Resin composition, method for producing inkjet printed matter, and method for producing article coated with coating material

Abstract

Provided are a resin composition, a method for producing inkjet printed matter, and a method for producing an article coated with a coating material, which are capable of imparting an excellent heat shielding effect to a coated base material. This resin composition comprises a color material and a binder resin, wherein the color material includes a white color material and a black color material, and the average reflectance at a wavelength of 780-2100 nm of a coating film which is formed when the resin composition is applied is not less than 55%.

Description

Resin composition, method for producing inkjet printed matter, and method for producing painted matter

[0001] The present invention relates to a resin composition, a method for producing an inkjet printed matter, and a method for producing a paint-coated matter. More specifically, the present invention relates to a resin composition, a method for producing an inkjet printed matter, and a method for producing a paint-coated matter, which are capable of imparting an excellent heat-shielding effect to a substrate to which they are applied.

[0002] Conventionally, coating compositions have been developed that can form coating films of light colors other than white and that contain carbon black (see Patent Document 1).

[0003] JP 2011-21126 A

[0004] However, the technology described in Patent Document 1 has poor heat-shielding properties, and there is a problem that, for example, when a coating film is formed on the surface of an outdoor unit of an air conditioner, the outdoor unit becomes too hot, causing malfunction.

[0005] The present invention has been made in view of the above-mentioned conventional inventions, and aims to provide a resin composition, a method for producing an inkjet printed item, and a method for producing a paint-coated item, which are capable of imparting an excellent heat-shielding effect to a substrate to which the composition is applied.

[0006] A resin composition according to one embodiment of the present invention that solves the above-mentioned problems is a resin composition containing a colorant and a binder resin, wherein the colorant includes a white colorant and a black colorant, and the average reflectance of a coating film formed when the resin composition is applied in the wavelength range of 780 to 2100 nm is 55% or more.

[0007] Furthermore, a method for producing an inkjet printed matter according to one aspect of the present invention, which solves the above-mentioned problems, is a method for producing an inkjet printed matter, comprising the steps of applying the above-mentioned resin composition onto a substrate by an inkjet method, and curing the applied resin composition with ultraviolet light.

[0008] Furthermore, one aspect of the present invention that solves the above problem is a method for producing a paint-coated article, which includes the steps of applying the resin composition onto a substrate by a spray method and thermally curing the applied resin composition.

[0009] Figure 1 is a graph showing the measurement results of solar reflectance, Figure 2 is a graph showing the change in substrate temperature over time, and Figure 3 is a graph showing the change in substrate temperature over time.

[0010] <Resin Composition> A resin composition according to one embodiment of the present invention contains a colorant and a binder resin. The colorant includes a white colorant and a black colorant. The coating film formed when the resin composition is applied has an average reflectance of 55% or more in the wavelength range of 780 to 2100 nm. Each of these components will be described below.

[0011] (Colorant) The resin composition of the present embodiment contains a white colorant and a black colorant as colorants. The colorants may contain other colorants, and preferably contain at least one of a yellow colorant and a red colorant.

[0012] White Colorant The white colorant is not particularly limited. Examples of white colorants include C.I. Pigment White 1, which is basic lead carbonate, C.I. Pigment White 4, which is made of zinc oxide, C.I. Pigment White 5, which is made of a mixture of zinc sulfide and barium sulfate, C.I. Pigment White 6, which is made of titanium dioxide, C.I. Pigment White 6:1, which is made of titanium dioxide containing other metal oxides, C.I. Pigment White 7, which is made of zinc sulfide, C.I. Pigment White 18, which is made of calcium carbonate, C.I. Pigment White 19, which is made of clay, C.I. Pigment White 20, which is made of titanium mica, C.I. Pigment White 21, which is made of barium sulfate, C.I. Pigment White 22, which is made of gypsum, C.I. Pigment White 26, which is made of magnesium oxide and silicon dioxide, and C.I. Pigment White 27, which is made of silicon dioxide. Pigment White 27, and C.I. Pigment White 28, which is made of anhydrous calcium silicate. Among these, it is preferable that the white coloring material contains a titanium oxide pigment, since excellent heat-shielding properties can be obtained.

[0013] The shape of the titanium oxide-based pigment is not particularly limited. Examples of the shape of the titanium oxide-based pigment include rod-like, spherical, particulate, and spindle-like shapes. Among these, the shape of the titanium oxide-based pigment is preferably rod-like. In this embodiment, "rod-like" refers to a shape with a minor axis of 0.1 to 0.8 μm and a major axis of 1.5 to 5 μm.

[0014] The content of the white coloring material is not particularly limited and may be appropriately selected depending on the form of the resin composition described below.

[0015] For example, when the resin composition is an aqueous resin composition, the content of the white coloring material in the resin composition is preferably 20% by mass or more, more preferably 30% by mass or more. Furthermore, the content of the white coloring material in the resin composition is preferably 60% by mass or less, more preferably 50% by mass or less. By having the content of the white coloring material within the above range, the aqueous resin composition is likely to form a coating film with excellent heat-shielding properties.

[0016] When the resin composition is a powder resin composition, the content of the white coloring material in the resin composition is preferably 20% by mass or more, more preferably 40% by mass or more. The content of the white coloring material in the resin composition is preferably 70% by mass or less, more preferably 60% by mass or less. When the content of the white coloring material is within the above range, the powder resin composition is likely to form a coating film having excellent heat-shielding properties.

