JPWO2012060390A1 - Coating composition and coating film forming method - Google Patents

Abstract

The problem to be solved by the present invention is that the coating composition can reduce the heating temperature and shorten the heating time in the coating process, and can obtain a coating film excellent in scratch resistance, impact resistance and stain resistance. Is to provide things. The present invention is a radically polymerizable unsaturated group obtained by reacting a caprolactone-modified hydroxyalkyl (meth) acrylate (a1) with a polyisocyanate compound (a2) and having an isocyanate equivalent weight in the range of 300 to 3,800. Provided is a coating composition comprising a containing compound (A), a non-aqueous dispersion type resin (B) and a photopolymerization initiator (C).

Description

[Cross-reference of related applications]
This application claims priority based on Japanese Patent Application No. 2010-248371 filed on Nov. 5, 2010, the entire disclosure of which is incorporated herein by reference.

  The present invention can reduce the heating temperature and shorten the heating time in the coating process, and can further provide a coating composition and a coating film formation that can obtain a coating film excellent in scratch resistance, impact resistance, and contamination resistance. Regarding the method.

  A clear coating film is formed on an automobile body such as a motorcycle, an automobile, or a container after an electrodeposition coating film, an intermediate coating film, a base coating film, and the like are formed as necessary. Clear coatings generally contain a thermosetting coating composition containing a thermosetting functional group-containing resin such as a hydroxyl group-containing acrylic resin and a crosslinking agent such as a melamine resin, an acid group-containing resin, and an epoxy group-containing resin. It is formed by a coating film forming method in which a thermosetting coating composition or the like is applied and then heated and cured. According to this coating film forming method, a coating film excellent in coating film performance such as adhesion and coating film hardness can be formed.

  In recent years, energy saving and productivity improvement are required in the painting process. Accordingly, coating compositions that can be cured at a low temperature and coating compositions that can be cured in a short time are expected. However, the thermosetting coating composition usually requires a heating temperature of 140 ° C. and a heating time of 20 to 40 minutes in a general coating process, and satisfies the requirements for energy saving and productivity improvement. is not.

  In Patent Document 1, as an invention for shortening the heating time, an ultraviolet curable and thermosetting material containing an ultraviolet curable polyfunctional (meth) acrylate, a polyhydric alcohol mono (meth) acrylate polymer, and a polyisocyanate compound is disclosed. An invention of a coating composition is disclosed. Furthermore, a method is disclosed in which a coating film is formed by applying this coating composition to an article to be coated, irradiating with ultraviolet rays, and then heat-curing for 30 minutes. However, this method cannot shorten the heating time. Further, it was not satisfactory in terms of scratch resistance.

  In addition, Patent Document 2 includes a urethane (meth) acrylate containing a (meth) acryloyl group and a free isocyanate group, optionally a polyisocyanate other than the urethane (meth) acrylate, an ultraviolet initiator that initiates free radical polymerization, And an invention of a coating composition containing a compound containing an isocyanate-reactive group. Furthermore, a coating film forming method is disclosed in which the coating composition is applied to a support, and the coating is cured by polymerization by ultraviolet irradiation, and then by a reaction between an NCO group and an isocyanate-reactive group. This method was not satisfactory in terms of scratch resistance and weather resistance.

  In addition, Patent Document 3 discloses that a base coating composition is applied on an object to form a base coating film, and then a clear coating composition is applied in a wet-on-wet process to form a clear coating film. Also disclosed is a method for forming a multilayer coating film in which a clear coating film is irradiated with high-energy radiation before baking or curing at the same time.

  The clear coating composition in this method of forming a multi-layer coating film contains a thermally curable component and a component containing a radical polymerizable double bond, and the thermally curable component is substantially free of radical polymerizable double components. It is characterized by not including bonds. However, this method could not lower the heating temperature. Furthermore, it was not satisfactory in terms of scratch resistance.

  Patent Document 4 discloses a coating composition comprising an organic solvent-type thermosetting paint, a non-aqueous polymer dispersion having an unsaturated group, a photopolymerization initiator, and, if necessary, a photosensitizer. Has been. This coating composition is advantageous in that it solves problems such as sagging, reduction of slippage of the coating film, and poor orientation of the metal flake pigment even in highly solidified coatings. However, it was not satisfactory in terms of scratch resistance, impact resistance, and contamination resistance.

  Patent Document 5 discloses a compound having three isocyanate groups in one molecule, a compound having one hydroxyl group and one or more (meth) acryloyl groups in one molecule, the total number of hydroxyl groups / total isocyanate. Disclosed is an invention of a coating composition containing a compound obtained by reacting at a ratio of the number of groups <1, a glass transition temperature of −50 to 0 ° C., an acrylic copolymer having a hydroxyl value of 50 to 350 mgKOH / g, and a radical polymerization initiator. Has been. However, this invention is not satisfactory in terms of weather resistance and scratch resistance.

JP-A-63-113085 JP 11-263939 A JP-T-2001-524868 JP 2000-230007 A JP 2008-208205 A

The present invention has been made in view of the above circumstances, and it is possible to reduce the heating temperature required for coating film curing, to reduce the coating equipment, etc., to reduce CO ₂ due to the shortening of the heating time, etc. It is an object of the present invention to provide a coating composition and a method for forming a coating film that can obtain a coating film having excellent properties, impact resistance, and stain resistance.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the specific radical polymerizable unsaturated group-containing compound (A), non-aqueous dispersion resin (B) and photopolymerization initiator (C). The present inventors have found that the above-mentioned problems can be solved by using a coating composition containing selenium, and have completed the present invention.

That is, the present invention provides the following items:
Item 1. Radical polymerizable unsaturated group-containing compound (A) obtained by reacting caprolactone-modified hydroxyalkyl (meth) acrylate (a1) with polyisocyanate compound (a2) and having an isocyanate equivalent weight in the range of 300 to 3,800 ), A non-aqueous dispersion resin (B) and a photopolymerization initiator (C).

  Item 2. The non-aqueous dispersion type resin (B) contains a dispersion stabilizer made of a polymer, and the dispersion stabilizer and the polymerizable unsaturated monomer (b1) dissolve, but the polymerizable unsaturated monomer. The polymer formed from the body is a dispersion of polymer fine particles (i) obtained by the polymerization reaction of the polymerizable unsaturated monomer in an organic liquid that does not substantially dissolve, The coating composition according to claim 1, wherein the agent has at least one chemically reactive group selected from an epoxy group, a carboxyl group, a hydroxyl group, an isocyanato group, and an alkoxysilyl group.

  Item 3. The coating composition according to claim 1 or 2, wherein the non-aqueous dispersion resin (B) has a polymerizable unsaturated group.

  Item 4. The coating composition according to any one of claims 1 to 3, wherein the polymerizable unsaturated group equivalent of the non-aqueous dispersion resin (B) is 660 to 10,000.

  Item 5. The non-aqueous dispersion resin (B2) is reacted with a polymerizable unsaturated compound (b2) having a complementary chemically reactive group capable of reacting with the chemically reactive group of the dispersion stabilizer portion of the non-aqueous dispersion resin (B). The coating composition according to any one of claims 1 to 4, wherein a polymerizable unsaturated group is introduced into the dispersion stabilizer portion of the polymer fine particles (i) in B).

  Item 6. The coating composition according to any one of claims 1 to 5, wherein the average particle size of the polymer particles in the non-aqueous dispersion resin (B) is 50 to 500 nm.

  Item 7. The coating composition according to any one of claims 1 to 6, comprising 1 to 50 parts by mass of the non-aqueous dispersion resin (B) in solids with respect to 100 parts by mass of the total solids of the coating composition.

  Item 8. Furthermore, the coating composition of any one of Claims 1-7 containing isocyanate compounds (D) other than the said compound (A).

  Item 9. Furthermore, the coating composition of any one of Claims 1-8 containing hydroxyl-containing resin (E).

  Item 10. The coating composition according to claim 9, wherein the glass transition temperature of the hydroxyl group-containing resin (E) is 0 ° C. or higher.

  Item 11. Furthermore, the coating composition of any one of Claims 1-10 containing radically polymerizable unsaturated group containing compound (F) other than the said compound (A).

Item 12. Applying a base coating composition containing a resin containing an active hydrogen group and a color pigment on an object to be coated to form a base coating film;
Next, a method for forming a multilayer coating film, comprising: a step of coating the coating composition according to any one of claims 1 to 11 to form a clear coating film; and a step of irradiating and heating active energy rays.

  Item 13. The coated article obtained by the coating-film formation method of Claim 12.

  According to the present invention, it is possible to obtain a coating composition that can reduce the heating temperature and shorten the heating time in the coating process, and can form a coating film having excellent scratch resistance and weather resistance. Also, the coating composition is applied onto the object to be coated to form a base coating film, and then a specific coating composition is applied as a clear coating film to form a clear coating film, and further irradiated with active energy rays. And the multilayer coating film excellent in adhesiveness and finished appearance can be obtained by using the multilayer coating-film formation method which heats.

  The coating film by the coating composition of the present invention has excellent scratch resistance and improved impact relaxation ability by improving the crosslinking density of the coating film due to the synergistic effect of the compound (A) and the non-aqueous dispersion resin (B). By improving, a coating film excellent in impact resistance can be formed. Furthermore, since it is a coating film provided with these functions, since a microscopic damage | wound is hard to attach to a coating film, the coating composition which can form the coating film which is excellent in stain resistance can be provided.

  The present invention is a radically polymerizable unsaturated group-containing compound obtained by reacting caprolactone-modified hydroxyalkyl (meth) acrylate (A) with a polyisocyanate compound and having an isocyanate equivalent weight in the range of 300 to 3,800 ( A) [hereinafter sometimes referred to simply as “compound (A)”. ] And a non-aqueous dispersion type resin (B), and the coating composition containing a photoinitiator (C).

  Further, a base coating composition is applied onto an object to be coated to form a base coating, and then the coating composition is applied to form a coating, followed by irradiation with active energy rays and heating. It relates to a forming method. Hereinafter, the coating composition and the coating film forming method of the present invention will be described in detail.

[Coating composition]
Compound (A)
Compound (A) is a compound obtained by reacting caprolactone-modified hydroxyalkyl (meth) acrylate (a1) with polyisocyanate compound (a2) and having an isocyanate equivalent weight in the range of 300 to 3,800.

  This compound (A) is excellent in curability by irradiation with active energy rays, and further excellent in curability at a low temperature (specifically, normal temperature to 100 ° C.). This makes it possible to lower the heating temperature and shorten the heating time in the painting process. Moreover, the coating film obtained from the coating composition containing this compound (A) is excellent in scratch resistance and weather resistance.

Caprolactone-modified hydroxyalkyl (meth) acrylate (a1)
In the present invention, caprolactone-modified hydroxyalkyl (meth) acrylate (a1) represents a compound represented by the following general formula.

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 2 to 6 carbon atoms, m represents an integer of 3 to 8, and n represents an integer of 1 to 5)

 Examples of such caprolactone-modified hydroxyalkyl (meth) acrylate (a1) include compounds represented by the following general formula (I):

(In formula (I), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 2 to 6 carbon atoms, and n is 1 to 5).

Specifically, the caprolactone-modified hydroxyalkyl (meth) acrylate includes “Placcel FA-1”, “Placcel FA-2”, “Placcel FA-2D”, “Placcel FA-3”, “Placcel FA-4”, “Placcel FA-5”, “Plaxel FM-1”, “Plaxel FM-2”, “Plaxel FM-2D”, “Plaxel FM-3”, “Plaxel FM-4”, “Plaxel FM-5” (any Can also be mentioned by Daicel Chemical Industries, trade name). Of these, caprolactone-modified hydroxyethyl acrylate in which R ¹ is a hydrogen atom and R ² is an ethylene group in the general formula (I) is preferable from the viewpoint of active energy ray curability. Similarly, in terms of active energy ray curability, caprolactone-modified hydroxyethyl acrylate in which n is in the range of 1 to 3 in general formula (I) is preferable.

Polyisocyanate compound (a2)
On the other hand, the polyisocyanate compound (a2) is a compound having two or more isocyanate groups in one molecule. For example, aliphatic polyisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, lysine diisocyanate, and burette type adducts or isocyanurate cycloadducts of these polyisocyanates; isophorone diisocyanate, 4,4 ′ -Methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 1,3-di (isocyanatomethyl) cyclohexane, 1,4-di (isocyanatomethyl) cyclohexane, 1 , 4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexane diisocyanate, etc. Nate compounds and burette-type adducts and isocyanurate cycloadducts of these polyisocyanates; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3 ′ -Dimethyl-4,4'-biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenylisocyanate) Aromatic biisocyanate compounds, such as poly (isocyanates) and the like, and burette-type or isocyanurate cycloadducts of these polyisocyanates; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-tri Polyisocyanate having three or more isocyanate groups in one molecule such as isocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate Isocyanate compounds and burette type adducts or isocyanurate cycloadducts of these polyisocyanates; ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexanetriol, etc. Polyols Isocyanate group to a hydroxyl group is a urethane adduct obtained by reacting a polyisocyanate compound and biuret type adducts of these polyisocyanate or isocyanurate ring adducts, and the like in a ratio to be excess. These can be used as one or a mixture of two or more. Among these, from the viewpoint of the weather resistance of the coating film, an isocyanurate cycloadduct of an aliphatic polyisocyanate compound is preferable, and an isocyanurate cycloadduct of hexamethylene diisocyanate is particularly preferable.

