JP2005232547A - Method for cleaning metallic member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for adequately cleaning a metallic member having processing oil stuck thereto. <P>SOLUTION: This cleaning method comprises pre-cleaning the metallic member with oil before cleaning it; and further comprises cleaning the metallic member preferably by using alkaline water obtained by electrolysis as a solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for cleaning a metal member, and more particularly to a method for cleaning a support sheet metal before forming a blade on a support sheet metal of a blade member such as a cleaning blade and a developing blade used in an electrophotographic apparatus.

  In various mechanical devices, a metal member is cut out from a metal material and manufactured by cutting, punching, stamping, polishing, or the like. In such a processing stage, machine oil, processing oil, industrial lubricating oil, etc. (hereinafter these may be abbreviated as “processing oil”) to prevent oxidation of metal materials and seizure during processing. Is used.

  Further, since the metal member is disliked to be oxidized even after processing, a processing oil for rust prevention or the like may be applied to the surface.

  That is, in any case, the processing oil or the like adheres to the surface of the metal member. Such a metal member to which processing oil or the like is attached is not a problem when used as it is, but it adheres to the surface when painting or bonding or directly forming another member on the metal member. May not work well because of the oil slick.

  For this reason, cleaning with a hydrocarbon solvent, an organic solvent such as an alcohol solvent, or a halon solvent such as a chlorofluorocarbon solvent is performed. In particular, cleaning with a chlorofluorocarbon solvent has been preferred because of a good surface condition after the cleaning. By the way, in recent years, the use of chlorofluorocarbon solvents has been regulated, and a cleaning method replacing chlorofluorocarbon solvent cleaning has been demanded.

  On the other hand, cleaning with other organic solvents is effective for cleaning attached oil, but not so much with chlorofluorocarbon solvents, and solvents with low boiling points have problems of ignition and explosion, such as fire prevention, explosion prevention, and deodorization. Countermeasures are necessary, and the removal of adhering oil is not sufficient with a solvent having a high boiling point.

  By the way, as a cleaning method that does not ignite or explode, there is an aqueous solvent using alkaline water containing caustic soda or ammonia, acidic water containing hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, etc., water containing a surfactant or industrial water itself. Are known. In the case of using alkaline water or acidic water, there is a problem of corrosion of the metal surface, and it is necessary to remove the attached alkaline or acidic water. In particular, when the metal is iron, it is coated with zinc or tin for surface protection, but these are easily affected by alkaline water or acidic water, and since an oxide film is formed on the surface, they are relatively good materials. Even if it is recommended aluminum, the coating film dissolves in alkaline water, and aluminum itself is attacked by alkaline water and acidic water, so that it is difficult to adopt as a cleaning method.

  In addition, washing with water containing surfactants is relatively good at removing oil containing processing oil, etc., but because it is water-based, it is not enough to suppress corrosion due to dissolved oxygen, and drainage is only oil. Instead, the included surfactant needs to be post-treated.

  In recent years, it has been attempted to include hydrogen in the wash water as a technique for suppressing corrosion due to dissolved oxygen from the situation (see, for example, Patent Document 1), but since hydrogen is used, various provisions for hydrogen (for example, Explosion-proof equipment, high-pressure gas equipment, etc.) are required.

  On the other hand, alkaline water or acidic water that does not use an alkaline component or acidic component, so-called electrolyzed water has come to the public for drinking, and attempts have been made to use this electrolyzed water for cleaning metal members (for example, Patent Documents 2 and 3).

  However, even with this method, washing with fresh water after washing such as washing with alkaline water or acidic water containing the electrolyte is not necessary, but the fixed oil may not be sufficiently washed because it does not contain electrolyte. It was.

  As a method for cleaning a metal member, a method of immersing the metal member in a cleaning solvent to remove deposits such as processing oil attached to the metal member (immersion type cleaning method) is known. However, since the detergency is low only by immersion type cleaning, it is necessary to degrease with an alkaline aqueous solution in advance and perform final cleaning with a brush roll before performing immersion type cleaning. As described above, the immersion cleaning method complicates the process and causes an increase in cost.

