JP2004018878A - Coating pretreatment apparatus and coating pretreatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating pretreatment apparatus by which space saving, the improvement of productivity, and the remarkable reduction in equipment expense/chemicals cost/the number of management stages/a load of waste water treatment can be attained even to a composite body of iron and aluminum. <P>SOLUTION: The apparatus is provided with a treatment tank 101 in which a degreasing/chemical conversion treatment liquid at least comprising a mixed solvent of a polar organic solvent and water in a weight ratio of 2.8:7.2 to 3.8:6.2, and sodium ions and/or lithium ions, phosphoric ions, zinc ions, nickel ions, manganese ions, nitrate ions and/or nitrite ions is filled, and an automobile body B is dipped, an aluminum chemical conversion treatment zone 300 provided on the poststage of the treatment tank 101, and spraying a chemical conversion treatment liquid for aluminum on the automobile body B, and a rinse tank 201 provided on the poststage of the aluminum chemical conversion treatment zone 300, and in which a cleaning liquid is filled and the automobile body B is dipped. The prestage of the treatment tank 101 is provided with a body warming zone 500 for warming the body B. <P>COPYRIGHT: (C)2004,JPO

Description

比較例
実施例における脱脂兼化成処理液の極性有機溶剤と水との重量比率を１：９とした以外は実施例と同じ条件で脱脂兼化成処理液及びアルミニウム化成処理液を作製し、同様の評価を行った。その結果を表２に示す。
【００９６】
【表２】

考察
表１及び表２の結果からも明らかなように、比較例の塗装前処理方法では、皮膜重量、結晶皮膜の緻密度合い、一次塗装密着性、二次塗装密着性の何れにおいても少々劣る〜不良であったのに対し、実施例の塗装前処理方法を採用することで、皮膜重量、結晶皮膜の緻密度合い、一次塗装密着性、二次塗装密着性の何れについても極めて良好〜少々劣るとなり、品質的にも問題がないことが確認された。
【図面の簡単な説明】
【図１】本発明の塗装前処理装置の実施形態を示すシステム図である。
【図２】本発明の塗装前処理装置の他の実施形態を示すシステム図である。
【図３】図２に示す塗装前処理装置における全没処理および半没処理を説明するための図である。
【図４】本発明に係るボディ加温ゾーンの他の実施形態を示す側面図および断面図である。
【符号の説明】
１０１…処理槽
２０１…リンス槽（リンス手段）
３００…アルミニウム化成処理ゾーン（アルミニウム化成処理手段）
３０１…アルミニウム用化成処理液補給タンク
３０２…配管
３０３…ポンプ
３０４…ノズル
３０７…回収槽
３０８…配管
３０９…ポンプ
５００…ボディー加温ゾーン
５０１…工水タンク
５０２…配管
５０３…ポンプ
５０４…シャワーノズル
５０５…熱交換機
５０６…乾燥炉の排気
５０７…脱臭装置[0001]
【Technical field】
The present invention relates to a pre-painting apparatus and a pre-painting method, and more particularly to a pre-painting apparatus and a pre-painting method suitable for use in a pre-painting line in which a composite body of iron and aluminum flows.
[0002]
[Background Art]
From the viewpoint of reducing weight, improving rigidity, or improving recyclability, the use of aluminum parts such as hoods, trunk lids, door inners, etc. in automobile bodies is being studied.
[0003]
As a pretreatment liquid for such a composite body of iron and aluminum, for example, Japanese Patent Application Laid-Open No. 2001-515959 discloses that a chemical treatment is performed only on an iron part in a first step, and a chemical conversion treatment is performed on an aluminum part in a second step. It has been proposed to perform processing.
[0004]
In the chemical treatment solution used in this pretreatment method, free or complex-bonded fluoride ions are added in order to precipitate or mask aluminum that has been eluted and eluted. The free fluoride concentration is limited to less than 8 / T (g / L, where T is the processing temperature (° C.)) so as to prevent the formation of a conversion coating, that is, to prevent a large amount of sludge from accumulating at one time.
[0005]
However, in the pretreatment method described in JP-T-2001-515959, since the chemical conversion treatment solution contains fluoride ions, aluminum sludge is accumulated in the tank, and it is necessary to remove and discard the sludge. In addition, if the concentration of free fluoride is not controlled to a predetermined value or less as described above, a chemical conversion coating is formed on the aluminum surface more than necessary, so that an operation or system for controlling and controlling the concentration of fluoride and controlling and controlling the replenisher is required. become.
[0006]
Further, since the aluminum chemical conversion treatment step is provided after the steel sheet chemical conversion treatment step, the total length of the pretreatment step is increased, which is disadvantageous in terms of space, processing time and equipment cost.
[0007]
DISCLOSURE OF THE INVENTION
The present invention provides a coating pretreatment apparatus and a coating pretreatment method that can achieve a space saving, an improvement in productivity, and a significant reduction in equipment costs, chemical costs, management man-hours, and wastewater treatment load even for a composite body of iron and aluminum. The purpose is to provide.
[0008]
To achieve the above object, according to the present invention, a mixed solvent of a polar organic solvent and water having a weight ratio of 2.8: 7.2 to 3.8: 6.2, sodium ion and / or lithium A treatment tank filled with a degreasing / chemical conversion treatment solution containing at least ions, phosphate ions, zinc ions, nickel ions, manganese ions, nitrate ions and / or nitrite ions, and immersed in an object to be coated; An aluminum chemical conversion treatment means provided at a subsequent stage for treating an object to be coated with a chemical conversion treatment solution for aluminum; a rinsing means provided at a stage subsequent to the aluminum chemical conversion treatment means for washing the object to be coated with a cleaning liquid; There is provided a coating pretreatment device provided with a heating means provided at a preceding stage of the tank and for heating an object to be coated (see claim 1).
[0009]
Further, in order to achieve the above object, according to the present invention, a first step of heating a composite automobile body of iron and aluminum having an aluminum or aluminum alloy part in at least a part of an outer plate portion; A mixture of a polar organic solvent and water having a weight ratio of 2.8: 7.2 to 3.8: 6.2, sodium ion and / or lithium ion, phosphate ion, and zinc ion. A second step of immersing in a degreasing and chemical conversion treatment liquid containing at least nickel ions, manganese ions, nitrate ions and / or nitrite ions, and a third step of treating the automobile body with an aluminum chemical conversion liquid. And a fourth step of cleaning the automobile body with a cleaning liquid. A pretreatment method for coating is provided (see claim 28).
