TW200427797A - Method for coated composite film - Google Patents

Abstract

Disclosed is a coated composite film formation method by a three-coat one-bake method, which can form a coated composite film excellent in appearance, in particular, gloss appearance, and excellent in anti-chipping properties. The method comprises forming an electrocoated film on a substrate, and then successively applying an intermediate paint, a base paint and a clear paint in a wet-on-wet manner, followed by baking and curing the applied three layers at once, wherein the baking and curing includes both a low-temperature heating stage of heating at a temperature which is 25 to 80% of a curing temperature for a time which is 5 to 30% of a curing time, and a high-temperature heating stage of heating at a temperature which exceeds 80% and is not more than 120% of a curing temperature for a time which is 30 to 130% of a curing time.

Description

200427797 发明 Description of the invention: [Technical Field of the Invention] 3 Field of the Invention The present invention relates to a method for forming a coated composite film, and in particular 5 relates to a method for forming a coated film through a three-coat baking method. Method for covering composite film. I: Prior technology:! BACKGROUND OF THE INVENTION There are two methods for forming coated composite films. One method 10 is to dry and harden each coating film individually after coating. Another method is to form a coated composite film by applying two or more coatings without hardening, and then hardening it once. For example, a two-layer baking method is usually used to form a metal coating film. JP-ANo. 11-114489 discloses a method for forming a coated composite film, which comprises continuously forming a color base coating film, a metal 15 base coating film, and a transparent coating film, and then baking and hardening three layers simultaneously,俾 Promote film appearance. When the intermediate coating film, the base coating film and the transparent coating film are formed by baking the three coating films once, the oven for curing the intermediate coating film can be eliminated. In this way, energy consumption can be reduced and operating time can be shortened, which has important advantages in terms of economics and environmental protection. However, in the three-coat film drying method, the three-layer coating film is laid in a wet state or a moisture-dry state. For this reason, the escape route of the solvent is reduced or limited. Therefore, the conventional continuous baking method or the two-coat baking method is used to increase the content of non-volatile components in the coated composite film. As a result, the solvent contained in one layer of coating film has a good effect. Especially when moving to the adjacent coating film during heating, the movement of the solvent tends to increase the so-called mixing phenomenon during baking and hardening. The adjacent coating films dissolve each other, and the components contained in the individual coating films are combined with each other. When the phase mixing phenomenon occurs, the result depends on the significant difference. In particular, the subtraction does not affect the optical science of the coated composite film.

On the other hand, JP-A No. 2000_84463 suggests a method of performing the drying and hardening steps under two-stage heating conditions as a method for forming a smooth coating film using a solvent-based thermosetting coating. The choice of this method Η) The solvent contained in the coating is removed by gentle evaporation, which can prevent rough edges on the surface of the coating film, but the three-coat baking method has the following problems.

