JP6909201B2 - Firing composition and its manufacturing method, and electrodeposition paint - Google Patents

Description

The present invention is a technique relating to a novel firing composition useful for coating, and an electrodeposition coating material capable of lowering a curing temperature while avoiding the use of an organic tin compound and having excellent rust prevention properties. Regarding the technology that can be provided.

In general, electrodeposition coating, in which coating is performed electrochemically, is excellent in corrosion resistance and circumvention, and is widely used for coating automobile bodies, parts, and the like. The coating process usually spans two to three steps (eg, three steps of undercoat-intermediate coat-topcoat). In the first-stage undercoating step, the adhesion or adhesion between the paint and the surface to be coated is improved, and effective rust prevention is provided. Then, an aesthetically pleasing painted surface is obtained by the next step of intermediate coating and top coating. For the general background of electrodeposition coating, refer to Non-Patent Document 1.

The paint composition used for electrodeposition coating usually contains a color pigment, a rust preventive, and other additives in addition to the resin. Focusing on rust preventives, the most excellent rust preventives are lead compounds such as lead chromate, lead silicate, and lead acetate. However, these lead compounds are harmful and problematic in their use. The inventors have previously proposed a specific calcined composition as an alternative material to lead compounds. That is, it is a technique shown in Patent Document 1, and by blending a specific firing composition obtained by firing a zinc compound and a tin compound in an electrodeposition coating material, not only excellent corrosion resistance but also stability of the electrodeposition bath is achieved. It is a technology with good properties.

Japanese Patent No. 4204049

Automotive Electroplated Coating Technology, Iron and Steel, No. 7, 1980, pp. 185-195

In electrodeposition coating, the coating film is strengthened by performing a baking process after electrodeposition coating. The baking temperature is, for example, 150 ° C. or higher. Since this high temperature may cause thermal strain or the like in the product to be coated, it is desired to reduce the temperature if possible. The temperature reduction is preferable in terms of labor saving of energy consumption and environmental and economic aspects. However, the firing composition according to the above proposal cannot be sufficiently cured by baking at a temperature lower than 150 ° C., and good coating film smoothness cannot be obtained.

Further, in order to accelerate the curing of the coating film, a curing catalyst is used in the coating composition, and as the curing catalyst, an organic tin compound such as dioctyl tin oxide (DOTO) has been used so far. However, organic tin compounds are strictly regulated from the viewpoint of environmental protection. Therefore, it is desired to avoid using such a problematic curing catalyst as much as possible.

Therefore, an object of the present invention is to provide a technique for utilizing firing, which can reduce the firing temperature to more than 150 ° C.

Another object of the present invention is to provide a coating technique utilizing firing, which can obtain a sufficient curing catalytic ability without using a curing catalyst, which is a problem from the viewpoint of environmental protection. Further objectives of the present invention will become clear from future description.

The inventors have found a new firing composition that is useful for enhancing rust prevention and curability, assuming that the firing technique is utilized.
The first calcined composition is a calcined product of a zinc compound and a bismuth compound, and the weight% Wz of zinc oxide and the weight% Wb of bismuth oxide and / and bismuth hydroxide are in a relationship of Wz ≧ Wb. Moreover, it is characterized by being a rust preventive and / and a curing catalyst.

The second firing composition is a calcined product of a zinc compound, a bismuth compound, and a silicon compound, and has a weight% Wz of zinc oxide, a weight% Wb of bismuth oxide and / and bismuth hydroxide, and a weight of silicon oxide. % Ws has a relationship of Wz ≧ Wb, Ws (where Wz ≧ Wb, Ws means Wz ≧ Wb and Wz ≧ Ws), and is a rust preventive or / and a curing catalyst. It is characterized by. This second firing composition further contains silicon oxide with respect to the first firing composition. As a result, due to the bulkiness or volume increase of silicon oxide, there is a slight difficulty in producing a large amount of the calcined composition in terms of equipment and handling as compared with the production of the first calcined composition. Separately, the first firing composition is advantageous in production.

