Colored granular article

Abstract

To provide a colored granular article having high heat-insulating performance.SOLUTION: A colored granular article A comprises a core particle B, and a colored layer T formed on a surface of the core particle B. The core particle B comprises an inorganic particle having an average particle size of 0.1 mm to 1.0 mm. The colored layer T is a fused coating material formed by a coating material C containing a glass frit and a heat-shielding pigment, the coating material C being fused onto a surface of the core particle B. The heat-shielding pigment contains an inorganic pigment having a solar reflectance of 20% to 30%.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to colored granular materials. More specifically, the present invention relates to colored granular materials comprising core particles and a coating material.

Background Art

[0002] Patent Document 1 describes heat-insulating granular materials. This heat-insulating granular material has a core material of granular materials with a particle size of 0.075 to 30.0 mm and a colored film covering substantially the entire surface of the core material. The colored film contains a heat-insulating pigment selected from those having a solar reflectance of 15% or more and 95% or less as defined in JIS A5759 and an anti-caking agent. The anti-caking agent is fine silica having a particle size of 2 to 10 μm, and the content is 0.05 to 10.0 parts by weight with respect to 100 parts by weight of the colored film. It is embedded in or adheres to the colored film and is exposed on the surface, and the surface content with respect to the colored film is 10 to 20%.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the heat-insulating granular materials as described in Patent Document 1, improvement of their heat-insulating performance is desired.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a colored granular material having high heat-insulating performance.

Means for Solving the Problems

[0006] The present invention relates to a colored granular material comprising a core particle and a colored layer formed on the surface of the core particle, wherein the core particle is composed of inorganic particles having an average particle diameter of 0.1 to 1.0 mm, and the colored layer is a deposit formed by welding a coating material C containing glass frit and a heat shielding pigment onto the surface of the core particle, and the heat shielding pigment contains an inorganic pigment having a solar reflectance of 20% to 30%.

Effect of the Invention

[0007] According to the present invention, a colored granular material with high sunlight reflection performance by a heat shielding pigment and high heat shielding effect can be easily obtained.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0009] 1. Overview The colored granular material A of the present embodiment includes a core particle B and a colored layer T (see FIG. 1). The colored layer T is formed on the surface of the core particle B. The core particle B is composed of inorganic particles having an average particle diameter of 0.1 to 1.0 mm. The colored layer T is a deposit, and a coating material C containing glass frit and a heat shielding pigment is welded onto the surface of the core particle B. The heat shielding pigment contains an inorganic pigment having a solar reflectance of 20% to 30%.

[0010] Since the colored particulate matter A of the present embodiment has a colored layer T containing a heat shielding pigment formed on the surface of the core particles B, the colored particulate matter A having high sunlight reflection performance by the heat shielding pigment and a high heat shielding effect can be obtained. Therefore, by providing the colored particulate matter A of the present embodiment as a decorative material on the surface of building materials such as roofing materials and wall materials, it is possible to suppress the temperature rise of the building materials while improving the designability of the appearance of the building materials.

[0011] 2. Details <Regarding the colored particulate matter> As shown in FIG. 1, the colored particulate matter A of the present embodiment includes core particles B and a colored layer T.

[0012] The core particles B are inorganic particles. As the inorganic particles, silica sand or chamotte can be used. The core particles B have an average particle diameter of 0.1 to 1.0 mm. If the average particle diameter of the core particles B is less than 0.1 mm, the core particles B may be too small and the handleability may be reduced. If the average particle diameter of the core particles B exceeds 1.0 mm, the core particles B may be too large and the heat shielding effect by the heat shielding pigment may not be sufficiently obtained. The average particle diameter of the core particles B in the present embodiment is the median diameter (d50). The average particle diameter of the core particles B can be measured, for example, with a laser diffraction particle size distribution measuring device. When the core particles B are silica sand, No. 5 silica sand (average particle diameter 0.51 mm), No. 6 silica sand (average particle diameter 0.35 mm), No. 7 silica sand (average particle diameter 0.19 mm), etc. can be used. By using core particles B having substantially uniform particle diameters, the uniformity of the heat applied to the core particles B during firing can be enhanced. Therefore, the variation in the heat history is reduced, and the discoloration of a part of the core particles B and the colored layer T into a color different from the target color is reduced, and the color unevenness of the colored particulate matter A can be reduced.

