JP2002265881A - Anionic electrodeposition coating composition, method for anionic electrodeposition coating and coated product obtained therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anionic electrodeposition coating composition having good storage stability and high anticorrosion properties and environmental compatibility, a method for anionic electrodeposition coating and a coated product obtained from the method. SOLUTION: This anionic electrodeposition coating composition is characterized as comprising a resin composition having carboxylic acid groups and propargyl groups. The resin composition preferably further has hydroxy groups. The contents of the carboxylic acid groups and the propargyl groups contained therein are 5-400 mmol of the carboxylic acid groups and 10-495 mmol of the propargyl groups based on 100 g of solids in the resin composition. The total content of the carboxylic acid groups and the propargyl groups is preferably <=500 mmol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anionic electrodeposition coating composition, an anion electrodeposition coating method, and a coating product obtained by the method, and more particularly, to an anion electrodeposition coating composition and anion which facilitate bath management. Electrodeposition coating method,
Further, the present invention relates to a coated article obtained thereby.

[0002]

2. Description of the Related Art Electrodeposition paints are widely used on objects to be coated such as building materials, ships, automobile bodies and parts because they can obtain high rust prevention and corrosion resistance.
This electrodeposition paint can be roughly classified into two types. One is a cationic electrodeposition paint and the other is an anionic electrodeposition paint. Anionic electrodeposition paints are said to be inferior in rust prevention and corrosion resistance as compared with cationic electrodeposition paints, and at coating sites, at present, cationic electrodeposition paints are often used.
However, when the cationic electrodeposition paint is electrodeposited, since the object to be coated is used as a cathode, it may be ionized and eluted depending on the object to be coated. In this case, a cationic electrodeposition paint is not used, but an anionic electrodeposition paint is used.

[0003] Such anionic electrodeposition paints include, for example,
Examples include those containing a base resin having a carboxylic acid group as a hydrating group and a hydroxyl group as a curing functional group, and a melamine resin as a curing agent. This curing system
In the heating and curing step after the electrodeposition coating, a condensation reaction by a dealcoholization reaction between a hydroxyl group of the base resin and an alkoxyl group of the melamine resin is used. However, in the electrodeposition coating line, processing equipment is required to prevent volatile components such as alcohol generated at this time from deteriorating the working environment in the electrodeposition coating line and causing environmental pollution by being discharged outside the line. There was a necessary problem. In addition, this reaction requires a relatively high temperature for heat curing, which is contrary to the recent trend toward energy saving.

In addition, the conventional electrodeposition paints are liable to be deteriorated by Joule heat or the like generated during the electrodeposition coating, and the appearance and film of the obtained electrodeposition coating film depend on the temperature of the electrodeposition bath. Due to the great change in thickness, strict control of the temperature of the electrodeposition bath in the electrodeposition coating process was required. Furthermore, these electrodeposition coatings contain harmful metals such as lead compounds in order to further enhance rust prevention and corrosion prevention. However, recent environmental considerations have restricted the use of such harmful metals.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to an anionic electrodeposition coating composition having good storage stability, high anticorrosion properties and high environmental compatibility, an anion electrodeposition coating method using the same, and a method for obtaining the same. It is intended to provide a painted product.

[0006]

SUMMARY OF THE INVENTION The present invention is an anionic electrodeposition coating composition comprising a resin composition having a carboxylic acid group and a propargyl group. Here, it is preferable that the resin composition further has a hydroxyl group. In addition, the carboxylic acid group and the propargyl group have a carboxylic acid group of 5 to 400 mmol and a propargyl group of 10 to 4 mmol per 100 g of the solid content of the resin composition.
95 mmol, and preferably the total content of carboxylic acid groups and propargyl groups is 500 mmol or less, contains 10 to 300 mmol of carboxylic acid groups and 50 to 400 mmol of propargyl groups, and contains carboxylic acid groups and propargyl groups. Is more preferably 400 mmol or less. Further, the resin composition preferably has an epoxy resin as a skeleton, more preferably a novolak cresol type epoxy resin or a novolak phenol type epoxy resin, and further preferably has a number average molecular weight of 700 to 5,000.

Further, the present invention provides an anion electrodeposition coating method for electrodepositing an anion electrodeposition paint on an object to be coated,
An anion electrodeposition coating method, wherein the anion electrodeposition coating composition is the anion electrodeposition coating composition described above. Furthermore, the present invention is a coated article obtained by the above-mentioned anion electrodeposition coating method.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTSAnionic electrodeposition coating composition  The anionic electrodeposition coating composition of the present invention contains carboxyl groups and
And a resin composition having a propargyl group
It is characterized by the following. Make up such a resin composition
Resin has a carboxyl group and propanol in one molecule.
It may have both a gil group, but it is not necessary
However, for example, a carboxyl group or a pro
It may have only one of the pargyl groups. This
In the latter case, these two types are used as the resin composition as a whole.
Has all of the curable functional groups. That is, the above tree
Fat compositions have carboxyl and propargyl groups.
Resin or resin containing only carboxyl groups
Or a mixture of resins having only propargyl groups and
Or even if they consist of a mixture of all these
Good. The anion electrodeposition coating composition used in the present invention contains
The resin composition contained is a carboxyl in the above sense.
And a propargyl group.

The anionic electrodeposition coating composition of the present invention is one in which a curing reaction is caused by a carboxyl group which is an electrolytically generated acid group generated during the electrodeposition coating process and a propargyl group. The carboxyl group is a hydrated functional group of the resin composition, and is generally neutralized by a neutralizing agent,
In an aqueous state, it becomes a carboxyl-anion group. Therefore, in the coating composition, the function of the carboxyl group as an acid group is blocked by the counter cationic group formed by the neutralizing agent. The carboxyl group blocked by this counter cation group undergoes an electrolytic oxidation reaction on the anode on the side of the object to be coated during the electrodeposition coating process, and although the counter cation group is deactivated, the acid group is reversible. To restore its function. The electrolytically active acid group is an acid group generated by the electrodeposition coating process as described above, and refers to a carboxyl group in the anionic electrodeposition coating composition of the present invention.

