KR0179685B1 - Surface treating composition for metallic material containing aluminum and surface treatment - Google Patents

Abstract

A surface of aluminiferous metal is brought into contact at 30 DEG C to 65 DEG C for 5 to 60 seconds with a surface treatment bath with a pH of 2.0 to 6.5 that contains phosphate ion, condensed phosphate ion, and a water soluble polymer in the following weight proportions: 1 - 30 : 0.1 - 10 : 0.2 - 20. This is followed by a water rinse and drying by heating. The water soluble polymer has a chemical structure conforming with formula (I), in which (i) each of X<1> and X<2> represents a hydrogen atom, a C1 to C5 alkyl group, or a C1 to C5 hydroxyalkyl group; (ii) each of Y<1> and Y<2> represents a hydrogen atom or a moiety "Z" that conforms to formula (II) or (III), wherein each of R<1>, R<2>, R<3>, R<4>, and R<5> represents a C1 to C10 alkyl group or a C1 to C10 hydroxyalkyl group; (iii) the average value for the number of Z moieties substituted on each phenyl ring in the polymer molecule is from 0.2 to 1.0; (iv) n is an integer with a value from 2 to 50; and (v) each polymer molecule contains at least one Z moiety.

Description

[Name of invention]

Polymer Compound Compositions and Methods for Surface Treatment of Aluminum-Containing Metallic Materials

Detailed description of the invention

[Background of invention]

[Field of Invention]

The present invention relates to a polymer compound surface treatment composition for an aluminum containing metal material and a method for surface treatment of an aluminum containing metal material therewith.

More specifically, the present invention provides a surface treatment of an aluminum-containing metal material with a polymer compound surface treatment composition and a polymer compound composition for an aluminum-containing metal material for imparting excellent corrosion resistance and excellent paint adhesion to the surface before coating the surface with the paint. It relates to a method for doing so.

The polymer compound composition and method of the present invention can be effectively used to surface-treat an aluminum-containing metal can produced by drawing and ironing processing, before coating and printing paint. Surface treatment significantly improves the corrosion and paint adhesion of the drawn and ironed cans, that is, the DI cans and imparts the improved sliding properties required for smooth conveyor transfer of the DI cans. The characteristics of the can that can be conveyed smoothly will be referred to later as slippage on the conveyor.

[Description of Related Fields]

Usually, surface treatment liquids for aluminum containing metal materials, that is, aluminum metal and aluminum alloy materials, are classified into chromate type surface treatment liquids and non-chromate type surface treatment liquids.

Typical chromate-type surface treatment solutions are chromate-chromate chemicals and phosphate-chromate chemicals.

The chromic acid-chromate chemical treatment solution was put to practical use around 1950 and is still widely used in aluminum alloy metal materials such as fin members of heat exchangers.

The chromic acid-chromate chemical treatment solution can form a film containing a certain amount of hexavalent chromium on the surface of a metal material, including chromic acid (CrO ₃ ) and hydrofluoric acid (HF) as a main component, and an accelerator added to the main component. .

The phosphate-chromate chemical treatment solution was based on the invention disclosed in US Pat. No. 2,438,877 in 1945. The chemical conversion solution contains chromic acid (CrO ₃ ), phosphoric acid (H ₃ PO ₄ ) and hydrofluoric acid (HF) as main components, and the film formed on the metal material from the chemical conversion solution is chromium phosphate (CrPO ₄ · 4H) as a main component. ₂ O). Since the resulting chemical conversion coating does not contain hexavalent chromium, the phosphate-chromate chemical treatment solution is very widely used to form an undercoat layer for coating the paint on the body and the lid of a beverage can.

A typical non-chromic acid type chemical treatment solution is an aqueous acidic coating liquid containing zirconium, titanium, zirconium compounds and at least one member selected from titanium compounds, phosphates and fluorides and having a pH of about 1.0 to 4.0. When applying the chemical conversion treatment to the surface of the aluminum-containing metal material with the typical non-chromate solution described above, a chemical conversion coating containing zirconium oxide and / or titanium oxide as a main component is formed on the metal material surface.

The non-chromate-type chemical treatment solution as described above has the advantage of no harmful hexavalent chromium in the resulting coating and the disadvantage that the resulting chemical conversion coating has poor corrosion resistance and paint adhesion than that produced from the chromate-type chemical treatment solution. have.

Chromate and non-chromate type chemical liquors contain fluorine containing compounds. However, in view of environmental pollution problem, it is recently required to provide a surface treatment liquid free of fluorine compounds.

