JPH04323400A - Pretreating method for metal surface for electrodeposition coating - Google Patents

Abstract

PURPOSE:To give an excellent anticorrosion to the surface of a metal such as iron and zinc by treating the metal surface with a pretreating agent for coating containing a specified chelate formative resin. CONSTITUTION:A metallic surface is treated by a pretreating agent for coating containing a chelate formative resin. The chelate formative resin forms a stable inner complex salt of five-membered ring or six-membered ring with divalent or trivalent metallic iron, and has at least one multidentate ligand in one molecule having at least one ligand which is capable of being formed by deprotonizing and at least one ligand which has lone pair, excluding the case where the multidentate ligand is a group shown by formula I wherein, R<1> and R<2> may be the same or different and are each a hydrogen atom, a halogen atom, an alkoxylalkyl group such as a nitro group. By this method, lowering of pollution by surface treatment and coating and high-grade anticorrosion can be attained.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a novel pre-painting method for metal surfaces for electrodeposition coating, which has good adhesion between the substrate and the electrodeposition coating and has excellent anti-corrosion properties. The present invention relates to a pretreatment method capable of providing coated materials.

0002

[Prior art and its problems] Pre-treatment for painting metals does not impair the finished appearance of the paint film, and (1) imparts corrosion resistance to the metal surface; (2) improves the adhesion between the metal surface and the paint film. This is done for the purpose of adding functions such as improving the durability of the coating film.

[0003] In the painting of automobile bodies, electrical equipment, etc., a combination of using phosphate treatment as a pre-painting treatment for metals and electrodeposition paint as a primer is widely adopted from the viewpoint of productivity, quality, usage efficiency, etc. There is.

[0004] In this combination, the electrodeposition paint is one of the water-based paints and is a typical low-pollution type paint, and plays a role in environmental conservation and resource saving. On the other hand, regarding phosphate treatment, phosphorus in wastewater from the phosphate treatment process causes eutrophication of water quality, causing water pollution, and it is predicted that there will be a shortage of phosphorus supply in the future. Therefore, there is an urgent need to develop a new paint pretreatment method to replace phosphate treatment.

[0005]

[Means for Solving the Problems] Therefore, the present inventors conducted intensive research in order to develop a novel pre-painting treatment method for metals that is suitable for forming electrodeposited coatings in place of the phosphate treatment method. . As a result, metals can be treated with paint pretreatment agents containing chelate-forming resins with specific polydentate coordination groups that can form stable 5- or 6-membered ring intramolecular complexes with +2- or +3-valent metal ions. The present inventors have discovered that by pre-treating the surface, it is possible to perform a pre-painting treatment that is as suitable for forming an electrodeposited coating as or better than phosphate treatment, and has completed the present invention.

That is, the present invention provides a ligand and a lone pair of electrons that can form a stable 5- or 6-membered ring intramolecular complex salt with a +2- or +3-valent metal ion and that can form an ion by deprotonation. A metal surface is treated with a coating pretreatment agent containing a chelate-forming resin having at least one polydentate coordination group in one molecule, each having at least one ligand. Pre-painting method for metal surfaces for coating (excluding cases where the multidentate coordination group is a group represented by the following formula [1], [2], [3] or [4]) This is what we provide.

[0007]

[Case 2]

(In each formula, R1 and R2 are the same or different and each represents a hydrogen atom, a halogen atom, a nitro group, a nitroso group, a cyano group, a hydrocarbon group having up to 18 carbon atoms, or an alkoxy group having up to 12 carbon atoms) (indicates an alkyl group) The paint pretreatment agent used in the method of the present invention is +2-valent or +
It has at least one ligand that can form a stable 5- or 6-membered ring intramolecular complex salt with a trivalent metal ion, and that can form an ion by deprotonation, and a ligand that has a lone pair of electrons. It is necessary to contain a chelate-forming resin having at least one polydentate coordination group in one molecule.

[0009] The above polydentate group is LHz, +2 valence or +3
When a valent metal ion is represented by Mm+, the following formula must be satisfied in order for the multidentate coordination group to form an intramolecular complex salt with the metal ion.

0010

[Chemical formula 3]

(wherein, [(Mm+)(Lz-)x] represents an intramolecular complex salt, m is 2 or 3, x is an integer from 1 to 3,
z is an integer from 1 to 3, m-xz=0, n is the coordination number of the metal ion Mm+, and coordination number per polydentate group (coordination as a monodentate ligand is number of children) is y, then n
=xy. ) If a specific example of the relationship of the above formula [5] is tabulated, it will be as shown in Table 1 below, for example.

0012

[Table 1]

[0013] Furthermore, in order for the polydentate group to form a stable complex with a metal ion, it is necessary to form a structurally stable 5- or 6-membered ring complex.

Furthermore, in order for the formed complex to exhibit sufficient anticorrosive properties, it is preferable that the following formula is satisfied.

2.303RTlog(KMA)-(-mFEo)
>0 [6] In the formula, R: Gas constant T: Temperature (°K) m: Charge number of metal ion F: Faraday constant Eo: Corrosion potential of metal KMA: In the complex formation reaction formula of the above formula [5] , complex stability constant expressed by the following formula [7] KMA=[[(Mm+)(Lz-)x]]/[Mm
+]・[LHz]x [7] 2.303 RTlog (KMA) in the above formula [6] corresponds to the free energy change due to the complex formation reaction, and -mF
Eo corresponds to the free energy change of corrosion.

In the present invention, the following are representative examples of the above-mentioned multidentate coordination group.

1 A group represented by the following formula [8].

[0018]

[C4]

(In the formula, G represents S or NH, k represents 0 or 1, and R3, R4, R5 and R6 are each the same or different and represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. or R1 , R2 , R3 and R
4 together with the two carbon atoms to which it is attached forms a substituted or unsubstituted o-phenylene group. ) 2 The following formula

[9], [10], [11] or [12]
A group represented by

[0020]

[C5]

(In the formula, R7 and R8 are the same or different and each represents a hydrogen atom, a halogen atom, a nitro group, a nitroso group, a cyano group, a hydrocarbon group having up to 18 carbon atoms, or an alkoxyalkyl group having up to 12 carbon atoms) (indicates the group)
3 A group represented by the following formula [13].

[0022]

[C6]

(wherein, j represents 1 or 2, R3,
R4, R5 and R6 have the same meanings as above. Moreover, R3, R4, R5 and R6, together with the carbon atom to which they are bonded, are substituted or unsubstituted o-
A phenylene group may also be formed. ) 4 A group represented by the following formula [14].

[0024]

[C7]

(In the formula, R9 is a hydrogen atom, and has 1 to 8 carbon atoms.
represents an alkyl group or a carboxyl group. )5 A group represented by the following formula [15].

[0026]

[Chemical formula 8]

(In the formula, R9 has the same meaning as above.) 6 A group represented by the following formula [16].

[0028]

[Chemical formula 9]

(In the formula, R9 has the same meaning as above.) In the polydentate group represented by the above formula [8], R
The alkyl group in 3, R4, R5 and R6 has 1 to 8 carbon atoms, preferably 4 or less, and the alkyl group may be a straight chain or a branched chain, such as methyl group, ethyl group, n-propyl group. group, isopropyl group, n-butyl group, isobutyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, and the like. Also, R
When 1, R2, R3 and R4 are combined with two bonded carbon atoms to form a divalent o-phenylene group, the o-phenylene group has a part of the o-phenylene group as an alkyl group. It may be substituted with a halogen element or the like, or it may be unsubstituted.

Representative examples of the group represented by the above formula [8] include:

[0031]

[Chemical formula 10]

[0032] etc.

The above formula

[9], [10], [11] or [
12], the hydrocarbon groups in R7 and R8 have 18 or less carbon atoms,
Preferably, the carbon number is 5 or less, and includes an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, and the like. Further, the alkoxyalkyl group in R7 and R8 has 12 or less carbon atoms, preferably 5 carbon atoms.
It is as follows.

Specific examples of the alkyl group, alkoxyalkyl group, cycloalkyl group, aralkyl group, and aryl group for R7 and R8 above are shown below.

