WO1999057210A1 - Paint composition containing luster pigment and method for forming composite coating - Google Patents

Abstract

An alumina flake which is likely to remarkably become uneven due to high lustrousness is used as a luster pigment for a metallic paint that can yield an even coating having a very good appearance. This can realize a composite automotive coating with high lustrousness and novel design heretofore unattainable. A coating with excellent design unattainable in the prior art can be formed by applying a luster pigment-containing paint composition containing alumina flakes and a viscosity modifier as a paint composition for forming a luster pigment-containing coating layer by a two-coat one-bake process or, if necessary, a three-coat two-bake or three-coat one-bake process to form a composite coating.

Description

 Specification

 Bright pigment-containing coating composition and method for forming composite coating film

 The present invention relates to a glitter pigment-containing coating composition containing alumina flakes, a method for forming a composite coating film using the glitter pigment-containing coating composition, which can be suitably used as a thermosetting coating, especially a top coating for automobiles. The present invention relates to a composite coating film formed by the method and an article having the composite coating film.

 Background art

 In general, as a top coating for automobiles, a brilliant pigment-containing paint called a metallic paint containing a brilliant pigment such as metal powder and / or mica is known. Among such brilliant pigments, a metallic paint containing aluminum powder or metal powder coated with a metal oxide changes the amount of reflected light depending on the viewing angle, and has high design properties.

 Among the items for evaluating the design properties of metallic paint, the glitter is greatly affected by the particle size and shape of the glitter pigment itself. Examples of glitter pigments having high glitter are described in JP-A-9-77512. In other words, in order to enhance the brilliant feeling of the metallic coating film, various studies have been conducted on the brilliant pigment itself and on a coating film forming method for deriving higher design properties.

 However, in the case of conventional glitter pigments, when used in combination with other glitter pigments or coloring pigments, the glitter is buried and becomes less noticeable.

 Summary of the Invention

The present invention uses alumina flakes, which have a strong luster and are easy to notice unevenness, as glitter pigments for metallic paints, which can form a coating film with high appearance and no irregularities, and have an unprecedented bright luster and a new design. An object of the present invention is to form a composite film for automobiles having a property. The present inventors applied a glittering pigment-containing coating composition containing alumina flakes and a viscosity controlling agent in a two-coat one-bake, and, if necessary, a three-coat two-beta or three-coat one-beta process, By forming a composite coating film, it was possible to provide a coating film with unprecedented design properties, and to clarify that the above problems could be solved.

 That is, the present invention relates to [1] a glitter-containing coating composition containing alumina flakes as a glitter pigment and a viscosity controlling agent. ;

 [2] A method for forming a composite coating film on a prepared substrate by two coats and one bake, wherein the first layer is formed by the glittering pigment-containing coating composition of the present invention. Coating method. ;

 [3] A method for forming a composite coating film on an undercoated base material in 3 coat 2 beta or 3 coat 1 beta, characterized in that the second layer is formed by the glitter pigment-containing coating composition of the present invention. The method for forming a composite coating film. ;

 [4] A composite coating film formed by the above method. ; And

 [5] An article having the composite coating film.

Is provided.

 Embodiment of the Invention

 Alumina flake, which is a glitter pigment used in the present invention, is obtained by coating aluminum oxide (A1203) with a metal oxide such as titanium dioxide, and has a particle size of 10 to 30 m and a thickness of 0.3. ~ 0.4 m. Preferred alumina flakes are flaky aluminum oxide containing titanium oxide described in JP-A-9-77512, paragraph No. 007. The production method is described in detail in paragraphs 01-111 to 017.

Such alumina flakes have high surface smoothness and a sharp particle size distribution, so that light scattering by fine particles is small. Furthermore, since the surface of the flaky alumina crystal with a high aspect ratio is coated with a metal oxide, a pearlescent pigment When a film is formed, a film with a strong shine that cannot be obtained with the conventional My Powder is obtained from both the highlight and shade positions, and the appearance is transparent and three-dimensional. Can be expressed. Examples of the above alumina flakes include, for example, SD such as “SDA—SI LVER W—3 (trade name)” sold by Merck Japan Ltd.

A series.

 By changing the seed amount of metal oxides (A1203, Ti02, Sn02, Zr02, Fe203, etc.), these colors can be changed from silver color to single color kappa or interference color to senna color. By using the method for forming a composite coating film of the present invention, a coating film having a higher luminance and a coating color having particularly strong glittering when exposed to strong light such as sunlight can be provided.

 The content of alumina flakes (PWC%) is from 0.01% to 15.0%. When the content exceeds the upper limit, the appearance of the coating film decreases, and when the content is lower than the lower limit, the glitter decreases. Preferably, it is from 0.1% to: 14.0%, more preferably from 1% to 13.0%.

 In the present invention, it is preferable that the above-mentioned alumina flakes are used alone as the glitter pigment in terms of design. However, when the above-mentioned alumina flake is used as a glittering pigment, a coating film having a strong shine and transparency, which cannot be obtained with the conventional my powder, from both the highlight and shade positions. Can be provided.

 Depending on the coating color, other glittering pigments can be used in combination. As other glittering pigments that can be used together, aluminum powder or my powder coated with a metal oxide such as titanium dioxide or iron oxide is generally used, but other flat pigments having glittering properties may also be used. . In addition, organic or inorganic coloring pigments or extenders can be used in combination with the alumina flakes.

Total pigment concentration in paint when pigments other than alumina flakes are used together (P WC%) is 0.1 to 80%, preferably 0.5% to 70%, and more preferably 1.0% to 60%. If the upper limit is exceeded, the appearance of the coating film will deteriorate.

 The bright pigment-containing coating composition of the present invention contains a viscosity controlling agent. The viscosity controlling agent is used to form a good and uniform coating film. As the viscosity control agent, generally, a compound exhibiting thixotropic properties can be used as a "sagging inhibitor". Such materials include, for example, swelling dispersions of fatty acid amides, amide-based fatty acids, polyamides such as long-chain polyaminoamide phosphates, and colloidal swelling dispersions of polyethylene oxide. Such as polyethylene.

