JP2000015712A - Lighting composite fresnel prism plate and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a dazzle and a rainbow pattern from developing by a method wherein a light scattering resin film is laminated onto the other side of a Fresnel prism plate so as to form a fine uneven surface for scattering the light. SOLUTION: In this Fresnel prism plate, on one side of a transparent resin plate, onto the other side of which a light scattering film 2 is laminated, a Fresnel prism 1 as a large number of projected strips, the section of which forms a continuous triangular shape, is formed. The light scattering resin film has a thickness of 25-300 μm. One side of the film, the other side of which has a self-adhesive layer having the thickness of 5-100 μm, has an uneven pattern and light scattering properties. As the favorable base material of the light scattering resin film a polyester-based polyethylene-terephthalate, a polycarbonate, a triacetyl cellulose, a poly(methyl methacrylate) or the like is exemplified as a proper base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
The present invention relates to a Fresnel prism plate for daylighting that can be suitably used for a daylighting window, a skylight, a daylighting dome, and the like for incorporating sunlight into buildings such as factories, buildings, and condominiums, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A glass plate is generally used as a transparent daylighting plate. However, since a simple glass plate has a low refractive power, it is difficult to take in external light to the interior of a room depending on the direction of incident light.
Only the part near the window becomes brighter, but it gets darker as you move away from the window. For this reason, it is desired that the incident light from the outdoors can be effectively taken into the interior of the room.

Conventionally, in order to improve the lighting condition, a linear Fresnel prism plate in which a Fresnel prism shape is formed on a transparent resin plate is used as a lighting plate so that a wide range of incident light can be effectively taken. (Japanese Patent Application Laid-Open Nos. 4-44001 and 9-54).
274, and Japanese Patent Application No. 4-31155, microfilm publication).

[0004]

However, since the linear Fresnel prism is a continuous aggregate of fine prisms, a rainbow pattern is formed in the lighting due to chromatic aberration, and the linear Fresnel prism plate can be used alone or in a general type. When used in combination with a flat glass plate, natural daylighting is difficult, and it is necessary to use in combination with a template glass having an uneven surface. Furthermore, a linear Fresnel lens system only deflects incident light and does not scatter incident light into a room, so that it may be dazzling at a specific angle.

An object of the present invention is to provide a Fresnel prism plate made of a transparent resin in which no rainbow pattern is generated in daylight and glare is eliminated.

[0006]

Means for Solving the Problems As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that a linear type Fresnel prism plate has a light scattering resin film laminated on the other surface of the Fresnel prism plate and has a fine structure. It has been found that the present invention has been found to eliminate glare and a rainbow pattern by forming an uneven surface to scatter light, thereby achieving the present invention.

That is, the present invention is characterized in that a Fresnel prism is formed on the other surface of a transparent resin plate in which a light-scattering resin film is laminated on one surface, as a large number of ridges having a continuous triangular cross section. It is a daylighting composite Fresnel prism plate.

In the present invention, the Fresnel prism comprises:
The prism pitch is 0.5 to 3 mm, the inclination angle of one slope (draft surface) is 80 to 88 °, the inclination angle of the other slope (Fresnel surface) is 30 ± 15 °, and the radius of curvature at the top is 0.02. It is preferably about 0.3 mm.

Also, a methacrylic resin plate can be preferably used as the transparent resin plate.

The light-scattering resin film has a thickness of 2
It is preferable that the film has a transparent uneven pattern on one side of the film with a thickness of 5 to 300 μm.

Further, the present invention provides a compound Fresnel prism for daylighting in which a melt-extruded transparent resin sheet is sandwiched between a grooved roll and a polishing roll, and the groove shape of the grooved roll is transferred to the sheet as a Fresnel prism. A method for manufacturing a plate, wherein the inclination angle of one slope is 80 to 8
8 °, V-shaped groove having an inclination angle of the other slope of 30 ± 15 ° and a depth of 0.3 to 1.5 mm has a pitch of 0.5 to 3 mm
The surface of the sheet is smoothed under tension of 1 to 10 kg / m (per roll length) by applying a tension of 1 to 10 kg / m (per roll length) after taking up the sheet and using a plurality of grooved rolls provided on the surface. A method for producing the above daylighting composite Fresnel prism plate, comprising laminating on the side.

