TW200914151A - Method for forming multi-layered coating film and article coated by the method - Google Patents

Abstract

Disclosed are: a method for forming a metallic multi-layered coating film having high luster, high hardness and high adhesion on a metallic material (MM); and a coated article having a coating film produced by the method. Specifically disclosed are: a method for forming a multi-layered coating film, which comprises the steps of: applying a base coat paint (BC) on the surface of an MM; applying a clear coat paint (CC) on the BC; and baking the BC and the CC simultaneously; ; wherein the BC comprises a melamine resin (MR), a hydroxyl-containing acrylic resin (AR) having a hydroxyl value of 50 to 100 mgKOH/g and a Tg of 50 to 100 DEG C, a cellulose resin (CR) and/or a microgel (MG), and a photoluminescent pigment, in which the ratio of the amount of the AR to the amount of the MR is 50:50 to 90:10 in terms of mass-based solid content and the ratio of the amount of the CR and/or the MG relative to the total solid content of the AR and the MR is 1.0 to 20 mass% in terms of solid content; and wherein the CC comprises an MR and an AR having a hydroxyl value of 50 to 100 mgKOH/g and a Tg of 70 to 100 DEG C, in which the ratio of the amount of the AR to the amount of the MR is 50:50 to 90:10 in terms of mass-based solid content; and a coated article produced by the method.

Description

200914151 IX. The invention relates to a method for forming a multi-layer coating film. In detail, a method for forming a multi-layer coating film is a method for forming a multi-layer coating film, which can be used for home appliances and office work. A metal material such as a metal material such as magnesium or stainless steel is formed on the surface of a metal material such as magnesium or stainless steel to form a multi-layer coating film having excellent light adhesion. [Prior Art] As a method of coating a magnesium alloy molded article, it is known that after the treatment, a primer coating material containing a urethane coating material containing a bright material is applied, followed by coating a liquid type urethane ethyl ester. The intermediate coating of the coating, and finally the resin coating as the top coating (for example, refer to the patent text however) This method is applied to the undercoating and the urethane coating, and is subjected to the mixing and preparation of the liquid, and has the undercoating and the intermediate coating. In each step of the coating step, there must be a UV irradiation step, which is difficult. Further, as a coating of metal coated with magnesium or magnesium alloy, a two-coating two-baked (also known as a metal coating) is known. Packed with a clear coat with colored pigments on the bottom of the light-reflecting sheet (and coated articles, and coated articles, the machine, the mobile alloy, the alloy, the high, the high Hardness, one method is to dilute 2 amino decanoic acid ethyl ester containing bright material 2 coating UV hardening property 1). Use 2 liquid type in the material to limit the use time to include the baking step to shorten the lack of steps Object Excellent color-marked "2 C 2 B") on the (base coat), e.g. 5200914151 see Patent Document 2). In Patent Document 2, an acrylic resin, a polystyrene resin, a base resin, an I resin, or the like is used as a resin for primer coating, and these resins are used in combination with an amine resin, a block polyisocyanate compound, or the like. (Refer to paragraph [0 0 1 9] of Patent Document 2). Further, in the literature 2, as the resin for forming the coating of the transparent layer, at least one selected from the group consisting of an acrylic resin, a polyester resin, an alkyd resin, a fluororesin, an ester resin, and a denatured resin of these resins is used. A mixture of a resin and an amine-based resin and/or a polyisocyanate compound (refer to paragraph [0 0 2 3] of Patent Document 2). In the present invention, a coating for primer coating is disclosed in the embodiment, wherein the resin contains a denatured epoxy resin and a denatured amino ester, and further, as a transparent coating, an acrylic resin containing cyanide is disclosed. A coating of an amine resin and an epoxy resin (refer to the actual score of Patent Document 2). The metal coating described in Patent Document 2 is intended to be excellent in coating (refer to the embodiment of the Patent Document 2 and the paragraph [section]). However, this method has a set and a baking step (also referred to as a drying step) in each step of the primer coating and the transparent layer, and it is difficult to shorten the step, and the interlayer of the primer layer and the transparent layer are caused by the inconsistency of the baking conditions. Good is also worrying. Moreover, as a method of coating a surface of a metal material, it is known that an acrylic resin powder coating material is used as a primer in a chemical conversion, a coating material is used as a primer, and an acrylic resin powder is a transparent coating material (t 〇p). The method of C 0 at) (for example, refer to Patent Document 3). Illustratively, a cross-linking agent is disclosed. This patent discloses a polycarbonate thermosetting cross-linking agent. The patent contains resin formic acid B, and the trimerization part is colored; 0047] after standing and after the adhesion, the color solvent is Topcoat 200914151 However, this method has the following disadvantages: since the powder coating is applied to the undercoating and topping, the baking step is included in each coating step to shorten the step; and, depending on the inconsistency of the baking conditions, The adhesion between the layers of the top coating is also worrying. In addition, since the acid resin-based powder clear coating is used as the top coating, the primer and the surface have to be painted to some extent in order to obtain the desired smoothness. Further, as a method for coating a vehicle, a thick film is obtained by electroplating, and a method is known in which an alloy such as an alloy or a master alloy is used, and a coating film having a gloss can be formed by a lower coating. The powder coating material is coated with a coating composition for intermediate coating containing a thickness of 0.01 to O.lem and a diameter of 1 to 60 #111, and the film thickness after drying is 0.1 to 3/zm, and further, the upper coating is applied. Paint Colored powder or colored transparent material (for example, see Patent Document 4). However, this method has the following disadvantages: since the powder coating is applied to the undercoating and topping, the baking step is included in each coating step to shorten the step; and, depending on the inconsistency of the baking conditions, Adhesive adhesion between the top coats is also a concern. Further, as a method of coating a plastic molded article, there is known a method of coating a liquid-based primer coating (A) containing (a) a polyester resin in a specific ratio; (b) an acrylic resin, In order to copolymerize a monomer mixture containing 30 to 80 parts by weight of decyl methacrylate, the glass transition temperature is 20 to 90 ° C, the weight average molecular weight is 5000 to 50000, 30 to 150 mgKOH/g; and (c a block of polyisocyanate, followed by a 2-liquid type clear coating (B), which contains: (d) an acrylic tree coated with a hard-to-coat and acrylic-based appearance, the ultra-thin becomes a bright coating Painted and difficult to apply and coated: Amount % glass transamination value of its fat ' 7 200914151 It is obtained by mixing and mixing monomers containing 15 to 50% by weight of decyl methacrylate. The transfer temperature is 20 to 90 ° C, the weight average amount is 3000 to 20000, the hydroxyl value is 30 to 150 mgKOH/g, and (e) the polycyanate (for example, refer to Patent Document 5). However, this method has the following points: since the use of the 2-liquid type in the top coat clear (passing means the transparent layer located in the uppermost layer) is limited by the usable time, and thus by the amino carboxylic acid The ester bond is formed into a film, and it is not expected to be a high hardness coating film having a lead hardness of 3 Å or more. Further, as a method of forming a coating film by a two-coating method, it is known that a method is specifically used for (d) 40 to 80% by weight of an ethylene complex, and (e) 10 to 50% by weight. Alkyl etherified melamine resin, (f) 0 to wt% of blocked polyisocyanate, (g) 0 to 20% by weight of cellulose resin '(h) 0 to 30% by weight of organic crosslinked microparticles The composition is used as a coating material, and (a) 40 to 90% by weight of a copolymer of a vinyl monomer mixture containing 20% by weight or more of a cycloalkyl acrylate, (b) 550 wt% The alkyl etherified melamine resin and (c) 5 to 50% by weight of a segmented polyisocyanate are used as a clear coating material (for example, refer to Document 6). However, this method has a drawback in that it is not expected to be a high-hardness coating film having a pen hardness of 3 Å or more because the surface-coated transparent layer has rubber elasticity based on urethane bonding. [Patent Document 1] Japanese Patent Laid-Open Publication No. JP-A-2006-1995-A-Patent Document No. JP-A No. 200 1 - 1 9 1 020 [Patent Document 3] 曰本特开平1 0 - 0 2 4 5 2 No. 4 No. 4 No. 4, No. 4, No. 4, No. 4, 2009, Japanese Patent Laid-Open [5] Japanese Patent Laid-Open Publication No. 4 - 1 5 4 6 2 5 [Patent Document 6] 曰本特开平 6 - 1 4 2 5 9 8 [Invention] [Problems to be Solved by the Invention] The object of the present invention is to provide a method for forming a multi-layer coating film which has gloss, high hardness and excellent adhesion when formed on a white alloy, especially an alloy, an is alloy or a non-mineral material. A method for forming a multi-layer coating film, and a coated article for forming a coating film by the multi-layer coating method. [Means for Solving the Problems] As a means for solving the above problems, the method for forming a multi-layer coating film according to the scope of the invention is characterized in that: (1) a step of applying a primer coating to a surface of a metal material, a coating material ( a) containing melamine resin, hydroxyl group-containing resin, cellulose resin and/or microgel having a hydroxyl value of 50 to 100 / g and a glass transition temperature (Tg) of 50 to 100 ° C And (b) the hydroxyl group-containing acrylic resin and melamine contact ratio, in a solid mass ratio of 50: 50 to 90: 10, and the ratio of the resin and/or microgel, relative to The total solid content of the hydroxyl-containing acrylic phase melamine resin is 1.0% by weight in terms of solid content; it is such that the metallized coating is formed into a base of the mgKOH dilute acid tree, and the ratio of the fat to the fat .Vusu series • Grease and three 20 quality 9 200914151 (2) The step of coating a clear coating (a) containing: melamine resin and its hydroxyl value of 50~100 mgKOH / g and glass transition temperature (T g) a hydroxyl-containing acrylic resin of 7 0 to 1 0 ° C; and, (b) Hydroxyl group-containing acrylic resin and a melamine resin ratio to solid content mass ratio is made 50: 50~90: 10; and (3) simultaneously curing the primer coating and clear coating of the above-described steps. The method of forming a multi-layer coating film according to the above aspect of the invention, wherein the surface of the metal material is subjected to a chemical conversion treatment and then a primer is applied. The third aspect of the patent application is a coated article obtained by the method for forming a multi-layer coating film according to the above-mentioned claim. [Effect] According to the present invention, it is possible to provide a method for forming a multi-layer coating film which can form a high hardness and excellent gloss on a surface of a metal material, particularly a surface of a magnesium alloy, an aluminum alloy or a stainless steel. Metal coating film. According to the present invention, there can be provided a method for forming a multi-layer coating film which, in relation to a primer coating, defines a solid content ratio of a hydroxyl group-containing acrylic resin and a melamine resin to a specific range, and defines a cellulose resin and/or a microgel. Since the solid content ratio is in a specific range, it is possible to obtain a coating film having excellent adhesion between the undercoat layer and the transparent layer, and excellent orientation and transparency. According to the present invention, there can be provided a method for forming a multi-layer coating film which relates to a hydroxy-containing acrylic resin and a three-point ratio in a specific range with respect to 10 200914151, thereby forming an excellent adhesion to the undercoat layer and the transparent layer. In accordance with the present invention, the surface of the metal material is pre-primed, so that the surface properties of the metal material can be further improved. According to the present invention, it is possible to provide a coated metal coating film formed by the method for forming a multi-layer coating film of the present invention. [Embodiment] [Best Mode for Carrying Out the Invention] The warp-containing acrylic acid resin used in the method for forming a multi-layer coating film of the present invention preferably has a value of from 50 to 100 mg to 90 mgKOH/g. If the hydroxyl value is less than 50 to obtain an undercoat layer having sufficient hardness, if the hydroxyl value is large, the undercoat layer becomes brittle, which is not preferable. Further, the base coating material contains a hydroxyl group-containing acrylic acid (T g) of 50 to 100 ° C, preferably 5 5 to 90 ° C, and the glass transition temperature of the hydroxyl group-containing acrylic resin may become small if it is small. Insufficient, if it is greater than 100 °c, the film is applied here, the so-called glass transition temperature is the value calculated below. 1 / Tg = Σ (mi/ Tgi) Solid form of melamine resin I Coating of hardness when recoating. The chemical treatment, the addition and the adhesion of the multi-layer coating film, which have an excellent photobase coating by the relevant hardness, and contain mgKOH/g, and 70 mgKOH/g cannot be used for 100 mgKOH/g resin. The glass transfer temperature is preferably 6 0~9 0 °C. At 5, the coating film will become brittle, so it is not good. According to the formula shown in the figure 11 200914151 T g : glass transition temperature of hydroxyl-containing acrylic resin mi : molar fraction of monomer i component

