JPH06184777A - Washing soap - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a cleaning agent which can efficiently wash and remove heat-treated oil after heat treatment of metal products without causing environmental pollution, and which can be easily recovered and regenerated. [Structure] A cleaning agent for cleaning and removing adhered heat-treated oil from a metal product heat-treated with heat-treated oil having a viscosity at 40 ° C in the range of 10 to 1000 cSt, and having an aromaticity of 60% or more. A detergent containing an aromatic compound having two benzene rings or one naphthalene ring in the molecule as an essential component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning agent used for cleaning a metal product, which is a heat-treated product, in heat treatment of a metal product called quenching, tempering and annealing and subsequent cleaning. Is.

[0002]

2. Description of the Related Art Conventionally, low-boiling halogen-based solvents such as trichloroethane have been used in degreasing cleaning for the purpose of removing oils and fats such as heat-treated oils adhered in the heat treatment process of metal products.

However, with increasing awareness of social environmental problems, many volatile halogen-based solvents such as trichloroethane cannot be used because they destroy ozone in the atmosphere or are toxic to the human body. Not preferable. As an alternative method to the cleaning using a volatile halogen solvent such as trichloroethane, a cleaning method using water or a cleaning agent containing water has been devised.

Furthermore, even if a mineral oil-based detergent is selected as a substitute for the volatile halogenated hydrocarbon, its detergency is inferior to that of the volatile halogenated hydrocarbon, so that the detergency is not improved and the viscosity is low. There is a tendency that the above-mentioned mineral oil-based detergents are used.

However, a heat-treated oil having a low viscosity has a problem that evaporation from the metal surface during heat treatment is severe and bubbles are generated in an extreme case, and it becomes difficult to dissipate heat uniformly and sufficiently. To do.

From this point of view, a high-viscosity heat-treated oil or a heat-treated oil containing a high-boiling point additive has been proposed. For the washing of metal products treated with such a heat-treated oil, a volatile halogen solvent such as trichloroethane is used. Has the above-mentioned environmental problems, and water or a detergent containing water as a component is insufficient for washing and removing heat-treated oil of high viscosity. That is, the cleaning power is poor, the regeneration of the cleaning liquid is difficult,
There are problems such as rust generation after waste liquid treatment and cleaning.

[0007]

DISCLOSURE OF THE INVENTION The present invention is an improvement over these drawbacks of the prior art, and can efficiently wash and remove heat-treated oil after heat treatment of metal products without causing environmental pollution. Moreover, it is an object of the present invention to provide a cleaning agent that can be easily collected and regenerated.

[0008]

Means for Solving the Problems As a result of intensive studies made by the present inventors in order to solve the above-mentioned drawbacks, the present inventors have found that the correlation between the aromaticity of a compound used as a detergent and the cleaning performance, that is, 40 ° C. It has been found that when a compound having an aromaticity of more than 60% is used as a cleaning agent for cleaning a heat-treated oil having a viscosity in the range of 10 to 1000 cSt, high cleaning performance is exhibited and no environmental pollution occurs. The present invention has been completed.

That is, the present invention has a viscosity of 10 at 40.degree.
A cleaning agent for cleaning and removing the adhered heat-treated oil from a metal product heat-treated with the heat-treated oil in the range of 1000 cSt, wherein a benzene ring is contained in a molecule having an aromaticity of 60% or more. The present invention provides a detergent comprising an aromatic compound having one or one naphthalene ring as an essential component.

The present invention will be further described below. The heat treatment of the present invention means heat treatment called quenching, tempering, and annealing performed on metal products such as bearing retainers and iron products such as gears. Usually, these heat treatments are performed by heating a metal product and immersing it in a heat treatment oil. The heat-treated oil that adheres to the metal product may adversely affect the subsequent processing such as the shot blasting process after the heat-treated product, so it is necessary to wash and remove it.

The heat-treated oil has a viscosity of 10 at 40 ° C.
Is in the range of up to 1000 cSt. 10 cSt
If the viscosity is less than 10, it is difficult to uniformly perform the heat treatment, while 10
A heat-treated oil having a viscosity of more than 00 cSt is too high in viscosity, so that the heat treatment becomes insufficient.

Specific heat-treated oils include those obtained by distillation of petroleum, those obtained by catalytic cracking, steam cracking, cracking (pyrolysis) or hydrocracking (hydrocracking) of petroleum, and partial nuclear hydrogenation of petroleum. Examples of the base oils include mineral oils such as those mentioned above or hydrocarbon oils such as olefin oligomers such as ethylene, propylene or higher α-olefins.

The preferred heat treated oil has a viscosity of 100 to 1000 cSt at 40 ° C. when the above mineral oil is used as the base oil.
It is in the range of.