The content of the carboxyl group contained in the resin composition contained in the anionic electrodeposition coating composition of the present invention is determined by satisfying the conditions of carboxyl groups and propargyl groups described below, and It is 5-400 mmol per 100 g of solids. 5mmol / 100g
If it is less than 3, sufficient throwing power and curability cannot be exhibited, and hydration properties and bath stability deteriorate.
If it exceeds 400 mmol / 100 g, deposition of the coating film on the surface of the article to be coated will be poor. The content of the carboxyl group, a more preferable content can be set according to the resin skeleton used, for example, novolak phenol type epoxy resin, in the case of novolak cresol type epoxy resin, per 100 g of resin composition solids 10-300m
mol, preferably 20 to 300 mmol.

The propargyl group contained in the resin composition contained in the anionic electrodeposition coating composition of the present invention causes a curing reaction with an electrolytically generated acid group generated during the electrodeposition coating process.
Thus, a curing system of the anionic electrodeposition coating composition of the present invention can be constituted.

The content of propargyl groups contained in the resin composition contained in the anionic electrodeposition coating composition of the present invention is determined by satisfying the conditions of carboxyl groups and propargyl groups described below, and It is 10-495 mmol per 100 g of solids. 10 mmol / 10
If it is less than 0 g, sufficient throwing power and curability cannot be exhibited, and if it exceeds 495 mmol / 100 g, hydration stability when used as an anionic electrodeposition paint may be adversely affected. For the content of the propargyl group, a more preferable content can be set according to the resin skeleton used.For example, in the case of a novolak phenol-type epoxy resin or a novolak cresol-type epoxy resin, the resin composition has a solid content of 100 g per 100 g. 50
Preferably it is ~ 400 mmol.

The resin serving as the skeleton of the resin composition contained in the anionic electrodeposition coating composition of the present invention is not particularly limited, but an epoxy resin is preferably used.
As the epoxy resin, those having at least two or more epoxy groups in one molecule are suitably used. Specifically, for example, epibis epoxy resin, diol,
Epoxidized polybutadiene; novolak phenol type polyepoxy resin; novolak cresol type polyepoxy resin; polyglycidyl acrylate; polyglycidyl ether of aliphatic polyol or polyether polyol;
Examples thereof include polyepoxy resins such as polyglycidyl ester of polybasic carboxylic acid. Of these, novolak phenol type polyepoxy resin, novolak cresol type polyepoxy resin, and polyglycidyl acrylate are preferable because polyfunctionalization for enhancing curability is easy. Note that a part of the epoxy resin may be a monoepoxy resin.

When the resin composition contained in the anionic electrodeposition coating composition of the present invention comprises a resin having the above epoxy resin as a skeleton, the resin composition has a number average molecular weight of 500 to 2,000.
0. When the number average molecular weight is less than 500, the coating efficiency of the anionic electrodeposition coating is deteriorated, and when it exceeds 20,000, a good film cannot be formed on the surface of the object to be coated.
It is possible to set a more preferable number average molecular weight according to the resin skeleton, for example, in the case of novolak phenol type epoxy resin, novolak cresol type epoxy resin,
It is preferably from 700 to 5000.

The total content of carboxyl groups and propargyl groups in the above resin composition is not more than 500 mmol per 100 g of solid content of the resin composition. 50
If it exceeds 0 mmol, the resin may not be actually obtained or the desired performance may not be obtained. The total content of the carboxyl group and propargyl group of the resin composition can be set to a more preferable content according to the resin skeleton used, for example, in the case of novolak phenol type epoxy resin, novolak cresol type epoxy resin Is preferably 400 mmol or less.

Some of the propargyl groups of the resin composition contained in the anionic electrodeposition coating composition of the present invention may be acetylated. Acetylide is a salt-like metal acetylenide. When a part of the propargyl group of the resin composition is acetylated, the content of the propargyl group is preferably 0.1 to 40 mmol per 100 g of the solid content of the resin composition. 0.1m
When the amount is less than 10 mol, the effect by acetylidation is not sufficiently exhibited, and when it exceeds 40 mmol, acetylidation is difficult. This content can be set in a more preferable range according to the metal used.

When a part of the above propargyl group is acetylated, the metal contained in the acetylated propargyl group is not particularly limited as long as it exhibits a catalytic action, and examples thereof include copper, silver, barium and the like. Transition metals. Of these, copper and silver are preferable in consideration of environmental compatibility, and copper is more preferable in terms of availability. When the propargyl group is acetylated by using copper, the content of the propargyl group to be acetylated in the resin composition is 100 g of solid content of the resin composition.
More preferably, it is 0.1 to 20 mmol.

The curing catalyst can be introduced into the resin by converting some of the propargyl groups of the resin composition contained in the anionic electrodeposition coating composition of the present invention into acetylide. By doing so, generally, it is not necessary to directly add an organic transition metal complex that is difficult to dissolve or disperse in an organic solvent or water to a paint, and even a transition metal can be easily converted into acetylide and introduced. Even a poorly soluble transition metal compound can be freely used in a coating composition. Further, unlike the case where a transition metal organic acid salt is used, metal ions are not removed by ultrafiltration, so that bath management and design of an anionic electrodeposition paint are facilitated.

