JPH09263712A - Powder coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder coating composition which forms a coating good in surface condition and having an excellent resistance to yellowing by heat. SOLUTION: A powder coating composition contg. 0.02-3 pts.wt. cobalt org. acid salt, or 0.01-5 pats.wt. cobalt and/or bismuth inorg. compd. to 100 pts.wt. polyol polyester/polyurethane is obtd.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a powder coating composition which forms a coating film having a good surface condition and excellent heat yellowing resistance.

[0002]

2. Description of the Related Art Conventionally, polyol / polyurethane curable powder coating materials have been widely used because of their good physical performance and weather resistance. However, the coating film formed with this curable powder coating develops color due to oxidation due to heat during baking of the coating film, influence of nitrogen oxides generated from gas components during baking in a gas furnace, and oxidation due to sulfur oxides. As a result, a coating easily turns yellow due to changes in baking temperature and baking time.
The degree of freedom in printing control width was small, and line compatibility was poor. Further, it is known that yellowing can be suppressed in this curable powder coating material by not using a catalyst, but in this case, sufficient baking cannot be performed at a normal baking temperature, and thus line compatibility is also low. There was a problem.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a powder coating composition which eliminates such drawbacks and maintains excellent coating performance while having a good surface condition and excellent heat yellowing. The purpose is to

[0004]

Means for Solving the Problems As a result of researches conducted by the present inventors in order to solve the above-mentioned problems, the polyol / polyurethane curable powder coating material has a predetermined amount of cobalt organic acid salt or cobalt and / or It has also been found that the addition of an inorganic compound of bismuth can prevent the formation of a chromophore in the coating film of the curable powder coating material and can significantly suppress the heat yellowing of the coating film. Therefore, the present invention provides a powder coating composition comprising 0.02 to 3 parts by weight of a cobalt organic acid salt based on 100 parts by weight of a polyol / polyurethane curable coating material. Further, the present invention relates to an inorganic compound of cobalt and / or bismuth of 0.0 with respect to 100 parts by weight of a polyol / polyurethane curing coating material.
A powder coating composition comprising 1 to 5 parts by weight is provided. Hereinafter, the present invention will be described in detail. The polyol / polyurethane curable coating material used in the present invention is not particularly limited in its main chain as long as it has a hydroxyl group. However, it is most effective for a polyol polyester / polyurethane curable powder coating material in which a chromophore is easily formed by nitrogen oxide or the like. The curable powder coating material is solid at room temperature and has a softening point of 40 to 150 ° C., especially 40 to 150 ° C.
It is preferably 120 ° C. The reason why the softening point is limited in this way is that when the softening point is lower than 40 ° C., the storage stability of the paint such as aggregation is remarkably lowered, and the softening point is 15
This is because if the temperature is higher than 0 ° C., the curing reaction will proceed during the kneading of the paint, and a sound coating film cannot be obtained. In the present invention, as the polyol polyester resin, polyester polyol, polyester amide polyol, lactone polyester polyol, etc. can be used.

The unsaturated dicarboxylic acids used in the production of the polyol polyester resin of the present invention include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, hexahydroterephthalic acid and hexahydroisophthalic acid. Dicarboxylic acids, their acid esters, acid anhydrides and the like. Moreover, when the example of the polyol used for manufacture of the said polyester polyol is given, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,5-pentane glycol, 1,6 -Hexane glycol, 3-methyl-1,5-pentane glycol, neopentyl glycol, 1,8-octane glycol, 1,9-nonanediol, diethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-di Methanol, dimer acid diol, trimethylolpropane, glycerin, hexanetriol, and glymes of N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine and ethylene oxide or propylene oxide adduct of bisphenol A. There is a call. Further, examples of amines used for the production of the polyesteramide polyol include hexamethylenediamine, xylenediamine, isophoronediamine, monoethanolamine, diamines such as isopropanoltriamine, triamine or aminoalcohol, and these alone or Two or more kinds can be used in combination.