[0017] Furthermore, when the resin composition is an ultraviolet-curable resin composition, the content of the white colorant in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more. Furthermore, the content of the white colorant in the resin composition is preferably 50% by mass or less, more preferably 40% by mass or less. When the content of the white colorant is within the above range, the ultraviolet-curable resin composition is likely to form a coating film with excellent heat-shielding properties.

[0018] Black Colorant The black colorant is not particularly limited as long as it is other than carbon black. The black colorant preferably contains at least one of a chromium-based pigment, a manganese-based pigment, an iron oxide-based pigment, and a titanium-based pigment. Chromium-based pigments include iron-chromium-based pigments, copper-chromium-based pigments, and cobalt-iron-chromium-based pigments. Manganese-based pigments include bismuth-manganese-based pigments, yttrium-manganese-based pigments, copper-iron-manganese-based pigments, cobalt-manganese-based pigments, and titanium-manganese-based pigments. Iron oxide-based pigments include magnetite pigments. Titanium-based pigments include titanium black pigments. Among these, the black colorant is preferably a manganese-based pigment, and more preferably a bismuth-manganese-based pigment. By using these black colorants, the resin composition can produce a coating film with superior shielding properties compared to when other black pigments such as carbon black are used.

[0019] The content of the bismuth manganese pigment in the black color material is not particularly limited. For example, the content of the bismuth manganese pigment in the black color material is preferably 80% by mass or more, more preferably 90% by mass or more, or even 100% by mass. This allows the resin composition to provide a coating film with better shielding properties.

[0020] The content of the black coloring material in the resin composition is preferably less than 5% by mass, and more preferably 3% by mass or less. The content of the black coloring material in the resin composition is preferably 0.1% by mass or more, and more preferably 1% by mass or more. By having the content of the black coloring material within the above range, the resin composition can easily form a light-colored coating film, such as a gray coating film, on a substrate to which it is applied while maintaining an excellent heat-shielding effect.

[0021] Other Coloring Materials The resin composition of the present embodiment may contain other coloring materials in addition to the white coloring material and black coloring material described above. The other coloring materials are not particularly limited. For example, the other coloring materials preferably contain at least one of a yellow coloring material and a red coloring material. This allows the resin composition to form various light-colored coating films on the substrate to which it is applied while maintaining an excellent heat-shielding effect.

[0022] The yellow colorant is not particularly limited. Examples of yellow colorants include iron oxide pigments, iron hydroxide pigments, chromate pigments, titanium nickel pigments, titanium chromium pigments, bismuth pigments, vanadium pigments, and praseodymium zirconium pigments. Among these, the yellow colorant is preferably an iron oxide pigment, iron hydroxide pigment, titanium nickel pigment, or titanium chromium pigment, more preferably an iron oxide pigment, iron hydroxide pigment, or titanium nickel pigment, and even more preferably an iron hydroxide pigment, because the average reflectance of the resulting coating film is likely to be 55% or more and a coating film with excellent heat-shielding properties is likely to be formed.

[0023] When a yellow colorant is contained, the content of the yellow colorant is not particularly limited. For example, the content of the yellow colorant in the resin composition is preferably 0.5% by mass or more, and more preferably 2% by mass or more. Furthermore, the content of the yellow colorant in the resin composition is preferably 20% by mass or less, and more preferably 10% by mass or less. When the content of the yellow colorant is within the above range, the resin composition has excellent heat-shielding properties and is easy to form various light-colored coating films.

[0024] The red colorant is not particularly limited. Examples of the red colorant include iron oxide pigments, iron zirconium pigments, iron-aluminum pigments, iron-zinc pigments, and manganese-aluminum pigments. Among these, the red colorant is preferably an iron oxide pigment or iron zirconium pigment, and more preferably an iron oxide pigment, because the resulting coating film is likely to have an average reflectance of 55% or more and is likely to form a coating film with excellent heat-shielding properties.

[0025] When a red colorant is contained, the content of the red colorant is not particularly limited. For example, the content of the red colorant in the resin composition is preferably 0.5% by mass or more, and more preferably 2% by mass or more. Furthermore, the content of the red colorant in the resin composition is preferably 10% by mass or less, and more preferably 5% by mass or less. When the content of the red colorant is within the above range, the resin composition has excellent heat-shielding properties and is easy to form various light-colored coating films.

[0026] (Binder Resin) The resin composition of the present embodiment contains a binder resin, which is contained for the purposes of adjusting the viscosity of the resin composition and controlling the hardness and shape of the resulting coating film, for example.

[0027] The binder resin is not particularly limited and may be appropriately selected depending on the form of the resin composition.

[0028] The resin composition is preferably in the form of an aqueous resin composition, a powder resin composition, or an ultraviolet-curable resin composition. By adopting these forms, the resin composition can be used in various forms.

[0029] When the resin composition is an aqueous resin composition, the binder resin preferably contains at least one of an acrylic emulsion, a urethane emulsion, and a fluorine emulsion.

[0030] The acrylic emulsion is not particularly limited. For example, an acrylic emulsion produced by (co)polymerizing a polymerizable unsaturated monomer by a known polymerization method (emulsion polymerization, suspension polymerization, dispersion polymerization, etc.) can be used. The emulsion polymerization method usually involves copolymerizing a polymerizable unsaturated monomer mixture using a polymerization initiator in the presence of water and an emulsifier. The emulsion polymerization may be carried out in multiple stages.

