JP2020080653A - Plant cultivation device and reflection sheet - Google Patents

Abstract

To provide a plant cultivation device that suppress flapping of a reflection sheet arranged on a side face of a cultivation rack or generation of curl or distortion on the reflection sheet.SOLUTION: There is provided a plant cultivation device comprising a cultivation rack 10 and a reflection sheet 20 which is arranged on a side face in a longitudinal direction of the cultivation rack 10, and has visible light reflectivity, in which the reflection sheet 20 has fixing parts 21 for fixing the reflection sheet 20 to the cultivation rack 10 in a first region on a first side, and an overlapped part 22 in a second region on a second side which opposes the first side and is positioned below the first side, and the overlapped part 22 has a folded structure in which the reflection sheet 20 is folded along a first direction crossing the first side and the second side.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a plant cultivation device and a reflection sheet.

As a method for cultivating plants such as vegetables, for example, artificial light type cultivation utilizing artificial light such as LEDs is known. As a plant cultivation device used for artificial light type cultivation, for example, in Patent Document 1, a plurality of struts, and a cultivation rack having a mounting portion on which a cultivating tank in which plants are planted are placed, A lighting device disposed on the cultivation rack at an interval above the mounting portion, and the lighting device is attached to the cultivation rack so that the height position of the lighting device with respect to the mounting portion can be changed. Is a plant cultivation device comprising a frame-shaped frame and a plurality of straight tubular LED lighting fixtures detachably attached to the frame, wherein a pair of frame members facing each other in the frame of the lighting device is specified. There is disclosed a plant cultivation device having the lamp receiving part. It is an object of this technology to provide a plant cultivation device capable of relatively easily attaching and detaching the LED lighting device to and from the frame of the lighting device and reducing the number of parts.

Further, in Patent Document 2, in a plant cultivation device including a cultivation rack having a mounting shelf for mounting a cultivation tank in which a plant is planted, and an LED lighting device arranged at an interval above the mounting shelf. There is disclosed a plant cultivation device in which a cultivation rack is provided with a support portion for supporting the LED lighting device so that the height position of the LED lighting device with respect to the mounting shelf can be changed. This technique has an object to provide a plant cultivation device capable of adjusting the light intensity applied to a plant.

JP, 2005-8126, A JP, 2013-17397, A

For example, by arranging the reflection sheet on the side surface of the cultivation rack, the plant can be efficiently irradiated with artificial light such as an LED. On the other hand, the reflective sheet arranged on the side of the cultivation rack has good operability when it is thin and light, but in the artificial light plant factory, the reflective sheet may flutter due to the effect of wind circulating in the vicinity of the cultivation layer. The reflection efficiency of artificial light of the reflection sheet may decrease. Further, the reflection sheet arranged on the side surface of the cultivation rack may be curled or distorted due to the influence of humidity during cultivation. Even in that case, the reflection efficiency of artificial light may decrease.

The present disclosure has been made in view of the above circumstances, and a main object of the present disclosure is to provide a plant cultivation device that suppresses fluttering of a reflection sheet and curling or distortion of the reflection sheet.

In the present disclosure, a first member capable of mounting a cultivation tank, a second member provided with a space provided for the first member, and a space provided for the first member, And a lighting rack arranged on the first member side of the second member, and a cultivation rack having a structure having a plurality of pillar members that fix the positions of the first member and the second member, Arranged on the side surface in the longitudinal direction of the cultivation rack, comprising a reflective sheet having visible light reflectivity, the reflective sheet, in the first region on the first side, fixes the reflective sheet to the cultivation rack. And having a fixing portion for, and facing the first side, in the second region of the second side located below the first side, has a weight portion, the weight portion, Provided is a plant cultivation device having a folding structure in which the reflection sheet is folded along a first direction intersecting the first side and the second side.

Further, in the present disclosure, it is used to be arranged on the side surface of the cultivation rack, a reflective sheet having visible light reflectivity, in the first region on the first side, the reflective sheet to the cultivation rack. A fixing portion for fixing is provided, and a weight portion is provided in a second region on the second side opposite to the first side, and the weight portion intersects the first side and the second side. Provided is a reflection sheet having a folding structure in which the reflection sheet is folded along a first direction.

The plant cultivation device according to the present disclosure has an effect of suppressing flapping of the reflection sheet and curling or distortion of the reflection sheet.

It is a schematic front view which shows an example of the cultivation rack in this indication. It is a schematic side view of FIG. It is a schematic perspective view which shows an example of the plant cultivation apparatus in this indication. It is the enlarged view which expanded the area|region R in FIG. It is a schematic plan view of the reflection sheet in FIG. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the hook in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication. It is explanatory drawing which illustrates the reflection sheet in this indication.

Hereinafter, the plant cultivation device and the reflection sheet according to the present disclosure will be described in detail.