In some cases, the peeling of the coating film occurs by so-called dicing wafers, and the dicing wafers occur when a moving vehicle hits vermiculite and the crane vermiculite hits the coating film. In the conventional method of forming a coated composite film, for example, an individual baking method for applying 15 coating materials and a one-time baking method for two coating films, the base coating film and the intermediate coating film are respectively baked and hardened. Therefore, strategies for cutting-resistant wafers can be achieved by forming a cutting-resistant wafer coating film above or below the intermediate coating film, or by adjusting the top coating film shell degree and the bottom coating film vandal degree to form an intermediate coating film that has not yet come off. For example, JP-A No. 2002-249699 and JP-A No. 9-208882 describe 20 kinds of wafer-cutting primer coating compositions, and the wafer coating film is cut after the coated composite film is formed. In addition, in JP-A No. 6-256714 or JP-A No. 6-254482, the improvement of the cut-resistant wafer properties is studied from the viewpoint of an intermediate coating composition, but the degree of improvement is not sufficient for a three-coat film drying method. 6 200427797 t ^^ Description; 1 Summary of the invention The present invention solves the conventional problems. The purpose of the present invention is to provide a three-coat film drying method to form a good appearance, especially the gloss 5 and excellent chip resistance. Method of coated composite film. The invention provides a method for manufacturing a coated composite film, comprising forming an electro-coated film on a substrate, and then continuously applying an intermediate coating, a base coating, and a transparent coating in a wet-on-wet manner, and then once Three layers applied for baking and hardening, of which 10 the baking and hardening include a low-temperature heating stage at 25% to 80% of the hardening temperature and heating for 5% to 30% of the hardening time; and a high temperature In the heating stage, it is heated at a temperature exceeding 80% but not higher than 120%, and the heating time is 30% to 130%. Embodiment C] 15 Detailed description of the preferred embodiment of the method for forming a coated composite film formed in Ben Maoming, the intermediate coating film is formed by an intermediate coating, the base coating film is formed by a base coating, and the transparent coating is formed. The film system is formed by a transparent paint, and each coating film is sequentially formed on a 20 substrate in a wet-on-wet manner. "" When the car body is used as a base material, an electric waist is formed on the car body steel plate in advance as a riding technique (commonly called a "bottom coating film"). In the application of the intermediate coating, the material is applied by multi-stage coating, preferably by electrostatic spraying for two-stage copper; or by electrostatic spraying and / or using a rotary 7 atomizing electrostatic coating machine, the The machine is called "# micro) bel", "# (micr〇) bei" or "metabel". The thickness of the dry coating film formed by the intermediate coating Intended use changed. A thickness of 10 to 60 microns can be used in many cases. When the thickness exceeds the upper limit, the sharpness of the image decreases, and in some cases, defects such as unevenness and concave fo appear in the coating, and when the thickness is lower than the lower limit, the surface may be covered and uneven coating may occur. In the method for forming a coated composite film of the present invention, a primer and a transparent coating are applied on an unhardened intermediate coating film by wet application to form a base coating film and a transparent coating film. The base coating used to form the base coating film can be applied by electrostatic spraying, or by using a rotary atomizing electrostatic coater such as a meta shell, pico shell, or micro shell machine. The dry thickness of the coating film is 5 to 35 microns, and preferably 7 to 25 microns. When the thickness of the base coating film exceeds 35 micrometers, the sharpness of the image is reduced, and unevenness or dents appear in some cases. When the thickness is less than 5 micrometers, the surface covering properties are insufficient, and occasionally a non-uniform coating (discontinuous film state) appears. When there is non-uniformity caused by the base coating film, or when it contains pigments, 'form a transparent coating film for protection, covering the small protrusions formed: 3 coating Γ 2 is particularly preferred to use a rotary atomizing electrostatic coating machine such as The coating film is formed by slightly releasing the shell machine. The dry thickness of the transparent coating film is preferably about 10 μm to 80 μm, and about 20 μm to 6 μm. When the dry thickness exceeds the upper limit, defects such as bursting and dents appear below. When the thickness is below the lower limit, there is no surface irregularity. The composite film thus coated is hardened by simultaneous heating. This method is commonly referred to as the three-coat film-sub-bake method. The thickness of the coated composite film is mostly 30 to 30 G micrometers and difficult to be 50 to 2 electric meters. When the thickness exceeds the upper limit, the physical properties of the film, such as a temperature cycle test, decrease. When the thickness is lower than the lower limit, the film strength decreases. In order to sufficiently harden the coating layer applied to the surface of the substrate, the curing conditions are set for the thermosetting paint. When _coating_ is hardened under conditions that do not satisfy the hardening conditions, the coated composite film is insufficient in degree, and the efficiency of the coated composite film is reduced. Generally used as the curing conditions of thermosetting coatings, setting the curing temperature (° c) and curing time. The hardening temperature refers to the ambient temperature where the coating film is dried and hardened by the conventional single-stage heating method. It is usually the temperature at which the coated composite film is placed to dry. The hardening temperature is determined based on the reaction temperature of the crosslinked system of the coated composite film and the actual production line facilities. The hardening time refers to the time required to harden the coated composite film at the hardening temperature. As for the hardening time, the optimal value is determined experimentally based on the type of coating and the thickness of the coated composite film. The time required for the hardening phase to obtain the actual required performance of the coated composite film is determined, and the hardening temperature of the facility mode of the application-only production line is considered. In the method of the present invention, the coated three-layered beef is roasted and hardened in a low temperature heating stage and a high temperature heating stage, and each stage is advanced in time. When performing low-temperature heating in a short time, the total heating time is not: when: 200427797 time, and the working efficiency will not be reduced. It is considered that because the deposited volatile components can be increased through the low-temperature heating stage, the mixing of the layers can be avoided. In the low temperature heating stage of Ben Sheming, the thermosetting coating layer formed on the surface of the substrate is 25% to 80% and preferably 35 to 60 ° /. The temperature is increased by 5 hours, and the hardening time is 5 to 30% and preferably 10 to 20%. When the curing temperature and curing time are outside this range, the technical effect is insufficient. For example, when the hardening temperature is 140 ° C, the low-temperature heating temperature is 35t: to 112 ° C and preferably 49C to 84C. When the hardening temperature is, the low-temperature heating temperature is 25. [To 80C and preferably 35 ° C to 60 ° C. Further, when the hardening time is 30 minutes, the 10 low-temperature heating time is 2 to 9 minutes and preferably 3 to 6 minutes. When the hardening time is 60 minutes, the low-temperature heating time is 3 to 18 minutes, and the best time is 6 to closing hours. In the high-temperature heating stage, the thermosetting coating layer is further heated at a temperature exceeding 80% of the hardening temperature but not at 120% and preferably at a temperature of 5% and preferably $ ㈣ to _ %time. When the hardening temperature and hardening time exceed the upper limit, stress and strain accumulate, and in some cases cracks appear on the coated composite film. For example, when the hardening temperature is a thief, the high-temperature heating temperature exceeds 112. 0 but is not higher than 16th generation and preferably 12th to 15th generation. When the hardening temperature is high, the high-temperature heating temperature exceeds 8 (rc but 20 is not less than 12 (TCi is preferably P. to E. In addition, when the hardening time is ^ Rico ', the current heating day is 10 to 40 minutes and more It is preferably 15 to 30 minutes, and the hardening time is 6G minutes, and the high-temperature heating time is _ to the financial clock, and preferably 30 to 60 minutes. Heating can be performed by a method known to those skilled in the art. Usually, the upper coating is applied. 10 200427797 Objects covered with thermosetting coating can be maintained in a drying oven adjusted to the heating temperature. In particular, the method includes: A procedure for placing the object to be coated in the drying oven, the object has been coated with thermosetting coating. The oven is controlled at a lower temperature heating temperature to maintain the low-temperature heating time, and then adjust the drying oven temperature to a high-temperature heating temperature, and maintain the high-temperature heating time; a procedure for preparing a tunnel-type dryer, in which the inlets at both ends and The outlet is open. The drying is carried out by the belt conveyor to move the material in the tunnel dryer 10, and the inside of the tunnel is divided into a low temperature zone and a high temperature zone. The temperature in the low temperature zone is adjusted to Warming temperature 'and adjusting the temperature of the south temperature zone to the warming temperature, first passing the object through the low temperature zone to the low temperature heating time, and then passing the object through the south temperature zone to the south temperature heating time, and a program including preparing a first The drying oven is adjusted to a low-temperature heating temperature of 15 degrees, and a second drying oven is adjusted to a high-temperature heating temperature, and then the object to be coated with the thermosetting coating is maintained in the first drying oven to undergo the low-temperature heating time, and to maintain the The object is subjected to high-temperature heating time in the second drying oven. Intermediate coating film 20 In the coating film forming method of the present invention, the intermediate coating is used to form an intermediate coating film, and the intermediate coating contains (a) a urethane-modified polyester Resin, (b) melamine resin, (c) block isocyanate compound, (d) non-aqueous dispersion resin with core-shell structure and (e) flake pigment. The intermediate coating further contains various organic or inorganic pigments and Expander pigment. 11 200427797 Polyurethane resin modified with urethane (a) can pass through hydroxyl-containing polyester resin and aliphatic isocyanate The compound is obtained by reaction. Generally, the polyester resin can be prepared by polycondensation of an acid component such as a carboxylic acid, an acid anhydride, and acid chloride with a monohydric alcohol or a polyhydric alcohol. The hydroxyl-containing 5 polyester resin used in the present invention contains a total of acid components. Molar number as a reference, 80 mol% or more of the acid component used in the polycondensation reaction of phthalic acid. When the content of isophthalic acid in the acid component is less than 80 mol%, the obtained hydroxyl-containing polyester resin The glass transition temperature (Tg) becomes lower than a desired range. The acid component other than isophthalic acid includes, for example, phosphophthalic acid, phosphobenzene 10 dianhydride, tetrahydrophosphoric acid, tetrahydrophosphophthalic anhydride, and Hydrophosphalic acid, hexahydrophosphic phthalic anhydride, methyltetrahydrophosphoric acid, methyltetrahydrophthalic anhydride, himic acid anhydride, trimellitic acid, trimellitic acid Trianhydride, pyromellitic acid, pyromellitic anhydride, terephthalic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, adipic acid, azelaic acid, sebacic acid Acid, 15 succinic acid, succinic anhydride, dodecenyl succinic acid, dodecenyl succinic anhydride, and the like. In addition, the acid component may contain acids other than polyvalent carboxylic acids and polyvalent carboxylic anhydrides which are commonly used in the preparation of polyester resins. Such acids include, for example, monocarboxylic acids and hydroxycarboxylic acids. As for the acid used for preparing the hydroxyl-containing polyester resin, isophthalic acid may be used alone, or other acids may be used in combination. 20 Polyacryl alcohols include, for example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-adipylene, 2,2-dimethyl-3 -Ethylpropyl-2,2-dimethyl-3-acrylic acid propionate, 2,2,2-trimethyl-1,3-pentanediol, polytetramethylene ether glycol, polyether Hexa 12 200427797 lactone polyol, glycerol, sorbitol, annotol1, trimethylolethane, trimethylolpropane, trimethylolbutane, hexanetriol, pentaerythritol, Dipentaerythritol and so on. In the preparation of the hydroxyl-containing polyester resin, in addition to the acid component and the polyhydric alcohol 5, other components that can react with these components can also be used. These other components include, for example, acid chlorides, acid derivatives of lactones, epoxy compounds, and dry and semi-dry oils and fatty acid derivatives thereof. Lactones can form graft chains by ring-opening addition to polyester resins formed from polyvalent carboxylic acids and polyhydric alcohols. Lactones include, for example, cold-propiolactone, dimethylpropiolactone, butyrolactone, 10-valerolactone, ε-caprolactone, γ-caprolactone, γ-caprolactone, crotonolide, pentyl Lactone, caprolactone, etc. Particularly, ε_caprolactone is most preferable. Specific examples include an epoxy compound such as Carjula E (manufactured by Shell Chemical Co.) caprolactones. The warp-containing polyester resin has a glass transition temperature (Tg) of 40 to 85 15 ° C and preferably 45 to 75 ° C. When the glass transition temperature (Tg) is lower than 40 ° C, the film hardness decreases. When Tg is higher than 80 ° c, the cut-resistant chip performance is reduced. The aliphatic isocyanate compound includes, for example, hexamethylene diisocyanate, dimethylhexamethylene diisocyanate, cyclohexane diisocyanate, mono-hexylmethane-4,4-diisocyanate, methylcyclohexane diisocyanate, and 20 Isophor S is the same as diisocyanate. In particular, the cut-resistant wafer performance and weather resistance of the coated composite film ^ good use of hexamethylene diisocyanate g or trimethylhexamethylene diisomyrate. Biuret, isocyanurate and adducts thereof can be used. The reaction of the hydroxyl-containing polyester resin with the aliphatic isocyanate compound can be carried out by a method known to those skilled in the art through 13 200427797. The urethane-modified polyester resin (a) has a number average molecular weight (Mη) of 1500 to 3000 and preferably 17,000 to 250,000. When the molecular weight is less than 1500, workability and hardenability are insufficient. When the molecular weight exceeds 3,000, the non-volatile content at the time of 5 coating is too low, but the working ability is inferior. The number average molecular weight here is determined by GPC method using polystyrene as a standard. The urethane-modified polyester resin ⑷ has a hydroxyl value (OHV) of preferably 30 to 180 and more preferably 40 to 160. When the hydroxyl value exceeds 180, the water resistance of the 10-coated composite film decreases. When the hydroxyl value is less than 30, the hardenability of the coated composite film decreases. In addition, the resin has an acid value (AV) of preferably 3 to 30 mg KOH / g, more preferably 5 to 25 mg KOH / g. When the acid value exceeds 30 mg KOH / g, the water resistance of the coated composite film decreases. When the acid value is less than 3 mg KOH / g, the hardenability of the coated composite film decreases. 15 Urethane-modified polyester resin (a) contained in the intermediate coating, based on the solid content of the resin, the content is 40 to 56% by weight and preferably 43 to 50% by weight . When the content is less than 40% by weight, the cut-resistant wafer efficiency becomes insufficient. When the content exceeds 56 ° /. At a weight ratio, the hardness of the coated composite film decreases. 20 Considering the improvement of the elasticity of the coated composite film by including a urethane-modified polyester resin as an intermediate coating component, the chip resistance of the coated composite film is also improved. The components of the melamine resin (b) and the block isocyanate compound (0 is used to harden the urethane-modified polyester resin 0) described later. 14 Melamine resins are not particularly limited, but include methylated melamine resins, butylated melamine resins, or methyl, butane, and beta-containing amidine resins. For example, "Cymel-303", "Sai ^ ^ Wu Wu 254", "U Ban" 128 "and" Ubon 20N60 "are sold by Mitsui Tokiyama, 1" and "Su Min The "sumimar series" is sold by Sumitomo Chemical. Based on the solid weight of the resin in the coating, the weight of the resin is 3, and the weight of the melamine resin (b) in the intermediate coating is 10 to 30%. And preferably, when 15 to 25% by weight is less than 10% by weight based on the summer content of azoxystrobin, the hardening of the coated composite 10 film is insufficient. When the content exceeds 20% by weight, the coated composite film after hardening is too hard and too brittle. Isocyanuric compounds of Ganjin segment are obtained by adding a blocking agent to an aliphatic isocyanate or a derivative thereof. When the neostigmine compound is heated, the latter dissociates to produce isocyanate groups, which react with the hydroxyl groups of the polyester resin modified with urethane to harden the material. 15