[0031] The polymerizable unsaturated monomer is not particularly limited. Examples of the polymerizable unsaturated monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, and stearyl (meth)acrylate. alkyl esters of acrylic acid or methacrylic acid such as acrylate; monoesters of polyhydric alcohols with acrylic acid or methacrylic acid, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol (meth)acrylate, and monoesters of such polyhydric alcohols with acrylic acid or methacrylic acid. Hydroxyl group-containing polymerizable unsaturated monomers such as compounds obtained by ring-opening polymerization of an esterified product with ε-caprolactone; carboxyl group-containing polymerizable unsaturated monomers such as acrylic acid, methacrylic acid, maleic acid, and maleic anhydride; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate; (meth)acrylamides or derivatives thereof such as acrylamide, methacrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-methylolacrylamide, N-methylolacrylamide methyl ether, and N-methylolacrylamide butyl ether; quaternary ammonium base-containing monomers such as 2-(methacryloyloxy)ethyltrimethylammonium chloride and 2-(methacryloyloxy)ethyltrimethylammonium bromide;(meth)acrylamido-alkanesulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid, sulfoalkyl (meth)acrylates such as 2-sulfoethyl (meth)acrylate, acrylonitrile, methacrylonitrile, vinyl acetate, styrene, vinyl toluene, α-methylstyrene, polyvinyl compounds such as allyl methacrylate, UV-absorbing or UV-stable polymerizable unsaturated monomers such as 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole and 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, and the like.

[0032] The urethane emulsion is an emulsion in which polyurethane is dispersed. The polyurethane is not particularly limited. For example, the polyurethane is synthesized by combining a diol compound and a diisocyanate compound and subjecting them to a polyaddition reaction.

[0033] The diol compound is not particularly limited. Examples of the diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3,3-dimethyl-1,2-butanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,2-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,2-diethyl-1,3-propanediol, and 2,4-dimethyl-1,3-propanediol. ethyl-2,4-pentanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, hydroquinone, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, polyester polyol, 4,4'-dihydroxy-diphenyl-2,2-propane, 4,4'-dihydroxyphenyl sulfone, and the like.

[0034] Examples of the diisocyanate compound include methylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenylene diisocyanate, 4,4'-biphenylene diisocyanate, dicyclohexylmethane diisocyanate, and methylenebis(4-cyclohexylisocyanate).

[0035] The fluororesin constituting the fluoroemulsion is not particularly limited. As an example, the fluororesin preferably contains at least one selected from a copolymer of a fluorine-containing monomer and a vinyl monomer, and a polyvinylidene fluoride-based resin. In this embodiment, the polyvinylidene fluoride-based resin is polyvinylidene fluoride (PVDF), a copolymer of vinylidene fluoride and another monomer, etc.

[0036] The copolymer of a fluorine-containing monomer and a vinyl monomer is more preferably a copolymer of a fluorine-containing monomer and a vinyl ether monomer described below.

[0037] Examples of the fluorine-containing monomer include tetrafluoroethylene, chlorotrifluoroethylene, trichlorofluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, and trifluoromethyltrifluoroethylene.

[0038] Examples of vinyl monomers include nonionic monoethylenically unsaturated monomers and bifunctional vinyl monomers. Examples of nonionic monoethylenically unsaturated monomers include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, and (meth)acrylic acid esters. Examples of (meth)acrylic acid esters include methyl acrylate, methyl methacrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl methacrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate. Examples of bifunctional vinyl monomers include divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butane-diol dimethacrylate, diethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

[0039] Examples of vinyl ethers include di- or trivinyl ether compounds such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, and trimethylolpropane trivinyl ether; and monovinyl ether compounds such as ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether-o-propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

[0040] The copolymerization ratio of the fluorine-containing monomer and the vinyl monomer is not particularly limited. For example, the copolymerization ratio is fluorine-containing monomer:vinyl monomer=3 to 1:1 to 2 (weight ratio). The polymerization method is not particularly limited. For example, the polymerization method may be solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc.

[0041] The copolymer of a fluorine-containing monomer and a vinyl monomer may be any of an alternating copolymer, a block copolymer, a random copolymer, and a graft copolymer. Among these, the fluororesin is preferably an alternating copolymer of fluoroethylene and a vinyl monomer. In this embodiment, the term "alternating copolymer" refers to a copolymer in which the number of bonds between fluoroethylene units and vinyl monomer units is far greater than the total number of bonds between fluoroethylene units and fluoroethylene units, and bonds between vinyl monomer units and vinyl monomer units. Specifically, the alternating copolymer of a fluorine-containing monomer and a vinyl monomer preferably contains 90 to 100 mol % of bonds between fluoroethylene units and vinyl monomer units. In this embodiment, the alternating copolymer may contain a small number of randomly bonded or block bonded moieties. The bonds may be, for example, 1 H NMR measurement and 29 They can be distinguished by Si NMR measurement, etc. Furthermore, for a method of analyzing alternating copolymerization, see, for example, Journal of Applied Polymer Science, Vol. 106, 1007-1013 (2007).

