JPH07216569A - Cleaning method - Google Patents

Abstract

(57) [Summary] [Object] To provide a cleaning method capable of efficiently and effectively utilizing an organic solvent-based cleaning agent such as a CFC-based cleaning agent or an alternative cleaning agent for a drainage cleaning agent. A cleaning process A for cleaning an object to be cleaned X by cleaning tanks 1 and 2 containing a cleaning agent D1 and a rinsing liquid D2 containing only one component in the cleaning agent D1 are contained, and an object to be cleaned X is cleaned. And a rinsing step B for sequentially rinsing and cleaning the article to be cleaned X by a plurality of rinsing and cleaning tanks 7 and 8 connected so that the rinsing liquid is sequentially sent in the direction opposite to the transfer direction. The cleaning effluent is collected from the cleaning tanks 1 and 2 of the cleaning step A, the rinsing cleaning effluent is recovered from the rinsing cleaning tank 7 on the most downstream side of the plurality of rinsing cleaning tanks, and the recovered cleaning effluent and rinse are collected. After the cleaning effluent is distilled to regenerate the rinsing liquid, the regenerated rinsing liquid is re-supplied to the rinsing cleaning tank 8 on the most upstream side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method for effectively utilizing a cleaning agent instead of an organic solvent-based cleaning agent such as CFC.

[0002]

2. Description of the Related Art In the manufacturing process of various industrial parts such as metal parts, plated parts, painted parts, electronic parts, semiconductor parts, etc., a chlorofluorocarbon solvent represented by Freon 113, trichloroethane, trichloroethylene, tetrachloroethylene, carbon tetrachloride, etc. Organic solvents such as are widely used as cleaning agents for removing oil stains and the like.

Further, the above-mentioned organic solvent type cleaning agent is also used as a draining cleaning agent after washing various parts with water. This is due to the high temperature (373K or more) (energy loss) that occurs when you try to dry the moisture attached to the object to be cleaned directly (the energy loss is large). This is because it is possible to avoid such problems that the object to be cleaned may be deformed (thermal expansion exceeding an allowable value), a space for cooling and heat shielding is required, and an installation area of the cleaning device is increased.

The term "drainage cleaning agent" as used herein means to replace the water adhering to the object to be cleaned (water replacement) by immersing or shower rinsing the object to be cleaned after washing with water.
After that, the cleaning agent is capable of drying the object to be cleaned by volatilizing it with room temperature or warm air of 333 K or less.

Recently, however, it has become clear that the release of CFCs leads to the destruction of the ozone layer and seriously affects the human body and biological systems. It is gradually reducing its use on a global scale, and in the future it is moving toward total elimination. Also,
Chlorine-based organic solvents such as trichlorethylene and tetrachloroethylene are also in the direction of tightening their use regulations due to environmental problems such as pollution of soil and groundwater.

Under these circumstances, a chlorofluorocarbon-based substance having an ozone depletion coefficient lower than that of the current chlorofluorocarbon-based solvent is being developed, and industrial production has already been partially advanced. Is not seen as a preferred alternative cleaning agent, as it is not completely destroyed.

[0007]

Therefore, as an alternative to the above-mentioned organic solvent-based cleaning agent, a water-based cleaning agent using a surfactant, which does not cause environmental destruction or environmental pollution, has been reviewed. Is beginning to be affected. However, a detergent with only a surfactant has a weak penetrating power, and for example, it cannot exhibit sufficient detergency against stains that have penetrated into the details of parts and oil stains that have a medium to high viscosity. There is.

Further, JP-B-63-50463 describes that a silicone compound is used for removing stains on knitted fabrics. This discloses a method of cleaning a knitted fabric using a liquid cleaning composition containing an effective amount of a cyclic siloxane having a Si number of 4 to 6 in a cleaning solvent. However, since the liquid cleaning composition containing the above-described silicone compound is intended for cleaning knitted fabrics, cleaning of general industrial products is not considered at all, and cyclic siloxane alone or cyclic siloxane and an organic solvent are not considered. Since it is a mixed system, washing for a system using water is not considered. Moreover, such a system is naturally
The dispersibility in water is extremely poor, it is difficult to uniformly mix even if a surface-active substance is used together, and phase separation immediately occurs. Therefore, it cannot be used as an aqueous detergent at all.

Further, in JP-A-53-56203, as an aerosol type aqueous cleaning composition, a chain polydimethylsiloxane having 2 to 3 silicon atoms per molecule is blended with a water-soluble cleaning composition. Is listed,
Since the blending amount is limited to about 0.02 to 0.1% by weight, it does not show the effect of sufficiently enhancing the detergency of the water-based cleaning composition.

From the above, it is possible to effectively and efficiently use an aqueous cleaning agent which does not cause environmental problems, has sufficient cleaning ability, and is stable enough to function as a cleaning agent. A cleaning method that makes it possible to use is strongly desired.

On the other hand, the use of lower alcohols such as isopropyl alcohol has been examined as a substitute for the above-mentioned organic solvent as a draining detergent. However, the isopropyl alcohol has a drawback that it has a flash point of 284.7K, which is lower than room temperature, and always causes a fire hazard under normal use conditions. In addition, isopropyl alcohol has a high compatibility with water, and even if the initial draining performance is retained, when it is used continuously, redissolved water will re-adhere, so that the draining performance will not deteriorate over time. Absent. Purification for removing water from isopropyl alcohol containing water and reusing it requires a large investment of equipment. Furthermore, isopropyl alcohol is highly toxic to the human body, and the use of isopropyl alcohol is currently being regulated.

When a hydrocarbon or higher alcohol having a flash point above room temperature is used, the removal of water is somewhat easy, but the volatility of water itself is low, and for example, at a low temperature of 333 K or less. Since it is difficult to dry, it cannot be used as a draining detergent. Such a problem is not limited to replacement with water and drying, and is a problem that similarly occurs when replacing with various liquids that are difficult to dry and when drying.

From the above, a drainage cleaning agent which does not cause environmental problems, has sufficient cleaning ability and liquid replacement / drying ability, and has almost no danger such as ignition is effective and effective. There is a strong demand for a cleaning method that enables efficient use.