Tgi: glass transition temperature (K) of the homopolymer obtained by polymerizing the monomer i component alone

Further, the weight average molecular weight of the hydroxyl group-containing acrylic resin contained in the primer coating is preferably 7,000 to 20,000, preferably 9000 to 15,000. When the weight average molecular weight of the hydroxyl group-containing acrylic resin is less than 7000, the alignment unevenness of the gloss pigment is likely to occur, and if it is more than 2,000, the atomization during atomization coating is deteriorated, and the obtained coating film is poor. The smoothness is lowered and thus is not good. The hydroxyl group-containing acrylic resin contained in the primer coating used in the method for forming a multi-layer coating film of the present invention can be obtained by a conventional method such as a radical polymerization method. Specific examples of the radically polymerizable monomer having a hydroxyl group copolymerizable monomer include, for example, acrylic acid 2 - thioacetic acid, 2 - propyl propyl acrylate, 3 - hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, allyl alcohol, acrylic acid and ten An adduct of versatic acid glycidyl ester, an adduct of mercapto acrylic acid and acetoacetic acid glycerol vinegar; acrylic acid 2 - thiophene methacrylate, 2 - propyl propyl acrylate 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, etc. An ethylene oxide and/or propylene oxide adduct of a hydroxyalkyl (meth) acrylate. The radically polymerizable monomer having a hydroxyl group may be used alone or in combination of two or more. As a specific example of other copolymerizable radical polymerizable monomer, 12 200914151 can be exemplified by decyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, Second butyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, methacrylate, ethyl methacrylate, decyl N-propyl acrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, second butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, methacrylic acid 2-ethylhexyl ester, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, styrene, acrylonitrile, mercapto acrylonitrile, and the like. These monomers may be used alone or in combination of two or more. As the radical polymerization initiator, for example, 2,2 '-azobisisobutyronitrile, 2,2'-azobis-2,4-dimercaptophthalonitrile, 4,4'-azo 4,4'-azobis(4-cyanovaleric acid), 1-azobis-1-cyclohexanone, dimethyl-2,2'-azobisisobutyrate Azo compounds such as esters; methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,5,5-tridecyl ketone peroxide, 1,1-bis(peroxybutyl butyl)-3,3,5 - Trimethylcyclohexane, 1,1-bis(peroxybutylbutyl)-cyclohexane, 2,2-bis(peroxybutylbutyl)octane, tert-butyl hydroperoxide, Hydrogen peroxide diisopropyl, diisopropyl peroxide, tributyl isopropyl peroxide, isobutyl peroxide, lauryl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate Ester, butyl peroxy2-ethyl hexanoate, tert-butyl peroxy neodecanoate, tert-butyl peroxy laurate, tert-butyl peroxy citrate , t-butyl peroxy isopropyl carbonate, third acetic acid peroxide Organic peroxides such as butyl ester. These 13 200914151 radical polymerization initiators may be used alone or in combination of two or more. The amount of the radical polymerization initiator to be added is not particularly limited, and is 0 to 〇 1 to 2 0 by mass based on the total amount of the radical polymerizable monomer. /. It is better. Further, the temperature of the radical polymerization varies depending on the type of the radical polymerization initiator, and is preferably carried out at a temperature of from 50 to 200 ° C, more preferably at a temperature of from 80 to 160 ° C. Go on. Examples of the organic solvent used in the production of the above-mentioned hydroxyl group-containing acrylic resin include alicyclic hydrocarbons such as cyclohexane and ethylcyclohexane; terpene benzene, diphenylbenzene, ethylbenzene, and aromatic light oil (naphtha). An aromatic hydrocarbon solvent; a ketone solvent such as propionium, methyl ethyl S, methyl isobutyl ketone, cyclohexanone or isophorone; ethyl acetate, n-butyl acetate, acetic acid An ester solvent such as methoxypropyl acetate, isobutyl acetate, 3-methoxypropenyl acetate or bis(2-ethylhexyl) adipate; dibutyl ether, tetrahydrofuran, 1, 4 - 2" Hyun > (1,4 - di ο X ane), 1, 3, 5 - 3. An ether solvent such as flavonoid; a nitrogen-containing solvent such as acetonitrile, valeronitrile, N,N-dimethylguanamine or N,N-diethylguanamine. The organic solvent may be used singly or in combination of two or more kinds of a mixed solvent. At this time, the solid content concentration of the hydroxyl group-containing acrylic resin can be arbitrarily selected within the range of the dispersion stability of the resin, and is usually a solid content concentration of 10 to 70% by mass. In the primer coating used in the method for forming a multi-layer coating film of the present invention, the melamine resin to be contained may be a conventional one, and examples thereof include a butyl ether melamine resin, a methyl ether melamine resin, and a mercaptobutyl group. Mixed etherified melamine resin and the like.

