JP2010150353A - Infrared reflective black pigment, method for producing the same, and paint and resin composition using the infrared reflective black pigment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared reflective black pigment whose principal component is cupric oxide and having excellent acid resistance as well as excellent infrared reflectiveness. <P>SOLUTION: The black pigment obtained by coating a surface of a cupric oxide particle with a surface treating agent has an average particle diameter of 0.02-5.0 μm, wherein the formed coating layer has acid resistance, the coating amount is 0.1-10 wt.% relative to the amount of the cupric oxide, and the black pigment has excellent acid resistance and a solar radiation reflectance, measured according to JIS R3106, of ≥18%. The black pigment having excellent acid resistance can be obtained by heat-treating a cupric oxide particle at a predetermined temperature after surface coating with the surface treating agent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an infrared-reflective black pigment capable of obtaining a heat-shielding paint having cupric oxide as a main component and excellent in acid resistance and having excellent infrared reflectivity.

  Roads, buildings, stockpile tanks, automobiles, ships, etc. used outdoors increase the internal temperature due to solar radiation, so sunlight is reduced by changing the exterior paint of buildings and automobiles from white to light. It is reflected to increase the heat shielding effect to some extent.

  However, in particular, the roofs of outdoor buildings are often dark to black in order to make the dirt inconspicuous. Compared to buildings and automobiles having a light-to-white appearance paint, it is easier to absorb sunlight, and the indoor temperature tends to rise remarkably. It is not preferable that the temperature of the interior becomes high during transportation and storage of the article.

  Therefore, from the viewpoint of energy saving for preventing global warming, it is strongly desired to suppress an increase in internal temperature of buildings and automobiles having a dark to black appearance.

  Conventionally, heat-shielding black paints are known in order to reduce an increase in internal temperature of buildings and automobiles having a dark-colored to black appearance coating (see, for example, Patent Documents 1 to 3). In addition, strontium iron oxide perovskite having excellent blackness is known (for example, see Patent Document 4). Further, magnesium and aluminum-containing iron oxides having excellent blackness are known (see, for example, Patent Document 5). However, it has the following problems.

Patent Document 1 describes a black calcined pigment having a spinel structure composed of CoO, Cr ₂ O ₃ and Fe ₂ O ₃ , which contains Cr and has an infrared region wavelength of 780 to 2500 nm. The average reflectance was less than 30%, and it was difficult to say that it had a sufficient heat shielding effect.

Patent Document 2 describes a black pigment composed of a calcined pigment containing Fe ₂ O ₃ as an essential component and containing Cr ₂ O ₃ , Mn ₂ O _3, or NiO, but contains Cr. Therefore, it is not preferable.

  Patent Document 3 describes a black complex oxide composed of rare earth elements, alkaline earth metals, and iron, but it is difficult to say that it has a sufficient heat shielding effect.

  Patent Document 4 describes a strontium iron oxide perovskite having excellent blackness, but has an average reflectance of 10% or less at a visible light region wavelength of 250 to 780 nm and an infrared region wavelength of 780. Since the average reflectance at ˜2500 nm is less than 30%, a sufficient heat shielding effect is not obtained.

  Patent Document 5 describes magnesium-aluminum-containing spinels with excellent blackness, but has an average reflectance of 10% or less at a visible light region wavelength of 250 to 780 nm and an infrared region wavelength of 780. Since the average reflectance at ˜2500 nm is less than 30%, a sufficient heat shielding effect is not obtained.

Patent Document 6 discloses experimental data that pigments mainly composed of CuO—Cr ₂ O ₃ have low solar reflectance and near infrared reflectance.

  In order to solve the above problems, the present applicant has developed an infrared reflective black pigment that does not contain harmful elements and has excellent infrared reflectivity, and has already filed a patent application (see Patent Document 7). This black pigment contains Fe, Co, and Al, and further includes a composite oxide containing one or more metal elements selected from Mg, Ca, Sr, Ba, Ti, Zn, Sn, Zr, Si, and Cu. The black pigment is an infrared reflective black pigment having an average particle diameter of 0.02 to 2.0 μm, does not contain harmful elements, and has excellent infrared reflectivity. However, it cannot be said that the reflectance in the infrared region wavelength of 1500 nm is sufficiently high.

