WO2021132246A1 - Coating composition, coating film obtained therefrom, and method for forming multilayered coating film - Google Patents

Coating composition, coating film obtained therefrom, and method for forming multilayered coating film Download PDF

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Publication number
WO2021132246A1
WO2021132246A1 PCT/JP2020/047970 JP2020047970W WO2021132246A1 WO 2021132246 A1 WO2021132246 A1 WO 2021132246A1 JP 2020047970 W JP2020047970 W JP 2020047970W WO 2021132246 A1 WO2021132246 A1 WO 2021132246A1
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Prior art keywords
coating film
resin
coating composition
coating
composition according
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PCT/JP2020/047970
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French (fr)
Japanese (ja)
Inventor
俊哉 池中
晋之介 河野
涼子 大西
水口　克美
Original Assignee
日本ペイント・オートモーティブコーティングス株式会社
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Publication of WO2021132246A1 publication Critical patent/WO2021132246A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D123/00—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
    • C09D175/04—Polyurethanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/02—Emulsion paints including aerosols
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/63—Additives non-macromolecular organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/65—Additives macromolecular

Definitions

  • the present invention relates to a coating composition, a coating film using the same, and a method for forming a multi-layer coating film.
  • automotive parts may contain polyolefin resins. Further, in order to impart the strength required for automobile parts, a polyolefin resin, a carbon pigment, a carbon fiber or the like may be used in combination. Therefore, such automotive parts usually have a black appearance.
  • automobile parts need to express various colors. For example, not only the expression of blackish colors is required, but also the expression of solid whites, whites including mica, and the like is required. Therefore, in order to develop the required color, it is usually made to conceal a black base by using a coating composition containing titanium oxide for automobile parts having a black appearance.
  • Patent Document 1 describes chlorine-method titanium oxide pigments, yellow iron oxide pigments, carbon black pigments having a primary average particle size in the range of 15 nm or more and 80 nm or less, and resins that are vehicle-forming components.
  • a coating composition containing the composition is disclosed.
  • Patent Document 1 discloses a coating film forming method in which a coating composition according to Patent Document 1 is applied to an object to be coated and a color-based coating film is laminated on the obtained coating film.
  • the film thickness of the coating film formed from this coating composition is increased. There is a need. Alternatively, it is necessary to form a coating film having a high concentration of titanium oxide.
  • the concentration of titanium oxide in the coating film is increased, the moisture resistance of the formed coating film may be inferior. Further, if the film thickness of the coating film containing titanium oxide is increased, the water resistance of the obtained coating film may be inferior. Therefore, there is a demand for a coating composition that can satisfactorily conceal the color tone of the object to be coated, for example, black color, even if the concentration of titanium oxide is not high. Further, in order to increase the film thickness of the coating film containing titanium oxide, it is necessary to form the coating film in a plurality of times, and simplification of the work process is required. In addition, there is a demand for a coating composition capable of concealing the color tone of the object to be coated, for example, black, while having a thinner film thickness.
  • An object of the present invention is to solve the above-mentioned problems and to provide a coating composition capable of concealing the color tone of the object to be coated, for example, black, while having a thinner film thickness. Furthermore, the present invention provides a coating composition capable of forming a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
  • a paint composition At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
  • Resin dispersion (D) and hardener (E) Including Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D)
  • Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A)
  • dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
  • the sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
  • the resin dispersion (D) is a polyester resin dispersion (D1), and the polyester resin in the polyester resin dispersion (D1) has a solubility parameter SP (D1) of 11.0. It is 12.0 or less.
  • the number average molecular weight of the polyester resin in the polyester resin dispersion (D1) is 6,000 or more and 20,000 or less.
  • the resin dispersion (D) is an acrylic resin emulsion (D2), and the acrylic resin in the acrylic resin emulsion (D2) has a solubility parameter SP (D2) of 8.0 or more 12 It is .0 or less, and the acrylic resin does not contain a glycidyl group.
  • the acrylic resin in the acrylic resin emulsion (D2) is the crosslinkable resin particles.
  • the maleic anhydride-modified polyolefin resin (A) is a maleic anhydride-modified chlorinated polyolefin resin.
  • the coating composition comprises particles selected from the group consisting of organic particles and inorganic particles.
  • the coating composition contains a coloring pigment, and the amount of the coloring pigment is 3% by mass or more and 150% by mass or less with respect to the total resin solid content of (A) to (E). .. [10]
  • the coating composition is an aqueous primer coating composition.
  • a method for forming a coating film which comprises a step of coating an object to be coated with the coating composition according to the present disclosure to form an uncured coating film, and a step of heat-curing the uncured coating film to form a coating film. I will provide a. [12] In another embodiment, the present disclosure.
  • a step of coating an object to be coated with the aqueous primer coating composition according to the present disclosure to form an uncured primer coating film A step of coating a base coating composition containing a bright pigment on an uncured aqueous primer coating composition to form an uncured base coating film.
  • the step of applying the clear coating composition on the uncured base coating film to form the uncured clear coating film, and the uncured primer coating film, the base coating film and the clear coating film are heat-cured to form a double layer.
  • a method for forming a multi-layer coating film which comprises a step of forming a layer coating film.
  • the coating composition of the present invention can form a thin film, and moreover, can form a coating film capable of hiding the color tone of the object to be coated. Further, the coating composition of the present invention can form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
  • plastic automobile parts are used in vehicles such as automobiles.
  • Automobile parts are required to have excellent strength, impact resistance, and the like, and are usually required to develop a color tone suitable for the automobile body.
  • automobile parts containing carbon materials and polyolefin resins are often black. Therefore, in order to develop a color tone that matches the automobile body, especially a white mica color tone, a white primer coating film is formed on a black object to be coated, and a white color base coating is applied on the primer coating film. It is necessary to form a film and further, a mica-containing base coating film, and to form a clear coating film on the outermost layer.
  • the required color tone for example, the color tone of white mica
  • the thickness of the white primer coating film containing a white pigment is usually increased or white. It is necessary to form a white primer coating with an increased amount of pigment.
  • titanium oxide which is generally used as a white pigment
  • the water resistance tends to decrease. Further, if the amount of titanium oxide is reduced, it becomes necessary to increase the film thickness.
  • the present invention is a coating composition. At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
  • A maleic anhydride-modified polyolefin resin
  • B glycidyl group-containing acrylic resin emulsion
  • C a urethane resin dispersion
  • Resin dispersion (D) and hardener (E) Including Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D)
  • Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A)
  • dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
  • the haze value of a coating film having a thickness of 30 ⁇ m formed from a mixture containing at least one of the above, a resin dispersion (D), and a curing agent (E) in the same mass ratio as that of the coating composition is 15% or more. It is a coating composition.
  • the present invention Maleic anhydride-modified polyolefin resin (A), Glycidyl group-containing acrylic resin emulsion (B), Urethane resin dispersion (C), Resin dispersion (D) and hardener (E) Including Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D)
  • the sex parameter SP (D) satisfies at least one relationship of the following equations (1) and (2).
  • the coating composition according to the present disclosure it is possible to form a coating film which is a thin film but can hide the color tone such as black and gray of the object to be coated. Therefore, the coating composition according to the present disclosure can form a thinner coating film as compared with, for example, a coating film containing titanium oxide. Further, since the coating film formed from the coating composition according to the present disclosure may have a white appearance, the color tone of the object to be coated, for example, black or gray, can be sufficiently concealed even though it is a thin film. Therefore, the coating film formed from the coating composition according to the present disclosure is a single-layered white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film, which is usually used. Can be provided with the functions of and.
  • a white primer coating film is usually formed on a black object to be coated, and a white color base is formed on the primer coating film. It is necessary to form a coating film and further, a mica-containing base coating film, and to form a clear coating film on the outermost layer.
  • a coating film formed from the coating composition according to the present disclosure is formed on a black object to be coated, and further, on the coating film according to the present disclosure.
  • a mica-containing base coating film can be formed, and a clear coating film can be formed on the outermost layer.
  • the coating film formed from the coating composition according to the present disclosure has the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film in a single layer. You can prepare for it. Therefore, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
  • the coating composition according to the present disclosure can form a thin film having a high hiding property, and can shorten the coating process, coating time, etc. in automobile parts. Therefore, it is possible to reduce the environmental load such as CO 2 reduction. Moreover, it is possible to form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
  • the coating composition according to the present disclosure will be described in more detail.
  • the coating composition according to the present disclosure is At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C). Resin dispersion (D) and hardener (E) including.
  • A maleic anhydride-modified polyolefin resin
  • B glycidyl group-containing acrylic resin emulsion
  • C urethane resin dispersion
  • Resin dispersion (D) and hardener (E) including.
  • the coating composition according to the present disclosure can form a thin film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance. Further, it is possible to form a coating film having the coating film strength required for automobile parts.
  • the coating composition contains all of the above components (A) to (E). That is, in one embodiment, the coating composition comprises a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C), a resin dispersion (D), and a curing agent. (E) is included.
  • solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A) the solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B), and the resin dispersion (D).
  • the solubility parameter SP (D) of the resin of the above satisfies at least one of the following formulas (1) and (2).
  • at least one of equations (1) and (2) is satisfied, that is, the absolute value of SP (D) minus SP (A), and SP (D) minus SP (B).
  • the coating composition according to the present disclosure can form a coating film having a high hiding property. Therefore, the coating film formed from the coating composition according to the present disclosure is a single-layered white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film, which is generally used. Can be provided with the functions of and. That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Further, for example, even if the color tone of the coating film formed on the coating film formed by the coating composition according to the present disclosure is the color tone of white mica, the desired color tone can be sufficiently expressed.
  • a coating film having a high hiding property for example, a thin film can be formed.
  • the solubility parameter SP value for the specific resin according to the present disclosure, by setting the solubility parameter SP value to a specific condition, extremely high hiding property can be obtained without deteriorating various physical properties such as coating film strength, adhesion and hardness.
  • the coating film to have can be formed.
  • the coating film becomes cloudy without being largely dependent on the white paint such as titanium oxide, the physical characteristics of the coating film tend to be inferior.
  • the coating composition according to the present disclosure contains a specific resin under specific conditions, the coating film is phase-separated and light is diffusely reflected due to the difference in refractive index, resulting in high hiding property and excellent coating film physical characteristics. It is considered that both can be held in a well-balanced manner.
  • the coating composition according to the present disclosure is an aqueous primer coating composition, various resin components can maintain a stable dispersed state. Therefore, the stability of the coating composition is maintained, and the coating film formed from such a coating composition can also exhibit high coating film physical characteristics, and moreover, the coating film physical properties are not impaired. It is presumed to show high concealment.
  • ⁇ 1.05 May have a relationship of, for example 1.40 ⁇
  • the solubility parameter SP value of these specific resins By setting the solubility parameter SP value of these specific resins to specific conditions, a coating film having higher hiding power can be formed, and even a thin film can have sufficient hiding power.
  • the thin film means a film thickness of about (20 ⁇ m or more and 35 ⁇ m or less), but is not limited to this numerical range.
  • the solubility parameter SP value of the specific resin according to the present disclosure it is possible to form a coating film having more excellent physical properties such as coating film strength, adhesion and hardness.
  • the conditions of the SP value may be used in combination.
  • the SP value is an abbreviation for solution parameter, which is a measure of solubility.
  • the SP value can be actually measured by the following method [References: SUH, CLARKE, J. Mol. P. S. A-1, 5, 1671 to 1681 (1967)].
  • an organic solvent is weighed in a 100 ml beaker, 10 ml of acetone is added using a whole pipette, and the mixture is dissolved by a magnetic stirrer.
  • a poor solvent is added dropwise to this sample using a 50 ml burette at a measurement temperature of 20 ° C., and the point at which turbidity occurs is defined as the amount of addition.
  • the poor solvent ion-exchanged water is used as the high SP poor solvent, and n-hexane is used as the low SP poor solvent, and the turbidity point is measured.
  • the SP value ⁇ of the organic solvent is given by the following formula.
  • the haze value of the coating film having a thickness of 30 ⁇ m formed from the mixture containing the curing agent (E) and the curing agent (E) in the same mass ratio as in the coating composition is 15% or more.
  • the haze value of the coating film having a thickness of 30 ⁇ m is 30% or more.
  • the haze value of the coating film having a thickness of 30 ⁇ m is 35% or more, for example, the haze value is 40% or more. The higher the haze value, the better the hiding property. Therefore, the higher the haze value, the more preferable.
  • the color tone of the object to be coated for example, black or silver
  • the coating film can have high hiding power and can exhibit white or a color close to white
  • a commonly used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film are used.
  • the function of the film can be provided by a coating film formed from the coating composition according to the present disclosure. Therefore, the coating film according to the present disclosure has the functions of a commonly used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film. Although it is a single layer, it can be prepared. Further, the layer structure can be made thinner as compared with the conventional multi-layer coating film, and the coating film forming step can be reduced. In addition, a desired color tone, particularly a color tone of white mica, can be satisfactorily expressed.
  • the preparation of a coating film for measuring the haze of a coating film having a thickness of 30 ⁇ m can be prepared based on the following method.
  • the haze value of a coating film having a thickness of 30 ⁇ m can be measured by a method compliant with JIS K7136: 2000 using a commercially available turbidity meter (for example, ⁇ 90 color measurement system manufactured by Nippon Denshoku Kogyo Co., Ltd.).
  • the solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A) according to the present disclosure may be, for example, 8.2 or more and 9.5 or less, and 8.3 or more and 9.3 or less. ..
  • the maleic anhydride-modified polyolefin resin (A) may be any derivative synthesized from the polyolefin resin and maleic anhydride, and is not particularly limited.
  • the maleic anhydride-modified polyolefin resin (A) may be of only one type or of two or more types.
  • the maleic anhydride-modified polyolefin resin (A) may be in an emulsion state, and such a resin (A) may be referred to as a maleic anhydride-modified polyolefin resin emulsion.
  • the maleic anhydride-modified polyolefin resin (A) means the maleic anhydride-modified polyolefin resin emulsion itself, and does not contain other emulsion resins.
  • the weight average molecular weight of the maleic anhydride-modified polyolefin resin (A) is preferably in the range of 20,000 or more and 200,000 or less, and more preferably in the range of 50,000 or more and 120,000 or less.
  • the weight average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.
  • GPC gel permeation chromatography
  • the weight average molecular weight is within such a range, for example, in the embodiment in which the coating composition according to the present disclosure is used as a primer coating composition, the strength required as a primer coating film can be maintained, and the coating material can be combined with the object to be coated. It is possible to maintain high adhesion and further suppress coagulation failure in the coating film.
  • the maleic anhydride-modified polyolefin resin (A) can be emulsified by a known method described in the present disclosure, and further, the stabilization of the coating composition can be shown. Further, for example, in the embodiment in which the polyolefin material is used for the object to be coated, the decrease in wettability can be suppressed and the adhesion of the material can be improved.
  • the maleic anhydride-modified polyolefin resin (A) may be, for example, 15% by mass or more and 40% by mass or less, and 20% by mass or more and 35% by mass or less, based on the total resin solid content in the coating composition according to the present disclosure. Good.
  • the total resin solid content in the coating composition according to the present disclosure means the total solid content of (A), (B), (C), (D) and (E).
  • the amount of the maleic anhydride-modified polyolefin resin (A) is within such a range, good adhesion can be maintained, for example, in a mode in which a polyolefin material is used for the object to be coated.
  • poor appearance can be suppressed, and for example, poor adhesion to the underlying coating film at the time of recoating can be suppressed.
  • a commonly used emulsification method such as a mechanical emulsification method, a method using an emulsifier or a basic substance, or a combination thereof can be used. It can.
  • an emulsifier When an emulsifier is used, the amount of the emulsifier can be appropriately set depending on the amount of the maleic anhydride-modified polyolefin resin (A), the basic substance, water and the like.
  • a basic substance When a basic substance is used, it can be appropriately set depending on the amount of maleic anhydride-modified polyolefin resin, water, etc., and in particular, the amount is such that the acid functional groups of the maleic anhydride-modified polyolefin resin (A) and the emulsifier are sufficiently neutralized. Further, it is preferable to set the pH of the obtained emulsion in consideration of 7 or more and 11 or less, more preferably 7.5 or more and 10.5 or less. When the pH value of the obtained maleic anhydride-modified polyolefin resin emulsion is within the above range, the stabilization of the emulsion can be maintained, for example, the release of a basic substance can be suppressed, and the water resistance can be improved.
  • the average particle size of the maleic anhydride-modified polyolefin resin in the emulsion is not particularly limited.
  • the average particle size is preferably 0.01 ⁇ m or more and 10 ⁇ m or less. Since the average particle size is within such a range, a large amount of emulsifier is not required. For example, if a large amount of emulsifier is contained, the water resistance of the coating film may be slightly inferior. On the other hand, by having the above average particle size, it is possible to suppress a decrease in water resistance of the coating film. In addition, the stability of the emulsion may be kept good.
  • the mass ratio of the structure derived from maleic anhydride (acid anhydride) in the maleic anhydride-modified polyolefin resin (A) is preferably 1% by mass or more and 10 or less by mass, more preferably. It is preferably 1.2% by mass or more and 5% by mass or less.
  • the mass ratio is within the above range, the maleic anhydride-modified polyolefin resin (A) can be appropriately emulsified, and the coating composition can be stabilized. In addition, it is possible to suppress a decrease in the water resistance of the coating film.
  • the maleic anhydride-modified polyolefin resin (A) may be a chlorinated maleic anhydride-modified polyolefin resin (A).
  • a chlorinated resin is referred to as a maleic anhydride-modified chlorinated polyolefin resin.
  • the chlorinated maleic anhydride-modified polyolefin resin (A) for example, in the embodiment of using the coating composition according to the present disclosure as a primer coating composition, the strength required as a primer coating film can be maintained, and the coating film can be coated. High adhesion with the coating can be maintained. In addition, cohesive failure in the coating film can be suppressed. In addition, it can show stabilization of the coating composition. Further, by chlorination, the melting point is lowered while maintaining the crystallinity of the crystalline polyolefin, and handling such as emulsification becomes easy.
  • the coating composition according to the present disclosure may contain a maleic anhydride-modified chlorinated polyolefin resin as a maleic anhydride-modified chlorinated polyolefin resin emulsion resin.
  • the chlorine content of the chlorinated polyolefin resin used for obtaining the maleic anhydride-modified chlorinated polyolefin resin emulsion is 15% by mass or more and 40% by mass or less, more preferably 20% by mass in the maleic anhydride-modified chlorinated polyolefin resin. % To 35% by mass or less.
  • the solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B) may be, for example, 9.9 or more and 11.5 or less, and may be 10 or more and 11 or less.
  • hydrophilic groups are required to stabilize the resin in the aqueous medium.
  • a carboxyl group, a hydroxyl group, an amino group and the like When a large amount of such hydrophilic groups are contained, various problems occur in the water resistance test. For example, a large amount of water is absorbed, blisters are generated, and delamination with the inferior membrane and upper membrane is likely to occur due to water swelling.
  • the cohesive force of the coating film can be improved by using the glycidyl group-containing acrylic resin emulsion (B).
  • the glycidyl group-containing acrylic resin emulsion (B) for example, in the case of a white coating film or a mica coating film, yellowing deterioration of the primer coating film that can be caused by the ultraviolet rays of sunlight reaching the primer can be prevented. Can be suppressed.
  • the glycidyl group-containing acrylic resin can be obtained by copolymerizing a radically polymerizable monomer containing a glycidyl group with another radically polymerizable monomer.
  • a radically polymerizable monomer containing a glycidyl group with another radically polymerizable monomer.
  • Functional group-containing monomers such as substances, and further, as (meth) acrylic acid alkyl ester, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, isopropyl (meth) acrylic acid, N-butyl (meth) acrylic acid, T-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, (meth) )
  • Acrylic resin emulsion (B) containing a glycidyl group can be obtained by copolymerizing with lauryl acrylate to obtain an aqueous emulsion.
  • aqueous emulsion examples include a method of subjecting to solvent polymerization and then emulsion by forced stirring or using an emulsifier in water, an emulsion polymerization method of copolymerizing in water using an emulsifier, and the like.
  • the mass ratio of the structure derived from the glycidyl group-containing monomer in the glycidyl group-containing acrylic resin in the emulsion (B) is preferably 30% by mass or more and 60% by mass or less. That is, it is preferable that the radically polymerizable monomer containing a glycidyl group is 30% by mass or more and 60% by mass or less in all the monomers used for the synthesis of the glycidyl group-containing acrylic resin.
  • the glycidyl group-containing acrylic resin in the emulsion (B) is preferably 20% by mass or more and 35% by mass or less in the total resin solid content in the coating composition according to the present disclosure. Within such a range, it is possible to suppress coagulation breakage / peeling of the coating film even under conditions such as subjecting to a water resistance test and then evaluating the adhesion of the coating film. Further, it is possible to prevent the degree of cross-linking from becoming too large, for example, it is possible to suppress cross-linking strain, and it is possible to suppress delamination with other coating films and objects to be coated in the initial adhesion.
  • the coating composition according to the present disclosure may comprise a urethane resin dispersion (C).
  • a urethane resin dispersion (C) a polyfunctional isocyanate compound, a polyol having two or more hydroxyl groups in one molecule, and hydrophilicity having both hydroxyl groups and carboxylic acid groups such as dimethylolpropanediol or dimethylolbutanediol.
  • the agent is reacted in the presence of a catalyst such as dibutyltin dilaurylate in an excess of isocyanate groups to obtain a urethane prepolymer, and then carboxylic acid is added to an organic base such as amines or an inorganic base such as sodium hydroxide or potassium hydroxide.
  • a catalyst such as dibutyltin dilaurylate in an excess of isocyanate groups
  • Examples thereof include a urethane resin dispersion obtained in combination with an emulsifier, if necessary; and a urethane resin dispersion obtained in combination with an emulsifier.
  • polyfunctional isocyanate compound examples include diisocyanates such as 1,6-hexanediisocyanate, lysine diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-toluene diisocyanate.
  • diisocyanates such as 1,6-hexanediisocyanate, lysine diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-toluene diisocyanate.
  • examples thereof include compounds and polyfunctional isocyanate compounds such as adducts, burettes, and isocyanurates thereof.
  • polyol examples include polyester polyol, polyether polyol, polycarbonate polyol and the like.
  • chain extender examples include low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, fracidimethanol, diamine glycol, triethylene glycol and tetraethylene glycol, and ethylene oxide and propylene.
  • low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, fracidimethanol, diamine glycol, triethylene glycol and tetraethylene glycol, and ethylene oxide and propylene.
  • Diamine acid such as (anhydrous) succinic acid, adipic acid, (anhydrous) futaric acid
  • diamine acid such as (anhydrous) succinic acid, adipic acid, (anhydrous) futal acid, and hydroxyl group at the terminal obtained from these anhydrides
  • the urethane resin in the urethane resin dispersion (C) may be, for example, 15% by mass or more and 40% by mass or less, and 20% by mass or more and 35% by mass or less, based on the total resin solid content in the coating composition according to the present disclosure. It may be there.
  • the amount of urethane resin in the urethane resin dispersion (C) is within the above range, for example, the coating film is subjected to a water resistance test and then the adhesion of the coating film is evaluated. Aggregate destruction and peeling can be suppressed. Further, it is possible to prevent the degree of cross-linking from becoming too large, for example, it is possible to suppress cross-linking strain, and it is possible to suppress delamination with other coating films and objects to be coated in the initial adhesion.
  • the resin dispersion (D) according to the present disclosure can be appropriately selected within a range that satisfies the specific conditions according to the present disclosure, particularly the conditions relating to the solubility parameter SP value.
  • the resin dispersion (D) is a resin dispersion comprising at least one selected from the group consisting of polyester resin dispersion (D1) and acrylic resin emulsion (D2).
  • the resin dispersion (D) may be either a polyester resin dispersion (D1) or an acrylic resin emulsion (D2).
  • the resin dispersion (D) is a polyester resin dispersion (D1).
  • the coating composition according to the present disclosure contains the polyester resin dispersion (D1), it is possible to form a coating film having excellent water resistance and excellent adhesion to the object to be coated.
  • the number average molecular weight of the polyester resin in the polyester resin dispersion (D1) may be 6,000 or more and 20,000 or less, for example, 8,500 or more and 20,000 or less.
  • the number average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.
  • the polyester resin dispersion (D1) may have a solubility parameter SP (D1) of, for example, 11.0 or more and 12.0 or less, and 11.1 or more and 11.9 or less. ..
  • solubility parameter SP (D1) is within such a range, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film.
  • a coating film having a high hiding property can be formed, the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are described in the present disclosure.
  • the coating film can be provided even though it is a single layer. That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
  • the glass transition temperature (Tg) of the polyester resin in the polyester resin dispersion (D1) may be, for example, 40 ° C. or higher and 80 ° C. or lower, and 55 ° C. or higher and 75 ° C. or lower. When the glass transition temperature (Tg) is within such a range, it is possible to form a coating film having excellent water resistance and excellent adhesion to an object to be coated.
  • the acid value of the polyester resin in the polyester resin dispersion (D1) may be, for example, 1 mgKOH / g or more and 10 mgKOH / g, or 1 mgKOH / g or more and 8 mgKOH / g.
  • the acid value is within such a range, a crosslinked structure can be formed by a crosslinking agent or the like, and as a result, the adhesion between the coating film and the object to be coated is arranged above the coating film according to the present disclosure. Adhesion with another coating film can be further improved.
  • the hydroxyl value of the polyester resin in the polyester resin dispersion (D1) may be, for example, 1 mgKOH / g or more and 20 mgKOH / g or less, and 1 mgKOH / g or more and 10 mgKOH / g or less.
  • the hydroxyl value is within such a range, excellent durability can be imparted to the coating film together with the curing agent (E) described later.
  • the average particle size (D50) of the polyester resin in the polyester resin dispersion (D1) may be, for example, 40 nm or more and 100 nm or less, and 50 nm or more and 90 nm or less.
  • polyester resin in the polyester resin dispersion (D1) examples include a condensate of a polybasic acid and a polyhydric alcohol.
  • the polybasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, succinic anhydride and the like.
  • the polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol and the like.
  • the polyester resin in the polyester resin dispersion (D1) preferably has a carboxy group and / or a sulfonic acid group.
  • the polyester has these hydrophilic groups, the dispersibility in water is improved, and as a result, a more uniform coating film can be formed from the coating composition containing the emulsion composition, and the coating film and the coating film can be coated. Adhesion to the coating film, and further, adhesion to other coating films arranged above the coating film can be further improved.
  • polyester resin dispersion (D1) for example, KA-5071S, KZT-8803, KT-8701, KZT-9204 (above, Unitika Ltd.), Byronal MD1200, MD1245, MD1480, MD1930, MD2000, MD1500.
  • Hi-Tech PE series such as PES-H001 (Toho Chemical Industry Co., Ltd.), New Track 2010 (Kao Co., Ltd.), Superflex 210 (Daiichi Kogyo Seiyaku Co., Ltd.), Plus Coat Z730, Z760, Z592, Z687 , Z690 (above, Goo Chemical Industry Co., Ltd.) and the like.
  • the polyester resin in the polyester resin dispersion (D1) may be, for example, 10% by mass or more and 35% by mass or less, and 15% by mass or more and 25% by mass or less in the total resin solid content in the coating composition according to the present disclosure. It may be there.
  • the resin dispersion (D) according to the present disclosure is an acrylic resin emulsion (D2).
  • the coating composition according to the present disclosure contains an acrylic resin emulsion (D2), it is possible to form a coating film having excellent water resistance and excellent adhesion to an object to be coated.
  • the acrylic resin emulsion (D2) is an emulsion of an acrylic resin that does not contain a glycidyl group.
  • the weight average molecular weight of the acrylic resin in the acrylic resin emulsion (D2) is not particularly limited, but may be generally 50,000 or more and 1,000,000 or less, for example, 100,000 or more and 800,000 or less. It may be there.
  • the weight average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.
  • the acrylic resin emulsion (D2) may have a solubility parameter SP (D2) of 8.0 or more and 12.0 or less.
  • the solubility parameter SP (D2) may be 8.3 or more and 8.9 or less, and may be 10.5 or more and 12.0 or less.
  • the solubility parameter SP (D2) is within such a range, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film.
  • a coating film having a high hiding property can be formed, the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are described in the present disclosure.
  • the coating film can be provided even though it is a single layer. That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
  • the acrylic resin in the acrylic resin emulsion (D2) can be obtained by polymerizing one or more radically polymerizable monomers.
  • Functional group-containing monomers such as (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and adducts of hydroxyethyl acrylate and ⁇ -caprolactone.
  • (meth) acrylic acid alkyl ester (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid isopropyl, (meth) acrylic acid N-butyl, (meth) acrylic acid t- Selected from butyl, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate.
  • Acrylic resin emulsion (D2) can be obtained by polymerizing one or more kinds of monomers to form an aqueous emulsion.
  • aqueous emulsion examples include a method of subjecting to solvent polymerization and then emulsion by forced stirring or using an emulsifier in water, an emulsion polymerization method of copolymerizing in water using an emulsifier, and the like.
  • the glass transition temperature (Tg) of the acrylic resin in the acrylic resin emulsion (D2) may be, for example, ⁇ 10 ° C. or higher and 100 ° C. or lower, and 0 ° C. or higher and 80 ° C. or lower.
  • the glass transition temperature (Tg) of the acrylic resin may be 10 ° C. or higher and 80 ° C. or lower.
  • the glass transition temperature (Tg) is within such a range, it can be dispersed in the coating film to exhibit higher hiding power.
  • the coating composition according to the present disclosure is used in a wet-on-wet system, the interface between the object to be coated and the upper coating film formed on the coating film formed from the coating composition according to the present disclosure. It is possible to suppress familiarity with and prevent inversion.
  • the acid value of the acrylic resin in the acrylic resin emulsion (D2) is preferably 2 mgKOH / g or more and 20 mgKOH / g or less, for example, 5 mgKOH / g or more and 10 mgKOH / g or less.
  • various stability such as storage stability, mechanical stability, stability against freezing, etc. of the acrylic resin emulsion (D2) and the coating composition according to the present disclosure containing the same can be obtained.
  • the curing reaction with the curing agent (E) at the time of forming the coating film sufficiently occurs, and various strengths, chipping resistance and water resistance of the coating film are improved.
