JP2021059776A - Lubricant film coated aluminum sheet - Google Patents

Abstract

To provide a lubricant film-coated aluminum sheet capable of showing excellent lubricity and bond durability.SOLUTION: A lubricant film-coated aluminum sheet 10 includes a substrate 1 comprising aluminum or an aluminum alloy, a chemical conversion coating 2 formed on the substrate 1, and containing at least one kind of titanium and zirconium, and a lubricant film 3 formed on the chemical conversion coating 2, in which the lubricant film 3 contains an acrylic acid-based polymer, and water-soluble ethylene oxide.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lubricating film-coated aluminum plate coated with a lubricating film.

Conventionally, when pressing a metal plate, a process of applying a lubricant to the surface of the metal plate is performed for the purpose of preventing damage to the mold and the metal plate and for improving the moldability of the metal plate. It has been subjected.
Here, when the target of press working is an aluminum plate, if the press working is performed with the lubricant applied, the chemical reaction proceeds due to the heat and pressure during processing, and the carboxyl groups and fats of the fatty acids in the lubricant A metal soap in which the ester group of the oil and the metal ion derived from the aluminum plate or the mold are bonded is produced. As a result, the aluminum plate is not only discolored or corroded with the formation of the metal soap, but is also liable to be damaged starting from the discolored or corroded portion.

In order to solve such a problem, research has been carried out on a lubricating film that can be suitably used for an aluminum plate and that can be removed after processing the aluminum plate, and an aluminum plate coated with the lubricating film. Such technology has been proposed.

Specifically, in Patent Document 1, an alkaline defilming type urethane resin containing a hydrophilic group, ^{a water-soluble zirconium compound of 1 to 50 mg / m 2 in} terms of metallic zirconium, and 100 parts by weight of the alkaline defilming type urethane resin are used. On the other hand, there is disclosed a lubricating film-coated aluminum plate in which a lubricating film containing 1 to 30 parts by weight and an average particle size of 0.1 to 30 μm is coated on the surface of a substrate. The lubricating aluminum plate coated with the lubricating film has a maximum absorption rate of 1 at the peak appearing ^{in 1700 cm-1} unit of the FT-IR spectrum after the alkaline defilming type urethane resin and the lubricant in the lubricating film are removed by the alkaline treatment. It is described in Patent Document 1 that a zirconium compound layer of% or less and 0.5 mg / m ^{2 or more in terms of metallic zirconium remains.}

Further, when joining the aluminum plate to another member, an adhesive method using an adhesive may be adopted. This bonding method has the advantage that it can be joined regardless of the thickness of the member to be joined and the joining location, and it is also possible to join different materials with dissimilar metals, resins, etc., and there are few restrictions on joining. However, the joint portion joined by the adhesive deteriorates due to the intrusion of moisture and the like, and the adhesive strength tends to decrease, so that sufficient adhesive durability is required.
The following techniques have been proposed as techniques for improving the adhesive durability of aluminum plates.

Specifically, Patent Document 2 discloses a method of treating an object to be treated with a chemical conversion treatment liquid containing at least one kind of zirconium fluorine complex and / or titanium fluorine complex as an adhesive application pretreatment method for a metal material. ing.

Japanese Unexamined Patent Publication No. 2011-5425 Japanese Unexamined Patent Publication No. 2006-152267

In Patent Document 1, although the lubricity of the aluminum plate coated with a lubricating film is examined, the technical behavior of each film at the time of adhesion is not examined at all, and there is room for examination about the adhesive durability. To do.
On the contrary, in Patent Document 2, although the adhesive durability of the metal material is examined, the lubricating film at the time of processing is not examined at all, and there is room for examination about the lubricity.

That is, until now, there has been no technology capable of achieving both lubricity and adhesive durability with respect to an aluminum plate coated with a lubricating film.

Therefore, an object of the present invention is to provide a lubricating film-coated aluminum plate capable of exhibiting excellent lubricity and adhesive durability.

The lubricating film-coated aluminum plate according to the present invention is formed on a substrate made of aluminum or an aluminum alloy, a chemical conversion-treated film containing at least one of titanium and zirconium formed on the substrate, and the chemical conversion-treated film. The lubricating film contains an acrylic acid-based polymer and a water-soluble ethylene oxide.

The lubricating film-coated aluminum plate according to the present invention is excellent in lubricity and adhesive durability.

It is sectional drawing of the aluminum plate coated with a lubricating film which concerns on this embodiment. It is a side view schematic diagram of the adhesive test body prepared by the adhesive durability test in an Example.

Hereinafter, embodiments (embodiments) for carrying out the lubricating film-coated aluminum plate according to the present invention will be described with reference to the drawings as appropriate.

[Aluminum plate coated with lubricating film]
As shown in FIG. 1, the lubricating film-coated aluminum plate according to the present embodiment includes a substrate 1, a chemical conversion-treated film 2 formed on the substrate 1, and a lubricating film 3. The lubricating film-coated aluminum plate 10 may further include an auxiliary film (not shown) composed of liquid oil on the surface of the lubricating film 3.

Note that FIG. 1 shows a configuration in which a chemical conversion coating film 2 and a lubricating film 3 (and an auxiliary film) are formed on both sides of the substrate 1 of the lubricating film-coated aluminum plate 10. Each film may be formed on one of the surfaces. Further, the lubricating film-coated aluminum plate 10 does not have to have each film on the entire surface (one side or both sides) of the substrate 1, and may be formed only in a press-processed area or the like, or a region other than the surface. It may be formed (for example, at the end).
Hereinafter, the substrate, the chemical conversion treatment film, the lubricating film, and the auxiliary film of the lubricating film-coated aluminum plate according to the present embodiment will be described in detail.