JP 2000-72990 A JP 2001-311049 A JP 2004-83616 A JP 2000-264639 A JP 2003-238164 A JP 2002-331611 A JP 2007-197570 A

There is CuO as a black pigment other than the black pigment. Although CuO is excellent in blackness and heat shielding properties, it has a problem in acid resistance. A black or brown pigment using CuO as a raw material has also been proposed, and a near-infrared reflective pigment containing a compound represented by the chemical formula Cu ₂ MgO ₃ is disclosed (Japanese Patent Laid-Open No. 2007-204296).

  Although some black pigments have been developed as black pigments that do not contain harmful elements and have excellent infrared reflectivity as described above, these pigments are not necessarily sufficient, and further improvements are required. Yes.

  An object of the present invention is to provide an infrared reflective black pigment which contains cupric oxide as a main component, has excellent infrared reflectivity and is excellent in acid resistance.

  The object can be achieved by the present invention as follows.

  That is, the present invention is a black pigment having an average particle diameter of 0.02 to 5.0 μm obtained by coating the surface of cupric oxide particles with a surface treatment agent, and the coating layer has acid resistance, An infrared reflective black pigment characterized in that the amount is 0.1 to 10% by weight based on cupric oxide (Invention 1).

  In the present invention, the surface treatment agent for coating the surface of the infrared reflective black pigment according to claim 1 is one or more compounds selected from Si, Al, Zr, Ti, Zn, and P, or an organic surface treatment. It is an infrared reflective black pigment characterized by being an agent (Invention 2).

Further, the present invention is an infrared reflective black pigment characterized in that the lightness (L ^* ) of the infrared reflective black pigment according to claim 1 or 2 is 30 or less (Invention 3).

  In addition, the present invention is an infrared reflective black pigment characterized in that the solar reflectance of the infrared reflective black pigment according to any one of claims 1 to 3 is 18% or more (Invention 4). ).

  The present invention also includes a coating step for coating the surface of the cupric oxide particles with a surface treatment agent, and a heat treatment for heat-treating the cupric oxide particles coated with the surface treatment agent at a temperature of 150 to 300 ° C. The method for producing an infrared reflective black pigment according to claim 1, characterized by comprising a step (Invention 5).

  Moreover, this invention paints the infrared reflective black pigment obtained by the infrared reflective black pigment of any one of Claims 1 thru | or 4, or the manufacturing method of the infrared reflective black pigment of Claim 5. It is the coating material characterized by mix | blending in the structure base material (this invention 6).

  Moreover, this invention uses the infrared reflective black pigment obtained by the manufacturing method of the infrared reflective black pigment of any one of Claims 1 thru | or 4, or the infrared reflective black pigment of Claim 5. And a colored resin composition (Invention 7).

  The infrared reflective black pigment according to the present invention is suitable as an infrared reflective black pigment because it contains cupric oxide as a main component, has excellent infrared reflectivity and is excellent in acid resistance.

  The configuration of the present invention will be described in more detail as follows.

  First, the infrared reflective black pigment according to the present invention will be described.

  The infrared reflective black pigment according to the present invention is a black pigment having an average particle diameter of 0.02 to 5.0 μm obtained by using cupric oxide particles as core particles and coating the surface of the particles with a surface treatment agent. The coating layer has acid resistance and the coating amount is 0.1 to 10% by weight with respect to cupric oxide.

  When the average particle diameter of the black pigment exceeds 5.0 μm, the particle size is too large, and the coloring power is reduced. When the average particle size is less than 0.02 μm, dispersion in the vehicle may be difficult. Preferably it is 0.025-4.8 micrometers, More preferably, it is 0.04-4.5 micrometers.

  The coating layer covering the surface of the cupric oxide particles needs to have acid resistance. In the infrared reflective black pigment according to the present invention, since the core particles are composed of cupric oxide particles having low acid resistance, acid resistance is ensured as a pigment by giving the coating layer covering the core particles acid resistance. . On the other hand, if the coating amount is less than 0.1% by weight based on cupric oxide, cupric oxide as the core particles cannot be sufficiently coated, and the acid resistance of the pigment becomes insufficient. On the other hand, if the coating amount exceeds 10% by weight with respect to cupric oxide, the acid resistance effect is saturated, and it is uneconomical to coat more than necessary.