JP-A 61-91,369, JP-A 1-172,406, 1-177,379, 1-177,380 for surface treatment liquids and surface treatment methods for imparting improved corrosion resistance and excellent paint adhesion to aluminum-containing metal materials. , 2-608 and 2-069 disclose the use of water soluble resins. In these conventional surface treatment solutions and methods, the surface of the metal material is treated with an aqueous polyhydric phenol compound. Conventional surface treatment solutions and methods have a disadvantage in that it is difficult to form a stable resin film completely on the surface of the metal material, and thus the resulting resin coated metal material does not exhibit sufficient corrosion resistance. Even in the invention of Japanese Patent Application Laid-open No. Hei 4-66,671, which discloses an improved method over the above-mentioned conventional method using a polyhydric phenol compound, there is a disadvantage that sometimes the resulting resin film exhibits insufficient paint adhesion.

Currently, for the surface treatment of DI aluminum cans formed from aluminum alloy plates by drawing and ironing processing, usually, non-chromate type surface treatment liquids selected from phosphate-chromate chemical treatment liquids and zirconium-containing coating liquids are used. do.

In DI aluminum cans its outer bottom surface is pasteurized without painting. In this case, if the outer bottom surface has insufficient corrosion resistance, this part of the DI aluminum can is oxidized and becomes black. This phenomenon is called bottom dome staining.

In order to prevent bottom dome discoloration, the coating itself formed on the aluminum can by surface treatment is required to exhibit high corrosion resistance just before the coating is applied thereto.

In the can manufacturing process, a plurality of cans are conveyed to the conveyor. If the outer surfaces of the can have high frictional forces with each other, the outer surfaces of the cans do not slide smoothly with each other and the cans rotate at an angle, which prevents the smooth conveying. In particular, smooth transfer is very important when the can is transferred to the printing stage.

Therefore, in the can manufacturing industry, it is very necessary to reduce the static friction coefficient of the outer surface of the can without affecting the paint or ink adhesion of the outer surface of the can with respect to each other.

In an attempt to improve the slidability of the outer surface of the can, Japanese Patent Laid-Open No. 64-85,292 discloses a metal containing a water-soluble organic substance selected from phosphate esters, alcohols, monovalent and polyvalent fatty acids, fatty acid derivatives, and mixtures of the above-mentioned compounds. Disclosed is a surface treating agent for cans. This surface treatment chemical effectively improves the slidability of aluminum cans. However, these surface treatment chemicals do not contribute to improving the corrosion resistance and paint adhesion of surface-coated cans.

[Overview of invention]

An object of the present invention is to provide an aqueous composition and method for surface-treating an aluminum-containing metal material in order to form a resin coating layer having good corrosion resistance and paint adhesion when applied to an aluminum-containing metal material surface.

Another object of the present invention is to provide an aqueous composition and method for surface-treating an aluminum-containing metal in the form of a DI can to form a resin coating layer that can impart improved corrosion resistance to the surface of the can in addition to high corrosion resistance and paint adhesion. To provide.

The above object can be achieved by the aqueous composition of the present invention for surface treatment of an aluminum-containing metal material, which is used as a main component.

(a) phosphate ions,

(b) condensed phosphate ions

(c) a plurality of polymer units of formula (I):

[Wherein X ¹ and X ² each independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and a hydroxyalkyl group having 1 to 5 carbon atoms; Y ¹ and Y ² each independently represent a member selected from the group consisting of a hydrogen atom and a substituent Z represented by the following formulas (II) and (III):

And

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a member selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and hydroxyalkyl groups having 1 to 10 carbon atoms ) The substituents Z bonded to each benzene ring of the polymerized unit may be the same or different from each other, and the number average value of the substituents Z bonded to each benzene ring of the polymerized unit is 0.2 to 1.0. The water-soluble polymer compound (c) has an average degree of polymerization of 2 to 50, and the phosphate ion (a), the condensed phosphate ion (b) and the water-soluble polymer compound (c) have a mixed weight ratio (a) :( b) :( c ) Is from 1 to 30: 0.1 to 10: 0.1 to 20.