  The reaction of the caprolactone-modified hydroxyalkyl (meth) acrylate (a1) and the polyisocyanate compound (a2) can be performed by a known method when the hydroxy group-containing compound and the polyisocyanate compound are reacted.

  The blending ratio of the caprolactone-modified hydroxyalkyl (meth) acrylate (a1) and the polyisocyanate compound (a2) is not particularly limited as long as the isocyanate equivalent of the component (A) to be obtained is within the above range.

  The above reaction can usually be carried out in an organic solution. Examples of organic solvents include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and ester solvents such as ethyl acetate, propyl acetate, isobutyl acetate, and butyl acetate. Can be mentioned. These can be used as one or a mixture of two or more. The reaction temperature is preferably from room temperature to 100 ° C., and the reaction time is preferably from 1 to 10 hours.

  In the above reaction, a catalyst such as dibutyltin dilaurate, dibutyltin diethylhexoate or dibutyltin sulfite may be used as necessary. The addition amount of the catalyst is preferably 0.01 to 1 part by mass and more preferably 0.1 to 0.5 part by mass with respect to 100 parts by mass of the total amount of reaction raw materials. A polymerization inhibitor such as hydroquinone monomethyl ether may be used. It is preferable that the addition amount of a polymerization inhibitor is 0.01-1 mass part with respect to 100 mass parts of total amounts of a reaction raw material.

  Since the radically polymerizable unsaturated group-containing compound (A) has an isocyanate group, the mixing ratio in the reaction of the caprolactone-modified hydroxyalkyl (meth) acrylate with the polyisocyanate compound is usually that of the isocyanate group of the polyisocyanate compound. The mixing ratio is an excess (isocyanate group / hydroxykyl group> 1.0) in an equivalent ratio with respect to the hydroxyl group of caprolactone-modified hydroxyalkyl (meth) acrylate. And the isocyanate equivalent of a radically polymerizable unsaturated group containing compound (A) can be adjusted by adjusting a mixing ratio.

  The compound (A) has an isocyanate equivalent weight in the range of 300 to 3,800. When the compound (A) has an isocyanate group within the above range, the coating composition of the present invention is excellent in curability at low temperatures. The isocyanate equivalent of the compound (A) is preferably in the range of 400 to 3,000, more preferably in the range of 500 to 3,000, from the viewpoint of scratch resistance of the coating film.

  Further, since the compound (A) has an isocyanate group, the compound (A) reacts with the chemically reactive group (x) when the non-aqueous dispersion type resin (B) has an active hydrogen group, and is strong. A coating film can be formed.

  By setting the isocyanate equivalent within the above range, a multilayer coating film having excellent scratch resistance is obtained, and the compound (A) is difficult to penetrate into the base coating film, and both the adhesion and the finished appearance are good. A membrane can be obtained.

  In particular, when the base coating composition is a coating composition containing a bright pigment, it is possible to prevent the compound (A) from being soaked into the base coating film, thereby preventing the orientation of the bright pigment in the base coating film from being disturbed. The finished appearance of the multilayer coating film is good.

  Here, in this specification, an isocyanate equivalent means the molar mass per isocyanate group. When the molecular weight of the compound is M and the number of isocyanate groups contained in one molecule of the compound is ν, the isocyanate equivalent is represented by M / ν. The isocyanate equivalent can be measured by back titration using dibutylamine. The reverse titration is performed by adding an excess of dibutylamine to the sample and reacting, and using bromophenol blue as a titration indicator to titrate the remaining dibutylamine with an aqueous hydrochloric acid solution.

  Furthermore, the compound (A) preferably has an unsaturated group equivalent of 300 to 2,000. More preferably, it is 500-1,000. When the unsaturated group equivalent is within these ranges, it is possible to obtain a coating film having more excellent scratch resistance and weather resistance.

  Here, in this specification, an unsaturated group equivalent means the molar mass per unsaturated group. When the g molecular weight of the compound is M and the number of unsaturated groups contained in one molecule of the compound is σ, the unsaturated group equivalent is expressed by M / σ. The unsaturated group equivalent can be measured by adding dodecyl mercaptan to a radical polymerizable unsaturated group and back titrating the remaining dodecyl mercaptan with an iodine solution.

  Here, the molecular weight of the compound (A) is not particularly limited. The weight average molecular weight is preferably 500 to 2,000, more preferably 800 to 1,500. It is significant that the weight average molecular weight is within these ranges in that the viscosity of the paint can be easily handled.

In the present invention, the weight average molecular weight uses tetrahydrofuran as a solvent, “HLC-8120GPC” (trade name, manufactured by Tosoh Corporation) as a gel permeation chromatograph, and “TSKgel G-4000H _XL ” as a column. one and two the "TSKgel G3000H _XL" and "TSKgel G2000H _XL" the one (trade name, all manufactured by Tosoh Corp.) using four, as a detector, using a differential refractometer Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 mL / min.

Non-aqueous dispersion type resin (B)
The non-aqueous dispersion type resin (B) used in the present invention is a resin in which polymer fine particles (i) that are not substantially dissolved in the organic liquid are dispersed in the organic liquid. The non-aqueous dispersion type resin (B) can be obtained by polymerizing a monomer in an organic liquid in the presence of a dispersion stabilizer as necessary. Here, although the dispersion stabilizer and the polymerizable unsaturated monomer (b1) are dissolved in the organic liquid, the polymer formed from the polymerizable unsaturated monomer is not substantially dissolved. As described above, since the non-aqueous dispersion resin (B) is a resin in which the polymer fine particles (i) are dispersed, the non-aqueous dispersion resin (B) is a non-aqueous polymer fine particle dispersion (B). It can also be shown. Hereinafter, the non-aqueous dispersion type resin (B) may be abbreviated as “NAD” (Non Aqueous Dispersion). “NAD” can be manufactured by the following manufacturing method.

  Examples of the dispersion stabilizer used in the above step include those made of a high molecular polymer used in the field of non-aqueous dispersion type resins, and the dispersion stabilizer has a chemically reactive group (x). It is desirable. Representative examples of the chemically reactive group (x) include an epoxy group, a carboxyl group, a hydroxyl group, an isocyanato group, an alkoxysilyl group, an alkoxymethyl group, an amino group, a carboxylic anhydride group, and a β-ketoester group. . Of these, an epoxy group, a carboxyl group, a hydroxyl group, an isocyanato group, and an alkoxysilyl group are preferable.

Examples of the dispersion stabilizer include the following:
Illustrative (1): Glycidyl (meth) acrylate is added to a part of the carboxyl group of a hydroxyl group-containing fatty acid self-condensed polyester such as 12-hydroxystearic acid to give about 0.5 to 1.5 (for example, about 1.0) a hydroxyl group-containing polyester macromer introduced with a polymerizable double bond.

  Example (2): A polyester macromer of Example (1) above, an epoxy group-containing polymerizable unsaturated monomer such as glycidyl methacrylate, and another polymerizable unsaturated monomer such as methyl methacrylate are copolymerized. A hydroxyl group-containing polyester / acrylic graft comb polymer in which a polymerizable double bond is introduced by adding (meth) acrylic acid to a part of the epoxy group of the copolymer.

  Example (3): A chemically reactive group-containing acrylic copolymer obtained by copolymerizing a monomer mixture containing a long-chain polymerizable unsaturated monomer and a polymerizable unsaturated monomer having a chemically reactive group Polymer (in this embodiment, examples of the chemically reactive group include an epoxy group, a hydroxyl group, and a carboxyl group). Examples of the long-chain polymerizable unsaturated monomer include n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like. Examples of the polymerizable unsaturated monomer having a chemically reactive group include glycidyl (meth) acrylate, (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, and the like. ;

  Example (4): A polymerizable unsaturated monomer having a functional group that reacts with the chemically reactive group is allowed to react with a part of the chemically reactive group of the acrylic copolymer obtained in Example (3) above. A chemically reactive group-containing acrylic copolymer having an average of about 0.5 to 1.5 (for example, about 1.0) polymerizable double bonds introduced into the molecule. Examples of the polymerizable unsaturated monomer having a functional group that reacts with the chemically reactive group (hereinafter referred to as a functional unsaturated monomer) include (meth) acrylic acid, glycidyl (meth) acrylate, and isocyanato. Examples thereof include a group-containing polymerizable unsaturated monomer and a hydroxyl group-containing polymerizable unsaturated monomer.

  In the present invention, the polymerizable double bond means a carbon-carbon double bond contained in an unsaturated group capable of radical polymerization. Here, examples of the polymerizable unsaturated group include a vinyl group, a (meth) acryloyl group, a (meth) acrylamide group, a vinyl ether group, and an allyl group.

  Among the above-mentioned dispersion stabilizers, particularly preferred dispersion stabilizers are those that can be dissolved in a relatively low polarity organic solvent such as an aliphatic hydrocarbon-based organic solvent, and can achieve the object of the present application. As the dispersion stabilizer that satisfies such conditions, the molecular weight, glass transition temperature, polarity (SP value of the polymer), hydroxyl value, acid value, etc. can be easily adjusted. Examples (3) and (4) The acrylic copolymer of (4) having an polymerizable double bond that can be grafted to the polymer fine particles (i) is preferable.

  The dispersion stabilizer in the non-aqueous dispersion type resin (B) preferably has a chemically reactive group (x), and the chemically reactive group (x) is exemplified above except for the polymerizable double bond (1). In the examples (2), (3) and (4), there can be mentioned chemically reactive groups which the dispersion stabilizer can have.

  Further, the dispersion stabilizer in the present invention can contain one or more, preferably 1 to 50, of chemically reactive groups (x) in one molecule, and the number average molecular weight is generally 1,000 to 50,000. , Preferably, it is in the range of 3,000 to 20,000, and the glass transition temperature is in the range of -20 to 60 ° C. The concentration of the chemically reactive group (x) in the dispersion stabilizer is preferably in the range of 0.02 to 8.0 mol / kg, more preferably 0.5 to 6.0 mol / kg. is there.

  When the dispersion stabilizer is according to the above example (3) or example (4), the monomer as the raw material is classified into a functional unsaturated monomer and a non-functional unsaturated monomer. You can also. The polymer fine particles (i) are vinyl resins (including acrylic resins) obtained by polymerizing the polymerizable unsaturated monomer (b1). The polymerizable unsaturated monomer (b1) is not particularly limited, and may be a functional unsaturated monomer or a non-functional unsaturated monomer.

  Here, as the polymerizable unsaturated monomer constituting the dispersion stabilizer when the dispersion stabilizer is exemplified (3) or (4), the functional unsaturated monomer is, for example, glycidyl. (Meth) acrylate, acrylic acid, methacrylic acid, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isocyanatoethyl (meth) acrylate, m-isopropenyl-α, α -Dimethylbenzyl isocyanate, (gamma) -methacryloyloxypropyl trimethoxysilane, aminoethyl (meth) acrylate, maleic anhydride, acetoacetoxyethyl (meth) acrylate, etc. can be mentioned.

  Examples of the non-functional unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth) acrylate. , Ester compounds of acrylic acid or methacrylic acid such as lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl methacrylate; biscoat 3F, biscoat 3MF, biscoat 8F, biscoat 8MF ( All of these are made by Osaka Organic Chemical Co., Ltd., trade name), fluorinated vinyl monomers such as perfluorocyclohexyl (meth) acrylate, vinyl fluoride; N, N-dimethylaminoethyl (meth) acrylate Nitrogen-containing vinyl monomers such as N, N-diethylaminoethyl (meth) acrylate and N, N-diethylmethacrylamide; vinyl ether monomers such as vinyl ethyl ether and vinyl butyl ether; styrene, α-methyl styrene, vinyl Examples thereof include aromatic vinyl monomers such as toluene; acrylonitrile, methacrylonitrile, divinylbenzene, ethylene glycol di (meth) acrylate, and the like. In the present invention, “(meth) acrylate” at the end means acrylate or methacrylate.

  Examples of the polymerizable unsaturated monomer constituting the polymer fine particles (i) include the above-mentioned functional unsaturated monomers and non-functional unsaturated monomers.