[0042] The polyvinylidene fluoride (PVDF) of this embodiment refers to a homopolymer of vinylidene fluoride. The PVDF of this embodiment may also be a composite in which the PVDF and another resin are entangled at the molecular level to form a composite, i.e., a composite of PVDF and another resin. An example of a composite of PVDF and another resin is a PVDF / acrylic composite. The polymerization method is not particularly limited. Examples of the polymerization method include suspension polymerization and emulsion polymerization.

[0043] The copolymer of vinylidene fluoride and another monomer refers to a copolymer of vinylidene fluoride and another monomer copolymerizable with vinylidene fluoride. In the copolymer of vinylidene fluoride and another monomer, the vinylidene fluoride component preferably accounts for 50% by weight or more, and more preferably 75% by weight or more of the total weight.

[0044] Examples of other monomers copolymerizable with vinylidene fluoride include fluorine-containing monomers such as tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, trifluorochloroethylene, and vinyl fluoride. The polymerization method is not particularly limited. Examples of the polymerization method include suspension polymerization and emulsion polymerization.

[0045] The content of the binder resin contained in the aqueous resin composition is not particularly limited. For example, the content of the binder resin in the aqueous resin composition is preferably 40% by mass or more, more preferably 50% by mass or more. Furthermore, the content of the binder resin in the aqueous resin composition is preferably 90% by mass or less, more preferably 70% by mass or less. When the content of the binder resin is within the above range, the aqueous resin composition has excellent long-term stability and improves adhesion between the coating film and the substrate.

[0046] The content of water in the aqueous resin composition is not particularly limited. For example, the content of water in the aqueous resin composition is preferably 5% by mass or more, more preferably 10% by mass or more. The content of water in the aqueous resin composition is preferably 30% by mass or less, more preferably 20% by mass or less. By keeping the water content within the above range, the aqueous resin composition can be adjusted to an appropriate viscosity for application by spraying or the like.

[0047] The aqueous resin composition may contain other additives in addition to the above components. The other additives are not particularly limited. Examples of the other additives include a curing agent, a curing catalyst, an ultraviolet absorber, a light stabilizer, a radical stabilizer, an anti-yellowing agent, a coating surface conditioner, a flow conditioner, a pigment dispersant, an antifoaming agent, a thickener, and a film-forming aid.

[0048] The method for producing the aqueous resin composition is not particularly limited. For example, the aqueous resin composition can be produced by various known methods.

[0049] When the resin composition is a powder resin composition, the binder resin preferably contains at least one of a polyester resin, a polyethylene resin, an epoxy resin, and a nylon resin.

[0050] The polyester resin is not particularly limited. For example, the polyester resin is preferably a polyester resin having a hydroxy group, and more preferably a polyester resin terminated with a hydroxy group.

[0051] The polyester resin preferably has an acid group (such as a carboxy group). The polyester resin having an acid group is, for example, a carboxyl group-terminated polyester resin.

[0052] The polyester resin may have both hydroxy groups and acid groups.

[0053] The weight-average molecular weight of the polyester resin is not particularly limited. For example, the weight-average molecular weight is preferably 3,000 to 50,000, and more preferably 5,000 to 40,000. The dispersity (weight-average molecular weight / number-average molecular weight) of the polyester resin is not particularly limited. For example, the dispersity is preferably 1 to 10, and more preferably 1.4 to 8. In this embodiment, the weight-average molecular weight and dispersity can be measured by gel permeation chromatography (GPC) as values ​​converted into standard polystyrene.

[0054] The polyethylene resin is not particularly limited, and examples thereof include ethylene homopolymers such as low-density polyethylene and high-density polyethylene, and linear low-density polyethylene, which is a copolymer of ethylene and an α-olefin.

[0055] The weight-average molecular weight of the polyethylene resin is not particularly limited. For example, the weight-average molecular weight is preferably 20,000 to 300,000, and more preferably 50,000 to 100,000.

[0056] The epoxy resin is not particularly limited, and examples thereof include phenol novolac epoxy resins, cresol novolac epoxy resins, cresol naphthol epoxy resins, biphenyl epoxy resins, biphenyl aralkyl epoxy resins, phenoxy resins, naphthalene skeleton epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, glycidyl ether epoxy resins, aromatic polyfunctional epoxy resins, aliphatic epoxy resins, aliphatic polyfunctional epoxy resins, alicyclic epoxy resins, and polyfunctional alicyclic epoxy resins.

[0057] The epoxy equivalent (g / eq) of the epoxy resin is not particularly limited. For example, the epoxy equivalent (g / eq) is preferably 200 to 3,000, and more preferably 500 to 2,000.

[0058] The weight-average molecular weight of the epoxy resin is not particularly limited. For example, the weight-average molecular weight is preferably 3,000 to 20,000, and more preferably 5,000 to 15,000.

[0059] The nylon resin is not particularly limited, and examples of the nylon resin include nylon 6, nylon 6,6, nylon 3, nylon 4, nylon 7, nylon 11, nylon 12, nylon 6,10, and nylon 6,12.

[0060] The weight-average molecular weight of the nylon resin is not particularly limited. For example, the weight-average molecular weight is preferably 3,000 to 100,000, and more preferably 5,000 to 50,000.

[0061] In addition to the above components, the powder resin composition may contain other components such as a lubricant, an antioxidant, an ultraviolet absorber, a pigment, an antistatic agent, and a flame retardant.