In addition, the method of the present invention for surface treatment of an aluminum-containing metal material is:

(A) As a main component:

(a) phosphate ions,

(b) condensed phosphate ions, and

(c) contacting the surface of the aluminum-containing metal material with a surface treatment aqueous solution having a pH of 6.5 or less, comprising at least one water-soluble polymer compound, at a temperature of 30 ° C. to 65 ° C. for a total contact time of 5 to 60 seconds;

Said water soluble polymer compound (c) comprises a plurality of polymerized units of formula (I):

[Wherein X ¹ and X ² each independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and a hydroxyalkyl group having 1 to 5 carbon atoms; Y ¹ and Y ² each independently represent a member selected from the group consisting of a hydrogen atom and a substituent Z represented by the following formulas (II) and (III):

And

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a member selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and hydroxyalkyl groups having 1 to 10 carbon atoms ), The substituents Z bonded to each benzene ring of the polymerized unit may be the same or different from each other, and the number average value of the substituents Z bonded to each benzene ring of the polymerized unit is from 0.2 to 1.0. (c) has an average degree of polymerization of 2 to 50, and the phosphate ions (a), the condensed phosphate ions (b) and the water-soluble polymer compound (c) have a mixed weight ratio (a): (b): (c) of 1 to 30: 0.1 to 10: 0.1 to 20,

(B) washing the resulting resin film layer on the surface of the aluminum containing metal material with water; And

(C) heat-drying the washed resin film layer.

The surface treatment liquid contains 1 to 30 g / liter of phosphate ions (a), 0.1 to 10 g / liter of condensed phosphate ions (b) and 0.1 to 20 g / liter of the water-soluble polymer compound (c) and preferably has a pH of 2.0 to 6.5. .

[Description of Preferred Embodiment]

The aqueous polymer compound composition of the present invention for surface treatment of an aluminum-containing metal material includes, as an essential component, at least one comprising (a) phosphate ions, (b) condensed phosphate ions and (c) a plurality of polymerized units of formula (I). Acidic aqueous solution comprising one water-soluble polymer compound.

The phosphate ions in the polymer compound compositions of the present invention may be supplied from phosphoric acid (H ₃ PO ₄ ), alkali metal salts of phosphoric acid, such as sodium phosphate and ammonium salts of phosphoric acid.

Condensed phosphate ions in the aqueous composition of the present invention include pyrophosphate ions, tripolyphosphate ions and tetrapolyphosphate ions. Condensed phosphate ions can be supplied from pyrophosphoric acid (H ₄ P ₂ O ₇ ), alkali metal salts of pyrophosphoric acid and alkali metal salts of tripolyphosphoric acid and tetrapolyphosphoric acid.

In the polymer compound composition of the present invention for surface treatment of an aluminum-containing metal material, the water-soluble polymer compound (c) having (a) phosphate ions, (b) condensed phosphate ions and polymerized unit (I) is 1 to 30: 0.1 to 10: 0.1 to 20, preferably 1 to 5: 0.5 to 3.0: 0.5 to 5, in a weight ratio (a) :( b) :( c).

If the proportion of phosphate ions is less than 1 part by weight relative to 0.1 to 10 parts by weight of the condensed phosphate (b) ion and 0.1 to 20 parts by weight of the polymer compound (c), the resulting surface treatment liquid reacts completely with the surface of the aluminum-containing metal material. The resin film layer thus formed is formed in an insufficient amount. Moreover, when the ratio of phosphate ion (a) is 30 weight part or more with respect to 0.1-10 weight part of condensed phosphate ion (b) and 0.1-20 weight part of polymer compounds (c), the resin composition produced will have sufficient resin film layer formed. It can be too expensive, though.

If the ratio of condensed phosphate ions (b) is less than 0.1 parts by weight with respect to 1 to 30 parts by weight of phosphate ions (a) and 0.1 to 20 parts by weight of the water-soluble polymer compound (c), the resulting surface treatment liquid may have insufficient etching effect. And therefore a sufficient resin coating layer cannot be formed on the metal material surface. If the ratio of the condensed phosphate ion (b) is 10 parts by weight or more with respect to the above-mentioned ratio of the phosphate ion (a) and the water-soluble polymer compound (c), the resulting surface treatment liquid exhibits an etching effect that is too strong to form the resin coating layer. Disturb.

If the proportion of the water-soluble polymer compound (c) is less than 0.1 parts by weight with respect to 1 to 30 parts by weight of phosphate ions (a) and 0.1 to 10 parts by weight of condensed phosphate ions (b), the resulting surface treatment liquid is formed on the surface of the metal material. Sufficient resin coating layer cannot be formed.