The aliphatic isocyanate and its derivative include, for example, a compound for producing a polyester resin modified with urethane Ss. Blocking agents include, for example, compounds having an active methylene group such as ethyl acetone, ethyl acetoacetate, and ethyl malonate. By using a blocking agent, the elasticity of the coated composite film is improved, and the chip resistance of the coated composite film is also improved. The glycine-dans gas acid compounds are produced, for example, by Asahi Chemical Industry Co., Ltd. as active methylene block isocyanate "Duranate MF-K60X". The content of the block isocyanate compound (c) of the intermediate coating is 15 to 30% by weight and preferably 17 15 200427797 to 25% by weight based on the resin solid content of the coating. When each b b y, Libita 3 罝 is less than 15% by weight, the hardenability is insufficient; and when the content is over =% by weight, the hardened film is too hard and brittle. ', Non-aqueous dispersion resin with a heart-cut structure can be prepared by copolymerizing a dispersion stabilizer resin and a copolymerizable monomer in a mixed solution containing an organic solvent. The copolymerization obtains a resin that is non-crosslinked, and the sister is insoluble. In the secret solution. There is no particular limitation on the monomers to be copolymerized to obtain non-parent particles in the presence of a stable stabilizer resin, as long as it is a group-polymerizable unsaturated monomer.