[0062] The method for producing the powder resin composition is not particularly limited. For example, the powder resin composition can be produced by various known methods, such as mixing and kneading the above-mentioned components using various kneading machines such as a Banbury mixer, a roll mixer, a kneader, or an extruder to produce pellets, pulverizing the pellets by a mechanical pulverization method or a freeze-pulverization method, and classifying the pellets to a predetermined particle size using a sieve.

[0063] When the resin composition is an ultraviolet-curable resin composition, the binder resin preferably contains a (meth)acrylate resin.

[0064] The (meth)acrylate resin is not particularly limited. Examples of the (meth)acrylate resin include polymers of alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, and 2-ethylhexyl methacrylate; hydroxy group-containing acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate; and hydroxy group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.

[0065] The weight average molecular weight (Mw) of the acrylic resin emulsion is not particularly limited. For example, Mw is preferably 5,000 to 100,000, and more preferably 10,000 to 50,000.

[0066] In addition to the above components, the ultraviolet-curable resin composition may contain a curing agent, an ultraviolet absorber, a light stabilizer, a film-forming aid, a leveling agent, an antifoaming agent, a curing catalyst, and the like, as appropriate.

[0067] The curing agent is not particularly limited, and examples thereof include carbodiimide-based curing agents, isocyanate-based curing agents, amine-based curing agents, acid anhydride-based curing agents, and oxazoline-based curing agents.

[0068] The carbodiimide curing agent is preferably one having two or more carbodiimide groups, and examples thereof include aromatic polycarbodiimides such as poly(4,4'-diphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(diisopropylphenylcarbodiimide), and poly(triisopropylphenylcarbodiimide); alicyclic polycarbodiimides such as poly(dicyclohexylmethanecarbodiimide); and aliphatic polycarbodiimides such as poly(diisopropylcarbodiimide).

[0069] The isocyanate curing agent may be any compound having two or more isocyanate groups per molecule, and may be any of general-purpose, yellowing-resistant, and non-yellowing types. General-purpose isocyanate curing agents include tolylene diisocyanate (TDI), isocyanurate, which is a TDI trimer, 4,4-diphenylmethane diisocyanate (MDI), and polymeric diphenylmethane diisocyanate (polymeric MDI). Yellowing-resistant isocyanate curing agents include xylylene diamine (XDI). Non-yellowing isocyanate curing agents include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), hydrogenated XDI, and hydrogenated MDI.

[0070] When a curing agent is contained, the content of the curing agent in the resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and is preferably 20% by mass or less, more preferably 10% by mass or less.

[0071] The method for producing the ultraviolet curable resin composition is not particularly limited. For example, the ultraviolet curable resin composition can be produced by various known methods.

[0072] Returning to the explanation of the resin composition as a whole, the resin composition of this embodiment has an average reflectance of 55% or more, preferably 60% or more, and more preferably 70% or more, at wavelengths of 780 to 2100 nm of the coating film formed when the resin composition is applied. The upper limit of the average reflectance is not particularly limited. The upper limit of the average reflectance is set appropriately based on the desired heat-shielding properties, etc. If the average reflectance is less than 55%, the heat-shielding properties of the resulting coating film from the resin composition are likely to be poor. In this embodiment, the average reflectance is determined by applying a commercially available fluororesin paint (Bonflon #1000SR top coat, manufactured by AGC Coatec Co., Ltd.) to a substrate (a chromate-treated aluminum steel plate) with an air spray at a rate of about 150 g / m 2 The resin composition was applied to a sheet of glass (prepared by coating and drying in an environment of 200°C for 3 minutes) so that the wet film thickness was 10 µm, and the average reflectance of the resulting coating film was measured using an ultraviolet-visible-near-infrared spectrophotometer (UV-3600plus, manufactured by Shimadzu Corporation) under conditions in accordance with JIS K 5602. The average reflectance (%) is the average reflectance in the near-infrared region of 780 nm to 2100 nm.

[0073] The use of the resin composition of the present embodiment is not particularly limited. For example, the resin composition may be an ink composition for inkjet printing (hereinafter referred to as an ink composition) or a coating composition.

[0074] In the case of an ink composition, the average particle diameter of the colorant is preferably 100 nm or more, and preferably 600 nm or less, and more preferably 400 nm or less. When the average particle diameter of the colorant is within the above range, the ink composition can be easily adjusted to have appropriate physical properties when inkjet printing is performed. Specifically, the ink composition is less likely to clog nozzles or the like when applied to a substrate, and has excellent ejection stability. In this embodiment, the average particle diameter can be measured by dynamic light scattering using a Zetasizer Nano series manufactured by Malvern Instruments.

[0075] The viscosity of the ink composition is not particularly limited. For example, the viscosity of the ink composition is preferably 2 mPa·s or more, and more preferably 5 mPa·s or more. Furthermore, the viscosity is preferably 50 mPa·s or less, and more preferably 30 mPa·s or less. When the viscosity is within the above range, the ink composition is less likely to cause ejection defects from the inkjet head and has excellent ejection stability. In this embodiment, the viscosity of the ink composition can be measured using a Brookfield viscometer (TVB-20LT, rotor rotation speed 60 rpm, manufactured by Toki Sangyo Co., Ltd.). The method for adjusting the viscosity within the above range is not particularly limited. For example, the viscosity can be adjusted by the amount of each component added or the type and amount of solvent added. The viscosity may be adjusted by using a viscosity modifier such as a thickener, as necessary.

