JP2003096401A - Active energy beam-curable powder coating and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy beam-curable powder coating by which a coated film having good smoothness is obtained without causing defect of an appearance due to microgel, mixed in coating particles, and a production method capable of providing the powder coating in good productivity, and to provide a coated film-forming method using the powder coating and to provide the coated material. SOLUTION: This active energy beam-curable powder coating has 5-50 μm average particle diameter and >=0.9 average circular degree. This method for producing the active energy beam-curable powder coating comprises spraying and drying an organic solvent solution containing an active energy beam-curable resin (A) as a coated film-forming component.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel and useful active energy ray-curable powder coating material and a method for producing the same. More specifically, it is a powder coating material having an average particle size of 5 to 50 μm, and in particular, an active energy ray-curable powder capable of providing a coating film having excellent fluidity and excellent appearance. TECHNICAL FIELD The present invention relates to a coating material and a manufacturing method thereof.

[0002]

2. Description of the Related Art Powder coatings are widely used in general metal coatings as environmentally friendly coatings that do not volatilize organic solvents into the atmosphere during coating. Among them, thermosetting powder coating materials have been recognized for their excellent coating film performance and have been applied to various applications.

On the other hand, the active energy ray-curable powder coating material can be cured in a short time by irradiating the active energy ray after being thermally melted at a low temperature, so that it is energy-saving and has a shorter process than the conventional thermosetting powder coating material. Is beginning to be noticed as a painting method that can be expected.

Since the powder coating material can be cured at a low temperature by irradiation with active energy rays, it is possible to coat a temperature-sensitive substrate such as wood, wood materials and synthetic resins. In such a powder coating material, it is desired that the powder coating material has a good fluidity and can provide a smooth surface even at a low baking temperature similarly to a conventional powder coating material, and at the same time has a good storage stability. JP-A-8-176471 and JP-A-8-176472 disclose binders for powder coatings in order to solve such an object, but the smoothness and appearance of the resulting coating film are conventional. It was still insufficient compared to the thermosetting type.

Conventionally, powder coating materials have generally been produced by a process (melt kneading method) such as dry mixing, melt kneading, cooling, pulverizing, and classifying a resin which is a film-forming component and, if necessary, various additives. The method is widely adopted. When the active energy ray-curable powder coating material is produced by this melt-kneading method, the melt-kneading is performed in a high shear mixer such as an extruder in the process. It is difficult to obtain a composition in which the homogeneity of each component is poor, the particle size distribution is wide, the particle shape is not uniform, and the average circularity is larger than a certain level. Therefore, there is a problem that the smoothness of the coating film obtained using the powder coating material and the physical properties of the coating film tend to deteriorate. In addition, there is a problem that a microgel is easily formed due to high shear during kneading, which deteriorates the productivity of the powder coating material and the appearance of the coating film.

[0006]

However, the inventors of the present invention have made earnest studies to solve the above-mentioned various drawbacks in the prior art and obtain a highly practical active energy ray-curable powder coating material and a coated article. Started.

[0007] The problem to be solved by the present invention is to provide an active energy ray-curable powder coating material which does not have a poor appearance due to microgels mixed in the coating particles and has a good smoothness. It is intended to provide a manufacturing method which can be provided with high productivity, a coating film forming method using the powder coating material, and a coated article.

[0008]

Means for Solving the Problems The inventors of the present invention have earnestly studied to solve the above problems, and as a result, as a coating film forming component, an active energy ray-curable resin (A) is an essential component. As a powder coating obtained by spray-drying an organic solvent solution containing as, does not deteriorate the productivity and coating appearance, and the smoothness of the formed coating, the coating properties are particularly excellent, etc. Heading out, the invention was completed here.

That is, in the present invention, the average particle size is 5 to 50.
An active energy ray-curable powder coating material containing an active energy ray-curable resin (A) having a micrometer and an average circularity of 0.9 or more.

The present invention also provides a method for producing an active energy ray-curable powder coating material, which comprises spray-drying an organic solvent solution containing an active energy ray-curable resin (A) as a coating film forming component. The average particle size obtained by the manufacturing method is 5 to 50 μm and the average circularity is 0.
The present invention provides an active energy ray-curable powder coating material having a content of 9 or more.

Further, the present invention uses the above active energy ray-curable powder coating as a top coating in a coating forming method for forming a single-layer or multi-layer coating on an object to be coated. The present invention also provides a method for forming a coating film, and a coated article having a coating film formed by the method for forming a coating film.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be specifically described below. The active energy ray-curable powder coating material of the present invention preferably has an average particle diameter of 5 to 50 μm. Considering the smoothness of a thin film, it is more preferably 1
It is 0 to 30 μm. The average particle diameter means the volume average median diameter, and can be measured, for example, with a laser diffraction particle size analyzer (SALD-2000) manufactured by Shimadzu Corporation.

The powder coating material of the present invention is essentially spherical, and its average circularity is preferably 0.9 or more. By using a spherical powder paint, the paint fluidity and repaintability are improved. From this viewpoint, it is preferable that the particles having a circularity of 0.9 or more have a frequency of 50% or more, and more preferably 70% or more.

The circularity and the average circularity referred to here are one of the particle shape indexes representing the unevenness of the particle surface,
It is expressed as the following equation.

Circularity = (perimeter of a circle having the same area as the projected area of particle) / (perimeter of projected image of particle)

Therefore, the circularity becomes 1 if the particle image is a perfect circle, and becomes smaller as the particle image deviates from the perfect circle and becomes elongated or uneven. The average circularity is calculated by dividing the sum of the circularity of each particle by the total number of particles. The shape and average circularity of the above powder coating material are determined by a flow type particle image analyzer (FPIA-
1000, manufactured by Toa Medical Electronics Co., Ltd. The shape of the powder coating material can also be confirmed by a scanning electron microscope.

The production of an active energy ray-curable powder coating material satisfying the above requirements is difficult by the conventional melt-kneading method, and the active energy ray-curable resin and various additives are dissolved or dispersed in a solvent. It is desirable to directly prepare the powder coating material by preparing the prepared raw material solution and removing the solvent. In such a method for producing a powder coating material, after spraying and dispersing in a large amount of poor solvent, a method of filtering and drying, a vacuum drying method, a freeze drying method, a spray drying method and the like are preferable, but in particular, the spray drying method is It is more preferable in that a powder coating having a small particle size distribution and a high average circularity can be stably produced.

