JP3577768B2 - Cleaning apparatus with distillation recovery device and cleaning method using the same - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a cleaning apparatus and a cleaning method, and more particularly, to a cleaning apparatus and a method for efficiently cleaning and removing oil adhering to an object to be cleaned such as a metal component and an electronic component, and is particularly preferable. More particularly, the present invention relates to an apparatus and a method suitable for cleaning a substrate for an electrophotographic photosensitive member.
[0002]
[Prior art]
For machine parts and electric parts, cutting oil and press oil are used in the cutting and pressing processes to reduce friction. In the heat treatment process, quenched products are returned to the heat treatment oil to reduce distortion. Oil adheres to In order to finish these parts, it is necessary to wash away the attached oil.
Conventionally, kerosene, hydrocarbon solvents such as benzene, chlorinated hydrocarbon solvents such as trichloroethane, freon solvents such as trichlorotrifluoroethane, and water-based detergents containing alkali and surfactants have been used for washing and removing adhering oil. Used.
[0003]
[Problems to be solved by the invention]
However, hydrocarbon solvents are flammable and require explosion-proof measures. Chlorinated hydrocarbons and chlorofluorocarbon solvents have problems such as toxicity and environmental pollution, and their use is restricted. In the case of a water-based cleaning agent, rinsing with a large amount of water in order to remove the cleaning agent and residual oil adhering to the object to be cleaned. There was a problem.
[0004]
In view of the problems of the cleaning agent, various efficient cleaning apparatuses have been developed to enhance the cleaning effect. In the case of hydrocarbon-based cleaning agents, a system is installed in which a distillate is installed to remove the dissolved oil from the object to be cleaned and dissolved in the cleaning agent, and the distillate is recycled and recycled, and the bottoms containing oil are removed from the system. Methods for adjusting the oil concentration in the rinse liquid are known. Further, in the case of a water-based cleaning agent, a method of diluting with a large amount of water in order to adjust the concentration of the cleaning agent and the residual oil in the rinsing liquid has been adopted. However, such a method not only requires a large amount of water, but also does not reduce the total amount of detergent and oil discharged to the external environment.
[0005]
[Means for Solving the Problems]
Accordingly, the present inventors have conducted intensive studies, performed rinsing in a rinsing tank, distilled the rinsing liquid in the rinsing tank that has become dirty, and reused both separated liquids to clean the rinsing liquid. In addition, the present invention has been found that a cleaning apparatus and a cleaning method which not only prevent contamination to the external environment but are economically excellent can be obtained because the amount of the detergent taken out of the system can be reduced while keeping the cleaning agent out of the system. That is, an object of the present invention is to provide a cleaning apparatus and a cleaning method which do not pollute the external environment and are economically excellent.
[0006]
Such a purpose is to wash an object to be washed in a washing tank, and then in a washing apparatus that performs rinsing in a rinsing tank, at least a part of the rinsing liquid after the rinsing is distilled, and the first liquid and the rinsing liquid having a composition close to the cleaning liquid are used. A washing apparatus characterized in that it is separated into a second liquid of the composition, and the first liquid is recovered and reused for rinsing the second liquid for washing.
and,
In a cleaning method of cleaning an object to be cleaned in a cleaning tank and then rinsing in a rinsing tank, at least a part of the rinse liquid after rinsing is distilled, and a first liquid having a composition close to the cleaning liquid and a second liquid having a composition close to the rinse liquid are used. Separated into two liquids, the first liquid for washing, the second liquid is recovered and reused for rinsing, a washing method,
Is easily achieved.
[0007]
Hereinafter, the present invention will be described in more detail.
The present invention is effective when the main components of the cleaning liquid and the rinsing liquid are different. As the rinsing liquid, the rinsing liquid has the ability to dissolve and remove the cleaning liquid, and the rinsing liquid that has been replaced and adhered to the object to be cleaned is easily removed in the drying step. It needs to be something. From this viewpoint, suitable rinsing liquids include water and alcohol. Among the alcohols, isopropyl alcohol (IPA) is preferred, but water is more preferred because alcohols must be explosion-proof in view of being flammable.
