JPWO2016093323A1 - Metal surface treatment liquid, method for producing surface treated metal material, surface treated metal material - Google Patents

Abstract

The present invention provides a metal surface treatment solution capable of obtaining a surface-treated metal material excellent in corrosion resistance, workability, chemical resistance, coating film adhesion and post-coating corrosion resistance. The metal surface treatment liquid of the present invention has an isocyanate group blocked with a blocking agent, and further has a blocked isocyanate (A) having an isocyanurate structure and a polyalkyleneoxy chain, a hydroxy group, an amino group, a sulfo group, and And an organic resin (B) having at least one functional group selected from the group consisting of carboxy groups.

Description

  The present invention relates to a metal surface treatment liquid, a method for producing a surface treatment metal material, and a surface treatment metal material.

In various fields such as home appliances, automobiles, and building materials, a technique of performing chromate treatment on a metal material such as a steel plate is generally used for the purpose of imparting corrosion resistance and coating film adhesion. However, since the chromate-treated film usually contains hexavalent chromium having a high environmental load, in recent years, there has been an increasing demand for the hexavalent chromium-free film, and various techniques have been proposed.
For example, Patent Document 1 discloses a coated metal material having a urethane-based resin film containing a polyurethane resin as a main component on a metal material, and describes that corrosion resistance and workability are excellent.

Japanese Patent Laid-Open No. 2007-075777

On the other hand, in recent years, with the enhancement of functionality of various products, the required performance for the metal materials used is also increasing.
For example, in addition to being required to further improve the corrosion resistance and workability which are characteristics required in Patent Document 1, the adhesion (coating film adhesion) of the coating film disposed on the metal material surface, It is also required to be excellent in corrosion resistance after being provided (corrosion resistance after painting) and chemical resistance to acids and alkalis.
The present inventors performed surface treatment of a metal material using a urethane resin as described in Patent Document 1 and evaluated various properties with respect to the obtained surface-treated metal material. There was nothing to satisfy with the level, and it was found that further improvement was necessary.

In view of the above circumstances, the present invention provides a metal surface treatment liquid capable of obtaining a surface-treated metal material excellent in corrosion resistance, workability, chemical resistance, coating film adhesion and post-coating corrosion resistance. Objective.
Another object of the present invention is to provide a method for producing a surface-treated metal material using a metal surface-treatment liquid, and a surface-treated metal material.

As a result of intensive studies on the above problems, the present inventors can obtain a desired effect by using a metal surface treatment liquid containing a blocked isocyanate having a predetermined structure and an organic resin having a predetermined functional group. I found out.
More specifically, the present inventors have found that the above object can be achieved by the following configuration.

(1) a blocked isocyanate (A) having an isocyanate group blocked by a blocking agent, and further having an isocyanurate structure and a polyalkyleneoxy chain;
A metal surface treatment solution comprising: an organic resin (B) having at least one functional group selected from the group consisting of a hydroxy group, an amino group, a sulfo group, and a carboxy group.
(2) The metal surface treatment liquid according to (1), wherein the blocked isocyanate (A) has a structural unit represented by the formula (1) described later and a structural unit represented by the formula (2) described later. .
(3) Further, at least one phosphorus-containing compound (D) selected from the group consisting of inorganic phosphoric acid, inorganic phosphate, organic phosphoric acid, organic phosphate, organic phosphonic acid, and organic phosphonate The metal surface treatment liquid according to (1) or (2) above, comprising:
(4) The metal surface treatment liquid according to (3) above, wherein the phosphorus-containing compound (D) contains at least one selected from the group consisting of an ammonium salt of inorganic phosphoric acid and an organic phosphonic acid.
(5) The metal surface treatment liquid according to (3) or (4) above, wherein the mass ratio (A / D) of the blocked isocyanate (A) and the phosphorus-containing compound (D) is 0.1 to 50.
(6) Further, at least one selected from the group consisting of zirconium, titanium, vanadium, cerium, molybdenum, cobalt, nickel, magnesium, calcium, cerium, zinc, niobium, yttrium, aluminum, tungsten, chromium, and barium. Metal surface treatment liquid in any one of said (1)-(5) containing the metal compound (C) containing these elements.
(7) The metal surface treatment liquid according to (6), wherein the metal compound (C) contains a zirconium element.
(8) The metal surface treatment liquid according to the above (6) or (7), wherein the metal compound (C) is zirconium ammonium carbonate, zirconium hydrofluoric acid or a salt thereof.
(9) Ratio {a / b} of the concentration a (g / L) of the effective isocyanate group contained in the blocked isocyanate (A) and the concentration b (g / L) of the functional group contained in the organic resin (B) The metal surface treatment liquid according to any one of (1) to (8), wherein is 0.001 to 30.0.
(10) The above-mentioned (1) to (9), wherein the concentration of the effective isocyanate group contained in the blocked isocyanate (A) is 0.01 to 20 g / L, and the concentration of the organic resin (B) is 5 to 100 g / L. The metal surface treatment liquid according to any one of (1).
(11) The metal surface treatment liquid according to any one of (1) to (10) above, wherein the blocked isocyanate (A) has a weight average molecular weight of 400 to 15000.
(12) The metal surface treatment liquid according to any one of (1) to (11), further including a silicon compound (E).
(13) Furthermore, the metal surface in any one of said (1)-(12) containing the inorganic compound (F) containing the at least 1 sort (s) of element selected from the group which consists of lithium, sodium, and potassium Treatment liquid.
(14) A surface-treated metal material comprising a step of bringing the metal surface treatment liquid according to any one of (1) to (13) into contact with the surface of the metal material, followed by heating and drying to form a film on the metal material. Production method.
(15) A surface-treated metal material comprising a metal material and a film formed by bringing the metal surface treatment liquid according to any one of (1) to (13) into contact with the metal material and drying by heating.

ADVANTAGE OF THE INVENTION According to this invention, the metal surface treatment liquid which can obtain the surface treatment metal material excellent in corrosion resistance, work resistance, chemical resistance, coating-film adhesiveness, and post-coating corrosion resistance can be provided.
Moreover, according to this invention, the manufacturing method of the surface treatment metal material using a metal surface treatment liquid, and a surface treatment metal material can also be provided.

Hereinafter, the metal surface treatment liquid, the surface treatment metal material and the production method thereof of the present invention will be described in detail. The reason why the desired effect can be obtained by using the metal surface treatment liquid of the present invention is presumed as follows.
The blocked isocyanate (A) has many polar groups in the molecule such as an isocyanurate structure containing an oxygen atom and a nitrogen atom and a polyalkyleneoxy chain containing an oxygen atom. These polar groups form a hydrogen bond with a hydroxyl group on the metal material, or form a covalent bond by heat drying, and as a result, the film is firmly bonded to the metal material. This characteristic has the effect of suppressing the bond breakage between the metal material and the film due to the increase in pH through the reduction reaction of dissolved oxygen that occurs under the film in a corrosive environment. In addition, since the adhesion point at the interface between the film and the metal material increases, it also has an action of suppressing film peeling and film destruction. Therefore, it acts effectively on corrosion control such as corrosion resistance.
Moreover, most of the isocyanate groups (blocked isocyanate groups) blocked by the blocking agent in the blocked isocyanate (A) contained in the metal surface treatment liquid are dissociated by heat drying, but a part of them is considered to remain. These unreacted blocked isocyanate groups can cause alkali hydrolysis in a corrosive environment, but act as an alkali catalyst and can form interactions and new bonds by reaction with coexisting reactants. It acts as a kind of repair function. Therefore, it acts as an ability to inhibit corrosion of the exposed portions of plating such as scratches and end surfaces.
Furthermore, since the film formed from the metal surface treatment liquid of the present invention contains a large number of polar groups, it exhibits excellent adhesion with the film disposed on the film. In this case, excellent coating film adhesion is exhibited by the formation of hydrogen bonds and / or covalent bonds between the functional groups contained in the coating film and the functional groups contained in the film.
Furthermore, the film formed from the metal surface treatment liquid of the present invention also effectively acts on chemical resistance (solvent resistance and water repellency). These are achieved by a curing reaction with the organic resin (B) coexisting with the blocked isocyanate (A). This is because the molecular weight of the entire coating increases due to the curing reaction, and the penetration of corrosion factors is achieved by the dense structure formed in the coating.