The alkyl group may be a straight chain or branched chain, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, n-hexyl group, n-hexyl group, etc.
-octyl group, 2-ethylhexyl group, n-dodecyl group and n-octadecyl group; examples of alkoxyalkyl group include 2-methoxyethyl group and 3-methoxypropyl group; examples of cycloalkyl group include cyclopentyl group; group, cyclohexyl group and 3-
Methylcyclohexyl group, etc.; As an aralkyl group,
For example, benzyl group, 4-methylbenzyl group, 4-isopropylbenzyl group, phenethyl group, etc.; examples of the aryl group include phenyl group, diphenyl group, naphthyl group, 4-methylphenyl group, etc.

The above formula

[9], [10], [11] or [
12] is a typical example of the polydentate coordination group represented by

0
037]

[Chemical formula 11]

[0038] etc.

Representative examples of the polydentate group represented by the above formula [13] are:

[0040]

[Chemical formula 12]

[0041] etc.

In the multidentate coordination group represented by the above formula [14], the alkyl group in R9 has 1 to 8 carbon atoms, preferably 4 or less, and the alkyl group may be a straight chain or a branched chain, Examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-hexyl group, n-octyl group, and 2-ethylhexyl group.

Representative examples of the polydentate group represented by the above formula [14] are:

[0044]

[Chemical formula 13]

[0045] etc.

Representative examples of the polydentate group represented by the above formula [15] are:

[0047]

[Chemical formula 14]

[0048] etc.

Representative examples of the polydentate group represented by the above formula [16] include:

[0050]

[Chemical formula 15]

[0051] etc.

These multidentate coordination groups described above form a stable intramolecular complex-type 5- or 6-membered chelate complex with a +2-valent or +3-valent metal ion. Metal ion Mm
A chelate complex formed from + and the above polydentate group,
The ligand that formed an ion by deprotonation of a polydentate group is A-, the ligand with a lone pair of electrons is B, and the ionic valence m, coordination number n, and polydentate coordination of the metal ion. The following is a model showing the coordination number y per group and the deprotonation number z per multidentate coordination group.

[0053]

[Chemical formula 16]

As described above, the polydentate group having a deprotonated ligand binds to +2- and +3-valent metal ions, neutralizes the charge of the metal ion, and increases the coordination of the metal ion. Forms an intramolecular complex with filled positions. Since the formed intramolecular complex salt has neutralized charges, it is difficult for corrosion current to flow when corroding metals, and it is structurally stable because it forms a 5-membered ring or a 6-membered ring.

In the method of the present invention, the chelate-forming resin contained in the paint pretreatment agent has at least one, preferably two or more, and more preferably 3 to 700 polydentate groups in one molecule. It is necessary to have one. When one molecule contains multiple polydentate coordination groups, the resin film becomes three-dimensional when chelate is formed, forming strong chelate bonds and increasing the crosslinking density of the resin film, which improves corrosion resistance. It is more advantageous in terms of

[0056] As a method for obtaining the above-mentioned chelate-forming resin by introducing a multidentate coordination group into the resin, for example, the following method (a) can be used.
Examples include methods of ~(f).

[0057] In order to introduce the multidentate coordination group represented by any of the above formulas [8] to [14] into the resin, for example, a reaction between a polymerizable double bond and an SH group or an NH2 group may be used. Methods (a) to (c) can be mentioned.

(a) A polymerizable double bond is provided at the end or side chain of the resin forming the base portion, and a compound represented by any of the following formulas [17] to [23] is added to this double bond. How to react.

[0059]

[Chemical formula 17]

(In each formula, G, R3, R4, R5,
R6, R7, R8, R9, k and j each have the above meaning. ) (b) An addition reaction product of a compound having a functional group such as a hydroxyl group and a polymerizable double bond and a compound represented by any of the above formulas [17] to [23], and a hydroxyl group in the reaction product. A method of reacting a functional group such as the like with a polymer having a reactive functional group such as an isocyanate group.

(c) A method of adding a compound represented by any one of the above formulas [17] to [23] and a silane compound or resin having an etherified silanol group and a polymerizable double bond. In addition, a compound or resin having a polydentate group represented by any of the formulas [8] to [14] obtained by this method and an etherified silanol group may be partially condensed, or an etherified silanol group may be partially condensed. A method of partial co-condensation with other silane compounds having silanol groups.

[0062] In order to introduce the multidentate coordination group represented by any of formulas [8] to [16] in formulas 1 to 6 above into the resin, the following methods (d) to (f) may be used. Can be done.

(d) Other polymerizable unsaturated compounds that can be copolymerized with a compound having a polydentate coordination group and a polymerizable double bond represented by any of the above formulas [8] to [16]. A method of copolymerizing with monomers.

(e) Addition reaction of a compound having a multidentate coordination group represented by any of the above formulas [8] to [16] and a polymerizable double bond with a resin having a primary amino group or a thiol group. How to do it.

(f) A compound having a multidentate coordination group represented by any of the above formulas [8] to [16] and a reactive group such as an alcoholic hydroxyl group, and a compound having the reactive group such as an isocyanate group or a carboxyl group. A method that utilizes the reaction between a group and a resin that has a reactive group.

In the method (a), the resin having a polymerizable double bond at the terminal or side chain is not particularly limited, and various resins obtained by known methods can be used. For example, glycidyl (meth)acrylate, 3
, 4-epoxycyclohexylmethyl (meth)acrylate, copolymers of epoxy group-containing polymerizable unsaturated monomers such as allyl glycidyl ether, and other polymerizable monomers, epoxy resins at the terminals or side chains of various epoxy resins such as bisphenol type, etc. It is obtained by adding a carboxyl group-containing polymerizable unsaturated compound such as (meth)acrylic acid to a resin having a group to open the epoxy group and introducing a polymerizable unsaturated group into the resin. This addition reaction can be carried out by heating both at about 50 DEG to 115 DEG C. for about 30 minutes to 8 hours in the presence of a reaction catalyst such as a quaternary ammonium salt or a polymerization inhibitor such as hydroquinone.

[0067] Furthermore, isocyanatoethyl (meth)acrylate,
It can also be obtained by introducing a polymerizable unsaturated group by adding an isocyanate compound containing a polymerizable unsaturated group such as m-isopropenyl phenyl isocyanate and m-isopropenyl-α,α-dimethylbenzyl isocyanate. This addition reaction can be carried out, for example, by reacting both at 20 to 100°C for about 1 to 10 hours in the presence of a tin-based catalyst such as dibutyltin octylate.

The resin having a polymerizable double bond at the terminal or side chain obtained as described above has the above formulas [17] to [2].
By reaction with a compound represented by any of 3),
A multidentate coordination group represented by any one of the formulas [8] to [14] is introduced into the resin.

Representative examples of the compounds represented by the above formulas [17] to [23] include thiosalicylic acid, thioglycolic acid, 3-mercaptopropionic acid, 2-mercaptopropionic acid, glycine, α-aminobutyric acid, leucine, Alanine, phenylalanine, O-mercaptophenol,
2-mercapto-3-naphthol, 1-mercapto-2
-naphthol, 2-mercapto-1-naphthol, 2-
aminoethanethiol, 3-aminopropanethiol,
2-aminopropanethol, 2-aminothiophenol, 2-hydroxybenzylamine, 2-hydroxy-
Examples include 5-methyl-benzylamine.

The above formula [1] to the polymerizable double bond in the resin
The addition reaction of the compounds represented by any one of [7] to [23] is carried out in the presence of a catalyst, for example, at a reaction time of about 20 to 100%.
This can be carried out by reacting at a temperature of about 1 to 24 hours. The compound represented by formula [22] has both a primary amino group and a thiol group, and in order to selectively add the primary amino group to the polymerizable double bond, the addition reaction is caused by the presence of the amine. It is preferable to carry out under an alkaline atmosphere, such as under an alkaline atmosphere.

