JP2007077499A - Surface-conditioning composition and surface-conditioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-conditioning composition which inhibits a metallic material from being electrochemically corroded during chemical conversion treatment, because a denser phosphate coating than ever with a sufficient coating weight can be formed on the surface of the metallic material, which conditions the surface of a metallic material that is hardly chemical-conversion-treated such as an aluminum-based material and a high-tensile steel sheet so that a chemical conversion coating having a sufficient coating weight can be formed thereon, which can shorten a chemical conversion treatment period of time due to the improvement of a chemical conversion treatability, and which has superior dispersion stability of phosphate particles of a metal in the surface-conditioning liquid. <P>SOLUTION: The surface-conditioning composition includes phosphate particles of a divalent or trivalent metal, and has a pH of 3 to 12. The phosphate particles of the divalent or trivalent metal has a D<SB>50</SB>of 3 μm or smaller. The surface-conditioning composition further includes (1) a phenolic compound and (2) a stabilizing agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface conditioning composition and a surface conditioning method.

  Auto bodies, home appliances, and the like have been commercialized by making metal materials such as steel plates, galvanized steel plates, and aluminum-based metal materials into metal moldings, painting, assembling, and the like. Coating of such a metal molded product is performed through various processes such as degreasing, surface adjustment, chemical conversion treatment, and electrodeposition coating.

  The surface conditioning treatment is a treatment that is performed in the next step, phosphate chemical conversion treatment, to form a chemical conversion film consisting of phosphate crystals uniformly, rapidly, and at a high density on the entire surface of the metal material. Usually, a crystal nucleus of a phosphate is formed on the surface of the metal material by immersing in a surface conditioning treatment solution. As a treatment liquid used for such surface conditioning treatment, a composition in which a divalent or trivalent metal phosphate is used in combination with various stabilizers is known (for example, Patent Document 1, Patent Document 2, Patent Document 3).

  In Patent Document 1, one or more selected from phosphate particles containing at least one divalent or trivalent metal including particles having a particle size of 5 μm or less, an alkali metal salt, an ammonium salt, or these At least selected from the group of anionic charged and dispersed oxide fine particles, an anionic water-soluble organic polymer, a nonionic water-soluble organic polymer, an anionic surfactant and a nonionic surfactant A preconditioning solution for surface adjustment prior to chemical conversion treatment of a metal phosphate crystal film containing 1 type and having a pH adjusted to 4 to 13 is disclosed.

  Patent Document 2 contains one or more phosphate particles selected from phosphates containing one or more divalent and / or trivalent metals, and (1) monosaccharides, One or more selected from saccharides and derivatives thereof, (2) orthophosphoric acid, polyphosphoric acid or organic phosphonic acid compound, vinyl acetate polymer or derivative thereof, or a monomer copolymerizable with vinyl acetate and vinyl acetate One or more water-soluble polymer compounds comprising a copolymer, or (3) at least one selected from a specific monomer or an α, β unsaturated carboxylic acid monomer and the above monomer A surface conditioning treatment solution prior to phosphate chemical conversion containing a polymer or copolymer obtained by polymerizing 50% by mass or less of a monomer copolymerizable with the polymer is disclosed. Furthermore, Patent Document 3 discloses a surface conditioning composition using a clay mineral in combination with a phosphate.

  However, even surface treatment liquids disclosed in these documents may have insufficient chemical conversion properties. For example, in a portion where an aluminum-based metal material is in contact with a steel plate or a galvanized steel plate, the aluminum-based metal material serves as an anode, and the steel plate or galvanized steel plate serves as a cathode. Corrosion reaction (electric corrosion) is likely to occur, and there is a problem that a chemical conversion film is hardly formed on the surface of the aluminum-based metal material during chemical conversion treatment. For this reason, in the chemical conversion treatment, development of a surface conditioning composition that can suppress the electrolytic corrosion of the aluminum-based metal material is desired.

In addition, when these surface-conditioning treatment liquids are applied to difficult-to-convert metal materials such as aluminum-based metal materials and high-tensile steel sheets, a chemical film having a sufficient coating amount on the surface of the metal material in the chemical conversion treatment. There is a problem that is not formed. Furthermore, in recent years, the required level of corrosion resistance has increased, and the formation of a denser chemical conversion film has been demanded. Further, these surface conditioning treatment liquids have a problem that the phosphate particles are likely to settle because the particle diameter of the phosphate particles is large and the dispersion stability of the particles in the treatment bath is insufficient. Therefore, there has been a demand for a surface conditioning composition that has solved these problems and has further superior properties.
Japanese Patent Laid-Open No. 10-245685 JP 2000-96256 A JP 59-226181 A

  The present invention is a surface conditioning composition used in the surface conditioning performed prior to the chemical conversion treatment in view of the above-mentioned present situation, and in the chemical conversion treatment reaction, it is possible to obtain a higher chemical conversion performance than before and a dense It is possible to form a metal conversion film, suppress electrolytic corrosion of the aluminum metal material during the chemical conversion treatment, and it is sufficient even when the chemical conversion treatment is performed on difficult metal conversion materials such as aluminum metal materials and high-tensile steel sheets. It is possible to provide a surface conditioning composition that is capable of forming a chemical film with a sufficient amount of film, and that can be shortened by improving chemical conversion, and that is excellent in long-term dispersion stability in a treatment bath. It is the purpose.

The surface conditioning composition of the present invention is a pH 3 to 12 surface conditioning composition containing divalent or trivalent metal phosphate particles, and the divalent or trivalent metal phosphoric acid. salt particles, D ₅₀ is at 3μm or less, the surface conditioning composition may further include (1) a phenolic compound, and is characterized in that those containing the (2) stabilizer.

  The divalent or trivalent metal phosphate particles are preferably zinc phosphate. The (1) phenolic compound is preferably at least one selected from the group consisting of flavonoids, tannins, gallic acid, lignin, catechins and pyrogallol. When the surface conditioning composition of the present invention is a surface conditioning treatment solution, the (1) phenolic compound is preferably contained at a concentration of 1 ppm to 1000 ppm. The (2) stabilizer is at least selected from the group consisting of phosphonic acid, phytic acid, polyphosphoric acid, phosphonic acid group-containing acrylic resins and vinyl resins, carboxyl group-containing acrylic resins and vinyl resins, saccharides, and layered clay minerals. One type is preferable. When the surface conditioning composition of the present invention is the surface conditioning treatment liquid, the (2) stabilizer is preferably contained at a concentration of 1 ppm to 1000 ppm.

  The present invention is also a surface conditioning method characterized by comprising a step of bringing a surface conditioning treatment liquid, which is the above-described surface conditioning composition, into contact with a metal material.

  In the present specification, the “surface adjustment composition” is a “surface adjustment treatment liquid” which is a treatment liquid for actually contacting the metal material in the surface adjustment treatment, and is diluted with the surface adjustment treatment. And a “concentrated dispersion” that is a dispersion of metal phosphate particles used to produce the liquid. The treatment liquid for surface adjustment is obtained by diluting the concentrated dispersion to a predetermined concentration with a solvent such as water, adding necessary additives, and then adjusting the pH.