 In addition, there are also organic bentonite-based materials such as organic acid silicate clay and montmorillonite, inorganic pigments such as aluminum silicate and barium sulfate, flat pigments which exhibit viscosity depending on the shape of the pigment, and polar groups. Non-crosslinked or cross-linked resin or particles utilizing the interaction of water can be mentioned as a viscosity control agent.

 In the present invention, the viscosity controlling agent may be used alone or in combination.

 However, those which do not affect the gloss and the coloring properties when formed into a coating film are preferred, and among the viscosity control agents described above, crosslinked resin particles are particularly preferred.

As such crosslinked resin particles, crosslinked resin particles which are insoluble in the organic solvent used in the coating composition of the present invention and have an average particle diameter of 0.02 to 0.5 m are often used. If the upper limit is exceeded, the stability will decrease. The above crosslinked resin particles are obtained by synthesizing a monomer having a zwitterionic group in the molecule as one of the polyhydric alcohol components, a resin having an emulsifying ability such as an alkyd resin or a polyester resin, and a polymerization initiator. And those obtained by emulsion-polymerizing an ethylenically unsaturated monomer in an aqueous medium in the presence of The monomer having the above zwitterionic group in the molecule is represented by one N (+) — R—C 0 0 (-) or -1 ^ (+) — 1—303 (-), Those having two or more hydroxyl groups can be used. As such a monomer, an aminosulfonic acid-type zwitterionic compound containing a hydroxyl group is preferable in the resin synthesis. Specifically, bishydroshetyltaurine and the like can be mentioned. The resin having an emulsifying zwitterionic group in the molecule synthesized using the above monomer has an acid value of 30 to 15 OragK0H / g, preferably 40 to 150 mgK0HZg. It is good to use a polyester resin having a number average molecular weight of 500 to 500, preferably 700 to 300. When the ratio exceeds the upper limit, the handleability of the resin decreases. When the ratio is below the lower limit, the resin having an emulsifying ability is detached when the coating film is formed, or the solvent resistance decreases.

 In the synthesis of the crosslinked resin particles, the ethylenically unsaturated monomer to be emulsion-polymerized preferably contains a monomer having two or more radically polymerizable ethylenically unsaturated groups in the molecule. Such a monomer having two or more radically polymerizable ethylenically unsaturated groups in the molecule accounts for 0.1 of all monomers.

It is preferable to contain it in the range of 10 to 10% by weight. The amount is selected to provide sufficient crosslinking to dissolve the particulate polymer in the solvent. The crosslinked resin particles used in the present invention are generally contained in an emulsion resin, do not contain a low-molecular emulsifier or a protective coide that lowers the performance when formed into a coating film, and more than two particles per molecule. Since the polymer is crosslinked by copolymerizing a monomer having a radically polymerizable ethylenically unsaturated group, the coating film has excellent water resistance, solvent resistance, gloss and the like.

The addition amount of the viscosity control agent in the present invention is 0.01 to 15 parts by weight, preferably 0.1 to 12 parts by weight, based on 100 parts by weight of the resin solid content of the coating composition of the present invention. Parts, more preferably from 0.2 to 9 parts by weight. If the added amount of the viscosity controlling agent exceeds 15 parts by weight, the appearance is deteriorated, and 0 .. 0: If it is less than the part, the viscosity control effect cannot be obtained, and it may cause infiltration or inversion between layers.

 The coating composition of the present invention contains a thermosetting film-forming resin. This resin disperses a glitter pigment and a viscosity control agent to form a cured coating film, and is not particularly limited. Generally, a thermosetting film-forming resin having at least one hydroxyl group selected from the group consisting of acrylic resin, polyester resin, alkyd resin, epoxy resin and the like can be used. Alternatively, it is used in combination with a curing agent such as a block isocyanate resin. From the viewpoints of weather resistance, pigment dispersibility and coating workability, it is preferable to combine an acryl resin having a hydroxyl group with an amino resin. The weight composition ratio between the thermosetting film-forming resin and the curing agent in the glitter pigment-containing coating composition of the present invention is 90Ζ10〜10Ζ90, preferably 80 820. ~ 50/50. If it exceeds the upper limit, the curability will decrease, and if it falls below the lower limit, a hard and brittle coating film will be formed.

 Furthermore, in the glitter pigment-containing coating composition of the present invention, a curing catalyst, an ultraviolet absorber, an antioxidant, a surface preparation agent, and the like can be used as necessary. The total solid content of the glitter pigment-containing coating composition of the present invention is from 20 to 70% by weight, and preferably from 30 to 50% by weight. Exceeding the upper and lower limits lowers paint stability. At the time of application, the amount is 10 to 60% by weight, preferably 20 to 50% by weight. If the upper limit is exceeded, the viscosity will be too high and the appearance of the coating will be reduced. If the lower limit is exceeded, the viscosity will be too low and poor appearance such as familiarity and unevenness will occur.

 The method for producing the coating composition of the present invention is not particularly limited, and any method known to those skilled in the art such as kneading and dispersing a compound such as a pigment using a kneader or a roll can be used.

The coating composition of the present invention may be used on any substrate, for example, wood, metal, glass, cloth, It can be advantageously used for plastics, foams and the like, especially for plastics and metal surfaces such as steel, aluminum, and alloys and structures thereof, but is particularly preferably used for metal products which can be electrodeposited by force.

 Examples of the metal product include iron, copper, aluminum, tin, zinc, and alloys containing these metals. Specific examples include car bodies and parts such as passenger cars, trucks, motorcycles, and buses. It is particularly preferable that these metals have been previously subjected to a chemical conversion treatment with phosphate, chromate, or the like.