  • the hydroxyl value of the acrylic resin in the acrylic resin emulsion (D2) is preferably 5 mgKOH / g or more and 20 mgKOH / g. More preferably, it is in the range of 10 mgKOH / g or more and 20 mgKOH / g.
  • the resin has appropriate hydrophilicity, workability and stability against freezing when used as a coating composition containing a resin emulsion are increased, and the curing agent (E) is used.
  • the coating film has high mechanical properties and can form a coating film having excellent chipping resistance, water resistance and solvent resistance.
  • the pH value of the acrylic resin emulsion (D2) may be, for example, 4 or more and 8 or less, and 4 or more and 7 or less.
  • the pH value is within such a range, the adhesion between the coating film and the object to be coated and the adhesion with another coating film arranged above the coating film according to the present disclosure can be further improved.
  • the average particle size (D50) of the acrylic resin in the acrylic resin emulsion (D2) may be, for example, 40 nm or more and 300 nm or less, and 50 nm or more and 150 nm or less.
  • the acrylic resin in the acrylic resin emulsion (D2) in the present disclosure can be appropriately selected as long as the solubility parameter SP (D2) in the acrylic resin emulsion (D2) satisfies the above-mentioned predetermined conditions.
  • the acrylic resin emulsion (D2) comprises an acrylic resin having at least one of a hydroxyl group and a carboxyl group, and includes, for example, an acrylic resin having a hydroxyl group and a carboxyl group.
  • the acrylic resin in the acrylic resin emulsion (D2) is a crosslinkable resin particle, for example, an acrylic resin particle having a crosslinkable property and further having at least one of a hydroxyl group and a carboxyl group. It may be there.
  • the acrylic resin having a hydroxyl group and a carboxyl group comprises (meth) acrylic acid alkyl ester (i), a carboxyl group-containing ethylenically unsaturated monomer (ii), and a hydroxyl group-containing ethylenically unsaturated monomer (iii). It can be obtained by emulsifying and polymerizing the monomer mixture containing the mixture.
  • the compounds exemplified below as components of the monomer mixture may be used alone or in combination of two or more.
  • metal (acrylic) means both acrylic and methacryl.
  • the (meth) acrylic acid alkyl ester (i) is used to form the main skeleton of the acrylic resin emulsion.
  • (meth) acrylic acid alkyl ester (i) examples include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, n-butyl (meth) acrylic acid, and (meth) acrylic.
  • Isobutyl acid t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, ( Examples thereof include dodecyl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate.
  • the carboxyl group-containing ethylenically unsaturated monomer (ii) improves various stability of the obtained acrylic resin emulsion such as storage stability, mechanical stability, and stability against freezing, and is a curing agent (E) at the time of coating film formation. ) Can be used to accelerate the curing reaction.
  • carboxyl group-containing ethylenically unsaturated monomer examples include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, etacrylic acid, propylacrylic acid, isopropylacrylic acid, itaconic acid, maleic anhydride and fumaric acid.
  • the hydroxyl group-containing ethylenically unsaturated monomer (iii) imparts hydrophilicity based on the hydroxyl group to the acrylic resin emulsion, which enhances workability and stability against freezing when used as a paint, and also serves as a curing agent (E). It is used to impart the curing reactivity of.
  • Examples of the hydroxyl group-containing ethylenically unsaturated monomer (iii) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, N-methylolacrylamide, and allyl alcohol. Examples thereof include ⁇ -caprolactone-modified (meth) acrylic monomer.
  • ⁇ -caprolactone-modified acrylic monomer examples include "Plaxel FA-1”, “Plaxel FA-2”, “Plaxel FA-3”, “Plaxel FA-4”, and “Plaxel FA” manufactured by Daicel Chemical Industries, Ltd. -5 ”,“ Praxel FM-1 ”,“ Praxel FM-2 ”,“ Praxel FM-3 ”,“ Praxel FM-4 ”,“ Praxel FM-5 ”and the like.
  • the monomer mixture may contain at least one monomer selected from the group consisting of styrene-based monomers, (meth) acrylonitrile and (meth) acrylamide as optional components, and the styrene-based monomers include ⁇ in addition to styrene. -Methylstyrene and the like can be mentioned.
  • the crosslinked monomer include ethylene glycol di (meth) acrylic acid and divinylbenzene.
  • Emulsion polymerization can be carried out by heating the monomer mixture in an aqueous liquid in the presence of a radical polymerization initiator and an emulsifier with stirring.
  • the reaction temperature is preferably about 30 to 100 ° C., and the reaction time is preferably about 1 to 10 hours.
  • the reaction temperature is adjusted by adding a monomer mixture or a monomer pre-emulsifying solution to a reaction vessel containing water and an emulsifier in a batch or dropping it for a while. It is good to do.
  • radical polymerization initiator a known initiator usually used in emulsion polymerization of an acrylic resin can be used.
  • a water-soluble free radical polymerization initiator for example, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate are used in the form of an aqueous solution.
  • a so-called redox-based initiator in which an oxidizing agent such as potassium persulfate, sodium persulfate, ammonium persulfate, or hydrogen peroxide is combined with a reducing agent such as sodium hydrogen sulfite, sodium thiosulfite, longalite, or ascorbic acid is an aqueous solution. Used in the form of.
  • the emulsifier is an anion system selected from a micelle compound having a hydrocarbon group having 6 or more carbon atoms and a hydrophilic moiety such as a carboxylate, a sulfonate or a sulfate partial ester in the same molecule.
  • a nonionic (nonionic) emulsifier is used.
  • anionic emulsifiers alkali metal salts or ammonium salts of sulfuric acid semiesters of alkylphenols or higher alcohols; alkali metal salts or ammonium salts of alkyl or allyl sulfonate; polyoxyethylene alkylphenyl ethers, polyoxyethylenes.
  • Examples thereof include an alkali metal salt or an ammonium salt of a sulfuric acid semi-ester of an alkyl ether or a polyoxyethylene allyl ether.
  • the nonionic emulsifier include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether and polyoxyethylene allyl ether.
  • these general-purpose anion-based and nonionic-based emulsifiers they also have radically polymerizable unsaturated double bonds in the molecule, that is, acrylic-based, methacrylic-based, propenyl-based, allyl-based, allyl ether-based, and maleic acid-based.
  • Various anion-based and nonionic-based reactive emulsifiers having a group such as, etc. are also used as appropriate alone or in combination of two or more.
  • auxiliary agent chain transfer agent
  • a mercaptan compound or a lower alcohol promotes smooth and uniform formation of the coating film from the viewpoint of promoting emulsion polymerization. From the viewpoint of improving the adhesiveness to the base material, it is often preferable, and it is carried out as appropriate depending on the situation.
  • the emulsion polymerization includes a normal one-step continuous monomer uniform dropping method, a core-shell polymerization method which is a multi-step monomer feed method, and a power feed polymerization method in which the monomer composition fed during polymerization is continuously changed. It can be legal.
  • a basic compound may be added to the obtained acrylic resin emulsion (D2) in order to neutralize a part or all of the carboxylic acid and maintain the stability of the acrylic resin emulsion (D2).
  • these basic compounds ammonia, various amines, alkali metals and the like can be appropriately used.
  • the acrylic resin in the acrylic resin emulsion (D2) may be, for example, 10% by mass or more and 35% by mass or less, and 15% by mass or more and 25% by mass or less, based on the total resin solid content of the coating composition according to the present disclosure. You can.
  • the curing agent is not particularly limited.
  • melamine resin blocked isocyanate, carbodiimide resin and the like are preferable.
  • the melamine resin is not particularly limited.
  • methoxy-type melamine and methoxy-butoxy mixed-type melamine can be mentioned.
  • Butoxy-type melamine can be hydrated and used by a method using an emulsifier, an acrylic resin, an alkyd resin or the like as an emulsifier.
  • the methoxy-type melamine resin is more preferable because it can be stabilized in water without using an emulsifier or the like.
  • the blocked isocyanate compound that can be used as the curing agent (E) in the present invention will be described.
  • the starting component of the blocked isocyanate compound is a di- or poly-isocyanate compound and a mixture thereof. However, these components react with a blocking agent to obtain a blocked isocyanate compound.
  • Preferred di- or poly-isocyanate compounds are aliphatic, alicyclic, aromatic aliphatic and heterocyclic polyisocyanates.
  • Polyisocyanates produced by the heteropolymerization reaction, polyisocyanates containing an ester group, preferably diisocyanates containing a uretdione group and diisocyanates containing a urea group are also suitable.
  • di- or poly-isocyanate compound examples include the following. p-xylylene diisocyanate, 1,5-diisocyanatomethylnaphthalene, 1,3-phenylenediocyanate, 1,4-phenylenediocyanate, 1-methylbenzene 2,5-diisocyanate, 1,3 dimethylbenzene 4,6-diisocyanate , 1,4 dimethylbenzene 2,5-diisocyanate, 1-nitrobenzene 2,5-diisocyanate, 1-methoxybenzene 2,4-diisocyanate, 1-methoxybenzene 2,5-diisocyanate, 1,3-dimethoxybenzene 4,6 -Diisocyanate, azobenzene 4,4'-diisocyanate, diphenyl ether 4,4'-diisocyanate, diphenylmethane 4,4'-diisocyanate, diphenyldimethylmethane 4,4'
  • Oxime compounds acetooxime, methylethylketooxime, methylisobutylketooxime, etc.
  • lactams ⁇ -caprolactam, etc.
  • active methylene compounds diethyl malonate, acetylacetone, etc.
  • Ethyl acetoacetate, etc. phenols (phenol, m-cresol, etc.), alcohols (methanol, ethanol, n-butanol, etc.), hydroxyl group-containing ether (methyl cellsolve, butyl cell solution, etc.), hydroxyl group-containing ester (methyl lactate) , Amil lactate, etc.), mercaptans (butyl mercaptan, hexyl mercaptan, etc.), acid amides (acetanilide, acrylic amide, dimer acid amide, etc.), imidazoles (imidazole, 2-ethylimidazole, etc.), acidimides (succinic acid, etc.) Examples thereof include imides (imides of phthalates, etc.), amines (dicyclohexylamines, etc.) and mixtures of two or more of these.
  • the curing agent (E) is preferably used in the range of 5% by mass or more and 15% by mass or less in the total resin solid content of the coating composition according to the present disclosure.
  • the amount of the curing agent is within such a range, the degree of cross-linking of the coating film can be increased, and a coating film having more excellent water resistance and adhesion can be formed.
  • the coating composition according to the present disclosure comprises particles selected from the group consisting of organic particles and inorganic particles. By including such particles, it can be expected that the hiding property is further improved due to the difference in refractive index between the binder resin and the particles.
  • the organic particles and the inorganic particles are particles different from the above components (A) to (D).
  • organic particles styrene resin, acrylic-styrene copolymer resin, acrylic-acrylonitrile copolymer resin, acrylic-styrene-acrylonitrile copolymer resin, acrylonitrile-methacrylonitrile copolymer resin, acrylic-acrylonitrile-methacrylonitrile copolymer resin, Examples thereof include vinylidene chloride-acrylonitrile copolymer resin.
  • the inorganic particles include glass such as soda glass silicate, aluminosilicate glass, and sodium borosilicate glass; fly ash, alumina, zirconia / titania, silicon booxide, silas, and black stone.
  • extender pigments such as calcium carbonate, barium sulfate, clay, and talc may be used in combination.
  • the coating composition according to the present disclosure further comprises a colored pigment.
  • the coloring pigment may be contained in an amount of 3% by mass or more and 150% by mass or less with respect to the total solid content of (A) to (E) (that is, in the total resin solid content of the coating composition according to the present disclosure). ..
  • the coloring pigment within such a range, it is possible to suppress an increase in viscosity at the time of curing, and further, it is possible to suppress a decrease in flowability. As a result, a good coating film appearance can be obtained.
  • the coating composition according to the present disclosure can form a coating film having a high hiding property, a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are generally used.
  • the coating film according to the present disclosure can be provided with the function of the above even though it is a single layer. That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed. Therefore, in the coating composition according to the present disclosure, for example, a coloring pigment may be added in order to function as a color-based coating film.
  • the coloring pigment is not particularly limited as long as it is a pigment used in ordinary paints.
  • azochelate pigments for example, from the viewpoint of obtaining a high-appearance coating film and improving weather resistance, azochelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, etc.
  • Organic coloring pigments such as dioxane pigments, quinacridone pigments, isoindolinone pigments, diketopyrrolopyrrole pigments, benzimidazolone pigments, metal complex pigments; titanium oxide, yellow lead, yellow iron oxide, red iron oxide, carbon Examples thereof include inorganic coloring pigments such as black.
  • the additive examples include an additive usually added in addition to the above components, for example, an ultraviolet absorber; an antioxidant; an antifoaming agent; a surface conditioner; a pinhole inhibitor and the like. These blending amounts are within the range known to those skilled in the art.
  • the coating composition according to the present disclosure is an aqueous primer coating composition. Since the aqueous primer coating composition according to the present disclosure can form a coating film having a high hiding property, it can be made thinner than a commonly used white primer coating film containing titanium oxide. Further, the coating film formed from the aqueous primer coating composition according to the present disclosure has various functions required as a primer coating film, for example, hiding property and chipping resistance of an object to be coated. Further, the primer coating film according to the present disclosure can have a function of a color-based coating film that can be arranged on the primer coating film. Therefore, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film.
  • the thickness of the coating film formed from the aqueous primer coating composition according to the present disclosure may be, for example, 15 ⁇ m or more and 40 ⁇ m or less, and 20 ⁇ m or more and 35 ⁇ m or less.
  • the primer coating film according to the present disclosure is such a thin film, it can satisfactorily conceal a color tone such as black color that an object to be coated may have, and in addition, it can have excellent water resistance.
  • the color tone of the coating film formed on the primer coating film is the color tone of white mica, it can be satisfactorily expressed.
  • the present disclosure comprises a step of coating an object to be coated with the coating composition according to the present disclosure to form an uncured coating film, and The step of heating and curing the uncured coating film to form a coating film is included.
  • a method for forming a coating film is provided.
  • the means for coating the coating composition according to the present disclosure is not particularly limited, and examples thereof include commonly used coating methods such as bell coating, air spray, and airless spray. These can be appropriately selected depending on the object to be coated.
  • the coating composition may be applied by an electrostatic coating machine.
  • conditions such as the discharge amount of the coating film can be appropriately set according to the required film thickness of the coating film and the like.
  • the film thickness of the coating film formed from the coating composition according to the present disclosure may be, for example, 10 ⁇ m or more and 40 ⁇ m or less, 12 ⁇ m or more and 38 ⁇ m or less, 15 ⁇ m or more and 35 ⁇ m, or 25 ⁇ m or more and 30 ⁇ m. It may be there.
  • the film thickness can be measured by the dry film thickness, and the dry film thickness can be measured by using SDM-miniR manufactured by SANKO.
  • a step of volatilizing water at a temperature of 40 ° C. or higher and 80 ° C. or lower for 1 to 10 minutes is also referred to as a preheating step.
  • baking and curing can be performed at a temperature of, for example, 80 ° C. or higher and 150 ° C. or lower, for example, 100 ° C. or higher and 130 ° C. or lower.
  • the baking curing time may be appropriately adjusted within the range of, for example, about 20 minutes to 40 minutes.
  • the present disclosure comprises a step of coating an object to be coated with the aqueous primer coating composition according to the present disclosure to form an uncured primer coating film.
  • a step of coating a base coating composition containing a bright pigment on the uncured aqueous primer coating composition to form an uncured base coating film and
  • a step of coating a clear coating composition on the uncured base coating film to form an uncured clear coating film and
  • the steps of heating and curing the uncured primer coating film, base coating film and clear coating film to form a multi-layer coating film and Provided is a method for forming a multi-layer coating film including.
  • the method for forming the multi-layer coating film will be described in more detail.
  • a preheating step of, for example, at a temperature of 40 ° C. or higher and 80 ° C. or lower for 1 to 10 minutes is performed as necessary, and an uncured primer coating film is applied.
  • the film thickness of the uncured primer coating film may be, for example, 10 ⁇ m or more and 40 ⁇ m or less, 12 ⁇ m or more and 38 ⁇ m or less, 15 ⁇ m or more and 35 ⁇ m, or 25 ⁇ m or more and 30 ⁇ m as a dry film thickness. Good.
  • an aqueous base coating composition containing a bright pigment for example, an aqueous base coating composition containing mica is coated on the obtained uncured primer coating film, and if necessary, for example, 40 ° C. or higher and 80 ° C.
  • An uncured base coating (for example, mica base coating) can be formed by performing a preheating step at the following temperature for 1 to 10 minutes. Further, the clear coating composition is applied onto the uncured base coating film to form an uncured clear coating film. After forming the uncured clear coating film, for example, at a temperature of 80 ° C. or higher and 150 ° C. or lower, for example, 100 ° C. or higher and 130 ° C. or lower, the uncured coating film and the uncured mica-based coating film according to the present disclosure. The uncured clear coating film can be baked and cured. The baking curing time may be appropriately adjusted within the range of, for example, about 20 minutes to 40 minutes.
  • the heat curing (baking) time means the time during which the surface of the base material actually keeps the target baking temperature, and more specifically, the time until the target baking temperature is reached should be taken into consideration. However, it means the time when the target temperature is reached and the temperature is maintained.
  • Examples of the heating device used to simultaneously bake the uncured film of the coating composition include a drying furnace using a heating source such as hot air, electricity, gas, or infrared rays. Further, it is preferable to use a drying oven in which two or more of these heating sources are used in combination because the drying time is shortened.
  • a coating film (a white primer coating film also used as a color base) formed from the coating composition according to the present disclosure, a mica (bright pigment) base, and a clear coating film are provided on the object to be coated.
  • Parts such as automotive parts, can be formed. Therefore, by using the coating composition according to the present disclosure for two layers of a general white primer and a color base, it is possible to show the functions of these two layers as a single layer. As a result, for example, the weight of the entire automobile part can be reduced, the painting process can be shortened, and the energy reduction (CO 2 ) can be reduced.
  • the aqueous base coating composition As the water-based base coating composition and the clear coating composition, known ones can be used.
  • the aqueous base coating composition that can be preferably used include an aqueous base coating composition containing a coating film-forming resin and a bright pigment.
  • the coating film-forming resin is not particularly limited, and examples thereof include acrylic resin, polyester resin, alkyd resin, epoxy resin, and urethane resin. From the viewpoint of pigment dispersibility and workability, a combination of an acrylic resin and / or a polyester resin and an amino resin and / or a blocked isocyanate resin as a curing agent is preferable. Only one type of the coating film-forming resin and the curing agent can be used, but two or more types can be used in order to balance the coating film performance.
  • the bright pigment is not particularly limited, and examples thereof include uncolored or colored metallic bright pigments such as metals or alloys and mixtures thereof, interfering mica, colored mica, white mica, graphite, colorless colored flat pigments, and the like. Can be done. One of these bright pigments may be used alone, or two or more thereof may be used in combination.
  • mica such as interference mica, colored mica, and white mica is preferably used. be able to.
  • the amount of the bright pigment contained in the water-based base coating composition is preferably in the range of, for example, 1 to 20% by mass with respect to 100 parts by mass of the resin solid content contained in the coating composition.
  • the film thickness of the uncured base coating film can be appropriately selected depending on the application, and for example, the dry film thickness is preferably 5 to 35 ⁇ m.
  • the film thickness of the uncured base coating film may be, for example, 8 ⁇ m or more and 15 ⁇ m or less, and 10 ⁇ m or more and 12 ⁇ m or less.
  • the clear coating composition is not particularly limited, and examples thereof include those containing a coating film-forming resin and, if necessary, a curing agent and other additives in a state of being dispersed or dissolved in a medium. ..
  • the coating film-forming resin include acrylic resin, polyester resin, epoxy resin, and urethane resin. These can be used in combination with curing agents such as amino resins and / or isocyanate resins. Further, from the viewpoint of transparency or acid etching resistance, a combination of an acrylic resin and / or a polyester resin and an amino resin, or an acrylic resin and / or a polyester resin having a carboxylic acid / epoxy curing system can also be used. ..
  • the clear coating composition can be coated by using a coating method known to those skilled in the art according to the coating form of the clear coating composition.
  • the film thickness of the uncured clear coating film is generally preferably 15 to 50 ⁇ m, more preferably 20 to 35 ⁇ m, and may be, for example, 25 ⁇ m or more and 30 ⁇ m or less.
  • a coating film formed from the coating composition according to the present disclosure can exhibit good adhesion to these water-based base coating compositions.
  • the coating film composition according to the present disclosure can form a coating film having a high hiding property, it is contained in a generally used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film.
  • the coating film according to the present disclosure can be provided with a function even though it is a single layer. That is, the process of forming the color-based coating film can be reduced.
  • the layer structure of the multi-layer coating film can be made thinner than that of the conventional multi-layer coating film, and even if the color tone of the coating film formed on the primer coating film is the color tone of white mica. , The desired white mica color tone can be expressed.
  • the object to be coated can be appropriately selected according to the intended use, function, and the like.
  • various objects to be coated that can be energized can be used as the object to be coated.
  • objects to be coated include cold-rolled steel sheets, hot-rolled steel sheets, stainless steel, electrogalvanized steel sheets, hot-dip galvanized steel sheets, zinc-aluminum alloy-based plated steel sheets, zinc-iron alloy-based plated steel sheets, and zinc-magnesium alloy-based plating.
  • Examples thereof include steel sheets, zinc-aluminum-magnesium alloy-based plated steel sheets, aluminum-based plated steel sheets, aluminum-silicon alloy-based plated steel sheets, and tin-based plated steel sheets.
  • These objects to be coated may be objects to be coated which have been subjected to a known chemical conversion treatment or the like. Further, these objects to be coated may be objects to be coated obtained by coating an electrodeposition coating plate with an intermediate coating paint and baking or preheating.
  • a plastic base material can be used as the object to be coated.
  • it may be a plastic base material used for automobile parts.
  • the automobile parts are not particularly limited, and examples thereof include bumpers, spoilers, grilles, and fenders.
  • the plastic base material contains polypropylene, polyolefin, or elastomer-modified polypropylene resin.
  • the elastomer-modified polypropylene resin is not particularly limited, and known commercially available ones can be used. Further, in addition to the resin, an additive may be added as needed. Further, an object to be coated made of ABS (acrylonitrile-butadiene-styrene) resin may be used.
  • % in the blending ratio means mass% unless otherwise specified.
  • the present invention is not limited to the examples described below.
  • the mixture was cooled to room temperature (25 ° C.) and filtered through a 400 mesh wire mesh to obtain a maleic anhydride-modified chlorinated polyolefin resin emulsion (A-2).
  • the non-volatile content of the emulsion was 30% by weight.
  • the solubility parameter SP (A) of the maleic anhydride-modified chlorinated polyolefin resin in the emulsion (A-2) was 9.3.
  • the SP value was measured by the method described in paragraph 0029 and paragraph 0030.
  • the reaction was carried out under reduced pressure conditions of 180 ° C. and 5 kPa or less for 2 hours to obtain a polyester having a hydroxyl group excess of 112 mgKOH / g and an acid value of 0.2 mgKOH / g.
  • 500 parts of this polyester polyol, 134 parts of dimethyl 5-sulfosodium isophthalate and 2 parts of tetrabutyl titanate were charged in another reaction vessel equipped with the same apparatus as the above reaction vessel, and in the same manner as above, The reaction vessel was set to 180 ° C.
  • a sulfonic acid group-containing polyester having a weight average molecular weight of 2117, a hydroxyl value of 53 mgKOH / g, and an acid value of 0.3 mgKOH / g.
  • 280 parts of the sulfonic acid group-containing polyester, 200 parts of polybutylene adipate, 35 parts of 1,4-butanediol, 118 parts of hexamethylene diisocyanate and 400 parts of methyl ethyl ketone were mixed with a stirring blade, a thermometer, a temperature control device, a dropping device, and a sample collection.
  • a reaction vessel with a mouth and a cooling tube was charged with nitrogen gas while stirring, and the liquid temperature was maintained at 75 ° C. to carry out a urethanization reaction to obtain a urethane polymer having an NCO content of 1%.
  • the liquid temperature in the reaction vessel was lowered to 40 ° C., and 955 parts of ion-exchanged water was uniformly dropped while sufficiently stirring to carry out phase inversion emulsification.
  • the internal temperature was lowered, and an aqueous solution of adipic acid hydrazide, which was a mixture of 13 parts of adipic acid hydrazide and 110 parts of ion-exchanged water, was added to carry out amine extension.
  • the temperature was raised to 60 ° C.
  • the acid value of the polyurethane resin in the polyurethane resin dispersion (C) was 11 mgKOH / g.
  • Polyester resin dispersion (D) Polyester resin dispersion (D1-1) MD1200 manufactured by Toyobo Co., Ltd. (resin solid content 34% by mass, number average molecular weight (Mn) 15000, acid value 1 mgKOH / g, hydroxyl value 5 mgKOH / g) was used.
  • the solubility parameter SP (D) of the polyester resin in MD1200 was 11.7.
  • the SP value was calculated by the method described in paragraph 0031.
  • Polyester resin dispersion (D1-2) BCD3120 (resin solid content 35% by mass, acid value 7 mgKOH / g, hydroxyl value 150 mgKOH / g) manufactured by DIC Corporation was used.
  • the solubility parameter of the polyester resin in BCD3120 was 10.9 for SP (D).
  • the SP value was calculated by the method described in paragraph 0031.
  • the aging reaction was carried out at 120 ° C. for 1 hour, and then a solution prepared by dissolving 0.1 part of t-butylperoxy-2-ethylhexanol in 4 parts of propylene glycol was further added for 1 hour. It was added dropwise to the reaction vessel. In each case, the internal stirring state and the liquid temperature of 120 ° C. were maintained. Then, the mixture was aged at 120 ° C. for 2 hours with stirring, then the internal temperature was cooled to 70 ° C., 9.5 parts of dimethylaminoethanol was added dropwise, and the mixture was stirred for 30 minutes. Further, while maintaining the internal temperature at 70 ° C.
  • ion-exchanged water was slowly added dropwise and cooled to room temperature (25 ° C.) to obtain a water-soluble acrylic resin solution.
  • the non-volatile content was adjusted to 30% using ion-exchanged water, and this was used as a pigment dispersion resin for a primer in the following pigment dispersion paste.
  • the pH of the obtained pigment-dispersed resin (water-soluble acrylic resin solution) was 8.2, and the weight average molecular weight of the acrylic resin was 42000.
  • the weight average molecular weight was determined in terms of polystyrene by a GPC apparatus using a TSK-gel-supermultip Albanyr HZ-M (manufactured by Tosoh Corporation) column and THF as a developing solvent.
  • Cymel 701 (nonvolatile content 82%, methylolated melamine) manufactured by Allnex was used.
  • Example 1 30 parts by mass of Aurolene S6479 (maleic anhydride-modified polyolefin resin (A-1), non-chlorinated) manufactured by Nippon Paper Co., Ltd., 15 parts by mass of the glycidyl group-containing acrylic resin emulsion (B) obtained in Production Example 2, manufactured. 25 parts by mass of the polyurethane resin dispersion (C) obtained in Example 3, 20 parts by mass of MD1200 (polyester resin dispersion (D1-1)) manufactured by Toyo Boseki, and Cymel 701 (hardener (E)) manufactured by Allnex.
  • Aurolene S6479 maleic anhydride-modified polyolefin resin (A-1), non-chlorinated) manufactured by Nippon Paper Co., Ltd.
  • Example 1 10 parts by mass were sequentially put into a stainless steel container equipped with a stirrer and mixed to obtain the coating composition of Example 1.
  • the above-mentioned compounding amount is a solid content conversion amount.
  • the SP value of Aurolen S6479 is 8.7, which is calculated by the method described in paragraph 0031.
  • Example 2 to 5 Comparative Examples 1 and 2
  • the coating compositions of Examples 2 to 5 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except that the constituent raw materials and the blending amounts were changed as shown in Table 2.
  • Example 1 using "Wider-71" (manufactured by Anest Iwata Co., Ltd.) on the surface of a Teflon sheet (70 mm x 150 mm x 0.1 mm) wiped with isopropyl alcohol in an environment of 25 ° C./70% RH.
  • the prepared coating composition was coated so as to have a dry film thickness of 30 ⁇ m, and dried at 60 ° C. for 5 minutes. Then, it was baked and cured at 120 ° C. for 30 minutes to form a coating film.
  • the obtained coating film was peeled off from a Teflon sheet, cut into 25 mm squares, attached to a zero-point corrected crow plate, and the haze value was measured with a turbidity meter attached to a ⁇ 90 color measuring system manufactured by Nippon Denshoku Kogyo Co., Ltd.
  • the haze value was measured in the same manner as described above. Table 2 shows the measurement results of the haze value.
  • Example 6 Titanium R960 manufactured by Dupont Co., Ltd. was added to the pigment dispersion resin of Production Example 4 to obtain a pigment paste having a PWC (Pigment Weight Concentration, pigment weight concentration) of 95%.
  • the PWC of the pigment paste means the amount of the pigment (mass of the pigment / solid content of the pigment-dispersed resin ⁇ 100) with respect to the solid content of the pigment-dispersed resin. 171 parts by mass of the pigment paste was added to 100 parts by mass of the coating composition produced in Example 1 to prepare a white primer coating having a PWC of 60%.
  • the above-mentioned compounding amount is a solid content conversion amount.
  • PWC of the white primer coating means the amount of the pigment (the mass of the pigment / the total resin solid content ⁇ 100) with respect to the total resin solid content in the white primer coating material, that is, the coating composition according to the present disclosure.
  • Examples 7 to 10, Comparative Examples 3 to 5 White primer coating materials of Examples 7 to 10 and Comparative Examples 3 to 5 were obtained in the same manner as in Example 6 except that the coating composition was changed as shown in Table 3.
  • the white primer paints of Comparative Examples 3 and 4 are the same.
  • the white primer coating material of Example 6 is applied to a black-and-white concealment test paper so that the film thickness changes stepwise, dried at 60 ° C. for 5 minutes, baked at 120 ° C. for 30 minutes, cooled, and then perpendicular to the object to be coated. The film thickness that was visually observed from the direction and indistinguishable between black and white was defined as the concealed film thickness.
  • the white primer coating materials of Examples 7 to 10 and Comparative Examples 3 to 5 were also evaluated for the concealing film thickness in the same manner as described above. The results of the concealment film thickness are shown in Table 3.