[substrate]
The substrate is made of aluminum or an aluminum alloy. The substrate is appropriately selected from various non-heat-treated aluminum alloys or heat-treated aluminum alloys specified in, for example, JIS H 4000: 2014, depending on the use of the lubricating film-coated aluminum plate. The non-heat-treated aluminum alloy is pure aluminum (1000 series), Al—Mn based alloy (3000 series), Al—Si based alloy (4000 series), and Al—Mg based alloy (5000 series). Examples of the heat-treated aluminum alloy include Al-Cu-Mg-based alloys (2000 series), Al-Mg-Si-based alloys (6000 series), and Al-Zn-Mg-based alloys (7000 series).
The thickness of the substrate can be appropriately set according to the use of the aluminum plate coated with the lubricating film.

When the lubricating film-coated aluminum plate is used for an automobile (specifically, an automobile panel), the substrate is preferably of high strength. Examples of the aluminum alloy constituting such a high-strength substrate include general-purpose alloys having a relatively high yield strength such as 5000 series, 6000 series, and 7000 series, and may be tempered if necessary. The substrate of the lubricating film-coated aluminum plate according to the present embodiment is very preferably a 5000 series or 6000 series aluminum alloy.

(5000 series aluminum alloy)
As an example of the composition of the 5000 series aluminum alloy, Mg: 2.5 to 5.5% by mass is contained, and Mn: 0.60% by mass or less, Cr: 0.35% by mass or less, Zr: 0 as appropriate. .50% by mass or less, Cu: 0.50% by mass or less, Zn: 0.50% by mass or less, Fe: 0.70% by mass or less, Si: 0.40% by mass or less, Ti: 0.30% by mass or less Examples thereof include an aluminum alloy containing one or more selected from the above, the balance of which is Al and unavoidable impurities.
The reasons for limiting the content of each element are as follows.

(Mg: 2.5 to 5.5% by mass)
Mg is an essential element that enhances work hardening ability by solid solution in the matrix phase and secures the required strength and durability as an aluminum alloy material plate. When the Mg content is 2.5% by mass or more, this effect can be sufficiently exerted. On the other hand, when the Mg content is 5.5% by mass or less, it is possible to suppress a decrease in intergranular corrosion resistance (corrosion resistance).

(Mn: 0.60% by mass or less)
Mn is an element that contributes to the improvement of molding processability. When the Mn content is 0.60% by mass or less, the amount of coarse crystals and precipitates containing this element is reduced, and it is possible to suppress deterioration of moldability.

(Cr: 0.35% by mass or less)
Cr is an element that contributes to the improvement of molding processability. When the Cr content is 0.35% by mass or less, the amount of coarse crystals and precipitates containing this element is reduced, and it is possible to suppress the deterioration of moldability.

(Zr: 0.50% by mass or less)
Zr is an element that contributes to the improvement of molding processability. When the Zr content is 0.50% by mass or less, the amount of coarse crystals and precipitates containing this element is reduced, and it is possible to suppress the deterioration of moldability.

(Cu: 0.50% by mass or less)
Cu is an element that has the effect of increasing the strength of the aluminum alloy plate by strengthening the solid solution. When the Cu content is 0.50% by mass or less, the slab castability does not deteriorate such as cracks in the slab on the manufacturing surface, and it is possible to suppress the inability to collect sound slabs to be used for rolling or the like. can do.

(Zn: 0.50% by mass or less)
Zn is an element having the effect of increasing the strength of the aluminum alloy plate by strengthening the solid solution and improving the press workability. When the Zn content is 0.50% by mass or less, it is possible to prevent the press workability from being lowered due to the remarkable aging hardening phenomenon in which the strength increases with the lapse of time after the plate is manufactured.

(Fe: 0.70% by mass or less, Si: 0.40% by mass or less, Ti: 0.30% by mass or less)
Fe, Si, and Ti may be contained within a range that does not interfere with the effects of the present invention. When these elements are contained, Fe is preferably 0.70% by mass or less, Si is 0.40% by mass or less, and Ti is preferably 0.30% by mass or less.

(Inevitable impurities)
The rest of the substrate is Al and unavoidable impurities. Examples of the unavoidable impurities include V, Ni, Sn, In, Ga, B, Sc and the like, which may be contained within a range that does not interfere with the effects of the present invention. The content of the elements in this case is 0.1% by mass or less individually, and 0.3% by mass or less in total.
The above-mentioned Mn, Cr, Zr, Cu, Zn, Fe, Si, and Ti may also be contained as unavoidable impurities, and the element content in this case is, for example, 0.1% by mass or less individually. The total is 0.3% by mass or less.

(6000 series aluminum alloy)
As an example of the composition of the 6000 series aluminum alloy, Mg: 0.2 to 1.5% by mass, Si: 0.3 to 2.3% by mass, Cu: 1.0% by mass or less are contained, and more appropriately. Ti: 0.1% by mass or less, B: 0.06% by mass or less, Be: 0.2% by mass or less, Mn: 0.8% by mass or less, Cr: 0.4% by mass or less, Fe: 0.5 Contains one or more selected from mass% or less, Zr: 0.2% by mass or less, V: 0.2% by mass or less, Zn: less than 0.5% by mass, and the balance consists of Al and unavoidable impurities. Examples include aluminum alloys.
The reasons for limiting the content of each element are as follows.

(Mg: 0.2 to 1.5% by mass)
Mg has the effect of improving the strength. When the Mg content is less than 0.2% by mass, the effect of improving the strength is small. On the other hand, if the Mg content exceeds 1.5% by mass, the moldability may be lowered.

(Si: 0.3 to 2.3% by mass)
Si has the effect of improving the strength. When the Si content is less than 0.3% by mass, the effect of improving the strength is small. On the other hand, if the Si content exceeds 2.3% by mass, the moldability and hot rollability may be deteriorated.

(Cu: 1.0% by mass or less)
Cu has the effect of improving the strength. However, if the Cu content exceeds 1.0% by mass, the corrosion resistance may be lowered. The Cu content preferably exceeds 0% by mass.

(Ti: 0.1% by mass or less)
Ti has the effect of making the crystal grains of the ingot finer and improving the moldability. However, if the Ti content exceeds 0.1% by mass, coarse crystallized products are formed, which may reduce moldability.