The above method (b) is a method in which the reaction order in the above method (a) is changed, and the above formulas [8] to [1]
4) A reaction product having a multidentate coordination group represented by any of the above and a functional group such as a hydroxyl group is first prepared, and the functional group of this product is reacted with a functional group in a polymer to increase the molecular weight. be.

In the method (c) above, the silane compound or resin having a polymerizable double bond and an etherified silanol group is preferably one having the following general formula [24
], resins obtained by partially condensing one or more of these silane compounds, and partial cocondensates of these silane compounds and other silanes having etherified silanol groups.

[0073]

[Chemical formula 18]

[In the formula, D represents an unsaturated hydrocarbon group or an unsaturated carbonyloxyalkyl group, and X represents a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, It represents an aryloxy group having 6 to 8 carbon atoms or an alicyclic hydrocarbon oxy group having 5 to 8 carbon atoms. Y and Z are the same or different and each represents an alkoxyl group having 1 to 18 carbon atoms, an aryloxy group having 6 to 8 carbon atoms, or an alicyclic hydrocarbon oxy group having 5 to 8 carbon atoms, and is the same as X. It may be. ] Representative examples of the silane compound represented by the above general formula [24] include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(n-propoxy)silane, allyltrimethoxysilane, β-acryloyloxyethyltrimethoxysilane, γ-Acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyl(methyldiethoxy)silane, γ-methacryloyloxypropyltriethoxysilane, β-methacryloyloxypropyltris(n-
butoxy) silane, γ-methacryloyloxypropyl tris(isopropoxy) silane, and the like.

Other silane compounds having an etherified silanol group that can be partially co-condensed with the silane compound represented by the above formula [24] include silane compounds having two or more etherified silanol groups. For example, silane compounds such as tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, isobutyltrimethoxysilane, ethyltrimethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, etc. , and partial cocondensates of these silane compounds.

Partial condensation of the silane compound represented by the above formula [24] and partial co-condensation of the silane compound represented by the above formula [24] with another silane compound having an etherified silanol group can be carried out using conventionally known methods. It can be carried out according to the condensation method of etherified silane compounds, and is generally carried out in the presence of an acid such as an organic acid such as acetic acid or an inorganic acid such as hydrochloric acid, and water at a temperature ranging from room temperature to the boiling point, preferably 50 to 90°C.
This can be done by heating. The amount of water may be increased or decreased as appropriate depending on the degree of condensation.

The silane compound or resin having the above polymerizable double bond and etherified silanol group is represented by the above formula [
A silane compound having a polydentate group represented by any one of the formulas [8] to [14] and an etherified silanol group by addition with a compound represented by any one of formulas [17] to [23] Or a resin can be obtained. The above-mentioned addition reaction is carried out in the presence of a catalyst, for example, in the presence of a catalyst.
This can be carried out by reacting at 100°C for about 1 to 24 hours. Resins obtained by this method are included in the chelate-forming resins of the present invention.

The above-mentioned chelate-forming resin can also be obtained by partially condensing the silane compound or resin obtained by the above-mentioned addition reaction or by partially co-condensing it with the above-mentioned other silane compound having an etherified silanol group. Partial condensation and partial co-condensation can be performed in the same manner as the partial (co)condensation method described above.

The chelate-forming resin obtained by the method (c) has an etherified silanol group, and this group reacts with moisture in the air and is hydrolyzed to form a silanol group. It can be a so-called moisture curing type that undergoes a crosslinking reaction.

[0080] In the methods (d) and (e) above,
A compound having a multidentate coordination group and a polymerizable double bond of any one of the formulas [8] to [16] can be obtained, for example, by the following method.

The hydroxyl group in the addition product of the compound represented by any one of formulas [17] to [23] and a hydroxyl group-containing unsaturated monomer such as 2-hydroxyethyl (meth)acrylate is replaced by isocyanatoethyl (meth)acrylate. ) Any of the above formulas [8] to [14] by adding to a polymerizable double bond-containing monoisocyanate compound such as acrylate, m-isopropenyl phenyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, etc. A compound having a polydentate group and a polymerizable double bond is obtained.

[0082] The reaction between the compound represented by any one of the formulas [17] to [23] and the hydroxyl group-containing unsaturated monomer can be carried out, for example, in the presence of a catalyst in an equimolar amount of about 20 to 1
This can be carried out by reacting at 00°C for about 1 to 24 hours.

The addition reaction between the above-mentioned addition product having a hydroxyl group and a monoisocyanate compound containing a polymerizable double bond is as follows:
For example, in the presence of a tin-based catalyst, equimolar amounts of both are approximately 20 to 1
This can be carried out by reacting at 00°C for about 1 to 10 hours.

The compound having a polydentate group and a polymerizable double bond represented by the above formula [15] is, for example, quinoline-
It can be obtained by heating 8-allyl ether at about 190 to 220°C for 2 to 8 hours to rearrange the allyl group to form 7-allyl-8-hydroxyquinoline.

[0085] The compound having a multidentate coordination group and a polymerizable double bond represented by the above formula [16] can be obtained by forming a complex by, for example, reacting kojic acid with a metal compound such as zinc chloride at room temperature. After blocking the phenolic hydroxyl groups in kojic acid and reacting this with a diisocyanate such as tolylene diisocyanate so that one of the two isocyanate groups in the diisocyanate reacts, - A metal complex having a polymerizable unsaturated group is obtained by reacting a hydroxyl group-containing polymerizable unsaturated compound such as hydroxyethyl (meth)acrylate with the remaining isocyanate group. Next, an acid such as acetic acid or formic acid is added to the obtained metal complex to separate the metal ions forming the complex from the complex, followed by washing with water and drying.

In the reaction between the complex in which the phenolic hydroxyl group is blocked and a diisocyanate, it is preferable that there is a difference in the reactivity of the two isocyanate groups in order for one isocyanate group in the diisocyanate to react.

In the method (d) above, the formula [8]
Other polymerizable unsaturated monomers used for copolymerization with the compound having a polydentate group and a polymerizable double bond according to any one of ~[16] include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, etc. ) acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,
Hexyl (meth)acrylate, 2-ethylhexyl (
C1-C18 alkyl esters of (meth)acrylic acid such as meth)acrylate and lauryl (meth)acrylate; C2-C8 hydroxy of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate Hydroxyl group-containing unsaturated monomers such as alkyl esters and allyl alcohol; Aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyltoluene; N,N-dimethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (
meth) acrylamide, dimethylaminoethyl (meth)
Polymerizable unsaturated monomers having secondary or tertiary amino groups such as acrylate and diethylaminopropyl (meth)acrylate; Saturated monomers include monomers such as vinyl acetate, (meth)acrylamide, (meth)acrylonitrile, and N-methylol(meth)acrylamide butyl ether, each of which can be used alone or in combination of two or more.

Copolymerization of the polymerizable double bond-containing adduct with the other polymerizable unsaturated monomer can be carried out by a known copolymerization method, for example, by combining the above components with a polymerization catalyst and preferably an organic solvent. This can be carried out by heating the reaction in the presence of.

In the method (e), the formula [8]
The resin to be reacted with the compound having a polydentate group and a polymerizable double bond according to any one of items 1 to 16 must have a primary amino group or a thiol group in the resin. Examples of the resin having a primary amino group include polyamide polyamine resins, acrylic resins having primary amino groups in side chains, and the like.

In the method (f) above, the formula [8]
As a compound having a polydentate coordination group represented by any one of ~[16] and a reactive group such as an alcoholic hydroxyl group,
Examples include addition products of the compound represented by any one of formulas [17] to [23] and a hydroxyl group-containing unsaturated monomer such as 2-hydroxyethyl (meth)acrylate, kojic acid, and the like.

[0091] As the resin having an isocyanate group or a carboxyl group that is reactive with the above-mentioned compound, conventionally known resins can be used, such as acrylic resins, polyester resins, and epoxy resins having an isocyanate group or a carboxyl group. When reacting kojic acid with a compound having an isocyanate group, the above (e),
As described in the method (f), it is preferable to block the phenolic hydroxyl groups in kojic acid by, for example, forming a complex with a metal ion in advance.