As an example of a commercially available butyl etherified melamine resin, there are: U-VAN 2 1 R ]4 200914151 (trade name, manufactured by Mitsui Chemicals, Inc.), SUPER BECKAMINE G - 8 2 1 - 6 0 (trade name, large Japanese Ink Chemical Industry Co., Ltd., etc., as an example of a commercially available oxime etherified melamine resin and methyl butyl etherified melamine resin, Cyme 1 3 2 7 (trade name, 曰本科特Industrial Co., Ltd.), NIKA LAC MS-1 1 (trade name, manufactured by Sakamoto Sanwa Chemical Co., Ltd.), etc. The mixing ratio of the hydroxypropyl maleic acid resin and the melamine resin used for the primer coating is a resin solid content ratio (mass ratio) of 5 0 / 5 0 〜 9 0 / 1 0 (hydroxyl acrylate resin / melamine resin), 7 0 / 3 0~9 0 / 1 0 is better. When the amount of the melamine resin in the total solid content is more than 50% by mass, the adhesion between the recoating and the transparent layer which becomes the lower layer becomes insufficient, and if it is less than 10% by mass, the bottom can not be obtained. Adequate adhesion of the lacquer layer. Here, recoating refers to a coating operation in which an undercoating material is applied to a transparent layer to form an undercoat layer. This recoating is carried out by recoating a product which is evaluated as a defective product due to a poor appearance on the surface of the final coating film, whereby it can be a good product, and the appearance of the surface of the final coating film is obtained. The defects include poor appearance due to foreign matter adhered during coating, poor appearance due to agglomerates of the coating material, and poor appearance due to repulsion of the clear coating material on the surface of the primer coating film. Further, in the primer coating used in the method for forming a multi-layer coating film of the present invention, the cellulose-based resin and/or microgel contained therein is used for the purpose of facilitating the two-coating-bake coating method. Here, the two-coating-bake coating method is also referred to as a wet-wet-wet-wet coating method, and the method is as follows: it is formed by applying a primer coating, and is Unhardened state 15

On the surface of the coating layer of 200914151, the coating layer is formed by coating the transparent coating of the I cloth, and then the coating layer formed by the primer coating and the coating layer formed by the transparent coating are baked to form the primer layer and the transparent layer. A composite layer of brush film. The cellulose-based resin may, for example, be a thermoplastic plastic based on cellulose (which is a natural molecule), and particularly a carboxylic acid-modified cellulose resin obtained by carboxylic acid, and may, for example, be acetic acid. As a suitable, for example, CAV-38 1-0.5, CAB-3 8 1-2, CAB-53 1-1, CAB-5 5 (trade name, Iraq) A commercially available acetic acid butyric acid fiber resin such as Shiman Kodak Co., Ltd. is suitable for use. The microgel in the present invention may, for example, be a polymer which is produced by emulsion polymerization of a polyfunctional monomer and an acid or vinyl monomer copolymerizable therewith. In non-moisture, it has a particle size in units of micrometers or less. When the emulsion polymerization is carried out, a polymerization initiator such as an inorganic persulfate, a water-soluble peroxide or an azo compound, or an emulsifier such as an anionic, a sub-system or a zwitterionic system can be used. Examples of the polyfunctionality (crosslinkable body include: glycol diacrylate, pentaerythritol tetraacrylate diol dimethacrylate, ethylene glycol diacrylate, diethylene glycol olefinate, and triethylene glycol). Alcohol diacrylate, trihydroxymercapto propane tripropylene® neopentyl glycol diacrylate, diethylene glycol dimercapto acrylate, triol dimethacrylate, divinyl benzene, etc. Also, as an acrylic olefin The monomer may be exemplified by decyl acrylate, ethyl acrylate, and propylene by the shape of a coating of sulphate sulphate. Example 1-0.5 vegan microparticle propylene dispersion organic cation) mono- and ethylene-propylene Ester, ethylene or acetic acid iso 16 200914151 propyl ester, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, benzene Ethylene and the like. As representative copolymer compositions, there are copolymers of styrene 'diethylene benzene; copolymers of alkyl acrylate and divinyl styrene; copolymers of alkyl acrylate, ethylene glycol and dimercapto acrylate. The polymer microparticles contained in the polymer non-aqueous dispersion liquid produced by the method described in JP-A-1-279902 are exemplified as the microgels which are suitable for use in the present invention. The suitable microgel-containing polymer non-aqueous dispersion can be produced by the following steps as described in Japanese Patent Laid-Open No. Hei. No. Hei. No. 1 - 279 9 2: (1) in the absence of soap or In the presence of an ester group-containing surfactant, the following components are: (a) a hydroxyl group-containing α, a /3 - ethylenically unsaturated monomer, (b) a polyfunctional group α, /3 - ethylenicity a saturated monomer, and (c) α, /3 - ethylidene and a monomer other than (a) and (b), which are subjected to emulsion polymerization using a water-soluble polymerization initiator, and an organic solvent is added thereto. After the polymer aqueous dispersion is added, the basic compound catalyst or the acidic compound catalyst is added, and the above-mentioned surfactant-containing surfactant and water-soluble polymerization start are still in a suspended state and at 95 ° C or lower. a step of completely hydrolyzing the agent; (2) adding an acidic compound or an organic compound to the suspension to neutralize the above basic compound catalyst or acidic compound catalyst, followed by adding the dispersion-stabilizing resin, and then adding an organic amine salt And let stand to separate into two layers: organic layer and water layer, and after removing the water layer, add water to wash The organic layer, an organic amine salt 17200914151 allowed to stand to separate and remove the aqueous layer is added in step; step residual water in the organic layer was removed (3). The amount of the cellulose resin and/or the microgel is from 1 to 0% by mass, and from 5 to 15% by mass based on 100 parts by mass of the total of the resin of the hydroxyl group-containing acrylic resin and the melamine resin. It is better.

When the amount of the cellulose resin and/or the microgel is less than 1.0% by mass, the drying property of the primer is insufficient, and the separation property of the transparent layer coating film is not good. If it is more than 20% by mass, the adhesion between the undercoat film and the transparent layer coating film is poor. Here, the term "separator" refers to a surface of a primer coating film formed on the surface of a metal material by application of a primer coating, and in the case where a clear coating material is applied when the primer coating is not dried, It is difficult for the coating composition in the undercoat film to diffuse to the characteristics of the applied clear coating. Therefore, if the separation property of the transparent layer coating film is good, in the case of applying the clear coating material to the undercoat layer, it is difficult for the component forming the transparent layer to penetrate the undercoat coating film, and the transparency can be achieved by the transparent layer. High gloss. However, in general, if the separation property of the undercoat layer and the transparent layer is improved, when the undercoat layer and the transparent layer become easy to be peeled off, the present invention can form a complex separation type and good adhesion. Layer coating film. Further, the undercoating material used in the method for forming a multi-layer coating film of the present invention contains a gloss pigment. Examples of the above-mentioned gloss pigment include a metal powder pigment and/or a pearl pigment. Examples of the metal powder pigment include: Ming. Powder, bronze powder, copper powder, tin powder, lead powder, zinc powder, iron phosphide, and the like. Mica powder coated with pearlescent metal, mica-like iron oxide, etc. 18 200914151 In addition to the above-mentioned gloss pigments, the above primer coating may contain pigments such as coloring pigments, body pigments, and, if necessary, ultraviolet absorbers, light stabilizers, antioxidants, surface conditioners, pigment dispersants, and hardening touches. Additives for coatings such as curing (curingcata 1 yst) and anti-settling agents. Examples of the coloring pigment include white pigments such as titanium oxide; black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, black iron oxide, and stearamine black; yellow iron oxide and titan yellow (titanye). Π 〇 w), monoazo yellow, condensed azo yellow, methylimine yellow, hunger acid, stupid and sinone, sulphonic acid, isoporphyrin, quinoline yellow, phenylamine Yellow pigments such as yellow and permanent yellow; orange pigments such as permanent orange; red iron oxide, naphthol AS azo red, anthanthrone, anthraquinonyl red, and perylene maroon ), 啥π丫 quinacridone is a red pigment, °°°°°°D 281⁄4 (diket 〇pyrr ο 1 〇pyrr ο 1 e), red 2B (Watching Red), permanent red, etc. Pigment; purple pigment such as diamond purple, fluorenone violet, di _ purple (di ο X azinevi ο 1 et); blue pigment such as lead blue, ugly blue, and threne blue; green pigment such as indigo green Wait. The above-mentioned extender pigment is used for the purpose of reinforcing and increasing the coating film. In the present invention, the above primer coating material can be suitably contained as a pigment which is known as a body pigment. Examples of the extender pigment include cerium oxide powder, precipitated barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, bismuth telluride, white carbon, shixia, talc, magnesium silicate, Shaobai, I. Lv pot white (g丨〇sswhite), mica powder, etc. 19 200914151 In the method for forming a multi-layer coating film of the present invention, a clear coating can be used. The hydroxyl group-containing acrylic resin used for the clear coating has a hydroxyl value of .5 0 to 1 0 0 m g Κ Ο Η / g, preferably 7 0 to 9 0 m g Κ Ο Η / g. If the carboxyl group value of the thiophanate-containing acid resin is less than 50 mg Κ Ο H / g, the glossiness is insufficient and the appearance of the coating film is deteriorated, and if it is more than 100 mg Κ Ο H / g, the coating is recoated. When the adhesion to the undercoat film of the transparent layer is insufficient, it is not preferable. Further, in order to obtain a composite coating film having a high hardness, the transparent layer forming the outermost layer film is required to be the hardest coating layer among the respective coating layers. Therefore, the glass transition temperature of the hydroxyl group-containing acrylic resin contained in the clear coating material for forming the transparent layer is preferably in a higher range than the glass transition temperature of the hydroxyl group-containing acrylic resin contained in the primer coating. Specifically, the glass transition temperature of the hydroxyl group-containing acrylic resin contained in the primer coating is preferably from 50 to 100 ° C. In contrast, the glass transition temperature of the hydroxyl group-containing acrylic resin contained in the clear coating is 70. Preferably, it is preferably 1 0 0 ° C, preferably 7 0 to 9 0 ° C.