The polyester polyol can be produced by a dehydration condensation reaction of the unsaturated dicarboxylic acid and a glycol, and the polyester amide polyol can be produced by a dehydration condensation reaction of the unsaturated dicarboxylic acid and an amine. The lactone-based polyester polyol is obtained by combining the unsaturated dicarboxylic acids with ε-caprolactone and alkyl-substituted ε.
-Caprolactone, δ-valerolactone, alkyl-substituted δ-valerolactone and the like can be produced by ring-opening polymerization with a cyclic ester (ie lactone) monomer. The polyurethane used as the curing agent in the present invention is not particularly limited in its main skeleton as long as it has a property that it can be used as a powder coating material. As the polyurethane-based curing agent used in the present invention, there is an isocyanate compound,
Specific examples thereof include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, metaxylene diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate). , Methylcyclohexane-
2,4- (or -2,6-)-diisocyanate, 1,
Some have two isocyanate groups such as 3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate.

In the present invention, a compound having a polyfunctional isocyanate group such as an isocyanurate body, a burette body, an adduct body or a polymer body of these isocyanate compounds can also be used as a curing agent. Examples of the compound include 4,4 ′, 4 ″ -triphenylmethane triisocyanate, 2,4-tolylene diisocyanate cyclic trimer, 2,6-tolylene diisocyanate cyclic trimer, 2, Mixtures of cyclic trimers of 4- and 2,6-tolylene diisocyanate, diphenyl methane-4,4'-diisocyanate trimer, 3 moles of diphenyl methane-4,4'-diisocyanate and trimethylolpropane 1 Reaction product with 3 moles of 2,4-tolylene diisocyanate and 3 moles of trimethylolpropane
Reaction product of 3 moles of 2,6-tolylene diisocyanate and 1 mole of trimethylol propane, reaction product of 3 moles of 2,4-tolylene diisocyanate and 1 mole of trimethylol ethane, 2 , 6-tolylene diisocyanate (3 mol) and trimethylol ethane (1 mol), and a mixture of 2,4- and 2,6-tolylene diisocyanate (3 mol) and trimethylol propane (1 mol). .

In the present invention, the mixing ratio of the polyol resin and the urethane curing agent is NCO to 1 mol of the hydroxyl group.
The molar ratio of the groups is 0.5 to 3.0, preferably 0.7 to 2.0 mol,
Particularly preferably, it is 0.8 to 1.5. The reason why the compounding ratio is limited in this way is that when the amount of the urethane curing agent is less than 0.5 mol, the curing property of the coating film will be poor and the physical performance of the coating film will be significantly reduced. If too much, the urethane curing agent remains as an unreacted material in the coating film,
This is because the physical properties of the coating film, especially the corrosion resistance, are significantly reduced. Further, the effect of preventing yellowing of the present invention cannot be expected.

In the present invention, the pigments usually used for paints can be used without particular limitation.
Specific examples of the pigment include titanium dioxide, red iron oxide, iron oxide, carbon black, phthalocyanine blue, phthalocyanine green, quinacridone, isoindoinone, coloring pigments such as azo compounds, silica, talc, calcium carbonate, and sedimentability. There are extender pigments such as barium sulfate, potassium titanate whiskers, and aluminum borate whiskers. In the present invention, it is preferable to add the pigment in an amount of 0 to 60 parts by weight, preferably 0 to 45 parts by weight, based on 100 parts by weight of the polyol polyester / polyurethane curing agent blend.

In the present invention, as an additive, a leveling agent, an antistatic agent, an ultraviolet absorbent, an anti-sagging agent, a surface modifier, etc. can be used, and further, a resin such as polyester resin, acrylic resin, petroleum resin, rosin or polyolefin. A modifier can be incorporated. In the present invention, a cobalt organic acid salt is added to the polyol / polyurethane curable coating material. In the present invention, the cobalt organic acid salt can be used alone or as a solution in which it is dissolved in a solvent. However, when a solvent is used, the boiling point of the solvent is preferably lower than the treatment temperature during kneading. This is because when the boiling point of the solvent is high, the solvent remains in the coating material, and the solvent is volatilized when forming the coating film by baking treatment or the like, and foam marks are left on the coating film surface.
Examples of the solvent used for the cobalt organic acid salt solution include xylene, toluene, and mineral spirits.

