Roof structure

Abstract

Provided is a roof structure comprising a roofing material and a lighting device for illuminating the lower surface of the roofing material, wherein the arithmetic average roughness Ra of the lower surface of the roofing material is 3.0 μm or greater. Also provided is a roof structure comprising a roofing material, wherein the roofing material has a surface layer formed on the lower surface of a base material, and the surface layer has a surface arithmetic average roughness Ra of at least 3.0 μm and a thickness of at least 50 μm.

Description

Roof structure

[0001] The present disclosure relates to roof structures.

[0002] For example, aluminum profiles are used as roof materials for carports, and these are sometimes electro-deposited or have wrapping sheets attached. Lighting fixtures for carports are mainly used (for example, downlights, line lights, and spotlights) that illuminate cars, people, and the floor.

[0003] On the other hand, in Patent Document 1, lighting fixtures (e.g., upper lights) that illuminate the underside of the roof material are used as lighting fixtures for carports. Here, the upper lights have multiple light-emitting elements installed along their longitudinal direction, and as the horizontal distance from the upper lights increases, the illuminance of the light illuminating the underside of the roof material decreases, creating a gradation of light.

[0004] Japanese Patent Application Laid-Open No. 2019-173303

[0005] However, because the underside of the roofing material is very smooth, the brightness of the indirect lighting decreases as the horizontal distance from the lighting fixture increases, and the dramatic effect of the indirect lighting is not fully utilized.

[0006] Therefore, the inventor has discovered a problem of providing a roof structure that provides high brightness indirect lighting even when the horizontal distance from the lighting fixture is long.

[0007] One aspect of the present disclosure is a roof structure comprising a roofing material and a lighting fixture for illuminating the underside of the roofing material, the roofing material having an arithmetic mean roughness Ra of 3.0 μm or more on the underside. Another aspect of the present disclosure is a roof structure comprising a roofing material having a surface layer formed on the underside of a base material, the surface layer having an arithmetic mean roughness Ra of 3.0 μm or more and a thickness of 50 μm or more.

[0008] FIG. 1 is a perspective view showing an example of a carport according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing an example of a lighting fixture for the carboat of FIG. 1. FIG. 3 is a cross-sectional view showing another example of a lighting fixture for the carboat of FIG. 1. FIG. 4 is a cross-sectional view showing another example of a lighting fixture for the carboat of FIG. 1. FIG. 5 is a cross-sectional view showing another example of a lighting fixture for the carboat of FIG. 1. FIG. 6 is a cross-sectional view showing an example of the laminated structure of the roofing material of FIG. 1. FIG. 7 is a schematic cross-sectional view illustrating a method for evaluating the luminance of indirect lighting for the test panels of Examples 1 and 3 and Comparative Example 1. FIG. 8 is a graph showing the measurement results of the luminance of indirect lighting for the test panels of Examples 2 and 4 and Comparative Example 2.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail.

[0010] The roof structure of this embodiment is not particularly limited as long as it includes a roofing material. The roof structure of this embodiment may further include lighting fixtures that illuminate the underside of the roofing material, i.e., the vertically lower surface. Examples of roof structures include carports and terraces.

[0011] As shown in FIG. 1 , the carport 1 includes support posts 2, a hollow roofing material 3, and a beam 4 fixed to the support posts 2 and securing the top surface of the roofing material 3. Here, a beam securing the underside of the roofing material 3 may be used instead of the beam 4. Furthermore, as shown in FIG. 2 , the carport 1 includes a lighting fixture 5 that illuminates the underside of the roofing material 3. The lighting fixture 5 includes a line light 51 as a linear light source, a cover 52 with a U-shaped cross section to which the line light 51 is secured, and a bracket 53 with an L-shaped cross section to which the cover 52 is secured. The illumination direction of the line light 51 is not parallel to the underside of the roofing material 3 but is inclined toward the underside of the roofing material 3. This reduces glare felt by those near the carport 1 and increases the illuminance of the light illuminating the underside of the roofing material 3. The cover 52 is secured to the bracket 53 with a flat head screw S1, and the bracket 53 is secured to the underside of the roofing material 3 with a flat head screw S2.