The spray drying method will be described below. The powder coating material of the present invention is obtained by spray drying an organic solvent solution containing a coating film forming component (hereinafter referred to as a powder coating material solution). The apparatus used for spray drying may be one capable of removing the organic solvent from the sprayed powder coating material solution, for example, by contacting the sprayed powder coating material solution with a heat source gas to volatilize the organic solvent. A spray drying device or the like can be used. Since the organic solvent is volatilized,
The device should be explosion proof. Further, from the viewpoint of keeping the vapor content of the solvent in the heat source gas low, which is used for drying the sprayed powder coating material raw material solution, it is desirable to provide a solvent recovery device.

In the case of using the above-mentioned spray dryer for contacting the sprayed powder coating material solution with the heat source gas to volatilize the organic solvent, the method of contacting the powder coating material solution and the heat source gas is not particularly limited. Instead, any method such as a co-current type, a counter-current type, a co-current / counter-current mixed type, which is commonly used, may be used.

Regarding the spraying method of the powder coating material solution,
Any of known and conventional types such as a rotating disk type, a two-fluid nozzle type, and a pressure nozzle type can be used. Factors for controlling the particle size during spraying include the rotation speed of the disk in the rotary disk system, the discharge speed from the nozzle in the two-fluid nozzle system, and the compression used by mixing with the raw material solution. The mixing ratio of air and the raw material solution, and the pressure nozzle type include the discharge pressure and the like, but these values may be appropriately determined according to the target particle size.

The feed rate of the raw material solution and the flow rate of the heat source gas may be appropriately determined according to the target particle size, but if the feed rate of the raw material solution and the flow rate of the heat source gas change during spray drying, Since the particle size, particle size distribution and non-volatile content of the obtained particles also change, it is desirable to keep it constant during spray drying.

Usually, the heat source gas containing particles obtained by spray drying is continuously guided to a classifying apparatus typified by a cyclone, and particles are collected and classified. In order to adjust the particle size distribution of the powder coating material of the present invention, when it is necessary to perform classification for removing coarse particles and fine particles, a commercially available general classifier can be used.

An inert gas is desirable as the heat source gas. Above all, it is preferable to use nitrogen gas in terms of cost and the like. The temperature of the heat source gas is a temperature at which the active energy ray-curable resin of the powder coating raw material solution does not substantially cause a curing reaction, that is, as a coating for the powder coating obtained even if a partial curing reaction occurs. It may be appropriately determined within a temperature range that does not substantially impair the performance of 1. The lower limit of the temperature of the heat source gas is not particularly limited, but in order to evaporate the solvent efficiently, 30 ° C or higher is preferable, and 40 ° C or higher is more preferable. Usually, the temperature of the heat source gas is 30 to 160 ° C., preferably 40.
It is appropriately determined within the range of to 130 ° C.

The flow rate of the heat source gas and the supply rate of the powder coating material solution may be appropriately adjusted according to the intended particle size under the condition that the nonvolatile content of the obtained particles is 99% by weight or more. . The pressure inside the apparatus is not particularly limited, and may be normal pressure, reduced pressure, or increased pressure.

Further, the non-volatile content concentration of the powder coating material solution at the time of spray drying may be appropriately determined according to the specifications of the spray drying apparatus and the spray drying conditions.

Further, in order to more efficiently evaporate the solvent, the powder coating material solution may be preheated before spray drying. At this time, the temperature for preheating is preferably 70 ° C. or lower in order to prevent gelation of the powder coating material raw material solution, and spray drying is preferably performed as soon as possible after preheating.

The powder coating material thus obtained can be used as it is as a powder coating material, but if desired, it may be secondarily dried by another drying method such as vacuum drying. In that case, in order to prevent gelation of the powder coating material, it is desirable that the secondary drying be performed at a temperature of about 70 ° C. or lower.

The powder coating material solution used in the present invention is
At a temperature lower than the temperature when spraying, for example, at room temperature,
It is preferable that the active energy ray-curable resin (A) is completely dissolved in the organic solvent. When completely dissolved, it is possible to obtain a powder coating having significantly improved coating appearance, particularly sharpness of the coating, as compared with mixing by melt-kneading which is performed in a conventional manufacturing method. Because.

Next, the organic solvent used in the present invention will be described. As the organic solvent, a solvent capable of dissolving the active energy ray-curable resin (A) can be used, and one kind or a combination of two or more kinds of solvents may be used, and the active energy ray-curable resin (A) is a solution. In the case of a resin obtained by the reaction, the solvent used in the reaction of the active energy ray-curable resin (A) can be used as it is, as a part or all of the organic solvent.

Further, it is also preferable that the organic solvent contains a high boiling point solvent having a boiling point of 150 to 300 ° C. under normal pressure. By using a high boiling point solvent as a part of the organic solvent, it is possible to obtain a powder coating material which forms a coating film without causing coating film defects such as armpits and pinholes. The high boiling point solvent may be a single component or a mixture of a plurality of components.

The boiling point of the high boiling point solvent at normal pressure is as follows:
150-300 degreeC is preferable, More preferably, it is 150-
One having a temperature of 250 ° C. is used. Furthermore, it is particularly preferable that the boiling point at normal pressure is +5 to + 150 ° C. with respect to the temperature when the powder coating material of the present invention is heated and melted.

The amount of the high-boiling solvent used is preferably 0.005 to 2 parts, more preferably 0.005 to 1 part, based on 100 parts of the solid content in the powder coating material solution.

If the boiling point of the high boiling point solvent at atmospheric pressure and the amount used are within the above ranges, an appropriate amount of the high boiling point solvent remains in the powder coating material of the present invention, resulting in coating defects such as cracks and pinholes. Can be prevented from being generated.

Specific examples of such high-boiling point solvents include, but are not limited to, alcohols such as n-hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, and benzyl alcohol; ethylene glycol, propylene glycol, and glycerin. Such as polyhydric alcohols; butyl cellosolve, hexyl cellosolve, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol monobutyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, methyl carbitol, ethyl carbitol, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol Glycol ethers, such as dibutyl ether;

Aromatic hydrocarbons such as propylbenzene, butylbenzene, pentylbenzene, diethylbenzene, dipropylbenzene, dipentylbenzene, dodecylbenzene, cyclohexylbenzene; Solvesso 1
00, Solvesso 150, Solvesso 200 (all manufactured by Exxon, USA); mixed hydrocarbons containing aromatic hydrocarbons; Exxon Naphtha No. 3, Exxon naphtha No. 5, Exxon Naphtha No. 6, Exxon Solvent No. 7, Isopar G, Isopar H, Isopar L, Isopar M, Exol D40, Exol D90, Exol D110 (all manufactured by US Exxon Corporation), IP Solvent 1620, IP Solvent 202
Mixed hydrocarbons containing aliphatic hydrocarbons such as 8 (manufactured by Idemitsu Petrochemical Co., Ltd.), Merbeil 20, Merbeil 30, Merbeil 40 (manufactured by Showa Shell Sekiyu Co., Ltd.), and mineral spirits;

Glycerin alkyl ether, glycerin alkyl ester; ketones such as diisobutyl ketone, methyl amyl ketone, cyclohexanone, isophorone; cyclohexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, isoamyl propionate, butyric acid alkyl ester Esters such as, stearic acid alkyl ester, benzoic acid alkyl ester, adipic acid dialkyl ester, phthalic acid dialkyl ester;

There are N-methylpyrrolidone, dimethylformamide, dimethylacetamide, ethylene carbonate and the like. Among the above-mentioned high-boiling solvents, the use of an aromatic solvent and / or an aliphatic solvent is preferably used because the effect of preventing the generation of coating film defects is more remarkable.