[0076] The surface tension of the ink composition is not particularly limited. The surface tension of the ink composition is preferably 20 dyne / cm or more, and more preferably 22 dyne / cm or more, at 25°C. The surface tension of the ink composition is preferably 40 dyne / cm or less, and more preferably 35 dyne / cm or less, at 25°C. When the surface tension is within the above range, the ink composition has excellent ejection stability. In this embodiment, the surface tension can be measured using a static surface tensiometer (plate method) (CBVP-A3, manufactured by Kyowa Interface Science Co., Ltd.).

[0077] In the case of a coating composition, for example, in the case of spray coating, the coating composition is preferably used in an NK-2 cup, and the time until the liquid stops flowing out of the cup is preferably 5 to 30 seconds, more preferably 10 to 20 seconds.

[0078] As described above, the resin composition of the present embodiment can impart an excellent heat-shielding effect to a substrate to which it is applied.

[0079] <Method for producing inkjet printed matter> A method for producing an inkjet printed matter according to one embodiment of the present invention includes a step of applying the above-described resin composition onto a substrate by an inkjet method, and a step of curing the applied resin composition with ultraviolet light. Each step will be described below. Note that the method for producing an inkjet printed matter according to this embodiment is only required to include these steps, and other steps are not particularly limited.

[0080] First, the resin composition is applied to a substrate by an inkjet method. The method for applying the resin composition (ink) to a substrate by the inkjet method is not particularly limited. Examples of such methods include continuous methods such as a charge modulation method, a microdot method, a charge spray control method, and an ink mist method, and on-demand methods such as a piezo method, a pulse jet method, a bubble jet (registered trademark) method, and an electrostatic suction method.

[0081] An inkjet device for applying ink supplies ink from an ink tank to a pressure chamber via an ink supply path, and applies an electrical signal corresponding to image data to a piezoelectric element to drive the piezoelectric element, thereby deforming a vibration plate that forms part of the pressure chamber, reducing the volume of the pressure chamber, and ejecting the ink in the pressure chamber as droplets from the ejection port of a nozzle (head).

[0082] There are two types of heads: shuttle type (multi-pass type) and line type (single-pass type). The multi-pass type uses a short serial head and performs recording by scanning the head in the width direction of the substrate. On the other hand, the single-pass type uses a full-line head that covers the entire area of ​​the substrate and forms an image over the entire surface of the substrate by moving the full-line head and the substrate relative to each other only once.

[0083] Furthermore, when an ink that is a resin composition is used in an inkjet system as in this embodiment, the ink may be a single-color ink in which various color materials (white color material, black color material, etc.) are mixed, or may be an ink set consisting of each ink (white ink containing a white color material, black ink containing a black color material, etc.).

[0084] The substrate to which the ink is applied is not particularly limited. Examples of substrates include metal plates such as steel plates, aluminum, and stainless steel; plastic plates or films such as acrylic, polycarbonate, ABS, polypropylene, polyester, and vinyl chloride; ceramic plates, concrete, wood, and glass. These substrates are preferably treated with a pretreatment agent before printing. Examples of pretreatment agents include fluorine-based paints, silicone-based paints, acrylic silicone-based paints, acrylic paints, epoxy-based paints, and urethane-based paints. Examples of methods for applying these pretreatment agents to the substrate include spraying, roll coating, curtain flow coating, brush coating, spatula coating, dipping, and inkjet printing. According to this embodiment, a printed product with excellent heat-shielding properties can be obtained.

[0085] The substrate to which the ink has been applied is then irradiated with ultraviolet light to cure. Specifically, the ink ejected onto the substrate is irradiated with ultraviolet light by an ultraviolet irradiation lamp attached to the inkjet device to cure. Examples of the ultraviolet irradiation lamp include a mercury lamp and a gas / solid-state laser. Among these, the ultraviolet irradiation lamp is preferably a mercury lamp or a metal halide lamp. Alternatively, the ultraviolet irradiation lamp may be an ultraviolet light-emitting diode (UV-LED) or an ultraviolet laser diode (UV-LD).

[0086] The cumulative amount of ultraviolet light during curing is not particularly limited. 2 It is preferable that the concentration is 60 mJ / cm or more. 2 It is more preferable that the integrated light amount is 500 mJ / cm or more. 2 Preferably, it is 400 mJ / cm or less. 2 The integrated light amount can be measured using, for example, an ultraviolet illuminance meter / actinometer (UV-351-25, manufactured by Oak Manufacturing Co., Ltd.) under conditions of a measurement wavelength range of 240 to 275 nm and a center measurement wavelength of 254 nm.

[0087] In the present embodiment, the manufacturing method is exemplified when the resin composition is an ultraviolet curable resin composition. Alternatively, when the resin composition is in another form (for example, an aqueous resin composition, a powder resin composition, etc.), an inkjet printed matter can be manufactured by a conventionally known manufacturing method.

[0088] For example, when the resin composition is an aqueous resin composition or a powder resin composition, a drying step may be employed instead of the UV curing step. The drying conditions are not particularly limited. For example, the drying temperature is preferably 50°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. The drying temperature is preferably 400°C or lower, more preferably 300°C or lower, and even more preferably 200°C or lower. The drying time is preferably 1 minute or longer, more preferably 2 minutes or longer, and even more preferably 3 minutes or longer. The drying time is preferably 60 minutes or shorter, more preferably 30 minutes or shorter, and even more preferably 10 minutes or shorter. Under these drying conditions, the colorant in the ink is less likely to discolor and the solvent can be removed. To prevent ink bleeding, drying is preferably performed simultaneously with or immediately after the ink is applied to the substrate.