 In general, the thickness of a coating film at the time of coating with the glitter pigment-containing coating composition of the present invention varies depending on a desired use, but in many cases, 5 to 40 jum is useful, and more preferably 10 to 40 jum. It is about 25 μηι. Exceeding the upper limit may cause problems such as blurring or flow during coating, while below the lower limit the base material cannot be concealed, causing film breakage.

 After coating on the base material, the coating film is cured, and a cured film having a high degree of crosslinking can be obtained at 100 to 180 ° C, preferably 120 to 160 ° C. Above the upper limit, the coating becomes hard and brittle, and below the lower limit, curing is not sufficient. The curing time varies depending on the curing temperature, but curing at 120 ° C to 160 ° C for 10 to 30 minutes is appropriate.

 The glitter pigment-containing coating composition of the present invention is generally preferably of a solution type, and if it is a solution type, it may be of an organic solvent type, an aqueous type (water-soluble, water-dispersible, emulsion) or a non-aqueous type. Either may be used.

In the case of using the effect pigment-containing coating with an aqueous coating material as a binder of the bright pigment containing organic coating compositions, U.S. Patent No. ^5, 1 5 1 1 2 5 No. Oyo Pi same 5, 1 8 3 No. 5,504, etc. can be used. In particular, an acrylic resin having an acrylamide group, a hydroxyl group and an acid group described in US Pat. No. 5,183,504 is combined with a melamine resin. The combined thermosetting film-forming resin is finished and has good appearance performance.

 In the case where the glitter pigment-containing coating composition of the present invention is applied to an automobile body to form an overcoat, an electrodeposition coating as a base coat, and a cured or uncured intermediate coat are applied to the chemically treated steel sheet. The coating is preferably performed by a coating method such as electrostatic coating or air spraying on the substrate on which the coating film is formed. In order to suppress uneven brightness, it is more preferable to paint in two stages than in one stage.

 Specifically, it is preferable from the viewpoint of design to form a composite coating film having a glittering base coating film composed of the glittering pigment-containing coating composition of the present invention and a clear film as an overcoating film. In that case, the following “coat-on-packet” application process is included

It is preferable to use a two-coat one-beta complex formation method.

 A step of applying the glitter pigment-containing coating composition of the present invention on a substrate to form a glitter base layer; applying a clear coating composition thereon without curing the base layer to form a clear layer; Forming step; and heating to harden the base layer and the clear layer.

 When the glitter pigment-containing paint is used in an aqueous type paint, the glitter pigment-containing coating film is previously coated at 60 to 100 ° before painting the clear paint in order to obtain a good finished coating film. It is desirable to heat at C for 2 to 10 minutes.

 The substrate may be an undercoated or an intermediate coated metal plate for an automobile body. Further, a color base coating film may be previously formed thereon for coloring the surface to be coated. In that case, a preferred coating method is a three-coat two-beta composite coating film forming method including the following steps.

A step of applying a water-based or solvent-based color-based coating composition on an undercoated or intermediate-coated substrate and heating and curing the composition to form a colorless MM; Forming a brilliant base layer by applying an object; forming a clear layer by applying a clear coating composition on this without curing the brilliant base layer And curing the glittering base layer and the clear layer by heating.

 The step of providing the glittering base on the color base coating film may be performed in an "Et. On." In that case, a preferred coating method is a three-coat one-bake composite coating film forming method including the following steps.

 A step of applying a water-based or solvent-based color base coating composition on an undercoated or intermediate coated substrate to form a color base layer; without curing the color base layer, A step of applying a composition to form a glittering base layer; a step of applying a clear coating composition thereon to form a clear layer without curing the glittering base layer; and by heating A step of curing the color base layer, the glitter layer 14 and the clear layer.

 However, in the above-described method for forming a composite coating film, in order to control the so-called “fit-in” between the coating films, the coating viscosity of the Taliya paint, the glitter pigment-containing paint and, if necessary, the color base paint is sequentially controlled. An excellent appearance can be obtained by controlling the viscosity of each formed coating film interface.

 As the electrodeposition paint applied on the substrate used in the method for forming a composite coating film of the present invention to form an undercoat layer, a cationic type and an anion type can be used. Gives an excellent composite coating. Cationic electrodeposition coating composition is a cathodic deposition type thermosetting electrodeposition coating composition which is based on a resin having a basic amino group and is made water-soluble by neutralization with an acid. It is painted with the paint as the cathode.

 Examples of the resin having a basic amino group used in the cationic electrodeposition coating include a bisamine-type epoxy resin and an epoxy group of a secondary amine (for example, a primary amine blocked by ketimination of diethylenetriamine or the like). Resins to which (secondary amine) has been added are preferred.

Further, as the crosslinking agent, block polyisocyanate sealed with a block agent such as alcohols, phenols, oximes, and lactams is used. It is preferable to use

 The above-mentioned cationic electrodeposition coating material contains a pigment such as a coloring pigment, an extender pigment, and a sunscreen pigment, a hydrophilic and / or hydrophobic solvent, an additive, and the like as necessary. The amount of the pigment can be 5 to 150 parts by weight based on 100 parts by weight of the resin solids.

 Usually, the electrodeposition coating film is preferably formed so as to have a film thickness after baking of 10 to 4 μππ, more preferably 15 to 25 / zm. Further, it is more preferable to perform a normal chemical conversion treatment before the electrodeposition coating. The intermediate coating composition for forming an undercoat layer in the method for forming a composite coating film of the present invention is used for concealing base defects, ensuring surface smoothness after top coating and imparting chipping resistance, and It is applied using an intermediate coating containing various colored and inorganic pigments and extenders.

