JP5627881B2 - Dirt separation and removal method - Google Patents

Description

  In the present invention, in the cleaning of precision industrial products such as precision machine parts, optical parts, electronic parts, printed circuit boards, metal processing oil, rust preventive oil, lubricating oil, grease, wax, flux, ink, liquid crystal, resin, etc. The present invention relates to a cleaning method capable of separating and removing dirt from a cleaning liquid in which is dissolved, and preventing and reducing the accumulation of dirt in the cleaning liquid.

  Conventionally, cleaning liquids used for cleaning precision industrial products include chlorinated solvents such as trichlorethylene, tetrachloroethylene, methylene chloride, trichloroethane, chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), paraffinic and naphthenic hydrocarbons. System solvents are known. When these are used as cleaning liquids, as a method for removing dirt accumulated in the cleaning liquid, a distillation method is used in which the cleaning liquid containing dirt is distilled to separate it into cleaning liquid and dirt. However, the distillation method requires a heater to heat and consumes a large amount of energy. Depending on the boiling point of the cleaning liquid, a vacuum device for distillation at a reduced pressure is required, and metal decomposition components such as acids are generated by thermal decomposition. There was a problem.

  Recently, a method has been proposed in which a plurality of solvents having different dissolving powers against dirt are mixed to deposit and separate the dirt dissolved in the cleaning liquid. For example, in a two tank cleaning machine used for steam cleaning, the cleaning liquid in the cleaning tank in which the dirt has dissolved and the rinse liquid in the rinse tank used for rinsing are mixed to remove the deposited dirt, and then the dirt is removed. A method has been proposed in which the washed liquid is returned to the washing tank (Patent Document 1, Patent Document 2). However, in this method, the saturated oil concentration in the mixed liquid of the cleaning liquid and the rinsing liquid is high, so that the dirt cannot be efficiently separated, and an excellent dirt separation effect cannot be obtained.

JP 2000-8095 A JP 2003-33730 A

  In the present invention, regardless of the type of various types of dirt, particularly metal processing oil, the dirt is effectively separated and removed from the cleaning liquid containing the dirt, and the dirt concentration in the cleaning liquid is lower than the concentration level at which the cleaning power of the cleaning liquid decreases. It is an object to be able to be suppressed to. By solving this problem, the object is to extend the life of the cleaning liquid, reduce the amount of waste liquid of the cleaning liquid, reduce the burden on the environment, and reduce costs.

As a result of intensive studies to solve the above problems, the present inventors have found that a solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C. and a vapor pressure at 20 ° C. The cleaning liquid containing the component (b) containing 1.33 × 10 ³ Pa or more is used to clean the object to be cleaned, and then the solvent (a) and the solvent for the cleaning liquid containing the dirt are cleaned. By setting the mass ratio of (b) to a specific ratio, it was found that the above-mentioned problems can be solved by separating and removing the dirt from the cleaning liquid containing the dirt, and the present invention has been made.

That is, the present invention is as follows.
1. Step 1. A solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C .;
Solvent (b) containing a component having a vapor pressure at 20 ° C. of 1.33 × 10 ³ Pa or more
(Here, the solvent (b) is a non-chlorine fluorine compound, and includes a compound in which at least half of the alkyl groups having no fluorine with respect to all alkyl groups in the molecule are included) .
After washing the dirt of the object to be washed in the washing tank using the washing liquid containing the mass ratio (a) / (b) = 40/60 to 60/40 ,
Step 2. The cleaning liquid containing the dirt is sent to the mixing tank,
Step 3. Add the solvent (b) or a mixed solution of the solvent (a) and the solvent (b) to the cleaning solution containing dirt in the mixing tank,
By setting the mass ratio of the solvent (a) and the solvent (b) to (a) / (b) = 10/90 to 29/71, dirt is precipitated from the cleaning liquid containing dirt ,
Step 4. Remove the dirt separated from the cleaning solution,
Step 5. The dirt that is finely dispersed in the cleaning liquid is separated and removed by passing the cleaning liquid through a filter.
Step 6. Send the cleaning liquid from which dirt has been removed to the cleaning tank,
Step 7. By heating the washing tank and evaporating the solvent (b),
The mass ratio of the solvent (a) to the solvent (b) in the cleaning liquid is (a) / (b) = 40 / 60-60 / 40,
Use again as a cleaning solution,
Step 8. Further, the solvent (b) evaporated in step 7 is condensed and used in step 3.
A method of separating and removing dirt.
2. The above 1. wherein the solvent (a) is a solvent containing one or more selected from glycol ether, glycol ether acetate and hydroxycarboxylic acid ester. A method for separating and removing the dirt described in 1.
3. Solvent (a) is a solvent containing and the 3-methyl-3-meth carboxymethyl-butanol and 3-methyl-3-meth carboxybutyl acetate, solvent (b) is 2H, 2H, 4H, 4H, 4H-perfluorobutane and 1, a solvent containing methyl perfluorobutyl ether and methyl perfluoroisobutyl ether. A method for separating and removing the dirt described in 1.
4.3- methyl-3 weight ratio of methemoglobin carboxymethyl butanol and 3-methyl-3-meth carboxybutyl acetate is 80 / 20~20 / 80, 2H, 2H, 4H, 4H, and 4H- fluoro butane, 2. The mass ratio of the mixture of methyl perfluorobutyl ether and methyl perfluoroisobutyl ether is 99/1 to 70/30. A method for separating and removing the dirt described in 1.

  By using the method for separating and removing dirt according to the present invention, dirt in the cleaning liquid, particularly dirt can be effectively separated regardless of the type of metal processing oil, and the dirt concentration in the cleaning liquid can be reduced. The concentration level can be suppressed to a level at which the cleaning power is reduced, and the life of the cleaning liquid is extended. Thereby, the running cost is reduced, the amount of waste is reduced, and the environmental load can be reduced.

Hereinafter, the best mode for carrying out the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
The present invention includes a solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C. and a solvent containing a component having a vapor pressure of at least 1.33 × 10 ³ Pa at 20 ° C. After washing the dirt of the object to be washed using a washing liquid containing b) at a specific ratio, the mass ratio of the solvent (a) to the solvent (b) in the washing liquid containing the dirt is (a) / (b ) = 10/90 to 29/71, the dirt is effectively separated and removed from the cleaning liquid containing the dirt.
In the present invention, the term “dirt” refers to metal working oils such as cutting oil, press oil, and plastic working oil used when machining precision machine parts and optical machine parts, greases, waxes, and soldering electrical and electronic parts. Means the flux used.

The solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C. used in the present invention is, for example, a compound such as an organic compound having an ether bond and / or an ester bond. . The organic compound having an ether bond used in the solvent (a) is a compound containing at least one ether bond (C—O—C) in the molecular structure, and the organic compound having an ester bond is It is a compound containing at least one ester bond (—COO—) in the molecular structure.
As a compound which has an ether bond, the compound specified by following General formula (1) can be mentioned, for example.

(Wherein R ¹ and R ² are an aliphatic compound residue or alicyclic ring having one or more selected from alkyl groups, alkenyl groups, cycloalkyl groups, acetyl groups, carbonyl groups, hydroxyl groups, ester bonds and ether bonds) Represents a compound compound residue, aromatic compound residue or heterocyclic compound residue, and R ^{3 to} R ⁶ represent hydrogen or an alkyl group.)

Preferable compounds having an ether bond include glycol ethers and glycol ether acetates.
Examples of glycol ethers include glycol ether monoalkyl ethers and glycol ether dialkyl ethers.
Here, the glycol ether monoalkyl ether is an aliphatic or alicyclic compound in which two hydroxyl groups are bonded to two different carbon atoms, and one hydrogen atom of the hydroxyl group is a hydrocarbon residue. Or it is the compound substituted by the hydrocarbon residue containing an ether bond. Glycol ether dialkyl ethers are aliphatic or alicyclic compounds in which two hydroxyl groups are bonded to two different carbon atoms, and both hydrogens of the two hydroxyl groups are hydrocarbon residues or ether bonds. It is a compound substituted with a hydrocarbon residue containing. Examples thereof include glycol ether monoalkyl ethers specified by the following general formula (2) and glycol ether dialkyl ethers specified by the following general formula (3).

(Wherein R ⁷ is an alkyl group having 1 to 6 carbon atoms, an alkenyl group or a cycloalkyl group, R ⁸ , R ⁹ and R ¹⁰ are hydrogen or a methyl group, n is an integer of 0 to 1, and m is 1 to 4) Indicates an integer.)

(Wherein R ¹¹ is an alkyl group, alkenyl group or cycloalkyl group having 1 to 6 carbon atoms, R ¹² is an alkyl group or alkenyl group having 1 to 4 carbon atoms, R ¹³ , R ¹⁴ and R ¹⁵ are hydrogen or methyl. Group, n represents an integer of 0 to 1, and m represents an integer of 1 to 4.)

  Further, the glycol ether monoalkyl ethers and glycol ether dialkyl ethers of the solvent (a) include a hydrophilic one and a hydrophobic one. Hydrophilic glycol ether monoalkyl ethers and hydrophilic glycol ether dialkyl ethers are glycol ethers that can be dissolved without phase separation from water when the glycol ethers / water are mixed at a mass ratio of 60/40 at 30 ° C. It is. Hydrophobic glycol ether monoalkyl ethers and hydrophobic glycol ether dialkyl ethers are glycol ethers that undergo phase separation from water when mixed in a mass ratio of 60/40 glycol ethers / water at 30 ° C. . Here, preferred hydrophilic glycol ether monoalkyl ethers and hydrophilic glycol ether dialkyl ethers are glycol ethers that can be dissolved in water at an arbitrary ratio at 30 ° C. Further, preferred hydrophobic glycol ether monoalkyl ethers and hydrophobic glycol ether dialkyl ethers are glycol ethers having a solubility in water of 60% by mass or less at 30 ° C.

  Specific examples of hydrophilic glycol ether monoalkyl ethers in glycol ether monoalkyl ethers include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-i-propyl ether, diethylene glycol mono-n. -Butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol and the like. Specific examples of the hydrophobic glycol ether monoalkyl ether include ethylene glycol mono-n-hexyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether and the like. Can be mentioned.

Incidentally, dipropylene glycol mono-n-propyl ether and dipropylene glycol mono-n-butyl ether are excellent in cleanability in flux cleaning. The stains in the flux cleaning are stains such as amine hydrochloride and organic acid that cause ionic residues, and stains such as polymerized rosin that cause white residues generated by the soldering process.
Furthermore, glycol ether monoalkyl ethers specified by the following general formula (4) such as 3-methoxybutanol, 3-methyl-3-methoxybutanol and the like have excellent detergency with respect to various stains, and are excellent. It is a compound that provides a cleaning effect.

(Wherein R ¹⁶ represents an alkyl group, alkenyl group, or cycloalkyl group having 1 to 6 carbon atoms, R ¹⁷ , R ¹⁸ , and R ¹⁹ represent hydrogen or a methyl group, and n represents an integer of 0 or 1)
In glycol ether dialkyl ethers, specific examples of hydrophilic glycol ether dialkyl ethers include diethylene glycol dimethyl ether and diethylene glycol diethyl ether. Specific examples of the hydrophobic glycol ether dialkyl ether include diethylene glycol di-n-butyl ether and dipropylene glycol dimethyl ether. Incidentally, diethylene glycol diethyl ether and dipropylene glycol dimethyl ether are particularly excellent in detergency against rosin contained in the flux component.
Furthermore, glycol ether dialkyl ethers specified by the following general formula (5), such as diethylene glycol di-n-butyl ether, are compounds that have a good detergency against various stains and have an excellent detergency effect. .

(Wherein R ²⁰ is an alkyl group having 4 to 6 carbon atoms, an alkenyl group, or a cycloalkyl group, R ²² , R ²³ , and R ²⁴ are hydrogen or a methyl group, R ²¹ is an alkyl group having 3 to 6 carbon atoms, An alkenyl group or a cycloalkyl group, n represents an integer of 0 or 1)
A combination of glycol ether monoalkyl ethers and glycol ether dialkyl ethers is more preferable because it has an excellent cleaning effect against various types of dirt.
Glycol ether acetates are compounds obtained by acetylating glycol ethers having a hydroxyl group, and are preferably specified by the following general formula (6).

Wherein R ²⁷ is an alkyl group having 1 to 6 carbon atoms, an alkenyl group or a cycloalkyl group, R ²⁸ , R ²⁹ and R ³⁰ are hydrogen or a methyl group, n is an integer of 0 to 1, and m is 1 to 4 Indicates an integer)

Specific examples include acetates of monoalkyl ethers such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate. be able to.
Examples of glycol ether acetates used in the present invention include dipropylene glycol monomethyl ether acetate, dipropylene glycol mono-n-propyl ether acetate, dipropylene glycol mono-n-butyl ether acetate, which do not produce alkoxyacetic acid in the metabolic system in the human body, 3-methoxybutyl acetate and 3-methyl-3-methoxybutyl acetate are preferred because they are less toxic.

  Moreover, as a compound which has an ester bond, the compound specified by following General formula (7) can be mentioned, for example.

Wherein R ²⁵ and R ²⁶ are an aliphatic compound residue or alicyclic ring having one or more selected from alkyl groups, alkenyl groups, cycloalkyl groups, acetyl groups, carbonyl groups, hydroxyl groups, ester bonds and ether bonds. Represents a compound residue, an aromatic compound residue and a heterocyclic compound residue.)

Specific examples of the compound having an ester bond include: n-butyl acetate, isoamyl acetate, 2-ethylhexyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, γ-butyrolactone, Examples include dimethyl succinate, dimethyl glutarate, dimethyl adipate, 3-methyl-3-methoxybutyl acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, and dipropylene glycol monobutyl ether acetate.
As the compound having an ester bond, hydroxycarboxylic acid esters are preferable. Hydroxycarboxylic acid esters are ester compounds having a hydroxyl group, and are preferably specified by the following general formula (8).

(In the formula, R ³¹ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group or a cycloalkyl group.)

Specific examples include lactic acid ester, malic acid ester, tartaric acid ester, citric acid ester, glycol monoester, glycerin monoester, glycerin diester, ricinoleic acid ester and castor oil.
Among the above components (b), lactic acid esters are particularly preferred, and specific examples thereof include methyl lactate, ethyl lactate, propyl lactate, butyl lactate and pentyl lactate.

Among the solvents (a), glycol ether, glycol ether acetate, and hydroxycarboxylic acid ester are preferable because the effect of suppressing the flammability of the alcohol used in combination is particularly high.
As the solvent (a), a solvent containing a compound having an ether bond and a compound having an ester bond is preferable. Specifically, more preferably a solvent containing a 3-methyl-3-meth carboxymethyl-butanol and 3-methyl-3-meth carboxybutyl acetate, the preferred ratio, and 3-methyl-3-meth alkoxy butanol 3- the weight ratio of methyl-3-meth carboxybutyl acetate is 80/20 to 20/80.

The solvent (b) used in the present invention is a solvent containing a component having a vapor pressure at 20 ° C. of 1.33 × 10 ³ Pa or more. Preferably, it is a solvent consisting only of a non-chlorine fluorine compound, and more preferably has no flash point.
The solvent (b) is exemplified below for each type of compound.
A non-chlorine fluorine compound is a fluorine compound in which a part of hydrogen atoms of hydrocarbons or ethers are substituted with only fluorine atoms and does not contain chlorine atoms. For example, it contains a chlorine atom of cyclic HFC (hydrofluorocarbon) specified by the following general formula (9), chain HFC specified by (10), or HFE (hydrofluoroether) specified by (11) And a compound composed of a carbon atom, a hydrogen atom, an oxygen atom, a fluorine atom, and a combination of two or more compounds selected from these.

_{C n H 2n-m F m} (9)
(4 ≦ n ≦ 6, 5 ≦ m ≦ 2n−1 n, m is an integer)
_{C x H 2x + 2-y} F y (10)
(4 ≦ x ≦ 6, 6 ≦ y ≦ 12 x and y are integers)
C _s F _{2s + 1} OR (11)
(4 ≦ s ≦ 6, R is an alkyl group having 1 to 3 carbon atoms)

Specific examples of the cyclic HFC specified by the formula (9) include 3H, 4H, 4H-fluorocyclobutane, 4H, 5H, 5H-fluorocyclopentane, 5H, 6H, 6H-nonafluorocyclohexane and the like. .
Specific examples of the chain HFC specified by the formula (10) include 1H, 2H, 3H, 4H-fluorobutane, 1H, 2H-fluorobutane, 1H, 3H-fluorobutane, 2H, 3H-fluorobutane and 4H. , 4H-fluorobutane, 1H, 1H, 3H-fluorobutane, 1H, 1H, 4H-fluorobutane, 1H, 2H, 3H-fluorobutane, 1H, 1H, 4H-fluorobutane, 2H, 2H, 4H, 4H, 4H-fluorobutane, 1H, 2H-fluoropentane, 1H, 4H-fluoropentane, 2H, 3H-fluoropentane, 2H, 4H-fluoropentane, 2H, 5H-fluoropentane, 1H, 2H, 3H-fluoropentane, 1H , 3H, 5H-fluoropentane, 1H, 5H, 5H-fluoropentane, 2H, 2H, 4H-fluoro Pentane, 1H, 2H, 4H, 5H-fluoropentane, 1H, 4H, 5H, 5H, 5H-fluoropentane, 1H, 2H-fluorohexane, 2H, 3H-fluorohexane, 2H, 4H-fluorohexane, 2H, 5H -Fluorohexane, 3H, 4H-fluorohexane and the like can be mentioned. More preferably, these non-chlorine fluorine compounds include compounds in which the number of alkyl groups having no fluorine is more than half of all alkyl groups in the molecule. Examples thereof include 2H, 2H, 4H, 4H, 4H-fluorobutane. These have higher solubility in metalworking oils and the like than other non-chlorine fluorine compounds, and as a result have excellent detergency.
Specific examples of HFE specified by the formula (11) include methyl perfluorobutyl ether, methyl perfluoroisobutyl ether, methyl perfluoropentyl ether, methyl perfluorocyclohexyl ether, ethyl perfluorobutyl ether, ethyl perfluoroisobutyl ether, and ethyl perfluoroethylene. A fluoropentyl ether etc. can be mentioned.

In the present invention, as the solvent (b) containing a component having a vapor pressure at 20 ° C. of 1.33 × 10 ³ Pa or more, one or two or more compounds selected from non-chlorine fluorine compounds are combined. Can be used. Preferable examples include cyclic HFC, HFE, or a combination thereof having high solubility in highly polar solvents such as alcohols, ketones, esters, glycol ethers, and the like, and having a low global warming potential. More preferable examples include 4H, 5H, 5H-fluorocyclopentane, methyl perfluorobutyl ether and methyl perfluoroisobutyl ether and a mixture thereof, and ethyl perfluorobutyl ether and ethyl perfluoroisobutyl ether and a mixture thereof. More preferred examples include methyl perfluorobutyl ether, methyl perfluoroisobutyl ether and mixtures thereof which are excellent in flash point suppression effect.
As the solvent (b), a solvent containing 2H, 2H, 4H, 4H, 4H-fluorobutane, methyl perfluorobutyl ether, and methyl perfluoroisobutyl ether is more preferable. Furthermore, the preferable mass ratio is 99/1-70/30 of the mass ratio of a mixture of 2H, 2H, 4H, 4H, 4H-fluorobutane, methyl perfluorobutyl ether and methyl perfluoroisobutyl ether.

Furthermore, the cleaning liquid may contain one or more compounds selected from the group consisting of alcohols, ketones, esters, and hydrocarbons as long as the flash point does not appear. Examples of these compounds are given below.
Examples of alcohols include methanol, ethanol, n-propanol, and isopropanol.
Examples of ketones include acetone and methyl ethyl ketone.
Examples of the esters include ethyl formate, propyl formate, isobutyl formate, methyl acetate, ethyl acetate, methyl propionate, and ethyl propionate.
As hydrocarbons, n-hexane, isohexane, cyclohexane, cyclohexene, 2-methylpentane, 2,3-dimethylbutane, n-heptane, 2-methylhexane, 3-methylhexane, 2,4-dimethylpentane, isooctane Etc.

As a method for separating and removing the dirt of the present invention, a solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C. and a vapor pressure of 1.33 × 10 ³ Pa at 20 ° C. After washing the dirt of the article to be washed with a cleaning liquid containing the solvent (b) containing the above components at a mass ratio (a) / (b) = 29/71 to 90/10, the dirt is removed. Method for separating and removing dirt from cleaning liquid containing dirt by setting mass ratio of solvent (a) and solvent (b) of the contained cleaning liquid to (a) / (b) = 10/90 to 29/71 It is.
It is necessary that the mass ratio (a) / (b) of the cleaning liquid for cleaning the dirt of the object to be cleaned is (a) / (b) = 29/71 to 90/10. Preferably, (a) / (b) = 35/65 to 80/20. More preferably, (a) / (b) = 40/60 to 60/40.

  Further, when separating and removing the dirt from the cleaning liquid containing the dirt, the mass ratio of the solvent (a) to the solvent (b) should be (a) / (b) = 10/90 to 29/71. is necessary. If the ratio of the solvent (a) is lower than (a) / (b) = 10/90, the ratio of the solvent (a) in the cleaning liquid containing dirt is low, and the efficiency is improved in the circulation type cleaning. Undesirable because it gets worse. On the other hand, when the ratio of the solvent (a) is higher than (a) / (b) = 29/71, the ratio of the solvent (a), which is a component that dissolves dirt, is high in the dirt-containing washing liquid. The saturated dissolution concentration of dirt increases. Therefore, it is difficult to separate the dirt, which is not desirable. The saturated dissolution concentration of dirt in the cleaning liquid is determined by the ratio of the solvent (a) in the cleaning liquid. That is, the lower the ratio of the solvent (a), the lower the saturated dissolution concentration of the soil, and the more easily the soil is deposited and separated.

When separating and removing dirt from the cleaning liquid containing dirt, the method of bringing the mass ratio of the solvent (a) and the solvent (b) into the above range is as follows: solvent (a) and solvent (b) in the liquid after addition As long as the mass ratio of the above is within the above range,
1) A method of adding the solvent (b),
2) A method of adding the solvent (a) and the solvent (b),
3) A method of adding a mixed solution obtained by mixing the solvent (a) and the solvent (b),
4) A method of adding a mixed solution A obtained by mixing the solvent (a) and the solvent (b) and a mixed solution B obtained by mixing the solvent (a) and the solvent (b), respectively.
5) A method of mixing and adding the mixed solution A in which the solvent (a) and the solvent (b) are mixed and the mixed solution B in which the solvent (a) and the solvent (b) are mixed,
Either method may be used.

An example of the method for separating and removing the dirt of the present invention will be specifically described with reference to FIG.
First, an object to be cleaned is put into a cleaning tank 1 containing a cleaning liquid containing a solvent (a) and a solvent (b) at a mass ratio (a) / (b) = 29/71 to 90/10. To clean the object to be cleaned. Next, the article to be washed is rinsed in the rinsing tank 2 containing the solvent (b).
The cleaning liquid containing dirt in the cleaning tank 1 is sent to the mixing tank 4 through the cleaning liquid supply pipe 12. Further, the solvent (b) having a high vapor pressure is evaporated by the heater 19 provided in the cleaning tank 1, and the solvent (b) is condensed by the cooling pipe 7. The condensed solvent (b) is also sent from the condensate pipe 8 to the mixing tank 4 through the water separator 3. Incidentally, the solvent (b) may be sent from the rinse tank 2 to the mixing tank 4.

And in the mixing tank 4, the washing | cleaning liquid containing a dirt and the condensate of a solvent (b) are mixed, and mass ratio of a solvent (a) and a solvent (b) is set to (a) / (b) = 10 / By setting it to 90-29 / 71, the dirt dissolved in the cleaning liquid containing the dirt is deposited from the solvent (a). Incidentally, although not shown in the figure, the deposited dirt may be discharged out of the system from the mixing tank 4.
Thereafter, the cleaning liquid in which the dirt is deposited is fed to the separation tank 5. In this cleaning liquid, dirt is not dissolved but is finely dispersed. In order to remove this dirt, the dirt is separated and removed from the cleaning liquid through a filter. When a certain amount of dirt floating in the separation tank and separated into the upper layer is accumulated, the electromagnetic valve 6 is activated and discharged out of the system. Then, the clean cleaning liquid from which the dirt has been removed is returned to the cleaning tank 1 from the liquid supply pipe 16 again.

  The cleaning method of the present invention includes cleaning of various fluxes, cleaning of thermosetting inks such as various solder resist inks applied to the substrate surface, UV curable ink, and liquid crystal cleaning, adhesion and sealing of various electrical and electronic components, etc. It is suitable for the field of cleaning of mixing and dispensing units (nozzles), liquid crystals and the like of epoxy and urethane type two-component resins used in the above. Furthermore, various processing oils used when processing precision machine parts, optical machine parts, etc., such as cutting oils, press oils, drawing oils, heat treatment oils, rust preventive oils, lubricating oils, greases, waxes, etc. It is particularly suitable for the cleaning field.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited only to these Examples.
In addition, the evaluation method and measurement method used for this invention, the test oil used for each test condition, and the oil separation rate of evaluation are as follows.

<Cleaning liquid>
Solvent (a): 3-methyl-3-methoxybutanol and 3-methyl-3-methoxybutyl acetate (mass ratio is 3-methyl-3-methoxybutanol / 3-methyl-3-methoxybutyl acetate = 40/60 )
Solvent (b): 2H, 2H, 4H, 4H, 4H-fluorobutane, methyl perfluorobutyl ether and methyl perfluoroisobutyl ether (mass ratio is HFC365mfc / HFE7100 = 90/10, HFC365mfc: 2H, 2H, 4H, 4H, 4H-fluorobutane, HFE7100: a mixture of methyl perfluorobutyl ether and methyl perfluoroisobutyl ether)
Cleaning liquid: A solvent (a) and a solvent (b) mixed at 50:50 are used.

<Test oil>
A: Cutting oil (Unicut Terrami AM30 (trademark), manufactured by Nippon Oil Corporation)
B: Press oil (Unipres Terrami DP68 (trademark), manufactured by Nippon Oil Corporation)
C: Plastic processing oil (Yushiron Former FM220 (trademark), manufactured by Yushiro Chemical Industry Co., Ltd.)
D: Drawing oil (Master Draw 533WD (trademark), manufactured by Idemitsu Kosan Co., Ltd.)

<Oil separation rate>
Add 5 ml of oil to 100 ml of washing liquid and shake with an automatic shaker for 1 hour to obtain a washing liquid containing dirt. The solvent (b) is added thereto, and the mass ratio of the solvent (a) / solvent (b) is changed to obtain a test solution. The test solution is shaken for 1 hour by an autoshaker, and 5 ml each of the dispersion immediately after shaking and the dispersion left to stand for 1 hour after shaking are sampled. These dispersions were put in an aluminum cup and dried in a vacuum dryer at 80 ° C. for 1 hour at 0 torr to obtain a dry residue. This was used as an oil, and the oil separation rate was calculated by the following formula.
W1 (g): Dry residue of 5 ml of dispersion immediately after shaking W2 (g): Dry residue of 5 ml of dispersion left to stand for 1 hour after shaking Oil separation rate (%) = (W1-W2) / W1 × 100
Evaluation is based on the following criteria.
A: Oil separation rate of 60% or more
○: Oil separation rate of 40% or more and less than 60% ×: Oil separation rate of less than 40%

[Example 1]
The solvent (b) was added to the test solution so that the mass ratio of the solvent (a) and the solvent (b) was 10/90, thereby preparing a test solution. The oil separation rate was measured by the above operation using this test solution. The oil separation rates of the test oils were cutting oil 79%, press oil 79%, plastic working oil 89%, and drawing oil 82%, showing very good results.

[Example 2]
The solvent (b) was added to the test solution so that the mass ratio of the solvent (a) and the solvent (b) was 25/75, thereby preparing a test solution. Other than that was carried out similarly to Example 1, and measured the oil separation rate. The oil separation rate was 50% or more for any of the test oils. The test results are shown in Table 1. The oil separation rates of the test oils were 61% cutting oil, 63% press oil, 80% plastic working oil, and 72% drawing oil, showing very good results.

[Example 3]
The solvent (a) and the solvent (b) are mixed at a mass ratio of 40/60 to obtain a mixture A. And a solvent (a) and a solvent (b) are mixed by mass ratio 10/90, and it is set as the liquid mixture B. These mixed solution A and mixed solution B are added to the test solution so that the mass ratio of the solvent (a) to the solvent (b) is 25/75, and the resultant is used as the test solution. Other than that was carried out similarly to Example 1, and measured the oil separation rate. The test results are shown in Table 1. The oil separation rates of the test oils were cutting oil 62%, press oil 64%, plastic working oil 83%, and drawing oil 75%, showing very good results.

[Comparative Example 1]
The solvent (b) was added to the test solution so that the mass ratio of the solvent (a) and the solvent (b) was 30/70, thereby preparing a test solution. Other than that was carried out similarly to Example 1, and measured the oil separation rate. The oil separation rate was 40% or more in any of the test oils. The test results are shown in Table 1. The oil separation rates of the test oils were cutting oil 40%, press oil 44%, plastic working oil 65%, and drawing oil 57%, showing good results.

[Comparative Example 2]
The solvent (b) was added to the test solution so that the mass ratio of the solvent (a) and the solvent (b) was 50/50 to obtain a test solution. Other than that was carried out similarly to Example 1, and measured the oil separation rate. The oil separation rate was less than 40% in any test oil. The test results are shown in Table 1. The oil separation rates of the test oils were cutting oil 2%, press oil 10%, plastic working oil 38%, and drawing oil 32%, and the oil separation rate was low.

[Comparative Example 3]
The solvent (b) was added to the test solution so that the mass ratio of the solvent (a) and the solvent (b) was 70/30, thereby preparing a test solution. Other than that was carried out similarly to Example 1, and measured the oil separation rate. The oil separation rates of the test oils were cutting oil 0%, press oil 0%, plastic working oil 21%, and drawing oil 11%, and the oil separation rates were even lower. Cutting oil and press oil were completely dissolved and no separation was observed.

It is an example of the washing | cleaning apparatus used for the method of isolate | separating and removing the dirt of this invention.

1 Washing tank 2 Rinse tank 3 Water separator 4 Mixing tank 5 Separating tank 6 Solenoid valve 7 Cooling pipe 8 Condensate pipe 9 Condensate pipe after water separation 10 Condensate liquid feed 11 Liquid feed pump 12 Wash liquid feed Pipe for liquid 13 Pump for liquid feeding 14 Pipe for liquid feeding 15 Pump for liquid feeding 16 Pipe for liquid feeding 17 Pump for liquid feeding 18 Ultrasonic 19 Heater

Claims (4)

Step 1. A solvent (a) containing a component having a vapor pressure of less than 1.33 × 10 ³ Pa at 20 ° C .;
Solvent (b) containing a component having a vapor pressure at 20 ° C. of 1.33 × 10 ³ Pa or more
(Here, the solvent (b) is a non-chlorine fluorine compound, and includes a compound in which at least half of the alkyl groups having no fluorine with respect to all alkyl groups in the molecule are included) .
After washing the dirt of the object to be washed in the washing tank using the washing liquid containing the mass ratio (a) / (b) = 40/60 to 60/40 ,
Step 2. The cleaning liquid containing the dirt is sent to the mixing tank,
Step 3. Add the solvent (b) or a mixed solution of the solvent (a) and the solvent (b) to the cleaning solution containing dirt in the mixing tank,
By setting the mass ratio of the solvent (a) and the solvent (b) to (a) / (b) = 10/90 to 29/71, dirt is precipitated from the cleaning liquid containing dirt ,
Step 4. Remove the dirt separated from the cleaning solution,
Step 5. The dirt that is finely dispersed in the cleaning liquid is separated and removed by passing the cleaning liquid through a filter.
Step 6. Send the cleaning liquid from which dirt has been removed to the cleaning tank,
Step 7. By heating the washing tank and evaporating the solvent (b),
The mass ratio of the solvent (a) to the solvent (b) in the cleaning liquid is (a) / (b) = 40 / 60-60 / 40,
Use again as a cleaning solution,
Step 8. Further, the solvent (b) evaporated in step 7 is condensed and used in step 3.
A method of separating and removing dirt. The method for separating and removing dirt according to claim 1, wherein the solvent (a) is a solvent containing one or more selected from glycol ether, glycol ether acetate and hydroxycarboxylic acid ester. Solvent (a) is a solvent containing and the 3-methyl-3-meth carboxymethyl-butanol and 3-methyl-3-meth carboxybutyl acetate,
The solvent (b) is 2H, 2H, 4H, 4H, 4H-fluorobutane, and
The method for separating and removing dirt according to claim 1, which is a solvent containing methyl perfluorobutyl ether and methyl perfluoroisobutyl ether. The weight ratio of 3-methyl-3-meth carboxymethyl-butanol and 3-methyl-3-meth carboxybutyl acetate is 80 / 20-20 / 80,
The soil according to claim 3, wherein the mass ratio of the mixture of 2H, 2H, 4H, 4H, 4H-fluorobutane and methyl perfluorobutyl ether and methyl perfluoroisobutyl ether is 99/1 to 70/30. Method.

Images