  Moreover, when using the composition for surface adjustment of this invention, after performing the pre-process required for a metal material, a surface adjustment process is performed and then a chemical conversion process is performed. That is, in the present specification, the “surface conditioning treatment” is a first phosphating treatment, which means a step of attaching metal phosphate particles to the surface of a metal material. “Chemical conversion treatment” means a second phosphate treatment following the surface conditioning treatment, and means a treatment for crystal growth of phosphate particles attached to the metal material surface by the surface conditioning treatment. To do. Further, in the present specification, a film made of a metal phosphate formed by a surface conditioning treatment is referred to as a “phosphate film”, and a film made of a metal phosphate particle formed by a chemical conversion treatment is made “chemical conversion”. It shall be indicated as “film”.

  The present invention is described in detail below.

<Surface conditioning composition>
The surface conditioning composition of the present invention further comprises (1) a phenolic compound added to the surface conditioning composition containing divalent or trivalent metal phosphate particles and (2) a stabilizer. Thus, the function of the surface conditioning composition is further improved, and a surface conditioning composition having excellent properties is provided. In addition, many of these (1) phenolic compounds have both antibacterial and degreasing properties, so there is no need for antibacterial agents and sterilization equipment that are widely used at present, and repelling caused by the introduction of oil in the previous process. Can be prevented. The surface adjustment composition of the present invention is a surface adjustment treatment liquid used for the surface adjustment treatment and a concentrated dispersion liquid used for diluting to prepare a surface adjustment treatment liquid. is there.

Surface conditioning composition of the present invention D ₅₀ of containing the following divalent or trivalent metal phosphate particles 3 [mu] m, the (1) phenolic compound and (2) a stabilizer. The surface conditioning composition of the present invention is superior in dispersion stability in the surface conditioning treatment liquid as compared with conventionally known surface conditioning compositions, and can suppress the electrolytic corrosion of the metal material during the chemical conversion treatment, A phosphate film having a sufficient coating amount can be formed even when applied to an incurable metal material such as an aluminum-based metal material and a high-tensile steel plate.

  Since the surface conditioning composition of the present invention contains (1) a phenolic compound, the zinc phosphate particles are very easily adsorbed to the phosphate particles adhered to the metal surface by the surface conditioning treatment. In addition, since the phenolic compound is a low molecular weight, it does not impair the pulverization / dispersion performance, and is particularly susceptible to surface oxide film and the like due to the interaction with the metal material surface such as hydrogen bonding and charging based on the phenolic hydroxyl group. It is presumed that it has excellent chemical conversion performance because it easily adheres to difficult-to-convert metal materials such as aluminum-based metal materials and high-tensile steel plates.

  In the case of applying a conventionally known surface conditioning treatment liquid containing divalent or trivalent metal phosphate particles to an incurable metal material such as an aluminum-based metal material or a high-tensile steel plate, the chemical conversion treatment is sufficient. However, when the surface conditioning composition of the present invention is used, there is a problem that an aluminum-based metal cannot be provided with sufficient corrosion resistance. It is possible to form a chemical film with a sufficient film amount during chemical conversion treatment even on a hard-to-convert metal material such as a material or a high-tensile steel plate.

  For this reason, sufficient corrosion resistance can be imparted to the metal material. In addition, when the surface conditioning treatment liquid of the present invention is applied to a metal material that has obtained good corrosion resistance with a conventional surface conditioning composition, such as a cold-rolled steel sheet and a galvanized steel sheet, The chemical conversion film formed in the subsequent chemical conversion treatment can be made denser, and thereby the corrosion resistance can be further improved.

  Further, as the metal material with which the surface conditioning treatment liquid is brought into contact, for example, an iron or zinc-based metal material and an aluminum-based metal material are used simultaneously, and the iron or zinc-based metal material and the aluminum-based metal material are in contact with each other. May have a part. When a chemical conversion treatment is performed on such a metal material, the aluminum-based metal material portion serves as an anode and the iron- or zinc-based metal material portion serves as a cathode in the contact portion during the chemical conversion treatment. There is a possibility that a chemical conversion film is difficult to be formed on the aluminum-based metal material portion.

  In the case of using the surface conditioning composition of the present invention, it is presumed that the chemical conversion treatment is accelerated by increasing the amount of the phosphate film adhered to the object to be treated. As a result, it is speculated that electrolytic corrosion can be suppressed in the aluminum-based metal material portion of the dissimilar metal contact portion between the iron- or zinc-based metal material and the aluminum-based metal material compared to the case where the conventional surface conditioning composition is used. Is done.

  For this reason, when the surface of the metal material having a portion where the iron or zinc-based metal material and the aluminum-based metal material are in contact with the surface conditioning treatment liquid of the present invention is then subjected to chemical conversion treatment Moreover, a chemical conversion film can be favorably formed on the aluminum-based metal material portion of the contact portion. Moreover, a chemical conversion film can be satisfactorily formed on the surface of the difficult-to-convert metal material.

[Phenolic compounds]
The surface conditioning composition of the present invention comprises (1) a phenolic compound. The (1) phenolic compound is, for example, a compound having two or more phenolic hydroxyl groups such as catechol, gallic acid, pyrogallol, tannic acid or the like and (1) a phenolic compound (for example, flavonoid, tannin). And polyphenol compounds including catechin, polyvinylphenol, water-soluble resol, novolac resin, etc.), lignin and the like. Among these, tannin, gallic acid, catechin and pyrogallol are particularly preferable in that the effects of the present invention are easily exhibited. The flavonoid is not particularly limited, and examples thereof include flavone, isoflavone, flavonol, flavanone, flavanol, anthocyanidin, aurone, chalcone, epigallocatechin garade, gallocatechin, theaflavin, soybean-in, genistin, rutin, and myricitrin.

(Tannin)
The tannin is a general term for an aromatic compound having a complex structure having a large number of phenolic hydroxyl groups widely distributed in the plant kingdom. The tannin may be hydrolyzed tannin or condensed tannin.

  Examples of the tannin include hamelian tannin, oyster tannin, chatannin, pentaploid tannin, gallic tannin, myrobalan tannin, dibidi tannin, argarovira tannin, valonia tannin, catechin tannin and the like. The tannin may be a hydrolyzed tannin obtained by decomposing tannin present in a plant by a method such as hydrolysis.

  Examples of the tannin include commercially available ones such as “tannic acid extract A”, “B tannic acid”, “N tannic acid”, “industrial tannic acid”, “purified tannic acid”, “Hi tannic acid”, “F Tannic acid ”,“ local tannic acid ”(both trade names, manufactured by Dainippon Pharmaceutical Co., Ltd.),“ tannic acid: AL ”(trade name, manufactured by Fuji Chemical Industries Ltd.), and the like can also be used. Moreover, you may use two or more types of the said tannin simultaneously. The lignin is a reticulated polymer compound having a propyl group-bonded phenol derivative as a basic unit.

  (1) By using the phenolic compound in combination with the surface conditioning composition, the adhesion of the metal phosphate particles to the metal material is improved. In addition to improving the stability, the stability of the surface conditioning composition is improved.

  That is, when the (1) phenolic compound is added, the storage stability and the stability of the surface conditioning treatment liquid when the concentrated dispersion is stored for a long period of time are excellent. Furthermore, even when hardness portions such as calcium ions and magnesium ions derived from tap water are mixed in the liquid, the surface adjustment composition can be obtained in which the metal phosphate particles hardly reaggregate. .