[0010]
In the coating pretreatment apparatus and the coating pretreatment method of the present invention, the degreasing treatment and the chemical treatment of the iron parts of the article to be coated are performed with the degreasing and chemical conversion treatment liquid filled in the treatment tank, and the degreasing treatment of the aluminum parts. I do. Since the degreasing / chemical conversion treatment liquid according to the present invention filled in the treatment tank does not contain a fluoride for etching aluminum, aluminum sludge does not accumulate in the treatment tank.
[0011]
With the degreasing and chemical conversion treatment liquid filled in the treatment tank of the present invention, aluminum components of the coating object are only subjected to degreasing treatment and no chemical conversion coating is formed. Spraying or immersing the chemical conversion treatment solution. In particular, when the aluminum component is on the outer plate portion of the object to be coated, a sufficient conversion coating can be formed only by spraying. Further, even when the aluminum component is on the inner plate portion of the object to be coated, a sufficient chemical conversion film can be formed by performing the immersion treatment or by considering the spraying method using a spray device.
[0012]
After the treatment with the chemical conversion treatment solution for aluminum, the entire object to be coated is washed by the next-stage rinsing means. Thus, the pre-coating process as a base such as the electrodeposition coating is completed. The object to be coated may be conveyed to a drying oven before being sent to the electrodeposition coating step.
[0013]
According to the present invention, since the degreasing and chemical conversion treatment liquid does not contain a fluoride for etching aluminum, accumulation of aluminum sludge in the treatment tank can be prevented. As a result, it is possible to reduce the number of work steps and system cost required for removing and disposing of aluminum sludge. Further, since the aluminum sludge itself is not generated, the number of man-hours and system cost related to the concentration control of the fluoride can be reduced as compared with the conventional pretreatment method.
[0014]
Furthermore, a chemical conversion treatment step for aluminum parts is provided at a stage subsequent to the degreasing and chemical conversion treatment tank. Particularly when a chemical conversion coating is formed by spray treatment, the process space and equipment costs can be significantly reduced as compared with immersion treatment. . By reducing the process space, the processing time is shortened, and the productivity of the automobile body is improved.
[0015]
In addition, in the present invention, since the object to be coated is heated in the preceding stage of the treatment tank, the surface tension of oil and the like attached to the object to be coated is reduced, thereby improving the efficiency of removing oil and dust.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
First Embodiment FIG. 1 is a system diagram showing a first embodiment of a coating pretreatment apparatus of the present invention. For example, an object to be coated such as an automobile body is used as a base treatment for electrodeposition coating. Fig. 4 shows a pre-coating treatment step for performing degreasing treatment, surface conditioning, and chemical conversion treatment.
[0018]
In particular, the automobile body B flowing through the coating line of this example is a composite body of iron and aluminum, in which aluminum parts are used for outer plates such as a hood, a trunk lid, and a door, and other parts are made of a steel plate. In the coating pretreatment device of the present invention, all the objects to be coated need not be limited to such an iron-aluminum composite body, and may be a mixed line of an iron-aluminum composite body and a steel plate body. In addition, even in the same iron-aluminum composite body, vehicle types having different adoption portions of aluminum parts may be mixed and flow.
[0019]
As shown in the figure, the vehicle body B is transported by a paint transport conveyor C while being mounted on a hanger H. In the present embodiment, a body heating zone 500 and two dipping tanks 101 and 201 are provided along the coating transport line C, and the upstream side in the transport direction indicated by the arrow in the drawing is a process for performing a degreasing process and a chemical conversion process. A tank 101 (hereinafter, also referred to as a degreasing chemical treatment tank 101), and a downstream side is a rinse tank 201 for cleaning the treated body B.
[0020]
The body heating zone 500 is provided in a stage preceding the processing bath 101, and is a step of heating the body B to preferably around 40 ° C. before the processing by the processing bath 101. In the example shown in FIG. 1, a working water tank 501 for storing working water, a pipe 502 and a pump 503 for guiding the working water to the body heating zone 500, and a shower provided in the pipe 502 and blowing hot water to the body B A nozzle 504 and a heat exchanger 505 that heats the working water to warm water of 40 ° C. or more by performing heat exchange with the working water are provided.
[0021]
As the heat source for heating the working water in the heat exchanger 505, the exhaust 506 of the drying furnace of the coating line is used, and in particular, the deodorized exhaust that has passed through the deodorizer 507 having a three-way catalyst or the like is used. Examples of the drying furnace used as a heat source include an electrodeposition drying furnace installed in a coating line, an intermediate coating drying furnace, a top coating drying furnace, a draining drying furnace, and the like, and mixing of a hydrocarbon component and a nitrogen oxide component. It is more preferable to use the exhaust of a draining / drying oven with less water. However, if the deodorized exhaust gas that has passed through the deodorizing device 507 is used as in this example, since it does not contain impurities, the exhaust gas from an electrodeposition drying furnace other than the draining drying furnace or the middle / overcoat drying furnace can be used equally. .
[0022]
Further, in this example, heat exchange is performed with the working water passing through the pipe 502 by using the heat exchanger 505, thereby warming the working water discharged from the shower nozzle 504. , The entire working water in the working water tank 501 may be heated by, for example, bubbling or the like, and sprayed from the shower nozzle 504 onto the body 9.
[0023]
The shower nozzle 504 is provided on the left and right side walls and the ceiling surface of the body heating zone 500, and sprays hot water on the outer plate and the inner plate of the body B. Since a predetermined time is required to spray hot water in the body heating zone 500, it is desirable to dispose the body heating zone 500 in a tact stop zone before being carried into the processing tank 101.
[0024]
Since the body B carried into the processing tank 101 is heated to a temperature of about 40 ° C. by the body heating zone 500, the surface tension of oil, dust, and the like attached to the body B decreases, and the body B Is carried into the treatment tank 101, the emulsification with the degreasing and chemical conversion treatment liquid is promoted. Thereby, the degreasing efficiency in the processing tank 101 is improved, and the dust removing efficiency is also improved.
[0025]
The treatment tank 101 is filled with a degreasing / chemical conversion treatment liquid, and the rinsing tank 201 is filled with pure water.
[0026]
The degreasing and chemical conversion treatment liquid used in this example is a treatment liquid capable of performing three types of treatments such as degreasing treatment, surface conditioning, and chemical conversion treatment in the same step. As such a degreasing / chemical conversion treatment solution, for example, a polar organic solvent, water, sodium ion and / or lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, nitrate ion and / or nitrite ion are used. A processing solution containing at least can be used. By using this processing liquid, the degreasing step, the surface conditioning step, and the chemical conversion step can be collectively performed in one step at the same time, greatly reducing the processing steps, simplifying the processing equipment, saving space, and improving productivity. Improvement, reduction of drug cost, and simplification of drug management can be achieved.