Further, the BET specific surface area of the infrared reflective black pigment according to the present invention is preferably 1 to 100 m ² / g. When the BET specific surface area is less than 1 m ² / g, the particles are coarse or the particles are sintered between the particles and the coloring power is reduced. More preferably, it is 1.5-75 m < ² > / g, More preferably, it is 1.8-60 m < ² > / g.

Further, the lightness (L ^* ) of the infrared reflective black pigment according to the present invention has an upper limit of about 30.0. When the lightness (L ^* ) exceeds 30, it is difficult to say that the blackness is excellent. More preferably, it is 28 or less.

The a ^* of the infrared reflective black pigment according to the present invention is preferably −1 to +10. When a ^* is outside the above range, it is difficult to say that the blackness is excellent. More preferably, it is -1 to +5.

The b ^* of the infrared reflective black pigment according to the present invention is preferably -5 to +10. When b ^* is outside the above range, it is difficult to say that the blackness is excellent. More preferably, it is -2 to +5.

  The infrared reflectivity of the infrared reflective black pigment according to the present invention is preferably 18% or more, more preferably 20% or more, when the lacquer color sample coating film is measured according to JIS R3106. . If the solar reflectance is less than 18%, it cannot be said that the solar reflectance is sufficiently high.

  In the infrared reflective black pigment according to the present invention, the average particle size of the cupric oxide particles as the core particles is 0.018 to 4.80 μm, preferably 0.02 to 4.5 μm, more preferably 0.04 to. 4.0 μm. When the average particle diameter of the cupric oxide particles is less than 0.018 μm, the intermolecular force is increased due to the finer particles, and aggregation tends to occur. Therefore, the surface treatment agent on the surface of the cupric oxide particles is uniform. The coating process becomes difficult. On the other hand, when the average particle diameter exceeds 4.8 μm, the resulting infrared reflective black pigment also becomes coarse particles and the coloring power decreases.

The shape of the cupric oxide particles is not limited to a specific shape, and spherical particles, granular particles, octahedral particles, hexahedron particles, polyhedron particles, etc., needle particles, spindle particles, rice particles, etc. Plate-like particles and the like can be used. Considering the dispersibility of the resulting black pigment, spherical particles and granular particles are preferred.
In addition to commercially available products, the cupric oxide particles can also be obtained by, for example, neutralizing copper sulfate aqueous solution with sodium hydroxide and sulfuric acid to obtain cupric hydroxide, washing with water, drying and heat treatment.

  The particle shape and particle size of the infrared reflective black pigment according to the present invention largely depend on the particle shape and particle size of the cupric oxide particles that are the core particles, and have a particle form similar to the core particles. Have a slightly larger particle size.

Moreover, the BET specific surface area of a cupric oxide particle is 1-200 m < ² > / g, Preferably it is 1.5-150 m < ² > / g, More preferably, it is 2.0-100 m < ² > / g. When the BET specific surface area is less than 1 m ² / g, the cupric oxide particle powder is coarse, and particles are sintered between the particles. The resulting black pigment is also coarse particles. As a result, the coloring power is reduced. When the BET specific surface area exceeds 200 m ² / g, it is easy to cause aggregation due to an increase in intermolecular force due to the refinement of the particles, and thus it is difficult to uniformly coat the surface of the cupric oxide particles with the surface treatment agent. Become.

  In the infrared reflective black pigment according to the present invention, the surface treatment agent that coats the cupric oxide particles as the core particles is one or more compounds selected from Si, Al, Zr, Ti, Zn, and P, or an organic system. A surface treating agent can be used.

  As one or more kinds of compounds selected from Si, Al, Zr, Ti, Zn, and P, as aluminum compounds, aluminum salts such as aluminum acetate, aluminum sulfate, aluminum chloride, and aluminum nitrate; and aluminates such as sodium aluminate Alkali salts can be used. As the silicon compound, No. 3 water glass, sodium orthosilicate, sodium metasilicate and the like can be used. As the zirconium compound, zirconium salts such as zirconium acetate, zirconium sulfate, zirconium chloride, and zirconium nitrate can be used. As the titanium compound, titanium salts such as titanium acetate, titanium sulfate, titanium chloride, and titanium nitrate can be used. As the zinc compound, zinc salts such as zinc acetate, zinc sulfate, zinc chloride, and zinc nitrate can be used. As the phosphorus compound, phosphates such as sodium hydrogen phosphate, sodium ammonium hydrogen phosphate, potassium phosphate, sodium polyphosphate, sodium hexametaphosphate and the like can be used.