Examples of the cobalt organic acid salt used in the present invention include cobalt naphthenate, cobalt octylate and cobalt laurate. In the present invention, polyol /
It is preferable to add 0.02 to 3 parts by weight, and especially 0.05 to 0.5 parts by weight of cobalt organic acid salt to 100 parts by weight of the polyurethane curable coating material. The reason for limiting the amount of the cobalt organic acid salt added is that if it is less than 0.02 parts by weight, the effect of the catalyst is insufficient, and if it is more than 3 parts by weight, the storage stability of the coating composition is lowered and the coating composition This is because the hydrophilicity of the product increases and the performance around water decreases. In addition, in the present invention, an inorganic compound mainly containing cobalt and / or bismuth can be added. The corresponding compounds are generally oxides, chlorides, and hydroxides, and these can be used alone or dissolved in a solvent. However, the solvent that dissolves is preferably one whose boiling point is lower than the temperature during kneading. When it is more than that, it remains in the coating system during the preparation of the coating composition, volatilizes out of the coating system during the coating film formation, leaving foam marks on the coating film, and a good coating film cannot be obtained. Further, in order to secure the storability of the compound itself, the one having lower water solubility is more preferable. It is suitable to use the inorganic compound in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight of the curable coating material. When the amount used is limited to 0.01 part by weight or less, the effect of the catalyst does not appear. On the contrary, when the amount is more than 5 parts by weight, the storage stability of the paint is adversely affected and the hydrophilicity is increased. This is because it is not preferable because the peripheral performance is deteriorated. The powder coating composition of the present invention is produced by adding pigments, various additives, etc., if necessary, in addition to the above-mentioned essential components, kneading at 70 to 150 ° C. using a kneader or roll, and pulverizing. can do. The coating composition of the present invention can be coated by spraying with a known preheating or non-preheating electrostatic gun, spraying with a friction charging gun, fluidized dipping, atmosphere dipping, or in-molding.

[0012]

EFFECT OF THE INVENTION The coating film formed from the powder coating composition of the present invention has a good yellowing resistance against heat and has a wide range of allowable conditions for the coating / baking process. Within the control of temperature and baking time, it is possible to manufacture a coated product with no yellowing and a uniform coating color. Especially,
When baking objects having different heat capacities in the same baking / drying oven, baking conditions are set in accordance with an object having a large heat capacity, so an object having a small heat capacity is overbaked, but the powder of the present invention is used. When the body coating composition is used, the difference in coating color between the objects to be coated having different heat capacities can be minimized. Further, even when the object to be coated is left in the baking oven due to an unexpected line stop, the object to be coated of the powder coating composition of the present invention has little color change, and the occurrence of defective products should be minimized. You can Further, the object to be coated with the powder coating composition of the present invention has little change in color with time even when it is subjected to a thermal history such as a lamp shade.

[0013]

EXAMPLES The present invention will be described in detail below with reference to examples. In the examples, "part" and "%" are based on weight.
In addition, Production Examples 1 to 8, Tables 1 to 5, Examples 1 to 3 and Comparative Examples 1 to 5 show the effects of coating materials using an organic acid salt of cobalt. In addition, Production Examples 9 to 18, Tables 6 to 9, Examples 4 to 9 and Comparative Examples 6 to 9 show the effects of coating materials using an inorganic compound of cobalt and / or bismuth. [Production Example 1] 55 parts of a thermosetting polyester resin "Ester Resin ER-6610" (trade name of Nippon Ester Co., Ltd.) having a hydroxyl value of 31 mgKOH / g, and a polyisocyanate resin "Vestagon B-1530" of IPDIε-caprolactam block ( Huls brand name) 7 parts, acrylic oligomer "Modaflow powder III" as an additive (Monsanto brand name) 0.5 part, benzoin as a defoamer
After kneading 0.2 parts, titanium oxide 35 parts as a color pigment, and cobalt naphthenate 0.3 parts as a catalyst at 135 ° C.,
Grind and classify with 150 mesh, average particle size 40μm
A powder coating material A was produced.