Further, the third calcined composition is a calcined product of a zinc compound, a titanium compound and a silicon compound, and the weight% Wz of zinc oxide, the weight% Wt of titanium oxide and the weight% Ws of silicon oxide are Wz ≧ Wt. , Ws (where Wz ≧ Wt, Ws means Wz ≧ Wt and Wz ≧ Ws), and is characterized by being a rust preventive and / and a curing catalyst. Titanium oxide in the third firing composition and bismuth oxide in the first and second firing compositions are common in that they are transition metal oxides having d-electrons that control their physical characteristics, and are fired. It is thought that they show similar physical properties.

Here, specific examples of the zinc compound, the bismuth compound, the silicon compound, and the titanium compound are as follows.
Zinc compound:
Examples thereof include zinc oxide, zinc hydroxide, zinc carbonate, zinc phosphate, zinc chloride, zinc nitrate, zinc acetate and the like.
Bismuth compound:
Bismuth oxide, bismuth hydroxide, basic bismuth carbonate, bismuth phosphate, bismuth chloride, bismuth oxychloride, bismuth nitrate, bismuth vanadate, bismuth zirconate, bismuth titanate, bismuth acetate, bismuth octylate, oxalic acid Bismuth, bismuth citrate, bismuth hypophagoic acid, basic bismuth salicylate, tri (dimethyldithiocarbamate) bismuth, aluminum triavietate bismuth, trineodecanoate bismuth, tris (2-ethylhexanoate) bismuth, tri Bismuth methanesulfonate, magnesium bismuth aluminosilicate, bismuth tetraoxovanadium acid, tris [2,2-dialkylalkanoic acid (C10)] bismuth, tris (methanesulfonic acid) bismuth, dibismuth tritartrate, bismuth dilactic acid, etc. Be done.
Silicon compound:
Examples thereof include silicon dioxide, silicon tetrachloride, tetramethoxysilane, and trimethylsilyl chloride.
Titanium compound:
Examples thereof include titanium oxide, titanium hydroxide, titanium tetrachloride, titanium tetraacetate, and tetraisopropoxytitanium.

Each of the first to third firing compositions of the present invention can be produced by mixing a powder mixture of each material with a solvent such as ethanol and firing at 300 ° C. to 1000 ° C. in an electric furnace.

Each such firing composition can be usefully used as a material for an electrodeposition coating material, specifically, a composition (corrosion preventive agent or rust preventive agent) for a cationic electrodeposition coating material. Further, it can be provided as an electrodeposition coating material containing the same. When these firing compositions are used as compositions for electrodeposition coatings, there are no particular restrictions on their handling, and they can be carried out in the same manner as in a normal pigment dispersion method. For example, each firing composition can be dispersed in a dispersion resin in advance to prepare a dispersion paste, and the dispersion paste can be blended. Examples of the pigment dispersion resin include epoxy-based quaternary ammonium salt-type resins and acrylic-based quaternary ammonium salt-type resins, which are usually used for cationic electrodeposition paints.

As the base resin, those having a number average molecular weight of 100 to 10,000, preferably 1000 to 3000, which are derived from the bisphenol type epoxy resin, can be used, and the base resin has a base equivalent of 40 to 150 (milli equivalent / 100 g). Preferably, it is 60 to 100 (milli equivalent / 100 g).

A blocked polyisocyanate compound is used as the cross-linking agent. The blocked isocyanate cross-linking agent can be obtained by an addition reaction between an isocyanate blocking agent and a polyfunctional isocyanate. It is desirable that the isocyanate blocking agent dissociates the block and regenerates free isocyanate groups when heated to 100 to 200 ° C. For example, caprolactam, phenol, ethanol, 2-ethylhexyl alcohol, butyl cellosolve, methyl ethyl ketokisum and the like. Further, as the polyfunctional isocyanate compound, a fatty acid, an alicyclic or aromatic polyisocyanate is used. For example, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and its isocyanates.