Among the chelate-forming resins obtained by methods (a) to (f) above, the resin obtained by method (c) can be made into a moisture-curing type, but chelate-forming resins obtained by other methods Formable resins can also be made moisture-curable by introducing etherified silanol groups into the resin.

In order to introduce an etherified silanol group into the resin, for example, an alcoholic hydroxyl group is allowed to exist in the resin, and a monoisocyanate compound having a silanol group etherified to the hydroxyl group is added to the resin using, for example, a tin-based catalyst. A method can be used in which the two are reacted at about 20 to 100° C. for about 1 to 10 hours in the presence of. Representative examples of the monoisocyanate compound having an etherified silanol group include γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, and the like.

The chelate-forming resin in the present invention may be obtained by methods other than the above methods (a) to (f) and their modification methods.

[0095] The chelate-forming resin in the present invention preferably has a film-forming ability, and has a number average molecular weight preferably in the range of about 500 to 500,000, and preferably in the range of 1,000 to 200,000. is more preferable. The chelate-forming resin needs to have at least one, preferably 2 to 700, polydentate groups in its molecule, and 0.2 to 700 polydentate groups are present in 1000 g of the resin. 3.5 mol, even 0.3 to 3.0
It is preferable to have mol.

As the base resin for the above-mentioned chelate-forming resin, various resins can be used as described above.
Acrylic resin, epoxy resin,
Preferred are polyester resins, alkyd resins, polyamide resins, and silicon-containing resins.

[0097] The painting pretreatment agent used in the present invention is:
Contains the above-mentioned chelate-forming resin, and has a film thickness of about 0.01 to 5.
Any material that can form a thin film of μm, preferably 0.1 to 3 μm, on the metal surface may be used, such as those obtained by dissolving or dispersing the above chelate-forming resin in an organic solvent, or those containing amino groups in the chelate-forming resin. If so, the amount of amino groups is adjusted so that the amine value of the resin is 30 to 130, and the amino groups are treated with acids such as organic acids such as formic acid, acetic acid, propionic acid, and lactic acid, such as hydrochloric acid, sulfuric acid, and phosphoric acid. It may be dispersed or dissolved in water by neutralizing it with an inorganic acid such as an acid and cationizing it.

When the chelate-forming resin contains acid groups such as carboxyl groups, the amount of acid groups is adjusted so that the acid value of the resin is 30 to 130, and the acid groups are treated with organic amines, ammonia, etc. It may be used by dispersing or dissolving it in water by neutralizing it with a base and anionizing it. From the viewpoint of safety and hygiene and handling, a water-based one is preferable.

When the resin is cationized as described above, the amino group contributing to cationization of the resin may be only this amino group when the multidentate coordination group has an amino group, or the amino group contributing to the cationization of the resin may be only this amino group, or the amino group contributing to the cationization of the resin may be only this amino group, or In addition to the amino group due to the coordination group, an amino group-containing compound may be introduced, and the amino group may be both the amino group in the multidentate coordination group and the amino group due to the introduced amino group-containing compound. When the multidentate coordination group does not have an amino group, it is necessary to introduce the above-mentioned amino group-containing compound into the resin for cationization.

The amino group-containing compound may be an aliphatic, alicyclic or aromatic-aliphatic primary or secondary compound.
amines (which can react with epoxy groups to form amino groups), tertiary amino monoisocyanates obtained by reaction of tertiary amino alcohols with diisocyanates (which can react with hydroxyl groups in the resin to form amino groups), A polymerizable unsaturated monomer having a secondary or tertiary amino group (for example, an amino group can be introduced into the resin by copolymerization in the method (d) above), etc. can be mentioned.

Examples of the above-mentioned primary or secondary amines include: (a) methylamine, ethylamine, n- or iso-propylamine, monoethanolamine, n- or is
Primary monoamines such as o-propanolamine; (b) diethylamine, diethanolamine, di-n-
or secondary monoamines such as di-iso-propanolamine, N-methylethanolamine, N-ethylethanolamine; (c) ethylenediamine, diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, methylaminopropylamine, dimethylaminoethylamine , primary or secondary polyamines such as dimethylaminopropylamine, and the like.

These primary or secondary amines are
If there is an epoxy group in the resin, it may be reacted with this epoxy group as it is, but generally when using a primary amine or N-hydroxyalkyl secondary amine among the above amines, this It is preferable to heat-react the compound with a ketone, aldehyde or carboxylic acid at, for example, about 100 to 230°C to modify it into an aldimine, ketimine, oxazoline or imidazoline, and then use this product. The reaction of these primary amines, secondary amines, and modified amines with the epoxy groups in the resin can be carried out, for example, by heating at a temperature of about 80 to about 200°C for about 2 to about 5 hours. can.

[0103] When the resin has a polymerizable unsaturated group, an amino group can also be introduced by adding a primary amine to the polymerizable unsaturated group. This addition reaction is carried out in the presence of an acid catalyst, for example, between about 20 and 100
This can be carried out by reacting at a temperature of about 1 to 24 hours.

[0104] When using a tertiary amino monoisocyanate as the amino group-containing compound, for example, 30-
The reaction may be carried out at a temperature of about 120° C. with the alcoholic hydroxyl groups in the resin until the absorption of the isocyanate groups is completely eliminated as determined by infrared absorption spectrum measurement.

[0105] Furthermore, in order to introduce an amino group using a polymerizable unsaturated monomer having a secondary or tertiary amino group, for example, in the method (d) above, the formula [8]
Secondary or tertiary as part or all of other polymerizable unsaturated monomers to be copolymerized with the compound having a polydentate group and a polymerizable double bond represented by any of ~[16]
A polymerizable unsaturated monomer having a grade amino group may be used.

When the resin is anionized as described above, examples of groups that contribute to anionization of the resin include acid groups such as carboxyl groups, sulfonic acid groups, and phosphoric acid groups. When the multidentate coordination group has an acid group such as a carboxyl group, the acid group that contributes to anionization may be only this acid group, or there may be other acid groups in the resin other than the acid groups due to the multidentate coordination group. Introducing the group
The acid group may be both an acid group in a polydentate coordination group and an acid group introduced other than this acid group. When the multidentate coordination group does not have an acid group, it is necessary to introduce an acid group into the resin.

[0107] In order to introduce these acid groups into the resin, for example, by providing an epoxy group in the resin and reacting with a polybasic acid having an excess molar amount of the above acid group with respect to the epoxy group. can be done. Examples of polybasic acids include (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, succinic acid, glutaric acid, adipic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) trimellitic acid, and pyrolytic acid. Examples include mellitic acid.

Other methods for introducing acid groups into the resin include, for example, in the method (d) above, copolymerization with a compound having a polydentate coordination group and a polymerizable double bond, and other polymerizable methods. A method of using an acid group-containing unsaturated monomer having the above acid group as part or all of the unsaturated monomer, or a method in which a polymerizable double bond is provided in the resin, and thiosalicylic acid, thioglycolic acid, etc. , a method of adding a thiocarboxylic acid having a thiol group such as p-mercaptobenzoic acid, and the like.

[0109] The painting pretreatment agent used in the present invention is:
It may consist only of a chelate-forming resin solution dissolved or dispersed in an organic solvent or water, but the chelate-forming resin may contain reactive groups such as hydroxyl groups in addition to the chelate-forming groups, It can be used in combination with a crosslinking agent that reacts with this reactive group.

For example, when the above-mentioned reactive group is a hydroxyl group, known polyisocyanate compounds,
Blocked polyisocyanate compounds, aminoplast resins, formaldehyde condensates of nitrogen-containing compounds such as urea, melamine, and benzoguanamine, and lower alkyl ethers of these condensates (alkyl groups have 1 to 4 carbon atoms), etc. can be used to crosslink at room temperature or by heating.

[0111] Furthermore, a blocked isocyanate group is introduced into the resin by allowing a hydroxyl group to exist in the chelate-forming resin and reacting a compound in which one of the isocyanate groups of the diisocyanate compound is blocked with a portion of the hydroxyl group. By doing so, a resin having self-crosslinking properties can be obtained.