The method of adding the high boiling point solvent to the powder coating material solution is not particularly limited, but, for example, the active energy ray added in advance as a part of the solvent for synthesizing the active energy ray curable resin is used. A method such as adding after the completion of the curing type resin synthesis or immediately before spray-drying the powder coating material solution is recommended because it is simple and easy.

As the organic solvent, well-known and commonly used organic solvents can be used in addition to the above-mentioned high boiling point solvent.

As typical examples of such organic solvents, methanol, ethanol, n-
Alkyl alcohols such as propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol;

Methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether,
Glycol ethers such as propylene glycol monopropyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; Exxon aromatic naphtha No. 2 (manufactured by Exxon, USA), such as mixed hydrocarbons containing aromatic hydrocarbons; n-pentane, n
-Aliphatic hydrocarbons such as hexane and n-octane;
Isopar C, Isopar E, Exor DSP100
/ 140, Exol D30 (all manufactured by Exxon, USA), IP Solvent 1016 (manufactured by Idemitsu Petrochemical Co., Ltd.), mixed hydrocarbons containing aliphatic hydrocarbons; cyclopentane, cyclohexane, methylcyclohexane,
Alicyclic hydrocarbons such as ethylcyclohexane;

Ethers such as tetrahydrofuran, dioxane, diisopropyl ether, di-n-butyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, acetic acid n -Butyl, isobutyl acetate, n-amyl acetate, isoamyl acetate, hexyl acetate, ethyl propionate, butyl propionate, and other esters;

From the viewpoint of improving the drying property of the paint particles during spray drying, the remaining solvent components of the organic solvent except the high boiling point solvent have a boiling point of 100 at normal pressure.
It is preferable that the solvent at a temperature of not more than 0 ° C. accounts for 65 to 100% by weight.

Next, the active energy ray curable resin (A)
I will describe. The active energy ray curable resin used in the powder coating material of the present invention may be any resin as long as it has an unsaturated double bond in the molecule. Examples of the active energy ray-curable resin (A) include unsaturated polyester resins, urethane (meth) acrylates, epoxy (meth) acrylates, polyester (meth) acrylates, etc.
In addition, the glass transition temperature is preferably 40 ° C. or higher from the viewpoint of flowing even at a low temperature to form a smooth coating film and preventing blocking during the storage process.

The unsaturated polyester resin is obtained by reacting a polyol with an unsaturated polybasic acid or its anhydride. As the polyol which is a constituent component of the unsaturated polyester resin, known and commonly used ones can be used. Among them, only representative ones are ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1 , 3-propylene glycol, 1,2-propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, neopentyl glycol, 1,3
-Butanediol, 2,3-butanediol, 1,4-
Butanediol, 1,6-hexanediol, 1,1,
8-octanediol, 1,9-nonanediol, 1,
10-decanediol, 2,2,4-trimethyl-1,
3-pentanediol, 3-methyl-1,5-pentanediol, dichloroneopentylglycol, dibromoneopentylglycol, hydroxypivalic acid neopentylglycol ester, cyclohexanedimethylol, 1,4-cyclohexanediol, hydroquinone ethylene oxide or Propylene oxide adduct, trimethylolethane, ethylene oxide or propylene oxide adduct of trimethylolethane,
Trimethylol propane, ethylene oxide or propylene oxide adduct of trimethylol propane,
Glycerin, ethylene oxide or propylene oxide adduct of glycerin, 3-methylpentane-1,
3,5-triol, pentaerythritol, spiroglycol, tricyclodecane dimethylol, hydrogenated bisphenol A, or “Newcol PM-8701”.
L, BA-E4, BA-E8 or BA-P6 "[Ethylene oxide or propylene oxide adduct of bisphenol A of Nippon Emulsifier Co., Ltd.] or" Carbodiol "[Toagosei Chemical Industry Co., Ltd. product] Carbonate diols such as

Representative examples of unsaturated polybasic acids or their anhydrides which are the constituents of the unsaturated polyester resin include maleic acid, fumaric acid, itaconic acid,
It is a known and commonly used α, β-unsaturated polybasic acid such as citraconic acid or chlorinated maleic acid, or an anhydride thereof.

Representative examples of saturated polybasic acids or their anhydrides that can be used in combination, if necessary, are phthalic acid, tetrahydrophthalic acid, monochlorophthalic acid, dichlorophthalic acid, trichlorophthalic acid, het acid, Hymic acid "[Hitachi Chemical Co., Ltd. product], chlorendic acid, dimer acid, adipic acid, pimelic acid, succinic acid,
Alkenyl succinic acid, sebacic acid, azelaic acid, 2,
2,4-trimethyl adipic acid, terephthalic acid, dimethyl terephthalic acid, 2-sodium sulfoterephthalic acid,
2-potassium sulfoterephthalic acid, isophthalic acid, 5-
Sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, or 5-sodium-sulfoisophthaldilower alkyl such as dimethyl or diethylstel, orthophthalic acid, 4-sulfophthalic acid, 1,10-
Examples thereof include decamethylenecarboxylic acid, muconic acid, oxalic acid, malonic acid, glutanoic acid, trimellitic acid, hexahydrophthalic acid, tetrabromophthalic acid, methylcyclohexenetricarboxylic acid, pyromellitic acid, and their anhydrides.

Further, linseed oil fatty acid, shiriniri oil fatty acid, safflower oil fatty acid, soybean oil fatty acid, rice bran fatty acid,
Known and commonly used fatty acids such as coconut oil fatty acid, castor oil fatty acid, cottonseed oil fatty acid and tall oil fatty acid may be used in combination.

Further, as the above-mentioned unsaturated polyester resin, an unsaturated polyester resin obtained by adding an unsaturated monoglycidyl compound to an unsaturated polyester resin containing a carboxyl group at a molecular end and an allyl ether group are used. Unsaturated polyester resin in a form containing an unsaturated polyester resin and a polymerizable monomer contained therein, or a urethane-modified unsaturated polyester resin obtained by urethanizing an unsaturated polyester resin with a polyvalent isocyanate, or unsaturated An epoxidized unsaturated polyester resin obtained by modifying a polyester resin with an epoxy compound can also be used.