In order to synthesize dispersion stabilizer resins and non-aqueous dispersions, it is preferred to use 10 polymerizable monomers having functional groups, because non-aqueous dispersions having functional groups can be combined with hardeners and dispersion stabilizers containing functional groups. The reaction forms a three-dimensionally cross-linked coated composite film. Daozhengye Nuwaya is not limited as long as it can stably synthesize a non-aqueous dispersion in an organic solvent. Particularly preferred is the use of acrylic resins,

15% resin, polyester resin, polycarbon resin, polyurethane resin, etc., which have a value of 10 to 25G and are more cautious, and have an acid value of G to KOH / g and preferably 0 to% mg. And the number average molecular weight is 800 to 100, and preferably, _, _. When the foregoing parameters exceed the upper limit, the handling properties of the resin are reduced, and the handling properties of the non-aqueous dispersion are also reduced. When the parameter is lower than the lower limit, the coating film may be desorbed, and when formulated into a coated composite film, the particle stability is reduced. The method for synthesizing the dispersion stabilizer resin is not particularly limited, but preferably includes a method of obtaining a resin through group polymerization in the presence of a group polymerization initiator 'and a method of obtaining a resin through a condensation method or addition reaction. In addition, 16 200427797 monomers used to obtain dispersions of antacene can be appropriately selected according to the properties of the resin, but the monomers ((fluorenyl, acid scale)) are preferably used, and these functional groups are used for the synthesis of non- The polymerizable monomers of the aqueous dispersion are detailed later (3); further-if necessary, monomers having functional groups such as glycidyl 5 group, isocyanate group, etc. can be used. In addition, the weight ratio of the dispersion stabilizer resin to the polymerizable monomer can be arbitrarily selected according to the purpose of use. For example, based on the total weight of the two components, the dispersion stabilizer resin is 3 to 80% by weight, particularly 5 to 60% by weight, and the polymerizable monomer is 97 to 20% by weight and particularly 95 to 40%. weight ratio. In addition, based on the total weight of 10, the total concentration of the dispersion stabilizer resin and the polymerizable monomer in the organic solvent is preferably 30 to 80% by weight, and particularly 40 to 60% by weight. The non-aqueous dispersion can be obtained by polymerizing a group-polymerizable monomer in the presence of a dispersion stabilizer resin. In this non-aqueous dispersion, the preferred hydroxyl value is 50 to 400, preferably 100 to 300, the acid value is 0 to 200 mg KOH / g and 15 is preferably 0 to 50 mg KOH / g and the average particle diameter ( 1) 5 ()) is from 0.05 to 10 microns and preferably from 0.1 to 2 microns. When the parameter is below the lower limit, the particle shape cannot be maintained. When the parameter exceeds the upper limit, the stability of the dispersion in the coating decreases. 20 representative examples of polymerizable monomers having functional groups for synthesizing non-aqueous dispersions include hydroxyl-containing monomers such as hydroxyethyl (meth) acrylate, propyl (meth) acrylate, and (meth) Hydroxybutyl acrylate, hydroxymethyl (meth) acrylate, acryl alcohol, and adducts of hydroxyethyl (meth) acrylate and ε-caprolactone. On the other hand, the monomer having an acid group includes, for example, a polymerizable monomer having a carboxyl group, a sulfonic acid 17 200427797 group, and the like. The monomer having a carboxyl group includes, for example, (meth) acrylic acid, crotonic acid, ethacrylic acid, propyl acrylic acid, isopropyl acrylic acid, itaconic acid, maleic anhydride, fumaric acid, and the like. The polymerizable monomer having a sulfonic acid group includes, for example, tertiary butylacrylamide sulfonic acid and the like. When a polymerizable monomer having an acid group is used, it is preferable that a part of the acid group is a carboxylic acid group. Further, the polymerizable monomer having a functional group includes, for example, a glycidyl group-containing unsaturated monomer such as glycidyl (meth) acrylate; and an isocyanate group-containing unsaturated monomer such as m-isopropenyldimethylformate. Benzyl isocyanate, ethyl isocyanate and the like. 10 Other polymerizable monomers include, for example, (meth) acrylic acid, such as methyl (meth) acrylate, ethyl (fluorenyl) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid. N-propyl ester, n-butyl (meth) acrylate, third butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate Octyl ester, lauryl (meth) acrylate, (fluorenyl) 15 stearyl acrylate and tridecyl (meth) acrylate; oil fatty acids and acrylic or fluorenyl acrylate monomers having an ethylene oxide structure Addition reaction products (such as the addition reaction products of stearic acid and glycidyl methacrylate, etc.); addition reaction products of ethylene oxide compounds containing Q or more alkyl groups and acrylic acid or methacrylic acid, styrene , Α-methylstyrene, ortho-fluorenyl 20 ethylene, m-fluorenyl styrene, p-methylstyrene, p-tert-butyl styrene, benzyl (fluorenyl) acrylate, itaconic acid Ester (dimethyl itaconic acid), maleate (maleic acid Methyl ester), fumarate (dimethyl fumarate); and other polymerizable monomers such as acrylonitrile, methyl acrylonitrile, methyl isopropenyl ketone, vinyl acetate, Veoba monomer ("trade name" manufactured by Shell Chemicals 18A Division), vinyl propionate, vinyl pivalate, propylene oxide, ethylene, propylene, butadiene, acrylic acid N, N_dimethyl Aminoaminoethyl, methylpropionate N, N-dimethylaminoethyl, acrylamide, and vinyl. Che Jiaojia's polymerization reaction used to obtain a non-aqueous dispersion was carried out in the presence of a group of human hair bowers. Group polymerization initiators include, for example, azo-based initiators, such as 2,2, -azo azoisobutyronitrile and 2,2, -azo hydrazone (2, 'dimethylvaleronitrile), peroxide Stupid formazan, laurel peroxide, tertiary butanone, etc. The polymerizable monomer is preferably 100 parts by weight with respect to the total amount, and such an initiator is 0.2 to 10 parts by weight and more preferably 0.5 to 5 parts by weight. The polymerization reaction which is preferably used to obtain a non-aqueous dispersion in an organic solvent containing a dispersion stabilizer resin is usually about 60. (: To 160. The temperature range is from 1 to 15 hours. In addition, the 'non-aqueous dispersion liquid is a particle component in a coating material different from the cross-linked polymer particles, but it has no effect on the coated composite film. The characteristic of forming a particle structure. In other words, the difference between a non-aqueous dispersion and a cross-linked polymer particle is that since the particle has no cross-linking position, the shape of the particle changes during the baking process and can be a resin component.