Examples of color pigments for intermediate coatings include organic azo chelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, dioxane pigments, and quinatari. Don-based pigments, isoindolinone pigments, metal complex pigments, etc., inorganic yellow salts, yellow iron oxide, red iron oxide, car pump racks, titanium dioxide, etc., and extender pigments such as calcium carbonate, barium sulfate, clay , Talc, etc. are used. As a standard, gray intermediate coatings with carbon black and titanium dioxide as the main pigments are often used, but it is also possible to use so-called color intermediate coatings, which combine various coloring pigments depending on the concealment of the top coat. it can. The thermosetting film-forming resin of the intermediate coating is not particularly limited, and a film-forming resin such as an acrylic resin, a polyester resin, an alkyd resin, an epoxy resin, or a urethane resin can be used. Is used in combination with a curing agent such as amino resin or block isocyanate resin. In terms of pigment dispersibility or workability, alkyd resin and A combination of a ester resin and an amino resin is preferred.

 The intermediate solid content of the intermediate coating is in the range of 30 to 70% by weight, preferably 35 to 55% by weight. At the time of application, the amount is 10 to 60% by weight, preferably 20 to 50% by weight. The intermediate coating is preferably applied on the heat-cured or uncured electrodeposition coating film by a method such as electrostatic coating, air spray, or airless spray. Is generally preferably about 10 to 60 / X m, more preferably about 20 to 50 // m. Above the upper limit, problems such as paint or sagging may occur during painting, and below the lower limit, the base cannot be concealed.

 The intermediate coating film itself can be heat-cured at a temperature of about 100 to 180 ° C., and in the present invention, a composite coating film is formed by combining with a glitter pigment-containing coating film and a clear coating film. Thereby, excellent appearance and coating film performance can be exhibited. Further, it is preferable to form a color base coating film on the intermediate coating film according to the saturation of the top coating color. A cured or uncured color base coating film is formed as the first layer of the top coat, and the second layer is formed with the glitter pigment-containing coating composition of the present invention. Further, a clear coating film is formed by wet-on-wet. Thus, it is possible to form a 3-coat 2-beta or 3-coat 1-back composite coating film having excellent design properties.

 Examples of the color pigment of the color-based paint used in the composite coating film forming method of the present invention include organic azo chelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, and perinone pigments. , Perylene pigments, dioxane pigments, quinatalidone pigments, isoindolinone pigments, metal complex pigments, inorganic yellow salts, yellow iron oxide, red iron oxide, red iron oxide, carbon black, titanium dioxide, etc. Examples thereof include calcium carbonate, barium sulfate, clay, and talc.

The thermosetting film-forming resin of the color base paint is not particularly limited. However, film-forming resins such as acrylic resin, polyester resin, alkyd resin, epoxy resin, and urethane resin can be used, and these can be used together with a curing agent such as an amino resin and a Z or block isocyanate resin. Used in combination. From the viewpoint of pigment dispersibility or workability, a combination of an acrylic resin and / or a polyester resin and an amino resin is preferable.

 When a composite coating film is formed by a three-coat, one-bake coating method, the glitter pigment-containing coating film of the present invention and the color base coating film are coated on an “et-on-et” basis. It is preferable to control the viscosity of the coating film.

 The addition amount of the viscosity control agent to the color base paint used for controlling the viscosity of the color base coating film is as follows: 0.1 to! 20 parts by weight based on 100 parts by weight of the resin solid content of the coating composition. Preferably it is added in an amount of 0.2 to 15 parts by weight, more preferably 0.3 to 10 parts by weight. When the amount of the crosslinked resin particles exceeds 20 parts by weight, the appearance is reduced, and when the amount is less than 0.1 part by weight, the effect of controlling the viscosity cannot be obtained, which causes the interlayer to be adapted or inverted.

The solids content in the color base paint is between 15 and 60% by weight, preferably between 20 and 55% by weight. The solid content at the time of application is 10 to 50 weight. / ₀ , preferably 20 to 45% by weight. The color base paint is preferably applied on the intermediate coating film or the electrodeposition coating film by a method such as electrostatic coating or air spraying. The dry film thickness of the formed coating film is generally 10 to 6 μm. It is preferably about ιη, and more preferably about 20 to 50 m. Above the upper limit, problems such as paint or sagging may occur during painting, and below the lower limit, the base cannot be concealed.

The color base coating film itself can be cured by heating at a temperature of about 100 to 180 ° C. When heat-cured alone, the bright pigment-containing coating composition of the present invention is applied thereon, and further, wet-on-ether By applying the Taliyah paint, a 3-coat 2-beta composite coating film can be formed. In addition, a color base coating film, a glitter pigment-containing coating film and a clear coating film are combined in an on-jet manner, a composite coating film is formed, and then heat-cured to form a three-coat one-beta composite coating. A film can be formed, and further excellent design properties can be exhibited.

 The form of the intermediate coating and the color base paint used in the present invention are preferably both of a solution type. If the solution type is a solution type, an organic solvent type, aqueous (water-soluble, water-dispersible, emulsion), non-aqueous dispersion Any type is acceptable. If necessary, a curing catalyst, a surface preparation agent and the like can be used.

 The taryer paint used in the method for forming a composite coating film of the present invention is formed to ensure surface smoothness and to impart other performance required for the coating film, and to such an extent that the transparency of the coating film is not impaired. Color pigments may be included.

 The thermosetting film-forming resin of the clear paint is not particularly limited, and a film-forming resin such as an acrylic resin, a polyester resin, an epoxy resin, or a urethane resin can be used. Is used in combination with a curing agent such as amino resin and / or block isocyanate resin. From the viewpoint of transparency or acid-etching resistance, a combination of an acrylic resin and Z or a polyester resin with an amino resin, or an acrylic resin and / or a polyester resin having an acid-epoxy hardening system is exemplified.

The solids content in the tarry coating is from 20 to 60% by weight, preferably from 35 to 55% by weight. The solid content at the time of coating is 10 to 50% by weight, preferably 20 to 50% by weight. It is preferable to apply the above-mentioned Tarry coating on an unhardened brilliant pigment-containing coating film by a method such as electrostatic coating or air spraying. The thickness is preferably about 0 μm, more preferably about 20 to 50 μπι. Exceed limit If this is not the case, paint or sagging may occur during painting, and if it is below the lower limit, the unevenness of the base cannot be concealed.