(Phenolic compound content)
The content of the phenol compound (1) in the concentrated dispersion is preferably 0.01 parts by mass and 1000 parts by mass with respect to 100 parts by mass of the solid content of phosphate particles. If the amount is less than 0.01 parts by mass, the adsorbing effect on the metal material may not be obtained due to insufficient adsorption to the phosphate particles. Even if it exceeds 1000 mass parts, the effect exceeding a desired effect is not acquired and it is not economical. The concentration is more preferably a lower limit of 0.1 parts by mass and an upper limit of 100 parts by mass, and even more preferably a lower limit of 0.5 parts by mass and an upper limit of 20 parts by mass. A particularly preferred concentration is a lower limit of 1 part by mass and an upper limit of 10 parts by mass.

  The content of the (1) phenol compound in the surface conditioning treatment solution is preferably 1 ppm as the lower limit and 1000 ppm as the upper limit. If it is less than 1 ppm, the metal is not sufficiently adsorbed on the phosphate particles, so that the adhesion of the metal phosphate particles to the surface of the metal material may not be promoted. Even if it exceeds 1000 ppm, the effect exceeding a desired effect is not acquired and it is not economical. The content is more preferably a lower limit of 5 ppm and an upper limit of 500 ppm, and further preferably a lower limit of 10 ppm and an upper limit of 200 ppm. A particularly preferable upper limit of the content is 100 ppm.

(Metal phosphate particles)
The surface conditioning composition of the present invention contains divalent or trivalent metal phosphate particles. The metal phosphate particles serve as crystal nuclei for obtaining a good chemical conversion film, and it is presumed that the chemical conversion reaction is promoted by adhesion of these particles to the surface of the metal material. .

The divalent or trivalent metal phosphate particles are not particularly limited. For example, Zn ₃ (PO ₄ ) ₂ , Zn ₂ Fe (PO ₄ ) ₂ , Zn ₂ Ni (PO ₄ ) ₂ , Ni ₃ (PO ₄ ) ₂ , Zn ₂ Mn (PO ₄ ) ₂ , Mn ₃ (PO ₄ ) ₂ , Mn ₂ Fe (PO ₄ ) ₂ , Ca ₃ (PO ₄ ) ₂ , Zn ₂ Ca (PO ₄ ) ₂ , Examples thereof include particles such as FePO ₄ , AlPO ₄ , CoPO ₄ , and Co ₃ (PO ₄ ) ₂ . Among these, zinc phosphate particles are preferred in that they have similarities to the chemical treatment phosphoric acid treatment, particularly the zinc phosphate-treated film crystals.

(Particle size of phosphate particles)
The D ₅₀ of the divalent or trivalent metal phosphate particles is 3 μm or less. The D ₅₀ by the above range, it is possible to form a dense chemical conversion film. Furthermore, if the particle diameter of the phosphate particles is large, there may be a problem that the metal phosphate particles are likely to settle in the surface conditioning treatment liquid due to the specific gravity.

On the other hand, the composition for surface conditioning of the present invention contains divalent or trivalent metal phosphate particles having an average particle diameter of 3 μm or less represented by D ₅₀ , and thus in the surface conditioning treatment liquid. The dispersion stability is excellent, and the precipitation of the metal phosphate particles in the surface conditioning treatment liquid can be suppressed, and a dense chemical conversion film can be formed after the chemical conversion treatment.

The D ₅₀ of the metal phosphate particles is preferably a lower limit of 0.01 μm and an upper limit of 3 μm. If it is less than 0.01 μm, the productivity of the surface conditioning treatment is poor and uneconomical. If it exceeds 3 μm, the surface adjustment function may not be sufficiently obtained, and the production efficiency of the chemical conversion treatment may be significantly reduced. More preferably, the lower limit is 0.1 μm and the upper limit is 1 μm.

Phosphate particles of the metal is preferably D ₉₀ of at 4μm or less. In this case, the metal phosphate particles not only have a D ₅₀ of 3 μm or less, but also have a D ₉₀ of 4 μm or less, so that the proportion of coarse particles present in the metal phosphate particles is relatively small. As described above, by using metal phosphate particles having a D ₅₀ of 3 μm or less, a chemical conversion film having fine phosphate crystals can be formed on the surface of the metal material by chemical conversion treatment in a short time.

However, when using a means such as pulverization to disperse to 3 μm or less, excessive pulverization causes a shortage of components that act as a dispersant due to an increase in specific surface area, resulting in re-aggregation of overdispersed particles and coarseness The particles may be formed, and the stability of the metal phosphate particle dispersion may be impaired. Further, the dispersibility of the metal phosphate particles varies depending on the formulation and dispersion conditions of the surface conditioning composition, which may cause thickening and reaggregation of fine particles. On the other hand, when the D ₉₀ of the metal phosphate particles is 4 μm or less, the above-described problems can be suppressed.

The lower limit of D ₉₀ of the metal phosphate particles is preferably 0.01 μm and the upper limit is 4 μm. If it is less than 0.01 μm, the particles may reaggregate. If it exceeds 4 μm, the proportion of fine metal phosphate particles decreases, which is inappropriate. The lower limit is more preferably 0.05 μm, and the upper limit is more preferably 2 μm.

The above D ₅₀ (volume 50% diameter) and D ₉₀ (volume 90% diameter) are based on the particle size distribution in the dispersion, and when the cumulative curve is obtained with the total volume of particles being 100%, the cumulative curves are respectively The particle size is 50% and 90%. The D ₅₀ can be measured using a particle size measuring device such as a light diffraction particle size measuring device (“LA-500”, trade name, manufactured by Horiba, Ltd.). In the present specification, when described as the average particle size shows a D _50.

(Phosphate particle content)
In the surface conditioning treatment liquid of the present invention, the content of the metal phosphate particles is preferably 50 ppm as the lower limit and 20000 ppm as the upper limit. If it is less than 50 ppm, the metal phosphate particles serving as crystal nuclei are insufficient, and a sufficient surface conditioning effect may not be obtained. Even if it exceeds 20000 ppm, the effect exceeding the desired effect is not obtained and it is not economical. The content is more preferably a lower limit of 150 ppm and an upper limit of 10000 ppm, and further preferably a lower limit of 250 ppm and an upper limit of 2500 ppm. The content is particularly preferably a lower limit of 500 ppm and an upper limit of 2000 ppm.

[Stabilizer]
The (2) stabilizer means a compound having an effect of improving the dispersion stability of divalent or trivalent metal phosphate particles in an aqueous solvent such as water. As such a compound, known compounds can be used, for example, phosphonic acid, phytic acid, polyphosphoric acid, phosphonic acid group-containing acrylic resins and vinyl resins, carboxyl group-containing acrylic resins and vinyl resins, saccharides, layered Examples thereof include clay minerals, colloidal silica, and acrylamide. Polyphosphoric acid, carboxyl group-containing acrylic resin, saccharides, layered clay mineral, colloidal silica, acrylic amide, phosphonic acid, and phytic acid are preferred because they are easily available. Of these compounds, two types may be used in combination.

(Carboxyl group-containing acrylic resin and vinyl resin)
The carboxyl group-containing acrylic resin and vinyl resin are not particularly limited, and can be obtained, for example, by polymerization of an unsaturated monomer composition containing a carboxyl group-containing unsaturated monomer such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid. Resin and the like. Polyacrylic acid is preferable because it is easily available.

(Phosphon group-containing acrylic resin and vinyl resin)
The phosphonic acid group-containing acrylic resin and vinyl resin are not particularly limited. For example, a monomer composition containing a phosphonic acid group-containing ethylenic monomer such as 3- (meth) acryloxypropylphosphonic acid is used. Examples thereof include resins obtained by polymerization.