[0012] The direction of illumination of the line light 51 may be parallel to the underside of the roof material 3. Furthermore, instead of the line light 51, the lighting fixture 5 may include a light source in which point light sources (for example, spotlights) are arranged in a line.

[0013] The bracket 53 may be fixed to the upper surface of the roof material 3 by a flat head screw S2 (see FIG. 3). In this case, by changing the shape of the bracket 53, the distance between the line light 51 and the underside of the roof material 3 can be adjusted as needed (see FIG. 4).

[0014] Instead of the cover 52 and bracket 53, a cover 52A having a U-shaped cross section with a recess on the side opposite to the side where the line light 51 is fixed and a bracket 53A having a rectangular cross section with a protrusion corresponding to the recess on the surface facing the cover 52A may be used (see FIG. 5). That is, the cover 52A is fitted into the bracket 53A. The bracket 53A is fixed to the support 2 with a flat head screw S3. In this case, the distance between the line light 51 and the underside of the roof material 3 can be adjusted appropriately by changing the position of the bracket 53A (see FIG. 6).

[0015] In addition to the lighting fixtures 5 that illuminate the underside of the roof material 3, lighting fixtures (for example, downlights, line lights, spotlights) that illuminate cars, people, and the floor surface may also be used.

[0016] As shown in Figure 7, the roofing material 3 has a surface layer 32 formed on the underside of the base material 31. The roofing material 3 may have the surface layer 32 formed on both the top and bottom surfaces of the base material 31. The surface layer 32 may also be formed on the surfaces of components constituting the carport 1 other than the base material 31. That is, the surface layer 32 may be formed on the surfaces of the posts 2 and the beams 4. For example, the surface layer 32 may be formed on the underside of the base material 31, the surfaces of the posts 2, and the surfaces of the beams 4.

[0017] The arithmetic mean roughness Ra of the surface S of the surface layer 32 is 3.0 μm or more, preferably 6.0 μm or more, and more preferably 7.5 μm or more. Because the arithmetic mean roughness Ra of the surface S of the surface layer 32 is 3.0 μm or more, when the underside of the roofing material 3 is illuminated using a line light 51, the brightness of the indirect lighting is high even if the horizontal distance from the lighting fixture 5 is long, and as a result, the dramatic effect of the indirect lighting is fully utilized. The arithmetic mean roughness Ra of the surface S of the surface layer 32 is, for example, 8.5 μm or less.

[0018] The maximum height roughness Rz of the surface S of the surface layer 32 is preferably 15.0 μm or more, more preferably 30.0 μm or more, and particularly preferably 35.0 μm or more. If the maximum height roughness Rz of the surface S of the surface layer 32 is 15.0 μm or more, when the line light 51 is used to illuminate the underside of the roof material 3, the brightness of the indirect lighting becomes high even if the horizontal distance from the lighting fixture 5 becomes long. The maximum height roughness Rz of the surface S of the surface layer 32 is, for example, 45.0 μm or less.

[0019] In this specification and claims, the arithmetic mean roughness Ra and maximum height roughness Rz of the surface of the surface layer are measured by a measurement method conforming to JIS B0601-2001. Here, it is preferable that the average values ​​of the arithmetic mean roughness Ra and maximum height roughness Rz of the surface S of the surface layer 32 measured in a predetermined direction (e.g., the longitudinal direction) and in a direction perpendicular to the predetermined direction (e.g., the lateral direction) are within the above-mentioned ranges, and it is even more preferable that both the arithmetic mean roughness Ra and maximum height roughness Rz of the surface S of the surface layer 32 measured in each direction are within the above-mentioned ranges.