  As the non-functional monomer, in the case of forming the dispersion stabilizer of Example (3) or Example (4), among them, the alkyl part of the ester has 3 (propyl) or more carbon atoms, preferably 6 (Hexyl) or higher ester compounds of acrylic acid or methacrylic acid are preferred. On the other hand, when forming polymer fine particles (i), carbon of styrene, acrylonitrile and the alkyl part of ester is particularly preferred. An ester compound of methacrylic acid having a number of 4 (butyl) or less can be mentioned, and among these, methyl methacrylate is particularly preferable.

  The polymer fine particles (i) may be internally cross-linked from the viewpoint of storage stability of the paint. As a part of the functional unsaturated monomer, for example, a monomer having two mutually reactive chemically reactive groups is used, and the chemically reactive groups are reacted with each other to form a chemical bond ( For example, the polymer fine particles obtained can be internally crosslinked by reacting with acrylic acid and glycidyl methacrylate, or by using a polyvinyl compound of divinylbenzene.

  The blending ratio of the dispersion stabilizer in the above step and the polymerizable unsaturated monomer (b1) used for the synthesis of the polymer fine particles (i) is based on the total solid content of both components. The mass ratio of / polymerizable unsaturated monomer (b1) is generally in the range of 5/95 to 70/30, preferably 10/90 to 60/40.

  In the above step, the organic solvent used in the polymerization reaction dissolves the dispersion stabilizer and the polymerizable unsaturated monomer (b1) forming the polymer fine particles (i), but the polymerizable unsaturated monomer. The polymer fine particles formed from the above are substantially insoluble and preferably have a low polarity. For example, fats having relatively low dissolving power such as VM & P naphtha, mineral spirit, solvent kerosene, aromatic naphtha, solvent naphtha, etc. Aliphatic or aromatic hydrocarbon compounds; aliphatic hydrocarbon compounds such as n-butane, n-hexane, n-heptane, n-octane, isononane, n-decane, n-dodecane; cyclopentane, cyclohexane, An alicyclic hydrocarbon-based compound such as cyclobutane is used. If necessary, polar solvents such as esters, ethers, ketones and alcohols can be used in a small proportion.

  In polymerizing the polymerizable unsaturated monomer (b1) into the polymer fine particles (i), a polymerization initiator is added, the polymerization temperature is set to 0 to 150 ° C., preferably 50 to 110 ° C., and the polymerization time is set. Usually, it is preferably 2 to 10 hours.

  Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-butyl peroctoate, and diacetyl peroxide; azobisisobutyronitrile and azobisdimethylvaleronitrile. And azo initiators such as dimethyl α, α′-azoisobutyrate; dialkylperoxydicarbonates such as diisopropylperoxydicarbonate; and redox initiators. The concentration of the polymerization initiator is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass with respect to the polymerizable unsaturated monomer.

  The non-aqueous dispersion resin (B) (“NAD”) used in the present invention is “NAD” in which a polymerizable unsaturated group is further introduced into the dispersion stabilizer portion in the polymer fine particle dispersion obtained as described above. There may be.

  “NAD” into which a polymerizable unsaturated group has been introduced is complementary that can react with the chemically reactive group (x) of the dispersion stabilizer part of the non-aqueous dispersion resin (B) obtained as described above. It is produced by reacting a polymerizable unsaturated compound (b2) having a chemically chemically reactive group (y).

  Among the combinations of the chemically reactive group (x) and the complementary reactive group (y), a combination selected from an epoxy group and a carboxyl group, a hydroxyl group and an isocyanate group, and an alkoxysilyl group and a hydroxyl group is preferable.

  The chemically reactive group (x) and the complementary reactive group (y) do not necessarily have to be one each, and if they are groups that do not react with each other, the dispersion stabilizer part and the polymer fine particle (i) part Two or more kinds of reactive groups may be present in each of these, and even if they are groups that react with each other, a dispersion stabilizer can be used as long as it is a combination of groups that are very reactive under normal conditions. It can coexist in each of the part and the polymer fine particle (i) part.

  Specific examples of the polymerizable unsaturated compound (b2) having the complementary reactive group (y) include epoxy groups such as glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and allyl glycidyl ether. Containing compounds; carboxyl group-containing compounds such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, N-methylolacrylamide, allyl Hydroxyl-containing compounds such as alcohols; isocyanato group-containing compounds such as cyanoacrylate, 2-isocyanatoethyl (meth) acrylate, m-isopropenyl-α, α-dimethylbenzyl isocyanate; γ-methacryloyloxypropylate Alkoxysilyl group-containing compounds such as methoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, vinyltriethoxysilane; alkoxymethyl groups such as N-methoxymethylacrylamide and N-butoxymethylacrylamide Compounds; amino group-containing compounds such as aminoethyl (meth) acrylate and aminopropyl (meth) acrylate; carboxylic acid anhydride group-containing compounds such as maleic anhydride and itaconic anhydride; β-ketoesters such as acetoacetoxyethyl (meth) acrylate Examples thereof include a group-containing compound.

  The introduction reaction of the polymerizable unsaturated group into the dispersion stabilizer portion is carried out under the condition that the chemically reactive group (x) to be combined and the complementary reactive group (y) react with each other (x) and (y) Depending on the type and the like, it can be appropriately performed.

  The amount of the polymerizable unsaturated compound (b2) having a complementary reactive group (y) in the introduction reaction of the polymerizable unsaturated group is based on 1 mol of the chemically reactive group (x) in the dispersion stabilizer. It is suitable that the complementary reactive group (y) in the polymerizable unsaturated compound is in the range of 0.1 to 1.5 mol, preferably 0.5 to 1.0 mol. In addition, the polymerizable unsaturated group equivalent in the resin of the polymer fine particle dispersion is preferably 660 to 10,000, more preferably 1,000 from the viewpoint of low temperature curability and finish of the coated film. A range of ~ 2,000 is preferred.

  The non-aqueous dispersion resin (B) preferably has an average particle diameter of 50 to 500 nm from the viewpoint of impact resistance and finish of the coating film. The particle size was measured by a [submicron particle size distribution measuring device “COULTER N4 type” (manufactured by Beckman Coulter)] (hereinafter the same).

Photopolymerization initiator (C)
As a photoinitiator (C) used for the coating composition of this invention, if it is an initiator which absorbs an active energy ray and generate | occur | produces a radical, it can be used without being specifically limited.

  Examples of the photopolymerization initiator include α-diketone compounds such as benzyl and diacetyl; acyloin compounds such as benzoin; acyloin ether compounds such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; thioxanthone and 2,4-diethyl Thioxanthone compounds such as thioxanthone, 2-isopropylthioxanthone, thioxanthone-4-sulfonic acid; benzophenone compounds such as benzophenone, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone; Michler's ketone compound; Acetophenone, 2- (4-toluenesulfonyloxy) -2-phenylacetophenone, p-dimethylaminoacetophenone, α, α'-dimethoxyacetoxybenzof Non, 2,2′-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- Acetophenone compounds such as (4-morpholinophenyl) -butan-1-one, α-isohydroxyisobutylphenone, α, α′-dichloro-4-phenoxyacetophenone, 1-hydroxy-cyclohexyl-phenyl-ketone; 2,4 Acylphosphine oxide compounds such as 1,6-trimethylbenzoyldiphenylphosphine oxide and bis (acyl) phosphine oxide; quinone compounds such as anthraquinone and 1,4-naphthoquinone; phenacyl chloride, trihalomethylphenylsulfone, tris (to Halomethyl) -s-halogen compounds such as triazine; peroxides such as di -t- butyl peroxide and the like. These can be used as one or a mixture of two or more.

  Examples of commercially available photopolymerization initiators (C) include Irgacure 184, Irgacure 261, Irgacure 500, Irgacure 651, Irgacure 907, Irgacure CGI 1700 (trade name, IRGACURE \ Irgacure \ Is a registered trademark), Darocur 1173 (Darocur 1173), Darocur 1116, Darocur 2959, Darocur 1664, Darocur 4043 (Merck Japan, trade name, Darocur \ Darocur is a registered trademark), KYACURE MBP (Kayacure MBP), KAXACURE DE , KAYACURE DMBI, KAYACURE EPA, KAYACURE OA (manufactured by Nippon Kayaku Co., Ltd., trade name, KAYACURE \ Kayacure is a registered trademark), VICURE 10 (Bicure 10), Vicure 55 [Product name, manufactured by STAUFFER Co., LTD.], TRIGONAL (registered trademark) P1 (Trigonal P1) [product name, manufactured by AKZO Co., LTD.], SANDORAY 1000 (Sandray 1000) [Sands (SANDOZ Co., LTD.), Product name], DEAP (Deep) (APJOHN Co., LTD., Product name), QUANTACURE PDO (Kantacure PDO), KantaCure ITX, KantaCure EPD [Trade name] manufactured by WARD BLEKINSOP Co., LTD.

Isocyanate compound (D)
The coating composition of the present invention can further contain an isocyanate compound (D) other than the compound (A).

  The isocyanate compound (D) is a compound having an isocyanate group in the molecule, and examples thereof include the polyisocyanate compounds exemplified in the description of the polyisocyanate compound (a2) which is a raw material of the compound (A). Of these, isocyanurate cycloadducts of aliphatic polyisocyanate compounds are preferred from the viewpoint of the weather resistance of the coating film, and isocyanurate cycloadducts of hexamethylene diisocyanate are particularly preferred.

Hydroxyl-containing resin (E)
The coating composition of the present invention can further contain a hydroxyl group-containing resin (E) other than the compound (B). The hydroxyl group-containing resin (E) is a resin having at least one hydroxyl group in one molecule. Examples of the hydroxyl group-containing resin (E) include resins having a hydroxyl group, such as polyester resins, acrylic resins, polyether resins, polycarbonate resins, polyurethane resins, epoxy resins, and alkyd resins. These can be used alone or in combination of two or more. Especially, it is preferable that a hydroxyl-containing resin (E) is a hydroxyl-containing acrylic resin from the point of the weather resistance of the coating film obtained.

  The hydroxyl group-containing acrylic resin is usually a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer, a method known per se, For example, it can be produced by copolymerization by a method such as a solution polymerization method in an organic solvent or an emulsion polymerization method in water.

  The hydroxyl group-containing polymerizable unsaturated monomer is a compound having at least one hydroxyl group and one polymerizable unsaturated bond in one molecule. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 2 A monoesterified product of (meth) acrylic acid such as hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and a dihydric alcohol having 2 to 8 carbon atoms; Ε-caprolactone modified product of monoesterified product of (meth) acrylic acid and dihydric alcohol having 2 to 8 carbon atoms; N-hydroxymethyl (meth) acrylamide; allyl alcohol, and polyoxyethylene chain whose molecular terminal is a hydroxyl group (Meth) acrylate etc. which have can be mentioned.

  Examples of the other polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (trade name, manufactured by Osaka Organic Chemical Industry Co., Ltd.), cyclohexyl (meta) ) Acrylate, methylcyclohexyl ( A) alkyl, cycloalkyl (meth) acrylate such as acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate; polymerizable unsaturated monomer having an isobornyl group such as isobornyl (meth) acrylate; adamantyl Polymerizable unsaturated monomers having an adamantyl group such as (meth) acrylate; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) ) Polymerizable unsaturated monomers having alkoxysilyl groups such as silane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane; perfluorobutylethyl (meth) Perfluoroalkyl (meth) acrylates such as acrylate and perfluorooctylethyl (meth) acrylate; polymerizable unsaturated monomers having a fluorinated alkyl group such as fluoroolefin; polymerization having a photopolymerizable functional group such as a maleimide group Unsaturated monomers; vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate and vinyl acetate; carboxyl groups such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate Containing polymerizable unsaturated monomer: (meth) acrylonitrile, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, glycidyl (meth) acrylate and amine Such as adducts with compounds Nitrogen polymerizable unsaturated monomer; polymerizable unsaturated monomer having two or more polymerizable unsaturated groups in one molecule such as allyl (meth) acrylate and 1,6-hexanediol di (meth) acrylate; Glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate , Epoxy group-containing polymerizable unsaturated monomers such as allyl glycidyl ether; (meth) acrylate having a polyoxyethylene chain whose molecular terminal is an alkoxy group; 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, Styrene sulfonic acid sodium salt, sulfoethyl Polymerizable unsaturated monomers having a sulfonic acid group such as tacrylate and its sodium salt or ammonium salt; 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, 2-methacryloyl Polymerizable unsaturated monomers having a phosphate group such as oxypropyl acid phosphate; 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy- 2-hydroxypropoxy) benzophenone, 2,2′-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2,2′-dihydroxy-4- (3-acryloyloxy) Polymerizable unsaturated monomer having an ultraviolet absorbing functional group such as 2-hydroxypropoxy) benzophenone, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole; 4- (meta ) Acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino- 2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano- 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6 UV-stable polymerizability of tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, etc. Unsaturated monomer; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formyl styrene, vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl) Examples thereof include polymerizable unsaturated monomer compounds having a carbonyl group such as ketone), and these can be used alone or in combination of two or more.