The unsaturated glycidyl compound, which is a component of the unsaturated polyester resin obtained by addition-reacting an unsaturated monoglycidyl compound with an unsaturated polyester resin containing a carboxyl group at the molecular end, is glycidyl. A glycidyl ester of an unsaturated monobasic acid such as acrylic acid or methacrylic acid such as acrylate or glycidyl methacrylate; a glycidyl ether of an unsaturated alcohol such as allyl alcohol or methallyl alcohol such as allyl glycidyl ether or methallyl glycidyl ether is particularly preferable. It is a representative thing.

The above-mentioned unsaturated polyester resin containing an allyl ether group is usually an unsaturated polybasic acid or its anhydride, and if necessary, an acid component and an alcohol component containing a saturated polybasic acid or its anhydride. And a compound having a functional group capable of reacting with a carboxyl group of an acid component or a hydroxyl group of an alcohol component and having an allyl ether group (hereinafter referred to as an allyl ether group-containing compound) are referred to as those obtained by condensation reaction. .

At this time, the allyl ether group-containing compound is
The mixture is mixed with other components and used for the reaction. As the allyl ether group-containing compound, any of the known and conventional ones can be used, but among them, typical ones are allyl alcohol, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether,
Triethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, tripropylene glycol monoallyl ether, polypropylene glycol monoallyl ether, 1,2-butylene glycol monoallyl ether,
1,3-butylene glycol monoallyl ether, hexylene glycol monoallyl ether, octylene glycol monoallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, glycerin monoallyl ether, glycerin diallyl ether, pentaerythritol monoallyl Allyl ether compounds of polyhydric alcohols such as ether, pentaerythritol diallyl ether and pentaerythritol triallyl ether; allyl ether compounds having an oxirane ring such as allyl glycidyl ether.

The acid component and the alcohol component, which are constituents of the unsaturated polyester resin containing an allyl ether group, are subjected to an addition reaction of an unsaturated monoglycidyl compound with the unsaturated polyester resin containing a carboxyl group at the molecular end. At most, an acid component or an alcohol component as used when preparing an unsaturated polyester can be applied.

Further, only the particularly representative polyvalent isocyanates used in the preparation of the above-mentioned urethanized unsaturated polyester resin will be exemplified, and 2,4-tolylene diisocyanate and 2,6- Tolylene diisocyanate, 1,3-xylene diisocyanate, (tetramethyl xylene diisocyanate), diphenylmethane-4,4-diisocyanate, 3-methyl-diphenylmethane diisocyanate, or 1,
Diisocyanate compounds having an aromatic ring such as 5-naphthalene diisocyanate; diisocyanate compounds having an aliphatic ring such as dicyclohexylmethane diisocyanate or isophorone diisocyanate;

Or an aliphatic diisocyanate compound such as hexamethylene diisocyanate or lysine diisocyanate; or a compound obtained by hydrogenating various aromatic ring-containing diisocyanate compounds such as those listed above, for example, hydrogenated xylylene diisocyanate or water. Bifunctional diisocyanate compound such as added diphenylmethane-4,4-diisocyanate; or burette type polyisocyanate compound obtained by reacting each diisocyanate compound with water; and further 2-isocyanatoethyl-2,6-diisocyanate hexanoate Examples of such trifunctional isocyanate compounds; or multimers obtained by converting each of the above diisocyanate compounds into isocyanurate.

The epoxy compounds used in the above-mentioned epoxidized unsaturated polyester resin are bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, neopentyl glycol diglycidyl ether, and hydrogenated compounds thereof.

The above-mentioned urethane (meth) acrylate is produced by the urethanization reaction of a compound containing at least one (meth) acryloyl group and a hydroxyl group in one molecule and a polyisocyanate compound,
It is also possible to use a polyol compound together if necessary.

At least one (meth) in one molecule used as a constituent of urethane (meth) acrylate
As the compound using an acryloyl group and a hydroxyl group in combination, known and conventional compounds can be used, but if only specific examples are given, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-
Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropyne glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate or various hydroxyl groups as described above (meth ) A ring-opening reaction product of an acrylate compound with ε-caprolactone and a modified product thereof.

As the polyol compound mentioned here, polyether polyol, polyester polyol, alkylene polyol, polycarbonate polyol, etc. can be used, and they may be used alone or in combination of two or more kinds, The molecular weight of the polyol compound is not limited, but one having a molecular weight of 100 or more and 5,000 or less is preferable.

Further, as the polyisocyanate which is a constituent component of the above-mentioned urethane (meth) acrylate,
It is needless to say that the polyisocyanate in the form of isocyanate and the isocyanate may be used alone or in combination. As such isocyanate compounds, only typical ones are exemplified, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, (tetramethyl xylene diisocyanate),
A diisocyanate compound having an aromatic ring such as diphenylmethane-4,4-diisocyanate, 3-methyl-diphenylmethane diisocyanate, or 1,5-naphthalenediisocyanate;

Diisocyanate compounds having an aliphatic ring such as dicyclohexylmethane diisocyanate or isophorone diisocyanate; or aliphatic diisocyanate compounds such as hexamethylene diisocyanate or lysine diisocyanate; or various aromatic ring-containing diisocyanate compounds as listed above. Bifunctional diisocyanate compounds such as compounds obtained by hydrogenation; or burette type polyisocyanate compounds obtained by reacting each diisocyanate compound with water; and 2-isocyanatoethyl-2,6
A trifunctional isocyanate compound such as diisocyanate hexanoate; or multimers obtained by converting each of the above diisocyanate compounds into an isocyanurate.

The above-mentioned epoxy (meth) acrylate is produced by ring-opening addition of an epoxy group of an epoxy compound with a compound sharing an active double bond and a carboxylic acid. As a compound that shares an active double bond and a carboxylic acid as a constituent of epoxy (meth) acrylate, known and conventional compounds can be used, but if only representative examples are given, (meth) acrylic acid, Half-esters of known and customary α, β-unsaturated polybasic acids or their anhydrides such as crotonic acid, isocrotonic acid or vinylacetic acid, and also maleic acid, fumaric acid, itaconic acid, citraconic acid, or chlorinated maleic acid. And so on.

As the epoxy compound, which is a constituent component of the present invention, known and commonly used epoxy compounds can be used. Of these, only typical ones are exemplified. Bisphenol A-epichlorohydrin type epoxy resin, bromine Bisphenol A-epichlorohydrin type epoxy resin, hydrogenated sphenol A-epichlorohydrin type epoxy resin, bisphenol F-epichlorohydrin type epoxy resin, hydrogenated sphenol F-epichlorohydrin type epoxy resin, neopentyl glycol-epichlorohydrin type epoxy resin, 1, 6-hexanediol-epichlorohydrin type epoxy resin, cyclic oxirane ring,
Various compounds such as an epoxy resin containing an epoxy group may be mentioned.

