JPH06279786A - Cleaning agent for dewaxing - Google Patents

Abstract

PURPOSE:To obtain the cleaning agent for dewaxing which is a practical substitute for a chlorinated solvent, is not deleterious to the environment and has a very high detergency. CONSTITUTION:The agent contains a hydrocatbon having a boiling point with in the range of 160-280 deg.C and an ester represented by the formula: R1COOR2 (wherein R1 and R2 are hydrocarbon groups the toral number of carbon atoms of which is 7-15).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning agent for removing waxes from materials such as ceramics, metal parts, mechanical parts, etc. to which waxes are attached in the manufacturing process.

[0002]

2. Description of the Related Art Conventionally, in the machining process of parts and the like in the precision machinery industry or the electronics industry, the parts are temporarily fixed,
Many kinds of waxes are used for the purpose of a protective mask such as etching or plating, and they are washed and removed at appropriate times after processing. As a cleaning agent to remove these,
Chlorinated solvents such as 1,1,1-trichloroethane or trichloroethylene have been used.

[0003]

At present, with increasing awareness of social environmental problems, chlorine-based solvents such as 1,1,1-trichloroethane are regarded as ozone depleting substances.
It has been agreed worldwide that its manufacture and use will be banned in the near future. Under such circumstances, in the industrial world where cleaning work is performed using these solvents, environmental safety,
At present, there is a demand for an alternative cleaning agent having excellent detergency as soon as possible. An object of the present invention is to provide a cleaning agent for waxes, which is excellent in environmental safety and detergency and has no problem in occupational safety.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in view of the above-mentioned circumstances, and as a result, have confirmed that a specific ester represented by the general formula (1) is added to a specific hydrocarbon at a certain level. It was found that when used together in a ratio, the detergency of waxes is remarkably increased, detergency that does not destroy the ozone layer and has no problem in occupational safety can be obtained, and the present invention has been completed. That is, in the present invention, (a) the boiling point is 160 ° C.
-280 ° C, the saturated alicyclic hydrocarbons within the range of 3
60% of a mixture with 0% by weight or more of saturated aliphatic hydrocarbons
To 95% by weight and (b) an ester represented by the general formula (1) R1 COOR2 ... (1) (wherein R1 and R2 are saturated aliphatic hydrocarbon groups or saturated alicyclic hydrocarbons). The cleaning agent is characterized by containing 5 to 40% by weight of R1 and R2 representing the total number of carbon atoms of R1 and R2).

As the hydrocarbon in the detergent of the present invention, saturated aliphatic hydrocarbons and saturated alicyclic hydrocarbons are used. Unsaturated hydrocarbons are often more toxic than saturated hydrocarbons, have problems in occupational safety, and have a peculiar strong odor, so they are not practical in the working environment. Furthermore, the unsaturated groups of unsaturated hydrocarbons become active sites, which easily cause a chemical reaction with polar compounds such as basic compounds contained in dirt (waxes), resulting in corrosion, discoloration, and rust of the washed objects. There are many possibilities to cause such as.

The saturated aliphatic hydrocarbons may be linear or branched, and the saturated alicyclic hydrocarbons may have only a ring or a straight chain. It may be a saturated hydrocarbon group having a chain or a branch bonded thereto. If the boiling point is in the range of 160 ° C to 280 ° C,
It is practical because the risk of ignition is low at normal washing temperatures, and an appropriate viscosity as a cleaning agent is maintained. If the boiling point is less than 160 ° C, the risk of ignition becomes extremely high, explosion-proof equipment for preventing it requires a large amount of money, and the usage conditions are extremely limited. is not. Further, when the boiling point thereof exceeds 280 ° C., the viscosity of the cleaning agent becomes high, so that it becomes difficult to remove the cleaning agent from the object to be cleaned after cleaning, which is also not practical.

Further, saturated hydrocarbons having the same boiling point range are
A mixture of saturated alicyclic hydrocarbons with 30% by weight or more of saturated aliphatic hydrocarbons is used. Most waxes contain high molecular weight hydrocarbons and natural pine resin for reasons such as adhesiveness. Since pine resin is mainly composed of abietic acid and its derivatives, it has a similar chemical structure. The use of a mixture with saturated aliphatic hydrocarbons containing 30% by weight or more of saturated alicyclic hydrocarbons
Synergistically favorable for soil solubility. If the saturated alicyclic hydrocarbon content is less than 30% by weight, the solubility of the wax is poor, which is not preferable.

The mixture of saturated alicyclic hydrocarbons and saturated aliphatic hydrocarbons having the same boiling point range and the weight range is preferably 60 to 95% by weight as a cleaning liquid. If it is less than 60% by weight, the influence of other components on the article to be cleaned cannot be ignored, and if it exceeds 95% by weight, the removal of stains may be extremely incomplete, which is not practical in any case. Absent.

Examples of saturated aliphatic hydrocarbons and saturated alicyclic hydrocarbons having a boiling point in the range of 160 ° C. to 280 ° C. include decane, dodecane, tridecane, tetradecane, pentadecane, 2, 2, 4, 4, 6, 8, 8-
Examples include heptamethylnonane, menthane, pinane, bicyclohexyl, decalin and the like. In the ester represented by the general formula (1), R1 and R2 are saturated aliphatic hydrocarbon groups or saturated alicyclic hydrocarbon groups, and R1 and R2 are
A compound having a total carbon number of 2 to 7 to 15, preferably 10 to 13, is used. These may be used alone or as a mixture of two or more kinds.