  • a new cartridge bell (new cartridge bell (trade name) manufactured by ABB) was applied to the water-based mica-based paint composition (AR-3020-1 # 7A21 manufactured by Nippon Paint Automotive Coatings) under the same environment. Using it, spray coating (dry film thickness 15 ⁇ m) was performed under coating conditions (gun distance: 200 mm, gun speed: 900 mm / s, rotation speed: 35000 rpm, shaping air pressure: 0.15 MPa). After drying at 80 ° C.
  • a clear paint composition (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) is applied onto the coating (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings) using Robobel 951.
  • Spray coating (dry film thickness 25 ⁇ m) was performed under the conditions of gun distance: 200 mm, gun speed: 700 mm / s, rotation speed: 25000 rpm, shaping air pressure: 0.07 MPa). Then, after setting for 10 minutes, it was dried at 120 ° C. for 30 minutes to form the multi-layer coating film of Example 6.
  • the white primer paints of Examples 7 to 10 and Comparative Examples 3 and 4 were also subjected to the same procedure as in Example 7 except that the film thickness of the white primer paint and / or the white primer was changed as shown in Table 3.
  • a multi-layer coating film of 10 to 10 and Comparative Examples 3 to 5 was formed.
  • the water-based color-based paint composition (AR-3020-1 # 7018 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) was used in the same environment using a new cartridge bell (new cartridge bell (trade name) manufactured by ABB).
  • Spray coating (dry film thickness 20 ⁇ m) was performed under electrostatic coating conditions (gun distance: 200 mm, gun speed: 900 mm / s, applied voltage: -60 kV, rotation speed: 35000 rpm, shaping air pressure: 0.15 MPa).
  • the water-based mica-based coating composition (AR-3020-1 # 7A21 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) was spray-coated (dry film thickness 15 ⁇ m) under the same conditions as the water-based color-based coating composition.
  • a clear coating composition (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) is electrostatically charged on the clear coating composition using Robobel 951.
  • Spray coating (dry film thickness 25 ⁇ m) was performed under the conditions of coating (gun distance: 200 mm, gun speed: 700 mm / s, applied voltage: -60 kV, rotation speed: 25000 rpm, shaping air pressure: 0.07 MPa). Then, after setting for 10 minutes, it was dried at 120 ° C. for 30 minutes to form a multi-layer coating film.
  • the multi-layer coating film obtained as described above was evaluated for xylene rubbing resistance, initial adhesion, water resistance, bending resistance, and finish in the following manner. These results are shown in Table 3.
  • the multi-layer coating film was immersed in a water resistant tank at 40 ° C. for 240 hours. After the immersion was completed, the coating film taken out from the water resistant tank was subjected to a checkered cellophane tape (registered trademark) peeling test within 1 hour after being taken out in accordance with JIS K5600-5-6. 100 2 mm square grids were prepared, a cellophane tape peeling test was performed, and the number of grids that did not peel was counted.
  • the evaluation criteria are as follows. 0/100 (without peeling) was regarded as a pass ( ⁇ ), and 1/100 to 100/100 (with peeling) was regarded as a failure (x).
  • ⁇ 1/100 to 100/100 (with peeling) was regarded as a failure (x).
  • ⁇ 1/100 to 100/100 (with peeling)
  • the color difference ⁇ E of the multi-layer coating film was measured using the multi-layer coating plate prepared in the reference example as a reference plate for white mica coating color.
  • a ⁇ E of less than 1 was regarded as a pass ( ⁇ ), and a ⁇ E of 1 or more was regarded as a fail (x).
  • the coating composition according to the present disclosure With the coating composition according to the present disclosure, a coating film having excellent base hiding properties can be formed. Therefore, with the coating composition according to the present invention, the number of coatings can be reduced as compared with the conventional case, and a coating film capable of hiding the black color of the object to be coated can be formed even though the film thickness is thinner. Further, the coating composition according to the present disclosure can form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
  • the coating films formed by using the coating compositions of Comparative Examples 1 and 2 have a low haze value, they are formed by using the white primer coatings of Comparative Examples 3 to 5 prepared from the coating compositions of Comparative Examples 1 and 2.
  • the white primer was inferior in the base hiding property.
  • the coating composition of the present invention can be suitably used in, for example, automobile vehicles and automobile parts.

Abstract

Provided is a coating composition capable of forming a coating film which is thin and, despite this, can hide the color of the coated object and which is excellent in terms of adhesion, chemical resistance, water resistance, flexing characteristics, and appearance.　This coating composition includes at least one ingredient selected from among a maleic-anhydride-modified polyolefin resin (A), a glycidyl-group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C) and further includes a resin dispersion (D) and a hardener (E), wherein the (A), (B), and (C) have solubility parameter SP values that satisfy a given relationship. In cases when a mixture comprising the at least one ingredient, the (D), and the (E) in the same mass proportions as in the coating composition is applied to form a coating film having a thickness of 30 μm, the coating film has a haze of 30% or higher.

Description

塗料組成物、それを用いた塗膜及び複層塗膜の形成方法Coating composition, coating film using it, and method for forming a multi-layer coating film
　本発明は、塗料組成物、それを用いた塗膜及び複層塗膜の形成方法に関する。 The present invention relates to a coating composition, a coating film using the same, and a method for forming a multi-layer coating film.
　近年、自動車等の車両において、プラスチック製の部品が使用されている。例えば、自動車用部品は、ポリオレフィン樹脂を含むことがある。また、自動車用部品として要求される強度を付与するために、ポリオレフィン樹脂とカーボン顔料、カーボン繊維等を併用することがある。したがって、このような自動車用部品は、通常、黒色の外観を有している。 In recent years, plastic parts have been used in vehicles such as automobiles. For example, automotive parts may contain polyolefin resins. Further, in order to impart the strength required for automobile parts, a polyolefin resin, a carbon pigment, a carbon fiber or the like may be used in combination. Therefore, such automotive parts usually have a black appearance.
　一方、自動車用部品は、様々な色を発現する必要がある。例えば、黒色系の色の発現が要求されるだけでなく、ソリッドの白色系、マイカを含む白色系等の色の発現が求められている。このため、求められる色を発現するために、通常、黒色の外観を有する自動車用部品を、酸化チタンを含む塗料組成物を用いて、黒色の下地を隠ぺいすることがなされている。 On the other hand, automobile parts need to express various colors. For example, not only the expression of blackish colors is required, but also the expression of solid whites, whites including mica, and the like is required. Therefore, in order to develop the required color, it is usually made to conceal a black base by using a coating composition containing titanium oxide for automobile parts having a black appearance.
　国際公開第２０１５／００２２９９号公報（特許文献１）は、塩素法酸化チタン顔料、黄色酸化鉄顔料、一次平均粒子径が１５ｎｍ以上８０ｎｍ以下の範囲内であるカーボンブラック顔料及びビヒクル形成成分である樹脂組成物を含む塗料組成物を開示する。また、特許文献１は、特許文献１に係る塗料組成物を、被塗物に塗装し、得られた塗膜上に、カラーベース塗膜を積層する塗膜形成方法を開示する。 International Publication No. 2015/002299 (Patent Document 1) describes chlorine-method titanium oxide pigments, yellow iron oxide pigments, carbon black pigments having a primary average particle size in the range of 15 nm or more and 80 nm or less, and resins that are vehicle-forming components. A coating composition containing the composition is disclosed. Further, Patent Document 1 discloses a coating film forming method in which a coating composition according to Patent Document 1 is applied to an object to be coated and a color-based coating film is laminated on the obtained coating film.
国際公開第２０１５／００２２９９号公報International Publication No. 2015/002299
　特許文献１に示される、酸化チタンを含む塗料組成物を用いて、被塗物が有する色調、例えば、黒色を隠ぺいするには、この塗料組成物から形成される塗膜の膜厚を厚くする必要がある。あるいは、酸化チタンの濃度を高くした塗膜を形成する必要がある。 In order to hide the color tone of the object to be coated, for example, black color by using the coating composition containing titanium oxide shown in Patent Document 1, the film thickness of the coating film formed from this coating composition is increased. There is a need. Alternatively, it is necessary to form a coating film having a high concentration of titanium oxide.
　しかし、塗膜において、酸化チタンの濃度を高くすると、形成された塗膜の耐湿性が劣る場合がある。また、酸化チタンを含む塗膜の膜厚を厚くすると、得られる塗膜の耐水性が劣る場合がある。
　このため、酸化チタンの濃度が高くなくても、被塗物が有する色調、例えば、黒色を良好に隠ぺいできる塗料組成物が要求されている。
　更に、酸化チタンを含む塗膜の膜厚を厚くするには、塗膜を複数回に分けて形成する必要があり、作業工程の簡素化が要求されている。
　加えて、より薄い膜厚でありながらも、被塗物が有する色調、例えば、黒色を隠ぺいできる塗料組成物が要求されている。 However, if the concentration of titanium oxide in the coating film is increased, the moisture resistance of the formed coating film may be inferior. Further, if the film thickness of the coating film containing titanium oxide is increased, the water resistance of the obtained coating film may be inferior.
Therefore, there is a demand for a coating composition that can satisfactorily conceal the color tone of the object to be coated, for example, black color, even if the concentration of titanium oxide is not high.
Further, in order to increase the film thickness of the coating film containing titanium oxide, it is necessary to form the coating film in a plurality of times, and simplification of the work process is required.
In addition, there is a demand for a coating composition capable of concealing the color tone of the object to be coated, for example, black, while having a thinner film thickness.
　本発明は、上述したような課題を解決し、より薄い膜厚でありながらも、被塗物が有する色調、例えば、黒色を隠ぺいできる塗料組成物を提供することを目的とする。更に、本発明は、密着性、耐薬品性、耐水性、屈曲性及び外観に優れた塗膜を形成できる塗料組成物を提供する。 An object of the present invention is to solve the above-mentioned problems and to provide a coating composition capable of concealing the color tone of the object to be coated, for example, black, while having a thinner film thickness. Furthermore, the present invention provides a coating composition capable of forming a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
　上記課題を解決するため、本発明は下記態様を提供する。
［１］塗料組成物であって、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）と、グリシジル基含有アクリル樹脂エマルション（Ｂ）と、ウレタン樹脂ディスパージョン（Ｃ）とからなる群から選択される少なくとも１種、
　樹脂ディスパージョン（Ｄ）、及び
　硬化剤（Ｅ）
を含み、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が、以下の式（１）及び式（２）の少なくとも１つを満たし、
　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
　上記少なくとも１種と、（Ｄ）と、（Ｅ）とを塗料組成物と同じ質量比率で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である、塗料組成物。
［２］別の実施態様において、本発明は下記態様を提供する。
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）、
　グリシジル基含有アクリル樹脂エマルション（Ｂ）、
　ウレタン樹脂ディスパージョン（Ｃ）、
　樹脂ディスパージョン（Ｄ）、及び
　硬化剤（Ｅ）
を含み、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が、以下の式（１）及び式（２）の少なくとも１つを満たし、
　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
　（Ａ）～（Ｅ）を前記塗料組成物と同じ質量比率で含む混合物から形成した厚さ１５μｍの塗膜のヘーズ値が１５％以上である、塗料組成物。
［３］一実施態様において、樹脂ディスパージョン（Ｄ）は、ポリエステル樹脂ディスパージョン（Ｄ１）であり、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂は、溶解性パラメータＳＰ（Ｄ１）が１１.０以上１２.０以下である。
［４］一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の数平均分子量が、６，０００以上２０，０００以下である。
［５］一実施態様において、樹脂ディスパージョン（Ｄ）は、アクリル樹脂エマルション（Ｄ２）であり、アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂は、溶解性パラメータＳＰ（Ｄ２）が８.０以上１２.０以下であり、アクリル樹脂は、グリシジル基を含有しない。
［６］一実施態様において、アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂が架橋性樹脂粒子である。
［７］一実施態様において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、無水マレイン酸変性塩素化ポリオレフィン樹脂である。
［８］一実施態様において、塗料組成物は、有機粒子及び無機粒子からなる群から選択される粒子を含む。
［９］一実施態様において、塗料組成物は、着色顔料を含み、着色顔料の量は、（Ａ）～（Ｅ）の樹脂固形分の合計に対し、３質量％以上１５０質量％以下である。
［１０］一実施態様において、塗料組成物は、水性プライマー塗料組成物である。
［１１］別の実施態様において、本開示は、
　被塗物に、本開示に係る塗料組成物を塗装し、未硬化の塗膜を形成する工程、及び
　未硬化の塗膜を加熱硬化させ、塗膜を形成する工程
を含む塗膜の形成方法を提供する。
［１２］別の実施態様において、本開示は、
　被塗物に、本開示に係る水性プライマー塗料組成物を塗装し、未硬化のプライマー塗膜を形成する工程、
　未硬化の水性プライマー塗料組成物の上に、光輝顔料を含むベース塗料組成物を塗装し、未硬化のベース塗膜を形成する工程、
　未硬化のベース塗膜の上に、クリヤー塗料組成物を塗装し、未硬化のクリヤー塗膜を形成する工程、及び
　未硬化のプライマー塗膜、ベース塗膜及びクリヤー塗膜を加熱硬化させ、複層塗膜を形成する工程
を含む複層塗膜の形成方法を提供する。 In order to solve the above problems, the present invention provides the following aspects.
[1] A paint composition
At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
Resin dispersion (D) and hardener (E)
Including
Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
| SP (D) -SP (A) | ≧ 1.0 (1),
| SP (D) -SP (B) | ≧ 1.0 (2),
A coating composition having a haze value of 15% or more of a coating film having a thickness of 30 μm formed from a mixture containing at least one of the above, (D) and (E) in the same mass ratio as the coating composition.
[2] In another embodiment, the present invention provides the following aspects.
Maleic anhydride-modified polyolefin resin (A),
Glycidyl group-containing acrylic resin emulsion (B),
Urethane resin dispersion (C),
Resin dispersion (D) and hardener (E)
Including
Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
| SP (D) -SP (A) | ≧ 1.0 (1),
| SP (D) -SP (B) | ≧ 1.0 (2),
A coating composition having a haze value of 15% or more of a coating film having a thickness of 15 μm formed from a mixture containing (A) to (E) in the same mass ratio as the coating composition.
[3] In one embodiment, the resin dispersion (D) is a polyester resin dispersion (D1), and the polyester resin in the polyester resin dispersion (D1) has a solubility parameter SP (D1) of 11.0. It is 12.0 or less.
[4] In one embodiment, the number average molecular weight of the polyester resin in the polyester resin dispersion (D1) is 6,000 or more and 20,000 or less.
[5] In one embodiment, the resin dispersion (D) is an acrylic resin emulsion (D2), and the acrylic resin in the acrylic resin emulsion (D2) has a solubility parameter SP (D2) of 8.0 or more 12 It is .0 or less, and the acrylic resin does not contain a glycidyl group.
[6] In one embodiment, the acrylic resin in the acrylic resin emulsion (D2) is the crosslinkable resin particles.
[7] In one embodiment, the maleic anhydride-modified polyolefin resin (A) is a maleic anhydride-modified chlorinated polyolefin resin.
[8] In one embodiment, the coating composition comprises particles selected from the group consisting of organic particles and inorganic particles.
[9] In one embodiment, the coating composition contains a coloring pigment, and the amount of the coloring pigment is 3% by mass or more and 150% by mass or less with respect to the total resin solid content of (A) to (E). ..
[10] In one embodiment, the coating composition is an aqueous primer coating composition.
[11] In another embodiment, the present disclosure.
A method for forming a coating film, which comprises a step of coating an object to be coated with the coating composition according to the present disclosure to form an uncured coating film, and a step of heat-curing the uncured coating film to form a coating film. I will provide a.
[12] In another embodiment, the present disclosure.
A step of coating an object to be coated with the aqueous primer coating composition according to the present disclosure to form an uncured primer coating film.
A step of coating a base coating composition containing a bright pigment on an uncured aqueous primer coating composition to form an uncured base coating film.
The step of applying the clear coating composition on the uncured base coating film to form the uncured clear coating film, and the uncured primer coating film, the base coating film and the clear coating film are heat-cured to form a double layer. Provided is a method for forming a multi-layer coating film, which comprises a step of forming a layer coating film.
　本発明の塗料組成物は、薄膜を形成でき、その上、被塗物が有する色調を隠ぺいできる塗膜を形成できる。更に、本発明の塗料組成物は、密着性、耐薬品性、耐水性、屈曲性及び外観に優れた塗膜を形成できる。 The coating composition of the present invention can form a thin film, and moreover, can form a coating film capable of hiding the color tone of the object to be coated. Further, the coating composition of the present invention can form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
　まず、本発明に至る過程を説明する。
　上述のように、自動車等の車両において、プラスチック製の自動車用部品が使用されている。自動車用部品は、優れた強度、衝撃性等が要求されており、更に、通常、自動車車体に合わせた色調を発現することが要求されている。
　例えば、カーボン材料とポリオレフィン樹脂とを含む自動車部品は、黒色であることが多い。このため、自動車車体に合わせた色調、特に白色系マイカの色調を発現するには、黒色の被塗物上に、白色のプライマー塗膜を形成し、このプライマー塗膜の上に、白色カラーベース塗膜、更に、マイカ含有ベース塗膜を形成し、最外層に、クリヤー塗膜を形成する必要がある。 First, the process leading to the present invention will be described.
As described above, plastic automobile parts are used in vehicles such as automobiles. Automobile parts are required to have excellent strength, impact resistance, and the like, and are usually required to develop a color tone suitable for the automobile body.
For example, automobile parts containing carbon materials and polyolefin resins are often black. Therefore, in order to develop a color tone that matches the automobile body, especially a white mica color tone, a white primer coating film is formed on a black object to be coated, and a white color base coating is applied on the primer coating film. It is necessary to form a film and further, a mica-containing base coating film, and to form a clear coating film on the outermost layer.
　すなわち、要求される色調、例えば白色系マイカの色調を発現するには、カーボン材料とポリオレフィン樹脂とを含む基材（被塗物）の有する黒色、灰色等の色調を十分に隠ぺいする必要がある。 That is, in order to express the required color tone, for example, the color tone of white mica, it is necessary to sufficiently conceal the color tone such as black and gray of the base material (object to be coated) containing the carbon material and the polyolefin resin. ..
　一方、上述のように、自動車部品の基材（被塗物）が有する黒色等の色調を十分に隠ぺいするには、通常、白色顔料を含む白色プライマー塗膜の膜厚を厚くする、又は白色顔料の量を増やした白色プライマー塗膜を形成する必要がある。
　しかし、白色顔料として一般的に用いられている酸化チタンを、水性プライマー塗料組成物に配合しプライマー塗膜を形成すると、耐水性が低下する傾向がある。
　また、酸化チタンの量を減らすと、膜厚を厚くする必要が生じてしまう。 On the other hand, as described above, in order to sufficiently conceal the color tone such as black possessed by the base material (object to be coated) of an automobile part, the thickness of the white primer coating film containing a white pigment is usually increased or white. It is necessary to form a white primer coating with an increased amount of pigment.
However, when titanium oxide, which is generally used as a white pigment, is blended with an aqueous primer coating composition to form a primer coating film, the water resistance tends to decrease.
Further, if the amount of titanium oxide is reduced, it becomes necessary to increase the film thickness.
　このような問題を解決すべく、本発明者らは鋭意検討し、本発明を完成させた。
　本発明は、塗料組成物であって、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）と、グリシジル基含有アクリル樹脂エマルション（Ｂ）と、ウレタン樹脂ディスパージョン（Ｃ）とからなる群から選択される少なくとも１種、
　樹脂ディスパージョン（Ｄ）、及び
　硬化剤（Ｅ）
を含み、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が以下の式（１）及び式（２）の少なくとも１つを満たし、
　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
　上記少なくとも１種と、樹脂ディスパージョン（Ｄ）と、硬化剤（Ｅ）とを塗料組成物と同じ質量比率で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である、塗料組成物である。 In order to solve such a problem, the present inventors diligently studied and completed the present invention.
The present invention is a coating composition.
At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
Resin dispersion (D) and hardener (E)
Including
Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one of the following equations (1) and (2).
| SP (D) -SP (A) | ≧ 1.0 (1),
| SP (D) -SP (B) | ≧ 1.0 (2),
The haze value of a coating film having a thickness of 30 μm formed from a mixture containing at least one of the above, a resin dispersion (D), and a curing agent (E) in the same mass ratio as that of the coating composition is 15% or more. It is a coating composition.
　別の実施態様において、本発明は、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）、
　グリシジル基含有アクリル樹脂エマルション（Ｂ）、
　ウレタン樹脂ディスパージョン（Ｃ）、
　樹脂ディスパージョン（Ｄ）、及び
　硬化剤（Ｅ）
を含み、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が以下の式（１）及び式（２）の少なくとも１つの関係を満たし、
　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
　（Ａ）～（Ｅ）を塗料組成物と同じ質量比率で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である、塗料組成物である。 In another embodiment, the present invention
Maleic anhydride-modified polyolefin resin (A),
Glycidyl group-containing acrylic resin emulsion (B),
Urethane resin dispersion (C),
Resin dispersion (D) and hardener (E)
Including
Solubility parameter SP (A) of maleic anhydride-modified polyolefin resin (A), solubility parameter SP (B) of glycidyl group-containing acrylic resin in emulsion (B), and dissolution of resin in resin dispersion (D) The sex parameter SP (D) satisfies at least one relationship of the following equations (1) and (2).
| SP (D) -SP (A) | ≧ 1.0 (1),
| SP (D) -SP (B) | ≧ 1.0 (2),
A coating composition having a haze value of 15% or more of a coating film having a thickness of 30 μm formed from a mixture containing (A) to (E) in the same mass ratio as the coating composition.
　本開示に係る塗料組成物であれば薄膜でありながらも被塗物が有する黒色、灰色等の色調を隠ぺいできる塗膜を形成できる。このため、本開示に係る塗料組成物は、例えば、酸化チタンを含む塗膜と比べて、より薄い塗膜を形成できる。
　また、本開示に係る塗料組成物から形成された塗膜は、白色の外観を有し得るため、被塗物が有する色調、例えば、黒色、灰色を、薄膜でありながらも十分に隠ぺいできる。このため、本開示に係る塗料組成物から形成された塗膜は、単層でありながらも、通常用いられている、酸化チタンを含む白色プライマー塗膜と、その上に配置されるカラーベース塗膜とが有する機能を備えることができる。 With the coating composition according to the present disclosure, it is possible to form a coating film which is a thin film but can hide the color tone such as black and gray of the object to be coated. Therefore, the coating composition according to the present disclosure can form a thinner coating film as compared with, for example, a coating film containing titanium oxide.
Further, since the coating film formed from the coating composition according to the present disclosure may have a white appearance, the color tone of the object to be coated, for example, black or gray, can be sufficiently concealed even though it is a thin film. Therefore, the coating film formed from the coating composition according to the present disclosure is a single-layered white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film, which is usually used. Can be provided with the functions of and.
　例えば、自動車車体に合わせた色調、特に白色系マイカの色調を発現するには、通常、黒色の被塗物上に、白色のプライマー塗膜を形成し、このプライマー塗膜の上に、白色カラーベース塗膜、更に、マイカ含有ベース塗膜を形成し、最外層に、クリヤー塗膜を形成する必要がある。
　これに対し、本開示に係る塗料組成物であれば、黒色の被塗物上に、本開示に係る塗料組成物から形成された塗膜を形成し、更に、本開示係る塗膜の上に、マイカ含有ベース塗膜を形成し、最外層に、クリヤー塗膜を形成できる。
　本開示に係る塗料組成物から形成された塗膜は、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、単層でありながらも備えることができる。
　したがって、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。さらに、所望の白色系マイカの色調を発現できる。 For example, in order to develop a color tone suitable for an automobile body, particularly a white mica color tone, a white primer coating film is usually formed on a black object to be coated, and a white color base is formed on the primer coating film. It is necessary to form a coating film and further, a mica-containing base coating film, and to form a clear coating film on the outermost layer.
On the other hand, in the case of the coating composition according to the present disclosure, a coating film formed from the coating composition according to the present disclosure is formed on a black object to be coated, and further, on the coating film according to the present disclosure. , A mica-containing base coating film can be formed, and a clear coating film can be formed on the outermost layer.
The coating film formed from the coating composition according to the present disclosure has the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film in a single layer. You can prepare for it.
Therefore, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
　更に、本開示に係る塗料組成物であれば、高い隠ぺい性を有する薄膜を形成でき、自動車用部品における塗装工程、塗装時間等を短縮できる。このため、ＣＯ２削減など、環境負荷の低減も可能となる。その上、優れた密着性、耐薬品性、耐水性、屈曲性及び外観を有する塗膜を形成できる。
　以下、本開示に係る塗料組成物について、より詳細に説明する。 Further, the coating composition according to the present disclosure can form a thin film having a high hiding property, and can shorten the coating process, coating time, etc. in automobile parts. Therefore, it is possible to reduce the environmental load such as CO 2 reduction. Moreover, it is possible to form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
Hereinafter, the coating composition according to the present disclosure will be described in more detail.
（塗料組成物）
　本開示に係る塗料組成物は、
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）と、グリシジル基含有アクリル樹脂エマルション（Ｂ）と、ウレタン樹脂ディスパージョン（Ｃ）とからなる群から選択される少なくとも１種、
　樹脂ディスパージョン（Ｄ）、及び
　硬化剤（Ｅ）
を含む。
　これにより、本開示に係る塗料組成物は、密着性、耐薬品性、耐水性、屈曲性及び外観に優れた薄膜を形成できる。さらに、自動車用部品において必要とされる塗膜強度を有する塗膜を形成できる。 (Paint composition)
The coating composition according to the present disclosure is
At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
Resin dispersion (D) and hardener (E)
including.
Thereby, the coating composition according to the present disclosure can form a thin film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance. Further, it is possible to form a coating film having the coating film strength required for automobile parts.
　一実施態様において、塗料組成物は、上記成分（Ａ）～（Ｅ）を全て含む。すなわち、一実施態様において、塗料組成物は、無水マレイン酸変性ポリオレフィン樹脂（Ａ）、グリシジル基含有アクリル樹脂エマルション（Ｂ）、及びウレタン樹脂ディスパージョン（Ｃ）、樹脂ディスパージョン（Ｄ）及び硬化剤（Ｅ）を含む。 In one embodiment, the coating composition contains all of the above components (A) to (E). That is, in one embodiment, the coating composition comprises a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C), a resin dispersion (D), and a curing agent. (E) is included.
　本開示において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が以下の式（１）及び（２）の少なくとも１つを満たす。
　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）
　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）
　このように、式（１）及び式（２）の少なくとも１つを満足する、すなわち、ＳＰ（Ｄ）からＳＰ（Ａ）を差し引いた絶対値、及びＳＰ（Ｄ）からＳＰ（Ｂ）を差し引いた値の絶対値の少なくとも１つを１．０以上とすることにより、被塗物が有する色調、例えば、黒色、銀色を、薄膜でありながらも十分に隠ぺいできる。
　更に、本開示に係る塗料組成物は、高い隠ぺい性を有する塗膜を形成できる。そのため、本開示に係る塗料組成物から形成された塗膜は、単層でありながらも、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を備えることができる。
　すなわち、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。さらに、例えば、本開示に係る塗料組成物により形成された塗膜の上に形成される塗膜の色調が白色系マイカの色調であっても、所望の色調を十分に発現できる。 In the present disclosure, in the solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A), the solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B), and the resin dispersion (D). The solubility parameter SP (D) of the resin of the above satisfies at least one of the following formulas (1) and (2).
| SP (D) -SP (A) | ≧ 1.0 (1)
| SP (D) -SP (B) | ≧ 1.0 (2)
Thus, at least one of equations (1) and (2) is satisfied, that is, the absolute value of SP (D) minus SP (A), and SP (D) minus SP (B). By setting at least one of the absolute values of the values to 1.0 or more, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film.
Further, the coating composition according to the present disclosure can form a coating film having a high hiding property. Therefore, the coating film formed from the coating composition according to the present disclosure is a single-layered white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film, which is generally used. Can be provided with the functions of and.
That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Further, for example, even if the color tone of the coating film formed on the coating film formed by the coating composition according to the present disclosure is the color tone of white mica, the desired color tone can be sufficiently expressed.
　ここで、本開示においては、これら特定の樹脂における溶解性パラメータＳＰ値を、特定の条件に設定することにより、高い隠ぺい性を有する塗膜、例えば、薄膜を形成できる。さらに、本開示に係る特定の樹脂について、溶解性パラメータＳＰ値を、特定の条件に設定することにより、塗膜強度、密着性、硬度などの諸物性を低下させることなく、極めて高い隠ぺい性を有する塗膜を形成できる。 Here, in the present disclosure, by setting the solubility parameter SP value in these specific resins to specific conditions, a coating film having a high hiding property, for example, a thin film can be formed. Further, for the specific resin according to the present disclosure, by setting the solubility parameter SP value to a specific condition, extremely high hiding property can be obtained without deteriorating various physical properties such as coating film strength, adhesion and hardness. The coating film to have can be formed.
　ところで、通常、酸化チタンなどの白色塗料に大きく依存することなく塗膜が白濁すると、塗膜物性等の性質が劣る傾向がある。しかし、本開示に係る塗料組成物は、特定の樹脂を特定の条件で含むため、塗膜が相分離し、屈折率差により光が乱反射することで高い隠ぺい性と、優れた塗膜物性とを共にバランスよく有することができると考えられる。その上、優れた密着性、耐薬品性、耐水性、屈曲性及び外観を有する塗膜を形成できる。
　特定の理論に限定して解釈すべきではないが、例えば、本開示に係る塗料組成物が水性プライマー塗料組成物である場合、各種樹脂成分は、安定した分散状態を保つことができる。このため、塗料組成物の安定性が保たれており、このような塗料組成物から形成される塗膜も、高い塗膜物性を呈することができ、その上、塗膜物性を損なうことなく、高い隠ぺい性示すものと推測される。 By the way, usually, when the coating film becomes cloudy without being largely dependent on the white paint such as titanium oxide, the physical characteristics of the coating film tend to be inferior. However, since the coating composition according to the present disclosure contains a specific resin under specific conditions, the coating film is phase-separated and light is diffusely reflected due to the difference in refractive index, resulting in high hiding property and excellent coating film physical characteristics. It is considered that both can be held in a well-balanced manner. Moreover, it is possible to form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
Although not limited to a specific theory, for example, when the coating composition according to the present disclosure is an aqueous primer coating composition, various resin components can maintain a stable dispersed state. Therefore, the stability of the coating composition is maintained, and the coating film formed from such a coating composition can also exhibit high coating film physical characteristics, and moreover, the coating film physical properties are not impaired. It is presumed to show high concealment.
　樹脂の分離をより容易に抑制して、隠ぺい性等の塗膜物性をより容易に得る観点から、一実施態様において、
　１.５≧｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０、かつ、
　１.５≧｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０
の関係を満足してよい。 In one embodiment, from the viewpoint of more easily suppressing the separation of the resin and more easily obtaining the physical characteristics of the coating film such as concealment.
1.5 ≧ | SP (D) -SP (A) | ≧ 1.0, and
1.5 ≧ | SP (D) -SP (B) | ≧ 1.0
You may be satisfied with the relationship.
　一実施態様において、樹脂の分離をより容易に抑制して、隠ぺい性等の塗膜物性をより容易に得る観点から、
　１.４５≧｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０５
の関係を満足してよく、例えば、
　１.４０≧｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.１０
の関係を満足してよい。 In one embodiment, from the viewpoint of more easily suppressing the separation of the resin and more easily obtaining the physical characteristics of the coating film such as concealment.
1.45 ≧ | SP (D) -SP (A) | ≧ 1.05
You may be satisfied with the relationship, for example
1.40 ≧ | SP (D) -SP (A) | ≧ 1.10
You may be satisfied with the relationship.
　一実施態様において、樹脂の分離をより容易に抑制して、隠ぺい性等の塗膜物性をより容易に得る観点から、
　１.４５≧｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０５
の関係を有してもよく、例えば、
　１.４０≧｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.１０
の関係を満足してよい。 In one embodiment, from the viewpoint of more easily suppressing the separation of the resin and more easily obtaining the physical characteristics of the coating film such as concealment.
1.45 ≧ | SP (D) -SP (B) | ≧ 1.05
May have a relationship of, for example
1.40 ≧ | SP (D) -SP (B) | ≧ 1.10
You may be satisfied with the relationship.
　これら特定の樹脂における溶解性パラメータＳＰ値を、特定の条件に設定することにより、より高い隠ぺい性を有する塗膜を形成でき、更に、薄膜であっても十分な隠ぺい性を有することができる。ここで、本開示において薄膜とは、（２０μｍ以上３５μｍ以下）程度の膜厚を意味するが、この数値範囲に限定されるものではない。
　更に、本開示に係る特定の樹脂について、溶解性パラメータＳＰ値を、特定の条件に設定することにより、塗膜強度、密着性、硬度などの諸物性がより優れた塗膜を形成できる。なお、上記ＳＰ値の条件を組合せて用いてもよい。 By setting the solubility parameter SP value of these specific resins to specific conditions, a coating film having higher hiding power can be formed, and even a thin film can have sufficient hiding power. Here, in the present disclosure, the thin film means a film thickness of about (20 μm or more and 35 μm or less), but is not limited to this numerical range.
Further, by setting the solubility parameter SP value of the specific resin according to the present disclosure to specific conditions, it is possible to form a coating film having more excellent physical properties such as coating film strength, adhesion and hardness. The conditions of the SP value may be used in combination.
　ＳＰ値とは、ｓｏｌｕｂｉｌｉｔｙ　ｐａｒａｍｅｔｅｒ（溶解性パラメータ）の略であり、溶解性の尺度となるものである。ＳＰ値は数値が大きいほど極性が高く、逆に数値が小さいほど極性が低いことを示す。 The SP value is an abbreviation for solution parameter, which is a measure of solubility. The larger the SP value, the higher the polarity, and conversely, the smaller the value, the lower the polarity.
　例えば、ＳＰ値は次の方法によって実測することができる［参考文献：ＳＵＨ、ＣＬＡＲＫＥ、Ｊ．Ｐ．Ｓ．Ａ－１、５、１６７１～１６８１（１９６７）］。 For example, the SP value can be actually measured by the following method [References: SUH, CLARKE, J. Mol. P. S. A-1, 5, 1671 to 1681 (1967)].
　サンプルとして、有機溶剤０．５ｇを１００ｍｌビーカーに秤量し、アセトン１０ｍｌを、ホールピペットを用いて加え、マグネティックスターラーにより溶解したものを使用する。このサンプルに対して測定温度２０℃で、５０ｍｌビュレットを用いて貧溶媒を滴下し、濁りが生じた点を滴下量とする。貧溶媒は、高ＳＰ貧溶媒としてイオン交換水を用い、低ＳＰ貧溶媒としてｎ－ヘキサンを使用して、それぞれ濁点測定を行う。有機溶剤のＳＰ値δは下記計算式によって与えられる。
δ＝（Ｖｍｌ １／２δｍｌ＋Ｖｍｈ １／２δｍｈ）／（Ｖｍｌ １／２＋Ｖｍｈ １／２）
Ｖｍ＝Ｖ１Ｖ２／（φ１Ｖ２＋φ２Ｖ１）
δｍ＝φ１δ１＋φ２δ２
Ｖi：溶媒の分子容（ｍｌ／ｍｏｌ）
φi：濁点における各溶媒の体積分率
δi：溶媒のＳＰ値
ｍｌ：低ＳＰ貧溶媒混合系
ｍｈ：高ＳＰ貧溶媒混合系 As a sample, 0.5 g of an organic solvent is weighed in a 100 ml beaker, 10 ml of acetone is added using a whole pipette, and the mixture is dissolved by a magnetic stirrer. A poor solvent is added dropwise to this sample using a 50 ml burette at a measurement temperature of 20 ° C., and the point at which turbidity occurs is defined as the amount of addition. As the poor solvent, ion-exchanged water is used as the high SP poor solvent, and n-hexane is used as the low SP poor solvent, and the turbidity point is measured. The SP value δ of the organic solvent is given by the following formula.
δ = (V ml 1/2 δ ml + V mh 1/2 δ mh ) / (V ml 1/2 + V mh 1/2 )
V m = V 1 V 2 / (φ 1 V 2 + φ 2 V 1 )
δ m = φ 1 δ 1 + φ 2 δ 2
Vi: Molecular volume of solvent (ml / mol)
φi: Volume fraction of each solvent at the turbidity point δi: SP value of solvent ml: Low SP poor solvent mixed system mh: High SP poor solvent mixed system
　また、ＳＰ値は、「Ｋ．Ｌ．Ｈｏｙ　Ｊ．Ｐ．Ｔ．４２，７６（１９７０）」に記載のエネルギーパラメーターを用い、「Ｐ．Ａ．Ｓｍａｌｌ　Ｊ．Ａｐｐｌ．Ｃｈｅｍ．３，７１（１９５３）」でＳｍａｌｌが提案した方法に従って算出できる。 Further, as the SP value, the energy parameter described in "KL Hoy JPT 42,76 (1970)" is used, and "PA Small J. Appl. Chem. 3,71 (1953)" is used. ) ”, It can be calculated according to the method proposed by Small.
　本開示において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）、グリシジル基含有アクリル樹脂エマルション（Ｂ）、及びウレタン樹脂ディスパージョン（Ｃ）からなる群から選択される少なくとも１種と、樹脂ディスパージョン（Ｄ）と硬化剤（Ｅ）とを、塗料組成物中と同じ質量割合で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である。
　一実施態様において、厚さ３０μｍの塗膜のヘーズ値は、３０％以上である。
　別の実施態様において、厚さ３０μｍの塗膜のヘーズ値は、３５％以上であり、例えば、ヘーズ値は、４０％以上である。
　ヘーズ値が高い程隠ぺい性が向上するため、ヘーズ値は高い程好ましい。 In the present disclosure, at least one selected from the group consisting of maleic anhydride-modified polyolefin resin (A), glycidyl group-containing acrylic resin emulsion (B), and urethane resin dispersion (C), and resin dispersion (D). The haze value of the coating film having a thickness of 30 μm formed from the mixture containing the curing agent (E) and the curing agent (E) in the same mass ratio as in the coating composition is 15% or more.
In one embodiment, the haze value of the coating film having a thickness of 30 μm is 30% or more.
In another embodiment, the haze value of the coating film having a thickness of 30 μm is 35% or more, for example, the haze value is 40% or more.
The higher the haze value, the better the hiding property. Therefore, the higher the haze value, the more preferable.
　塗膜のヘーズ値が上記範囲であることにより、被塗物が有する色調、例えば、黒色、銀色を、薄膜でありながらも十分に隠ぺいできる。
　また、塗膜は高い隠ぺい性を有することができ、白色又は白色に近い色を示し得るので、一般的に用いられている酸化チタンを含む白色プライマー塗膜と、その上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗料組成物から形成された塗膜を備えることができる。
　よって、本開示に係る塗料組成物は、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗膜は単層でありながらも備えることができる。
　更に、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。また、所望の色調、特に、白色系マイカの色調を良好に発現できる。 When the haze value of the coating film is within the above range, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film.
In addition, since the coating film can have high hiding power and can exhibit white or a color close to white, a commonly used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film are used. The function of the film can be provided by a coating film formed from the coating composition according to the present disclosure.
Therefore, the coating film according to the present disclosure has the functions of a commonly used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film. Although it is a single layer, it can be prepared.
Further, the layer structure can be made thinner as compared with the conventional multi-layer coating film, and the coating film forming step can be reduced. In addition, a desired color tone, particularly a color tone of white mica, can be satisfactorily expressed.
　本開示において、厚さ３０μｍの塗膜のヘーズを測定するための塗膜の調製は、次の方法に基づき作成できる。 In the present disclosure, the preparation of a coating film for measuring the haze of a coating film having a thickness of 30 μm can be prepared based on the following method.
　厚さ３０μｍの塗膜のヘーズ値の測定は、市販の濁度計（例えば、日本電色工業社製　Σ９０カラー測定システム）を用いて、ＪＩＳ　Ｋ７１３６：２０００に準拠した方法により測定できる。 The haze value of a coating film having a thickness of 30 μm can be measured by a method compliant with JIS K7136: 2000 using a commercially available turbidity meter (for example, Σ90 color measurement system manufactured by Nippon Denshoku Kogyo Co., Ltd.).
　以下、塗料組成における各成分について、説明する。
［無水マレイン酸変性ポリオレフィン樹脂（Ａ）］
　本開示に係る無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）は、例えば、８．２以上９．５以下であってよく、８．３以上９．３以下であってよい。 Hereinafter, each component in the coating composition will be described.
[Maleic anhydride-modified polyolefin resin (A)]
The solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A) according to the present disclosure may be, for example, 8.2 or more and 9.5 or less, and 8.3 or more and 9.3 or less. ..
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、ポリオレフィン樹脂と無水マレイン酸から合成された誘導体であればよく、特に制限されるものではない。無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、１種のみであってもよいし、２種以上であってもよい。 The maleic anhydride-modified polyolefin resin (A) may be any derivative synthesized from the polyolefin resin and maleic anhydride, and is not particularly limited. The maleic anhydride-modified polyolefin resin (A) may be of only one type or of two or more types.
　本開示において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、エマルションの状態であってよく、このような樹脂（Ａ）を、無水マレイン酸変性ポリオレフィン樹脂エマルションと称する場合がある。この態様において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、無水マレイン酸変性ポリオレフィン樹脂エマルション自体を意味するものであり、他のエマルション樹脂を含まないものとする。 In the present disclosure, the maleic anhydride-modified polyolefin resin (A) may be in an emulsion state, and such a resin (A) may be referred to as a maleic anhydride-modified polyolefin resin emulsion. In this aspect, the maleic anhydride-modified polyolefin resin (A) means the maleic anhydride-modified polyolefin resin emulsion itself, and does not contain other emulsion resins.
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の重量平均分子量は、２０，０００以上２００，０００以下の範囲であることが好ましく、５０，０００以上１２０，０００以下の範囲にあることがより好ましい。重量平均分子量は、ポリスチレンを標準として用いて、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）の測定結果から算出することができる。重量平均分子量がこのような範囲内であることにより、例えば、本開示に係る塗料組成物をプライマー塗料組成物として使用する態様において、プライマー塗膜として要求される強度を保持でき、被塗物との密着性を高く保持でき、更に、塗膜内での凝集破壊を抑制できる。また、無水マレイン酸変性ポリオレフィン樹脂（Ａ）を、本開示に行ける既知の方法により乳化でき、更に、塗料組成物の安定化を示すことができる。
　更に、例えば、被塗物にポリオレフィン素材を用いる態様において、濡れ性の低下を抑制でき、素材の密着性を高めることができる。 The weight average molecular weight of the maleic anhydride-modified polyolefin resin (A) is preferably in the range of 20,000 or more and 200,000 or less, and more preferably in the range of 50,000 or more and 120,000 or less. The weight average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard. When the weight average molecular weight is within such a range, for example, in the embodiment in which the coating composition according to the present disclosure is used as a primer coating composition, the strength required as a primer coating film can be maintained, and the coating material can be combined with the object to be coated. It is possible to maintain high adhesion and further suppress coagulation failure in the coating film. Further, the maleic anhydride-modified polyolefin resin (A) can be emulsified by a known method described in the present disclosure, and further, the stabilization of the coating composition can be shown.
Further, for example, in the embodiment in which the polyolefin material is used for the object to be coated, the decrease in wettability can be suppressed and the adhesion of the material can be improved.
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、例えば、本開示に係る塗料組成物における全樹脂固形分中１５質量％以上４０質量％以下であってよく、２０質量％以上３５質量％以下であってよい。
　本明細書中、本開示に係る塗料組成物における全樹脂固形分とは、（Ａ）、（Ｂ）、（Ｃ）、（Ｄ）及び（Ｅ）の固形分の合計を意味する。 The maleic anhydride-modified polyolefin resin (A) may be, for example, 15% by mass or more and 40% by mass or less, and 20% by mass or more and 35% by mass or less, based on the total resin solid content in the coating composition according to the present disclosure. Good.
In the present specification, the total resin solid content in the coating composition according to the present disclosure means the total solid content of (A), (B), (C), (D) and (E).
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）の量がこのような範囲内であることにより、例えば、被塗物にポリオレフィン素材を用いる態様において、密着性を良好に保つことができる。また、外観不良を抑制でき、例えば、リコート時における下地塗膜に対する密着不良を抑制できる。 When the amount of the maleic anhydride-modified polyolefin resin (A) is within such a range, good adhesion can be maintained, for example, in a mode in which a polyolefin material is used for the object to be coated. In addition, poor appearance can be suppressed, and for example, poor adhesion to the underlying coating film at the time of recoating can be suppressed.
　無水マレイン酸変性ポリオレフィン樹脂（Ａ）をエマルション化する方法としては、機械的乳化法、乳化剤や塩基性物質を用いる方法、及びこれらの組み合わせなど、一般的に用いられている乳化方法を用いることができる。乳化剤を用いる用合、乳化剤の量については、無水マレイン酸変性ポリオレフィン樹脂（Ａ）、塩基性物質、水の量などにより適宜設定できる。塩基性物質を用いる場合、無水マレイン酸変性ポリオレフィン樹脂、水等の量により適宜設定でき、特に、無水マレイン酸変性ポリオレフィン樹脂（Ａ）及び乳化剤の酸官能基が十分に中和される量であること、さらに、得られるエマルションのｐＨが７以上１１以下、より好ましくは７．５以上１０．５以下となることを考慮して設定することが好ましい。得られる無水マレイン酸変性ポリオレフィン樹脂エマルションのｐＨ値が上記範囲内であることにより、エマルションの安定化を保持でき、例えば、塩基性物質の遊離を抑制でき、耐水性を向上できる。 As a method for emulsifying the maleic anhydride-modified polyolefin resin (A), a commonly used emulsification method such as a mechanical emulsification method, a method using an emulsifier or a basic substance, or a combination thereof can be used. it can. When an emulsifier is used, the amount of the emulsifier can be appropriately set depending on the amount of the maleic anhydride-modified polyolefin resin (A), the basic substance, water and the like. When a basic substance is used, it can be appropriately set depending on the amount of maleic anhydride-modified polyolefin resin, water, etc., and in particular, the amount is such that the acid functional groups of the maleic anhydride-modified polyolefin resin (A) and the emulsifier are sufficiently neutralized. Further, it is preferable to set the pH of the obtained emulsion in consideration of 7 or more and 11 or less, more preferably 7.5 or more and 10.5 or less. When the pH value of the obtained maleic anhydride-modified polyolefin resin emulsion is within the above range, the stabilization of the emulsion can be maintained, for example, the release of a basic substance can be suppressed, and the water resistance can be improved.
　当該エマルション中の無水マレイン酸変性ポリオレフィン樹脂の平均粒径は、特に制限されず、例えば、一実施態様において、平均粒径は、０．０１μｍ以上１０μｍ以下であることが好ましい。平均粒径がこのような範囲内であることにより、乳化剤を多量に必要としない。
　例えば、乳化剤を多量に含むと、塗膜の耐水性がやや劣ることがある。一方、上記平均粒径を有することにより、塗膜の耐水性の低下を抑制できる。また、エマルションの安定性を良好に保つことがある。 The average particle size of the maleic anhydride-modified polyolefin resin in the emulsion is not particularly limited. For example, in one embodiment, the average particle size is preferably 0.01 μm or more and 10 μm or less. Since the average particle size is within such a range, a large amount of emulsifier is not required.
For example, if a large amount of emulsifier is contained, the water resistance of the coating film may be slightly inferior. On the other hand, by having the above average particle size, it is possible to suppress a decrease in water resistance of the coating film. In addition, the stability of the emulsion may be kept good.
　一実施態様において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）中、無水マレイン酸（酸無水物）に由来する構造の質量比率は、１質量％以上１０以下質量％であることが好ましく、より好ましくは１．２質量％以上５質量％以下であるのがよい。当該質量比率が上記範囲内であることにより、無水マレイン酸変性ポリオレフィン樹脂（Ａ）の乳化を適切に行うことができ、塗料組成物の安定化を図ることができる。また、塗膜の耐水性が低下することを抑制できる。 In one embodiment, the mass ratio of the structure derived from maleic anhydride (acid anhydride) in the maleic anhydride-modified polyolefin resin (A) is preferably 1% by mass or more and 10 or less by mass, more preferably. It is preferably 1.2% by mass or more and 5% by mass or less. When the mass ratio is within the above range, the maleic anhydride-modified polyolefin resin (A) can be appropriately emulsified, and the coating composition can be stabilized. In addition, it is possible to suppress a decrease in the water resistance of the coating film.
　一実施態様において、無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、塩素化された無水マレイン酸変性ポリオレフィン樹脂（Ａ）であってよい。本明細書において、このような塩素化された樹脂を、無水マレイン酸変性塩素化ポリオレフィン樹脂と記載する。
　塩素化した無水マレイン酸変性ポリオレフィン樹脂（Ａ）を用いることにより、例えば、本開示に係る塗料組成物をプライマー塗料組成物として使用する態様において、プライマー塗膜として要求される強度を保持でき、被塗物との密着性を高く保持できる。
　また、塗膜内での凝集破壊を抑制でき。加えて、塗料組成物の安定化を示すことができる。
　更に、塩素化することにより、結晶性ポリオレフィンの結晶性を維持したまま融点を低下させ、乳化などのハンドリングが容易となる。 In one embodiment, the maleic anhydride-modified polyolefin resin (A) may be a chlorinated maleic anhydride-modified polyolefin resin (A). In the present specification, such a chlorinated resin is referred to as a maleic anhydride-modified chlorinated polyolefin resin.
By using the chlorinated maleic anhydride-modified polyolefin resin (A), for example, in the embodiment of using the coating composition according to the present disclosure as a primer coating composition, the strength required as a primer coating film can be maintained, and the coating film can be coated. High adhesion with the coating can be maintained.
In addition, cohesive failure in the coating film can be suppressed. In addition, it can show stabilization of the coating composition.
Further, by chlorination, the melting point is lowered while maintaining the crystallinity of the crystalline polyolefin, and handling such as emulsification becomes easy.
　一実施態様において、本開示に係る塗料組成物は、無水マレイン酸変性塩素化ポリオレフィン樹脂を、無水マレイン酸変性塩素化ポリオレフィン樹脂エマルション樹脂として含むことができる。無水マレイン酸変性塩素化ポリオレフィン樹脂エマルションを得る際に用いる塩素化ポリオレフィン樹脂の塩素含有率は、無水マレイン酸変性塩素化ポリオレフィン樹脂中の１５質量％以上４０質量％以下であり、より好ましくは２０質量％以上～３５質量％以下である。
　このような量で塩素を含むことで、乳化を容易に行うことができ、更に、被塗物、例えば、ポリオレフィン素材に対する密着性、特に、ポリプロピレン素材への密着性を十分に保持できる。 In one embodiment, the coating composition according to the present disclosure may contain a maleic anhydride-modified chlorinated polyolefin resin as a maleic anhydride-modified chlorinated polyolefin resin emulsion resin. The chlorine content of the chlorinated polyolefin resin used for obtaining the maleic anhydride-modified chlorinated polyolefin resin emulsion is 15% by mass or more and 40% by mass or less, more preferably 20% by mass in the maleic anhydride-modified chlorinated polyolefin resin. % To 35% by mass or less.
By containing chlorine in such an amount, emulsification can be easily performed, and further, the adhesion to the object to be coated, for example, the polyolefin material, particularly the adhesion to the polypropylene material can be sufficiently maintained.
［グリシジル基含有アクリル樹脂エマルション（Ｂ）］
　エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）は、例えば、９．９以上１１．５以下であってよく、１０以上１１以下であってよい。 [Glysidyl group-containing acrylic resin emulsion (B)]
The solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B) may be, for example, 9.9 or more and 11.5 or less, and may be 10 or more and 11 or less.
　水性塗料組成物の態様においては、樹脂を水性媒体中で安定化させるために親水性基を多く必要とする。例えば、カルボキシル基、ヒドロキシル基、アミノ基などである。このような親水性基を多く含有する場合は、耐水性試験において様々の問題が発生する。例えば、水を多く吸収し、ブリスター発生、水膨潤することによる下膜や上膜との層間剥離などが起こりやすい。
　これに対して、本開示に係る塗料組成物においては、グリシジル基含有アクリル樹脂エマルション（Ｂ）を用いることで、塗膜の凝集力を向上させることができる。
　また、グリシジル基含有アクリル樹脂エマルション（Ｂ）を含むことにより、例えば、白系塗膜、マイカ系塗膜の場合、太陽光の紫外線がプライマーまで達することにより引き起こされ得るプライマー塗膜の黄変劣化を抑制できる。 In aspects of the aqueous coating composition, many hydrophilic groups are required to stabilize the resin in the aqueous medium. For example, a carboxyl group, a hydroxyl group, an amino group and the like. When a large amount of such hydrophilic groups are contained, various problems occur in the water resistance test. For example, a large amount of water is absorbed, blisters are generated, and delamination with the inferior membrane and upper membrane is likely to occur due to water swelling.
On the other hand, in the coating composition according to the present disclosure, the cohesive force of the coating film can be improved by using the glycidyl group-containing acrylic resin emulsion (B).
Further, by containing the glycidyl group-containing acrylic resin emulsion (B), for example, in the case of a white coating film or a mica coating film, yellowing deterioration of the primer coating film that can be caused by the ultraviolet rays of sunlight reaching the primer can be prevented. Can be suppressed.
　グリシジル基含有アクリル樹脂は、グリシジル基を含有するラジカル重合性モノマーと他のラジカル重合性モノマーとを共重合させることにより得ることができる。例えば、グリシジルメタクリレート、グリシジルアクリレート等と（メタ）アクリル酸、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリル酸ヒドロキシプロピル、（メタ）アクリル酸ヒドロキシブチル、アクリル酸ヒドロキシエチルとε－カプロラクトンとの付加物などの官能基含有モノマー、更には、（メタ）アクリル酸アルキルエステルとして、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸Ｎ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸ｎ－オクチル、（メタ）アクリル酸ラウリル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸ラウリルとの共重合を行って水性エマルションとすることで、グリシジル基含有アクリル樹脂エマルション（Ｂ）を得ることができる。 The glycidyl group-containing acrylic resin can be obtained by copolymerizing a radically polymerizable monomer containing a glycidyl group with another radically polymerizable monomer. For example, addition of glycidyl methacrylate, glycidyl acrylate and the like with (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyethyl acrylate and ε-caprolactone. Functional group-containing monomers such as substances, and further, as (meth) acrylic acid alkyl ester, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, isopropyl (meth) acrylic acid, N-butyl (meth) acrylic acid, T-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, (meth) ) Acrylic resin emulsion (B) containing a glycidyl group can be obtained by copolymerizing with lauryl acrylate to obtain an aqueous emulsion.
　水性エマルション化としては、溶剤重合した後、水中に強制攪拌や乳化剤等を用いてエマルション化する方法、水中で乳化剤を用いて共重合するエマルション重合法等が挙げられる。 Examples of the aqueous emulsion include a method of subjecting to solvent polymerization and then emulsion by forced stirring or using an emulsifier in water, an emulsion polymerization method of copolymerizing in water using an emulsifier, and the like.
　エマルション（Ｂ）中のグリシジル基含有アクリル樹脂中、グリシジル基含有モノマーに由来する構造の質量比率は、３０質量％以上６０質量％以下であることが好ましい。すなわち、グリシジル基含有アクリル樹脂の合成に用いる全モノマー中、グリシジル基を含有するラジカル重合性モノマーが３０質量％以上６０質量％以下であることが好ましい。 The mass ratio of the structure derived from the glycidyl group-containing monomer in the glycidyl group-containing acrylic resin in the emulsion (B) is preferably 30% by mass or more and 60% by mass or less. That is, it is preferable that the radically polymerizable monomer containing a glycidyl group is 30% by mass or more and 60% by mass or less in all the monomers used for the synthesis of the glycidyl group-containing acrylic resin.
　乳化重合から得られるエポキシエマルションにおいては、乳化剤量などに注意することが必要である。塗膜中に残存して、耐水性などを低下させることもあるからである。 In the epoxy emulsion obtained from emulsion polymerization, it is necessary to pay attention to the amount of emulsifier. This is because it may remain in the coating film and reduce water resistance and the like.
　エマルション（Ｂ）中のグリシジル基含有アクリル樹脂は、本開示に係る塗料組成物における全樹脂固形分中２０質量％以上３５質量％以下が好ましい。
　このような範囲以内であることにより、例えば、耐水性試験に付し、その後塗膜の密着性評価を行うような条件であっても、塗膜の凝集破壊・剥離を抑制できる。また、架橋度が大きくなりすぎることを回避でき、例えば、架橋歪みを抑制でき、初期密着において、他の塗膜、被塗物との層間剥離を抑制できる。 The glycidyl group-containing acrylic resin in the emulsion (B) is preferably 20% by mass or more and 35% by mass or less in the total resin solid content in the coating composition according to the present disclosure.
Within such a range, it is possible to suppress coagulation breakage / peeling of the coating film even under conditions such as subjecting to a water resistance test and then evaluating the adhesion of the coating film. Further, it is possible to prevent the degree of cross-linking from becoming too large, for example, it is possible to suppress cross-linking strain, and it is possible to suppress delamination with other coating films and objects to be coated in the initial adhesion.
［ウレタン樹脂ディスパージョン（Ｃ）］
　一実施態様において、本開示に係る塗料組成物は、ウレタン樹脂ディスパージョン（Ｃ）を含み得る。例えば、ウレタン樹脂ディスパージョン（Ｃ）として、多官能イソシアネート化合物、１分子中に２個以上の水酸基を有するポリオール、及びジメチロールプロパンジオール又はジメチロールブタンジオール等の水酸基とカルボン酸基を共に有する親水化剤をジブチル錫ジラウリレート等の触媒の存在下、イソシアネート基過剰の状態で反応させてウレタンプレポリマーを得た後、アミン類等の有機塩基又は水酸化ナトリウム、水酸化カリウム等の無機塩基によりカルボン酸を中和し、イオン交換水を加えて水性化した後、更に鎖伸長剤により高分子量化して得られたウレタン樹脂ディスパージョン等；カルボン酸を有しないウレタンプレポリマーを合成した後、カルボン酸やスルホン酸、エチレングリコール等の親水基を有したジオール又はジアミンを用いて鎖伸長し、その後で、上記塩基性物質で中和して水性化し、必要により更に鎖伸長剤を用いて高分子量化して得られたウレタン樹脂ディスパージョン等；必要により乳化剤も併用して得られたウレタン樹脂ディスパージョン等；を挙げることができる。 [Urethane resin dispersion (C)]
In one embodiment, the coating composition according to the present disclosure may comprise a urethane resin dispersion (C). For example, as the urethane resin dispersion (C), a polyfunctional isocyanate compound, a polyol having two or more hydroxyl groups in one molecule, and hydrophilicity having both hydroxyl groups and carboxylic acid groups such as dimethylolpropanediol or dimethylolbutanediol. The agent is reacted in the presence of a catalyst such as dibutyltin dilaurylate in an excess of isocyanate groups to obtain a urethane prepolymer, and then carboxylic acid is added to an organic base such as amines or an inorganic base such as sodium hydroxide or potassium hydroxide. Urethane resin dispersion obtained by neutralizing the acid and adding ion-exchanged water to make it aqueous, and then further increasing the molecular weight with a chain extender; after synthesizing a urethane prepolymer having no carboxylic acid, the carboxylic acid Chain extension is performed using a diol or diamine having a hydrophilic group such as sulfonic acid or ethylene glycol, and then neutralized with the above basic substance to make it aqueous, and if necessary, further increased in molecular weight using a chain extender. Examples thereof include a urethane resin dispersion obtained in combination with an emulsifier, if necessary; and a urethane resin dispersion obtained in combination with an emulsifier.
　多官能イソシアネート化合物としては、１，６－ヘキサンジイソシアネート、リジンジイソシアネート、イソホロンジイソシアネート、シクロヘキサン－１，４－ジイソシアネート、キシリレンジイソシアネート、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート等のジイソシアネート化合物、及びこれらのアダクト体、ビューレット体、イソシアヌレート体等の多官能イソシアネート化合物を挙げることができる。 Examples of the polyfunctional isocyanate compound include diisocyanates such as 1,6-hexanediisocyanate, lysine diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-toluene diisocyanate. Examples thereof include compounds and polyfunctional isocyanate compounds such as adducts, burettes, and isocyanurates thereof.
　ポリオールとして、ポリエステルポリオール、ポリエーテルポリオール、ポリカーボネートポリオール等を挙げることができる。 Examples of the polyol include polyester polyol, polyether polyol, polycarbonate polyol and the like.
　鎖延長剤としては、エチレングリコール、プロピレングリコール、１，４－ブタンジオール、ネオペンチルグリコール、フラシジメタノール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール等の低分子量ジオール化合物、及びこれらにエチレンオキサイド、プロピレンオキサイド、テトラヒドロフラン等を付加重合させたポリエーテルジオール化合物；上記低分子量ジオール化合物と（無水）コハク酸、アジピン酸、（無水）フタール酸等ジカルボン酸及びこれらの無水物から得られる末端に水酸基等を有するポリエステルジオール；トリメチロールエタン、トリメチロルブロパン等の多価アルコール；モノエタノールアミン、ジエタノールアミン、トリエタノールアミン等のアミノアルコール；エチレンジアミン、プロピレンジアミン、ブチレンジアミン、ヘキサメチレンジアミン、フェニレンジアミン、トルエンジアミン、キシレンジアミン、イソホロンジアミン等のジアミン化合物；水、アンモニア、ヒドラジン、二塩基酸ヒドラジド等を挙げることができる。 Examples of the chain extender include low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, fracidimethanol, diamine glycol, triethylene glycol and tetraethylene glycol, and ethylene oxide and propylene. Polyether diol compound obtained by addition polymerization of oxide, tetrahydrofuran, etc .; Diamine acid such as (anhydrous) succinic acid, adipic acid, (anhydrous) futaric acid, and diamine acid such as (anhydrous) succinic acid, adipic acid, (anhydrous) futal acid, and hydroxyl group at the terminal obtained from these anhydrides Polyhydric diols; polyhydric alcohols such as trimethylolethane, trimethylolbropan; aminoalcohols such as monoethanolamine, diethanolamine, triethanolamine; ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, phenylenediamine, toluenediamine, Diamine compounds such as xylene diamine and isophorone diamine; water, ammonia, hydrazine, dibasic acid hydrazide and the like can be mentioned.
　ウレタン樹脂ディスパージョン（Ｃ）中のウレタン樹脂は、例えば、本開示に係る塗料組成物における全樹脂固形分中１５質量％以上４０質量％以下であってよく、２０質量％以上３５質量％以下であってよい。
　ウレタン樹脂ディスパージョン（Ｃ）中のウレタン樹脂の量が上記範囲以内であることにより、例えば、耐水性試験に付し、その後塗膜の密着性評価を行うような条件であっても、塗膜の凝集破壊・剥離を抑制できる。また、架橋度が大きくなりすぎることを回避でき、例えば、架橋歪みを抑制でき、初期密着において、他の塗膜、被塗物との層間剥離を抑制できる。 The urethane resin in the urethane resin dispersion (C) may be, for example, 15% by mass or more and 40% by mass or less, and 20% by mass or more and 35% by mass or less, based on the total resin solid content in the coating composition according to the present disclosure. It may be there.
When the amount of urethane resin in the urethane resin dispersion (C) is within the above range, for example, the coating film is subjected to a water resistance test and then the adhesion of the coating film is evaluated. Aggregate destruction and peeling can be suppressed. Further, it is possible to prevent the degree of cross-linking from becoming too large, for example, it is possible to suppress cross-linking strain, and it is possible to suppress delamination with other coating films and objects to be coated in the initial adhesion.
［樹脂ディスパージョン（Ｄ）]
　本開示に係る樹脂ディスパージョン（Ｄ）は、本開示に係る特定の条件、特に、溶解性パラメータＳＰ値に関する条件を満たす範囲で、適宜選択できる。 [Resin dispersion (D)]
The resin dispersion (D) according to the present disclosure can be appropriately selected within a range that satisfies the specific conditions according to the present disclosure, particularly the conditions relating to the solubility parameter SP value.
　一実施態様において、樹脂ディスパージョン（Ｄ）は、ポリエステル樹脂ディスパージョン（Ｄ１）及びアクリル樹脂エマルション（Ｄ２）からなる群から選択される少なくとも１種を含む樹脂ディスパージョンである。
　例えば、樹脂ディスパージョン（Ｄ）は、ポリエステル樹脂ディスパージョン（Ｄ１）又はアクリル樹脂エマルション（Ｄ２）のいずれか一方であってもよい。 In one embodiment, the resin dispersion (D) is a resin dispersion comprising at least one selected from the group consisting of polyester resin dispersion (D1) and acrylic resin emulsion (D2).
For example, the resin dispersion (D) may be either a polyester resin dispersion (D1) or an acrylic resin emulsion (D2).
　　（ポリエステル樹脂ディスパージョン（Ｄ１））
　一実施態様において、樹脂ディスパージョン（Ｄ）は、ポリエステル樹脂ディスパージョン（Ｄ１）である。本開示に係る塗料組成物が、ポリエステル樹脂ディスパージョン（Ｄ１）を含むことにより、耐水性に優れ、被塗物に対する密着性に優れた塗膜を形成できる。 (Polyester resin dispersion (D1))
In one embodiment, the resin dispersion (D) is a polyester resin dispersion (D1). When the coating composition according to the present disclosure contains the polyester resin dispersion (D1), it is possible to form a coating film having excellent water resistance and excellent adhesion to the object to be coated.
　ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の数平均分子量は、６，０００以上２０，０００以下であってよく、例えば、８，５００以上２０，０００以下であってよい。数平均分子量は、ポリスチレンを標準として用いて、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）の測定結果から算出することができる。 The number average molecular weight of the polyester resin in the polyester resin dispersion (D1) may be 6,000 or more and 20,000 or less, for example, 8,500 or more and 20,000 or less. The number average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.
　一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）は、溶解性パラメータＳＰ（Ｄ１）が、例えば、１１.０以上１２.０以下であってよく、１１.１以上１１.９以下であってよい。溶解性パラメータＳＰ（Ｄ１）がこのような範囲内であることにより、被塗物が有する色調、例えば、黒色、銀色を薄膜でありながらも十分に隠ぺいできる。更に、高い隠ぺい性を有する塗膜を形成できるので、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗膜は単層でありながらも備えることができる。
　すなわち、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。さらに、所望の白色系マイカの色調を発現できる。 In one embodiment, the polyester resin dispersion (D1) may have a solubility parameter SP (D1) of, for example, 11.0 or more and 12.0 or less, and 11.1 or more and 11.9 or less. .. When the solubility parameter SP (D1) is within such a range, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film. Further, since a coating film having a high hiding property can be formed, the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are described in the present disclosure. The coating film can be provided even though it is a single layer.
That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
　ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂のガラス転移温度（Ｔｇ）は、例えば、４０℃以上８０℃以下であってよく、５５℃以上７５℃以下であってよい。ガラス転移温度（Ｔｇ）がこのような範囲内であることにより、耐水性に優れ、被塗物に対する密着性に優れた塗膜を形成できる。 The glass transition temperature (Tg) of the polyester resin in the polyester resin dispersion (D1) may be, for example, 40 ° C. or higher and 80 ° C. or lower, and 55 ° C. or higher and 75 ° C. or lower. When the glass transition temperature (Tg) is within such a range, it is possible to form a coating film having excellent water resistance and excellent adhesion to an object to be coated.
　一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の酸価は、例えば、１ｍｇＫＯＨ／ｇ以上１０ｍｇＫＯＨ／ｇであってよく、１ｍｇＫＯＨ／ｇ以上８ｍｇＫＯＨ／ｇであってよい。酸価がこのような範囲内であることにより、架橋剤等によって架橋構造を形成することができ、その結果、塗膜と被塗物の密着性、本開示に係る塗膜の上方に配置される別の塗膜との密着性をより向上できる。 In one embodiment, the acid value of the polyester resin in the polyester resin dispersion (D1) may be, for example, 1 mgKOH / g or more and 10 mgKOH / g, or 1 mgKOH / g or more and 8 mgKOH / g. When the acid value is within such a range, a crosslinked structure can be formed by a crosslinking agent or the like, and as a result, the adhesion between the coating film and the object to be coated is arranged above the coating film according to the present disclosure. Adhesion with another coating film can be further improved.
　一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の水酸基価は、例えば、１ｍｇＫＯＨ／ｇ以上２０ｍｇＫＯＨ／ｇ以下であってよく、１ｍｇＫＯＨ／ｇ以上１０ｍｇＫＯＨ／ｇ以下であってよい。水酸基価がこのような範囲内であることにより、後述する硬化剤（Ｅ）と共に、塗膜に対して優れた耐久性を付与できる。 In one embodiment, the hydroxyl value of the polyester resin in the polyester resin dispersion (D1) may be, for example, 1 mgKOH / g or more and 20 mgKOH / g or less, and 1 mgKOH / g or more and 10 mgKOH / g or less. When the hydroxyl value is within such a range, excellent durability can be imparted to the coating film together with the curing agent (E) described later.
　一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の平均粒子径（Ｄ５０）は、例えば、４０ｎｍ以上１００ｎｍ以下であってよく、５０ｎｍ以上９０ｎｍ以下であってよい。 In one embodiment, the average particle size (D50) of the polyester resin in the polyester resin dispersion (D1) may be, for example, 40 nm or more and 100 nm or less, and 50 nm or more and 90 nm or less.
　ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂としては、例えば多塩基酸と多価アルコールとの縮合物等を挙げることができる。多塩基酸としては、例えば無水フタル酸、イソフタル酸、テレフタル酸、アジピン酸、無水コハク酸等を挙げることができる。多価アルコールとしては、例えばエチレングリコール、プロピレングリコール、１，３－ブチレングリコール、１，６－ヘキサンジオール、ポリエチレングリコール、ポリプロピレングリコール等を挙げることができる。 Examples of the polyester resin in the polyester resin dispersion (D1) include a condensate of a polybasic acid and a polyhydric alcohol. Examples of the polybasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, succinic anhydride and the like. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol and the like.
　一実施態様において、ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂は、カルボキシ基及び／又はスルホン酸基を有することが好ましい。ポリエステルがこれらの親水基を有することで、水への分散性が良好となり、その結果、当該エマルション組成物を含む塗料組成物からより均一な塗膜を形成することができ、当該塗膜と被塗物との密着性、更には、当該塗膜の上方に配置される他の塗膜との密着性をより向上できる。 In one embodiment, the polyester resin in the polyester resin dispersion (D1) preferably has a carboxy group and / or a sulfonic acid group. When the polyester has these hydrophilic groups, the dispersibility in water is improved, and as a result, a more uniform coating film can be formed from the coating composition containing the emulsion composition, and the coating film and the coating film can be coated. Adhesion to the coating film, and further, adhesion to other coating films arranged above the coating film can be further improved.
　ポリエステル樹脂ディスパージョン（Ｄ１）として市販品を使用でき、例えば、ＫＡ－５０７１Ｓ、ＫＺＴ－８８０３、ＫＴ－８７０１、ＫＺＴ－９２０４（以上、ユニチカ社）、バイロナールＭＤ１２００、ＭＤ１２４５、ＭＤ１４８０，ＭＤ１９３０，ＭＤ２０００、ＭＤ１５００（以上、東洋紡社）、ＰＥＳ－Ｈ００１等のハイテックＰＥシリーズ（東邦化学工業社）、ニュートラック２０１０（花王社）、スーパーフレックス２１０（第一工業製薬社）、プラスコートＺ７３０、Ｚ７６０、Ｚ５９２、Ｚ６８７、Ｚ６９０（以上、互応化学工業社）などを挙げることができる。 Commercially available products can be used as the polyester resin dispersion (D1), for example, KA-5071S, KZT-8803, KT-8701, KZT-9204 (above, Unitika Ltd.), Byronal MD1200, MD1245, MD1480, MD1930, MD2000, MD1500. (Toyo Spinning Co., Ltd.), Hi-Tech PE series such as PES-H001 (Toho Chemical Industry Co., Ltd.), New Track 2010 (Kao Co., Ltd.), Superflex 210 (Daiichi Kogyo Seiyaku Co., Ltd.), Plus Coat Z730, Z760, Z592, Z687 , Z690 (above, Goo Chemical Industry Co., Ltd.) and the like.
　ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂は、例えば、本開示に係る塗料組成物における全樹脂固形分中１０質量％以上３５質量％以下であってよく、１５質量％以上２５質量％以下であってよい。 The polyester resin in the polyester resin dispersion (D1) may be, for example, 10% by mass or more and 35% by mass or less, and 15% by mass or more and 25% by mass or less in the total resin solid content in the coating composition according to the present disclosure. It may be there.
　（アクリル樹脂エマルション（Ｄ２））
　一実施態様において、本開示に係る樹脂ディスパージョン（Ｄ）は、アクリル樹脂エマルション（Ｄ２）である。本開示に係る塗料組成物が、アクリル樹脂エマルション（Ｄ２）を含むことにより、耐水性に優れ、被塗物に対する密着性に優れた塗膜を形成できる。
　ただし、アクリル樹脂エマルション（Ｄ２）は、グリシジル基含有アクリル樹脂エマルション（Ｂ）とは異なり、グリシジル基を含有しないアクリル樹脂のエマルションである。 (Acrylic resin emulsion (D2))
In one embodiment, the resin dispersion (D) according to the present disclosure is an acrylic resin emulsion (D2). When the coating composition according to the present disclosure contains an acrylic resin emulsion (D2), it is possible to form a coating film having excellent water resistance and excellent adhesion to an object to be coated.
However, unlike the glycidyl group-containing acrylic resin emulsion (B), the acrylic resin emulsion (D2) is an emulsion of an acrylic resin that does not contain a glycidyl group.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂の重量平均分子量は、特に限定されないが、一般的に５０，０００以上１，０００，０００以下であってよく、例えば、１００，０００以上８００，０００以下であってよい。重量平均分子量は、ポリスチレンを標準として用いて、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）の測定結果から算出することができる。 The weight average molecular weight of the acrylic resin in the acrylic resin emulsion (D2) is not particularly limited, but may be generally 50,000 or more and 1,000,000 or less, for example, 100,000 or more and 800,000 or less. It may be there. The weight average molecular weight can be calculated from the measurement result of gel permeation chromatography (GPC) using polystyrene as a standard.
　一実施態様において、アクリル樹脂エマルション（Ｄ２）は、溶解性パラメータＳＰ（Ｄ２）が８.０以上１２.０以下であってよい。
　別の実施態様において、溶解性パラメータＳＰ（Ｄ２）は、８．３以上８．９以下であってよく、１０．５以上１２.０以下であってよい。 In one embodiment, the acrylic resin emulsion (D2) may have a solubility parameter SP (D2) of 8.0 or more and 12.0 or less.
In another embodiment, the solubility parameter SP (D2) may be 8.3 or more and 8.9 or less, and may be 10.5 or more and 12.0 or less.
　溶解性パラメータＳＰ（Ｄ２）がこのような範囲内であることにより、被塗物が有する色調、例えば、黒色、銀色を、薄膜でありながらも十分に隠ぺいできる。
　更に、高い隠ぺい性を有する塗膜を形成できるので、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗膜は単層でありながらも備えることができる。
　すなわち、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。さらに、所望の白色系マイカの色調を発現できる。 When the solubility parameter SP (D2) is within such a range, the color tone of the object to be coated, for example, black or silver, can be sufficiently concealed even though it is a thin film.
Further, since a coating film having a high hiding property can be formed, the functions of a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are described in the present disclosure. The coating film can be provided even though it is a single layer.
That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂としては、１種以上のラジカル重合性モノマーを重合させることにより得ることができる。例えば、（メタ）アクリル酸、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリル酸ヒドロキシプロピル、（メタ）アクリル酸ヒドロキシブチル、アクリル酸ヒドロキシエチルとε－カプロラクトンとの付加物などの官能基含有モノマー、更には、（メタ）アクリル酸アルキルエステルとして、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸Ｎ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸ｎ－オクチル、（メタ）アクリル酸ラウリル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸ラウリルから選択される１種以上のモノマーを重合して水性エマルションとすることで、アクリル樹脂エマルション（Ｄ２）を得ることができる。水性エマルション化としては、溶剤重合した後、水中に強制攪拌や乳化剤等を用いてエマルション化する方法、水中で乳化剤を用いて共重合するエマルション重合法等が挙げられる。 The acrylic resin in the acrylic resin emulsion (D2) can be obtained by polymerizing one or more radically polymerizable monomers. Functional group-containing monomers such as (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and adducts of hydroxyethyl acrylate and ε-caprolactone. Furthermore, as (meth) acrylic acid alkyl ester, (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid isopropyl, (meth) acrylic acid N-butyl, (meth) acrylic acid t- Selected from butyl, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate. Acrylic resin emulsion (D2) can be obtained by polymerizing one or more kinds of monomers to form an aqueous emulsion. Examples of the aqueous emulsion include a method of subjecting to solvent polymerization and then emulsion by forced stirring or using an emulsifier in water, an emulsion polymerization method of copolymerizing in water using an emulsifier, and the like.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂のガラス転移温度（Ｔｇ）は、例えば、－１０℃以上１００℃以下であり、０℃以上８０℃以下であってよい。また、アクリル樹脂のガラス転移温度（Ｔｇ）は、１０℃以上８０℃以下であってよい。ガラス転移温度（Ｔｇ）がこのような範囲内であることにより、塗膜中に分散してより高い隠ぺい性を示すことができる。
　また、本開示に係る塗料組成物をウェットオンウェット方式において用いる態様においても、被塗物、及び本開示に係る塗料組成物から形成される塗膜の上に形成される上側塗膜との界面でのなじみを抑制し反転を防ぐことができる。 The glass transition temperature (Tg) of the acrylic resin in the acrylic resin emulsion (D2) may be, for example, −10 ° C. or higher and 100 ° C. or lower, and 0 ° C. or higher and 80 ° C. or lower. The glass transition temperature (Tg) of the acrylic resin may be 10 ° C. or higher and 80 ° C. or lower. When the glass transition temperature (Tg) is within such a range, it can be dispersed in the coating film to exhibit higher hiding power.
Further, also in the embodiment in which the coating composition according to the present disclosure is used in a wet-on-wet system, the interface between the object to be coated and the upper coating film formed on the coating film formed from the coating composition according to the present disclosure. It is possible to suppress familiarity with and prevent inversion.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂の酸価は、２ｍｇＫＯＨ／ｇ以上、２０ｍｇＫＯＨ／ｇ以下であることが好ましく、例えば、５ｍｇＫＯＨ／ｇ以上、１０ｍｇＫＯＨ／ｇ以下である。この範囲の樹脂の酸価とすることにより、アクリル樹脂エマルション（Ｄ２）、及びそれを含む本開示に係る塗料組成物の保存安定性、機械的安定性、凍結に対する安定性等の諸安定性が向上し、また、塗膜形成時における硬化剤（Ｅ）との硬化反応が十分起こり、塗膜の諸強度、耐チッピング性、耐水性が向上する。 The acid value of the acrylic resin in the acrylic resin emulsion (D2) is preferably 2 mgKOH / g or more and 20 mgKOH / g or less, for example, 5 mgKOH / g or more and 10 mgKOH / g or less. By setting the acid value of the resin in this range, various stability such as storage stability, mechanical stability, stability against freezing, etc. of the acrylic resin emulsion (D2) and the coating composition according to the present disclosure containing the same can be obtained. Further, the curing reaction with the curing agent (E) at the time of forming the coating film sufficiently occurs, and various strengths, chipping resistance and water resistance of the coating film are improved.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂の水酸基価は５ｍｇＫＯＨ／ｇ以上２０ｍｇＫＯＨ／ｇであることが好ましい。より好ましくは、１０ｍｇＫＯＨ／ｇ以上２０ｍｇＫＯＨ／ｇの範囲である。
　この範囲の樹脂の水酸基価とすることにより、樹脂が適度な親水性を有し、樹脂エマルションを含む塗料組成物として用いた場合における作業性、凍結に対する安定性が増すと共に、硬化剤（Ｅ）との硬化反応性も十分である。
　更に、塗膜の機械的性質が高く、耐チッピング性、耐水性及び耐溶剤性に優れた塗膜を形成できる。 The hydroxyl value of the acrylic resin in the acrylic resin emulsion (D2) is preferably 5 mgKOH / g or more and 20 mgKOH / g. More preferably, it is in the range of 10 mgKOH / g or more and 20 mgKOH / g.
By setting the hydroxyl value of the resin in this range, the resin has appropriate hydrophilicity, workability and stability against freezing when used as a coating composition containing a resin emulsion are increased, and the curing agent (E) is used. The curing reactivity with and is also sufficient.
Further, the coating film has high mechanical properties and can form a coating film having excellent chipping resistance, water resistance and solvent resistance.
　一実施態様において、アクリル樹脂エマルション（Ｄ２）のｐＨ値は、例えば、４以上８以下であってよく、４以上７以下であってよい。ｐＨ値がこのような範囲内であることにより、塗膜と被塗物の密着性、本開示に係る塗膜の上方に配置される別の塗膜との密着性をより向上できる。 In one embodiment, the pH value of the acrylic resin emulsion (D2) may be, for example, 4 or more and 8 or less, and 4 or more and 7 or less. When the pH value is within such a range, the adhesion between the coating film and the object to be coated and the adhesion with another coating film arranged above the coating film according to the present disclosure can be further improved.
　一実施態様において、アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂の平均粒子径（Ｄ５０）は、例えば、４０ｎｍ以上３００ｎｍ以下であってよく、５０ｎｍ以上１５０ｎｍ以下であってよい。 In one embodiment, the average particle size (D50) of the acrylic resin in the acrylic resin emulsion (D2) may be, for example, 40 nm or more and 300 nm or less, and 50 nm or more and 150 nm or less.
　本開示におけるアクリル樹脂エマルション（Ｄ２）中のアクリル樹脂は、少なくとも、アクリル樹脂エマルション（Ｄ２）における溶解性パラメータＳＰ（Ｄ２）が上記所定の条件を満たす範囲で、適宜選択できる。 The acrylic resin in the acrylic resin emulsion (D2) in the present disclosure can be appropriately selected as long as the solubility parameter SP (D2) in the acrylic resin emulsion (D2) satisfies the above-mentioned predetermined conditions.
　一実施態様において、アクリル樹脂エマルション（Ｄ２）は、水酸基及びカルボキシル基のうち少なくとも１方を有するアクリル樹脂を含み、例えば、水酸基及びカルボキシル基を有するアクリル樹脂を含む。
　また、一実施態様において、アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂は、架橋性樹脂粒子であり、例えば、架橋性を有し、更に、水酸基及びカルボキシル基のうち少なくとも一方を有するアクリル樹脂粒子であってよい。 In one embodiment, the acrylic resin emulsion (D2) comprises an acrylic resin having at least one of a hydroxyl group and a carboxyl group, and includes, for example, an acrylic resin having a hydroxyl group and a carboxyl group.
Further, in one embodiment, the acrylic resin in the acrylic resin emulsion (D2) is a crosslinkable resin particle, for example, an acrylic resin particle having a crosslinkable property and further having at least one of a hydroxyl group and a carboxyl group. It may be there.
　一実施態様において、水酸基及びカルボキシル基を有するアクリル樹脂は、（メタ）アクリル酸アルキルエステル（ｉ）、カルボキシル基含有エチレン性不飽和モノマー（ｉｉ）、及び水酸基含有エチレン性不飽和モノマー（iii）を含むモノマー混合物を乳化重合して得ることができる。尚、モノマー混合物の成分として以下に例示される化合物は、１種又は２種以上を適宜組み合わせて使用してよい。尚、本明細書中において、「メタ（アクリル）」とは、アクリルまたはメタクリルの両方を表す。 In one embodiment, the acrylic resin having a hydroxyl group and a carboxyl group comprises (meth) acrylic acid alkyl ester (i), a carboxyl group-containing ethylenically unsaturated monomer (ii), and a hydroxyl group-containing ethylenically unsaturated monomer (iii). It can be obtained by emulsifying and polymerizing the monomer mixture containing the mixture. The compounds exemplified below as components of the monomer mixture may be used alone or in combination of two or more. In addition, in this specification, "meta (acrylic)" means both acrylic and methacryl.
（メタ）アクリル酸アルキルエステル（ｉ）はアクリル樹脂エマルションの主骨格を構成するために使用する。 The (meth) acrylic acid alkyl ester (i) is used to form the main skeleton of the acrylic resin emulsion.
　（メタ）アクリル酸アルキルエステル（ｉ）の具体例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸オクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸イソボルニル等が挙げられる。 Specific examples of the (meth) acrylic acid alkyl ester (i) include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, n-butyl (meth) acrylic acid, and (meth) acrylic. Isobutyl acid, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, ( Examples thereof include dodecyl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate.
　カルボキシル基含有エチレン性不飽和モノマー（ｉｉ）は、得られるアクリル樹脂エマルションの保存安定性、機械的安定性、凍結に対する安定性等の諸安定性を向上させ、塗膜形成時における硬化剤（Ｅ）との硬化反応を促進するために使用できる。 The carboxyl group-containing ethylenically unsaturated monomer (ii) improves various stability of the obtained acrylic resin emulsion such as storage stability, mechanical stability, and stability against freezing, and is a curing agent (E) at the time of coating film formation. ) Can be used to accelerate the curing reaction.
　カルボキシル基含有エチレン性不飽和モノマーとしては、例えば、アクリル酸、メタクリル酸、クロトン酸、イソクロトン酸、エタクリル酸、プロピルアクリル酸、イソプロピルアクリル酸、イタコン酸、無水マレイン酸及びフマル酸等が挙げられる。 Examples of the carboxyl group-containing ethylenically unsaturated monomer include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, etacrylic acid, propylacrylic acid, isopropylacrylic acid, itaconic acid, maleic anhydride and fumaric acid.
　水酸基含有エチレン性不飽和モノマー（iii）は、水酸基に基づく親水性をアクリル樹脂エマルションに付与し、これを塗料として用いた場合における作業性や凍結に対する安定性を増すと共に、硬化剤（Ｅ）との硬化反応性を付与するために使用する。 The hydroxyl group-containing ethylenically unsaturated monomer (iii) imparts hydrophilicity based on the hydroxyl group to the acrylic resin emulsion, which enhances workability and stability against freezing when used as a paint, and also serves as a curing agent (E). It is used to impart the curing reactivity of.
　水酸基含有エチレン性不飽和モノマー（iii）としては、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、Ｎ－メチロールアクリルアミド、アリルアルコール、ε－カプロラクトン変性（メタ）アクリルモノマー等が挙げられる。 Examples of the hydroxyl group-containing ethylenically unsaturated monomer (iii) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, N-methylolacrylamide, and allyl alcohol. Examples thereof include ε-caprolactone-modified (meth) acrylic monomer.
　ε－カプロラクトン変性アクリルモノマーの具体例としては、ダイセル化学工業株式会社製の「プラクセルＦＡ－１」、「プラクセルＦＡ－２」、「プラクセルＦＡ－３」、「プラクセルＦＡ－４」、「プラクセルＦＡ－５」、「プラクセルＦＭ－１」、「プラクセルＦＭ－２」、「プラクセルＦＭ－３」、「プラクセルＦＭ－４」及び「プラクセルＦＭ－５」等が挙げられる。 Specific examples of the ε-caprolactone-modified acrylic monomer include "Plaxel FA-1", "Plaxel FA-2", "Plaxel FA-3", "Plaxel FA-4", and "Plaxel FA" manufactured by Daicel Chemical Industries, Ltd. -5 ”,“ Praxel FM-1 ”,“ Praxel FM-2 ”,“ Praxel FM-3 ”,“ Praxel FM-4 ”,“ Praxel FM-5 ”and the like.
　モノマー混合物は、任意成分として、スチレン系モノマー、（メタ）アクリロニトリル及び（メタ）アクリルアミドからなる群から選ばれる少なくとも１種のモノマーを含んでよく、また、スチレン系モノマーとしては、スチレンのほかにα－メチルスチレン等が挙げられる。また、架橋モノマーとして、エチレングリコールジ（メタ）アクリル酸、ジビニルベンゼン等が挙げられる。 The monomer mixture may contain at least one monomer selected from the group consisting of styrene-based monomers, (meth) acrylonitrile and (meth) acrylamide as optional components, and the styrene-based monomers include α in addition to styrene. -Methylstyrene and the like can be mentioned. Examples of the crosslinked monomer include ethylene glycol di (meth) acrylic acid and divinylbenzene.
　乳化重合は、上記モノマー混合物を水性液中で、ラジカル重合開始剤及び乳化剤の存在下で、攪拌下加熱することによって実施することができる。反応温度は例えば３０～１００℃程度として、反応時間は例えば１～１０時間程度が好ましく、水と乳化剤を仕込んだ反応容器にモノマー混合物又はモノマープレ乳化液の一括添加又は暫時滴下によって反応温度の調節を行うとよい。 Emulsion polymerization can be carried out by heating the monomer mixture in an aqueous liquid in the presence of a radical polymerization initiator and an emulsifier with stirring. The reaction temperature is preferably about 30 to 100 ° C., and the reaction time is preferably about 1 to 10 hours. The reaction temperature is adjusted by adding a monomer mixture or a monomer pre-emulsifying solution to a reaction vessel containing water and an emulsifier in a batch or dropping it for a while. It is good to do.
　ラジカル重合開始剤としては、通常アクリル樹脂の乳化重合で使用される公知の開始剤が使用できる。具体的には、水溶性のフリーラジカル重合開始剤として、例えば、過硫酸カリウム、過硫酸ナトリウム、過硫酸アンモニウムなどの過硫酸塩が水溶液の形で使用される。また、過硫酸カリウム、過硫酸ナトリウム、過硫酸アンモニウム、過酸化水素などの酸化剤と、亜硫酸水素ナトリウム、チオ硫酸ナトリウム、ロンガリット、アスコルビン酸等の還元剤とが組み合わされたいわゆるレドックス系開始剤が水溶液の形で使用される。 As the radical polymerization initiator, a known initiator usually used in emulsion polymerization of an acrylic resin can be used. Specifically, as a water-soluble free radical polymerization initiator, for example, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate are used in the form of an aqueous solution. In addition, a so-called redox-based initiator in which an oxidizing agent such as potassium persulfate, sodium persulfate, ammonium persulfate, or hydrogen peroxide is combined with a reducing agent such as sodium hydrogen sulfite, sodium thiosulfite, longalite, or ascorbic acid is an aqueous solution. Used in the form of.
　乳化剤としては、炭素数が６以上の炭素原子を有する炭化水素基と、カルボン酸塩、スルホン酸塩又は硫酸塩部分エステルなどの親水性部分とを同一分子中に有するミセル化合物から選ばれるアニオン系又は非イオン系（ノニオン系）の乳化剤が用いられる。このうちアニオン系の乳化剤としては、アルキルフェノール類又は高級アルコール類の硫酸半エステルのアルカリ金属塩又はアンモニウム塩；アルキル又はアリルスルホナートのアルカリ金属塩又はアンモニウム塩；ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルエーテル又はポリオキシエチレンアリルエーテルの硫酸半エステルのアルカリ金属塩又はアンモニウム塩などが挙げられる。また非イオン系の乳化剤としては、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルエーテル又はポリオキシエチレンアリルエーテルなどが挙げられる。またこれら一般汎用のアニオン系、ノニオン系乳化剤の他に、分子内にラジカル重合性の不飽和二重結合を有する、すなわちアクリル系、メタクリル系、プロペニル系、アリル系、アリルエーテル系、マレイン酸系などの基を有する各種アニオン系、ノニオン系反応性乳化剤なども適宜、単独又は２種以上の組み合わせで使用される。 The emulsifier is an anion system selected from a micelle compound having a hydrocarbon group having 6 or more carbon atoms and a hydrophilic moiety such as a carboxylate, a sulfonate or a sulfate partial ester in the same molecule. Alternatively, a nonionic (nonionic) emulsifier is used. Among these, as anionic emulsifiers, alkali metal salts or ammonium salts of sulfuric acid semiesters of alkylphenols or higher alcohols; alkali metal salts or ammonium salts of alkyl or allyl sulfonate; polyoxyethylene alkylphenyl ethers, polyoxyethylenes. Examples thereof include an alkali metal salt or an ammonium salt of a sulfuric acid semi-ester of an alkyl ether or a polyoxyethylene allyl ether. Examples of the nonionic emulsifier include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether and polyoxyethylene allyl ether. In addition to these general-purpose anion-based and nonionic-based emulsifiers, they also have radically polymerizable unsaturated double bonds in the molecule, that is, acrylic-based, methacrylic-based, propenyl-based, allyl-based, allyl ether-based, and maleic acid-based. Various anion-based and nonionic-based reactive emulsifiers having a group such as, etc. are also used as appropriate alone or in combination of two or more.
　また、乳化重合の際、メルカプタン系化合物や低級アルコールなどの分子量調節のための助剤（連鎖移動剤）の併用は、乳化重合を進める観点から、また塗膜の円滑かつ均一な形成を促進し基材への接着性を向上させる観点から、好ましい場合も多く、適宜状況に応じて行われる。 In addition, during emulsion polymerization, the combined use of an auxiliary agent (chain transfer agent) for adjusting the molecular weight, such as a mercaptan compound or a lower alcohol, promotes smooth and uniform formation of the coating film from the viewpoint of promoting emulsion polymerization. From the viewpoint of improving the adhesiveness to the base material, it is often preferable, and it is carried out as appropriate depending on the situation.
　また、乳化重合としては、通常の一段連続モノマー均一滴下法、多段モノマーフィード法であるコア・シェル重合法、重合中にフィードするモノマー組成を連続的に変化させるパワーフィード重合法など、いずれの重合法もとることができる。 The emulsion polymerization includes a normal one-step continuous monomer uniform dropping method, a core-shell polymerization method which is a multi-step monomer feed method, and a power feed polymerization method in which the monomer composition fed during polymerization is continuously changed. It can be legal.
　また、得られたアクリル樹脂エマルション（Ｄ２）に対し、カルボン酸の一部又は全量を中和してアクリル樹脂エマルション（Ｄ２）の安定性を保つため、塩基性化合物を添加してもよい。これら塩基性化合物としては、アンモニア、各種アミン類、アルカリ金属などを適宜使用することができる。 Further, a basic compound may be added to the obtained acrylic resin emulsion (D2) in order to neutralize a part or all of the carboxylic acid and maintain the stability of the acrylic resin emulsion (D2). As these basic compounds, ammonia, various amines, alkali metals and the like can be appropriately used.
　アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂は、例えば、本開示に係る塗料組成物の全樹脂固形分中１０質量％以上３５質量％以下であってよく、１５質量％以上２５質量％以下であってよい。 The acrylic resin in the acrylic resin emulsion (D2) may be, for example, 10% by mass or more and 35% by mass or less, and 15% by mass or more and 25% by mass or less, based on the total resin solid content of the coating composition according to the present disclosure. You can.
［硬化剤（Ｅ）］
　硬化剤としては特に限定されない。例えば、本開示に係る塗料組成物として安定性を考慮すると、メラミン樹脂、ブロックイソシアネート、カルボジイミド樹脂等が好ましい。
　メラミン樹脂としては、特に限定されない。例えば、メトキシ型メラミン、メトキシ・ブトキシ混合型メラミンを挙げることができる。
　ブトキシ型メラミンは、乳化剤、アクリル樹脂、アルキッド樹脂等を乳化剤とするような方法で水性化して用いることができる。
　メトキシ型メラミン樹脂は乳化剤などを用いることなく水性安定化できるのでより好ましい。例えば、Ａｌｌｎｅｘ社製のサイメルシリーズのサイメル３００、３０１、３０３、３５０、３７０、７７１、３２５、３２７、７０３、７１２、７１５、７０１、２６７、２８５、２３２、２３５、２３６、２３８、２１１、２５４、２０４、２１２、２０２、２０７等を挙げることができる。 [Curing agent (E)]
The curing agent is not particularly limited. For example, considering the stability of the coating composition according to the present disclosure, melamine resin, blocked isocyanate, carbodiimide resin and the like are preferable.
The melamine resin is not particularly limited. For example, methoxy-type melamine and methoxy-butoxy mixed-type melamine can be mentioned.
Butoxy-type melamine can be hydrated and used by a method using an emulsifier, an acrylic resin, an alkyd resin or the like as an emulsifier.
The methoxy-type melamine resin is more preferable because it can be stabilized in water without using an emulsifier or the like. For example, Allnex's Cymel series Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712, 715, 701, 267, 285, 232, 235, 236, 238, 211, 254. , 204, 212, 202, 207 and the like.
　以下、本発明で硬化剤（Ｅ）として使用できるブロックイソシアネート化合物について説明する。ブロックイソシアネート化合物出発成分は、ジ－又はポリ－イソシアネート化合物及びこれらの混合物である。但し、これらの成分は、ブロック化剤と反応してブロックイソシアネート化合物が得られる。 Hereinafter, the blocked isocyanate compound that can be used as the curing agent (E) in the present invention will be described. The starting component of the blocked isocyanate compound is a di- or poly-isocyanate compound and a mixture thereof. However, these components react with a blocking agent to obtain a blocked isocyanate compound.
　好ましいジ－又はポリ－イソシアネート化合物としては、脂肪族、脂環式、芳香脂肪族及び複素環式のポリイソシアネートである。カルボジイミド基を含むポリイソシアネート、アロファネート基を含むポリイソシアネート、イソシアヌレート基を含むポリイソシアネート、ウレタン及び／又は尿素基を含むポリイソシアネート、アシル化尿素基を含むポリイソシアネート、ビューレット基を含むポリイソシアネート、ヘテロ重合反応によって生成したポリイソシアネート、エステル基を含むポリイソシアネート、好ましくはウレトジオン基を含むジイソシアネート及び尿素基を含むジイソシアネートも適当なものである。 Preferred di- or poly-isocyanate compounds are aliphatic, alicyclic, aromatic aliphatic and heterocyclic polyisocyanates. Polyisocyanate containing carbodiimide group, polyisocyanate containing allophanate group, polyisocyanate containing isocyanurate group, polyisocyanate containing urethane and / or urea group, polyisocyanate containing acylated urea group, polyisocyanate containing burette group, Polyisocyanates produced by the heteropolymerization reaction, polyisocyanates containing an ester group, preferably diisocyanates containing a uretdione group and diisocyanates containing a urea group are also suitable.
　ジ－又はポリ－イソシアネート化合物の具体例としては下記のものが挙げられる。ｐ－キシリレンジイソシアネート、１，５－ジイソシアナトメチルナフタレン、１，３－フェニレンジイソシアネート、１，４－フェニレンジイソシアネート、１－メチルベンゼン２，５－ジイソシアネート、１，３ジメチルベンゼン４，６－ジイソシアネート、１，４ジメチルベンゼン２，５－ジイソシアネート、１－ニトロベンゼン２，５－ジイソシアネート、１－メトキシベンゼン２，４－ジイソシアネート、１－メトキシベンゼン２，５－ジイソシアネート、１，３－ジメトキシベンゼン４，６－ジイソシアネート、アゾベンゼン４，４’－ジイソシアネート、ジフェニルエーテル４，４’－ジイソシアネート、ジフェニルメタン４，４’－ジイソシアネート、ジフェニルジメチルメタン４，４’－ジイソシアネート、ナフタレン１，５－ジイソシアネート、３，３’－ジメチルビフェニル４，４’－ジイソシアネート、ジフェニルジスルフィド４，４’－ジイソシアネート、ジフェニルスルホン４，４’－ジイソシアネート、１－メチルベンゼン２，４，６－トリイソシアネート、１，３，５－トリメチルベンゼン２，４，６－トリイソシアネート、トリフェニルメタン４，４’，４”－トリイソシアネート、４，４’－ジイソシアナト－（１，２）－ジフェニルエタン、二量体１－メチル－２，４－フェニレンジイソシアネート、二量体
１－イソプロピル－２，４－フェニレンジイソシアネート、二量体２，４’ジイソシアナトジフェニルスルフィド、３，３’－ジイソシアナト－４，４’－ジメチル－Ｎ，Ｎ’－ジフェニル尿素、３，３’－ジイソシアナト－２，２’－ジメチル－Ｎ，Ｎ’－ジフェニル尿素、３，３’－ジイソシアナト－２，４’－ジメチル－Ｎ，Ｎ’－ジフェニル尿素、Ｎ，Ｎ’－ビス［４（４－イソシアナトフェニルメチル）フェニル］尿素、Ｎ，Ｎ’－ビス［４（２－イソシアナトフェニルメチル）フェニル］尿素。 Specific examples of the di- or poly-isocyanate compound include the following. p-xylylene diisocyanate, 1,5-diisocyanatomethylnaphthalene, 1,3-phenylenediocyanate, 1,4-phenylenediocyanate, 1-methylbenzene 2,5-diisocyanate, 1,3 dimethylbenzene 4,6-diisocyanate , 1,4 dimethylbenzene 2,5-diisocyanate, 1-nitrobenzene 2,5-diisocyanate, 1-methoxybenzene 2,4-diisocyanate, 1-methoxybenzene 2,5-diisocyanate, 1,3-dimethoxybenzene 4,6 -Diisocyanate, azobenzene 4,4'-diisocyanate, diphenyl ether 4,4'-diisocyanate, diphenylmethane 4,4'-diisocyanate, diphenyldimethylmethane 4,4'-diisocyanate, naphthalene 1,5-diisocyanate, 3,3'-dimethyl Biphenyl 4,4'-diisocyanate, diphenyl disulfide 4,4'-diisocyanate, diphenyl sulfone 4,4'-diisocyanate, 1-methylbenzene 2,4,6-triisocyanate, 1,3,5-trimethylbenzene 2,4 , 6-Triisocyanate, triphenylmethane 4,4', 4 "-triisocyanate, 4,4'-diisocyanato- (1,2) -diphenylethane, dimer 1-methyl-2,4-phenylenediisocyanate, Dimeric 1-isopropyl-2,4-phenylenediisocyanate, dimer 2,4'diisocyanatodiphenylsulfide, 3,3'-diisocyanato-4,4'-dimethyl-N, N'-diphenylurea, 3 , 3'-Diisocyanato-2,2'-dimethyl-N, N'-diphenylurea, 3,3'-diisocyanate-2,4'-dimethyl-N, N'-diphenylurea, N, N'-bis [ 4 (4-isocyanatophenylmethyl) phenyl] urea, N, N'-bis [4 (2-isocyanatophenylmethyl) phenyl] urea.
　ブロックイソシアネート化合物を得るために使用されるブロック化剤としてはオキシム化合物（アセトオキシム、メチルエチルケトオキシム、メチルイソブチルケトオキシムなど）、ラクタム類（ε－カプロラクタムなど）、活性メチレン化合物（マロン酸ジエチル、アセチルアセトン、アセト酢酸エチルなど）、フェノール類（フェノール、ｍ－クレゾールなど）、アルコール類（メタノール、エタノール、ｎ－ブタノールなど）、水酸基含有エーテル（メチルセルソルブ、ブチルセルソルブなど）、水酸基含有エステル（乳酸メチル、乳酸アミルなど）、メルカプタン類（ブチルメルカプタン、ヘキシルメルカプタンなど）、酸アミド類（アセトアニリド、アクリルアマイド、ダイマー酸アミドなど）、イミダゾール類（イミダゾール、２－エチルイミダゾールなど）、酸イミド類（コハク酸イミド、フタル酸イミドなど）、アミン類（ジシクロヘキシルアミンなど）及びこれらの２種類以上の混合物が挙げられる。 Oxime compounds (acetooxime, methylethylketooxime, methylisobutylketooxime, etc.), lactams (ε-caprolactam, etc.), active methylene compounds (diethyl malonate, acetylacetone, etc.) are used as blocking agents to obtain blocked isocyanate compounds. Ethyl acetoacetate, etc.), phenols (phenol, m-cresol, etc.), alcohols (methanol, ethanol, n-butanol, etc.), hydroxyl group-containing ether (methyl cellsolve, butyl cell solution, etc.), hydroxyl group-containing ester (methyl lactate) , Amil lactate, etc.), mercaptans (butyl mercaptan, hexyl mercaptan, etc.), acid amides (acetanilide, acrylic amide, dimer acid amide, etc.), imidazoles (imidazole, 2-ethylimidazole, etc.), acidimides (succinic acid, etc.) Examples thereof include imides (imides of phthalates, etc.), amines (dicyclohexylamines, etc.) and mixtures of two or more of these.
　硬化剤（Ｅ）は、本開示に係る塗料組成物の全樹脂固形分中５質量％以上１５質量％以下の範囲で用いることが好ましい。硬化剤の量がこのような範囲内であることにより、塗膜の架橋度を高くでき、より耐水性及び密着性に優れた塗膜を形成できる。 The curing agent (E) is preferably used in the range of 5% by mass or more and 15% by mass or less in the total resin solid content of the coating composition according to the present disclosure. When the amount of the curing agent is within such a range, the degree of cross-linking of the coating film can be increased, and a coating film having more excellent water resistance and adhesion can be formed.
　［その他成分］
　一実施態様において、本開示に係る塗料組成物は、有機粒子及び無機粒子からなる群から選択される粒子を含む。このような粒子を含むことにより、バインダー樹脂と当該粒子の屈折率差により隠蔽性が更に向上することが期待できる。 [Other ingredients]
In one embodiment, the coating composition according to the present disclosure comprises particles selected from the group consisting of organic particles and inorganic particles. By including such particles, it can be expected that the hiding property is further improved due to the difference in refractive index between the binder resin and the particles.
　有機粒子及び無機粒子は、上記成分（Ａ）～（Ｄ）と異なる粒子である。例えば、有機粒子として、スチレン樹脂、アクリル－スチレン共重合樹脂、アクリル－アクリロニトリル共重合樹脂、アクリル－スチレン－アクリロニトリル共重合樹脂、アクリロニトリル－メタアクリロニトリル共重合樹脂、アクリル－アクリロニトリル－メタアクリロニトリル共重合樹脂、塩化ビニリデン－アクリロニトリル共重合樹脂等が挙げられる。
　また、無機粒子として、珪酸ソーダガラス、アルミノ珪酸ガラス、硼珪酸ソーダガラス等のガラス；フライアッシュ、アルミナ、ジルコニア・チタニア、ホウ化ケイ素、シラス、黒曜石等が挙げられる。
　また、炭酸カルシウム、硫酸バリウム、クレー、タルク等の体質顔料を併用しても良い。 The organic particles and the inorganic particles are particles different from the above components (A) to (D). For example, as organic particles, styrene resin, acrylic-styrene copolymer resin, acrylic-acrylonitrile copolymer resin, acrylic-styrene-acrylonitrile copolymer resin, acrylonitrile-methacrylonitrile copolymer resin, acrylic-acrylonitrile-methacrylonitrile copolymer resin, Examples thereof include vinylidene chloride-acrylonitrile copolymer resin.
Examples of the inorganic particles include glass such as soda glass silicate, aluminosilicate glass, and sodium borosilicate glass; fly ash, alumina, zirconia / titania, silicon booxide, silas, and black stone.
In addition, extender pigments such as calcium carbonate, barium sulfate, clay, and talc may be used in combination.
　一実施態様において、本開示に係る塗料組成物は、更に、着色顔料を含む。この態様において、（Ａ）～（Ｅ）の固形分の合計に対し（すなわち、本開示に係る塗料組成物の全樹脂固形分中）、着色顔料を３質量％以上１５０質量％以下で含み得る。
　このような範囲内で着色顔料を含むことにより、硬化時の粘性が増大することを抑制でき、更に、フロー性が低下することも抑制できる。その結果、良好な塗膜外観を得ることができる。 In one embodiment, the coating composition according to the present disclosure further comprises a colored pigment. In this embodiment, the coloring pigment may be contained in an amount of 3% by mass or more and 150% by mass or less with respect to the total solid content of (A) to (E) (that is, in the total resin solid content of the coating composition according to the present disclosure). ..
By including the coloring pigment within such a range, it is possible to suppress an increase in viscosity at the time of curing, and further, it is possible to suppress a decrease in flowability. As a result, a good coating film appearance can be obtained.
　ここで、本開示に係る塗料組成物は、高い隠ぺい性を有する塗膜を形成できるので、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗膜は単層でありながらも備えることができる。
　すなわち、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。さらに、所望の白色系マイカの色調を発現できる。
　このため、本開示に係る塗料組成物においては、例えば、カラーベース塗膜としての機能を奏するために、着色顔料を添加してもよい。 Here, since the coating composition according to the present disclosure can form a coating film having a high hiding property, a commonly used white primer coating film containing titanium oxide and a color-based coating film arranged on the white primer coating film are generally used. The coating film according to the present disclosure can be provided with the function of the above even though it is a single layer.
That is, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film. Furthermore, the desired white mica color tone can be expressed.
Therefore, in the coating composition according to the present disclosure, for example, a coloring pigment may be added in order to function as a color-based coating film.
　着色顔料としては、通常の塗料に使用される顔料であれば特に限定されない。例えば、高外観の塗膜を得る点、及び、耐候性を向上させる観点から、アゾキレート系顔料、不溶性アゾ系顔料、縮合アゾ系顔料、フタロシアニン系顔料、インジゴ顔料、ペリノン系顔料、ペリレン系顔料、ジオキサン系顔料、キナクリドン系顔料、イソインドリノン系顔料、ジケトピロロピロール系顔料、ベンズイミダゾロン系顔料、金属錯体顔料等の有機系着色顔料；酸化チタン、黄鉛、黄色酸化鉄、ベンガラ、カーボンブラック等の無機系着色顔料等が挙げられる。 The coloring pigment is not particularly limited as long as it is a pigment used in ordinary paints. For example, from the viewpoint of obtaining a high-appearance coating film and improving weather resistance, azochelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, etc. Organic coloring pigments such as dioxane pigments, quinacridone pigments, isoindolinone pigments, diketopyrrolopyrrole pigments, benzimidazolone pigments, metal complex pigments; titanium oxide, yellow lead, yellow iron oxide, red iron oxide, carbon Examples thereof include inorganic coloring pigments such as black.
　添加剤としては、上記成分の他に通常添加される添加剤、例えば、紫外線吸収剤；酸化防止剤；消泡剤；表面調整剤；ピンホール防止剤等が挙げられる。これらの配合量は当業者の公知の範囲である。 Examples of the additive include an additive usually added in addition to the above components, for example, an ultraviolet absorber; an antioxidant; an antifoaming agent; a surface conditioner; a pinhole inhibitor and the like. These blending amounts are within the range known to those skilled in the art.
　［水性プライマー塗料組成物］
　一実施態様において、本開示に係る塗料組成物は、水性プライマー塗料組成物である。本開示に係る水性プライマー塗料組成物は、高い隠ぺい性を有する塗膜を形成できるので、一般的に使用されている、酸化チタンを含む白色プライマー塗膜と比べ、薄膜化が可能である。
　また、本開示に係る水性プライマー塗料組成物から形成された塗膜は、プライマー塗膜として要求される様々な機能、例えば、被塗物の隠ぺい性、耐チッピング性を備える。更に、本開示に係るプライマー塗膜は、プライマー塗膜上に配置され得るカラーベース塗膜が有する機能を備えることができる。
　したがって、従来の複層塗膜と比べて、層構造を薄くでき、更に、塗膜形成工程を削減できる。 [Aqueous primer coating composition]
In one embodiment, the coating composition according to the present disclosure is an aqueous primer coating composition. Since the aqueous primer coating composition according to the present disclosure can form a coating film having a high hiding property, it can be made thinner than a commonly used white primer coating film containing titanium oxide.
Further, the coating film formed from the aqueous primer coating composition according to the present disclosure has various functions required as a primer coating film, for example, hiding property and chipping resistance of an object to be coated. Further, the primer coating film according to the present disclosure can have a function of a color-based coating film that can be arranged on the primer coating film.
Therefore, the layer structure can be made thinner and the coating film forming step can be reduced as compared with the conventional multi-layer coating film.
　一実施態様において、本開示に係る水性プライマー塗料組成物から形成された塗膜の厚さは、例えば、１５μｍ以上４０μｍ以下であってよく、２０μｍ以上３５μｍ以下であってよい。本開示に係るプライマー塗膜は、このような薄膜でありながらも、被塗物が有し得る黒色などの色調を良好に隠ぺいでき、その上、優れた耐水性を有することができる。その上、例えば、上記プライマー塗膜の上に形成される塗膜の色調が白色系マイカの色調であっても、良好に発現できる。 In one embodiment, the thickness of the coating film formed from the aqueous primer coating composition according to the present disclosure may be, for example, 15 μm or more and 40 μm or less, and 20 μm or more and 35 μm or less. Although the primer coating film according to the present disclosure is such a thin film, it can satisfactorily conceal a color tone such as black color that an object to be coated may have, and in addition, it can have excellent water resistance. Moreover, for example, even if the color tone of the coating film formed on the primer coating film is the color tone of white mica, it can be satisfactorily expressed.
　［塗膜の形成及び複層塗膜の形成］
　別の実施態様において、本開示は、被塗物に、本開示に係る塗料組成物を塗装し、未硬化の塗膜を形成する工程、及び、
前記未硬化の塗膜を加熱硬化させ、塗膜を形成する工程を含む、
塗膜の形成方法を提供する。 [Formation of coating film and formation of multi-layer coating film]
In another embodiment, the present disclosure comprises a step of coating an object to be coated with the coating composition according to the present disclosure to form an uncured coating film, and
The step of heating and curing the uncured coating film to form a coating film is included.
A method for forming a coating film is provided.
　本開示に係る塗料組成物を塗装する手段は特に限定されず、例えば、ベル塗装、エアースプレー、エアレススプレー等の一般に用いられている塗装方法等を挙げることができる。これらは被塗物に応じて適宜選択することができる。例えば、塗料組成物の塗装を静電塗装機により行ってもよい。また、塗膜の吐出量などの条件は、必要とされる塗膜の膜厚などに応じて適宜設定できる。 The means for coating the coating composition according to the present disclosure is not particularly limited, and examples thereof include commonly used coating methods such as bell coating, air spray, and airless spray. These can be appropriately selected depending on the object to be coated. For example, the coating composition may be applied by an electrostatic coating machine. In addition, conditions such as the discharge amount of the coating film can be appropriately set according to the required film thickness of the coating film and the like.
　本開示に係る塗料組成物から形成される塗膜の膜厚は、例えば、１０μｍ以上４０μｍ以下であってよく、１２μｍ以上３８μｍ以下であってよく、１５μｍ以上３５μｍであってよく、２５μｍ以上３０μｍであってよい。膜厚は乾燥膜厚で測定でき、乾燥膜厚は、ＳＡＮＫＯ社製ＳＤＭ－ｍｉｎｉＲを用いて測定することができる。 The film thickness of the coating film formed from the coating composition according to the present disclosure may be, for example, 10 μm or more and 40 μm or less, 12 μm or more and 38 μm or less, 15 μm or more and 35 μm, or 25 μm or more and 30 μm. It may be there. The film thickness can be measured by the dry film thickness, and the dry film thickness can be measured by using SDM-miniR manufactured by SANKO.
　本開示に係る塗料組成物を塗装後に、例えば、４０℃以上８０℃以下の温度で１～１０分間水分を揮散させる工程を入れることが好ましい（このような工程をプレヒート工程ともいう）。 After painting the coating composition according to the present disclosure, it is preferable to include, for example, a step of volatilizing water at a temperature of 40 ° C. or higher and 80 ° C. or lower for 1 to 10 minutes (such a step is also referred to as a preheating step).
　上記塗料組成物の塗装後、例えば、８０℃以上１５０℃以下、例えば、１００℃以上１３０℃以下の温度で焼付け硬化を行うことができる。
　焼付け硬化の時間は、例えば、２０分～４０分程度の範囲内で適宜調整してよい。 After coating the coating composition, baking and curing can be performed at a temperature of, for example, 80 ° C. or higher and 150 ° C. or lower, for example, 100 ° C. or higher and 130 ° C. or lower.
The baking curing time may be appropriately adjusted within the range of, for example, about 20 minutes to 40 minutes.
　一実施態様において、本開示は、被塗物に、本開示に係る水性プライマー塗料組成物を塗装し、未硬化のプライマー塗膜を形成する工程と、
　上記未硬化の水性プライマー塗料組成物の上に、光輝顔料を含むベース塗料組成物を塗装し、未硬化のベース塗膜を形成する工程と、
　上記未硬化のベース塗膜の上に、クリヤー塗料組成物を塗装し、未硬化のクリヤー塗膜を形成する工程と、
　上記未硬化のプライマー塗膜、ベース塗膜及びクリヤー塗膜を加熱硬化させ、複層塗膜を形成する工程と、
を含む、複層塗膜の形成方法を提供する。
　以下、複層塗膜の形成方法についてより詳細に説明する。 In one embodiment, the present disclosure comprises a step of coating an object to be coated with the aqueous primer coating composition according to the present disclosure to form an uncured primer coating film.
A step of coating a base coating composition containing a bright pigment on the uncured aqueous primer coating composition to form an uncured base coating film, and
A step of coating a clear coating composition on the uncured base coating film to form an uncured clear coating film, and
The steps of heating and curing the uncured primer coating film, base coating film and clear coating film to form a multi-layer coating film, and
Provided is a method for forming a multi-layer coating film including.
Hereinafter, the method for forming the multi-layer coating film will be described in more detail.
　本開示に係る水性プライマー塗料組成物を被塗物に塗装した後、必要に応じて、例えば、４０℃以上８０℃以下の温度で１～１０分間のプレヒート工程を行い、未硬化のプライマー塗膜を形成することができる。未硬化のプライマー塗膜の膜厚は、乾燥膜厚として、例えば、１０μｍ以上４０μｍ以下であってよく、１２μｍ以上３８μｍ以下であってよく、１５μｍ以上３５μｍであってよく、２５μｍ以上３０μｍであってよい。 After applying the aqueous primer coating composition according to the present disclosure to an object to be coated, a preheating step of, for example, at a temperature of 40 ° C. or higher and 80 ° C. or lower for 1 to 10 minutes is performed as necessary, and an uncured primer coating film is applied. Can be formed. The film thickness of the uncured primer coating film may be, for example, 10 μm or more and 40 μm or less, 12 μm or more and 38 μm or less, 15 μm or more and 35 μm, or 25 μm or more and 30 μm as a dry film thickness. Good.
　次いで、得られた未硬化のプライマー塗膜上に、光輝顔料を含む水性ベース塗料組成物、例えば、マイカを含む水性ベース塗料組成物を塗装し、必要に応じて、例えば、４０℃以上８０℃以下の温度で１～１０分間のプレヒート工程を行い、未硬化のベース塗膜（例えばマイカベース塗膜）を形成することができる。
　更に、未硬化のベース塗膜上に、クリヤー塗料組成物を塗装し、未硬化のクリヤー塗膜を形成する。未硬化のクリヤー塗膜を形成した後、例えば、８０℃以上１５０℃以下、例えば、１００℃以上１３０℃以下の温度で、本開示に係る未硬化の塗膜、未硬化のマイカベース塗膜、未硬化のクリヤー塗膜の焼付け硬化を行うことができる。
　焼付け硬化の時間は、例えば、２０分～４０分程度の範囲内で適宜調整してよい。 Next, an aqueous base coating composition containing a bright pigment, for example, an aqueous base coating composition containing mica is coated on the obtained uncured primer coating film, and if necessary, for example, 40 ° C. or higher and 80 ° C. An uncured base coating (for example, mica base coating) can be formed by performing a preheating step at the following temperature for 1 to 10 minutes.
Further, the clear coating composition is applied onto the uncured base coating film to form an uncured clear coating film. After forming the uncured clear coating film, for example, at a temperature of 80 ° C. or higher and 150 ° C. or lower, for example, 100 ° C. or higher and 130 ° C. or lower, the uncured coating film and the uncured mica-based coating film according to the present disclosure. The uncured clear coating film can be baked and cured.
The baking curing time may be appropriately adjusted within the range of, for example, about 20 minutes to 40 minutes.
　このような加熱硬化（焼付け）時間であっても、塗膜の硬化を充分に行え、優れた耐水性及び耐ガソホール性を有する複層塗膜を形成できる。更に、従来と比べて、加熱硬化時間を短縮しながらも、タック性及び研ぎ性に優れた複層塗膜（硬化塗膜）を形成できる。
　なお、この加熱硬化（焼付け）時間は、基材表面が実際に目的の焼き付け温度を保持しつづけている時間を意味し、より具体的には、目的の焼き付け温度に達するまでの時間は考慮せず、目的の温度に達してから該温度を保持しつづけているときの時間を意味する。 Even with such a heat curing (baking) time, the coating film can be sufficiently cured, and a multi-layer coating film having excellent water resistance and gasohol resistance can be formed. Further, it is possible to form a multi-layer coating film (cured coating film) having excellent tackiness and sharpness while shortening the heat curing time as compared with the conventional case.