[0089] The resulting printed matter is an inkjet printed matter to which the ink is applied. Such printed matter has an excellent heat-shielding effect due to the use of the resin composition. Therefore, the inkjet printed matter is suitable as a substrate for use in outdoor units of air conditioners, outdoor distribution boards, exterior panels, etc.

[0090] <Method for manufacturing a paint-coated article> A method for manufacturing a paint-coated article according to one embodiment of the present invention includes a step of applying the above-described resin composition to a substrate by spraying, and a step of thermally curing the applied resin composition. Each step will be described below. Note that the method for manufacturing a paint-coated article according to this embodiment may include these steps, and other steps are not particularly limited.

[0091] First, the resin composition is applied by spraying onto a substrate, which is the same as that described above in relation to the method for producing an inkjet printed matter.

[0092] The conditions for the spray method are not particularly limited. For example, in the electrostatic spray method, the paint atomized by air pressure or the like is negatively charged and the object to be coated is positively charged, so that the paint can be electrically applied to the object to be coated.

[0093] Spray devices include airless spray, air spray, electrostatic spray, and ultrasonic spray.

[0094] The substrate to which the ink has been applied is then thermally cured. The thermal curing conditions are not particularly limited. For example, the thermal curing temperature is preferably 50°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. The thermal curing temperature is preferably 400°C or lower, more preferably 300°C or lower, and even more preferably 200°C or lower. The thermal curing time is preferably 1 minute or longer, more preferably 2 minutes or longer, and even more preferably 3 minutes or longer. The thermal curing time is preferably 60 minutes or shorter, more preferably 30 minutes or shorter, and even more preferably 10 minutes or shorter. Under these thermal curing conditions, the coloring material in the ink is less likely to discolor, and the solvent can be removed. To prevent ink bleeding, thermal curing is preferably performed simultaneously with or immediately after the ink is applied to the substrate.

[0095] The resulting coated article is a paint-coated article to which the resin composition is applied. Due to the use of the resin composition, such a paint-coated article has an excellent heat-shielding effect. Therefore, the paint-coated article is suitable as a substrate for use in an outdoor unit of an air conditioner, an outdoor distribution board, an exterior panel, etc.

[0096] An embodiment of the present invention has been described above. The present invention is not particularly limited to the above embodiment. Note that the above embodiment mainly describes an invention having the following configuration.

[0097] (1) A resin composition comprising a colorant and a binder resin, wherein the colorant comprises a white colorant and a black colorant, and wherein the average reflectance of a coating film formed when the resin composition is applied at a wavelength of 780 to 2100 nm is 55% or more.

[0098] According to this configuration, the resin composition can impart an excellent heat-shielding effect to the substrate to which it is applied.

[0099] (2) The resin composition according to (1), wherein the content of the black coloring material in the resin composition is less than 5% by mass.

[0100] According to this configuration, the resin composition can form a gray coating film on a substrate to which it is applied while maintaining an excellent heat-shielding effect.

[0101] (3) The resin composition according to (1) or (2), wherein the white coloring material contains a titanium oxide pigment and is rod-shaped.

[0102] According to this configuration, the resin composition can impart an excellent heat-shielding effect to the substrate to which it is applied.

[0103] (4) The resin composition according to any one of (1) to (3), wherein the coloring material further includes at least one of a yellow coloring material and a red coloring material.

[0104] According to this configuration, the resin composition can form various light-colored coating films on the substrate to which it is applied while maintaining an excellent heat-shielding effect.

[0105] (5) The resin composition according to (1) or (2), wherein the resin composition is a waterborne resin composition, a powder resin composition, or an ultraviolet-curable resin composition.

[0106] According to this configuration, the resin composition can take various forms such as a water-based resin composition, a powder resin composition, or an ultraviolet-curable resin composition.

[0107] (6) The resin composition according to (5), wherein, when the resin composition is an aqueous resin composition, the binder resin contains at least one of an acrylic emulsion, a urethane emulsion, or a fluorine emulsion; when the resin composition is a powder resin composition, the binder resin contains at least one of a polyester resin, a polyethylene resin, an epoxy resin, or a nylon resin; and when the resin composition is an ultraviolet-curable resin composition, the binder resin contains a (meth)acrylate resin.

[0108] According to this configuration, the resin composition, in each form such as an aqueous resin composition, a powder resin composition, or an ultraviolet-curable resin composition, can impart an excellent heat-shielding effect to a substrate to which it is applied.

[0109] (7) The resin composition according to any one of (1) to (6), wherein the resin composition is an ink composition for inkjet printing, and the average particle diameter of the colorant is 100 to 600 nm.

[0110] According to this configuration, the resin composition can be easily adjusted to have appropriate physical properties when inkjet printing is performed.

[0111] (8) A method for producing an inkjet printed matter, comprising the steps of: applying the resin composition according to any one of (1) to (7) onto a substrate by an inkjet method; and curing the applied resin composition with ultraviolet light.

[0112] According to this configuration, the resulting coated (printed) material has an excellent heat-shielding effect.

