JPWO2017081731A1 - Metal surface treatment composition, method for producing metal material - Google Patents

Abstract

An object of the present invention is to provide a metal that forms a surface-treated coating layer on the surface of a metal substrate, which has excellent flexibility, flat surface corrosion resistance, solvent resistance, alkali degreasing portion corrosion resistance, processed portion corrosion resistance, bent portion corrosion resistance, and coating adhesion. It is to provide a surface treatment composition. Moreover, the subject of this invention is providing the manufacturing method of the metal material which used the metal surface treatment composition. The metal surface treatment composition of the present invention is a metal surface treatment composition containing a urethane resin, and the urethane resin is obtained by reacting a urethane prepolymer with water and at least one of a predetermined polyamine compound. The urethane prepolymer is a predetermined polyisocyanate (A), a predetermined polyol (B), a predetermined diol (C) having a weight average molecular weight of more than 600, and a predetermined diol (D) having a weight average molecular weight of 500 or less. And a predetermined tertiary amine compound (E).

Description

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

Conventionally, in various fields such as home appliances, automobiles, and building materials, surface treatment of a metal substrate (for example, a steel plate) using a metal surface treatment composition has been performed. Such a metal surface treatment composition is used as one of the purposes for maintaining the appearance of the metal substrate over a long period of time in various environments.
The metal surface treatment composition may contain a resin binder, and among such resin binders, the use of water-based resins is increasing due to recent demands for reducing environmental burdens.
As the water-based resin contained in the metal surface treatment composition, for example, an acrylic resin, an epoxy resin, a urethane resin, or the like is used, and among these, a urethane resin is useful because it is excellent in various performance balances.

  As a metal surface treatment composition containing such a urethane resin, for example, Patent Document 1 discloses that “a compound having two or more active hydrogen atoms (A), an organic polyisocyanate (B), and a tertiary amino acid”. A cationic urethane prepolymer (D) obtained by neutralizing a tertiary amino group contained in a urethane prepolymer having a chain extender (C) having a group as a constituent element with an acid or quaternizing with a quaternizing agent , A water-based paint composition for surface treatment of a metal material containing a cationic water-based urethane resin (F) chain-extended using water or a polyamine compound (E) (Claim 1).

International Publication No. 2005/092998

However, the present inventors synthesized a urethane resin with reference to the description in Example 10 of Patent Document 1 (urethane resin of Comparative Synthesis Example 9 of the present invention), and examined a metal surface treatment composition containing the same. However, when a metal material provided with a surface treatment coating layer formed using this metal surface treatment composition is bent, it becomes clear that the surface treatment coating layer is cracked and has poor flexibility. It was.
In addition to the above flexibility, the surface-treated coating layer is also required to be excellent in flat part corrosion resistance, solvent resistance, alkaline degreasing part corrosion resistance, processed part corrosion resistance, bent part corrosion resistance, and coating adhesion.

  Therefore, the present invention provides a metal surface on which a surface treatment coating layer having excellent flexibility, flat surface corrosion resistance, solvent resistance, alkaline degreasing portion corrosion resistance, processed portion corrosion resistance, bent portion corrosion resistance and coating adhesion is formed on the surface of a metal substrate. It aims at providing the processing composition and the manufacturing method of a metal material using the same.

As a result of intensive studies on the problem, the present inventors have found that a metal material in which a surface treatment coating layer is formed using a metal surface treatment composition containing a urethane resin obtained by a specific urethane prepolymer is excellent in flexibility. As a result, they have reached the present invention. Furthermore, the metal material in which the surface treatment film layer is formed using the metal surface treatment composition containing a urethane resin obtained by a specific urethane prepolymer is not only flexible but also has a flat surface corrosion resistance, solvent resistance, and alkaline degreasing. The present inventors have found that it is excellent in part corrosion resistance, processed part corrosion resistance, bent part corrosion resistance, and paint adhesion, and has reached the present invention.
That is, the present inventors have found that the problem can be solved by the following configuration.

[1]
A metal surface treatment composition containing a urethane resin,
The urethane resin is obtained by reacting a urethane prepolymer with at least one of water and a polyamine compound not containing a tertiary amine,
The urethane prepolymer comprises a polyisocyanate (A) having a cyclohexane ring structure, a polyol (B) having a benzene ring not containing a nitrogen atom, and a diol having a weight average molecular weight not containing a benzene ring and a nitrogen atom of more than 600 ( A metal obtained by reacting C) with a diol (D) having a weight average molecular weight of 500 or less, which does not contain a benzene ring and a nitrogen atom, and a tertiary amine compound (E) having two or more active hydrogens Surface treatment composition.
[2]
The metal surface treatment composition according to the above [1], wherein the diol (D) has a weight average molecular weight of 60 or more and 400 or less.
[3]
The metal surface treatment composition according to the above [1] or [2], wherein the diol (C) has a weight average molecular weight of 800 or more and 4000 or less.
[4]
The charged amount of the diol (C) is such that the polyisocyanate (A), the polyol (B), the diol (C), the diol (D) and the tertiary amine used in the production of the urethane prepolymer. The metal surface treatment composition according to any one of [1] to [3], which is 3 to 40% by mass relative to the total amount of the compound (E).
[5]
The charged amount of the diol (D) is such that the polyisocyanate (A), the polyol (B), the diol (C), the diol (D) and the tertiary amine used in the production of the urethane prepolymer. The metal surface treatment composition according to any one of [1] to [4], which is 1 to 20% by mass relative to the total amount of the compound (E).
[6]
The metal surface treatment composition according to any one of [1] to [5], wherein the diol (C) includes a polyether diol.
[7]
The metal surface treatment composition according to the above [6], wherein the polyether diol is at least one compound selected from polyethylene glycol, polypropylene glycol and polybutylene glycol.
[8]
[1] to [7], wherein the polyisocyanate (A) is at least one compound selected from isophorone diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, and dicyclohexylmethane 4,4′-diisocyanate. ] The metal surface treatment composition as described in any one of.
[9]
A metal base material, and a surface treatment coating layer formed on the surface of the metal base material, a method for producing a metal material,
The metal surface treatment composition according to any one of the above [1] to [8], wherein the surface of the metal base material is surface treated to form the surface treatment coating layer. Production method.

  As shown below, according to the present invention, a surface-treated coating layer having excellent flexibility, flat surface corrosion resistance, solvent resistance, alkaline degreasing portion corrosion resistance, processed portion corrosion resistance, bent portion corrosion resistance, and coating adhesion is formed on a metal substrate. It is possible to provide a metal surface treatment composition that is formed on the surface of the metal. Moreover, this invention can provide the manufacturing method of the metal material using the metal surface treatment composition.

Below, the metal surface treatment composition of this invention is demonstrated.
In the present invention, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the case of using the “polyol of triol or higher that does not contain a benzene ring and a nitrogen atom”, which will be described later, in the production of the urethane prepolymer, the “polyisocyanate (A) used in the production of the urethane prepolymer, polyol ( The total amount of “B), diol (C), diol (D) and tertiary amine compound (E)” includes the charged amount of “polyol higher than triol not containing benzene ring and nitrogen atom”. Shall be. That is, in the present invention, when “polyol having a benzene ring and a nitrogen atom not included” is used for the production of the urethane prepolymer, the total amount is “polyisocyanate used for the production of the urethane prepolymer ( A), polyol (B), diol (C), diol (D), tertiary amine compound (E) and the total amount of polyols not less than triol containing no benzene ring and nitrogen atom ”.

<Metal surface treatment composition>
The metal surface treatment composition of the present invention is a metal surface treatment composition containing a urethane resin, wherein the urethane resin comprises a urethane prepolymer and at least one of a polyamine compound not containing water and a tertiary amine. Obtained by reaction.
The urethane prepolymer includes a polyisocyanate (A) having a cyclohexane ring structure, a polyol (B) not containing a nitrogen atom and containing a benzene ring, and a diol having a weight average molecular weight exceeding 600 and not containing a benzene ring and a nitrogen atom. It is obtained by reacting (C) with a diol (D) having a weight average molecular weight of 500 or less, which does not contain a benzene ring and a nitrogen atom, and a tertiary amine compound (E) having two or more active hydrogens.
According to the metal surface treatment composition of the present invention, by containing a urethane resin obtained by a specific urethane prepolymer, flexibility, flat surface corrosion resistance, solvent resistance, alkaline degreasing portion corrosion resistance, processed portion corrosion resistance, bending portion A surface-treated coating layer (hereinafter also simply referred to as “coating”) having excellent corrosion resistance and paint adhesion can be formed.
Although the details of this reason have not yet been clarified, it is assumed that the reason is as follows.