  Organic surface treatment agents include stearic acid or salts thereof, rosin, alkoxysilanes, fluoroalkylsilanes, silane coupling agents, organosilicon compounds such as organopolysiloxanes, titanates, aluminates, and zirconates. Examples thereof include a ring agent, a low molecular or high molecular surfactant, and a phosphoric acid compound.

  Specific examples of the organosilicon compound include methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, and ethyl. Alkoxysilanes such as triethoxysilane, propyltriethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane and decyltriethoxysilane, trifluoropropyltrimethoxysilane, tridecafluorooctyltri Methoxysilane, heptadecafluorodecyltrimethoxysilane, trifluoropropyltriethoxysilane, heptadecafluorodecyltrie Fluoroalkylsilanes such as xylsilane and tridecafluorooctyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane Silane cups such as γ-methacryloyloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane Examples include ring agents, organopolysiloxanes such as polysiloxane, methylhydrogen polysiloxane, and modified polysiloxane.

  Examples of titanate coupling agents include isopropyl tristearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethylaminoethyl) titanate, tetraoctyl bis (ditridecyl phosphate) titanate, tetra (2- Examples include 2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, and bis (dioctylpyrophosphate) ethylene titanate.

  Examples of the aluminate coupling agent include acetoalkoxy aluminum diisopropylate, aluminum diisopropoxy monoethyl acetoacetate, aluminum trisethyl acetoacetate, and aluminum trisacetylacetonate.

  Examples of the zirconate coupling agent include zirconium tetrakisacetylacetonate, zirconium dibutoxybisacetylacetonate, zirconium tetrakisethylacetoacetate, zirconium tributoxymonoethylacetoacetate, zirconium tributoxyacetylacetonate and the like.

  Examples of the low molecular surfactant include alkylbenzene sulfonate, dioctyl sulfone succinate, alkylamine acetate, alkyl fatty acid salt and the like. Examples of the polymeric surfactant include polyvinyl alcohol, polyacrylate, carboxymethylcellulose, acrylic acid-maleate copolymer, and olefin-maleate copolymer.

  Examples of phosphoric acid compounds include organic phosphorus compounds such as phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters, and phosphonic acids.

  Next, the manufacturing method of the infrared reflective black pigment which concerns on this invention is described.

  First, cupric oxide particles are used as core particles, and the surface of the core particles is coated with a surface treatment agent. Then, the infrared-reflective black pigment according to the present invention can be obtained by heat-treating the particles coated with the surface treatment agent at a temperature of 150 to 300 ° C. By mixing cupric oxide particles and a surface treatment agent, an infrared-reflective black pigment coated with the particle surface can be obtained, but in this state, the chemical resistance of the coating layer, particularly acid resistance is insufficient. It is. The same applies when the particles coated with the surface treatment agent are heat-treated at a temperature of less than 150 ° C. On the other hand, the coating layer becomes sufficiently strong at a temperature of 300 ° C. and does not need to be heated above 300 ° C. Further, heating at a temperature higher than necessary exceeding 300 ° C. is not preferable because the specific surface area of the cupric oxide particles that are the core particles decreases.

  The surface treatment agent may be coated on the surface of the core particles according to a conventional method such as a dry method or a wet method. In the case of dry processing, the core particles and the surface treatment agent may be mechanically mixed and stirred, or may be mechanically mixed and stirred while spraying the surface treatment agent on the core particles. Almost all of the added surface treatment agent is coated on the surface of the core particles.

  In order to uniformly coat the surface of the core particles with the surface treatment agent, it is preferable to previously unaggregate the core particles using a pulverizer.

