Information code, information recording medium and article

Abstract

To provide an information code that can give information without affecting a design of a base material and has high detection sensitivity by an infrared ray.SOLUTION: Provided is an information code in which information readable by infrared irradiation is recorded. The information code has an infrared reflection part and an infrared absorption part. The infrared reflection part and the infrared absorption part have a similar color in hue, and the infrared reflection part and the infrared absorption part are visible light impermeable.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to an information code, an information recording medium, and an article. [Background technology]

[0002] One of the remote sensing technologies using light is LiDAR (Laser Imaging Detection and Ranging), which irradiates an object with near-infrared light, visible light, and / or ultraviolet light and measures the light reflected and / or scattered by the object to detect the distance and direction from the irradiation position to the object. LiDAR technology is essential for autonomous driving systems, for example, that detect obstacles in vehicles and automatically brake, or measure the speed and distance of surrounding vehicles to control the speed and distance of the vehicle itself.

[0003] On the other hand, information codes in which optically readable information is recorded are widely used in various fields, such as product management, production management, distribution management, counterfeit prevention management, etc. If this technology can be applied to the automated driving system, it will be possible to record not only vehicle position control, but also road sign-like information such as regulations and instructions, road surface information, etc., and build a more advanced automated driving system.

[0004] In recent years, the use of information codes recorded with information readable by infrared irradiation in road-to-vehicle cooperative communication systems for vehicle driving assistance, advanced driving assistance, autonomous driving technology, and the like has been under consideration. Information codes are typically patterns that are visible to the naked eye (especially two-color black and white patterns), and are generally written using laser marking or ink marking technology. However, patterns that are visible to the naked eye may reduce the design of the item to which the information code is attached. In addition, if a two-color black and white information code is attached to the road surface, it may be mistaken for an existing white line, etc. If the information code is made small enough to be inconspicuous in order to prevent misrecognition, there is a risk that the detection sensitivity will decrease.

[0005] As an information code that takes design into consideration, Patent Document 1 describes an information-recording laminated material that includes a microsphere fixing layer in which transparent microspheres are aligned; a reflective layer that reflects light transmitted through the transparent microspheres, and a transparent resin layer, both of which are provided on the opposite side of the exposed surface of the transparent microspheres; the reflective layer is provided approximately at the focal point of the transparent microspheres so as to retroreflect at least a portion of the light that is incident on the transparent microspheres back approximately in the direction of incidence; the exposed surface of the transparent microspheres is covered with the transparent resin layer, thereby shifting the focal point of the transparent microspheres from the position of the reflective layer to reduce the retroreflectivity, and information is recorded based on the difference in retroreflectivity between a portion with the transparent resin layer and a portion without the transparent resin layer.

[0006] Patent Document 2 describes an information medium having a substrate 20 having an optically readable information code 10, and a retroreflective layer 30 that is present on the region of the substrate 20 where the information code 10 is arranged and that exhibits retroreflection under retroreflective conditions, in which the retroreflective layer 30 has a transparent sphere layer 31 having transparent spheres with an average particle size y, and the information code 10 has a combination of a first position detection pattern composed of a first light color region and a first dark color region, where the first light color region includes a portion with a width less than 4y, and a second position detection pattern composed of a second light color region and a second dark color region, where the second dark color region includes a portion with a width less than 4y, and in which the information code 10 can be optically read through the retroreflective layer 30 under non-retroreflective conditions. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2007-192883 A [Patent Document 2] JP 2019-40231 A Summary of the Invention [Problem to be solved by the invention]

[0008] The conventional information codes described in Patent Documents 1 and 2 have a complicated manufacturing process and are made of transparent materials, making it difficult to obtain a reflected light of sufficient intensity. In addition, in order to increase the intensity of the reflected light, it is necessary to use expensive materials.

[0009] An object of the present disclosure is to provide an information code that can impart information without affecting the design of a substrate and that has high infrared detection sensitivity. [Means for solving the problem]

[0010] The present disclosure provides the following aspects. [1] An information code in which information that can be read by infrared irradiation is recorded, the information code has an infrared reflecting portion and an infrared absorbing portion, The infrared reflecting portion and the infrared absorbing portion have similar hues, and The infrared reflective portion and the infrared absorbing portion are opaque to visible light. Information code. [2] The information code according to [1], wherein a color difference (ΔE) between the infrared reflective portion and the infrared absorbing portion is 5.0 or less. [3] The infrared reflectance (RR) of the infrared reflective portion is 50% or more, The information code according to [1] or [2], wherein the infrared absorbing portion has an infrared reflectance (RA) of less than 50%. [4] The information code according to any one of [1] to [3], wherein a ratio (RR / RA) of an infrared reflectance (RR) in the infrared reflecting portion to an infrared reflectance (RA) in the infrared absorbing portion is 1.5 or more. [5] The information code according to [3] or [4], wherein the infrared reflectance is one selected from the group consisting of an average spectral reflectance in a wavelength range of 780 to 2,500 nm, an average spectral reflectance in a wavelength range of 830 to 915 nm, and a spectral reflectance at a wavelength of 905 nm and / or a wavelength of 1,550 nm. [6] A substrate and an information code disposed on the substrate, The information code is an information code according to any one of claims 1 to 4, An article, wherein the color difference (ΔE) between the substrate and the infrared reflective portion is 5.0 or less, and / or the color difference (ΔE) between the substrate and the infrared absorbing portion is 5.0 or less. [7] The infrared reflective portion is formed from an infrared reflective coating composition, The infrared reflective coating composition comprises: A coating composition comprising a film-forming resin (A) and a color pigment (B), The color pigment (B) contains a pigment (B1) capable of reflecting near infrared rays, When the reflectance in the wavelength range of 800 to 2,500 nm is taken as the near-infrared reflectance, The pigment (B1) includes at least one pigment selected from the group consisting of a white pigment having a near-infrared reflectance of 60% or more, a chromatic pigment having a near-infrared reflectance of 50% or more, and a black pigment having a near-infrared reflectance of 30% or more, and one selected from a white pigment having a near infrared reflectance of 60% or more and a chromatic pigment having a near infrared reflectance of 50% or more; The information code according to any one of [1] to [4], wherein the pigment (B1) contains an organic pigment, and a content of the organic pigment in the total amount of the pigment (B1) is 3 mass % or more. [8] The color pigment (B) is a white pigment having a spectral reflectance of 70% or more at wavelengths of 905 nm and / or 1,550 nm; an organic red pigment having a spectral reflectance of 50% or more at the wavelength; an inorganic red pigment having a spectral reflectance of 20% or more at the wavelength; an organic yellow pigment having a spectral reflectance of 60% or more at the wavelength; an inorganic yellow pigment having a spectral reflectance of 20% or more at the wavelength; a blue pigment having a spectral reflectance of 40% or more at the wavelength; An organic black pigment having a spectral reflectance of 30% or more at the wavelength, and An inorganic black pigment having a spectral reflectance of 15% or more at the above wavelength. The information code described in [7], which includes at least one selected from the group consisting of: [9] The information code according to [7] or [8], wherein the content of the carbon pigment in the color pigment (B) is less than 0.2 mass% with respect to 100 mass% of a total amount of the color pigment (B).

[10] The infrared absorbing portion is formed from an infrared absorbing coating composition, The infrared absorbing coating composition comprises: Contains a film-forming resin and a color pigment, The color pigment includes a carbon pigment, The information code according to any one of [7] to [9], wherein the content of the carbon pigment is 0.2 mass % or more and 50 mass % or less with respect to 100 mass % of the total amount of the color pigments.

[11] An information recording medium having an information code according to any one of [1] to [4].

[12] An information code described in any one of [1] to [4], which is for a road-to-vehicle cooperative communication system. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide an information code that can impart information without affecting the design of a substrate and has high infrared detection sensitivity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The information code for this disclosure is: An information code in which information that can be read by infrared irradiation is recorded, the information code has an infrared reflecting portion and an infrared absorbing portion, The infrared reflecting portion and the infrared absorbing portion have similar hues, and The infrared reflecting portion and the infrared absorbing portion are opaque to visible light.

[0013] The information code of the present disclosure can provide information without affecting the design and has high infrared detection sensitivity. Although the present disclosure should not be interpreted as being limited to a specific theory, the reason why the information code of the present disclosure can have such an effect is considered to be as follows.

[0014] That is, in the information code of the present disclosure, the infrared reflecting portion and the infrared absorbing portion have the same hue and can be designed to be the same color as the substrate, so that even if both the infrared reflecting portion and the infrared absorbing portion are opaque to visible light, the impact on the design of the article is reduced. And, since both the infrared reflecting portion and the infrared absorbing portion are opaque to visible light, it is considered possible to increase the detection sensitivity by infrared rays while reducing the impact on the design of the article. Furthermore, by providing both the infrared absorbing portion and the infrared reflecting portion, there is also the advantage that an information code can be provided regardless of the infrared reflection characteristics of the substrate.

[0015] In one embodiment, a color being similar to another color may mean, for example, that the color difference (ΔE) between the two colors is preferably 5.0 or less. Such a color difference (ΔE) may be more preferably 0 or more and 4.0 or less, even more preferably 0 or more and 3.5 or less, and even more preferably 0 or more and 3.0 or less.

[0016] In one embodiment, the term "visible light opaque" may preferably mean that the average light transmittance at a wavelength of 380 to 780 nm is less than 30%. The average light transmittance at a wavelength of 380 to 780 nm may preferably be 0% or more and 25% or less, more preferably 0% or more and 20% or less.

[0017] In another embodiment, the visible light opaqueness may preferably mean that the hiding ratio is 70% or more as measured in accordance with JIS K 5600-4-1. The hiding ratio may preferably be 75% or more and 100% or less, more preferably 80% or more and 100% or less.

[0018] In the information code, the infrared reflecting parts and the infrared absorbing parts are arranged to form a pattern containing information. Such an information code may be a one-dimensional code (one-dimensional symbol) in which the infrared reflecting parts and the infrared absorbing parts are arranged in stripes in one direction, or a two-dimensional code (two-dimensional symbol) in which the infrared reflecting parts and the infrared absorbing parts are arranged in two mutually orthogonal directions (for example, the vertical direction and the horizontal direction). An example of such a two-dimensional code is QR Code (registered trademark).

[0019] The information code may be applied to a remote sensing technology. Specifically, the sensing may be a remote sensing technology, which may be a technology for irradiating a detection target with near-infrared rays, detecting reflected light and / or scattered light from the irradiated position, and determining the distance and direction from the emitting position of the near-infrared rays to the irradiated position.

[0020] The wavelength of the near-infrared light used in the sensing is preferably 800 nm or more, more preferably 900 nm or more, and preferably 2,500 nm or less, more preferably 2,000 nm or less, and even more preferably 1,600 nm or less. The shorter the wavelength of near-infrared light, the more linear it is, and the longer the wavelength, the easier it is to eliminate the effects of sunlight. Currently, the wavelengths used in sensing are mainly 905 nm and / or 1,550 nm.

[0021] The infrared reflectance (RR) of the infrared reflecting portion is preferably 50% or more, more preferably 60% or more, and even more preferably 65% ​​or more, and the upper limit may be, for example, 100% or less, and even 90% or less. When the infrared reflectance (RR) of the infrared reflecting portion is in this range, it can be easy to increase the detection sensitivity by infrared rays.

[0022] The infrared reflectance (RA) of the infrared absorbing portion is preferably less than 50%, more preferably 40% or less, and even more preferably 30% or less, and the lower limit may be, for example, 0% or more, and even 10% or more. When the infrared reflectance (RA) of the infrared absorbing portion is in this range, it can be easy to increase the detection sensitivity by infrared rays.

[0023] The ratio (RR / RA) of the infrared reflectance (RR) in the infrared reflecting portion to the infrared reflectance (RA) in the infrared absorbing portion is preferably 1.5 or more, more preferably 1.8 or more, and even more preferably 2.0 or more, and may be, for example, 10 or less, and further 8 or less. When the ratio (RR / RA) is in this range, it can be easy to increase the detection sensitivity by infrared rays.

[0024] In the present disclosure, the infrared reflectance may be one selected from the group consisting of an average spectral reflectance in a wavelength range of 780 to 2,500 nm, an average spectral reflectance in a wavelength range of 830 to 915 nm, and a spectral reflectance at a wavelength of 905 nm and / or a wavelength of 1,550 nm. In one embodiment, the infrared reflectance may be an average spectral reflectance in a wavelength range of 780 to 2,500 nm, in another embodiment, the infrared reflectance may be an average spectral reflectance in a wavelength range of 830 to 915 nm, and in yet another embodiment, the infrared reflectance may be a spectral reflectance at a wavelength of 905 nm and / or a wavelength of 1,550 nm.