(B: 0.06% by mass or less)
B has the effect of improving the moldability by making the crystal grains and crystallized products of the ingot finer. However, if the B content exceeds 0.06% by mass, coarse crystallized products are formed, which may reduce moldability.

(Be: 0.2% by mass or less)
Be has the effect of improving the hot rollability and moldability of the aluminum alloy. However, when the Be content exceeds 0.2% by mass, the effect is saturated.

(Mn: 0.8% by mass or less, Cr: 0.4% by mass or less, Fe: 0.5% by mass or less, Zr: 0.2% by mass or less, V: 0.2% by mass or less)
Mn, Cr, Fe, Zr, and V each have the effect of improving the strength. However, when the content of these elements exceeds a predetermined value, specifically, Mn is 0.8% by mass, Cr is 0.4% by mass, Fe is 0.5% by mass, and Zr is 0.2% by mass. If% and V exceed 0.2% by mass, coarse crystallized products are formed in both cases, which may reduce moldability.

(Zn: less than 0.5% by mass)
Zn may be contained within a range that does not interfere with the effects of the present invention. The Zn content is preferably less than 0.5% by mass.

(Inevitable impurities)
The rest of the substrate is Al and unavoidable impurities.
The above-mentioned Cu, Ti, B, Be, Mn, Cr, Fe, Zr, and Zn may be contained as unavoidable impurities, and the element content in this case is, for example, 0.1% by mass or less individually. The total is 0.3% by mass or less.
When a large amount of scrap material or low-purity aluminum bullion is used in the production of the substrate, these elements are inevitably mixed in, so that the effect of the present invention is not hindered as described above. It is allowed to be contained in the range.

[Chemical conversion coating]
The chemical conversion treatment film is a film containing at least one of titanium and zirconium. The titanium of the chemical conversion treatment film is preferably at least one of titanium oxide and titanium fluoride, and the zirconium of the chemical conversion treatment film is preferably at least one of zirconium oxide and zirconium fluoride.
Since this chemical conversion coating contains at least one of titanium and zirconium, it improves stability against deterioration factors such as water, oxygen, and chloride ions, and suppresses hydration on the substrate surface in a wet environment. As a result, excellent adhesive durability can be exhibited.
In addition to titanium and zirconium, the balance of the chemical conversion coating is composed of aluminum and impurities. Here, the remaining aluminum contains aluminum oxide, aluminum fluoride and the like.

(Titanium and zirconium content)
If the total amount of the titanium film amount and the zirconium film amount of the chemical conversion treatment film ^{is less than 3 mg / m 2} , the effect of suppressing hydration on the surface of the substrate may not be sufficiently exhibited. Further, if this total amount ^{exceeds 17 mg / m 2} , the inside of the film is likely to be destroyed during adhesion.
Therefore, the total amount of the titanium film amount and the zirconium film amount of the chemical conversion treatment film ^{is preferably 3 mg / m 2} or more and 17 mg / m ² or less.

The total amount of the titanium film amount and the zirconium film amount ^{is preferably 5 mg / m 2} or more from the viewpoint of suppressing hydration on the surface of the substrate, and 15 mg / m 2 or more from the viewpoint of suppressing the destruction inside the film during adhesion. m ² or less, and more preferably at most 13 mg / ^{m 2.}

If the amount of the titanium film of the chemical conversion treatment film ^{is less than 1 mg / m 2} , the above-mentioned effect of suppressing hydration may not be sufficiently exhibited. Further, if the amount of the titanium film ^{exceeds 10 mg / m 2} , the effect is saturated and not only the production cost is increased, but also the inside of the film is liable to be destroyed at the time of adhesion.
Therefore, the amount of titanium film in the chemical conversion treatment film ^{is preferably 1 mg / m 2} or more and 10 mg / m ² or less.

^{The amount of the titanium film is preferably 2} mg / m 2 or more from the viewpoint of suppressing hydration on the surface of the substrate ^{, and 8 mg / m 2} or less from the viewpoint of suppressing an increase in manufacturing cost and destruction inside the film during adhesion. Is preferable.

If the amount of the zirconium film of the chemical conversion treatment film ^{is less than 1 mg / m 2} , the above-mentioned effect of suppressing hydration may not be sufficiently exhibited. Further, if the amount of the zirconium film ^{exceeds 10 mg / m 2} , the effect is saturated and not only the production cost is increased, but also the inside of the film is likely to be destroyed at the time of adhesion.
Therefore, the amount of zirconium film in the chemical conversion treatment film ^{is preferably 1 mg / m 2} or more and 10 mg / m ² or less.

^{The amount of the zirconium film is preferably 2} mg / m 2 or more from the viewpoint of suppressing hydration on the surface of the substrate ^{, and 8 mg / m 2} or less from the viewpoint of suppressing an increase in manufacturing cost and destruction inside the film during adhesion. Is preferable.

(Thickness of chemical conversion coating)
The thickness of the chemical conversion treatment film is not particularly limited as long as the titanium film amount, the zirconium film amount, or the total amount is a predetermined amount, but is preferably 10 to 150 nm, for example. This is because if the thickness of the chemical conversion treatment film is less than 10 nm, it becomes difficult to maintain the adhesive durability, and if this thickness exceeds 150 nm, the inside of the film is likely to be destroyed.

[Lubricating film]
The lubricating film is a film formed by forming a lubricating composition on the surface of a substrate (painting or the like) and then drying it, and contains an acrylic acid-based polymer and water-soluble ethylene oxide as main components.
Then, in combination with the chemical conversion treatment film described above, this lubricating film can exhibit excellent lubricity without suppressing or impeding the adhesive durability exhibited by the chemical conversion treatment film.

(Acrylic acid-based polymer)
The acrylic acid-based polymer has an effect of enhancing the adhesion to the substrate by containing a polar group. It has been confirmed by experiments that the acrylic acid-based polymer alone does not exhibit excellent adhesive durability.
As acrylic acid-based polymers, polyacrylic acid obtained by polymerizing acrylic acid, alkali metal salt of acrylic acid, ammonia acid alkali salt, (poly) methacrylic acid, acrylic acid ester copolymerization, and styrene / polyacrylic acid both. Examples thereof include a polymer and a polymer of an acrylamide derivative of N-methylolacrylamide.