In addition, for example, resin particles called NAD (non-aqueous dispersion) can be used, which is described in Coloring Material Issue 48 (1975), pages 28-34, and is used for NAD coatings. The content of the non-aqueous dispersion liquid resin (d) of the intermediate coating is 4 to 15% by weight and preferably 5 to 12% by weight based on the weight of the resin solid content. When the content is less than 4% by weight, the appearance of the coated composite film is insufficient; while when the content is more than 15% by weight, the cut-resistant wafer performance is reduced. 200427797 By using non-aqueous dispersion resin (d), it is possible to prevent miscibility between coatings and improve appearance. The flake pigment (e) includes mica, alumina, talc and silica; from the viewpoint of chip performance, talc is preferred. 5 The preferred flake pigment (e) has a size having a long diameter of 1 to 10 m and a number average particle diameter of 2 to 6 m. When the long diameter is outside this range, the appearance of the film is poor, and sufficient chip-cutting resistance cannot be obtained. When the particle diameter is out of this range, the appearance of the coated composite film becomes worse by the same way, and sufficient chip-cutting resistance cannot be obtained. 10 When the resin solid content of the coating is 100 parts by weight, the content of the flake pigment (e) is 0.4 to 2 parts by weight. It is more preferably 0.5 to 1.5 parts by weight. When the content is outside the range, the adhesiveness with the base coating film is decreased, and sufficient chip-resistant chip performance cannot be obtained. Other resins that can be included are not particularly limited, including acrylic resins, polyester resins, alkyd resins, and epoxy resins. These resins may be used alone or in combination of two or more. Colored pigments include, for example, azo-chelated pigments, insoluble azo-based pigments, azo-based pigments, phthalocyanine-based pigments, and benzonaphthone-based pigments. Pigments, pigments based on pernaphthol, 20 pigments based on dioxane, pigments based on fluoracridone, pigments based on isoindolinone, metal complex pigments Etc. as organic base. As for the inorganic base, chrome yellow, yellow iron oxide, red iron oxide, carbon black, titanium dioxide, and the like can be used. In addition, extender pigments can be used, including # 5 carbonate, barium sulfate, aluminum powder, kaolin, and the like. 20 200427797 As the standard, a gray-based coloring pigment containing carbon black and titanium dioxide is used as the main pigment. In addition, coloring pigments having a color tone compatible with that of the top coat, and a combination of various pigments can also be used. In addition, in order to prevent the layers from being compatible with the top coating film and maintain the coating work ability, a rheological agent may be added to the intermediate coating. Rheological agents include, for example, materials that generally have thixotropic properties, such as polyamine-based chemical agents such as swelling dispersions of fatty acid amidines, ammonium fatty acids, long-chain polyamine ammonium phosphates, etc .; polyethylene-based Chemical agents such as colloidal swelling dispersions of polyethylene oxide; chemical agents based on organic bentonite such as organic acid smectite, montmorillonite 10, etc .; inorganic pigments such as aluminum silicate, barium sulfate, etc .; flake The viscosity displayed by the pigment is determined based on the shape of the pigment, crosslinked resin particles, and the like. The total solid content of the intermediate coating used in the present invention is 30 to 80% by weight and preferably 35 to 65% by weight when applied. When the content is outside this range, paint stability decreases. When the content exceeds the upper limit, the viscosity is too high, and the appearance of the coated composite film decreases. When the content is lower than the lower limit, the viscosity is too low, and the appearance of deterioration such as miscibility and unevenness of the layers occurs. In addition to these ingredients, other additives commonly added to coatings such as surface conditioners, antioxidants, defoamers, etc. can also be blended into the intermediate coatings used in the present invention. The mixing amount is in a range known to those skilled in the art. 20 In addition, other resins may be contained in urethane-modified polyester resins. This resin is not particularly limited, but includes a propionic acid resin, a polyester resin, an alkyd resin, an epoxy resin, and the like. The resins can be used alone or in combination of two or more. A method for preparing the coating composition used in the present invention includes the following limitation: 21, 2004, 27, 797, 22, 4 inches. The method is well known to those skilled in the art, such as using this, Cambodian machine, roller and SG mill to knead and disperse pigments. Either method can be used. Base coating film 5 is used for the lion-shaped square base coating of the present invention to use a transparent coating material. The primer contains a film-forming resin, a hardener, a coloring pigment, and if necessary, a gloss color pigment. The film-forming resin contained in the primer is not particularly limited, and examples thereof include acrylic resins, polyurethane resins, alkyd resins, epoxy resins, and urethane resins. These resins may be used alone or in combination of two or more. The film-forming resin can be used in combination with a hardener. From the viewpoints of various performances and the cost of the obtained coating film, it is preferred to use an amine-based resin and / or a block isocyanate resin. Based on the solid content and weight of the film-forming resin, the hardener content is preferably 20 to 60% by weight. And more preferably 30 to 50% by weight. When the content is less than 20% by weight, the hardening ability is insufficient. When the content is higher than 60% by weight, the hardened film is too hard and brittle. In addition, as for the coloring pigment, for example, a coloring pigment, which is exemplified by the intermediate paint, may be contained. There is no particular limitation on the shape of the glossy color pigment that the primer selectively contains. Glossy color pigments can be further colored. For example, a glossy color pigment having an average particle diameter (ho) of 2 to 50 m and a thickness of 0 "to 5 m is preferred. In addition, it has a gloss with an average particle diameter in the range of 10 to 35 micrometers. The pigment concentration (PWC) of the gloss color pigments in coatings is usually 20.0% by weight or less. When the concentration exceeds the upper limit, the appearance of the coating film decreases. The concentration is preferably 0.01 to 18.0% by weight, and more preferably 0.1 to 15.0% by weight. When the content of the gloss 5 color pigment exceeds 20.0% by weight, the appearance of the coating film decreases. Gloss color pigments include, for example, uncolored or tinted metallic gloss color pigments of metals or alloys such as metal, copper, zinc, iron, nickel, tin, alumina, and mixtures thereof. In addition, interference mica pigments, muscovite pigments, graphite pigments, and other pigmented flake pigments can also be used in combination. In the coating, the total pigment concentration (PWC) of the gloss color pigment and all other pigments is 0.1 to 50% by weight, preferably 0.5 to 40% by weight, and more preferably 1.0 to 30% by weight. When the concentration exceeds the upper limit, the appearance of the coating film decreases. 15 Also, as with intermediate coatings, to maintain coating workability, it is better to add a rheological agent to the primer. Rheological agents are used to form coatings that are free of inhomogeneities and depressions. They usually contain chemicals with thixotropic properties. As for this rheological agent, the rheological agent exemplified for the intermediate coating may be contained. In addition to these ingredients, additives such as surface modifiers, rheological agents, antioxidants, UV inhibitors, and defoamers that are usually added to coatings can also be blended into the base coatings used in the present invention. Its mixing amount is within the range known to those skilled in the art. The base coating material used in the present invention has a total solids content of 10 to 60% by weight and preferably 15 to 50% by weight when applied. When the content is higher than the upper limit or lower, the stability of the coating is reduced. When the content exceeds the upper limit, the viscosity is too high, and the appearance of the coating film is reduced. When the content is lower than the lower limit, the viscosity is too low, and the appearance of the layers is miscible and uneven. Clear coating film 5 In order to form a clear coating film, a clear paint is used. There are no particular restrictions on clear coatings. Instead, clear coatings containing film-forming thermosetting resins and hardeners can be used. As for the clear coating form, it includes, for example, a solution type, an aqueous type, and a powder type. In terms of transparency and resistance to acid etching, solution-based clear coatings are better than 10, such as including acrylic resins and / or polyester resins and amine resins, acrylic resins and / or polyester resins and isocyanate compounds. And acrylic resins and / or polyester resins having a carboxylic acid-epoxy curing system. In addition, the water-based transparent coating material includes, for example, a resin-containing coating material, which is obtained by neutralizing a film-forming resin of an exemplary water-based transparent coating material with an alkali, and does not easily become water-based. Neutralization can be performed before or after polymerization by adding tertiary amines such as dimethylethanolamine and triethylamine. Conversely, as the powder type clear coating material, conventional powder coating materials such as thermoplastic powder coating materials and thermosetting powder coating materials can be used. Because it contains a coating film with better physical properties, a thermosetting powder coating is preferred. Thermosetting powder coatings include, for example, epoxy transparent powder coatings, acrylic powder coatings, and polyester resin powder coatings, but acrylic powder coatings with better weather resistance are particularly preferred. . As for the powder type transparent coating used in the present invention, since it does not contain 24 200427797 volatile substances when hardened, it can obtain better appearance and rarely yellowing. Therefore, it is mainly based on acrylic resins containing epoxy resins and polyvalent carboxylic acids. Powder coatings are particularly preferred. In addition, as with intermediate coatings, in order to maintain coating workability, it is preferable to add a rheological agent to the clear coating. As for rheological agents, they usually contain thixotropic chemicals. As for the rheological agent, the rheological agent exemplified for the intermediate coating may be contained. If necessary, a hardening catalyst, a surface conditioner, and the like may be contained. Substrate The coated composite film forming method of the present invention is preferably applied to various substrates, such as metal, plastic, and foamed materials. Preferred are metal and shaped articles. This method is particularly suitable for metal products that can be coated by cations. Metal products include, for example, iron, copper, aluminum, tin, zinc, and the like, and alloys containing these metals. Specific embodiments include car bodies and components of automobiles, trucks, motorcycles, buses, and the like. Particularly preferred metals are those that have been chemically treated with phosphate, chromate, etc. in advance. In addition, on the substrate used in the coated composite film forming method of the present invention, an electrodeposition coating film may be formed on a chemically-treated steel sheet. As for the electrodeposition coating for forming an electrodeposition coating film, a cationic or anionic type may be used, and a cationic electrodeposition coating composition is preferable, and the coating can obtain a coating film with excellent corrosion resistance. Examples The present invention will be described in detail in the following examples, but the present invention is by no means limited to these examples. "Parts" and "percentages" in the following are based on weight. Preparation Example 1 25 200427797 Preparation of Polyurethane Resin Modified with Urethane 44. Isophthalic acid, 20 parts of hexaargon phthalic acid, 40 parts of azelaic acid, 300 parts of trimethylolpropane and 200 parts of neopentyl glycol was placed in a 2 liter reaction vessel. The reaction vessel was equipped with a nitrogen introduction tube, a stirrer, a temperature regulator, a 5 addition funnel and a cooling tube equipped with a decanter; when the raw materials were dissolved by heating, it became ' It can be stirred, 0.2 parts of dibutyltin oxide is added, and stirring is started, and the temperature of the reaction layer is changed from 180 °. 〇 Rising slowly to 22 ° C for 3 hours. The resulting condensation water is removed by system distillation. When the temperature reached 220 ° C, maintaining the temperature for 1 hour 'slowly added 20 parts of xylene to the reaction layer, and allowed 10 condensation reactions in the presence of a solvent. When the resin acid value reached 10 mgKOH / g, the material was cooled to 100C 'and 100 parts of hexamethylene diisocyanate was slowly added over a period of 30 minutes. In addition, 'the temperature was maintained for 1 hour, and 200 parts of xylene and 2000 parts of butyric acid acetate were added' to obtain a polyester resin modified with an amino ester, having a solid content of 70%, an average molecular weight of 2000, and an acid. Valence 8 mg KOH / g, hydroxyl value 120 15 and resin Tg 60 ° C. Preparation Example 2 Preparation of Non-Aqueous Dispersion Liquid (a) Preparation of dispersion liquid stabilizer resin 90 parts of butyl acetate was placed in a container equipped with a stirrer, a temperature controller, and a reflux 20 condenser. Then 20 parts of the solution have the following composition: Table 1 Methyl methacrylate Stearyl methacrylate 2-hydroxyethyl acrylate Azo isobutyronitrile 38.9 parts 38.8 parts 22.3 parts 5.0 parts

