WO2013099749A1 - Electrodeposition coating composition, and dissociation catalyst therefor - Google Patents

Abstract

Provided is an organotin-free cationic electrodeposition coating composition which is capable of ensuring excellent coating film curability under baking conditions identical to those used in common practice, without including an organotin compound. According to the present invention, provided is an electrodeposition coating composition including (A) a quaternary phosphonium salt represented by formula (1), and (B) a base resin (in formula (1): R1-R4 are the same as or different to one another, each of which representing a C1-8 hydrocarbon group, an aromatic hydrocarbon group, or a C1-8 hydrocarbon group or an aromatic hydrocarbon group substituted by a functional group other than a hydroxyl group; and X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide).

Description

Electrodeposition coating composition, dissociation catalyst for electrodeposition coating composition

The present invention includes an organic tin-free electrodeposition coating composition that does not contain an organic tin compound and can ensure good coating curability under the same baking conditions as the present, and is contained in this composition. It relates to a dissociation catalyst.

In order to protect the metal material from corrosion and maintain its aesthetics during use, the surface is generally painted. Electrodeposition coating is a primer coating for parts with a bag structure such as automobiles, electrical appliances, etc., because it has better throwing power and less environmental pollution than air spray coating and electrostatic spray coating. As a result, it has been widely put into practical use. In particular, cationic electrodeposition coating can be applied continuously, and is therefore widely used as a method for undercoating a large article such as an automobile body that requires high corrosion resistance.

Cationic electrodeposition coating generally uses a coating component as a cathode in a cationic electrodeposition coating composition in which a binder component containing a cationic resin and a curing agent is dispersed in an aqueous medium containing a neutralizing agent such as an organic acid. It is performed by immersing and applying a voltage.

When a voltage is applied between the electrodes during the coating process, an electrodeposition coating film is deposited on the surface of the cathode (substrate) due to an electrochemical reaction. Since the electrodeposition coating film thus formed contains a curing agent together with a cationic resin, the coating film is cured by baking the coating film after completion of electrodeposition coating, and a desired cured coating film is formed. Is done.

As the cationic resin used in the cationic electrodeposition coating composition, an amine-modified epoxy resin is used from the viewpoint of corrosion resistance, and as a curing agent, a block crosslinking agent in which a reactive site is blocked with a blocking agent (eg, polyisocyanate). Block polyisocyanates blocked with a blocking agent such as alcohol have been used.

Further, in order to improve the curability, which is a measure of various performances of the coating film, a dissociation catalyst of a block cross-linking agent is added, and an organic tin compound has been used as a typical dissociation catalyst.

However, organotin compounds can cause deodorization catalyst poisoning in baking furnaces in painting lines, and future use may be restricted due to recent environmental regulations for organotin compounds. It has been desired to develop a cationic electrodeposition coating composition that uses a dissociation catalyst instead of.

Cationic electrodeposition coating compositions using zinc borate, quaternary ammonium organic acid salts, zinc compounds and the like as alternative dissociation catalysts for the organotin compounds have been proposed (Patent Documents 1 to 3).
However, these compounds have insufficient effects as dissociation catalysts, and the curability and anticorrosion properties are not practically satisfactory.

Further, as a cationic electrodeposition coating composition not containing an organic tin compound, a cationic electrodeposition coating composition containing a water-soluble or water-dispersible phosphonium group-containing compound obtained by reacting a phosphonium group-containing compound with an epoxy compound is provided. It has been proposed (Patent Document 4). However, this technique is intended to improve the anticorrosion property, and the effect as a dissociation catalyst is not satisfactory, and it is necessary to add an organic tin compound such as dibutyltin oxide as a dissociation catalyst.

Thus, there has never been a cationic electrodeposition coating composition that does not contain an organic tin compound and can ensure good coating curability under the same baking conditions as the current one.

JP 7-331130 A Japanese Patent Laid-Open No. 11-152432 JP 2000-336287 A JP 2002-265878 A

The present invention has been made in view of the above circumstances, and does not contain an organic tin compound, and an organic tin-free cationic electrodeposition coating composition that can ensure good coating curability under the same baking conditions as the current one. The purpose is to provide goods.

That is, according to the present invention, the general formula (1):

[Wherein R ¹ to R ⁴ are the same or different and each has 1 to 8 carbon atoms substituted with a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, or a functional group other than a hydroxyl group. A hydrocarbon group or an aromatic hydrocarbon group is represented. X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide. An electrodeposition coating composition containing a quaternary phosphonium salt A represented by formula (II) and a base resin B is provided.

In order to solve the above-mentioned problems, the present inventors evaluated the performance of many substances as a dissociation catalyst of a block cross-linking agent (block polyisocyanate, etc.). As a result, an electric charge containing a quaternary phosphonium salt having a specific structure was obtained. The present inventors have found that the coating composition has very excellent characteristics and have completed the present invention.

It should be noted that the quaternary phosphonium salt is similar to the quaternary ammonium salt in terms of electronic structure, but the performance of the quaternary phosphonium salt as a dissociation catalyst is nonetheless It was a surprising result that far exceeded.