(Water-soluble ethylene oxide)
The water-soluble ethylene oxide has an effect of improving the lubricity of the lubricating film, and can exhibit excellent lubricity when combined with the acrylic acid-based polymer described above. It has been experimentally confirmed that this water-soluble ethylene oxide alone does not exhibit excellent adhesive durability.
Examples of the water-soluble ethylene oxide include polyoxyethylene alkyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, and polyoxyethylene behenyl ether. The polyoxyethylene alkyl ether is "RO- (CH ₂ CH ₂ O) _n- H" (in the formula, R represents an alkyl group having 20 to 24 carbon atoms, and n is the number of repeating units). It is an aliphatic glycol ether compound represented by.

When n, which is the number of repeating units of ethylene oxide (CH ₂ CH ₂ O) in the formula, is 40 or more, the main chain of the polyoxyethylene alkyl ether becomes long, and the substrate and gold during processing (for example, during press processing) become long. The friction between the mold and the mold can be sufficiently reduced by the lubricating film according to the present embodiment. As a result, the lubricity at the time of processing the lubricating film-coated aluminum plate is improved, and good moldability can be obtained.
Therefore, the number of repeating units n of ethylene oxide (CH ₂ CH ₂ O) in the formula is preferably 40 or more.

Further, as the number of repeating units n in the formula increases, the melting point of the polyoxyethylene alkyl ether increases. As a result, it is possible to improve the blocking resistance by suppressing the occurrence of a phenomenon in which the aluminum plates are stuck to each other via the lubricating film due to an increase in temperature during storage. In addition, as the number of repeating units n in the formula increases, the lubricity described above can be further improved.
Therefore, from the viewpoint of improving blocking resistance, the number of repeating units n in the formula is preferably 60 or more, more preferably 70 or more, further preferably 90 or more, and particularly preferably 100 or more.
The melting point can be measured according to JIS K 2235: 2009.

On the other hand, the upper limit of the number of repeating units n in the formula is not particularly limited, but from the viewpoint of manufacturing difficulty and cost increase of the polyoxyethylene alkyl ether itself, for example, 450 or less, 300 or less, 200 or less, 150 or less can be mentioned. Be done.

R in the formula is an alkyl group, but if the number of carbon atoms is less than 20, the lubricity becomes insufficient. On the other hand, if the number of carbon atoms exceeds 24, it becomes difficult to obtain it.
Therefore, the alkyl group of R in the formula has 20 to 24 carbon atoms.

The polyoxyethylene alkyl ether contained in the lubricating film may contain one type, but may contain two or more types having different molecular weights and molecular chain lengths.
When there are two or more types of polyoxyethylene alkyl ethers, it is preferable that the value of each n is within a predetermined range of the above-mentioned n value, but the average value of n is within the above-mentioned predetermined range of the value of n. It suffices to be inside. When there are two or more types of polyoxyethylene alkyl ethers, the value of the carbon number of each R alkyl group is preferably within the predetermined range of the above-mentioned carbon number, but the average value of the carbon number is It suffices if it is within the predetermined range of the carbon number described above.
The average value of n and the average value of the number of carbon atoms may be calculated after being identified by, for example, analysis such as a chromatograph.

By using two or more types of polyoxyethylene alkyl ethers having different molecular weights and molecular chain lengths, the melting point (freezing point) of the lubricating composition can be adjusted to control the shape of the mold, press temperature, press pressure, and other press working conditions. A lubricating composition having suitable lubricity can be obtained. Further, the melting point of the lubricating composition can be adjusted to obtain a lubricating composition suitable for temperature, geographical factors, storage environment and the like.

(Lubricating film: film amount)
When the amount of the lubricating film is 0.10 g / m ² or more, sufficient lubricity can be ensured. On the other hand, when the amount of the lubricating film is 2.00 g / m ² or less, it is possible to avoid a decrease in adhesive durability.
Therefore, the amount of the lubricating film ^{is preferably 0.10 g / m 2} or more and 2.00 g / m ² or less.

The amount of the lubricating film ^{is preferably 0.20 g / m 2} or more, and more preferably 0.25 g / m ² or more, from the viewpoint of ensuring lubricity. ^{The amount of the lubricating film is preferably 1.00 g / m 2} or less, more preferably 0.60 g / m ² or less, from the viewpoint of ensuring adhesive durability.

(Lubricating film: other components)
As described in Example 3 of Japanese Patent Publication S51-003702, for example, the lubricating composition constituting the lubricating film includes various compounds other than the acrylic acid-based polymer and the water-soluble ethylene oxide, and the styrene / maleic anhydride copolymer. The coalescence, Ca stearate, Zn stearate, carnauba wax and the like may be appropriately contained.
Further, the lubricating composition constituting the lubricating film is, for example, an antioxidant, a conductive additive, a surfactant, a thickener, as long as it does not interfere with the effects of the acrylic acid-based polymer and the water-soluble ethylene oxide. Defoamers, leveling agents, dispersants, desiccants, stabilizers, anti-skin agents, anti-mold agents, preservatives, anti-freezing agents and the like may be appropriately contained.
As the solvent of the lubricating composition, water, alcohols, ketones and the like may be used.

The antioxidant is preferably contained in the lubricating composition in order to prevent thermal decomposition of the polyoxyethylene alkyl ether. Specifically, when the lubricating composition is heated and melted and held for a long time when forming a lubricating film on a substrate, ethylene oxide in the polyoxyethylene alkyl ether structure reacts with surrounding oxygen and gradually oxidizes and decomposes. However, antioxidants can suppress this decomposition reaction.