26 200427797 was added to it, and the temperature was raised by heating and stirring. 85 parts of the remaining mixed solution was added at 10 t: dropwise for 3 hours, and then 0.5 part of azobisisobutyronitrile and 10 parts of butyl acetate solution were added dropwise over a period of 30 minutes. The reaction solution was stirred under reflux for 2 hours to increase the rate of change to resin. After the reaction was completed, an acrylic resin was obtained with a solid content of 50%, a number average molecular weight of 5600, and an SP value of 9.5. (b) Preparation of non-aqueous dispersion liquid 90 parts of butyl acetate and 60 parts (a) Preparation of dispersion resin stabilized acrylic resin obtained in a container, the container is equipped with a stirrer, a condenser 10 and a temperature controller . Then it has a solution with the following composition: Table 2 Styrene 7.0 parts methacrylic acid 1.8 parts methyl methacrylate 12.0 parts ethyl acrylate 8.5 parts 2-hydroxyethyl acrylate 40.7 parts azoisobutyronitrile 1.4 parts at 100 ° C The solution was added dropwise for 3 hours, and then 0.1 part of azobisisobutyronitrile and 1 part of butyl acetate solution were added dropwise over a period of 30 minutes. The reaction solution was continuously stirred for 15 hours and stirred for 1 hour to obtain an emulsion with a solid content of 60% and a particle diameter of 180 nm. This emulsion was diluted with butyl acetate to obtain a core-shell type butyl acetate dispersion with a non-aqueous dispersion content of 40%, a viscosity of 300 cps (25 ° C), and a particle diameter of 180 nm. This non-aqueous dispersion resin has a Tg of 23 ° C, a hydroxyl value of 162, and an SP value of 11.8; the difference between the SP value of the dispersion-stabilized resin in the shell portion and the non-aqueous 27 200427797 dispersion resin is 2.3. Example 1 107 parts of an intermediate coating, a urethane-modified polyester resin 5 varnish, 280 parts of CR-97 (titanium oxide manufactured by Ishihara Industries), 13 parts of MA-100 (carbon black pigment) , Manufactured by Mitsubishi Chemical Corporation), 7 parts of MS-100 (scaly talc, manufactured by Fuji Talc), 47 parts of butyl acetate and 47 parts of xylene are placed in a 1 liter valley state, and the amount is equal to the total amount of feed GB503M (glass beads with a particle diameter of 1.6 * m), the material was dispersed at room temperature using a table type 8 (} mill for 3 hours and 10 hours to obtain a gray pigment paste. When the dispersion was completed, the particle diameter was measured using a grinding table to be 5 microns or less. The glass beads were filtered to obtain a pigment paste. The pigment paste was prepared as an intermediate coating having the composition shown in Table 3. The coating used a No. 4 Ford Cup with ethoxyethyl propionate / S-100 (aromatic hydrocarbon solvent, Exxon). (Manufactured by the company) = [Diluted to 19 seconds / 20 ° C. The non-volatile content at the time of application is 49/0. The intermediate coating composition pigment paste 100 parts polyester resin 130 parts non-aqueous dispersion 53 parts I Amine, fat ("Ubibond 128 (trade name)" made by Mitsui Cyteck Co., Ltd. 71 copies Product name "} 71 parts resin solids ratio g double resin / non-aqueous dispersion / melamine resin / block isocyanate 50/10/20/20 pigment ratio titanium oxide / carbon black / talc 28 / 1.3 / 0.7 PWC 30 % 28 200427797 The base paint is a metallic base pigment "Orga τ〇 600 600 Metal" (made by Japan Coatings Co., Ltd.) based on melamine melamine. _ (Aromatic hydrocarbon solvent, manufactured by Exxon Corporation) The mixed solvent is diluted to Πsec / 2 (TC. The non-volatile content at the time of coating application is 31%. The non-volatile content at the time of deposition is 65%. Clear coating 10 15 20 Transparent paint "Mark Saga" j〇〇 (made by Japan Coatings Co., Ltd.), which is mainly based on hardened milky resin, uses No. 4 Ford Cup with ethoxyethyl propionate / SU) 0 (Aromatic hydrocarbon solvent, manufactured by Exxon Corporation) Diluted to 26 ^ 20t. The non-volatile content at the time of coating application was · In addition, the non-volatile content of the deposited day was 61%. The coated composite Method for forming thin film, cationic electrodeposition coating "PowwerT 叩" v_2〇 " ) Electrodeposition coated on the steel plate of SPC, the thickness of the steel plate is 0.8mm, the length is 30cm, the width is 10cm, and it has been treated with phosphoric acid. At 160. (: Bake dry 30 knives. Then the steel plate on which the electrodeposition coating film has been formed is attached to the mobile coating and intermediate coating by the "micro shell machine" (rotary atomizing electrostatic coating machine). A coating film with a dry film thickness of 20 microns was formed. Leave it for 10 minutes to allow it to harden.