The epoxy group-containing acrylic resin mentioned here includes, for example, a vinyl monomer having an epoxy group (epoxy group-containing monomer) and another vinyl monomer copolymerizable therewith. It is referred to as having a form such that it is obtained by polymerization.

Known conventional methods can be applied to prepare the epoxy group-containing acrylic resin, but the epoxy group-containing vinyl monomer and, if necessary, other copolymerizable vinyl monomers can also be used. The method of using these monomers to polymerize each of these monomers in an organic solvent is recommended because it is the simplest method. As the polymerization initiator and solvent used at that time, known and conventional ones can be used as they are.

As the epoxy group-containing vinyl monomer, only typical ones will be exemplified. Glycidyl (meth) acrylate and β-methylglycidyl (meth).
Various epoxy group-containing monomers such as acrylate, glycidyl vinyl ether, and allyl glycidyl ether; (2-oxo-1,3-oxolane) such as (2-oxo-1,3-oxolane) methyl (meth) acrylate ) Group-containing vinyl monomers; various alicyclic groups such as 3,4-epoxycyclohexyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and 3,4-epoxycyclohexylethyl (meth) acrylate Formula epoxy group-containing vinyl monomers and the like.

Other vinyl monomers copolymerizable with the epoxy group-containing vinyl monomer include (meth)
Acrylic acid, crotonic acid, or their esters, and various known and commonly used ethylenically unsaturated monomers can also be used. These alone,
Two or more kinds may be used in combination.

If only representative examples of the above-mentioned ester of (meth) acrylic acid are given,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate,
Isobutyl (meth) acrylate, t (meth) acrylic acid
ert-butyl or n-hexyl (meth) acrylate,

Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate,
2-Methyl acrylate (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate or stearyl (meth) acrylate, such as alkyl (meth) acrylate,

Benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate or tetrahydrofurfuryl (meth) acrylate,

Alternatively, various alkyl carbitol (meth) s such as ethyl carbitol (meth) acrylate
In addition to acrylates, further, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate or dicyclopentenyloxyethyl (meth) acrylate;

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate or (meth)
Hydroxyl group-containing (meth) acrylic acid esters such as 4-hydroxybutyl acrylate;

Polyethylene glycol mono (meth) acrylate or polypropylene glycol mono (meth)
Acrylate, etc., and various hydroxyl group-containing (meth) acrylic acid esters such as those listed above
-The so-called lactone-modified hydroxyl group-containing (meth) acrylate in the form of ring-opening reaction with caprolactone.

In addition to these, for example, γ- (meth) acryloyloxypropyltrimethoxysilane, γ-
Various hydrolyzable silyl group-containing monomers such as (meth) acryloyloxypropyltriethoxysilane or γ- (meth) acryloyloxypropylmethyldimethoxysilane;

Various fluorine-containing α-olefins such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene or hexafluoropropylene;

Alternatively, perfluoroalkyl perfluorovinyl ether or (per) fluoroalkyl vinyl ether such as trifluoromethyl trifluorovinyl ether, pentafluoroethyl trifluorovinyl ether or heptafluoropropyl trifluorovinyl ether (where the carbon number of the alkyl group is 1
It should be within the range of ~ 18. ) Etc.,
Such as various fluorine-containing vinyl monomers,

Further, vinyl ester group-containing vinyl monomers such as mono [(meth) acryloyloxyethyl] phosphate, acidic phosphoric acid (meth) acrylic acid ester or (meth) acryloyloxyethyl phenyl phosphate. .

Further, other typical ethylenically unsaturated monomers copolymerizable with the epoxy group-containing vinyl monomer are exemplified by fumaric acid, maleic acid or itaconic acid. Mono- or diesters of various polyvalent carboxyl group-containing monomers with monoalkyl alcohols having 1 to 18 carbon atoms; styrene, vinyltoluene, α-methylstyrene or p-
various aromatic vinyl compounds such as tert-butylstyrene;

(Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, Ni
so-propyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N-iso-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-amyl (meth) acrylamide, N
-(Meth) acrylamide, N-hexyl (meth) acrylamide, N-heptyl (meth) acrylamide or N-2-ethylhexyl (meth) acrylamide,

N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth)
Acrylamide, N-n-propoxymethyl (meth) acrylamide, N-iso-propoxymethyl (meth)
Acrylamide or Nn-butoxymethyl (meth)
Acrylamide,

Alternatively, N-iso-butoxymethyl (meth) acrylamide, N-tert-butoxymethyl (meth) acrylamide, N-amyloxymethylacrylamide, N-hexyloxy (meth) acrylamide,
N-heptyloxymethyl (meth) acrylamide, N-
Octyloxymethyl (meth) acrylamide, N-2-
Various amino group-containing amide vinyl monomers such as ethyl-hexyloxymethyl (meth) acrylamide or diacetone (meth) acrylamide;

Various dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate or diethylaminoethyl (meth) acrylate; tert-butylaminoethyl (meth) acrylate, tert-butylaminopropyl (meth) acrylate , Aziridinylethyl (meth) acrylate, pyrrolidinylethyl (meth) acrylate, piperidinylethyl (meth) acrylate, (meth) acryloylmorpholine, N-vinyl-2-pyrrolidone, N-
Various nitrogen-containing vinyl monomers such as vinylcaprolactam, N-vinyloxazoline or (meth) acrylonitrile;

Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, C ₉ branched (branched) aliphatic vinyl carboxylate, C Various aliphatic vinyl carboxylates such as ₁₀ branched (branched) aliphatic vinyl carboxylates, C ₁₁ branched (branched) aliphatic vinyl carboxylates or vinyl stearate;

Vinyl esters of various carboxylic acids having a cyclic structure, such as vinyl cyclohexanecarboxylate, vinyl methylcyclohexanecarboxylate, vinyl benzoate or vinyl p-tert-butylbenzoate;

Various alkyl vinyl ethers such as ethyl vinyl ether, hydroxyethyl vinyl ether, hydroxy n-butyl vinyl ether, hydroxyisobutyl vinyl ether, cyclohexyl vinyl ether or lauryl vinyl ether;

Such as vinyl chloride or vinylidene chloride,
It is various halogenated olefins other than the above-mentioned fluoroolefins, or various α-olefins such as ethylene, propylene or butene-1.

As the radical polymerization initiator used in the preparation of the epoxy group-containing acrylic resin, various conventionally known compounds can be used.