The present invention has been made in order to solve the above-mentioned problems, and effectively and effectively uses an alternative cleaning agent of an organic solvent type cleaning agent such as a CFC type cleaning agent or a drainage cleaning agent. It is an object of the present invention to provide a cleaning method capable of cleaning.

[0015]

[Means and Actions for Solving the Problems] That is, the cleaning method of the present invention comprises a cleaning step of cleaning an object to be cleaned with a cleaning tank containing a cleaning agent, and only one component in the cleaning agent. A rinsing step in which a rinsing liquid is accommodated, and a plurality of rinsing cleaning tanks are connected so that the rinsing liquid is sequentially fed in a direction opposite to the transfer direction of the object to be cleaned, and a rinsing step of rinsing and cleaning the object to be cleaned after cleaning. And recovering the cleaning drainage liquid from the cleaning tank in the cleaning step, and collecting the rinse cleaning drainage liquid from the rinse cleaning tank on the most downstream side of the plurality of rinse cleaning tanks, and the recovered cleaning drainage liquid and The rinsing step is performed while the rinse effluent is distilled to regenerate the rinsing liquid, and then the regenerated rinsing liquid is re-supplied to the rinsing bath on the most upstream side.

Examples of the cleaning agent used in the cleaning method of the present invention include

[Chemical 7] (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
A monovalent organic group, l represents an integer of 0 to 5) and a linear polydiorganosiloxane represented by

[Chemical 8] (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
A monovalent organic group, m is an integer of 3 to 7) and at least 1 selected from cyclic polydiorganosiloxanes represented by
An example of a non-aqueous cleaning agent is one in which at least one selected from a surfactant and a hydrophilic solvent is mixed with one type of low-molecular-weight polyorganosiloxane. The rinsing detergent consisting only of the low molecular weight polyorganosiloxane is used as the rinsing liquid.

The above low molecular weight polyorganosiloxane is
It is a substance that exerts a strong penetrating power against dirt, exhibits good displaceability with various liquids containing water by itself, and has high vapor pressure, low heat of vaporization, low surface tension and the like. R ¹ in the above formulas (1) and (2) is a substituted or unsubstituted
A monovalent organic group, such as an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, or a phenyl group.
Such as monovalent unsubstituted hydrocarbon group, trifluoromethyl group
Examples of the monovalent substituted hydrocarbon group, and the terminal R ¹ in the above formula (1) further includes an amino group, an amide group, an acrylate group, a mercaptan group, etc. The methyl group is most preferred from the viewpoints of maintaining the properties and volatility.

In the system as described above, the low molecular weight polyorganosiloxane is regenerated from the cleaning effluent and the rinse cleaning effluent by distillation and reused as a rinsing liquid. Thus, by regenerating the low molecular weight polyorganosiloxane as a rinse liquid from the cleaning drainage and the rinse cleaning drainage, the cleaning agent and the rinse can be used effectively and efficiently. And, the low-molecular weight polyorganosiloxane and the non-aqueous detergent added with a surfactant or a hydrophilic solvent exhibit strong drainability and strong penetrating power to stains, and thus have been conventionally used. It has cleaning and liquid displacement effects comparable to those of CFCs, and has extremely low erosiveness to various base materials, and basically does not contain halogen elements such as chlorine and bromine in its constituent components. Therefore, there is almost no possibility of causing environmental destruction or environmental pollution as in the case of a CFC-based organic solvent cleaning agent.

As the low molecular weight polyorganosiloxane used as a non-aqueous detergent, those having a cyclic structure are preferable from the viewpoint of liquid displacing property, penetrability and the like. Further, octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane are preferable. Siloxane and mixtures thereof are preferred.
Under severe conditions in which acids and alkalis may be mixed, it is preferable to use the linear low molecular weight polyorganosiloxane represented by the above formula (1) from the viewpoint of stability.

The aqueous cleaning agent used in the cleaning method of the present invention includes, for example, linear polydiorganosiloxane represented by the above formula (1) and cyclic polydiorganosiloxane represented by the above formula (2). At least one chosen
A series of low molecular weight polyorganosiloxanes,

[Chemical 9] (In the formula, R ² represents an alkyl group or a phenyl group, and A represents a polyoxyalkylene group) A polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit in one molecule An example is a four-component cleaning agent containing an agent and water, or a three-component cleaning agent containing the above polyoxyalkylene group-containing polyorganosiloxane, a surfactant, and water.
When these water-based detergents are used, the one component, water, is used as the rinse liquid.

In the system as described above, water is regenerated from the cleaning effluent and the rinsing cleaning effluent by distillation and reused as the rinsing liquid. As described above, by regenerating the water as the rinse liquid from the cleaning drainage liquid and the rinse cleaning drainage liquid, the cleaning agent and the rinse liquid can be used effectively and efficiently.

According to the above water-based cleaning agent, the above (1)
The low molecular weight polyorganosiloxane represented by the formula or (2) has a strong penetrating power to the interface between the soil and the matrix, and the detergent has a detergency against the soil, which is comparable to the conventional CFC type. The resulting cleaning effect is obtained, and by using the polyoxyalkylene group-containing polyorganosiloxane together, good dispersion stability in an aqueous system can be obtained. Even in a three-component system including a polyoxyalkylene group-containing polyorganosiloxane, a surfactant and water, a sufficient cleaning effect can be obtained due to the penetrating power of the polyoxyalkylene group-containing polyorganosiloxane to stain. And because it is water-based, there is no concern about environmental damage or environmental pollution.

As the low molecular weight polyorganosiloxane used as an aqueous detergent, octamethylcyclotetrasiloxane having a cyclic structure, decamethylcyclopentasiloxane and a mixture thereof, and a straight chain are used as a low molecular weight polyorganosiloxane. It is particularly preferable to use octamethyltrisiloxane, decamethyltetrasiloxane, or the like having a chain structure. In the area where the alkaline of the water-based cleaning agent is strong,
From the viewpoint of stability of polysiloxane, those having a linear structure represented by the above formula (1) are preferable.