In the production method of the present invention, the melt-extruded transparent resin sheet is once sandwiched between polishing rolls and cooled, and the surface of the sheet exiting between the polishing rolls is heated to a temperature higher than the Vicat softening temperature of the transparent resin. It is preferable that the sheet is sandwiched between the grooved roll and the polishing roll and that the sheet coming out from between the grooved roll and the polishing roll is taken off while air-cooling.

Further, the temperature of the grooved roll is higher than that of the polishing roll, and the Vicat softening temperature of the transparent resin is ±
Preferably, the temperature is 20 ° C.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent resin constituting the transparent resin plate in the present invention is a resin having a haze of 10% or less as measured according to JIS K-7105. Specifically, for example, methacrylic resin, polycarbonate resin, polystyrene resin, styrene-methyl methacrylate copolymer resin and the like can be mentioned. Particularly preferred is a methacrylic resin.

The methacrylic resin used in the present invention includes a resin mainly composed of methyl methacrylate, such as a homopolymer of methyl methacrylate, or methyl methacrylate and methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile acrylic acid, It includes a copolymer with any one or more of copolymerizable monomers such as methacrylic acid, 2-hydroxyacrylate, maleic anhydride, styrene, and α-methylstyrene. These may be used alone or may be blended.

In order to maintain transparency and simultaneously provide impact resistance, an impact-resistant methacrylic resin blended with a methacrylic rubber elastic material is used. The methacrylic rubber elastic material is disclosed in Japanese Patent Application Laid-Open No. 53-55854. No., JP-A-55-9
No. 4,917, and JP-A-61-32346. Briefly, it is a multi-stage polymer produced by a multi-stage sequential polymerization method in which an elastic layer and an inelastic layer are alternately formed around an acrylic polymer core material.

As shown in FIG. 1, the Fresnel prism plate of the present invention has Fresnel prisms formed on the other surface of a transparent resin plate having a light-scattering film 2 laminated on one surface and a large number of triangular ridges having a continuous cross section. A prism 1 is formed.

The light-scattering resin film has a thickness of 25 to 3
One side of the film has an uneven pattern and has a light diffusing property, and the other side is made of an adhesive layer having a thickness of 5 to 100 μm.

The light-scattering resin film substrate is made of generally available polyethylene terephthalate polyester,
Polycarbonate, triacetyl cellulose, polymethyl methacrylate and the like are preferably mentioned as suitable ones.

The thickness is preferably from 25 to 300 μm. If the thickness is less than 25 μm, the film strength is insufficient, and 300
If it exceeds μm, the rigidity increases and the secondary workability of bonding is inferior. In particular, 50 to 100 μm is a preferable thickness.

It is preferred that the film has a transparent uneven pattern on one surface. The uneven pattern is not particularly limited as long as it has a light scattering property.However, a fine irregular surface in which resin beads are dispersed on the surface of the film base material from the one having the rough irregular surface of the template glass pattern is used. Can be used as appropriate.

The method of laminating the light-scattering resin film on one side of a transparent resin substrate is not particularly limited, and a method such as heat fusion or visco-compression bonding is appropriately selected.

For example, as a method of using an adhesive, a glass transition temperature of a resin whose main component is transparent is -50 to -130.
Polybutyl acrylate in the range of ° C., acrylic acid ester system using 2-ethylhexyl polyacrylate,
Polyisobutylene, SBR, natural rubber, urethane-acryl, epoxy-acrylate, silicone rubber, vinyl chloride or vinyl acetate content of 15
Preferred is a 40% ethylene-vinyl acetate system. Further, as the tackifier, rosin, rosin ester and derivatives thereof, terpene resin, hydrocarbon resin and the like are used, and as a softening agent, fatty acid ester, animal and vegetable oil, wax, and petroleum heavy fraction are used. It is appropriately selected from the compatibility with the component resin.