  The hydroxyl group-containing resin (E) is generally 30 to 300 mgKOH / g, particularly 40 to 250 mgKOH / g, more particularly 50 to 200 mgKOH / g, from the viewpoint of curability at low temperature and the water resistance of the resulting coating film. It preferably has a hydroxyl value within the range.

  The hydroxyl group-containing resin (E) preferably has an acid group such as a carboxyl group from the viewpoint of increasing the reactivity with the compound (A).

  The hydroxyl group-containing resin (E) preferably has an acid value in the range of 1 to 25 mgKOH / g, particularly 1 to 20 mgKOH / g.

  The hydroxyl group-containing resin (E) generally has a weight average molecular weight in the range of 3,000 to 100,000, particularly 4,000 to 50,000, more preferably 5,000 to 30,000.

  The hydroxyl group-containing resin (E) preferably has a glass transition temperature of 0 ° C. or higher, particularly 3 ° C. to 50 ° C. from the viewpoint of scratch resistance and weather resistance.

  Here, the glass transition temperature (° C.) is a static glass transition temperature. For example, using a differential scanning calorimeter “DSC-50Q type” (manufactured by Shimadzu Corporation, trade name), a sample is taken into a measuring cup and vacuumed. After the solvent was completely removed, the change in calorie was measured in the range of -100 degrees to 100 degrees at a temperature increase rate of 3 degrees / minute, and the first baseline change point on the low temperature side was taken as the glass transition temperature.

Radical polymerizable unsaturated group-containing compound (F)
The coating composition of the present invention may further contain a radical polymerizable unsaturated group-containing compound (F) other than the compound (A).

  Other examples of the radical polymerizable unsaturated group-containing compound (F) include a monofunctional radical polymerizable unsaturated group-containing compound and a polyfunctional radical polymerizable unsaturated group-containing compound.

  Examples of the monofunctional radical polymerizable unsaturated group-containing compound include esterified products of monohydric alcohol and (meth) acrylic acid. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (Meth) acrylate, neopentyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, N-acryloyloxyethylhexahydro Examples include phthalimide. Also, for example, hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid Carboxyl group-containing (meth) acrylates such as 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate and 5-carboxypentyl (meth) acrylate; glycidyl groups such as glycidyl (meth) acrylate and allyl glycidyl ether -Containing radically polymerizable unsaturated group-containing compounds; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene; N, N-dimethylaminoethyl (meth) acrylate, N, N-die Nitrogen-containing alkyl (meth) acrylates such as tilaminoethyl (meth) acrylate and Nt-butylaminoethyl (meth) acrylate; acrylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, Examples thereof include polymerizable amide compounds such as N-dimethylaminoethyl (meth) acrylamide.

  Examples of the polyfunctional radical polymerizable unsaturated group-containing compound include esterified products of polyhydric alcohol and (meth) acrylic acid. Specifically, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) Acrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol di (meth) acrylate, Dipentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, bisphenol A ethylene oxide modified di (meth) acrylate, etc. Meth) acrylate compounds; glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane propylene oxide modified tri (meth) acrylate, trimethylolpropane ethylene oxide modified tri (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, ε-caprolactone-modified tris (acryloxyethyl) isocyanurate and other tri (meth) acrylate compounds; penta (erythritol) tetra (meth) acrylate and other tetra (meth) acrylate compounds; other dipentaerythritol penta (meth) acrylates And dipentaerythritol hexa (meth) acrylate. Furthermore, urethane (meth) acrylate resin, epoxy (meth) acrylate resin, polyester (meth) acrylate resin and the like can be mentioned. The urethane (meth) acrylate resin is obtained, for example, by using a polyisocyanate compound, a hydroxylalkyl (meth) acrylate, and a polyol compound as raw materials and reacting them in an amount such that the hydroxyl group is equimolar or excessive with respect to the isocyanate group. be able to. These radically polymerizable unsaturated group-containing compounds can be used alone or in combination of two or more.

  The radical polymerizable unsaturated group-containing compound preferably contains a trifunctional or higher functional radical polymerizable unsaturated group-containing compound from the viewpoint of scratch resistance of the coating film.

  In addition, it is preferable that the radically polymerizable unsaturated group containing compound contains the radically polymerizable unsaturated group containing compound which has a hydroxyl group from a low temperature curability point.

  The radical polymerizable unsaturated group-containing compound preferably has an unsaturated group equivalent of 100 to 5,000 from the viewpoint of low temperature curability and finish of the multilayer coating film. More preferably, it is 500-3,000.

Other components The coating composition of the present invention may further comprise a normal coating material such as a curing catalyst, a thickener, an antifoaming agent, a rust inhibitor, a plasticizer, an organic solvent, a surface conditioner, an anti-settling agent, etc. Additives can be used alone or in combination of two or more.

  The coating composition of the present invention may be either an organic solvent-type coating composition or a water-based coating composition, but is preferably an organic solvent-type coating composition from the viewpoint of storage stability and the like. In the present specification, the water-based coating composition is a coating in which the main component of the solvent is water, and the organic solvent-type coating composition is a coating that does not substantially contain water as a solvent.

  The organic solvent used in the case of the organic solvent type paint is not particularly limited. Specifically, for example, ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl amyl ketone, ethyl isoamyl ketone, diisobutyl ketone, methyl hexyl ketone; ethyl acetate, butyl acetate, methyl benzoate, methyl propionate Ester compounds such as tetrahydrofuran, dioxane and dimethoxyethane; glycol ether compounds such as propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate; aromatic hydrocarbon compounds and aliphatic hydrocarbon compounds Is mentioned.

  The content of each of the above components in the coating composition of the present invention is not particularly limited, but the following range is preferable from the viewpoint of coating stability and coating film performance.

  Although content (solid content) of a compound (A) is not specifically limited, Preferably, it is 1-90 mass parts with respect to 100 mass parts of solid content in a coating composition, More preferably, it is 10-85 mass. Part. These ranges are significant in terms of scratch resistance and weather resistance.

  The content (solid content) of the non-aqueous dispersion resin (B) is not particularly limited, but is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the solid content in the coating composition of the present invention. Yes, more preferably 1.5 to 48 parts by mass. These ranges are significant in terms of the storage stability of the paint and the impact resistance of the coating film.

  Although content (solid content) of a photoinitiator (C) is not specifically limited, Preferably, it is 1-10 mass parts with respect to 100 mass parts of solid content in the coating composition of this invention. More preferably, it is 2 to 6 parts by mass.

  The content (solid content) of the isocyanate compound (D) is preferably 30 parts by mass or less, more preferably 3 to 25 masses with respect to 100 parts by mass of the solid content in the coating composition of the present invention. Part. These ranges are significant in terms of acid resistance and low-temperature curability of the coating film.

  The content (solid content) of the hydroxyl group-containing resin (E) is preferably 70 parts by mass or less, more preferably 5 to 60 with respect to 100 parts by mass of the solid content in the coating composition of the present invention. Part by mass. These ranges are significant in terms of scratch resistance and weather resistance.

  The content (solid content) of the radical polymerizable unsaturated group-containing resin (F) is preferably 30 parts by mass or less with respect to 100 parts by mass of the solid content in the coating composition of the present invention. These ranges are significant in terms of low-temperature curability.

  In the present invention, the ratio of the compound (A) and the non-aqueous dispersion resin (B) in the coating composition is 99/1 to 50 / in mass ratio of the former / the latter based on the total solid content of both components. 50, more preferably 97/3 to 52/48. These ranges are significant in terms of scratch resistance, impact resistance and stain resistance of the coating film.

  Moreover, the compounding ratio of the compound (A), the non-aqueous dispersion resin (B) and the isocyanate compound (D) blended as required is the isocyanate group of the compound (A) and the isocyanate compound (D) blended as necessary. In the case where the total amount of N and the non-aqueous dispersion resin (B) has a hydroxyl group, the range where the equivalent ratio is NCO / OH = 0.20 to 2.80 is preferable, and is 0.25 to 2.00. A range is more preferred. These ranges are significant in terms of scratch resistance and weather resistance of the coating film.

  When the isocyanate compound (D) is contained in the coating composition, the compounding ratio of the compound (A) and the isocyanate compound (D) is such that the isocyanate group that the compound (A) has and the isocyanate group that the isocyanate compound (D) has. The equivalent ratio of NCO of the compound (A) / NCO of the isocyanate compound (D) is preferably 0.10 to 7.50, and more preferably 0.20 to 4.00. These ranges are significant in terms of acid resistance of the coating film.

[Coating film forming method]
The method for forming a coating film by using the coating composition of the present invention comprises forming a base coating film by coating a base coating composition described later on an object to be coated, and coating the coating composition of the present invention on the base coating film. Then, a coating film is formed, and further, irradiation with active energy rays and heating are performed. In addition, since the coating composition of this invention can form the coating film which is excellent in abrasion resistance, impact resistance, and stain resistance, it is preferable to use it as a clear coating applied to the uppermost layer. Hereinafter, the case where the coating composition of the present invention is used as a clear coating is described as a preferred embodiment of the present invention. When the coating composition of the present invention is used as a base coating, it can be carried out according to the following.

The object to be coated is not particularly limited. For example, metal materials such as iron, aluminum, brass, copper, stainless steel, tinplate, galvanized steel, alloyed zinc (Zn-Al, Zn-Ni, Zn-Fe, etc.) plated steel; polyethylene resin, polypropylene resin, acrylonitrile -Butadiene-styrene (ABS) resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, epoxy resin and other plastic materials such as various FRPs; glass, cement, concrete and other inorganic materials; wood A fiber material (paper, cloth, etc.) and the like, among which a metal material and a plastic material are suitable.

  In addition, the use of the object to which the coating film forming method is applied is not particularly limited. For example, an outer plate portion of an automobile body such as a passenger car, a truck, a motorcycle, or a bus; an automobile part; a mobile phone, an audio device, etc. And the like. Among them, the outer plate portion of an automobile body and automobile parts are preferable.

  The object to be coated may be obtained by subjecting the metal surface of the metal material or a vehicle body formed from the metal material to a surface treatment such as phosphate treatment, chromate treatment, zirconium treatment, or complex oxide treatment. Good. Further, the object to be coated may be one obtained by forming various electrodeposition coatings, water-based or organic solvent-type intermediate coatings or cured coatings on the metal material, the vehicle body, etc. Accordingly, preheating may be performed.

  Further, the object to be coated may be an uncured or cured film of an aqueous or organic solvent-type primer coating on the plastic material, and further subjected to preheating (preheating) as necessary. Also good.

  Here, from the viewpoint of saving process and energy saving to reduce the number of times of baking and energy consumption in the heat drying furnace, the above primer coating is not preheated (preheated) using an organic solvent type primer and is applied onto the primer coating. It is desirable to use a water-based paint as the base paint composition. Next, the base coating composition will be described.

Base coating composition The base coating composition contains a resin containing active hydrogen groups and a color pigment. Examples of the active hydrogen group possessed by the resin containing the active hydrogen group include a hydroxyl group, a hydroxyphenyl group, and an amino group. In the present invention, a hydroxyl group-containing resin is preferable from the viewpoint of weather resistance. Examples of the hydroxyl group-containing resin include a hydroxyl group-containing acrylic resin, a hydroxyl group-containing polyester resin, a hydroxyl group-containing polyurethane resin, and a hydroxyl group-containing polyether resin. Of these, a hydroxyl group-containing acrylic resin is preferred from the viewpoint of weather resistance.

  Examples of the hydroxyl group-containing acrylic resin include the hydroxyl group-containing polymerizable unsaturated monomer listed in the above-mentioned “Hydroxyl group-containing resin (E)” and other polymerizable unsaturated monomers copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer. It can be produced by copolymerizing the same monomer with the method described above.

  When used for the base coating composition, the hydroxyl value of the resin having a hydroxyl group is preferably in the range of 0.5 to 200 mgKOH / g. If it is less than 0.5 mgKOH / g, adhesion and hardness are lowered, while if it exceeds 200 mgKOH / g, the water resistance of the resulting multilayer coating film may be lowered, which is not preferable.

  Moreover, when using for a base coating composition, it is preferable that the resin which has a hydroxyl group generally has a weight average molecular weight within the range of 1,000-200,000, especially 2,000-100,000.

  Moreover, when using for a base coating composition, it is preferable that resin which has a hydroxyl group has the glass transition point temperature in the range of 0 degree or more, especially 3-50 degree | times from the point of a weather resistance and an abrasion resistance.