Further, the influence of R ¹ to R ⁴ in the general formula (1) on the performance was not large, and the evaluation result did not change greatly between 1 and 8 carbon atoms. When R ¹ to R ⁴ were a phenyl group, the evaluation results were slightly inferior to those when R ¹ to R ⁴ were an alkyl group, but sufficient results for practical use were obtained. Furthermore, although made many evaluated if R ^{1 ~} R ⁴ are all in consideration of the time of the experiment are the same, was evaluated for the case where R 1 ^~ R ⁴ are different from each other, R ¹ ~ because if R ⁴ are all identical and similar results were obtained, it was found that it is not necessary R 1 ^~ R ⁴ are not all identical.

Also, the influence of X in the general formula (1) on the performance was not great, and almost the same evaluation results were obtained with various organic acids and sulfonic acids. When X was a halide, the evaluation result was slightly inferior to that of an organic acid or sulfonic acid, but a result that could sufficiently withstand practical use was obtained.

In Patent Document 4, a quaternary phosphonium salt having an alkyl group substituted with a hydroxyl group is used as an anticorrosive agent. However, when the catalytic performance of this substance was evaluated, good results were not obtained. On the other hand, when the catalytic performance of the quaternary phosphonium salt having an alkyl group substituted with an alkoxy group was evaluated, the same result as that of the quaternary phosphonium salt having an unsubstituted alkyl group was obtained. From these results, it was concluded that if the substituents of R ¹ to R ⁴ were other than a hydroxyl group, the influence on the evaluation results was not significant.

According to the present invention, it is possible to provide a cationic electrodeposition coating composition excellent in curability, corrosion resistance, and finish properties equivalent to or higher than that in the case where it is blended without using an organic tin compound. .

Hereinafter, the details of the present invention will be described.

Electrodeposition paint composition The electrodeposition paint composition of the present invention comprises:
General formula (1):

[Wherein R ¹ to R ⁴ are the same or different and each has 1 to 8 carbon atoms substituted with a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, or a functional group other than a hydroxyl group. A hydrocarbon group or an aromatic hydrocarbon group is represented. X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide. A quaternary phosphonium salt A and a base resin B.

<Quaternary phosphonium salt A>
In the general formula (1), R ¹ to R ⁴ are the same or different and each is substituted with a functional group other than a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, or a hydroxyl group. Represents 8 to 8 hydrocarbon groups or aromatic hydrocarbon groups.

Examples of the hydrocarbon group having 1 to 8 carbon atoms include saturated carbonization such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, and octyl group. Examples thereof include unsaturated hydrocarbon groups such as a hydrogen group, a vinyl group, an allyl group, a prenyl group, a crotyl group, and a cyclopentadienyl group.
Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, and a benzyl group.
Examples of the hydrocarbon group having 1 to 8 carbon atoms or aromatic hydrocarbon group substituted with a functional group other than a hydroxyl group include an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, and an ethoxyethyl group. Can be mentioned.
Of these, a hydrocarbon group having 1 to 8 carbon atoms is preferable, and an ethyl group and a butyl group are particularly preferable.

In general formula (1), X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide.
Examples of the organic acid of the organic acid group include aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, 2-ethylbutyric acid, 2-ethylhexanoic acid, succinic acid, maleic acid, glycolic acid, and glyceric acid Aliphatic hydroxycarboxylic acids such as lactic acid, dimethylolpropionic acid, dimethylolbutyric acid, dimethylolvaleric acid, tartaric acid, malic acid, hydroxymalonic acid, dihydroxysuccinic acid, trihydroxysuccinic acid, hydroxymethylmalonic acid, Aromatic carboxylic acids such as benzoic acid, and amino acids such as glycine and N-acetylglycine. Of these organic acids, formic acid, acetic acid, lactic acid, dimethylolpropionic acid and dimethylolbutyric acid are preferred, and formic acid and acetic acid are particularly preferred.
Examples of the aliphatic sulfonic acid group include methanesulfonic acid, dodecylbenzenesulfonic acid, alkyl (C14-18) sulfonic acid, olefin (C14-16) sulfonic acid, and the like.
Examples of the aromatic sulfonic acid group include benzenesulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, and the like.
Examples of the halide include iodide, bromide, chloride, and fluoride.
You may use these individually or in combination of 2 or more types.

The quaternary phosphonium salt A of the present invention can be produced by a known method.
For example, a quaternary phosphonium organic acid salt or a quaternary phosphonium aliphatic or aromatic sulfonate can be converted into a quaternary phosphonium halide by a nucleophilic reaction between a tertiary phosphine compound such as tributylphosphine and triphenylphosphine and an alkyl halide. After being obtained, it can be produced by salt exchange with a desired organic acid anion or an aliphatic or aromatic sulfonate anion.
It can also be produced by subjecting a commercially available quaternary phosphonium halide to a desired organic acid anion or an aliphatic or aromatic sulfonate anion. Furthermore, it can be produced by neutralizing a commercially available quaternary phosphonium hydroxide with a desired organic acid or an aliphatic or aromatic sulfonic acid.
In addition, the quaternary phosphonium hydroxide is obtained by obtaining a quaternary phosphonium halide by a nucleophilic reaction between a tertiary phosphine compound such as tributylphosphine or triphenylphosphine and an alkyl halide. It is obtained by passing through a packed column and replacing the halide with hydroxide.