[0024]

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

FIG. 1 is a diagram showing a structural example of a cleaning apparatus to which the cleaning method of the present invention is applied. The cleaning apparatus shown in FIG. 1 roughly includes a cleaning and / or water replacement step (cleaning step) A and a cleaning step (rinsing step) B.

In the washing and / or water replacement step A which is the first step, the first washing tank 1 and the second washing tank 2 and the draining tank 3 having both the sedimentation separation function and the overflow separation function are provided. It is provided. The first cleaning tank 1 and the second cleaning tank 2 are connected by a drain pipe 2a and an overflow pipe 2b. If necessary, ultrasonic waves, rocking, mechanical stirring, cleaning agent heating, brushing, etc. are used in combination in the first cleaning tank 1 and the second cleaning tank. In the first step, spraying of a cleaning agent may be applied instead of the immersion type cleaning tank.

In the first and second cleaning tanks 1 and 2,
As a draining detergent, a cleaning agent D1 obtained by adding at least one selected from a surfactant and a hydrophilic solvent to the low molecular weight polyorganosiloxane represented by the above formulas (1) and (2) is contained, respectively. Has been done. The above-mentioned drainage cleaning agent is named as an example of water, which is a typical liquid that can be replaced by a low molecular weight polyorganosiloxane, and is used as a drainage cleaning agent when replacing or cleaning another liquid. Of course, it can be used as an agent. The target liquid may be any liquid that is insoluble or sparingly soluble in the low molecular weight polyorganosiloxane and has a surface tension larger than that of the low molecular weight polyorganosiloxane. Specifically, water, water containing a dirt component, various liquids using water as a dispersion medium, for example, a mixed liquid with alcohol or a liquid in which various substances are dissolved, an aqueous cleaning agent, a non-aqueous liquid Examples include cleaning agents.

The low molecular weight polyorganosiloxane represented by the above-mentioned formulas (1) and (2) exhibits a good substitution property with various liquids containing water by itself, such as warm air of 333 K or less. Can be easily volatilized and dried. Even with such a low molecular weight polyorganosiloxane alone, it is possible to obtain sufficient liquid displacement and drying properties, but at least one selected from a surfactant and a hydrophilic solvent is added to the above low molecular weight polyorganosiloxane. By using the compounded composition, it is possible to impart more excellent cleaning properties, drainage properties, and the like.

The surfactant added to the low molecular weight polyorganosiloxane contributes especially to the improvement of drainage property and the cleaning property, and a polyoxyalkylene alkyl ether sulfonate is preferably used as the surfactant. , Anionic surfactants such as phosphate esters, polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, nonionic surfactants such as polyoxyalkylene alkyl ethers, amphoteric surfactants such as imidazoline derivatives, alkylamine salts, Alkyl fourth
Examples include cationic surfactants such as secondary ammonium salts, and other examples include terpene compounds extracted from natural products, higher fatty acid esters, etc., which rarely exist as a single substance. It is also possible to use synthetic compounds in which a part of the chemical structure of each compound as described above is replaced with a fluorine atom or a silicon atom. Further, in particular, when considering the effect as a draining detergent by combination with a low molecular weight polyorganosiloxane, it is preferable to use a nonionic surfactant. The composition ratio of the surfactant is not particularly limited, but it is preferably 20 parts by weight or less, and more preferably 3 parts by weight or less with respect to 100 parts by weight of the low molecular weight polyorganosiloxane.

As the hydrophilic solvent, those having compatibility with the low molecular weight polyorganosiloxane are used, and those having a flash point of 313 K or more are practically suitable. This hydrophilic solvent also contributes to the improvement of water displacement. Examples of such a hydrophilic solvent include polyhydric alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and diethylene glycol monobutyl ether, and their derivatives. For example, diethylene glycol monobutyl ether is particularly preferable from the viewpoint of compatibility with low molecular weight polyorganosiloxane and safety to human body. Since these compounds have improved volatility in the coexistence with low molecular weight polyorganosiloxanes, water substitution by this compound alone,
Drying is also possible. The composition ratio of the hydrophilic solvent is not particularly limited, but it is a low molecular weight polyorganosiloxane.
It is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, relative to 100 parts by weight.

The specific gravity of the above-mentioned detergent D1 containing the surfactant and the hydrophilic solvent can be set smaller than that of water and larger than that of oil-based stains. Therefore, the water Y brought in by the object to be cleaned X is settled and separated below the cleaning agent D1 containing the surfactant contained in the first and second cleaning tanks 1 and 2, respectively. Further, when the oil-and-fat-based dirt Z is attached to the object to be cleaned X, the oil-and-fat-based dirt Z is the cleaning agent D1 containing the surfactant contained in the first and second cleaning tanks 1 and 2. Are floated above each other. The cleaning agent D1 also has a cleaning effect on general dirt such as oil-based dirt and solid dirt such as flakes as described above.

Examples of the object (cleaning object) of the above-mentioned drainage cleaning agent include industrial parts having a hard surface made of metal, ceramics, plastic, and the like, and more specifically, metal parts, surface-treated parts, These include electronic parts, semiconductor parts, electric parts, precision machine parts, optical parts, glass parts, and ceramic parts.

The water Y sedimented and separated in the second washing tank 2 is
It is intermittently discharged to the first cleaning tank 1 side by the drain pipe 2a. In addition, the water Y that has been separated by sedimentation in the first cleaning tank 1
Is intermittently discharged to the cleaning agent regenerating mechanism C described later by the drain pipe 4. Further, the drain pipe 3a provided in the drainage tank 3 is also connected to the cleaning agent regeneration mechanism C. Further, the oil-based dirt Z floated and separated in the first cleaning tank 1 and the second cleaning tank 2 successively overflows and is discharged from the system through an overflow pipe 5 provided in the first cleaning tank 1. It The cleaning agent D1 containing the surfactant contained in the first cleaning tank 1 and the second cleaning tank 2 is constantly circulated through the filter 6, and the solid matter in the cleaning agent D1 is circulated by the filter 6. , Water particles, undissolved substances, etc. are removed.