The metal surface treatment liquid contains at least a blocked isocyanate (A) and an organic resin (B).
Hereinafter, various components contained in the metal surface treatment liquid will be described in detail, and then the surface-treated metal material and the manufacturing method thereof will be described in detail.

<Block isocyanate (A)>
The metal surface treatment liquid contains a blocked isocyanate (A) having an isocyanate group (blocked isocyanate group) blocked with a blocking agent, and further having an isocyanurate structure and a polyalkyleneoxy chain.
The blocked isocyanate is a product obtained by reacting an isocyanate group of an isocyanate compound with a blocking agent, and when heated, the protecting group (residue of the blocking agent) is dissociated to regenerate the isocyanate group. The blocked isocyanate having a lower dissociation temperature regenerates the isocyanate group at a relatively low temperature. The regenerated isocyanate group undergoes a crosslinking reaction with a later-described organic resin (B) having a predetermined functional group to form a bond.

The type of the blocking agent used for blocking (protecting) the isocyanate group is not particularly limited, and usually a compound having one active hydrogen in the molecule is preferably used.
For example, phenol blocking agents (for example, phenol, cresol), lactam blocking agents (for example, caprolactam, valerolactam), oxime blocking agents (for example, formamide oxime, acetamide oxime, methyl ethyl ketoxime), active methylene blocking agents ( For example, diethyl malonate, dimethyl malonate), alcohol-based blocking agent (for example, methanol, ethanol, ethylene glycol monobutyl ether), pyrazole-based blocking agent (for example, 3,5-dimethylpyrazole), mercaptan-based blocking agent (for example, Butyl mercaptan), acid amide blocking agents (eg acetanilide, acetic acid amide), imidazole blocking agents (eg imidazole), amine blocking agents (eg diphenyl) Min, aniline), imine block agent (eg, ethyleneimine), urea block agent (eg, urea, thiourea), oxime block agent, active methylene block agent, and pyrazole block agent. Preferably mentioned.
Among these, a 1,3-dicarbonyl compound or a nitrogen-containing cyclic compound is more preferable.
As the blocking agent, a blocking agent having an electron-withdrawing group such as malonates and pyrazoles is suitable and has an effect of lowering the dissociation temperature.
All isocyanate groups may be blocked with one blocking agent, or two or more blocking agents may be used in combination.

  The dissociation temperature of the blocked isocyanate (A) (the temperature at which the blocked isocyanate group is dissociated) is not particularly limited, but it is often 60 to 180 ° C. From the viewpoint of ease of handling, alkali resistance, and coating film adhesion. 80 to 120 ° C is preferable.

The content of the isocyanate group blocked by the blocking agent in the blocked isocyanate (A) is not particularly limited, but the content of the effective isocyanate group in the blocked isocyanate (A) is the corrosion resistance, processing resistance, chemical resistance, coating 0.5 to 10% by mass in the total mass of the blocked isocyanate (A) is that the film adhesion and the post-coating corrosion resistance are more excellent (hereinafter simply referred to as “the effect of the present invention is more excellent”). Preferably, 1 to 7% by mass is more preferable.
In addition, content of an effective isocyanate group shows content of the isocyanate group after dissociating the blocking group which blocks an isocyanate group from a blocked isocyanate group in blocked isocyanate (A).
The content (concentration) of the effective isocyanate group is specified by an isocyanate equivalent, and is measured according to the method specified in JIS K1603-1. Isocyanate equivalent is the number of grams of blocked isocyanate (A) containing 1 g equivalent of isocyanate groups. The isocyanate equivalent is preferably 150 to 5000, more preferably 300 to 4500, and still more preferably 400 to 4000.

  The blocked isocyanate (A) has an isocyanurate structure (isocyanurate ring structure). The isocyanurate structure is a structure represented by the following formula (X). * Represents a binding position.

The isocyanurate structure is obtained by cyclization and trimerization of isocyanate groups of various diisocyanates or triisocyanates.
Examples of the diisocyanate include 1,4-tetramethylene diisocyanate, ethyl (2,6-diisocyanate) hexanoate, 1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, 2,2,4- or 2,4,4. Aliphatic diisocyanates such as trimethylhexamethylene diisocyanate; 1,3- or 1,4-bis (isocyanate methylcyclohexane), 1,3- or 1,4-diisocyanate cyclohexane, 3-isocyanate-methyl-3,5,5 An alicyclic diisocyanate such as trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4′-diisocyanate, 2,5- or 2,6-diisocyanate methylnorbornane; m- or p-phenylene diisocyanate Anate, tolylene-2,4- or 2,6-diisocyanate, diphenylmethane-4,4′-diisocyanate, 1,3-bis (2-isocyanate 2-propyl) benzene, naphthalene-1,5-diisocyanate, diphenyl-4 , 4′-diisocyanate, 4,4′-diisocyanate 3,3′-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate and the like. .
Examples of the triisocyanate include aliphatic triisocyanates such as 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate 4-isocyanate methyloctane, 2-isocyanatoethyl (2,6-diisocyanate) hexanoate; Examples include alicyclic triisocyanates such as 5- or 2,6-diisocyanate methyl-2-isocyanatopropyl norbornane; aromatic triisocyanates such as triphenylmethane triisocyanate and tris (isocyanatephenyl) thiophosphate.
The number of isocyanurate structures contained in the blocked isocyanate (A) is not particularly limited, but 1 to 10 is preferable and 1 to 4 is more preferable in that the effect of the present invention is more excellent.

The blocked isocyanate (A) has a polyalkyleneoxy chain (for example, a polyethyleneoxy chain, a polypropyleneoxy chain).
The polyalkyleneoxy chain is a chain having a structural unit (repeating unit) represented by the formula (2).
Formula (2)-(LO) _n-
In said formula (2), L represents an alkylene group. The number of carbon atoms contained in the alkylene group is not particularly limited, but 2 to 10 is preferable and 2 to 4 is more preferable in that the effect of the present invention is more excellent.
The number of structural units (repeating units) represented by n is not particularly limited, but is preferably 2 to 1000 (preferably an integer of 2 to 1000) and more preferably 5 to 400 in terms of more excellent effects of the present invention. 10 to 200 are more preferable.
The molecular weight of the polyalkyleneoxy chain is not particularly limited, but is preferably from 100 to 10,000, more preferably from 200 to 5,000, from the viewpoint that the effect of the present invention is more excellent.
The content of the polyalkyleneoxy chain in the blocked isocyanate (A) is not particularly limited, but 10 to 70% by mass is preferable in the total mass of the blocked isocyanate (A) in terms of more excellent effects of the present invention. The mass% is more preferable.

The weight average molecular weight of the blocked isocyanate (A) is not particularly limited, but is often 300 to 20000, is excellent in handleability, and is more excellent in the effects of the present invention, preferably 400 to 15000, more preferably 1000 to 7000. .
The weight average molecular weight of the blocked isocyanate (A) affects the physical properties of the film to be formed. In particular, the weight average molecular weight of the blocked isocyanate (A) is preferably a high molecular weight (preferably, a weight average molecular weight of 400 to 15000) from the viewpoint of imparting excellent elasticity and strength to the film. Excellent elasticity and hardness not only provide mechanical resistance such as chemical resistance such as chemical resistance, but also mechanical resistance such as scratch resistance and abrasion resistance to the film. Also effective. The film thus obtained effectively acts on the adhesion to the metal material due to the high polarity of the blocked isocyanate (A) itself.

The blocked isocyanate (A) is preferably a self-emulsifying type blocked isocyanate. The self-emulsifying type blocked isocyanate intends that the compound itself has an affinity for water and can be emulsified and dispersed in water.
When the blocked isocyanate (A) is self-emulsified in the metal surface treatment liquid described later, the particle size of the blocked isocyanate (A) particles in the metal surface treatment liquid is 0.00 in that the effect of the present invention is more excellent. 01-1.0 micrometer is preferable and 0.05-0.5 micrometer is more preferable.

(Preferred embodiment)
A preferred embodiment of the blocked isocyanate (A) is an embodiment having a structural unit represented by the formula (1) and a structural unit represented by the above formula (2) in that the effect of the present invention is more excellent. It is done. * Represents a binding position.