<Basic concept of curing catalytic ability>
Each of the first to third firing compositions of the present invention not only functions as a rust preventive, but also functions as a curing catalyst. However, it is effective to additionally add a known curing catalyst in order to further enhance the rust preventive property and the curable property. By adding fatty acid bismuth, particularly bismuth trioctylate, the curing temperature can be further effectively lowered to, for example, about 130 ° C., and at the same time, the rust preventive property can be further enhanced.
<Preferable example of the curing catalyst to be added>
As the curing catalyst to be added, fatty acid bismuth (preferably C _4-15 fatty acid bismuth), particularly bismuth trioctylate can be used alone, but trioctyl can be obtained by using a mixture of bismuth trioctylate and ethylenediamine. The amount of bismuth acid used can be reduced. Specifically, it has the following form.
(1) A mixture of tris (2-ethylhexanoate) bismuth and N, N, N', N'-tetrakis (2-hydroxyethyl) ethylenediamine.
(2) A mixture of tris (2-ethylhexanoate) bismuth and N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine.
(3) A mixture of trineodecanoate bismuth and N, N, N', N'-tetrakis (2-hydroxyethyl) ethylenediamine.
(4) A mixture of trineodecanoate bismuth and N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine.

In the neutralization and water solubilization of the electrodeposition coating composition of the present invention, the substrate resin and the blocked isocyanate cross-linking agent are dispersed in an aqueous medium using organic acids such as formic acid, acetic acid, propionic acid, lactic acid and sulfamic acid as neutralizing agents. Do it by doing.

To the electrodeposition coating composition of the present invention, as a coating additive, for example, pigments such as titanium white, carbon black, talc, clay, and silica can be dispersed with a pigment dispersion resin and added as a pigment paste. Further, if necessary, other rust preventive pigments such as aluminum phosphate, aluminum phosphomolybate, barium borate and the like, and paint additives such as a surface conditioner and an organic solvent can be blended.

The electrodeposition coating composition of the present invention is coated on the surface of a base material by cationic electrodeposition coating. The cationic electrodeposition coating composition is an electrodeposition bath comprising an electrodeposition coating composition having a solid content concentration of 15 to 25% by weight adjusted with deionized water and a pH adjusted to a range of 5.5 to 7.0. Keep at 20 to 30 ° C. and carry out under the condition of voltage 100 to 400V.

The film thickness of the coating film formed by using the electrodeposition coating composition of the present invention is, for example, 10 to 50 μm, and the baking temperature of the coating film is, for example, 130 ° C. to 150 ° C. In the technique for utilizing the fired product proposed above, when baking at 150 ° C. or 130 ° C., pear-shaped protrusions appeared on the painted surface and the smoothness was lost. However, by utilizing this invention, it has become possible to obtain good coating film smoothness even at a low baking temperature of 130 ° C.
Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples.
[Manufacturing Example 1]

In a 500 ml beaker, 76 g of zinc oxide, 4 g of bismuth hydroxide, and 20 g of silicon oxide are weighed, and a mixed solvent of 176 ml of ethanol, 20 ml of isopropyl alcohol and 4 ml of methyl ethyl ketone is added and dispersed. Mix for 24 hours using a ball mill. Then, it is transferred to an eggplant flask, and the solvent is removed under reduced pressure with a rotary evaporator to obtain a powder mixture of zinc oxide, bismuth hydroxide, and silicon oxide. The obtained powder mixture was heated in a high-speed heating electric furnace (box furnace KBF848N2 / manufactured by Koyo Lindbergh Co., Ltd.) at 20 ° C. to 10 ° C./min and fired at 800 ° C. for 1 hour to obtain a white fired product. The composition of the obtained white calcined product was zinc oxide / bismuth oxide / silicon oxide = 73.7 / 6.9 / 19.4% by weight (theoretical value: zinc oxide / bismuth oxide / silicon oxide = 73/7/20% by weight). 90 g of butyl acetate is added to 10 g of the white calcined product and dispersed with a paint shaker for 5 hours to obtain 100 g of the 10% solid solution of Production Example 1.
[Manufacturing Example 2]

By adding 100 g of the 10% solid solution of Production Example 1 described above to 34 g of the 10% solution described in E2 described later and mixing, the fired product of Production Example 1 and 134 g of a 10% solution having a weight ratio of bismuth trioctylate of 7.5 / 2.5 are obtained. obtain. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 2.
[Manufacturing Example 3]