[Production Example 2] "Ester resin ER-66"
10 parts to 55 parts, 7 parts of "Vestagon B-1530", 0.5 parts of "Modaflow Powder III" as an additive, 0.2 parts of benzoin as a defoaming agent, and 3 parts of titanium oxide as a coloring pigment.
5 parts, 0.3 part of cobalt octylate as a catalyst at 130 ° C
After kneading, the mixture was pulverized and classified with a 150 mesh to produce a powder coating material B having an average particle size of 40 μm. [Production Example 3] 53 parts of thermosetting polyester resin "ester resin ER-6570" (trade name of Nippon Ester Co., Ltd.) having a hydroxyl value of 40 mgKOH / g, and polyisocyanate resin "Vestagon B-1065" of IPDIε-caprolactam block ( (Huls brand name) 12 parts, "Modaflow Powder III" 0.5 part as an additive, benzoin 0.2 part as a defoamer, titanium oxide 35 parts as a color pigment,
0.7 part of cobalt laurate as a catalyst was kneaded at 130 ° C., then pulverized and classified with 150 mesh to produce a powder coating C having an average particle size of 40 μm.

[Production Example 4] "Ester Resin ER-66"
10 parts to 55 parts, 7 parts of "Vestagon B-1530", 0.5 parts of "Modaflow Powder III" as an additive, 0.2 parts of benzoin as a defoaming agent, and 3 parts of titanium oxide as a coloring pigment.
5 parts, 135 parts dibutyne dilaurate 0.3 part as a catalyst
After kneading at ℃, it was pulverized and classified with 150 mesh to produce a powder coating material D having an average particle diameter of 40 μm. [Production Example 5] 55 parts of "ester resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow powder III" as an additive, 0.2 part of benzoin as a defoaming agent, and oxidation as a color pigment. 35 parts of titanium and 3.5 parts of cobalt naphthenate as a catalyst were kneaded at 130 ° C., then pulverized and classified with 150 mesh to obtain an average particle size of 40.
A μm powder coating E was produced.

[Production Example 6] "Ester resin ER-66
10 parts to 55 parts, 7 parts of "Vestagon B-1530", 0.5 parts of "Modaflow Powder III" as an additive, 0.2 parts of benzoin as a defoaming agent, and 3 parts of titanium oxide as a coloring pigment.
After kneading 5 parts at 130 ° C., pulverizing and classifying with 150 mesh, a powder coating F having an average particle size of 40 μm was produced. [Production Example 7] 55 parts of "ester resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, 0.2 part of benzoin as a defoaming agent, and a coloring pigment. As a catalyst, 35 parts of titanium oxide and 0.01 part of cobalt naphthenate as a catalyst were kneaded at 135 ° C., pulverized, and classified with 150 mesh to produce a powder coating material G having an average particle size of 40 μm.

[Production Example 8] "Ester resin ER-66"
10 parts to 55 parts, 7 parts of "Vestagon B-1530", 0.5 parts of "Modaflow Powder III" as an additive, 0.2 parts of benzoin as a defoaming agent, and 3 parts of titanium oxide as a coloring pigment.
5 parts, 0.3 parts of dibutyltin dilaurate as a catalyst,
Phenolic antioxidant "Adeka Stab AO-50" (product name manufactured by Adeka Argus Chemical Co., Ltd.) as an antioxidant 0.5
Part, dilauryl thiodipropionate (DLTP) 0.5
Parts were kneaded at 135 ° C., then pulverized and classified with 150 mesh to produce a powder coating material H having an average particle size of 40 μm.
The powder coatings A to H are applied to a 0.8 mm thick steel plate and the film thickness is about 40 μm.
To achieve m, paint with a friction charging gun "The Friction" (trade name of Matsuo Sangyo Co., Ltd.), 180 ° C x 10 minutes, 20
Baking was performed under the conditions of 0 ° C. × 10 minutes, 230 ° C. × 10 minutes, and 230 ° C. × 2 hours, and four types of coated steel sheets were prepared and various experiments were conducted. 1. Yellowing resistance test A coated plate standard at 200 ° C. for 10 minutes, coated plate 40μ under each baking condition based on a color difference of 40 μm (L, a, b)
The color difference (ΔE) from m was measured. The average value of n = 3 was calculated.