When the glass transition temperature of the hydroxyl group-containing acrylic resin contained in the clear coating is less than 70 ° C, the coating film hardness is insufficient, and if it exceeds 100 ° C, the coating film becomes brittle, which is not preferable. Further, the weight average molecular weight of the hydroxyl group-containing acrylic resin contained in the clear coating material is preferably 7,000 to 15,000, more preferably 9000 to 15,000. When the weight average molecular weight of the hydroxy group-containing acrylic resin is less than 7,000, the moisture resistance of the coating film is insufficient, and if it exceeds 1 500, the smoothness of the coating film is lowered, which is not preferable. Further, the acid value of the hydroxyl group-containing acrylic resin is preferably in the range of 5 to 15 m g Κ Η Η / g. If the acid value is less than 5 mgKOH/g, the hardness of the coating film becomes 20 200914151, and if it is more than 15 mgKOH / g, it is not good when it is recoated. The trimeric amide resin contained in the clear coating can be used by the user or the melamine resin used as the primer coating in the transparent hydroxy-containing acrylic resin and the melamine resin used in the method for forming the multi-layer coating film of the present invention. Mixing ratio, the ratio of the component (the hydroxyl group-containing acrylic resin/melamine resin is 50/50 to 90/10, preferably 60/40 to 80/20. The total amount of the solid melamine resin containing the hydroxy acrylic resin and the melamine resin, if When it is more than 50% by mass, re-adhesiveness cannot be obtained, and if it is less than 1% by mass, sufficient coating can not be obtained, and the transparent coating may contain materials, inscriptions, pearlescent pigments, etc., and as matting. The matting may contain a dioxide dioxide, a resin beads, or the like, and further contains an additive for a coating such as an ultraviolet absorber, a light stabilizer, an antioxidant, or a surface hardening catalyst. In the method, although the surface of the material can be directly coated with the primer coating, if the purpose is to improve the adhesion of the surface of the metal material, The surface of the preferred material is chemically processed, and then the primer for the surface of the metal material to be treated is applied. The primer used in the method for forming a multi-layer coating film of the present invention is only a material. When the adhesion between the surface and the primer is improved, it is preferable to use a primer containing an epoxy resin and a hardener. The adhesion is low, and the conventional resin is the same. The hardness of the coating during the coating. There is a pigmentation agent, which can be adjusted as needed, in the metallization primer coating: in the gold where the formation should be able to make a gold primer, 21 200914151 as a primer The epoxy resin preferably contains two or more epoxy groups in one molecule, and a conventionally known epoxy resin such as a liquid epoxy resin or a solid epoxy resin can be used without particular modification. The epoxy resin of the present invention comprises a denatured epoxy resin denatured with a denaturant. Examples of the denaturing agent include a monocarboxylic acid having a linear or branched carbon number of 1 to 18 and having an unsaturated hydrocarbon chain or a saturated hydrocarbon chain; succinic acid or its anhydride 'maleic acid or an anhydride thereof, Adipic acid, sebacic acid, sebacic acid, dodecanedioic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, isophthalic acid, p-nonanoic acid, naphthalenedicarboxylic acid, and a dicarboxylic acid such as a dimer acid; a polyvalent carboxylic acid such as trimellitic anhydride or pyromellitic acid; a compound containing a slow group such as a carboxyl group-containing ethylene copolymer; and a compound containing an isocyanate group; And cyclic ester compounds such as caprolactone. Further, in the case of using a solid epoxy resin, it can be used by dissolving or dispersing it in an organic solvent capable of dissolving or dispersing the solid epoxy resin. As a commercially available epoxy resin which can be used in the present invention, JER1001'JER1002'JER1003 > JER1055 'JER1004'JER1007 (above is Japan Epoxy Resins Co., Ltd.), EPOTOHTO YD series 134 (EPOTOHTO YD-134) , 011, 012, 013, 014, 0 1 7 , 7 0 1 1 R, 9 0 7 (above is Dongdu Chemical Co., Ltd.), DER662E, 663 UE, 664U, 667E (above is made by The Dow Chemical Company) Bisphenol/epi alcohol type epoxy resin, etc.; as a denatured epoxy resin, EPICLON P-439 and EPICLON H-3 05-45 (above: Otsuka Ink Chemical Industry Co., Ltd.) , ARAKYD 9201N, ARAKYD 9203N, ARAKYD 9208 (above is Arakawa Chemical Industry Co., Ltd. 22 200914151 system). As the curing agent to be added to the primer, at least one of the following may be selected as a suitable example: a melamine resin, a blocked polyisocyanate compound, a polyamide resin, an amine compound, and the like. When the hardener is a melamine resin or a blocked polyisocyanate compound, the primer is treated as a one-component paint, and if the hardener is a polyamide resin or an amine compound, the primer is used as a two-component paint. To handle. The melamine resin used as a hardener in the primer may be the same as the melamine resin used as a primer coating or a clear coating.