In addition, if the ratio of the water-soluble polymer compound (c) is 20 parts by weight or more with respect to the above-mentioned ratio of the phosphate ion (a) and the water-soluble polymer compound (b), the resulting surface treatment liquid is too expensive to be expensive in the surface treatment process. Will be heard.

The water-soluble polymer compound (c) usable in the present invention consists of a number of polymerized (repeating) units of formula (I) with a degree of polymerization n of 2 to 50:

In the polymerization unit of formula (I), X ¹ and X ² are each independently of the other hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, for example methyl, ethyl, n-propyl, isopropyl and n-butyl, Hydroxyalkyl group having 1 to 5 carbon atoms, for example, a member selected from the group consisting of methoxy and ethoxy, wherein Y ¹ and Y ² are each independently a hydrogen atom and formulas (II) and (III) Represents a member selected from the group consisting of substituents Z represented by:

And

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, for example methyl, ethyl, propyl and butyl groups, having 1 to 10 carbon atoms It is a member selected from the group consisting of hydroxyalkyl groups, for example methoxy and ethoxy groups.

In the water-soluble polymer compound having a polymerization unit of formula (I), the substituents Z represented by Y ¹ and Y ² bonded to each benzene ring of the polymerization unit may be the same or different from each other. The water soluble polymer compound (c) should have at least one substituent Z bonded to at least one respective benzene ring of at least one polymerized unit of formula (I). That is, the number average value of the substituent Z couple | bonded with each benzene ring of the polymerization unit of Formula (I) is 0.2-1.0. The number average of the substituents Z bonded to each benzene ring of the polymerized unit will be referred to below as the average substituent Z-substituted number. The average substituent Z-substituted number is calculated as follows.

When the water-soluble polymer compound (c) has an average polymerization number of 10, this polymer compound (c) has 20 benzene rings. When 10 of the 20 benzene rings each have one substituent Z, this polymer compound has an average substituent Z-substituted number of [(1 × 10) + (0 × 10)] / 20 = 0.5.

If the average substituent Z-substitution number is less than 0,2, the synthesized polymer compound exhibits insufficient water solubility, and the resulting aqueous surface treatment compositions and solutions exhibit insufficient stability during storage and use. Also, if the average substituent Z-substituted number is 1.0 or more, that is, if the polymer compound has at least one benzene ring substituted with two or more substituents Z, the resulting polymer compound exhibits too high water solubility, making it difficult to form a resin coating layer.

The alkyl and hydroxyalkyl groups represented by X ¹ and X ² in formula (I) have 1 to 5 carbon atoms. If the number of carbon atoms in the alkyl and hydroxyalkyl groups is 6 or more, the molecules of the resulting polymer compound are too large to cause steric hindrance, thus making it difficult to form a resin film layer having sufficient density and excellent corrosion resistance.

The alkyl group and the hydroxyalkyl group represented by R ¹ , R ² , R ³ , R ⁴ and R ⁵ in formulas (II) and (III) for the substituent Z have 1 to 10 carbon atoms. If the number of carbon atoms is 11 or more, the resulting polymer compound molecule is so large that the resulting resinous coating layer has a low density and exhibits an insufficient corrosion-etching effect.

The polymer compound (c) has an average degree of polymerization of 2 to 50. If the average degree of polymerization is less than 2, the resulting resin film layer exhibits an insufficient corrosion-etching effect. If the average degree of polymerization exceeds 50, the resulting aqueous surface treatment compositions and solutions exhibit insufficient stability during storage and use and are therefore difficult to use.

The pH of the aqueous surface treated polymer compound composition of the present invention is not limited within its specific range. Usually, the pH of the aqueous surface treatment composition of the present invention is preferably adjusted to a level of 6.5 or less.

In the process of the invention, the aqueous surface treatment liquid is prepared from the polymer compound composition, preferably by diluting it with water, and the pH of the aqueous solution is adjusted to a pH of 6.5 or less, preferably from 2.0 to 6.5.

If the pH is above 6.5, the resulting aqueous surface treatment solution is unstable during storage and use and the polymer compound (c) easily precipitates out of aqueous solution. If the pH is less than 2.0, the resulting aqueous solution may exhibit too high etching characteristics with respect to the aluminum-containing metal material surface, making it difficult to form the resin surface-coating layer.

The pH of the aqueous surface treatment liquid can be adjusted by using an acid such as phosphoric acid, nitric acid or hydrochloric acid or by using a base such as sodium hydroxide, sodium carbonate or ammonium hydroxide. If no environmental pollution occurs, hydrofluoric acid can be used to adjust the pH.