  Therefore, a cleaning method for supplying gas from the air supply system and generating gas-dissolved water in which the gas is dissolved in the cleaning water in the high-pressure vessel, and jetting the cleaning water containing the gas to the object to be cleaned (for example, Patent Document 4) and a method of heating and pressurizing alkaline electrolyzed water generated by electrolyzing water or an aqueous electrolyte solution and spraying the object to be cleaned (for example, refer to Patent Document 5) have been studied. .

However, in these methods, the cleaning can be performed without any problem as long as the processing oil or the like is simply attached to the metal member. However, the deterioration of the oil or the adhesion of dust due to processing or long-term storage on the metal member. In the case where the processing oil or the like is stuck due to the attachment of denatured oil during transportation, a sufficient cleaning effect cannot be obtained.
JP-A-58-37200 JP-A-7-75784 JP-A-8-1160 JP-A-6-71233 JP 2001-327934 A

  Therefore, an object of the present invention is to provide a method that can perform cleaning well in cleaning a metal member to which processing oil or the like is fixed.

  In order to solve the above-mentioned problems, the inventors of the present invention have intensively studied.When the metal member is washed, the metal member is immersed in fresh processing oil or the like in advance, and the one pulled up is immediately subjected to washing. The present inventors have found that the surface of the metal member can be easily cleaned even when oil is fixed, and have further studied and finally reached the present invention.

  That is, the present invention is a method for cleaning a metal member, characterized in that preliminary cleaning with oil is performed when the metal member is cleaned.

  The solvent used for washing is water, and the water is alkaline electrolyzed water, particularly alkaline electrolyzed water having a pH of 8 to 12, or when the solvent is water, the washing is preferably performed by high-pressure jet water, It is preferable that the metal member is a support sheet metal for a blade member for an electrophotographic apparatus.

  In the method for cleaning a metal member according to the present invention, prior to cleaning, the oil component, which is fixed to the metal member only by washing (wetting) with oil, particularly processing oil, etc., is easily removed, and an ordinary oil component that is difficult to remove by washing is easily obtained. Since there is no adverse effect such as corrosion on the surface of the member, it can be cleaned, so there is almost no need for equipment enhancement, and its utility value is high.

  The metal member targeted by the present invention is a member used as a structural member of various machines such as iron, stainless steel, brass, etc., ranging from a structural housing to small parts such as gears. These members are often coated with oils such as machine oils, processing oils, industrial lubricating oils, etc. from the raw material stage before processing to prevent surface oxidation. Processing oil or the like is used.

  It is preferable that the metal member is covered with an oil film that has a rust-proofing effect if used as it is, but this oil film may be a hindrance when the surface is painted or used in combination with other members. It often becomes. In particular, those that have been stored for a long time or those that use processing oil or the like at the time of processing often have an oil film adhering to them, and usually require fairly aggressive cleaning. However, if the cleaning method of the present invention is employed, cleaning can be easily performed.

  Examples of metal members that are used integrally with other members include various blade members used in electrophotographic apparatuses. This blade member is normally attached to a support metal plate, which is a metal member, with a blade made of elastic rubber as an integral unit. In manufacturing this blade member, the support sheet metal is washed.

  Regarding the raw material of the metal member, the raw metal plate of the support sheet metal will be described as follows: galvanized steel sheet, zinc-nickel plated steel sheet, zinc-iron plated steel sheet, zinc-chromium plated steel sheet, zinc-aluminum plated steel sheet, zinc-titanium plated steel sheet Zinc-based electroplating such as zinc-magnesium-plated steel sheet, zinc-manganese-plated steel sheet, hot-dip plating, vapor-deposited steel sheet, aluminum or aluminum alloy-plated steel sheet, lead or lead alloy-plated steel sheet, tin or tin alloy-plated steel sheet, and These plating layers containing a small amount of different metal elements or impurities such as cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, antimony, tin, copper, cadmium, arsenic, etc. And / or silica, alumina, tita There is obtained by dispersing inorganic substances such as A, and further, more plating and other types of plating such as iron plating, iron - those multilayer plating combining phosphorous plating, and the like. One type of surface treatment is non-chromium surface treatment, and the support sheet metal is preferably subjected to non-chromium surface treatment.