(Sugar)
The saccharide is not particularly limited, and examples thereof include polysaccharides, polysaccharide derivatives, and alkali metal salts such as sodium salts and potassium salts thereof.

  Examples of the polysaccharide include cellulose, methylcellulose, ethylcellulose, methylethylcellulose, hemicellulose, starch, methyl starch, ethyl starch, methylethyl starch, agar, carrageenan, alginic acid, pectic acid, guar gum, tamarind gum, locust bean gum, konjac mannan Dextran, xanthan gum, pullulan, gellan gum, chitin, chitosan, chondroitin sulfate, heparin, hyaluronic acid and the like.

  Examples of the polysaccharide derivative include carboxymethyl cellulose (CMC), hydroxyethyl cellulose, starch glycolic acid, agar derivative, carrageenan derivative and the like obtained by carboxyalkylating or hydroxyalkylating the polysaccharide. Carboxymethylcellulose is preferred because of its high effect of improving dispersion stability.

(Layered clay mineral)
The layered clay mineral is not particularly limited, and examples thereof include smectites such as montmorillonite, beidellite, saponite and hectorite; kaolinites such as kaolinite and halloysite; vermiculite such as dioctahedral vermiculite and trioctahedral vermiculite. Family: Teniolite, tetrasilicic mica, mascobite, illite, sericite, phlogopite, biotite and other mica etc .; hydrotalcite; pyrophyllolite; Kanemite, macatite, iraite, magadiite, kenyaite and other layered polysilicates Etc. These layered clay minerals may be natural minerals or synthetic minerals by hydrothermal synthesis, melting method, solid phase method or the like.

  Among them, the smectite group is preferable because of the high effect of improving the dispersion stability, and natural hectorite and / or synthetic hectorite is more preferable. Thereby, more excellent dispersion stability can be imparted to the concentrated dispersion, and the dispersion efficiency can be further increased.

  The (2) stabilizer has a negative charge in the solution, and this adsorbs to the surface of the divalent or trivalent metal phosphate particles, whereby the divalent or trivalent metal phosphorus. The repulsion between the acid salt particles occurs, and it is possible to adhere to the surface of the metal material with a uniform density without collecting too much as crystal nuclei. Thereby, it is estimated that a favorable chemical conversion film is formed in the chemical conversion treatment.

  The stabilizer (2) not only prevents the precipitation of zinc phosphate particles in the surface conditioning treatment liquid, but also prevents the precipitation of zinc phosphate particles in the concentrated dispersion, The dispersion stability can be maintained.

(Stabilizer content)
In the concentrated dispersion, the content of the (2) stabilizer is preferably 0.01 parts by mass and 1000 parts by mass with respect to 100 parts by mass of phosphate particle solid content. If the amount is less than 0.01 parts by mass, the effect of preventing sedimentation may not be sufficiently obtained. Even if it exceeds 1000 mass parts, the effect exceeding a desired effect is not acquired and it is not economical. The content is more preferably a lower limit of 0.1 parts by mass and an upper limit of 100 parts by mass, and even more preferably a lower limit of 0.5 parts by mass and an upper limit of 25 parts by mass. The content is particularly preferably a lower limit of 1 part by mass and an upper limit of 10 parts by mass.

  In the surface conditioning treatment liquid, the content of the stabilizer (2) is preferably 1 ppm as the lower limit and 1000 ppm as the upper limit. If it is less than 1 ppm, the effect as the stabilizer (2) may not be sufficiently obtained. Even if it exceeds 1000 ppm, the effect exceeding a desired effect is not acquired and it is not economical. The lower limit is more preferably 10 ppm, more preferably 500 ppm, and even more preferably 10 ppm and 200 ppm. A particularly preferable upper limit of the content is 100 ppm. The (2) stabilizer may be used in combination of two or more.

[Chelating agent and / or surfactant]
The surface conditioning composition of the present invention may further contain a chelating agent and / or a surfactant. By containing a chelating agent, even when hardness components such as magnesium ions and calcium ions in tap water are mixed in the surface conditioning composition of the present invention, aggregation of metal phosphate particles is suppressed, and surface conditioning is performed. The stability of the treatment bath can be improved.

(Chelating agent)
The chelating agent is not particularly limited as long as it can form a chelate with a hardness component such as magnesium ion or calcium ion. For example, citric acid, tartaric acid, pyrophosphoric acid, sodium tripolyphosphate, EDTA, gluconic acid, succinic acid. Examples include acids and malic acid, and compounds and derivatives thereof.

(Chelating agent content)
In the treatment liquid for surface adjustment, the content of the chelating agent is preferably a lower limit of 1 ppm and an upper limit of 10,000 ppm. If it is less than 1 ppm, the hardness component in tap water cannot be chelated sufficiently, and metal cations such as calcium ions, which are hardness components, may aggregate metal phosphate particles. Even if it exceeds 10,000 ppm, the effect exceeding the desired effect is not obtained, and there is a possibility that it reacts with the active ingredient of the chemical conversion treatment liquid and inhibits the chemical conversion treatment reaction. The content is more preferably a lower limit of 10 ppm and an upper limit of 1000 ppm. A more preferable upper limit of the content is 200 ppm.

(Surfactant)
The surfactant is more preferably an anionic surfactant or a nonionic surfactant. When the anionic surfactant or the nonionic surfactant is contained in the surface conditioning composition of the present invention, in the chemical conversion treatment after the surface conditioning treatment, for example, an iron or zinc-based metal material and an aluminum-based surfactant. It is possible to satisfactorily form a chemical film having a sufficient coating amount on the aluminum-based metal material portion of the electrolytic corrosion portion with the metal material, and to reduce the difference in coating amount between the chemical coating of the general portion and the electrolytic corrosion portion. . In addition, a dense chemical conversion film can be formed on the surfaces of various metal materials. Furthermore, it is possible to form a chemical conversion film having a sufficient film amount even on difficult-to-convert metal materials such as aluminum-based metal materials and high-tensile steel plates.

  The nonionic surfactant is not particularly limited, but a nonionic surfactant having a hydrophilic / hydrophobic balance (HLB) of 6 or more is preferable. For example, polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene Derivatives, oxyethylene-oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, alkyl alkanodeamide, nonylphenol , Alkyl nonylphenol, polyoxyalkylene glycol, alkylamine oxide, acetylene diol, polyoxyethylene noni Examples include silicon surfactants such as phenyl ether and polyoxyethylene alkylphenyl ether-modified silicon, and fluorine surfactants in which at least one hydrogen atom in the hydrophobic group of the hydrocarbon surfactant is substituted with a fluorine atom. be able to. Of these, polyoxyethylene alkyl ethers and polyoxyalkylene alkyl ethers are preferred because the effects of the present invention can be further obtained. These may be used alone or in combination of two or more.

  Although it does not specifically limit as said anionic surfactant, For example, fatty acid salt, alkyl sulfate ester salt, alkyl ether sulfate ester salt, alkylbenzenesulfonate, alkylnaphthalenesulfonate, alkylsulfosuccinate, alkyldiphenylether disulfonate , Polybisphenol sulfonate, alkyl phosphate, polyoxyethyl alkyl sulfate, polyoxyethyl alkyl allyl sulfate, alpha olefin sulfonate, methyl taurate, polyaspartate, ether carboxylate, Naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, alkyl ether phosphate ester salt and the like can be mentioned. Especially, the alkyl ether phosphate ester salt is preferable from the point which can acquire the effect of this invention more.