The content of the quaternary phosphonium salt A in the electrodeposition coating composition of the present invention is not particularly limited, but usually, for example, 0.05 to 30 mass with respect to 100 parts by mass of the base resin B in the electrodeposition coating composition. Part, preferably 0.1 to 10 parts by weight. Even if the addition amount is out of the range of 0.1 to 10 parts by mass, no major problem is caused in the paint performance, but if it is within the range of 0.1 to 10 parts by mass, curability, anticorrosion, A practical balance such as stability of the electrodeposition paint is particularly improved. Further, the content of the quaternary phosphonium salt A is preferably 1 part by mass or more, more preferably 4 parts by mass or more, and further preferably 7 parts by mass or more with respect to 100 parts by mass of the base resin B. In this case, it is because curability and adhesiveness become especially high. The content of the quaternary phosphonium salt A is, for example, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 with respect to 100 parts by mass of the base resin B. 10, 15, 20, 25, 30 parts by mass, and may be within a range between any two of the numerical values exemplified here.

In addition to the quaternary phosphonium salt A and the base resin B, the electrodeposition coating composition in the present invention contains a curing agent C, a metal compound D, a neutralizing agent E, and other additives as necessary. can do.

<Base resin B>
As the base resin B, any resin such as an epoxy resin, an acrylic resin, a polybutadiene resin, an alkyd resin, and a polyester resin can be used, and among them, a polyamine resin such as an amine-added epoxy resin is preferable.

Examples of the amine-added epoxy resin include (i) an adduct of a polyepoxy compound and a primary monoamine or polyamine, a secondary monoamine or polyamine, or a 1,2 mixed polyamine (for example, US Pat. No. 3,984,843). (Ii) an adduct of a polyepoxide compound and a secondary monoamine or polyamine having a ketiminated primary amino group (see, for example, US Pat. No. 4,017,438); iii) A reaction product obtained by etherification of a polyepoxide compound and a hydroxy compound having a primary amino group that has been ketiminated (see, for example, JP-A-59-43013).

The polyepoxide compound used in the production of the amine-added epoxy resin is a compound having two or more epoxy groups in one molecule, and generally has a value of at least 200, preferably 400 to 4000, more preferably 800 to 2000. Those having a number average molecular weight are suitable, and those obtained by reaction of a polyphenol compound and epichlorohydrin are particularly preferred.

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, tetra (4-hydroxyphenyl) ) -1,1,2,2-ethane, 4,4-dihydroxydiphenylsulfone, phenol novolak, cresol novolak, and the like.

The polyepoxide compound may be partially reacted with polyol, polyether polyol, polyester polyol, polyamine amide, polycarboxylic acid, polyisocyanate compound, or the like. The polyepoxide compound may further be obtained by graft polymerization of ε-caprolactone, an acrylic monomer, or the like. *

The base resin B may be of any type of an external crosslinking type and an internal (or self) crosslinking type. The base resin B may contain a block cross-linked portion (eg, a block polyisocyanate group) in which a cross-linked portion (eg: isocyanate group) is blocked with a blocking agent, and a block cross-linking agent (eg: block poly) having a block cross-linked portion. The electrodeposition coating composition may contain a curing agent C comprising an isocyanate compound. The cross-linking reaction requires a cross-linked part and an active hydrogen-containing part (for example, an amino group) that reacts with the cross-linking part. Is an internal cross-linking type, and when only one of these is contained in the base resin B, it is an external cross-linking type.
Examples of the internal cross-linking type include those in which a block polyisocyanate group or the like is introduced into the molecule of the base resin B. As a method for introducing the blocked polyisocyanate group into the base resin B, a known method can be used. For example, a reaction between a free isocyanate group in the partially blocked polyisocyanate compound and an active hydrogen-containing part in the base resin. Can be introduced.

<Curing agent C>
When the base resin B is an external cross-linking resin, the curing agent C used in combination is a block cross-linking agent having a block cross-linking portion (eg, a block polyisocyanate compound) or a compound having an active hydrogen-containing portion (eg: Amino resin). More specifically, when the base resin B contains an active hydrogen-containing part, it is preferable to use a block cross-linking agent, and when the base resin B contains a block cross-linking part, active hydrogen is used. It is preferable to use a compound having an inclusion part.

The block polyisocyanate compound can be obtained by addition reaction of a theoretical amount of a polyisocyanate compound and an isocyanate blocking agent.

Examples of the polyisocyanate compound include aromatic or aliphatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, and isophorone diisocyanate. The terminal isocyanate containing compound obtained by making low molecular weight active hydrogen containing compounds, such as ethylene glycol, propylene glycol, a trimethylol propane, hexane triol, castor oil, react with the compound and the excess of these isocyanate compounds can be mentioned. *

As the isocyanate blocking agent, it is blocked by adding to the isocyanate group of the polyisocyanate compound, and the blocked polyisocyanate compound produced by the addition is stable at room temperature and when heated to about 100 to 200 ° C., It is desirable to be able to dissociate and regenerate free isocyanate groups.

Examples of the blocking agent include halogenated hydrocarbons such as 1-chloro-2-propanol and ethylene chlorohydrin, heterocyclic alcohols such as furfuryl alcohol and alkyl group-substituted furfuryl alcohol, phenol, m-cresol, phenols such as p-nitrophenol, p-chlorophenol and nonylphenol, oximes such as methyl ethyl ketoxime, methyl isobutyl ketone oxime, acetone oxime and cyclohexanone oxime, active methylene compounds such as acetylacetone, ethyl acetoacetate and diethyl malonate, ε-caprolactam, aliphatic alcohols such as methanol, ethanol, n-propanol and isopropanol, aromatic alcohols such as benzyl alcohol, ethylene glycol monomethyl ether , It may be mentioned ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol ethers monomethyl ether and the like.