  Non-chromium surface treatment means, for example, acrylic resin, polyolefin resin, polyurethane resin, polycarbonate resin, epoxy resin, polyester resin, alkyd resin, and polymers obtained by partially modifying them on a metal surface. Or a layer such as one selected from a water-based resin selected from a copolymer or the like or a solvent-based resin, or a mixture of two or more types is provided, and in particular, a resin that can be cross-linked as a resin. It is preferable.

  As the degree of cleaning, it is usually appropriate that the surface tension measured according to JIS-K6768 is 360 μN / cm or more. If the surface tension is equal to or greater than this value, the surface of the metal member can be painted and integrated with other members in terms of quality, and in particular, the quality of the manufactured blade member can be sufficiently satisfied in the manufacture of the blade member. Become. If this value is 400 μN / cm or more, it can be determined that the film has been completely cleaned.

  In the present invention, the metal member is cleaned by the process flow shown in FIG.

  First, preliminary cleaning 1 with oil is performed on the metal member. Next, the pre-cleaning oil adhering and remaining on the surface of the metal member by pre-cleaning is washed off by the main cleaning 2 together with the oil stains fixed to the metal member. Finally, the cleaning solvent attached to the surface of the metal member is dried 3. Since the metal member after completion of drying does not have oil for surface protection, it is usually supplied to the next step, for example, the coating step, or the integration step with other members, without taking much time.

  The preliminary cleaning is performed as a pre-process of the main cleaning, and in the present invention, is a cleaning using oil. Although not always necessary, in the present invention, preliminary cleaning may be further performed by various cleaning methods prior to preliminary cleaning using this oil.

  Examples of the oil used for the preliminary cleaning include machine oil, processing oil, industrial lubricating oil (for example, No. 615: Japanese working oil) used for metal processing and rust prevention. It is desirable that the viscosity be as low as possible. This has an affinity for the oil component fixed on the surface of the metal member, and in the main cleaning with various solvents after dissolving the oil fixed to the pre-cleaned oil, preferably an aqueous cleaning agent, particularly with water, This is because it can be easily washed.

  In the present invention, it is not necessary to pre-clean the entire surface of the metal member. For example, when the metal member is a support sheet metal of the blade member, only a portion necessary for forming and bonding the blade of the support sheet metal is pre-cleaned. It may be. That is, it is only necessary to pre-clean only the portions of the metal member that are to be cleaned, and the oil from the pre-cleaning remains attached.

  Further, it is not necessary that the oil component fixed to the surface of the metal member is completely removed by the preliminary cleaning, and it is sufficient that the oil used by the preliminary cleaning penetrates the fixed oil. For example, not only immersion cleaning with processing oil, spray cleaning, wiping cleaning with an oil-impregnated cloth, etc., but a necessary amount of oil may be held on the surface of the metal member. Examples of the method for retaining the oil on the surface of the metal member include dipping, spraying, application using a sponge, cloth, and the like. Preferably, it is spray injection. It is desirable that the injection pressure be 0.05 MPa or less. Since the oil used in the preliminary cleaning in the present invention is in a very small amount, a sufficient cleaning effect can be obtained. Therefore, when the injection pressure exceeds 0.05 MPa, extra oil is deposited or oil smoke is generated.

  In the preliminary cleaning, the oil adheres to the surface of the metal member, but it is desirable to spread the oil adhering after the adhesion treatment uniformly over the entire cleaning region. Examples of the spreading method include a gas injection method, a method of spreading using a sponge, a blade, and the like. After the spreading operation, it is desirable that the pre-cleaning oil existing on the metal member is 10 μm or less. If it is 10 μm or more, the amount of oil necessary to remain after pre-cleaning is exceeded, increasing the load of water cleaning in the next step, and as a result, the metal member cleaning ability tends to be reduced.