2. Impact resistance test Using a DuPont type tester, a 1/2 inch diameter was placed on the surface of the coating film, and the maximum height (cm) of cracking of the coating film when a 500 g weight was dropped from the vertical direction ) Was measured. 3. Erichsen test The amount of extrusion (mm) until a crack occurs in the coating film when it is extruded from the back surface of the coating film with a punch using an Erichsen tester. 4. State of coated surface It was judged visually. 5. Salt Spray Test The peel width from the cut surface after 300 hours of SST was determined. 6. Moisture resistance test The state of the coating film after 300 hours was visually observed using a humidity resistance tester at 50 ° C. 7. Adhesiveness The adhesion was carried out in accordance with JIS-K-5400 8.5.2, and the number of remaining / 100 in 100 substrate squares was determined. 8. Storage stability After the coating material was left in a constant temperature bath at 40 ° C for 15 days, it was coated with the coating material and the state of the coated surface when the coating film was formed under the baking condition of 200 ° C x 10 minutes was visually confirmed.

[0019]

[Table 1]Table 1 (Compound composition) ──────────────────────────────────── Powder coating composition A B C D E F G H Ester resin ER66210 55 55 55 55 55 55 55 55 Ester resin ER6570 53 Vestagon B-1530 7 7 7 7 7 7 7 Vestagon B-1065 12 Modaflow powder III 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Benzoin 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Titanium oxide 35 35 35 35 35 35 35 35 Cobalt naphthenate 0.3 3.5 0.01 Cobalt octylate 0.3 Cobalt laurate 0.7 DBTDL 0.3 0.3 AO-50 0.5 DLTP 0.5 ──────────────── ───────────────────── As is clear from the table, the powder coating compositions A to C are the present invention.
Of the above, and D to H are comparative examples.

[0020]

[Table 2]Table 2 ──────────────────────────────────── Example comparison 1 2 3 1 2 3 4 5Powder coating A B C D E F G H Baking conditions 200 ° C x 10 minutes Yellowing resistance Impact resistance 50 50 50 50 50 30 20 50 Erichsen 7 <7 <7 <7 <7 <7 <3.1 2.9 7 <Coating surface condition Good Good Good Good Good Good Good Good Good Salt spray 2> 2> 2> 2> 50 2> 2> 2> Moisture resistance Abnormal Abnormal Abnormal Abnormal Abrasive Abnormal Abnormal Abnormal None None None None None None None Adhesive 100 100 100 100 100 42 48 100 Good storage Good Good Good Good Good gloss Good Good Good Stability

[0021]

[Table 3]Table 3 ──────────────────────────────────── Example comparison 1 2 3 1 2 3 4 5Powder coating A B C D E F G H Baking conditions 180 ° C x 10 minutes Yellowing resistance 0.21 0.33 0.30 1.02 0.26 0.24 0.27 0.62 Impact resistance 50 50 50 50 50 10 10 50 Erichsen 7 <7 <7 <7 <7 <7 <0.1 0.1 7 <Coated surface condition Good Good Good Good Good Good Good Good Salt water spray 2> 2> 2> 2> 2> 10 <10 <2> Moisture resistance Abnormal Abnormal Abnormal Abnormal Abrasive Abrasive Abnormal Abnormal None None None None None None None Adhesion 100 100 100 100 100 29 30 100

[0022]

[Table 4]Table 4 ──────────────────────────────────── Example comparison 1 2 3 1 2 3 4 5Powder coating A B C D E F G H Baking conditions 230 ° C x 10 minutes Yellowing resistance 1.81 1.76 1.92 5.21 1.90 1.83 1.87 2.48 Impact resistance 50 50 50 50 50 50 50 50 Erichsen 7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <Good coating condition Good Good Good Good Good Good Good Salt spray 2> 2> 2> 2> 2> 2> 2> 2> Moisture resistance Abnormal Abnormal Abnormal Abnormal Abrasive Abnormal Abnormal Abnormal None None None None None None None None Adhesiveness 100 100 100 100 100 100 100 100