Of these, only typical ones are exemplified by 2,2'-azobisisobutyronitrile, 2,2'-azobis-methylbutyronitrile and 2,2'-. Azobis-2,4-dimethylvaleronitrile, 1,1'-azobis-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, 2,2 '-
Azobis- (2-amidinopropene) dihydrochloride, 2-t
ert-butylazo-2-cyanopropane, 2,2'-
Azobis (2-methyl-propionamide) dihydrate,
2,2'-azobis [2- (2-imidazolin-2-yl) propene] or 2,2'-azobis (2,2,4
Various azo compounds such as -trimethylpentane);

Alternatively, benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, potassium persulfate, tert-butyl peroxy neodecanoate, tert-butyl peroxypivalate, tert-butyl peroxy-2-ethylhexano Ate, tert-butyl peroxyisobutyrate, 1,1-bis-tert-butyl peroxy-
3,3,5-trimethylcyclohexane or tert
-Butyl peroxy laurate,

Tert-butyl peroxyisophthalate, tert-butyl peroxyacetate, tert
Various ketone peroxides such as -butyl peroxybenzoate, dicumyl peroxide or di-tert-butyl peroxide; peroxy ketals; hydroperoxides; dialkyl peroxides; diacyl peroxides; peroxy Esters; peroxydicarbonates; or hydrogen peroxide.

As the organic solvent used in the preparation of the epoxy group-containing vinyl copolymer, known and commonly used organic solvents can be used.

As typical examples of such organic solvents, methanol, ethanol, n-
Alkyl alcohols such as propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol;

Methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether,
Glycol ethers such as propylene glycol monopropyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; Exxon aromatic naphtha No. 2 (manufactured by Exxon, USA), such as mixed hydrocarbons containing aromatic hydrocarbons; n-pentane, n
-Aliphatic hydrocarbons such as hexane and n-octane;
Isopar C, Isopar E, Exor DSP100
/ 140, Exol D30 (all manufactured by Exxon, USA), IP Solvent 1016 (manufactured by Idemitsu Petrochemical Co., Ltd.), mixed hydrocarbons containing aliphatic hydrocarbons; cyclopentane, cyclohexane, methylcyclohexane,
Alicyclic hydrocarbons such as ethylcyclohexane;

Ethers such as tetrahydrofuran, dioxane, diisopropyl ether and di-n-butyl ether; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, acetic acid n -Butyl, isobutyl acetate, n-amyl acetate, isoamyl acetate, hexyl acetate, ethyl propionate, butyl propionate, and other esters. Also, a small amount of water can be used in combination with the organic solvent.

If necessary, a chain transfer agent may be used, but of these, only typical ones will be exemplified. Dodecyl mercaptan, lauryl mercaptan, thioglycolic acid ester and mercapto. Such as ethanol or α-methylstyrene dimer.

As a method for producing a powder coating material by spray-drying the epoxy group-containing acrylic resin solution, the solvent used in the reaction is distilled off and then redissolved in an organic solvent, or The solvent used in the reaction can be used as it is as a part or all of the organic solvent.

The above-mentioned polyester (meth) acrylate is a saturated or unsaturated polyester containing at least one (meth) acryloyl group in one molecule. For example, it is produced by subjecting the polyester polyol exemplified as the raw material of the above-mentioned polyurethane (meth) acrylate to an esterification reaction of acrylic acid or its ester-forming derivative by a conventional method.

The active energy ray-curable resin (A) may be used in combination with a polymerizable unsaturated oligomer as long as the storage stability of the powder coating is not impaired.

As the polymerizable unsaturated oligomer, only typical ones are exemplified by neopentyl glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, and EO-modified di (meth) phosphate. Acrylate, triethylene glycol di (meth)
Acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexamethylene diol di (meth) acrylate,
2 such as tetraethylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate
Functional (meth) acrylate; trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, PO-modified glycerin tri (meth) ) Acrylate, pentaerythritol tri (meth)
Examples include trifunctional (meth) acrylates such as acrylate.

Of course, each of the polymerizable unsaturated oligomers described above may be used alone or in combination of two or more kinds.

When curing these active energy ray-curable resins (A), as the active energy rays,
Various ionizing radiations such as α-rays, β-rays, γ-rays, neutron rays, X-rays, electron rays, etc., and ultraviolet rays, as well as visible light, can be used. Alternatively, in the case of curing by irradiation with visible light, it is necessary to add a photopolymerization initiator in advance.

As the photopolymerization initiator, various known and commonly used compounds can be used, but among them, only typical ones can be used.
-Phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one ("Darocur 1173"),
1- (4-isopropylphenyl) -2-hydroxy 2
-Methylpropan-1-one ("Darocur 111
6 ") or 1-hydroxycyclohexyl phenyl ketone (" Irgacure 184 "),

4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone ("Darocur 2959"), 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone (“Irgacure 907”), 2,2-dimethoxy-
2-Phenylacetophenone ("Irgacure 65
Various acetophenones, such as 1 ");

Benzoin, benzoin methyl ether,
Various benzoins such as benzoin isoethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-
Various benzophenones such as 4'-methyldiphenyl sulfide and 3,3'-dimethyl-4-methoxybenzophenone;

Thioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4
Various thioxanthones such as diethylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone; 4,4′-dimethylaminobenzophenone (also known as Michler's ketone), 4,4′-diethylaminobenzophenone, α-acyloxime ester, benzyl , Anthraquinones such as methyl benzoyl formate ("Vicure 55"), 2-ethyl anthraquinone;

Various acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide ("Lucillin TPO"); or 3,3 ', 4,4'-tetra (tert-butylperoxycarbonyl). ) Various compounds such as benzophenone [“BTTB” manufactured by NOF Corporation] or acrylated benzophenone.

Typical examples of the photopolymerization initiator for curing visible light include camphorquinone, 3-ketocoumarin, anthraquinone, α-naphthyl, acenaphthene, benzyl, p, p'-dimethoxybenzyl or p, various dicarbonyl systems such as p′-dichlorobenzyl; or various thioxanthone systems such as 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone or 2,4-dimethylthioxanthone;

Alternatively, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (“lucirin TP
O "), 2,6-dimethylbenzoyldiphenylphosphine oxide or benzoyldiethoxyphosphine oxide, and various acylphosphine oxide-based compounds, and further α-acyloxime ester (" Canturcure PDO ") and the like. , Various compounds, and the like.

The above-mentioned photopolymerization initiators may be used alone or in combination of two or more kinds. The amount of the photopolymerization initiator to be blended is the active energy ray-curable resin (A).
0.1 to 10 parts by weight is suitable for 100 parts by weight of.