In the cleaning step (rinsing step) B which is the second step, a third cleaning tank 7 and a shower rinse tank 8 are provided. A buffer tank 9 is provided below the shower rinse tank 8. Between the buffer tank 9 and the third cleaning tank 7, the cleaning agent D2 is sent from the buffer tank 9 to the third cleaning tank 7. They are connected by an overflow pipe 9b and also by a drain pipe 9a. Ultrasonic waves, rocking, mechanical stirring, cleaning agent heating, brushing, and the like are also used in the third cleaning tank 7 as required.

The third cleaning tank 7 contains, as a rinse solution, a cleaning agent D2 containing only the same silicone composition as the low molecular weight polyorganosiloxane used in the first step A. The cleaning agent D2 can be set to have a specific gravity smaller than that of water and larger than that of oil-based stains. Therefore, as in the cleaning tank in the first step A, the water Y is settled and separated below the cleaning agent D2, and the oil-based dirt Z is floated and separated above the cleaning agent D2. As the cleaning agent D2, a low molecular weight polyorganosiloxane having a structure different from that of the low molecular weight polyorganosiloxane in the cleaning agent D1 can be used.

The water Y sedimented and separated in the third cleaning tank 7 is
It is discharged to the cleaning agent regeneration mechanism C intermittently by the drain pipe 10. Further, the oil-fat-based dirt Z floated and separated in the third cleaning tank 7 is discharged from the overflow pipe 11 to the outside of the system. Further, the cleaning agent D stored in the third cleaning tank 7
2 is constantly circulated through the filter 12, and the filter 12 causes solids, water particles,
Undissolved substances are removed.

Then, the article to be cleaned X is sequentially sent from the first step A to the second step B, and after being washed and drained, it is dried by a warm air dryer or the like (not shown). The cleaning process is completed by the application. Since the above-mentioned cleaning agents D1 and D2 have a strong draining property (draining property), a cleaning / water displacement effect comparable to that of the conventionally used flon type can be obtained, and the corrosiveness is extremely low. Therefore, more stable cleaning can be performed on various base materials. Also,
Since the constituents thereof basically do not contain halogen elements such as chlorine and bromine, there is almost no possibility of causing environmental destruction or environmental pollution unlike organic solvent-based drainage cleaners such as CFCs.

Recovery and reuse of the cleaning agent in the above cleaning device are as follows. As described above, the drain pipes 4, 3a and 10 provided in the first, second and third cleaning tanks 1, 2, 7 and the draining tank 3 are connected to the cleaning agent regenerating mechanism C. . The cleaning agent D1 or D2 contained in each cleaning tank is constantly purified by the filters 6 and 12. However, when the cleaning agent becomes extremely dirty, the cleaning agent regenerating mechanism C from the drain pipes 4 and 10 is used. It is sent by the water supply pump 13 to the fractional purification. Further, the cleaning agent D1 accumulated in the drainage tank 3 is also intermittently sent to the cleaning agent regenerating mechanism C.

In the cleaning agent regenerating mechanism C, first, the filter 14 separates the liquid from the solid, and the solid content is discarded.
Only the liquid is sent to the distiller 15. In the distiller 15, separation is performed by utilizing the difference in boiling points of each component in the cleaning agent, water, oil-based dirt and the like. The water and the like remaining in the distiller 15 is further separated by the decanter 16.

Here, in the cleaning agent used in the above cleaning apparatus, the cleaning agent D1 is the cleaning agent D2 containing only low molecular weight polyorganosiloxane to which a surfactant or a hydrophilic solvent is added. D1 and cleaning agent D
The low molecular weight polyorganosiloxane, that is, the detergent D2 can be separated and extracted from each of the two.
Is played. In addition, the components other than the regenerated cleaning agent D2, that is, the surfactant, the water, and the like are discarded.

The regenerated cleaning agent D2 is sent to the blender 18 for supplying the cleaning agent D1 to the shower rinse tank 8, the third cleaning tank 7 or the second cleaning tank 2 through the pipe 17. In the shower rinse tank 8, the regenerated cleaning agent D2 is used.
Alternatively, shower cleaning is performed only with the cleaning agent D2 containing no impurities by the new cleaning agent D2 sent from the cleaning agent supply pipe 19. In addition, in the blender 18, a recycled or new cleaning agent D2 and a surfactant supply pipe 20
The new surfactant sent from the above is mixed and a new cleaning agent D1 is prepared. The cleaning agent D1 is supplied to the second cleaning tank 2 as needed.

With the cleaning apparatus having the above-described structure, the water (liquid) draining detergent containing the low molecular weight polyorganosiloxane can be used efficiently and effectively, and the low molecular weight polyorganosiloxane can be used. It becomes possible to fully exhibit the characteristics of the water (liquid) draining detergent.

In the embodiment described above, an example using the non-aqueous cleaning agent D1 in which the surfactant and the hydrophilic solvent are added to the low molecular weight polyorganosiloxane in the first step (cleaning step) has been described. In place of the non-aqueous detergent D1, an aqueous detergent, that is, at least 1 selected from the above-mentioned linear polydiorganosiloxane represented by the formula (1) and cyclic polydiorganosiloxane represented by the formula (2).
A low molecular weight polyorganosiloxane of the type described above (3)
A four-component water-based detergent D1 containing a polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit represented by the formula in one molecule, a surfactant, and water, or the above polyoxyalkylene. It is also possible to use a three-component water-based detergent D1 containing a group-containing polyorganosiloxane, a surfactant, and water.

In this case, water which is one component of the above-mentioned water-based cleaning agent is used as the cleaning agent D2 which is a rinsing solution, and water is regenerated by distillation from the cleaning effluent and the rinse cleaning effluent. Then, as in the above-described embodiment, it is used for shower rinsing and preparation of a new cleaning agent D1. As described above, by reusing water from the cleaning drainage and the rinse cleaning drainage, the water-based cleaning agent can be used efficiently and effectively.

In the above-mentioned water-based detergent, the low molecular weight polyorganosiloxane exerts a strong penetrating power for stains as described above, but these alone are hardly soluble in water and have poor dispersion stability, Since there is a possibility of phase separation in water, by using together with a polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit represented by the formula (3) in one molecule, good water resistance can be obtained. It is possible to obtain sufficient dispersion stability, and it is possible to sufficiently exhibit the strong penetrating power of the low molecular weight polyorganosiloxane against stains. Furthermore, by using a surfactant together, the cleaning performance can be improved.