Another preferred heat treated oil is 40
For base oils whose viscosity at 10 ° C is in the range of 10 to 100 cSt,
A heat-treated oil composition containing a high-boiling point additive having a molecular weight of 1000 or more that can be dissolved in the base oil. Examples of the high-boiling point additive that dissolves in such a base oil include asphalt and pitch. When these are added, the viscosity of the heat-treated oil composition increases, so that the viscosity range is 4
The amount is such that the viscosity at 0 ° C. falls within the range of 10 to 1000 cSt. Usually, the high boiling point additive is in the range of 0.01 to 10 wt% with respect to the heat treated oil composition. The upper limit of the molecular weight of the high-boiling point additive is not particularly limited, but if the molecular weight is too high, the viscosity of the heat-treated oil composition obtained will be too high, and therefore the molecular weight is usually 100,000 or less.

The viscosity at 40 ° C. is 10 to 100 cSt.
Examples of the base oil in the range are the above-mentioned mineral oils and hydrocarbon oils such as olefin oligomers.

Since the above heat-treated oil has a relatively high viscosity, its amount is large, but it tends to remain on the surface of the heat-treated metal product. The residual heat-treated oil adversely affects post-processing of metal products, such as shot blasting. Therefore, in the present invention, cleaning is performed with a cleaning agent containing an aromatic compound having two benzene rings or one naphthalene ring in the molecule having an aromatic degree of 60% or more as an essential component.

Here, the degree of aromaticity means the ratio of the number of aromatic carbons in the molecule of the compound to the total number of carbons (number of aromatic carbons / total number of carbons) × 100 (%). A compound having an aromaticity of less than 60% is insufficient for cleaning and removing the heat-treated oil as described above. In addition, aromatic compounds having one benzene ring, such as benzene and toluene, are not preferable because they have a high degree of aromaticity and are safe to the human body and have a low flash point.

Further, although some aromatic hydrocarbons having three or more benzene rings or two or more naphthalene rings have high aromaticity, they generally have too high a viscosity, so that they can be cleaned by ultrasonic cleaning. It is not preferable because the cleaning effect is reduced.

Examples of the aromatic compound having two benzene rings or one naphthalene ring in the molecule having an aromaticity of 60% or more include diaryl ethers such as ditolyl ether having one oxygen atom. In addition to the above, specifically, an aromatic hydrocarbon having two benzene rings having a total carbon number of 13 to 18 or an aromatic hydrocarbon having one naphthalene ring having a total carbon number of 11 to 16 is exemplified. . Aromatic hydrocarbons having two benzene rings having a total carbon number of more than 18 are not preferable because the aromaticity is lowered and thus the detergency is lowered and the viscosity is increased. Total carbon number is 1
The same applies to an aromatic hydrocarbon having one naphthalene ring having 6 or more. More specifically, the following general formulas (1) to (3)
The compound represented by

[0020]

[Chemical 1]

[0021] In the formula, R ¹ and R ² are the same or different groups and represent hydrogen or an alkyl group. p ¹ and q ¹ are each independently 1 to
Represents an integer of 4.

[0022]

[Chemical 2]

In the formula, Ar _{1 and} Ar ₂ are the same or different groups and represent a benzene ring or a cyclohexane ring, and R ³ and R ⁴ are the same or different groups and represent hydrogen, an alkyl group or a cyclohexyl group. . p ² and q ² each independently represent an integer of 1 to 4. n is 1 or 2
Is. However, the number of benzene rings contained in the aromatic compound represented by the formula (2) is limited to two.

[0024]

[Chemical 3]

In the formula, R ⁵ and R ⁶ represent the same or different hydrogen or alkyl group. m represents an integer of 1 to 6.
p ³ and q ³ each independently represent an integer of 1 to 4.

Examples of the compound represented by the formula (1) include dimethylnaphthalene, ethylnaphthalene, isopropylnaphthalene, diethylnaphthalene and diisopropylnaphthalene.

Examples of the compound represented by the formula (2) include methylbiphenyl, dimethylbiphenyl, ethylbiphenyl, isopropylbiphenyl, diethylbiphenyl, butylbiphenyl, diisopropylbiphenyl, hexylbiphenyl and partially hydrogenated terphenyl.

Examples of the compound represented by the formula (3) include 1,1-diphenylethane, 1,2-diphenylethane, benzyltoluene, ditolylmethane, phenyltolylethane, diphenylbutane and butyldiphenylethane.

The compounds used as the cleaning agent of the present invention may be used alone or as a mixture.

In the present invention, in addition to the detergent comprising the above compound, alcohols, ethers, esters,
It is possible to add acetals, ketones, nitroalkanes, glycols. Further, a surfactant and an antioxidant can be added as required.