The pressure-sensitive adhesive layer is coated with the above-mentioned pressure-sensitive adhesive by a commonly used coating method such as transfer printing, knife coater, roll coater, gravure coater or the like.
It is dried by heating with steam or the like.

The thickness of the pressure-sensitive adhesive is preferably used in the range of 5 to 100 μm. If the thickness is less than 5 μm, it is difficult to form the pressure-sensitive adhesive uniformly, and if it exceeds 100 μm, for example, under high temperatures in summer, defects such as wrinkles are apt to occur during compounding, which is not preferable. More preferred thickness is 10 to 50 μm
It is. In addition, it usually has a protective and masking film to protect the adhesive layer.

The Fresnel prism in the Fresnel prism plate of the present invention is formed as a large number of ridges having a continuous triangular cross section. The Fresnel prism has a prism pitch of 0.5 to 3 mm and a flat surface. The angle of inclination of one slope (hereinafter, referred to as “draft surface”) with respect to the other slope (hereinafter, referred to as “draft surface”) is 80 to 88 °.
It is preferable that the inclination angle of the “Fresnel surface” is 30 ± 15 ° and the radius of curvature at the top is 0.02 to 0.30 mm.

When the prism pitch is less than 0.5 mm, the depth of the V-shaped groove between the Fresnel prisms becomes shallow, so that a good Fresnel surface cannot be obtained, and a mold for shaping the Fresnel prism is manufactured. Is difficult to perform. If the prism pitch exceeds 3 mm, the V-shaped groove between the Fresnel prisms becomes deep, and the releasability of the Fresnel prism portion deteriorates, and a portion that becomes a horizontal plane is likely to occur. Preferably, it is 0.7 to 1.5 mm.

The inclination angle of the inclined surface of the Fresnel prism with respect to the horizontal plane is determined by the draft angle of the mold for the draft surface. In addition, the Fresnel surface is determined by the angle at which sunlight and scattered light are collected and the desired deflection angle.

That is, if the angle of inclination of the draft surface exceeds 88 °, the releasability from the mold deteriorates, and if it is less than 80 °, the lighting efficiency deteriorates. Preferably, it is 85 ± 2 °.

The slope angle of the Fresnel surface is related to the incident angle of the light to be collected. For example, when the slope angle of the Fresnel surface of the Fresnel prism is 15 °, sunlight at an altitude of 75 ° or more cannot be received. 0-75 ° sunlight and scattered light can be received. The altitude angle of sunlight changes every moment depending on latitude, season and time. In Japan, the elevation angle of the sun before and after the equinox day and the equinox day is approximately 50-6.
At 0 °. Therefore, the inclination angle of the Fresnel surface is usually 3
It is preferable to set the angle to 0 ± 15 °. In this case, 0
60 ± 15 ° sunlight and scattered light can be collected.

As shown in FIG. 2, by giving an appropriate radius of curvature to the top 3 of the Fresnel prism, the incident light is prevented from being split into a wavelength distribution, and a width is obtained for the deflection angle. Therefore, it is possible to eliminate the rainbow pattern from daylighting, which is preferable. In FIG. 2, 4
Denotes a draft surface, and 5 denotes a Fresnel surface.

The radius of curvature of the top is preferably 0.02 to 0.3 mm. If it is less than 0.02 mm, a rainbow pattern is likely to occur. If it exceeds 0.3 mm, the Fresnel surface becomes small, and there is a problem in the lighting property. Preferably 0.15 ±
0.10 mm.

The thickness of the Fresnel prism plate of the present invention is 0.1 mm.
A range of 5 to 5 mm is preferable, but not particularly limited.

The Fresnel prism plate of the present invention can be manufactured by heating a transparent resin plate having a smooth surface and performing vacuum forming, pressure forming, compression molding, or the like. When manufactured by a molding method using an extruded sheet molding method, which is sandwiched between a grooved roll engraved with a prism-shaped V-shaped groove and a polishing roll, a large product can be easily obtained.