In formula (1), X represents a bivalent hydrocarbon group each independently.
The number of carbon atoms contained in the divalent hydrocarbon group is not particularly limited, and is preferably 1 to 20, more preferably 2 to 20, and even more preferably 4 to 12 in terms of more excellent effects of the present invention.
Examples of the divalent hydrocarbon group include a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, or a combination thereof. The divalent aliphatic hydrocarbon group may be linear, branched or cyclic. The cyclic may be either monocyclic or polycyclic, and examples of the monocyclic aliphatic hydrocarbon group include cyclohexanediyl. Examples of the polycyclic aliphatic hydrocarbon group include adamantanediyl group and norbornanediyl group. Etc.
Among these, as the divalent hydrocarbon group, an alkylene group having 1 to 6 carbon atoms, an aliphatic six-membered ring group in which an alkyl group may be substituted, or xylylene in which an alkyl group may be substituted Preferred are groups and the like.

R ₁ represents a residue of the blocking agent. The residue of the blocking agent means a residue obtained by removing a hydrogen atom from a blocking agent that can react with an isocyanate group. The kind of blocking agent is as having mentioned above.
Of these, an alkylamino group having 3 to 8 carbon atoms, a 1,3-dicarbonyl group having 2 to 8 carbon atoms, or a pyrazole group having 2 to 8 carbon atoms is preferable.

  The number of structural units represented by the formula (1) in the blocked isocyanate (A) is not particularly limited, but is the same as the number of the isocyanurate structures described above.

  The production method of the blocked isocyanate (A) is not particularly limited and a known method is adopted. For example, a polyisocyanate having an isocyanurate structure is produced by reacting a polyisocyanate such as diisocyanate, and then a blocking agent. Is added to protect a part of the isocyanate group, and a polyalkyleneoxy compound is further added. The polyalkyleneoxy compound has a structural unit (repeating unit) represented by the above formula (2) and has a group capable of reacting with an isocyanate group such as a hydroxy group at the terminal (preferably both terminals). A compound.

When synthesizing a polyisocyanate having an isocyanurate structure, a catalyst (for example, a basic catalyst) may be used as necessary. Examples of catalysts include tetraalkylammonium hydroxide, alkylcarboxylic acid such as alkyl metal salts such as tin, zinc and lead, metal alcoholates such as sodium and potassium, and aminosilyl group-containing compounds such as hexamethyldisilazane. And Mannich bases, combined use of tertiary amines and epoxy compounds, and phosphorus compounds such as tributylphosphine. These may use only 1 type or may use 2 or more types together.
In addition, when a basic catalyst is used as a catalyst, it is preferable to neutralize with an acidic compound as needed. An acidic compound may use only 1 type or may use 2 or more types together.

<Organic resin (B)>
The metal surface treatment liquid contains an organic resin (B) having at least one functional group selected from the group consisting of a hydroxy group, an amino group, a sulfo group, and a carboxy group.
The organic resin (B) includes at least one functional group selected from the group consisting of a hydroxy group, an amino group, a sulfo group, and a carboxy group, and the amino group is more advantageous in that the effect of the present invention is more excellent. Or a carboxy group is preferable.
The type of resin (resin structure) of the organic resin (B) is not particularly limited as long as it has the functional group. For example, an epoxy resin, a urethane resin, a phenol resin, or an acrylic resin having the functional group. An acrylic-ethylene copolymer, an acrylic-styrene copolymer, an alkyd resin, a polyester resin, or the like can be used. Among these, an aqueous organic resin that can be dispersed in an aqueous medium is preferable.

Specific examples of the organic resin (B) include, for example, aromatic epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, modified polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl. Aliphatic epoxy resins such as ether-modified products are exemplified. These epoxy resins may be cationized by introduction of an amino group, anionized by introduction of a carboxy group, or nonionic by introduction of a nonionic group such as ethylene oxide.
Similarly, the cationic urethane resin is preferably cationized, anionized or nonionic by introducing at least one group of an amino group, a carboxy group and an ethylene oxide group into the resin.
As a monomer constituting the urethane resin, both a yellowing isocyanate and a non-yellowing isocyanate can be used. The polyol species may have both an aromatic structure and an aliphatic structure.
Similarly, the polyester resin is preferably cationized, anionized, or nonionic by introducing at least one group of an amino group, a carboxy group, and an ethylene oxide group. In addition, there is no restriction | limiting in the monomer which comprises resin.
Examples of the phenol resin include resins having a main structure such as novolac type phenol, resol type phenol, and polyvinyl phenol. In aqueous formation, it can be cationized, anionized, or nonionic by introducing at least one group of an amino group, a carboxy group and an ethylene oxide group.
Similarly, the acrylic resin can be cationized, anionized, non-ionized and water-based by introducing at least one of an amino group, a carboxy group and an ethylene oxide group. In addition, there is no restriction | limiting in the monomer which comprises resin.
The organic resin (B) is preferably water-based by a self-emulsification method, but may be water-based using a cationic surfactant, a nonionic surfactant, an anionic surfactant or a reactive emulsifier. . Any of these may be used alone or in combination of two or more.
Various organic resins (B) may be graft-modified. The hydroxyl value of the organic resin (B) is preferably 1 to 1000 mgKOH / g. Moreover, as an amine value of organic resin (B), it is preferable that it is 1-800 mgKOH / g. Moreover, it is preferable that it is 1-100 mgKOH / g as an acid value of organic resin (B).

<Other optional components>
The metal surface treatment liquid may contain components other than the blocked isocyanate (A) and the organic resin (B). Hereinafter, the optional components will be described in detail.

(Metal compound (C))
The metal surface treatment liquid is at least selected from the group consisting of zirconium, titanium, vanadium, cerium, molybdenum, cobalt, nickel, magnesium, calcium, cerium, zinc, niobium, yttrium, aluminum, tungsten, chromium, and barium. A metal compound (C) containing one kind of element may be contained. These compounds are effective for improving the corrosion resistance of the surface-treated metal material, act as a dissociation catalyst for the blocked isocyanate group, and further as a reaction promoter for the isocyanate group, and affect the properties of the film in the surface-treated metal material.

  Examples of the zirconium compound (compound containing zirconium element) include inorganic acid salts such as zirconium carbonate, chloride, nitrate, and sulfate, zirconium oxide and organic acid salts of zirconium, zirconium tetraisopropoxide, diiso Organic zirconium compounds such as zirconium alkoxides such as propoxyzirconium diacetylacetonate and diisopropoxyzirconium ditriethanolaminate, zirconium tetraacetylacetonate and chelate complexes containing zirconium atoms can be used. Of these, ammonium zirconium carbonate or zirconium hydrofluoric acid or a salt thereof is preferable in that the effect of the present invention is more excellent.

  As a titanium compound (compound containing a titanium element), for example, titanium alkoxide, a chelate complex containing a titanium atom, an inorganic salt of titanium, an organic acid salt, and an organic titanium compound are preferable.

  As the vanadium compound (compound containing a vanadium element), for example, a vanadium alkoxide, a chelate complex containing vanadium, an inorganic salt of vanadium, an organic salt, and an oxide are preferable. Specifically, vanadium oxyacetylacetonate, metavanadate, Sodium metavanadate, potassium metavanadate, ammonium metavanadate, vanadium bisacetylacetonate, vanadyl diacetylacetonate, vanadium pentoxide, vanadium trioxide, vanadium fluoride, vanadium phosphate, vanadium sulfate, vanadium oxalate, vanadium oxytriiso Examples thereof include propoxide, vanadium oxytributoxide, vanadium oxytriisobutoxide, vanadium oxytriethanolamate and the like.

  As a cerium compound (compound containing a cerium element), for example, a cerium alkoxide, a chelate complex containing cerium, an inorganic salt, an organic salt and an oxide of cerium are preferable.

  As the molybdenum compound (compound containing molybdenum element), for example, molybdenum alkoxide, a chelate complex containing molybdenum, molybdenum inorganic salt, organic salt and oxide are preferable.

  As the cobalt compound (compound containing cobalt element), for example, cobalt alkoxide, chelate complex containing cobalt, cobalt inorganic salt, organic salt and oxide are preferable.