  As an apparatus used for mixing and stirring the core particles and the surface treatment agent, an apparatus capable of applying a shearing force to the powder layer is preferable, and an apparatus capable of simultaneously performing shearing, spatula and compression, for example, a wheel type kneader It is preferable to use a ball-type kneader, a blade-type kneader, or a roll-type kneader. A wheel-type kneader can be used more effectively.

  Examples of the wheel-type kneader include edge runners (synonymous with “mix muller”, “Simpson mill”, “sand mill”), multi-mal, stotz mill, wet pan mill, conner mill, ring muller, etc., preferably edge Runners, multi-mals, stocks mills, wet pan mills and ring mullers are preferred, and edge runners are more preferred. As the ball kneader, there is a vibration mill. Examples of the blade type kneader include a Henschel mixer, a planetary mixer, and a nauta mixer. As the roll type kneader, there is an extruder.

  The mixing and stirring conditions of the core particles and the surface treatment agent may be appropriately adjusted so that the surface treatment agent is coated as uniformly as possible on the surface of the core particles, and the line load is 19.6 to 1960 N / cm (2 to 2). 200 kg / cm), more preferably 98 to 1470 N / cm (10 to 150 kg / cm), most preferably 147 to 980 N / cm (15 to 100 kg / cm), and the treatment time is 5 minutes to 24 hours. More preferably, the range is from 10 minutes to 20 hours, and the stirring speed is preferably from 2 to 2000 rpm, more preferably from 5 to 1000 rpm, and most preferably from 10 to 800 rpm.

  For example, when the silane coupling agent is dry-processed with a Henschel mixer, the core particles, water, auxiliary agent, and alcohol are premixed for 1 hour at a low speed. Then, it adjusts to high speed rotation and maintains at 130 degreeC for 1 hour, Then, it cools and discharges with water. Thereafter, it is heated at 150 ° C. for 1 hour.

  Moreover, when surface-treating zinc stearate by a dry method, it is treated with a vibration mill for 30 minutes and then dried at a temperature of 150 ° C. with a dryer.

  In the wet method, one or more soluble compounds selected from Si, Al, Zr, Ti, Zn, and P are added to a slurry of cupric oxide particles dispersed in a wet state while adjusting the pH with acid or alkali. -Mix and cover. Thereby, the surface of a core particle can be coat | covered with a hydroxide or an oxide. In the case of an organic surface treatment agent, the organic surface treatment agent may be put on and coated on the wet-dispersed core particle slurry.

  For example, while stirring cupric oxide particles as core particles in pure water, No. 3 water glass, sulfuric acid, and sodium hydroxide were added dropwise so that the pH was 6-8, and maintained at 80 ° C. for 1 hour. Then, it is washed with water and dried. Thereafter, heating may be performed at a temperature of 150 ° C. for 1 hour.

  When two or more kinds of surface treatment agents are used, for example, zirconium sulfate, sodium aluminate, sulfuric acid, and sodium hydroxide have a pH of 6 while stirring cupric oxide particles as core particles in pure water. After adding dropwise so as to be ˜8 and maintaining at 80 ° C. for 1 hour, it is washed with water and filtered and dried. Further, it may be heated at a temperature of 180 ° C. for 1 hour.

  Next, a paint containing the infrared reflective black pigment according to the present invention will be described.

  The blending ratio of the infrared reflective black pigment in the paint according to the present invention can be used in the range of 0.5 to 100 parts by weight with respect to 100 parts by weight of the paint base material, and the handleability of the paint is taken into consideration. For example, it is preferably 1.0 to 100 parts by weight.

  As the paint constituent base material, a resin, a solvent, and if necessary, fats and oils, an antifoaming agent, an extender pigment, a drying accelerator, a surfactant, a curing accelerator, an auxiliary agent and the like are blended.

  Resins include acrylic resin, alkyd resin, polyester resin, polyurethane resin, epoxy resin, phenol resin, melamine resin, amino resin, vinyl chloride resin, silicone resin, gum rosin that are usually used for solvent-based paints and oil-based printing inks. Rosin resin such as lime rosin, maleic acid resin, polyamide resin, nitrocellulose, ethylene-vinyl acetate copolymer resin, rosin modified phenolic resin, rosin modified maleic resin and other rosin modified resins, petroleum resin, fluororesin, etc. be able to. For water-based paints, water-soluble acrylic resins, water-soluble styrene-maleic acid resins, water-soluble alkyd resins, water-soluble melamine resins, water-soluble urethane emulsion resins, water-soluble epoxies commonly used for water-based paints and water-based inks Resins, water-soluble polyester resins, water-soluble fluororesins, and the like can be used.