Since the polyisocyanate (A) having a cyclohexane ring structure is easy to handle as an isocyanate compound and the cyclohexane ring itself is chemically stable, it improves the solvent resistance of the surface treatment coating layer (urethane resin coating). It is effective.
In addition, the polyol (B) that does not contain a nitrogen atom and contains a benzene ring is chemically stable in the benzene ring itself, and has a bulky structure and high cohesiveness. In addition, it is effective for improving the corrosion resistance of the bent portion.
Therefore, by using a urethane resin having a cyclohexane ring structure and a benzene ring, the above-described effects derived from these structures act synergistically, and the solvent resistance, flexibility, planar portion corrosion resistance, and bending portion of the urethane resin film It is estimated that the corrosion resistance can be improved.

On the other hand, the urethane resin obtained by using the polyisocyanate (A) having a cyclohexane ring structure and the polyol (B) not containing a nitrogen atom and containing a benzene ring is too cohesive in the formed film. , It has brittle physical properties (brittleness) and tends to have low film strength.
Here, the strength of the film formed of the urethane resin is expressed by the cohesiveness of the urethane resin. It has been found that it is effective to use a polymer polyol for the production of a urethane resin, specifically, a urethane prepolymer, in order to impart an appropriate cohesiveness to the extent that brittleness does not appear in the formed film. It was.
As a result of studies by the present inventors, it is clear that a diol (C) having a weight average molecular weight of more than 600 that does not contain a benzene ring and a nitrogen atom needs to be used as a polymer polyol that improves the coating strength of a urethane resin. It became. That is, the brittleness of the resulting urethane resin coating is reduced and the coating strength is improved by producing the urethane resin using the diol (C) having a weight average molecular weight of more than 600 and containing no benzene ring and nitrogen atom. It is presumed that the processed part corrosion resistance, the flexibility, the bent part corrosion resistance and the paint adhesion are improved.

When the diol (C) having a weight average molecular weight not containing a benzene ring and a nitrogen atom is more than 600 for the production of a urethane resin, the coating strength of the urethane resin can be improved as described above, but this is excessively introduced. Rotating, the cohesiveness is lowered, and the coating strength of the urethane resin may be lowered.
As a result of further investigations by the present inventors on such problems, the use of low molecular polyols in the production of urethane resins, specifically urethane prepolymers, resulted in excessive coating strength of the urethane resin. It was found that the decrease can be suppressed. Specifically, by using a diol (D) having a weight average molecular weight of 500 or less that does not contain a benzene ring and a nitrogen atom, the reaction point due to active hydrogen derived from a low molecular polyol increases, and the coating strength of the urethane resin. As a result of suppressing an excessive decrease in the coating strength, it is presumed that the coating adhesion, flexibility and corrosion resistance of the bent portion are improved.

  Hereinafter, the component contained in the metal surface treatment composition of this invention and the component which may be contained are demonstrated.

<< Urethane resin >>
The urethane resin contained in the metal surface treatment composition of the present invention is obtained by reacting a urethane prepolymer with at least one of water and a polyamine compound not containing a tertiary amine. Specifically, the isocyanate group contained in the urethane prepolymer reacts with at least one of water and a polyamine compound not containing a tertiary amine to form a urea bond.

<Urethane prepolymer>
The urethane prepolymer is a component used for the production of a urethane resin, and includes at least a polyisocyanate (A) having a cyclohexane ring structure, a polyol (B) not containing a nitrogen atom and containing a benzene ring, a benzene ring and a nitrogen atom. A diol (C) having a weight average molecular weight of more than 600 containing no benzene, a diol (D) having a weight average molecular weight of 500 or less containing no benzene ring and a nitrogen atom, and a tertiary amine compound having two or more active hydrogens ( E) and a reaction.
Specifically, the hydroxyl group contained in the polyol (B), the diol (C) and the diol (D) reacts with the isocyanate group contained in the polyisocyanate (A) to form a urethane bond. To do. Further, the isocyanate group contained in the polyisocyanate (A) reacts with the hydrogen atom (active hydrogen) contained in the tertiary amine compound (E) to form a urethane bond or a urea bond.
In addition, the urethane prepolymer of the present invention has an isocyanate group derived from the polyisocyanate (A) having a cyclohexane ring structure in order to react with at least one of water and a polyamine compound not containing a tertiary amine as described above. It is what you have.

(Polyisocyanate having a cyclohexane ring structure (A))
A polyisocyanate (A) having a cyclohexane ring structure (hereinafter, also simply referred to as “polyisocyanate (A)”) is used for producing a urethane prepolymer.
Since the urethane prepolymer obtained by using the polyisocyanate (A) has a bulky cyclohexane ring structure, the solvent resistance of the urethane resin coating (surface treatment coating layer) containing this tends to be further improved.
The cyclohexane ring structure includes a bicyclic structure having a cyclohexane structure such as norbornene. A plurality of cyclohexane ring structures may be contained in the polyisocyanate (A).

(Amount of polyisocyanate (A) charged)
In the production of the urethane prepolymer described later, the amount of the polyisocyanate (A) charged is the polyisocyanate (A), polyol (B), diol (C), diol (D) and diol (D) used in the production of the urethane prepolymer. The total amount of the tertiary amine compound (E) is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, still more preferably 40 to 65% by mass, and 50 It is especially preferable that it is -60 mass%.
When the charged amount of the polyisocyanate (A) is within the above range, the solvent resistance of the urethane resin coating containing the polyisocyanate (A) tends to be further improved.
In the present invention, in the case of using a “polyol having a benzene ring and a nitrogen atom not containing a triol” described later in the production of the urethane prepolymer, the total amount of the polyols having a benzene ring and a polyol having a nitrogen atom not contained is added to the above total amount. Include in quantity.

(Types of polyisocyanate (A))
The polyisocyanate (A) is not particularly limited as long as it has one or more cyclohexane rings and two or more isocyanate groups. For example, isophorone diisocyanate, 1,3- or 1 , 4-bis (isocyanatomethyl) cyclohexane, 1,3- or 1,4-diisocyanate cyclohexane, 3-isocyanate-methyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane 4,4′-diisocyanate, 2,5 -Or 2,6-diisocyanatomethylnorbornane, 2,5- or 2,6-diisocyanatemethyl-2-isocyanatopropylnorbornane and the like. The polyisocyanate (A) may be a dimer or a trimer such as a uretdione structure or an isocyanurate structure, and has three or more isocyanate groups in one molecule as an adduct using a polyfunctional polyol. Polyisocyanates can also be used.
A polyisocyanate (A) may be used individually by 1 type, and may be used together 2 or more types.
Among the above, the polyisocyanate (A) is at least one selected from isophorone diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane and dicyclohexylmethane 4,4′-diisocyanate from the viewpoint that the solvent resistance is further improved. The compound is preferably a seed compound, and more preferably dicyclohexylmethane 4,4′-diisocyanate.

(Polyol (B) containing no benzene ring and no nitrogen atom)
The polyol (B) containing no nitrogen atom and containing a benzene ring (hereinafter, also simply referred to as “polyol (B)”) is used in the production of the urethane prepolymer.
The urethane prepolymer (urethane resin) obtained using the polyol (B) tends to have physical properties of high elasticity and high Tg due to the rigidity of the benzene ring. As described above, since the urethane resin having high elasticity and high Tg has a barrier property at the benzene ring portion, the flat portion corrosion resistance, the bent portion corrosion resistance, and the flexibility of the urethane resin coating (surface treatment coating layer) including this are improved. To do.

(Polyol (B) charge amount)
In the production of the urethane prepolymer described later, the amount of the polyol (B) charged is the polyisocyanate (A), polyol (B), diol (C), diol (D) and third used in the production of the urethane prepolymer. Although it can be normally made into 1-40 mass% with respect to the total amount of a secondary amine compound (E), it is preferable that it is 1-30 mass%, and it is more preferable that it is 3-25 mass%. More preferably, it is 6 to 20% by mass.
When the charged amount of the polyol (B) is 3% by mass or more, the planar portion corrosion resistance and the bent portion corrosion resistance are further improved. Moreover, since it is 25 mass% or less, since the expression of the brittleness of a film can be suppressed, it exists in the tendency for a flexibility and a bending part corrosion resistance to improve more.
In the present invention, in the case of using a “polyol having a benzene ring and a nitrogen atom not containing a triol” described later in the production of the urethane prepolymer, the total amount of the polyols having a benzene ring and a polyol having a nitrogen atom not contained is added to the above total amount. Include in quantity.