  As the nickel compound (compound containing nickel element), for example, nickel alkoxide, chelate complex containing nickel, nickel inorganic salt, organic salt and oxide are preferable.

  As a magnesium compound (compound containing a magnesium element), for example, magnesium alkoxide, a chelate complex containing magnesium, an inorganic salt, an organic salt and an oxide of magnesium are preferable.

  Examples of the calcium compound (compound containing calcium element) include calcium carbonate, calcium phosphate, calcium nitrate, and calcium sulfate.

  Examples of the cerium compound (compound containing a cerium element) include cerium oxide, cerium acetate, cerium (III) or (IV) nitrate, cerium ammonium nitrate, cerium sulfate, and cerium chloride.

  Examples of the zinc compound (compound containing zinc element) include zinc carbonate, zinc phosphate, zinc nitrate, zinc sulfate, zinc acetate, zinc fluoride, zinc oxide, zinc chloride, zinc tetraethylate, zinc tetrapropylate, Examples thereof include zinc tetrabutyrate, zinc tetraacetylacetonate, zinc monoacetylacetonate, and zinc claurate.

  As the niobium compound (compound containing niobium element), for example, niobium alkoxides, chelate complexes containing niobium, niobium inorganic salts, organic salts and oxides are preferable. Specifically, niobium oxide, niobium hydroxide, niobium nitrate Sodium niobate, calcium niobate, magnesium niobate, niobic acid, niobium fluoride, niobium chloride, sodium metaniobate, magnesium niobium oxide, niobium pentaethylate, niobium pentabutyrate and the like.

  As the yttrium compound (compound containing an yttrium element), for example, yttrium alkoxide, a chelate complex containing yttrium, an inorganic salt of yttrium, an organic salt, and an oxide are preferable.

  As an aluminum compound (compound containing an aluminum element), for example, an aluminum alkoxide, a chelate complex containing aluminum, an inorganic salt, an organic salt, and an oxide of aluminum are preferable.

  As a tungsten compound (compound containing a tungsten element), for example, vanadium alkoxide, a chelate complex containing tungsten, an inorganic salt, an organic salt, and an oxide of tungsten are preferable.

  Examples of the chromium compound (compound containing chromium element) include chromic acid, dichromic acid, chromium carbonate, chromium chloride, chromium phosphate, chromium nitrate, chromium fluoride, chromium sulfate, chromium acetylacetonate, strontium chromate, etc. Is mentioned.

  Examples of the barium compound (compound containing a barium element) include barium nitrate, barium carbonate, and barium oxide.

(Phosphorus-containing compound (D))
The metal surface treatment liquid includes at least one phosphorus-containing compound selected from the group consisting of inorganic phosphoric acid, inorganic phosphate, organic phosphoric acid, organic phosphate, organic phosphonic acid, and organic phosphonate ( D) may be included. These compounds easily form multivalent ions and can interact (for example, ionic bonds) with the coexisting polar group. That is, the phosphorus-containing compound (D) acts as a pseudo cross-linking point in the film, thereby affecting the properties of the film formed from the metal surface treatment liquid. In addition, the metal compound (C) mentioned above is not contained in a phosphorus containing compound (D).
Examples of inorganic phosphoric acid and salts thereof include phosphoric acid (orthophosphoric acid), phosphorous acid, triphosphoric acid, hypophosphorous acid, monophosphoric acid such as hypophosphoric acid, monophosphoric acid derivatives and salts, metaphosphoric acid, tripolyphosphoric acid, Examples thereof include condensed phosphoric acids such as tetraphosphoric acid and hexaphosphoric acid, derivatives and salts of condensed phosphoric acids, and the like.
Examples of the organic phosphoric acid and salts thereof include alkyl phosphoric acid, phosphoric acid monoester (for example, monododecyl dihydrogen phosphate, monotridecyl dihydrogen phosphate, etc.) and salts thereof, phosphoric acid diester (for example, didodecyl hydrogen phosphate, phosphorous Acid ditridecyl hydrogen and the like) and salts thereof. Specific examples of the organic phosphoric acid include compounds represented by R ₁₀ O—P (═O) (OR ₁₁ ) (OR ₁₂ ). R ₁₀ represents an organic group, and R ₁₁ and R ₁₂ each independently represent a hydrogen atom or an organic group. Examples of the organic group include a hydrocarbon group (for example, an alkyl group, an aryl group, or a group obtained by combining these).
Examples of the organic phosphonic acid and salts thereof include hydroxyethylidene diphosphonic acid, aminotri (methylenephosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, ethylenediamine-N, N, N ′, N′-tetra ( Methylenephosphonic acid), hexamethylenediamine-N, N, N ′, N′-tetra (methylenephosphonic acid), diethylenetriamine-N, N, N ′, N ″, N ″ -penta (methylenephosphonic acid), Examples include 2-phosphonobutane-1,2,4-tricarboxylic acid and salts thereof. Specific examples of the organic phosphonic acid include compounds represented by R ₁₀ —P (═O) (OR ₁₁ ) (OR ₁₂ ). R ₁₀ represents an organic group, and R ₁₁ and R ₁₂ each independently represent a hydrogen atom or an organic group. Examples of the organic group include a hydrocarbon group (for example, an alkyl group, an aryl group, or a group obtained by combining these).
In addition, although it does not restrict | limit especially as salts, such as inorganic phosphate (salt of inorganic phosphoric acid), organic phosphate (salt of organic phosphoric acid), and organic phosphonate (salt of organic phosphonic acid), For example, alkali Mention may be made of metal salts, ammonium salts and amine salts. Examples of the alkali metal ions constituting the alkali metal salt include lithium ions, sodium ions, and potassium ions. In addition, the amine constituting the amine salt is not particularly limited. For example, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine; dimethylethanolamine, diethylethanol Monoalkyl represented by amine, alkanolalkylamine such as 2-amino-2-methyl-propanolamine; chemical formula: R ¹ NH ₂ (wherein R ¹ represents a hydrocarbon group having 8 to 20 carbon atoms) Examples include primary amines; alkyldiaminopropane represented by the chemical formula: R ² NH (CH ₂ ) ₃ NH ₂ (wherein R ² represents a hydrocarbon group having 5 to 17 carbon atoms).
Among these, inorganic phosphoric acid, inorganic phosphate, organic phosphonic acid, or organic phosphonate is preferred in terms of more excellent effects of the present invention, and inorganic phosphate (for example, ammonium salt of inorganic phosphoric acid, inorganic An alkali metal salt of phosphoric acid, an amine salt of inorganic phosphoric acid) or an organic phosphonic acid is more preferred, and an ammonium salt of inorganic phosphoric acid (preferably phosphoric acid) or an organic phosphonic acid is particularly preferred.

(Silicon compound (E))
The metal surface treatment liquid may contain a silicon compound (E).
The silicon compound (E) is preferably at least one of inorganic silicon compounds such as alkali metal silicates and colloidal silica, or organic silicon compounds such as silane coupling agents.
Examples of the inorganic silicon compound include lithium silicate, sodium silicate, potassium silicate, and colloidal silica. Examples of the silane coupling agent include vinyltrichlorosilane, vinyltris (2-methoxyethoxysilane), vinyltriethoxysilane, vinyltrimethoxysilane, 3- (methacryloyloxypropyl) trimethoxysilane, 2- (3,4, Epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N- (2-aminoethyl) -3- Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, tetra- or trimethoxysilane (tetramethoxy Silane, methyl trimethoxy silane, ethyl trimethoxy silane, n- propyl trimethoxysilane and the like) and the like. Moreover, a glycidyl group-containing partial condensate obtained by a demethanol reaction of tetra or trimethoxysilane and glycidol can also be used.

(Inorganic compound (F))
The metal surface treatment liquid may contain an inorganic compound (F) containing at least one element selected from the group consisting of lithium, sodium, and potassium. The inorganic compound (F) does not include the above-described metal compound (C), phosphorus-containing compound (D), and silicon compound (E).
Specific examples of the inorganic compound (F) include hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, nitrates such as lithium nitrate, fluorides such as sodium fluoride, sulfates such as sodium sulfate, and the like. Can be mentioned.