[0008]
On the other hand, the cleaning liquid is not particularly limited, but it is necessary to clean the rinsing liquid in consideration of a drying step, and it is preferable that the rinsing liquid be on the distilling side. In the present invention, the rinsing liquid partially containing the cleaning liquid is partially distilled to separate the cleaning liquid and the rinsing liquid, but as the cleaning agent on the cleaning liquid side, the boiler has a higher boiling point than the rinsing liquid, A cleaning agent which does not cause azeotropy and has a large relative volatility is preferred. From such a viewpoint, preferred detergents are water-soluble high-boiling organic solvents, and particularly preferred are pyrrolidone compounds and glycol compounds. The preferred composition of the cleaning liquid is 40% by weight or less (hereinafter abbreviated as "%") of water and 60% or less of the cleaning agent, particularly preferably 20% or less, and more preferably 10 to 15% of the cleaning agent.
[0009]
Suitable pyrrolidones include N-alkyl-2-pyrrolidone (alkyl group is methyl, ethyl, propyl group and the like), 2-pyrrolidone, 3-pyrrolidone and the like, and γ-butyrolactone, N, N-dialkylacetamide (alkyl Groups are methyl, ethyl, propyl groups, etc.). As the glycols, alkylene glycols (alkylene groups containing ethylene, propylene, butylene groups, etc. and higher hydrocarbon olefins and higher and alcohol groups having adjacent methylene groups interposed therebetween) are preferable.
In the distillation recovery device, the packing and the tray stage may include a device for increasing the separation efficiency, and may be either a batch operation or a continuous operation, and is not particularly limited. Structurally, it is only necessary that the lower pot has a heat source, the upper side for cooking has a cooler, and can separate a second liquid having a composition close to the rinsing liquid and a first liquid having a composition close to the cleaning liquid.
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist.
[0010]
【Example】
[Example 1]
With reference to the drawings below, in the step of rinsing after washing the oil-adhered article of the present invention, a part of the rinsing liquid containing the cleaning agent is distilled and recovered to separate the rinsing liquid and the cleaning liquid, A system for returning to the rinsing tank and the washing tank, respectively, will be described.
FIG. 1 shows an example in which a liquid containing 15% or more of water as a mixture of N-methyl-2-pyrrolidone (NMP) and water is selected as a cleaning liquid, and water is selected as a rinsing liquid. In this case, both the cleaning liquid and the rinsing liquid are incombustible. If the distillation / recovery unit is also operated as a bottom liquid having a ratio of the cleaning liquid to the rinsing liquid determined by the temperature of the pot 14, the distillation / recovery unit is also non-combustible. Features that can be handled by physical systems appear. For example, at a pot temperature of 106 ° C., a bottoms of 35% water is formed, separated as a bottoms having a composition close to the cleaning liquid composition, and collected in the cleaning tank 1.
[0011]
The object to be cleaned 8 is passed through the transport systems 11, 12, and 13, is cleaned in the cleaning tank 1, is continuously rinsed in the rinsing tank 2, and then moves to a drying step. The cleaning liquid 9 containing the defatted oil overflowing from the cleaning tank 1 enters the oil separation tank 3 and the floating oil is collected. The lower layer cleaning liquid is pressurized by a pump and circulated to the cleaning tank 1 through a pipe 10.
Since the rinsing tank 2 contains the cleaning liquid brought from the cleaning tank 1, a part of the rinsing liquid is led to the distillation and recovery unit 4 through the pipe 5 and distilled, so that the distillate 6 has a composition similar to that of the rinsing liquid. The two liquids are separated into a bottom 7 and a first liquid having a composition close to the cleaning liquid, and are collected in the rinsing tank 2 and the cleaning tank 1, respectively.