As the so-called sensitizer used in combination with such a photopolymerization initiator to increase the curing efficiency, various known and conventional sensitizers can be used and applied.
Of these, only typical ones will be exemplified. First, as amines, triethylamine, triethanolamine, methyldiethanolamine, triisopropanolamine or n-
Butylamine or N-methyldiethanolamine,

Alternatively, diethylaminoethyl (meth) acrylate, 2-dimethylaminoethylbenzoic acid, 4-
Ethyl dimethylaminobenzoate, (n-butoxy) ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate or polymerizable tertiary amine ("Uvecryl P
-104, P-105 or P-115 ").

Further, there are ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles and the like, and further, other nitrogen-containing compounds and the like.

Further, in the powder coating material of the present invention, a polymerization inhibitor may be used if necessary for the purpose of preventing gelation during storage. As such a polymerization inhibitor, any of various known and commonly used compounds can be used. Among them, 3,5-bistersialbutyl-4-hydroxy can be used as long as only typical ones are listed. Examples include toluene, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether (methoquinone), and paratertiary butyl catechol.

The method for adding the above-mentioned photopolymerization initiator, sensitizer and polymerization inhibitor is not particularly limited, but for example, it is added immediately before spray drying the powder coating material solution, or the active energy ray is added. When the curable resin is obtained by a solution reaction, it is recommended to add it after the reaction is completed because it is simple. At that time, the photopolymerization initiator, the sensitizer, the polymerization inhibitor and the like are preferably completely dissolved in the organic solvent. When completely dissolved, the active energy ray-curable resin, photopolymerization initiator, sensitizer, and polymerization inhibitor are more uniform than in the case of mixing by melt-kneading, which is used in conventional manufacturing methods. This is because it is possible to obtain a powder coating composition which is mixed with the above-mentioned and whose coating film physical properties and coating film appearance, particularly sharpness of the coating film, are remarkably improved.

The powder coating material of the present invention thus obtained is
The substrate to be coated is coated by various known and conventional methods such as an electrostatic spraying method, a triboelectrification coating method, and fluidized dipping. Next, the coated article thus obtained can be heated and melted in the air circulation furnace or by radiant heat such as infrared rays to a temperature higher than the melting temperature of the powder coating material, and then can be cured by irradiating with active energy rays. .

The powder coating material of the present invention can be suitably used as a topcoat coating material in a coating film forming method for forming a single-layer or multi-layer coating film on an object to be coated, and particularly, it has excellent smoothness. Have. If necessary, the powder coating can be mixed with a surface conditioner, a leveling agent, an antifoaming agent, an anti-cissing agent, a thixotropy-imparting agent, a sensitizer, etc., and further, curing inhibition is not caused. Of course, the use of pigments and dyes within the range is also possible.

The active energy ray-curable powder coating material of the present invention thus obtained is suitable for coating woodwork products such as plywood and furniture, or for coating various base materials including metal coating.

[0120]

EXAMPLES Next, the present invention will be described more specifically by reference examples, examples and comparative examples, but it goes without saying that the present invention is not limited to these examples.
In the following, all "parts" mean "parts by weight" unless otherwise specified.

Synthesis Example 1 [Unsaturated polyester resin (R-
1)] A reaction vessel equipped with a stirrer, a thermometer, a rectification column and a nitrogen gas inlet was charged with 270 parts of neopentyl glycol, 400 parts of hydrogenated bisphenol A and 330 parts of maleic anhydride and stirred in a nitrogen atmosphere. However, after dehydration-condensation reaction up to an acid value of 20, maleic anhydride 160 parts and glycidyl methacrylate 190 parts were reacted until an acid value of 20 was reached, with a number average molecular weight of 3,200 and a glass transition temperature of 56 ° C. Saturated polyester resin (R-1) was obtained.

Synthesis Example 2 [Intermediate (R-2a) of polyurethane (meth) acrylate (R-2)] A reaction vessel equipped with a thermometer, a stirrer and a reflux condenser was charged with 167 parts of hexamethylene diisocyanate. 65 ° C
The temperature was raised to. Next, 116 parts of 2-hydroxyethyl acrylate was reacted dropwise for 2 hours. After the dropping was completed, the temperature was raised to 75 ° C. and the reaction was carried out for 5 hours to obtain an intermediate (R-2a).

Synthesis Example 3 [Urethane (meth) acrylate (R-2)] 1,4-butanediol (560 parts) and succinic anhydride (535) were placed in a reaction vessel equipped with a stirrer, a thermometer, a rectification column and a nitrogen gas inlet. Then, 4 parts were dehydrated and condensed to obtain a polyester resin having a hydroxyl value of 100. 500 parts of this polyester resin and 254 parts of (R-2a) obtained in Synthesis Example 2 were uniformly dissolved in 500 parts of methyl ethyl ketone and reacted at 70 ° C. for 8 hours to give a urethane having a number average molecular weight of 1,500 and a glass transition temperature of 62 ° C. (Meth) acrylate (R-2) was obtained. Further, the obtained urethane (meth) acrylate (R-2) was added to 1
The solid urethane (meth) acrylate (R′-2) was obtained by removing the methyl ethyl ketone while maintaining it at 00 ° C. under reduced pressure of about 20 Torr.

Synthesis Example 4 [Epoxy (meth) acrylate (R-3)] 100 parts of xylene was placed in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet, and the temperature was raised to 130 ° C. did. In addition, 45 parts of glycidyl methacrylate, 5 parts of n-butyl methacrylate, 35 parts of methyl methacrylate and 15 parts of styrene as monomers, and 4 parts of tert-butyl peroxy 2-ethylhexanoate as a polymerization initiator. The mixture consisting of was added dropwise over 5 hours. After the dropping was completed, the temperature was kept at the same temperature for 10 hours, and the polymerization reaction was continued.
The temperature dropped to. Acrylic acid (22 parts), hydroquinone monomethyl ether (0.01 parts), and triphenylphosphine (0.08 parts) were charged and reacted, and further 110
The temperature was raised to 0 ° C. to complete the reaction, and the nonvolatile content was 56.
Epoxy (meth) acrylate (R-3) having 0%, a number average molecular weight of 3,200 and a glass transition temperature (resin solid content) of 60 ° C. was obtained. Furthermore, the obtained epoxy (meth)
Acrylate (R-3) at 170 ° C., about 20 Torr
By keeping under reduced pressure and removing xylene,
Solid epoxy (meth) acrylate (R'-3) was obtained.