Hereinafter, a preferred method of manufacturing the Fresnel prism plate of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic view showing an example of an apparatus for manufacturing a Fresnel prism plate used in the present invention, and FIG. 4 is an enlarged view of a grooved roll 12 used in the present invention.

In FIG. 3, 11 is a polishing roll for cooling (usually a mirror surface), 12 is a grooved roll for cooling and forming a Fresnel prism, 13 is a polishing roll for cooling (usually a mirror surface), 14 is an extruded sheet, 15 is a T-die lip, 16 is a take-up roll, 21
Is a light-scattering film roll roll, 22 is a protective film winding device, 23 is a tension roll, 24 is a protective film, 25 is an uneven light scattering surface, and 26 is an adhesive layer surface. Polishing rolls 11 and 13 are arranged on the left and right sides of the grooved roll 12 located at the center, and the transparent resin sheet 14 extruded from the T-die lip is the grooved roll 1.
2 and grooved roll 1 from between polishing roll 11 on the left side
The adhesive layer surface 26 of the light-scattering resin film is laminated on the smooth surface side of the sheet 14 after passing between the second and right polishing rolls 13, and is then taken off by the take-off roll 16. On the surface of the grooved roll 12, as shown in FIG. 4, a number of fine V-shaped grooves are provided in a ring shape.

In the case of the apparatus shown in FIG. 3, the molten transparent resin sheet 14 melted in an extruder (not shown) and extruded through a T-die lip 15 immediately becomes a fine V-shaped sheet. The groove is sandwiched between the grooved roll 12 and the polishing roll 11 provided in a ring shape and cooled. At this time, the V-shaped groove formed on the surface of the grooved roll 12 is transferred to the transparent resin sheet 14, whereby the Fresnel prism is shaped, and the cooling between the grooved roll 12 and the polishing roll 13 is further performed. Then, the Fresnel prism plate is obtained by being taken off by a take-off roll 16.

In the case of the apparatus shown in FIG. 3, the temperature of the grooved roll 12 is preferably higher than that of the polishing roll 11, and moreover, the temperature of the Vicat softening temperature of the transparent resin ± 20 ° C. When the temperature of the grooved roll 12 is lower than the temperature of the polishing roll 11, the transparent resin is easily wound around the polishing roll 11,
It is difficult to transfer the sheet 14 to the sheet. Even if the temperature of the grooved roll 12 is higher than the temperature of the polishing roll 11, if the temperature exceeds the Vicat softening temperature of the transparent resin + 20 ° C., the adhesion of the sheet 14 to the grooved roll 12 becomes strong, and the mold release deteriorates. Therefore, the transition to the polishing roll 13 becomes difficult, and the Vicat softening temperature of the transparent resin is −20 ° C.
If the temperature is lower than the lower limit, the biting of the transparent resin into the grooved roll 12 becomes dull, and the pattern transfer of the V-shaped groove becomes weak.

The light-scattering resin film is made of the sheet 1
4, the temperature of 20 to 100 ° C., and the tension of the light-scattering resin film is 1 to 10 kg / m (per roll length)
The tension is continuously supplied, and the roll pressure is 0.5 to 4 ton / m. The laminate is uniformly laminated by pressing and laminating to form a composite. The continuous production is easy, the process is simple, and mass production is possible. Excellent and preferred.

If the temperature of the sheet 14 is lower than 20 ° C., uneven lamination is likely to occur and the film is easily peeled off, which is not preferable. On the other hand, when the temperature exceeds 100 ° C., the temperature is too high, and the protective film 24 is disadvantageous. The preferable temperature is 40 to 70 ° C., and the bonding strength when composited is high, which is preferable.

If the tension is less than 1 kg / m, peeling of the protective film 24 will not be performed smoothly, resulting in tension unevenness, which is not preferable. Further, it is preferable to use an expander roll or a spiral roll type roll as the tension roll because wrinkles are suppressed. Also, if the tension is 10
If it exceeds kg / m, the tensile stress of the film remains, causing the Fresnel prism plate to warp.

When the roll pressure is less than 0.5 ton / m, air is easily entrained, and when the roll pressure exceeds 4 ton / m, optical distortion occurs in the Fresnel prism plate, which is not preferable.