[0013] The core particle B preferably has an iron oxide content of 0.1 mass% or less. This can reduce the color unevenness of the colored granular material A. Since iron oxide changes from yellow to brownish - red due to the heat during firing when the coating material C is welded to the core particle B, if its content is more than 0.1 mass%, it may affect the color of the core particle B itself or the color of the colored layer T, and there may be a risk of generating a colored granular material A that has changed color to a color different from the target color.

[0014] The core particle B preferably has little variation in discoloration due to heat. When only the core particle B is fired, the color difference (ΔE (JIS Z8730)) within the fired core particle B is L * a * b * preferably 3 or less in the color system (JIS Z8729). That is, when only the granular material of the core particle B is fired, the overall color difference of the fired core particle B is L * a * b * such that it is 3 or less in the color system. If the color difference ΔE is larger than this value, the variation in discoloration of the core particle B may affect the colored layer T, and there may be a risk of color unevenness occurring in the colored granular material A. Incidentally, the smaller the color difference ΔE, the more preferable it is. Since the lighter the color of the coating material C, the more likely the influence of the variation in discoloration of the core particle B is to appear, it is preferably 2 or less. Incidentally, "firing only the core particle B" refers to performing baking such as firing the core particle B without mixing it with the coating material C.

[0015] The coloring layer T is formed on the surface of the core particles B. The coloring layer T is a weld deposit of the coating material C. The coating material C contains glass frit and a heat-insulating pigment. Then, after the glass frit in the coating material C is heat-melted in a state containing the heat-insulating pigment and adheres to the surface of the core particles B, the heat-melted glass frit cools and solidifies on the surface of the core particles B in a state containing the heat-insulating pigment. Thereby, the coloring layer T including the heat-insulating effect covers the entire surface of the core particles B and the colored granular material A is formed. Note that the surface of the core particles B is preferably completely covered with the coloring layer T, but it is sufficient that 90% or more, more preferably 95% or more of the surface area of the core particles B is covered with the coloring layer T.

[0016] The glass frit is a powder of a vitreous inorganic substance (glass powder), and a known one can be used. For example, those obtained using alkali metal oxides such as Na2O and K2O, alkaline earth metal oxides such as CaO3, silicic acid such as SiO2 or salts thereof as main raw materials, and in addition, ZnO, PbO, Al2O3, etc. as raw materials can be used. Further, the glass frit preferably has alkali resistance, and furthermore, it is preferable to use a powder having a size of 0.2 to 10 μm.

[0017] The heat-insulating pigment has a higher reflectance of sunlight than ordinary pigments, and in particular, those having a higher reflectance of sunlight in the infrared region are preferable. Therefore, the colored granular material A provided with the coloring layer T containing the heat-insulating pigment can suppress the rise in temperature as compared with the colored granular material provided with the coloring layer containing an ordinary pigment. A known one can be used, for example, inorganic pigments containing iron (Fe), chromium (Cr), and oxides thereof can be used. The heat-insulating pigment is in powder form, and it is preferable to use one having an average particle size of 0.2 to 3 μm, and more preferably one having an average particle size of 0.5 to 1.0 μm. The average particle size of the heat-insulating pigment can be measured in the same manner as the average particle size of the core particles B.

[0018] In this embodiment, it is preferable that the ratio of the average particle diameter of the core particles B to the average particle diameter of the heat insulating pigment is from 1000:1 to 200:1. That is, it is preferable that the average particle diameter of the core particles B is 200 to 1000 times the average particle diameter of the heat insulating pigment. Thereby, the dispersibility of the heat insulating pigment in the colored layer T can be improved, and the heat insulating effect by the colored layer T can be improved.

[0019] The heat insulating pigment contains an inorganic pigment having a solar reflectance of 20% to 30%. When the heat insulating pigment is an inorganic pigment having a solar reflectance of 20% to 30%, the heat insulating pigment has high sunlight reflection performance, and it is easy to obtain the colored particulate matter A having a high heat insulating effect by the colored layer T. The solar reflectance of the heat insulating pigment is more preferably 23% to 29%.