Examples of the antioxidant include those having a semicarbazide group and those having a phenol group. Specifically, bullet-tri (hexamethylene-N, N-dimethylsemicarbazide), 1,6-hexamethylenebis (N, N-methylsemicarbazide), 2,6-di-t-butyl-4-methylphenol. , 2,2'-Methylenebis (6-t-butyl-4-methylphenol) and the like. The content of the antioxidant is preferably 2 to 3% by mass with respect to the entire lubricating composition.

[Auxiliary film]
The auxiliary film is a layer formed by forming (painting, etc.) liquid oil on the surface of the lubricating film, but it is not an essential film in the lubricating film-coated aluminum plate according to the present embodiment.

(Auxiliary film: component)
The auxiliary film is composed of a liquid oil containing petroleum-based hydrocarbon as a main component. The phrase "mainly composed of petroleum-based hydrocarbons" means that the content of petroleum-based hydrocarbons in the liquid oil is 50% by mass or more, preferably 60% by mass or more, and 70% by mass or more. As mentioned above, 80% by mass or more is more preferable.
Petroleum-based hydrocarbons are not particularly limited, and examples thereof include chain-type saturated hydrocarbons having 8 to 18 carbon atoms. Examples of substances other than petroleum-based hydrocarbons in liquid oil include fatty acid esters, rust inhibitors, extreme pressure agents, and surfactants.

(Auxiliary film: film amount)
When the amount of the auxiliary film is 0.3 g / m ² or more, sufficient discoloration resistance (resistance to discoloration of the substrate due to rust or the like) can be ensured. On the other hand, if the amount of the auxiliary film ^{exceeds 1.0 g / m 2} , the effect of improving the discoloration resistance is saturated and coating unevenness may easily occur.
Therefore, the amount of the auxiliary film is preferably ^{0.3 to 1.0 g / m 2. The amount of the auxiliary film is preferably 0.4 g / m 2} or more from the viewpoint of improving discoloration resistance, and ^{preferably 0.8 g / m 2} or less from the viewpoint of suppressing the occurrence of coating unevenness. 6 g / m ² or less is more preferable.

(Auxiliary film: kinematic viscosity)
If the kinematic viscosity of the liquid oil constituting the auxiliary film at 40 ° C. is less than 1 cSt, the uniformity of the film amount at the time of painting may not be ensured. On the other hand, if the kinematic viscosity of the liquid oil constituting the auxiliary film at 40 ° C. exceeds 7 cSt, it becomes difficult to paint by an electrostatic coating method or the like at room temperature.
Therefore, the kinematic viscosity of the liquid oil constituting the auxiliary film at 40 ° C. is preferably 1 to 7 cSt. The kinematic viscosity of the liquid oil constituting the auxiliary film at 40 ° C. is more preferably 2 cSt or more from the viewpoint of uniformity of the film amount, and more preferably 6 cSt or less from the viewpoint of ease of coating.
Examples of such liquid oil include PD4000T (kinematic viscosity 2cSt) manufactured by JX, Preton R303P (kinematic viscosity 4cSt) manufactured by Sugimura Chemical Industrial, and the like.

(Each measurement method)
The titanium film amount (metal titanium equivalent amount) and the zirconium film amount (metal zirconium equivalent amount) of the chemical conversion treatment film can be measured by fluorescent X-ray (XRF: X-ray Fluorescense Analysis).
Further, the thickness of the chemical conversion-treated film can be measured by a glow discharge emission analyzer (GD-OES: Glow Discharge Optical Measurement Spectroscopy).

The method for measuring the amount of the lubricating film and the auxiliary film is not particularly limited, but for example, the film thickness of the lubricating film and the auxiliary film is measured with an infrared film thickness meter, and the weight of each film and the weight of each film obtained in advance are measured. The amount of each film may be calculated from the measured film thickness value based on the correlation formula with the film thickness.
The method for measuring the kinematic viscosity of the liquid oil constituting the auxiliary film at 40 ° C. is not particularly limited, and examples thereof include the method described in JIS K 2283: 2000.

[Use]
Since the lubricating film-coated aluminum plate according to the present embodiment is lightweight and has excellent lubricity and adhesive durability, it is required to be lightweight and is a component member of an automobile that is subjected to complicated processing and adhesive treatment. In particular, it can be suitably used as an automobile panel.

[Manufacturing method of aluminum plate coated with lubricating film]
Next, a method for manufacturing the lubricating film-coated aluminum plate according to the present embodiment will be described.
The method for producing a lubricating film-coated aluminum plate includes a substrate manufacturing step, a chemical conversion treatment film forming step, and a lubricating film forming step, and may further include an auxiliary film forming step.
Hereinafter, each step will be described in detail.

(Substrate manufacturing process)
The substrate manufacturing process is a step of manufacturing a substrate by rolling. Specifically, the substrate can be produced by the following procedure.

An aluminum alloy having a predetermined composition is melted and cast by continuous casting to produce an ingot (melting casting step), and the manufactured ingot is subjected to homogenization heat treatment (homogenization heat treatment step). Next, the ingot that has been homogenized and heat-treated is hot-rolled to produce a hot-rolled plate (hot-rolling step). Next, the hot-rolled plate is roughly annealed or intermediate-annealed at 300 to 580 ° C., and cold-rolled at least once with a final cold rolling ratio of 5% or more to produce a cold-rolled plate having a predetermined plate thickness. (Cold rolling process). By setting the temperature of rough annealing or intermediate annealing to 300 ° C. or higher, the effect of improving moldability is further exhibited, and by setting the temperature to 580 ° C. or lower, deterioration of moldability due to the occurrence of burning can be easily suppressed. By setting the final cold rolling ratio to 5% or more, the effect of improving moldability is further exhibited. The conditions for the homogenizing heat treatment and the hot rolling are not particularly limited, and may be the conditions when a hot-rolled sheet is usually obtained. Further, intermediate annealing does not have to be performed.

Further, after the cold rolling, cold rolling with a low processing rate such as skin pass rolling for straightening plate flatness and rolling using an electric discharge textured (EDT) processing roll for surface roughness control. May be done.