[0027]
The degreasing and chemical conversion treatment liquid of this example will be described in more detail. The weight ratio of the mixed solvent of the polar organic solvent and water is 2.8: 7.2 to 3.8: 6.2, preferably 3.0: 7.2. 7.0-3.8: 6.2, more preferably 3.3: 6.7-3.8: 6.2, more preferably 3.3: 6.7-3.5: 6.5, Most preferably, it is 3.5: 6.5.
[0028]
Examples of the polar organic solvent of this example include ethylene glycol and other lower alkyl ethers or lower alkyl esters represented by (—CH ₂ —CH ₂ —O—) _n (where n = 1 to 4), propylene glycol or dipropylene. Glycols and other lower alkyl ethers or lower alkyl esters, diethylene glycol, triethylene glycol, tetraethylene glycol and other lower alkylene glycols, lower alcohols and esters thereof can be exemplified.
[0029]
As the ethylene glycol-based lower alkyl ether or lower alkyl ester, for example, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether and other ethylene glycol ethers, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether and the like diethylene glycol ether And triethylene glycol mono-n-butyl ether, tetraethylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate and the like.
[0030]
Examples of the lower alkyl ether or lower alkyl ester of propylene glycol or dipropylene glycol include, for example, propylene glycol butyl ether, dipropylene glycol monomethyl ether, and polypropylene glycol monoethyl ether.
[0031]
In addition, examples of the lower alcohol include alcohols having 1 to 8, preferably 1 to 5, and more preferably 1 to 4 carbon atoms. Specific examples include glycol alcohols such as ethyl alcohol, isopropyl alcohol, tertiary butyl alcohol, methoxydimethylpentanol, diacetone alcohol, 2-methoxyethanol, and 2-ethoxymethanol.
[0032]
Examples of the esters include ethyl lactate, methoxybutyl acetate and butyl lactate.
[0033]
Among the above-mentioned polar organic solvents, at least one selected from the group consisting of diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, and propylene glycol monoalkyl ether It is most preferred to employ more than one glycol compound or a mixed solvent of these glycol compounds and a lower alcohol.
[0034]
The alkyl group in these glycol compounds is preferably an alkyl group having 1 to 5 carbon atoms. The lower alcohol is preferably an alcohol having 1 to 8 carbon atoms, more preferably an alcohol having 1 to 5 carbon atoms, and most preferably an alcohol having 1 to 4 carbon atoms.
[0035]
The degreasing and chemical conversion solution of this example is obtained by adding sodium ion and / or lithium ion, phosphate ion, zinc ion, nickel ion, manganese ion, nitrate ion and / or nitrite ion to the above-mentioned mixed solvent of polar organic solvent and water. At least.
[0036]
It is preferable that the phosphate ion is contained in an amount of 0.2 to 0.5 part by weight based on 100 parts by weight of the mixed solvent. If the content is out of this range, the amount of oil mixed in is large, and the desired good zinc phosphate coating is not formed at the time of poor stirring. The source of the phosphate ions is not particularly limited, and examples thereof include orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, and phosphorus pentoxide. It is also possible to supply as an anion to metal ions (sodium ion and / or lithium ion, zinc ion, nickel ion, manganese ion) contained in the degreasing / chemical conversion treatment liquid.
[0037]
Zinc ions have a function of forming a zinc phosphate chemical conversion film together with phosphate ions. The zinc ion is preferably contained in an amount of 0.5 to 0.7 parts by weight based on 100 parts by weight of the mixed solvent. If the content is out of this range, the amount of oil mixed in is large, and the desired good zinc phosphate coating is not formed at the time of poor stirring. Examples of the supply source of the zinc ion include inorganic acid salts such as zinc oxide, zinc carbonate, zinc nitrate, zinc chloride, zinc sulfate, and zinc phosphate.
[0038]
Nickel ions have a function of improving the corrosion resistance of the uncoated object. Nickel ions are preferably present in an amount of 0.09 to 0.23 parts by weight based on 100 parts by weight of the mixed solvent. If the content is out of this range, the amount of oil mixed in is large, and the desired good zinc phosphate coating is not formed at the time of poor stirring. Examples of the supply source of the nickel ions include inorganic acid salts such as nickel nitrate and nickel phosphate.
[0039]
Manganese ions have a function of improving wet coating adhesion of an object containing zinc metal. Manganese ion is preferably used in an amount of 0.03 to 0.16 parts by weight based on 100 parts by weight of the mixed solvent. If the content is out of this range, the amount of oil mixed in is large, and the desired good zinc phosphate coating is not formed at the time of poor stirring. Examples of the source of the manganese ion include inorganic acid salts such as manganese nitrate and manganese phosphate.
[0040]
The nitrate ion and / or nitrite ion is preferably 3.5 to 10.8 parts by weight based on 100 parts by weight of the mixed solvent. If the content is out of this range, the amount of oil mixed in is large, and the desired good zinc phosphate coating is not formed at the time of poor stirring.
[0041]
It is preferable that sodium ion and / or lithium ion be contained in an amount of 0.8 to 3.3 parts by weight based on 100 parts by weight of the mixed solvent. The sodium ions and / or lithium ions have a function of making the zinc phosphate coating crystals formed on the surface of the article to be dense together with the water of the degreasing and chemical conversion treatment solution. Examples of the sodium ion supply source include sodium nitrate, sodium phosphate, sodium nitrite, and sodium hydroxide. Further, part or all of sodium nitrate can be replaced with sodium nitrite. By the action of nitrite ions, the etching power of the acid is further enhanced, and the promotion of the chemical reaction can be expected.
[0042]
Further, the sodium ion can be replaced with a lithium ion which is common as a monovalent alkali metal. Specifically, 50% to 98%, preferably 60% to 90%, more preferably 70% to 80% of the total amount of sodium ions and lithium ions is replaced with lithium ions. By including lithium ions in the degreasing and chemical conversion treatment liquid, the crystals of the zinc phosphate film become more dense and the coating adhesion is further improved. Examples of the supply source of lithium ions include inorganic acid salts such as lithium nitrate, lithium phosphate, and lithium nitrite.
[0043]
Incidentally, it is preferable that the degreasing / chemical conversion treatment solution is treated at a temperature of 40 ° C to 60 ° C for 3 minutes to 10 minutes.
[0044]
By using the degreasing and chemical conversion treatment liquid having the above composition, even if a large amount of oil is mixed in the degreasing and chemical conversion treatment liquid, or even if the stirring state of the degreasing and chemical conversion treatment liquid is poor, corrosion resistance and A zinc phosphate conversion coating having excellent film adhesion can be formed.