[0112] The painting pretreatment agent used in the present invention is:
Furthermore, if necessary, it may contain an oxidizing agent such as sodium chlorate and nitrous acid; and an etching aid such as ethylenediaminetetraacetate. Further, the concentration of the chelate-forming resin in the coating pretreatment agent is preferably within the range of 0.1 to 10% by weight, and more preferably within the range of 0.5 to 5% by weight. The pre-painting agent is used to pre-treat the metal surface for electrodeposition by contacting it with the surface of the metal material by dipping, spraying, roll coating, brushing, spin coating, squeezing, etc. It will be done.

[0113] Metal surfaces to be pretreated include surfaces of metals such as iron, zinc, copper, aluminum, and alloys of these metals, and surfaces of these metals subjected to phosphate treatment, chromate treatment, boehmite treatment, and anodizing treatment. Examples include surfaces that have been subjected to chemical conversion treatments such as.

In the method of the present invention, electrodeposition coating is performed on the metal surface which has been subjected to the above coating pretreatment. The electrodeposition paint used in this electrodeposition coating may be cationic or anionic, and any electrodeposition paint used in the field of electrodeposition coating can be used.

Typical examples of cationic electrodeposition paints include polyamine resins such as amine-added epoxy resins, such as (i) polyepoxide compounds and primary mono- and polyamines, secondary mono- and polyamines, or mixed primary and secondary polyamines. (e.g., U.S. Pat. No. 3,984,299)
(see US Pat. No. 4,017,438); (ii) adducts of polyepoxide compounds and secondary mono- and polyamines having ketiminated primary amino groups (see, for example, US Pat. No. 4,017,438); (iii) polyepoxide compounds and ketimine A reaction product obtained by etherification with a hydroxy compound having a primary amino group (e.g.
43013) etc. as a resin component.

The polyepoxide compound used in the production of the polyamine resin is a compound having two or more epoxy groups in one molecule, and generally has at least 200, preferably 400 to 4000, and more preferably 800 to 20 epoxy groups.
Those having a number average molecular weight within the range of 0.00 are suitable, and those obtained by the reaction of polyphenol compounds and epichlorohydrin are particularly preferred.

[0117] Examples of the polyphenol compound that can be used for forming the polyepoxide compound include bis(4).
-hydroxyphenyl)-2,2-propane, 4,4'
-dihydroxybenzophenone, bis(4-hydroxyphenyl)-1,1-ethane, bis(4-hydroxyphenyl)-1,1-isobutane, bis(4-hydroxy-tert-butyl-phenyl)-2,2-propane ,
Bis(2-hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene, bis(2,4-dihydroxyphenyl)methane, tetra(4-hydroxyphenyl)-1
, 1,2,2-ethane, 4,4'-dihydroxydiphenylsulfone, phenol novolak, cresol novolak, and the like.

[0118] The polyepoxide compound may be one partially reacted with a polyol, polyether polyol, polyester polyol, polyamide amine, polycarboxylic acid, polyisocyanate compound, etc., and may also be one reacted with ε-caprolactone, acrylic monomer, etc. It may also be obtained by graft polymerization.

[0119] If good weather resistance is required for the electrodeposited coating, an amino group-containing acrylic resin or a nonionic acrylic resin with excellent weather resistance may be used alone as the resin component. It is convenient to use the amine-added epoxy resin in combination with the above-mentioned amine-added epoxy resin.

The above-described amine-added epoxy resin can be cured using a curing agent such as a polyisocyanate compound blocked with alcohol or a melamine resin, if necessary.

In addition, amine-added epoxy resins that can be cured without using a curing agent can also be used, such as resins in which β-hydroxyalkyl carbamate groups are introduced into polyepoxide materials (for example, JP-A-59-1999-1).
155470); a type of resin that can be cured by transesterification (for example, Japanese Patent Application Laid-Open No. 55-8043);
(see Publication No. 6), etc. can also be used.

[0122] The preparation of a cationic aqueous solution or aqueous dispersion of the resin for cationic electrodeposition paints is usually carried out by neutralizing the resin with a water-soluble organic acid such as formic acid, acetic acid, or lactic acid to make it water-solubilized or water-dispersed. This can be done by doing.

Typical examples of anionic electrodeposition paints include polycarboxylic acid resins, such as saturated or unsaturated alkyd resins having carboxyl groups and their oil modifications, acrylic resins having carboxyl groups, and maleated polybutadiene resins. Examples include those containing resin as a resin component. This polycarboxylic acid resin can be made of blocked polyisocyanate compounds, melamine resins,
It can be cured using an amino resin such as a urea resin.

[0124] The anionic aqueous solution or aqueous dispersion of the resin for anionic electrodeposition coatings is usually prepared by neutralizing the resin with a basic substance, ie, an organic amine or ammonia, and
This can be carried out by water solubilization or water dispersion.

[0125] In both cationic and anionic electrodeposition paints, the aqueous solution or aqueous dispersion of the above-mentioned resin is further added with conventional paint additives, such as coloring pigments such as titanium white, carbon black, and red iron. , yellow lead, etc.; extender pigments such as talc, calcium carbonate, mica, clay, silica, etc.; rust preventive pigments such as chromium pigments such as strontium chromate and zinc chromate, lead pigments such as basic lead silicate, lead chromate, etc. ;Furthermore, other additives can be blended. Examples of other additives include dispersion aids (nonionic surfactants, etc.); coating surface anti-repellents (acrylic resins, fluororesins, silicone resins, etc.); curing accelerators (lead, bismuth, tin, etc.) Examples include organic polymer fine particles (such as acrylic resin) with a particle size of about 0.01 to 0.5 μm for the purpose of improving coverage on the end face of the material.

In the method of the present invention, the metal surface is brought into contact with the paint pretreatment agent by a dipping method or the like to form a film of the paint pretreatment agent on the metal surface to a dry film thickness of about 0.01 to 5 μm.
m, preferably 0.1 to 3 μm, and if necessary, cured by heating etc., and then applied the cationic or anionic electrodeposition paint to the metal surface subjected to the pre-painting treatment. This is an electrodeposition coating. When the coating pretreatment agent is cured, it may be cured before the electrodeposition coating, or it may be cured simultaneously with the electrodeposition coating after the electrodeposition coating.

[0127] Generally, when applying cationic electrodeposition coating to a metal surface that has been subjected to the above-mentioned pre-painting treatment, the cationic electrodeposition paint is diluted with deionized water or the like so that the solid content concentration of the cationic electrodeposition paint is about 5 to 40% by weight. Further, it can be carried out using an electrodeposition bath whose pH is adjusted within the range of 5.5 to 8.0.

[0128] As the method and apparatus for carrying out cationic electrodeposition coating, methods and apparatus known per se that have been conventionally used in cationic electrodeposition coating can be used. Cationic electrodeposition coating conditions are not particularly limited, but generally include bath temperature: 15-35°C (preferably 20-30°C), voltage: 100-400V (preferably 200-300V), Current density: 0.01-3A/dm
2. Current application time: 30 seconds to 10 minutes, pole area ratio (A/C)
: 6/1 to 1/6, distance between electrodes: 10 to 100 cm, and electrodeposition is preferably performed in a stirring state. The thickness (dry state) of the electrodeposition coating film to be formed is 5 to 70 μm, preferably 10 μm.
Conveniently, it is in the range ˜50 μm. The formed electrodeposited coating film can be removed by omitting the water washing treatment or by using an ultrafiltrate,
After washing with deionized water or reverse osmosis membrane filtrate, the temperature is higher than the curing start temperature of the electrodeposition coating, preferably 100 to 25
It can be cured by heating to 0°C, more preferably 150 to 200°C.

[0129] Generally, when performing anionic electrodeposition coating on a metal surface subjected to the above coating pretreatment, the anionic electrodeposition coating is diluted with deionized water or the like so that the solid content concentration of the anionic electrodeposition coating becomes 5 to 40% by weight. Furthermore, it can be carried out using an electrodeposition bath whose pH is adjusted within the range of 7 to 9.