Examples of the blocked polyisocyanate compound to be used as a curing agent in the primer include a compound in which a polyisocyanate compound which is not yellowed by a block agent is blocked, and specifically, a polyisocyanate compound such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate or hydrogenated dimethyl diisocyanate, and the adducts thereof (adduct) (for example, an addition reaction product formed by an addition reaction of the above various isocyanate compounds and a trans group-containing compound), a biuret (for example, an addition by a urea bond and an isocyanate group) Reaction-derived addition reaction product), and such dimers (uretidione), trimers (trimeric isononates), by ordinary isocyanate blocks Chemical agents (for example, phenols such as phenol, m-nonylphenol, xylenol; alcohols such as methanol, ethanol, butanol, 2-ethylhexanol, cyclohexanol; caprolactam, mercaptoethyl ketone oxime Ethylacetate B , Diethyl malonate or the like of the blocks and the like containing the compound having an active hydrogen). 23 200914151 As a polyamine resin contained in a primer as a hardener, it is usually a resin which has an amine group at both ends after reacting with a fatty acid dimer (dimer acid) and a diamine, according to a dimer acid and The molar ratio of the amine is adjusted to adjust the molecular weight. The amine compound to be used as a curing agent in the primer is a polyamine, an S&amine polyamine, a cyclic amine or an aromatic amine. The content ratio of the epoxy resin and the hardener contained in the primer of the present invention, the solid content ratio (epoxy resin/hardener) is preferably 60/40 to 9000/100, and particularly preferably 75/25. ~85/15. When the solid content ratio is less than 10% by mass, the adhesion to the material is insufficient, and when the solid content ratio is less than 40% by mass, the adhesion of the undercoat film may be Become inadequate. The primer is intended to enhance the corrosion resistance of the coating film and may contain an anti-rust pigment. As the rust preventive pigment, a pigment for the undercoating paint can usually be used. As a specific anti-rust pigment, for example, a chromium-based pigment such as zinc chromate or strontium chromate or a non-polluting anti-rust pigment containing no chromium can be used, but from the viewpoint of environmental protection, pollution-free rust prevention is used. Pigments are preferred. Examples of the pollution-free rust preventive pigment include (1) a phosphate-based rust preventive pigment, a magnesium phosphate-based rust preventive pigment, an aluminum phosphate-based rust preventive pigment, a calcium phosphate-based rust preventive pigment, and a zinc phosphite-based rust preventive pigment. a polymeric phosphate-based rust preventive pigment such as a magnesium phosphite-based rust preventive pigment, a calcium phosphite-based rust preventive pigment, and an aluminum phosphite-based rust preventive pigment; (2) a surface of a particle composed of a polymeric phosphate is treated with a metal compound (3) Molybdenum acid rust-proof pigment, cyanamide-based rust-proof pigment, and cyanamide-based rust-proof pigment, etc.; and (4) cerium oxide. These may be used alone or in combination of two or more. 24 200914151 In the primer, if necessary, it can be used as a coating material, such as inorganic pigments other than rust-preventing pigments, organic pigments, and processed poetry as organic pigments. For example, it can be exemplified: az 厥 1 ake ) Department of S, too green pigment, indig ο pigment, lanthanide pigment, 啥 黄 yellow, two-¥ " well (di ο X azine) pigment, 啥σ kettone pigment, different A quinone-based pigment, a metal complex pigment, or the like. Further, examples of the inorganic pigment include yellow iron oxide, red ocher, and titanium dioxide black. In the present invention, the shape of the metal material as the object to be coated may be a shape or may be formed. As the type of the metal material, a town alloy, an alloy, or a non-ferrous steel can be cited, and a magnesium alloy is particularly suitable. The magnesium alloy may be, for example, AZ9 1D of JIS standard, and the like may be, for example, an ADC 1 such as JIS, and the like stainless steel may be SUS304 of JIS standard. Examples of the coated article by the method for forming a multi-layer coating film of the present invention include a mobile phone, a digital camera, an audio-visual equipment, an inner/outer component of an electronic vehicle, a cosmetic container, and the like. These metal materials are intended to enhance the properties of the undercoat layer on the metal surface, and it is preferred to treat the metal species prior to the application of the primer. The magnesium alloy is preferably treated by a degreasing treatment such as a solvent or an aging emulsion, and further subjected to a pickling treatment, followed by a chemical treatment such as a chromic acid manganese-based or an organic adsorption type. For aluminum and aluminum alloys, it is preferable to carry out the following treatment: after removing the pigment or the like. Materials, 吲哚 吲哚, examples, carbon for the board such as: the place where the aluminum is combined, such as the sample, the adhesion, the formation, the sex, the grease filling 25 200914151, the washing process, the surface adjustment step, and then the alkaline-chromium The chemical conversion treatment of the acid salt system, the phosphoric acid chromate system, and the phosphoric acid system is preferred. For the stainless steel, the degreasing treatment, the chromate treatment after the water washing treatment, the polishing, the beading, the pickling, and the like are preferred. Further, a method for forming a multi-layer coating film of the present invention by applying a powder primer to each of the metal materials which have been subjected to the chemical conversion treatment is also possible, and the metal material is preferably coated on the surface of the metal material which has been processed. The surface of the primer layer formed by baking is coated with a primer coating, and the coating is not applied to harden it, but is coated in a wet and wet manner while baking the primer coating and the clear coating. As a method of applying primer, primer coating, and clear coating, such as air spray coating, airless spray coating, electrostatic coating, dipping, etc., it is preferable to spray coating. The solvent to be used for the coating of the spray coating may, for example, be a conventional solvent such as an aromatic solvent, an ester solvent or an alcohol solvent. The suitable viscosity of the liquid primer is preferably 1 〇 to 30 seconds measured by Iwata N K2 (20 ° C), and the dry coating film of the primer is preferably ～50/zm, preferably 10~3〇μπι. The suitable viscosity of the primer coating is preferably 7 to 10 seconds as measured by Iwata NK2 (20 〇C), and the thickness of the dried coating film is preferably 5, preferably 10 to 3 0 /z m. The suitable viscosity of the clear coating is preferably 10 to 30 seconds measured by Iwata NK2 (20 ° C), and the thickness of the dried coating film is preferably 1 cm, preferably 10 to 40 / / m. Department, chrome, carry, need, install, etc. Surface, lacquer and baking primer, exemplified by the use of squeezing, _ viscous cup ίο viscous cup, 4 0 /z m viscous cup 丨~5 0 // 26

200914151 When the primer coating and the clear coating are applied in a wet-stacking manner, it is preferable to apply the primer coating at room temperature for several minutes, and then apply the clear coating to the coating film of the primer coating. on. Further, in the case where the two coating films of the undercoat layer and the transparent layer are simultaneously cured, after the clear coating material is applied, the mixture is allowed to stand at room temperature for 5 to 30 minutes, and then heated at a temperature of 1 0 0 1 0 0 ° C. 1 2 0 0 minutes, preferably 15 to 30 ° C for 15 to 30 minutes. [Examples] Hereinafter, the present invention will be specifically described by way of Production Examples, Examples and Comparative Examples. In addition, as long as it is not specifically denied, "parts" and "%" mean "mass parts" and "quality. /." <Production of Acrylic Resin B-1 for Primer Coating> In a four-necked flask equipped with a thermometer, a stirrer, a circulation cooler, and a drip leak, 66.3 parts of dioxane and 4 parts of Solvesso #100 were added. (Name of the product, manufactured by Esso Chemical Co., Ltd., which is an aromatic light oil), and n-butanol. The contents of the four-necked flask were heated to 140 ° C. Next, in this four-necked flask, 7 1.4 parts of decyl methacrylate, butyl acrylate, and 21 parts of methacrylic acid 2 - a mixture of a hydroxypropyl ester, a polymerizable monomer of 1.1 parts of propionic acid, and 2.3 parts of an initiator, that is, a mixture of t-butylperoxy-2-ethylhexanoate. The material was dropped from the dropping funnel at a constant rate for 2 hours. After dropping the knot, the contents of the four-necked bottle were kept at the circulating temperature for 1 hour, and then the contents were cold-coated and then coated with white hoppers. 〇 ».5 dilute acetylene burning 27 200914151 to 1 0 5 °C. After cooling to 105 ° C, 'in a cooled four-necked flask, a mixed solution of 0.4 parts of peroxyethylhexanoic acid, third butyl vinegar and 7 parts of xylene was dropped at a constant rate of 3 0. minute. Thereafter, the contents of the four-necked flask were kept at 1 0 5 ° C for 3 hours to terminate the polymerization reaction. From the obtained polymerization reaction liquid, an acrylic resin B for a primer coating having a solid content of 50% by mass, a hydroxyl value of 8, an acid value of 9, a glass transition temperature of 8 2 ° C, and a weight average molecular weight of 12 〇〇〇 is obtained. -1. <Production of acrylic resin B·2 to 6 for primer coatings> In the same manner as B-1, except that a monomer (polymerizable monomer) of the type shown in Table 1 was used instead of W. The acrylic resin B-2~B-6 was obtained for the primer coating. Further, the characteristic value of the obtained resin is shown in Table 1 °. In addition, "PLACCELFM-1D" in the table is a trade name, and is an alkyl ester of an unsaturated fatty acid manufactured by D本D aice 1 Chemical Industry Co., Ltd. Modified ε - already cool.

Table 1] L 1 J —-— Acrylic resin for primer coating (3⁄4 酸酸树爿日> Valley liquid name B-1 B-2 B-3 B-4 B-5 Β·6 Reaction solvent xylene 66.3 66.3 66.3 66.3 66.3 66.3 s〇lvSso#100 4.0 4.0 4.0 4.0 4.0 4.0 n-Butyl ester 20 20 20 20 20 20 Dropped monomeric methacrylate 71.4 63.6 63 4S.6 50 85 Stupid ethylene 20 18 Butyl acrylate 6.5 6.6 3.5 30 Tert-butyl methacrylate 1.0 2-Hydroxyethyl methacrylate 9.4 19 19 PLACCEL FM-1D 35.5 2-Hydroxypropyl methacrylate 21 9.8 10 Propionate 1.1 1.1 1 1.1 1.0 1.0 Start Agent peroxy-2-ethylhexanoic acid == δ δ 2.3 2.3 2.3 2.3 2.3 2.3 Additional initiator j ^ 2-ethylhexanoic acid tert-butyl ester 0.4 0.4 0.4 0.4 0.4 0.4 Dimethyl stupid 7.0 7.0 7.0 7.0 7.0 7.0 Total — 200.0 200.0 200.0 200.0 200.0 200.0 28 200914151 Characteristic value Resin solids (%) 50 50 50 50 50 50 Hydroxyl value 82 82 41 120 82 39 Glass transfer temperature (°c) 82 55 82 82 30 102 Weight average Molecular weight 12000 12000 12000 12000 12000 12000 Acid value 9 7 8 9 8 8 <Microgel (polymer (Manufacturing of the aqueous dispersion), the manufacturing method described in the lower left column and the lower right column of the first page of the Japanese Patent Publication No. 1 - 2 7 9 0 2 2, as in the "Production Example A 1", is as follows To prepare a polymer aqueous dispersion A 1. ", that is, in a flask equipped with a stirring device, a circulation cooler, two dropping funnels, a nitrogen introduction tube, and a thermometer, adding 380 parts of deionized water and 7.4 parts RAPISOL B90 (manufactured by Nippon Oil & Fat Co., Ltd., a trade name of sodium bis(2-ethylhexyl)sulfosuccinate, the active ingredient is 90%), that is, a surfactant solution is added, and the temperature is raised under nitrogen. At 80 ° C, an aqueous solution of a polymerization initiator (0.2 5 parts of sodium persulfate dissolved in 10 parts of deionized water) was added. After reaching 80 ° C again, the temperature of the mixture in the flask was maintained. At 80 ± 2 °C, a mixture of α, /3 - ethylenically unsaturated monomers (1.2 parts of 2-hydroxyethyl C methacrylate, 3 parts of ethylene glycol dimercaptoacrylate) Mix of ester, 15 parts styrene and 80.8 parts n-butyl methacrylate The compound) was dropped for 3 hours. In the dropwise addition of the monomer mixture, an aqueous solution of the polymerization initiator (a) (an aqueous solution obtained by dissolving 0.25 parts of sodium persulfate in 10 parts of deionized water) was dropped for 2 hours after the start of the dropwise addition. . After the dropwise addition of the α, /3 -ethylenically unsaturated monomer mixture and the aqueous polymer initiator aqueous solution (a) forming the particles, the polymerization was further carried out by heating at 80 ° C for 2 hours to prepare a polymer aqueous dispersion. Liquid A1. In the method of "Production Example B1" described on pages 1 to 19 of the "Publication No. 1-279902", the microgel is produced as follows.