[0025] In the present disclosure, the infrared reflectance can be measured using a spectrophotometer in accordance with JIS K 5602:2008. Specifically, the average spectral reflectance in the wavelength range of 780 to 2,500 nm can be calculated by measuring the spectral reflectance in the wavelength range of 780 to 2,500 nm using a spectrophotometer in accordance with JIS K 5602:2008 and arithmetically averaging the obtained spectral reflectances. The average spectral reflectance in the wavelength range of 830 to 915 nm can be calculated by measuring the spectral reflectance in the wavelength range of 830 to 915 nm using a spectrophotometer in accordance with JIS K 5602:2008 and arithmetically averaging the obtained spectral reflectances. The spectral reflectance at wavelengths of 905 nm and / or 1,550 nm can be measured using a spectrophotometer in accordance with JIS K 5602:2008. As the spectrophotometer, for example, a spectrophotometer (manufactured by Shimadzu Corporation, SHIMADZU-UV3600, etc.) can be used.

[0026] The lightness (L* value) of the infrared reflective portion may be, for example, 80 or less, and further 70 or less, and may be, for example, 5 or more, and further 15 or more.

[0027] The lightness (L* value) of the infrared absorbing portion may be, for example, 80 or less, and further 70 or less, and may be, for example, 5 or more, and further 15 or more.

[0028] The lightness of the infrared reflecting portion and the infrared absorbing portion can be measured using a color difference meter in accordance with, for example, JIS K 5600-4-4 3.2 and JIS K 5600-4-5. For example, a CM-600d (manufactured by Konica Minolta) can be used as the color difference meter.

[0029] The thickness of the infrared reflective portion may be preferably 10 to 3,000 μm, more preferably 10 to 2,000 μm, and further preferably 10 to 1,500 μm.

[0030] The thickness of the infrared absorbing part may be preferably 10 to 3,000 μm, more preferably 10 to 2,000 μm, and further preferably 10 to 1,500 μm.

[0031] (Infrared reflector) The infrared reflecting portion may be made of any material, and is preferably formed from an infrared reflective coating composition.

[0032] The infrared reflective coating composition preferably comprises: A coating composition comprising a film-forming resin (A) and a color pigment (B), The color pigment (B) includes at least one selected from the group consisting of white pigments having a near-infrared reflectance of 60% or more, chromatic pigments having a near-infrared reflectance of 50% or more, and black pigments having a near-infrared reflectance of 30% or more, where the reflectance in the wavelength range of 800 to 2,500 nm is defined as the near-infrared reflectance.

[0033] The infrared reflective coating composition can realize a marking that exhibits high retroreflectivity (particularly retroreflectivity at a high incidence angle) even when formed on a road surface, without being mistaken for a white line. Although the present disclosure should not be interpreted as being limited to a specific theory, the reason why the infrared reflective coating composition can exhibit such an effect is thought to be as follows. Since the infrared reflective coating composition uses a pigment having a specific near-infrared reflectance as a color pigment, it is thought that the resulting coating film can reflect near-infrared rays and exhibit high retroreflectivity.

[0034] [Coating film forming resin (A)] The film-forming resin (A) is a resin capable of forming a coating film, and resins commonly used in the field of paints can be used. Examples of the film-forming resin (A) include thermosetting resins such as acrylic resins, polyester resins, polyurethane resins, alkyd resins, polyether resins, fluororesins, epoxy resins, silicone resins, and urea resins, room temperature curing resins, and photocuring resins, and it is preferable to include at least one selected from acrylic resins, polyester resins, polyurethane resins, and urea resins. The film-forming resin (A) may be one that forms a coating film by itself, or may be one that forms a coating film by the action of a crosslinking agent (C) described later. The film-forming resin (A) may be one type, or two or more types may be used in combination.

[0035] The acrylic resin represents a polymer having a unit derived from a monomer having a (meth)acryloyl group, and can be prepared by polymerizing a monomer mixture containing the monomer having a (meth)acryloyl group. The monomer mixture may further contain a monomer having an ethylenically unsaturated bond other than the monomer having a (meth)acryloyl group. In this specification, (meth)acrylic acid represents acrylic acid and methacrylic acid.

[0036] Examples of the monomer having a (meth)acryloyl group include (meth)acrylic acid; (meth)acrylic acid alkyl esters having a linear or branched alkyl group having 1 to 20 carbon atoms; (meth)acrylic monomers having a hydroxy group, such as hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and N-methylol (meth)acrylamide; lactone adducts of the (meth)acrylic monomers having a hydroxy group; and (meth)acrylonitrile.

[0037] Examples of the monomer having an ethylenically unsaturated group include, in addition to the monomer having a (meth)acryloyl group, monomers having a carboxy group such as crotonic acid, itaconic acid, and fumaric acid; anhydrides of the monomers having a carboxy group; and vinyl monomers such as styrene.

[0038] The polyester resin refers to a polymer having a plurality of ester bonds in the main chain, and can be obtained as a reaction product of a polyol and a polycarboxylic acid; an addition polymerization product of a cyclic ester; a reaction product of the reaction product of the polyol and polycarboxylic acid with a cyclic ester; etc.

[0039] The polyol is a compound having two or more hydroxy groups in one molecule, and examples thereof include aliphatic polyols such as ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,4-pentanediol, neopentyl glycol, and 1,5-hexanediol; alicyclic polyols such as hydrogenated bisphenol A and 1,4-cyclohexanedimethanol; aromatic polyols such as bisphenol A and hydroxyalkylated bisphenol A; trifunctional or higher polyols such as glycerin, ammonium nitrile, trimethylolethane, trimethylolpropane, trimethylolbutane, hexanetriol, pentaerythritol, and dipentaerythritol; sugar alcohols such as sorbitol; tris(hydroxyethyl)isocyanate; and N,N-bis(2-hydroxyethyl)dimethylhydantoin.

[0040] The number of hydroxy groups contained in the polyol is preferably 2 or more, or may be 3 or more, and is preferably 6 or less, and more preferably 4 or less, in one molecule.

[0041] The polyol may be used alone or in combination of two or more kinds.

[0042] The polycarboxylic acid means a compound having two or more carboxy groups in one molecule. The polycarboxylic acid includes aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid; alicyclic polycarboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, cyclohexane-1,4-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and methyl-5-norbornene-2,3-dicarboxylic acid; aliphatic polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, adipic acid, sebacic acid, succinic acid, and dodecenylsuccinic acid; hydroxy acids of lactose; anhydrides of the aromatic polycarboxylic acids, the alicyclic polycarboxylic acids, and the aliphatic polycarboxylic acids; and the like. The polycarboxylic acids may be used alone or in combination of two or more.

[0043] The cyclic ester includes, for example, ε-caprolactone.

[0044] The polyester resin also includes modified products of the polyester resin described above. The resin can be modified by reacting a modifying agent with the end of the main chain constituting the resin. Examples of the modifying agent include compounds having reactive groups such as an isocyanate group, a hydroxyl group, and a carboxyl group, and a silicone skeleton. Examples of the modified polyester resin include urethane modified polyester resin, epoxy modified polyester resin, acrylic modified polyester resin, and silicone modified polyester resin.

[0045] Examples of the urethane resin include a reaction product of a polyol with a polyisocyanate, a reaction product of the reaction product with a chain extender that is used as needed, and the like.

[0046] The polyol means a compound having two or more hydroxy groups in one molecule. Examples of the polyol include aliphatic polyols such as ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,4-pentanediol, neopentyl glycol, 1,5-hexanediol, and 1,6-hexanediol; alicyclic polyols such as hydrogenated bisphenol A and 1,4-cyclohexanedimethanol; aromatic polyols such as bisphenol A and hydroxyalkylated bisphenol A (particularly, bisphenol hydroxypropyl ether); trifunctional or higher polyols such as glycerin, ammonium nitrate, trimethylolethane, trimethylolpropane, trimethylolbutane, hexanetriol, pentaerythritol, and dipentaerythritol; and high molecular weight polyols (for example, polyols having a weight average molecular weight of 800 or more) such as polyether polyols, acrylic polyols, polyurethane polyols, polyester polyols, and polyesteramide polyols. The polyol may be used alone or in combination of two or more kinds.

[0047] The number of hydroxy groups contained in the polyol is 2 or more, and may be 3 or more, but is preferably 6 or less, and more preferably 4 or less.

[0048] The polyisocyanate means a compound having two or more isocyanate groups in one molecule. Examples of the polyisocyanate include aliphatic polyisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, and hexamethylene diisocyanate; alicyclic polyisocyanates such as 1,3-cyclopentane diisocyanate, 1,4-dicyclohexylmethane diisocyanate, 1,2-cyclohexane diisocyanate, isophorone diisocyanate, norbornane diisocyanate methyl, and hydrogenated xylylene diisocyanate; Examples of the polyisocyanate include aromatic polyisocyanates such as 4-tolylene diisocyanate, 1,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, metaxylylene diisocyanate, naphthylene diisocyanate, and 3,3'-dimethyl-4,4'-biphenylene diisocyanate; and polymers such as biuret, isocyanurate, uretidine, and allophanate of the aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. One type of polyisocyanate may be used, or two or more types may be used in combination.

[0049] The chain extender means a compound having one or more active hydrogen atoms in one molecule, and water or an amine compound can be used. Examples of the amine compound include aliphatic polyamines such as ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, and tetraethylenepentamine; aromatic polyamines such as tolylenediamine, xylylenediamine, and diaminodiphenylmethane; alicyclic polyamines such as diaminocyclohexylmethane, piperazine, 2,5-dimethylpiperazine, and isophoronediamine; hydrazine compounds such as hydrazine, succinic acid dihydrazide, adipic acid dihydrazide, and phthalic acid dihydrazide; alkanolamines such as hydroxyethyldiethylenetriamine, 2-[(2-aminoethyl)amino]ethanol, and 3-aminopropanediol; and the like.

[0050] In one embodiment, the urethane resin may be an ester-based urethane resin, an ether-based urethane resin, or a carbonate-based urethane resin.

[0051] The epoxy resin may, for example, be an epoxy resin having two or more epoxy groups in one molecule.Specific examples of the epoxy resin include glycidyl ester resins, glycidyl ether resins such as condensation products of bisphenol A and epichlorohydrin, and condensation products of bisphenol F and epichlorohydrin, and alicyclic epoxy resins, linear aliphatic epoxy resins, bromine-containing epoxy resins, phenol novolac epoxy resins, and cresol novolac epoxy resins.

[0052] The urea resin may be a reaction product of a polyamine compound and a polyisocyanate compound, etc. The polyamine compound and the polyisocyanate compound may be separately blended to form a two-liquid coating composition. The polyamine compound is a compound having two or more amino groups. The polyamine compound includes at least one selected from an aliphatic polyamine compound, an alicyclic polyamine compound, and an aromatic polyamine compound, and preferably includes at least one selected from an aliphatic polyamine compound and an alicyclic polyamine compound.

[0053] The amino group is preferably a primary or secondary amino group. In one embodiment, the amino group may be present in the molecular chain of the polyamine compound or at the molecular terminal. The polyamine compound may be, for example, 12 HN-R 11 -NHR 12 (In the formula, R 1 is a divalent C 1-30 represents a hydrocarbon group, R 11 The -CH2- contained in the formula (I) is -O-, -CO- or -NR 12 -, R 12 is a monovalent C 1-30 represents a hydrocarbon group or a hydrogen atom. 1-30 The hydrocarbon group is C1-30 Aliphatic hydrocarbon group, C 3-30 Alicyclic hydrocarbon groups and C 6-30 Examples of the aromatic hydrocarbon groups include aromatic hydrocarbon groups.

[0054] The aliphatic polyamine compound means a polyamine compound that does not have a ring structure in its molecular structure. Examples of such aliphatic polyamine compounds include alkylene polyamine compounds, polyalkylene polyamine compounds, and other aliphatic polyamine compounds.

[0055] Examples of the alkylene polyamine compound include methylene diamine, ethylene diamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, and 1,10-diaminodecane. Examples of the polyalkylene polyamine compound include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexamethylenetetramine. Other aliphatic polyamine compounds include, for example, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, and bishexamethylenetriamine.

[0056] The alicyclic polyamine compound means a polyamine compound having an alicyclic structure in the molecular structure.