  Solvents include soybean oil, toluene, xylene, thinner, butyl acetate, methyl acetate, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, etc. Glycol ether solvents, ester solvents such as ethyl acetate, butyl acetate, and amyl acetate, aliphatic hydrocarbon solvents such as hexane, heptane, and octane, alicyclic hydrocarbon solvents such as cyclohexane, and petroleum-based solvents such as mineral spirits Solvents, ketone solvents such as acetone and methyl ethyl ketone, alcohol solvents such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol, aliphatic hydrocarbons, and the like can be used.

  Water-based paint solvents include water and alcohol-based solvents usually used for water-based paints such as ethyl alcohol, propyl alcohol and butyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve and other glycol ether solvents, diethylene glycol , Oxyethylene or oxypropylene addition polymers such as triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, alkylene glycol such as ethylene glycol, propylene glycol, 1,2,6-hexanetriol, glycerin, It can be used by mixing with a water-soluble organic solvent such as 2-pyrrolidone.

  As oils and fats, boil oils obtained by processing dry oils such as linseed oil, persimmon oil, sea lion oil, safflower oil and the like can be used.

  Antifoaming agents include Nopco 8034 (product name), SN deformer 477 (product name), SN deformer 5013 (product name), SN deformer 247 (product name), SN deformer 382 (product name) (all of these are San Nopco Commercially available products such as manufactured by Co., Ltd., Antihome 08 (trade name), Emulgen 903 (trade name) (all of which are manufactured by Kao Corporation) can be used.

  Next, the resin composition containing the infrared reflective black pigment according to the present invention will be described.

  The blending ratio of the infrared reflective black pigment in the resin composition according to the present invention can be used in the range of 0.01 to 200 parts by weight with respect to 100 parts by weight of the resin, and the handling property of the resin composition is taken into consideration. Thus, the amount is preferably 0.05 to 150 parts by weight, more preferably 0.1 to 100 parts by weight.

  As a constituent substrate in the resin composition according to the present invention, an additive such as a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, and various stabilizers, if necessary, together with an infrared reflective black pigment and a known thermoplastic resin. Is blended.

  Examples of the resin include polyolefins such as polyethylene, polypropylene, polybutene, and polyisobutylene, polyvinyl chloride, polymethylpentene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, styrene-acrylic acid ester copolymer, styrene-vinyl acetate copolymer, Acrylonitrile-butadiene-styrene copolymer, acrylonitrile-EPDM-styrene copolymer, acrylic resin, polyamide, polycarbonate, polyacetal, polyurethane and other thermoplastic resins, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, Silicone resin, rosin ester, rosin, natural rubber, synthetic rubber and the like can be used.

  The amount of the additive may be 50% by weight or less based on the sum of the infrared reflective black pigment and the resin. When the content of the additive exceeds 50% by weight, the moldability is lowered.

  The resin composition according to the present invention is prepared by mixing a resin raw material and an infrared reflective black pigment in advance, and then applying a strong shearing action under heating using a kneader or an extruder to produce an infrared reflective black pigment. The aggregate is broken and the infrared reflective black pigment is uniformly dispersed in the resin composition, and then molded into a shape suitable for the purpose.

  The resin composition according to the present invention can also be obtained via a master batch pellet.

  The master batch pellet in the present invention is a blender such as a ribbon blender, a Nauter mixer, a Henschel mixer, a super mixer, etc., if necessary, a binder resin as a constituent substrate of a paint and a resin composition and the infrared reflective black pigment. Kneaded with a well-known single-screw kneading extruder or twin-screw kneading extruder, etc., then cut or kneaded with the above mixture with a Banbury mixer, pressure kneader or the like It is manufactured by crushing, molding or cutting.

  As for the supply of the binder resin and the infrared reflective black pigment to the kneader, each of them may be supplied at a predetermined ratio, or a mixture of both may be supplied.