[0023]

[Table 5]Table 5 ──────────────────────────────────── Example comparison 1 2 3 1 2 3 4 5Powder coating A B C D E F G H Baking conditions 230 ° C x 120 minutes Yellowing resistance 2.95 2.89 3.02 11.3 2.93 3.43 3.04 5.31 Impact resistance 50 50 50 50 50 50 50 50 Erichsen 7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <Good coating condition Good Good Good Good Good Good Good Good Salt spray 2> 2> 2> 2> 2> 2> 2> 2> Moisture resistance Abnormal Abnormal Abnormal Abnormal Abrasive Abnormal Abnormal Abnormal None None None None None None None None Adhesiveness 100 100 100 100 100 100 100 100 As is clear from Tables 3-5, comparison with Examples 1, 2, 3
Comparative Examples 3 and 4 have a large color difference under each printing condition,
The management width is narrow. Comparative Example 2, as compared with Examples 1, 2, and 3.
4 is poor in curability at 200 ° C. for 10 minutes or less
Poor physical properties and corrosion resistance.

[Production Example 9] Thermosetting polyester resin having a hydroxyl value of 31 mgKOH / g ["ester resin ER-6
610 "(trade name of Nippon Ester Co., Ltd.)]]
PDI ε-caprolactam block polysocyanate resin [“Vestagon B-1530” (trade name, manufactured by Huls)] 7 parts, acrylic oligomer as an additive [“Modaflow powder III” (trade name, manufactured by Monsanto)] 0.5
Parts, benzoin 0.2 part as a defoamer, titanium oxide 35 parts as a color pigment, and cobalt oxide 0.3 parts as a catalyst.
The mixture was kneaded and pulverized at 0 ° C. and classified with 150 mesh to produce a powder coating material A ′ having an average particle size of 40 μm. [Production Example 10] "Ester resin ER-6610" 55
Parts, "Vestagon B-1530" 7 parts, "Modaflow Powder III" 0.5 parts as an additive, benzoin 0.2 part as a defoamer, titanium oxide 35 parts as a color pigment, cobalt chloride 0 as a catalyst. Knead and pulverize 3 parts at ℃ 15
Classification was performed with 0 mesh to produce a powder coating material B'having an average particle diameter of 40 µm.

[Production Example 11] Hydroxyl value 40 mg KOH / g
Thermosetting polyester resin [[Ester Resin ER-
6570 "(trade name of Nippon Ester Co., Ltd.)"]
12 parts of polydiocyanate resin of IPDI ε-caprolactam block [“Vestagon B-1065” (trade name, manufactured by Huls)], “Modaflow Powder II” as an additive
I "0.5 part, benzoin 0.2 part as a defoamer, titanium oxide 35 parts as a color pigment, and cobalt hydroxide as a catalyst.
0.7 part was kneaded and pulverized at a temperature of 150 ° C., and classified with 150 mesh to produce a powder coating C ′ having an average particle size of 40 μm. [Production Example 12] "Ester resin ER-6610" 55
"Vestagon B-1530" 7 parts, "Modaflow Powder III" 0.5 parts as an additive, benzoin 0.2 part as a defoamer, titanium oxide 35 parts as a color pigment, bismuth oxide 0 as a catalyst. Knead and pulverize 3 parts at ℃ 15
Classification was performed with 0 mesh to produce a powder coating D'having an average particle size of 40 µm.

[Production Example 13] "Ester resin ER-6
610 "55 parts," Vestagon B-1530 "7 parts,
0.5 parts of "Modaflow Powder III" as an additive, 0.2 parts of benzoin as a defoaming agent, 35 parts of titanium oxide as a color pigment, and 0.3 parts of bismuth hydroxide as a catalyst at 135 ° C.
Was kneaded, pulverized, and classified with a 150 mesh to produce a powder coating E'having an average particle diameter of 40 μm. [Production Example 14] (Comparative Example) 55 parts of "Ester Resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, and benzoin of 0.5 part as a defoaming agent. 2 copies,
35 parts of titanium oxide as a coloring pigment and 0.3 part of dibutyltin dilaurate as a catalyst were kneaded at 135 ° C., pulverized, and 1
Classification was carried out with 50 mesh to produce a powder coating F ′ having an average particle size of 40 μm.