The heat curing (baking) time means the time during which the surface of the base material actually keeps the target baking temperature, and more specifically, the time until the target baking temperature is reached should be taken into consideration. However, it means the time when the target temperature is reached and the temperature is maintained.
　塗料組成物の未硬化膜を同時に焼き付けるのに用いる加熱装置として、例えば、熱風、電気、ガス、赤外線などの加熱源を利用した乾燥炉などが挙げられる。また、これら加熱源を２種以上併用した乾燥炉を用いると、乾燥時間が短縮されるため好ましい。 Examples of the heating device used to simultaneously bake the uncured film of the coating composition include a drying furnace using a heating source such as hot air, electricity, gas, or infrared rays. Further, it is preferable to use a drying oven in which two or more of these heating sources are used in combination because the drying time is shortened.
　このような工程を経て、被塗物上に、本開示に係る塗料組成物から形成された塗膜（カラーベース兼用白色プライマー塗膜）と、マイカ（光輝顔料）ベースと、クリヤー塗膜とを有する部品、例えば自動車用部品を形成できる。
　したがって、一般的な白色プライマーとカラーベースの２層を、本開示に係る塗料組成物を用いることで、これらの２層が有する機能を単層で示すこと可能となる。
　この結果、例えば、自動車用部品全体の軽量化、塗装工程の短縮、更には、エネルギー低減（ＣＯ２）の低減を奏することができる。 Through such a step, a coating film (a white primer coating film also used as a color base) formed from the coating composition according to the present disclosure, a mica (bright pigment) base, and a clear coating film are provided on the object to be coated. Parts, such as automotive parts, can be formed.
Therefore, by using the coating composition according to the present disclosure for two layers of a general white primer and a color base, it is possible to show the functions of these two layers as a single layer.
As a result, for example, the weight of the entire automobile part can be reduced, the painting process can be shortened, and the energy reduction (CO 2 ) can be reduced.
　上記水性ベース塗料組成物、クリヤー塗料組成物は、既知のものを使用できる。
　好適に用いることができる水性ベース塗料組成物として、例えば、塗膜形成樹脂および光輝顔料を含む水性ベース塗料組成物が挙げられる。上記塗膜形成性樹脂としては特に限定されず、例えば、アクリル樹脂、ポリエステル樹脂、アルキド樹脂、エポキシ樹脂、ウレタン樹脂等が挙げられる。顔料分散性や作業性の点から、アクリル樹脂及び／又はポリエステル樹脂と、硬化剤としてアミノ樹脂及び／又はブロックイソシアネート樹脂を組み合わせたものが好ましい。上記塗膜形成性樹脂及び硬化剤はそれぞれ、１種のみ使用することもできるが、塗膜性能のバランス化を計るために、２種又はそれ以上の種類を使用することもできる。 As the water-based base coating composition and the clear coating composition, known ones can be used.
Examples of the aqueous base coating composition that can be preferably used include an aqueous base coating composition containing a coating film-forming resin and a bright pigment. The coating film-forming resin is not particularly limited, and examples thereof include acrylic resin, polyester resin, alkyd resin, epoxy resin, and urethane resin. From the viewpoint of pigment dispersibility and workability, a combination of an acrylic resin and / or a polyester resin and an amino resin and / or a blocked isocyanate resin as a curing agent is preferable. Only one type of the coating film-forming resin and the curing agent can be used, but two or more types can be used in order to balance the coating film performance.
　上記光輝顔料としては特に限定されず、例えば、金属又は合金等の無着色若しくは着色された金属性光輝顔料及びその混合物、干渉マイカ、着色マイカ、ホワイトマイカ、グラファイト又は無色有色偏平顔料等を挙げることができる。これらの光輝顔料は１種を単独で用いてもよく、２種またはそれ以上を併用してもよい。例えば上記水性ベース塗料組成物を塗装して形成される塗膜が、光輝感を伴う白色系の色調を有する塗膜である場合は、干渉マイカ、着色マイカ、ホワイトマイカなどのマイカを好適に用いることができる。 The bright pigment is not particularly limited, and examples thereof include uncolored or colored metallic bright pigments such as metals or alloys and mixtures thereof, interfering mica, colored mica, white mica, graphite, colorless colored flat pigments, and the like. Can be done. One of these bright pigments may be used alone, or two or more thereof may be used in combination. For example, when the coating film formed by coating the above-mentioned water-based base coating composition is a coating film having a white color tone with a brilliant feeling, mica such as interference mica, colored mica, and white mica is preferably used. be able to.
　水性ベース塗料組成物中に含まれる光輝顔料の量は、塗料組成物中に含まれる樹脂固形分１００質量部に対して、例えば１～２０質量％の範囲内であるのが好ましい。 The amount of the bright pigment contained in the water-based base coating composition is preferably in the range of, for example, 1 to 20% by mass with respect to 100 parts by mass of the resin solid content contained in the coating composition.
　水性ベース塗料組成物を塗装する場合には、エアー静電スプレー又はベル静電塗装による多ステージ塗装、好ましくは２ステージで塗装するか、あるいは、エアー静電スプレーとベル静電塗装機とを組み合わせた塗装方法により行うことが好ましい。未硬化のベース塗膜の膜厚は、用途に応じて適宜選択することができ、例えば乾燥膜厚として５～３５μｍであることが好ましい。例えば、マイカを含むベース塗料組成物を用いる場合、未硬化のベース塗膜の膜厚は、例えば、８μｍ以上１５μｍ以下であってよく、１０μｍ以上１２μｍ以下であってよい。 When painting the water-based base coating composition, multi-stage coating by air electrostatic spray or bell electrostatic coating, preferably two-stage coating, or a combination of air electrostatic spray and bell electrostatic coating machine. It is preferable to use a different coating method. The film thickness of the uncured base coating film can be appropriately selected depending on the application, and for example, the dry film thickness is preferably 5 to 35 μm. For example, when a base coating composition containing mica is used, the film thickness of the uncured base coating film may be, for example, 8 μm or more and 15 μm or less, and 10 μm or more and 12 μm or less.
　上記クリヤー塗料組成物としては特に限定されず、例えば、媒体中に分散または溶解された状態で、塗膜形成樹脂、そして必要に応じた硬化剤およびその他の添加剤を含むものを挙げることができる。塗膜形成樹脂としては、例えば、アクリル樹脂、ポリエステル樹脂、エポキシ樹脂、ウレタン樹脂などが挙げられる。これらはアミノ樹脂および／またはイソシアネート樹脂などの硬化剤と組み合わせて用いることができる。また、透明性または耐酸エッチング性などの点から、アクリル樹脂および／もしくはポリエステル樹脂とアミノ樹脂との組み合わせ、または、カルボン酸・エポキシ硬化系を有するアクリル樹脂および／もしくはポリエステル樹脂などを用いることもできる。 The clear coating composition is not particularly limited, and examples thereof include those containing a coating film-forming resin and, if necessary, a curing agent and other additives in a state of being dispersed or dissolved in a medium. .. Examples of the coating film-forming resin include acrylic resin, polyester resin, epoxy resin, and urethane resin. These can be used in combination with curing agents such as amino resins and / or isocyanate resins. Further, from the viewpoint of transparency or acid etching resistance, a combination of an acrylic resin and / or a polyester resin and an amino resin, or an acrylic resin and / or a polyester resin having a carboxylic acid / epoxy curing system can also be used. ..
　クリヤー塗料組成物の塗装は、クリヤー塗料組成物の塗装形態に従った、当業者に公知の塗装方法を用いて行うことができる。未硬化のクリヤー塗膜の膜厚は、乾燥膜厚として、一般に１５～５０μｍが好ましく、２０～３５μｍであることがより好ましく、例えば、２５μｍ以上３０μｍ以下であってよい。 The clear coating composition can be coated by using a coating method known to those skilled in the art according to the coating form of the clear coating composition. The film thickness of the uncured clear coating film is generally preferably 15 to 50 μm, more preferably 20 to 35 μm, and may be, for example, 25 μm or more and 30 μm or less.
　本開示に係る塗料組成物から形成された塗膜であれば、これら水性ベース塗料組成物に対しても良好な密着性を奏することができる。 A coating film formed from the coating composition according to the present disclosure can exhibit good adhesion to these water-based base coating compositions.
　本開示に係る塗料組成物は、高い隠ぺい性を有する塗膜を形成できるので、一般的に使用されている、酸化チタンを含む白色プライマー塗膜とその上に配置されるカラーベース塗膜とが有する機能を、本開示に係る塗膜は単層でありながらも備えることができる。
　すなわち、カラーベース塗膜の形成工程を削減できる。その上、従来の複層塗膜と比べて、複層塗膜の層構造を薄くでき、更に、上記プライマー塗膜の上に形成される塗膜の色調が白色系マイカの色調であっても、所望の白色系マイカの色調を発現できる。 Since the coating film composition according to the present disclosure can form a coating film having a high hiding property, it is contained in a generally used white primer coating film containing titanium oxide and a color base coating film arranged on the white primer coating film. The coating film according to the present disclosure can be provided with a function even though it is a single layer.
That is, the process of forming the color-based coating film can be reduced. Moreover, the layer structure of the multi-layer coating film can be made thinner than that of the conventional multi-layer coating film, and even if the color tone of the coating film formed on the primer coating film is the color tone of white mica. , The desired white mica color tone can be expressed.
　［被塗物］
　被塗物は、用途、機能などに応じて適宜選択できる。
　一実施態様において、被塗物として、通電可能な種々の被塗物を用いることができる。使用できる被塗物として例えば、冷延鋼板、熱延鋼板、ステンレス、電気亜鉛めっき鋼板、溶融亜鉛めっき鋼板、亜鉛－アルミニウム合金系めっき鋼板、亜鉛－鉄合金系めっき鋼板、亜鉛－マグネシウム合金系めっき鋼板、亜鉛－アルミニウム－マグネシウム合金系めっき鋼板、アルミニウム系めっき鋼板、アルミニウム－シリコン合金系めっき鋼板、錫系めっき鋼板などが挙げられる。
　これら被塗物は、既知の化成処理などを施した被塗物であってよい。また、これら被塗物は、電着塗板に中塗り塗料を塗装し、焼き付け又はプレヒートして得られた被塗物であってもよい。 [Object to be coated]
The object to be coated can be appropriately selected according to the intended use, function, and the like.
In one embodiment, as the object to be coated, various objects to be coated that can be energized can be used. Examples of objects to be coated include cold-rolled steel sheets, hot-rolled steel sheets, stainless steel, electrogalvanized steel sheets, hot-dip galvanized steel sheets, zinc-aluminum alloy-based plated steel sheets, zinc-iron alloy-based plated steel sheets, and zinc-magnesium alloy-based plating. Examples thereof include steel sheets, zinc-aluminum-magnesium alloy-based plated steel sheets, aluminum-based plated steel sheets, aluminum-silicon alloy-based plated steel sheets, and tin-based plated steel sheets.
These objects to be coated may be objects to be coated which have been subjected to a known chemical conversion treatment or the like. Further, these objects to be coated may be objects to be coated obtained by coating an electrodeposition coating plate with an intermediate coating paint and baking or preheating.
　一実施態様において、被塗物としてプラスチック基材を用いることができる。例えば、自動車用部品に使用する、プラスチック基材であってよい。自動車用部品としては特に限定されず、バンパー、スポイラー、グリル、フェンダー等を挙げることができる。 In one embodiment, a plastic base material can be used as the object to be coated. For example, it may be a plastic base material used for automobile parts. The automobile parts are not particularly limited, and examples thereof include bumpers, spoilers, grilles, and fenders.
　プラスチック基材は、ポリプロピレンやポリオレフィンまたはエラストマー変性ポリプロピレン樹脂を含む。エラストマー変性ポリプロピレン樹脂は、特に限定されず、公知の市販のものを使用することができる。更に、樹脂以外に必要に応じて添加剤を添加したものであってもよい。また、ＡＢＳ（アクリロニトリル－ブタジエン－スチレン）樹脂製の被塗物を用いてもよい。 The plastic base material contains polypropylene, polyolefin, or elastomer-modified polypropylene resin. The elastomer-modified polypropylene resin is not particularly limited, and known commercially available ones can be used. Further, in addition to the resin, an additive may be added as needed. Further, an object to be coated made of ABS (acrylonitrile-butadiene-styrene) resin may be used.
　以下、本発明を実施例によって説明する。実施例中、配合割合において％とあるのは特に言及がない限り質量％を意味する。本発明は以下に記載した実施例に限定されるものではない。 Hereinafter, the present invention will be described by way of examples. In the examples,% in the blending ratio means mass% unless otherwise specified. The present invention is not limited to the examples described below.
［製造例１　無水マレイン酸変性塩素化ポリオレフィン樹脂エマルション（Ａ）の製造］
　攪拌羽根、温度計、滴下装置、温度制御装置、窒素ガス導入管及び冷却管を備えた反応容器に、無水マレイン酸変性塩素化ポリオレフィン「スーパークロン８９２ＬＳ」（日本製紙社製、塩素含有率２２％、重量平均分子量８０，０００：日本製紙社提示値）２８８部、界面活性剤「エマルゲン９２０」（花王社製）６２部、芳香族炭化水素溶剤「ソルベッソ１００」（エクソン社製）７４部、酢酸カービトール３２部を仕込み、１１０℃まで昇温し、この温度で１時間加熱して樹脂などを溶解させたのち、１００℃以下に冷却した。次いで、ジメチルエタノールアミン６部を溶解させたイオン交換水７１０部を冷却しながら１時間かけて滴下し、転相乳化した。その後、室温（２５℃）まで冷却し、４００メッシュの金網でろ過して、無水マレイン酸変性塩素化ポリオレフィン樹脂エマルション（Ａ－２）を得た。当該エマルションの不揮発分は３０重量％であった。エマルション（Ａ－２）中の無水マレイン酸変性塩素化ポリオレフィン樹脂の溶解性パラメータＳＰ（Ａ）は、９．３であった。ＳＰ値は、段落００２９及び段落００３０に記載の方法により実測した。 [Production Example 1 Production of Maleic anhydride-Modified Chlorinated Polyolefin Resin Emulsion (A)]
Maleic anhydride-modified chlorinated polyolefin "Supercron 892LS" (manufactured by Nippon Paper Co., Ltd., chlorine content 22%) in a reaction vessel equipped with a stirring blade, thermometer, dropping device, temperature control device, nitrogen gas introduction tube and cooling tube. , Weight average molecular weight 80,000: value presented by Nippon Paper Co., Ltd.) 288 parts, surfactant "Emargen 920" (manufactured by Kao) 62 parts, aromatic hydrocarbon solvent "Solbesso 100" (manufactured by Exxon) 74 parts, acetic acid 32 parts of hydrocarbon was charged, the temperature was raised to 110 ° C., heated at this temperature for 1 hour to dissolve the resin and the like, and then cooled to 100 ° C. or lower. Then, 710 parts of ion-exchanged water in which 6 parts of dimethylethanolamine was dissolved was added dropwise over 1 hour while cooling, and phase inversion emulsification was performed. Then, the mixture was cooled to room temperature (25 ° C.) and filtered through a 400 mesh wire mesh to obtain a maleic anhydride-modified chlorinated polyolefin resin emulsion (A-2). The non-volatile content of the emulsion was 30% by weight. The solubility parameter SP (A) of the maleic anhydride-modified chlorinated polyolefin resin in the emulsion (A-2) was 9.3. The SP value was measured by the method described in paragraph 0029 and paragraph 0030.
［製造例２　グリシジル基含有アクリル樹脂エマルション（Ｂ）の製造］
　脱イオン水１１８部とＰＶＡ２１８ＥＥ（クラレ社製のポリビニルアルコール）６部とニューコール７１４（日本乳化剤社製のアニオン性界面活性剤）３部との混合物に、アクリル系単量体成分としてのメタクリル酸グリシジル３０部、メタクリル酸ラウリル１３部、アクリル酸ｎ－ブチル１部およびメチルメタクリル酸５６部、ならびに、ラジカル重合開始剤としてのラウリルパーオキサイド２部を混合したものを加えた。これを、ホモジナイザーを用いて８０００ｒｐｍで３０分間攪拌して、原料分散液を得た。ＳＡＬＤ－２２００（島津製作所性レーザ回折式粒度分布測定装置）を用いて測定した原料分散液中の樹脂粒子の平均粒径は０．５μｍであった。この原料分散液を、８０℃に加熱した脱イオン水１３７部に、攪拌しながら２時間かけて滴下し、滴下終了後、そのまま４時間攪拌を継続した。冷却後、４００メッシュの篩でろ過してグリシジル基含有アクリル樹脂エマルション（Ｂ）を得た。当該エマルション中のアクリル樹脂粒子の平均粒径を、ＳＡＬＤ－２２００を用いて測定したところ、０．８μｍであった。エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）は、１０．６であった。ＳＰ値は、段落００３１に記載の方法により計算した。 [Production Example 2 Production of glycidyl group-containing acrylic resin emulsion (B)]
Methacrylic acid as an acrylic monomer component in a mixture of 118 parts of deionized water, 6 parts of PVA218EE (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) and 3 parts of Neucol 714 (anionic surfactant manufactured by Nippon Emulsifier Co., Ltd.). A mixture of 30 parts of glycidyl, 13 parts of lauryl methacrylate, 1 part of n-butyl acrylate and 56 parts of methyl methacrylate, and 2 parts of lauryl peroxide as a radical polymerization initiator was added. This was stirred with a homogenizer at 8000 rpm for 30 minutes to obtain a raw material dispersion. The average particle size of the resin particles in the raw material dispersion measured using SALD-2200 (Shimadzu Corporation laser diffraction type particle size distribution measuring device) was 0.5 μm. This raw material dispersion was added dropwise to 137 parts of deionized water heated to 80 ° C. over 2 hours with stirring, and after the addition was completed, stirring was continued for 4 hours. After cooling, it was filtered through a 400 mesh sieve to obtain a glycidyl group-containing acrylic resin emulsion (B). The average particle size of the acrylic resin particles in the emulsion was measured using SALD-2200 and found to be 0.8 μm. The solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B) was 10.6. The SP value was calculated by the method described in paragraph 0031.
［製造例３　ポリウレタン樹脂ディスパージョン（Ｃ）の製造］
　攪拌羽根、温度計、滴下装置、温度制御装置、窒素ガス導入管、サンプル採取管及び冷却管付き還流装置を備えた耐圧反応容器に、窒素ガスを通じながらアジピン酸１１００部と３－メチルー１，５－ペンタンジオール９００部と、テトラブチルチタネート０．５部とを仕込み、容器内液の反応温度を１７０℃に設定し、脱水によるエステル化反応を行い、酸価が０．３ｍｇＫＯＨ／ｇ以下になるまで継続した。次いで、１８０℃、５ｋＰａ以下の減圧条件下で２時間反応を行い、水酸基過１１２ｍｇＫＯＨ／ｇ、酸価０．２ｍｇＫＯＨ／ｇのポリエステルを得た。次いで、上記反応容器と同じ装置のついた別の反応容器に、このポリエステルポリオール５００部と、５－スルホソジウムイソフタル酸ジメチル１３４部及びテトラブチルチタネート２部を仕込み、上記と同じようにして、窒素ガスを通じながら、反応容器を１８０℃に設定してエステル化を行い、最終的に重量平均分子量２１１７、水酸基価５３ｍｇＫＯＨ／ｇ、酸価０．３ｍｇＫＯＨ／ｇのスルホン酸基含有ポリエステルを得た。 [Manufacturing Example 3 Production of Polyurethane Resin Dispersion (C)]
1100 parts of adipic acid and 3-methyl-1,5 are passed through a pressure-resistant reaction vessel equipped with a stirring blade, a thermometer, a dropping device, a temperature control device, a nitrogen gas introduction tube, a sampling tube, and a reflux device with a cooling tube. -900 parts of pentandiol and 0.5 part of tetrabutyl titanate are charged, the reaction temperature of the liquid in the container is set to 170 ° C., and the esterification reaction is carried out by dehydration, and the acid value becomes 0.3 mgKOH / g or less. Continued until. Then, the reaction was carried out under reduced pressure conditions of 180 ° C. and 5 kPa or less for 2 hours to obtain a polyester having a hydroxyl group excess of 112 mgKOH / g and an acid value of 0.2 mgKOH / g. Next, 500 parts of this polyester polyol, 134 parts of dimethyl 5-sulfosodium isophthalate and 2 parts of tetrabutyl titanate were charged in another reaction vessel equipped with the same apparatus as the above reaction vessel, and in the same manner as above, The reaction vessel was set to 180 ° C. for esterification while passing through nitrogen gas to finally obtain a sulfonic acid group-containing polyester having a weight average molecular weight of 2117, a hydroxyl value of 53 mgKOH / g, and an acid value of 0.3 mgKOH / g.
　上記スルホン酸基含有ポリエステル２８０部、ポリブチレンアジペート２００部、１，４－ブタンジオール３５部、ヘキサメチレンジイソシアネート１１８部及びメチルエチルケトン４００部を、攪拌羽根、温度計、温度制御装置、滴下装置、サンプル採取口及び冷却管付き反応容器に窒素ガスを通じながら仕込み、攪拌しながら液温を７５℃に保持してウレタン化反応を行い、ＮＣＯ含有率が１％であるウレタンポリマーを得た。続いて、上記反応容器中の液温を４０℃に下げて、十分攪拌しながらイオン交換水９５５部を均一に滴下して転相乳化を行った。次いで、内部温度を下げて、アジピン酸ヒドラジド１３部とイオン交換水１１０部とを混合したアジピン酸ヒドラジド水溶液を添加してアミン伸張を行った。次いで、若干の減圧状態で６０℃に温度をあげて脱溶剤を行い、終了した時点で、ポリウレタン樹脂ディスパージョンの固形分が３５％になるようにイオン交換水を追加して、ポリウレタン樹脂ディスパージョン（Ｃ）を得た。ポリウレタン樹脂ディスパージョン（Ｃ）中のポリウレタン樹脂の酸価は、１１ｍｇＫＯＨ／ｇであった。 280 parts of the sulfonic acid group-containing polyester, 200 parts of polybutylene adipate, 35 parts of 1,4-butanediol, 118 parts of hexamethylene diisocyanate and 400 parts of methyl ethyl ketone were mixed with a stirring blade, a thermometer, a temperature control device, a dropping device, and a sample collection. A reaction vessel with a mouth and a cooling tube was charged with nitrogen gas while stirring, and the liquid temperature was maintained at 75 ° C. to carry out a urethanization reaction to obtain a urethane polymer having an NCO content of 1%. Subsequently, the liquid temperature in the reaction vessel was lowered to 40 ° C., and 955 parts of ion-exchanged water was uniformly dropped while sufficiently stirring to carry out phase inversion emulsification. Next, the internal temperature was lowered, and an aqueous solution of adipic acid hydrazide, which was a mixture of 13 parts of adipic acid hydrazide and 110 parts of ion-exchanged water, was added to carry out amine extension. Next, the temperature was raised to 60 ° C. under a slight reduced pressure to remove the solvent, and when the solvent was removed, ion-exchanged water was added so that the solid content of the polyurethane resin dispersion was 35%, and the polyurethane resin dispersion was added. (C) was obtained. The acid value of the polyurethane resin in the polyurethane resin dispersion (C) was 11 mgKOH / g.
（樹脂ディスパージョン（Ｄ））
　ポリエステル樹脂ディスパージョン（Ｄ１－１）
　東洋紡社製のＭＤ１２００（樹脂固形分３４質量％、数平均分子量（Ｍｎ）は１５０００、酸価１ｍｇＫＯＨ／ｇ、水酸基価５ｍｇＫＯＨ／ｇ）を用いた。ＭＤ１２００中のポリエステル樹脂の溶解性パラメータＳＰ（Ｄ）は１１.７であった。ＳＰ値は、段落００３１に記載の方法により計算した。 (Resin dispersion (D))
Polyester resin dispersion (D1-1)
MD1200 manufactured by Toyobo Co., Ltd. (resin solid content 34% by mass, number average molecular weight (Mn) 15000, acid value 1 mgKOH / g, hydroxyl value 5 mgKOH / g) was used. The solubility parameter SP (D) of the polyester resin in MD1200 was 11.7. The SP value was calculated by the method described in paragraph 0031.
　ポリエステル樹脂ディスパージョン（Ｄ１－２）
　ＤＩＣ社製のＢＣＤ３１２０（樹脂固形分３５質量％、酸価７ｍｇＫＯＨ／ｇ、水酸基価１５０ｍｇＫＯＨ／ｇ）を用いた。ＢＣＤ３１２０中のポリエステル樹脂の溶解性パラメータをＳＰ（Ｄ）は１０.９であった。ＳＰ値は、段落００３１に記載の方法により計算した。 Polyester resin dispersion (D1-2)
BCD3120 (resin solid content 35% by mass, acid value 7 mgKOH / g, hydroxyl value 150 mgKOH / g) manufactured by DIC Corporation was used. The solubility parameter of the polyester resin in BCD3120 was 10.9 for SP (D). The SP value was calculated by the method described in paragraph 0031.
［製造例４～７　アクリル樹脂エマルション（Ｄ２）の製造］
　表１に示すアクリル単量体成分を使用する以外は、製造例２と同様の方法で、表１に示すアクリル樹脂エマルション（Ｄ２－１）～（Ｄ２－４）を得た。当該アクリル樹脂エマルションについて、段落００３１に記載の方法で計算したＳＰ値（Ｄ）、及びＳＡＬＤ－２２００を用いて測定した平均粒子径を表１に示す。 [Production Examples 4 to 7 Production of Acrylic Resin Emulsion (D2)]
Acrylic resin emulsions (D2-1) to (D2-4) shown in Table 1 were obtained in the same manner as in Production Example 2 except that the acrylic monomer component shown in Table 1 was used. Table 1 shows the SP value (D) calculated by the method described in paragraph 0031 and the average particle size measured using SALD-2200 for the acrylic resin emulsion.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
［製造例５　顔料分散樹脂］
　攪拌羽根、滴下装置、温度制御装置、窒素ガス導入管及び冷却管を備えた反応容器にプロピレングリコールモノメチルエーテル５５部を仕込み、窒素ガスを導入しつつ、攪拌下１２０℃まで昇温した。次に、２－ヒドロキシメチルメタクリレート１２部、メタクリル酸９部、イソブチルメタクリレート３５部、ｎ－ブチルアクリレート４４部からなる重合性モノマー混合物と、ｔ－ブチルパーオキシ－２－エチルヘキサナート１部をプロピレングリコール８部に溶解した溶液とを、内部攪拌にてそれぞれ３時間かけて滴下した。次いで、滴下終了後、１２０℃の状態で１時間熟成反応を行った後、さらに、ｔ－ブチルパーオキシ－２－エチルヘキサナート０．１部をプロピレングリコール４部に溶解した溶液を、１時間かけて反応容器に滴下した。いずれの場合も内部攪拌状態と液温１２０℃を維持していた。その後、攪拌しながら、１２０℃で２時間熟成し、次いで、内部温度を７０℃まで冷却し、ジメチルアミノエタノール９．５部を滴下して３０分攪拌した。さらに内部温度を７０℃に保持して攪拌しながら、イオン交換水１６７部をゆっくりと滴下し、室温（２５℃）まで冷却し、水溶性アクリル樹脂溶液を得た。イオン交換水を用いて、不揮発分を３０％に調整し、これを、以下の顔料分散ペーストにおけるプライマー用顔料分散樹脂として用いた。得られた顔料分散樹脂（水溶性アクリル樹脂溶液）のｐＨは８．２で、アクリル樹脂の重量平均分子量は４２０００であった。重量平均分子量は、ＴＳＫ－ｇｅｌ－ｓｕｐｅｒｍｕｌｔｉｐоｒ　ＨＺ－Ｍ（東ソー社製）カラム、及び展開溶媒としてＴＨＦを用い、ＧＰＣ装置にてポリスチレン換算で決定した。 [Production Example 5 Pigment Dispersed Resin]
55 parts of propylene glycol monomethyl ether was charged into a reaction vessel equipped with a stirring blade, a dropping device, a temperature control device, a nitrogen gas introduction tube and a cooling tube, and the temperature was raised to 120 ° C. under stirring while introducing nitrogen gas. Next, a polymerizable monomer mixture consisting of 12 parts of 2-hydroxymethyl methacrylate, 9 parts of methacrylic acid, 35 parts of isobutyl methacrylate and 44 parts of n-butyl acrylate and 1 part of t-butylperoxy-2-ethylhexanate are propylene. The solution dissolved in 8 parts of glycol was added dropwise over 3 hours by internal stirring. Then, after completion of the dropping, the aging reaction was carried out at 120 ° C. for 1 hour, and then a solution prepared by dissolving 0.1 part of t-butylperoxy-2-ethylhexanol in 4 parts of propylene glycol was further added for 1 hour. It was added dropwise to the reaction vessel. In each case, the internal stirring state and the liquid temperature of 120 ° C. were maintained. Then, the mixture was aged at 120 ° C. for 2 hours with stirring, then the internal temperature was cooled to 70 ° C., 9.5 parts of dimethylaminoethanol was added dropwise, and the mixture was stirred for 30 minutes. Further, while maintaining the internal temperature at 70 ° C. and stirring, 167 parts of ion-exchanged water was slowly added dropwise and cooled to room temperature (25 ° C.) to obtain a water-soluble acrylic resin solution. The non-volatile content was adjusted to 30% using ion-exchanged water, and this was used as a pigment dispersion resin for a primer in the following pigment dispersion paste. The pH of the obtained pigment-dispersed resin (water-soluble acrylic resin solution) was 8.2, and the weight average molecular weight of the acrylic resin was 42000. The weight average molecular weight was determined in terms of polystyrene by a GPC apparatus using a TSK-gel-supermultipоr HZ-M (manufactured by Tosoh Corporation) column and THF as a developing solvent.