  Next, main cleaning with various solvents is performed on the metal member that has been pre-cleaned with oil. The solvent used here is, for example, an organic solvent-based cleaning liquid (for example, a hydrocarbon-based solvent, an alcohol-based solvent, a silicon-based solvent), an aqueous-based solvent, or the like, as long as the pre-cleaning oil attached to the surface of the metal member is sufficiently washed away Detergents (industrial water, electrolyzed water, alkaline cleaners, neutral cleaners, acidic cleaners), semi-aqueous cleaners (for example, water combined with a flammable solvent such as hydrocarbon, glycol ether, methylpyrrolidone, surfactant) Any of these may be used. Moreover, as this washing | cleaning, it is also possible to combine two or more different solvent systems as needed.

  From the viewpoint of safety, water-based ones, particularly water, are preferable. In the case of water, those containing almost no acidic component or alkaline component are desirable. Recently developed electrolyzed water contains almost no inorganic ions, and is provided as proton ion rich water (acidic electrolyzed water) or alkali ion rich water (alkaline electrolyzed water) by electrolysis of water. It is preferable because it has a higher washing ability than deionized water, and can be used in the present invention. In particular, alkaline electrolyzed water is preferable because of its excellent ability to wash oil. In addition, pH 8-12 is preferable as an alkaline degree in this case, Preferably pH 9-11 is suitable. If the pH of the alkaline electrolyzed water is lower than 8, the degreasing performance tends to be low, and a sufficient cleaning effect may not be obtained. On the other hand, when the pH of the alkaline electrolyzed water is higher than 12, the surface of the metal member is easily corroded by the influence of strong alkalinity, which may cause defects in quality.

  There are various methods, such as a method of immersing a metal member in water, a method of immersing ultrasonic waves applying ultrasonic waves, a method of spraying water, a method of wiping with a cloth containing water, etc. Any method can be used as long as the oil adhered to the surface is removed by the pre-cleaning. However, the method of cleaning by jetting water at a high pressure is preferable because the oil film on the surface of the metal member is peeled off by the high-pressure water. In this case, the high-pressure jet water is jetted from the nozzle onto the surface of the metal member at a pressure of 0.2 to 1.0 MPa. When this pressure is lower than 0.2 MPa, the collision energy is too small and sufficient cleaning may not be obtained. When the pressure is higher than 1.0 MPa, the surface of the metal member is roughened by the impact force of high-pressure water. May occur, and quality problems may occur.

  Further, the temperature of the washing water in the water washing is desirably 50 to 70 ° C. If the temperature is less than 50 ° C., removal of adhering oil tends to be insufficient, and it takes time to dry the metal member after washing, so the cost of the drying device is high and the surface of the metal member rusts during drying. There is. On the other hand, when the temperature exceeds 70 ° C., the surface of the metal member is likely to deteriorate, and depending on the material of the metal member, it may be deformed, resulting in a quality defect.

  After the main cleaning, the metal member is dried and supplied to the next step. In addition, there are various drying methods such as a method of blowing dry air (including nitrogen), a method of passing through a drying furnace under reduced pressure or normal pressure, a method of wiping with a dry cloth, etc., but the next step without oxidizing the metal member surface Any method may be used as long as the method can be supplied to. In addition, it is not always necessary to cooperate with the next step by storing the cleaned and dried metal member in a clean atmosphere.

  Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to these examples.

  First, the cleaning power evaluation will be described.

・ Evaluation of degree of cleaning (surface tension)
The evaluation of the degree of cleaning of the surface of the metal member was based on the surface tension measured based on JIS-K6768. That is, the surface tension of a sample left under the temperature and humidity conditions defined by JIS is measured using a wet tension test mixture (manufactured by Wako Pure Chemical Industries, Ltd.). If the surface tension is 360 μN / cm or more, it is determined that the surface is cleaned.

-Surface corrosion After drying, the surface state of the cleaned part was observed with a magnifying glass of 10 times magnification to observe whether corrosion or roughness was observed.