  The master batch pellet in the present invention has an average major axis of 1 to 6 mm, preferably 2 to 5 mm. The average minor axis is 2 to 5 mm, preferably 2.5 to 4 mm. When the average major axis is less than 1 mm, the workability at the time of producing the pellet is bad and not preferable. When the thickness exceeds 6 mm, the difference from the size of the binder resin for dilution is large, and it becomes difficult to sufficiently disperse. Moreover, the shape can be various, and can be indefinite and spherical, cylindrical, flakes, and the like.

  As the binder resin used for the master batch pellet in the present invention, the same resin as the resin for resin composition can be used.

  The composition of the binder resin in the masterbatch pellet may be the same resin as the diluent binder resin or a different resin, but if different resins are used, What is necessary is just to determine in consideration of the various characteristics determined by the compatibility.

  The amount of the infrared reflective black pigment blended in the master batch pellet is 1 to 200 parts by weight, preferably 1 to 150 parts by weight, more preferably 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin. . When the amount is less than 1 part by weight, the melt viscosity at the time of kneading is insufficient, and it is difficult to disperse and mix the infrared reflective black pigment. When the amount exceeds 200 parts by weight, since there is little binder resin for the infrared reflective black pigment, good dispersion and mixing of the infrared reflective black pigment is difficult, and the resin composition can be changed by a slight change in the addition amount of the master batch pellet. Since the content of the infrared-reflective black pigment blended in the product greatly changes, it is difficult to prepare the desired content, which is not preferable. Also, mechanical wear is severe and not suitable.

<Action>
The most important point in the present invention is that the infrared reflective black pigment according to the present invention contains cupric oxide as a main component, does not contain harmful elements, has excellent infrared reflectivity, and is excellent in acid resistance. It is a fact.

  Although the infrared-reflective black pigment according to the present invention uses cupric oxide that is excellent in infrared reflectivity but inferior in acid resistance as a core particle, the surface of the core particle is coated with an acid-resistant coating layer, Excellent acid resistance was achieved while having high infrared reflectivity.

Moreover, the infrared reflective black pigment according to the present invention does not contain a harmful metal element such as Cr ⁶⁺ and is a safe pigment.

  A typical embodiment of the present invention is as follows.

  The average particle size of the particles was measured by measuring the particle size of 350 particles shown in the electron micrograph, and the average value was shown.

  The specific surface area was shown by the value measured by BET method.

  Contained in organosilane compounds or polysiloxanes produced from the amount of Si, Al, Zr, Ti, Zn and P present in the interior and surface of cupric oxide particles and infrared reflective black pigments, and organic surface treatment agents Each of the amount of Si used was measured using a “fluorescence X-ray analyzer 3063M type” (manufactured by Rigaku Denki Kogyo Co., Ltd.) according to JIS K0119 “General Rules for Fluorescence X-ray Analysis”.

The hue (L ^* value, a ^* value, b ^* value) of the infrared reflective black pigment was prepared by mixing 0.5 g of a sample and 0.5 ml of castor oil with a Hoover type Mahler to form a paste. .5 g, kneaded and coated to form a coating piece (coating thickness: about 30 μm) coated on cast-coated paper using a 150 μm (6 mil) applicator. Measurement was performed using “MSC-IS-2D” (manufactured by Suga Test Instruments Co., Ltd.), and the color index (L ^* value, a ^* value, b ^* value) was indicated according to JIS Z8729.

  The solar reflectance of the infrared-reflective black pigment was measured according to JIS R3106 using a “spectrophotometer UV-3100PC” (Shimadzu Corporation) for the coating piece prepared for measuring the above hue.

  The acid resistance of the infrared reflective black pigment was evaluated in accordance with JIS K5101-8 “Pigment Test Method Part 8: Chemical Resistance”. Add 2 g of pigment and 20 ml of 2% sulfuric acid to the test tube and seal it for 5 minutes. After shaking and allowing to stand at room temperature, the Cu amount of the solution after filtration and separation was measured by ICP, and dissolved Cu was analyzed.

The paint containing the infrared reflective black pigment was evaluated in the following manner.
In mayonnaise bin (internal volume 140 ml), 90 g of glass beads, 10 g of black pigment, 16.0 g of amino alkyd resin (clear), 6.0 g of solvent were mixed, dispersed for 40 minutes with a paint conditioner, and further aluminum alkyd resin ( After adding 50 g of (clear), it was dispersed with a paint conditioner for 5 minutes and separated from glass beads. Thereafter, the mixture was allowed to stand for 24 hours to precipitate the black pigment. Evaluation was made based on the ease and difficulty of redispersibility when the precipitate was stirred with a stirrer.

Example 1
Add 2.5% by weight of silane coupling agent (1% by weight in terms of SiO ₂ ), 0.25% by weight of water and 1.75% by weight of alcohol to CuO particles, and reserve for 1 hour at low speed with a Henschel mixer. Mixed. Thereafter, the Henschel mixer was adjusted to high speed rotation, maintained at 130 ° C. for 1 hour, cooled with water and discharged. Thereafter, the core particles coated with the surface treatment agent were heat-treated at 150 ° C. for 1 hour. The heat-treated product was pulverized to obtain a black pigment having an average particle size of 0.3 μm and a BET specific surface area of 9.5 m ² / g.

The coating amount of the obtained black pigment was 1% by weight in terms of SiO _{2 with} respect to the core particles, and the solar reflectance was 25%. As a result of evaluating acid resistance, the concentration of Cu in the solution was as low as 890 ppm, and the redispersibility after settling in the paint was also good.

Example 2
While stirring in pure water, 6.0% by weight of sodium aluminate (2% by weight in terms of Al ₂ O ₃ ) is added dropwise to CuO particles so that sulfuric acid and sodium hydroxide have a pH of 6-8. And maintained at 80 ° C. for 1 hour, then washed with water and dried by filtration. Thereafter, heat treatment was performed at a temperature of 250 ° C. for 1 hour. The heat-treated product was pulverized to obtain a black pigment having an average particle size of 0.85 μm and a BET specific surface area of 2.6 m ² / g.
The coating amount of the obtained black pigment was 2% by weight in terms of Al ₂ O _{3 with} respect to the core particles, and the solar reflectance was 28%. As a result of evaluating acid resistance, the concentration of Cu in the solution was as small as 340 ppm, and the redispersibility after settling in the paint was also good.

Example 3 to Example 4, Comparative Example 1 to Comparative Example 4
A black pigment was obtained in the same manner as in Example 1 except that the surface treatment method, the surface treatment agent, the coating amount, and the heat treatment temperature after the surface treatment were changed.

  Tables 1 and 2 show the production conditions of Examples 1 to 4 and Comparative Examples 1 to 4, the properties of the obtained infrared reflective black pigment, the properties of the paint and the coating film.

  The infrared reflective black pigment according to the present invention is suitable as an infrared reflective black pigment because it is excellent in infrared reflectivity and acid resistance.

Claims (7)

  A black pigment having an average particle diameter of 0.02 to 5.0 μm obtained by coating the surface of cupric oxide particles with a surface treatment agent, the coating layer has acid resistance, and the coating amount is cupric oxide An infrared reflective black pigment characterized by being 0.1 to 10% by weight based on the weight.   The surface treatment agent that coats the surface of the infrared reflective black pigment according to claim 1 is one or more compounds selected from Si, Al, Zr, Ti, Zn, and P, or an organic surface treatment agent. Infrared reflective black pigment. An infrared reflective black pigment, wherein the infrared reflective black pigment according to claim 1 or 2 has a lightness (L ^* ) of 30 or less.   The infrared reflective black pigment, wherein the infrared reflective black pigment according to any one of claims 1 to 3 has a solar reflectance of 18% or more. A coating step of coating the surface of the cupric oxide particles with a surface treatment agent;
A heat treatment step of heat-treating the cupric oxide particles coated with the surface treatment agent at a temperature of 150 to 300 ° C .;
The manufacturing method of the infrared reflective black pigment of Claim 1 characterized by the above-mentioned.   The infrared reflective black pigment according to any one of claims 1 to 4 or the infrared reflective black pigment obtained by the method for producing an infrared reflective black pigment according to claim 5 is blended in a paint constituting substrate. A paint characterized by   It colored using the infrared reflective black pigment obtained by the infrared reflective black pigment of any one of Claims 1 thru | or 4, or the manufacturing method of the infrared reflective black pigment of Claim 5. A resin composition.