The above polyoxyalkylene group-containing polyorganosiloxane is a component that exhibits an affinity for water with a polyoxyalkylene group bonded to a silicon atom and forms a stable aqueous dispersion or aqueous solution.
It also has the function of penetrating into the interface between the dirt and the base material such as the metal to which it adheres to remove the dirt, and also has the defoaming effect. Such a polyoxyalkylene group-containing polyorganosiloxane can be obtained by subjecting a polyorganosiloxane having a hydrosilyl group and a polyoxyalkylene compound having an unsaturated group at the terminal to an addition reaction in the presence of a platinum catalyst. .

The polyoxyalkylene group of A in the above formula (3) is

[Chemical 10] (In the formula, R ³ is an alkylene group having 1 to 8 carbons and 4 carbons.
To a divalent group selected from the group consisting of β-hydroxypropyleneoxyalkylene groups and polymethyleneoxyalkylene groups, R ⁴ is an alkylene group having 2 to 4 carbon atoms, R ⁵ is a hydrogen atom and a monovalent group. Is a terminal group selected from the organic groups, and n is a positive integer).

The siloxane forming the main skeleton of the polyoxyalkylene group-containing polyorganosiloxane is not particularly limited. The organic group bonded to the silicon atom of this siloxane is basically a methyl group, but within the range that does not impair the effects of the present invention, monovalent carbonization such as ethyl group, propyl group, butyl group, phenyl group, etc. It may contain a hydrogen group or a monovalent substituted hydrocarbon group such as a trifluoromethyl group.

Further, the molecular weight and the molecular weight per one polyoxyalkylene group are not particularly limited, and even if these values are large, they can be sufficiently water-soluble or stabilized by using a surfactant in combination. It can be dispersed in water. However, practically, one having a molecular weight of about 100 to 5000 per polyoxyalkylene group is preferable. Further, in the polyoxyalkylene chain, the oxyethylene portion in the total polyoxyalkylene is preferably 40 mol% or more. Further, the amount of the polyoxyalkylene group is not particularly limited, but it is more preferably 5 mol% or more based on all the organic groups bonded to the silicon atom of the polyorganosiloxane in view of the stability of the system. Examples of such polyoxyalkylene group-containing polyorganosiloxane include

[Chemical 11] (Wherein p, q, r and s are positive integers) such as chain polysiloxane,

[Chemical 12] (Wherein t 1, u and v represent positive integers).

The surfactant is a component which dissolves or emulsifies and stabilizes stains peeled off by the above-mentioned low molecular weight polyorganosiloxane and polyoxyalkylene group-containing polyorganosiloxane. Such a surfactant is classified into a cationic type, an anionic type, a nonionic type, an amphoteric type and a complex type of these depending on the chemical structure that exerts the activity. It is possible to use. However, when considering the effect of the combination with the polyoxyalkylene group-containing polyorganosiloxane, it is preferable to use any of anionic, nonionic and amphoteric surfactants, and particularly, an anionic / nonionic combination or By using the surfactant of the combination of the amphoteric system and the nonionic system, a remarkable synergistic effect can be obtained between the detergency of the surfactants and the permeability of the low molecular weight polyorganosiloxane or the polyoxyalkylene group-containing polyorganosiloxane described above. .

Among these surfactants, preferably used are polyoxyalkylene alkyl ether sulfonates, anionic surfactants such as phosphoric acid ester, polyhydric alcohol fatty acid ester, polyoxyalkylene fatty acid ester, polyoxy. Examples include nonionic surfactants such as alkylene alkyl ethers, amphoteric surfactants such as imidazoline derivatives, cationic surfactants such as alkylamine salts and alkyl quaternary ammonium salts, and others exist as a single substance. I don't do much,
Examples include terpene compounds extracted from natural products, higher fatty acid esters, and the like. It is also possible to use synthetic compounds in which a part of the chemical structure of each compound as described above is replaced with a fluorine atom or a silicon atom.

The composition ratio in the above-mentioned four-component water-based detergent is not particularly limited, but the surfactant is a polyoxyalkylene group-containing polyorganosiloxane 1
In the range of 10 to 1000 parts by weight with respect to 00 parts by weight, the low molecular weight polyorganosiloxane is 1000 parts by weight or less per 100 parts by weight of the total amount of the surfactant and the polyoxyalkylene group-containing polyorganosiloxane. It is preferable to blend in.

If the content of the surfactant is too small, the detergency becomes weak, and if it is too large, the permeability becomes weak. Also,
If the blending amount of the low molecular weight polyorganosiloxane is too large, it will be difficult to disperse in the system, and the stability as an aqueous detergent will be reduced. A more preferable compounding ratio of the above-mentioned surfactant is 30 to 700 parts by weight, and more preferably 50 to 300 parts by weight, based on 100 parts by weight of the polyoxyalkylene group-containing polyorganosiloxane. A more preferable compounding ratio of the low molecular weight polyorganosiloxane is 10 parts by weight to
It is in the range of 1000 parts by weight. The amount of water in the four-component water-based detergent is not particularly limited, but 40% by weight in the total composition from the viewpoint of detergent stability.
It is preferably not less than the above, more preferably 70 ~ 99.5
It is in the range of% by weight.

Incidentally, the polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit represented by the above formula (3) in one molecule is, as described above, itself the stain and the adhesion thereof. Since it has the effect of penetrating into the interface with the base material such as existing metal and peeling off dirt, it exhibits the effect as a water-based detergent even with the above-mentioned three-component system of polyoxyalkylene group-containing polyorganosiloxane, surfactant and water. To do. The compounding ratio at this time is based on the above-mentioned four-component water-based detergent. Above 3
For component-based or 4-component water-based detergents, the values at room temperature obtained by the permeability evaluation canvas method specified in the Japanese Industrial Standard JIS test method for textile fabrics are 15 or less, 10 or less.
Hereinafter, it is preferable to design the compounding ratio so as to be 5 or less. Further, since the cleaning performance of these water-based cleaning agents depends on the pH value of the liquid itself, it is preferable to adjust the alkaline range. A more preferred pH value is in the range 8-14.