The solid content weight ratio of the base resin B / curing agent C is preferably 1 to 9, and more preferably 1.5 to 4.

<Metal compound D>
Examples of the metal compound D include compounds such as potassium, titanium, iron, copper, zinc, and bismuth, and compounds containing an organic group such as organic acid metal salts or metal alkoxides are preferable.

Examples of the potassium compound include potassium formate, potassium acetate, potassium propionate, potassium 2-ethylbutyrate, potassium 2-ethylhexanoate, potassium lactate, potassium dimethylolpropionate, and potassium benzoate.
Examples of the titanium compound include tetraisopropoxy titanium, tetrabutoxy titanium, diisopropoxy titanium bis (2-ethyl hexanate), isopropoxy titanium tris (2-ethyl hexanate), and the like.
Examples of the iron compound include basic iron acetate (III) and iron (III) 2-ethylhexanoate.
Examples of the copper compound include copper formate, copper acetate, copper propionate, copper 2-ethylbutyrate, copper 2-ethylhexanoate, copper lactate, copper dimethylolpropionate, and copper benzoate.
Examples of zinc compounds include zinc formate, zinc acetate, zinc propionate, zinc 2-ethylbutyrate, zinc 2-ethylhexanoate, zinc lactate, zinc dimethylolpropionate, zinc benzoate, and zinc acetylacetonate. It is done.
Examples of the bismuth compound include bismuth acetate and bismuth 2-ethylhexanoate.

Among the above metal compounds D, zinc compounds are particularly preferable because of their curability and the availability of raw materials. You may use these individually or in combination of 2 or more types.

The content of the metal compound D in the electrodeposition coating composition of the present invention is not particularly limited, but is usually 0.5 to 2 mol, preferably 0.5 to 1. mol, based on 1 mol of the quaternary phosphonium salt A. 5 moles. When it exists in the said range, the effect of the adhesiveness and sclerosis | hardenability improvement at low temperature is acquired. Further, if the molar ratio of the metal compound D / 4 quaternary phosphonium salt A exceeds 10, the effect of improving the adhesion and curability at low temperature is small, so the molar ratio of the metal compound D / 4 quaternary phosphonium salt A is 10 or less. Is preferred.

<Neutralizing agent E>
The electrodeposition coating composition of the present invention may further include a neutralizing agent E for dispersing the above components in water. Examples of the neutralizing agent E include aliphatic carboxylic acids such as acetic acid, formic acid, propionic acid, and lactic acid. The amount of the neutralizing agent E varies depending on the amount of amino groups in the base resin B, and may be any amount that can be dispersed in water. The pH of the electrodeposition paint is in the range of 3.0 to 9.0. What is necessary is just to keep. In the present invention, the number of equivalents of the neutralizing agent E necessary for neutralizing the amino group contained in the base resin B is 0.25 to 1.5, preferably 0.5 to 1.25. When it is in the above range, the effect of improving the finish, throwing power, low temperature curability and the like of the composition can be obtained.

<Other additives>
In the electrodeposition coating composition of the present invention, if necessary, conventional pigment pigments, extender pigments, organic solvents, pigment dispersants, coating surface modifiers, surfactants, antioxidants, ultraviolet absorbers, etc. Paint additives can be blended.

Method for Producing Electrodeposition Paint Composition The electrodeposition paint composition of the present invention can be prepared, for example, by mixing the above components.
First, the base resin B and the curing agent C are mixed, and the neutralizing agent E is added. After adding the quaternary phosphonium salt A to this, the quaternary phosphonium salt A may be dispersed in an aqueous medium which is water alone or a mixture of water and a hydrophilic organic solvent. May be added. If necessary, the electrodeposition coating composition of the present invention can be obtained by mixing the pigment dispersion paste. The above pigment dispersion paste is mixed with a predetermined amount of a pigment dispersant and a pigment, and then a normal dispersion apparatus such as a ball mill or a sand grind mill is used until the particle size of the pigment in the mixture becomes a predetermined uniform particle size. It can be obtained by dispersing. The paint additive can be added to the system at any stage.

Coating method of electrodeposition coating composition The electrodeposition coating composition of the present invention can be applied to the surface of a desired substrate by electrodeposition coating.
Generally, electrodeposition coating is diluted with deionized water or the like so that the solid content concentration is about 5 to 40% by weight, and the pH is adjusted within the range of 3.0 to 9.0. An electrodeposition bath composed of a coating composition can be usually adjusted to a bath temperature of 15 to 45 ° C. and under a load voltage of 100 to 400V.

The film thickness of the electrodeposition coating film that can be formed using the electrodeposition coating composition of the present invention is not particularly limited, but is generally 5 to 40 μm, particularly 10 to 10 μm based on the cured coating film. Within the range of 30 μm is preferable. The baking temperature of the coating film is generally in the range of 100 to 200 ° C., preferably 140 to 180 ° C. on the surface of the object to be coated, and the baking time is 5 to 60 minutes, preferably about 10 to 30 minutes. It is preferable that the surface of the object to be coated is held.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited thereby. “Parts” and “%” indicate “parts by mass” and “% by mass”.