(Type of polyol (B))
The polyol (B) is not particularly limited as long as it has one or more benzene rings and two or more hydroxy groups and does not have a nitrogen atom. For example, resorcinol, 2-methylresorcinol, bisphenol A, aromatic phenols such as bisphenol S, bisphenol F, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, anthraflavic acid, 1,5-dihydroxyanthraquinone; bisphenol A-ethylene oxide 2 mol adduct, bisphenol A -Ethylene oxide 4 mol adduct, bisphenol A-ethylene oxide 6 mol adduct, bisphenol A-ethylene oxide 10 mol adduct, bisphenol A-propylene oxide 2 mol adduct, bisphenol A-propylene oxide 4 mol , Polyether polyols having a benzene ring such as bisphenol A-propylene oxide 6 mol adduct, bisphenol A-propylene oxide 10 mol adduct; aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid And ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 2-methylpropanediol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3 -Polyester polyol having a benzene ring obtained by polycondensation with polyols such as methylpentanediol; transesterification reaction between diphenyl carbonate and polyol, ethylene carbonate and Polycarbonate polyol having a benzene ring derived from the transesterification reaction of a polyol such as phenol A; and the like.
A polyol (B) may be used individually by 1 type, and may be used together 2 or more types.
Among the above, the polyol (B) is preferably a polyether polyol having a benzene ring from the viewpoint that the strength of the coating is further improved. When the polyol (B) is a polyether polyol, the planar portion corrosion resistance of the coating is further improved.

(Diol (C) containing a benzene ring and a nitrogen atom and having a weight average molecular weight of more than 600)
By using a diol (C) having no weight of benzene ring and nitrogen atom and having a weight average molecular weight of more than 600 (hereinafter also simply referred to as “diol (C)”) in the production of a urethane resin (urethane prepolymer), urethane is obtained. As a result of reducing the brittleness of the resin film and improving its strength, the processed part corrosion resistance, flexibility, bent part corrosion resistance, and paint adhesion are improved.

(Amount of diol (C) charged)
In the production of the urethane prepolymer described later, the amount of the diol (C) charged is selected from the polyisocyanate (A), polyol (B), diol (C), diol (D) and third used in the production of the urethane prepolymer. Although it can usually be made into 1-50 mass% with respect to the total amount of a secondary amine compound (E), it is preferable that it is 3-40 mass%, and it is more preferable that it is 5-35 mass%. More preferably, it is 10-30 mass%.
When the charged amount of the diol (C) is within the above range, the coating adhesion of the urethane resin coating, the processed portion corrosion resistance, the flexibility, and the bent portion corrosion resistance tend to be further improved.
In the present invention, in the case of using a “polyol having a benzene ring and a nitrogen atom not containing a triol” described later in the production of the urethane prepolymer, the total amount of the polyols having a benzene ring and a polyol having a nitrogen atom not contained is added to the above total amount. Include in quantity.

(Weight average molecular weight of diol (C))
The weight average molecular weight of the diol (C) is more than 600, preferably more than 600 and 10000 or less, more preferably more than 600 and 5,000 or less, still more preferably 800 to 4000, and more preferably 1000 to 3000. It is particularly preferred that
When the weight average molecular weight of the diol (C) is within the above range, the processed part corrosion resistance, the flexibility, and the bending part corrosion resistance of the urethane resin coating are more excellent.
Moreover, since the weight average molecular weight of diol (C) is 4000 or less, the fall of the reactivity of diol (C) can be suppressed, and as a result of diol being favorably introduce | transduced in a urethane prepolymer (urethane resin), it is urethane. Flexibility is imparted to the resin coating, and an excellent coating is obtained due to the processed portion corrosion resistance, flexibility, and bending portion corrosion resistance of the coating.
On the other hand, when the weight average molecular weight of the diol (C) is 600 or less, the viscosity of the urethane resin obtained by using the diol (C) becomes insufficient, and the processed part corrosion resistance, the flexibility, and the bending part corrosion resistance of the urethane resin coating are reduced. Is insufficient.
The weight average molecular weight of each component in the present invention is a value measured by GPC (gel permeation chromatography) unless otherwise specified.

(Diol (C) type)
The diol (C) is not particularly limited as long as it does not contain a benzene ring and a nitrogen atom and has a weight average molecular weight exceeding 600. For example, polyether diol, polyester diol, polycarbonate diol and the like can be used.
Examples of the polyether diol include polyethylene glycol, polypropylene glycol, polybutylene glycol (polytetramethylene ether glycol), and the like. The polyether diol is produced, for example, by addition polymerization of alkylene oxide such as ethylene oxide or propylene oxide under a basic catalyst.
Examples of the polyester diol include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid and pimelic acid as acid species, unsaturated carboxylic acids such as castor oil and sebacic acid, and ethylene glycol as alcohol species. Propylene glycol, tetraethylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neo Examples thereof include those produced by esterification with pentyl glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, cyclohexyldimethanol, 1,3-adamantanediol, and the like. .
Examples of the polycarbonate diol include those produced by ring-opening polymerization of cyclic esters such as ε-caprolactone with glycol. Specifically, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like, and the above polyester What was manufactured by making the alcohol seed | species quoted with diol react is mentioned.
Diol (C) may be used individually by 1 type, and may use 2 or more types together.

Among the above, the diol (C) preferably contains a polyether diol. By using polyether diol, the coating adhesion of the urethane resin film and the cohesiveness of the urethane resin can be further improved, and the processed portion corrosion resistance, the flexibility, and the bent portion corrosion resistance can be improved.
The polyether diol is more preferably at least one compound selected from polyethylene glycol, polypropylene glycol, and polybutylene glycol from the viewpoint that the various effects described above are more exhibited.

  Among the diols (C) used in the production of the urethane prepolymer of the present invention, when a polyether diol is used, the urethane resin of the present invention has an ether bond in the main chain. In the case where the urethane resin of the present invention has an ether bond, the brittleness of the coating that is manifested by the introduction of a benzene ring and a cyclohexane ring is further alleviated by the action of the ether bond. As a result, the coating becomes tougher and the processed part corrosion resistance, flexibility, and bent part corrosion resistance become more excellent.

  When using polyether diol, it is preferable to use together at least one of the polyester diol and polycarbonate diol mentioned above from a viewpoint that a flexibility improves more.

(Diol (D) having a weight average molecular weight of 500 or less and containing no benzene ring and nitrogen atom)
A diol (D) having a weight average molecular weight of 500 or less that does not contain a benzene ring and a nitrogen atom (hereinafter, also simply referred to as “diol (D)”) is used for the production of a urethane resin, thereby being derived from a low molecular polyol. Since the number of reaction points due to active hydrogen increases, it is possible to suppress a decrease in the strength of the urethane resin coating, and to improve the coating adhesion, flexibility, and bending portion corrosion resistance of the coating.

(Diol (D) charge amount)
In the production of the urethane prepolymer described later, the amount of the diol (D) charged is the polyisocyanate (A), polyol (B), diol (C), diol (D) and third used in the production of the urethane prepolymer. Although it can be normally made into 1-25 mass% with respect to the total amount of a secondary amine compound (E), it is preferable that it is 1-20 mass%, and it is more preferable that it is 2-15 mass%. More preferably, it is 3-10 mass%.
It exists in the tendency for the coating adhesiveness of the film of a urethane resin to improve more because the preparation amount of a diol (D) exists in the range of 1-20 mass%. In particular, when the amount of the diol (D) is in the range of 2 to 15% by mass, the coating adhesion of the urethane resin coating, the flexibility, and the corrosion resistance of the bent portion tend to be further improved.
In the present invention, in the case of using a “polyol having a benzene ring and a nitrogen atom not containing a triol” described later in the production of the urethane prepolymer, the total amount of the polyols having a benzene ring and a polyol having a nitrogen atom not contained is added to the above total amount. Include in quantity.

(Weight average molecular weight of diol (D))
The weight average molecular weight of the diol (D) is 500 or less, but the upper limit is preferably 400 or less, and more preferably 250 or less. Moreover, it is preferable that a lower limit is 60 or more, and it is more preferable that it is 100 or more.
When the weight average molecular weight of the diol (D) is 500 or less, the coating adhesion of the coating is excellent. Moreover, when the weight average molecular weight of diol (D) exists in the said range, the effect that coating adhesiveness is more excellent is acquired.