In the process of the invention, preferably the aqueous surface treatment solution is:

1 to 30 g / liter of phosphate ion (a),

0.1-10 g / liter of condensed phosphate ion (b) and

0.1 to 20 g / liter of water-soluble composition (c)

It includes, pH is 2.0 to 6.5.

If the concentration of phosphate ions (a) is less than 1 g / liter, the formation of the resinous coating layer may be difficult. If the concentration is more than 30 g / liter, the resulting aqueous surface treatment solution is too expensive and the surface treatment process is expensive. It can be a disadvantage.

In addition, if the concentration of the condensed phosphate ion (b) is less than 0.1 g / liter, the resulting aqueous surface treatment liquid may exhibit etching characteristics on the surface of the metal material which is too poor, resulting in insufficient formation of the resin coating layer. If it is 10 g / liter or more, the resulting aqueous surface treatment liquid may exhibit too high etching characteristics, so that the reaction between the solution for forming the resin film layer and the surface of the metal material may be hindered.

In addition, if the concentration of the water-soluble polymer compound (c) is less than 0.1 g / liter, the resulting aqueous surface treatment solution cannot completely form the resin coating layer, and if the concentration is 20 g / liter or more, the resulting surface treatment solution is too expensive. The surface treatment process can be an economic disadvantage.

In the surface treatment method of the present invention, when aluminum ions are eluted from the aluminum-containing metal material into the aqueous surface treatment solution, the water-soluble polymer compound (c) can react with the aluminum ions and the resulting aluminum complex with the polymer compound (c). Can be precipitated from the aqueous surface treatment liquid. In order to prevent precipitation, it is preferable to add an aluminum ion-blocking agent to the aqueous surface treatment liquid. Preferably the aluminum ion-blocking agent comprises at least one member selected from EDTA, Cy-DTA, triethanolamine, gluconic acid, heptogluconic acid, oxalic acid, tartaric acid, malic acid and organophosphoric acid. However, containment agents are not limited to the compounds described above. If environmental pollution does not occur in wastewater treatment, hydrofluoric acid may be used as a containment agent.

In the process of the present invention, the aqueous surface treatment liquid as described above is an aluminum-containing metal material for a total contact time of 5 to 60 seconds, preferably 10 to 20 seconds at a temperature of 30 to 65 ° C, preferably 40 to 50 ° C. Is in contact with the surface.

In an embodiment of the contacting step, the aluminum containing metal material is immersed in the aqueous surface treatment liquid for 5 to 60 seconds at a temperature of 30 to 65 ° C.

In another embodiment of the contacting step, the aqueous surface treatment liquid is sprayed onto the aluminum containing metal material surface for a total contact time of 5 to 60 seconds at a temperature of 30 to 65 ° C. In this embodiment, the spraying operation is preferably performed in two or more steps for 5 to 60 seconds in combination with the spraying time and the interval time at intervals of 2 to 5 seconds.

In the spraying operation, sometimes the resin coating layer formed by bubbles in the aqueous surface treatment liquid contains bubbles. In this case, the foaming and foaming conditions may vary depending on the spraying device and the conditions. If foaming cannot be prevented by adjusting the spraying device and conditions, an antifoaming agent is added to the aqueous surface treatment liquid. There is no restriction on the type and amount of the antifoaming agent as long as the addition of the antifoaming agent does not inhibit the paint adhesion of the resulting resin film layer.

The aqueous polymer compound composition of this invention for surface-treating an aluminum containing metal material is manufactured as follows.

An aqueous solution containing phosphate ions (a) and condensed phosphate ions (b) in a mixed weight ratio in the above-described range is prepared by dissolving phosphoric acid or phosphate and condensed phosphoric acid or condensed phosphate in water and stirring the solution. If the pH of the solution is above 7.0, acid is added to the solution to bring the pH down to a predetermined level of less than 7. Then, while stirring the solution, the water-soluble polymer compound (c) is added to an aqueous solution containing phosphate ions (a) and condensed phosphate ions (b), and then the pH of the resulting aqueous solution is adjusted to a predetermined level of 6.5 or less.

The resin film layer formed on the surface of the aluminum metal material will be described in detail below.