In a flask equipped with a stirring device, a circulation cooler, a dropping funnel and a thermometer, 100 parts of the above aqueous polymer dispersion A 1 , 400 parts of decyl amyl ketone and 4 5 · 3 parts of 3 equivalents were added. Aqueous sodium hydroxide solution. The contents of the flask were heated to 85 ° C, and hydrolysis reaction was carried out at 85 ± 2 ° C for 3 hours. Next, the temperature was lowered to 80 ° C, 4 5.3 parts of a three-equivalent aqueous solution of hydrochloric acid was added to the contents of the flask to be neutralized, and then 143 parts of a solution of the acrylic resin A as a particle-dispersed resin was added. After stirring the contents of the flask for 10 minutes, 50 parts of a 20% aqueous solution of triethylamine acetate was added, and the stirring was stopped and allowed to stand, because the upper layer was separated from the organic layer and the lower layer of the polymer particles. The water layer is removed while the lower layer of water is removed. 400 parts of deionized water was added to the remaining organic layer in which the polymer particles were dispersed, and the temperature was raised to 70 ° C under stirring, and 25 parts of a 20 % aqueous solution of triethylamine acetate was added at 70 ° C. , stop stirring directly and let stand. Since the second layer is separated into the upper layer of the organic layer in which the polymer particles are dispersed and the lower layer of the water layer, the lower layer of the water layer is removed. In the remaining organic layer, it was found that 2.6 mass% of moisture remained depending on the card type moisture analyzer. Next, the temperature of the organic layer was cooled to 50 ° C, and 14 parts of ortho-methyl formate was dropped from the dropping funnel for 30 minutes, and then reacted at 50 ° C for 30 minutes. After that, add 200 parts of diphenylbenzene, and install a Dean-Stark trap (Dean-Stark trap) between the circulating cooler and the flask to connect the upper part of the circulating cooler and the aspirator for heating. 200914151 The flask was depressurized under stirring, and 5 Ο 4 parts of solvent was distilled off at 300 ° 1 0 0 mm H g and 80 ° 10 ° C to obtain a microgel (polymer non-polymer Aqueous dispersion). The resulting microgel had a heating residual of 50%, 2%, based on a Brookfield viscometer at 20 °C, 60 rpm, and the viscosity was 543 cps' according to Malvern Instruments L. The "A utosizer (trade name)" manufactured by td) measures an average particle diameter of 83 nm, and the moisture content is 0.1% according to the card type moisture meter. Further, the above acrylic resin A was prepared as follows. Namely, 42 parts of diphenylbenzene was added to a reactor equipped with a stirring device, a circulation cooler, a dropping funnel, a nitrogen gas introducing tube, and a thermometer. While introducing nitrogen into the reactor, the contents of the reactor were stirred and heated. When the temperature of the contents reached 140 ° C, 6 3.0 parts of the reactor were subjected to 36.4 parts of methyl group. N-butyl acrylate, 11.7 parts of 2-ethylhexyl methacrylate, hydrazine, 1 part of 2-hydroxyethyl methacrylate, 0.8 parts of a monomer mixture of acrylic acid, and 3.0 parts of a polymerization initiator, that is, The mixed solution of the third butyl benzoate was dropwise dropped by a dropping funnel for 2 hours while maintaining the contents of the reactor at 140 °C. After maintaining at 1400 ° C for 2 hours after dropping, the contents of the reactor were cooled and taken out. The content of the acrylic resin A was separated from this content. The acrylic resin A had a heating residual of 60% and a number average molecular weight of 650. <Production of Acrylic Resin C-1 for Clear Coating Material> An acrylic resin C-1 to C-6 for a clear coating material was obtained in the same manner as in the case of B-1 except that the materials were replaced by the materials shown in Table 2. Further, the characteristic values of the obtained 31 200914151 resin are shown in Table 2. [Table 2] Acrylic resin for transparent layer _ Acrylic resin solution name C-1 (J-2 03 C-4 C-5 C-6 Reaction solvent Solvesso # 100 70.5 70.5 70.5 70.5 70.5 70.5 n-butyl ester 20 20 20 20 20 20 Dropped monomer methyl methacrylate 61.7 78.7 63.7 58.2 46.7 85.7 Stupid ethylene 10 10 10 8.0 Butyl acrylate 8.0 1.0 15.0 6.5 25 Third butyl methacrylate 2.0 2-hydroxyethyl methacrylate 19 19 10 24 19 2-hydroxypropyl methacrylate 11 Acrylic acid 1.3 1.3 1.3 1.3 1.3 1.3 Starting agent peroxy-2-ethylhexanoic acid tert-butyl ester 2.1 2.1 2.1 2.1 2.1 2.1 Additional initiator transperoxide-2- Tert-butyl ethyl hexanoate 0.4 0.4 0.4 0.4 0.4 0.4 Solvesso # 100 7.0 7.0 7.0 7.0 7.0 7.0 Total 200.0 200.0 200.0 200.0 200.0 200.0 Characteristic value Resin solid content (%) 50 50 50 50 50 50 Hydroxyl value S2 82 43 104 82 43 Glass transition temperature (°c) 74 92 63 75 39 102 Weight _ average molecular weight 12000 12000 12000 12000 12000 12000 Acid price 10 10 10 10 10 10 <Preparation of primer coating BC-1> at 48.6 parts In the acrylic resin B-1 for coating, while stirring mix,

To a uniform mixture was prepared by gradually adding 9 parts of an aluminum pigment (aluminium paste 6340NS, trade name, manufactured by Toyo Kogyo Co., Ltd.) which was wetted with 15 parts of an organic solvent to form a paste. Next, 8 parts of melamine resin (Cymel 325, trade name, manufactured by Nippon Cyan Industrial Co., Ltd.) and 2.2 parts of epoxy resin (E PIΚ Ο TE 1 0 0 1 P, trade name, manufactured by Japan Epoxy Resins Co., Ltd.) were sequentially mixed. 60% solution, 14 parts CAB (CAB 531-1 'trade name, manufactured by Eastman Kodak Company) 20% solution, 〇 2 parts as anti-settling agent BYK-41 〇 (trade name, BYK Chemical Co., Ltd.), 3 parts of a 10% solution of Additol XL480 32 200914151 (trade name 'Cytec Surface Specialties Co., Ltd.) as a surface conditioner, and stirred to make a primer BC-1. <Preparation of primer coating materials B C - 2 to B C -1 1> The primer coating materials BC-2 to BC-11 were obtained in the same manner as in the case of B C -1 except that the materials were replaced by the materials shown in Table 3.