FIG. 5 is a schematic view showing another example of the apparatus for manufacturing a Fresnel prism plate used in the present invention. The apparatus shown in FIG. 5 differs from the apparatus shown in FIG. The heating device 17 for heating the sheet 14 coming out between the polishing rolls 11 and 13 and the smooth surface side of the sheet 14 coming out between the polishing roll 13 and the grooved roll 12 are air-cooled. An air stick device 18 is provided. The apparatus shown in FIG. 5 also has a film laminating mechanism similar to that of the apparatus shown in FIG. 3, and laminates films under the same conditions.

In the case of the apparatus shown in FIG. 5, it is melted in an extruder (not shown),
Sheet 14 of molten transparent resin extruded through
Is cooled by being sandwiched between the polishing rolls 11 and 13 and heated by the heating means 17 when it exits between the polishing rolls 11 and 13, and then sandwiched between the grooved roll 12 and the polishing roll 13 to form a Fresnel prism. The shaping is performed, and then the smooth surface side of the sheet 14 is taken off while being air-cooled by the air stick device 18. The heating of the sheet 14 by the heating means 17 is such that the surface of the sheet 14 on the side in contact with the grooved roll 12 is at or above the Vicat softening temperature of the transparent resin. Further, the air cooling of the sheet 14 by the air stick device 18 prevents the pattern of the V-shaped groove once formed from being collapsed by the heat storage of the sheet 14. As described above, by performing such heating and air cooling after cooling once, shape transferability can be improved.

In the case of the apparatus shown in FIG. 5, for the same reason as described in the apparatus shown in FIG. 3, the temperature of the grooved roll 12 is higher than that of the polishing roll 13, and the Vicat softening temperature of the transparent resin is ± 20. Preferably it is at a temperature of ° C.

The temperature of the polishing rolls 11 and 13 in both the apparatus shown in FIG. 3 and the apparatus shown in FIG.
Generally, it is preferable to set the temperature to 60 ° C. or higher, which makes it easier to prevent the sheet 14 from warping. Further, it is preferable to set the polishing roll 13 to a higher temperature. The temperature difference between the polishing rolls 11 and 13 is preferably set to 65 ° C. or less, more preferably 10 to 30 ° C.

In any of the apparatuses, the diameters of the polishing rolls 11 and 13 and the grooved roll 12 are not particularly limited, and it is not necessary to unify them to the same diameter.
It is preferably at least 00 mm, particularly preferably the same diameter of 250 to 500 mm.

In any of the apparatuses, the grooved roll 12
The V-shaped groove provided on the surface of the
3 mm, one slope (hereinafter referred to as a horizontal plane)
The angle of inclination of the “draft surface”) is 80-88 °,
The other inclined surface (hereinafter, referred to as “Fresnel surface”) has an inclination angle of 30 ± 15 ° and a depth of 0.3 to 1.5 mm.

The pitch of the V-shaped groove, the inclination angle of the draft surface, and the inclination angle of the Fresnel surface need to be within the above ranges for the same reason as described for the Fresnel prism plate.

On the other hand, if the depth of the V-shaped groove is less than 0.3 mm, it is difficult to form a good Fresnel surface because it is too shallow.
If it is 1.5 mm or more, the releasability will be poor.

Any method can be used to manufacture the grooved roll 12, but generally, engraving, etching and the like are preferably used. The surface roughness of the grooved roll 12 is J
It is preferably 6S or less of IS.B-0601.

According to this method, when the sheet 14 is sandwiched between the polishing rolls 11 and 13 and the grooved roll 12, an unfilled portion of the transparent resin is left at the bottom corner of the V-shaped groove, so that the Fresnel prism is activated. It is possible to have an appropriate radius of curvature at the top of the Fresnel prism without significantly impairing the shape. In other words, the Fresnel prism shape on the Fresnel prism plate surface obtained by this method is
Although the height differs depending on the viscosity (fluidity) of the transparent molten resin at the time of extrusion, the height of the Fresnel prism formed as a ridge having a triangular cross section is approximately １ ／ or more of the depth of the V-shaped groove, and While the inclination angle of the draft surface is satisfactorily transferred, the top tends to have an appropriate radius of curvature as shown in FIG.