The three-component or four-component water-based detergent as described above includes the polyoxyalkylene group-containing polyorganosiloxane, the surfactant and water, and, if necessary, the above formula (1) or (2). It can be easily obtained by mixing and stirring a low molecular weight polyorganosiloxane represented by the formula. Upon mixing, a known disperser can be used to easily obtain the aqueous detergent.

In addition, the above-mentioned water-based detergents include a pH adjusting agent and an adsorption agent which are added to ordinary water-soluble detergents depending on the nature, amount, adhesion state, washing conditions, etc. of the applied dirt substance. Agents, solid granules, synthetic builders, rust preventives, antistatic agents, etc. may be blended as an auxiliary agent for cleaning, a value added enhancer after cleaning, etc., and depending on the intended use, they are considered to have an important position.

Examples of the object (cleaning object) of using the above-mentioned water-based cleaning agent include industrial parts having a hard surface made of metal, ceramics, plastics, and the like, and more specifically, metal parts and surfaces. Processing parts, electronic parts, semiconductor parts, electric parts, precision machine parts, optical parts,
These include glass parts and ceramic parts. Further, as a specific example of a general-purpose cleaning process, ultrasonic cleaning, mechanical stirring, spraying, or the like for various components as described above, followed by washing with water (pure water or ion-exchanged water is preferable), It is general to perform draining finishing by hot air drying or the like.
Incidentally, the treatment of the deteriorated water-based cleaning agent can be easily made pollution-free by applying a general wastewater treatment technique after separating the contaminants with a filter or the like.

According to the above-mentioned water-based cleaning agent of the present invention, a strong penetrating force for the interface between the stain and the matrix by the low molecular weight polyorganosiloxane represented by the above-mentioned formula (1) or (2), and the interface Due to the cleaning power against dirt caused by the activator, a cleaning effect comparable to that of the conventionally used flon type can be obtained. By using the polyoxyalkylene group-containing polyorganosiloxane together, good dispersion stability in an aqueous system can be obtained. can get. In addition, even if it is a three-component system consisting of a polyoxyalkylene group-containing polyorganosiloxane, a surfactant and water, due to the penetrating power of the polyoxyalkylene group-containing polyorganosiloxane against dirt,
A sufficient cleaning effect can be obtained. And because it is water-based, there is no concern about environmental damage or environmental pollution.

Next, the results of a specific evaluation of the cleaning performance and liquid replacement performance of the above-mentioned water-based cleaning agent and liquid-draining cleaning agent will be described.

First, the evaluation results of the water-based detergent will be described.

Example 1 As the polyoxyalkylene group-containing polyorganosiloxane, two types represented by the following formulas (5) and (6) were prepared.

[0062]

[Chemical 13]

[Chemical 14] Next, the polyoxyalkylene-modified silicone represented by the formula (5) (A1), the polyoxyalkylene-modified silicone represented by the formula (6) (A2), and sodium laurate (B1 as a surfactant. ) And polyoxyethylene octylphenyl ether (B2) (polyoxyethylene: 20 moles) and water in a weight ratio of 5: 5: 4: 4: 82, and weigh each component in a specified amount. After that, the mixture was put into a homomixer and mixed with stirring to obtain an aqueous cleaning agent P1.

Example 2 A composition of polyoxyalkylene group-containing polyorganosiloxane of A1, sodium laurate (B1) and polyoxyethylene octylphenyl ether (B2) as a surfactant, and water are shown in Table 1. A predetermined amount was weighed so that the ratio was obtained, and an aqueous cleaning agent P2 was obtained in the same manner as in Example 1.

Examples 3 to 5 Polyoxyalkylene-modified silicones of (A1) and (A2), (B1), (B2), and (B3) described above as surfactants.
Dioctyl sodium sulfosuccinate as the above, octamethylcyclotetrasiloxane (D1) and octamethyltrisiloxane (D2) as the low molecular weight polyorganosiloxane, and water, respectively, are selected and used, and an aqueous cleaning solution having the composition ratio shown in Table 1 is used. Agents P3 to P5 were produced in the same manner as in Example 1.

Comparative Examples 1 to 3 Three kinds of water-based detergents whose composition ratios are shown in Table 1 were prepared in the same manner as in the above Examples except that the polyoxyalkylene group-containing polyorganosiloxane was not used.

The properties of the aqueous cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated according to the methods shown below. The results are also shown in Table 1.

Permeability evaluation test Measured according to the canvas method / JIS method. The smaller the value is, the higher the permeability is, which is advantageous for cleaning the details.

Detergency Evaluation Test Spindle oil is applied on a steel plate and baked at 408 K for 48 hours to prepare a test piece. The time required for cleaning the baked oil and fat (ultrasonic cleaning) of this test piece is measured. The smaller the value, the stronger the detergency.

Stability test Each detergent was put in a transparent glass bottle having a volume of 200 ml, sealed, heated at 323 K for 6 hours, then gradually cooled to 298 K, and the appearance was observed.

[0070]

[Table 1] As is clear from the evaluation results shown in Table 1, the above 3
It can be seen that both the component type and the four component type water-based cleaning agents have excellent cleaning power and penetrating power, and can be sufficiently used for applications where solvent-based cleaning agents such as CFCs have been conventionally used. Moreover, it is also highly practical because it has excellent stability. On the other hand, none of the water-based cleaning agents according to the comparative examples was satisfactory in both cleaning power and penetrating power.

Example 6 In the manufacturing process of a liquid crystal device, the liquid crystal cell is put in a high vacuum and the liquid crystal material is sealed in the device. At this time, although the exhaust processing is performed by a diffusion vacuum pump having a large exhaust performance, since the diffusion oil gradually enters the vacuum system as mist, it is necessary to occasionally maintain the pump by cleaning the pump to remove the oil.

This example is a specific example in which the above-mentioned water-based cleaning agent is applied in place of the conventionally used triethane cleaning agent. That is, silicone oil as diffusion oil
Stainless SUS with F-4 (Shin-Etsu Chemical Co., Ltd.) attached
The parts to be cleaned were pump parts made of 304 and nickel-plated material. The composition of the aqueous cleaning agent used is as shown below.

While 80% by weight of ion-exchanged water was sufficiently stirred at room temperature, 6% by weight of polyoxyalkylene group-containing polyorganosiloxane represented by the following formula (7) was gradually added to give a colorless and transparent product. A homogeneous solution was obtained.

[0074]

[Chemical 15] On the other hand, as a surfactant, a special nonionic adecanol
A mixture of 8% by weight of B-4001 (manufactured by Asahi Denka Co., Ltd.) and 6% by weight of anionic TWA-2023 (manufactured by Yatasha Yushi Co., Ltd.) having a sulfate ester pluronic structure was added to the above water / siloxane solution. added. The water-based detergent thus obtained is diluted with ion-exchanged water at an arbitrary ratio to obtain the above silicone oil.
As a result of attempting to wash F-4, 10 times the amount of water diluted at room temperature
Stirring immersion for 30 minutes, 313K for 30 times dilution, rocking immersion for 1 minute, or 293K, ultrasonic cleaning for 1 minute, 323K for 50 times dilution, 1
It was possible to satisfactorily remove each by ultrasonic cleaning for a minute.

As a comparison with the present invention, the same cleaning was performed in the same manner using a composition system containing only the above-mentioned surfactant, which does not contain polyoxyalkylene group-containing polyorganosiloxane among the above-mentioned cleaning agents. Even when used together, with 10-fold dilution, the silicone oil remained unwashed well even after immersion for 10 minutes at room temperature. Also, under the same conditions at this concentration, it took 5 minutes or more at 338K or higher.

From these results, the outstanding cleaning effect of the water-based cleaning agent containing the polyoxyalkylene group-containing polyorganosiloxane was shown.

Example 7 The polyoxyalkylene group-containing polyorganosiloxane and low molecular weight polyorganosiloxane described above also contribute to a dramatic increase in the cleaning effect of a commercially available water-soluble detergent.

Chemiclean MS-109 aqueous solution (manufactured by Sanyo Kasei Co., Ltd.), which is a low-foaming, rust-preventive cleaning agent containing a surfactant, which is often used for cleaning mechanical parts and metal parts.
To 65% by weight, 3% by weight of the polyoxyalkylene-modified silicone (A1) represented by the above formula (5) used in Example 1, 5% by weight of hexamethylcyclotrisiloxane and 17% by weight of deionized water were mixed, A new cleaning agent was prepared.

This was diluted 20 times with ion-exchanged water and the detergency was evaluated by the method shown below. The results are shown in Table 2. In addition, as a comparative example, Chemiclean MS-109 commercial detergent diluted with 20 times water was also shown.

Test method (1) Washing test-1 The following contaminants were dipped and applied on a degreased aluminum plate (AC-4A), air-dried, and then agitated (40 times diluted with each washing liquid).
Soak for 15 seconds to 1 minute. Next, after soaking in water and air-drying, the contaminants are transferred with an adhesive tape and attached to a white paper, and the reflectance is measured with a colorimeter to obtain the cleaning rate.

Pollutants Spindle oil 78% Fatty acid ester 15% Chlorinated paraffin 5% Carbon black 2% Cleaning rate (%) = Rw-Rs / Ro-Rs Ro: Raw white paper reflectance Rs: Standard pollutant reflectance Rw: reflectance of the contaminated plate after cleaning (2) Cleaning test-2 In the same manner as in the above cleaning test-1, contaminants are added by adding 2% of carbon black to water-soluble cutting oil (emulsion type). The cleaning rate is calculated in the same manner as above.

[0082]

[Table 2] A similar test was performed using a commercially available water-based detergent, super-efficiency detergent EP-680.
(Ep Japan Co., Ltd.), emulsion-type degreasing detergent Van Rise D-20 (Tokiwa Chemical Industry Co., Ltd.), and strong special cleaning liquid Hikari Ace (Akiko Tsusho Co., Ltd.). The combined use of the contained polyorganosiloxane and the low molecular weight polyorganosiloxane resulted in remarkable detergency.

Example 8 The above-mentioned water-based cleaning agent also exhibits a remarkable effect in cleaning the flux used for mounting (wiring) components on a printed circuit board. Flux is roughly classified into rosin-based and water-based flux, but since it is said that it is particularly difficult to clean the rosin-based flux, a specific example thereof will be shown.

As a pretreatment process for solder-plating the components on the printed circuit board, after applying the WW-based rosin ester,
Completed wiring through 03-523K solder bath. It was confirmed that the flux was completely removed by shower-rinsing this with the following aqueous cleaning agent at 308 K for 45 seconds.

The water-based detergent used here was 2% by weight of a polyoxyalkylene group-containing polyorganosiloxane represented by the following formula (8), and 3% by weight of an amphoteric surfactant Senkanol FM (manufactured by Nippon Dye-Chemical Co., Ltd.). % And sodium / N-cocoylmethyltaurine nonionic surfactant Nikkor CMT-
30% (manufactured by Nippon Surfactant Co., Ltd.) is made up to 100% by weight with ion-exchanged water.

[0086]

[Chemical 16] When the above-mentioned water-based cleaning agent was diluted 10 times with ion-exchanged water and used, the results satisfied the accelerated aging test, surface insulation resistance test, ionic residue test, etc. that cleared the MIL-F-14256C standard (US). was gotten.

Next, the evaluation results of the drainage cleaning agent (non-aqueous cleaning agent) will be described.

Examples 9 to 17 As low molecular weight polyorganosiloxanes, octamethyltrisiloxane (E1), octamethylcyclotetrasiloxane (E2) and decamethylcyclopentasiloxane (E3)
As a surfactant, polyoxyethylene oleyl ether (F1) (POE = 6mol) and polyoxyethylene octylphenyl ether (F2) (POE = 10mol)
To prepare diethylene glycol monobutyl ether (G1) as a hydrophilic solvent.

Then, by selectively using each of these components,
Drainage detergents were prepared according to the composition ratios shown in Table 3.