(Diol (D) type)
Examples of the diol (D) include ethylene glycol (62.07 g / mol), propylene glycol (76.09 g / mol), 1,5-pentanediol (104.15 g / mol), 1,6-hexanediol ( 118.17 g / mol), 1,7-heptanediol (132.2 g / mol), 1,8-octanediol (146.23 g / mol), 1,9-nonanediol (160.25 g / mol), 1 , 10-decanediol (174.28 g / mol), neopentyl glycol (104.15 g / mol), 2-methyl-1,3-propanediol (90.12 g / mol), 3-methyl-1,5- Pentanediol (118.17 g / mol), 1,4-cyclohexyldimethanol (146.14 g / mol) Alkyl diols such as 1,3-adamantanediol (168.23 g / mol), diethylene glycol (106.12 g / mol), triethylene glycol (150.17 g / mol), tetraethylene glycol (194.23 g / mol), penta Polyalkylene glycols such as ethylene glycol (238.28 g / mol), hexaethylene glycol (282.33 g / mol), heptaethylene glycol (323.28 g / mol), dipropylene glycol (134.17 g / mol), and dimethylol And propionic acid (134 g / mol). These may be used individually by 1 type and may use 2 or more types together.
Among these, the diol (D) is preferably a polyalkylene glycol. When the diol (D) is a polyalkylene glycol, it is possible to increase the Tg of the coating while maintaining coating adhesion, flexibility, and bending portion corrosion resistance. Since Tg is one of the measures representing the cohesiveness, the higher cohesiveness is maintained, and as a result, the coating adhesion of the coating can be further improved.

(Tertiary amine compound (E) having two or more active hydrogens)
A tertiary amine compound (E) having two or more active hydrogens (hereinafter also simply referred to as “tertiary amine compound (E)”) is used in the production of the urethane prepolymer.
The active hydrogen of the tertiary amine compound (E) reacts with the polyisocyanate (A) to obtain a urethane prepolymer (urethane resin) into which a group derived from the tertiary amine compound (E) is introduced. It is done.
The tertiary amine compound (E) only needs to contain two or more active hydrogens, for example, two substituents having active hydrogens such as amino group, hydroxy group, hydroxyamino group, and thiol group. It is preferable that it is contained above.

The tertiary amine compound (E) contributes to the improvement of water dispersibility of the urethane prepolymer (urethane resin) when introduced into the urethane prepolymer (urethane resin). Thereby, the urethane resin of this invention can exist stably in water.
In addition, the tertiary amine compound (E) contributes to aggregation when the urethane resin is formed into a film by electrical interaction of polar groups of the tertiary amine compound (E). As a result, the film obtained from the urethane resin becomes stronger, and thus has high elasticity and high Tg properties. By providing this property, alkali resistance (alkali degreasing portion corrosion resistance) is improved.

Here, the interface between the urethane resin coating (surface treatment coating layer) and the metal substrate tends to be alkaline under the coating because the reduction reaction of dissolved oxygen proceeds. A film having insufficient alkali resistance not only promotes alkaline hydrolysis of the film, but also breaks the bond at the interface between the film and the metal substrate, and easily causes peeling of the film.
For such a problem, the urethane resin of the present invention is potentially excellent in alkali resistance because the structure derived from the tertiary amine compound (E) (tertiary amine) is introduced. That is, since the cationic group (tertiary amine) is in the relationship of an alkaline group (anion) and a counter ion and has resistance to alkali, it has good corrosion resistance and alkali detergency required for metal surface treatment. Bring results.
In addition, the fact that the urethane resin of the present invention has high cohesiveness is one of the factors excellent in alkali resistance. Since the highly cohesive urethane resin has many points of adhesion to the base material (metal material), it sufficiently adheres to the base material and does not easily peel even in an alkaline environment.

(The amount of the tertiary amine compound (E) charged)
In the production of the urethane prepolymer described later, the charged amount of the tertiary amine compound (E) is the polyisocyanate (A), polyol (B), diol (C), diol (D) used in the production of the urethane prepolymer. ) And the total amount of the tertiary amine compound (E), it can usually be 1 to 20% by mass, preferably 2 to 15% by mass, and 2 to 13% by mass. It is more preferable that the content is 3 to 10% by mass.
It exists in the tendency for the alkali resistance of the film of a urethane resin to improve more because the preparation amount of a tertiary amine compound (E) exists in the said range.
In the present invention, in the case of using a “polyol having a benzene ring and a nitrogen atom not containing a triol” described later in the production of the urethane prepolymer, the total amount of the polyols having a benzene ring and a polyol having a nitrogen atom not contained is added to the above total amount. Include in quantity.

(Type of tertiary amine compound (E))
The tertiary amine compound (E) is not particularly limited as long as it is a tertiary amine having two or more active hydrogens. For example, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, Nt N-alkylamino dialkanolamines such as butyldiethanolamine and N- (3-aminopropyl) diethanolamine, triethanolamine, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, bis (2- Trialkanolamines such as hydroxyethyl) aminotris (hydroxymethyl) methane, 1-bis (2-hydroxyethyl) amino-2-propanol, 2,2′-diamino-N-methyldiethylamine, N, N ′, N ″ -Trimethyldiethylenetriamine, tris (2-aminoethyl) Le) polyamines such as amine. These amines may be used as salts with organic acids such as formic acid and acetic acid, inorganic acids such as hydrochloric acid and sulfuric acid, and quaternized with alkylating agents such as dimethyl sulfate, diethyl sulfate and methyl iodide. May be used. As the tertiary amine compound (E), N-alkylamino dialkanolamine, particularly N-methyldiethanolamine is preferable.

The urethane resin of the present invention may be obtained by neutralizing a structural portion (tertiary amine) derived from the tertiary amine compound (E) with an acid or the like. Examples of the acid used in this case include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, tartaric acid, malic acid, malonic acid, adipic acid and other organic carboxylic acids, methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfone Examples include organic acids such as organic sulfonic acids such as acids, and inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, bromic acid, and phosphoric acid. These acids may be used alone or in combination of two or more.
Further, the structural portion (tertiary amine) derived from the tertiary amine compound (E) may be quaternized. Specific examples of the quaternizing agent used for quaternization include sulfates such as dimethyl sulfate and diethyl sulfate, and alkyl halides such as methyl chloride, benzyl chloride, methyl bromide, benzyl bromide, and methyl iodide. , Carbonate esters such as dimethyl carbonate and diethyl carbonate. These quaternizing agents may be used alone or in combination of two or more. Further, an acid as a neutralizing agent and a quaternizing agent may be used in combination.
In the present specification, these acids and quaternizing agents are sometimes referred to as ionizing agents.

  When the metal surface treatment composition of the present invention contains an additive such as an inorganic rust preventive agent as other components described later, a structural portion derived from the tertiary amine compound (E) (tertiary Since the amine) improves the miscibility of additives such as inorganic rust preventives, it is possible to form a coating (surface treatment coating layer) that is superior in corrosion resistance.

(Other components (F) that can be used in the production of urethane prepolymer)
Other components (F) other than those described above may be used for the production of the urethane prepolymer of the present invention. Examples of the other component (F) include a polyisocyanate other than the polyisocyanate (A), a polyol not containing a benzene ring and a nitrogen atom other than the polyol (B), the diol (C) and the diol (D). , Organic solvents, polyamines other than the tertiary amine compound (E), ionizing agents, acids, organometallic compounds, and the like.

(Polyisocyanates other than polyisocyanate (A))
The polyisocyanate other than the polyisocyanate (A) is not particularly limited. For example, 1,4-tetramethylene diisocyanate, ethyl (2,6-diisocyanate) hexanoate, 1,6-hexamethylene diisocyanate, 1,12- Aliphatic diisocyanates such as dodecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate; m- or p-phenylene diisocyanate, 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 ′ − Aromatic diisocyanates such as dimethyldiphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate, tetramethylxylylene diisocyanate; 1,3,6-hexamethylene triisocyanate, 1,8 -Aliphatic triisocyanates such as diisocyanate-4-isocyanate methyloctane and 2-isocyanatoethyl (2,6-diisocyanate) hexanoate; aromatic triisocyanates such as triphenylmethane triisocyanate and tris (isocyanatephenyl) thiophosphate; Can be mentioned. The polyisocyanate other than the polyisocyanate (A) may be a dimer or trimer such as a uretdione structure or an isocyanurate structure, and 3 or more per molecule as an adduct using a polyfunctional polyol. A polyisocyanate having an isocyanate group can be used.
Among these, aromatic polyisocyanates such as aromatic diisocyanates and aromatic triisocyanates are preferably used, and aromatic diisocyanates are preferably used. Thereby, the corrosion resistance of a bending part may improve more.