  The anionic surfactant can be used after being neutralized with ammonia or an amine-based neutralizer. Examples of the amine-based neutralizer include diethylamine (DEA), triethylamine (TEA), monoethanolamine (META), diethanolamine (DETA), triethanolamine (TETA), dimethylethanolamine (DMEA), and diethylethanolamine. (DEEA), isopropylethanolamine (IPEA), diisopropanolamine (DIPA), 2-amino-2-methylpropanol (AMP), 2- (dimethylamino) -2-methylpropanol (DMAP), morpholine (MOR), N-methylmorpholine (NMM), N-ethylmorpholine (NEM), etc. can be mentioned. Of these, 2-amino-2-methylpropanol (AMP) is preferably used.

(Surfactant content)
In the surface conditioning treatment liquid, the content of the anionic surfactant or nonionic surfactant is preferably 3 ppm as the lower limit and 500 ppm as the upper limit. The effect of this invention can be acquired favorably that it is in the said range. The lower limit is more preferably 5 ppm, and the upper limit is more preferably 300 ppm. You may use independently and may use 2 or more types together.

[Metal nitrite]
In order to further suppress the generation of rust, the surface conditioning composition may contain a divalent or trivalent metal nitrite as necessary.

[Dispersion medium]
The surface conditioning composition may contain a dispersion medium in which divalent or trivalent metal phosphate particles are dispersed. Examples of the dispersion medium include an aqueous medium containing 80% by mass or more of water. As the medium other than water, various water-soluble organic solvents can be used, but the content of the water-soluble organic solvent should be kept low, preferably 10% by mass or less, more preferably 5% by mass of the aqueous medium. It is as follows. A dispersion composed only of water can also be used.

  The water-soluble organic solvent is not particularly limited, and examples thereof include alcohol solvents such as methanol, ethanol, isopropanol, and ethylene glycol; ether solvents such as ethylene glycol monopropyl ether, butyl glycol, and 1-methoxy-2-propanol; Examples thereof include ketone solvents such as acetone and diacetone alcohol; amide solvents such as dimethylacetamide and methylpyrrolidone; ether solvents such as ethyl carbitol acetate. Two or more of these may be used in combination.

[Alkali salt]
The above surface conditioning composition further includes soda ash for the purpose of stabilizing divalent or trivalent metal phosphate particles in a dispersion medium and forming a fine chemical conversion film in the chemical conversion treatment step performed next. Alkali salts may be added.

  Regarding the above various additives, the type, amount of addition, and the like may be appropriately selected.

[PH of surface conditioning composition]
The pH of the surface conditioning composition is preferably a lower limit pH 3 and an upper limit pH 12. If the pH is less than 3, the divalent or trivalent metal phosphate particles are likely to dissolve and become unstable, which may affect the next step. When pH exceeds 12, there exists a possibility that the influence of a chemical conversion defect may be seen by causing the pH rise of the chemical conversion treatment bath of the following process. The lower limit of the pH of the surface conditioning composition is more preferably pH 6, and the upper limit is more preferably pH 11.

<Method for producing surface conditioning composition>
The surface conditioning composition of the present invention can be produced, for example, by the following method. When zinc phosphate is used as the divalent or trivalent metal phosphate particles, the zinc phosphate particles can be obtained using, for example, zinc phosphate used as a raw material. The raw material zinc phosphate is represented by Zn ₃ (PO ₄ ) ₂ .4H ₂ O and is generally a colorless, crystalline solid, but a commercially available product in a white powder state is available.

  As a method for producing the raw material zinc phosphate, for example, when a dilute solution of zinc sulfate and disodium hydrogen phosphate is mixed and heated at a molar ratio of 3: 2, the tetraphosphate of zinc phosphate becomes a crystalline precipitate. Generate as Alternatively, zinc phosphate tetrahydrate can be obtained by reacting a diluted phosphoric acid aqueous solution with zinc oxide or zinc carbonate. Tetrahydrate crystals are orthorhombic and have three transformations. When heated, it becomes a dihydrate at 100 ° C, a monohydrate at 190 ° C, and an anhydrate at 250 ° C. As the zinc phosphate in the present invention, any of these tetrahydrates, dihydrates, monohydrates, and anhydrous hydrates can be used, but generally available tetrahydrates can be used as they are.

  The shape of the divalent or trivalent metal phosphate particles of the raw material is not particularly limited, and any shape can be used. Commercially available products are generally in the form of white powder, but the shape of the powder may be any shape such as fine particles, plates, scales, and the like. The particle diameter of the divalent or trivalent metal phosphate particles of the raw material is not particularly limited, but is usually a powder having an average particle diameter of about several μm. In particular, products that are commercially available as rust preventive pigments, such as products that have a buffering effect enhanced by treatment for imparting basicity, are preferably used.

  As will be described later, in the present invention, a stable concentrated dispersion in which divalent or trivalent metal phosphate particles are finely dispersed in a dispersion medium can be prepared. A stable surface treatment effect can be obtained regardless of the primary particle size and shape of the metal phosphate particles.

  It is preferable to use the above-mentioned raw material divalent or trivalent metal phosphate particles finely dispersed in advance in a dispersion medium. The method for preparing a concentrated dispersion in which divalent or trivalent metal phosphate particles are dispersed in an aqueous medium is not limited. Preferably, the raw material is contained in the above-described dispersion medium such as water or a water-soluble organic solvent. This can be achieved by blending a divalent or trivalent metal phosphate, and performing wet grinding in the presence of the above-mentioned (1) phenol compound and (2) stabilizer. Moreover, you may add the above-mentioned (1) phenol type compound after the preparation of the said thick dispersion liquid, or after the dilution as needed.

  In obtaining a concentrated dispersion of divalent or trivalent metal phosphate particles, the raw divalent or trivalent metal phosphate is wet-pulverized with an aqueous medium when preparing the concentrated dispersion. Although it is convenient in terms of the process, the wet pulverization may be carried out in a dispersion medium other than the concentrated medium and then prepared by solvent replacement.

  In the preparation of the concentrated dispersion, the blending amount of the divalent or trivalent metal phosphate of the raw material is usually lower limit of 0.5% by mass and upper limit of 50% by mass with respect to the concentrated dispersion. preferable. If the amount is less than 0.5% by mass, the content of the divalent or trivalent metal phosphate is too small, and the effect of the surface conditioning treatment solution prepared using the concentrated dispersion can be sufficiently obtained. There is a risk of not. If it exceeds 50 mass%, it becomes difficult to obtain a uniform and fine particle size distribution by wet grinding, and the phosphate particles of divalent or trivalent metal may be easily re-aggregated. The blending amount is more preferably a lower limit of 1% by mass and an upper limit of 40% by mass, and particularly preferably a lower limit of 10% by mass and an upper limit of 30% by mass.

  Moreover, it is preferable that the addition amount of said (1) phenol type compound and (2) stabilizer is a minimum 0.1 mass% and an upper limit 50 mass% with respect to a thick dispersion liquid. If it is less than 0.1% by mass, a concentrated dispersion suitable for the preparation of the surface conditioning treatment liquid may not be obtained. If it exceeds 50% by mass, the dispersibility may be reduced due to the influence of excess (1) phenolic compound and / or (2) stabilizer, and even if the dispersion is sufficient, the economy Is not advantageous. The lower limit is more preferably 0.5% by mass, and the upper limit is more preferably 20% by mass.