By mixing 34 g of the 10% solid solution of bismuth trioctylate described in E2 with 34 g of the 10% solid solution of the calcined product of Production Example 1, 68 g of the 10% solution having a 5/5 weight ratio is obtained. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 3.
[Manufacturing Example 4]

Similarly, 20 g of a 10% solid solution of bismuth trioctylate is mixed with 6.8 g of a 10% solid solution of the fired product of Production Example 1 to obtain a 10% solution having a weight ratio of 2.5 / 7.5. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 4.
[Manufacturing Example 5]

Weigh 60 g of zinc oxide, 20 g of titanium oxide, and 20 g of silicon oxide in a 500 ml beaker, and add a mixed solvent of 176 ml of ethanol, 20 ml of isopropyl alcohol, and 4 ml of methyl ethyl ketone to disperse. Mix for 24 hours using a ball mill. Then, it is transferred to an eggplant flask, and the solvent is removed under reduced pressure with a rotary evaporator to obtain a powder mixture of zinc oxide, bismuth hydroxide, and silicon oxide. The obtained powder mixture was heated in a high-speed heating electric furnace (box furnace KBF848N2 / manufactured by Koyo Lindbergh Co., Ltd.) at 20 ° C. to 10 ° C./min and fired at 800 ° C. for 1 hour to obtain a white fired product. The composition of the white calcined product was zinc oxide / titanium oxide / silicon oxide = 59.6 / 20.1 / 20.3% by weight (theoretical value: zinc oxide / titanium oxide / silicon oxide = 60/20/20% by weight). 90 g of butyl acetate is added to 10 g of the obtained white calcined product and dispersed with a paint shaker for 5 hours to obtain 100 g of a 10% solid solution of Production Example 5.
[Manufacturing Example 6]

By mixing 34 g of the 10% solid solution of bismuth trioctylate described in E2 with 100 g of the 10% solid solution of the calcined product of Production Example 5, 134 g of the calcined product of Production Example 1 and a 10% solution having a 7.5 / 2.5 weight ratio of bismuth trioctylate are obtained. .. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 6.
[Manufacturing Example 7]

By mixing 34 g of the 10% solid solution of bismuth trioctylate with 34 g of the 10% solid solution of the calcined product of Production Example 5, 68 g of the 10% solution having a 5/5 weight ratio is obtained. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 7.
[Manufacturing Example 8]

By mixing 20 g of a 10% solid solution of bismuth trioctylate with 6.8 g of a 10% solid solution of the fired product of Production Example 5, 26.8 g of a 10% solution having a weight ratio of 2.5 / 7.5 is obtained. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 8.
[Manufacturing Example 9]

Weigh 60 g of zinc oxide and 60 g of bismuth hydroxide in a 500 ml beaker, and add a mixed solvent of 176 ml of ethanol, 20 ml of isopropyl alcohol and 4 ml of methyl ethyl ketone to disperse. Mix for 24 hours using a ball mill. Then, it is transferred to an eggplant flask, and the solvent is removed under reduced pressure with a rotary evaporator to obtain a powder mixture of zinc oxide and bismuth hydroxide. The obtained powder mixture was heated in a high-speed heating electric furnace (box furnace KBF848N2 / manufactured by Koyo Lindbergh Co., Ltd.) at 20 ° C to 10 ° C / min and fired at 800 ° C for 1 hour to obtain a slightly yellow fired product. .. The composition of the slightly yellow calcined product was zinc oxide / bismuth oxide = 51.8 / 48.2% by weight (theoretical value; zinc oxide / bismuth oxide = 52.7 / 47.3% by weight). 90 g of butyl acetate is added to 10 g of the obtained slightly yellow calcined product and dispersed with a paint shaker for 5 hours to obtain 100 g of a 10% solid solution of Production Example 9.
[Manufacturing example 10]