[0012]
[Example 2]
An example in which N-methyl-2-pyrrolidone (NMP) is selected as the cleaning liquid and isopropyl alcohol (IPA) is selected as the rinsing liquid will be described. In this case, since both the cleaning liquid and the rinsing liquid are flammable substances, considering a process for combusting flammable substances, as shown in FIG. Example 1 is the same as Example 1 except that a well-known distilling device 15 for recovering an oil component is installed.
[0013]
In the case of FIG. 1, the apparatus utilizes low oil solubility specific to NMP to water system. On the other hand, in the second embodiment, since the oil solubility is high, the apparatus depends on the still 15.
Alternatively, even if the distillation unit 15 is not used, the entire amount of the washing solution may be replaced when the oil content is almost saturated and dissolved. In such a case, the washing solution is separated into the washing solution and the rinsing solution by the distillation and recovery unit 4 and distilled. There is no change in the configuration of the present invention in which the first liquid and the second liquid are returned to the respective target tanks.
[0014]
【The invention's effect】
If the main components of the cleaning liquid and the rinsing liquid are different, the rinsing liquid is contaminated by the carry-out of the cleaning liquid to the rinsing liquid due to repeated cleaning, and a part of the rinsing liquid is distilled to perform the rinsing with a clean rinsing liquid. Separating the washing liquid and the rinsing liquid through a recovery unit, and collecting them in the original tank respectively, prevents pollution to the external environment due to a considerable reduction in the amount of waste rinsing liquid, and furthermore, the amount of new rinsing liquid input The economy can be improved by the reduction.
Therefore, it is possible to reduce the loss amount of the cleaning agent taken out of the system by collecting the loss amount of the cleaning solution to the rinsing side, and to increase the rinsing efficiency by reducing the concentration of the cleaning solution component in the rinsing solution. And the number of rinsing tanks can be reduced.
In particular, when the water-soluble high-boiling organic solvent system is a cleaning agent and the rinsing liquid is water, the cleaning liquid components accumulate in the rinsing liquid. By returning the water as a liquid to the rinsing tank and returning the high boiling organic solvent as the bottom liquid to the washing tank, the loss is reduced, the apparatus is simplified, and the effect is large.
The present invention can be used for cleaning various articles, and is suitably used, for example, for cleaning a substrate for an electrophotographic photosensitive member.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a specific example of an apparatus and a method of the present invention.
FIG. 2 is an explanatory view showing a specific example of the apparatus and method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Washing tank 2 Rinse tank 3 Oil separator 4 Distillation recovery machine 5 Rinse liquid path before distillation 6 Second liquid path 7 First liquid path 8 Object to be cleaned 9 Cleaning liquid containing degreased oil 10 Pipes 11, 12, 13 Transport system 14 Kettle 15 Distiller 16 Oil path

Claims (6)

In a cleaning apparatus for cleaning an object to be cleaned in a cleaning tank and then rinsing in a rinsing tank, at least a part of the rinse liquid after rinsing is distilled, and a first liquid having a composition close to the cleaning liquid and a second liquid having a composition close to the rinse liquid are used. A cleaning apparatus comprising separating two liquids, collecting the first liquid for rinsing the second liquid for rinsing, and reusing the second liquid for rinsing. In a cleaning method of cleaning an object to be cleaned in a cleaning tank and then rinsing in a rinsing tank, at least a part of the rinse liquid after rinsing is distilled, and a first liquid having a composition close to the cleaning liquid and a second liquid having a composition close to the rinse liquid are used. A washing method comprising separating into two liquids, collecting and reusing the first liquid for washing and the second liquid for rinsing. The cleaning method according to claim 2, wherein a main component of the cleaning liquid is a water-soluble high-boiling organic solvent, and a main component of the rinsing liquid is water. The cleaning method according to claim 3, wherein the water-soluble high-boiling organic solvent is a pyrrolidone compound. The cleaning method according to claim 3, wherein the water-soluble high-boiling organic solvent is a glycol compound. The method according to claim 4, wherein the pyrrolidone compound is N-methyl-2-pyrrolidone.

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