[Table 3] Primer Coating BC-1 BC-2 BC-3 BC-4 BC-5 BC-6 BC-7 BC-8 BC-9 BC-10 BCM1 Acrylic Resin Solution B-1 48.6 59.3 36.7 52.8 29.5 54.5 Acrylic resin solution B-2 45.0 Acrylic resin solution B-3 48.6 Acrylic resin solution B-4 48,6 Acrylic resin solution B-5 48.6 Propylene resin solution B-6 48.6 Tripolyamide resin 1) 8 12.3 8 8 8 8 9.4 5.7 1.8 22.5 8.9 Epoxy resin solution 2) 2.2 2 2.2 2.2 2.2 2.2 2.6 1.6 2.3 1.3 2.4 Cellulose to 14 13.5 14 14 14 14 1.5 30.8 17.9 20 Microgel 4) 7 Aluminium pigment 5) 9 9 9 9 9 9 9 7 7 8.5 9 Anti-settling agent 6, 4 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Episode transfer agent 7) 1 3 3 3 3 3 3 3 3 3 3 3 Organic solvent ^ 15 15 15 15 15 15 15 15 15 15 15 Total -- 1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 The solid content ratio of acrylic resin is 80/ 20 70/ 30 80/ 20 80/ 20 80/ 20 80/ 20 80/ 20 80/ 20 95/ 5 45/ 55 80/ 20 Relative to all solids of acrylic resin and terpene amide resin The ratio of cellulose or microgel is 9.1% 8.6% 9.1% 9.1% 9.1% 9.1% 0.8% 26.9% 12.9% 12.2% 10.2% &lt;Production of clear coating CC-1~CC-8&gt; The raw materials shown in Table 4 were uniformly stirred to prepare a clear coating CC·1 to CC-8. 33 200914151 [Table 4] Clear Coating CC-1 CC-2 CC-3 CC-4 CC-5 CC-6 CC-7 CC-8 Acrylic Resin Solution C-1 58.6 47 80.4 Acrylic Resin Solution C-2 65.4 Acrylic Tree Wax solution C-3 58.6 Acrylic resin solution C-4 58.6 Acrylic resin solution C-5 58.6 Acrylic resin solution C-6 58.6 Melamine resin 1) 24.4 17.6 36 2.6 24.4 24.4 24.4~^ 24.4 Surface conditioner 7) 3 3 3 3 3 3 3 3 Organic Solvent 8) 14 14 14 14 14 14 14 14 Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Solids ratio of acrylic resin and melamine resin 60/40 70/30 45/55 95/5 60/40 60 /40 60/40 60/40 Notes in Table 3 and Table 4: 1) Melamine resin · "Cymel 325", manufactured by Sakamoto Industrial Co., Ltd., trade name, solid content 80% 2) Epoxy Resin solution: 60% xylene solution manufactured by Japan Epoxy Resins Co., Ltd. under the trade name "EPIKOTE 1 001 P" 3) Cellulose: cellulose acetate butyrate (CAB), manufactured by Eastman Kodak Company, under the trade name "C 200% ethyl acetate solution of AB 5 3 1 -1" 4) Microgel: an organic crosslinked fine particle polymer nonaqueous dispersion produced in Production Example B1 of Table 5 of JP-A-1-279902, heating residue of 50% 5) aluminum pigment: Aluminum paste 6340NS", manufactured by Toyo Aluminum Co., Ltd., is the trade name, heating residue is 70% by mass. 6) Anti-settling agent: "B YK-4 1 0", made by BYK Chemical Co., Ltd. 7) Surface conditioner: manufactured by Nihon Cytec Industries Inc., trade name "Additol XL480 j of 34 200914151 1 ο % bismuth benzene solution 8 ) Dilution solvent: diphenylbenzene / acetic acid Ester = 7 0 / 30 mixed solution &lt;coating film test method&gt; (1) Primer refers to the dry coating primer coating, and after standing at room temperature for 3 minutes, the surface of the coating film is contacted with a finger to evaluate the coating film. Dryness of the surface. 〇: The surface is dry, the finger is not sticky X: The surface is not dry enough, the finger remains sticky (2) Appearance (Ming alignment) By indicating the difference in brightness with the direction of vision The index, that is, the angular reflection (FF value) is evaluated. As the measuring device, a commercially available metal feeling evaluation device (ALCOP LMR1 00, manufactured by Fuji Industrial Co., Ltd.) was used. 〇: FF value is 1.7 or more X: F F value is less than 1.7 (3) Appearance (transparent smoothness) The smoothness of the surface of the integrated coating film was visually judged. 〇: It is quite smooth (the unevenness of the coating film is hardly visible) △: The smoothness is lowered (the unevenness of the coating film is visible) X: The smoothness is considerably lowered (the unevenness of the coating film is remarkable) (4) The adhesion is made by a cutting machine Cutting the cutting line on the surface of the coating film to make it reach the substrate, and making a square of 1.0 mm long and 1.0 mm wide, and sticking the adhesive cellophane adhesive 35 200914151 to the surface, The number of remaining coating films on the square after the rapid peeling at 20 °C. This adhesion is used to evaluate the adhesion of the primer coating layer, the undercoat layer, and the transparent layer = 〇: 100 all residual Δ: 99 to 95 residual X: 94 remaining (5) pencil The hardness of the film surface is indicated by the Japan Paint Inspection Association's Mitsubishi UNI hardness test pencil, which has a pencil hardness of 3 inches, while holding a 45 degree angle and pushing forward about 10 mm with a load of about 1 kg. Investigate the occurrence of peeling, cracking and damage of the coating film. 〇: 5 times back and forth, without peeling, cracking and damage of the coating film X: 5 times back and forth, peeling, cracking and damage of the coating film more than once (6) Recoatability will be as shown in Example 1. The test plate prepared by the method is placed at room temperature for one day, and is not sanded on the coating film of the clear paint, but the same primer paint and clear paint are used for the tester. The test panels of the recoatability test were obtained by the same conditions as those of the test panels, which were coated and baked in a wet-stacked manner. The test plate was allowed to stand for 3 days at room temperature for the above adhesion test. The evaluation criteria are the same as the adhesion test. This recoatability test is a test method mainly for investigating the adhesion of a transparent layer and a primer applied thereto. 36 200914151 (Example 1) Commercially available magnesium alloy (Mg) which was chemically treated by a manganese phosphate-based chemical conversion agent (magnesium alloy treatment agent (magbond) P10: trade name &gt; manufactured by Japan Painter Co., Ltd.) -Al-Zn alloy, equivalent to the surface of JIS specification AZ91D), by (Bellfine Primer Ν ο. 500) (trade name, manufactured by BASF Coatings Co., Ltd., epoxy resin / melamine The cross-linking primer was applied by air spray to a dry coating film thickness of 20/zm to form a primer coating film. The primer film was baked at 160 ° C for 20 minutes. Next, the viscosity of the primer BC-1 was adjusted by adding a mixed dilution solvent (dichloromethane/butyl acetate = 50/500 mixed solution) to a rock viscosity cup Ν K 2 for 12 seconds. (20 ° C). On the surface of the above primer, the viscosity-adjusting primer BC-1 was applied by air spray to a dry film thickness of 1 5 &quot; m. After the coating film of the primer coating was allowed to stand at room temperature for 3 minutes, the clear coating CC-1 was applied to the coating film of the primer coating which was not hardened by air spraying to a dry film thickness of 25 /zm. The viscosity of the transparent coating CC-1 is adjusted by adding a mixed dilution solvent (diphenylbenzene/butyl acetate = 5 0 / 50 mixed solution) to the viscosity of the Iwata viscosity cup NK2 for 16 seconds (20 °C). The coating film of the undercoating material and the coating film of the clear coating material formed on the coating film were baked at 160 ° C for 20 minutes to obtain a test plate. The results of the coating film test are shown in Table 5. [Table 5] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Metal material town alloy alloy alloy alloy alloy alloy aluminum alloy non-mineral steel primer P-1 P-1 P-1 P-1 P-1 P-1 P-2 Primer Coating BC-1 BC-2 BC-1 BC-2 BC-11 BC-1 BC-1 Clear Coating CC-1 CC-1 CC-2 CC-2 CC-1 CC-1 CC-1 Primer Dryness 〇〇〇〇〇〇〇 Appearance (Ming Alignment) 〇〇〇〇〇〇〇37 200914151 Appearance (transparent smoothness) 〇〇 〇〇〇〇〇 Adhesion 〇〇〇〇〇〇〇 Pencil hardness 〇〇〇〇〇〇〇 Recoatability _ 1 〇〇〇〇〇〇〇 Acrylic resin butyl g (°C) 82 55 82 55 82 82 82 Dp Acrylic resin hydroxyl value 82 82 82 82 Bu S2 82 82 AC/MF solid fraction ratio 80/20 70/30 80/20 70/30 80/20 80/20 80/20 Cellulose or microgel amount 8.9% 8.9% 8.9% 8.9% 8.9% 8.9% 8.9% Acrylic resin Tg(°C) 74 74 92 92 74 74 74 CC Acrylic resin hydroxyl value S2 82 82 82 82 82 82 AC/MF solid fraction ratio 60/40 60/40 70/30 70/30 60/40 60/40 60/40