 Although the clear coating film itself can be cured by heating at a temperature of about 100 to 180 ° C., in the present invention, a clear coating film, a coating film containing a brilliant pigment, or a paint base film is used. By forming a composite coating film by combining with a glitter pigment-containing coating film and curing by heating, excellent appearance and coating film performance can be exhibited.

 The clear coating preferably contains a viscosity control agent for coating with the glitter pigment-containing coating composition of the present invention and wet-on-wet. The amount of the viscosity control agent to be added to the clear paint is 0.01 to 10 parts by weight, preferably 0.02 to 8 parts by weight, based on 100 parts by weight of the resin solid content of the coating composition. And more preferably in an amount of from 0.3 to 6 parts by weight. When the amount of the viscosity controlling agent exceeds 10 parts by weight, the appearance is deteriorated. When the amount is less than 0.1 part by weight, the effect of controlling the viscosity cannot be obtained, which causes the interlayer to be adapted or inverted.

 As the form of the clear paint used in the present invention, a solution type is preferably used. If the solution type is a solution type, any of an organic solvent type, an aqueous type (water-soluble, water-dispersible, emulsion) and a non-aqueous type can be used. May be. If necessary, a curing catalyst, a surface preparation agent and the like can be used.

 In most cases, the thickness of the composite coating film containing the glitter pigment-containing coating film as at least one layer is 30 to 300 m. Preferably it is 50 to 250 μm. Exceeding the upper limit lowers the physical properties of the film, such as thermal cycling, and lowering the lower limit lowers the strength of the film itself.

 Example

 Hereinafter, the present invention will be described in detail with reference to Examples. Parts mean parts by weight unless otherwise specified.

Manufacturing example

Preparation of crosslinked resin particles In a reaction vessel equipped with a stirring and heating device, a thermometer, a nitrogen inlet tube, a cooling tube, and a decanter, add 131 parts of bishydroxyxyl taurine, 208 parts of neopentyl glycol, 296 parts of phthalic anhydride, and azeline 376 parts of an acid and 30 parts of xylene were charged and heated. Water generated by the reaction was removed by azeotropic distillation with xylene. The reaction solution temperature was set at 210 ° C. over about 3 hours from the start of reflux, and stirring and dehydration were continued until the acid value equivalent to carboxylic acid became 135 nigK0Hg (solid content). .

 After cooling the liquid temperature to 140 ° C, 500 parts of “Kajura E10 (trade name; glycidyl ester of versatic acid manufactured by Shell)” was dropped in 30 minutes, and thereafter, Stirring was continued for 2 hours to complete the reaction. Acid value of solids 5

An amphoteric group-containing polyester resin having an S mgKOH / g, a hydroxyl value of 9 lmgK0H / g, and a number average molecular weight of 1,250 was obtained.

 10 parts of this zwitterion-containing polyester resin, 140 parts of deionized water, 1 part of dimethylethanolamine, 50 parts of styrene and 50 parts of ethylene glycol dimethacrylate were vigorously placed in a stainless steel beaker. A monomer suspension was prepared by stirring. Also, an aqueous initiator solution was prepared by mixing 0.5 part of azobiscyanovaleric acid, 40 parts of deionized water and 0.32 parts of dimethylethanolamine.

 A reaction vessel equipped with a stirring and heating device, a thermometer, a nitrogen inlet tube, and a cooling tube was charged with 5 parts of the above-described amphoteric group-containing polyester resin, 280 parts of deionized water, and 0.5 part of dimethylethanolamine. The temperature was raised to 80 ° C. Here, 25 1 part of the monomer suspension and 40.8 2 parts of the aqueous initiator solution were simultaneously added dropwise over 60 minutes, and the reaction was further continued for 60 minutes, and then the reaction was terminated.

A crosslinked resin particle emulsion having a particle diameter of 55 nra measured by a dynamic light scattering method was obtained. Xylene is added to the crosslinked resin particle emulsion, water is removed by azeotropic distillation under reduced pressure, the medium is replaced with xylene, and the solid content is 20 times. Thus, a xylene solution of cocoa resin particles in an amount of% was obtained.

Example 1

Preparation of brilliant pigment-containing coating composition

 Prepare a pigment paste by dispersing a part of the thermosetting acrylic resin and the coloring pigment in the following formulation with a desktop disperser using glass beads as a dispersion medium until the particle size becomes 5 μm or less. did. In addition, the crosslinked resin particles were gradually added during the stirring of the mixture of the resin and the solvent, and were uniformly dispersed in the solution. Thereafter, the pigment paste and the remaining components were sequentially added to prepare a bright pigment-containing coating composition.

Bright pigment-containing paint composition formulation

 S D A— S I L VE R W— 3

 (Alumina flake manufactured by Merck) 5.8 Degussa Carbon FW-200 (black pigment manufactured by Dedasa) 2.4 Cyanine Blue 5206 (blue pigment manufactured by Dainichi Seika) 1.3 Thermosetting acrylic resin (Nippon Paint resin) , 76.7 hydroxyl value 45, acid value 15, number average molecular weight 211 000, solid content 55%)

 Diamond HR 2048 35.2

 (Thermosetting acrylic resin manufactured by Mitsubishi Rayon,

 (Solid content 60%)

 Yupan 20 N 60 45.3

 (Methyl melamine resin manufactured by Mitsui Cytec,

 (Solid content 60%)

Crosslinked resin particles (manufactured by Nippon Paint Co., Ltd., solid content 20%) 4.5 Dispalon KS 273 N (Kusumoto Kasei Co., Ltd., surface preparation agent) 0.2 n ptananol 4.0 Xylene 0 7

 3.9 Total 200.0 Resin solids Hardener solids ratio = 7/3

 PWC = 9.5%

 Katsubachi resin particle content (resin solids ratio) = 1.0%

How to make a composite coating for appearance evaluation

 Zinc phosphate treated 0.8 mm thick, 1 OcmX 30 cm dull copper plate is coated with epoxy resin and block isocyanate-curable cationic electrodeposition paint (Nippon Paint Co., Ltd., “Power Top U-50 ( (Product name) J) was electrodeposited to a dry film thickness of about 20 / xm and baked for 160 minutes for 30 minutes. Spray-painted an intermediate paint (Nippon Paint Co., Ltd., Olga TO-H850Gray (trade name)) to a dry film thickness of about 30 μm, and baked at 140 ° C for 20 minutes. did.