& Then the primer is divided into two stages using a "micro shell machine" and "meta shell machine" f, and then the dry film thickness is 15 microns. The interval between the two applications was 2.5 minutes. 2nd curing after 8 minutes. Then use a "micro-shell machine" to coat the coating in stages 29 200427797. The dry film of the clear coating is as fine as 35 microns and hardened for 10 minutes. The curing condition of the laminated composite film was a curing temperature of 14 °. 〇, the hardening time is 30 minutes. The coated plate thus prepared was placed in a 40 cc first drying oven, maintained for 55 minutes, and moved to a second drying oven set at 140 ° C., and maintained for 20 minutes. The coated plate was then removed from the drying oven and allowed to cool to room temperature. (1) Visually evaluate whether the coated composite film after the hardening has a glossy appearance. The test results are shown in Table 5. Table 4 Evaluation criteria 3 Excellent gloss appearance, it seems that the thickness of the transparent coating is sufficient 2 The gloss appearance is slightly worse, it seems that the thickness of the transparent coating is small, the gloss appearance is inferior, it seems that the clear coating is not applied, and then a coated coating made by Big Chemie The coated composite film appearance measuring device "Wave Scan D0I" tests the surface state of the coated composite film after hardening. The results are shown in Table 15. The value of 5 ° / Beijing Wa indicates that the rough measure of the surface beading is up to millimeters, and the gloss appearance of the coated composite concrete is shown. — Represents the rough measurement of the surface bead i to 3 mm, and represents the surface hiding property of the coated composite film. Wd Table 7F The thickness of the beaded surface of the compound film set on laterite is 3 to 1 mm, which indicates that the composite film coated with 20 is smooth. As the value becomes smaller, the measured value becomes better. (3) In addition, the properties of the cut-resistant wafers of the coated board were evaluated. The test results are shown in Table 5 below. 30 2 0 0 ^ 119 volts with a glabero tester (manufactured by Su㈣ Testing Instruments), 3,000 pieces of 7 crushed stones are at a distance of 35 cm, and the air pressure is 30 kgf / piece The square centimeter collided with the film at an angle of 45 degrees. After washing with water and drying, the peeling test was performed using an industrial adhesive tape manufactured by Nichiban. After that, the glass diameter and number of glasses were visually observed and evaluated for peeling. Examples 2 to 4 According to the same method as described in Example 1, but the curing temperature and curing time were changed as shown in Table 5. The cured coated composite film was prepared and tested. The test results are shown in Table 5 · 10 Comparative Example 1 According to the same method as in Example 1, but heating at 140 ° C in one step for 30 minutes, the baking and curing steps of the uncured coated composite film were performed. The coated composite film and test. The test results are shown in Table 6. 15 Comparative Example 2 The same method as described in Example 1 was used, but using a polyester-melamine based intermediate coating manufactured by Japan Coatings Co., Ltd. "Oga "H870 gray" · As an intermediate coating, the hardening temperature and hardening time were changed as shown in Table 6. The hardened coated composite film was prepared and tested. The test results are shown in Table and 20 6. Reference Example 1 Cationic electrodeposition Coating "Baltorp V-20" (manufactured by Japan Coatings Co., Ltd.) is electrodeposited and coated on SPC steel plate. The steel plate is 0.8 mm thick, 30 cm long and 10 cm wide. Overlay 31 to form a coating film, forming a dry film with a thickness of 20 microns, and then baking and drying for 30 minutes 1 mile. Then the steel plate on which the electrodeposition coating film has been formed is attached to the moving body, and the "micro shell" Machine (rotary atomizing electrostatic coating machine) is applied with intermediate coating on the move to form a dry film with a thickness of 20 microns. After application, it is left to harden for 10 minutes. This coated plate is placed in the setting The drying oven was placed at 140 ° C for 20 minutes. Then the coated plate was taken out of the drying oven and allowed to cool to room temperature. The primer and transparent coating were applied to the coated plate as in Example 丨 to obtain a coated composite film. After this preparation The cover plate was placed in a 14th generation drying oven and maintained for 30 minutes. Then the coated plate was recorded and cooled to room temperature. According to the marriage method of the method described in Example 丨, the obtained hardened coated The composite film. The test results are shown in Table 6. Reference Example 2 The same method as described in Reference Example 1 was used, but the poly-melamine-based intermediate coating "Omega TO Η 870 Gray" manufactured by Japan Coatings Co. was used as The intermediate coating, curing temperature and curing time were changed as shown in Table 6. The cured composite film was prepared. The results are shown in Table 200427797 Table 5 Example No. 1 2 3 4 Intermediate coated composite film Kind Example 1 Example 1 Example 1 Example 1 Bake dry----Coated composite film Bake dry low temperature 40 ° Cx 5 minutes 60 ° Cx 3 minutes 60 ° Cx 5 minutes 100 ° Cx 5 minutes South temperature 140 ° Cx 30 minutes 140 ° Cx 30 minutes 140 ° Cx 30 minutes 140 ° Cx 30 minutes Appearance (visual evaluation) 3 3 3 3 Surface state Wa 16.3 14.7 13.6 16.6 Wc 13.4 14.4 12.2 16.2 Wd 8.7 8.2 7.3 10.3 Financial chip wafer peeling Diameter 2 mm 1.8 mm 1.7mm 2mm number 20 18 16 19