Production Example 1 (Production of base resin B)
1900 parts of “jER1001” (Japan Epoxy Resin, bisphenol A type epoxy resin having an epoxy equivalent of about 950) is dissolved in 1012 parts of butyl cellosolve, 124 parts of diethylamine is added dropwise at 80 to 100 ° C., and then kept at 120 ° C. for 2 hours. Thus, an epoxy resin-amine adduct having an amine value of 47 was obtained.

Next, 1000 parts of dimer acid type polyamide resin having an amine value of 100 (trade name “Versamide 460”, product of Henkel Hakusui Co., Ltd.) is dissolved in 429 parts of methyl isobutyl ketone and heated to 130 to 150 ° C. under reflux. The water produced was distilled off to change the terminal amino group of the amide resin to ketimine. This was held at 150 ° C. for about 3 hours, and cooled to 60 ° C. after the distillation of water stopped. Next, this product was added to the epoxy resin-amine adduct, heated to 100 ° C., held for 1 hour, and then cooled to room temperature. Then, 4433 parts of varnish B-1 of epoxy resin-amino-polyamide addition resin having an amine value of 65 ( Solid content: 70%) was obtained.

Production Example 2 (Production of curing agent C)
After flowing nitrogen and sufficiently removing the water in the reaction vessel, 675 parts of 2,4- / 2,6-tolylene diisocyanate and 769 parts of MIBK were charged and mixed. In a nitrogen atmosphere, 1119 parts of 2-ethylhexanol was added dropwise at 70 to 90 ° C., and then maintained at 90 ° C. until the free isocyanate became 0.5% or less of the charged isocyanate, and then allowed to cool to room temperature to block 2563 parts of polyisocyanate C-1 (solid content: 70%) were obtained.

Production Example 3 (Production of tetrabutylphosphonium acetate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide), and 17.5 parts (0.3 mol) of acetic acid, 80 parts of ionic water was charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 93 parts of tetrabutylphosphonium acetate as a yellow transparent liquid.

Production Example 4 (Production of tetrabutylphosphonium formate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide), and 17.5 parts (0.3 mol) of formic acid, deionized 80 parts of ionic water was charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 89 parts of tetrabutylphosphonium formate as a yellow transparent liquid.

Production Example 5 (Production of tetrabutylphosphonium dimethylol propionate)
In a flask, 200 parts of a 40% strength aqueous solution of tetrabutylphosphonium hydroxide (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide) and 39.1 parts of dimethylolpropionic acid (0.3 mol) ), 100 parts of deionized water were charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 114 parts of tetrabutylphosphonium dimethylolpropionate as a yellow transparent liquid (crystallized at room temperature).

Production Example 6 (Production of tetrabutylphosphonium lactate)
In a flask, 200 parts of 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide), and 26.3 parts (0.3 mol) of lactic acid, 100 parts of ionic water was charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 101 parts of tetrabutylphosphonium lactate as a yellow transparent liquid.

Production Example 7 (Production of tetrabutylphosphonium (acetylaminoacetate))
In a flask, 200 parts of 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide) and 34.2 parts of N-acetylglycine (0.3 mol) ), 100 parts of deionized water were charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 109 parts of tetrabutylphosphonium (acetylaminoacetate) as a yellow transparent liquid.

Production Example 8 (Production of bis (tetrabutylphosphonium) tartrate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide), and 11 parts (0.15 mol) of L-tartaric acid, 100 parts of ionic water was charged and heated to 70-80 ° C. After reacting by stirring for 1 hour, water was concentrated to obtain 97 parts of bis (tetrabutylphosphonium) tartrate as a yellow transparent liquid.

Production Example 9 (Production of bis (tetrabutylphosphonium) malate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 moles as tetrabutylphosphonium hydroxide), and 8.5 parts (0.15 moles) of maleic acid, 100 parts of deionized water was charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 92 parts of bis (tetrabutylphosphonium) malate as a yellow transparent liquid.

Production Example 10 (Production of tetrabutylphosphonium benzoate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide), and 35.6 parts (0.3 mol) of benzoic acid, 100 parts of deionized water was charged and heated to 70-80 ° C. After reacting by stirring for 1 hour, water was concentrated to obtain 111 parts of tetrabutylphosphonium benzoate as a yellow transparent liquid.

Production Example 11 (Production of tetrabutylphosphonium-p-toluenesulfonate)
In a flask, 200 parts of a 40% strength tetrabutylphosphonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.3 mol as tetrabutylphosphonium hydroxide) and 57 parts of p-toluenesulfonic acid monohydrate ( 0.3 mol) and 100 parts of deionized water were charged and heated to 70-80 ° C. After reacting by stirring for 1 hour, water was concentrated to obtain 129 parts of tetrabutylphosphonium-p-toluenesulfonate as a pale yellow transparent liquid.

Production Example 12 (Production of tetrabutylphosphonium hydroxide aqueous solution)
Dissolve 20 parts of tetrabutylphosphonium bromide in 250 ml of ion-exchanged water, and pass through a column packed with 300 ml of strongly basic ion-exchange resin (IRA402BL-CL; pre-treated with 10% NaOH from Organo). 40 ml of ion-exchanged water was passed through to obtain 300 parts of a 5% strength aqueous solution of tetrabutylphosphonium hydroxide (0.05 mol as tetrabutylphosphonium hydroxide). The resulting aqueous solution was concentrated to make a 40% aqueous solution.

Production Example 13 (Production of tetraethylphosphonium hydroxide aqueous solution)
Dissolve 20 parts of tetraethylphosphonium bromide in 250 ml of ion-exchanged water, and pass through a column packed with 300 ml of strongly basic ion exchange resin (IRA402BL-CL; manufactured by Organo Co., Ltd., previously treated with 10% NaOH). 40 ml of exchange water was passed through to obtain 300 parts of a 5% concentration aqueous tetraethylphosphonium hydroxide solution (0.08 mol as tetraethylphosphonium hydroxide). The resulting aqueous solution was concentrated to make a 40% aqueous solution.

Production Example 14 (Production of tetraethylphosphonium acetate)
To 300 parts (0.08 mol as tetraethylphosphonium hydroxide) of the tetraethylphosphonium hydroxide aqueous solution obtained in Production Example 12, 4.8 parts (0.08 mol) of acetic acid was charged and heated to 70 to 80 ° C. After reacting by stirring for 1 hour, water was concentrated to obtain 16.5 parts of tetraethylphosphonium acetate as a yellow transparent liquid.

Production Example 15 (Production of tetraphenylphosphonium acetate)
Dissolve 20 parts of tetraphenylphosphonium bromide in 250 parts of methanol, and pass through a column packed with 300 ml of strongly basic ion exchange resin (IRA402BL-CL; manufactured by Organo Co., Ltd., previously treated with 10% NaOH), followed by methanol. 40 parts of water was passed through to obtain 300 parts of a 5% strength tetraphenylphosphonium hydroxide methanol solution (0.05 mol as tetraphenylphosphonium hydroxide). To 300 parts of the resulting tetraphenylphosphonium hydroxide methanol solution was charged 3 parts (0.05 mol) of acetic acid and heated to 70-80 ° C. After reacting by stirring for 1 hour, methanol was concentrated to obtain 19 parts of tetraphenylphosphonium acetate as a yellow transparent liquid.

Production Example 16 (Production of tetrahexylphosphonium acetate)
In the flask, 30 parts of trihexylphosphine (Tokyo Chemical Industry Co., Ltd. reagent) and 12.6 parts of hexyl chloride (Tokyo Chemical Industry Co., Ltd. reagent) were reacted at 150 ° C. for 16 hours in a nitrogen atmosphere. The reaction solution was cooled to 50 ° C. and neutralized by adding 6.7 parts of 5% sodium hydroxide. The reaction solution was heated at 100 ° C. for 1 hour, and then water was added thereto to obtain 85.2 parts of a colorless transparent slightly viscous aqueous solution. The content of tetrahexylphosphonium chloride was 50%.

40 parts of tetrahexylphosphonium chloride aqueous solution was passed through a column packed with 300 ml of strongly basic ion exchange resin (IRA402BL-CL; manufactured by Organo, previously treated with 10% NaOH), followed by 260 parts of purified water. As a result, 300 parts of a 6% concentration tetrahexylphosphonium hydroxide aqueous solution (0.05 mol as tetrahexylphosphonium hydroxide) was obtained. To 300 parts of the resulting aqueous tetrahexylphosphonium hydroxide solution, 3 parts (0.05 mol) of acetic acid was charged and heated to 70-80 ° C. After reacting by stirring for 1 hour, water was concentrated to obtain 20 parts of tetrahexylphosphonium acetate as a pale yellow liquid.

Production Example 17 (Production of tetraoctylphosphonium acetate)
In a flask, 30 parts of trioctylphosphine (Tokyo Chemical Industry Co., Ltd. reagent) and 12 parts of octyl chloride (Tokyo Chemical Industry Co., Ltd. reagent) were reacted at 150 ° C. for 16 hours in a nitrogen atmosphere. The reaction solution was cooled to 50 ° C. and neutralized by adding 6.7 parts of 5% sodium hydroxide. The reaction solution was heated at 100 ° C. for 1 hour, and then water was added to obtain 84 parts of a colorless transparent slightly viscous aqueous solution. The content of tetraoctylphosphonium chloride was 50%.

Forty parts of tetraoctylphosphonium chloride aqueous solution was passed through a column packed with 300 ml of strongly basic ion exchange resin (IRA402BL-CL; made by Organo in advance 10% NaOH treatment), followed by 260 parts of purified water. As a result, 300 parts of a 6% concentration tetraoctylphosphonium hydroxide aqueous solution (0.04 mol as tetraoctylphosphonium hydroxide) was obtained. To 300 parts of the obtained tetraoctylphosphonium hydroxide aqueous solution, 2.4 parts (0.04 mol) of acetic acid was charged and heated to 70 to 80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 19.8 parts of tetraoctylphosphonium acetate as a pale yellow liquid.

Production Example 18 (Production of tributyl (methoxyethyl) phosphonium acetate)
In the flask, 30 parts of tributylphosphine (Tokyo Chemical Industry Co., Ltd. reagent) and 14 parts of chloroethyl methyl ether (Tokyo Chemical Industry Co., Ltd. reagent) were reacted at 150 ° C. for 16 hours in a nitrogen atmosphere. The reaction solution was cooled to 50 ° C. and neutralized by adding 9.5 parts of 5% sodium hydroxide. The reaction solution was heated at 100 ° C. for 1 hour, and then water was added to obtain 88 parts of a colorless and transparent slightly viscous aqueous solution. The content of tributyl (methoxyethyl) phosphonium chloride was 50%.

40 parts of an aqueous solution of tributyl (methoxyethyl) phosphonium chloride was passed through a column packed with 300 ml of strongly basic ion exchange resin (IRA402BL-CL; manufactured by Organo, previously treated with 10% NaOH), followed by 260 parts of purified water. Water was passed through to obtain 300 parts of a 6% concentration tributyl (methoxyethyl) phosphonium hydroxide aqueous solution (0.07 mol as tributyl (methoxyethyl) phosphonium hydroxide). To 300 parts of the obtained tributyl (methoxyethyl) phosphonium hydroxide aqueous solution, 4.2 parts (0.07 mol) of acetic acid was charged and heated to 70 to 80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 20 parts of tributyl (methoxyethyl) phosphonium acetate as a pale yellow liquid.

Production Example 19 (Production of zinc 2-ethylbutyrate)
A flask equipped with a Dean-Stark dewatering tube was charged with 39.2 parts (0.34 mol) of 2-ethylbutyric acid and 50 parts of n-heptane, and then 13.8 parts (0.17 mol) of zinc oxide were added. The mixture was heated to the reflux temperature of n-heptane, and the resulting water was refluxed and dehydrated for 1 hour. After reaction, n-heptane was concentrated to obtain 50 parts of zinc 2-ethylbutyrate as a milky white solid.

Production Example 20 (Production of zinc dimethylolpropionate)
A flask was charged with 40 parts (0.3 mol) of dimethylolpropionic acid and 50 parts of water, and then 12 parts (0.15 mol) of zinc oxide were added and heated to 80 to 90 ° C. After stirring for 1 hour and reacting, the water was concentrated to obtain 50 parts of zinc dimethylolpropionate as a milky white solid.

Production Example 21 (Production of Isopropyl Titanium Tris (2-ethylhexanate))
A flask was charged with 25.5 parts (0.09 mol) of tetraisopropoxytitanium and 39 parts (0.27 mol) of 2-ethylhexanoic acid and heated to 80 to 90 ° C. The resulting isopropanol was distilled off under reduced pressure to obtain 50 parts of isopropyl titanium tris (2-ethylhexanate) as a yellow transparent liquid.

Comparative Production Example 1 (Production of tetramethylammonium acetate)
In a flask, 200 parts of a 25% concentration tetramethylammonium hydroxide aqueous solution (Tokyo Chemical Industry Co., Ltd. reagent, 0.55 mol as tetramethylammonium hydroxide), and 33 parts (0.55 mol) of acetic acid, deionized water 80 parts were charged and heated to 70-80 ° C. After stirring and reacting for 1 hour, water was concentrated to obtain 73 parts of tetramethylammonium acetate as a pale yellow solid.

Comparative Production Example 2 (Production of tris (3-hydroxypropyl) butylphosphonium bromide)
Under a nitrogen atmosphere, 20 parts (0.1 mol) of tris (3-hydroxypropyl) phosphine (Hishicolin P-500; manufactured by Nippon Chemical Industry Co., Ltd.) and 80 parts of toluene were added to the flask and mixed with stirring. Subsequently, 13.7 parts (0.1 mol) of n-butyl bromide was added and reacted at 100 ° C. for 24 hours. After completion of the reaction, toluene was concentrated under reduced pressure to obtain 34.5 parts of tris (3-hydroxypropyl) butylphosphonium bromide as a white solid.

Examples 1-32 and Comparative Examples 1-4 (production of electrodeposition coating composition)
The components shown in Tables 1 to 3 were blended in the proportions (parts by mass) shown in Tables 1 to 3, and mixed and dispersed to produce an electrodeposition coating composition.

Tetrabutylphosphonium bromide: General reagent Zinc acetate: Special grade reagent Product name “Neostan U-600”: Bismuth 2-ethylhexanoate Basic iron acetate (III): Special grade copper acetate: Special grade reagent Potassium acetate: Special grade reagent

Test example 1 (curability confirmation test)
The electrodeposition coating compositions obtained in Examples 1 to 32 and Comparative Examples 1 to 4 were subjected to chemical conversion treatment with Palbond # 3020 (trade name, manufactured by Nihon Parkerizing Co., Ltd., zinc phosphate treatment agent). A 70 mm cold-rolled dull steel plate was immersed, and this was used as a cathode for electrodeposition coating. The electrodeposition conditions were a voltage of 250 V and an electrodeposition coating film having a film thickness (based on the dry film thickness) of about 20 μm was formed.

The coating film was washed with water and then baked. The baking was performed using an electric hot air dryer at baking temperatures of 150 ° C./20 minutes, 160 ° C./20 minutes, and 170 ° C./20 minutes.
Each obtained electrodeposition coating plate was immersed in acetone at 40 ° C. for 24 hours, and the coating film weight residual ratio before and after the evaluation was evaluated according to the following criteria, thereby confirming the curability of the coating film. The results are shown in Tables 1 to 3.
A: 95% or more B: 85% or more to less than 95% C: 75% or more to less than 85% D: less than 75%

Test Example 2 (Anti-corrosion test)
Each electrodeposition coated plate obtained by baking was subjected to a salt cut resistance test for 840 hours in accordance with JISZ-2371 so that the electrodeposition coating film was covered with a knife so as to reach the substrate. The rust and blister width were evaluated according to the following criteria. The results are shown in Tables 1 to 3.
A: The maximum width of rust and blisters is less than 2mm from the cut part (one side)
B: The maximum width of rust and blisters is 2 mm or more and less than 3 mm (one side) from the cut part, and blisters are considerably conspicuous on the flat part. C: The maximum width of rust and blisters is 3 mm or more from the cut part and over the entire coated surface. Generation of blisters

Test Example 3 (Adhesion test)
Each electrodeposition coating plate obtained by baking is subjected to cross cutting of 100 pieces of 2 mm mass with a cutter specified in 7.2 (e) of JIS K5400, and a cellophane adhesive tape specified in JIS Z1522 is adhered, It peeled at a stretch so that a tape and a coating surface hold | maintained about 30 degrees, and the state of peeling was evaluated. Results are shown in Tables 1 to 3.
A: peeling area 0-2%
B: Peeling area 2% or more and less than 5% C: Peeling area 5% or more and less than 30% D: Peeling area 30% or more

Test Example 4 (Paint stability test)
The state of the electrodeposition paint stored for one month under the following storage conditions was visually confirmed. The results are shown in Tables 1 to 3.
Storage temperature: 15 to 35 ° C., Storage humidity: 30 to 70%, Storage container: Tin can ○: No abnormal state such as separation is observed even after one month has elapsed over time: X: Separation after one month has elapsed over time, etc. An abnormal condition is seen

Discussion With reference to Examples 1 to 5, in Examples 2 and 4 in which the content of the dissociation catalyst A was 0.1 or 0.5 parts by mass, the curability and adhesion were slightly inferior. In Examples 1, 3, and 5 in which the content is 4 parts by mass or more, curability and adhesion are excellent, and in Example 3 in which the content of the dissociation catalyst A is 10.3 parts by mass, all evaluations The highest evaluation results were obtained for the items. From this result, it was found that the content of the dissociation catalyst A is preferably 1 part by mass or more with respect to 100 parts by mass of the base resin B, and is saturated at 10 parts by mass.

Referring to Examples 1 and 6 to 21, it was found that the influence of the difference in the hydrocarbon group of the quaternary phosphonium salt on the evaluation result was small. Further, referring to Examples 17 to 18, it was found that when R ¹ to R ^{4 in} the general formula (1) are phenyl groups or when X is a halide, the evaluation results are slightly inferior.

Referring to Example 21, even when the R ^{1 ~} R ⁴ in the general formula (1) are different from each other, the R 1 ^~ R ⁴ are the same evaluation result as all the same is obtained, and substituted with an alkoxy group The quaternary phosphonium salt having an alkyl group thus obtained was found to give the same evaluation result as that of the unsubstituted one.

Further, referring to Comparative Example 3, it was found that the catalyst performance of the quaternary ammonium salt was much lower than that of the quaternary phosphonium salt. Further, referring to Comparative Example 4, it was found that the catalytic performance of the quaternary phosphonium salt having an alkyl group substituted with a hydroxyl group is much lower than that of the quaternary phosphonium salt having an unsubstituted alkyl group.

Referring to Examples 22 to 32, the combined use of a quaternary ammonium salt and a metal compound improves the curability and adhesion particularly at low temperature baking, and among the metal compounds, a zinc compound is particularly preferable. I understood. Further, referring to Examples 22 to 25, it was found that in Example 25 in which the molar ratio of the metal compound / quaternary ammonium salt was 11, the ratio of the metal compound was too large and the catalyst performance was slightly lowered.

Claims (8)

1. General formula (1):
   

   

   [Wherein R ¹ to R ⁴ are the same or different and each has 1 to 8 carbon atoms substituted with a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, or a functional group other than a hydroxyl group. A hydrocarbon group or an aromatic hydrocarbon group is represented. X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide. An electrodeposition coating composition containing a quaternary phosphonium salt A represented by formula (I) and a base resin B.
2. In the general formula (1), the substituents represented by R ¹ to R ⁴ are the same or different and are each selected from the group consisting of a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, and an alkoxyalkyl group. The electrodeposition coating composition according to claim 1, which is at least one selected.
3. Furthermore, the electrodeposition coating composition of Claim 1 or 2 containing the metal compound D.
4. The electrodeposition coating composition according to claim 3, wherein the metal compound D is at least one compound selected from the group consisting of potassium, titanium, iron, copper, zinc, and bismuth.
5. The electrodeposition coating composition according to claim 3 or 4, wherein the metal compound D is at least one compound selected from the group consisting of organic acid metal salts and metal alkoxides.
6. 6. The electrodeposition coating composition according to claim 3, wherein the metal compound D is a zinc compound.
7. The electrodeposition coating composition according to any one of claims 3 to 6, wherein a molar ratio of the metal compound D / the quaternary phosphonium salt A is 0.5 to 2.
8. General formula (1):
   

   

   [Wherein R ¹ to R ⁴ are the same or different and each has 1 to 8 carbon atoms substituted with a hydrocarbon group having 1 to 8 carbon atoms, an aromatic hydrocarbon group, or a functional group other than a hydroxyl group. A hydrocarbon group or an aromatic hydrocarbon group is represented. X represents an organic acid group, a hydroxyl group, an aliphatic sulfonic acid group, an aromatic sulfonic acid group, or a halide. ] The dissociation catalyst for electrodeposition coating compositions which consists of quaternary phosphonium salt A represented by these.