  Examples of the color pigment include aluminum pigments, pearl powder, graphite, bright pigments such as MIO, titanium white, phthalocyanine blue, and carbon black. If necessary, extender pigments may be blended. Although the compounding quantity of a color pigment is not specifically limited, For example, the range of 1-150 mass parts is preferable with respect to 100 mass parts of solid content in a base coating material, More preferably, it is the range of 1-100 mass parts.

  The base coating composition may contain a curing agent. As the curing agent, a compound having a crosslinkable functional group that can react with an active hydrogen group in a resin containing an active hydrogen group is usually used. As such a curing agent, for example, amino resins, polyisocyanate compounds, blocked polyisocyanate compounds and the like can be suitably used. A hardening | curing agent can be used individually or in combination of 2 or more types, respectively.

  Examples of the amino resin include a partial or completely methylolated amino resin obtained by reacting an amino component such as melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and the aldehyde. As the amino resin, a melamine resin is preferable.

  A commercially available product can be used as the melamine resin. Examples of the commercially available products include “Cymel 202”, “Cymel 203”, “Cymel 238”, “Cymel 251”, “Cymel 303”, “Cymel 323”, “ Cymel 324, Cymel 325, Cymel 327, Cymel 350, Cymel 385, Cymel 1156, Cymel 1158, Cymel 1116, Cymel 1130 (Nippon Cytec Industries, Inc.) CYMEL / Cymel is a registered trademark), “Uban 120”, “Uban 20HS”, “Uban 20SE60”, “Uban 2021”, “Uban 2028”, “Uban 28-60” (above, manufactured by Mitsui Chemicals, Ltd. -Van \ U-VAN is a registered trademark).

  Melamine resins can be used alone or in combination of two or more. The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule.

  The blocked polyisocyanate compound is obtained by adding a blocking agent to the isocyanate group of the polyisocyanate compound, and reacts with a hydroxyl group by dissociating the blocking agent upon heating to regenerate the isocyanate group. Can do. The dissociation temperature of the blocking agent is usually within the range of about 60 to about 140 degrees, preferably about 70 to about 120 degrees.

  The content of the curing agent in the base coating composition is from 1 to 70 parts by mass, particularly from 1 to 60 parts by mass with respect to 100 parts by mass in total of the resin containing the active hydrogen group and the curing agent in terms of weather resistance More particularly, it is preferable to be in the range of 1 to 50 parts by mass. In the base coating composition, additives for coatings such as an ultraviolet absorber, a light stabilizer, an antioxidant, a surface conditioner, a pigment dispersant, and a curing catalyst can be blended as necessary. The base coating composition may be either an organic solvent-type coating composition or an aqueous coating composition. From the viewpoint that volatile organic compounds (VOC) in the coating process can be reduced, the base coating composition is preferably an aqueous coating composition.

Formation of base coating film The base coating film is formed by coating a base coating composition on an object to be coated. The base coating composition has a solid content of usually 15% by mass or more, particularly 20 to 35% by mass, and further has a viscosity of 20 to 40 seconds / Ford Cup # 4/20 degrees. It is preferable to adjust within the range.

  The coating method is not particularly limited, and for example, the coating can be performed by air spray, airless spray, rotary atomizer, dip coating, brush or the like. Electrostatic application may be performed during coating. The film thickness of the base coating film formed by applying the base coating composition is usually preferably in the range of 3 to 30 μm, particularly 7 to 25 μm, more particularly 10 to 20 μm based on the cured coating film.

  On the formed base coating film, the clear paint according to the present invention is applied. The base coating film may be cured when the coating composition is applied onto the coating film, or may be uncured.

  Heating is usually performed to cure the base coating film. Examples of the heating conditions include a time of 5 to 30 minutes at a temperature of 80 to 150 ° C. When uncured, preliminary heating (preheating) and air blowing can be performed to lower the volatile content of the base coating film or remove the volatile content. The preheating can be usually performed by directly or indirectly heating the coated object to be coated in a drying furnace at a temperature of 50 to 110 ° C., preferably 60 to 90 ° C. for 1 to 30 minutes.

  Moreover, air blow can be normally performed by spraying the air heated to normal temperature or the temperature of 25 to 80 degreeC on the coating surface of the to-be-coated object.

Formation of clear paint film The method of applying the clear paint is not particularly limited. For example, it can be applied by air spray, airless spray, rotary atomizing coater, dip coating, brush or the like. Electrostatic application may be performed during coating. The coating film thickness is usually 10 to 100 μm, preferably 10 to 50 μm in terms of cured film thickness.

  After coating, preliminary heating (preheating) and air blowing can be performed to reduce the volatile content of the coating film immediately after coating or to remove the volatile content. The preheating can be usually performed by directly or indirectly heating the coated object to be coated in a drying furnace at a temperature of 50 to 110 ° C., preferably 60 to 90 ° C. for 1 to 30 minutes. Moreover, air blow can be normally performed by spraying the air heated to normal temperature or the temperature of 25 to 80 degreeC on the coating surface of the to-be-coated object.

  When curing the clear paint, heating and active energy ray irradiation are performed. The order of heating and active energy ray irradiation is not particularly limited, and active energy ray irradiation may be performed after heating, heating may be performed after active energy ray irradiation, and heating and active energy ray irradiation are performed simultaneously. May be.

  Moreover, when performing said heating and active energy ray irradiation simultaneously, it is good also considering the heat (for example, the heat | fever which a lamp | ramp emits) from the irradiation source of an active energy ray as a heat source. Furthermore, when the active energy ray irradiation is performed after the heating, the active energy ray irradiation may be performed in a state in which the object to be coated is heated (a state having residual heat).

  The heating conditions are not particularly limited. For example, it can be heated at a temperature of 50 to 140 ° C. for 1 to 60 minutes. In the present invention, the clear paint has thermosetting properties at a low temperature, and it is desired to have scratch resistance, weather resistance, stain resistance, impact resistance, etc. without heating at a high temperature (for example, 100 ° C. or higher). Therefore, it is preferable to heat at a temperature of 50 to 100 ° C. In addition, since the clear paint is cured even by active energy rays, it is preferable to heat for 1 to 30 minutes because desired performance such as scratch resistance and weather resistance can be obtained without heating for a long time. It is more preferable to heat for 20 minutes.

Examples of the active energy ray include ultraviolet light, visible light, and laser light (near infrared light, visible light laser, ultraviolet laser, etc.). Its dose is usually 100~5,000mJ / cm ^2, preferably preferably in the range of 300~3,000mJ / cm ^2. As the active energy ray irradiation source, conventionally used ones such as ultra-high pressure, high pressure, medium pressure, low pressure mercury lamp, FusionUV electrodeless lamp, chemical lamp, carbon arc lamp, xenon lamp, metal halide A light source obtained from each light source such as a lamp, a fluorescent lamp, a tungsten lamp, and sunlight, a light beam in a visible region cut by an ultraviolet cut filter, and various lasers having an oscillation line in the visible region can be used. In addition, a pulsed emission type active energy ray irradiation apparatus can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Part” and “%” indicate “part by mass” and “% by mass” unless otherwise specified.

Production of hydroxyl-containing acrylic resin emulsion (Production Example 1) Hydroxyl-containing acrylic resin emulsion 130 parts of deionized water and Aqualon KH-10 (Note 1) in a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device ) 0.52 part was charged, stirred and mixed in a nitrogen stream, and heated to 80 ° C. Next, 1% of the total amount of the following monomer emulsion (1) and 5.3 parts of a 6% aqueous ammonium persulfate solution were introduced into the reaction vessel and maintained at 80 ° C. for 15 minutes. Then, the remaining monomer emulsion (1) was dripped in the reaction container hold | maintained at the same temperature over 3 hours, and it age | cure | ripened for 1 hour after completion | finish of dripping. Thereafter, the following monomer emulsion (2) was added dropwise over 1 hour and aged for 1 hour. Thereafter, 40 parts of a 5% dimethylethanolamine aqueous solution was gradually added to the reaction vessel and cooled to 30 ° C. The obtained reaction solution was discharged while being filtered through a 100 mesh nylon cloth, and the average particle size was 100 nm [submicron particle size distribution measuring device “COULTER N4 type” (manufactured by Beckman Coulter, Inc.) Diluted and measured at 20 ° C. A hydroxyl group-containing acrylic resin emulsion having a solid content of 30%, an acid value of 33 mgKOH / g, and a hydroxyl value of 25 mgKOH / g was obtained.

  (Note 1) Aqualon KH-10: Polyoxyethylene alkyl ether sulfate ester ammonium salt: 97% active ingredient manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

  Monomer emulsion (1): 42 parts deionized water, 0.72 parts Aqualon KH-10 (see Note 1), 2.1 parts methylenebisacrylamide, 2.8 parts styrene, 16.1 parts methyl methacrylate, ethyl acrylate 28 parts and 21 parts of n-butyl acrylate were mixed and stirred to obtain a monomer emulsion (1).

  Monomer emulsion (2): Deionized water 18 parts, Aqualon KH-10 (see Note 1) 0.31 parts, ammonium persulfate 0.03 parts, methacrylic acid 5.1 parts, 2-hydroxyethyl acrylate 5.1 parts Then, 3 parts of styrene, 6 parts of methyl methacrylate, 1.8 parts of ethyl acrylate and 9 parts of n-butyl acrylate were mixed and stirred to obtain a monomer emulsion (2).

Production of hydroxyl group-containing polyester resin (Production Example 2) Production of hydroxyl group-containing polyester resin solution (PE1) In a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and water separator, 109 parts of trimethylolpropane, 1 , 6-hexanediol, 126 parts of hexahydrophthalic anhydride and 120 parts of adipic acid were added and the temperature was raised between 160 ° C. and 230 ° C. over 3 hours, followed by condensation at 230 ° C. for 4 hours. Next, in order to add a carboxyl group to the obtained condensation reaction product, 38.3 parts of trimellitic anhydride was further added, reacted at 170 ° C. for 30 minutes, and then diluted with 2-ethyl-1-hexanol. Thus, a hydroxyl group-containing polyester resin solution (PE1) having an acid value of 46 mgKOH / g, a hydroxyl value of 150 mgKOH / g, a solid content of 70%, and a weight average molecular weight of 6,400 was obtained.

(Production Example 3) Production of hydroxyl group-containing polyester resin solution (PE2) A hydroxyl group-containing polyester was produced in the same manner as in Production Example 2 except that 2-ethyl-1-hexanol as a dilution solvent was changed to ethylene glycol mono-n-butyl ether. A resin solution (PE2) was obtained.

Production of glitter pigment concentrate (Production Example 4) Production of glitter pigment concentrate (P1) 19 parts of aluminum pigment paste “GX-180A” (Asahi Kasei Metals Co., Ltd., metal content 74%) in a stirring and mixing vessel , 35 parts of 2-ethyl-1-hexanol, 8 parts of a phosphoric acid group-containing resin solution (Note 2) and 0.2 part of 2- (dimethylamino) ethanol were mixed uniformly to give a bright pigment concentrate (P1) Got.

  (Note 2) Phosphate group-containing resin solution: A mixed solvent of 27.5 parts of methoxypropanol and 27.5 parts of isobutanol is placed in a reaction vessel equipped with a thermometer, a thermostat, a stirrer, a reflux condenser and a dropping device. 6. Heat to 110 ° C., 25 parts of styrene, 27.5 parts of n-butyl methacrylate, 20 parts of “isostearyl acrylate” (trade name, Osaka Organic Chemical Industries, Ltd., branched higher alkyl acrylate), 4-hydroxybutyl acrylate Mixture 121.5 consisting of 5 parts, 15 parts of a phosphoric acid group-containing polymerizable monomer (Note 3), 12.5 parts of 2-methacryloyloxyethyl acid phosphate, 10 parts of isobutanol and 4 parts of t-butylperoxyoctanoate Is added to the above mixed solvent over 4 hours, and 0.5 parts of t-butylperoxyoctanoate is added. A mixture of finely Isopropanol 20 parts was added dropwise for 1 hour. Thereafter, the mixture was aged and stirred for 1 hour to obtain a phosphate group-containing resin solution having a solid content of 50%. The acid value due to the phosphoric acid group of this resin was 83 mgKOH / g, the hydroxyl value derived from 4-hydroxybutyl acrylate was 29 mgKOH / g, and the weight average molecular weight was 10,000.

  (Note 3) Phosphoric acid group-containing polymerizable monomer: Into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device, put 57.5 parts of monobutyl phosphate and 41 parts of isobutanol and raise the temperature to 90 ° C. After warming, 42.5 parts of glycidyl methacrylate was added dropwise over 2 hours, followed by stirring and aging for another hour. Thereafter, 59 parts of isopropanol was added to obtain a phosphate group-containing polymerizable monomer solution having a solid content of 50%. The acid value due to the phosphate group of the obtained monomer was 285 mgKOH / g.