[0130] As the method and apparatus for carrying out anionic electrodeposition coating, methods and apparatus known per se that have been conventionally used in anionic electrodeposition coating can be used. The anion electrodeposition coating conditions are not particularly limited, but generally the voltage is 15 to 300V and the voltage is 30 to 300V.
Apply second direct current. Also, the thickness of the electrodeposited film (
(in dry state) is conveniently in the range from 3 to 70 μm, preferably from 5 to 50 μm. After electrodeposition coating, the electrodeposition coating film is washed with water, or the washing treatment is omitted, and the temperature is higher than the curing start temperature of the electrodeposition paint, preferably 100 to 250°C.
, more preferably by heating to 120 to 180°C.

[0131] In the method of the present invention, when performing cationic electrodeposition coating on a pretreated metal surface, it is necessary that the cationic electrodeposition coating does not cause deterioration due to dissolution or peeling of the pretreatment film. It is preferable to use a cationic agent as the coating pretreatment agent. On the other hand, when performing anionic electrodeposition coating on a metal surface that has been pretreated, it is necessary that the anionic electrodeposition coating not cause deterioration due to dissolution or peeling of the pretreatment film. It is preferable to use one.

[0132] Among the combinations of pre-painting treatment agent and electrodeposition coating,
Cationic electrodeposition coating is preferable from the viewpoint of corrosion resistance of the formed electrodeposition coating itself, and from the viewpoint of safety and hygiene, the pretreatment agent should be water-based, and the pretreatment agent should not deteriorate during cationic electrodeposition coating. A cationic type is preferable from the viewpoint of not causing. That is, a combination of a water-based cationic pretreatment agent and cationic electrodeposition coating is particularly preferred.

The electrodeposited coating material obtained by the method of the present invention may be used as it is, or a paint may be applied thereon. This coating system is not particularly limited, and includes, for example, an electrodeposition coating material-top coating, and a coating in which a primer such as an intermediate coating, a chipping primer, or a stone guard primer is applied between the two.

[0134]

Effects of the Invention In the method of the present invention, a novel coating containing a chelate-forming resin having a polydentate coordination group having a ligand capable of forming an ion by deprotonation and a ligand having a lone pair of electrons is obtained. A pretreatment agent is used, and the multidentate coordination group of the resin in the pretreatment film formed by pretreatment of the metal surface is a stable 5-membered ring in the form of an intramolecular complex salt with a +2 or +3 valent metal ion. Alternatively, since a six-membered ring chelate complex can be formed, excellent anticorrosion properties can be imparted to the surfaces of metals such as iron, zinc, copper, and aluminum that generate +2- or +3-valent metal ions.

[0135] Furthermore, the pre-painting treatment performed in the present invention shows the same or better electrodeposition properties than the conventional zinc phosphate treatment, and the pre-painting treatment layer is prevented from deteriorating during electrodeposition coating. This method eliminates the problem of water contamination caused by phosphorus during phosphate treatment, and is non-polluting. When combined with electrodeposition coating, surface treatment and coating can achieve low pollution and high corrosion resistance.

[0136]

[Examples] The present invention will be specifically explained below with reference to Examples. In addition, hereinafter, "parts" and "%" are based on weight unless otherwise specified.

[0137]

[Production Example 1] In a flask, add 2 ml of isopropyl alcohol.
0 parts and 25 parts of butyl acetate were mixed together, heated to 85°C, and maintained at the same temperature. The following monomer mixture was added dropwise into this over 2 hours.

A mixture of 50 parts of glycidyl methacrylate, 30 parts of hydroxyethyl methacrylate, 20 parts of styrene and 2 parts of azobisvaleronitrile.

After the dropwise addition was completed, the temperature was kept at 85°C for another 2 hours, and then 0.1 part of hydroquinone was added to remove the solvent.
Part of the solvent was distilled off to obtain a resin solution with a solid content of 80%.

[0140] In another flask, add 28% of n-butyl alcohol.
．． 6 parts of tetraethylammonium bromide and 25 parts of acrylic acid were mixed together, heated and maintained at 110°C under air blowing, and 125 parts of the resin solution with a solid content of 80% obtained above was added thereto for 2 hours. It dripped. After the dropwise addition was completed, the mixture was maintained at the same temperature for 3 hours to obtain an adduct solution (A) having a polymerizable unsaturated group. This adduct solution was cooled to 60°C, and 33.2 parts of o-mercaptophenol, 10.1 parts of p-mercaptobenzoic acid, 2.5 parts of triethylamine, and 111.2 parts of n-butyl alcohol were blended therein. , the solid content was reduced to 50 by reacting at 60°C for 2 hours under nitrogen gas blowing.
% chelating resin solution was obtained.

The resulting 50% chelate resin solution 336.
6 parts triethylamine 6.6 parts and deionized water 22 parts
45 parts were blended to make it aqueous. 42.1 to this aqueous compound
part of Cymel 303 (manufactured by Mitsui Cyanamid Co., Ltd., methylated melamine resin) and 6.3 parts of Naicure 522
5 (manufactured by King Industries, USA, curing acid catalyst)
were blended and mixed uniformly to produce a treatment liquid (1).

[0142]

[Production Example 2] In a flask, the adduct solution obtained in Production Example 1 (
A) 179.6 parts, 2-mercapto-3-naphthol 4
6.3 parts, p-mercaptobenzoic acid 10.1 parts, triethylamine 2.5 parts and n-butyl alcohol 23.
0 parts were blended and reacted at 60° C. for 2 hours under nitrogen gas blowing to obtain a chelate-forming resin solution with a solid content of 50%.

[0143] Obtained 50% chelate resin solution 261.
5 parts to 6.6 parts of triethylamine and 29 parts of deionized water
63 parts were blended to make it aqueous. 32.7 to this aqueous compound
part Cymel 303 and 4.9 parts Naicure 522
5 was blended and mixed uniformly to produce a treatment liquid (2).

[0144]

[Production Example 3] In a flask, the adduct solution obtained in Production Example 1 (
A) 179.6 parts, o-aminothiophenol 32.9
parts, 19.7 parts of acetic acid and 127 parts of n-butyl alcohol.
．． 8 parts were blended and reacted at 40° C. for 3 hours under nitrogen gas blowing. Then, 4.8 parts of diethylamine was added to this mixture, and the mixture was reacted at 40° C. for 2 hours to obtain a chelate-forming resin solution with a solid content of 50%.

The resulting 50% chelate resin solution 364.
8 parts were mixed with 46 parts of formic acid and 4111 parts of deionized water to make it aqueous. Add 46 parts of Cymel 303 to this aqueous product.
and 6.9 parts of Naicure 5225 were blended and mixed uniformly to produce a treatment liquid (3).

[0146]

[Production Example 4] 40 parts of toluene and 60 parts of methyl isobutyl ketone were mixed in a flask, and the mixture was heated and maintained at 90°C. A mixed solution of 20 parts of styrene, 20 parts of n-butyl acrylate, 60 parts of isocyanatoethyl methacrylate and azobisvaleronitrile was added dropwise to this mixture over 2 hours under nitrogen gas blowing, and then heated to 90°C for 1 hour. Holds time. Next, the temperature was raised to 100°C and maintained, and a mixture of 1 part of azobisvaleronitrile and 10 parts of toluene was dropped into the mixture over 1 hour. A resin solution containing the groups was obtained.

Next, 210 parts of the resin solution obtained above was added to 70 parts of the resin solution.
A mixture of 18.4 parts of ethylene glycol monoethyl ether, 45 parts of 2-hydroxyethyl acrylate, and 0.2 parts of tin octylate was added dropwise to the mixture over 1 hour, and the temperature was maintained at the same temperature for another 1 hour and 30 minutes. A resin solution (B) having isocyanate groups and polymerizable double bonds blocked by ethylene glycol monoethyl ether was obtained.