 On the obtained intermediate coating film, the bright pigment-containing coating composition prepared in Example 1 was coated with ethyl ethyl toluene / solvesso 100 nosorenolesso 150 = 20/50/20/1 0 Using a No. 4 Ford Cup, diluted with a No. 4 Ford Cup to 13 seconds and adjusted the viscosity, and adjusted the electrostatic coating machine (“Au to RE A”) to a dry film thickness of about 18 μπι. (Trade name) ", Ransberg 'Gema Co., Ltd.), spray-painted with two-stage paint at an atomizing pressure of 4 kg / cm2, and allowed to stand for 3 minutes.

Next, in the wet-on-wet coating, the following “Olga TO-563 Clear (trade name)” paint A was used with Solvesso 100 / xylene = 60/40 diluted thinner. And diluted with No.4 Ford Cup for 20 seconds, paint to a dry film thickness of about 30 and set for about 7 minutes. After the baking, baking was performed at 140 ° C. for 20 minutes to prepare a coated plate for evaluation and used for evaluation.

Top coatings used to form composite coatings

Clear paint A

 "Olga T O-5 6 3 Clear (brand name)"

 Acrylic / melamine-curable clear paint manufactured by Nippon Paint Co., Ltd.

 榭 Resin solid content ratio of hardener solid content = 65/35

 P WC-0%

Evaluation standard of coating film appearance

 Visual evaluation was performed indoors by 10 people who could evaluate the finish of the coating film, and the results were comprehensively summarized according to the following criteria.

 〇 ； Excellent

 △: Normal

 X; inferior

Designability evaluation criteria

 10 people who can evaluate the finish of the coating film are visually evaluated in a room where sunlight shines on a part of the painted board while the sunlight is applied to the room, and the glittering feeling (the feeling that the particles are shining) The results for the feeling of depth (feeling of light coming from the coating film 內) were comprehensively summarized according to the following criteria.

 5; pretty good

 4 ； Excellent

 3; normal feeling

 2; slightly inferior

 1; considerably poor

 Table 1 below shows the evaluation results of the above items.

Examples 2 to 5 Except for changing the addition amount of the crosslinked resin particles and the addition amount of the alumina flake as shown in Table 1 below, the same procedure as in Example 1 was carried out to produce a glittering pigment-containing coating composition and evaluate its appearance. A painted plate was prepared and evaluated. The results are shown in Table 1.

Comparative Examples 1-4

Except for changing the amount of the crosslinked resin particles, the amount of the alumina flake, and the type of glitter pigment as shown in Table 1, the same procedure as in Example 1 was carried out to produce a glitter pigment-containing coating composition. A coated plate for appearance evaluation was prepared and evaluated. The results are shown in Table 1.

table 1

* Iliodin 103 W-3 is a my flour made by Merck Japan.

Example 6

 Method for forming composite coating film by 2 coats and 1 bake

Preparation of brilliant pigment-containing coating composition

 A part of the thermosetting acrylic resin and the coloring pigment in the following formulation are dispersed in advance with a desktop disperser using glass beads as a dispersing medium until the particle size becomes 5 / m or less. Prepared. In addition, the crosslinked resin particles were gradually added during the stirring of the mixture of the resin and the solvent, and were uniformly dispersed in the solution. Thereafter, the pigment paste and the remaining components were sequentially added to prepare a glittering pigment-containing coating composition.

Formulation of coating composition containing bright pigment

 S DA—SIL VER W—3 (Alumina flake from Merck) 5.8 Degussa carbon FW—200 (Black pigment from Degussa) 2.4 Cyanine blue 5206 (Blue pigment from Dainichi Seika) 1.3 Thermosetting Acrylic resin (Nippon Paint resin, 76.7 hydroxyl value 45, acid value 15, number average molecular weight 21000, solid content 55%)

 Diamond HR 2048 35.2

 (Thermosetting acrylic resin manufactured by Mitsubishi Rayon,

 (Solid content 60%)

 Uban 20 N 60 45.3

 (Methyl melamine resin manufactured by Mitsui Cytec,

 (Solid content 60%)

Crosslinked resin particles (manufactured by Nippon Paint Co., Ltd., solid content 20%) 9.1 Dispalon KS 273N (Kusumoto Kasei Co., Ltd., surface preparation agent) 0.2 n-butanol 4.0 xylene 6.1 Toluene .3.9 Total 200.0 Resin solids Z Hardener solids ratio = 7 3

 PWC = 9.5%

Method of forming composite coating

 Dried cation electrodeposition paint ("Power Top U-50" (trade name), manufactured by Nippon Paint Co., Ltd.) on a 0.8 mni, 1 OcmX 30 cm dull steel plate treated with zinc phosphate. Electrodeposition was applied so that the film thickness became about 20 μπι, and baked for 160 and 30 minutes. Next, a gray intermediate paint (Nippon Paint Co., Ltd., Olga TO-H850 Gray (trade name)) is sprayed on the obtained electrodeposition coating film to a dry film thickness of about 3 ◦ μm. Painted and baked at 140: 20 minutes to make a coating film.