[0020] <Regarding the method for producing the colored particulate matter> FIG. 2 shows a production apparatus for the colored particulate matter A of this embodiment. This apparatus includes a mixer 2, a dryer 3, a firing furnace 4, and a cooler 5. The mixer 2 mixes the core particles B and the coating material C. The mixture M of the core particles B and the coating material C is in a state where the coating material C is covered and adhered on the surface of the core particles B. As the mixer 2, for example, a sand mill can be used.

[0021] The dryer 3 is for drying the mixture M of a plurality (a large number) of core particles B and the coating material C before firing by the firing machine 4, and a rotary tubular dryer can be used. In this case, the rotary tubular dryer includes a tubular body 3a configured to rotate by a drive source (not shown), and the tubular body 3a is disposed so as to be inclined downward from the material inlet 3b at one end thereof toward the material outlet 3c at the other end. Reference numeral 3d is a heating unit for heating the mixture M. As the heating unit 3d, for example, a burner can be used, and hot air can be blown into the body 3a from the material inlet 3b to dry. By blowing hot air from the side of the material inlet 3b in this way, the mixture M can be rapidly heated by the hot air, and cloudiness due to crystallization of the coating material C can be prevented. The hot air blown from the side of the material inlet 3b is exhausted from the material outlet 3c. Further, a plurality of stirring fins can be provided on the inner surface of the body 3a. By this stirring fin, the mixture M blown up in the body 3a is efficiently heated by the hot air when it falls.

[0022] The firing machine 4 fires the dried mixture M and welds (thermally welds) the coating material C onto the surfaces of the plurality (a large number) of core particles B, thereby firing a colored layer T on the surfaces of the core particles B to form colored granular materials A. As this firing machine 4, a rotary kiln can be used. This rotary kiln includes a tubular body 4a configured to rotate by a drive source (not shown), and the tubular body 4a is disposed so as to be inclined downward from the material inlet 4b at one end thereof toward the material outlet 4c at the other end.

[0023] Further, the body 4a is formed by providing a refractory layer formed of a refractory such as refractory bricks on the entire inner surface of a metal outer cylinder 20. Reference numeral 4d is a heating unit for heating the mixture. As the heating unit 4d, for example, a burner can be used, and the mixture can be fired by radiating a flame into the body 4a from the material outlet 4c. Hot air is exhausted from the material inlet 4b.

[0024] Here, as the body 4a of the firing machine 4, it is preferable to form a plurality of stepped portions on its inner surface by forming its inner diameter to gradually increase from the material inlet 4b side toward the material outlet 4c side. For example, a plurality of tubular bodies with different inner diameters can be longitudinally connected in the order of the size of the inner diameter, and the connecting portion between adjacent tubular bodies can be formed as a stepped portion. By providing such a plurality of stepped portions, the stirring efficiency can be enhanced. Further, by making the inner diameter of the body 4a on the material inlet 4b side smaller than other portions, when the core particles B immediately after the coating material C adheres fall and are stirred in the body 4a due to the rotation of the body 4a, the impact can be reduced. Therefore, it becomes difficult for the coating material C to peel off from the core particles B.

[0025] Moreover, the temperature distribution inside the body 4a on the material inlet 4b side of the body 4a can be reduced, and the firing spots can be decreased. On the other hand, by making the inner diameter of the body 4a on the material outlet 4c side larger than other portions, the core particles B (colored granular materials A) formed with the colored layer T can be vigorously stirred so as not to agglomerate due to fusion. Also, the temperature of the colored granular materials A can be gradually increased toward the material outlet 4c side, and it can be made difficult for insufficient firing to occur.

[0026] Also, by making the cross-sectional shape of the inner peripheral surface of the body 4a into a polygon such as an octagon, the joint portions of each side can also be formed as stepped portions. Thereby, the core particles B (colored granular materials A) coated with the coating material C can be moderately stirred, and it can be made difficult for the color development to become uneven or for the core particles B to fuse into a lump.

[0027] The cooler 5 cools a plurality (a large number) of colored granular materials A (core particles B forming a colored layer T), and a rotary tubular cooler can be used. In this case, the rotary tubular cooler has a tubular body 5a configured to rotate by a driving source (not shown), and the tubular body 5a is arranged inclined downward from a material inlet 5b at one end to a material outlet 5c at the other end. The cooler 5 is also provided with a cold air supplying section 6. The cold air supplying section 6 is configured to blow cold air into the body 5a from the material inlet 5b of the body 5a.