[0045]
Returning to FIG. 1, the degreasing / chemical conversion treatment liquid in the treatment tank 101 is sucked by the pipe 105 and the pump 106, and is returned to the treatment tank 101 by the pipe 111 and the pump 110 via the treatment liquid supply tank 109. A dust removing device 102, a chemical sludge removing device 103, and an oil removing device 104 are provided in the middle of the pipe 105. The iron dust is passed through the dust removing device 102, the chemical sludge removing device 103, and the oil removing device 104. The processing liquid containing water, such as dust, chemical sludge, and a polar organic solvent from which oil has been removed, is temporarily stored in the processing liquid supply tank 109. A new degreasing / chemical conversion liquid is supplied and adjusted by a pump 108 from the processing liquid tank 107 containing the new degreasing / chemical conversion liquid to the processing liquid supply tank 109, and the adjusted degreasing / chemical conversion treatment is performed. The liquid is returned to the degreasing chemical treatment tank 101 by the piping 111 and the pump 110 described above.
[0046]
The dust removing device 102 is for removing dust particles such as iron powder contained in the processing liquid in the processing tank 101. The removed dust particles are discarded, and the processing liquid from which the dust particles are removed is used as the next chemical sludge removing device. 103. Specific devices that can be used as the dust removing device 102 of this example include a settling tank, a centrifugal separator, and a magnet separator. These settling tanks, centrifugal separators, and magnetic separators can be used alone or in combination, and in particular, the dust removal device 102 that combines the settling tank and the magnetic separator has a high dust removal rate, preferable.
[0047]
However, the dust removing device 102 according to the present example is not limited to the above-described three forms, but includes other forms. In addition, the dust removing device 102 of this example is provided in the pipe 105, but may be provided inside or outside the processing tank 101 itself.
[0048]
The chemical sludge removing device 103 is for removing chemical sludge contained in the processing liquid that has passed through the above-described dust removing device 102, and the removed chemical sludge is discarded. The oil is sent to the oil removing device 104. As the chemical sludge removal device 103, any filter can be used without particular limitation as long as the sludge concentration of the processing liquid in the processing tank 101 is suppressed to within 150 ppm and does not contaminate the processing liquid. .
[0049]
The oil removing device 104 removes the oil contained in the processing liquid that has passed through the chemical sludge removing device 103 described above. The removed oil is discarded, and the processing liquid from which the oil has been removed is supplied to the processing liquid supply tank 109. Sent to Examples of the oil removing device 104 that can be used in this example include a heated oil removing device, a coalescer oil removing device, and an ultrafiltration oil removing device.
[0050]
Of these, the heated oil removal device is preferably applied to an aqueous solution containing a nonionic surfactant as a degreasing component.When this is heated to a specific temperature or higher, it itself becomes insoluble in water, This is an oil-removing device that utilizes the characteristics of a nonionic surfactant, such as oil-water separation into two phases, an oil phase and a water phase, each of which is composed of a nonionic surfactant.
[0051]
In addition, the coalescer type oil removing device is a method of breaking down a water-oil emulsion by passing oil droplets dispersed in an aqueous solution with a size of several μm through a filter, thereby expanding and growing the oil droplets. It is an oil removal device that can float and recover.
[0052]
The ultrafiltration type oil removing device uses ultrafiltration, that is, using a filter having a mesh of about 0.01 to 0.001 μm, and applying pressure at a low pressure of about 0.5 to 5 × 10 ⁻⁵ Pa or This is an oil removing device using a filtration method of separating colloid particles from a solvent by suction filtration.
[0053]
These heated oil removal equipment, coalescer oil removal equipment, and ultrafiltration oil removal equipment are selected according to the required degree of oil-water separation, and can be used alone or in combination.
[0054]
Between the treatment tank 101 and the rinsing tank 201 shown in FIG. 1, an aluminum chemical treatment zone 300 for spraying a chemical conversion treatment liquid for aluminum onto the automobile body B is provided. The aluminum chemical conversion treatment zone 300 is inclined so that the floor surface of the booth is the lowest surface at the center thereof so that the sprayed chemical conversion treatment liquid for aluminum does not flow into the treatment tank 101 and the rinsing tank 201 of the preceding stage as much as possible. ing.
[0055]
Further, a nozzle 304 for spraying the chemical conversion liquid for aluminum onto the automobile body B passing through the aluminum chemical conversion zone 300 is attached to the pipe 302, and an aluminum chemical conversion liquid supply tank containing the chemical conversion liquid for aluminum is contained. The chemical conversion treatment liquid is supplied from 301 by a pump 303. In the example shown in FIG. 1, a plurality of nozzles 304 for spraying an aluminum chemical conversion liquid onto a hood, a trunk lid, and a door, which are aluminum parts, are provided on an automobile body B on each of a ceiling surface and a side surface of a booth. I have.
[0056]
The aluminum chemical treatment liquid collected on the floor of the booth is collected in the recovery tank 307 and returned to the aluminum chemical treatment liquid supply tank 301 by the pipe 308 and the pump 309. A pipe 308 connected to the collection tank 307 includes a dust removal device 310 for removing dust contained in the collected chemical conversion treatment liquid for aluminum, and aluminum and iron (produced by processing in the processing tank 101 in the preceding stage). A chemical sludge removing device 311 for removing chemical sludge and an oil removing device 312 for removing oil. As the dust removing device 310, the chemical sludge removing device 311 and the oil removing device 312, the specific examples exemplified as the dust removing device 102, the chemical sludge removing device 103 and the oil removing device 104, respectively, can be used.
[0057]
The chemical conversion treatment solution for aluminum used in this example is not particularly limited, and examples thereof include hexafluorotitanate and hexafluorozirconate. Such a new aluminum chemical conversion liquid is stored in an aluminum chemical conversion liquid tank 305 and supplied to an aluminum chemical conversion liquid supply tank 301 by a pump 306, whereby the aluminum chemical conversion liquid sprayed from the nozzle 304 onto the automobile body B is adjusted. Is done.
[0058]
Incidentally, the chemical conversion treatment solution for aluminum is preferably treated at a pH of 2.5 to 10 and a temperature of 20 ° C to 70 ° C for 20 seconds to 100 seconds.
[0059]
A rinsing tank 201 is provided at a stage subsequent to the aluminum chemical conversion treatment zone 300, and the automobile body B on which the chemical conversion film is formed in the treatment tank 101 and the aluminum chemical conversion treatment zone 300 is washed with pure water. In this example, the outer plate and the inner plate of the vehicle body B are cleaned by immersing the vehicle body B in the rinsing tank 201, but it can also be realized by a spray process other than the dipping process.