[Production Example 15] (Comparative Example) 55 parts of "Ester Resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, and a defoaming agent. Benzoin 0.2 parts,
Titanium oxide (35 parts) as a color pigment and cobalt chloride (3.5 parts) as a catalyst were kneaded and pulverized at 135 ° C., pulverized, and classified with a 150 mesh to produce a powder coating material G ′ having an average particle diameter of 40 μm. [Production Example 16] (Comparative Example) 55 parts of "Ester Resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, and 0.5 part of benzoin as a defoaming agent. 2 copies,
As a coloring pigment, 35 parts of titanium oxide was kneaded at 135 ° C., pulverized, and classified with 150 mesh to obtain an average particle diameter of 40 μm.
Powder coating H'of [Production Example 17] (Comparative Example) 55 parts of "ester resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, and benzoin of 0.5 as a defoaming agent. 2 copies,
35 parts of titanium oxide as a color pigment and 0.005 part of cobalt chloride as a catalyst were kneaded and pulverized at 135 ° C., pulverized, and classified with a 150 mesh powder coating J ′ having an average particle diameter of 40 μm.
Was manufactured.

[Production Example 18] (Comparative Example) 55 parts of "ester resin ER-6610", 7 parts of "Vestagon B-1530", 0.5 part of "Modaflow Powder III" as an additive, and a defoaming agent. Benzoin 0.2 parts,
35 parts of titanium oxide as a color pigment, 0.3 part of dibutyltin dilaurate as a catalyst, and 0.5 part of a phenolic antioxidant [“Adeka Stab AO-50” (trade name, manufactured by ADEKA ARGUS CHEMICAL CO., LTD.)] As an antioxidant. Kneading 0.5 parts of dilauryl thiodipropionate (DLTP) at 135 ° C.,
Grind and classify with 150 mesh, average particle size 40μ
m powder coating K'was produced. Table 6 shows the compositions of the coating materials produced in Production Examples 9 to 18. Eight kinds of powder coatings thus obtained were coated on a 0.8 mm thick steel plate by a friction electrification gun (Matsuo Sangyo The Friction) so that the film thickness was about 40 μm. ℃ × 10 minutes, 200 ℃
Baking was carried out for × 10 minutes, 230 ° C. × 10 minutes, 230 ° C. × 2 hours, four types of coated plates were prepared, and various evaluation tests were conducted. The experimental method is as follows.

1. Yellowing resistance test A coated plate standard at 200 ° C. for 10 minutes and a coated plate 40 μ under each baking condition based on a color value of 40 μm (L, a, b)
The color difference (ΔE) from m was measured. The average value of n = 3 was calculated. 2. Impact resistance test The impact resistance test was performed according to JIS-K-5400 8.4.2. 3. Erichsen test The test was performed according to JIS-K-5400 8.2.1. 4. State of coated surface It was judged visually. 5. Salt spray test It was conducted in accordance with JIS-K-5400 9.2.2. 6. Moisture resistance test It was performed in accordance with JIS-K-5400 9.2.2. 7. Adhesiveness Performed in accordance with JIS-K-5400 8.5.2.
The number of remaining 100/100 of the squares was calculated. 8. Storage stability test 200 ℃ × 1 when left in a thermostat at 40 ℃ for 15 days
The state of the coated surface when the coating film was formed under the baking condition of 0 minutes was visually measured.