[0028] By blowing cold air from the material inlet 5b side in this way, the core particles B on which the colored layer T is formed can be rapidly cooled by the cold air, and the color development of the colored layer T can be made approximately uniform and clear. Furthermore, the coating material C that did not adhere to the core particles B and the unnecessary fine powder generated by the cracks of the core particles B are lighter than normal colored granular material A (those whose colored layer T has not peeled off) and can be blown out from the material outlet 5c by supplying cold air, and the normal colored granular material A and the unnecessary fine powder can be easily separated. Furthermore, by exhausting air from the material outlet 5c, the colored granular material A can be discharged smoothly with good flow.

[0029] In addition, a plurality of stirring fins can be provided on the inner surface of the body 5a. The stirring fins protrude from the inner surface of the body 5a toward the center, and are arranged in a line in the circumferential direction of the body 5a. The stirring fins allow the colored granular material A blown up to be efficiently cooled by cold air as it falls. In addition, the colored granular material A that has melted slightly and formed lumps can be broken up by the impact of falling. Water may be sprayed on the outside of the body 5a for cooling.

[0030] In the manufacturing apparatus of the colored granular material A, a dryer supply means 30 including a transport pipe 30a, a tank 30b, and a transport conveyor 30c is provided to supply the mixture M from the mixer 2 to the dryer 3. The mixture M discharged from the mixer 2 is temporarily stored in the tank 30b through the transport pipe 30a. The mixture M stored in the tank 30b is discharged in a fixed quantity, conveyed by the transport conveyor 30c, and fed into the dryer 3.

[0031] Also, a firing machine supply means 40 including a transport pipe 40a, a tank 40b, and a transport conveyor 40c is provided to supply the mixture M from the dryer 3 to the firing machine 4. The mixture M discharged from the dryer 3 is temporarily stored in the tank 40b through the transport pipe 40a. The mixture M stored in the tank 40b is discharged in a fixed quantity, conveyed by the transport conveyor 40c, and fed into the firing machine 4.

[0032] Furthermore, a cooler supply means 50 composed of a vibrating feeder is provided to supply the colored granular material A from the firing machine 4 to the cooler 5. The vibrating feeder is formed in a tubular double structure composed of an inner pipe 50a and an outer pipe 50b, and the colored granular material A discharged from the firing machine 4 moves inside the inner pipe 50a of the vibrating feeder and is fed into the cooler 5. Also, by passing cooling water through the space formed between the inner pipe 50a and the outer pipe 50b, the colored granular material A fed into the cooler 5 can be cooled in advance by at least a little.

[0033] When manufacturing the colored granular material A using the above-described apparatus, the following steps are taken. First, the core particles B and the coating material C are mixed. At this time, in order to enhance the adhesion of the coating material C to the core particles B or adjust the viscosity, a binder (paste) such as sodium silicate (water glass) or water can be blended into the coating material C. In this case, with respect to 100 parts by mass of the core particles B, the coating material C can be 1 to 3 parts by mass, the binder can be 1 to 3 parts by mass, and the water can be 0.3 to 1 part by mass, but it is not limited thereto. Then, a substantially uniform mixture M containing the core particles B, the coating material C, the binder, and water is prepared. This mixture M is adhered in a state where the coating material C is covering the surface of the core particles B.

[0034] Next, through the dryer supply means 30, the mixture M prepared in the mixer 2 is continuously and quantitatively supplied from the mixer 2 to the dryer 3. The mixture M is conveyed along the inclination from the material inlet 3b to the material outlet 3c while being agitated by the rotation of the body 3a. Also, the mixture M is heated and dried by the heat from the heating section 3d inside the body 3a. The drying temperature can be 90 to 150 °C at the temperature of the material outlet 3c, and the drying time (the time passing through the body 3a) can be 5 to 10 minutes, but it is not limited thereto. By this drying, the moisture content of the mixture can be made, for example, 1% or less. Also, the rotation speed of the body 3a can be, for example, 4 to 7 rpm.