[0020] The gloss of the surface layer 32 at an incident angle of 60° is preferably 5.4 or less, more preferably 4.5 or less, and particularly preferably 4.0 or less. If the gloss of the surface layer 32 at an incident angle of 60° is 5.4 or less, when the line light 51 is used to illuminate the underside of the roofing material 3, the brightness of the indirect lighting is high even if the horizontal distance from the lighting fixture 5 is long. The gloss of the surface layer 32 at an incident angle of 60° is, for example, 2.0 or more.

[0021] The surface layer 32 preferably contains polyolefin wax particles. This allows the arithmetic mean roughness Ra of the surface S of the surface layer 32 to be 3.0 μm or more. The content of the polyolefin wax particles in the surface layer 32 is not particularly limited, but is, for example, 0.1 mass% or more and 3.0 mass% or less. The volume-based median diameter D50 of the polyolefin wax particles is not particularly limited, but is, for example, 6.0 μm or more and 9.0 μm or less. The volume-based median diameter D50 is the particle size at 50% of the integrated value of the volume-based particle size distribution measured by a laser diffraction / scattering method.

[0022] The polyolefin wax particles are not particularly limited, but examples thereof include polyethylene wax particles, polypropylene wax particles, and polytetrafluoroethylene (PTFE) modified polyethylene wax particles.

[0023] The thickness of the surface layer 32 is not particularly limited, but is, for example, 30 μm or more. From the viewpoint of concealment, the thickness of the surface layer 32 is preferably 50 μm or more, and from the viewpoint of the brightness of indirect lighting, the thickness is preferably 70 μm or more. When the thickness of the surface layer 32 is 50 μm or more, the substrate 31 is concealed without being visible through the surface layer 32. When the thickness of the surface layer 32 is 70 μm or more, light is easily diffused on the surface S of the surface layer 32.

[0024] The surface layer 32 is formed by applying a powder coating containing, for example, a curable resin, a color pigment, a curing agent, and polyolefin wax particles to the substrate 31 and then curing the powder coating. The powder coating may further contain a surface conditioner, a plasticizer, a curing accelerator, an ultraviolet absorber, a light stabilizer, an antioxidant, a flowability adjuster, a sagging prevention agent, an antifoaming agent, etc.

[0025] The curable resin is not particularly limited, but examples thereof include hydroxyl group-containing polyesters, epoxy resins, and reactive group-containing fluorine resins, and two or more of these may be used in combination.

[0026] The hydroxyl group-containing polyester may be a known polyester used in curable resins for powder coatings, preferably having a softening point of 100°C or higher and 150°C or lower. Hydroxyl group-containing polyesters can be obtained, for example, by reacting a carboxylic acid component with a polyhydric alcohol component. Examples of the carboxylic acid component include polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,2-octadecanedicarboxylic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, trimellitic acid, and pyromellitic acid; lower alkyl esters or anhydrides of polycarboxylic acids; and hydroxycarboxylic acids such as malic acid, tartaric acid, 1,2-hydroxystearic acid, and parahydroxybenzoic acid. Examples of polyhydric alcohol components include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, spiroglycol, 1,10-decanediol, 1,4-cyclohexanedimethanol, trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol.

[0027] The epoxy resin may be a known one used as a curable resin for powder coatings, preferably having a softening point of 50°C or higher and 150°C or lower. Examples of epoxy resins include bisphenol A diglycidyl ether resin, bisphenol F diglycidyl ether resin, aminoglycidyl ether resin, bisphenol AD ​​diglycidyl ether resin, bisphenol Z diglycidyl ether resin, o-cresol novolac epoxy resin, phenol novolac epoxy resin, biphenol glycidyl ether resin, epoxy resin having a cyclopentadiene skeleton, epoxy resin having a naphthalene skeleton, and GMA acrylic resin. Instead of epoxy resins other than those listed above, resins in which the substituents of the above epoxy resins have been converted to other substituents, such as modified resins modified by CTBN or esterification, may also be used.