Next, the above resin solution (B) was cooled to 60°C, 58.6 parts of thioglycolic acid and 35 parts of triethylamine were blended, and after reacting at 60°C for 2 hours under nitrogen gas blowing, methyl Chelate-forming resin solution (C) with 40% solids by adding 113.8 parts of isobutyl ketone
I got it.

[0149] Regarding the obtained chelate-forming resin solution, it was confirmed that the SH group of thiosalicylic acid had undergone an addition reaction and no SH group remained. Confirmed by color reaction.

[0150] In another flask, 40 parts of toluene and 60 parts of methyl isobutyl ketone were mixed, and the mixture was heated and maintained at 90°C. A mixture of 30 parts of styrene, 30 parts of n-butyl acrylate, 30 parts of 2-hydroxyethyl acrylate, 10 parts of acrylic acid, and 2 parts of azobisvaleronitrile was added dropwise into the solution over 2 hours, and after the addition was completed, the temperature was increased to the same temperature. It was held for 1 hour. The temperature was then raised to and maintained at 100° C., and a mixture of 1 part of azobisvaleronitrile and 10 parts of toluene was added dropwise thereto over 1 hour. After the dropwise addition was completed, the temperature was maintained at the same temperature for 1 hour, and then cooled. Next, 14 parts of triethylamine and 37 parts of methyl isobutyl ketone were added to this to obtain a neutralized resin solution (D) with a solid content of 40%.

[0151] 56 parts of the chelate-forming resin solution (C) with a solid content of 40% obtained above and 24 parts of the neutralized resin solution (D) with a solid content of 40% obtained above were uniformly mixed in 720 parts of deionized water. The mixture was mixed and stirred to make it aqueous, producing a treatment liquid (4).

[0152]

[Production Example 5] In a flask, 500 parts of Epicote 1001 (manufactured by Shell Chemical Co., Ltd.), 143 parts of methyl isobutyl ketone
72 parts of acrylic acid, 0.6 parts of hydroquinone, and 5.7 parts of tetraethylammonium bromide were mixed and reacted at 115°C for 3 hours under air blowing to obtain a solution of an adduct having a polymerizable unsaturated group. Obtained. This adduct solution was heated at 60°C.
137 parts of o-aminobenzoic acid, 433.7 parts of dimethylformamide and 1 part of trichloroacetic acid were added thereto.
After blending 65 parts and reacting at 60° C. for 8 hours, it was cooled and 101 parts of triethylamine and 1000 parts of deionized water were added to form a precipitate. This precipitate was collected, washed with water, and dried to obtain a chelate-forming resin (E).

Next, 80 parts of the chelate-forming resin (E) obtained above was dissolved in 100 parts of methoxypropanol, and 14.2 parts of triethylamine and 300 parts of deionized water were added thereto to make it aqueous. Further, this aqueous product was mixed with Cymel 30,320 parts, Naicure 5,225 (3 parts), isopropanol (10 parts), and deionized water (2,806 parts) to produce a treatment liquid (5).

[0154]

[Production Example 6] In a flask, 206 parts of Denacol EX521 (manufactured by Nagase Kasei Co., Ltd., polyol polyglycidyl ether, average molecular weight of about 1200, epoxy equivalent of about 200), 70 parts of methyl isobutyl ketone, 72 parts of acrylic acid,
0.3 parts of hydroquinone and 2.8 parts of tetraethylammonium bromide were blended and heated at 115°C under air blowing.
The mixture was reacted for 3 hours to obtain an adduct solution having a polymerizable unsaturated group. The adduct solution was cooled to 50°C and o
- 123 parts of hydroxybenzylamine, 46.5 parts of formic acid and 225 parts of ethyl alcohol were blended and
The reaction was carried out for a period of time to obtain a chelate-forming resin solution (F) with a solid content of 54%.

[0155] In another flask, add methyl isobutyl ketone 3.
6 parts of Epikote 1001 and 15 parts of diethanolamine were mixed and reacted at 120°C for 3 hours, then cooled to 60°C and maintained at the same temperature. Next, a mixture of 117 parts of a monoblock obtained by blocking one of the two isocyanate groups of tolylene diisocyanate with ethylene glycol monoethyl ether, 50 parts of methyl isobutyl ketone, and 0.05 parts of tin octylate was added to the mixture for 1 hour. After dripping, heat to 65℃ and keep at the same temperature for 1 hour.
The mixture was held for a period of time and then cooled to obtain a resin solution. Furthermore, 1.0 part of tin octylate and 122 parts of ethanol were added to this resin solution.
92 parts of methyl ethyl ketone and 7 parts of formic acid to obtain a neutralized resin solution (G) with a solid content of 40%.

10 parts of the chelate-forming resin solution (F) with a solid content of 54% obtained above and the neutralized resin solution (F) with a solid content of 40% (
G) 10 parts of emulsion were uniformly mixed, this mixture was blended into 300 parts of deionized water, stirred to form an emulsion liquid, and 26.7 parts of a 0.2% nitrous acid aqueous solution was further blended into this. A treatment liquid (6) was produced.

[0157]

[Production Example 7] In a flask, 221.6 parts of quinoline-8-allyl ether and 221.6 parts of mineral spirit were mixed and heated at 200°C for 5 hours, then cooled to room temperature. -Hydroxyquinoline solution was obtained.

When a 10% aqueous sodium hydroxide solution was added to this solution under stirring, a precipitate was generated, and this precipitate was separated to obtain 7-allyl-8-hydroxyquinoline Na salt.

To 221.6 parts of 7-allyl-8-hydroxyquinoline Na salt obtained above, 5 parts of methyl isobutyl ketone was added.
17 parts and 60 parts of acetic acid were added, dissolved and neutralized at room temperature, and washed with water to obtain 7-allyl-8- with a solid content of 30%.
A hydroxyquinoline solution was obtained.

In another flask, 738.6 parts of the 30% 7-allyl-8-hydroxyquinoline solution obtained above, 444.6 parts of methyl isobutyl ketone, and Tomide #245 were added.
(Manufactured by Fuji Kasei Kogyo Co., Ltd., polyamide polyamine resin)
800 parts and 60 parts of acetic acid were blended and heated at 70° C. for 5 hours to cause an addition reaction between amino groups and allyl groups in the resin to obtain a chelate-forming resin solution (H) with a solid content of 50%.

[0161] Epikote #828 (manufactured by Shell Chemical Co., Ltd., epoxy resin, molecular weight approximately 350) was dissolved in methyl isobutyl ketone to 20 parts of the obtained chelate-forming resin solution (H) with a solid content of 50%. 40% solids solution 3
7.5 parts of methyl isobutyl ketone and 472.5 parts of xylene were blended to obtain a treatment liquid (7).

[0162]

[Production Example 8] In a flask, 142 parts of kojic acid, 698 parts of tetrahydrofuran and 68 parts of zinc chloride were mixed,
The mixture was stirred at 25° C. for 30 minutes to block the phenolic hydroxyl groups in kojic acid to obtain a zinc kojic acid complex solution.

The resulting zinc kojate complex solution was maintained at 50° C., and 174 parts of tolylene diisocyanate was added dropwise over 1 hour while stirring to prepare a monoisocyanate solution.

In a separate flask, 116 parts of 2-hydroxyethyl acrylate and 2 parts of tin octylate were mixed,
While maintaining the temperature at 70°C, 1046.5 parts of the monoisocyanate solution obtained above was added dropwise over 1 hour while stirring, and the mixture was further reacted for 2 hours to introduce a polymerizable unsaturated group, followed by degassing and purification. Ta. Next, acetic acid was added to separate the complexed zinc ions from the complex, followed by washing with water and drying to obtain a monomer (J) having a polymerizable unsaturated group and a chelate-forming group and represented by the following structural formula. .

[0165]

[Chemical formula 19]

[0166] In a separate flask, the monomer obtained above (J
) and 1172 parts of methyl isobutyl ketone, and after dissolving them, tomide #245 8
00 parts and 60 parts of acetic acid were mixed and heated at 70°C for 5 hours to cause an addition reaction between the amino groups and polymerizable unsaturated groups in the resin to form a chelate-forming resin solution (K) with a solid content of 50%. Obtained.