The method for obtaining a concentrated dispersion in which the divalent or trivalent metal phosphate particles are finely dispersed in a D ₅₀ of 3 μm or less is not limited, but preferably the raw material is a divalent or trivalent metal. In the present invention, 0.5 to 50% by mass of the phosphate and (1) the phenolic compound and (2) the stabilizer are present to be 0.1 to 50% by mass and wet pulverized. The wet pulverization method is not particularly limited, and a general wet pulverization means may be used. For example, a bead mill represented by a disk type, a pin type, etc., a high pressure homogenizer, an ultrasonic disperser, etc. A medialess disperser or the like can be used.

In the wet pulverization, by monitoring the D ₉₀ of the divalent or trivalent metal phosphate particles, overdispersion can be prevented, and aggregation, thickening, reaggregation of fine particles, and the like can be prevented. In the present invention, it is preferable to be 4μm or less D _90. In addition, it is desirable to select blending and dispersion conditions that do not cause overdispersion.

According to the method for preparing the concentrated dispersion described above, the D ₅₀ of the divalent or trivalent metal phosphate particles in the aqueous medium can be adjusted to 3 μm or less, and the composition for surface adjustment is excellent in stability. As a result, a concentrated dispersion having excellent performance can be obtained. D ₅₀ can usually be adjusted to a desired average particle size in the range of 0.01 to 3 [mu] m.

By preparing a concentrated dispersion by the method for preparing a concentrated dispersion described above, even if it is a divalent or trivalent metal phosphate exceeding 3 μm, D ₅₀ should be dispersed in the liquid in a state of 3 μm or less. Can do. The same applies to a divalent or trivalent metal phosphate having a primary particle diameter of about several tens of μm. This is because the primary particle diameter of metal phosphate particles can be reduced by wet grinding according to the above-described method without using a divalent or trivalent metal phosphate having a small primary particle diameter. Also means. According to the above-described method, the D ₅₀ of the divalent or trivalent metal phosphate particles in the concentrated dispersion can be 3 μm or less, further 1 μm or less, and further 0.2 μm or less.

The above-mentioned concentrated dispersion can arbitrarily adjust the D ₅₀ of divalent or trivalent metal phosphate particles in the liquid in the range of 0.01 μm to 3 μm or less in accordance with the intended use. Excellent concentrated dispersion.

Since the ratio of coarse particles having a particle diameter exceeding D ₉₀ can be reduced by the wet pulverization method, in particular, D ₉₀ is 4 μm or less, further 2.6 μm or less, further 0.3 μm or less and having a large dispersion diameter. It is possible to obtain a concentrated dispersion with a suppressed particle size and a sharp particle size distribution. For this reason, it is presumed that the divalent or trivalent metal phosphate particles are finely dispersed in the aqueous medium and the dispersion state is stable. In addition, since the proportion of coarse particles is low, the divalent or trivalent metal phosphate particles in the surface conditioning composition contribute to the efficient formation of crystal nuclei, and the particle size distribution is sharp. Therefore, in the surface conditioning treatment step, crystal nuclei with a more uniform and fine grain size are formed, and the subsequent chemical conversion treatment step results in the formation of a uniform chemical conversion film, and the chemical conversion formed on the surface of the resulting chemical conversion treatment steel sheet. The film should be uniform and excellent, and this should improve the processability of bag parts of complex structures and difficult-to-form metal materials such as aluminum-based metal materials and high-tensile steel plates. Is guessed.

  In particular, the concentrated dispersion is to obtain a concentrated dispersion having a high concentration in which a divalent or trivalent metal phosphate is blended to 10% by mass or more, further 20% by mass or more, and further 30% by mass or more. You can also. For this reason, the processing liquid for surface adjustment which exhibits high performance can be prepared easily.

  Other components (divalent or trivalent metal nitrite, dispersion medium, thickener, etc.) may be mixed with the concentrated dispersion obtained as described above. The mixing method of the concentrated dispersion and the other components is not particularly limited. For example, other components may be added to the concentrated dispersion and mixed, or other components may be added during the preparation of the concentrated dispersion. You may mix | blend.

  The surface adjustment treatment liquid is prepared, for example, by diluting the concentrated dispersion with an aqueous medium such as water. The surface conditioning treatment liquid is excellent in dispersion stability and can perform a good surface treatment on a metal material. The (1) phenolic compound may be added to the aqueous medium simultaneously with the addition of the divalent or trivalent metal phosphate, or the concentrated dispersion in which the divalent or trivalent metal phosphate is dispersed. Although it may be added to the liquid, it may be added after dilution of the concentrated dispersion.

<Surface adjustment method>
The surface conditioning method of the present invention comprises a step of bringing a surface conditioning treatment liquid, which is a surface conditioning composition, into contact with a metal surface. In this way, in addition to iron and zinc-based metal materials, fine particles of divalent or trivalent metal phosphates are uniformly attached to the surface of inferior metal materials such as aluminum-based metal materials and high-tensile steel plates. And a chemical conversion film having a sufficient amount can be formed in the chemical conversion treatment step. In addition, for example, a plurality of types of metal materials such as iron or zinc-based metal materials and aluminum-based metal materials can be subjected to surface conditioning treatment at the same time, and a chemical conversion film can be formed better.

  The method for bringing the surface adjustment treatment liquid into contact with the metal material surface in the surface adjustment method is not particularly limited, and a conventionally known method such as dipping or spraying can be appropriately employed.

  The metal material subjected to the surface adjustment is not particularly limited, and various metal materials generally subjected to chemical conversion treatment, for example, iron-based materials such as galvanized steel sheet, aluminum-based metal material, magnesium alloy or cold-rolled steel sheet, and high-tensile steel sheet. Applicable to metal materials. Further, for example, the present invention can also be suitably applied to applications in which a plurality of types of metal materials such as steel or galvanized steel sheet and an aluminum-based metal material are simultaneously subjected to surface conditioning treatment.

  Moreover, it can use for a degreasing | defatting and surface adjustment process using the composition for surface adjustment of this invention. Thereby, the water washing process after a degreasing process can be skipped. In the degreasing and surface conditioning step, a known inorganic alkali builder, organic builder or the like may be added in order to increase the detergency. Moreover, you may add a well-known condensed phosphate etc. In the surface adjustment, the contact time between the surface adjustment composition and the surface of the metal material and the temperature of the surface adjustment composition are not particularly limited, and can be performed under conventionally known conditions.

  The chemical conversion treatment steel sheet can be manufactured by performing the above-mentioned surface adjustment and then performing chemical conversion treatment with a chemical conversion treatment agent containing phosphate. The chemical conversion treatment method is not particularly limited, and various known methods such as immersion (dip) treatment, spray treatment, and electrolytic treatment can be applied. A plurality of these may be combined. The phosphate constituting the metal conversion film to be deposited is not particularly limited as long as it is a metal phosphate, and is not limited at all, such as zinc phosphate, iron phosphate, manganese phosphate, and zinc calcium phosphate. Although not intended, zinc phosphate is preferred. In the chemical conversion treatment, the contact time between the chemical conversion treatment agent and the surface of the metal material and the temperature of the chemical conversion treatment agent are not particularly limited, and can be performed under conventionally known conditions.

  After the surface adjustment and the chemical conversion treatment, a coated steel sheet can be produced by further coating. The coating method is generally electrodeposition coating. The paint used for the coating is not particularly limited, and various kinds of paints generally used for coating the chemical conversion treated steel sheet, for example, epoxy melamine paint, cationic electrodeposition paint, polyester-based intermediate coating, and polyester-based top coating can be exemplified. . In addition, the well-known method of passing through a washing | cleaning process after a chemical conversion treatment and before coating is employ | adopted.