The resin film layer formed by the method of the present invention is a resin material derived from a water-soluble polymer compound (c) having, as a main component, a phosphate derived from phosphate ions (a) and a condensed phosphate ion (b) and a polymerized unit of formula (I). Organic-inorganic composite layer comprising a. During the contact between the aqueous surface treatment liquid and the aluminum-containing metal material surface, the metal material surface is etched by phosphate ions (a) and condensed phosphate ions (b). Due to the etching, the pH at the interface between the solution and the etched metal material surface increases in part and therefore phosphate precipitates on the metal material surface.

In addition, in the polymer compound (c), the amino or aluminum substituent Z has metal-chelating properties so that the polymer compound (c) reacts with the etched and activated surface portion of the metal material to produce a constant coordination polymer compound. Due to the production of phosphate and coordination polymer compounds, an organic-inorganic composite layer is formed on the metal material surface.

The condensed phosphate ions (b) contained in the aqueous surface treatment solution effectively promote the formation of polymer-metal coordination compounds to form organic-inorganic composite layers on the surface of aluminum-containing metal materials with improved stability over a wide range of pH. can do. In addition, the heat-drying step applied to the washed resin film layer further polymerizes the resulting coordination polymer compound.

When high corrosion resistance is required, the resin coating layer is preferably heat treated at a temperature of 170 to 250 ° C. for 1 to 10 minutes, for example at 200 ° C. for 1 minute to increase the degree of polymerization of the polymer compound.

The aluminum containing metal material that can be used in the method of the present invention is preferably selected from aluminum materials and aluminum containing materials, such as aluminum-manganese alloys, aluminum magnesium alloys and aluminum-silicon alloy materials, and includes sheets, rods, pipes and It may be in the form of a wire. The shape and size of the metal material is not limited.

The resin polymer compound composition of the present invention optionally includes a preservative or antifungal agent. These additives effectively prevent rot or mold formation of the aqueous polymer compound composition or aqueous surface treatment liquid during storage or use at low temperatures. Preferably, hydrogen peroxide is used for this purpose.

The surface treatment method of the present invention using the above-mentioned aqueous surface treatment liquid will be described below.

Before the surface treatment, the surface of the aluminum-containing metal material is washed and degreased with an acid or alkaline washing liquid or an organic solvent, and the washed or degreased surface is washed with water.

The surface of the aluminum-containing metal material is then contacted with the aqueous surface treatment liquid by dipping or spraying at a temperature of 30 to 65 ° C. for 5 to 60 seconds.

The resulting resin film layer on the surface of the metal material is washed with water, washed with deionized water and finally heat dried.

In the contacting step, the aqueous surface treatment liquid is used at a temperature of 30 to 65 ° C. If the temperature is 30 ° C. or less, the aqueous surface treatment liquid cannot sufficiently react with the metal material surface and a sufficient resin coating layer cannot be obtained. In addition, a contact temperature of 65 ° C. or higher causes high energy costs and economic disadvantages even if the resulting resin film layer itself is sufficient.

Immersion time should be 5 to 60 seconds. Immersion time of 5 seconds or less is insufficient to form a sufficient resin film layer having high corrosion resistance. In addition, the immersion time of 60 seconds or more cannot improve the performance of the resulting resin film layer.

When the aqueous surface treatment solution is applied to the surface of the metal material by spraying operation, if the solution is continuously sprayed over a predetermined time, a partial increase in pH cannot occur at the interface between the surface of the metal material and the solution so that the resin film layer is completely formed. Can't be. Therefore, it is preferable to perform the spray operation intermittently. In other words, the spraying operation is preferably carried out in two or more steps at intervals of 2 to 5 seconds during the entire contacting time where the sum of the spraying time and the interval time is 5 to 60 seconds. The total contact time of 5 seconds or less is insufficient to complete the reaction of the solution with the metal material surface to provide a resin coating layer having excellent corrosion resistance.

Moreover, the contact time of 60 seconds or more cannot improve the performance of the resin film layer produced | generated.

EXAMPLE

The invention will be further illustrated by the following examples.

In each example and comparative example, the composition and surface treatment method of the aqueous surface treatment solution as described in detail below were used and the following tests were carried out.

[exam]

(1) corrosion resistance

In order to measure the corrosion resistance, namely the boiling water bottom dome discoloration resistance, the DI can was immersed in boiling tap water for 30 minutes and the degree of bottom dome discoloration on the surface of the can was visually evaluated as follows.

(2) paint adhesion

The paint adhesion properties were measured as follows.