On the intermediate coating film obtained, Echiru bright pigment containing paint acetic acid prepared in Example 6 Z toluene _/ / Solvent Tsu source 1 00 / Solvent Tsu source 1 50- 20Z50 20 1 0 dilution thinner Use the No.4 Ford Cup with 2

The product diluted with 0 for 13 seconds and adjusted in viscosity is atomized by an electrostatic coating machine ("Au to REA (trade name)", manufactured by Randsburg-Gemma Co., Ltd.) so that the dry film thickness becomes about 18 μπι. Spray painting was carried out by two-stage painting at a pressure of 4 kg / cm2, and the setting was left for 3 minutes.

 Next, the wet 'on' wet paint was applied to the Olga TO-5

6 3 CLEAR (trade name) ”Paint A was diluted with No.4 Ford cup in 20 seconds using a dilution thinner of Solvesso 100 noxylene == 60 to 40, and the dry film thickness was approx. After coating at 30 / zm and setting for about 7 minutes, it was baked at 140 ° C for 20 minutes to prepare a coated plate for evaluation and used for evaluation.

Top coat used to form composite coatings Clear paint A

 "Olga T O-5 6 3 Clear (brand name)"

 Acrylic and melamine curing clear paint manufactured by Nippon Paint Co., Ltd.

 Resin solids Hardener solids ratio = 65/35

 P W C = 0%

Designability evaluation criteria

 Ten people, who can evaluate the finish of the coating film, perform a visual evaluation in a room where sunlight shines on a part of the painted board while the sun is exposed to it, and evaluate the glitter (the feeling that the particles are shining). The results for the feeling of depth (feeling of light coming from inside the coating film) were comprehensively summarized according to the following criteria. Table 2 shows the evaluation results.

 5; pretty good

 4 ； Excellent

 3; normal feeling

 2; slightly inferior

 1; considerably poor

Examples 7 and 8

 Except for changing the type of alumina flakes as shown in Table 2 below, a glitter pigment-containing coating composition was manufactured and a coated plate for appearance evaluation was prepared and evaluated by the same procedure as in Example 6. . The results are shown in Table 2.

Comparative Examples 5 and 6

 A glitter pigment-containing coating composition was produced, and a coated plate for appearance evaluation was prepared and evaluated in the same procedure as in Example 6, except that the my powder was used instead of the alumina flakes as shown in Table 2. . The results are shown in Table 2.

Example 9

3 coat 2 beta Preparation of bright pigment-containing coating composition

 A part of the thermosetting acrylic resin and a coloring pigment were previously dispersed by a desktop disperser using glass beads as a dispersing medium until the particle size became 5 nm or less, thereby preparing a pigment paste. Further, the crosslinked resin particles were gradually added during the stirring of the mixed solution of the resin and the solvent, and were uniformly dispersed in the solution. Thereafter, the pigment paste and the remaining components were sequentially added to prepare a bright pigment-containing coating composition.

Method of forming composite coating

A zinc electrodeposited 0.8 mm, 10 cm x 30 cm dull steel sheet is coated with a cation electrodeposition paint (Nippon Paint Co., Ltd., Power Top U-50 (trade name) J) with a dry film thickness of approximately 20 electrodeposition coating so that μπ, 1 60 ^c gave come t :, baked for 30 minutes. then, the obtained electrodeposition coating paint film on a white preparative intermediate coating B (Nippon base into Co., " Olga TO-H860 white middle coat (trade name) J) was spray-coated to a dry film thickness of about 30 m, and baked at 140 ° C for 20 minutes.

 A color base paint C (“OLGA TO-646 White Color Base (brand name)” manufactured by Nippon Paint Co., Ltd.) was spray-coated on the obtained white intermediate coating film so as to have a dry film thickness of about 30 μm. After setting for about 7 minutes, baking was performed at 140 ° C for 20 minutes.

Next, the bright pigment-containing coating composition containing the coloring pigment prepared above was used in a diluted thinner of ethyl acetate / toluene Solvesso 100 / solvesso 150 = 20Z50 / 20/10. Then, using a No. 4 Ford tool, dilute and adjust the viscosity at 13 ° C at 20 ° C for 13 seconds, and adjust the electrostatic coating machine (“Au to RE”) so that the dry film thickness is about 18 μιη. A (trade name) ", Randsburg. Gemma) spray-painted at an atomizing pressure of 4 kg / cm2 and set for about 3 minutes. Furthermore, in the wet-on-wet coating, the above-mentioned "Orga TO-563 Clear (trade name)" paint A was used with Solvesso 100 Noxylene = 60/40 diluted thinner. , No. 4 Ford cup diluted to 20 seconds, painted to a dry film thickness of about 30 xm, set for about 7 minutes, and baked at 140 ° C for 20 minutes A coated plate for evaluation was prepared and used for evaluation. Table 2 shows the evaluation results.

Top coatings used to form composite coatings

Clear paint A

 "Olga TO-5 6 3 Taliyah (brand name) J

 Acrylic and melamine-curable Taliyah paint manufactured by Nippon Paint Co., Ltd.

 Resin solids Z hardener solids ratio = 65/35

 P W C = 0%

White intermediate paint B

 Γ Olga TO-H 860 white middle coat (product name)

 Made by Nippon Paint Co., Ltd., polyester melamine curable paint

 Resin solids / hardener solids ratio = 70/30

 PWC = 44%

Color base paint C

 "Olga TO-6 4 6 White Color Base Paint (Product Name)"

 Made by Nippon Paint Co., Ltd., polyester '' melamine curable paint

 Resin solids Hardener solids ratio = 65/35

 P W C = 45%

Comparative Example 7

A glitter pigment-containing paint composition was prepared in the same procedure as in Example 9 except that powder of my powder was used instead of alumina flakes as shown in Table 2. went. The results are shown in Table 2. Example 10

 3 coats 1 beta composite coating method

Preparation of bright pigment-containing coating composition

 As shown in Table 2, a glitter pigment-containing coating composition was prepared in the same manner as in Example 9 except that the addition amounts of the coloring pigment and the crosslinked resin particles were changed.