(Chemical conversion coating film forming process)
The chemical conversion treatment film forming step is a step of forming a chemical conversion treatment film on the substrate. Specifically, a chemical conversion treatment film can be formed by the following procedure.

A treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound is supplied to the surface of the substrate and brought into contact with the substrate for a predetermined time, and then washed with water to remove the treatment liquid. The treatment liquid in contact with the surface of the substrate reacts with the substrate to form a chemical conversion treatment film containing at least one of titanium and zirconium. The treatment liquid may be supplied in any form of the spraying method or the dipping method in the chemical conversion treatment film forming step, and the washing with water may be in any form of the spraying method or the dipping method. Further, the concentration and contact time of the treatment liquid may be set so that the titanium film amount, the zirconium film amount, and the total film amount described above are predetermined amounts.
In addition to the above, there is a method of applying a treatment liquid containing at least one of a titanium fluoride compound and a zirconium fluoride compound, and the treatment may be performed by either method. The treatment liquid applied to the surface of the substrate reacts with the substrate to form a chemical conversion treatment film containing at least one of titanium and zirconium. The treatment liquid in the chemical conversion coating film forming step may be applied in any of the indirect charging type (bell type) electrostatic coating method, the spray type (no electric field) coating method, the dipping method, and the coating method described later. Good. Further, the coating amount of the treatment liquid may be set so that the titanium film amount, the zirconium film amount, and the total film amount described above are predetermined amounts.

Here, the titanium fluoride compound is, for example, a fluorotitanate such as K ₂ TiF ₆ , (NH ₄ ) ₂ TiF ₆ , a fluoro titanate acid such as _{H 2} TiF _6. The zirconium fluoride compound, for _example, K ₂ ZrF _6, and the like fluorozirconate such _(NH 4) 2 ZrF _6, fluoro zirconate acid such as H 2 ZrF _6.

Then, in the chemical conversion treatment film forming step, before supplying or applying the treatment liquid to the substrate surface, an alkali cleaning treatment for removing the oil remaining on the substrate surface, a water washing treatment for removing the alkali, and removing the aluminum oxide film and the magnesium oxide film. The acid washing treatment for removing the acid and the water washing treatment for removing the acid may be carried out as appropriate.
Further, in the chemical conversion treatment film forming step, after supplying and washing the treatment liquid with water or applying the treatment liquid, a drying treatment for drying the water washing water or the treatment liquid on the surface of the substrate may be appropriately performed.

(Lubrication film forming process)
The lubricating film forming step is a step of forming a lubricating film on the chemical conversion treatment film.
Examples of the method for forming the lubricating film include a coating method. Industrially, a lubricating film is formed by coating a substrate in an aqueous solution state with a lubricating composition by roll coating or the like, and then drying the substrate.

In the roll coating method, the paint that is the aqueous solution in the coater pan is lifted by a pickup roll and transferred directly to the applicator roll, or transferred once to the transfer roll and then transferred to the applicator roll to be continuously passed. This is a method of painting the substrate with an applicator roll. The roll coating method is a method that can uniformly coat in the width direction and the longitudinal direction.
As a method of controlling the film thickness (film thickness) of the lubricating film, the concentration of the paint (dilution concentration with an aqueous solvent) may be adjusted. That is, if a paint adjusted to a high concentration is applied, the amount of film is large (thick film), and if a paint adjusted to a low concentration is applied, the amount of film is small (thin film). Further, when the nip pressure between the pickup roll and the applicator roll (or transfer roll) at the time of roll coating is increased, the film becomes thicker, and when the nip pressure is decreased, the film becomes thinner.
The coating method (roll coating method) has been described as a method for forming the lubricating film, but the method is not particularly limited to this method, and for example, an indirect charging type (bell type) electrostatic coating method, a spray type (no electric field) coating method, and the like. Conventionally known methods such as a dipping method can be adopted.

The paint applied to the substrate is made into a coating film (lubricating film) by volatilizing and drying the water as a solvent in a furnace or the like. At this time, if the heating temperature is high, ethylene oxide in the coating material (lubricating composition) is thermally decomposed. Therefore, the temperature reached by the substrate is preferably about 120 ° C. or lower, and about 70 ° C. for efficient volatilization and drying. The above is preferable.

(Auxiliary film forming process)
The auxiliary film forming step is a step of forming an auxiliary film on the lubricating film.
Examples of the method of forming the auxiliary film include a conventionally known method such as a coating method as well as a method of forming a lubricating film, a method of immersing in liquid oil, a method of spraying liquid oil, and the like. The method of forming the auxiliary film is different from the method of forming the lubricating film, and after the auxiliary film is formed on the lubricating film, the work of actively heating and drying is not performed.

(Other processes)
The method for manufacturing the lubricating film-coated aluminum plate is as described above, but other steps may be included during or before and after each of the steps as long as the steps are not adversely affected.

For example, in the substrate manufacturing step, a solution treatment step of performing a solution treatment and a preliminary aging treatment step of performing a preliminary aging treatment may be provided after cold rolling (including skin pass rolling and the like). The pre-aging treatment is preferably carried out by low-temperature heating at 40 to 120 ° C. for 8 to 36 hours within 72 hours after the completion of the solution treatment. By performing the preliminary aging treatment under these conditions, it is possible to improve the moldability of the aluminum plate (substrate) coated with the lubricating film and the strength after the lubricating film is removed, painted, and heated (baked).

Further, after the substrate manufacturing step and before the lubricating film forming step, a cutting step of cutting the long substrate into a single-wafer shape may be provided. In this case, the lubricating film and the auxiliary film may be formed on the cut surface (end face) of the substrate in the lubricating film forming step and the auxiliary film forming step.
Further, a foreign matter removing step for removing foreign matter on the surface of the substrate or the resin film and a defective product removing step for removing defective products may be provided.

Next, the lubricating film-coated aluminum plate according to the present invention will be specifically described by comparing an example satisfying the requirements of the present invention with a comparative example not satisfying the requirements of the present invention.