When the total number of carbon atoms of R1 and R2 is less than 7, the volatility becomes high, so that the composition of the detergent changes greatly during the cleaning operation, and when the total number of carbon atoms exceeds 15, the melting point is high. As a result, the liquid stability of the cleaning agent becomes poor, which is not preferable in terms of quality. The ester represented by the general formula (1) is used in an amount of 5 to 40% by weight. If it is less than 5% by weight, the effect of dissolving dirt may be significantly reduced, and if it exceeds 40% by weight,
It has a non-negligible effect on the item being washed, or emits a peculiar odor, making it impractical.

Examples of the ester represented by the general formula (1) include hexyl acetate, heptyl acetate, octyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate,
Cyclohexyl acetate, decyl acetate, dodecyl acetate, dihydroterpinyl acetate, butyl cyclohexyl acetate, methyl caprylate, ethyl caprylate, propyl caprylate, butyl caprylate, pentyl caprylate, methyl pelargonate, ethyl pelargonate, propyl pelargonate , Butyl pelargonate, Pentyl pelargonate, Methyl caprate, Ethyl caprate, Propyl caprate, Butyl caprate, Pentyl caprate, Methyl undecanoate, Ethyl undecanoate, Propyl undecanoate, Butyl undecanoate, Pentyl undecanoate, Laurine Methyl acid, ethyl laurate, propyl laurate, butyl laurate, methyl tridecanoate, ethyl tridecanoate, propyl tridecanoate, methyl myristate, ethyl myristate And the like.

In the cleaning agent of the present invention, if necessary, for example, maintaining the liquid stability of the cleaning agent, improving the stability of the object to be cleaned, or improving the workability, as long as the effect is not impaired. It is possible to add various stabilizers, additives, antifoaming agents, etc. Examples of stabilizers, additives and defoamers include alcohols, ethers, glycol ethers, acetals, ketones, fatty acids, nitroalkanes, amines, amides, aminoethanols, benzotriazoles, etc. Can be mentioned.

When the cleaning agent of the present invention is used to clean an object to be cleaned which is soiled, for example, it is cleaned in a cleaning tank containing the cleaning agent of the present invention and then dried in a vacuum dryer. Alternatively, a method of rinsing with alcohol, for example, a rinsing tank containing one kind or a mixture of two or more kinds of methanol, ethanol, isopropyl alcohol, etc., and then drying with warm air such as nitrogen or air. By doing it continuously,
It can be effectively cleaned. In the cleaning tank and the rinsing tank, not only simple immersion cleaning but also combination of rocking, vibration, ultrasonic waves, submerged jet, spray, shower, etc. is effective for cleaning property. Further, each of the cleaning tank and the rinsing tank may be one tank, or may be two tanks or more.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0015]

Examples 1 to 8 and Comparative Examples 1 to 4 As shown in FIG. 1, the first tank and the second tank of a four-tank type washing machine equipped with an ultrasonic oscillator are used in Examples 1 to 1 shown in Table 1. 8 and the cleaning agents of Comparative Examples 1 to 4 were charged into a cleaning tank, and the third
Isopropyl alcohol was charged into the tank and the fourth tank to form a rinse tank. The temperatures of the first tank and the second tank were 60 ° C., and the temperatures of the third tank and the fourth tank were room temperature.

As the object to be washed, various waxes (trade name: micron wax, lead wax manufactured by Nikka Seiko Co., Ltd.) were uniformly melted on a mirror-finished SUS test piece (80 × 20 × 2 mm) at 120 ° C. Ten pieces of coated and solidified material (applied amount of about 0.5 g / sheet) made of stainless steel wire mesh with a cylindrical shape of 30 mesh (diameter 50 mm, height 10
0 mm) was prepared.

The object to be washed is placed in the first tank for 3 minutes, and then in the second tank.
It was immersed in the liquid for 3 minutes in the bath and washed while shaking and applying ultrasonic waves. Next, the item to be washed is placed in the third tank for 1 minute and then in the fourth tank.
After immersing in the liquid for 1 minute, rinsing was performed while shaking and applying ultrasonic waves. Finally, wash the item to be washed with a dryer having an explosion-proof structure.
It was dried at ℃ and normal pressure.

After drying, the appearance finish is visually evaluated and 100 ml of carbon tetrachloride is used to extract the residual organic matter from the washed product. This amount (mg) is used as an oil content meter [manufactured by NIC Corp. Name: OIL-20]. The results are shown in Table 2.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

Industrial Applicability The cleaning method of the present invention is a practical cleaning agent which is safe for the environment, has no problems in terms of occupational safety, and has extremely excellent cleaning performance. Therefore, the cleaning agent of the present invention is an excellent cleaning agent that practically substitutes for a conventional cleaning agent using a chlorine-based solvent or the like.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an apparatus for cleaning and rinsing using the cleaning agent of the present invention.

[Explanation of symbols]

 A Cleaning agent of the present invention B Isopropyl alcohol

Claims (1)

[Claims] 1. A mixture of 60% by weight to 95% by weight of (a) a saturated alicyclic hydrocarbon having a boiling point in the range of 160 ° C. to 280 ° C. and having a saturated alicyclic hydrocarbon content of 30% by weight or more. % And (b) ester represented by general formula (1) R1 COOR2 ... (1) (wherein R1 and R2 are saturated aliphatic hydrocarbon groups or saturated alicyclic hydrocarbon groups) 5 to 40% by weight of the total number of carbon atoms of R1 and R2 is represented by 7 to 15).