[0028] The reactive group-containing fluororesin may be a known one used in curable resins for powder coatings, and has a reactive group that reacts with the curing agent. Examples of reactive groups include hydroxyl, carboxyl, amide, amino, nitrile, glycidyl, and isocyanate groups. Among these, hydroxyl groups are preferred from the viewpoint of stability and control of melt viscosity of the reactive group-containing fluororesin. The reactive group-containing fluororesin is obtained by copolymerizing a reactive group-containing monomer with a fluorine-containing monomer. Examples of fluorine-containing monomers include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, bromotrifluoroethylene, chlorotrifluoroethylene, pentafluoropropylene, hexafluoropropylene, and (per)fluoroalkyl trifluorovinyl ether (wherein the (per)fluoroalkyl group has 1 to 18 carbon atoms). The reactive group-containing fluororesin may also be obtained by copolymerization with other monomers. Examples of the other monomers include vinyl ethers, olefins, allyl ethers, vinyl esters, allyl esters, (meth)acrylic acid esters, and crotonates.

[0029] The color pigment may be any known color pigment used in powder coatings, including, for example, inorganic pigments such as titanium oxide, yellow iron oxide, titanium yellow, and red iron oxide, and organic pigments such as cyanine blue, cyanine green, permanent yellow FGL, permanent red F5RK, carbazole, quinacridone red, and carbon black, and two or more of these may be used in combination.

[0030] The curing agent may be any known curing agent used in powder coatings. The curing agent is not particularly limited as long as it can react with the curable resin to form crosslinks, and examples thereof include blocked isocyanate curing agents, amine curing agents, and epoxy curing agents, and two or more of these may be used in combination.

[0031] Powder coatings are manufactured by known methods. The manufacturing method of powder coatings includes, for example, a premixing step, a melt-kneading step, a pulverizing step, and a classification step. The premixing step is a step of premixing the raw material composition of the powder coating using a mixer such as a Henschel mixer or a super mixer. The melt-kneading step is a step of melt-kneading the premix using various types of extruders. At this time, it is preferable to use a cooler such as a cooling roll or a cooling conveyor to cool and solidify the molten kneaded material into pellets. The pulverizing step is a step of pulverizing the molten kneaded material using a pulverizer such as a hammer mill or a jet mill. The classification step is a step of classifying the pulverized material using a classifier such as a vibration sieve, an ultrasonic sieve, or a cyclone classifier.

[0032] When applying the powder paint to the substrate 31, for example, the powder paint is applied to the substrate 31, and then dried and heat-cured as necessary. Examples of methods for applying the powder paint include electrostatic coating, electrostatic spraying, atomization, fluidized bed dipping, spraying, spraying, thermal spraying, and plasma thermal spraying. The temperature at which the powder paint is heat-cured is, for example, 110°C or higher and 230°C or lower.

[0033] The material constituting the substrate 31 is not particularly limited, but examples thereof include metals such as aluminum, steel, and stainless steel, resins such as polycarbonate, acrylic resin, and vinyl chloride, fiber reinforced plastics (FRP), and wood. Among these, metals are preferred from the viewpoint of the strength of the substrate 31, and aluminum is preferred from the viewpoint of the light weight of the substrate 31.

[0034] When the roofing material is made of aluminum, condensation is likely to occur due to radiative cooling due to the high thermal conductivity of aluminum. On the other hand, the roofing material 3 has a surface layer 32 with low thermal conductivity formed on the underside of the base material 31, which prevents condensation from dripping from the underside of the roof body 3.

[0035] In the carport 1, the upper surface of the roof material 3 is fixed to the beams 4, and the lower surface of the roof material 3 is flat. Therefore, when the line light 51 is used to illuminate the lower surface of the roof material 3, the brightness of the indirect lighting is high even if the horizontal distance from the lighting fixture 5 is long.

[0036] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and the above embodiments may be modified as appropriate within the scope of the present disclosure. For example, instead of forming the surface layer 32 on the lower surface of the base material 31, physical processing may be performed so that the arithmetic mean roughness Ra of the lower surface of the base material is 3.0 μm or more, or a base material (e.g., wood or artificial wood) whose lower surface has an arithmetic mean roughness Ra of 3.0 μm or more may be used.