[0060]
In addition, since dust, chemical sludge, and oil adhering to the vehicle body B are mixed into the pure water in the rinsing tank 201, the pure water in the rinse tank 201 is sucked by the pipe 202 and the pump 203, and the dust removing device of the aluminum chemical treatment zone 300 in the preceding stage is removed. After supplying the dust, the chemical conversion sludge, and the oil component to the liquid 310, the aluminum conversion liquid is reused as pure water. At this time, the cleaning liquid in the rinsing tank 201 sucked by the pipe 202 and the pump 203 may be supplied to the recovery tank 307 of the aluminum chemical conversion treatment zone 307. Although not shown, new pure water is supplied into the rinse tank 201 from a separately provided pure water supply device.
[0061]
Next, the operation will be described.
[0062]
The white body B, which has been welded and assembled in the vehicle body process, is transported by the overhead conveyor C while being mounted on the coating hanger H, and first, hot water is sprayed on the outer plate and the inner plate in the body heating zone 500. As a result, the body B is heated to a temperature of about 40 ° C., the surface tension of oil and dust attached to the body B decreases, and when the body B is carried into the processing tank 101, the degreasing and chemical conversion liquid And the emulsification with is promoted. As a result, the degreasing efficiency in the processing tank 101 is improved, and the dust removal efficiency is also improved.
[0063]
Next, the body B is immersed in the processing bath 101. By being immersed in the treatment tank 101, dust and oil such as iron powder attached to the vehicle body B are removed into the treatment tank 101 by the cleaning and degreasing effect of the degreasing and chemical conversion treatment liquid. Further, in the steel body parts of the automobile body B from which oil has been removed, a reaction between the degreasing and chemical conversion treatment solution and iron occurs, and a chemical conversion film of zinc phosphate is formed thereon.
[0064]
However, aluminum parts of the automobile body B are only subjected to dust removal and degreasing, but do not react with the degreasing and chemical conversion treatment liquid, and no chemical conversion film is formed. That is, since the degreasing and chemical conversion treatment liquid of the present example does not contain a fluoride for etching aluminum, the chemical conversion sludge of aluminum is not accumulated in the processing tank 101, and the above-described conventional Japanese Patent Application Laid-Open No. 2001-515959 has been described. Compared with the pretreatment method disclosed in the gazette, it is possible to reduce the number of work steps and system cost required for removing and disposing of aluminum sludge. Further, since the aluminum sludge itself is not generated, the number of man-hours and system cost related to the concentration control of the fluoride can be reduced as compared with the conventional pretreatment method.
[0065]
The degreasing / chemical conversion treatment liquid in the treatment tank 101 is sucked into a pipe 105 by a pump 106 and passes through a dust removal device 102 to remove dust particles such as iron powder contained in the treatment solution. By passing through 103, iron conversion sludge contained in the processing liquid is removed, and further through passing through an oil removing device 104, oil such as press oil contained in the processing liquid is removed.
[0066]
The degreasing / chemical conversion treatment liquid from which the dust, the chemical sludge and the oil have been removed is sent to the treatment liquid supply tank 109, where a fresh degreasing / chemical conversion treatment liquid is replenished from the processing liquid tank 107 by the pump 108, and appropriately. After the adjustment, it is returned to the processing tank 101 by the pipe 111 and the pump 110. As described above, since the degreasing and chemical conversion treatment liquid in the treatment tank 101 is closed by the pipes 105 and 111, the cost can be reduced by reducing material costs and the burden on the wastewater treatment step can be reduced. Further, the use of the degreasing and chemical conversion treatment liquid can reduce the number of man-hours for controlling the pretreatment conditions. Furthermore, the use of this degreasing and chemical conversion treatment liquid can greatly reduce the number of washing steps, and the amount of the washing liquid used reduces the load on the wastewater treatment step.
[0067]
The automobile body B that has passed through the processing tank 101 is sent to the aluminum chemical conversion treatment zone 300, and a chemical conversion treatment liquid for aluminum is sprayed from the nozzle 304. The treatment liquid in the aluminum chemical treatment liquid supply tank 301 is sucked by the pump 303 and sprayed from the nozzle 304 via the pipe 302 onto mainly aluminum parts of the automobile body B. The chemical conversion solution for aluminum sprayed on the automobile body B is collected on the floor of the booth, collected in the collection tank 307, and sucked by the pump 309 therefrom. After passing through the dust removing device 310, the chemical sludge removing device 311 and the oil removing device 312, the dust, the chemical sludge of aluminum or iron, and the oil contained in the aluminum processing liquid are removed, and then through the pipe 308. It is returned to the aluminum chemical conversion treatment liquid supply tank 301.
[0068]
By the treatment in the aluminum conversion treatment zone 300, a chemical conversion coating treatment can be performed on an aluminum component used as an outer plate component such as a hood, a trunk lid, and a door. In particular, when these aluminum parts are used for the outer panel parts of the automobile body B, a sufficient chemical conversion film can be formed only by the spray treatment as in this example, and as a result, the aluminum chemical conversion treatment step is performed. Length can be kept to a minimum.
[0069]
Finally, the vehicle body B that has passed through the aluminum chemical conversion treatment zone 300 is immersed in the rinsing tank 201 to clean the processing liquid attached to the vehicle body B. Thereafter, the automobile body is transported to a drying oven to be dried, and is sent to an electrodeposition coating process as a base coating. At this time, the cleaning liquid in the rinsing tank 201 is guided by the pipe 202 and the pump 203 to the upstream of the dust remover 310 in the pipe 308, passes through the dust remover 310, the chemical sludge remover 311 and the oil remover 312, and then passes through the aluminum remover. It is supplied to the chemical conversion liquid supply tank 301. Thereby, the pure water in the rinsing tank 201 can be effectively used.
[0070]
2nd Embodiment FIG. 2 is a system diagram showing a second embodiment of the coating pretreatment device of the present invention. The drawing shows a pre-coating treatment step of performing a degreasing treatment, a surface conditioning, and a chemical conversion treatment as a base treatment of the electrodeposition coating. The present embodiment is basically different from the above-described first embodiment in that a dipping tank 313 is employed in the aluminum chemical conversion treatment zone 300. Other configurations are the same as those of the first embodiment, and thus the same components are denoted by the same reference numerals.
[0071]
The aluminum chemical conversion treatment zone 300 of this example is provided with an aluminum chemical conversion treatment tank 313 filled with an aluminum chemical conversion treatment solution, and the automobile body B conveyed by the conveyor C is completely submerged or moved along the locus of the conveyor C. Half-submerged.