(Production Example 5) Production of glitter pigment concentrate (P2) The same glitter as in Production Example 4 except that 35 parts of 2-ethyl-1-hexanol was changed to 35 parts of ethylene glycol mono-n-butyl ether. A pigment concentrate (P2) was obtained.

Production of Base Paint Composition (Production Example 6) Production of 1 150 parts of the hydroxyl group-containing acrylic resin emulsion obtained in Production Example 1, 64 parts of the hydroxyl group-containing polyester resin solution (PE1) obtained in Production Example 2, and the glitter pigment concentrate obtained in Production Example 4 (P1) ) 62 parts and 12.5 parts of “Cymel 202” (trade name, manufactured by Nippon Cytec Industries, Inc., melamine resin, solid content 80%) were mixed uniformly, and deionized water and 2- (dimethylamino) ethanol were further added. In addition, the base coating composition No. having a pH of 8.0 and a solid content of 23% was used. 1 was obtained.

(Production Example 7) Base coating composition No. Production of 2 150 parts of the hydroxyl group-containing acrylic resin emulsion obtained in Production Example 1, 64 parts of the hydroxyl group-containing polyester resin solution (PE2) obtained in Production Example 3, and the bright pigment concentrate (P2) obtained in Production Example 5 ) 62 parts and 12.5 parts of “Cymel 202” were further mixed, and further deionized water and 2- (dimethylamino) ethanol were added to form a base coating composition No. having a pH of 8.0 and a solid content of 23%. 2 was obtained.

Production of Compound (A) (Production Example 8) Production of Compound (A-1) Solution In a reaction vessel equipped with a stirrer, thermometer, reflux condenser and dropping device, 33.8 parts of methoxypropyl acetate, hexamethylene diisocyanate A mixture of 50.0 parts of an isocyanurate cycloadduct (NCO content 21%), 0.02 part of dibutyltin dilaurate, and 0.2 part of hydroquinone monomethyl ether was charged. The mixture was heated to 50 ° C. with stirring. Subsequently, Plaxel FA-2D (trade name, manufactured by Daicel Chemical Industries, General Formula (I), R ¹ is a hydrogen atom, and R ² is an ethylene group while the temperature of the mixture does not exceed 60 ° C. , 85.2 parts of caprolactone-modified hydroxyethyl acrylate wherein n is 2) is added dropwise over 8 hours, and the mixture is further stirred at 60 ° C. for 1 hour to obtain a compound (A-1) solution having a solid content of 80%. It was. The isocyanate equivalent of the obtained compound (A-1) was 2,731, the unsaturated group equivalent was 546, and the weight average molecular weight was 1,366.

(Production Examples 9 to 16)
In Production Example 8, compounds (A-2) to (A-7) and (A′-1) and (A′−) were obtained in the same manner as in Production Example 8, except that the formulation was changed to the formulation shown in Table 1. 2) A solution was obtained. Table 1 shows the isocyanate equivalent, unsaturated group equivalent, and weight average molecular weight of the obtained compound.

(Note 4) Plaxel FA-1: trade name, manufactured by Daicel Chemical Industries, caprolactone-modified hydroxyethyl acrylate in which R ¹ is a hydrogen atom, R ² is an ethylene group, and n is 1 in the general formula (I).

(Note 5) Plaxel FM-3: trade name, manufactured by Daicel Chemical Industries, caprolactone-modified hydroxyethyl methacrylate in which R ¹ is a methyl group, R ² is an ethylene group, and n is 3 in the general formula (I).

Production of non-aqueous dispersion resin (B) (Production Example 17) Production of dispersion stabilizer [I] In a reaction vessel, 69 parts of xylene was blended and heated to 125 ° C., and the following monomers were contained therein. And the mixture of the polymerization initiator was dripped over 4 hours, and it age | cure | ripened for 2 hours after dripping, and obtained the acrylic resin varnish.
2-ethylhexyl methacrylate 30 parts glycidyl methacrylate 60 parts n-butyl acrylate 10 parts t-butyl peroxide 4.6 parts The resulting acrylic resin varnish had a solid content of 60% and the number average molecular weight of the resin was about 3,800. It was.

  To 167 parts of the acrylic resin varnish 60% solid content obtained as described above, 0.9 part of acrylic acid, 0.01 part of 4-tert-butylpyrocatechol and 0.1 part of dimethylaminoethanol were added at 125 ° C. For 3 hours to obtain a dispersion stabilizer solution [I] having a solid content of about 60%. The number of polymerizable double bonds introduced into the dispersion stabilizer was about 1.0 on average per molecule from the measurement of the resin acid value.

(Production Example 18) Production of Dispersion Stabilizer [II] 69 parts of xylene was blended in a reaction vessel, heated to 125 ° C and held, and a mixture of the following monomer and polymerization initiator was added to this over 4 hours. After the dropping, aging was performed for 2 hours to obtain an acrylic resin varnish (α).
2-ethylhexyl methacrylate 30 parts 2-hydroxyethyl acrylate 30 parts n-butyl acrylate 40 parts t-butyl peroxide 4.6 parts The resulting acrylic resin varnish (α) has a solid content of 60%, and the number average molecular weight of the resin is About 3,800.

  To 167 parts of 60% solid acrylic resin varnish (α) obtained as described above, 2.6 parts of 2-isocyanatoethyl methacrylate and 0.01 part of 4-tert-butylpyrocatechol were added at 125 ° C. The mixture was stirred for 3 hours to obtain a dispersion stabilizer solution [II] having a solid content of about 60%. The number of polymerizable double bonds introduced into the dispersion stabilizer was about 1.0 on average per molecule from the measurement of the resin acid value.

(Production Example 19) Production of Dispersion Stabilizer [III] To 167 parts of the acrylic resin varnish (α) obtained in Production Example 18, 2.6 parts of γ-methacryloyloxypropyltrimethoxysilane and 4-tert-butylpyrocatechol 0.01 part was added and stirred at 125 ° C. for 3 hours to obtain a dispersion stabilizer solution [III] having a solid content of about 60%. The number of polymerizable double bonds introduced into the dispersion stabilizer was about 1.0 on average per molecule from the measurement of the resin acid value.

(Production Example 20) Production of non-aqueous dispersion resin (B-1)
In a reaction vessel, 83.3 parts of a dispersion stabilizer [I] having a solid content of about 60% obtained in Production Example 17 above, 100 parts of heptane and 16.2 parts of xylene were blended, and the following monomers and A mixture of polymerization initiators was added dropwise over 4 hours, followed by aging for 2 hours to obtain a fine particle dispersion having a solid content of 50%.
Styrene 10 parts methyl methacrylate 24 parts methyl acrylate 10 parts 2-hydroxyethyl acrylate 56 parts 2,2′-azobisisobutyronitrile 1.5 parts The particle size of the dispersed fine particles of the obtained fine particle dispersion is the average particle size [Submicron particle size distribution measuring device “COULTER N4 type” (manufactured by Beckman Coulter, Inc.)] (hereinafter the same), about 250 nm. In a separate reaction vessel, 200 parts of the fine particle dispersion having a solid content of about 50% and 10 parts of acrylic acid obtained as described above were charged and reacted at reflux temperature for 6 hours to obtain a dispersion stabilizer part of the dispersed fine particles. A non-aqueous dispersion resin (B-1) (solid content of about 52%) having a polymerizable unsaturated group introduced therein was obtained. The polymerizable unsaturated group equivalent in the resin of the obtained polymer fine particle dispersion was 769.

(Production Example 21) Production of non-aqueous dispersion resin (B-2) In a reaction vessel, 83.3 parts of dispersion stabilizer (II) having a solid content of about 60% obtained in Production Example 18 above, 100 parts of heptane, and 16.2 parts of xylene was blended, and a mixture of the following monomer and polymerization initiator was added dropwise at reflux temperature over 4 hours, followed by aging for 2 hours to obtain a fine particle dispersion having a solid content of about 50%. .
Styrene 10 parts methyl methacrylate 22 parts methyl acrylate 10 parts methacrylic acid 2 parts glycidyl methacrylate 56 parts 2,2′-azobisisobutyronitrile 1.5 parts The diameter was about 250 nm.

  In a separate reaction vessel, 200 parts of the fine particle dispersion having a solid content of about 50% and 10 parts of 2-isocyanatoethyl methacrylate obtained as described above were charged, and reacted at reflux temperature for 6 hours. A non-aqueous dispersion type resin (B-2) (solid content: about 52%) in which a polymerizable double bond was introduced into the dispersion stabilizer portion was obtained. The polymerizable unsaturated group equivalent in the resin of the obtained polymer fine particle dispersion was 1,250.

(Production Example 22) Production of non-aqueous dispersion type resin (B-3) In a reaction vessel, 83.3 parts of a dispersion stabilizer [III] of about 60% solid content obtained in Production Example 19 above, 100 parts of heptane, and 16.2 parts of xylene was blended, and a mixture of the following monomer and polymerization initiator was added dropwise at reflux temperature over 4 hours, followed by aging for 2 hours to obtain a fine particle dispersion having a solid content of about 50%. .
Styrene 10 parts methyl methacrylate 22 parts methyl acrylate 10 parts glycidyl methacrylate 56 parts 2,2′-azobisisobutyronitrile 1.5 parts The average particle diameter of the dispersed fine particles of the obtained fine particle dispersion is about 250 nm. Met.

  In a separate reaction vessel, 200 parts of the fine particle dispersion having a solid content of about 50% obtained as described above and 10 parts of γ-methacryloyloxypropyltrimethoxysilane were charged and reacted at reflux temperature for 6 hours to disperse. A non-aqueous dispersion type resin (B-3) (solid content: about 52%) in which a polymerizable double bond was introduced into the dispersion stabilizer portion of the fine particles was obtained. The polymerizable unsaturated group equivalent in the obtained polymer fine particle dispersion resin was 1,250.

(Production Example 23) Production of non-aqueous dispersion type resin (B-4) (Production of non-aqueous dispersion type resin having no polymerizable unsaturated group in the dispersion stabilizer portion)
In a reaction vessel, 83.3 parts of a dispersion stabilizer solution [I] having a solid content of about 60% obtained in Production Example 17 above, 100 parts of heptane and 16.2 parts of xylene were blended, and the following monomers were added at reflux temperature. And the mixture of the polymerization initiator was dripped over 4 hours, and it aged 2 hours after dripping, and obtained non-aqueous dispersion-type resin (B-4) about 50% of solid content.
Styrene 10 parts methyl methacrylate 24 parts methyl acrylate 10 parts 2-hydroxyethyl acrylate 56 parts 2,2′-azobisisobutyronitrile 1.5 parts The particle size of the dispersed fine particles of the obtained fine particle dispersion is the average particle size And about 250 nm.

Production of hydroxyl group-containing resin (E) (Production Example 24) Production of hydroxyl group-containing acrylic resin solution (E-1)
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device was charged with 80 parts of xylene and stirred at 100 ° C. while blowing nitrogen gas, and styrene 10 parts methyl methacrylate 40 parts i-butyl methacrylate. 8 parts n-butyl acrylate 20 parts 2-hydroxyethyl acrylate 20 parts acrylic acid 2 parts 2,2′-azobisisobutyronitrile A mixture of 4 parts is added dropwise at a uniform rate over 3 hours, and 2 parts at the same temperature. Aged for hours. Thereafter, a mixture of 10 parts of xylene and 0.5 part of 2,2′-azobisisobutyronitrile was added dropwise to the reaction vessel over 1 hour, and aged for 1 hour after completion of the addition, containing a hydroxyl group having a solid content of 55%. An acrylic resin solution (E-1) was obtained. The resulting hydroxyl group-containing acrylic resin had an acid value of 15.6 mgKOH / g, a hydroxyl value of 96.6 mgKOH / g, a weight average molecular weight of 20,000, and a glass transition temperature of 14.6 ° C.

(Production Example 25) Production of hydroxyl group-containing acrylic resin solution (E-2)
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device was charged with 80 parts of xylene and stirred at 100 ° C. while blowing nitrogen gas, and styrene 10 parts methyl methacrylate 40 parts i-butyl methacrylate. 8 parts n-butyl acrylate 10 parts 2-hydroxyethyl acrylate 30 parts acrylic acid 2 parts 2,2'-azobisisobutyronitrile A mixture of 4 parts is added dropwise at a uniform rate over 3 hours, and 2 parts at the same temperature. Aged for hours. Thereafter, a mixture of 10 parts of xylene and 0.5 part of 2,2′-azobisisobutyronitrile was added dropwise to the reaction vessel over 1 hour, and aged for 1 hour after completion of the addition, containing a hydroxyl group having a solid content of 55%. An acrylic resin solution (E-2) was obtained. The resulting hydroxyl group-containing acrylic resin had an acid value of 15.6 mg KOH / g, a hydroxyl value of 144.9 mg KOH / g, a weight average molecular weight of 20,000, and a glass transition temperature of 13.6 ° C.