Comparative Examples 4 to 8 Freon 113, methylene chloride, isopropyl alcohol and ethanol were prepared as conventional drainage detergents, and five types of drainage detergents whose composition ratios are shown in Table 3 were prepared.

These Examples 9 to 17 and Comparative Examples 4 to 8
The various properties of each of the drainage detergents were evaluated according to the following methods. The results are also shown in Table 3.

Drainability Various base materials (stainless steel plate, ceramics, polycarbonate, Ni-plated steel plate) were washed with water and then immersed in each water-drainage cleaning agent. The drainage detergents of Examples 13 to 15 were further rinsed with the low-molecular weight polyorganosiloxane used. Then, oven drying was performed at 323K. Then, the dried watermarks (stains due to scales) were observed visually and by a scanning electron microscope, and evaluated according to the following criteria.

XX: When the base material was eroded in the draining step and the evaluation could not be reached.

X: When a watermark was visually observed.

O: When no watermark was visually observed.

⊚: When a watermark of 50 μm or more was not observed by a scanning electron microscope.

Continuous drainage performance Using a stainless steel plate as a base material, the appearance after 50 drainage tests were evaluated in the same manner as above.

Dryability After the stainless steel plate was dipped in each cleaning agent, it was oven-dried at 333 K, and it was touched every 5 minutes to see if it was dry, and the time was recorded in units of 5 minutes.

[0099]

[Table 3] As is clear from the evaluation results shown in Table 3, all of the draining detergents using low molecular weight polyorganosiloxane are excellent in draining property, and are suitable for applications where organic solvent-based detergents such as CFCs have been conventionally used. It turns out that it can be fully used.

Further, the water-draining detergents of Comparative Examples 4 and 5 using methylene chloride and isopropyl alcohol had rusting property and eroding property with respect to metal films and plastics. On the other hand, all of the drainage cleaning agents according to the examples are stable to metal films and plastics, and have sufficient drainability even to ceramics having a large surface roughness. It can be seen that it can be used with sufficient reliability for parts, semiconductor parts, plastic parts, ceramic parts and the like. In addition, isopropyl alcohol was miscible with water, which caused reattachment of water to the substrate. Furthermore, it is found that the addition of a surfactant or a hydrophilic solvent further improves the water drainage property, and is effective for industrial use.

[0101]

As described above, according to the cleaning method of the present invention, it is possible to effectively and efficiently use an alternative cleaning agent or rinsing solution for an organic solvent type cleaning agent such as a CFC type which has environmental problems. In addition to being able to do so, it becomes possible to make full use of those characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a cleaning device to which a cleaning method of the present invention is applied.

[Explanation of symbols]

 A: cleaning process (cleaning and / or water replacement process) B: rinsing process (cleaning process) C: cleaning agent regeneration mechanism 1 ... first cleaning tank 2 ... second cleaning tank 3 ... Draining tank 7 ... Third cleaning tank 8 ... Shower rinse tank 14 ... Filter 15 ... Distiller 16 ... Decanter

 ─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 2-65842 (32) Priority date Hei 2 (1990) March 16 (33) Priority claim country Japan (JP) (72) Inventor Noriaki Yagi 2121-D103 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa (72) Inventor Nobuhiro Saito 908-10 Toriyama, Ota-shi, Gunma Prefecture (72) Inventor Akitsugu Kurita 1322-24 (72) Inventor, Ota-shi, Gunma Prefecture Yoshiaki Takezawa 1418-9 Izumicho, Ota City, Gunma Prefecture

Claims (5)

[Claims] 1. A cleaning process for cleaning an object to be cleaned by a cleaning tank containing a cleaning agent, and a rinsing liquid containing only one component in the cleaning agent is accommodated, which is reverse to the transfer direction of the object to be cleaned. A plurality of rinse washing tanks connected so that the rinse liquid is sequentially sent in a direction, comprising a rinsing step of rinsing and washing the object to be washed after the washing, and the washing drainage liquid from the washing tank of the washing step. With collecting
Of the plurality of rinse cleaning tanks, the rinse cleaning drainage liquid is collected from the downstreammost rinse cleaning tank, and the collected cleaning drainage liquid and rinse cleaning drainage liquid are distilled to regenerate the rinse liquid, and then this regeneration is performed. A cleaning method, wherein the rinsing step is performed while re-supplying a rinsing liquid to the rinsing cleaning tank on the most upstream side. 2. The cleaning method according to claim 1, wherein the cleaning agent is: (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
A linear polydiorganosiloxane represented by a monovalent organic group, and l is an integer of 0 to 5; (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
At least a monovalent organic group, m is an integer of 3 to 7) selected from cyclic polydiorganosiloxanes
Using a detergent in which at least one selected from a surfactant and a hydrophilic solvent is mixed with one type of low molecular weight polyorganosiloxane, and using the rinse agent of the low molecular weight polyorganosiloxane alone as the rinse liquid. A cleaning method comprising regenerating the low molecular weight polyorganosiloxane by the distillation. 3. The cleaning method according to claim 1, wherein the cleaning agent is: (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
A linear polydiorganosiloxane represented by a monovalent organic group, and l represents an integer of 0 to 5; (In the formula, R ¹ is the same or different and is substituted or unsubstituted.
A monovalent organic group, m is an integer of 3 to 7) and at least 1 selected from cyclic polydiorganosiloxanes represented by
A series of low molecular weight polyorganosiloxanes, and (In the formula, R ² represents an alkyl group or a phenyl group, and A represents a polyoxyalkylene group) A polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit in one molecule A cleaning method comprising using a cleaning agent containing an agent and water, using water as the rinse liquid, and regenerating the water by the distillation. 4. The cleaning method according to claim 1, wherein the cleaning agent is: (In the formula, R ² represents an alkyl group or a phenyl group, and A represents a polyoxyalkylene group) A polyoxyalkylene group-containing polyorganosiloxane having at least one siloxy unit in one molecule A cleaning method comprising using a cleaning agent containing an agent and water, using water as the rinse liquid, and regenerating the water by the distillation. 5. The cleaning method according to claim 1, wherein, as the pretreatment of the distillation, the cleaning waste liquid and the rinse cleaning waste liquid are filtered.