The cleaning with the cleaning agent of the present invention can be carried out by a conventional method. For example, a metal product heat-treated with the heat-treated oil, for example, an iron product, is immersed in a cleaning tank containing the cleaning agent of the present invention in a conventional manner to easily wash and remove the heat-treated oil attached to the metal product. can do. At the time of cleaning, the cleaning effect can be enhanced by ultrasonic treatment that is appropriately performed. After the cleaning, the cleaning agent adhering to the metal product as the object to be cleaned can be easily removed by appropriately drying, for example, warm air drying or vacuum drying.

The cleaning agent obtained by cleaning the adhered heat-treated oil, that is, the cleaning agent mixed with the heat-treated oil is usually regenerated and repeatedly used. This regeneration is usually carried out by separating the heat-treated oil mixed in the detergent by simple distillation.

[0033]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 A bearing retainer (made of iron) having an inner diameter of 42 mm, an outer diameter of 45 mm and a thickness of 14 mm was heated and then tempered by immersing it in a heat-treated oil having a viscosity of 253 cSt at 40 ° C. and a mineral oil as a base oil. Then, after adhering oil, it was left at room temperature for 1 day.

The retainer as an object to be cleaned thus prepared was cleaned for 5 minutes with an ultrasonic cleaning apparatus filled with 1,1-diphenylethane. After washing, air blowing was performed for 1 minute, and then hot air drying was performed at 80 ° C. The detergency was evaluated by extracting the oil remaining in the object to be cleaned after washing and drying under the reflux of carbon tetrachloride and then measuring the oil in the carbon tetrachloride with an infrared oil meter (trade name: HORIBA OCMA-220). It was performed by quantification. The results are shown in Table 1.

Example 2 Except that isopropyl biphenyl was used as a cleaning agent,
A cleaning test was performed in the same manner as in Example 1. The results are shown in Table 1.

Example 3 Except that isopropyl naphthalene was used as a cleaning agent,
The cleaning test was performed as in Example 1. The results are shown in Table 1.

Comparative Example 1 A cleaning test was conducted in the same manner as in Example 1 except that dodecylbenzene was used as the cleaning agent. The results are shown in Table 1.

[0039]

[Table 1]

Example 4 A gear (made of iron) having an outer diameter of 49 mm and a thickness of 27 mm was set at 40 ° C.
After being heated in a heat-treated oil having a viscosity of 25.7 cSt and added with 2.0% by weight of asphalt, it was tempered by immersing it to allow oil to adhere, and then left at room temperature for 1 day.

The object to be cleaned thus prepared was cleaned with an ultrasonic cleaning device filled with benzyltoluene for 5 minutes.

After washing, air blowing was performed for 1 minute, and then hot air drying was performed at 80 ° C. The detergency was evaluated by extracting the oil remaining in the object to be cleaned after washing and drying under the reflux of carbon tetrachloride and then measuring the oil in the carbon tetrachloride with an infrared oil meter (trade name: HORIBA OCMA-220). It was performed by quantification. The results are shown in Table 2.

Example 5 A cleaning test was conducted in the same manner as in Example 4 except that phenyltolylethane was used as the cleaning agent. The results are shown in Table 2.

Example 6 Except that butyldiphenylmethane was used as the cleaning agent,
A cleaning test was conducted in the same manner as in Example 4. The results are shown in Table 2.

Comparative Example 2 A cleaning test was conducted in the same manner as in Example 4 except that a normal paraffin fraction having a distillation range of 205 to 250 was used as the cleaning agent. The results are shown in Table 2.

[0046]

[Table 2]

[0047]

By using the cleaning agent of the present invention, the heat-treated oil can be cleaned and removed at a high level, and environmental pollution does not occur. Further, since the cleaning agent of the present invention has a lower boiling point than that of the heat-treated oil, it can be easily separated from the heat-treated oil by simple distillation, and the cleaning agent can be easily recovered and regenerated. In particular, the cleaning agent of the present invention enables selective and effective cleaning of high-viscosity heat-treated oil which is currently under development or heat-treated oil containing a high-boiling point additive.

Claims (3)

[Claims] 1. A cleaning agent for cleaning and removing the heat-treated oil adhered from a metal product heat-treated with the heat-treated oil having a viscosity at 40 ° C. in the range of 10 to 1000 cSt, wherein the aromaticity is 60. %, A detergent containing an aromatic compound having two benzene rings or one naphthalene ring in the molecule as an essential component. 2. The heat-treated oil comprises mineral oil as a base oil at 40 ° C.
Has a viscosity of 100 to 1000 cSt.
The cleaning agent according to. 3. The heat-treated oil has a viscosity of 10 to 40 ° C.
The detergent according to claim 1, which is a heat-treated oil composition in which an additive having a molecular weight of 1000 or more is added in the range of 100 cSt.