(Dicarboxylic acid diester (G))
The metal surface treatment liquid may contain a dicarboxylic acid diester (G). These act as a film-forming aid for forming a uniform film.
Specific examples of the dicarboxylic acid diester (G) include succinic acid diesters such as diethoxyethyl succinate and dioctyl succinate, adipic acid diesters such as diisopropyl adipate, diisobutyl adipate and diethoxyethyl adipate, diethyl sebacate, Examples thereof include sebacic acid diesters such as diisopropyl sebacate and dioctyl sebacate.

(solvent)
The metal surface treatment liquid may contain water as a solvent. Moreover, the organic solvent may be contained so that it may mention later.

(Other ingredients)
In the metal surface treatment solution, in order to promote the dissociation of the blocked isocyanate (A) or the reaction between the isocyanate group dissociated from the blocking agent and the functional group in the organic resin (B), an acidic catalyst ( For example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid), basic catalysts (eg, ammonia, trimethylamine, triethylamine), or metal catalysts can be added.
Metal surface treatment solutions include organic solvents that improve film-forming properties and film drying properties, surfactants that improve wettability, thickeners to adjust the coating amount, antifoaming agents that suppress foaming, welding An electroconductive substance for improving the property and a coloring pigment for improving the design can be blended within a range not impairing the liquid stability of the metal surface treatment liquid and the effect of the present invention.

<Metal surface treatment liquid>
The metal surface treatment liquid contains the various components described above.
The content of the blocked isocyanate (A) in the metal surface treatment liquid is not particularly limited, but the concentration of the effective isocyanate group of the blocked isocyanate (A) in the metal surface treatment liquid is 0.00 in that the effect of the present invention is more excellent. It is preferably 01 to 20 g / L, more preferably 0.01 to 15 g / L, and still more preferably 0.05 to 10 g / L.
The content of the organic resin (B) in the metal surface treatment liquid is not particularly limited, but is preferably 5 to 100 g / L and more preferably 10 to 100 g / L in terms of more excellent effects of the present invention. More preferably, it is 15-90 g / L.
The mass content ratio of the blocked isocyanate (A) and the organic resin (B) in the metal surface treatment liquid is not particularly limited, but the concentration of the effective isocyanate group in the blocked isocyanate (A) is more excellent in the effect of the present invention. Ratio of a (g / L) to the concentration b (g / L) of the functional group selected from the group consisting of the above-mentioned hydroxy group, amino group, sulfo group and carboxy group in the organic resin (B) ( The effective isocyanate group concentration a / functional group concentration b) is preferably 0.001 to 30.0, more preferably 0.01 to 30, and further preferably 0.5 to 30. 1.0 to 15 is particularly preferable, and 2.5 to 10 is most preferable.
The concentration (g / L) of the effective isocyanate group represents the amount (g) of the effective isocyanate group in the metal surface treatment liquid (1 L), and the concentration (g / L) of the functional group represents the metal surface treatment liquid (g / L). 1L) represents the amount (g) of the functional group in 1L).

When the metal compound (C) is contained in the metal surface treatment liquid, the content of the metal compound (C) in the metal surface treatment liquid is not particularly limited, but is 0.1 to 50 g in that the effect of the present invention is more excellent. / L is preferable, and 0.3 to 10 g / L is more preferable.
When the phosphorus-containing compound (D) is contained in the metal surface treatment liquid, the content of the phosphorus-containing compound (D) in the metal surface treatment liquid is not particularly limited, but is 0.1 in that the effect of the present invention is more excellent. It is preferably ˜50 g / L, more preferably 0.2 to 30 g / L, and still more preferably 0.3 to 10 g / L.
When the metal surface treatment liquid contains a silicon compound (E), the content of the silicon compound (E) in the metal surface treatment liquid is not particularly limited, but is 0.1 to 50 g in that the effect of the present invention is more excellent. / L, more preferably 0.2 to 30 g / L, and still more preferably 0.3 to 10 g / L.
When the metal surface treatment liquid contains an inorganic compound (F), the content of the inorganic compound (F) in the metal surface treatment liquid is not particularly limited, but is 0.1 to 50 g in that the effect of the present invention is more excellent. / L, and more preferably 0.5 to 50 g / L.
When the dicarboxylic acid diester (G) is contained in the metal surface treatment liquid, the content of the dicarboxylic acid diester (G) in the metal surface treatment liquid is not particularly limited, but is 0.01 because the effect of the present invention is more excellent. It is preferably ˜50 g / L, and more preferably 0.05 to 10 g / L.

When the metal surface treatment liquid contains the metal compound (C), the mass ratio (A / C) of the blocked isocyanate (A) to the metal compound (C) in the metal surface treatment liquid is not particularly limited, but the effect of the present invention. Is more preferable, 0.1 to 50 is preferable, 0.1 to 25 is more preferable, and 0.1 to 10 is more preferable.
When the phosphorus-containing compound (D) is contained in the metal surface treatment liquid, the mass ratio (A / D) of the blocked isocyanate (A) and the phosphorus-containing compound (D) in the metal surface treatment liquid is not particularly limited. 0.1 to 50 is preferable, 0.2 to 30 is more preferable, 0.3 to 10 is more preferable, and 0.5 to 10 is particularly preferable.
When the metal surface treatment liquid contains a silicon compound (E), the mass ratio (A / E) of the blocked isocyanate (A) and the silicon compound (E) in the metal surface treatment liquid is not particularly limited, but the effect of the present invention. Is more preferable, and 0.1-50 is preferable and 0.2-30 is more preferable.
When the metal surface treatment liquid contains an inorganic compound (F), the mass ratio (A / F) of the blocked isocyanate (A) and the inorganic compound (F) in the metal surface treatment liquid is not particularly limited, but the effect of the present invention. Is more preferable, and 0.1-50 is preferable and 0.5-50 is more preferable.
When the dicarboxylic acid diester (G) is contained in the metal surface treatment liquid, the mass ratio (A / G) of the blocked isocyanate (A) and the dicarboxylic acid diester (G) in the metal surface treatment liquid is not particularly limited. 5 to 100 is preferable in that the effect is more excellent.

The pH of the metal surface treatment solution is not particularly limited as long as the effects of the present invention can be achieved, but is preferably in the range of pH 3 to 11 in terms of more excellent effects of the present invention.
Although there is no restriction | limiting in particular about solid content concentration of a metal surface treatment liquid, as long as the effect of this invention can be achieved, It is preferable that it is the range of 1-40 mass% at the point which the effect of this invention is more excellent.

<Method for producing surface-treated metal material>
The method for producing the surface-treated metal material using the above-described metal surface treatment liquid is not particularly limited, but usually, the above-described metal surface treatment liquid is brought into contact with the surface of the metal material and dried by heating to form a film on the metal material. Forming.
Below, the metal material which is a to-be-processed object is explained in full detail first, and the procedure of the post process is explained in full detail.

(Metal material)
The type of the metal material is not particularly limited, and cold-rolled steel sheet, hot-rolled steel sheet, galvanized steel sheet, aluminum-containing galvanized steel sheet, electrogalvanized steel sheet, alloyed galvanized steel sheet, zinc-nickel plated steel sheet, alloy steel sheet and plated steel sheet; Generally well-known metal materials, such as metal plates other than steel plates, such as an aluminum plate, a copper plate, a titanium plate, and a magnesium plate, can be used. Particularly suitable metal materials are galvanized steel sheets such as galvanized steel sheets, aluminum-containing galvanized steel sheets, electrogalvanized steel sheets, alloyed galvanized steel sheets, zinc nickel plated steel sheets, and vapor-deposited galvanized steel sheets.

Prior to the treatment with the metal surface treatment liquid, it is not essential, but in order to remove the oil and dirt adhering to the metal material that is the object to be treated, alkali washing with a degreasing agent, hot water washing, pickling, solvent washing, etc. are usually performed. Combined as appropriate.
Moreover, although it is usually unnecessary, before the treatment with the metal surface treatment liquid, a ground treatment can be applied for the purpose of further improving the corrosion resistance of the metal material and the adhesion between the film and the metal material. The method for the base treatment is not particularly limited, and examples thereof include surface adjustment treatment for attaching a metal such as Fe, Co, Ni, Cu, Zn, Mn, Zr, Ti, or V, and chemical conversion treatment.
In any of the above treatments, it is preferable to wash with water so that the treatment liquid does not remain on the surface of the metal material.