(Polyol containing no benzene ring and nitrogen atom other than polyol (B), diol (C) and diol (D))
As the polyol (B), the diol (C) and the diol other than the diol (D) and a polyol not containing a nitrogen atom, a polyol having a benzene ring and a triol or more not containing a nitrogen atom can be used. , Trimethylolpropane, pentaerythritol and the like.
Such a polyol of triol or higher which does not contain a benzene ring and a nitrogen atom can have a branched structure in the molecular structure of the urethane prepolymer (urethane resin) to be obtained. Such a branched structure has an effect of increasing the cohesiveness of the urethane resin, and as a result, is effective in corrosion resistance, chemical resistance, solvent resistance, and the like. In addition, since the urethane resin itself is toughened, it is possible to further improve resistance to strong processing such as bending. Since the apparent volume of the urethane resin having a branched structure is increased as compared with a case where the urethane resin does not have a branched structure, an adverse effect on the surface treatment performance can be reduced even with a urethane molecule having a relatively small molecular weight. In particular, it is effective in improving the alkali degreasing portion corrosion resistance (alkali resistance) and the bent portion corrosion resistance.
Of the triol or higher polyols containing no benzene ring and nitrogen atom, trimethylolpropane (TMP) is preferred.
In the case of using a polyol having a benzene ring and a triol or higher that does not contain a nitrogen atom for the production of a urethane prepolymer, the amount charged is the polyisocyanate (A), polyol (B), It is preferably 0.5 to 18% by mass with respect to the total amount of the diol (C), the diol (D), the tertiary amine compound (E), and the triol or higher polyol not containing a benzene ring and a nitrogen atom. It is more preferable that it is 3-10 mass%. Thereby, it exists in the tendency for alkali resistance and bending part corrosion resistance to improve more.

  As described above, the urethane resin of the present invention preferably has a branched structure. However, the method of introducing the branched structure is limited to using a polyol having a benzene ring and a triol or higher that does not contain a nitrogen atom. It is not something that can be done.

  The organic solvent is used as a solvent for reacting each component described above. Examples of such organic solvents include, but are not limited to, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, and ether solvents such as tetrahydrofuran and 1,4-dioxane. Solvents, nitrile solvents such as acetonitrile and acrylonitrile, acrylate solvents such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, amide solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, Examples thereof include sulfoxide solvents such as dimethyl sulfoxide. These organic solvents may be removed by a vacuum distillation method after production of the urethane prepolymer or urethane resin, if necessary, from the viewpoint of reducing environmental burden.

<Method for producing urethane prepolymer and urethane resin>
The urethane prepolymer of the present invention reacts at least the polyisocyanate (A), the polyol (B), the diol (C), the diol (D), and the tertiary amine compound (E). Obtained.
The urethane resin of the present invention is obtained by reacting the urethane prepolymer obtained as described above with at least one of water and a polyamine compound not containing a tertiary amine.
Below, an example (manufacturing method 1-6) of the manufacturing method of the urethane prepolymer and urethane resin of this invention is shown.
(Manufacturing method 1)
A urethane prepolymer is prepared by dissolving polyisocyanate (A), polyol (B), diol (C), diol (D), and tertiary amine compound (E) in an organic solvent and reacting them. A method in which a part or all of the tertiary amine is ionized with an ionizing agent and emulsified by adding water (Production Method 2)
A urethane prepolymer is prepared by dissolving polyisocyanate (A), polyol (B), diol (C), diol (D), and tertiary amine compound (E) in an organic solvent and reacting them. Emulsification by adding water while ionizing a part or all of the tertiary amine therein with an ionizing agent and extending the chain with a chain extender such as polyamine (Production Method 3)
A urethane prepolymer is prepared by reacting polyisocyanate (A), polyol (B), diol (C), diol (D), and tertiary amine compound (E) without using an organic solvent. A method in which a part or all of the tertiary amine in the prepolymer is quaternized with an ionizing agent and emulsified by adding water (production method 4).
After ionizing the tertiary amine compound (E) with an acid or an alkylating agent, the urethane prepolymer is reacted by adding and reacting the polyisocyanate (A), polyol (B), diol (C), diol (D). A method of preparing and emulsifying part or all of the tertiary amine in the urethane prepolymer by ionizing with an ionizing agent and adding water (production method 5)
After reacting polyisocyanate (A), polyol (B), diol (C), and diol (D) with an organic solvent, a tertiary amine compound (E) is further added to form a tertiary amine structure at the terminal site. A method of preparing a urethane prepolymer having water, emulsifying a part or all of a tertiary amine in the urethane prepolymer by ionizing with an ionizing agent and adding water (production method 6)
After reacting polyisocyanate (A), polyol (B), diol (C), and diol (D) with an organic solvent, a tertiary amine compound (E) is further added to form a tertiary amine structure at the terminal site. A method of preparing a urethane prepolymer having a water content, emulsifying by adding water while ionizing a part or all of a tertiary amine in the urethane prepolymer with an ionizing agent and extending the chain with a chain extending agent such as polyamine. In the production methods 1 to 6, known emulsifiers may be used.

<Polyamine not containing water and tertiary amine>
Both the water and the polyamine containing no tertiary amine used for the production of the polyurethane resin have a chain extending action. Since the chain-extended urethane resin has a urea bond in the molecule, it is highly cohesive and suitable for increasing the strength of the coating.
Examples of polyamines not containing tertiary amines include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine. 3,3′-dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, 1,3-bisaminomethylcyclohexane, 2-aminoethylaminopropyltrimethoxysilane; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine; Razine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionic acid hydrazide, 3-semicarbazidepropylcarbazic acid ester, semicarbazide-3 -Semicarbazide methyl-3,5,5-trimethylcyclohexane; and the like can be used. Among these, it is preferable to use hydrazine or ethylenediamine.

The amount of the polyamine not containing water and tertiary amine is preferably 0.1 to 600 parts by mass, more preferably 0.2 to 500 parts by mass with respect to 100 parts by mass of the urethane prepolymer. preferable. By being in this range, the effect | action by adding the polyamine which does not contain water and a tertiary amine improves more.
When only one of polyamines not containing water and a tertiary amine is used, the above-mentioned “amount of polyamine not containing water and a tertiary amine” means water or a tertiary amine. Refers to the charge amount of only one of polyamines not containing.

<< Other components that can be contained in the metal surface treatment composition >>
The metal surface treatment composition of the present invention may contain components other than those described above. Components other than the above include, for example, film-forming aids (such as organic solvents) that improve film-forming properties and film drying properties, surfactants that improve wettability, antifoaming agents and leveling agents that suppress foaming , Conductive materials for improving weldability, coloring pigments for improving design, rust preventives that suppress the generation of rust, stability of metal surface treatment composition and blending in a range that does not impair the effects of the present invention Can do.

  Although it does not specifically limit as a film-forming adjuvant, For example, glycols, such as methanol, ethanol, 2-propyl alcohol, t-butyl alcohol, etc .; Ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monopropyl ether Alkyl ethers; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as tetrahydrofuran and 1,4-dioxane; nitrile solvents such as acetonitrile and acrylonitrile Acrylate solvents such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate; dimethylformamide, dimethylacetamide, N-methyl Amido solvents such as loridone and N-ethylpyrrolidone; sulfoxides such as dimethyl sulfoxide; dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, diethyl succinate, diethyl glutarate, diethyl adipate And the like, and the like. These film-forming aids may be used alone or in combination of two or more.

  Examples of the surfactant include nonionic surfactants such as alkyl allyl ether, alkyl ether, alkyl ester, and alkyl amine, and fatty acid salts, alkyl sulfate esters, aliphatic amine sulfates, Anionic surfactants such as sulfonates of basic fatty acid esters can be mentioned. These surfactants may be used alone or in combination of two or more.

Examples of the conductive substance include conductive metal fine powder and carbon fine powder.
Examples of the color pigment include inorganic pigments such as carbon black and titanium oxide, and organic pigments such as phthalocyanine.

  Examples of the rust preventive include phosphoric acid compounds, chromic acid compounds, vanadium compounds, molybdate compounds, zirconium compounds, titanium compounds, cerium compounds, manganese compounds, tungstic compounds, boric acid compounds. , Nitric compounds, hydrofluoric acid, colloidal silica, and the like.

  Other additives include, for example, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacrylpropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoethyl-3-aminopropyltri Examples include silane coupling agents such as methoxysilane, organic titanium compounds such as tetraisopropoxy titanium and tetra n-butoxy titanium, tetraisopropoxy zirconium, and tetra n-butoxy zirconium. Since these additives exhibit an antifoaming effect, the handleability is improved. At the same time, the film-forming effect is advantageous for corrosion resistance and solvent resistance.