To the obtained chelate-forming resin solution (K) with a solid content of 50%, a solution of Epicote #828 dissolved in methyl isobutyl ketone with a solid content of 40% was added.
5 parts, 470 parts of methyl isobutyl ketone, and 472.5 parts of xylene were blended to obtain a treatment liquid (8).

[0168]

[Examples 1 to 8] Treatment solutions (1) to (1) obtained in Production Examples 1 to 8
8), treated film layers were formed on the following various materials by various methods.

[0169] The types of materials are as follows.

0.8m/m cold rolled dull steel plate 0.8
m/m Iron-zinc alloy plated steel plate・0.8m/m
Aluminum plate/0.8 m/m Zinc phosphate treated cold rolled steel plate [Treatment with Palbond 3020 (manufactured by Nippon Parkerizing Co., Ltd., zinc phosphate treatment agent)] The method for forming the treated film layer is as follows.

[0171] Examples 1 and 2 are bar coater coating-1
Bake at 40°C for 20 minutes - wash with water, Example 3 is dip coating - 1
Bake at 40°C for 20 minutes - wash with water, Example 4 is dip coating - 1
Baking at 70°C for 20 minutes - Washing with water. Example 5 is a spin coating method in which excess processing liquid is removed by centrifugal force after application of the processing solution - Baking at 140°C for 20 minutes - Washing with water. Example 6 is by immersion. Automatic precipitation method - washing with water - baking at 170°C for 20 minutes. In Examples 7 and 8, the treated film layer was formed by coating with a bar coater - baking at 80°C for 20 minutes - washing with water.

[0172] Electrodeposition coating was then performed on the various materials on which the treated film layer had been formed. The electrodeposition coating conditions were as follows.

[0173] In Examples 1, 2, 4, and 5, Elekron No. 7100 Gray (manufactured by Kansai Paint Co., Ltd., anionic electrodeposition paint, maleated polybutadiene resin gray paint, abbreviated as "Anion-1" in Table 1) was used, and the film thickness was 20 μm at an applied voltage of 200 V. Anion electrodeposition coating was performed so that After the electrodeposition coating, the plate was washed with water and then baked at 160° C. for 30 minutes to obtain an electrodeposition coated plate.

In Examples 3, 6, 7, and 8, Elekron No. The applied voltage was Cationic electrodeposition coating was performed at 250 V to a film thickness of 20 μm. After the electrodeposition coating, the plate was washed with water and then baked at 170° C. for 30 minutes to obtain an electrodeposition coated plate.

[0175]

[Comparative Example 1] Instead of subjecting the material to the chelate-forming surface treatment, a zinc phosphate treated plate treated with Palbond 3020 was used, and anionic electrodeposition coating was applied thereon in the same manner as in Example 1.

[0176]

Comparative Example 2 Instead of subjecting the material to chelate-forming surface treatment, a chromic acid-treated plate was used, and anionic electrodeposition coating was applied thereon in the same manner as in Example 1.

[0177]

[Comparative Example 3] The material was not subjected to chelate-forming surface treatment, and anionic electrodeposition coating was applied thereon in the same manner as in Example 1 without any treatment.

In Comparative Examples 1 to 3, electrodeposition coated plates were obtained by washing with water after electrodeposition coating and baking at 160° C. for 30 minutes.

[0179]

[Comparative Example 4] Comparative Example 1 was carried out in the same manner as in Example 3, except that the same cationic electrodeposition coating was used instead of the anionic electrodeposition coating.

[0180]

[Comparative Example 5] Comparative Example 2 was carried out in the same manner as in Example 3, except that cationic electrodeposition coating was used instead of anionic electrodeposition coating.

[0181]

[Comparative Example 6] Comparative Example 3 was carried out in the same manner as in Example 3, except that cationic electrodeposition coating was used instead of anionic electrodeposition coating.

In Comparative Examples 4 to 6, electrodeposition coated plates were obtained by washing with water after electrodeposition coating and baking at 170° C. for 30 minutes.

The electrodeposited plates obtained in Examples 1 to 8 and Comparative Examples 1 to 6 were tested for finished appearance, salt spray resistance, hot water immersion resistance, and impact resistance. The test results are shown in Tables 2 and 3.

[0184]

[Table 2]

[0185]

[Table 3]

[0186] The tests in Tables 2 and 3 were conducted according to the following test method.

Finished appearance: The surface of the electrodeposition coated plate is visually observed and evaluated for bumps, dents, and smoothness. Good results are rated as ◎, those with no practical problems but with slight yuzu skin are rated as ○, and poor results are marked as ×.

[0188] Salt water spray resistance: A test was conducted according to JIS Z 2371 by making a cross cut on an electrodeposition coated plate. The salt water spray time was 48 hours for those coated with anion-1 and 240 hours for those coated with cation-2.
It was time. After testing, apply cellophane adhesive tape to the cross-cut part of the coated plate and peel it off rapidly to determine the peeling width on one side of the cross-cut part and the maximum length of the rusted width.

[0189] Temperature salt water immersion resistance: A cross cut was made on the electrodeposited plate, and after immersing it in 5% saline solution at 50°C for 240 hours, the coated plate was pulled up and air-dried. Then, a cellophane adhesive tape was tightly attached to the cross cut part and the plate was rapidly soaked. Determine the peeling width on one side of the cross-cut portion and the maximum length of the rusting width.

[0190] Impact resistance: JIS K 5400
8.3.2 (1990), a DuPont impact resistance test is conducted in an atmosphere at 20°C. Weight 500g
, with the center of impact having a tip diameter of 1/2 inch, showing the maximum falling weight height without causing damage to the paint film. In addition, 50cm
is the maximum value.

In addition, Examples 1, 2, 4, and 5 and Comparative Example 1 in which cold-rolled steel sheets are used as raw materials and anionic electrodeposition paints are applied.
, In the step 3, the electrodeposition characteristics during anionic electrodeposition coating (
The relationship between the applied voltage and the maximum film thickness obtained at a bath temperature of 30°C (coulomb yield) was investigated. The results are shown in Table 4.

[0192]

[Table 4]

In addition, Examples 3, 6, 7, and 8 and Comparative Example 4 in which a cold-rolled steel plate is used as a material and are coated with cationic electrodeposition paint
, 6, the electrodeposition characteristics during cationic electrodeposition coating were investigated. The results are shown in Table 5.

[0194]

[Table 5]

Claims (1)

[Scope of Claims] [Claim 1] A ligand capable of forming a stable 5- or 6-membered ring intramolecular complex salt with a +2- or +3-valent metal ion, and capable of forming an ion by deprotonation; A metal surface is treated with a coating pretreatment agent containing a chelate-forming resin having at least one polydentate coordination group in each molecule, each having at least one ligand having a lone pair of electrons. A method for pre-treatment of a metal surface for electrodeposition coating (provided that the multidentate coordination group is of the following formula [1] or [2])
, [3] or [4] is excluded. ). [Image Omitted] (In each formula, R1 and R2 are the same or different,
It represents a hydrogen atom, a halogen atom, a nitro group, a nitroso group, a cyano group, a hydrocarbon group having 18 or less carbon atoms, or an alkoxyalkyl group having 12 or less carbon atoms. ) [Claim 2
10. The coating pretreatment method according to claim 1, wherein the multidentate coordination group has one each of a ligand capable of forming an ion by deprotonation and a ligand having a lone pair of electrons. 3. The coating pretreatment method according to claim 1, wherein the chelate-forming resin is a resin having 2 to 700 polydentate coordination groups in one molecule. 4. The chelate-forming resin in the pre-painting treatment agent is cationic, and the electrodeposition coating performed after treatment with the pre-painting treatment agent is cationic electrodeposition coating.
3. The painting pretreatment method according to any one of 3. 5. The chelate-forming resin in the pre-painting treatment agent is anionic, and the electrodeposition coating performed after the treatment with the pre-painting treatment agent is an anionic electrodeposition coating.
3. The painting pretreatment method according to any one of 3.