Example 1 (Preparation example of active energy ray-curable powder coating material (X-1) according to the present invention) 100 parts of resin (R-1), Irgacure 651 (photopolymerization initiator manufactured by Ciba Geigy) 4 parts, benzoin 0.5
And 1 part of Modaflow (a leveling agent manufactured by Monsanto Co., Ltd.) were dissolved by heating in 150 parts of methyl ethyl ketone. This organic solvent solution was spray-dried using an explosion-proof vertical descending cocurrent spray dryer equipped with a solvent recovery device, using a rotating disk system as the spray system. Rotation speed of the disk is 15,000 rpm
Then, nitrogen gas was used as the heat source gas, and the raw material solution and the heat source gas were brought into contact with each other in a vertically descending cocurrent manner. Gas temperature is 1
It was set to 20 ° C. The powder coating material raw material solution preheated to 60 ° C. is sprayed into the spray drying device at a supply rate of 0.5 kg / hr, and the particles of the powder coating material dried in the device are collected by a cyclone. Powder coating (X-1)
Got The average particle size of the particles was 32 μm, and the average circularity was 0.92.

Example 2 (Preparation example of active energy ray-curable powder coating material (X-2) according to the present invention) 170 parts of resin (R-2), Irgacure 651 (photopolymerization initiator manufactured by Ciba Geigy) 4 parts, benzoin 0.5
And 1 part of Modaflow (Monsanto's leveling agent) were dissolved by heating in 65 parts of methyl ethyl ketone to obtain a powder coating material (X-2) of the present invention in the same manner as in Example 1. The average particle size of the particles is 36 μm, and the average circularity is 0.9.
It was 4.

Example 3 (Preparation example of active energy ray-curable powder coating material (X-3) according to the present invention) 180 parts of resin (R-3), Irgacure 651 (photopolymerization initiator manufactured by Ciba Geigy) 4 parts, benzoin 0.5
And 1 part of Modaflow (a leveling agent manufactured by Monsanto) were dissolved in 70 parts of methyl ethyl ketone by heating to obtain a powder coating material (X-3) of the present invention in the same manner as in Example 1. The average particle size of the particles is 34 μm, and the average circularity is 0.9.
It was 3.

Comparative Reference Example 1 (Preparation of active energy ray-curable powder coating material (Z-1) by melt-kneading) 100 parts of resin (R-1), Irgacure 651 (photopolymerization initiator manufactured by Ciba Geigy) 4 Part, benzoin 0.5
Part, Modaflow (Monsanto leveling agent) 1 part
Is mixed with a Henschel mixer, and Busus Conider PR4
A 6-type uniaxial kneader was used to melt-knead the mixture at 100 ° C. for 100 revolutions, cool it, pulverize it, and classify it with a 200-mesh wire net to obtain a powder coating (Z-1). The average particle size was 45 μm and the average circularity was 0.81.

Comparative Reference Example 2 (Preparation of Active Energy Ray-Curable Powder Coating (Z-2) by Melt Kneading Method) Comparative Reference Example except that Resin (R-1) was changed to Resin (R'-2) A powder coating material (Z-2) was obtained in the same manner as in 1.
The average particle size was 48 μm and the average circularity was 0.85.

Comparative Reference Example 3 (Preparation of Active Energy Ray-Curable Powder Coating (Z-3) by Melt Kneading Method) Comparative Reference Example except that Resin (R-1) was changed to Resin (R'-3) A powder coating material (Z-3) was obtained in the same manner as in 1.
The average particle size was 47 μm and the average circularity was 0.80.

Powder coatings (X-1) obtained in Examples
(X-3) and comparative reference powder coatings (Z-1) to (Z-
3) was coated on a 0.8 mm thick polished steel plate treated with zinc phosphate with an electrostatic spray coating machine for powder coating.
This test board is heated and melted in an air circulation furnace, and then
One 80W mercury lamp with a conveyor speed of 10m /
By irradiation under the condition of minutes, various test plates having a cured coating film were obtained. The evaluation and judgment results of these coating films are summarized in Table 1.

[0132]

[Table 1]

<< Procedure for Evaluation and Evaluation of Various Properties of Paint and Coating Film >> Film thickness: Measured with an electromagnetic film thickness meter. Smoothness: Five-step evaluation and judgment were performed by visual judgment. Evaluation "5"; Evaluation of very smooth and smooth coated surface "4"; Evaluation of small rounds "3"; Evaluation of large rounds "2"; Evaluation of large rounds and many fine dust skin When observed: Evaluation “1”; when there is a large round, the fine dust skin is remarkable, and the appearance of the coating film is significantly impaired.

Appearance of coating film: The presence or absence of spots in the coating film due to the formation of microgel was visually determined. Evaluation "◎"; Evaluation of smooth coating surface "○"; Evaluation of slight spots of microgel etc. Evaluation "x": Large number of spots of microgel etc. Coating gloss ； Depending on JIS-K5400 specular gloss It was measured.

Impact resistance: The impact resistance was judged by the height (cm) at which a crack was generated by dropping a 500 g weight on a punch having a diameter of 1/2 inch using a Du-Pont impact tester on the surface of the coating film. .

[0136]

As has been made clear by the detailed description above,
The active energy ray-curable powder coating material according to the present invention has the object of the present invention that, in particular, it has excellent finished appearance, smoothness, and coating film physical properties of the coating film obtained, as compared with the case of the comparative example. The manifestation of various effects is observed.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 163/10 C09D 163/10 167/06 167/06 175/14 175/14 F term (reference) 4D075 AE03 EA02 EA21 EB22 EB33 EB35 EB38 EB57 4J038 DD181 FA251 FA261 FA281 MA02 MA12 MA14 NA01 NA23 PA02 PA07 PA17 PC02 PC06

Claims (7)

[Claims] 1. An active energy ray-curable powder coating material containing an active energy ray-curable resin (A) having an average particle diameter of 5 to 50 μm and an average circularity of 0.9 or more. 2. The active energy ray-curable resin (A) is
The active energy ray-curable powder according to claim 1, which is at least one resin selected from the group consisting of an unsaturated polyester resin, urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate. Body paint. 3. A method for producing an active energy ray-curable powder coating material, which comprises spray-drying an organic solvent solution containing an active energy ray-curable resin (A) as a coating film forming component. 4. The active energy ray-curable resin (A) is
The active energy ray-curable powder according to claim 3, which is at least one resin selected from the group consisting of an unsaturated polyester resin, urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate. Body paint manufacturing method. 5. An active energy ray-curable powder coating material having an average particle diameter of 5 to 50 μm and an average circularity of 0.9 or more, which is obtained by the production method according to claim 3. 6. A coating film forming method for forming a single-layer or multi-layer coating film on an object to be coated, wherein the active energy ray-curable powder coating composition according to claim 1, 2 or 5 is applied on top. A method for forming a coating film, which is used as a coating material. 7. A coated article having a coating film formed by the method for forming a coating film according to claim 6.