail below. <Diamine (D amine)> Examples of diamines that can be used in the present invention are as follows. (At least one of R ₁ and R ₂ is an alkyl group) Dibutylaminododecylamine ethylaminoethylamine diethylaminoethylamine (R is an alkenyl group) Di-2-propenylaminoethylamine di-9-octadecenyl Aminobutylamine (R is a cycloalkyl group) Cyclohexylaminoethylamine (R is an alkylaryl group) 3,5-dimethylphenylaminobutylamine (R is an aralkyl group) Benzylaminooctylamine (R is an aralkyl group) aryl group) Phenylaminobutylamine In the present invention, D amine is contained in the coolant.
Preferably, the amount is 0.001 to 1% by weight, more preferably 0.005 to 0.5% by weight.
If it is less than 0.001% by weight, the effect of the present invention will not be achieved, and if it exceeds 1% by weight, the effect will not improve and it will be uneconomical. D
The amine may be added to the drain stock solution or may be added to the coolant. <Other components> In the present invention, mineral oil, fats and oils, extreme pressure additives, surfactants, antifoaming agents, metal anticorrosives, antioxidants, etc. can be arbitrarily selected from those conventionally used for draining. It can be used as (Manufacturing method) In order to manufacture the water-soluble cutting fluid of the present invention, each component may be mixed according to a conventional method. (Example) Next, the present invention will be described with reference to Examples. However, the present invention is not limited to this in any way. Table 1 lists the emulsion type and Table 2 lists the soluble type drainer compositions. (Numbers indicate weight%.)

【table】

[Table] The following experiments were conducted to evaluate the performance of the drainers shown in Tables 1 and 2. (1) Preparation of sample solution Dilute the drainers of Examples and Comparative Examples listed in Table-1 and Table-2 with sterile water, and dilute the drainers of Table-1 to 3% by weight and the drainers of Table-2 to 2% by weight. % and used as a sample solution. (2) Microbial deterioration resistance test Pour 400 ml of each sample solution into a sterilized 500 ml flat-bottomed flask, and use putrid emulsion as a starter (2 x 10 ⁸ viable bacteria/ml, 1 x 10 ⁴ fungi/
ml) 1% by weight after the start of the experiment 1, 2, 4, 8, 13,
The cells were inoculated at 17-day intervals and cultured with shaking (200 rpm) at 30°C for 21 days. Then, on days 0, 3, 7, 14, and 21, a portion of each sample solution was collected aseptically.
Measure the number of viable bacteria and fungi, and at the same time measure the PH,
Changes in appearance and odor were observed. Furthermore, the rust prevention performance was also observed. In addition, the number of viable bacteria was measured by the plate counting method using an ordinary agar medium. Fungal counts were determined by plate counting using potato dextrose agar medium supplemented with antibiotics (chloramphenicol and tetracycline). In addition, rust prevention properties were observed using the cast iron chip method. That is, approximately 15 g of dry-cut casting chips (FC-25, 8-12 mesh) were collected in a Petri dish (inner diameter approximately 60 mm, approximately 25 ml of sample liquid was added to this, shaken thoroughly, and left undisturbed for approximately 4 minutes. Next, the sample solution was removed by the decanting method, and the state of rust that developed on the Petri dish was examined over time. Tables 3 and 4 show the measurement results over time. From the results shown in Table 3 and Table 4, it is clear that the colander of the present invention has better microbial resistance than the conventional colander.

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[Table] (3) Iron ion elution prevention ability test 400 ml of the sample solution prepared by the method in (1) above and dry-cut casting chips (FC-25, 8-12
40g of the sample solution was placed in a 500ml Erlenmeyer flask, sealed with a cotton plug, and shaken at 37°C for 20 days (rotation speed: 150 rpm) to degrade the sample solution. After cooling, it was filtered through No. 5A filter paper to obtain a degraded liquid. Changes in the appearance of this degraded liquid were observed, and the iron ion concentration was measured. The results are shown in Table-5.

[Table] From the results in Table 5, it is clear that the drainer of the present invention has a better ability to prevent iron ions than the conventional drainer. (Effects of the Invention) In the drainer of the present invention, the coolant is less likely to rot, mold is less likely to grow, less iron ions are leached out, and it is not inferior to conventional drainers in other performances.

Claims (1)

[Scope of Claims] 1. A water-soluble cutting fluid characterized by containing a diamine represented by the following formula. However, R ₁ is a hydrogen atom or has a carbon number of 1 to 24
an alkyl group, alkenyl group, cycloalkyl group, alkylaryl group, aralkyl group or aryl group. R ₂ is an alkyl group, alkenyl group, cycloalkyl group, alkylaryl group, aralkyl group or aryl group having 1 to 24 carbon atoms. n
is 2 or an integer from 4 to 18.