The thickness of the Fresnel prism plate manufactured according to the present invention is generally in the range of 0.5 to 5 mm, but is not particularly limited. The thickness of the Fresnel prism plate is determined by adjusting the intervals between the polishing rolls 11, 13 and the grooved roll 12.

In the Fresnel prism plate of the present invention, other components such as a filler, a diffusing agent, a release material, and the like, as long as the color tone, optical characteristics and other physical properties of the transparent resin plate are not impaired.
Additives such as a heat stabilizer, an antioxidant, a light stabilizer, and an ultraviolet absorber can be contained in any process such as when producing a transparent resin raw material or when molding a transparent resin plate. In particular, in the case of applying a shape by a polishing roll and a grooved roll using an extruded sheet molding method using a T die, higher fatty acids,
It is preferable to mix a release agent of higher fatty acid esters.

[0056]

The present invention will be described below in detail with reference to examples and comparative examples. In addition, the evaluation and the measuring method in an Example and a comparative example are as follows.

(1) Fresnel prism cross-sectional shape The Fresnel prism cross-sectional shape is obtained by embedding and solidifying a small sample of a molded product in an epoxy resin, cutting out the cross-section of the Fresnel prism-formed surface with a microtome, observing with a microscope, and observing the Fresnel prism. , The pitch of the prism, the inclination angle of the Fresnel surface, the inclination angle of the draft surface, and the radius of curvature of the top were measured.

(2) Presence or absence of rainbow pattern The Fresnel prism plate was held over external light, and the appearance of the rainbow pattern was visually determined. When a rainbow pattern was observed, it was evaluated as x, and when no rainbow pattern was observed, it was evaluated as ○.

(3) Luminance of Fresnel Prism Surface A linear Fresnel prism plate is installed vertically in a part of a dark room with the linear surface of the prism plate facing upward, and a fluorescent lamp is used from a height of about 30 ° in front. Irradiate spot light,
Brightness meter (Minolta CS
100 type).

(4) Vicat softening temperature Measured according to JIS K7206.

Example 1 Using an extruder connected to the apparatus shown in FIG. 5, a methacrylic resin (trade name: Del Powder 70H, manufactured by Asahi Kasei Kogyo) having a Vicat softening temperature of 113 ° C. was melted at a molding temperature of 250 ° C. Extruded, width 1200
into a sheet 14 through a T-die lip 15 mm, sandwiched between mirror-like polishing rolls 11 and 13 having a diameter of 350 mm (set temperature: 100 ° C.), thickness 2 mm, width 1200 m
m molten resin plate, heating device (far infrared heater) 1
After heating only the surface layer of the sheet 14 to 113 ° C. in step 7, the sheet 14 is sandwiched between a polishing roll 13 and a grooved roll 12 having a diameter of 350 mm (set temperature: 105 ° C.). The adhesive layer side of a 50 μm-thick light-diffusing resin film (commercially available product) having an uneven pattern on one surface is tensioned to 3.0 kg / m (per roll length)
And the Fresnel prism plate was continuously formed. At this time, the temperature of the sheet 14 was 50 ° C., and the roll pressure was 1.0 ton / m.

In the V-shaped groove of the grooved roll, the inclination angle of the draft surface was 87 °, the inclination angle of the Fresnel surface was 35 °, the depth was 0.65 mm, and the pitch was 1.0 mm.

Table 1 shows the evaluation results. Even if the luminance of the prism plate surface is measured from any angle, there is no glare, and the light is uniformly scattered and bright.

Comparative Example 1 A single-layer Fresnel prism was produced under the same conditions as in Example 1 except that the light-scattering resin film was not laminated.

Table 1 shows the evaluation results. A spot light source having a height of about 30 ° becomes horizontal incident light and is dazzling at a specific position.