(procedure)
The method for contacting the metal surface treatment liquid with the metal material is not particularly limited, and examples thereof include coating methods such as a roll coater method, a dipping method, a spray method, and a bar coating method.
Moreover, there is no restriction | limiting in particular about the process liquid temperature at the time of contact, However, 10-60 degreeC is preferable and 15-40 degreeC is more preferable.
Further, after bringing the metal material into contact with the metal surface treatment liquid, the metal material is subjected to heat drying treatment. There is no restriction | limiting in particular as a heating-drying method, A dryer, a hot air furnace, a high frequency induction heating furnace, an infrared furnace etc. are mentioned. In order to enhance the coating effect by promoting curing and crosslinking of the blocked isocyanate (A) and the organic resin (B), heat drying with a hot air furnace, an induction heating furnace, an electric furnace or the like is preferable. The heating and drying temperature is not particularly limited, but the ultimate metal material temperature during drying is preferably 50 to 250 ° C, and more preferably 70 to 220 ° C.

By performing the above treatment, a surface-treated metal material having a metal material and a film disposed on the surface thereof is obtained.
The coating amount (film mass) of the film is not particularly limited, and is preferably 0.05 to 10.0 g / m ² , more preferably 0.1 to 8.0 g / m ^{2 in} terms of more excellent effects of the present invention. 0.1 to 5.0 g / m ² is more preferable.

The basic physical properties of the film are usually measured by a DMA (Dynamic Viscoelastic Device) and obtained as a storage elastic modulus and a loss elastic modulus. The storage elastic modulus represents an elastic component that reacts instantaneously to a given stress like a spring, while the loss elastic modulus represents a viscous component that reacts with a delay to the given stress. That is, the storage elastic modulus is a component that directly affects the strength of the film, and a film having a higher storage elastic modulus can be said to be a hard film. The loss elastic modulus is a component representing softness, and a film having a high loss elastic modulus can be said to be a softer film. The temperature at which the loss modulus reaches a maximum value is indicated by the maximum loss tangent Tanδ. If this temperature is too high, the film is brittle, while if it is too low, the film becomes soft.
The storage elastic modulus at room temperature of the film is preferably 0.1 to 5 GPa, more preferably 0.2 to 4 GPa, and 0.5 to 2 GPa in that the effect of the present invention is more excellent. Is more preferable.
Further, the temperature (Tanδmax) showing the maximum loss tangent Tanδ of the film is preferably 25 to 80 ° C, more preferably 30 to 75 ° C, more preferably 30 to 70 in terms of more excellent effects of the present invention. More preferably, the temperature is C.

A coating film may be formed on the surface of the surface-treated metal material described above (on the film) as necessary. The obtained coating film is excellent in adhesion and corrosion resistance.
The paint may be an aqueous paint or a solvent-based paint. The type of curing is not particularly limited, and may be thermosetting or electron beam curing. Further, on the surface (on the film) of the surface-treated metal material of the present invention, not only a general paint but also a film coat such as a laminate may be performed.

  The above-described surface-treated metal material can be used for various applications, and examples thereof include members for home appliances and building materials.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples of the present invention, but the present invention is not limited to these examples.

<1. Synthesis of blocked isocyanate (A)>
1.1 Preparation of polyisocyanate 300 g of each isocyanate shown in “Isocyanate species” column of Table 1 was added to a reactor equipped with a stirrer (1 L separable flask), and trimethylbenzylammonium · 0.1 g of hydroxide was added. After 4 hours, when the conversion rate of the reaction solution reached 38%, 0.2 g of phosphoric acid was added to stop the reaction.

2.2 Preparation of blocked isocyanate The preparation method of blocked isocyanate is described below. The “polyisocyanate” used in each synthesis example was a polyisocyanate prepared by the above procedure using the isocyanates listed in the “Isocyanate species” column of each synthesis example described in Table 1.
However, in Synthesis Example A10 described below, monomer 1,6-hexamethylene diisocyanate was used.
The blocked isocyanates synthesized in the following synthesis examples were so-called self-emulsifying type blocked isocyanates.

(Synthesis Example A1)
Polyisocyanate (100 g), diethyl malonate (63.5 g) and sodium methoxide (1.0 g) were charged to the reactor and heated at 65-70 ° C. Subsequently, polyethylene glycol (188.4 g) (number of repeating units (n): 22) was added to the reaction solution, the reaction solution temperature was raised to 70 ° C., and held for 5 hours. Thereafter, water (430 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Examples A2, A6)
Polyisocyanate (100 g), 3,5-dimethylpyrazole (28.8 g) and sodium methoxide (1.0 g) were charged to the reactor and heated at 65-70 ° C. Next, polyethylene glycol (188.4 g) was added to the reaction solution, the reaction solution temperature was raised to 70 ° C., and held for 5 hours. Thereafter, water (430 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.
In the production of A2 and A6, the type of polyethylene glycol was changed so that the weight average molecular weight was obtained as shown in Table 1. Specifically, polyethylene glycol (number of repeating units (n): 22) was used in the synthesis of A2, and polyethylene glycol (number of repeating units (n): 180) was used in the synthesis of A6. .

(Synthesis Example A3)
A blocked isocyanate emulsion was prepared according to the same procedure as in Synthesis Example A2 except that polyethylene glycol was changed to polypropylene glycol (number of repeating units (n): 17).

(Synthesis Example 4)
Polyisocyanate (100 g), 3,5-dimethylpyrazole (31.6 g) and sodium methoxide (1.0 g) were charged to the reactor and heated at 65-70 ° C. Next, polyethylene glycol (640 g) (number of repeating units (n): 91) was added to the reaction solution, and the reaction solution temperature was raised to 70 ° C. and held for 5 hours. Thereafter, water (1100 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Example A5)
Polyisocyanate (100 g), 3,5-dimethylpyrazole (26.2 g) and sodium methoxide (1.0 g) were charged to the reactor and heated at 65-70 ° C. Subsequently, polyethylene glycol (136.6 g) (number of repeating units (n): 68) was added to the reaction solution, and the reaction solution temperature was raised to 70 ° C. and held for 5 hours. Thereafter, water (350 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Examples A7 and A8)
A blocked isocyanate emulsion was prepared in the same manner as in Synthesis Example A2 except that 3,5-dimethylpyrazole was changed to methyl ethyl ketoxime or ethylene glycol monobutyl ether.

(Synthesis Example A9)
Polyisocyanate (100 g), 3,5-dimethylpyrazole (26.2 g) and sodium methoxide (1.0 g) were charged to the reactor and heated at 65-70 ° C. Next, polyethylene glycol (3571 g) (the number of repeating units (n): 409) was added to the reaction solution, and the reaction solution temperature was raised to 70 ° C. and held for 5 hours. Thereafter, water (5600 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Example A10)
Isocyanate (100 g), diethyl malonate (190.5 g) and sodium methoxide (1.0 g) were charged to the reactor and the reaction was heated at 65-70 ° C. Thereafter, water (530 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Example A11)
Polyisocyanate (100 g), diethyl malonate (95.2 g) and sodium methoxide (1.0 g) were charged to the reactor and the reaction was heated at 65-70 ° C. Thereafter, water (290 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

(Synthesis Example A12)
Polyisocyanate (100 g), dimethylpyrazole (75.7 g) and sodium methoxide (1.0 g) were charged to the reactor and the reaction was heated at 65-70 ° C. Thereafter, water (260 g) was added to the reaction solution while stirring the reaction solution to prepare a blocked isocyanate emulsion.

  The weight average molecular weight of the obtained blocked isocyanate was obtained as a weight average molecular weight in terms of polyethylene glycol by determining the relative molecular weight distribution of the blocked isocyanate by GPC (gel permeation chromatography). GPC measurement conditions are as follows.