[0072]
Here, the full immersion treatment, so-called full dip treatment, refers to a treatment in which the entire vehicle body B is immersed in an aluminum chemical conversion solution, whereas the half immersion treatment, so-called half-dip treatment, This refers to a process in which only the lower part from the upper line (see B1 in FIG. 3) of the door panel is immersed in the aluminum chemical conversion solution. FIG. 3 shows the liquid surface after each immersion treatment. When the part made of aluminum material in the car body B is not above the upper line B1 of the door panel, for example, when the roof panel and the pillar are made of iron, the car body B does not need to be completely immersed. Since a component made of an aluminum material only needs to be immersed, a half dipping process can be employed. Even if the roof panel is made of an aluminum material, the car body B is used as a half-dip to carry out the chemical conversion treatment of the lower aluminum parts from the upper line B1 of the door panel, and a spray device is used for a roof that is not immersed. May be configured to spray an aluminum chemical conversion solution.
[0073]
When a half-dip is used, the capacity of the treatment tank and rinsing tank can be set smaller than that of a full-dip, so that the initial cost of the aluminum chemical treatment liquid can be reduced and the aluminum chemical treatment liquid can be heated. Energy required for the operation can be reduced.
[0074]
The aluminum chemical conversion liquid in the dipping tank 313 is returned to the aluminum chemical conversion liquid supply tank 301 by the pipe 308 and the pump 309. In addition, a pipe 308 connected to the dipping tank 313 includes a dust removing device 310 for removing dust contained in the chemical conversion treatment liquid for aluminum, aluminum and iron (produced in the processing of the preceding processing tank 101). A chemical sludge removing device 311 for removing the chemical sludge and an oil removing device 312 for removing the oil component are provided. As the dust removing device 310, the chemical sludge removing device 311 and the oil removing device 312, the specific examples exemplified as the dust removing device 102, the chemical sludge removing device 103 and the oil removing device 104, respectively, can be used.
[0075]
The chemical conversion treatment solution for aluminum used in this example is not particularly limited, and examples thereof include hexafluorotitanate and hexafluorozirconate. Such a new aluminum chemical conversion liquid is stored in an aluminum chemical conversion liquid tank 305, supplied to an aluminum chemical conversion liquid supply tank 301 by a pump 306, adjusted to an appropriate value here, and then supplied to a pipe 302 and a pump 303. Is supplied to the dipping tank 313.
[0076]
The coating pretreatment apparatus of this example employs a dipping tank 313 such as a full dip or a half dip as the aluminum conversion treatment means, and thus is particularly excellent in processing when an aluminum material is employed for the inner plate.
[0077]
Further, a body heating zone 500 is also provided in the preceding stage of the processing tank 101 of this example, and the body B is heated to about 40 ° C. by spraying hot water on the body B before being immersed in the processing tank 101. As a result, the surface tension of oil, dust, and the like attached to the body B decreases, and when the body B is carried into the treatment tank 101, the emulsification with the degreasing and chemical conversion treatment liquid is promoted. As a result, the degreasing efficiency in the processing tank 101 is improved, and the dust removal efficiency is also improved.
[0078]
Third embodiment In the first and second embodiments described above, the body B is blown with hot water in the body heating zone 500, but in this example, the body B is blown with hot air. For this reason, as shown in FIG. 4, a furnace body 508 is provided in the body heating zone 500, and air supply ducts 509 are provided on both left and right sides in the furnace body 508, and an exhaust duct 510 is provided on the ceiling surface. Is provided.
[0079]
Then, the exhaust gas from the drying furnace 506 of the coating line described in the first embodiment is guided to the deodorizing device 507 by the fan 506a, and the deodorized exhaust gas that has passed through the deodorizing device 507 is introduced into the intake duct 509 and blown onto the body 9. The hot air blown to the body 9 in the furnace body 508 is exhausted from the exhaust duct 510 by the fan 511.
[0080]
Also in this example, since the body B is heated to about 40 ° C. before being carried into the processing tank 101, the surface tension of oil, dust, and the like attached to the body B decreases, and the body B When it is carried into the tank, emulsification with the degreasing and chemical conversion treatment liquid is promoted. Thereby, the degreasing efficiency in the processing tank 101 is improved, and the dust removing efficiency is also improved.
[0081]
The configuration of the body heating zone 500 of this example can be replaced with any of the above-described body heating zone 500 of the first embodiment (FIG. 1) and the second embodiment (FIG. 2).
[0082]
The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0083]
In the vehicle body B of the above-described embodiment, parts such as the door, the trunk lid, and the door are aluminum parts, but may be an aluminum alloy.
[0084]
【Example】
Hereinafter, the effects of the present invention were confirmed by Examples and Comparative Examples that further embody the present invention. The following examples are for confirming the effects of the degreasing and chemical conversion treatment liquid used in the above-described embodiment.
[0085]
The degreasing and chemical conversion treatment solution of Example <br/> Example, sodium nitrate as a diethylene glycol monoethyl ether (DEGMEE), sodium compound as a source of sodium ions as the polar organic solvent, lithium as a source of lithium Lithium nitrate as a compound, orthophosphoric acid as a source of phosphate ions, zinc nitrate as a zinc compound serving as a source of zinc ions, nickel nitrate and manganese ion as a source of nickel compounds serving as a source of nickel ions Using manganese nitrate as a manganese compound, the composition was adjusted as shown in Table 1.
[0086]
Hexafluorozirconate (Deoxylyte 54C manufactured by Henkel) was used as the chemical conversion treatment solution for aluminum in the examples.
[0087]
Three types of test pieces are prepared: cold-rolled steel sheet (CRS), galvanized steel sheet (ZE), and aluminum 6111 (AL). After degreasing with acetone, three kinds of rust-preventive oils (Lactclean manufactured by Cosmo Oil Co., Ltd.) K, manufactured by Idemitsu Kosan Idemitsu NR3, equal amounts mixed oil 0.5 g / ^{m 2} was applied in the Nippon oil Nonrasuto PN-1), was prepared a test piece having an oil surface for testing. The test piece was surface-treated with the above-described degreasing and chemical conversion treatment solution and a chemical conversion treatment solution for aluminum, and the properties and performance of the obtained zinc phosphate coating, that is, the coating weight, the density of the crystal coating, and the primary coating adhesion. And the secondary coating adhesion was evaluated. Table 1 shows the results.
[0088]
The treatment with the degreasing and chemical conversion treatment liquid was performed by dipping a test piece into the treatment liquid, the treatment time was 300 seconds, and the temperature of the treatment liquid was 40 ° C. The treatment with the chemical conversion treatment solution for aluminum was performed by spraying the treatment solution on the test piece, and the spray time was set to 20 seconds, 30 seconds, and 100 seconds. The pH of the chemical conversion treatment solution for aluminum was 4.0, and the solution temperature was 40 ° C.