Epoxy urea resin paint for cans was coated on the can surface to a thickness of 5-7 μm and baked at a temperature of 215 ° C. for 4 minutes. The painted cans were cut into rectangular specimens 5 mm wide and 150 mm long. Rectangular specimens were attached to each other with a polyamide resin film by a thermocompression method to provide a specimen. The specimen was subjected to a 180 degree peel test to determine its peeling strength.

The greater the peel strength, the higher the paint adhesiveness of the can.

Generally speaking, aluminum cans having a peel strength of 4.0 kgf / 5 mm or more can be put to practical use.

(3) slipperiness

Slidability of the can was evaluated by measuring the static friction coefficient of the outer peripheral surface of the can. The lower the static friction coefficient, the higher the slipperiness of the can.

Generally speaking, cans having a static friction coefficient of 1.0 or less are practically useful.

Example 1

A can produced from an aluminum-manganese alloy plate by drawing and ironing was prepared by Nihon Parkerizing KK. The cans were degreased by spraying onto the can surface for 60 seconds at, then the can was washed and dried.

The washed surface of the DI aluminum alloy can was sprayed three times at intervals of 5 seconds each time for 5 seconds each with an aqueous surface treatment solution 1 having the composition shown below and heated at a temperature of 60 ° C. The total contact time was 25 seconds.

Then, the resin film layer formed on the surface of the can was washed with water and spray-washed with deionized water having a resistance of 3,000,000 µm or more for 10 seconds, and finally dried at a temperature of 180 ° C. with a hot air dryer.

Aqueous Surface Treatment Solution (1)

Example 2

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment solution 2 having the composition shown below at a temperature of 60 ° C. for 20 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Solution (2)

Example 3

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 3 having the composition shown below at a temperature of 35 ° C. for 60 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Solution (3)

Example 4

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

An aqueous surface treatment solution 4 having the composition shown below and heated to a temperature of 65 ° C. was sprayed three times at intervals of 2 seconds for 6 seconds each time to the washed surface of the can. The total contact time was 22 seconds.

The resulting resin film layer formed on the surface of the can was then washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Solution (4)

Example 5

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 5 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Solution (5)

Example 6

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

An aqueous surface treatment solution 6 having the composition shown below and heated to a temperature of 60 ° C. was sprayed twice at intervals of 5 seconds each time for 5 seconds to the washed surface of the can. The total contact time was 15 seconds.

The resulting resin film layer formed on the surface of the can was then washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (6)

Example 7

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment solution 7 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (7)

Comparative Example 1

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

An aqueous surface treating solution 8 having the composition shown below and heated to a temperature of 60 ° C. was sprayed five times at intervals of 5 seconds each time for 4 seconds to the washed surface of the can. The total contact time was 40 seconds. The resulting resin film layer formed on the surface of the can was then washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (8)

Comparative Example 2

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 9 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (9)

Comparative Example 3

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 10 having the composition shown below at a temperature of 60 ° C. for 5 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (10)

[Comparative Example 4]

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 11 having the composition shown below at a temperature of 60 ° C. for 20 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (11)

[Comparative Example 5]

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 12 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (12)

Comparative Example 6

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 13 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (13)

This polymeric compound (5) has the following formula (IV):

The aqueous surface treatment liquid 13 is the same as that disclosed in Japanese Patent Laid-Open No. 4-66671.

Comparative Example 7

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

The washed cans were then immersed in an aqueous surface treatment liquid 14 having the composition shown below at a temperature of 60 ° C. for 30 seconds.

The resulting resin film layer formed on the surface of the can was washed and dried under the same conditions as in Example 1.

Aqueous Surface Treatment Liquid (14)

This polymer compound (6) is the same as that disclosed in Japanese Patent Laid-Open No. 2-608, and is represented by the following Formula (V):

Comparative Example 8

The same DI aluminum alloy cans as in Example 1 were washed in the same manner as in Example 1.

Aqueous surface treatment solution prepared by dissolving 2% by weight of a non-chromate type surface treatment solution manufactured by Nippon Parkarizing Co., Ltd. under the trademark Arogin 404 was applied every 5 seconds at a time of 5 seconds on the cleaned surface of the can. Sprayed three times for a second. The total contact time was 25 seconds.

The resulting resin film layer formed on the surface of the can was then washed and dried under the same conditions as in Example 1.

[Test result]

The test results of Examples 1 to 7 and Comparative Examples 1 to 8 are shown in Table 2.