(Production Example 26) Production of hydroxyl group-containing acrylic resin (E-3) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 80 parts of xylene were charged and stirred at 100 ° C while blowing nitrogen gas. Styrene 10 parts methyl methacrylate 33 parts i-butyl methacrylate 8 parts n-butyl acrylate 27 parts 2-hydroxyethyl acrylate 20 parts acrylic acid 2 parts 2,2′-azobisisobutyronitrile 4 parts Was dripped at a uniform rate over 3 hours and further aged at the same temperature for 2 hours. Thereafter, a mixture of 10 parts of xylene and 0.5 part of 2,2′-azobisisobutyronitrile was added dropwise to the reaction vessel over 1 hour, and aged for 1 hour after completion of the addition, containing a hydroxyl group having a nonvolatile content of 55%. An acrylic resin (E-3) solution was obtained. The obtained hydroxyl group-containing acrylic resin (E-3) had an acid value of 15.6 mgKOH / g, a hydroxyl value of 96.6 mgKOH / g, a weight average molecular weight of 20,000, and a glass transition temperature of 3.9 ° C. It was.

(Production Example 27) Production of hydroxyl group-containing acrylic resin (E-4) In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 80 parts of xylene were charged and stirred at 100 ° C while blowing nitrogen gas. In this, a mixture of styrene 20 parts methyl methacrylate 40 parts i-butyl methacrylate 18 parts 2-hydroxyethyl acrylate 20 parts acrylic acid 2 parts 2,2′-azobisisobutyronitrile 4 parts uniformly over 3 hours The solution was added dropwise at a rate and aged at the same temperature for 2 hours. Thereafter, a mixture of 10 parts of xylene and 0.5 part of 2,2′-azobisisobutyronitrile was added dropwise to the reaction vessel over 1 hour, and aged for 1 hour after completion of the addition, containing a hydroxyl group having a nonvolatile content of 55%. An acrylic resin (E-4) solution was obtained. The obtained hydroxyl group-containing acrylic resin (E-4) had an acid value of 15.6 mgKOH / g, a hydroxyl value of 96.6 mgKOH / g, and a weight average molecular weight of 20,000. The glass transition temperature was 45.6 ° C.

(Production Example 28) Production of hydroxyl group-containing acrylic resin (E-5) In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and dropping device, 80 parts of xylene were charged and stirred at 100 ° C while blowing nitrogen gas. In this, a mixture of styrene 10 parts methyl methacrylate 20 parts i-butyl methacrylate 8 parts n-butyl acrylate 40 parts 2-hydroxyethyl acrylate 20 parts acrylic acid 2 parts 2,2′-azobisisobutyronitrile 4 parts Was dripped at a uniform rate over 3 hours and further aged at the same temperature for 2 hours. Thereafter, a mixture of 10 parts of xylene and 0.5 part of 2,2′-azobisisobutyronitrile was added dropwise to the reaction vessel over 1 hour, and aged for 1 hour after completion of the addition, containing a hydroxyl group having a nonvolatile content of 55%. An acrylic resin (E-5) solution was obtained. The obtained hydroxyl group-containing acrylic resin (E-5) had an acid value of 15.6 mgKOH / g, a hydroxyl value of 96.6 mgKOH / g, and a weight average molecular weight of 20,000. The glass transition temperature was -14.0 ° C.

Production of urethane acrylate (F-1) (Production Example 29)
In a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and air blowing device,
Isophorone diisocyanate 888 parts 2-hydroxyethyl acrylate 464 parts Hydroquinone monomethyl ether 0.7 part was charged, and the temperature was raised to 80 ° C. while blowing air into the reaction vessel. After confirming that all of the acrylate had reacted,
Pentaerythritol 136 parts Butyl acetate 372 parts Dibutyltin dilaurate 0.2 part is added and kept at 80 ° C, and after confirming that all the isophorone diisocyanate has reacted substantially, it is cooled and urethane acrylate having a non-volatile content of 80% A resin (F-1) solution was obtained. Unsaturated group equivalent of the obtained urethane acrylate resin (F-1) was 372.

Production of coating composition (Example 1) Coating composition No. Production of 1 67.13 parts of the 80% solution of the compound (A-1) obtained in Production Example 8 (solid content 53.7 parts), non-aqueous dispersion type resin (B-1) 52 obtained in Production Example 20 % Solution 89.0 parts (solid content 46.3 parts), Darocur (registered trademark) 1173 (trade name, manufactured by Merck Japan, photopolymerization initiator), and TINUVIN (registered trademark) 384 (trade name) , Ciba Specialty Chemicals Co., Ltd., UV absorber) was uniformly mixed, and the solid content was adjusted with butyl acetate. 1 was obtained.

  Coating composition No. The equivalent ratio of the total amount of the isocyanate groups (NCO) of the component (A) in 1 and the hydroxyl group (OH) of the component (B) is NCO / OH = 0.11.

(Examples 2 to 11 and Comparative Examples 1 to 5) 2-No. 16
In Example 1, the composition of each component was changed to the composition shown in Table 2, and in the same manner as Example 1, the coating composition No. 2-No. 16 was obtained. In addition, the compounding quantity of Table 2 shows the compounding quantity of solid content.

  (Note 6) “-” indicates that an isocyanate group was not confirmed.

(Example 12) Coating composition No. Production of 17 Compound (A-1) 80% solution obtained in Production Example 8 (63.9 parts) (solid content 51.1 parts), Non-aqueous dispersion resin (B-1) 52 obtained in Production Example 20 % Solution 84.8 parts (solid content 44.1 parts), Darocur® 1173 3.0 parts, hexamethylene diisocyanate isocyanurate cycloadduct (NCO content 21%) 4.8 parts, and TINUVIN ( (Registered trademark) 384 was uniformly mixed, and butyl acetate was further added so that the solid content was 50%. 17 was obtained.

  Coating composition No. The equivalent ratio of the total amount of isocyanate groups (NCO) in component (A) and component (D) in 17 to the hydroxyl group (OH) in component (B) is NCO / OH = 0.28, and component (A) The equivalent ratio of the isocyanate group (NCO) possessed by and the isocyanate group (NCO) possessed by the component (D) is NCO of the component (A) / NCO of the component (D) = 0.65.

(Examples 13 to 23, Comparative Examples 6 to 9) Coating composition No. 18-No. Production of No. 32 In Example 12, except that the blending of each component was changed to the blending shown in Table 3, the coating composition No. 50 having a solid content of 50% in Production Examples 50 to 64 was prepared in the same manner as in Example 12. 18-No. 32 was obtained. In addition, the compounding quantity of Table 3 shows the compounding quantity of solid content.

(Example 24) Coating composition No. 33
Compound (A-1) 80% solution 29.8 parts (solid content 23.8 parts) obtained in Production Example 8 and non-aqueous dispersion type resin (B-1) 52% solution 9 obtained in Production Example 20 9 2 parts (solid content 4.8 parts), DAROCURE (registered trademark) 1173 3.0 parts, hexamethylene diisocyanate isocyanurate cycloadduct (NCO content 21%) 11.9 parts, obtained in Production Example 24 Hydroxyl-containing resin (E-1) 80% solution 74.4 parts (solid content 59.5 parts) and TINUVIN (registered trademark) 384 2.0 parts are mixed uniformly, and the solid content is further 50%. By adding butyl acetate, the coating composition no. 33 was obtained. Coating composition No. The equivalent ratio of the total amount of isocyanate groups (NCO) in component (A) and component (D) in 33 to the hydroxyl group (OH) in component (B) is NCO / OH = 0.66, and component (A) The equivalent ratio of the isocyanate group (NCO) of the component (D) to the isocyanate group (NCO) of the component (D) is NCO of the component (A) / NCO of the component (D) = 0.12.

(Examples 25-44, Comparative Examples 10-13) Coating composition No. 34-57
In Example 24, a coating composition having a solid content of 50% in Examples 25 to 44 and Comparative Examples 10 to 13 was used in the same manner as in Example 24 except that the composition of each component was as shown in Tables 4 and 5. No. 34-57 were obtained. In addition, the compounding quantity of Table 4 and Table 5 shows the compounding quantity of solid content.

(Example 45) Coating composition No. 58
Compound (A-1) 80% solution 25.6 parts (solid content 20.5 parts) obtained in Production Example 8 and non-aqueous dispersion type resin (B-1) 52% solution 5 obtained in Production Example 17 0.03 (solid content 2.6 parts), Darocur (registered trademark) 1173 3.0 parts, hexamethylene diisocyanate isocyanurate cycloadduct (NCO content 21%) 10.3 parts, obtained in Production Example 24 Hydroxyl-containing resin (E-1) 80% solution 64.1 parts (solid content 51.3 parts), TINUVIN (registered trademark) 384 2.0 parts, urethane acrylate resin (F-1) obtained in Production Example 29 19.3 parts of an 80% solution (15.4 parts of non-volatile content) were uniformly mixed, and butyl acetate was further added so that the solid content was 50%. 58 was obtained. Coating composition No. 58, the equivalent ratio of the total amount of isocyanate groups (NCO) of component (A) and component (D) to hydroxyl group (OH) of component (B) is NCO / OH = 0.70, and component (A) The equivalent ratio of the isocyanate group (NCO) of the component (D) to the isocyanate group (NCO) of the component (D) is NCO of the component (A) / NCO of the component (D) = 0.12.

(Examples 46-77, Comparative Examples 14-17) Coating composition No. 59-94
In Example 45, the coating composition having a solid content of 50% in Examples 46 to 77 and Comparative Examples 14 to 17 was used in the same manner as in Example 45 except that the composition of each component was as shown in Tables 6 and 7. No. 59-94 were obtained. In addition, the compounding quantity of Table 6 and Table 7 shows the compounding quantity of solid content.

Preparation of coating material A Cold- rolled steel sheet (JIS G3020, size 400 × 300 × 0.8 mm) subjected to degreasing and zinc phosphate treatment and cationic electrodeposition coating “ELECRON GT-10” (trade name: manufactured by Kansai Paint Co., Ltd.) An epoxy resin polyamine-based cationic resin using a block polyisocyanate compound as a curing agent) is electrodeposited so as to have a film thickness of 20 μm based on the cured coating film, and heated at 170 ° C. for 20 minutes to be crosslinked and cured. An electrodeposition coating was obtained.

  On the obtained electrodeposition coating surface, an intermediate coating “Lugabake TP-65-2 (white coating color)” (manufactured by Kansai Paint Co., Ltd., polyester resin / melamine resin type, organic solvent type) is cured by air spray. Was coated to a film thickness of 30 μm, heated at 140 ° C. for 30 minutes to be crosslinked and cured, and a coated plate on which an intermediate coating film was formed was designated as an article A to be coated.

Preparation of Coating Object B Polypropylene NX-280AK (manufactured by Mitsubishi Oil Chemical Co., Ltd., plate thickness 3.2 mm) was subjected to trichloroethane vapor degreasing for 1 minute and then dried at 80 ° C. for 10 minutes. Next, “SOFLEX No. 1000” (manufactured by Kansai Paint Co., Ltd., polyolefin-containing conductive organic solvent primer primer) was applied as a primer with a dry film thickness of 15 μm and set at room temperature for 3 minutes to prepare an article to be coated.

Preparation of article C Polypropylene NX-280AK (manufactured by Mitsubishi Oil Chemical Co., Ltd., plate thickness: 3.2 mm) was subjected to trichloroethane vapor degreasing for 1 minute and then dried at 80 ° C. for 10 minutes. Next, “ASCALEX # 2850” (trade name, manufactured by Kansai Paint Co., Ltd., polyolefin-containing conductive water-based primer paint) was applied as a primer with a dry film thickness of 15 μm, and setting was performed at room temperature for 5 minutes to prepare an article to be coated.

Preparation of article D Polypropylene NX-280AK (manufactured by Mitsubishi Oil Chemical Co., Ltd., plate thickness: 3.2 mm) was subjected to trichloroethane vapor degreasing for 1 minute and then dried at 80 ° C. for 10 minutes. Next, “Ascalex # 2850” (trade name, manufactured by Kansai Paint Co., Ltd., polyolefin-containing conductive water-based primer paint) is applied as a primer with a dry film thickness of 15 μm and pre-heated at 80 ° C. for 3 minutes (preheating) to be coated. It was a thing.

Method for forming multilayer coating film (Example 78)
The base coating composition No. obtained in Production Example 6 was applied to the article A to be coated. 1 was coated using a rotary atomizing coating machine so that the dry film thickness was 15 μm, and preheated at 80 ° C. for 3 minutes. Subsequently, the coating composition No. obtained in Example 1 was used. 1 was used as a clear paint, and air spray coating was performed so that the dry film thickness was 20 μm. Then, after preheating at 50 degreeC for 3 minute (s), the active energy ray was irradiated with the irradiation amount of 1,500 mJ / cm < ² > using the ultra high pressure mercury lamp. Subsequently, it was dried at 90 ° C. for 10 minutes to obtain a test plate.