Surface conditioning composition of the present invention, divalent or trivalent metal phosphate particles D ₅₀ is 3μm or less, (1) phenolic compound and (2) PH3～12 of containing a stabilizer Is. In this way, when a metal material having a dissimilar metal contact portion between an iron or zinc-based metal material and an aluminum-based metal material is surface-adjusted with a surface-conditioning treatment liquid, and then a chemical conversion treatment is performed. A sufficient amount of chemical conversion film can be satisfactorily formed on the aluminum-based metal material portion of the dissimilar metal contact portion. Further, even when applied to difficult-to-convert metal materials such as aluminum-based metal materials and high-tensile steel plates, it is possible to form a conversion film having a sufficient coating amount.

Furthermore, since a specific component is used, the formation of a chemical conversion film on the surface of the metal material can be promoted, and a dense chemical conversion film can be formed, and the D ₅₀ is 3 μm or less. Therefore, the dispersion stability in the surface conditioning treatment liquid is also excellent. Therefore, the composition for surface adjustment can be suitably used for surface adjustment of various metal materials.

  Since the surface conditioning composition of the present invention has the above-described configuration, it is applied to metal materials such as iron, zinc, and aluminum, particularly to difficult-to-form metal materials such as aluminum-based metal materials and high-tensile steel sheets in the surface conditioning treatment In this case, a sufficient amount of chemical film can be formed on the surface of the metal material in the subsequent chemical conversion treatment. It is possible to suppress the electric corrosion.

  In addition, the dispersion stability is also excellent. Therefore, the surface conditioning composition of the present invention can be suitably used for various metal materials used in automobile bodies, home appliances and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited only to these examples. In the following examples, “part” and “%” mean “part by mass” and “% by mass” unless otherwise specified. Incidentally, _(a measurement method, as follows) D ₅₀ of Examples 1-9, the zinc phosphate particles in the surface conditioning composition of Comparative Examples 1-6 below are as shown in Table 1 . Further, in the surface adjustment treatment, the treatment liquid for actually contacting the metal material is referred to as “surface adjustment treatment liquid”, and metal phosphate particles used for diluting to produce the surface adjustment treatment liquid. The dispersion is denoted as “concentrated dispersion”. The treatment liquid for surface adjustment is obtained by diluting the concentrated dispersion to a predetermined concentration with a solvent such as water, adding necessary additives, and then adjusting the pH.

<Preparation of Example 1 Surface Conditioning Composition>
To 60 parts by mass of pure water, 1 part by mass of pyrogallol, 1 part by mass of polyphosphoric acid (“SN2060”, trade name, manufactured by San Nopco) and 20 parts by mass of zinc phosphate particles are added, and the remaining water is added to the total amount The amount was 100 parts by mass. Zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed with an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Examples 2 and 3 Preparation of surface conditioning composition>
A treatment liquid for surface adjustment was prepared in the same manner as in Example 1 except that the types of (1) phenolic compound and (2) stabilizer were changed as shown in Table 1.

<Example 4 Preparation of surface conditioning composition>
"SN2060" (supra) 1 mass part of solid content and 20 mass parts of zinc phosphate particles were added to 60 mass parts of pure water, and the remaining water was added to make 100 mass parts in total. Zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed with an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, pyrogallol was added to 50 ppm, and the pH was adjusted to 9 with NaOH to prepare a surface conditioning treatment solution. Obtained.

<Example 5 Preparation of surface conditioning composition>
To 60 parts by mass of pure water, 1 part by mass of tannic acid (reagent), 1 part by mass of “SN2060” (described above) and 20 parts by mass of zinc phosphate particles are added, and the remaining water is added to make 100 parts by mass in total. And neutralized with NaOH. To this, zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed by an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Example 6 Preparation of surface conditioning composition>
60 parts by mass of pure water, 1 part by mass of pyrogallol, 1 part by mass of “SN2060” (supra), 1 part by mass of smectite (“Kunipia F”, trade name, manufactured by Kunimine Kogyo Co., Ltd.) and 20 parts by mass of zinc phosphate particles The remaining water was added to make 100 parts by mass in total. Zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed with an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Examples 7 and 8 Preparation of surface conditioning composition>
A surface adjustment treatment solution was prepared in the same manner as in Example 6 except that (1) the phenolic compound and (2) the type of stabilizer were changed as shown in Table 1.

<Preparation of Example 9 Surface Conditioning Composition>
60 parts by mass of water, 1 part by mass of tannic acid (reagent), 1 part by mass of polyphosphoric acid solid, 1 part by mass of urethane resin (“TAFIGEL PUR40”, trade name, manufactured by Enomoto Kasei Co., Ltd.) and 20 parts by mass of zinc phosphate particles And the remaining water was added to make 100 parts by mass, and neutralized with NaOH. Zirconia beads (1 mm) were added thereto at a filling rate of 80%, and dispersed with an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Comparative Example 1 Preparation of Surface Adjustment Composition>
“SN2060” (supra) 1 part by mass of solid content and 20 parts by mass of zinc phosphate particles were added to 60 parts by mass of pure water, and the remaining water was added to make 100 parts by mass in total. Zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed with an SG mill for 180 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Preparation of Comparative Examples 2-3 for Surface Adjustment>
(2) A metal surface treatment solution was prepared in the same manner as in Comparative Example 1 except that the type of stabilizer was changed as shown in Table 1.

<Comparative Example 4 Preparation of surface conditioning composition>
To 60 parts by mass of pure water, 1 part by mass of polyacrylic acid (“SN44C”, trade name, manufactured by San Nopco) and 20 parts by mass of zinc phosphate particles are added, and the remaining water is added to make 100 parts by mass in total. did. Zirconia beads (1 mm) were added at a filling rate of 80%, and dispersed with a SG mill until a predetermined particle size was obtained. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Comparative Example 5 Preparation of surface conditioning composition>
60 parts by weight of pure water, 1 part by weight of “SN44C” (supra) solids, 1 part by weight of colloidal silica (“Snowtex N”, trade name, manufactured by Nissan Chemical Industries) and 20 parts by weight of zinc phosphate particles The remaining water was added to make 100 parts by mass in total. The zirconia beads (1 mm) filling ratio was 80%, and the mixture was dispersed in an SG mill for 360 minutes. The resulting concentrated dispersion was diluted with tap water to a zinc phosphate concentration of 0.1%, and the pH was adjusted to 9 with NaOH to obtain a surface conditioning treatment liquid.

<Comparative Example 6 Preparation of surface conditioning composition>
A titanium phosphate-based powder surface conditioning composition (“5N10”, trade name, manufactured by Nippon Paint Co., Ltd.) was diluted to 0.1% with tap water, and the pH was adjusted to 9 with NaOH.

<Examples 1-9 and Comparative Examples 1-6>
[Preparation of test plate 1]
Cold rolled steel plate (SPC) (70 mm x 150 mm x 0.8 mm), aluminum plate (Al) (# 6000 series, 70 mm x 150 mm x 0.8 mm), galvanized steel sheet (GA) (70 mm x 150 mm x 0.8 mm) Each of the high-strength steel plates (70 mm x 150 mm x 1.0 mm) was degreased at 40 ° C for 2 minutes using a degreasing agent ("Surf Cleaner EC92", 2%, trade name, manufactured by Nippon Paint Co., Ltd.). Then, the surface adjustment treatment was carried out at room temperature for 30 seconds using the surface adjustment treatment liquid obtained in Examples and Comparative Examples. Subsequently, each metal plate was subjected to a chemical conversion treatment at 35 ° C. for 120 seconds by a dipping method using a zinc phosphate treatment solution (“Surfdyne SD6350”, trade name, manufactured by Nippon Paint Co., Ltd.), washed with water, washed with pure water, and dried. A test plate was obtained.