Table 2 clearly shows the excellent corrosion resistance, paint adhesion and slipperiness of the surface treated aluminum alloy cans of Examples 1-7 using the polymer compound compositions and surface treatment methods of the present invention.

However, the surface-treated aluminum alloy cans of Comparative Examples 1 to 8 using surface treatment liquids different from those of the present invention had insufficient at least one of corrosion resistance, paint adhesion and slipperiness.

As described above, the polymer compound composition and the surface treatment method of the present invention effectively form a chemical conversion resin coating layer having excellent corrosion resistance and paint adhesion on the aluminum-containing metal material surface.

When the polymer compound composition and the surface treatment method of the present invention are applied to an aluminum-containing metal can manufactured by drawing-ironing before the paint coating and printing process, the resulting special resin coating layer not only has excellent corrosion resistance and paint adhesion on the surface of the can, Gives significantly improved slipperiness, which is important for smooth conveying of cans.

In addition, since the polymer compound composition and the surface treatment liquid useful in the method of the present invention are free of chromium and fluorine, the present invention has the advantage of reducing the load on the wastewater treatment system.

Claims (7)

As components, (a) phosphate ions, (b) condensed phosphate ions, and (c) multiple polymerized units of formula (I): [Wherein X ¹ and X ² each independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and a hydroxyalkyl group having 1 to 5 carbon atoms; Y ¹ and Y ² each independently represent a member selected from the group consisting of a hydrogen atom and a substituent Z represented by the following formulas (II) and (III): And Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a member selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and hydroxyalkyl groups having 1 to 10 carbon atoms ), The substituents Z bonded to each benzene ring of the polymerized unit may be the same or different from each other, and the number average value of the substituents Z bonded to each benzene ring of the polymerized unit is 0.2 to 1.0]. Wherein the water-soluble polymer compound (c) has an average degree of polymerization of 2 to 50, and the phosphate ions (a), the condensed phosphate ions (b) and the water-soluble polymer compound (c) have a mixed weight ratio (a): (b) :( c) is 1 to 30: 0.1 to 10: 0.1 to 20, the aqueous composition for surface treatment of aluminum-containing metal material. The aqueous composition of claim 1 wherein the phosphate ion is derived from at least one member selected from the group consisting of phosphoric acid, alkali metal phosphates and ammonium phosphate. The aqueous composition of claim 1 wherein the condensed phosphate ion is derived from at least one member selected from the group consisting of pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid and alkali metal and ammonium salts of the acid. (5) A surface-treated aqueous solution having a pH of 6.5 or less comprising (a) phosphate ions, (b) condensed phosphate ions, and (c) at least one water-soluble polymer compound at a temperature of 30 ° C to 65 ° C. Contacting the surface of the aluminum containing metal material for a total contact time of 60 seconds; (B) washing the resulting resin film layer on the surface of the aluminum containing metal material with water; And (C) heat drying the washed resin film layer, wherein the water-soluble polymer compound (c) comprises a plurality of polymerized units of formula (I): [Wherein X ¹ and X ² each independently represent a member selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and a hydroxyalkyl group having 1 to 5 carbon atoms; Y ¹ and Y ² each independently represent a member selected from the group consisting of a hydrogen atom and a substituent Z represented by the following formulas (II) and (III): And Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent a member selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and hydroxyalkyl groups having 1 to 10 carbon atoms ), The substituents Z bonded to each benzene ring of the polymerized unit may be the same or different from each other, and the number average value of the substituents Z bonded to each benzene ring of the polymerized unit is 0.2 to 1.0]. The water-soluble polymer compound (c) has an average degree of polymerization of 2 to 50, and the phosphate ions (a), the condensed phosphate ions (b) and the water-soluble polymer compound (c) have a mixed weight ratio (a): (b) :( c) is from 1 to 30: 0.1 to 10: 0.1 to 20. The surface treatment liquid according to claim 4, wherein the surface treatment liquid contains 1 to 30 g / liter of phosphate ions (a), 0.1 to 10 g / liter of condensed phosphate ions and 0.1 to 20 g / liter of the water-soluble polymer compound (c), and has a pH of 2.0 to 6.5. Method characterized in that. The method according to claim 4, wherein the aluminum-containing metal material is immersed in the surface treatment solution for 5 to 60 seconds. The method according to claim 4, wherein the surface treatment liquid is sprayed on the surface of the aluminum-containing metal material for 5 to 60 seconds at intervals of 2 to 5 seconds, in combination with the spraying time and the interval time in two or more steps.