(Comparative Example 2) A commercially available 15 cm square Fresnel lens having a smooth surface on one side manufactured by a compression molding method was evaluated.
Table 1 shows the results. A spot light source having a height of about 30 ° becomes horizontal incident light and is dazzling at a specific position.

[0067]

[Table 1]

[0068]

As described above, it is possible to provide a Fresnel prism in which no rainbow pattern is generated in lighting and glare is eliminated.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing an example of a Fresnel prism plate of the present invention.

FIG. 2 is an enlarged schematic cross-sectional view of the Fresnel prism portion of FIG.

FIG. 3 is a schematic view showing an example of a manufacturing apparatus for a Fresnel prism plate used in the present invention.

FIG. 4 is an enlarged view of a grooved roll used in the present invention.

FIG. 5 is a schematic view showing another example of the apparatus for manufacturing a Fresnel prism plate used in the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Fresnel prism 2 Light scattering resin film 3 Top 4 Draft surface 5 Fresnel surface 11 Polishing roll 12 Grooved roll 13 Polishing roll 14 Sheet 15 T die lip 16 Take-off roll 17 Heating device 18 Air stick device 21 Light scattering film roll winding Material 22 Protective film take-up device 23 Tension roll 24 Protective film 25 Irregular light scattering surface 26 Adhesive layer surface

Continued on the front page F term (reference) 2H042 CA13 CA15 CA17 4F213 AA21 AD08 AD10 AD24 AF01 AG01 AG03 AG28 AH75 AH76 AR04 AR06 AR13 WA06 WA12 WA15 WA43 WA53 WA74 WB02 WC03

Claims (7)

[Claims] 1. A daylighting device comprising: a transparent resin plate having a light-scattering resin film laminated on one surface; and a Fresnel prism formed on the other surface of the transparent resin plate as a plurality of ridges having a continuous triangular cross section. Composite Fresnel prism plate. 2. The Fresnel prism has a prism pitch of 0.5 to 3 mm, an inclination angle of one inclined surface (draft surface) of 80 to 88 °, and an inclination angle of the other inclined surface (Fresnel surface) of 30 ± 15 °. , The radius of curvature at the top is 0.02 to 0.3 m
The composite Fresnel prism plate for daylighting according to claim 1, wherein m is m. 3. The composite Fresnel prism plate for daylighting according to claim 1, wherein the transparent resin is a methacrylic resin. 4. The light-scattering resin film having a thickness of 25 to
The composite Fresnel prism plate for lighting according to any one of claims 1 to 3, wherein the film has a transparent uneven pattern on one side of the film having a thickness of 300 µm. 5. A sheet of transparent resin melt-extruded is sandwiched between a grooved roll and a polishing roll,
A method for producing a daylighting composite Fresnel prism plate in which a groove shape of a grooved roll is transferred to a sheet as a Fresnel prism, wherein an inclination angle of one slope is 80 to 88 ° and an inclination angle of the other slope is 30 ± 15 °. , 0.3-1.5m depth
Using a grooved roll having a large number of V-shaped grooves with a pitch of 0.5 to 3 mm provided on the surface thereof in a ring shape, and further following sheet take-up, the tension of the light-scattering resin film is reduced by 1 to 1
The method according to any one of claims 1 to 4, wherein the sheet is laminated on the smooth surface side of the sheet under a tension of 0 kg / m (per roll length). 6. A sheet of transparent resin melt-extruded is once sandwiched between polishing rolls and cooled, and the surface of the sheet coming out of between the polishing rolls is heated to a temperature equal to or higher than the Vicat softening temperature of the transparent resin, and then the grooved roll is heated. 6. The method for manufacturing a composite Fresnel prism plate for daylighting according to claim 5, wherein the sheet is sandwiched between the polishing rolls, and the sheet coming out from between the grooved roll and the polishing roll is air-cooled and taken off. . 7. The temperature of the grooved roll is higher than that of the polishing roll, and the Vicat softening temperature of the transparent resin is ± 20.
The method for producing a daylighting composite Fresnel prism plate according to claim 5 or 6, wherein the temperature is set to ° C.