[Preparation of test material]
(substrate)
As a substrate, an aluminum alloy plate having a thickness of 1.2 mm made of 5182 alloy specified in JIS H 4000: 2014 was prepared, and cut out so as to have a width of 150 mm and a length of 200 mm. Then, the aluminum plate was subjected to alkaline degreasing, water washing, then acid washing and water washing.

Then, the aluminum plate washed with water after the acid washing was immersed in a treatment liquid (50 ° C.) containing 150 ppm of fluorotitanate acid and 250 ppm of fluorozircone acid for an arbitrary time. Then, after washing with water, it was dried at room temperature.
As for the test materials 5 to 8, the aluminum plate washed with water after being pickled was directly dried to obtain a pickled material.

A 1: 1 mixture of an acrylic acid-based lubricant and a water-soluble ethylene oxide-based lubricant was dissolved in water to produce an aqueous solution having a solid content concentration of about 5 to 15%. Then, the test materials 1 to 3 and 6 to 8 are coated on the evaluation surface using bar coaters # 4 to # 8, and then dried in a furnace so that the ultimate temperature of the substrate becomes 100 ° C. , A test material provided with a lubricating film (type A in Table 1) containing an acrylic acid-based polymer and a water-soluble ethylene oxide was prepared.

As a comparative example, test materials 4 and 5 that do not form a lubricating film, test material 9 that has a solid lubricant as a lubricating film (type B in Table 1), and water-soluble ethylene oxide-based lubricant are coated and water-soluble. A test material 10 having a lubricating film containing ethylene oxide (type C in Table 1) and a lubricating film containing only an acrylic acid-based lubricant and a lubricating film containing an acrylic acid-based polymer (type D in Table 1) were provided. A test material 11 and a test material 12 provided with liquid oil as a lubricating film (type E in Table 1) were prepared.
As for the test materials 9 to 11, similarly to the test materials 1 to 3 and 6 to 8, each lubricant was dried in the furnace so that the reaching temperature of the substrate reached 100 ° C. after coating.

The "acrylic acid-based lubricant" used was Milbond (registered trademark) MC560J (manufactured by Nichiyu), and the "water-soluble ethylene oxide-based lubricant" was Nonion B250 (manufactured by Nichiyu), which was a "solid lubricant". Was E1 (manufactured by Zeller), and the "liquid oil" was PD4000T (manufactured by JX).
The mill bond MC560J is composed of polyacrylic acid (60 to 90 wt%), styrene / maleic anhydride copolymer (6 to 20 wt%), stearic acid salt (3 to 23 wt%), and carbana wax (0 to 6 wt%). Nonion B250 is composed of polyoxyethylene alkyl ether (RO- (CH ₂ CH ₂ O) _n- H, carbon number R is 22, n is 50, average molecular weight is 2500, and melting point is 53 ° C.). I used the one. Further, PD4000T was a liquid oil containing a petroleum-based hydrocarbon as a main component (containing about 85%), and had a kinematic viscosity at 40 ° C. of 2 cSt.

Next, the method of measuring the amount of the film, the friction coefficient measurement test, and the contents of the adhesive durability test are shown.

[Measuring method]
(Amount of chemical conversion coating)
The amount of titanium film and the amount of zirconium film were measured by fluorescent X-rays (LAB CENTER XRF-1800, manufactured by Shimadzu Corporation).
Specifically, the correlation between the immersion time in the treatment liquid and the film amount was obtained in advance, and the film amount was calculated from the immersion time. The amount of film was measured by randomly selecting one from a plurality of test materials treated under the same conditions, and coating on both sides within a range of 30 mmφ centered on the center of gravity of the test material having a width of 150 mm and a length of 200 mm. The amount was measured and the average value was calculated.

(Amount of lubricating film)
The amount of the lubricating film was measured by an infrared film thickness meter (manufactured by AMEPA, TYPE: OFIS2.0, VerNr: 4.1) or a weight change before and after peeling of the lubricating film.
When the film thickness is measured with an infrared film thickness meter, the film thickness of the lubricating film obtained by the measurement is based on the correlation formula between the weight of the lubricating film and the film thickness of the lubricating film obtained in advance. From the values, the amount of the lubricating film of the test material was calculated.
When the amount of the film was measured by changing the weight, the lubricating film was peeled off by washing with water.

[Test method]
(Friction coefficient test)
With respect to the test material prepared by the above method, a load of 200 g was applied to the test material using a Bowden tester, and the friction coefficient when sliding three times back and forth was measured.
As shown in Table 1, the friction coefficient test was carried out when the surface of the test material was not oiled and when a predetermined oil was applied to the surface of the test material.
Then, when the oil was applied, the one having a friction coefficient of 0.10 or less was evaluated as having good lubricity "◯", and the one having a friction coefficient exceeding 0.10 was evaluated as having poor lubricity "x".
The friction coefficient when not lubricated is shown as a reference value, but it is preferable that this friction coefficient is also 0.10 or less.

(Adhesive durability test)
Two of the same test materials prepared by the above method were cut into a width of 25 mm and a length of 100 mm, and as shown in FIG. 2, one was used as the lower test piece 11 and the other was used as the upper test piece 12, and both test pieces were used. Was laminated and pasted with a thermosetting epoxy resin adhesive 20 so as to have a wrap length of 10 mm (adhesive area: 25 mm × 10 mm) to prepare an adhesive test piece 30. At this time, glass beads (particle size 250 μm) were added to the adhesive 20 to adjust the thickness of the adhesive 20 to 250 μm. Then, it was baked and cured at 175 ° C. × 20 minutes.
Before adhering both test pieces with an adhesive, the adhesive test piece 30 is coated with PD4000T on the surfaces of both test pieces and held for 7 days under the condition of 40 ° C. × 90% RH (treatment with time before adhesion). ) ("With pre-adhesion aging treatment" in Table 1) and with adhesives attached to both test pieces without this pre-adhesion aging treatment (Table 1 "Without pre-adhesion aging treatment"). , Prepared.