[0113] (9) A method for producing a paint-coated article, comprising the steps of applying the resin composition according to any one of (1) to (6) onto a substrate by a spray method, and thermally curing the applied resin composition.

[0114] According to this configuration, the resulting coated object (painted object) has an excellent heat-shielding effect.

[0115] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0116] The raw materials used are as follows. (Colorants) White colorant: titanium oxide pigment, Typec PFR404, manufactured by Ishihara Sangyo Kaisha, Ltd., rod-shaped (minor axis 0.3 to 0.5 μm, major axis 2 to 4 μm) Black colorant 1: Bi-Mn pigment, Black 6301, manufactured by Asahi Chemical Industry Co., Ltd. Black colorant 2: carbon black, NiPex35, manufactured by Orion Engineered Carbons Co., Ltd. Yellow colorant: iron oxide pigment dispersion, Ocher RD230, manufactured by Toyocolor Co., Ltd. (Binder resin) Resin: acrylic resin, Acronal YJ2720D, manufactured by BASF Japan Ltd., acrylic-styrene emulsion, Tg=9°C

[0117] Example 1, Comparative Example 1, and Reference Example 1 Resin compositions of Example 1, Comparative Example 1, and Reference Example 1 were prepared according to the formulations (units: parts by mass) shown in Table 1 below. Specifically, the resin compositions were prepared by mixing each component with a binder resin using a mixer and filtering the mixture. The resulting resin composition was applied to a substrate (hot-dip galvanized steel sheet: TP Giken Co., Ltd.) by air spraying, and then dried in a dryer at 180°C for 3 minutes to produce a coated product. The resulting coating film had a dry film thickness of approximately 30 μm.

[0118]

[0119] When producing the above prints, the solar reflectance (%) of each ink was evaluated according to the following evaluation criteria. The substrate temperature (front and back) of the obtained prints was also measured. The results are shown in Figures 1 to 3. Figure 1 is a graph showing the measurement results of solar reflectance. Figures 2 and 3 are graphs showing the change in substrate temperature over time.

[0120] <Substrate temperature> Immediately after drying, each print was irradiated with a xenon lamp at a distance of 25 cm, and the temperatures of the front and back surfaces of the substrate were measured using a thermograph (model number G-100EX, seller: Nippon Avionics Co., Ltd.) from immediately after drying (initial stage) until 60 minutes later.

[0121] <Solar reflectance> For the front and back surfaces of the substrate of each of the obtained prints, the solar reflectance (%) in the near-infrared region of 780 nm to 2100 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer (UV-3600plus, manufactured by Shimadzu Corporation) under conditions in accordance with JIS K 5602.

[0122] As shown in FIG. 1 , the printed material of Example 1 of the present invention had a higher solar reflectance in the infrared region (particularly 780 nm to 2100 nm) and exhibited excellent heat-shielding properties compared to the printed material of Comparative Example 1. Despite being colored and containing a black colorant, the printed material of Example 1 had excellent heat-shielding properties comparable to those of the white printed material of Reference Example 1. Furthermore, as shown in FIGS. 2 and 3 , the printed material of Example 1 of the present invention had a substrate surface temperature approximately 3 to 4°C lower than that of the printed material of Comparative Example 1. Despite being colored and containing a black colorant, the printed material of Example 1 had excellent heat-shielding properties comparable to those of the white printed material of Reference Example 1. This suggests that the resin composition and printed material of the present invention, when applied to equipment installed outdoors, such as the outdoor unit of an air conditioner, can suppress temperature increases in such equipment and are effective in preventing equipment failures. Furthermore, the resin composition and printed material of the present invention can be used in variations other than white (e.g., light colors such as gray and beige), which is thought to improve the flexibility of the appearance of the equipment to which they are applied.

Claims

1. A resin composition comprising a colorant and a binder resin, the colorant including a white colorant and a black colorant, and a coating film formed when the resin composition is applied has an average reflectance of 55% or more at wavelengths of 780 to 2100 nm.

2. The resin composition according to claim 1, wherein the content of the black coloring material in the resin composition is less than 5 mass %.

3. The resin composition according to claim 1 or 2, wherein the white coloring material contains a titanium oxide pigment and is rod-shaped.

4. The resin composition according to claim 1 or 2, wherein the coloring material further includes at least one of a yellow coloring material and a red coloring material.

5. The resin composition according to claim 1 or 2, wherein the resin composition is a water-based resin composition, a powder resin composition or an ultraviolet-curable resin composition.

6. The resin composition according to claim 5, wherein, when the resin composition is an aqueous resin composition, the binder resin comprises at least one of an acrylic emulsion, a urethane emulsion, or a fluorine emulsion; when the resin composition is a powder resin composition, the binder resin comprises at least one of a polyester resin, a polyethylene resin, an epoxy resin, or a nylon resin; and when the resin composition is an ultraviolet-curable resin composition, the binder resin comprises a (meth)acrylate resin.

7. The resin composition according to claim 1 or 2, which is an ink composition for ink-jet printing, and the average particle size of the coloring material is 100 to 600 nm.

8. A method for producing an inkjet print, comprising the steps of: applying the resin composition according to claim 1 or 2 onto a substrate by an inkjet method; and curing the applied resin composition with ultraviolet light.

9. A method for producing a coated article, comprising the steps of: applying the resin composition according to claim 1 or 2 onto a substrate by a spray method; and thermally curing the applied resin composition.