  The number of heating steps until preparation of the test plate was 5 times (total of pre-heated and heat-dried electrodeposition coating, intermediate coating, base coating, and clear coating). Table 8 shows the evaluation results used for the evaluation of the obtained test plate.

(Examples 79-166, Comparative Examples 18-34)
In Example 78, a test plate was prepared in the same manner as in Example 78 except that the base coating composition and the coating composition were changed to the base coating composition and the coating composition described in Tables 8 to 13, and were used for various evaluations. Provided. The evaluation results are shown in Tables 8 to 13.

Examination results of articles B to D (Examples 167, 176, 185)
“Soflex # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object B to have a dry film thickness of 15 μm. Was electrostatically coated and set at room temperature for 3 minutes.

Next, the coating composition No. obtained in Example 48 was used. 61 was used as a clear paint and air spray coating was applied so that the dry film thickness was 20 μm. Subsequently, after preheating (preheating) at 50 ° C. for 3 minutes, an active energy ray was irradiated with an irradiation amount of 1,500 mJ / cm ² using an ultrahigh pressure mercury lamp. Subsequently, it was dried at 90 ° C. for 10 minutes to obtain a test plate (Example 167).

  Coating composition No. The coating composition No. obtained in Example 52 instead of No. 61 was used. A test plate was obtained in the same manner as in Example 167 except that 65 was used (Example 176). Coating composition No. The coating composition No. obtained in Example 53 instead of No. 61 was used. A test plate was obtained in the same manner as in Example 167 except that 66 was used (Example 185).

(Examples 168, 177, 186)
“Soflex # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object B to have a dry film thickness of 15 μm. And pre-heated (preliminary heating) at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 169, 178, 187)
The base coating composition No. obtained in Production Example 6 was applied to the article B to be coated. 1 was electrostatically coated so that the dry film thickness was 15 μm, and preheated (preliminary heating) at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 170, 179, 188)
A “SOFLEX # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object C to have a dry film thickness of 15 μm. Was electrostatically coated and set at room temperature for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 171, 180, 189)
A “SOFLEX # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object C to have a dry film thickness of 15 μm. And pre-heated (preliminary heating) at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 172, 181, 190)
The base coating composition No. obtained in Production Example 6 was applied to the article C to be coated. 1 was electrostatically coated so that the dry film thickness was 15 μm, and preheating (preheating) was performed at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 173, 182 and 191)
“Soflex # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object D to have a dry film thickness of 15 μm. Was electrostatically coated and set at room temperature for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 174, 183, 192)
“Soflex # 420 Silver” (trade name, polyester urethane-based one-component organic solvent-based metallic paint manufactured by Kansai Paint Co., Ltd.) as a base coating composition is applied to the object D to have a dry film thickness of 15 μm. And pre-heated (preliminary heating) at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps.

(Examples 175, 184, 193)
The base coating composition No. obtained in Production Example 6 was applied to the article D to be coated. 1 was electrostatically coated so as to have a dry film thickness of 15 μm, and preheating (preheating) was performed at 80 ° C. for 3 minutes. A test plate was obtained in the same manner as in Examples 167, 176 and 185 except for these steps. Table 14 shows the paint contents and test results of Examples 167 to 193.

Test method (Note 7) Solvent resistance:
Apply a load of about 1 kg / cm ^{2 to} the coating surface of the test plate with gauze soaked in acetone and reciprocate between about 5 cm length until a mark is made. The solvent resistance was evaluated according to the following criteria:
S: No trace even after 200 round trips A: No trace after 100-200 round trips B: No trace after 50-99 round trips C: No trace after 49 round trips

(Note 8) Adhesion:
After making 100 2mm x 2mm gobang eyes on the coating film according to JIS K 5600-5-6 (1990) on the coating surface of the test plate, sticking an adhesive tape on the surface and peeling it off rapidly, The number of goby eye coatings remaining on the paint surface was evaluated:
S: Remaining number / total number = 100/100, no edge missing A: Remaining number / total number = 100/100, no edge missing B: Remaining number / total number = 99 to 90/100 C: Remaining number / total number = 89 or less / 100.

(Note 9) Finishability:
The finish was evaluated for each test plate by the following visual evaluation and gloss measurement:
<Visual evaluation>
Each test plate was visually observed, and the degree of occurrence of metallic unevenness was evaluated according to the following criteria:
S: Almost no metallic unevenness is observed and the coating film has an extremely excellent appearance. A: Although metallic unevenness is slightly observed, the coating film has an excellent coating appearance. B: The metallic unevenness is recognized and the coating film appearance is slightly inferior. C: Many metallic irregularities are observed, and the coating film appearance is poor.
<Gloss measurement>
The glossiness of each coated surface was measured according to the specular glossiness (60 degrees) of JIS K5600-4-7 (1999). The measured gloss was evaluated according to the following criteria:
S: Specular gloss is 90 or more A: Specular gloss is 70 or more and less than 90 B: Specular gloss is 50 or more and less than 70 C: Specular gloss is less than 50

(Note 10) Scratch resistance:
Each test plate was subjected to a Taber abrasion test (abrasion wheel CF-10P, load 500 g, 100 revolutions) in accordance with ASTM D1044. About the coating film before and behind a test, the glossiness of each coating surface was measured according to the specular glossiness (60 degree | times) of JISK5600-4-7 (1999). The glossiness after the test relative to the glossiness before the test was determined as a gloss retention (%) and evaluated according to the following criteria:
S: Gloss retention 90% or more A: Gloss retention 80% or more and less than 90% B: Gloss retention 60% or more and less than 80% C: Gloss retention 20% or less.

(Note 11) Weather resistance:
Each test plate was subjected to a 2000-hour weather resistance test using a sunshine weatherometer in accordance with JIS K 5600-7-8 (1999). The appearance and adhesion of the test plate after the test was evaluated:
<Appearance (after weathering test)>
S: No abnormality is observed on the surface of the coating film, and the color difference ΔE based on JIS Z 8730 is less than 0.3 in the initial and post-test test plates. A: Slight yellowing is observed but cracking occurs. No, there is no problem when the product is a product in which ΔE conforming to JIS Z 8730 is 0.3 or more and less than 0.5 in the test plate in the initial stage and after the test. Although cracking is not observed, the color difference ΔE based on JIS Z 8730 is 0.5 or more and less than 0.8 in the test plate at the initial stage and after the test. C: Yellowing of the coating film is recognized, In the test plate at the initial stage and after the test, the color difference ΔE based on JIS Z 8730 is 0.8 or more, or cracking occurs.
<Adhesion (after weathering test)>
After making 100 2mm x 2mm gobangs on the coated surface according to JIS K 5600-5-6 (1990) on each coated surface, affixing adhesive tape to the surface and removing it rapidly, The number of remaining gobang eyes was evaluated:
S: Remaining number / total number = 100/100, no edge missing A: Remaining number / total number = 100/100, no edge missing B: Remaining number / total number = 99 to 90/100 C: Remaining number / total number = 89 or less / 100.

(Note 12) Acid resistance:
0.5 mL of 1% sulfuric acid aqueous solution was dropped on the surface of each coating film and left in an atmosphere of a temperature of 20 ° C. and a relative humidity of 65% for 24 hours, and then the coating film surface was wiped with gauze and the appearance was visually evaluated:
S: No abnormalities on the coating film surface A: Slight traces on the coating film surface but disappear when washed with water B: Discoloration or slight whitening observed on the coating film surface C: Discoloration of the coating film surface Or it is markedly whitened.

(Note 13) Impact resistance:
Using a DuPont impact tester, the test was performed under the conditions of a diameter of 1/2 inch of hitting point, a height of falling weight of 20 cm, and a measurement atmosphere of 20 ° C., and the impacted convex and concave portions were visually evaluated:
S: No abnormality on the back surface A: Some small cracks are seen on the back surface B: Some small cracks are seen on the back surface C: Large cracks are seen on the back surface.

(Note 14) Contamination resistance:
A pollutant composed of a mixture of mud, carbon black, mineral oil and clay was adhered to the test plate and rubbed lightly on the coating surface of each test coating plate. This was left for 24 hours in a constant temperature and humidity chamber at 20 ° C. and 75% RH, and then the coated surface was washed with running water, and the degree of contamination of the coated film was evaluated according to the following criteria based on the lightness difference (ΔL) of the coated plate. The smaller the ΔL value, the better the stain resistance. ΔL was calculated by the following formula:
ΔL = (L value before stain resistance test) − (L value after stain resistance test)
The L value was measured using CR400 manufactured by Konica Minolta (trade name, tristimulus value direct-reading color meter D65 light source 2 ° field of view, diffuse illumination vertical light reception (d / 0)). The L value is a value based on the CIE 1976 L ^* a ^* b ^* color system:
S is ΔL <0.2,
A is 0.2 ≦ ΔL <1,
B is 1 ≦ ΔL <2,
C is 2 ≦ ΔL.

(Note 15) Storage stability:
The coating composition was hermetically stored in a constant temperature room at 40 ° C. for 1 month, and then painted and evaluated for finish by the above method for each test plate. Those with good finish compared to the initial stage were marked with “〇”.

(Note 16) Number of heating steps:
In the preheating of the water-based primer coating, the preheating of the base coating composition, the preheating of the clear coating composition, and heat drying, the total number of heating was used as a measure of energy saving.

(Note 17) Overall evaluation:
In the technical field relating to the painting of automobile bodies to which the present invention belongs, all the performances of solvent resistance, adhesion, finish, scratch resistance, weather resistance, acid resistance, impact resistance, contamination resistance and storage stability are provided. It is important to be good. Therefore, a comprehensive evaluation of each paint was performed according to the following criteria:
S: Solvent resistance, adhesion, finish (visual), finish (gloss), scratch resistance, weather resistance (appearance), weather resistance (adhesion), acid resistance and stain resistance are all S ;
A: all of the above items are S or A and at least one is A;
B: all of the above items are S, A or B and at least one is B;
C: All of the above items are S, A, B or C, and at least one is C.

Claims (13)

Radical polymerizable unsaturated group-containing compound (A) obtained by reacting caprolactone-modified hydroxyalkyl (meth) acrylate (a1) with polyisocyanate compound (a2) and having an isocyanate equivalent weight in the range of 300 to 3,800 ), A non-aqueous dispersion resin (B) and a photopolymerization initiator (C). The non-aqueous dispersion type resin (B) contains a dispersion stabilizer made of a polymer, and the dispersion stabilizer and the polymerizable unsaturated monomer (b1) dissolve, but the polymerizable unsaturated monomer. The polymer formed from the body is a dispersion of polymer fine particles (i) obtained by the polymerization reaction of the polymerizable unsaturated monomer in an organic liquid that does not substantially dissolve, The coating composition according to claim 1, wherein the agent has at least one chemically reactive group selected from an epoxy group, a carboxyl group, a hydroxyl group, an isocyanato group, and an alkoxysilyl group. The coating composition according to claim 1, wherein the non-aqueous dispersion resin (B) has a polymerizable unsaturated group. The coating composition according to claim 1, wherein the non-aqueous dispersion resin (B) has a polymerizable unsaturated group equivalent of 660 to 10,000. The non-aqueous dispersion resin (B2) is reacted with a polymerizable unsaturated compound (b2) having a complementary chemically reactive group capable of reacting with the chemically reactive group of the dispersion stabilizer portion of the non-aqueous dispersion resin (B). The coating composition according to claim 1, wherein a polymerizable unsaturated group is introduced into the dispersion stabilizer portion of the polymer fine particles (i) in B). The coating composition according to claim 1, wherein the average particle size of the polymer particles in the non-aqueous dispersion resin (B) is 50 to 500 nm. The coating composition of Claim 1 which contains 1-50 mass parts of non-aqueous dispersion-type resin (B) by solid content with respect to 100 mass parts of total solid content of a coating composition. Furthermore, the coating composition of Claim 1 containing isocyanate compounds (D) other than the said compound (A). Furthermore, the coating composition of Claim 1 containing hydroxyl-containing resin (E). The coating composition according to claim 9, wherein the glass transition temperature of the hydroxyl group-containing resin (E) is 0 ° C. or higher. Furthermore, the coating composition of Claim 1 containing radically polymerizable unsaturated group containing compound (F) other than the said compound (A). Applying a base coating composition containing a resin containing an active hydrogen group and a color pigment on an object to be coated to form a base coating film;
Next, a method for forming a multilayer coating film, comprising: a step of coating the coating composition according to claim 1 to form a clear coating film; and a step of irradiation and heating with active energy rays. The coated article obtained by the coating-film formation method of Claim 12.