The metal surface treatment composition of the present invention may further contain various known additives that are generally used as necessary. Examples of such additives include rust preventive pigments, dyes, inorganic crosslinking agents, organic crosslinking agents (for example, blocked isocyanate crosslinking agents, epoxy crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, melamine crosslinking agents). Agent), anti-blocking agent, viscosity modifier, thickener, dispersion stabilizer, light stabilizer, antioxidant, ultraviolet absorber, inorganic filler, organic filler, plasticizer, lubricant, antistatic agent, etc. It is done.
Moreover, the metal surface treatment composition of this invention may contain an acrylic resin, an epoxy resin, a polyester resin, a polyamide resin, etc.

[Metallic material manufacturing method]
The method for producing a metal material of the present invention is a method for producing a metal material having a metal substrate and a surface-treated coating layer formed on the surface of the metal substrate, and includes the above-described metal surface treatment composition. And a step of surface-treating the surface of the metal substrate to form the surface-treated coating layer.
Since the metal material thus obtained has the surface treatment coating layer, the above-described excellent effect of the surface treatment coating layer is exhibited.
As a surface treatment method using the metal surface treatment composition, a known method described later can be employed.

<Metal base material>
The type of metal base material constituting the metal material is not particularly limited, and is a cold-rolled steel sheet, hot-rolled steel sheet, hot-dip galvanized steel sheet, aluminum-containing galvanized steel sheet, electrogalvanized steel sheet, galvannealed steel sheet, zinc-nickel plating Steel plates, zinc-cobalt-plated steel plates, vapor-deposited galvanized steel plates, nickel-plated steel plates, tin-plated steel plates, carbon steel plates such as stainless steel plates, alloy steel plates and plated steel plates; metal plates other than steel plates such as aluminum plates, copper plates, titanium plates and magnesium plates Generally known materials such as can be used. Particularly suitable metal base materials are galvanized steel sheets such as hot dip galvanized steel sheets, aluminum-containing galvanized steel sheets, electrogalvanized steel sheets, alloyed galvanized steel sheets, zinc nickel plated steel sheets, zinc cobalt plated steel sheets, and evaporated galvanized steel sheets. It is.

Here, the metal substrate may be subjected to a chromate treatment or a phosphate treatment as a base treatment.
In recent years, the trend toward non-chromium has increased due to problems such as environmental pollution, occupational health, and safety. However, if the surface treatment coating layer of the present invention is provided, a metal that has not been subjected to chromate treatment or phosphate treatment. Even if a base material is used, sufficient corrosion resistance, chemical resistance, solvent resistance and paint adhesion can be exhibited.

<Surface treatment film layer>
The surface treatment coating layer is formed using the above metal surface treatment composition, and the metal surface treatment composition is converted into a metal base by a known method (for example, coating method, dipping method, spray method, electrolytic method, etc.). It is formed by applying to the surface of the material.

Here, prior to the treatment with the metal surface treatment agent, cleaning with a degreasing agent (acid-based or alkali-based), hot water washing, pickling, solvent washing, etc. is appropriately performed in order to remove oil and dirt adhering to the metal substrate. You may carry out in combination.
Further, before the treatment with the metal surface treatment liquid, surface adjustment may be performed for the purpose of further improving the corrosion resistance of the coating or further improving the coating adhesion. The method for adjusting the surface is not particularly limited, and examples thereof include a chemical conversion treatment for depositing a metal such as Fe, Co, Ni, Cu, Zn, Mn, Zr, Ti, or V, and a phosphate chemical conversion treatment.
In washing the surface of the metal substrate, it is preferable to wash with water after washing from the viewpoint of reducing the residue of the cleaning agent remaining on the surface of the metal substrate.

  Hereinafter, the metal surface treatment composition of the present invention will be described in detail using examples. However, the present invention is not limited to this.

[Urethane resin]
Prior to the preparation of the metal surface treatment compositions of Examples and Comparative Examples, urethane resins used for the compositions were produced.

<Synthesis Example 1>
In a 2 L separable flask equipped with a stirrer, 63 g of bisphenol A-polyoxyethylene 2-mol adduct (New Pole BPE-20T, manufactured by Sanyo Chemical Industries, Ltd.) (B1 described later) as a benzene ring supply source, polymer polyol supply source As polyethylene glycol (PEG2000, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (C1 described later) 67 g, N-methyldiethanolamine (amino alcohol MDA, manufactured by Nippon Emulsifier Co., Ltd.) (described later E1) 30 g; (Manufactured by Nippon Shokubai Co., Ltd.) (D1 described later) 30 g and isophorone diisocyanate (Desmodur I, Bayer manufactured) (230 g described later) (230 g described later) were added together with 400 g of methyl ethyl ketone and sufficiently dissolved. After reacting this mixed solution at 80 ° C. for about 5 hours, it was confirmed that 3% or less isocyanate group was contained, and 25 g of dimethyl sulfate (an ionizing agent A described later) was added as an ionizing agent (urethane prepolymer). Manufacturing of).
Next, 1000 g of deionized water was added to prepare a urethane emulsion (production of urethane resin). Methyl ethyl ketone was removed from the obtained urethane emulsion by a vacuum distillation method to prepare a urethane emulsion having a urethane resin concentration of 25% by mass. Table 1 shows each component used in this synthesis and the amount charged (% by mass). Hereinafter, the urethane emulsion thus obtained is also referred to as a urethane resin of Synthesis Example 1.

<Synthesis Examples 2-84>
A urethane emulsion of Synthesis Examples 2 to 84 (a urethane resin of Synthesis Examples 2 to 84) was prepared in the same manner as in Synthesis Example 1 except that the components and preparation amounts (mass%) in Table 1 were used.

<Synthesis Example 85>
Except for using 25 g of ionizing agent B (85% phosphoric acid) instead of 25 g of ionizing agent A (dimethyl sulfate), the urethane emulsion of Synthesis Example 85 (the urethane of Synthesis Example 85) was prepared in the same manner as in Synthesis Example 1. Resin) was prepared.

<Synthesis Example 86>
The urethane emulsion of Synthesis Example 86 (the urethane resin of Synthesis Example 86) was prepared in the same manner as in Synthesis Example 1 except that 10 g of ionizing agent C (formic acid) was used instead of 25 g of ionizing agent A (dimethyl sulfate). Prepared.