After holding the prepared adhesive test piece 30 under the following cycle conditions for 10 days, the unbonded parts of the lower and upper test pieces 11 and 12 were grasped, and a shear tensile test was performed at a speed of 13 mm / min. Then, the fractured form of the adhesive test piece 30 was observed and the adhesive strength was calculated according to the following procedure to evaluate the adhesive durability.
Three of each adhesive test piece 30 were prepared, and the following cohesive fracture rate and adhesive strength were taken as the average value of the three.

(Cycle condition)
・ 50 ℃ SST pH3 45 minutes ・ 50 ℃ × 30% RH 2 hours ・ 50 ℃ × 95% RH 3 hours 15 minutes

(Adhesive durability test: fracture form)
Observe the peeled state of the adhesive test piece 30 after the tensile test, and disintegrate the internal fracture of the adhesive 20, the interface between the lower test piece 11 and the adhesive 20, and the upper test piece 12 and the adhesive 20. The peeling at the interface with and was taken as the interface failure, and the cohesive failure rate as an index of the failure form was calculated by the following equation (1).
Cohesive fracture rate (%) = 100-{(interfacial peeling area of lower test piece 11 / adhesive area of lower test piece 11) x 100 + (interfacial peeling area of upper test piece 12 / adhesive area of upper test piece 12) × 100)} ・ ・ ・ (1)

(Adhesive durability test: Adhesive strength)
From the stress-strain diagram obtained during the tensile test, the value obtained by dividing the maximum stress at break by the adhesive area was defined as the adhesive strength.

The adhesive strength is 14.0 MPa or more and the cohesive fracture rate (CF rate) is 90% or more in both the case of "without aging treatment before adhesion" and the case of "with aging treatment before adhesion". Those with good adhesive durability were evaluated as "○", and those other than those with poor adhesive durability were evaluated as "×".

Table 1 below shows the composition of each test material and the test results.
In addition, "-" in the test result in Table 1 indicates that the test has not been carried out.

[Examination of results]
Since the test materials 1 to 3 satisfied all the requirements specified in the present invention, it was confirmed that they were excellent in lubricity and adhesive durability.
On the other hand, since the test materials 4 to 12 did not satisfy the requirements specified in the present invention, it was confirmed that at least one of the lubricity and the adhesive durability had an unfavorable result.

Specifically, since the test material 4 was not provided with the lubricating film itself, the numerical value of the friction coefficient was large, resulting in inferior lubricity.
Since the test material 5 was not provided with the lubricating film itself, the numerical value of the friction coefficient was large, resulting in inferior lubricity.
Since the test materials 6 to 8 were not provided with the chemical conversion treatment film itself, the result was that the adhesive durability was inferior.
Since the lubricating film of the test material 9 was a solid lubricant rather than the one specified in the present invention, the numerical value of the friction coefficient was large, resulting in inferior lubricity.
The test material 10 was found to be inferior in adhesive durability because the lubricating film did not contain an acrylic acid-based polymer.
The test material 11 was found to be inferior in adhesive durability because the lubricating film did not contain water-soluble ethylene oxide.
Since the lubricating film of the test material 12 was a liquid oil rather than the one specified in the present invention, the numerical value of the friction coefficient was large, resulting in inferior lubricity.

Since the lubricating film of the test materials 1 to 3 contained both an acrylic acid-based polymer and a water-soluble ethylene oxide, both of them were applied to each other's substrate surface (specifically, the surface of the chemical conversion-treated film). It is presumed that the interfacial peeling was suppressed as a result of reducing the binding force and being properly absorbed (mixed) by the adhesive. In addition, since the lubricating film of the test materials 1 to 3 contained both an acrylic acid-based polymer and a water-soluble ethylene oxide, hydration was suppressed on the substrate surface in a moist environment played by the chemical conversion treatment film. It exhibited high adhesive strength and CF rate even with pre-adhesion aging treatment without interfering with the effect.

On the other hand, since the lubricating film of the test materials 10 and 11 contained one of the acrylic acid-based polymer and the water-soluble ethylene oxide, the acrylic acid-based polymer or the water-soluble ethylene oxide was present on the substrate surface ( In detail, it is presumed that the bonding force to the surface of the chemical conversion coating film) remained strong, did not mix properly with the adhesive, and the interfacial peeling was not suppressed.

Further, by comparing the results of the test material 5 (pickling) and the test materials 6 to 8 (pickling + the lubricating film of the present invention), it can be confirmed that the adhesive durability due to the lubricating film of the present invention is significantly reduced. Comparing the results of test material 4 (TiZr chemical conversion treatment film) and test materials 1 to 3 (TiZr chemical conversion treatment film + lubricating film of the present invention), the decrease in adhesive durability due to the lubricating film of the present invention is I could hardly confirm it.
That is, from these results, it can be seen that the TiZr chemical conversion coating film suppresses the decrease in adhesive durability due to the lubricating film of the present invention, and the combination of this chemical conversion coating film and the lubricating film has a very excellent effect. It turned out to be effective.

The lubricating film-coated aluminum plate according to the present invention has been described in detail by showing embodiments and examples, but the gist of the present invention is not limited to the above-mentioned contents, and the scope of rights thereof is the scope of claims. Must be interpreted based on the description in. Needless to say, the content of the present invention can be modified or changed based on the above description.

1 Substrate 2 Chemical conversion coating 3 Lubricating film 10 Lubricating film coated aluminum plate (aluminum plate)
11 Lower test piece 12 Upper test piece 20 Adhesive 30 Adhesive test piece

Claims (3)

A substrate made of aluminum or an aluminum alloy, a chemical conversion treatment film containing at least one of titanium and zirconium formed on the substrate, and a lubricating film formed on the chemical conversion treatment film are provided.
The lubricating film is a lubricating film-coated aluminum plate containing an acrylic acid-based polymer and water-soluble ethylene oxide. The lubricating film-coated aluminum plate according to claim 1, wherein the amount of the lubricating film is 0.10 g / m ² or more and 2.00 g / m ^{2 or less.} The lubricating film-coated aluminum plate according to claim 1 or 2, which is used for an automobile panel.

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