[0035] Next, through the firing machine supply means 40, the mixture M dried by the dryer 3 is continuously and quantitatively supplied from the dryer 3 to the firing machine 4. The mixture M is conveyed along the inclination from the material inlet 4b to the material outlet 4c while being agitated by the rotation of the cylinder 4a. Also, the mixture M is fired by the heat from the heating section 4d inside the cylinder 4a. The firing temperature can be 400 to 450°C at the temperature of the material outlet 4c, and the firing time (the time to pass through the cylinder 4a) can be 15 to 20 minutes, but it is not limited thereto. By this firing, the coating material C is thermally welded onto the surface of the core particles B to form the colored layer T, and the colored granular material A can be obtained. Also, the rotation speed of the cylinder 4a can be, for example, 4 to 7 rpm. Incidentally, the conditions for firing only the core particles B can also use the conditions for firing the above mixture M.

[0036] Next, through the cooler supply means 50, the colored granular material A (core particles B formed with the colored layer T) fired by the firing machine 4 is continuously supplied from the firing machine 4 to the cooler 5. The colored granular material A is conveyed along the inclination from the material inlet 5b to the material outlet 5c while being agitated by the rotation of the cylinder 5a. Also, the colored granular material A is cooled by the cold air from the cold air supply section 6 inside the cylinder 5a. The cooling temperature can be 100 to 130°C at the temperature of the material outlet 5c, and the cooling time (the time to pass through the cylinder 5a) can be 5 to 10 minutes, but it is not limited thereto. By this cooling, the colored layer T can be solidified. Also, the rotation speed of the cylinder 5a can be, for example, 4 to 7 rpm. The cold air can be supplied as it is from the outside air.

[0037] When using the above manufacturing apparatus, the moisture contained in the mixture of the core particles B and the coating material C can be reduced as much as possible by the dryer 3. In the firing machine 4, it becomes difficult to fire a large number of core particles in a lump state, and it is easy to manufacture the uniform colored granular material A with substantially uniform particle diameters, and the pulverization process after cooling can be made unnecessary.

[0038] <Summary> As described above, the colored granular material A according to the first aspect includes a core particle B and a colored layer T formed on the surface of the core particle B. The core particle B is composed of inorganic particles having an average particle diameter of 0.1 to 1.0 mm. The colored layer T is a weld deposit obtained by welding a coating material C containing glass frit and a heat insulating pigment onto the surface of the core particle B. The heat insulating pigment includes an inorganic pigment having a solar reflectance of 20% to 30%.

[0039] According to the first aspect, a colored granular material A having high solar light reflection performance by the heat insulating pigment and a high heat insulating effect can be easily obtained.

[0040] The second aspect is the colored granular material A according to the first aspect, wherein the ratio of the average particle diameter of the core particle B to the average particle diameter of the heat insulating pigment is 1000:1 to 200:1.

[0041] According to the second aspect, the dispersibility of the heat insulating pigment in the colored layer T is improved, and a colored granular material A having a high heat insulating effect can be easily obtained.

[0042] The third aspect is the colored granular material A according to the first or second aspect, wherein the core particle B has an iron oxide content of 0.1 mass% or less.

[0043] According to the third aspect, the core particle B is less likely to change color due to heat when forming the colored layer T, and a colored granular material A with less color unevenness can be easily obtained.

Examples

[0044] Table 1 shows the properties of heat insulating pigments P1 to P7 and ordinary pigments (pigments that are not heat insulating pigments) P8 to P10. Among the heat insulating pigments P1 to P7 and the ordinary pigments P8 to P10, the heat insulating pigments applicable to the colored granular material of the present embodiment are P5, P6, and P7.

[0045] Regarding the colored granular materials using heat insulating pigments P1 to P7 and ordinary pigments P8 to P10, after being made into a paint and applied (spraying amount 345 g / m 2 ), L * , a * , b *, the solar reflectance (%) and the infrared reflectance (%) were measured. For the above coating, colored granules and an acrylic resin were uniformly mixed at a mass ratio of 2:1 to prepare a paint. This paint was uniformly spread to a thickness of 3 mm on a mold on a flat plate and air-dried for one day to cure and form a sheet.

[0046] Then, using this sheet and a spectrophotometer conforming to JIS K 5602, the spectral reflectance in the wavelength range of 300 nm to 2500 nm was obtained, and using this spectral reflectance, the solar reflectance (entire wavelength range) and the red reflectance (near-infrared region: 780 nm to 2500 nm) were calculated. L * a * b * L in the color system * , a * , b * For the measurement of, a color difference meter (model number CR-310) manufactured by Minolta was used.