Each component described in Table 1 to be described later is as follows. In addition, the preparation amount (mass%) of each component described in Table 1 is based on the total amount of the components (A) to (E), and when the component (F) is used, this is also included in the total amount. Including calculation. In addition, all the urethane prepolymers obtained by each synthesis example contained an isocyanate group.
<Polyisocyanate (the following part is polyisocyanate (A) having a cyclohexane ring structure)>
A1: Isophorone diisocyanate (Desmodur I, manufactured by Bayer)
A2: 1,3-bis (isocyanate methyl) cyclohexane (Takenate 600, manufactured by Mitsui Chemicals)
A3: Dicyclohexylmethane 4,4′-diisocyanate (Desmodur W, manufactured by Bayer)
A4: Tolylene diisocyanate (Cosmonate T80, manufactured by Mitsui Chemicals)
A5: Hexamethylene diisocyanate (50M-HDI, manufactured by Asahi Kasei Corporation)
<Polyol (B) not containing nitrogen atom and containing benzene ring>
B1: Bisphenol A-polyoxyethylene 2-mole adduct (New Pole BPE20T, manufactured by Sanyo Chemical Industries)
B2: Aromatic dibasic polyester polyol (Teslac 2508-70, manufactured by Hitachi Chemical Co., Ltd.)
B3: Polycarbonate diol (Nipporan 981, manufactured by Tosoh Corporation)
<Polymer polyol (part of the following is a diol (C) having a weight average molecular weight of more than 600 which does not contain a benzene ring and a nitrogen atom)>
C1: Polyethylene glycol (PEG2000, Mw2000, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
C2: Polypropylene glycol (Uniol D700, Mw700, manufactured by NOF Corporation)
C3: Polyethylene glycol (PEG1000, Mw1000, manufactured by Sanyo Chemical Industries)
C4: Polyethylene glycol (PEG 4000, Mw 3000, manufactured by Sanyo Chemical Industries)
C5: Polypropylene glycol (Uniol D4000, Mw4000, manufactured by NOF Corporation)
C6: Polybutylene glycol (Uniol PB4800, Mw5000, manufactured by NOF Corporation)
C7: Polyethylene glycol (PEG6000, Mw8600, manufactured by Sanyo Chemical Industries)
C8: Polyester polyol (Nipporan 4040, Mw2000, manufactured by Tosoh Corporation)
C9: Polycarbonate glycol (Nipporan 982R, Mw2000, manufactured by Tosoh Corporation)
C10: Polypropylene glycol (Sanix PP2000, Mw2000, manufactured by Sanyo Chemical Industries)
C11: Polybutylene glycol (PTMG2000, Mw2000, manufactured by Mitsubishi Chemical Corporation)
C12: C1 + C8 (mass ratio 1: 1)
C13: C1 + C9 (mass ratio 1: 1)
C14: Polyester glycol (K-FLEX XM360, Mw520, manufactured by KING)
<Low molecular polyol (a part of the following is a diol (D) having a weight average molecular weight of 500 or less that does not contain a benzene ring and a nitrogen atom)>
D1: Diethylene glycol (diethylene glycol, Mw106, manufactured by Nippon Shokubai Co., Ltd.)
D2: Ethylene glycol (ethylene glycol, Mw 62, manufactured by Nippon Shokubai Co., Ltd.)
D3: Tetraethylene glycol (tetraethylene glycol, Mw194, manufactured by Nippon Shokubai Co., Ltd.)
D4: Polyethylene glycol (PEG400, Mw400, manufactured by Sanyo Chemical Industries)
D5: Polyethylene glycol (PEG500, Mw500, manufactured by Kanto Chemical Co., Inc.)
D6: 1,6-hexanediol (1,6-hexanediol, Mw106, manufactured by Ube Industries)
D7: Cyclohexanedimethanol (CHDM-D, Mw144, manufactured by EASTMAN)
D8: 1,5-pentanediol (1,5-pentanediol, Mw104, manufactured by Ube Industries)
D9: Polyester polyol (Placcel 205, Mw530, manufactured by Daicel Chemical Industries)
<Tertiary amine compound (E)>
E1: N-methyldiethanolamine (amino alcohol MDA, manufactured by Nippon Emulsifier Co., Ltd.)
<Polyol more than triol not containing benzene ring and nitrogen atom>
F1: Trimethylolpropane (TMP, manufactured by Perstorp)
<Ionizing agent>
Ionizing agent A: dimethyl sulfate (dimethyl sulfate, manufactured by Enomoto Chemical Co.)
Ionizing agent B: 85% phosphoric acid (manufactured by Nippon Chemical Industry Co., Ltd.)
Ionizing agent C: Formic acid (manufactured by Junsei Kagaku)
<Other components (used in any of Comparative Examples 9 to 12 described later)>
Melamine: Melamine (Pure Chemical Co., Ltd.)
Adipic acid dihydrazide: Adipic acid dihydrazide (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Comparative Synthesis Examples 1-12>
Except having set it as the component of Table 1, and the preparation amount (mass%), it was made into the manufacturing method similar to the synthesis example 1, and prepared the urethane emulsion of the comparative synthesis examples 1-8 (the urethane resin of the synthesis examples 1-8). .
Further, urethane emulsions of Comparative Synthesis Examples 9 to 11 (urethane resins of Comparative Synthesis Examples 9 to 11) were synthesized according to Example 10, Example 11, and Example 9 of International Publication No. 2005/092998, respectively.
Further, the urethane emulsion of Comparative Synthesis Example 12 (the urethane resin of Comparative Synthesis Example 12) was synthesized according to Production Example 1 of JP-A-10-110093.

[Metal surface treatment composition]
Each evaluation test was implemented using the metal surface treatment composition containing each urethane resin obtained as mentioned above.
Below, after explaining about the test material (metal base material) used for an evaluation test, preparation of a metal surface treating agent, and a surface treatment method, each evaluation test method and evaluation result are shown.

<Sample material (metal substrate)>
The following materials were used as test materials (metal base materials) for surface treatment.
GI: Hot-dip galvanized steel sheet (plate thickness: 0.6 mm, plating coverage: 50 g / m ^{2 on} one side)
EG: electrogalvanized steel sheet (plate thickness: 0.6 mm, plating adhesion: 20 g / m ^{2 on} one side)
GL: Hot-dip galvanized steel sheet (plate thickness: 0.4 mm, plating coverage: 75 g / m ^{2 on} one side)

<Preparation of metal surface treatment composition>
100 parts by mass of the urethane resin of the synthesis example and the comparative synthesis example, 186 parts by mass of water, 20 parts by mass of colloidal silica, 10 parts by mass of 75% phosphoric acid, 10 parts by mass of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Silicone) Were added and mixed well to prepare metal surface treatment compositions of Examples and Comparative Examples.

<Surface treatment>
After degreasing the above test material (metal substrate) with an alkaline degreasing agent Fine Cleaner E6406 (20 g / L building bath, 60 ° C., 10 seconds spray, spray pressure 0.5 kg / cm ² ) manufactured by Nihon Parkerizing, Spray water washing was performed for 10 seconds.
The above degreased specimen (metal substrate) was coated by bar coating so that the film thickness after drying of the metal surface treatment composition was 2 μm, and 150 ° C. (PMT: highest of specimens during baking) (Plate temperature).

<Evaluation test>
(Corrosion resistance)
Various corrosion resistance tests were performed on the GI, EG, and GL treated plate samples subjected to the surface treatment as described above. Evaluation methods and evaluation criteria are as follows.

-Plane part corrosion resistance Based on the salt spray test method (JIS-Z-2371), the ratio (%) of the white rust generation | occurrence | production area | region 240 hours after salt spray was calculated | required, and the following references | standards evaluated. About the flat part corrosion resistance, Δ or more was regarded as acceptable.
◎: Less than 5% ◎: 5% or more and less than 10% ○○: 10% or more and less than 20% ○: 20% or more and less than 30% Δ: 30% or more and less than 40% ×: 40% or more

-Corrosion resistance of the processed part The test piece extruded 8 mm with an Erichsen tester was found based on the salt spray test method (JIS-Z-2371), and the ratio (%) of white rust generation area after 720 hours of salt spray was determined as follows. Evaluation was made according to the criteria. About processed part corrosion resistance, (triangle | delta) or more was set as the pass.
◎: Less than 5% ◎: 5% or more and less than 10% ○○: 10% or more and less than 20% ○: 20% or more and less than 30% Δ: 30% or more and less than 40% ×: 40% or more

・ Corrosion resistance of alkaline degreasing part (alkali resistance)
The treated plate sample was sprayed with a degreasing agent aqueous solution adjusted to 65 ° C. with alkaline degreasing agent Fine Cleaner E6406 manufactured by Nihon Parkerizing Co., Ltd. at 20 g / L for 2 minutes, washed with water and dried.
Then, based on the salt water spray test method (JIS-Z-2371), the ratio (%) of the white rust generation | occurrence | production area 72 hours after salt water spraying was calculated | required, and the following references | standards evaluated. Regarding alkali resistance, Δ or more was regarded as acceptable.
◎: Less than 5% ◎: 5% or more and less than 10% ○○: 10% or more and less than 20% ○: 20% or more and less than 30% Δ: 30% or more and less than 40% ×: 40% or more

-Bending portion corrosion resistance Two plates having the same thickness as the original plate were stacked and sandwiched between the processed plate samples and subjected to 180 degree bending. Then, based on the salt spray test method JIS-Z-2371, the ratio (%) of the white rust generation | occurrence | production area 48 hours after salt spray was calculated | required, and the following references | standards evaluated. About the bending part corrosion resistance, Δ or more was regarded as acceptable.
◎: Less than 5% ◎: 5% or more and less than 10% ○○: 10% or more and less than 20% ○: 20% or more and less than 30% Δ: 30% or more and less than 40% ×: 40% or more

(Paint adhesion)
Using the melamine alkyd paint (Delicon # 700, manufactured by Dainippon Paint Co., Ltd.), the above-mentioned treated plate sample was coated. The coating was performed by bar coating. After coating, baking was performed at 140 ° C. for 20 minutes. At that time, the coating of the bar coat was adjusted so that the film thickness after baking and drying was 25 μm. Thereafter, extrusion processing of 7 mm was performed with Erichsen, the processed part was peeled off with tape, and the ratio (%) of the peeled area after tape peeling was evaluated based on the following evaluation criteria. Regarding coating adhesion, Δ or more was regarded as acceptable.
◎◎: 0% peel area (no peel)
A: Peeling area is more than 0% and less than 5% B: Peeling area is 5% or more and less than 10% B: Peeling area is 10% or more and less than 20% B: Peeling area is 20% or more and less than 30% X: Peeling area 30% or more

(Solvent resistance)
The gauze impregnated with methyl ethyl ketone (MEK) was slid 10 times while being pressed against the above-treated surface treated sample with a 1 kg load, and then the appearance was measured with a color difference meter (manufactured by Nippon Denshoku Co., Ltd.) as follows. Evaluation was performed based on the evaluation criteria. Regarding solvent resistance, Δ or more was regarded as acceptable.
◎◎: △ E Less than 0.5 ◎: △ E 0.5 or more and less than 1 ○○: △ E 1 or more and less than 1.5 ○: △ E 1.5 or more and less than 2 △: △ E 2 or more and less than 3 ×: △ E 3 or more

(Flexibility)
Carbon black was blended in the metal surface treatment compositions of the examples and comparative examples, and bar coating was applied to the test material to 3 μm, followed by drying at 150 ° C. (PMT). Carbon black was blended so as to be 5% by mass with respect to 100% by mass of the total amount of carbon black and each metal surface treatment composition in Examples and Comparative Examples.
The treated plate sample was subjected to 180 ° bending (OT bending), and cracks in the bent portion were visually evaluated according to the following evaluation criteria. As for the flexibility, Δ or more was regarded as acceptable.
◎◎: No crack ◎: 1 to 5 cracks (no crack exceeding 1 cm)
◯: 6 to 15 cracks of 1 cm or less (no cracks exceeding 1 cm)
○: 1 cm or less cracks 16 to 25 (no cracks exceeding 1 cm)
Δ: 26 or more cracks of 1 cm or less (no cracks exceeding 1 cm)
×: Cracks exceeding 1 cm are observed

<Evaluation results>
The results of the above evaluation tests are shown in Table 1 below.