Measurement model: SC-8010 manufactured by Tosoh Corp. Column: Shodex Ohpak SB-G + Ohpak SB-806MHQ × 2 solution: DMF / 0.06M LiBr / 0.04MH ₃ PO ₃
Temperature: Column thermostat 40 ° C
Flow rate: 0.05 ml / min Concentration: 0.1 wt / Vol%
Injection volume: 50 μl
Solubility: Complete dissolution Pretreatment: 0.45 μm Filter detector: Differential refractometer

A1 to A9 synthesized above contained an isocyanurate structure (structural unit represented by formula (1)) and a polyalkyleneoxy chain (structural unit represented by formula (2)).
A10 did not contain an isocyanurate structure and a polyalkyleneoxy chain, and A11 and A12 did not contain a polyalkyleneoxy chain.
In Table 1 below, in the “polymerization form” column, “trimer” is intended to include an isocyanurate structure, and “monomer” is intended to indicate that the isocyanate is in a monomer state.
“Dissociation temperature” represents the dissociation temperature of a blocked isocyanate group.
“Particle size” represents the particle size of the blocked isocyanate in each blocked isocyanate emulsion.
“Number of alkyleneoxy” represents the number of alkyleneoxy units (n in formula (2)).
“Effective NCO%” intends the content (mass%) of an effective isocyanate group in each blocked isocyanate.

In addition, each symbol in the said table | surface represents the following.
HDI: 1,6-hexamethylene diisocyanate, IPDI: 3-isocyanate-methyl-3,5,5-trimethylcyclohexyl isocyanate, TMXDI: 1,3-bis (2-isocyanate 2-propyl) benzene, TDI: tolylene-2 , 6-diisocyanate, PEG: polyethylene glycol, PPG: polypropylene glycol, DEM: diethyl malonate, DMP: 3,5-dimethylpyrazole, MEKO: methyl ethyl ketoxime, EGB: ethylene glycol monobutyl ether

<2. Preparation of metal surface treatment solution>
Using the blocked isocyanate (A) shown in Table 1, in the combinations and proportions shown in Tables 2 to 4, the blocked isocyanate (A), the organic resin (B), the metal compound (C), the phosphorus-containing compound (D), Preparation of metal surface treatment liquid used in Examples and Comparative Examples by mixing silicon compound (E), inorganic compound (F) and dicarboxylic acid diester (G) in this order and adjusting the concentration with deionized water did.

B1: Epoxy resin (Watersol EFD-5560, DIC) (type of functional group: hydroxy group)
B2: Urethane resin (Hydran COR-70, DIC) (type of functional group: amino group)
B3: Acrylic resin (Watersol S-701, DIC) (Type of functional group: carboxy group)

C1: ammonium zirconium carbonate C2: zirconium hydrofluoric acid

D1: Ammonium phosphate D2: Hydroxyethylidene diphosphonic acid D3: Triethanolamine phosphate

E1: 3-glycidoxypropyltrimethoxysilane

F1: Lithium hydroxide

G1: Diisobutyl adipate

<3. Surface treatment>
Hereinafter, a case where a hot dip galvanized steel sheet, an electrogalvanized steel sheet, or a cold rolled steel sheet is used as a test material will be described in the order of a surface treatment method, an evaluation method, and an evaluation result. The evaluation results are summarized in Tables 2 to 4.
[1. Material]
GI: Hot-dip galvanized steel sheet (plate thickness: 0.8 mm, basis weight: 60 g / m ² )
EG: electrogalvanized steel sheet (plate thickness: 0.8 mm, basis weight: 20 g / m ² )
CRS: Cold-rolled steel sheet (thickness: 0.8 mm)

[2. Surface treatment method]
(1) Degreasing Each material is degreased with Alkali degreasing agent Fine Cleaner E6406 (20 g / L building bath, 60 ° C., 10 seconds spray, spray pressure 0.5 kg / cm ² ) manufactured by Nippon Parkerizing Co., Ltd. 10 seconds.

(2) Coating and drying Each metal surface treatment solution is applied to each material degreased in (1) above by bar coating so that the film mass becomes 1 g / m ² , and dried at 150 ° C. (PMT). A sample was prepared.

[3. Evaluation item]
(1) Corrosion resistance (1-1) Regarding GI and EG For the GI and EG treated plate samples prepared in the examples and comparative examples, the following flat portion and end face portions were subjected to a corrosion resistance test. The evaluation method is as follows.
(Flat part)
Based on the salt spray test method JIS-Z-2371, the white rust generation area ratio after 240 hours of salt spray (the ratio of the white rust generation area to the total area of the flat portion) was determined and evaluated according to the following criteria. About plane part corrosion resistance, (double-circle) -square was set as the pass.
[Evaluation criteria]
◎: White rust generation area ratio 10% or less ○: White rust generation area ratio 10% or more and less than 20% □: White rust generation area ratio 20% or more and less than 30% △: White rust generation area ratio 30% or more and less than 60% × : White rust generation area ratio 60% or more

(End face)
The salt spray test prescribed | regulated to JIS-Z2371 was implemented for 48 hours, the rust width from an end surface was visually evaluated, and it evaluated in accordance with the following references | standards. About end surface part corrosion resistance, (double-circle) was set as the pass.
[Evaluation criteria]
◎: Rust width less than 5 mm ○: Rust width 5 mm or more and less than 7 mm □: Rust width 7 mm or more and less than 8.5 mm Δ: Rust width 8.5 mm or more and less than 10 mm ×: Rust width 10 mm or more

(1-2) Regarding CRS The following corrosion resistance test was performed on the CRS-treated plate samples produced in the examples and comparative examples. The evaluation method is as follows.
(Flat part)
Based on the salt spray test method JIS-Z-2371, the white rust generation area ratio after 72 hours of salt spray (ratio of the white rust generation area to the total area of the flat portion) was determined and evaluated according to the following criteria. For corrosion resistance, ◎ to □ were accepted.
[Evaluation criteria]
◎: White rust generation area ratio 10% or less ○: White rust generation area ratio 10% or more and less than 20% □: White rust generation area ratio 20% or more and less than 30% △: White rust generation area ratio 30% or more and less than 60% × : White rust generation area ratio 60% or more

(2) Processing resistance Both sides of the treated plate sample were drawn at a speed of 100 mm / min while applying a load of 10 kN using a 20 mm × 50 mm flat indenter, and the appearance of the test piece (treated plate sample) was visually observed. Evaluation was made to determine the ratio of the discolored area (the ratio of the discolored area to the area of the drawn portion) and evaluated according to the following criteria. Regarding the processing resistance, ◎ to □ were regarded as acceptable.
[Evaluation criteria]
◎: No change ○: Discolored area ratio more than 0% to 10% or less □: Discolored area ratio more than 10% to 30% or less △: Discolored area ratio more than 30% to 50% or less ×: Discolored area ratio Is over 50%

(3) Chemical resistance (3-1) Alkali resistance A degreasing agent used in the above degreasing was adjusted to 65 ° C. and sprayed on the treated plate sample for 2 minutes. Thereafter, the appearance of the test piece (treated plate sample) was observed with the naked eye and evaluated according to the following criteria. About alkali resistance, (double-circle) was set as the pass.
[Evaluation criteria]
◎: No change ○: Discolored area ratio more than 0% to 10% or less □: Discolored area ratio more than 10% to 30% or less △: Discolored area ratio more than 30% to 50% or less ×: Discolored area ratio More than 50% (3-2) acid resistance The treated plate sample was immersed in a 1% aqueous sulfuric acid solution for 5 hours. Thereafter, the appearance of the test piece (treated plate sample) was observed with the naked eye and evaluated according to the following criteria. For acid resistance, ◎ to □ were accepted.
[Evaluation criteria]
◎: No change ○: Discolored area ratio more than 0% to 10% or less □: Discolored area ratio more than 10% to 30% or less △: Discolored area ratio more than 30% to 50% or less ×: Discolored area ratio Is over 50%

(4) Coating Film Adhesion Each treated plate sample was painted using a melamine alkyd paint (Delicon # 700, manufactured by Dainippon Paint Co., Ltd.). The coating was performed by bar coating. After coating, baking was performed at 140 ° C. for 20 minutes, and a coating film (surface treated product) having a thickness of 25 μm was formed after drying.
Using two plates having the same thickness as the original plate, the coating film (surface treated product) was sandwiched and bent 180 degrees, the folded portion was peeled off, and evaluated according to the following criteria. About coating-film adhesiveness, (double-circle) was set as the pass.
[Evaluation criteria]
◎: No peeling ○: Peeling area is more than 0% and 10% or less □: Peeling area is more than 10% and 30% or less △: Peeling area is more than 30% and 50% or less ×: Peeling area is more than 50%