Table 6 Example No. Comparative Example 1 Comparative Example 2 Reference Example 1 Reference Example 2 Types of Composite Films Coated in the Middle Example 1 Orga TO Example 1 Orga TO Bake--140 ° Cx 30 minutes 140 ° Cx 0 minutes The coated composite film is baked at low temperature-60 ° Cx 5 minutes--South temperature 140 ° Cx 30 minutes 140 ° Cx 30 minutes 140 ° Cx 30 minutes 140 ° Cx 30 minutes Appearance (visual evaluation) 2 1 3 3 Surface state Wa 23.1 45.3 13.1 12.9 Wb 21.0 61.4 11.5 11.4 Wc 18.5 35.6 8.4 9.1 Financial cut wafer peel diameter 2 mm 3.5 mm 2.0 mm 2.5 mm Number 20 106 16 30

33 200427797 In the embodiment of the present invention, even if the coated composite film is formed by the three-coat film baking method, the same gloss appearance obtained by the three-coat film baking method can be obtained. In addition, the coating system of the present invention has the property of cut-resistant wafers equal to the properties of the coated composite thin film obtained by the three-coating and double-baking method, but the number of baking-drying is reduced. Brief description of L scheme] (none) [Representative symbol table of main elements of diagram] (none)

34

Claims (1)

200427797 Patent application scope: 1. A method for manufacturing a coated composite film, comprising forming an electro-coated film on a substrate, and then continuously applying an intermediate coating, a primer and a wet and wet method, and A clear coating, followed by three layers of 5 baking and hardening at a time, wherein the baking and hardening includes a low-temperature heating stage at 25% to 80% of the hardening temperature and heating of 5% to 30% of the hardening time Time; and a high-temperature heating stage, which is a time between 30% and 130% of the hardening time when the heating exceeds 80% but not more than 120% of the hardening temperature. 10 2. The method of claim 1, wherein the intermediate coating comprises: (a) 40 to 56% by weight of a urethane-modified polyester resin having a number average molecular weight of 1500 to 3000, It is obtained by reacting an aliphatic isocyanate compound with a hydroxyl-containing polyester resin having a glass transition temperature (Tg) of 40 ° C to 80 ° C 15. The polyester resin is obtained by using an acid having 80% or more isophthalic acid. Ingredients and polyhydric alcohols are obtained by condensation polymerization; (b) 10 to 30% by weight of melamine resin; (c) 15 to 30% by weight of block isocyanate compounds; 20 (d) 4 to 15% by weight of having Core-shell structured non-aqueous dispersion liquid resin, the content of (a) to (d) is based on the weight of the solid content of the resin; Based on 100 parts by weight of resin solid content. 35 200427797 3. The method according to item 2 of the patent application, wherein the block isocyanate compound is a compound block having an active methylene group. 4. A coated composite film formed by a method such as any one of claims 1 to 3 of the scope of patent application. 36 200427797 (1) Designated representative map: (1) The designated representative map in this case is: (). (None) (II) Brief description of the element representative symbols of this representative diagram: 捌 If there is a chemical formula in this case, please disclose the chemical formula that can best show the characteristics of the invention: