JP2005177694A - Hard surface post-washing treatment method, and detergent composition used for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard surface post-washing treatment method which has superior basic washing capacity (scale washability, rinsing property of the detergent), requires no large equipment nor treatment cost in rinsing waste water treatment, and reduces environmental load (waste water load and amount of industrial waste), and a detergent composition used for it. <P>SOLUTION: The hard surface post-washing treatment method includes: washing a washing object having the hard surface using a detergent composition containing anion surfactant and a slightly water soluble organic solvent; rinsing the washing object with water, adding a multivalent metal salt to the rinse waste liquid and mixing and leaving standing the resultant; and separating it into two phases of a liquid phase containing the slightly water soluble organic solvent and water phase then discharging the water phase. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to machining oils such as cutting oils and rolling oils used in parts processing, rust preventive oils, lubricating oils, cutting metal powders, fixing agents (wax, pitch, etc.) attached to optical lenses, and fluxes attached to electronic parts The present invention relates to a post-cleaning treatment method for hard surfaces such as metal parts, such as liquid crystals attached to a liquid crystal panel, optical lenses, glass, electronic parts and precision parts, and a cleaning composition used therefor.

In general, cleaning fluids such as cutting oils attached during processing of parts, fixing agents attached to optical lenses, fluxes attached to electronic components, liquid crystals attached to liquid crystal panels, etc. have conventionally been used with chlorine / fluorocarbon solvents, Alternative fluorocarbon solvents, non-halogen solvents such as hydrocarbons, or aqueous / semi-aqueous detergents containing surfactants are used.
The use of chlorine and chlorofluorocarbon solvents is restricted to destroy the ozone layer. There are many problems with cleaning performance for alternative CFCs. In addition, hydrocarbon solvents have a significant safety problem because they exhibit odor problems and flammability.

On the other hand, as for the water-based and semi-aqueous cleaning agents with less problems as described above, cleaning products having high cleaning properties have been developed by using various surfactants (see Patent Document 1). However, since this water-based / quasi-water-based cleaning agent is basically rinsed with water (hereinafter referred to as “rinse”), the environmental load due to the rinse waste liquid / drainage is the biggest problem.
In a general aqueous / quasi-aqueous cleaning process, water is used to remove the cleaning agent adhering to the object cleaned in the cleaning tank and a slight amount of remaining dirt. Since this rinse waste liquid contains these detergent components, it is necessary to remove these components in order to release them into rivers and the like. The biggest problem when using this water-based / quasi-water-based cleaning agent is the treatment of the rinsing waste liquid / drainage.

As a method of removing these cleaning agent components from the rinsing waste liquid and wastewater generated when using aqueous and semi-aqueous cleaning agents, and discharging and reusing them as clean water, a sedimentation separation method (typical example: coagulation precipitation) has been used. Method), membrane treatment method (typical example: UF, RO membrane treatment method, etc.), biodegradation method (typical example: activated sludge method, etc.), adsorption method (typical example: activated carbon adsorption method, foam separation method, etc.), levitation Separation methods (typical examples: pressurized flotation methods, extraction methods, etc.) have been used.
Active research has been conducted on the sedimentation separation method, and excellent flocculants such as inorganic flocculants such as polyaluminum chloride (PAC) and polyferric sulfate, and polymer flocculants such as polyacrylamide have been developed. .

However, this sedimentation separation method has problems such as a complicated method for adding the agglutinating agent, separation of the agglomerates in a floc form, and time for the separation treatment, and increased equipment costs.
The above membrane treatment method is particularly effective because the RO membrane treatment has a high removal rate, but there are many problems in equipment, running cost, etc., and biodegradation methods are also commonly used. There are difficulties in running costs.

Furthermore, although the activated carbon adsorption method is effective, it is applied only in limited applications because of running costs and operational complexity. In addition, the foam separation method is a technique that makes good use of the characteristic of foaming property of a surfactant, but there are problems such as equipment scale and cost, and a target removal object is limited to a surfactant.
Furthermore, as a method of flotation separation, although there are relatively simple facilities for pressurized flotation, there is a problem in the removal rate.

In addition, extraction methods include extraction with phenol (see Patent Document 2), extraction with an amine-based solvent (see Patent Document 3), and extraction with water-insoluble anionic oil (Patent Document). 4), extraction with waxy synthetic oil (see Patent Document 5), and extraction with higher alcohols of C8 or higher (see Patent Document 6).
However, the extraction methods described in these documents and the like have a problem in that it is necessary to dare to add a relatively expensive extraction substance to the waste water, and there are many problems in running cost.

On the other hand, there is also known a method (see Patent Document 7) in which a detergent or the like is simply removed from a rinse liquid using a cloud point of a nonionic surfactant. The cleaning agent has a problem in that the cleaning agent itself is low in water solubility, and the cleaning agent remaining, particularly the cleaning agent held in the closed hole, the gap or the like cannot be rinsed, and satisfactory cleaning quality cannot be obtained.
Japanese Patent Laid-Open No. 7-150192 (Claims, Examples, etc.) JP-A-48-94257 (Claims, Examples, etc.) JP-A-51-62558 (Claims, Examples, etc.) JP-A-52-69 (Claims, Examples, etc.) Japanese Patent Application Laid-Open No. 55-94678 (Claims, Examples, etc.) JP-A-7-195065 (Claims, Examples, etc.) JP-A-4-122480 (Claims, Examples, etc.)

  The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to solve this problem. The present invention has excellent basic cleaning ability (stain cleansing ability, rinse ability of cleaning agent), and is a great facility for rinsing waste liquid treatment. It is an object of the present invention to provide a post-cleaning treatment method for a hard surface and a cleaning composition used therefor, which can reduce the environmental load (drainage load, industrial waste amount) without requiring any processing costs.

  As a result of diligent studies to solve the above-described conventional problems, the present inventors have solved the basic problems of cleaning and rinsing performance and environmental problems of rinsing drainage treatment when using an aqueous cleaning agent. As a result of intensive research, the combination of a specific post-cleaning treatment method for hard surfaces and a cleaning composition used therefor, both good cleaning and rinsing properties, and simple equipment from rinse waste liquid The present invention has been found to provide a post-cleaning treatment method for a hard surface and a cleaning composition used therefor, which can remove a cleaning agent component and the like quickly and at a low cost, and can reduce the environmental load. The present invention has been completed.

（４） 更に、水を５〜７０質量％含む上記（３）記載の洗浄剤組成物。
（５） 上記（１）又は（２）記載の洗浄後処理方法に用いる洗浄剤組成物であって、アニオン界面活性剤及び水難溶性有機溶剤を含有し、該洗浄剤組成物を水で１０倍希釈した液に塩化カルシウム２０００ｐｐｍを添加して混合後、２５℃、２４時間静置した際、水相と水難溶性有機溶剤を含む液体相のニ相に分離することを特徴とする洗浄剤組成物。 That is, the present invention resides in the following (1) to (5).
(1) An object having a hard surface is washed using a detergent composition containing an anionic surfactant and a poorly water-soluble organic solvent, and then the object to be washed is rinsed with water, The hard surface is characterized by including a post-cleaning treatment step in which a metal salt is added, mixed and allowed to stand, separated into two phases, a liquid phase containing a poorly water-soluble organic solvent and an aqueous phase, and the aqueous phase is discharged. Post-cleaning treatment method.
(2) The post-cleaning treatment method for a hard surface according to the above (1), wherein when the rinsing waste liquid is separated, the aqueous phase is discharged via a W / O type emulsification system.
(3) A cleaning composition used in the post-cleaning treatment method described in (1) or (2) above, wherein the cleaning composition contains the following 1), 2) and / or 3). A cleaning composition.
1) An anionic surfactant in which the anionic surfactant polyvalent metal salt is oil-soluble or oil-dispersible when the counter ion to the anion of the anionic surfactant is a polyvalent metal ion.
2) At least one poorly water-soluble organic solvent selected from hydrocarbons, esters, ethers, and ketones.
3) A poorly water-soluble glycol ether solvent represented by the following general formula (I).

(4) The cleaning composition according to (3), further containing 5 to 70% by mass of water.
(5) A cleaning composition used in the post-cleaning treatment method according to (1) or (2) above, comprising an anionic surfactant and a poorly water-soluble organic solvent, and the cleaning composition is 10 times with water. 2,000 ppm calcium chloride is added to the diluted solution, mixed, and then allowed to stand for 24 hours at 25 ° C., the composition is separated into a water phase and a liquid phase containing a poorly water-soluble organic solvent. .

  According to the present invention, it has an excellent basic cleaning ability (fouling cleaning property, cleaning agent rinsing property), does not require a large amount of equipment and processing costs for rinsing waste liquid treatment, and has an environmental load (drainage load, industrial waste amount) ) And a cleaning composition used therefor are provided.

Hereinafter, embodiments of the present invention will be described in detail.
According to the post-cleaning treatment method for a hard surface of the present invention, a cleaning object having a hard surface is cleaned using a cleaning composition containing an anionic surfactant and a poorly water-soluble organic solvent, and then the cleaning object is rinsed with water. Then, after adding a polyvalent metal salt to the rinsing waste liquid, mixing and allowing to stand, separating into two phases of a liquid phase containing a poorly water-soluble organic solvent and an aqueous phase, and a post-washing treatment step for discharging the aqueous phase It is characterized by including.

FIG. 1 is a process diagram showing an example of an embodiment of a post-cleaning post-treatment method of the present invention.
In the post-cleaning treatment method of this embodiment, as shown in FIG. 1, (a) a cleaning composition containing an anionic surfactant and a poorly water-soluble organic solvent is placed in a cleaning tank, and the cleaning tank has a hard surface. (B) A preliminary rinsing tank (hereinafter referred to as “reservoir rinse tank”) is provided immediately after cleaning, and the cleaning agent components are efficiently rinsed and removed with a small amount of water. And a step of (c) periodically or continuously replacing the waste rinse waste liquid with clean water, adding a polyvalent metal salt to the discharged residual rinse waste liquid, and separating the cleaning agent component. Yes, it is a post-cleaning method that can reduce the rinse drainage load drained from the overflow rinse tank of (d) and the separation tank of (c) to 1/10 to 1/100 of the conventional method. It reduces the environmental impact of the agent.

In the method of the present invention, first, an object to be cleaned having a hard surface is cleaned using a cleaning composition containing an anionic surfactant and a poorly water-soluble organic solvent.
The cleaning composition used in the method of the present invention needs to contain the following (1), (2) and / or (3).
(1) An anionic surfactant in which the anionic surfactant polyvalent metal salt becomes oil-soluble or oil-dispersible when the counter ion to the anion of the anionic surfactant is a polyvalent metal ion.
(2) At least one poorly water-soluble organic solvent selected from hydrocarbons, esters, ethers, and ketones.
(3) A poorly water-soluble glycol ether solvent represented by the following general formula (I).

As the anionic surfactant of the above (1) that can be used, when the counter ion to the anion of the anionic surfactant is a polyvalent metal ion, the anionic surfactant polyvalent metal salt is oil-soluble or oil-dispersible. If it becomes, it will not specifically limit, For example, alkylbenzene sulfonate, soap, alpha olefin sulfonate, alkyl sulfate ester salt, alkyl ether sulfonate, dialkyl sulfo succinate, paraffin sulfonate, etc. are mentioned. .
Preferred anionic surfactants are anionic surfactants such as dialkylsulfosuccinates and paraffinsulfonates that form a polyvalent metal salt with a polyvalent metal ion and exhibit good liquidity.

Examples of the poorly water-soluble organic solvent (2) that can be used include at least one selected from hydrocarbon solvents, ester solvents, ether solvents, and ketone solvents (each alone or a mixture of two or more). It is done.
Preferably, the poorly water-soluble organic solvent having a solubility in water at 25 ° C. of 3% by mass (hereinafter abbreviated as “%”), more preferably 1% or less, and particularly preferably 0.5% or less. It is desirable that
Specific examples of the hydrocarbon-based agent include n-octane, n-decane, n-dodecane, dodecene, tetradecene, and isoparaffin. Examples of the ester solvent include benzyl acetate, 2-ethylhexyl acetate, isopropyl stearate, diethyl malonate, and the like. Examples of the ether solvent include butyl phenyl ether, pentyl phenyl ether, and diphenyl ether solvent. Examples of the ketone solvent include acetophenone.

Examples of the poorly water-soluble glycol ether solvent (3) that can be used include those represented by the general formula (I). The poorly water-soluble glycol ether solvent is also a kind of poorly water-soluble organic solvent.
Preferably, it is a poorly water-soluble glycol ether having a solubility in water at 25 ° C. of 5% or less, more preferably 2% or less, and particularly preferably 1% or less.
Specific examples include ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol mono 2-ethylhexyl ether, diethylene glycol mono 2-ethylhexyl ether, diethylene glycol dibutyl ether, phenoxyethanol, and diethylene glycol monophenyl ether.

  The detergent composition of the present invention contains the anionic surfactant of (1) above and the (2) poorly water-soluble organic solvent and / or (3) the poorly water-soluble glycol ether solvent. Furthermore, water (purified water, distilled water, ion-exchanged water, pure water, ultrapure water, etc.) can be added to improve the cleanability of polar dirt and reduce flammability. Preferably, it is desirable to contain 5 to 70%, more preferably 5 to 60%, particularly preferably 10 to 40% of water with respect to the total amount of the cleaning composition.

The cleaning composition used in the present invention can contain the above-mentioned anionic surfactant, poorly water-soluble organic solvent, poorly water-soluble glycol ether, and water in any ratio, but considering the cleaning properties and phase separation properties. Respectively,
(1) Anionic surfactant: 3 to 40%
(2) Slightly water-soluble organic solvent: 0 to 80%
(3) Water-insoluble glycol ether: 0 to 80%
(4) Water: 0-60%
It is preferable to contain [however, one of the above (2) and (3) is not 0%. ].
Furthermore, in order to improve the separability,
(1) Anionic surfactant: 5 to 30%
(2) Slightly water-soluble organic solvent: 0 to 70%
(3) poorly water-soluble glycol ether: 10 to 50%
(4) Water: 5-60%
It is more preferable to contain.
In addition, it is more preferable that the cleaning composition of the present invention is uniformly and uniformly integrated in order to obtain stable cleaning and rinsing properties. Further, within the range not affecting the expression of the effect of the present invention, nonionic surfactants, organic chelating agents, preservatives, organic alkali agents such as alkanolamine, inorganic substances such as potassium hydroxide, sodium hydroxide, sodium carbonate An alkali agent can be contained.

The object to be cleaned of the present invention is various kinds of dirt adhering to a hard surface, for example, various kinds of dirt adhering to metal processed parts, optically processed parts, glass plate processed parts, resin processed parts, semiconductor parts, etc. It is.
As the metal processing parts, processing oils used for processing video heads, hard disk drive parts, copying machine drive parts, CRT electron gun parts and the like used in electronic devices and the like are objects to be cleaned in the present invention.
In addition, as optical components, fixing agents (pitch, wax), abrasives, and the like that adhere during processing of camera lenses, CDs, CD-Rs, DVD pickup lenses, spectacle lenses, prisms, and the like are objects of cleaning of the present invention. .
Further, as glass plate processed parts, liquid crystals, abrasives, foreign substances, etc., which are adhered during processing of liquid crystal panels, PDP panels, HDD glass substrates, and the like are objects to be cleaned in the present invention. In addition, as the resin processed product, a resin lens, a gear used for a driving unit of an electronic device, a lens chip attached to a jig or the like, a lubricating oil, and the like are objects to be cleaned in the present invention.

In the present invention, the object to be cleaned having a hard surface is cleaned with the cleaning composition having the above-described configuration (cleaning step), and then, as shown in FIG. Easily rinse and remove detergent components with a small amount of water, replace the waste rinse waste liquid regularly or continuously with clean water, add polyvalent metal salt to the discharged waste rinse waste liquid, and clean the detergent The components are separated.
In this embodiment, a reservoir rinse tank is installed in front of the overflow rinse tank of (d), most of the detergent components are removed in the reservoir rinse tank, and the detergent components are taken out into the overflow rinse tank drainage. This is a significant reduction.
Examples of the polyvalent metal salt used in the present invention include polyaluminum chloride (PAC), aluminum sulfate (sulfuric acid band), polyferric sulfate (polyiron), calcium chloride, magnesium chloride, magnesium sulfate and the like. Is possible. A polyacrylamide-based, polyvinylamidine, dimethylaminoethyl methacrylate-based cationic polymer flocculant may be used in combination as appropriate.

As a method for separating the rinsing waste liquid shown in FIG. 1 (c), a liquid phase containing a poorly water-soluble organic solvent (this phase) can be obtained simply by adding several tens to several thousand ppm of a polyvalent metal salt and stirring and standing. Can be separated into a water phase liquid and a slightly water-soluble glycol ether solvent, a polyvalent metal salt of an anionic surfactant, and a soil component. In this case, it is usually an O / W type emulsification system. Preferably, the poorly water-soluble organic solvent phase is accumulated, and the volume ratio of the poorly water-soluble solvent phase is increased. As a result, the aqueous phase / slightly water-soluble organic solvent phase = 80/20 to 5/95, more preferably 70 / If it adjusts so that it may be set to 30-50 / 50, and it isolate | separates via a W / O type | mold emulsification system, a separation speed and a separation precision will increase and it is the most preferable practically.
As described above, the post-cleaning treatment method of the present invention has been specifically described with respect to the batch type rinsing waste liquid treatment. However, a part of the overflow rinsing waste water shown in FIG. It is also possible.
The detergent composition was diluted 10-fold with water, added with 2000 ppm of calcium chloride, mixed, and allowed to stand at 25 ° C. for 24 hours to form a two-phase liquid phase containing an aqueous phase and a poorly water-soluble organic solvent. It can also be determined whether or not the detergent composition is compatible with the present process, using as an index whether or not it is separated.

  The post-cleaning treatment method of the present invention is suitable for separation of a waste liquid for rinsing with a relatively thick cleaning component. That is, in a general cleaning process that has been used conventionally without a rinsing tank, rinsing is performed while diluting the detergent composition taken out of the cleaning tank with a large amount of water. Due to the large amount, wastewater treatment facilities become large. However, the retained rinse water in the process of the present invention only needs to be replaced with clean water about once / day, and the cleaning agent component brought into the rinse water discharged from the overflow rinse tank and the separation tank is also 1 / There is an effect of reducing to 10/100, and the rinse drainage load can be greatly reduced. In addition, since the rinse waste liquid to be treated is small (capacity of the reservoir rinse tank: about 200 kg), the separation process becomes small, and the equipment investment can be suppressed.

  The method of the present invention is not limited to the process shown in FIG. 1 but can be applied to spray cleaning, brush cleaning, and the like. Moreover, not only the batch type but also the continuous exchange method can be used for exchanging the rinsing waste liquid.

In the present invention configured as described above, an object to be cleaned having a hard surface is cleaned using a cleaning composition containing an anionic surfactant and a poorly water-soluble organic solvent, and then the object to be cleaned is rinsed with water. , Including a post-cleaning treatment step of adding a polyvalent metal salt to the rinsing waste liquid, mixing and allowing to stand, separating into a liquid phase containing a poorly water-soluble organic solvent and an aqueous phase, and discharging the aqueous phase Therefore, it has excellent basic cleaning ability (cleaning of dirt, rinseability of cleaning agent), does not require a lot of equipment and processing costs for rinsing waste liquid treatment, and has an environmental load (drainage load, industrial waste amount) This is a post-cleaning treatment method for hard surfaces that can be reduced.
In addition, the cleaning composition of the present invention is easy to separate because the phase separation is performed in a liquid state as compared with cleaning compositions containing a conventional anionic surfactant and solvent, and the separation rate is high. Quick and easy separation. Moreover, since the separation and extraction rate of the poorly water-soluble organic solvent is high and the mixing rate in the aqueous phase is extremely low, the load on the waste water is small and it is environmentally friendly.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example etc.

[Examples 1-7 and Comparative Examples 1-3]
Each cleaning composition (100% by mass in total) having the composition shown in Table 1 below was prepared.
Using each of the obtained cleaning compositions, a cleaning test is performed on liquid crystal panels, optical lenses, and precision aluminum parts, which are objects to be cleaned, according to the following methods, and cleaning properties, rinsing properties, and separation properties are measured by the following methods. -The separation rate was evaluated.
These results are shown in Table 1 below.

1) Cleaning test The following parts were repeatedly cleaned by the ultrasonic cleaning process shown in FIG.
Liquid crystal panel: Panel gap, panel with liquid crystal on the surface Optical lens: Optical lens with wax-based fixing agent on the surface Precision aluminum parts: Video head with cutting oil attached (Precise parts with closed screw holes)

2) Evaluation b) Evaluation of detergency Liquid crystal panel: After washing for 5 minutes, after rinsing for 5 minutes and after rinsing for 5 minutes, dried at 80 ° C for 30 minutes and polarized liquid crystal (dirt) remaining on the gap and surface. The detergency was evaluated according to the following evaluation criteria observed with a microscope.
Optical lens: Washed for 5 minutes, rinsed for 5 minutes, rinsed for 5 minutes, rinsed for 5 minutes at 80 ° C., and dried at 80 ° C. for 30 minutes. The wax (dirt) remaining on the surface portion was visually evaluated on the following evaluation criteria.
Precision aluminum parts: 5 minutes after washing, 5 minutes after rinsing, 5 minutes after overflow rinsing, dried at 80 ° C for 30 minutes, and the cutting oil remaining in the closed screw hole is observed with a polarizing microscope. Evaluated.
Evaluation criteria:
○: Dirt is not recognized.
(Triangle | delta): Some dirt is recognized.
X: A lot of dirt is recognized.