(Example 1)
To the support sheet metal for blades manufactured from chromate-treated galvanized steel sheet (trade name: gin-coated steel sheet, manufactured by Nippon Steel Corp.), industrial lubricating oil (trade name: No. 615, manufactured by Nippon Tool Oil Co., Ltd.) After spray coating for 3 seconds, air blow was performed so that the entire surface was uniform. The thickness of the oil film was about 7 μm. The support metal plate to which this oil was adhered was washed with alkaline electrolyzed water having a pH of 9 (manufactured by an electrolytic ionic water washing system device manufactured by Takahashi Metal Co., Ltd.). Thereafter, sufficient drying was performed by hot air drying, and the surface tension was measured. As a result, it was 420 μN / cm and was completely washed. The results are shown in Table 1 along with the presence or absence of surface corrosion.

(Example 2)
In Example 1, the support sheet metal was washed in the same manner as in Example 1 except that industrial water was used instead of alkaline electrolyzed water. The surface tension of the obtained support sheet metal was measured and found to be 380 μN / cm. The results are shown in Table 1.

(Example 3)
In Example 1, the manufacturing raw material of the support sheet metal for the blade is a galvanized steel sheet having a non-chromium surface treatment containing urethane-modified olefin resin and acrylic-modified olefin resin (trade name: ZINCOAT 21, manufactured by Nippon Steel Corp. The procedure was the same as in Example 1 except that this was replaced. When the surface tension of the support sheet metal was measured, it was 420 μN / cm and was completely cleaned. The results are shown in Table 1.

(Comparative Example 1)
In Example 3, the surface tension of the support sheet metal obtained by performing the washing with alkaline electrolyzed water of pH 9 directly on the manufactured support sheet metal without pre-washing with oil and then sufficiently drying by hot air drying. Was measured. The surface tension was 350 μN / cm, which was judged as insufficient cleaning. The results are shown in Table 1.

  If preliminary cleaning with oil is not performed (Comparative Example 1), the surface tension of the support sheet metal becomes low, indicating that the cleaning is insufficient. In addition, if preliminary washing with oil is performed, the quality is improved and satisfactory even with washing with industrial water (Example 2).

Example 4
In Example 3, washing was performed in the same manner as in Example 3 except that washing with alkaline electrolyzed water having a pH of 9 was performed by high-pressure jetting with a washing water jetting pressure of 0.5 MPa. Table 2 shows the results of the cleaning power evaluation.

(Example 5)
In Example 4, washing was performed in the same manner as in Example 4 except that alkaline electrolyzed water having a pH of 13 (manufactured by an electrolytic ionic water washing system apparatus manufactured by Takahashi Metal Co., Ltd.) was used as the alkaline electrolyzed water. Table 2 shows the results of the cleaning power evaluation.

(Example 6)
In Example 4, cleaning was performed in the same manner as in Example 4 except that the cleaning water injection pressure was set to 0.1 MPa. Table 2 shows the results of the cleaning power evaluation.

(Example 7)
In Example 4, cleaning was performed in the same manner as in Example 4 except that the cleaning water injection pressure was set to 1.5 MPa. Table 2 shows the results of the cleaning power evaluation.

  As can be seen from Table 2, all the cleaning methods of the present invention provide satisfactory cleaning results. In addition, although alkaline electrolyzed water used in this cleaning is adjusted to pH 13 (Example 5) or the injection pressure is set to 1.5 MPa (Example 7), there is no problem in use in the next step. Some surface corrosion was observed. Further, when the injection pressure is 0.1 MPa (Example 6), there is a tendency that the cleaning is insufficient.

It is a process flow figure of the cleaning method of the present invention.

Explanation of symbols

1 Pre-cleaning 2 Main cleaning 3 Drying

Claims (6)

  A method for cleaning a metal member, comprising pre-cleaning with oil when cleaning the metal member.   The method for cleaning a metal member according to claim 1, wherein the solvent used for cleaning is water.   The method for cleaning a metal member according to claim 2, wherein the water is alkaline electrolyzed water.   The method for cleaning a metal member according to claim 3, wherein the alkaline electrolyzed water has a pH of 8-12.   The method for cleaning a metal member according to any one of claims 2 to 4, wherein the cleaning is performed with high-pressure jet water.   The method for cleaning a metal member according to any one of claims 1 to 5, wherein the metal member is a support metal plate of a blade member for an electrophotographic apparatus.

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