[Preparation of test plate 2]
Similarly to the preparation 1 of the test plate described above, the degreased aluminum plate 3 and the galvanized steel plate 2 are produced, and the degreased aluminum plate 3 and the galvanized steel plate 2 are clipped as shown in FIG. Connected. Next, the surface adjustment treatment, chemical conversion treatment, water washing, pure water washing, and drying were performed on the connected metal plate in the same manner as in the production of the test plate 1 to obtain a test plate. Table 1 shows the composition ratio of the surface conditioning treatment liquid obtained above.

[Evaluation test]
Evaluation was carried out by the following method, and the results are shown in Table 2. About the steel plate produced by preparation 2 of the test plate, the portion of the electrolytic corrosion portion 1 of the aluminum plate 3 was evaluated. In Table 2, those prepared in test plate preparation 1 are “SPC”, “GA”, “Al”, “high-tensile steel plate”, and those prepared in test plate preparation 2 are “Al ( "Electrical corrosion part)".

(Measurement of particle size of zinc phosphate particles)
About the particle diameter of the zinc phosphate particle contained in the processing liquid for surface adjustment obtained in the production example or the comparative production example, an optical diffraction particle size measuring device (“LA-500”, trade name, manufactured by Horiba, Ltd.) is used. The particle size distribution was measured, D ₅₀ (average diameter of the dispersion) and D ₉₀ were monitored, and D ₅₀ and D ₉₀ were determined.

(Film appearance)
The appearance of the formed film was visually evaluated according to the following criteria. In addition, after drying, the presence or absence of rust was visually observed. When rust was generated, “partial rust” and “rust” were indicated depending on the degree.
◎: The entire surface is uniformly and finely coated. ○: The entire surface is coated roughly. △: Partially uncoated. ×: The chemical conversion film is hardly formed. The crystal size of the formed chemical conversion film. Was measured with an electron microscope.

(Amount of adhesion)
After the surface conditioning treatment, the mixture was allowed to stand for 1 minute, and after drying, the amount of phosphate particles adhered was measured with a fluorescent X-ray measurement apparatus (“XRF-1700”, trade name, manufactured by Shimadzu Corporation).

(Amount of chemical conversion film (C / W))
The amount of chemical conversion film on the SPC test plate and GA test plate was measured by “XRF-1700” (supra).

  If a metal material with relatively high chemical conversion reactivity such as SPC or GA is used, it is desirable to form crystals as dense as possible. Therefore, the chemical conversion performance is better when the crystal particle size is smaller and the coating amount is smaller. Is judged to be high. On the other hand, in the case of a hard-to-convert metal material such as an aluminum-based metal material or a high-tensile steel plate, the chemical conversion treatment reactivity is low, so that it is necessary to increase the amount of the crystal film. For this reason, it is judged that the chemical conversion performance is higher as the coating amount is larger.

(Stability)
The stability of the surface adjustment treatment liquid when the previous step degreasing treatment liquid is mixed with the surface adjustment treatment liquid obtained in the production example is assumed to have been brought into the surface adjustment treatment liquid. Out) The liquid obtained by mixing the 1/100 diluted solution was placed in an incubator at 30 ° C. for 90 days, and then the SPC chemical conversion was evaluated and compared with the initial value, and evaluated according to the following criteria. In addition, when the processing liquid for surface adjustment was rotten, it was described as rotting.
○: Appearance of the film equivalent to that at the beginning Δ: Inferior to the initial value, but a film is formed ×: Almost no chemical conversion film is formed

(Wettability)
About the wettability of the surface conditioning treatment liquid obtained in the production example, the test piece-treated degreasing liquid (above) was used, and after degreasing at 40 ° C. for 1 minute, it was brought into the surface conditioning processing liquid. Assuming that, the liquid prepared by mixing the test piece-treated degreasing liquid (supra) 1/100 diluted solution was subjected to surface conditioning treatment at room temperature for 30 seconds, and the wettability of the test piece was evaluated according to the following criteria.
○: No repelling △; Edge repelling only ×: Full repelling

(Corrosion resistance)
The test plate after the chemical conversion treatment was subjected to cationic electrodeposition coating with a cationic electrodeposition paint (“Powernix 110”, trade name, manufactured by Nippon Paint Co., Ltd.) so as to have a dry film thickness of 20 μm, washed with water and heated at 170 ° C. for 20 minutes. Then, baking was performed to prepare a test plate. Two longitudinally parallel cuts were made so as to reach the substrate, and then subjected to a salt dip test (5% salt water, 35 ° C., 480 h immersion), and then the cut part was tape-peeled and the peel width was evaluated.

  In the case of using the surface conditioning treatment liquid of the example, a sufficient amount of chemical film is formed for all of the cold-rolled steel sheet, the galvanized steel sheet, the hot-rolled steel sheet, and the high-tensile steel sheet, A sufficient amount of chemical conversion film was formed on the electrolytic corrosion portion of the aluminum plate at the dissimilar metal contact portion between the aluminum plate and the galvanized steel plate. That is, the surface conditioning treatment liquids of the examples were able to form a chemical film having a sufficient film amount even if different metal materials were treated simultaneously. In addition, a chemical film with a sufficient amount of film could be formed even when using a surface-conditioning treatment solution which was left for a long time after dilution.

  The surface conditioning composition of the present invention can be suitably used for various metal materials used in automobile bodies, home appliances and the like.

It is the schematic of the electrolytic corrosion aluminum test board used in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric corrosion part 2 Galvanized steel plate 3 Aluminum plate 4 General part 5 Clip

Claims (7)

A surface conditioning composition having a pH of 3 to 12 and containing divalent or trivalent metal phosphate particles,
The divalent or trivalent metal phosphate particles have a D ₅₀ of 3 μm or less,
The surface conditioning composition further comprises:
A composition for surface conditioning comprising (1) a phenolic compound and (2) a stabilizer.   The surface conditioning composition according to claim 1, wherein the divalent or trivalent metal phosphate particles are zinc phosphate.   The surface conditioning composition according to claim 1 or 2, wherein the (1) phenolic compound is at least one selected from the group consisting of flavonoids, tannins, gallic acid, lignin, catechins and pyrogallol.   The surface conditioning composition according to claim 1, 2 or 3, wherein the surface conditioning treatment liquid contains 1 to 1000 ppm of the (1) phenol compound.   The (2) stabilizer is at least selected from the group consisting of phosphonic acid, phytic acid, polyphosphoric acid, phosphonic acid group-containing acrylic resins and vinyl resins, carboxyl group-containing acrylic resins and vinyl resins, saccharides, and layered clay minerals. The composition for surface conditioning of Claim 1, 2, 3 or 4 which is 1 type.   The composition for surface adjustment according to claim 1, 2, 3, 4 or 5, comprising 1 to 1000 ppm of the stabilizer (2) as a surface adjustment treatment liquid.   A surface conditioning method comprising the step of bringing the surface conditioning composition according to claim 1, 2, 3, 4, 5 or 6 into contact with a metal material.

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