Further, the resin composition contained in the anionic electrodeposition coating composition of the present invention may contain a carbon-carbon double bond, if desired. Since the carbon-carbon double bond has high reactivity, curability can be further improved.

The content of the carbon-carbon double bond is preferably from 10 to 485 mmol per 100 g of the solid content of the resin composition, after satisfying the conditions for the content of the propargyl group and the carbon-carbon double bond described later. 10 mmol / 1
If the amount is less than 00 g, sufficient curability cannot be exhibited by the addition, and if it exceeds 485 mmol / 100 g, hydration stability when used as an anionic electrodeposition paint may be adversely affected. The content of the carbon-carbon double bond can be set to a more preferable content according to the resin skeleton used, for example, novolak phenol type epoxy resin, in the case of novolak cresol type epoxy resin, a resin composition 20 per 100g solids
Preferably it is ~ 375 mmol.

When the above-mentioned carbon-carbon double bond is contained,
The total content of the propargyl group and the carbon-carbon double bond is 80 to 450 per 100 g of the solid content of the resin composition.
It is preferably within the range of mmol. 80 mmol
If less than the curability may be insufficient,
If the amount exceeds 450 mmol, the content of the carboxyl group is reduced, and the storage stability of the coating composition may be insufficient. The total content of the propargyl group and the carbon-carbon double bond, a more preferable content can be set according to the resin skeleton used, for example, in the case of novolak phenol type epoxy resin, novolak cresol type epoxy resin , And more preferably 100 to 395 mmol.

When the above-mentioned carbon-carbon double bond is contained, the total content of the above-mentioned carboxyl group, propargyl group and carbon-carbon double bond is determined by the solid content of the resin composition.
It is preferably 500 mmol or less per 0 g.
If the amount exceeds 500 mmol, the resin may not be actually obtained or the desired performance may not be obtained. The total content of the carboxyl group, propargyl group and carbon-carbon double bond, depending on the resin skeleton used,
A more preferable content can be set. For example, in the case of a novolak phenol type epoxy resin or a novolak cresol type epoxy resin, the content is more preferably 400 mmol or less.

The resin composition contained in the anionic electrodeposition coating composition of the present invention may be obtained, for example, by adding a compound having a functional group reactive with an epoxy group and a propargyl group to an epoxy resin having at least two epoxy groups in one molecule. (I) obtaining an epoxy resin composition having a hydroxyl group and a propargyl group by reacting an acid anhydride with a hydroxyl group of the epoxy resin composition obtained in the step (i) to obtain a carboxyl group. Can be suitably produced by the step (ii) of introducing

Compounds having a functional group and a propargyl group which react with the epoxy group (hereinafter referred to as "compound (A)"
) May be a compound containing both a functional group that reacts with an epoxy group such as a hydroxyl group and a carboxyl group and a propargyl group, and specific examples thereof include propargyl alcohol and propargylic acid. it can. Of these, propargyl alcohol is preferred in terms of availability and ease of reaction.

If the resin composition contained in the anionic electrodeposition coating composition of the present invention has a carbon-carbon double bond, if necessary, it reacts with an epoxy group in the above step (i). A compound having a functional group and a carbon-carbon double bond (hereinafter, referred to as “compound (B)”) may be used in combination with the compound (A). The compound (B) may be, for example, a compound containing both a functional group that reacts with an epoxy group such as a hydroxyl group and a carboxyl group and a carbon-carbon double bond. Specifically, when the group that reacts with the epoxy group is a hydroxyl group, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, allyl alcohol, methacryl alcohol And the like. When the group that reacts with the epoxy group is a carboxyl group, acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid,
Phthalic acid, itaconic acid; half esters such as maleic acid ethyl ester, fumaric acid ethyl ester, itaconic acid ethyl ester, mono (meth) acryloyloxyethyl succinate, mono (meth) acryloyloxyethyl phthalate; oleic acid Linoleic acid, ricinoleic acid and the like; and natural unsaturated fatty acids such as linseed oil and soybean oil.

In the step (i), the compound (A) is reacted with the epoxy resin having at least two epoxy groups in one molecule to obtain an epoxy resin composition having a hydroxyl group and a propargyl group, Alternatively, the compound (A) and, if necessary, the compound (B) are reacted to obtain an epoxy resin composition having a hydroxyl group, a propargyl group and a carbon-carbon double bond. In this latter case, in the step (i), the compound (A)
The compound (B) and the compound (B) may be mixed in advance and then used in the reaction, or the compound (A) and the compound (B) may be used separately in the reaction. The functional group that reacts with the epoxy group of the compound (A) and the functional group that reacts with the epoxy group of the compound (B) may be the same or different.

In the step (i), when the compound (A) and the compound (B) are reacted, the mixing ratio of the two may be set so as to have a desired functional group content. What is necessary is just to set so that it may become content of a propargyl group and a carbon-carbon double bond mentioned above.

The reaction conditions in the above step (i) are usually at room temperature or at 80 to 140 ° C. for several hours. In addition, if necessary, a known component necessary for advancing a reaction such as a catalyst or a solvent can be used. The completion of the reaction can be confirmed by measuring the epoxy equivalent, and the introduced functional group can be confirmed by measuring the nonvolatile content of the obtained resin composition or analyzing the instrument. The reaction product thus obtained is generally a mixture of an epoxy resin having one or more propargyl groups, or an epoxy resin having one or more propargyl groups and one or more carbon-carbon double bonds. Is a mixture of In this sense, a resin composition having a propargyl group or a propargyl group and a carbon-carbon double bond can be obtained by the step (i). The hydroxyl group of the epoxy resin composition obtained in the above step (i) was obtained by ring-opening the epoxy group.
It becomes a grade hydroxyl group.

After the step (i), the epoxy group remaining in the epoxy resin composition obtained in the step (i) is opened by, for example, a hydroxycarboxylic acid compound or an alkanolamine compound. The ring can be converted to a primary or secondary hydroxyl group. Further, when there is an epoxy group remaining without reacting in the epoxy resin composition obtained in the step (i) after the step (i), for example, the epoxy group is reacted with an amine compound to be eliminated. Is preferred.

In the step (ii), a hydroxyl group of the epoxy resin composition obtained in the step (i) is reacted with an acid anhydride to introduce a carboxyl group into the epoxy resin composition. . The method for introducing a carboxyl group is not particularly limited, and a method well known by those skilled in the art can be exemplified. The acid anhydride is not particularly limited, and examples thereof include succinic anhydride, phthalic anhydride, and hexahydrophthalic anhydride.

The reaction of the above step (ii) is carried out, for example, by mixing the epoxy resin composition having a propargyl group obtained in the above step (i) with a predetermined amount set to have the above-mentioned carboxyl group content. Mixed with the above acid anhydride of
Usually, stirring can be performed at 50 to 90 ° C. for several hours. The end point of the reaction can be determined by measuring the acid equivalent or the hydroxyl value, but from the viewpoint of measurement accuracy, it is preferable to use the measurement of the acid equivalent as a guide. Confirmation of introduction of a carboxyl group in the obtained resin composition can be performed by a potentiometric titration method.

When a part of the propargyl group of the resin composition contained in the anionic electrodeposition coating composition of the present invention is converted to acetylide, the epoxy resin composition having a hydroxyl group and a propargyl group obtained in the above step (i) can be used. The product can be reacted with a metal compound to convert some of the propargyl groups in the epoxy resin composition into acetylides. The metal compound is preferably a transition metal compound that can be converted to acetylide, for example,
Examples include complexes or salts of transition metals such as copper, silver or barium. Specific examples thereof include copper acetylacetone, copper acetate, silver acetylacetone, silver acetate, silver nitrate, zinc acetate, barium acetylacetone, and barium acetate. Among these, compounds of copper or zinc are preferable from the viewpoint of environmental compatibility, and for example, copper acetate or zinc acetate is preferable in view of ease of bath management.

The reaction conditions for converting a part of the propargyl group to acetylide are usually several hours at 40 to 70 ° C. The progress of the reaction can be confirmed by coloring of the obtained resin composition, disappearance of methine proton by nuclear magnetic resonance spectrum, and the like. Thus, the reaction point at which the propargyl group in the resin composition is converted into acetylide at a desired ratio is confirmed, and the reaction is terminated. The resulting reaction product is generally a mixture of epoxy resins in which one or more of the propargyl groups has been acetylated. The above-obtained epoxy resin composition in which a part of the propargyl group is acetylated is subjected to the above step (ii).
Can introduce a carboxyl group.

The step of converting a part of the propargyl group of the epoxy resin composition to acetylide and the step (i)
In i), the reaction conditions can be set in common, so that both steps can be performed simultaneously. The method of performing both steps at the same time is advantageous because the manufacturing process can be simplified.

In this way, a resin composition having a carboxyl group and a propargyl group, and if necessary, a carbon-carbon double bond and a part of the propargyl group which is acetylated can be produced. In addition, acetylide
Although there are rarely those which have explosive properties in a dry state, the production method of the present invention is carried out in an aqueous medium, and the target substance can be obtained as an aqueous composition, so that there is no safety problem.

Other methods for obtaining the resin composition contained in the anionic electrodeposition coating composition of the present invention include, for example, the compound (A) or the compounds (A) and (B); After adding and reacting a compound having an aldehyde group with a functional group that reacts with an epoxy group such as p-hydroxybenzaldehyde to obtain an epoxy resin composition having a hydroxyl group, a propargyl group and an aldehyde group, and then oxidizing the aldehyde group And a method of introducing a carboxyl group by adding a compound having a carboxyl group and a functional group capable of reacting a nucleophilic relatively strong epoxy group such as aminoacetic acid. Can be mentioned.

The anionic electrodeposition coating composition of the present invention can be made aqueous by neutralizing the above resin composition to a predetermined neutralization rate with a neutralizing agent. The neutralizing agent is not particularly limited, and examples thereof include a basic compound, and specifically, an amine compound. The amine compounds are not particularly limited, and include, for example, primary to tertiary monofunctional and polyfunctional aliphatic amines,
Examples thereof include amine compounds such as alicyclic amines and aromatic amines, for example, alkylamines having 2 to 8 carbon atoms such as monomethylamine, dimethylamine, trimethylamine, triethylamine, propylamine, diisopropylamine and tributylamine; Monoethanolamine, dimethanolamine, methylethanolamine, dimethylethanolamine, cyclohexylamine, morpholine, N-methylmorpholine, pyridine, pyrazine,
Examples thereof include piperidine, imidazoline, and imidazole, and alkanolamines such as monoethanolamine, diethanolamine, and dimethylethanolamine are preferable from the viewpoint of aqueous dispersion stability. These may be used alone or in combination of two or more. The neutralization ratio is not particularly limited, and the molar ratio of the amino group of the amine compound to the carboxyl group of the resin composition is, for example, 20 to 120%.

The anionic electrodeposition coating composition of the present invention contains the above resin composition. In the anionic electrodeposition coating composition of the present invention, the use of a curing agent is not necessarily required because the above-described resin composition itself has curability. However, it may be used to further improve the curability. Such a curing agent is not particularly limited, and for example, a compound having a plurality of at least one kind of a propargyl group and a carbon-carbon double bond, for example, a polyepoxide such as novolak phenol and a pentaerythritol tetraglycidyl ether such as Compounds obtained by subjecting a polyglycidyl compound to an addition reaction with a compound having a propargyl group such as propargyl alcohol or a compound having a carbon-carbon double bond such as acrylic acid can be exemplified.

In the anionic electrodeposition coating composition of the present invention, it is not always necessary to use a curing catalyst. But,
When it is necessary to further improve the curability depending on the curing reaction conditions, a commonly used transition metal compound or the like may be appropriately added as necessary. Such compounds are not particularly limited, for example, nickel, cobalt, manganese, palladium, for transition metals such as rhodium,
Examples thereof include those in which a ligand such as cyclopentadiene or acetylacetone or a carboxylic acid such as acetic acid is bonded. The compounding amount of the curing catalyst is preferably 0.1 to 20 mmol per 100 g of the solid content of the anionic electrodeposition coating composition.

The anionic electrodeposition coating composition of the present invention may further contain a resin composition having an aliphatic hydrocarbon group. By blending the resin composition having the above aliphatic hydrocarbon group, the impact resistance of the obtained coating film is improved. As the resin composition having an aliphatic hydrocarbon group, a carboxyl group of 5 to 400 mmol per 100 g of the resin composition solids.
1, an organic group having 80 to 135 mmol of an aliphatic hydrocarbon group which may have an unsaturated double bond having 8 to 24 carbon atoms in a chain and an organic group having a terminal of an unsaturated double bond having 3 to 7 carbon atoms, and propargyl At least one of groups 10 to 315
mmol, and a carboxyl group, having 8 to 8 carbon atoms.
The resin composition has a total content of an aliphatic hydrocarbon group which may contain 24 unsaturated double bonds in the chain, an organic group having 3 to 7 carbon atoms and an organic group having a terminal unsaturated double bond, and a propargyl group. Those having 500 mmol or less per 100 g of solid content can be mentioned.

When a resin composition having an aliphatic hydrocarbon group is added to the anionic electrodeposition coating composition of the present invention, 5-400 mmol of carboxyl groups per 100 g of resin solid content of the anion electrodeposition coating composition, carbon Number 8-2
4, a total of 10 to 300 mmol of an aliphatic hydrocarbon group which may contain an unsaturated double bond in the chain, and 10 to 300 mmol of a propargyl group and an organic group having an unsaturated double bond having 3 to 7 carbon atoms at the terminal. 485 mmol, and a carboxyl group, an aliphatic hydrocarbon group and a propargyl group which may have an unsaturated double bond having 8 to 24 carbon atoms in the chain, and an unsaturated double bond having 3 to 7 carbon atoms. The total content of the organic group having at the terminal is 500 mmol or less per 100 g of the resin solid content of the anionic electrodeposition coating composition, and the chain may include the unsaturated double bond having 8 to 24 carbon atoms. The content of the aliphatic hydrocarbon group is preferably 3 to 30% by weight based on the solid resin content of the anionic electrodeposition coating composition.

When a resin composition having an aliphatic hydrocarbon group is blended with the anionic electrodeposition coating composition of the present invention, when the carboxyl group is less than 5 mmol / 100 g, hydration and bath stability are poor. There is a risk of going bad. 400
When the amount exceeds mmol / 100 g, the deposition of the coating film on the surface of the article to be coated may be deteriorated, or the curability may not be sufficiently obtained. Further, 80 mmol of an aliphatic hydrocarbon group having 8 to 24 carbon atoms, which may contain an unsaturated double bond in the chain.
If it is less than / 100 g, the improvement in impact resistance is insufficient, and if it exceeds 350 mmol / 100 g, the handleability of the resin composition may be difficult. When the total of the propargyl group and the organic group having an unsaturated double bond having 3 to 7 carbon atoms at the terminal is less than 10 mmol / 100 g,
Even when used in combination with other resins or curing agents, there is a possibility that sufficient curability may not be exhibited, and if it exceeds 315 mmol / 100 g, the impact resistance may not be sufficiently improved. is there. A carboxyl group, an aliphatic hydrocarbon group and a propargyl group which may have an unsaturated double bond having 8 to 24 carbon atoms in the chain, and an organic group having an unsaturated double bond having 3 to 7 carbon atoms at the terminal. The total content is 500 mmo per 100 g of the solid content of the resin composition.
1 or less. If it exceeds 500 mmol, the resin may not be actually obtained or the desired performance may not be obtained.

The anionic electrodeposition coating composition of the present invention may further contain, if necessary, other components used in ordinary anionic electrodeposition coating compositions. The other components are not particularly limited, and include, for example, paint additives such as a coloring pigment, a pigment-dispersed resin, a surfactant, an antioxidant, and an ultraviolet absorber.

The coloring pigment is not particularly limited, and is generally used in anionic electrodeposition coatings such as coloring pigments such as titanium dioxide, carbon black and red iron oxide; and extender pigments such as kaolin, clay and talc. And the like. When the above-mentioned coloring pigment is used in the anionic electrodeposition coating composition of the present invention, it is preferably 50% by weight or less based on the solid content of the anion electrodeposition coating composition. In addition, as a method of mixing the color pigment with the resin composition, for example, a method of preparing a dispersion paste in a pigment dispersion resin in advance and mixing it with the resin composition can be exemplified. .

The anionic electrodeposition coating composition of the present invention can be obtained by mixing the above-mentioned resin composition and, if necessary, the above-mentioned components and dissolving or dispersing in water. When used for anionic electrodeposition coating, the solid content is 1
It is preferably prepared so as to have a bath solution of 0 to 30% by weight. Further, it is preferable that the content of the propargyl group, the carbon-carbon double bond and the carboxyl group in the anionic electrodeposition coating composition is adjusted so as not to deviate from the range of the above-mentioned resin composition.

The curing temperature of the anionic electrodeposition coating composition of the present invention is preferably adjusted to 130 to 220 ° C. When the curing temperature is lower than 130 ° C., the smoothness of the multilayer coating film obtained by further coating the coating film obtained using the anionic electrodeposition coating composition of the present invention may be reduced. There is. When the curing temperature is higher than 220 ° C., the curability of the multilayered coating film may be reduced, thereby deteriorating the coating film performance, or the color difference of the multilayer coating film after applying the top coat may be caused. There is.

[0047]Anion electrodeposition coating method  In the anion electrodeposition coating method of the present invention,
It is characterized by electrodeposition coating of Nion electrodeposition paint
is there. Coated object in the anion electrodeposition coating method of the present invention
Is not particularly limited, and may be iron, aluminum, copper,
Metals such as lead and tin and metal such as alloys, conductive plus
Ticks and their surface-treated products.

As a method of coating, for example, the object to be coated is immersed in the anionic electrodeposition coating composition to form an anode, and a voltage of usually 50 to 450 V is applied between the anode and the cathode. An example of a method for performing the method can be given. When the applied voltage is less than 50 V, electrodeposition becomes insufficient and
If the voltage exceeds 0 V, the power consumption increases, which is not economical. When a voltage is applied within the above range using the anionic electrodeposition coating composition, a uniform film can be formed on the entire surface of the material without causing a sharp increase in the film thickness in the electrodeposition process. . The bath liquid temperature of the anionic electrodeposition coating composition when the above voltage is applied is usually 10 to 4
5 ° C. is preferred. On the other hand, the time for applying the voltage varies depending on the electrodeposition conditions, but is generally 2 to 4 minutes.

In the above-mentioned electrodeposition process, a voltage is applied between the object to be coated as a cathode and an anode, and a voltage is further applied to the deposited film to thereby obtain an electric resistance per unit volume of the film. The value can be increased.

The electrodeposited film thus obtained may be used as it is or after washing with water after completion of the electrodeposition process.
The coating can be cured by baking at 0 ° C., preferably 150-200 ° C. for 10-40 minutes to complete the coating. In addition, the intermediate coating uncured coating film is formed by so-called wet-on-wet coating the electrodeposition coating film obtained as described above without curing the electrodeposition coating film, which will be described later. It is also possible to carry out a two-coat one-bake system in which a multi-layer coating is obtained by simultaneously heating the coatings.

In the anion electrodeposition coating method of the present invention,
The thickness of the cured electrodeposition coating film is preferably from 10 to 25 μm.
If it is less than 10 μm, the corrosion resistance and rust resistance may be insufficient, and if it is more than 25 μm, the paint is wasted and it is not economical.

The coated article of the present invention is obtained by the above-mentioned anion electrodeposition coating method. Further, the coated article of the present invention can further form an intermediate coating film and / or a top coating film required on the surface according to the purpose.
The intermediate coating film can be formed by applying an intermediate coating material, and the top coating film can be formed by applying an upper coating material.

For example, the intermediate coating film has properties such as adhesion, smoothness, sharpness, overbake resistance, and weather resistance when the painted object is an automobile body outer panel. It is preferable that a thermosetting paint containing a binder and a curing agent is generally used as the intermediate paint to form such an intermediate paint film. As the above binder,
For example, acrylic resin, polyester resin, alkyd resin, and epoxy resin can be used. As the curing agent, various ones can be selected according to the curable functional group of the binder, and examples thereof include an amino resin, a blocked isocyanate compound, an aliphatic polycarboxylic acid and an anhydride thereof, and an epoxy resin. Resins and the like can be mentioned. The intermediate coating can take various forms such as a solvent, an aqueous or water-dispersed type, and a powder.

The overcoat film has a finished appearance (sharpness, smoothness, gloss, etc.), weather resistance (gloss retention, color retention, chalking resistance, etc.), chemical resistance, water resistance, moisture resistance. It is preferable to have a property excellent in properties, curability and the like. As such a top coating, a solid color paint used as a one-coat solid, a two-coat
Base paints and clear paints that can be applied by the bake coating method can be mentioned. It is preferable that these top coats are of a thermosetting type containing a binder and a curing agent. As the binder and the curing agent for the top coat, those described above for the middle coat can be used. The solid color paint contains a known inorganic or organic coloring pigment such as carbon black, phthalocyanine blue, and titanium dioxide. In addition, the base paint may contain a well-known glittering material such as aluminum flake and mica flake in addition to the inorganic or organic coloring pigment. On the other hand, the clear paint does not contain a pigment, but may contain the above-mentioned color pigment or glitter material to the extent that transparency is not impaired. These top coats may be water-based, solvent-based or powdery, but are preferably water-based or powdery from the viewpoint of environmental protection. In the case of water, for example, the carboxyl group of the binder is neutralized with an amine to give water solubility, and in the case of powder, the glass transition temperature can be made higher than room temperature to take each form. it can. The intermediate coating and the top coating may contain additives such as extenders, curing accelerators, leveling agents, ultraviolet absorbers, and light stabilizers.

For the coating of the intermediate coating and the top coating, a coating method known by those skilled in the art can be used according to the form of each coating, for example, a spray coating method, a brush coating method, a dip coating method. , An electrostatic coating method or the like can be used. In particular, it is preferable to use an electrostatic coating method in a coating process in an automobile body manufacturing line.
As for the thickness of the intermediate coating and the top coating and the heating conditions after coating, values and conditions suitable for the respective coating types can be adopted.

As described above, a multilayer coating film can be obtained by laminating an intermediate coating film and a top coating film on the electrodeposition coating film obtained by the anion electrodeposition coating method of the present invention.

[0057]

【Example】Production Example 1 Carboxyl group and propargyl group
Of epoxy resin composition 1 having  Epotote YDCN-703 having an epoxy equivalent of 205.8
(O-cresol novolak epoxy manufactured by Toto Kasei Co., Ltd.
Resin) 2470 parts by weight of propargyl alcohol 875
Parts by weight and dimethylbenzylamine 2.4 parts by weight
Equipped with a thermostat, thermometer, nitrogen introduction pipe and reflux cooling pipe
Temperature to 110 ° C under nitrogen atmosphere
And reacted for 3 hours, the epoxy equivalent became 5000
By the way, it is cooled down to 60 ° C.
Unreacted propargyl alcohol is distilled at 50 mmHg
The epoxy resin composition containing a propargyl group.
Obtained. Further, 1080 parts by weight of succinic anhydride was added.
Raise the temperature and hold at 120 ° C for 4 hours to obtain acid equivalent of resin solid content.
250.0 mmol / 100 g, number average molecular weight (Police
Carboxyl group of propene
An epoxy resin composition 1 having a lugyl group was obtained.

[0058]Production Example 2 Carboxyl group and propargyl
Preparation of Epoxy Resin Composition 2 Having Group  Epotote YDCN-703 having an epoxy equivalent of 205.8
To 2470 parts by weight of propargyl alcohol 580 parts by weight
Parts, 488 parts by weight of p-hydroxybenzaldehyde,
Stirrer, thermometer, 2.4 parts by weight of methylbenzylamine
Separable frus with nitrogen inlet and reflux condenser
In addition, the temperature is raised to 110 ° C under a nitrogen atmosphere, and
When the epoxy equivalent reached 5000,
100 parts by weight of deionized water and potassium permanganate
2.4 parts by weight of aluminum and the temperature was raised, and the temperature was maintained at 100 ° C for 6 hours.
Holding, resin equivalent of acid equivalent 119 mmol / 100g,
Carboxyl group having a number average molecular weight of 3636 and propargyl
An epoxy resin composition 2 aqueous solution having a group was obtained.

[0059]Production Example 3 Carboxyl group and propargyl
Preparation of Epoxy Resin Composition 3 Having Group  Epotote YDCN-703 having an epoxy equivalent of 205.8
To 2470 parts by weight of propargyl alcohol 730 parts by weight
Parts, 2.4 parts by weight of dimethylbenzylamine,
Separable with a meter, nitrogen inlet and reflux condenser
In addition to the flask, the temperature was raised to 110 ° C under a nitrogen atmosphere,
When the epoxy equivalent reaches 1500 after reacting for hours
Add 120 parts by weight of glycine (aminoacetic acid)
Holding at 10 ° C for 2 hours, resin equivalent of acid equivalent 50mm
1/100 g, carboxyl group having a number average molecular weight of 3213
And epoxy resin composition 3 having propargyl group
Was.

[0060]Example 1 Anionic electrodeposition coating composition 1  Carboxyl group and propargyl group obtained in Production Example 1
200 parts by weight of epoxy resin composition 1 having
Fill 20 parts by weight of ethanolamine with Chemistara.
Minutes, then add deionized water gradually to solidify
A 20% by weight dispersion was obtained. Furthermore, this dispersion
1000 parts by weight of the liquid was heated to 55 ° C.
0.4 parts by weight and 1,0 parts by weight of zinc acetate were added and the temperature was raised
And stirred at 55 ° C. for 3 hours to obtain an anionic electrodeposition coating composition.
The product 1 was obtained.

[0061]Example 2 Anionic electrodeposition coating composition 2  The carboxyl group and the propargyl group obtained in Production Example 2
200 parts by weight of an aqueous solution of epoxy resin composition 2 having
Add 15 parts by weight of methylethanolamine to Chemistara
And mix thoroughly, then add deionized water to solidify
A 20% by weight dispersion was obtained. Furthermore, this dispersion
1000 parts by weight of the liquid was heated to 55 ° C.
0.4 parts by weight and 1,0 parts by weight of zinc acetate were added and the temperature was raised
And stirred at 55 ° C. for 3 hours to obtain an anionic electrodeposition coating composition.
The product 2 was obtained.

[0062]Example 3 Anionic electrodeposition coating composition 3  Carboxyl group and propargyl group obtained in Production Example 3
200 parts by weight of epoxy resin composition 3 having
Fill 15 parts by weight of ethanolamine with Chemistara.
And then add deionized water to reduce solids to 2%.
A dispersion of 0% by weight was obtained. Further, the dispersion 10
00 parts by weight to 55 ° C.
The mixture was added with 1,0 parts by weight of zinc acetate, and the temperature was increased.
C. for 3 hours to obtain an anionic electrodeposition coating composition 3.
Was.

[0063]Example 4  The anion electrodeposition coating composition 1 obtained in Example 1 was used as a cathode.
Transfer to a stainless steel container to be used as an electrodeposition bath.
50 × 0.8mm zinc phosphate treated steel sheet
And immersed in the film so that the film becomes an anode.
Electrodeposition coating was performed so as to have a thickness of 5 μm. After electrodeposition coating,
Lift the painted object from the electrodeposition bath in the stainless steel container and wash it with water
And put in a drying oven set at 180 ° C for 30 minutes to heat
To form an anion electrodeposition coating on the surface of the workpiece
Test plate 1 was obtained.

[0064]Examples 5 and 6  Instead of the anionic electrodeposition coating composition 1 obtained in Example 1
The anion electrodeposition obtained in Examples 2 and 3, respectively
Example 4 was repeated except that coating compositions 2 and 3 were used.
Similarly, test plates 2 and 3 were obtained.

[0065]Comparative Example 1  Instead of the anionic electrodeposition coating composition 1 obtained in Example 1
, Power Mite # 3000 (Merami manufactured by Nippon Paint Co., Ltd.)
Curable acrylic resin anion electrodeposition paint, solid content 20
Wt%), except that
Test plate 4 was obtained.

[0066]Comparative Example 2  Power Top U-80 (Nippon Paint Co., Ltd.
Socyanate-curable amino epoxy resin based cationic electrodeposition
Stainless steel container with paint, solid content 20% by weight) as anode
To the electrodeposition bath, where it is 75 × 150 × 0.8 mm
Dip the zinc phosphate treated steel sheet as the object to be coated,
So that the dry film thickness becomes 15 μm
Electrodeposition coating was performed. After electrodeposition coating, the object to be coated is made of stainless steel.
Pull up from the electrodeposition bath in the container, wash with water, set to 180 ° C
Into the drying oven for 30 minutes and heat it,
Test plate 5 having a cationic electrodeposition coating film formed on its surface was obtained.

<Evaluation Test> The anionic electrodeposition coating compositions 1 to 3 obtained in Examples 1 to 3 and Comparative Examples 1 and 2
The following evaluation tests were performed on Power Mite # 3000 and Power Top U-80 used in the above, and on Test Plates 1 to 5 obtained in Examples 4 to 6 and Comparative Examples 1 and 2. In addition, the evaluation result was shown in 1.

[0068]Storage stability  Each of the obtained anionic electrodeposition coating compositions 1-3 and power
Mite # 3000 and Power Top U-80 at 50 ℃
After storing for 40 days in a thermostat set at
It was evaluated visually. The evaluation criteria were as follows. ：: No change from initial stage △: Slightly thickened ×: Thickened

[0069]Environmental compatibility  Each of the obtained anionic electrodeposition coating compositions 1-3 and power
Lead in Mite # 3000 and Powertop U-80
The presence or absence of harmful heavy metals such as was evaluated. ○: Hazardous heavy metals are not contained ×: Hazardous heavy metals are contained

[0070]Corrosion protection  Apply a cutter knife to the surface of the coating film on each test plate obtained.
Put the cross cut to reach the salt spray test (5 wt% diet
(Salt water, 35 ° C) for 960 hours.
Kure is visually evaluated, and the cut part is peeled off with tape.
Then, the maximum tape peeling width from the cut portion was evaluated. It
The evaluation criteria were as follows. Blistering ○: very little ×: many ・ peeling width ○: less than 2 mm ×: 2 mm or more

[0071]

[Table 1]

As is clear from Table 1, the anionic electrodeposition coating composition of the present invention has excellent storage stability. In addition, since it does not contain harmful heavy metals such as lead, it does not cause environmental pollution. Furthermore, if the anionic electrodeposition coating composition of the present invention is used, a coating film having good corrosion resistance can be obtained.

[0073]

The anionic electrodeposition coating composition of the present invention contains a resin composition having a carboxyl group and a propargyl group, and thus has excellent storage stability.
This is thought to be due to the fact that the curing reaction of the anionic electrodeposition coating composition of the present invention is based on activated carboxyl groups and propargyl groups generated by electrodeposition coating.

The anionic electrodeposition coating composition of the present invention can provide an electrodeposition coating film having excellent corrosion resistance without using a rust-preventive pigment containing a harmful heavy metal such as lead. This is because the anionic electrodeposition coating composition containing the resin composition having a carboxyl group and a propargyl group has a higher anticorrosion property of a coating film obtained from itself than a conventionally used anion electrodeposition coating composition. This is considered to be due to the fact that the carboxyl group in the coating film disappears due to the curing reaction.

Further, since the anionic electrodeposition coating composition of the present invention does not contain harmful heavy metals such as lead, there is no risk of causing environmental pollution, and there is no need to treat wastewater containing harmful metals. It is economical.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ichiro Kawakami 19-17 Ikedanakamachi, Neyagawa-shi, Osaka F-term in Nippon Paint Co., Ltd. (reference) 4J038 DB001 DB071 GA01 GA03 GA06 PA04

Claims (8)

[Claims] 1. An anionic electrodeposition coating composition comprising a resin composition having a carboxylic acid group and a propargyl group. 2. The anionic electrodeposition coating composition according to claim 1, wherein the resin composition further has a hydroxyl group. 3. The carboxylic acid group and the propargyl group have a carboxylic acid group content of 5 to 400 mmol and a propargyl group content of 10 to 100 mmol per 100 g of the solid content of the resin composition.
The anionic electrodeposition coating composition according to claim 1, wherein the composition contains from 495 to 495 mmol, and the total content of the carboxylic acid group and the propargyl group is 500 mmol or less. 4. 4. The resin composition according to claim 1, wherein said carboxylic acid group and propargyl group have a carboxylic acid group content of 10 to 300 mmol and a propargyl group content of 5 to 100 g per 100 g of solid content of said resin composition.
The anionic electrodeposition coating composition according to any one of claims 1 to 3, which contains 0 to 400 mmol and has a total content of a carboxylic acid group and a propargyl group of 400 mmol or less. 5. The anionic electrodeposition coating composition according to claim 1, wherein the resin composition has an epoxy resin as a skeleton. 6. The epoxy resin is a novolak cresol type epoxy resin or a novolak phenol type epoxy resin, and has a number average molecular weight of 700 to 5,000.
The anionic electrodeposition coating composition according to claim 5, which is: 7. An anion electrodeposition coating method according to claim 1, wherein the anion electrodeposition coating method comprises electrodeposition coating an anion electrodeposition coating material on an object to be coated. An anion electrodeposition coating method, which is a composition. 8. A coated article obtained by the anion electrodeposition coating method according to claim 7.