By mixing 34 g of the 10% solid solution of bismuth trioctylate described in E2 with 100 g of the 10% solid solution of the calcined product of Production Example 9, 134 g of the calcined product of Production Example 9 and a 10% solution having a weight ratio of bismuth trioctylate of 7.5 / 2.5 are obtained. .. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 10.
[Manufacturing Example 11]

By mixing 34 g of the bismuth trioctylate 10% solid solution with 34 g of the calcined product of Production Example 9, 68 g of the 10% solution having a 5/5 weight ratio is obtained. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 11.
[Manufacturing Example 12]

By mixing 20 g of a 10% solid solution of bismuth trioctylate with 6.8 g of a 10% solid solution of the calcined product of Production Example 9, 26.8 g of a 10% solution having a weight ratio of 2.5 / 7.5 is obtained. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 12.
[E1 (preparation of DOTO 5% solution)]

To 15 g of dioctyl tin oxide (DOTO), 285 g of butyl acetate is added and dispersed with a paint shaker for 5 hours to obtain 300 g of a 5% solution.
[E2 (Preparation of 10% solution of bismuth trioctylate)]

Add 270 g of butyl acetate to 30 g of bismuth trioctylate (manufactured by BiCAT, 8210 Shepherd) and disperse with a paint shaker for 5 hours to obtain 300 g of a 10% solution.
[Curability test-1 (gel fraction)]

Polyol [Acridic A801 (manufactured by DIC Corporation)] 30 g and blocked isocyanate [Duranate TPA-B80X (manufactured by DIC Corporation] 13.3 g, silicon-containing surface conditioner LHP-95 (manufactured by Kusunoki Kasei Co., Ltd.) 0.05 g, BYK- It was prepared by adding 0.1 g of 333 (manufactured by Kusunoki Kasei Co., Ltd.) and further adding 1.34 g of a 10% butyl acetate solution of the calcined product described in Production Example 1. The amount of catalyst for acrylic polyol + polyisocyanate was 0.5%. The prepared solution was coated on a polypropylene plate using a bar coater. Subsequently, the coated plate was dried at a temperature of 130 ° C. for 30 minutes. The coating film applied to the polypropylene plate was peeled off and immersed in acetone at 20 ° C. for 24 hours. The weight residual ratio was measured. The results are shown in Table 1 (Table 1-1 and Table 1-2) as Examples 1 to 12 and Comparative Examples 1 and 2.

A large value of the residual rate indicates that the activity is higher, and a residual rate of 65 or more is effective, preferably a residual rate of 75 to 90. Increasing the amount of bismuth trioctylate tends to increase the residual rate (and corrosion resistance). When considering the experimental results, it can be considered that the blending amount of bismuth trioctylate is 0.5 or more, preferably about 1 to 5 with respect to 1 fired product. As will be described later, when a mixture of bismuth trioctylate and ethylenediamine is used as an additional curing catalyst instead of bismuth trioctylate alone, the amount of bismuth trioctylate used can be reduced.

[Production example of clear emulsion]

Epon 1004 (epoxy resin manufactured by Yuka Shell Co., Ltd., trade name): 475 g is dissolved in butyl cellosolve: 253 g, and 31 g of diethylamine is added dropwise at 90 to 100 ° C and held at 120 ° C for 3 hours to have an amine value of 47. An amine adduct was obtained. Next, 250 g of a polyamide resin having an amine value of 100 was dissolved in 107 g of methyl isobutyl ketone, and reflux dehydration was performed at 140 to 150 ° C. to ketimine the terminal amino groups of the polyamide resin. Hold at 150 ° C for 4 hours, confirm that there is no distilling of water, cool to a liquid temperature of 50 ° C, add to the epoxyamine adduct, hold at 80 ° C for 1 hour, solid content 70%, amine value 66. Epoxyamino-polyamide adduct resin varnish was obtained. The above epoxy-amino-polyamide-added resin varnish (34 g) and 15% acetic acid (4 g) are mixed with 9.4 g of a butyl cellosolve block product of xylylene diisocyanate, and 50 g of deionized water is added dropwise to obtain a cation electrodeposition clear emulsion having a solid content of 33%. rice field.
[Manufacturing of pigment-dispersed resin]

Epototo YD-128 (epoxy equivalent 187, epoxy resin manufactured by Toto Kasei Co., Ltd., trade name) 275 g, Eport YD-011 (epoxy equivalent 475, epoxy resin manufactured by Toto Kasei Co., Ltd., trade name) 349 g, propylene glycol monomethyl ether 342 g The mixture was charged, heated to 100 ° C, stirred for 1 hour, and cooled to 80 ° C. Next, 95 g of diethylaminopropylamine and 77 g of diethanolamine were charged, held at 100 ° C. for 2 hours, and cooled to 70 ° C. The solid content of the obtained dispersed resin was 70%. This resin was neutralized with acetic acid so as to have a pH of 6.5 when the pigment was dispersed, and then dispersed.
[Adjustment of pigment paste]

The mixture was dispersed according to the composition shown in Table 1, pulverized and adjusted with a sand mill to obtain a pigment paste.

Add 12 g of the pigment pastes of Examples 1 to 13 of Formulations 1 to 13 and Comparative Examples 1 to 2 of Formulations 14 to 15 shown in Table 2 to 61 g of a cationic electric-worn clear emulsion having a solid content of 33% with stirring, and deionized water. Diluted with 27 g to obtain a cationic electrodeposition paint.
[Painting test]

A cold-rolled dull steel sheet of 0.8 × 150 × 70 mm treated with zinc phosphate was dipped in the electrodeposition coating materials obtained in Examples 1 to 13 and Comparative Examples 1 to 3 to serve as a cathode, and electrodeposition coating was performed. The electrodeposition conditions were a voltage of 280 V, a film thickness of about 20 μm was applied, and the film was washed with water and then baked. Baking was performed in a gear oven at 130 ° C. for 20 minutes. The performance test results of the obtained baked coating film are shown in Table 2 (Table 2-1 and Table 2-2).
[Bath stability test]

The electrodeposition coating materials obtained in Examples 1 to 13 and Comparative Examples 1 and 2 were filtered through a 400-mesh wire mesh after a lapse of 1 month at 30 ° C., and the amount remaining on the wire mesh was measured and evaluated according to the following criteria.
◎: Less than 5 mg 〇: 6 to 10 mg
Δ: 11 to 80 mg
×: 81 mg or more [curability test 2]

The appearance of the coated surface of the electrodeposited coating film baked at 130 ° C. was visually observed when the coated surface was rubbed back and forth 20 times with gauze impregnated with methyl ethyl ketone. The evaluation criteria are as follows.
〇: No scratches on the coated surface △: Scratched on the coated surface ×: The coated surface melts and the substrate can be seen [corrosion resistance test]

Cross-cut scratches were made with a knife until the substrate was reached, and a salt spray test was conducted for 1000 hours in accordance with JIS-Z-2731, and the evaluation was made based on the rust and blistering width of the knife-cut portion. The evaluation criteria are as follows.
◎: Rust and blistering width is less than 1 mm from the knife cut part 〇: Rust and blistering width is 1.1 to 2 mm from the knife cut part
Δ: Rust and blistering width is 2.1 to 3 mm from the knife cut part
×: Rust and blistering width is 3.1 mm or more from the knife cut part [Coating film smoothness test]

The appearance of the coating film was visually inspected and evaluated.
〇: Good △: Slightly bad ×: Bad

As described above, according to the embodiment of the present invention, even when the baking temperature or the curing temperature is lowered to about 130 ° C., the result of excellent coating film smoothness and excellent rust prevention is obtained. I was able to.

Next, a case where a mixture of bismuth trioctylate and ethylenediamine is used as an additional curing catalyst will be described. MIK-1 and MIK-2 were prepared as additional mixtures (hardeners).
<Creation of curing agent MIK-1>
To a 500 ml eggplant flask, 50 g of BiCAT8210 [manufactured by Shepherd (bismuth trioctylate 28 wt% Bi)] was added under a nitrogen gas atmosphere. Next, after stirring at an outside temperature of 40 ° C. for 30 minutes, 90 g of N, N, N', N'-tetrakis (2-hydroxyethyl) ethylenediamine was gradually added. Fever was observed in the reaction system, and the color changed from yellow to orange. The mixture was reacted at an outside temperature of 50 ° C. for 1 hour to obtain 140 g of the title mixture. The bismuth concentration was a quantitative yield of 10 wt%.

<Creation of curing agent MIK-2>
72 g of BiCAT 8210 [manufactured by Shepherd (bismuth trioctylate 28 wt% Bi)] was added to a 500 ml eggplant flask in a nitrogen gas atmosphere. Next, after stirring at an outside temperature of 40 ° C. for 30 minutes, 60 g of N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine was gradually added. Fever was observed in the reaction system, and the color changed from yellow to orange. After the exotherm subsided, 68 g of diethylene glycol monoethyl ether was added, and the mixture was reacted at an outside temperature of 50 ° C. for 1 hour to obtain 200 g of the title mixture. The bismuth concentration was a quantitative yield of 10.2 wt%.
Then, using these curing agents MIK-1 and MIK-2, the compositions of Production Examples 14 and 15 were obtained.
[Manufacturing Example 14]

By adding 250 g of the 10% solid solution of Production Example 1 described above to 8.3 g of the mixture of MIK-1 and mixing, the calcined product of Production Example 1 and a 10% solution of a 7.5 / 2.5 weight ratio of MIK-1 258.3 g. To get. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 14.

[Manufacturing example 15]

By adding 510 g of the 10% solid solution of Production Example 1 described above to 17 g of the mixture of MIK-2 and mixing, 527 g of the calcined product of Production Example 1 and a 10% solution of a 7.5 / 2.5 weight ratio of MIK-2 is obtained. .. Subsequently, the solution is concentrated under reduced pressure and dried to obtain the composition of Production Example 14.

Table 3 shows the experimental results in the form in which each mixture of MIK-1 and MIK-2 was added. From the results, it can be seen that when each mixture of MIK-1 and MIK-2 is added, the amount of bismuth trioctylate used is significantly reduced in terms of the amount of bismuth trioctate as compared with the case of bismuth trioctylate alone. It is considered that this is because MIK-1 and MIK-2 have improved stability and compatibility with a hydrophilic solvent containing water, and the hydrolysis of bismuth trioctylate is suppressed. By suppressing hydrolysis, liberation of octyl acid can be avoided and safety can be improved, and the amount of bismuth trioctylate used can be reduced, which is advantageous in terms of cost. Here, when the amount of bismuth is examined in the gel fractions (residual rate) of MIK-1 and MIK-2 in the experimental results, the amount of bismuth trioctylate to be blended is preferably 0.05 or more with respect to the calcined product 1. Is about 0.1 to 1. In this respect, it can be seen that when each mixture of MIK-1 and MIK-2 is added, the amount of bismuth trioctylate used is clearly reduced as compared with the case of bismuth trioctylate alone.

Therefore, by using the compositions of Production Examples 14 and 15 containing the mixtures of MIK-1 and MIK-2, the composition of Production Example 2 is included under the same conditions as described above. Corrosion resistance and coating film smoothness were examined. The results are shown in Table 4. In all cases, corrosion resistance and coating film smoothness were good, and curability at a temperature of 130 ° C. was also confirmed.

Claims (18)

It is a material of an electrodeposition coating composition, and is a firing composition capable of reducing the baking temperature associated with electrodeposition coating to more than 150 ° C.
It is a calcined product of a zinc compound and a bismuth compound, and the weight% Wz of zinc oxide and the weight% Wb of bismuth oxide and / and bismuth hydroxide have a relationship of Wz ≧ Wb, and a rust preventive or / and A firing composition, which is a curing catalyst. It is a material of an electrodeposition coating composition, and is a firing composition capable of reducing the baking temperature associated with electrodeposition coating to more than 150 ° C.
It is a calcined product of zinc compound, bismuth compound and silicon compound, and the weight% Wz of zinc oxide, the weight% Wb of bismuth oxide and / and bismuth hydroxide, and the weight% Ws of silicon oxide are Wz ≥ Wb, Ws ( Here, Wz ≧ Wb, Ws means Wz ≧ Wb and Wz ≧ Ws), and the firing composition is a rust preventive and / and a curing catalyst. It is a material of an electrodeposition coating composition, and is a firing composition capable of reducing the baking temperature associated with electrodeposition coating to more than 150 ° C.
It is a calcined product of a zinc compound, a titanium compound and a silicon compound, and the weight% Wz of zinc oxide, the weight% Wt of titanium oxide and the weight% Ws of silicon oxide are Wz ≧ Wt, Ws (where Wz ≧ Wt, Wz ≧ Wt, Ws. Ws means Wz ≧ Wt and Wz ≧ Ws), and is a calcining composition characterized by being a rust preventive and / and a curing catalyst. A composition having a curing catalytic ability, which comprises additionally mixing a fatty acid bismuth compound with a fired product according to any one of claims 1 to 3. The composition of claim 4, wherein the fatty acid bismuth compound is bismuth trioctylate. A composition having a curing catalytic ability, which comprises additionally mixing a mixture of bismuth trioctylate and ethylenediamine with respect to any one of the fired products of claims 1 to 3. The method for producing a fired product according to claim 1, which comprises firing in the range of 300 ° C. to 1000 ° C. The method for producing a fired product according to claim 2, wherein the fired product is fired in the range of 300 ° C. to 1000 ° C. The method for producing a fired product according to claim 3, wherein the fired product is fired in the range of 300 ° C. to 1000 ° C. In an electrodeposition coating material containing a rust preventive and / and a curing catalyst in the coating composition, the rust preventive and / and the curing catalyst are a calcined product of a zinc compound and a bismuth compound, and the weight% Wz of zinc oxide and the like. , and weight% Wb of bismuth oxide and / or hydroxide bismuth Chi also a relationship Wz ≧ Wb, moreover, characterized in that it is possible to a temperature lower than 0.99 ° C. the temperature of the baking due to the electrodeposition coating , Electrodeposition paint. The electrodeposition coating material according to claim 10, wherein the fatty acid bismuth is additionally mixed with the fired product. The electrodeposition coating material according to claim 10, wherein a mixture of bismuth trioctylate and ethylenediamine is additionally mixed with the fired product. In an electrodeposition coating material containing a rust preventive and / and a curing catalyst in the coating composition, the rust preventive and / and the curing catalyst is a calcined product of a zinc compound, a bismuth compound and a silicon compound, and is a weight% of zinc oxide. Wz, weight% Wb of bismuth oxide and / and bismuth hydroxide, and weight% Ws of silicon oxide are Wz ≧ Wb, Ws (where Wz ≧ Wb, Ws means Wz ≧ Wb and Wz ≧ Ws. Chi also the relationship between the meaning), moreover, characterized in that it is possible to a temperature lower than 0.99 ° C. the temperature of the baking due to the electrodeposition coating, electrodeposition coating. The electrodeposition coating material according to claim 13, wherein the fatty acid bismuth is additionally mixed with the fired product. The electrodeposition coating material according to claim 13, wherein a mixture of bismuth trioctylate and ethylenediamine is additionally mixed with the fired product. An electrodeposition coating material containing a rust preventive and / and a curing catalyst in the coating composition, wherein the rust preventive and / and the curing catalyst is a calcined product of a zinc compound, a titanium compound and a silicon compound, and is composed of zinc oxide. The relationship between the weight% Wz, the weight% Wt of titanium oxide, and the weight% Ws of silicon oxide is Wz ≧ Wt, Ws (where Wz ≧ Wt, Ws means Wz ≧ Wt and Wz ≧ Ws). Chi also, moreover, be characterized in that it can be a temperature lower than 0.99 ° C. the temperature of the baking due to the electrodeposition coating, electrodeposition coating. The electrodeposition coating material according to claim 16, wherein the fatty acid bismuth is additionally mixed with the fired product. The electrodeposition coating material according to claim 13, wherein a mixture of bismuth trioctylate and ethylenediamine is additionally mixed with the fired product.