[0037] Examples of the present disclosure will be described below, but the present disclosure is not limited to these examples. In these examples, evaluation was performed using a test panel instead of a roof structure.

[0038] [Examples 1 to 4, Comparative Examples 1 and 2] (Preparation of powder coatings) The raw materials (curable resin, pigment, curing agent, polyolefin (PO) wax particles, and surface conditioner) were blended in the blending amounts [mass %] shown in Table 1 and then premixed. Next, the premix was melt-kneaded and then cooled. Next, the melt-kneaded product was pulverized and classified to obtain powder coatings.

[0039] (Preparation of Test Plate) A 1.5 mm thick anodized aluminum plate was hung vertically and electrostatically coated with a powder paint to a thickness of 70 to 90 μm using a corona-charged electrostatic powder coater at a voltage of −90 kV. Next, the plate was thermally cured in an electric furnace at 180° C. for 30 minutes, and then allowed to cool to room temperature to form a surface layer, thereby obtaining a test plate.

[0040]

[0041] Details of the raw materials in Table 1 are as follows: Curable resin: hydroxyl group-containing polyester U-Pica Coat GV570 (manufactured by Japan U-Pica) Black pigment: carbon black MA100 (manufactured by Mitsubishi Chemical) White pigment: titanium oxide Ti-Pure R-706 (manufactured by Chemours) Curing agent: ε-caprolactam blocked isocyanate VESTAGON (registered trademark) B1530 (manufactured by Evonik Degussa) PO wax particles: PTFE-modified polyethylene wax particles Ceraflower 969 (manufactured by BYK) having a volume-based median diameter D50 of 6 μm Surface conditioner: Resiflow P67 (manufactured by ESTRON CHEMICAL), IRGAFOS 168 (manufactured by BASF), and benzoin (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0042] [Arithmetic mean roughness Ra and maximum height roughness Rz of the surface of the surface layer] The arithmetic mean roughness Ra and maximum height roughness Rz of the surface of the surface layer (10 cm × 15 cm) were measured using a surface roughness measuring instrument, Surfcorder SE500 (manufactured by Kosaka Laboratory). At this time, the arithmetic mean roughness Ra and maximum height roughness Rz were measured in the longitudinal direction (direction 1) and the transverse direction (direction 2) perpendicular to the longitudinal direction.

[0043] [Glossiness of Surface Layer at an Incident Angle of 60°] Using a portable glossmeter GMX-701 (manufactured by Murakami Color Research Laboratory), the glossiness of the surface layer at an incident angle of 60° was measured with the substrate aligned horizontally.

[0044] Table 2 shows the properties of the test plates.

[0045]

[0046] [Brightness of indirect lighting] A test plate 6 and a lighting fixture 7 equipped with a line light 71 and a cover 72 having an L-shaped cross section were arranged as shown in Fig. 8 to illuminate the upper surface of the test plate 6. At this time, the distance I between the upper surface of the test plate 6 and the lower surface of the line light 71 was set to 11 mm, and the brightness at a horizontal distance D from the surface of the test plate 6 facing the lighting fixture 7 was measured using a camera fixed above the test plate 6. Here, the lighting fixture 7 was installed on a support stand 8.

[0047] FIG. 9 shows the measurement results of the luminance of the test panels of Examples 1 and 3 and Comparative Example 1 under indirect lighting.

[0048] 9, in comparison with the test plate of Comparative Example 1, the test plates of Examples 1 and 3 have a high luminance of indirect lighting even when the horizontal distance D from the surface of test plate 6 facing the lighting fixture 7 is increased. This is because the arithmetic mean roughness Ra of the surface of the upper surface of the test plates of Examples 1 and 3 is 3.0 μm or more.

[0049] FIG. 10 shows the measurement results of the luminance of the test panels of Examples 2 and 4 and Comparative Example 2 under indirect lighting.