  The “charge amount” column in Table 1 represents the mass% of the charge of each component used in the production of the urethane prepolymer.

As shown in the evaluation results of Table 1, when the metal surface treatment composition containing the urethane resin of the example is used, the flexibility, the flat surface corrosion resistance, the solvent resistance, the alkaline degreasing portion corrosion resistance, the processed portion corrosion resistance, the bent portion It was shown that a surface-treated coating layer having excellent corrosion resistance and paint adhesion can be formed on the surface of a metal substrate.
Moreover, by contrast of Examples 1-4, by containing the polyol (trimethylol propane) more than triol which does not contain a benzene ring and a nitrogen atom (Examples 3 and 4), alkali resistance (alkali degreasing part corrosion resistance) and bending It was shown that the partial corrosion resistance was further improved.
Comparison of Examples 1, 2 and 8 showed that solvent resistance was further improved when dicyclohexylmethane 4,4′-diisocyanate was used as polyisocyanate (A) (Example 8).
By contrast with Examples 5-11, the amount of polyisocyanate (A) used is the polyisocyanate (A), polyol (B), high molecular diol (C), low molecular diol (D) used in the production of the urethane prepolymer. ) And the tertiary amine compound (E) in a total amount of 40 to 65% by mass (Examples 7 to 10), the solvent resistance was further improved.
Comparison of Examples 8, 12 and 13 showed that when polyether polyol was used as polyol (B) (Example 8), the planar portion corrosion resistance was further improved.
By comparison with Examples 14 to 20, the amount of polyol (B) charged is polyisocyanate (A), polyol (B), high molecular diol (C), low molecular diol (D) used in the production of the urethane prepolymer. It was shown that the bending portion corrosion resistance was further improved by being 6 to 20% by mass with respect to the total amount of the tertiary amine compound (E) (Examples 16 and 17).
By comparing Examples 21 to 26, by using the diol (C) having a weight average molecular weight in the range of 800 to 4000 (Examples 22 to 24), the processed portion corrosion resistance, the flexibility, and the bent portion corrosion resistance are further improved. Was shown to do. The same tendency was confirmed for Examples 28 to 30 in the comparison of Examples 27 to 32.
Moreover, by contrast with Examples 33-40, the preparation amount of diol (C) is polyisocyanate (A) used for manufacture of a urethane prepolymer, a polyol (B), high molecular diol (C), low molecular diol ( D) and the tertiary amine compound (E) and other components (F) with respect to the total amount of 3 to 40% by mass (Examples 34 to 39), coating adhesion, processed part corrosion resistance, It was shown that the flexibility and the corrosion resistance of the bent portion are further improved. Furthermore, it is shown that these effects are exhibited more significantly when the amount of the diol (C) is in the range of 5 to 35% by mass (Examples 35 to 38). The same tendency was confirmed also about Examples 42-45 in.
When a metal surface treatment composition containing a urethane resin produced using a polyether diol as the diol (C) is used according to the comparison between Examples 46 to 51 and the comparison between Examples 52 to 57 (Examples 48 to 51, 54 to 57), it was shown that the processed part corrosion resistance, the flexibility and the bent part corrosion resistance become better. In particular, as a diol (C), a polyether diol and at least one of a polyester diol and a polycarbonate diol are used in combination (Examples 50, 51, 56, and 57), and the flexibility is further improved. It has been shown.
The comparison of Examples 58 to 64 shows that the coating adhesion is further improved when the weight average molecular weight of the diol (D) is in the range of 60 to 400 (Examples 58 to 60 and 62 to 64). It was done.
By comparison with Examples 65-71, the charged amount of diol (D) is polyisocyanate (A), polyol (B), high molecular diol (C), low molecular diol (D) used in the production of urethane prepolymer. It was shown that the coating adhesion was further improved by being 1 to 20% by mass with respect to the total amount of the tertiary amine compound (E) (Examples 65 to 70).
By comparing Examples 72 to 77, the amount of the tertiary amine compound (E) charged is polyisocyanate (A), polyol (B), high molecular diol (C), low molecular weight used in the production of the urethane prepolymer. Alkali resistance (alkali degreasing part corrosion resistance) is further improved by being 2 to 15% by mass with respect to the total amount of diol (D) and tertiary amine compound (E) (Examples 73 to 76). It has been shown.
By comparison with Examples 78 to 84, the amount of the polyol (trimethylolpropane) of triol or higher containing no benzene ring and nitrogen atom is used for the production of the urethane prepolymer, polyisocyanate (A), polyol (B), By being 3-10 mass% with respect to the total amount of high molecular diol (C), low molecular diol (D), tertiary amine compound (E), and other components (F) (Example 80- 81), alkali resistance (alkali degreasing portion corrosion resistance) and bending portion corrosion resistance were further improved.
By comparing Examples 1, 85, and 86, it was shown that even if the type of ionizing agent was changed, all had excellent effects.
It was also shown that excellent effects were obtained when GI (Examples 27I to 32I) and GL (Examples 27L to 32L) were used as test agents.

  On the other hand, when the metal surface treatment composition containing the urethane resin of the comparative example was used, it was shown that a surface treatment film layer having desired performance cannot be formed on the surface of the metal substrate.

Claims (9)

A metal surface treatment composition containing a urethane resin,
The urethane resin is obtained by reacting a urethane prepolymer with at least one of water and a polyamine compound not containing a tertiary amine,
The urethane prepolymer includes a polyisocyanate (A) having a cyclohexane ring structure, a polyol (B) not containing a nitrogen atom and containing a benzene ring, and a diol having a weight average molecular weight exceeding 600 and not containing a benzene ring and a nitrogen atom ( A metal obtained by reacting C) with a diol (D) having a weight average molecular weight of 500 or less, which does not contain a benzene ring and a nitrogen atom, and a tertiary amine compound (E) having two or more active hydrogens Surface treatment composition.   The metal surface treatment composition according to claim 1, wherein the diol (D) has a weight average molecular weight of 60 or more and 400 or less.   The metal surface treatment composition according to claim 1 or 2, wherein the diol (C) has a weight average molecular weight of 800 or more and 4000 or less.   The charged amount of the diol (C) is such that the polyisocyanate (A), the polyol (B), the diol (C), the diol (D) and the tertiary amine used in the production of the urethane prepolymer. The metal surface treatment composition of any one of Claims 1-3 which is 3-40 mass% with respect to the total amount of a compound (E).   The charged amount of the diol (D) is such that the polyisocyanate (A), the polyol (B), the diol (C), the diol (D) and the tertiary amine used in the production of the urethane prepolymer. The metal surface treatment composition according to any one of claims 1 to 4, which is 1 to 20% by mass relative to the total amount of the compound (E).   The metal surface treatment composition according to claim 1, wherein the diol (C) includes a polyether diol.   The metal surface treatment composition according to claim 6, wherein the polyether diol is at least one compound selected from polyethylene glycol, polypropylene glycol, and polybutylene glycol.   The polyisocyanate (A) is at least one compound selected from isophorone diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, and dicyclohexylmethane 4,4'-diisocyanate. 2. The metal surface treatment composition according to item 1. A metal base material, and a surface treatment coating layer formed on the surface of the metal base material, a method for producing a metal material,
The manufacturing method of a metal material which has the process of surface-treating the surface of the said metal base material with the metal surface treatment composition of any one of Claims 1-8, and forming the said surface treatment film layer.