[0089]
The evaluation results were carried out by classifying the coating weight, the density of the crystalline coating, the adhesion of the primary coating, and the adhesion of the secondary coating into four categories: 極 め て very good, 良好 good, △ slightly poor, and × bad.
[0090]
The film weight was measured after the test piece after the treatment was dried with a dryer. Here, the film weight is converted into the weight (g) per 1 m ^{2, and the} weight of the film is ² to 3.5 g / cm 2 in order for the zinc phosphate chemical conversion film to have excellent rust prevention and coating properties as a coating base. Since a uniform and dense crystal film of about m ² is required, the film weight is ² to 2.5 g / m ² (very good), 2.6 to 3.5 g / m ² ○ ( good), if 1.5~1.9g / ^{m 2} △ (slightly poor), was evaluated as × (poor) is less than 1.5 g / ^{m 2.}
[0091]
The density of the crystal film was determined by sampling a sample from the center of the test piece after the treatment, and observing the shape and size of the zinc phosphate crystal film with a scanning electron microscope (SEM).
[0092]
In this embodiment, A (extremely good) if the crystal size indicating the denseness is 5 μm or less, B (good) if it is more than 5 μm to 10 μm or less, and C (somewhat inferior) if it is more than 10 μm to 20 μm or less. If it is larger than 20 μm, it was evaluated based on the criterion D (defective).
[0093]
The primary coating adhesion was evaluated by coating the test piece after the treatment. Specifically, an electrodeposition paint (Shindo # 80V manufactured by Shinto Herberts Automotive Systems Co., Ltd.) was applied to the treated test piece by applying a voltage of 200V for 3 minutes, and then the test piece was heated at 170 ° C. Baking was performed for 20 minutes to form an electrodeposited film thickness of 15 to 20 μm. Using the test piece on which the electrodeposition coating film thus obtained was formed, the coated surface of the test piece was cut into 100 squares at 1 mm intervals with an NT cutter according to JIS K5400 grid test, and a cellophane tape was used. (Nichiban, width 18 mm) was applied, and after 2 minutes, the cellophane tape was peeled off, and the number of coating films remaining in 100 cells was evaluated by the number of cells.で あ れ ば (very good) when the number of remaining coating films is 100, （(good) when 95 to 99, △ (slightly poor) when 85 to 94, and × when 84 or less. (Poor).
[0094]
The secondary coating adhesion is determined by forming an electrodeposited coating similar to the primary coating adhesion test described above, and immersing it in warm water to deliberately degrade the adhesion of the coating and then adhere the coating. It evaluates sex. In hot water immersion, the test piece on which the electrodeposition coating film is formed is immersed in warm water at 40 ° C. ± 1 ° C. for 1000 hours. The adhesion was evaluated in accordance with the JIS K5400 grid test in the same manner as the primary coating adhesion.
[0095]
[Table 1]

Comparative example A degreasing / chemical conversion liquid and an aluminum chemical conversion liquid were prepared under the same conditions as in the example except that the weight ratio of the polar organic solvent and water in the degreasing / chemical conversion liquid in the example was set to 1: 9. Then, the same evaluation was performed. Table 2 shows the results.
[0096]
[Table 2]

Discussion As is clear from the results of Tables 1 and 2, in the coating pretreatment method of the comparative example, the coating weight, the denseness of the crystal coating, the primary coating adhesion, and the secondary coating adhesion are all considered. By using the pre-coating method of the example, the coating weight, the density of the crystalline coating, the primary coating adhesion, and the secondary coating adhesion were all very good. ~ It was slightly inferior, and it was confirmed that there was no problem in quality.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of a coating pretreatment device of the present invention.
FIG. 2 is a system diagram showing another embodiment of the coating pretreatment device of the present invention.
FIG. 3 is a view for explaining a full immersion process and a half immersion process in the coating pretreatment apparatus shown in FIG. 2;
FIG. 4 is a side view and a sectional view showing another embodiment of the body heating zone according to the present invention.
[Explanation of symbols]
101: Treatment tank 201: Rinse tank (rinse means)
300 ... aluminum chemical conversion treatment zone (aluminum chemical conversion treatment means)
Numeral 301: Chemical conversion liquid supply tank for aluminum 302 ... Piping 303 ... Pump 304 ... Nozzle 307 ... Recovery tank 308 ... Piping 309 ... Pump 500 ... Body heating zone 501 ... Water tank 502 ... Piping 503 ... Pump 504 ... Shower nozzle 505 ... heat exchanger 506 ... drying furnace exhaust 507 ... deodorizing device

Claims (38)

A mixed solvent of a polar organic solvent and water having a weight ratio of 2.8: 7.2 to 3.8: 6.2, sodium ion and / or lithium ion, phosphate ion, zinc ion, nickel ion, and manganese ion A treatment tank in which a degreasing and chemical conversion treatment solution containing at least nitrate ions and / or nitrite ions is filled, and an object to be coated is immersed;
Aluminum chemical conversion treatment means provided at the subsequent stage of the treatment tank and treating the object to be coated with a chemical conversion treatment solution for aluminum,
Rinsing means provided at a subsequent stage of the aluminum chemical conversion treatment means, for washing the article to be coated with a washing liquid,
A coating pre-processing device, which is provided in a preceding stage of the processing tank and includes a heating unit for heating an object to be coated. The coating pretreatment apparatus according to claim 1, wherein the heating unit uses exhaust gas from a coating drying furnace as a heat source. The coating pretreatment device according to claim 1, wherein the heating unit sprays hot water on the object. The coating pretreatment apparatus according to claim 3, wherein the heating unit sprays hot water, which has been heat-exchanged with an exhaust gas from a coating drying furnace, to the object. The coating pretreatment device according to claim 1, wherein the heating unit blows warm air onto the object. The coating pretreatment apparatus according to claim 5, wherein the heating unit blows deodorized exhaust air exhausted from a coating / drying furnace and passing through a deodorizing device onto the workpiece. 