Note: In Table 5, 'BC denotes an undercoat layer, CC denotes a transparent layer, AC denotes an acrylic resin, and MF denotes a melamine resin fv (Examples 2 to 5, Comparative Examples 1 to 1 4) except as shown in Tables 5 to 7. A test plate was produced in the same manner as in Example 1 except that the primer coating and the clear coating were replaced. The test results are shown in Tables 5 to 7. (Example 6) In place of the material, a commercially available aluminum alloy (Al-Si-Cu-based alloy, ADC12 equivalent to JIS standard) was replaced by an organic metal salt system (pwc〇at 3753: trade name 'Japan Parkerizing Co., Ltd. Limited) A test plate was produced in the same manner as in Example 1 except for the production of the company. The results of the coating film test are shown in Table 5. (Example 7) The material was replaced with a commercially available stainless steel (austenite type, SUS304 equivalent to JIS standard), and the composition was chromated (Palchrome R282: trade name, manufactured by Nippon Parkerizing Co., Ltd.) , primer with epoxy resin / guanamine polyamine cross-linking type (Bell fine 38 200914151

Primer No. 2000: trade name, manufactured by BASF Coatings Co., Ltd.) A test plate was produced in the same manner as in Example 1. The results of the film test are shown in Table 5.

f 61 61 Ϊ is also compared with Example 1 匕 匕 〖 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 匕 ; 匕匕Comparative example 10 Metal material k Han alloy&lt;Xi alloy ί 溪 alloy&gt; α alloy&lt; 合金 镇 镇 镇 镇 镇 i town alloy alloy alloy primer P-1 P-1 P-1 P-1 P -1 P-1 Fl P-1 P-1 P-1 Primer Coating BC-3 BC-4 BC-5 BC-6 BC-7 BC-8 BC-9 | BC-10 BC-1 BC-1 Transparent Coating CC-1 CC-1 CC-1 CC-1 CC] CC-1 CC-1 CC-1 CC-3 CC-4 Primer Dryness 〇〇〇〇X 〇〇υ uo Appearance (Aluminum Alignment) Sex) 〇〇〇〇X 〇〇0 (J 〇 Appearance (transparent smoothness) 〇〇〇〇〇oio 〇△ 〇 Adhesion △ X 1 〇〇〇X △ X o X Pencil hardness X 〇X 〇〇〇 X 〇o X Recoatability △ 1 X 〇X 〇X Δ XXX BC CC Acrylic resin Tg(°c) 82 82 30 102 82 82 82 82 82 82 Acrylic resin hydroxy value 41 120 82 39 82 82 82 82 82 82 AC/MF solids ratio 80/ 20 80/ 20 80/ 20 80/ 20 80/ 20 80/ 20 95/ 5 45/ 55 80/ 20 80/ 20 Cellulose or micro-condensation 8.9% 8.9% 8.9% 8.9% 0.8% 26.8% 10.6% 5.6% 8.9% 8.9% Acrylic resin Tg(°C) 74 74 74 74 74 74 74 74 74 74 Propylene resin Μ value 82 82 82 82 82 82 82 82 82 82 AC/MF solid fraction 60/ 40 60/ 40 60/ 40 60/ 40 60/ 40 60/ 40 60/ 40 60/ 40 45/ 55 95/ 5 [Table 7] Comparative Example 11 Comparative Example 12 Comparative Example 13 Comparative Example 14 Metallic material, money alloy, alloy alloy alloy alloy primer P-1 P-1 P-1 P-1 Primer coating BC-1 BC-1 BC-1 BC-1 Clear coating CC-5 CC-6 CC-7 CC-8 Primer Dryness 〇〇〇〇 Appearance (Aluminum Alignment) 〇X 〇〇 Appearance (Transparent Smoothness) 〇X 〇〇Adhesion 〇〇〇〇Pencil Hardness X 〇X 〇Reset S Δ X 〇X BC Acrylic resin Tg(°c) 82 82 82 82 Acrylic resin value 82 82 82 82 AC/MF solid fraction 80/ 20 80/ 20 80/ 20 80/ 20 Cellulose or microgel amount 8.9% 8.9% 8.9% 8.9% 39 200914151 Acrylic resin Tg(°c) 63 75 39 102 Acrylic resin value 43 104 82 43 AC/MF solid content ratio 60/ 40 60/ 40 60/ 40 60/ 40 Note: in Tables 6 and 7 In the middle, BC denotes an undercoat layer: layer, AC means acrylic resin, MF means melamine &lt;summary&gt; It is apparent from the results shown in Tables 5 to 7 that Examples 1 to 7 are dry on the primer. Any of properties, appearance, hardness, and recoatability are excellent. In Comparative Example 1, the hydroxyl group-containing value of the primer coating was less than 50 mgKOH / g, and the adhesion and the pen hardness were good; in Comparative Example 2, the hydroxy-containing acrylic resin was mgKOH / g, adhesion, and then Poor paintability. In the glass of the hydroxyl group-containing acrylic resin of the primer coating, it was transferred at 50 ° C, so the pencil hardness was poor; in Comparative Example 4, the temperature was 100 ° C or more, and thus the recoatability was poor. Further, since the amount of the cellulose-based resin of the primer coating material is less than 1.0% by mass in terms of the hydroxy group-containing acrylic resin and the melamine resin, the undercoating paint has poor coating properties and is 25 mass%. In Comparative Example 6 of /〇 or more, the coating property of the layer was poor. Further, in Comparative Example 7, since the total amount of the fat in the solid content of the acrylic resin and the melamine resin was less than 10% by mass, the adhesion and the pencil hardness of Example 8 were that the amount of the melamine resin was more than 50% by mass. /. , CC means transparent resin. According to the adhesion of the present invention, the re-coating property of the pencil acrylic resin is greater than 100. In the case 3, the temperature (Tg) is less than the glass transition, in Comparative Example 5, relative to 1 0 0 After the entire resin was solidified, the adhesion between the dry touch and the melamine tree in the primer coating were poor, and the recoatability was not 40 200914151. In Comparative Example 9, the amount of the melamine resin in the entire solid content of the acrylic resin and the melamine resin for the clear coating was more than 50% by mass, so the appearance (transparent smoothness) and the recoatability were poor, and the amount of the melamine resin was small. In Comparative Example 10 of less than 10% by mass, sufficient coating film hardness could not be obtained. In Comparative Example 11, the hydroxyl group-containing acrylic resin used for the clear coating had a value of less than 50 mg Κ Ο H / g, and thus the hardness of the pen was poor, and the recoatability was poor. In Comparative Example 2, the hydroxy group-containing acrylic acid was used. The hydroxyl value of the resin is more than 100 mg Κ Ο H / g, so the appearance and recoatability are poor. In Comparative Example 13, the glass transition temperature (T g) of the hydroxyl group-containing acrylic resin used for the clear coating was less than 70 ° C, so the pencil hardness was poor, and in Comparative Example 14, the glass transition temperature was 1 〇〇. Above °C, the recoatability is poor. [Simple description of the diagram] None [Key component symbol description] None 41

Claims (1)

200914151 X. Patent application scope: 1. A method for forming a multi-layer coating film, comprising: (1) a step of applying a primer coating on a surface of a metal material, the primer coating (a) comprising: melamine resin, Hydroxyl-containing acrylic resin, cellulose-based resin and/or microgel, and gloss having a hydroxyl value of 50 to 100 mgKOH/g and a glass transition temperature (Tg) of 50 to 100 °C And (b) the ratio of the hydroxyl group-containing acrylic resin to the melamine resin, in the solid content ratio of 50:50 to 9000:10, and the cellulose resin and/or microgel The ratio of the solid content of the hydroxyl group-containing acrylic resin and the melamine resin is 1.0 to 20% by mass in terms of solid content; (2) the step of applying a clear coating, the transparent coating (a) contains: a melamine resin and a hydroxyl group-containing acrylic resin having a value of 50 to 100 mgKOH/g and a glass transition temperature (Tg) of 70 to 100 ° C; and, (b) a ratio of the hydroxyl group-containing acrylic resin to the melamine resin, in a solid form The mass ratio is 50: 50~90: 10; and (3) the step of simultaneously baking the above primer coating and the above clear coating. 2. The method for forming a multi-layer coating film according to claim 1, wherein the surface of the metal material is subjected to a chemical conversion treatment and then a primer is applied. A coated article obtained by the method for forming a multi-layer coating film according to the above-mentioned claim. 42 200914151 VII. Designated representative map: (1) The representative representative of the case is: No (2). The representative symbol of the representative figure is a simple description: No. 8. If there is a chemical formula in this case, please reveal the best indication of the characteristics of the invention. Chemical formula: none