(5) Corrosion resistance after coating (5-1) Regarding GI and EG The coating film obtained in (4) above is cross-cut with an NT cutter (A300 type, manufactured by NT Corporation), and salt water defined in JIS-Z2371 The spray test was conducted for 480 hours, the rust width from the crosscut was visually evaluated, and evaluated according to the following criteria. As for the corrosion resistance after painting, ◎ to □ were accepted.
[Evaluation criteria]
◎: Rust width less than 5 mm ○: Rust width 5 mm or more and less than 7 mm □: Rust width 7 mm or more and less than 8.5 mm Δ: Rust width 8.5 mm or more and less than 10 mm ×: Rust width 10 mm or more

(5-2) Regarding CSR The coating film obtained in (4) above is subjected to a cross cut with an NT cutter (A300 type, manufactured by NT Corporation), and a salt spray test defined in JIS-Z2371 is carried out for 120 hours. The rust width from the crosscut was visually evaluated and evaluated according to the following criteria. As for the corrosion resistance after painting, ◎ to □ were accepted.
[Evaluation criteria]
◎: Rust width less than 3 mm ○: Rust width 3 mm to less than 6 mm □: Rust width 6 mm to less than 7.5 mm Δ: Rust width 7.5 mm to less than 10 mm ×: Rust width 10 mm or more

Table 2 below shows the results using hot dip galvanized steel sheets (GI) as test materials, Table 3 shows the results using electrogalvanized steel sheets (EG) as test materials, and Table 4 shows cold results as test materials. The result using a rolled steel sheet (CRS) is represented.
Moreover, the density | concentration column of blocked isocyanate (A) in Tables 2-4 represents the density | concentration (g / L) of the effective isocyanate group contained in blocked isocyanate (A) in a metal surface treatment liquid. Moreover, the density | concentration column of the organic resin (B) in Tables 2-4 represents the density | concentration (g / L) of the organic resin (B) in a metal surface treatment liquid.
In Tables 2 to 4, “a / b” means the concentration a (g / L) of the effective isocyanate group contained in the blocked isocyanate (A) and the functionality contained in the organic resin (B) in the metal surface treatment liquid. The ratio {a / b} of the group (at least one functional group selected from the group consisting of a hydroxy group, an amino group, a sulfo group, and a carboxy group) with the concentration b (g / L).
In Tables 2 to 4, “A / C” represents the ratio of the mass of the blocked isocyanate (A) to the mass of the metal compound (C), and “A / D” represents the mass of the blocked isocyanate (A) and phosphorus content. The ratio between the mass of the compound (D), “A / E” is the mass ratio of the blocked isocyanate (A) to the mass of the silicon compound (E), and “A / F” is the mass of the blocked isocyanate (A). And “A / G” represents the ratio of the mass of the blocked isocyanate (A) to the mass of the dicarboxylic acid diester (G), respectively.
“Storage elastic modulus” and “Tan δ max” in Table 2 represent temperatures indicating the storage elastic modulus and the maximum loss tangent Tan δ at room temperature of the coatings produced in each Example and each Comparative Example. The “storage modulus” and “Tanδmax” were measured by RSA-G2 (TA instrument).

As can be seen from Tables 2 to 4, it was confirmed that the surface-treated metal material obtained by applying the metal surface treatment liquid of the present invention exhibits various excellent properties.
Especially, from the comparison of Examples A1 to A14, the ratio (a / b) of the concentration of effective isocyanate groups (g / L) / the concentration of functional groups in organic resin (B) (g / L) was 0.01. In the case of -30 (preferably 0.5-30, more preferably 1.0-15), it was confirmed that a more excellent effect was obtained.
Moreover, it was confirmed from the comparison of Example A15-A19 that the more excellent effect is acquired when the dissociation temperature of block isocyanate is 120 degrees C or less.
Moreover, it was confirmed from the comparison with Example A20 and Example A17 that the more excellent effect is acquired in the range whose weight average molecular weights of block isocyanate are 400-15000.
From the comparison of Examples A21 to A26, the content (A / D) of the blocked isocyanate (A) and the phosphorus-containing compound (D) is 0.5 to 50 (preferably 0.2 to 30, more preferably In the case of 0.3 to 10), it was confirmed that a more excellent effect was obtained.
Moreover, it was confirmed from the comparison with Example A24, A28, and A30 that a more excellent effect is acquired when phosphorus containing compound (D) is an ammonium salt of inorganic phosphoric acid or organic phosphonic acid.
On the other hand, it was confirmed that when the metal surface treatment liquid described in the comparative example that does not satisfy the predetermined requirements was used, the desired effect could not be obtained.

Claims (15)

A blocked isocyanate (A) having an isocyanate group blocked by a blocking agent, and further having an isocyanurate structure and a polyalkyleneoxy chain;
A metal surface treatment solution comprising: an organic resin (B) having at least one functional group selected from the group consisting of a hydroxy group, an amino group, a sulfo group, and a carboxy group. The metal surface treatment liquid according to claim 1, wherein the blocked isocyanate (A) has a structural unit represented by the formula (1) and a structural unit represented by the formula (2).
(In formula (1), each X independently represents a divalent hydrocarbon group. R ₁ represents a residue of the blocking agent. * Represents a bonding position.)
Formula (2)-(LO) _n-
(In Formula (2), L represents an alkylene group. N represents 2-1000.)   Furthermore, including at least one phosphorus-containing compound (D) selected from the group consisting of inorganic phosphoric acid, inorganic phosphate, organic phosphoric acid, organic phosphate, organic phosphonic acid, and organic phosphonate, The metal surface treatment liquid according to claim 1 or 2.   The metal surface treatment liquid according to claim 3, wherein the phosphorus-containing compound (D) includes at least one selected from the group consisting of an ammonium salt of inorganic phosphoric acid and an organic phosphonic acid.   The metal surface treatment liquid according to claim 3 or 4, wherein a mass ratio (A / D) of the blocked isocyanate (A) and the phosphorus-containing compound (D) is 0.1 to 50.   And at least one element selected from the group consisting of zirconium, titanium, vanadium, cerium, molybdenum, cobalt, nickel, magnesium, calcium, cerium, zinc, niobium, yttrium, aluminum, tungsten, chromium, and barium. The metal surface treatment liquid of any one of Claims 1-5 containing the metal compound (C) to contain.   The metal surface treatment liquid according to claim 6, wherein the metal compound (C) contains a zirconium element.   The metal surface treatment liquid according to claim 6 or 7, wherein the metal compound (C) is zirconium ammonium carbonate, zirconium hydrofluoric acid or a salt thereof.   Ratio {a / b} of the concentration a (g / L) of the effective isocyanate group contained in the blocked isocyanate (A) and the concentration b (g / L) of the functional group contained in the organic resin (B) The metal surface treatment liquid according to claim 1, wherein is 0.001 to 30.0.   The concentration of an effective isocyanate group contained in the blocked isocyanate (A) is 0.01 to 20 g / L, and the concentration of the organic resin (B) is 5 to 100 g / L. The metal surface treatment liquid according to item 1.   The metal surface treatment liquid according to any one of claims 1 to 10, wherein the blocked isocyanate (A) has a weight average molecular weight of 400 to 15000.   Furthermore, the metal surface treatment liquid of any one of Claims 1-11 containing a silicon compound (E).   Furthermore, the metal surface treatment liquid of any one of Claims 1-12 containing the inorganic compound (F) containing the at least 1 sort (s) of element selected from the group which consists of lithium, sodium, and potassium.   A method for producing a surface-treated metal material, comprising: bringing the metal surface treatment liquid according to any one of claims 1 to 13 into contact with a surface of the metal material, followed by drying by heating to form a film on the metal material.   A surface-treated metal material comprising: a metal material; and a film formed by bringing the metal surface treatment liquid according to any one of claims 1 to 13 into contact with the metal material and drying by heating.