7. The pre-coating treatment according to claim 1, wherein at least a part of the object to be coated is a composite automobile body of iron and aluminum having at least a part of an outer plate portion made of aluminum or an aluminum alloy. apparatus. The aluminum conversion treatment means includes an aluminum conversion treatment solution supply tank containing the adjusted aluminum conversion treatment solution, and a spray device for spraying the aluminum conversion treatment solution in the aluminum conversion treatment solution supply tank onto the substrate. The coating pretreatment device according to any one of claims 1 to 7, comprising: The aluminum chemical treatment means is a recovery tank for collecting the aluminum chemical treatment liquid sprayed on the article to be coated, and returns the aluminum chemical treatment liquid collected in the recovery tank to the aluminum chemical treatment liquid supply tank. The coating pretreatment device according to claim 8, comprising a first piping system. The first piping system includes a dust removing unit that removes dust contained in the chemical conversion liquid for aluminum collected in the collection tank, and a chemical sludge contained in the chemical conversion liquid for aluminum collected in the collection tank. The coating pretreatment apparatus according to claim 9, further comprising: chemical sludge removing means for removing oil; and oil removing means for removing oil contained in the chemical conversion treatment liquid for aluminum collected in the recovery tank. 11. The pre-coating treatment according to claim 10, further comprising a second piping system for leading the cleaning liquid of the rinsing means to the recovery tank and / or the most upstream means of the dust removing means, the chemical sludge removing means, and the oil removing means. apparatus. The coating pretreatment apparatus according to any one of claims 1 to 11, wherein the aluminum chemical treatment unit includes an aluminum chemical treatment tank filled with the aluminum chemical treatment liquid and immersed in the article to be coated. The coating pretreatment apparatus according to claim 12, wherein the article is completely submerged in the aluminum chemical conversion treatment tank. The coating pretreatment apparatus according to claim 12, wherein the article is half-submerged in the aluminum chemical conversion treatment tank. The aluminum chemical conversion treatment means supplies an aluminum chemical conversion treatment liquid supply tank containing the adjusted aluminum chemical conversion treatment liquid, and supplies the aluminum chemical conversion treatment liquid in the aluminum chemical conversion treatment liquid supply tank to the aluminum chemical conversion treatment tank. The pre-coating according to any one of claims 12 to 14, comprising: a third piping system; and a fourth piping system for returning the chemical conversion treatment liquid for aluminum in the aluminum chemical conversion treatment tank to the chemical conversion treatment liquid supply tank for aluminum. Processing equipment. The fourth piping system includes dust removing means for removing dust contained in the aluminum chemical conversion treatment liquid in the aluminum chemical conversion treatment tank, and chemical conversion sludge contained in the aluminum chemical conversion treatment liquid in the aluminum chemical conversion treatment tank. The coating pretreatment apparatus according to claim 15, comprising: chemical sludge removing means for removing oil; and oil removing means for removing oil contained in the chemical conversion liquid for aluminum in the aluminum chemical treatment tank. 17. The pretreatment apparatus according to claim 16, further comprising a fifth piping system that guides the cleaning liquid of the rinsing unit to the most upstream unit among the dust removing unit, the chemical sludge removing unit, and the oil removing unit. The coating pretreatment device according to any one of claims 1 to 17, wherein the polar organic solvent includes at least one of glycol ether and diethylene glycol ether. The coating pretreatment apparatus according to any one of claims 1 to 18, comprising 0.8 to 3.3 parts by weight of sodium ions and / or lithium ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. . 19. The pretreatment apparatus according to claim 18, wherein the molar ratio of the sodium ions to the lithium ions is 50:50 to 2:98. 2. The composition according to claim 1, comprising 0.2 to 0.5 parts by weight of phosphate ions and 0.5 to 0.7 parts by weight of zinc ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. 20. The coating pretreatment device according to any one of 20. The coating pretreatment apparatus according to any one of claims 1 to 21, comprising 0.09 to 0.23 parts by weight of nickel ions based on 100 parts by weight of the mixed solvent of the polar organic solvent and water. 23. The coating pretreatment apparatus according to claim 1, wherein manganese ions are contained in an amount of 0.03 to 0.16 parts by weight based on 100 parts by weight of the mixed solvent of the polar organic solvent and water. The coating pretreatment according to any one of claims 1 to 23, comprising 3.5 to 10.8 parts by weight of nitrate ions and / or nitrite ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. apparatus. The coating pretreatment according to any one of claims 1 to 24, wherein the temperature of the treatment liquid filled in the treatment tank is 40C to 60C, and the immersion time of the object is 3 minutes to 10 minutes. apparatus. The coating pretreatment apparatus according to any one of claims 1 to 25, wherein the chemical conversion treatment liquid for aluminum includes at least one of hexafluorotitanate and hexafluorozirconate. 27. The pH of the chemical conversion treatment liquid for aluminum sprayed on the article to be coated is 2.5 to 10, the temperature is 20 ° C. to 70 ° C., and the time of spraying on the article is 20 seconds to 100 seconds. A coating pretreatment device according to any one of the above. A first step of heating an iron-aluminum composite vehicle body having an aluminum or aluminum alloy component on at least a portion of the skin;
A mixture of a polar organic solvent and water having a weight ratio of 2.8: 7.2 to 3.8: 6.2, sodium ion and / or lithium ion, phosphate ion, zinc ion; A second step of immersing and treating in a degreasing and chemical conversion treatment solution containing at least nickel ions, manganese ions, nitrate ions and / or nitrite ions;
A third step of treating the automobile body with a chemical conversion treatment solution for aluminum;
A fourth step of cleaning the automobile body with a cleaning liquid. The coating pretreatment method according to claim 28, wherein the polar organic solvent contains at least one of glycol ether and diethylene glycol ether. The coating pretreatment method according to claim 28 or 29, wherein 0.8 to 3.3 parts by weight of sodium ions and / or lithium ions is contained with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. 31. The coating pretreatment method according to claim 30, wherein the molar ratio of the sodium ion to the lithium ion is 50:50 to 2:98. 29. The composition according to claim 28, comprising 0.2 to 0.5 parts by weight of phosphate ions and 0.5 to 0.7 parts by weight of zinc ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. 31. The coating pretreatment method according to any one of 31. The coating pretreatment method according to any one of claims 28 to 32, comprising 0.09 to 0.23 parts by weight of nickel ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. The coating pretreatment method according to any one of claims 28 to 33, wherein manganese ions are contained in an amount of 0.03 to 0.16 parts by weight based on 100 parts by weight of the mixed solvent of the polar organic solvent and water. The coating pretreatment according to any one of claims 28 to 34, comprising 3.5 to 10.8 parts by weight of nitrate ions and / or nitrite ions with respect to 100 parts by weight of the mixed solvent of the polar organic solvent and water. Method. The coating pretreatment method according to any one of claims 28 to 35, wherein the temperature of the degreasing / chemical conversion treatment solution is 40C to 60C, and the immersion time of the automobile body is 3 minutes to 10 minutes. The coating pretreatment method according to any one of claims 28 to 36, wherein the chemical conversion treatment liquid for aluminum contains at least one of hexafluorotitanate and hexafluorozirconate. The pH of the chemical conversion treatment solution for aluminum sprayed on the vehicle body is 2.5 to 10, the temperature is 20C to 70C, and the time of spraying on the vehicle body is 20 seconds to 100 seconds. Pretreatment method for coating described in Crab.

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