[0047] Also, for the heat-insulating pigments P1 to P7, the solar reflectance (%) of the pigment alone is shown in Table 1. Also, for the heat-insulating pigments P1 to P7 and the ordinary pigments P8 to P10, the average particle size of the pigment alone, the average particle size of the core particles, and the ratio of the average particle size of the core particles to the average particle size of the pigment (average particle size of the core particles: average particle size of the pigment) are shown in Table 1. The solar reflectance (%) and the average particle size of the pigment alone were the values published in the catalog. Also, the ratio of the average particle size of the core particles to the average particle size of the pigment was calculated using the average particle size of No. 5 silica sand (510 μm) as the average particle size of the core particles.

[0048] The solar reflectance (%) and the infrared reflectance (%) of the colored granules using the heat-insulating pigments P1 to P7 and the ordinary pigments P8 to P10 after coating are shown in FIGS. 3 and 4, respectively.

[0049]

Table 1

[0050] Figure 5 shows the temperature changes of the colored granular materials using heat-insulating pigments P1 to P7 and normal pigment P8. The colored granular materials were prepared using, as a plurality (a large number) of core particles, 500 g of Tajiro No. 5 (trade name, raw sand), 0.5 g of glass frit (glass powder), 1.0 g of calcium carbonate (SS#80), 5.0 g of pigment (heat-insulating pigment P1 to P7 or normal pigment P8), and 10.0 (wt%) of water glass. Then, the pigment, frit, and calcium carbonate were mixed, the raw sand was added, and the mixture was stirred for 3 minutes. After that, the container of the stirrer was replaced, and the mixture was stirred again for 1 minute (to prevent uneven stirring). Next, water glass (10 wt%, 62.5 g) was added while stirring, and the mixture was stirred for 3 minutes. After that, the container was replaced, and the mixture was stirred again for 3 minutes. Then, the mixture was divided into 2.5 kg portions and placed in an electric furnace and fired at 650 °C (to prevent uneven baking) to obtain colored granular materials having colored layers containing heat-insulating pigments P1 to P7 or normal pigment P8, respectively. Note that the colored granular materials used in the above "coating formation" were also prepared in the same manner.

[0051] Regarding the colored granular materials thus obtained, the change over time in the surface temperature due to lamp irradiation was confirmed. The lamp conditions were set to a halogen lamp with an illuminance of 40,000 LUX. Also, the temperature evaluation conditions were such that the temperature was measured every 2 minutes for a total of 60 minutes.

[0052] As shown in Figure 5, the colored granular materials using heat-insulating pigments P1 to P7 were able to suppress the temperature rise more than the colored granular materials using normal pigment P8.

[0053] Figure 6 shows the temperature changes of the colored granular materials using heat-insulating pigment P6. Here, two types of core particles were used, namely No. 5 silica sand and a mixture of No. 6 and No. 7 silica sands. The production of the colored granular materials was carried out in the same manner as in the case shown in Figure 5. Also, the change over time in the surface temperature of the colored granular materials due to lamp irradiation was confirmed, and it was carried out in the same manner as in the case shown in Figure 5 except that the illuminance was set to 15,000 LUX.

[0054] As shown in Figure 6, almost no difference in the temperature change of the colored granular materials due to the difference in the average particle diameter of the core particles was observed.

Explanation of symbols

[0055] A Colored Granule B Core Particle C Coating Material T Colored Layer

Claims

1. A colored particulate matter comprising core particles and a colored layer formed on the surface of the core particles, wherein the core particles are composed of inorganic particles having an average particle diameter of 0.1 to 1.0 mm, the colored layer is a weld deposit formed by welding a coating material containing glass frit and a heat insulating pigment to the surface of the core particles, the heat insulating pigment contains an inorganic pigment having a solar reflectance of 20% to 30%, colored particulate matter.

2. The ratio of the average particle diameter of the core particles to the average particle diameter of the heat insulating pigment is 1000:1 to 200:1, The colored particulate matter according to Claim 1.

3. The core particles have an iron oxide content of 0.1% by mass or less, The colored particulate matter according to Claim 1 or 2.

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