[0057] Examples of the alicyclic polyamine compound include 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (e.g., norbornadiamine), bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane (e.g., 4,4'-diaminodicyclohexylmethane, etc.), isophoronediamine, menthenediamine (MDA), 1,4-bis-(8-aminopropyl)-piperazine, piperazine-1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-(2''-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

[0058] The aromatic polyamine compound means a polyamine compound having an aromatic ring in the molecular structure. Examples of aromatic polyamine compounds include bis(cyanoethyl)diethylenetriamine, o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, phenylenediamine, naphthylenediamine, diaminodiphenylmethane, diaminodiethylphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenylether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, and polytetramethylene oxide-di-p-aminobenzoate.

[0059] As the polyamine compound, one type may be used alone, or two or more types may be used in combination.

[0060] The polyisocyanate means a compound having two or more isocyanate groups in one molecule. Examples of the polyisocyanate include aliphatic polyisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, and hexamethylene diisocyanate; alicyclic polyisocyanates such as 1,3-cyclopentane diisocyanate, 1,4-dicyclohexylmethane diisocyanate, 1,2-cyclohexane diisocyanate, isophorone diisocyanate, norbornane diisocyanate methyl, and hydrogenated xylylene diisocyanate; Examples of the polyisocyanate include aromatic polyisocyanates such as 4-tolylene diisocyanate, 1,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, metaxylylene diisocyanate, naphthylene diisocyanate, and 3,3'-dimethyl-4,4'-biphenylene diisocyanate; and polymers such as biuret, isocyanurate, uretidine, and allophanate of the aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. One type of polyisocyanate may be used, or two or more types may be used in combination.

[0061] The equivalent ratio between the isocyanate group of the polyisocyanate compound and the amino group of the polyamine compound (e.g., NCO / NH2 in the case of a secondary amine) is preferably 0.5 to 2.0, more preferably 0.8 to 1.2. The amino group used in calculating the equivalent ratio refers to the amino group involved in the reaction with the polyisocyanate (e.g., the amino group present at the molecular terminal). The equivalent ratio within the above range has the advantage that the water resistance of the coating film formed is improved.

[0062] The coating film-forming resin (A) may have a hydrophilic group such as an anionic group, a cationic group, or a nonionic group. Examples of the anionic group include a carboxy group and a sulfonic acid group, and examples of the cationic group include an amino group and a quaternary ammonium group. Examples of the nonionic group include a polyoxyalkylene unit. The hydrophilic group can be introduced by using a compound having a hydrophilic group as a raw material for the coating film-forming resin (A), for example.

[0063] When the coating film-forming resin (A) has an anionic group, the infrared reflective coating composition may contain a basic compound capable of neutralizing the anionic group, and when the coating film-forming resin (A) has a cationic group, the infrared reflective coating composition may contain an acidic compound capable of neutralizing the cationic group.

[0064] When the film-forming resin (A) has an anionic group, the acid value of the film-forming resin (A) is preferably from 5 mgKOH / g to 50 mgKOH / g, more preferably from 5 mgKOH / g to 30 mgKOH / g.

[0065] When the film-forming resin (A) has a cationic group, the amine value of the film-forming resin (A) is preferably from 5 mgKOH / g to 50 mgKOH / g, more preferably from 5 mgKOH / g to 30 mgKOH / g.

[0066] The film-forming resin (A) may have a hydroxy group. When the film-forming resin (A) has a hydroxy group, the hydroxy value of the film-forming resin (A) is preferably from 5 mgKOH / g to 35 mgKOH / g, more preferably from 7 mgKOH / g to 30 mgKOH / g, and even more preferably from 10 mgKOH / g to 25 mgKOH / g.

[0067] The acid value and the hydroxyl value are both based on solid content and can be measured in accordance with JIS K 0070:1999. The amine value is based on solid content and can be measured in accordance with JIS K 0070:1999. Measurements can be made in accordance with K 7237.

[0068] The coating film-forming resin (A) may be a resin that can be dissolved in an organic solvent described below, or may be an aqueous resin. Examples of the aqueous resin include water-soluble resins that can be dissolved in an aqueous medium, and water-dispersible resins that can be dispersed in an aqueous medium, such as colloidal dispersion type and emulsion type (emulsion polymerization type and forced emulsification type).

[0069] The weight average molecular weight of the coating film-forming resin (A) may be, for example, 2,000 or more and 10,000,000 or less, 10,000 or more and 2,000,000 or less, or 50,000 or more and 2,000,000 or less. The weight average molecular weight of the coating film-forming resin (A), in the case of the emulsion-type water-dispersible resin, may be, for example, from 50,000 to 10,000,000, from 100,000 to 2,000,000, or from 150,000 to 500,000. In the case of a resin that can be dissolved in an aqueous medium or an organic solvent, the weight average molecular weight of the coating film-forming resin (A) may be, for example, 2,000 or more and 100,000 or less, 10,000 or more and 80,000 or less, or 50,000 or more and 80,000 or less. In this specification, the weight average molecular weight is a value measured by gel permeation chromatography and converted into polystyrene equivalent.

[0070] The content of the coating film-forming resin (A) is preferably from 15 to 95% by mass, more preferably from 20 to 93% by mass, and even more preferably from 30 to 90% by mass, based on 100% by mass of the solid content of the infrared reflective coating composition.

[0071] In this specification, the solid content of the resin means the total solid content of the coating film-forming resin (A) and the crosslinking agent (C) used as needed, which will be described later, and can be determined by measuring the heating residue (mass of the residue after heating at 105°C for 60 minutes) in accordance with JIS K 5601-1-2 (2008).

[0072] The infrared reflective coating composition may also use a thermoplastic resin in addition to the coating film forming resin (A) to the extent that the physical properties of the coating film formed are not affected. Examples of the thermoplastic resin include chlorinated olefin resins such as chlorinated polyethylene and chlorinated polypropylene; homopolymers or copolymers containing vinyl chloride, vinyl acetate, vinylidene chloride, or the like as monomer components; cellulose resins; acetal resins; alkyd resins; chlorinated rubber resins; modified polypropylene resins (acid anhydride modified polypropylene resins, etc.); fluororesins (for example, vinylidene fluoride resins, vinyl fluoride resins, copolymers of fluorinated olefins and vinyl ethers, copolymers of fluorinated olefins and vinyl esters), etc. The thermoplastic resins may be used alone or in combination of two or more. By using a thermoplastic resin in combination, it becomes easier to adjust the physical properties of the coating film formed according to the purpose.

[0073] [Coloring pigment (B)] The color pigment (B) is a pigment having a color such as a chromatic color or an achromatic color, and contains a pigment (B1) capable of reflecting near-infrared rays. The near-infrared reflectance of the pigment (B1) is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more, and is also acceptable to be 100% or less, 90% or less, or 80% or less. By containing the pigment (B1), when near-infrared rays are irradiated, the irradiated light is reflected and / or scattered with high intensity, which can contribute to improving the detection accuracy in LiDAR technology.

[0074] In this specification, the near-infrared reflectance refers to the arithmetic average value of the spectral reflectance measured in the wavelength range of 800 to 2,500 nm in accordance with JIS K 5602: 2008. The spectral reflectance can be measured using a spectrophotometer.

[0075] In this specification, the near-infrared reflectance of a pigment can be measured as the reflectance of a coating film containing the pigment. In detail, the pigment, resin, and solvent described in Measurement Example 1 of Near-Infrared Reflectance and Spectral Reflectance of Pigments described later are mixed so that the pigment mass concentration (also referred to as PWC) shown in the following formula is 3 to 50 mass%, and dispersed using a dispersing machine at a rotation speed of 1,800 rpm for 60 minutes to obtain a dispersion. Then, using a black and white hiding power test paper (manufactured by Nippon Test Panel Co., Ltd.) as a base, the coating is applied using an 8 mil doctor blade so that the thickness after drying is about 50 μm, and dried at 60 ° C for 20 minutes to obtain a dried coating film. In accordance with JIS K 5602: 2008, the spectral reflectance of the part of the dried coating film where the base is white is measured in the wavelength range of 800 to 2,500 nm using a spectrophotometer, and the arithmetic average value is the near-infrared reflectance of the pigment. The spectral reflectance at wavelengths of 905 nm and 1,550 nm described later can also be measured in accordance with the method for measuring the spectral reflectance described above. For example, a spectrophotometer (Shimadzu Corporation, SHIMADZU-UV3600, etc.) can be used for the measurement. Pigment mass concentration (PWC: mass%) = (pigment solid content) / (pigment solid content + resin solid content) x 100

[0076] In addition, when measuring the near-infrared reflectance and the spectral reflectance, the pigment mass concentration of each pigment is set to a concentration at which the white and black of the base cannot be seen through when a dry coating film is formed on the black-and-white hiding power test paper. In this specification, the pigment mass concentration of each pigment is set to 25% by mass for organic red pigments, 30% by mass for inorganic red pigments, 25% by mass for organic yellow pigments, 30% by mass for inorganic yellow pigments, 20% by mass for blue pigments, 45% by mass for white pigments, 3% by mass for organic black pigments, and 50% by mass for inorganic black pigments.

[0077] The pigment (B1) preferably includes a pigment selected from the group consisting of chromatic pigments and achromatic pigments. The chromatic pigment includes any pigment with a color saturation exceeding 0, such as red pigments, green pigments, blue pigments, and yellow pigments. It is preferable to include at least one selected from the group consisting of red pigments, blue pigments, and yellow pigments, and it is more preferable to include at least one selected from the group consisting of red pigments, blue pigments, and yellow pigments.

[0078] The pigment (B1) may be an organic pigment and / or an inorganic pigment. The organic pigment tends to have high saturation and high near-infrared reflectance, while the inorganic pigment tends to have high weather resistance. In a total of 100% by mass of the pigment (B1), the content of the organic pigment may be 0% by mass or more and 100% by mass or less, 0.3% by mass or more and 70% by mass or less, 0.5% by mass or more and 15% by mass or less, or 0.5% by mass or more and 8% by mass or less. The content of the inorganic pigment in a total of 100 mass% of the pigment (B1) may be 0 mass% or more and 100 mass% or less, 5 mass% or more and 99 mass% or less, 10 mass% or more and 50 mass% or less, or 10 mass% or more and 20 mass% or less.

[0079] The near-infrared reflectance of the red pigment as the pigment (B1) is, for example, preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and still more preferably 55% or more. For example, it is also acceptable for it to be 80% or less, and even 70% or less. The spectral reflectance of the red pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 20% or more, more preferably 25% or more, even more preferably 30% or more, and even more preferably 35% or more. For example, it is acceptable for it to be 90% or less, or even 85% or less.

[0080] The red pigment may be an organic pigment and / or an inorganic pigment. The content of the organic pigment in the red pigment may be 0% by mass, 1% by mass or more and 100% by mass or less, or 20% by mass or more and 50% by mass or less.

[0081] The near-infrared reflectance of the organic red pigment is preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and still more preferably 55% or more. For example, it is acceptable for the reflectance to be 80% or less, and even 70% or less.

[0082] The spectral reflectance of the organic red pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 40% or more, more preferably 50% or more, even more preferably 55% or more, and still more preferably 60% or more. For example, it is acceptable for it to be 90% or less, or even 85% or less.

[0083] The near infrared reflectance of the inorganic red pigment is preferably 40% or more, more preferably 45% or more, and for example, it is acceptable for it to be 80% or less, and even 70% or less.

[0084] The spectral reflectance of the inorganic red pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 20% or more, more preferably 30% or more, and is, for example, acceptable to be 90% or less, and further 85% or less.

[0085] Examples of red pigments as the pigment (B1) include organic red pigments such as Fastogen Super Magenta RH, Fastogen Red 7100Y, Fastogen Super Red 500RG, Fastogen Super Red ATY, Fastogen Super Blue Violet RVS, Rubicron Red 400RG, Rubicron Red 500RG (all manufactured by DIC Corporation), and CINILEX DPP RED SR1C (manufactured by CINIC chemicals), and inorganic red pigments such as Todacolor 120ED (manufactured by Toda Kogyo Co., Ltd.) and BAYFERROX 130M (manufactured by Lanxess AG).

[0086] The near-infrared reflectance of the blue pigment as pigment (B1) is preferably 40% or more, more preferably 45% or more, and for example, it is acceptable for it to be 80% or less, and even 70% or less.

[0087] The spectral reflectance of the blue pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 30% or more, more preferably 35% or more, and is also acceptable to be, for example, 90% or less, or even 85% or less.

[0088] Examples of the blue pigments include Dipyroxide Color Blue 9453 (manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd.), Fastogen Blue 9453, Fastogen Blue RS, Fastogen Blue 5380, Fastogen Super Blue 6070S (all manufactured by DIC Corporation), Cyanine Blue 5240KB, Cyanine Blue 5050 (all manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd.), HELIOGEN BLUE L7460 (manufactured by BASF), Dipyroxide Color Green 9310 (manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd.), Fastogen Green 2 YK, Fastogen Green MY (all manufactured by DIC Corporation), and Lionol Green 6YKP-N (manufactured by Toyo Color Co., Ltd.).

[0089] The near-infrared reflectance of the yellow pigment is preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and even more preferably 55% or more. For example, it is acceptable for the reflectance to be 90% or less, and even more preferably 85% or less.

[0090] The spectral reflectance of the yellow pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 15% or more, more preferably 20% or more, even more preferably 25% or more, and still more preferably 30% or more. For example, it is acceptable for it to be 95% or less, or even 90% or less.

[0091] The yellow pigment may be an organic pigment and / or an inorganic pigment. The content of the organic pigment in the yellow pigment may be 0% by mass, 1% by mass or more, or 10% by mass or more. The content may be 50% by mass or less, with the upper limit being 100% by mass.

[0092] The near-infrared reflectance of the organic yellow pigment is preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and still more preferably 55% or more. For example, it is acceptable for the reflectance to be 90% or less, and even more preferably 85% or less.

[0093] The spectral reflectance of the organic yellow pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and still more preferably 55% or more. For example, it is acceptable for it to be 95% or less, or even 90% or less.

[0094] The near-infrared reflectance of the inorganic yellow pigment is preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and even more preferably 55% or more. For example, it is acceptable for the reflectance to be 90% or less, and even more preferably 85% or less.

[0095] The spectral reflectance of the inorganic yellow pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 20% or more, more preferably 25% or more, and is also acceptable to be, for example, 90% or less, and further 85% or less.

[0096] As the yellow pigment, for example, Symuler Fast is an organic yellow pigment. Yellow 4192 (manufactured by DIC Corporation), HOSTAPERM YELLOW H3G (manufactured by Clariant Japan Co., Ltd.), etc. Examples of inorganic yellow pigments include Syco Pearl Yellow L-1110, Syco Pearl Yellow L-1100 (both manufactured by BASF), and TAROX synthetic iron oxide YM1100 (manufactured by Titanium Industries Co., Ltd.).

[0097] The chromatic pigment as the pigment (B1) preferably contains a red pigment, a blue pigment, and a yellow pigment, for example, a mixture of Symuler Fast Yellow 4192 (manufactured by DIC Corporation) as a yellow pigment, Fastogen Red 7100Y (manufactured by DIC Corporation) as a red pigment, and Lionol Blue FG7980 (manufactured by Toyo Color Co., Ltd.) as a blue pigment.

[0098] The total content of the red pigment, blue pigment, and yellow pigment in the chromatic pigment is, for example, 20% by mass or more, preferably 30% by mass or more, with the upper limit being 100% by mass.

[0099] The content of the chromatic pigment in the pigment (B1) may be, for example, 0% by mass or more, 1% by mass or more, or 5% by mass or more, and may be, for example, 100% by mass or less, 70% by mass or less, 50% by mass or less, 25% by mass or less, 20% by mass or less, or 18% by mass or less.

[0100] The achromatic pigment includes any pigment whose chroma is 0. Examples of the achromatic pigment include white pigments, gray pigments, and black pigments, and include white pigments and black pigments.

[0101] The near-infrared reflectance of the white pigment as the pigment (B1) is preferably 60% or more, more preferably 65% ​​or more, even more preferably 70% or more, and still more preferably 75% by mass or more. For example, it is acceptable for the reflectance to be 99% or less, and even more preferably 90% or less.

[0102] Examples of the white pigment include titanium oxides such as TIPAQUE CR-97 and TIPAQUE CR-95 (both manufactured by Ishihara Sangyo Kaisha), and Typepure R-902 (manufactured by DuPont).

[0103] The spectral reflectance of the white pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 60% or more, more preferably 65% ​​or more, even more preferably 70% or more, and still more preferably 75% by mass or more. For example, it is acceptable for it to be 99% or less, or even 90% or less.

[0104] The content of the white pigment in the pigment (B1) may be, for example, 0% by mass or more, 1% by mass or more, or 3% by mass or more, and may be 100% by mass or less, 99% by mass or less, or 90% by mass or less, for example, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0105] The near-infrared reflectance of the black pigment as the pigment (B1) is preferably 5% or more, more preferably 8% or more, even more preferably 10% or more, and still more preferably 15% or more. For example, it is acceptable for the reflectance to be 90% or less, and even more preferably 85% or less.

[0106] The spectral reflectance of the black pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 5% or more, more preferably 8% or more, even more preferably 10% or more, and still more preferably 15% or more. For example, it is acceptable for it to be 90% or less, or even 85% or less.

[0107] The black pigment may be an organic pigment and / or an inorganic pigment. The content of the organic pigment in the black pigment may be 0% by mass, 1% by mass or more, 20% by mass or more, or 50% by mass or less, with the upper limit being 100% by mass.

[0108] The near-infrared reflectance of the organic black pigment is preferably 20% or more, more preferably 30% or more, even more preferably 35% or more, and still more preferably 40% or more. For example, it is acceptable for the reflectance to be 80% or less, and even 70% or less.

[0109] The spectral reflectance of the organic black pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 40% or more, more preferably 50% or more, even more preferably 55% or more, and even more preferably 60% or more. For example, it is acceptable for it to be 90% or less, or even 85% or less.

[0110] The near infrared reflectance of the inorganic black pigment is preferably 30% or more, more preferably 40% or more, and is also acceptable to be, for example, 80% or less, and further 70% or less.

[0111] The spectral reflectance of the inorganic black pigment at wavelengths of 905 nm and / or 1,550 nm is preferably 5% or more, more preferably 10% or more, and is, for example, acceptable to be 85% or less, or even 80% or less.

[0112] Examples of the black pigments include inorganic black pigments such as Dipyroxide Color Black 9590, Dipyroxide Color Brown 9290, Dipyroxide Color Brown 9211 (all manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), Black 411 (manufactured by The Shepherd Color Company), and Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), and organic black pigments such as Chromofine Black A-1103 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), Fastogen Super Black MX (manufactured by DIC Corporation), Paliogen Black S0084, Paliotole Black L0080 (all manufactured by BASF), and Hoster Palm Brown HFR-01 (manufactured by Clariant Japan Co., Ltd.).

[0113] The content of the black pigment in the pigment (B1) may be 0% by mass or more, 1% by mass or more, or 5% by mass or more, and may be, for example, 50% by mass or less, 45% by mass or less, or 40% by mass or less.

[0114] The total content of the white pigment and the black pigment in the achromatic pigment is, for example, 50% by mass or more, preferably 60% by mass or more, with the upper limit being 100% by mass.

[0115] The content of the achromatic pigment may be 0 parts by mass or more, 10 parts by mass or more, or 50 parts by mass or more relative to 100 parts by mass of the chromatic pigment, and may be, for example, 20,000 parts by mass or less, 10,000 parts by mass or less, 5,000 parts by mass or less, or 2,500 parts by mass or less.

[0116] The pigment (B1) may be used alone or in combination of two or more kinds.

[0117] In one embodiment, the pigment (B1) includes at least one selected from the group consisting of a white pigment having a near-infrared reflectance of 60% or more, a chromatic pigment having a near-infrared reflectance of 50% or more, and a black pigment having a near-infrared reflectance of 5% or more. By including these pigments in the pigment (B1), it is possible to improve the near-infrared detection accuracy of the resulting coating film in LiDAR technology, and preferably, it is possible to improve the near-infrared detection accuracy of the LiDAR technology while maintaining low brightness.

[0118] The pigment (B1) preferably includes at least one selected from the group consisting of a white pigment having a near-infrared reflectance of 60% or more, a blue pigment having a near-infrared reflectance of 50% or more, a red pigment having a near-infrared reflectance of 50% or more, a yellow pigment having a near-infrared reflectance of 50% or more, and a black pigment having a near-infrared reflectance of 30% or more; a white pigment having a spectral reflectance of 70% or more at wavelengths of 905 nm and / or 1,550 nm, an organic red pigment having a spectral reflectance of 50% or more at wavelengths of 905 nm and / or 1,550 nm, an organic red pigment having a spectral reflectance of 20% or more at wavelengths of 905 nm and / or 1,550 nm, and a black pigment having a near-infrared reflectance of 30% or more. or more, an inorganic red pigment having a spectral reflectance of 60% or more at wavelengths of 905 nm and / or 1,550 nm, an organic yellow pigment having a spectral reflectance of 20% or more at wavelengths of 905 nm and / or 1,550 nm, a blue pigment having a spectral reflectance of 40% or more at wavelengths of 905 nm and / or 1,550 nm, an organic black pigment having a spectral reflectance of 50% or more at wavelengths of 905 nm and / or 1,550 nm, and an inorganic black pigment having a spectral reflectance of 15% or more at wavelengths of 905 nm and / or 1,550 nm.

[0119] The total content of the pigment (B1) in the color pigment (B) may be 20% by mass or more, 30% by mass or more, or 50% by mass or more, and may be, for example, 100% by mass or less, 98% by mass or less, or 95% by mass or less.

[0120] The color pigment (B) may contain a color pigment (b) other than the pigment (B1) to the extent that it does not affect the near-infrared reflectance and spectral reflectance of the coating film obtained from the infrared reflective coating composition. As the color pigment (b), any compound classified as a pigment in the Color Index other than the pigment (B1) can be used. As the color pigment (b), for example, an inorganic black pigment can be mentioned, and as the inorganic black pigment, for example, a carbon pigment such as carbon black can be mentioned. The content (pigment mass concentration) of the color pigment (b) in the color pigment (B) may be 1 mass% or less, 0.5 mass% or less, or 0.1 mass% or less. When the content of the color pigment (b) is within this range, infrared absorption can be suppressed in the infrared reflecting part, and the detection sensitivity by infrared can be further improved.

[0121] The content of the carbon pigment in the color pigment (B) is preferably less than 0.2% by mass, more preferably less than 0.08% by mass, and the lower limit may be 0% by mass, based on 100% by mass of the total amount of the color pigment (B). When the content of the carbon pigment is within this range, infrared absorption in the infrared reflecting portion can be suppressed, and the detection sensitivity by infrared can be further improved.

[0122] The average primary particle diameter (D50) of the color pigment (B) may be preferably 1 nm or more and 500 nm or less, more preferably 5 nm or more and 300 nm or less. The average primary particle diameter (D50) of the color pigment (B) may be measured using a laser Doppler type particle size analyzer (e.g., Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.)).

[0123] The content of the organic pigment may be from 0 to 100% by mass, from 0.3 to 70% by mass, from 0.5 to 10% by mass, or from 3 to 8% by mass, based on a total of 100% by mass of the pigment (B). The content of the inorganic pigment may be from 0% by mass to 100% by mass, from 5% by mass to 99% by mass, from 10% by mass to 50% by mass, or from 10% by mass to 20% by mass, based on a total of 100% by mass of the pigment (B).

[0124] The content (pigment mass concentration) of the pigment (B) is preferably 5 mass% or more, more preferably 8 mass% or more, and even more preferably 10 mass% or more, based on 100 mass% of the total solid content of the coating film-forming resin (A), the pigment (B), and the crosslinking agent (C) used as necessary, which will be described later, and is preferably 55 mass% or less, more preferably 50 mass% or less, and even more preferably 45 mass% or less.

[0125] The content (pigment mass concentration) of the pigment (B1) is preferably 1 mass% or more, more preferably 3 mass% or more, and even more preferably 5 mass% or more, based on 100 mass% of the total solid content of the coating film-forming resin (A), the pigment (B), and the crosslinking agent (C) used as necessary, which will be described later, and is preferably 55 mass% or less, more preferably 50 mass% or less, and even more preferably 45 mass% or less.

[0126] The lightness (L* value) of the coating film obtained by the infrared reflective coating composition is preferably 80 or less, and may be, for example, 5 or more. Also, for example, it may be 70 or less, and may be 15 or more. By using the infrared reflective coating composition, visibility in LiDAR technology can be maintained even if the lightness (L* value) of the coating film is low. The lightness (L* value) of the coating film may change depending on the thickness (film thickness) of the coating film.

[0127] In this specification, the brightness of the coating film can be measured in the same manner as the brightness of the coating film containing the pigment. In detail, the pigment, resin and solvent described in Measurement Example 1 of Near-Infrared Reflectance and Spectral Reflectance of Pigments described later are mixed so that the pigment mass concentration is 3 to 50 mass%, and dispersed using a dispersing machine at a rotation speed of 1,800 rpm for 60 minutes to obtain a dispersion. Then, using a black and white hiding power test paper (manufactured by Nippon Test Panel Co., Ltd.) as a base, the coating is applied so that the thickness after drying is about 100 μm, and dried at 60 ° C. for 20 minutes to obtain a dried coating film. The brightness of the white base part of the dried coating film obtained in accordance with JIS K 5600-4-4 3.2 and JIS K 5600-4-5 can be measured and used as the brightness. The brightness can be measured, for example, using a color difference meter CM-600d (manufactured by Konica Minolta, Inc.).

[0128] When the desired lightness of the coating film is L*0, the relationship between L*0 and the range of the pigment mass concentration of each pigment is expressed by the following formula. That is, the pigment mass concentration of each pigment may be in a range that satisfies the following formula. Furthermore, L*0 can take a value within the range described above as the lightness of the coating film. L*0=0.7(W)-0.6(IR)-5.5(OR)+0.4(IY)-3.2(OY)-5.7(OB)-0.2(IBL)-0.3(OBL)+48.5...Equation (1) Here, (W) is the pigment mass concentration (% by mass) of the white pigment, (IR) is the pigment mass concentration (% by mass) of the inorganic red pigment, (OR) is the pigment mass concentration (% by mass) of the organic red pigment, (IY) is the pigment mass concentration (% by mass) of the inorganic yellow pigment, (OY) is the pigment mass concentration (% by mass) of the organic yellow pigment, (OB) is the pigment mass concentration (% by mass) of the blue pigment, (IBL) is the pigment mass concentration (% by mass) of the inorganic black pigment, and (OBL) is the pigment mass concentration (% by mass) of the organic black pigment.

[0129] When the target near-infrared reflectance of the coating film is X0(%), the relationship between X0(%) and the pigment mass concentration of each pigment is expressed by the following formula. That is, the pigment mass concentration of each pigment may be in a range that satisfies the following formula. Furthermore, X0(%) can take a value within the range described above as the near-infrared reflectance of the coating film. X0=0.5(W)-1.4(IR)+0.1(OR)-0.6(IY)-1.8(OY)-3.1(OB)-0.2(IBL)-13.2(OBL)+61.0...Formula (2)

[0130] When the spectral reflectance of the target coating film at a wavelength of 905 nm is Y0 (%), the relationship between this and the pigment mass concentration of each pigment is expressed by the following formula. That is, the pigment mass concentration of each pigment may be in a range that satisfies the following formula. Furthermore, Y0 (%) can take a value within the range described above as the spectral reflectance of the coating film at a wavelength of 905 nm. Y0=0.6(W)-2.9(IR)+3.5(OR)-1.2(IY)-0.9(OY)-3.0(OB)-0.8(IBL)-1.2(OBL)+68.0...Formula (3)

[0131] When the spectral reflectance of the target coating film at a wavelength of 1,550 nm is Z0 (%), the relationship between Z0 (%) and the pigment mass concentration of each pigment is expressed by the following formula. That is, the pigment mass concentration of each pigment may be in a range that satisfies the following formula. Furthermore, Z0 (%) can take a value in the range described above as the spectral reflectance of the coating film at a wavelength of 905 nm. Z0=0.3(W)-0.2(IR)-2.4(OR)-0.2(IY)-1.4(OY)-2.0(OB)+0.1(IBL)-8.5(OBL)+68.0...Equation (4)

[0132] The lightness of the coating film may be 80 or less. In this case, various combinations of pigment mass concentrations are calculated using formula (1). Among these combinations, a combination of pigment concentrations that makes the near-infrared reflectance, the spectral reflectance at a wavelength of 905 nm, and the spectral reflectance at a wavelength of 1,550 nm equal to or greater than a desired value (for example, 15% or greater) can be calculated using formulas (2) to (4).

[0133] [Crosslinker (C)] The infrared reflective coating composition may contain a crosslinking agent (C) in addition to the coating film-forming resin (A) and the pigment (B). The crosslinking agent (C) is a compound capable of forming a crosslinked structure in the coating film-forming resin (A) by forming a chemical bond and / or a physical bond, and may be a compound having two or more groups having an active hydrogen atom, such as a hydroxy group, a carboxy group, or an amino group, in one molecule; or a compound having two or more groups capable of reacting with the group having an active hydrogen atom in one molecule. When the coating film-forming resin (A) has a group having an active hydrogen atom or a group capable of reacting with the group having an active hydrogen atom, it may react with the crosslinking agent (C) to form a crosslinked structure in the coating film-forming resin (A).

[0134] Examples of the crosslinking agent (C) include polyisocyanate compounds, blocked polyisocyanate compounds, amino resins, phenolic resins, polycarboxylic acids, etc. These may be used alone or in combination of two or more.

[0135] The polyisocyanate compound means a compound having two or more isocyanate groups in one molecule. Examples of the polyisocyanate include aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and mixtures thereof, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, and mixtures thereof, naphthylene-1,5-diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and xylylene diisocyanate; alicyclic polyisocyanates such as dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hydrogenated xylylene diisocyanate; and aliphatic polyisocyanates such as hexamethylene diisocyanate.

[0136] The blocked polyisocyanate compound (hereinafter, sometimes referred to as "BI") refers to a compound in which the isocyanate group of the isocyanate compound is blocked with a blocking agent.

[0137] The blocking agent may be any compound having an active hydrogen-containing compound, and examples of the blocking agent include phenolic compounds such as phenol, cresol, and xylenol; lactam compounds such as ε-caprolactam, δ-valerolactam, and γ-butyrolactam; aliphatic alcohol compounds such as methanol, ethanol, n-, i-, or t-butyl alcohol; glycol ether compounds such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, and propylene glycol monomethyl ether; aromatic alcohol compounds such as benzyl alcohol; oxime compounds such as formamidoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, and cyclohexane oxime; and active methylene compounds such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, and acetylacetone. By mixing the polyisocyanate compound with the blocking agent, the free isocyanate groups of the polyisocyanate compound can be blocked.

[0138] The amino resin means a resin obtained by addition polymerization of an aldehyde to a compound having an amino group. The amino resin is preferable because it has excellent crosslinking reactivity with the coating film-forming resin (A), especially in the absence of a catalyst.

[0139] Examples of the amino resin include melamine resin and urea resin, with melamine resin being preferred.

[0140] The melamine resin means a thermosetting resin synthesized from melamine and aldehyde. The melamine resin has a triazine nucleus and three reactive functional groups (-NX1X2) per triazine nucleus. The melamine resin may be of four types: a fully alkylated type containing only -N(CH2OR)2 [R represents an alkyl group having 1 to 8 carbon atoms, the same below] as a reactive functional group; a methylol group type containing -N(CH2OR)(CH2OH) as a reactive functional group; an imino group type containing -N(CH2OR)(H) as a reactive functional group; and a methylol / imino group type containing -N(CH2OR)(CH2OH) and -N(CH2OR)(H) or -N(CH2OH)(H) as a reactive functional group. The melamine resin may be of one type or of two or more types in combination. The melamine resin and the polyisocyanate compound may be used in combination as the crosslinking agent (C). If necessary, a metal catalyst such as a tin compound or a titanium compound may be used.

[0141] Examples of the phenol compound include glycidyl ether type resins such as a condensation reaction product of bisphenol A and epichlorohydrin, and a condensation reaction product of bisphenol F and epichlorohydrin; alicyclic epoxy resins, linear aliphatic epoxy resins, bromine-containing epoxy resins, phenol novolac type epoxy resins, and cresol novolac type epoxy resins.

[0142] The polycarboxylic acid means a compound having two or more carboxy groups in one molecule. The polycarboxylic acid includes aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid; alicyclic polycarboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, cyclohexane-1,4-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and methyl-5-norbornene-2,3-dicarboxylic acid; aliphatic polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, adipic acid, azelaic acid, sebacic acid, succinic acid, and dodecenylsuccinic acid; hydroxy acids of lactose; anhydrides of the aromatic polycarboxylic acids, the alicyclic polycarboxylic acids, and the aliphatic polycarboxylic acids; and the like.

[0143] In one embodiment, the crosslinking agent (C) is preferably one or more selected from the group consisting of polyisocyanate compounds, blocked polyisocyanate compounds, and amino resins.

[0144] The content of the crosslinking agent (C) may be, for example, 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, based on 100 parts by mass of the total of 100 parts by mass of the coating film-forming resin (A) and the crosslinking agent (C), and may be, for example, 50 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less.

[0145] The total content of the film-forming resin (A) and the crosslinking agent (C) in the solid content of the infrared reflective coating composition is preferably 30 mass% or more, more preferably 40 mass% or more, even more preferably 45 mass% or more, and is preferably 99 mass% or less, more preferably 95 mass% or less, even more preferably 90 mass% or less.

[0146] [Solvent (D)] The infrared reflective coating composition may further contain a solvent (D). The solvent (D) preferably contains an aqueous medium (D1) and / or an organic solvent (D2).

[0147] The aqueous medium (D1) includes water, a hydrophilic solvent, and a mixture of water and a hydrophilic solvent.

[0148] Examples of the hydrophilic solvent include glycol-based solvents such as ethylene glycol, propylene glycol, butanediol, pentanediol, diethylene glycol, dipropylene glycol, and triethylene glycol; glycol ether-based solvents such as ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate; alcohol-based solvents such as methanol, ethanol, and isopropyl alcohol; ketone-based solvents such as acetone; and N-methyl-2-pyrrolidone. The use of such a hydrophilic solvent has the advantage that the obtained infrared reflective coating composition has good wettability with the substrate.

[0149] Examples of the organic solvent (D2) include ether solvents such as dioxane and tetrahydrofuran; ester solvents such as 3-methoxybutyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone; aromatic hydrocarbon solvents such as toluene, T-SOL 100, and T-SOL 150 (all manufactured by Exxon Chemical); hydrocarbon solvents such as pentane, iso-pentane, hexane, iso-hexane, and cyclohexane; and mineral oils such as solvent naphtha and mineral spirits. These may be used alone or in combination of two or more.

[0150] The infrared reflective coating composition may be an aqueous coating composition containing mainly an aqueous medium (D1) as the solvent (D), or may be a solvent-based coating composition containing mainly an organic solvent (D2) as the solvent (D). When the infrared reflective coating composition is an aqueous coating composition, the content of the aqueous medium (D1) in the solvent (D) is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 100% by mass or less. When the infrared reflective coating composition is a solvent-based coating composition, the content of the organic solvent (D2) in the solvent (D) is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 100% by mass or less.

[0151] The content of the solvent (D) in the infrared reflective coating composition is preferably 0 mass % or more, more preferably 10 mass % or more, even more preferably 20 mass % or more, and is preferably 70 mass % or less, more preferably 60 mass % or less.

[0152] The infrared reflective coating composition may be a water-based coating, an organic solvent-based coating, or a solventless coating, for example, a powder coating.

[0153] Aggregate The infrared reflective coating composition may further contain aggregate (E). In the present disclosure, aggregate (E) is a granular material having an irregular shape and is different from pigment (B). When the infrared reflective coating composition contains aggregate (E), retroreflectivity can be improved, and in particular, it can be easy to further improve information code detectability when an infrared laser such as LiDAR is used.

[0154] Examples of materials constituting the aggregate (E1) include fine particles such as SiO2, TiO2, Al2O3, Cr2O3, ZrO2, FeO, Fe2O3, CaP, CrO, Al2O3·SiO2, 3Al2O3·2SiO2, zirconia silicate, ceramic beads, and mixtures thereof. The fine particles refer to particles, spheres, or hollow spheres.

[0155] The average particle size of the aggregate (E) may be preferably 50 μm or more, more preferably 50 μm or more and 3,000 μm or less, even more preferably 70 μm or more and 2,500 μm or less, still more preferably 100 μm or more and 2,000 μm or less, even more preferably 150 μm or more and 2,000 μm or less, and even more preferably 200 μm or more and 2,000 μm or less. The average particle size of the aggregate (E) means the volume average particle size (D50), and can be measured by a sieving method (for example, a JIS test sieve (manufactured by Iida Manufacturing Co., Ltd.)). As the sieve, for example, a sieve with an opening size of 106 μm or more and 3,360 μm or less can be used, and specifically, sieves with opening sizes of 150 μm, 180 μm, 212 μm, 250 μm, 300 μm, 425 μm, 500 μm, 710 μm, 1,000 μm, and 1,700 μm can be used.

[0156] In the present disclosure, the average particle diameter of the aggregate (E) means a weighted average value of the amount of the residue on each sieve (sieve residue: mass %) and the average particle diameter of the aggregate that passed through all sieves using three or more sieves with different mesh diameters, the average particle diameter of the aggregate (remainder) that did not pass through the sieve with the largest mesh diameter is the mesh diameter of the sieve with the largest mesh diameter, and the average particle diameter of the residue on the other sieves is the average value of the mesh diameter of the sieve and the mesh diameter of a sieve that is one size smaller than the sieve.

[0157] The aggregate (E) may be a commercially available product, such as Serasand HR-C, Serasand HR-S, Serasand HR-B (manufactured by Bishu Kosan Co., Ltd.), or White Silica (manufactured by Yamamori Tsuchimoto Kogyosho Co., Ltd.).

[0158] The content of the aggregate (E) is preferably 5% by mass or more and 85% by mass or less, more preferably 10% by mass or more and 70% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on 100% by mass of the total solid content of the film-forming resin (A), the pigment (B), the aggregate (E), and the crosslinking agent (C) used as needed. In the present disclosure, the content of the aggregate (E) in 100% by mass of the total solid content of the film-forming resin (A), the pigment (B), the aggregate (E), and the crosslinking agent (C) used as needed is also referred to as the mass concentration of the aggregate (E).

[0159] The infrared reflective coating composition may further contain other additives. Examples of the other additives include surface conditioners, extender pigments, colorants such as dyes, waxes, luster pigments, fillers (different from the aggregate (E), which may contain particularly particulate fillers, etc.), ultraviolet absorbers (benzophenone-based ultraviolet absorbers, etc.), antioxidants (phenol-based, sulfoid-based, hindered amine-based antioxidants, etc.), plasticizers, coupling agents (silane-based, titanium-based, zirconium-based coupling agents, etc.), anti-sagging agents, thickeners, pigment dispersants, pigment wetting agents, leveling agents, color separation inhibitors, precipitation inhibitors, antifoamers, antifreeze agents, emulsifiers, preservatives, fungicides, antibacterial agents, stabilizers, etc. These additives may be used alone or in combination of two or more.

[0160] Examples of the luster pigment include mica, aluminum foil, tin foil, gold foil, silver foil, titanium gold foil, stainless steel foil, and metal foil such as nickel or copper foil.

[0161] In one embodiment, the infrared reflective coating composition preferably comprises: The coating composition comprises the film-forming resin (A) and the color pigment (B), The color pigment (B) contains a pigment (B1) capable of reflecting near infrared rays, When the reflectance in the wavelength range of 800 to 2,500 nm is taken as the near-infrared reflectance, The pigment (B1) includes at least one pigment selected from the group consisting of a white pigment having a near-infrared reflectance of 60% or more, a chromatic pigment having a near-infrared reflectance of 50% or more, and a black pigment having a near-infrared reflectance of 30% or more, and one selected from a white pigment having a near infrared reflectance of 60% or more and a chromatic pigment having a near infrared reflectance of 50% or more; The pigment (B1) contains an organic pigment, and the content of the organic pigment in the total amount of the pigment (B1) is 3 mass % or more.

[0162] The infrared reflective coating composition can be prepared by dissolving or dispersing the coating film-forming resin (A) and the pigment (B), as well as the aggregate (E) used as necessary, the crosslinking agent (C) and other additives in the solvent (D) used as necessary. The order of mixing the various materials used is not particularly limited, and for example, the pigment (B) and / or aggregate (E) and a part of the coating film-forming resin (A) may be mixed in advance to form a pigment paste, and then mixed with the remaining components and other components used as necessary to produce the infrared reflective coating composition. The infrared reflective coating composition can be prepared by mixing each component using a mixer, disperser, kneader, etc., such as a sand grind mill, ball mill, blender, paint shaker, or disperser.

[0163] In the present disclosure, the technical scope of the infrared reflective coating composition also includes a coating film formed by preparing a preliminary coating composition using the coating film-forming resin (A) and pigment (B) as well as the crosslinking agent (C) and other additives used as needed, and then spraying aggregate (E) onto the coating film on which the preliminary coating composition has been applied, or a coating film on which aggregate (E) has been sprayed and then further sprayed with the preliminary coating composition.

[0164] The method for producing an infrared reflective part using the infrared reflective coating composition is not particularly limited, but in one embodiment, Applying the infrared reflective coating composition onto a substrate to obtain a coating film; and and drying the coating film to obtain an infrared reflective portion (first production method).

[0165] The coating film is preferably applied so that the thickness of the wet coating film is preferably from 10 μm to 3,000 μm, more preferably from 20 μm to 2,500 μm, and even more preferably from 30 μm to 2,000 μm. The coating can be carried out by a coating method such as spray coating, bar coater coating, air knife coating, gravure coating, brush coating, air gun coating, air electrostatic gun coating, dip coating, roller coating, or the like.

[0166] The drying conditions for drying the coating film are not particularly limited, and may be natural drying or forced drying using a dryer or the like. The drying temperature may be preferably 20°C or more and 200°C or less, more preferably 70°C or more and 180°C or less, and even more preferably 80°C or more and 140°C or less. The drying time may be preferably 10 minutes or more and 24 hours or less, more preferably 10 minutes or more and 60 minutes or less, and even more preferably 15 minutes or more and 45 minutes or less. As the heating means, hot air heating, infrared heating, induction heating, etc. may be used.

[0167] (Infrared absorbing part) The infrared absorbing portion may be made of any material, may be the substrate itself, or may be formed from an infrared absorbing coating composition, and is preferably formed from an infrared absorbing coating composition.

[0168] The infrared absorbing coating composition preferably comprises: Contains a film-forming resin and a color pigment, The color pigment includes a carbon pigment, The content of the carbon pigment is from 0.2% by mass to 50% by mass in terms of 100% by mass of the total amount of the color pigments.

[0169] The infrared absorbing coating composition contains a carbon pigment and can absorb infrared rays, and therefore, by using such an infrared absorbing coating composition, the detection sensitivity by infrared rays can be further increased.

[0170] As the coating film-forming resin in the infrared absorbing coating composition, the same resins as the coating film-forming resin (A) in the infrared reflective coating composition can be used.

[0171] Specifically, the coating film-forming resin in the infrared absorbing coating composition includes the acrylic resin, the polyester resin, the polyurethane resin, the alkyd resin, the polyether resin, the fluororesin, the epoxy resin, the silicone resin, or the urea resin, such as a thermosetting resin, a room temperature curing resin, or a photocuring resin, and is preferably one or more selected from the acrylic resin, the polyester resin, the polyurethane resin, and the urea resin. In addition, the coating film-forming resin may be the coating film-forming resin (A) alone that forms a coating film, or may be the coating film formed by the action of a crosslinking agent. The coating film-forming resin may be one type, or two or more types may be used in combination.

[0172] In the infrared absorbing coating composition, the coating film-forming resin may have a hydrophilic group such as an anionic group, a cationic group, or a nonionic group. Examples of the anionic group include a carboxy group and a sulfonic acid group, and examples of the cationic group include an amino group and a quaternary ammonium group. Examples of the nonionic group include a polyoxyalkylene unit. The hydrophilic group can be introduced by using a compound having a hydrophilic group as a raw material for the coating film-forming resin.

[0173] When the coating film-forming resin has an anionic group, the infrared absorbing coating composition may contain a basic compound capable of neutralizing the anionic group, and when the coating film-forming resin has a cationic group, the infrared absorbing coating composition may contain an acidic compound capable of neutralizing the cationic group.

[0174] In the infrared absorbing coating composition, when the coating film-forming resin has an anionic group, the acid value of the coating film-forming resin is preferably 5 mgKOH / g or more and 50 mgKOH / g or less, more preferably 5 mgKOH / g or more and 30 mgKOH / g or less.

[0175] In the infrared absorbing coating composition, when the coating film-forming resin has a cationic group, the amine value of the coating film-forming resin (A) is preferably 5 mgKOH / g or more and 50 mgKOH / g or less, more preferably 5 mgKOH / g or more and 30 mgKOH / g or less.

[0176] In the infrared absorbing coating composition, the film-forming resin may have a hydroxyl group. When the film-forming resin has a hydroxyl group, the hydroxyl value of the film-forming resin is preferably from 5 mgKOH / g to 35 mgKOH / g, more preferably from 7 mgKOH / g to 30 mgKOH / g, and even more preferably from 10 mgKOH / g to 25 mgKOH / g.

[0177] In the infrared absorbing coating composition, the coating film-forming resin may be a resin that can be dissolved in an organic solvent described below, or may be an aqueous resin. Examples of the aqueous resin include water-soluble resins that can be dissolved in an aqueous medium, and water-dispersible resins that can be dispersed in an aqueous medium, such as colloidal dispersion type and emulsion type (emulsion polymerization type and forced emulsification type).

[0178] In the infrared absorbing coating composition, the weight average molecular weight of the coating film-forming resin may be, for example, 2,000 or more and 10,000,000 or less, 10,000 or more and 2,000,000 or less, or 50,000 or more and 2,000,000 or less. In the infrared absorbing coating composition, the weight average molecular weight of the coating film-forming resin, in the case of the emulsion-type water-dispersible resin, may be, for example, 50,000 or more and 10,000,000 or less, 100,000 or more and 2,000,000 or less, or 150,000 or more and 500,000 or less. In the case of a resin that can be dissolved in an aqueous medium or an organic solvent, the weight average molecular weight of the coating film-forming resin may be, for example, 2,000 or more and 100,000 or less, 10,000 or more and 80,000 or less, or 50,000 or more and 80,000 or less. In this specification, the weight average molecular weight is a value measured by gel permeation chromatography and converted into polystyrene equivalent.

[0179] The content of the film-forming resin is preferably 15% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 85% by mass or less, and even more preferably 30% by mass or more and 75% by mass or less, based on 100% by mass of the solid content of the infrared absorbing coating composition.

[0180] In this specification, the solid content of the infrared absorbing coating composition means the portion excluding the solvent (D) described below from all the components of the infrared absorbing coating composition.

[0181] The infrared absorbing coating composition may also use a thermoplastic resin in addition to the coating film forming resin (A) to the extent that the physical properties of the coating film formed are not affected. Examples of the thermoplastic resin include chlorinated olefin resins such as chlorinated polyethylene and chlorinated polypropylene; homopolymers or copolymers containing vinyl chloride, vinyl acetate, vinylidene chloride, etc. as monomer components; cellulose resins; acetal resins; alkyd resins; chlorinated rubber resins; modified polypropylene resins (acid anhydride modified polypropylene resins, etc.); fluororesins (for example, vinylidene fluoride resins, vinyl fluoride resins, copolymers of fluorinated olefins and vinyl ethers, copolymers of fluorinated olefins and vinyl esters), etc. The thermoplastic resins may be used alone or in combination of two or more. By using a thermoplastic resin in combination, it becomes easier to adjust the coating film properties of the coating film formed according to the purpose.

[0182] As the color pigment in the infrared absorbing coating composition, any compound classified as a pigment in the color index can be used.Specifically, the pigment can be, for example, an organic color pigment such as azo chelate pigment, insoluble azo pigment, condensed azo pigment, monoazo pigment, disazo pigment, diketopyrrolopyrrole pigment, benzimidazolone pigment, phthalocyanine pigment, indigo pigment, thioindigo pigment, perinone pigment, dioxane pigment, quinacridone pigment, isoindolinone pigment, naphthol pigment, pyrazolone pigment, anthraquinone pigment, anthrapyrimidine pigment, metal complex pigment, etc.; inorganic color pigment such as yellow lead, yellow iron oxide, chromium oxide, molybdate orange, red iron oxide, titanium yellow, zinc white, carbon black, titanium dioxide, cobalt green, phthalocyanine green, ultramarine blue, cobalt blue, phthalocyanine blue, cobalt violet, etc.

[0183] The color pigment preferably contains a carbon pigment, which improves infrared absorption properties and makes it easier to increase the infrared detection sensitivity of the obtained information code.

[0184] The content of the carbon pigment is preferably 0.2% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and even more preferably 1% by mass or more and 35% by mass or less, based on 100% by mass of the total amount of the color pigments. When the content of the carbon pigment is in this range, the detection sensitivity by infrared rays can be further improved.

[0185] The infrared absorbing coating composition may further contain a visible light transmitting infrared absorbing pigment. In the present disclosure, "visible light transmitting" may mean not being opaque to visible light. Examples of visible light transmitting infrared absorbing pigments include fine powders such as tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), cesium-doped tungsten oxide (CWO), and lanthanum hexaboride (LaB6). By including these, it may be easier to improve infrared absorbing performance without affecting the appearance.

[0186] The infrared absorbing coating composition may contain a crosslinking agent. As the crosslinking agent, the same compounds as those exemplified as the crosslinking agent (C) in the infrared absorbing coating composition may be used. Specifically, the crosslinking agent may include the polyisocyanate compound, the blocked polyisocyanate compound, the amino resin, the phenol resin, the polycarboxylic acid, and the like. These may be used alone or in combination of two or more.

[0187] In the infrared absorbing compound, the content of the crosslinking agent may be, for example, 3 parts by mass or more, 7 parts by mass or more, 10 parts by mass or more, or 20 parts by mass or more, per 100 parts by mass of the total of the coating film-forming resin and the crosslinking agent, and may be, for example, 50 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less.

[0188] In the infrared absorbing compound, the total content of the film-forming resin and the crosslinking agent in the solid content of the infrared absorbing coating composition is preferably 30 mass % or more, more preferably 40 mass % or more, even more preferably 45 mass % or more, and is preferably 95 mass % or less, more preferably 90 mass % or less, even more preferably 85 mass % or less.

[0189] The infrared absorbing coating composition may further contain a solvent. As such a solvent, any of the compounds exemplified as the solvent (D) in the infrared reflective coating composition can be used. The solvent preferably contains the aqueous medium (D1) and / or the organic solvent (D2).

[0190] The infrared absorbing coating composition may be an aqueous coating composition mainly containing the aqueous medium (D1) as a solvent, or may be a solvent-based coating composition mainly containing the organic solvent (D2) as a solvent (D). When the infrared absorbing coating composition is an aqueous coating composition, the content of the aqueous medium (D1) in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 100% by mass or less. When the infrared absorbing coating composition is a solvent-based coating composition, the content of the organic solvent (D2) in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 100% by mass or less.

[0191] The content of the solvent in the infrared absorbing coating composition is preferably 0 mass % or more, more preferably 10 mass % or more, even more preferably 30 mass % or more, and is preferably 70 mass % or less, more preferably 60 mass % or less.

[0192] The infrared absorbing coating composition may be a water-based coating, an organic solvent-based coating, or a solventless coating, for example, a powder coating.

[0193] The infrared absorbing coating composition may further contain other additives. Examples of the other additives include surface conditioners, extender pigments, colorants such as dyes, waxes, the luster pigments, fillers (different from the aggregate (E), and may contain particularly particulate fillers, etc.), ultraviolet absorbers (benzophenone-based ultraviolet absorbers, etc.), antioxidants (phenol-based, sulfoid-based, hindered amine-based antioxidants, etc.), plasticizers, coupling agents (silane-based, titanium-based, zirconium-based coupling agents, etc.), anti-sagging agents, thickeners, pigment dispersants, pigment wetting agents, leveling agents, color separation inhibitors, precipitation inhibitors, antifoaming agents, antifreezing agents, emulsifiers, preservatives, fungicides, antibacterial agents, stabilizers, etc. These additives may be used alone or in combination of two or more.

[0194] The method for forming the infrared absorbing portion using the infrared absorbing coating composition is not particularly limited, but in one embodiment, the infrared absorbing portion can be produced by the same method as the first production method for producing the infrared reflective portion. Specifically, Applying the infrared absorbing coating composition onto a substrate to obtain a coating film; and and drying the coating film to obtain an infrared absorbing portion.

[0195] The coating film is preferably applied so that the thickness of the wet coating film is preferably from 10 μm to 3,000 μm, more preferably from 20 μm to 2,500 μm, and even more preferably from 30 μm to 2,000 μm. The coating can be carried out by a coating method such as spray coating, bar coater coating, air knife coating, gravure coating, brush coating, air gun coating, air electrostatic gun coating, dip coating, roller coating, or the like.

[0196] The drying conditions for drying the coating film are not particularly limited, and may be natural drying or forced drying using a dryer or the like. The drying temperature may be preferably 20°C or more and 200°C or less, more preferably 70°C or more and 180°C or less, and even more preferably 80°C or more and 140°C or less. The drying time may be preferably 10 minutes or more and 24 hours or less, more preferably 10 minutes or more and 60 minutes or less, and even more preferably 15 minutes or more and 45 minutes or less. As the heating means, hot air heating, infrared heating, induction heating, etc. may be used.

[0197] The technical scope of the present disclosure also includes an article comprising a substrate and an information code of the present disclosure disposed on the substrate, wherein the color difference (ΔE) between the substrate and the infrared reflective portion is 5.0 or less and / or the color difference (ΔE) between the substrate and the infrared absorbing portion is 5.0 or less. In the present disclosure, the color difference (ΔE) between the substrate and the infrared reflecting portion and / or the infrared absorbing portion can be controlled by changing one or more hues of the infrared reflecting portion, the infrared absorbing portion, and the substrate, and may be controlled by changing the hue of the infrared reflecting portion and / or the infrared absorbing portion, or may be controlled by changing the hue of the substrate. Typically, the color difference (ΔE) can be controlled by changing the hue of the infrared reflecting portion and / or the infrared absorbing portion.

[0198] The color difference (ΔE) between the substrate and the infrared reflective portion can be 5.0 or less, preferably 0 or more and 4.0 or less, and more preferably 0 or more and 3.0 or less.

[0199] The color difference (ΔE) between the substrate and the infrared absorbing portion may be 5.0 or less, preferably 0 or more and 4.0 or less, and more preferably 0 or more and 3.0 or less.

[0200] Examples of the substrate (also referred to as "substrate") include metal plates and members made of metal plates, as well as plastic members, inorganic material members, wooden members, paved surfaces such as road surfaces, and the like.

[0201] Examples of the metal sheet include metal sheets such as zinc-plated steel sheets, zinc-aluminum alloy-plated steel sheets, aluminum alloy-plated steel sheets, hot-dip zinc-aluminum-magnesium alloy-plated steel sheets, stainless steel sheets, and cold-rolled steel sheets, which are manufactured by a hot-dip process or an electrolytic process. In addition to these steel sheets or plated steel sheets, metal sheets such as aluminum sheets (including aluminum alloy sheets) can also be used as the coating target. The metal sheet is preferably surface-treated. Specifically, the metal sheet is preferably subjected to a pretreatment such as an alkaline degreasing treatment, a hot water washing treatment, or a water washing treatment, and then a chemical conversion treatment. The chemical conversion treatment may be performed by a known method, and examples thereof include a non-chromate treatment such as a chromate treatment or a zinc phosphate treatment. The surface treatment can be appropriately selected depending on the steel sheet to be used, but a treatment that does not contain heavy metals is preferable.

[0202] Examples of the plastic member include an acrylic plate, a polyvinyl chloride plate, a polycarbonate plate, an ABS plate, a polyethylene terephthalate plate, and a polyolefin plate.

[0203] Examples of the inorganic member include ceramic building materials and glass substrates described in JIS A 5422, JIS A 5430, etc., such as calcium silicate boards, pulp cement boards, slag gypsum boards, magnesium carbonate boards, asbestos-perlite boards, wood chip cement boards, hard wood cement boards, concrete boards, lightweight aerated concrete boards, and concrete structures.

[0204] Examples of the wooden members include lumber, laminated lumber, plywood, particle board, fiber board, improved wood, chemically treated wood, and floorboards.

[0205] Examples of the pavement such as the road surface include asphalt pavement, concrete pavement, and brick pavement.

[0206] Specific examples of items to which the information codes disclosed herein can be applied include various products for sale, driving paths, road structures (e.g., pavements, road markings, sidewalks, crosswalks, drainage facilities, at-grade intersection structures, bridges, earthworks, tunnels, turnouts, traffic safety facilities (e.g., multi-level crossing facilities, guardrails, protective fences, lighting facilities, visual delineators, road reflectors, etc.), traffic islands, bus stops, parking lanes, parking lots, etc.), various building structures and their internal equipment, railway structures, various protective facilities, various vehicles and their accessories, pedestrian wear, utility poles, the interior walls of various building structures, etc. EXAMPLES

[0207] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these.

[0208] <Measurement Example 1 of Near-Infrared Reflectance and Spectral Reflectance of Pigments> Measurement example of near infrared reflectance of inorganic yellow pigments and spectral reflectance at wavelengths of 905 nm and / or 1,550 nm As a coating resin, (A-1) Aroset 5534-SB60 21.0 parts by mass, as a solvent (D2-1) T-SOL 100 (manufactured by Exxon Chemical Co., Ltd.) 6.0 parts by mass, as an inorganic yellow pigment (B1-3) Sico Pearl Yellow L-1110 22.0 parts by mass were mixed, and then dispersed with SG mill (medium: glass beads) until the dispersed particle size of the pigment becomes 10 μm or less. Next, (A-1) 51.0 parts by mass was added, and mixed with stirring using a disperser to obtain a main agent.

[0209] 62.0 parts by mass of Duranate TSA-100 (C-1) as a crosslinking agent and 38.0 parts by mass of T-SOL 100 (manufactured by Exxon Chemical Co.) as a solvent (D2-1) were mixed with stirring using a disper to obtain a curing agent.

[0210] The base agent and curing agent obtained above were mixed in a mass ratio of 9:1 to obtain a coating composition (pigment mass concentration: 30.0 mass%). The obtained coating composition was applied to a black and white hiding power test paper (manufactured by Nippon Test Panel Co., Ltd.) using an 8 mil doctor blade so that the dry film thickness was 50 μm, and after drying at 60° C. for 20 minutes, it was left to stand at room temperature for 1 day to obtain a coating film. The reflectance of the resulting coating film in the white base area was measured at wavelength intervals of 2 nm in the wavelength range of 800 to 2,500 nm using a spectrophotometer (Shimadzu Corporation, SHIMADZU-UV3600) according to a method conforming to JIS K 5602. The arithmetic mean value of the reflectance at each wavelength obtained was taken as the near-infrared reflectance of the inorganic red pigment. The near-infrared reflectance at 905 and 1,550 nm is the value of the spectral reflectance at each wavelength.

[0211] The near-infrared reflectance and spectral reflectance of each of the other pigments were measured in the same manner as in Measurement Example 1 of Near-Infrared Reflectance and Spectral Reflectance of Pigments, except that the type and mass concentration of each pigment were set to the amounts shown in Table 1.

[0212] [Table 1]

[0213] <Production Example 1> White pigment paste manufacturing example 22.0 parts by mass of (A-1) Aroset 5534-SB60 as a coating resin, 7.0 parts by mass of (D2-1) T-SOL 100 (manufactured by Exxon Chemical Co.) as a solvent, and 34.0 parts by mass of (B1-1) TIPAQUE CR-97 as a white pigment were mixed, and then dispersed using an SG mill (medium: glass beads) until the dispersed particle size of the pigment was 10 μm or less. Next, 37.0 parts by mass of (A-1) was added and mixed while stirring using a disper to obtain a white pigment paste (P-1).

[0214] Examples of pigment paste manufacturing Except for changing the type and amount of the pigment used as shown in Table 2, the same procedure as in Production Example 1 was carried out to obtain pigment pastes (P-2 to P-6) of each pigment.

[0215] [Table 2]

[0216] Example of manufacturing clear coat for adjustment 26.0 parts by mass of (A-1) Aroset 5534-SB60 as a coating resin, 8.0 parts by mass of (D2-1) T-SOL 100 (manufactured by Exxon Chemical Co.) as a solvent, and 21.0 parts by mass of (B2-1) N heavy carbon (manufactured by Maruo Calcium Co.) as an extender pigment were mixed, and then dispersed using an SG mill (medium: glass beads) until the dispersed particle size of the pigment was 50 μm or less. Next, 45.0 parts by mass of (A-1) was added and mixed while stirring using a disper to obtain a adjusting clear (W-1).

[0217] <Example 1> The white pigment paste (P-1) 41.8 parts by mass, the red pigment paste (P-2) 9.4 parts by mass, the yellow pigment paste (P-3) 27.0 parts by mass, the blue pigment paste (P-5) 2.5 parts by mass, and the adjusting clear (W-1) 203.4 parts by mass were mixed while stirring with a disper to obtain a main agent (S1-1). Further, 62.0 parts by mass of Duranate TSA-100 (C-1) as a crosslinking agent and 38.0 parts by mass of T-SOL 100 (manufactured by Exxon Chemical Co.) were mixed with stirring using a disper to obtain a curing agent (K-1). The above-obtained base agent (S1-1) (284.1 parts by mass) and hardener (K-1) (34.6 parts by mass) were mixed with stirring using a disperser to obtain an infrared reflective coating composition (XR-1). The base agent (S1-1) and hardener (K-1) were mixed in a mass ratio of 9:1.

[0218] Production example of infrared absorbing coating composition The white pigment paste (P-1) (64.3 parts by weight), the red pigment paste (P-2) (4.5 parts by weight), the yellow pigment paste (P-3) (27.8 parts by weight), the carbon pigment paste (P-6) (7.5 parts by weight), and the adjustment clear (W-1) (172.3 parts by weight) were mixed while stirring with a disper to obtain a main agent (S2-1). Further, as a crosslinking agent, 62.0 parts by mass of Duranate TSA-100 (C-1) and 38.0 parts by mass of T-SOL 100 (manufactured by Exxon Chemical Co.) were mixed with stirring using a disper to obtain a curing agent (K-1). The above-obtained base agent (S2-1) 276.5 parts by mass and hardener (K-1) 30.7 parts by mass were mixed with stirring using a disperser to obtain an infrared absorbing coating composition (XA-1). The base agent (S2-1) and hardener (K-1) were mixed in a mass ratio of 9:1.

[0219] <Examples 2 to 7, Comparative Examples 1 to 2> Each coating film (test piece) was obtained in the same manner as in Coating Film (Test Piece) Production Example 1, except that the types and amounts of pigment paste, adjustment clear, crosslinking agent, and solvent used were changed as shown in Table 3. When the coating composition contained other materials, the other materials were mixed with various pigment pastes and adjusting clears when the base material was produced to prepare the base material.

[0220] Details of each component used in the Examples and Comparative Examples shown in the following table are as follows. Paint film forming resin (A) (A-1) Aroset 5534-SB60 (acrylic polyol resin, manufactured by Nippon Shokubai Co., Ltd.): weight average molecular weight: 50,000, acid value: 10 mg KOH / g, hydroxyl value: 38 mg KOH / g, solid content concentration: 60% by mass Extender pigment (B2) (B2-1) N heavy carbon (heavy calcium carbonate, manufactured by Maruo Calcium Co., Ltd.) Crosslinker (C) (C-1) Duranate TSA-100 (HDI isocyanurate type polyisocyanate, manufactured by Asahi Kasei Corporation); NCO content: 20.6%, solid content: 100% by mass Solvent (D) (D2-1) T-SOL 100 (aromatic hydrocarbon solvent, manufactured by Exxon Chemical)

[0221] [Table 3]

[0222] <Example of creating a 2D information code> The periphery of the substrate (70 cm × 70 cm) described below was masked with masking tape so that a central 50 cm × 50 cm square portion was exposed. The infrared absorbing coating composition obtained above was spray-coated on the exposed portion so that the dry film thickness was 100 μm, and the resulting mixture was left to stand at room temperature for one day to obtain an infrared absorbing portion. Next, a template with an opening so as to obtain a specified two-dimensional information code was placed on top of the obtained infrared absorbing part, and the infrared reflective coating composition obtained above was spray-painted onto the opening so as to give a dry film thickness of 100 μm. The resulting coating was left to stand at room temperature for one day to obtain a two-dimensional information code in which an infrared absorbing part and an infrared reflective part are adjacent to each other.

[0223] Comparative Example 1 The periphery of the substrate 3 (70 cm x 70 cm) described below was masked with masking tape so that a central 50 cm x 50 cm square portion was exposed. A template with an opening was placed in the exposed portion so that a predetermined two-dimensional information code could be obtained, and the infrared reflective coating composition (XR-2) used in Example 2 was spray-painted onto it so that the dry film thickness was 100 μm, and the mixture was left to stand at room temperature for one day to obtain a two-dimensional information code consisting only of an infrared reflective portion.

[0224] Comparative Example 2 The periphery of the substrate 1 (70 cm x 70 cm) described below was masked with masking tape so that a central 50 cm x 50 cm square portion was exposed. A template with an opening was placed in the exposed portion so that a predetermined two-dimensional information code could be obtained, and the infrared absorbing coating composition (XA-2) used in Example 2 was spray-painted onto it so that the dry film thickness was 100 μm, and the mixture was left to stand at room temperature for one day, obtaining a two-dimensional information code consisting only of an infrared absorbing portion.

[0225] The following three types of substrates were used: Object 1: A tinplate (manufactured by TP Giken Co., Ltd.) was spray-painted with Nippe Fine Urethane U-100 dark brown (manufactured by Nippon Paint Co., Ltd.) so that the dry film thickness was 100 μm, and then cured and dried at room temperature for one day to obtain coated object 1 (L*=28.8, a*=1.1, b*=2.9). Object 2: Nippe Fine Urethane U-100 gray beige (Nippon Paint) was spray-painted onto a tinplate (TP Giken) so that the dry film thickness was 100μm, and then cured and dried at room temperature for one day to obtain coated object 2 (L*=51.9, a*=2.2, b*=6.9). Object 3: A slate board (TP Giken Co., Ltd., 70 x 70 x 0.5 cm) was used as is (L*=72.0, a*=-1.7, b*=4.2).

[0226] <Evaluation method> 1) Color difference (ΔE) The hues (L* value, a* value, b* value) and color differences (ΔE) of the infrared reflecting portion, infrared absorbing portion and coated object obtained in the examples and comparative examples were measured using a colorimeter CM-600d (manufactured by Konica Minolta) in accordance with JIS K 5600-4-4 3.2 and JIS K 5600-4-5.

[0227] 2) Near-infrared reflectance and spectral reflectance The test pieces obtained in the examples and comparative examples were measured for reflectance in the wavelength range of 800 to 2,500 nm at 2 nm intervals using a spectrophotometer (Shimadzu Corporation, SHIMADZU-UV3600) according to a method conforming to JIS K 5602. The arithmetic mean value of the reflectance at each wavelength obtained was taken as the near-infrared reflectance of the coating film. The near-infrared reflectance at 905 and 1,550 nm is the value of the spectral reflectance at each wavelength.

[0228] The information code thus produced was placed directly facing the evaluator at a distance of 5 m, and the evaluation was carried out visually. A score of 1 or higher was deemed to be a pass. 3: Almost unrecognizable even when viewed up close 2: It is not recognizable at first glance, but becomes recognizable upon closer inspection. 1: It is not visible at first glance, but becomes clearly visible when you focus on it. 0: Clearly recognizable without focusing

[0229] 4) Information code readability The two-dimensional information codes obtained in the examples and comparative examples were photographed using a night vision camera SP868A (manufactured by SIGHTRON Corporation). After that, the image was printed on a blank sheet of paper and evaluated for readability using the QR Code (registered trademark) reading function of the iPhone (registered trademark) SE (3rd generation). The evaluation criteria were as follows. A score of 2 or more was considered a pass. 5: Can be read more than 9 times out of 10 4: Can be read 7 to 8 times out of 10 3: Can be read 5 to 6 times out of 10 2: Can be read 3 to 4 times out of 10 1: Can be read more than once and less than twice in 10 times 0: Cannot be read even once in 10 times

[0230] [Table 4]

[0231] Examples 1 to 7 are examples of the present invention, and when the information codes were produced, the difference between the infrared reflecting parts and the infrared absorbing parts, and the difference from the coated object, was not easily noticeable, and the information codes were readable. Comparative Example 1 is an example in which an information code was created using only an infrared reflecting part, without providing an infrared absorbing part. In this example, the color difference between the information code and the coated object was large, and although the difference was easily noticeable, the information code was difficult to read. Comparative Example 2 is an example in which an information code was created using only an infrared absorbing part, without providing an infrared reflecting part. In this example, the difference between the information code and the coated object was not very noticeable, but the information code was difficult to read. [Industrial Applicability]

[0232] The information code of the present disclosure can provide information without affecting the design of the substrate, and has high infrared detection sensitivity. Therefore, the information code of the present disclosure can be suitably used for various products sold, driving paths, road structures (e.g., pavement, road markings, sidewalks, pedestrian crossings, drainage facilities, at-grade intersections, bridges, earthworks, tunnels, turnouts, traffic safety facilities (e.g., grade separation facilities, guardrails, protective fences, lighting facilities, delineators, road reflectors, etc.), traffic islands, bus stops, parking lanes, parking lots, etc.), various building structures and their internal equipment, railway structures, various protective facilities, various vehicles and their accessories, pedestrian wear, utility poles, the inner walls of various building structures, etc.

Claims

1. An information code in which information that can be read by infrared irradiation is recorded, the information code has an infrared reflecting portion and an infrared absorbing portion, The infrared reflecting portion and the infrared absorbing portion have similar hues, and The infrared reflective portion and the infrared absorbing portion are opaque to visible light. Information code.

2. 2. The information code according to claim 1, wherein a color difference (.DELTA.E) between the infrared reflective portion and the infrared absorbing portion is 5.0 or less.

3. The infrared reflectance (RR) of the infrared reflective portion is 50% or more, The information code according to claim 1 , wherein the infrared absorbing portion has an infrared reflectance (RA) of less than 50%.

4. 2. The information code according to claim 1, wherein a ratio (RR / RA) of an infrared reflectance (RR) of said infrared reflecting portion to an infrared reflectance (RA) of said infrared absorbing portion is 1.5 or more.

5. 5. The information code according to claim 3, wherein the infrared reflectance is one selected from the group consisting of an average spectral reflectance in a wavelength range of 780 to 2,500 nm, an average spectral reflectance in a wavelength range of 830 to 915 nm, and a spectral reflectance at a wavelength of 905 nm and / or a wavelength of 1,550 nm.

6. A substrate and an information code disposed on the substrate, The information code is an information code according to any one of claims 1 to 4, An article, wherein the color difference (ΔE) between the substrate and the infrared reflective portion is 5.0 or less, and / or the color difference (ΔE) between the substrate and the infrared absorbing portion is 5.0 or less.

7. The infrared reflective portion is formed from an infrared reflective coating composition, The infrared reflective coating composition comprises: A coating composition comprising a film-forming resin (A) and a color pigment (B), The color pigment (B) contains a pigment (B1) capable of reflecting near infrared rays, When the reflectance in the wavelength range of 800 to 2,500 nm is taken as the near-infrared reflectance, The pigment (B1) includes at least one pigment selected from the group consisting of a white pigment having a near-infrared reflectance of 60% or more, a chromatic pigment having a near-infrared reflectance of 50% or more, and a black pigment having a near-infrared reflectance of 30% or more, and one selected from a white pigment having a near infrared reflectance of 60% or more and a chromatic pigment having a near infrared reflectance of 50% or more; The information code according to any one of claims 1 to 4, wherein the pigment (B1) contains an organic pigment, and a content of the organic pigment in a total amount of the pigment (B1) is 3 mass % or more.

8. The color pigment (B) is a white pigment having a spectral reflectance of 70% or more at a wavelength of 905 nm and / or 1,550 nm; an organic red pigment having a spectral reflectance of 50% or more at the wavelength; an inorganic red pigment having a spectral reflectance of 20% or more at the wavelength; an organic yellow pigment having a spectral reflectance of 60% or more at the wavelength; an inorganic yellow pigment having a spectral reflectance of 20% or more at the wavelength; a blue pigment having a spectral reflectance of 40% or more at the wavelength; An organic black pigment having a spectral reflectance of 30% or more at the wavelength, and An inorganic black pigment having a spectral reflectance of 15% or more at the wavelength. The information code according to claim 7, comprising at least one selected from the group consisting of:

9. The information code according to claim 7 , wherein a content of the carbon pigment in the color pigment (B) is less than 0.2% by mass in 100% by mass of a total amount of the color pigment (B).

10. The infrared absorbing portion is formed from an infrared absorbing coating composition, The infrared absorbing coating composition comprises: Contains a film-forming resin and a color pigment, The color pigment includes a carbon pigment, 8. The information code according to claim 7, wherein a content of the carbon pigment is 0.2% by mass or more and 50% by mass or less with respect to 100% by mass of a total amount of the color pigments.

11. An information recording medium having the information code according to any one of claims 1 to 4.

12. The information code according to any one of claims 1 to 4, which is for a road-to-vehicle cooperative communication system.

Images