[0050] 10, compared with the test plate of Comparative Example 2, the test plates of Examples 2 and 4 have a high luminance of indirect lighting even when the horizontal distance D from the surface of test plate 6 facing the lighting fixture 7 is increased. This is because the arithmetic mean roughness Ra of the surface of the upper surface of the test plates of Examples 2 and 4 is 3.0 μm or more.

[0051] DESCRIPTION OF SYMBOLS 1 Carport, 2 Support, 3 Roofing material, 31 Base material, 32 Surface layer, 4 Beam, 5 Lighting fixture, 51 Line light, 52 Cover, 53 Bracket, 6 Test plate, 7 Lighting fixture, 71 Line light, 72 Cover, 8 Support base, S Surface, S1 Flat head screw, S2 Flat head screw, S3 Flat head screw

Claims

1. A roof structure comprising: a roofing material; and a lighting fixture that illuminates the underside of the roofing material, wherein the roofing material has an arithmetic mean roughness Ra of 3.0 μm or more on its underside.

2. The roof structure according to claim 1, wherein the roofing material has a surface layer formed on the underside of the base material, and the surface layer has an arithmetic mean roughness Ra of 3.0 μm or more.

3. The roof structure of claim 2, wherein the facing layer comprises polyolefin wax particles.

4. A roof structure according to claim 2 or 3, wherein the surface layer has a thickness of 50 μm or more.

5. A roof structure according to any one of claims 2 to 4, wherein the substrate comprises aluminum.

6. A roof structure according to any one of claims 1 to 5, wherein the roofing material has an arithmetic mean roughness Ra of the lower surface of 6.0 μm or more.

7. A roof structure according to any one of claims 1 to 6, wherein the roofing material has a gloss of 5.4 or less at an incidence angle of 60° on the underside.

8. The roof structure according to claim 7, wherein the roofing material has a gloss of 4.5 or less at an incident angle of 60° on the lower surface.

9. A roof structure according to any one of claims 1 to 8, wherein the roofing material has a maximum height roughness Rz of 15.0 μm or more on the lower surface.

10. The roof structure according to claim 9, wherein the roofing material has a maximum height roughness Rz of 30.0 μm or more on the lower surface.

11. A roof structure as described in any one of claims 1 to 10, further comprising: a beam to which the roof material is fixed; and a support to which the beam is fixed; wherein the lighting fixture comprises a light source, a cover to which the light source is fixed, and a bracket to which the cover is fixed; and the bracket is fixed to the roof material or the support.

12. The roof structure of claim 11, wherein the beam secures the top surface of the roofing material.

13. A roof structure according to any one of claims 1 to 12, which is a carport.

14. A roof structure comprising a roofing material, the roofing material having a surface layer formed on the underside of a base material, the surface layer having an arithmetic mean roughness Ra of 3.0 μm or more and a thickness of 50 μm or more.

15. The roof structure of claim 14, wherein the facing layer comprises polyolefin wax particles.

16. The roof structure of claim 14 or 15, wherein the substrate comprises aluminum.

17. A roof structure according to any one of claims 14 to 16, wherein the roofing material has an arithmetic mean roughness Ra of the lower surface of 6.0 μm or more.

18. A roof structure according to any one of claims 14 to 17, wherein the roofing material has a gloss of 5.4 or less at an incidence angle of 60° on the lower surface.

19. The roof structure according to claim 18, wherein the roofing material has a gloss of 4.5 or less at an incidence angle of 60° on the lower surface.

20. A roof structure according to any one of claims 14 to 19, wherein the roofing material has a maximum height roughness Rz of 15.0 μm or more on the lower surface.

21. The roof structure according to claim 20, wherein the roofing material has a maximum height roughness Rz of 30.0 μm or more on the lower surface.

22. The roof structure according to any one of claims 14 to 21, further comprising: a beam to which the roof material is fixed; and a support to which the beam is fixed.

23. The roof structure of claim 22, wherein the beam secures the top surface of the roofing material.

24. A roof structure according to any one of claims 14 to 23, which is a carport.

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