Method of forming composite coating

 Zinc phosphate-treated 0.8 orchid, 1 OcmX 3 Ocm dull steel plate, coated with cation electrodeposition paint (Nippon Paint Co., Ltd., “Power Top U-50 (trade name) J)” It was electrodeposited at 20 μπι and baked at 160 ° C. for 30 minutes, and then a color intermediate coating D (Nippon Paint Co., Ltd., “Orga TO-H840 White Color Base (trade name) J) was spray-coated to a dry film thickness of about 30 / zm and baked at 140 ° C for 20 minutes.

 A color base paint E (Nippon Paint Co., Ltd., “Olga TO-H 300 White Base Color (brand name))” was coated on the obtained color intermediate coating film with ethyl ethyl toluene acetate Z Solvesso 100Z Solvent. Using a diluted thinner with a thickness of 150 = 20Z50 // 20/1 0, diluted to 13 seconds at 20 ° C using a No. 4 feed cup Spray painting with 1-stage painting with an atomizing pressure of 4 kg / cm2 using an electrostatic painting machine (“Au to RE A (trade name) j, manufactured by Ransburgh Gemma Co., Ltd.)” to obtain 10 μιη, and set for about 3 minutes I left it.

Next, the bright pigment-containing coating composition obtained by using the coloring pigment previously obtained in combination with the previously obtained coloring pigment was diluted to 13 seconds and the viscosity thereof was adjusted by wet-on-wet. The spray coating was carried out at an atomizing pressure of 4 kg / cm2 using an electrostatic coating machine (“Au to RE A (trade name)”, manufactured by Ransburgh Gemma Co., Ltd.), and the setting was set again for about 3 minutes. In addition, wet “on” wet coating was used to dilute “olga TO-563 clear (product name)” paint A shown above with Solvesso 100 / xylene = 60/40. Using a thinner, dilute for 20 seconds with a No. 4 Ford cup, apply it to a dry film thickness of about 30 m, set it for about 7 minutes, and apply it at 140 ° C. After baking for 20 minutes, a coated plate for evaluation was prepared and used for evaluation. Table 2 shows the evaluation results.

Top coatings used to form composite coatings

Clear paint A

 "Olga TO-5 6 3 Talya 1 (brand name)"

 Acrylic / melamine-curable clear paint manufactured by Nippon Paint Co., Ltd.

 Resin solids Z hardener solids ratio = 65/35

 PWC = 0%

Color intermediate paint D

 "Olga TO-H840 White Color Base (Product Name)"

 Made by Nippon Paint Co., Ltd., polyester ♦ Melamine curable paint

 Resin solids hardener solids ratio = 70/3/3

 PWC = 45%

Color base paint E

 “Olga TO—H300 White Base Color Paint (trade name) J Nippon Paint Co., Ltd., acrylic / melamine curable paint

 榭 Fat solids Hardener solids ratio = 65/35

 PWC = 45%

Comparative Example 8

A glitter pigment-containing coating composition was produced, and a coated plate for appearance evaluation was prepared and evaluated in the same procedure as in Example 10 except that the powdered my powder was used instead of the alumina flakes as shown in Table 2. . The results are shown in Table 2. Table 2

* Iriozin 502 W-3, 504 W— 3 is a my flour made by Merck Japan.氺 Netitanium CR-97 is a white pigment manufactured by Ishihara Sangyo. The invention's effect

 A layer formed of the glitter pigment-containing coating composition of the present invention is formed on a substrate undercoated with an electrodeposition coating and an intermediate coating, and a layer of a clear coating composition is further formed thereon. By using the composite coating film forming method described above, it is possible to form a novel composite coating film having an unprecedented brilliant feeling and a new design without deteriorating the finished appearance.

 In particular, the degree of gloss (gloss intensity) of the brilliant pigment changes depending on the viewing angle. However, the coating film containing the alumina flakes has a more brilliant sensation than before. A slight change in gloss can be recognized according to the degree of inclination of the film surface, and the color tone changes variously depending on the viewing angle. On the other hand, when the glossiness of the glittering pigment is slightly weak, the color of the non-brilliant pigment is superior on the coating surface. Therefore, for example, the viewing angle is different between the lower part and the upper part of a large area, and the lower part has a strong gloss effect and the glitter is better, while the upper part has a weak gloss effect and is a non-brilliant colored pigment. There is also a situation where the color is superior. In this case, different color tones coexist at the same time on one coating film surface, and express a higher design effect than ever before.

Claims

a * 5 Range of request

 1. A glittering pigment-containing coating composition containing a glittering pigment and a viscosity controlling agent, containing alumina flakes coated with aluminum oxide as a glittering pigment and containing crosslinked resin particles as a viscosity controlling agent. Shine '1 «paint-containing paint composition.

 2. A step of applying the coating composition according to claim 1 on an undercoated or intermediate-coated substrate to form a glittering base layer;

 A step of applying a clear coating composition thereon to form a clear layer without curing the base layer; and

 Curing the base layer and the clear layer by heating;

And a method for forming a composite coating film.

 3. A step of applying a water-based or solvent-based color base coating composition on an undercoated or intermediate-coated substrate and heat curing to form a color base coating film;

 Forming a glittering base layer by applying the coating composition according to claim 1 thereon;

 A step of applying a clear coating composition thereon to form a clear layer without curing the glittering base layer; and

 Curing the glittering base layer and the clear layer by heating.

 4. A step of applying a water-based or solvent-based color base coating composition on an undercoated or intermediate-coated substrate to form a color base layer;

 A step of applying the coating composition according to claim 1 thereon to form a glittering base layer without curing the color base layer;

 A step of forming a talli layer by applying a clear coating on the brilliant base layer without curing the brilliant base layer; and

 Curing the color base layer, the glittering base layer and the clear layer by heating;

 And a method for forming a composite coating film.

5. Formed by the composite coating film forming method according to any one of claims 2 to 4. Composite coating.

6. Article _c having a composite coating according to claim 5