B) Evaluation of rinsing properties Prepare 10 liquid crystal panels, optical lenses, and precision aluminum parts that have been washed with carbon tetrachloride in advance, wash for 5 minutes, rinse for 5 minutes, rinse for 5 minutes, rinse for 5 minutes, and then at 80 ° C for 30 minutes. dry. For each part, 10 parts were sonicated with 100 cc of water at 80 ° C. for 10 minutes, and then 100 cc of residual detergent extracted water was compliant with TOC (organic carbon: JIS K01202. Equipment used: Shimadzu Corporation Residual cleaning agent was quantified by TOC-500 (manufactured by company, the same applies hereinafter), and the rinse property was evaluated according to the following evaluation criteria.
Evaluation criteria:
○: TOC is less than 10 ppm.
(Triangle | delta): TOC is 10-50 ppm.
X: TOC exceeds 50 ppm.

C) Evaluation of separability i) Normal separation (O / W)
Washing is repeated until the TOC due to the detergent component and the dirt component in the rinsing tank water shown in FIG. 1 rises to about 5%, and 0.2% of CaC12 is added to the rinsing waste liquid as a polyvalent metal salt and stirred at 25 ° C. For 30 minutes.
While confirming the phase separation properties (liquid, floc, etc.) of the upper layer containing a mixture of the poorly water-soluble organic solvent and dirt components (cutting oil, liquid crystal, wax) that have been separated, measure the TOC of the lower separated water phase, The separation rate was calculated by the following formula.
Separation rate (%) = 100 × (rinse waste liquid TOC before separation−separated aqueous phase TOC) / rinse drainage TOC before separation)

ii) Forced W / O separation The separation operation of i) was repeated, the separated aqueous phase was discarded, and 700 cc of a mixture of a poorly water-soluble organic solvent and a soil component (cutting oil, liquid crystal, wax) was prepared. Then, 300 cc of a waste rinse waste liquid in which 0.2% of CaC12 was added and stirred into the waste liquid waste rinsed to 5% TOC. After weakly stirring to form a W / O type emulsification system, stationary separation was performed, and the separation rate was calculated in the same manner as i) above.

  As is clear from the results shown in Table 1 above, Examples 1 to 7, which are the scope of the present invention, have better cleaning and rinsing properties than Comparative Examples 1 to 3, which are outside the scope of the present invention, and It was found that the detergent component separated into a liquid and showed a high separation rate. In particular, when separation is performed in the W / O emulsification systems of Examples 2, 4, 6 and 7, the separation rate is remarkably improved (equilibrium separation within 10 minutes) and a separation rate of 90% or more is exhibited. understood.

It is a process figure which shows an example of embodiment of the washing | cleaning post-processing method of the hard surface of this invention.

Claims (5)

  A cleaning object having a hard surface is cleaned using a cleaning composition containing an anionic surfactant and a poorly water-soluble organic solvent, and then the cleaning object is rinsed with water, and then a polyvalent metal salt is added to the rinsing waste liquid. Post-cleaning treatment of hard surfaces, which includes a post-cleaning treatment step that drains the aqueous phase by adding, mixing and standing, separating into two phases, a liquid phase containing a poorly water-soluble organic solvent and an aqueous phase. Method.   The post-treatment method for cleaning a hard surface according to claim 1, wherein the aqueous phase is discharged via a W / O type emulsification system when separating the rinse waste liquid. A cleaning composition for use in the post-cleaning treatment method according to claim 1 or 2, wherein the cleaning composition contains the following (1), (2) and / or (3). Cleaning composition.
(1) An anionic surfactant in which the anionic surfactant polyvalent metal salt becomes oil-soluble or oil-dispersible when the counter ion to the anion of the anionic surfactant is a polyvalent metal ion.
(2) At least one poorly water-soluble organic solvent selected from hydrocarbons, esters, ethers, and ketones.
(3) A poorly water-soluble glycol ether solvent represented by the following general formula (I).

  Furthermore, the cleaning composition of Claim 3 which contains 5-70 mass% of water.   A cleaning composition for use in the post-cleaning treatment method according to claim 1 or 2, comprising an anionic surfactant and a poorly water-soluble organic solvent, and calcium chloride in a solution obtained by diluting the cleaning composition 10 times with water. A detergent composition, which is separated into two phases of a liquid phase containing an aqueous phase and a poorly water-soluble organic solvent when 2000 ppm is added and mixed and left to stand at 25 ° C. for 24 hours.

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