［硬化剤（Ｅ）］
　Ａｌｌｎｅｘ社製のサイメル７０１（不揮発分８２％、メチロール化メラミン）を用いた。 [Curing agent (E)]
Cymel 701 (nonvolatile content 82%, methylolated melamine) manufactured by Allnex was used.
［塗料組成物の調製］
（実施例１）
　日本製紙社製のアウローレンＳ６４７９（無水マレイン酸変性ポリオレフィン樹脂（Ａ－１）、非塩素化）３０質量部、製造例２で得られたグリシジル基含有アクリル樹脂エマルション（Ｂ）１５質量部、製造例３で得られたポリウレタン樹脂ディスパージョン（Ｃ）２５質量部、東洋紡社製のＭＤ１２００（ポリエステル樹脂ディスパージョン（Ｄ１－１））２０質量部、及びＡｌｌｎｅｘ社製のサイメル７０１（硬化剤（Ｅ））１０質量部を、拌装置のついたステンレス製容器に順次投入して混合することにより、実施例１の塗料組成物を得た。上記配合量は、固形分換算量である。アウローレンＳ６４７９のＳＰ値は８．７であり、段落００３１に記載の方法により計算したものである。 [Preparation of paint composition]
(Example 1)
30 parts by mass of Aurolene S6479 (maleic anhydride-modified polyolefin resin (A-1), non-chlorinated) manufactured by Nippon Paper Co., Ltd., 15 parts by mass of the glycidyl group-containing acrylic resin emulsion (B) obtained in Production Example 2, manufactured. 25 parts by mass of the polyurethane resin dispersion (C) obtained in Example 3, 20 parts by mass of MD1200 (polyester resin dispersion (D1-1)) manufactured by Toyo Boseki, and Cymel 701 (hardener (E)) manufactured by Allnex. ) 10 parts by mass were sequentially put into a stainless steel container equipped with a stirrer and mixed to obtain the coating composition of Example 1. The above-mentioned compounding amount is a solid content conversion amount. The SP value of Aurolen S6479 is 8.7, which is calculated by the method described in paragraph 0031.
（実施例２～５、比較例１及び２）
　表２に示すように構成原料及び配合量を変更した以外は、実施例１と同様にして、実施例２～５並びに比較例１及び２の塗料組成物を得た。 (Examples 2 to 5, Comparative Examples 1 and 2)
The coating compositions of Examples 2 to 5 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except that the constituent raw materials and the blending amounts were changed as shown in Table 2.
［ヘーズ値の測定］
　イソプロピルアルコールでワイピングしたテフロンシート（７０ｍｍ×１５０ｍｍ×０．１ｍｍ）の表面に、２５℃／７０％ＲＨの環境下で、「ワイダ―７１」（アネスト磐田社製）を用いて、実施例１で調製した塗料組成物を乾燥膜厚３０μｍとなるよう塗装し、６０℃で５分間乾燥させた。その後、１２０℃で３０分間焼付け硬化を行い、塗膜を形成した。得られた塗膜をテフロンシートから剥し、２５ｍｍ角にカットし、ゼロ点補正したカラス板に貼り付け、日本電色工業社製Σ９０カラー測定システムに付属する濁度計でヘーズ値を測定した。実施例２～５並びに比較例１及び２についても、上記と同様にしてヘーズ値を測定した。ヘーズ値の測定結果を表２に示す。 [Measurement of haze value]
In Example 1 using "Wider-71" (manufactured by Anest Iwata Co., Ltd.) on the surface of a Teflon sheet (70 mm x 150 mm x 0.1 mm) wiped with isopropyl alcohol in an environment of 25 ° C./70% RH. The prepared coating composition was coated so as to have a dry film thickness of 30 μm, and dried at 60 ° C. for 5 minutes. Then, it was baked and cured at 120 ° C. for 30 minutes to form a coating film. The obtained coating film was peeled off from a Teflon sheet, cut into 25 mm squares, attached to a zero-point corrected crow plate, and the haze value was measured with a turbidity meter attached to a Σ90 color measuring system manufactured by Nippon Denshoku Kogyo Co., Ltd. In Examples 2 to 5 and Comparative Examples 1 and 2, the haze value was measured in the same manner as described above. Table 2 shows the measurement results of the haze value.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
［顔料含有塗料組成物の調製］
（実施例６）
　デュポン社製チタンＲ９６０を製造例４の顔料分散樹脂に加えてＰＷＣ（Ｐｉｇｍｅｎｔ　Ｗｅｉｇｈｔ　Ｃｏｎｃｅｎｔｒａｔｉｏｎ、顔料重量濃度）が９５％の顔料ペーストを得た。顔料ペーストのＰＷＣは、顔料分散樹脂の固形分に対する顔料の量（顔料の質量／顔料分散樹脂の固形分×１００）を意味する。
　実施例１で製造した塗料組成物１００質量部に当該顔料ペースト１７１質量部を添加し、ＰＷＣが６０％である白プライマー塗料を調製した。上記配合量は、固形分換算量である。また、白プライマー塗料のＰＷＣは、白プライマー塗料、すなわち、本開示に係る塗料組成物における全樹脂固形分に対する顔料の量（顔料の質量／全樹脂固形分×１００）を意味する。 [Preparation of pigment-containing paint composition]
(Example 6)
Titanium R960 manufactured by Dupont Co., Ltd. was added to the pigment dispersion resin of Production Example 4 to obtain a pigment paste having a PWC (Pigment Weight Concentration, pigment weight concentration) of 95%. The PWC of the pigment paste means the amount of the pigment (mass of the pigment / solid content of the pigment-dispersed resin × 100) with respect to the solid content of the pigment-dispersed resin.
171 parts by mass of the pigment paste was added to 100 parts by mass of the coating composition produced in Example 1 to prepare a white primer coating having a PWC of 60%. The above-mentioned compounding amount is a solid content conversion amount. Further, PWC of the white primer coating means the amount of the pigment (the mass of the pigment / the total resin solid content × 100) with respect to the total resin solid content in the white primer coating material, that is, the coating composition according to the present disclosure.
（実施例７～１０、比較例３～５）
　表３に示すように塗料組成物を変更した以外は、実施例６と同様にして、実施例７～１０及び比較例３～５の白プライマー塗料を得た。なお、比較例３及び４の白プライマー塗料は同じである。 (Examples 7 to 10, Comparative Examples 3 to 5)
White primer coating materials of Examples 7 to 10 and Comparative Examples 3 to 5 were obtained in the same manner as in Example 6 except that the coating composition was changed as shown in Table 3. The white primer paints of Comparative Examples 3 and 4 are the same.
［白プライマーの隠蔽性］
　白黒隠蔽試験紙に実施例６の白プライマー塗料を段階的に膜厚が変化するように塗布し、６０℃で５分乾燥後、１２０℃で３０分焼き付け、冷却後、被塗物に対し垂直方向から目視にて観察し、白黒が区別できない膜厚を隠蔽膜厚とした。実施例７～１０及び比較例３～５の白プライマー塗料についても、上記と同様にして隠蔽膜厚を評価した。隠蔽膜厚の結果を表３に示す。 [Concealment of white primer]
The white primer coating material of Example 6 is applied to a black-and-white concealment test paper so that the film thickness changes stepwise, dried at 60 ° C. for 5 minutes, baked at 120 ° C. for 30 minutes, cooled, and then perpendicular to the object to be coated. The film thickness that was visually observed from the direction and indistinguishable between black and white was defined as the concealed film thickness. The white primer coating materials of Examples 7 to 10 and Comparative Examples 3 to 5 were also evaluated for the concealing film thickness in the same manner as described above. The results of the concealment film thickness are shown in Table 3.
［複層塗膜の形成］
（実施例６～１０、比較例３～５の白プライマー塗料を用いた複層被膜：３コート１ベーク）
　イソプロピルアルコールでワイピングしたポリプロピレン素材（７０ｍｍ×１５０ｍｍ×３ｍｍ）の表面に、２５℃／７０％ＲＨの環境下で、「ワイダ－７１」（アネスト磐田社製）により、実施例６の白プライマー塗料をスプレー塗装（乾燥膜厚２５μｍ）し、６０℃で５分間乾燥した。次に、水性マイカベース塗料組成物（日本ペイント・オートモーティブコーティングス社製のＡＲ－３０２０－１♯７Ａ２１）を同じ環境下で、新カートリッジベル（ＡＢＢ社製の新カートリッジベル（商品名））を使用して塗装条件（ガン距離：２００ｍｍ、ガン速度：９００ｍｍ／ｓ、回転数：３５０００ｒｐｍ、シェーピングエアー圧：０．１５ＭＰａ）でスプレー塗装（乾燥膜厚１５μｍ）した。８０℃で５分間乾燥した後、その上に、ロボベル９５１を使用してクリヤー塗料組成物（日本ペイント・オートモーティブコーティングス社製のＲ－２５５０－１及び硬化剤Ｈ－２５５０の混合物）を塗装（ガン距離：２００ｍｍ、ガン速度：７００ｍｍ／ｓ、回転数：２５０００ｒｐｍ、シェーピングエアー圧：０．０７ＭＰａ）条件下でスプレー塗装（乾燥膜厚２５μｍ）した。その後、１０分間セッティングした後、１２０℃で３０分間乾燥し、実施例６の複層塗膜を形成した。
　実施例７～１０並びに比較例３及び４の白プライマー塗料についても、表３に示すように白プライマー塗料及び／又は白プライマーの膜厚を変更した以外は、上記と同様にして、実施例７～１０及び比較例３～５の複層塗膜を形成した。 [Formation of multi-layer coating film]
(Multi-layer coating using white primer paints of Examples 6 to 10 and Comparative Examples 3 to 5: 3 coats and 1 bake)
On the surface of a polypropylene material (70 mm × 150 mm × 3 mm) wiped with isopropyl alcohol, the white primer coating material of Example 6 was applied by “Wider-71” (manufactured by Anest Iwata Co., Ltd.) in an environment of 25 ° C./70% RH. It was spray coated (dry film thickness 25 μm) and dried at 60 ° C. for 5 minutes. Next, a new cartridge bell (new cartridge bell (trade name) manufactured by ABB) was applied to the water-based mica-based paint composition (AR-3020-1 # 7A21 manufactured by Nippon Paint Automotive Coatings) under the same environment. Using it, spray coating (dry film thickness 15 μm) was performed under coating conditions (gun distance: 200 mm, gun speed: 900 mm / s, rotation speed: 35000 rpm, shaping air pressure: 0.15 MPa). After drying at 80 ° C. for 5 minutes, a clear paint composition (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) is applied onto the coating (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings) using Robobel 951. Spray coating (dry film thickness 25 μm) was performed under the conditions of gun distance: 200 mm, gun speed: 700 mm / s, rotation speed: 25000 rpm, shaping air pressure: 0.07 MPa). Then, after setting for 10 minutes, it was dried at 120 ° C. for 30 minutes to form the multi-layer coating film of Example 6.
The white primer paints of Examples 7 to 10 and Comparative Examples 3 and 4 were also subjected to the same procedure as in Example 7 except that the film thickness of the white primer paint and / or the white primer was changed as shown in Table 3. A multi-layer coating film of 10 to 10 and Comparative Examples 3 to 5 was formed.
（参考例（従来例）：４コート１ベーク）
　イソプロピルアルコールでワイピングしたポリプロピレン素材（７０ｍｍ×１５０ｍｍ×３ｍｍ）の表面に、２５℃／７０％ＲＨの環境下で、「ワイダ－７１」（アネスト磐田社製）により、水性白色導電プライマー塗料（日本ペイント・オートモーティブコーティングス社製ＷＢ－１３１０ＣＤ）をスプレー塗装（乾燥膜厚１５μｍ）し、６０℃で５分間乾燥した。その後、水性カラーベース塗料組成物（日本ペイント・オートモーティブコーティングス社製ＡＲ－３０２０－１＃７０１８）を同じ環境下で、新カートリッジベル（ＡＢＢ社製の新カートリッジベル（商品名））を使用して静電塗装条件（ガン距離：２００ｍｍ、ガン速度：９００ｍｍ／ｓ、印加電圧：－６０ｋＶ、回転数：３５０００ｒｐｍ、シェーピングエアー圧：０．１５ＭＰａ）でスプレー塗装（乾燥膜厚２０μｍ）した。次に、水性マイカベース塗料組成物（日本ペイント・オートモーティブコーティングス社製のＡＲ－３０２０－１♯７Ａ２１）を水性カラーベース塗料組成物と同様の条件でスプレー塗装（乾燥膜厚１５μｍ）した。８０℃で５分間乾燥した後、その上に、ロボベル９５１を使用してクリヤー塗料組成物（日本ペイント・オートモーティブコーティングス社製のＲ－２５５０－１及び硬化剤Ｈ－２５５０の混合物）を静電塗装（ガン距離：２００ｍｍ、ガン速度：７００ｍｍ／ｓ、印加電圧：－６０ｋＶ、回転数：２５０００ｒｐｍ、シェーピングエアー圧：０．０７ＭＰａ）条件下でスプレー塗装（乾燥膜厚２５μｍ）した。その後、１０分間セッティングした後、１２０℃で３０分間乾燥し、複層塗膜を形成した。 (Reference example (conventional example): 4 coats, 1 bake)
Aqueous white conductive primer paint (Nippon Paint) on the surface of polypropylene material (70 mm x 150 mm x 3 mm) wiped with isopropyl alcohol in an environment of 25 ° C / 70% RH with "Wider-71" (manufactured by Anest Iwata). (WB-1310CD manufactured by Automotive Coatings Co., Ltd.) was spray-coated (dry film thickness 15 μm) and dried at 60 ° C. for 5 minutes. After that, the water-based color-based paint composition (AR-3020-1 # 7018 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) was used in the same environment using a new cartridge bell (new cartridge bell (trade name) manufactured by ABB). Spray coating (dry film thickness 20 μm) was performed under electrostatic coating conditions (gun distance: 200 mm, gun speed: 900 mm / s, applied voltage: -60 kV, rotation speed: 35000 rpm, shaping air pressure: 0.15 MPa). Next, the water-based mica-based coating composition (AR-3020-1 # 7A21 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) was spray-coated (dry film thickness 15 μm) under the same conditions as the water-based color-based coating composition. After drying at 80 ° C. for 5 minutes, a clear coating composition (a mixture of R-25501 and a curing agent H-2550 manufactured by Nippon Paint Automotive Coatings Co., Ltd.) is electrostatically charged on the clear coating composition using Robobel 951. Spray coating (dry film thickness 25 μm) was performed under the conditions of coating (gun distance: 200 mm, gun speed: 700 mm / s, applied voltage: -60 kV, rotation speed: 25000 rpm, shaping air pressure: 0.07 MPa). Then, after setting for 10 minutes, it was dried at 120 ° C. for 30 minutes to form a multi-layer coating film.
　上記のようにして得られた複層塗膜について、以下の要領で、耐キシレンラビング性、初期密着性、耐水性、耐屈曲性、及び仕上がりを評価した。これらの結果を表３に示す。 The multi-layer coating film obtained as described above was evaluated for xylene rubbing resistance, initial adhesion, water resistance, bending resistance, and finish in the following manner. These results are shown in Table 3.
［耐キシレンラビング性］
　キシレンを含んだガーゼで複層塗膜に５００ｇの荷重を加え、８往復ラビング試験を行い、粘着性、しわ、フクレ、ハガレ等の異常の有無を評価した。異常が認められない場合は合格（○）、少しでも異常が認められた場合は不合格（×）とした。 [Xylene rubbing resistance]
A load of 500 g was applied to the multi-layer coating film with gauze containing xylene, and an 8-reciprocating rubbing test was performed to evaluate the presence or absence of abnormalities such as adhesiveness, wrinkles, blisters, and peeling. If no abnormality was found, it was passed (○), and if any abnormality was found, it was rejected (×).
［初期密着性］
　ＪＩＳ－Ｋ－５６００－５－６に準拠して評価した。具体的には、カッターナイフで複層塗膜上に、２ｍｍの碁盤目１００個を作り、その上にセロハン粘着テープを完全に付着させ、テープの一方の端を持ち上げて上方に剥がした。この剥離動作を同一箇所で３回実施し、１桝目内で塗膜が面積比５０％以上剥がれた正方桝目の個数を数えた。０個を合格（○）とし、１個以上を不合格（×）とした。 [Initial adhesion]
Evaluation was made in accordance with JIS-K-5600-5-6. Specifically, 100 2 mm grids were made on the multi-layer coating film with a cutter knife, cellophane adhesive tape was completely adhered onto the grid, and one end of the tape was lifted and peeled upward. This peeling operation was carried out three times at the same location, and the number of square squares in which the coating film was peeled off by an area ratio of 50% or more in the first square was counted. 0 was passed (○) and 1 or more was rejected (×).
［耐水性］
　４０℃の耐水槽に複層塗膜を２４０時間浸漬させた。浸漬終了後、耐水槽から取り出した塗膜について、取り出してから１時間以内にＪＩＳ　Ｋ５６００－５－６に準拠して、碁盤目セロテープ（登録商標）剥離試験を行った。２ｍｍ角の１００個の碁盤目を用意し、セロハンテープ剥離試験を行い、剥がれなかった碁盤目数を数えた。評価基準は以下の通りである。０／１００（剥離なし）を合格（○）とし、１／１００～１００／１００（剥離あり）を不合格（×）とした。また、耐水槽から取り出した直後の塗膜外観が初期と比較して、少しのフクレがある場合は△（不合格）とした。著しいフクレ（ブリスター）については×とした。 [water resistant]
The multi-layer coating film was immersed in a water resistant tank at 40 ° C. for 240 hours. After the immersion was completed, the coating film taken out from the water resistant tank was subjected to a checkered cellophane tape (registered trademark) peeling test within 1 hour after being taken out in accordance with JIS K5600-5-6. 100 2 mm square grids were prepared, a cellophane tape peeling test was performed, and the number of grids that did not peel was counted. The evaluation criteria are as follows. 0/100 (without peeling) was regarded as a pass (◯), and 1/100 to 100/100 (with peeling) was regarded as a failure (x). In addition, when the appearance of the coating film immediately after being taken out from the water resistant tank was slightly blistered as compared with the initial appearance, it was marked as Δ (failed). Significant blisters (blisters) were marked with x.
［耐屈曲性］
　ＪＩＳ　Ｋ　５６００－５－１：１９９９（耐屈曲性）に準拠して、φ２０ｍｍの円筒形マンドレルにて耐屈曲性試験を行った。複層塗膜の耐屈曲性を、以下の基準に基づき評価した。
　○（合格）：塗膜ワレが起こらず良好
　△（不合格）：一部塗膜ワレが発生
　×（不合格）：全面に塗膜ワレが発生 [Bending resistance]
A bending resistance test was conducted with a cylindrical mandrel having a diameter of 20 mm in accordance with JIS K 5600-5-1: 1999 (flexing resistance). The bending resistance of the multi-layer coating film was evaluated based on the following criteria.
○ (Pass): Good without coating film cracking △ (Failure): Partial coating film cracking occurs × (Failure): Coating film cracking occurs on the entire surface
[仕上がり]
　ミノルタ社製ＣＲ４００色差計を用いて、参考例で作成した複層塗膜板を白マイカ塗色の基準板として複層塗膜の色差ΔＥを測定した。ΔＥが１未満を合格（〇）とし、１以上を不合格（×）とした。 [finish]
Using a CR400 color difference meter manufactured by Minolta Co., Ltd., the color difference ΔE of the multi-layer coating film was measured using the multi-layer coating plate prepared in the reference example as a reference plate for white mica coating color. A ΔE of less than 1 was regarded as a pass (◯), and a ΔE of 1 or more was regarded as a fail (x).
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　本開示に係る塗料組成物であれば、優れた下地隠ぺい性を有する塗膜を形成することができる。そのため、本発明に係る塗料組成物であれば、塗装回数を従来よりも低減でき、より薄い膜厚でありながらも、被塗物が有する黒色を隠ぺいできる塗膜を形成できる。
　更に、本開示に係る塗料組成物であれば、密着性、耐薬品性、耐水性、屈曲性及び外観に優れた塗膜を形成できる。 With the coating composition according to the present disclosure, a coating film having excellent base hiding properties can be formed. Therefore, with the coating composition according to the present invention, the number of coatings can be reduced as compared with the conventional case, and a coating film capable of hiding the black color of the object to be coated can be formed even though the film thickness is thinner.
Further, the coating composition according to the present disclosure can form a coating film having excellent adhesion, chemical resistance, water resistance, flexibility and appearance.
　一方、比較例１及び２の塗料組成物を用いて形成した塗膜はヘーズ値が低いため、比較例１及び２の塗料組成物から調整した比較例３～５の白プライマー塗料を用いて形成した白プライマーは、下地隠ぺい性が劣っていた。 On the other hand, since the coating films formed by using the coating compositions of Comparative Examples 1 and 2 have a low haze value, they are formed by using the white primer coatings of Comparative Examples 3 to 5 prepared from the coating compositions of Comparative Examples 1 and 2. The white primer was inferior in the base hiding property.
　そのため、比較例１の白プライマーを用いて複層塗膜を形成する際、下地隠ぺい性を確保するために、比較例３のように、白プライマーを４０μｍと厚くする必要があった。しかし、白プライマーは顔料濃度が高いため硬く、更に白プライマーが厚膜化したことにより、耐水性及び耐屈曲性が低下した。一方、比較例４及び５のように、白プライマーの膜厚が３０μｍと薄いと、下地隠ぺい性が不十分となり、更に、所望の発色が得られず、白さが乏しく、仕上がりが劣っていた。 Therefore, when forming a multi-layer coating film using the white primer of Comparative Example 1, it was necessary to increase the thickness of the white primer to 40 μm as in Comparative Example 3 in order to secure the base hiding property. However, the white primer is hard due to the high pigment concentration, and the thicker film of the white primer lowers the water resistance and bending resistance. On the other hand, when the film thickness of the white primer was as thin as 30 μm as in Comparative Examples 4 and 5, the background hiding property was insufficient, the desired color development could not be obtained, the whiteness was poor, and the finish was inferior. ..
　本発明の塗料組成物は、例えば、自動車車両、自動車用部品において好適に使用することができる。 The coating composition of the present invention can be suitably used in, for example, automobile vehicles and automobile parts.

Claims (12)

  1. 　塗料組成物であって、
    　無水マレイン酸変性ポリオレフィン樹脂（Ａ）と、グリシジル基含有アクリル樹脂エマルション（Ｂ）と、ウレタン樹脂ディスパージョン（Ｃ）とからなる群から選択される少なくとも１種、
    　樹脂ディスパージョン（Ｄ）、及び
    　硬化剤（Ｅ）
    を含み、
    　前記無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、前記エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び前記樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が、以下の式（１）及び式（２）の少なくとも１つを満たし、
    　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
    　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
    　前記少なくとも１種と、（Ｄ）と、（Ｅ）とを前記塗料組成物と同じ質量比率で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である、塗料組成物。     It is a paint composition
    At least one selected from the group consisting of a maleic anhydride-modified polyolefin resin (A), a glycidyl group-containing acrylic resin emulsion (B), and a urethane resin dispersion (C).
    Resin dispersion (D) and hardener (E)
    Including
    In the solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A), the solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B), and the resin dispersion (D). The solubility parameter SP (D) of the resin satisfies at least one of the following formulas (1) and (2).
    | SP (D) -SP (A) | ≧ 1.0 (1),
    | SP (D) -SP (B) | ≧ 1.0 (2),
    A coating composition having a haze value of 15% or more of a coating film having a thickness of 30 μm formed from a mixture containing at least one of the above, (D) and (E) in the same mass ratio as the coating composition.
  2. 　無水マレイン酸変性ポリオレフィン樹脂（Ａ）、
    　グリシジル基含有アクリル樹脂エマルション（Ｂ）、及び
    　ウレタン樹脂ディスパージョン（Ｃ）、
    　樹脂ディスパージョン（Ｄ）、及び
    　硬化剤（Ｅ）
    を含み、
    　前記無水マレイン酸変性ポリオレフィン樹脂（Ａ）の溶解性パラメータＳＰ（Ａ）、前記エマルション（Ｂ）中のグリシジル基含有アクリル樹脂の溶解性パラメータＳＰ（Ｂ）、及び前記樹脂ディスパージョン（Ｄ）中の樹脂の溶解性パラメータＳＰ（Ｄ）が、以下の式（１）及び式（２）の少なくとも１つを満たし、
    　｜ＳＰ（Ｄ）－ＳＰ（Ａ）｜≧１.０　　（１）、
    　｜ＳＰ（Ｄ）－ＳＰ（Ｂ）｜≧１.０　　（２）、
    　（Ａ）～（Ｅ）を前記塗料組成物と同じ質量比率で含む混合物から形成した厚さ３０μｍの塗膜のヘーズ値が１５％以上である、塗料組成物。     Maleic anhydride-modified polyolefin resin (A),
    Glycidyl group-containing acrylic resin emulsion (B), and urethane resin dispersion (C),
    Resin dispersion (D) and hardener (E)
    Including
    In the solubility parameter SP (A) of the maleic anhydride-modified polyolefin resin (A), the solubility parameter SP (B) of the glycidyl group-containing acrylic resin in the emulsion (B), and the resin dispersion (D). The solubility parameter SP (D) of the resin satisfies at least one of the following formulas (1) and (2).
    | SP (D) -SP (A) | ≧ 1.0 (1),
    | SP (D) -SP (B) | ≧ 1.0 (2),
    A coating composition having a haze value of 15% or more of a coating film having a thickness of 30 μm formed from a mixture containing (A) to (E) in the same mass ratio as the coating composition.
  3. 　前記樹脂ディスパージョン（Ｄ）は、ポリエステル樹脂ディスパージョン（Ｄ１）であり、
    　前記ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂は、溶解性パラメータＳＰ（Ｄ１）が１１.０以上１２.０以下である、請求項１又は２に記載の塗料組成物。     The resin dispersion (D) is a polyester resin dispersion (D1).
    The coating composition according to claim 1 or 2, wherein the polyester resin in the polyester resin dispersion (D1) has a solubility parameter SP (D1) of 11.0 or more and 12.0 or less.
  4. 　前記ポリエステル樹脂ディスパージョン（Ｄ１）中のポリエステル樹脂の数平均分子量が、６，０００以上２０，０００以下である、請求項３に記載の塗料組成物。 The coating composition according to claim 3, wherein the number average molecular weight of the polyester resin in the polyester resin dispersion (D1) is 6,000 or more and 20,000 or less.
  5. 　前記樹脂ディスパージョン（Ｄ）は、アクリル樹脂エマルション（Ｄ２）であり、
    　前記アクリル樹脂エマルション（Ｄ２）中のアクリル樹脂は、溶解性パラメータＳＰ（Ｄ２）が８.０以上１２.０以下であり、
    　前記アクリル樹脂は、グリシジル基を含有しない、請求項１又は２に記載の塗料組成物。     The resin dispersion (D) is an acrylic resin emulsion (D2).
    The acrylic resin in the acrylic resin emulsion (D2) has a solubility parameter SP (D2) of 8.0 or more and 12.0 or less.
    The coating composition according to claim 1 or 2, wherein the acrylic resin does not contain a glycidyl group.
  6. 　前記アクリル樹脂エマルション（Ｄ２）中の前記アクリル樹脂が架橋性樹脂粒子である、請求項５に記載の塗料組成物。 The coating composition according to claim 5, wherein the acrylic resin in the acrylic resin emulsion (D2) is crosslinkable resin particles.
  7. 　前記無水マレイン酸変性ポリオレフィン樹脂（Ａ）は、無水マレイン酸変性塩素化ポリオレフィン樹脂である、請求項１から６のいずれか１項に記載の塗料組成物。 The coating composition according to any one of claims 1 to 6, wherein the maleic anhydride-modified polyolefin resin (A) is a maleic anhydride-modified chlorinated polyolefin resin.
  8. 　有機粒子及び無機粒子からなる群から選択される粒子を含む、請求項１から７のいずれか１項に記載の塗料組成物。 The coating composition according to any one of claims 1 to 7, which comprises particles selected from the group consisting of organic particles and inorganic particles.
  9. 　着色顔料を含み、
    　前記着色顔料の量は、（Ａ）～（Ｅ）の固形分の合計に対し、３質量％以上１５０質量％以下である、請求項１から８のいずれか１項に記載の塗料組成物。     Contains coloring pigments
    The coating composition according to any one of claims 1 to 8, wherein the amount of the coloring pigment is 3% by mass or more and 150% by mass or less with respect to the total solid content of (A) to (E).
  10. 　前記塗料組成物は、水性プライマー塗料組成物である、請求項１から９のいずれか１項に記載の塗料組成物。 The coating composition according to any one of claims 1 to 9, wherein the coating composition is an aqueous primer coating composition.
  11. 　被塗物に、請求項１～１０のいずれかに記載の塗料組成物を塗装し、未硬化の塗膜を形成する工程、及び
    前記未硬化の塗膜を加熱硬化させ、塗膜を形成する工程
    を含む塗膜の形成方法。     The step of coating the object to be coated with the coating composition according to any one of claims 1 to 10 to form an uncured coating film, and heat-curing the uncured coating film to form a coating film. A method for forming a coating film including a step.
  12. 　被塗物に、請求項１０記載の水性プライマー塗料組成物を塗装し、未硬化のプライマー塗膜を形成する工程、
    　前記未硬化の水性プライマー塗料組成物の上に、光輝顔料を含むベース塗料組成物を塗装し、未硬化のベース塗膜を形成する工程、
    　前記未硬化のベース塗膜の上に、クリヤー塗料組成物を塗装し、未硬化のクリヤー塗膜を形成する工程、及び
    　前記未硬化のプライマー塗膜、ベース塗膜及びクリヤー塗膜を加熱硬化させ、複層塗膜を形成する工程
    を含む複層塗膜の形成方法。     A step of coating an object to be coated with the aqueous primer coating composition according to claim 10 to form an uncured primer coating film.
    A step of coating a base coating composition containing a bright pigment on the uncured aqueous primer coating composition to form an uncured base coating film.
    A step of applying a clear coating composition on the uncured base coating film to form an uncured clear coating film, and heating and curing the uncured primer coating film, the base coating film and the clear coating film. , A method for forming a multi-layer coating film, which comprises a step of forming a multi-layer coating film.
PCT/JP2020/047970 2019-12-27 2020-12-22 Coating composition, coating film obtained therefrom, and method for forming multilayered coating film WO2021132246A1 (en)

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