[0030]

[Table 6]Table 6 Powder coating A'B 'C'D'E'F'G'H'J'K' Esters 55 55 55 55 55 55 55 55 55 Resin ER6610 Esters 53 Resin ER6570 Vestagon 7 7 7 7 7 7 7 7 7 B-1530 Vestagon 12 B-1065 Modaflow 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Powder III Benzoin 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Titanium oxide 35 35 35 35 35 35 35 35 35 35 Cobalt oxide 0.3 0.005 Cobalt chloride 0.3 3.5 Cobalt hydroxide 0.7 Bismuth oxide 0.3 Bismuth hydroxide 0.3 DBTDL 0.3 0.3 AO-50 0.5 DLTP 0.5

[0031]

[Table 7] Table 7 Baking conditions (200 ° C x 10 minutes) Example Comparison Example 4 5 6 7 8 9 6 7 8 9 Powder coating A'B 'C'D'E'F'G'H'J'K' Evaluation test 2. (cm) 50 50 50 50 50 50 50 30 20 50 3. (mm) 7 <7 <7 <7 <7 <7 <7 <7 <3.2 3.1 7 <4. Good Good Good Good Good Good Good Good Good Good Good Good 5. (mm) 2>2>2>2>2>2> 5.0 2>2>2> 6. abnormal abnormal abnormal abnormal abnormal abnormal Tsuya引abnormal abnormal None None None None None None None None None abnormal 7.100 100 100 100 100 100 100 49 42 100 8 .Coating condition Good Good Good Good Good Good Good Gloss Good Good Good Good

[0032]

[Table 8] Table 8 Baking conditions (180 ° C x 10 minutes) Example Comparative Example 4 5 6 7 8 9 6 6 7 8 9 Test number A'B ' C'D ' E'F ' G'H ' I'J ' 1. 0.21 0.23 0.30 0.29 0.22 1.02 0.20 0.26 0.24 0.62 2. (cm) 50 50 50 50 50 50 50 10 10 50 3. (mm) 7 <7 <7 <7 <7 <7 <7 <0.1 0.1 7 <4. Good Good Good Good Good Good Good Good Good Good Good Good 5. (mm) 2>2>2>2>2>2>2> 10 <10 <2> 6. abnormal abnormal abnormal abnormal abnormal abnormal Tsuya引Tsuya引Tsuya引None None None None None None None abnormal 7.100 100 100 100 100 100 100 30 29 100

[0033]

[Table 9] Table 9 Baking conditions (230 ° C x 10 minutes) Example Comparative ratio Comparative test 4 5 6 7 8 9 6 7 8 9 Number A ′ B ′ C ′ D ′ E ′ F ′ G ′ H ′ I ′ J ′ 1. 1.81 1.76 1.92 1.79 1.83 5.21 1.80 1.90 1.83 2.48 2. (cm) 50 50 50 50 50 50 50 50 50 50 3. (mm) 7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <4. Good Good Good Good Good Good Good Good Good Good Good 5. (mm) 2>2>2>2>2>2>2>2>2>2> 6. Abnormal Abnormal Abnormal Abnormal Abnormal Abnormal Gloss Abnormal Abnormal Abnormal None None None None None None None None None None 7.100 100 100 100 100 100 100 100 100 100

[0034]

[Table 10] Table 10 Baking conditions (230 ° C x 120 minutes) Example Example Comparative example Evaluation test 4 5 6 7 8 9 6 7 8 9 Number A ′ B ′ C ′ D ′ E ′ F ′ G ′ H ′ I ′ J ′ 1. 2.95 2.89 3.02 3.24 3.06 15.1 3.06 2.93 3.43 5.31 2. (cm) 50 50 50 50 50 50 50 50 50 50 3. (mm) 7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <7 <4. Good Good Good Good Good Good Good Good Good Good Good 5. (mm) 2>2>2>2>2>2>2>2>2>2> 6. Abnormal Abnormal Abnormal Abnormal Abnormal Abnormal Gloss Abnormal Abnormal Abnormal None None None None None None None None None None 7.100 100 100 100 100 100 100 100 100 100

Claims (2)

[Claims] 1. A polyol / polyurethane curable paint 1
A powder coating composition comprising 0.02 to 3 parts by weight of a cobalt organic acid salt with respect to 00 parts by weight. 2. A polyol / polyurethane curing coating 1
A powder coating composition comprising 0.01 to 5 parts by weight of an inorganic compound of cobalt and / or bismuth with respect to 00 parts by weight.