A. Plant Cultivating Device A plant cultivating device according to the present disclosure will be described with reference to the drawings. 1 is a schematic front view showing an example of a cultivation rack, and FIG. 2 is a schematic side view of FIG. Further, FIG. 3 is a schematic perspective view showing an example of the plant cultivation device, and FIG. 4 is an enlarged view in which a region indicated by reference symbol R in FIG. 3 is enlarged.

As shown in FIGS. 1 and 2, the cultivation rack 10 includes a first member 12 on which a cultivation tank 11 can be placed, a second member 13 provided with a space for the first member 12, and a second member 13. A lighting member 14 arranged with a space provided for one member 12 and arranged on the first member side 12 with respect to the second member 13, and a plurality of fixing the positions of the first member 12 and the second member 13. A pillar member 15 and a structure 16 having a pillar member 15. The cultivation rack 10 in FIGS. 1 and 2 has a structure in which the structures 16 are stacked in four stages. Although not particularly shown, the cultivation rack 10 may be provided with a culture solution supply device for supplying the culture solution to the cultivation tank 11.

In addition, as shown in FIGS. 3 and 4, the plant cultivation device 100 includes a cultivation rack 10 and a reflection sheet 20 that is arranged on a side surface of the cultivation rack 10 in the longitudinal direction LD and has visible light reflectivity. Further, the reflection sheet 20 has a fixing portion 21 for fixing the reflection sheet 20 to the cultivation rack 10 in the first region on the first side 20α side. Further, the reflection sheet 20 has a weight portion 22 in a second region facing the first side 20α and on the second side 20β side located below the first side 20α. The weight portion 22 has a folding structure in which the reflection sheet 20 is folded along the first direction D ₁ intersecting the first side 20α and the second side 20β.

According to the present disclosure, since the reflection sheet has the specific weight portion, it is possible to prevent the reflection sheet from flapping and curling or distorting when the reflection sheet is placed on the cultivation rack. In addition, since the weight portion has a folding structure in which the reflection sheet is folded, it is possible to prevent the reflection sheet from flapping, curling or distorting by utilizing the own weight of the folded reflection sheet. It is advantageous in cost as compared with the case of using other weights.

Further, according to the present disclosure, by arranging the reflection sheet on the side surface in the longitudinal direction of the cultivation rack, the plant can be efficiently irradiated with artificial light such as an LED. In particular, by using a reflective sheet having a good diffuse reflectance, the plant can be efficiently irradiated with artificial light. As a result, the number of light sources of the lighting device can be reduced, and as a result, equipment cost and running cost can be reduced.

1. Reflective sheet The reflective sheet in the present disclosure is arranged on the side surface in the longitudinal direction of the cultivation rack. The “side surface in the longitudinal direction of the cultivation rack” refers to the side surface of the cultivation rack that is located in the longitudinal direction of the cultivation rack. The “side surface of the cultivation rack” means a surface specified by the first member, the second member and the pillar member. For example, when the shape of the cultivation rack is a rectangular parallelepiped, the four surfaces of the six surfaces excluding the top surface and the bottom surface correspond to the side surfaces of the cultivation rack. Further, the “longitudinal direction of the cultivation rack” refers to the longitudinal direction of the first member and the second member. The reflection sheet is preferably arranged so as to cover both ends of the first member and the second member on the side surface in the longitudinal direction of the cultivation rack.

The reflection sheet according to the present disclosure may be arranged on the side surface in the longitudinal direction of the cultivation rack, and for example, as shown in FIG. 3, it is preferable that the reflection sheet is arranged on the two side surfaces in the longitudinal direction of the cultivation rack 10. .. Although not shown, the reflection sheet may be arranged on only one of the side surfaces in the longitudinal direction of the cultivation rack. Further, the reflection sheet according to the present disclosure may be arranged on a lateral side surface of the cultivation rack, in addition to a lateral side surface of the cultivation rack. The shape of the reflection sheet is not particularly limited, and examples thereof include a square and a rectangle. In particular, the reflection sheet is preferably rectangular (e.g., long sheet).

Moreover, the reflection sheet has a fixing portion for fixing the reflection sheet to the cultivation rack in the first region on the first side side. Here, as shown in FIG. 4, the first side 20α of the reflection sheet is preferably a side along the longitudinal direction LD of the cultivation rack. In particular, it is preferable that the direction of the first side 20α and the longitudinal direction LD are parallel to each other when seen in a plan view. The first region is a region near the first side. Specifically, the first region is the first side (end portion) when the length of the side intersecting the first side 20α of the reflection sheet (for example, the length of the side along the vertical direction in FIG. 4) is X. ) To X/2. FIG. 5 is a schematic plan view of the reflection sheet in FIG. 4, and a region from the first side 20α to X/2 is a first region 20A. The first area may be an area from the first side to X/3.

Moreover, the reflection sheet has a weight portion in a second region on the second side, which faces the first side and is located below the first side. Here, as shown in FIG. 4, the second side 20β of the reflection sheet faces the first side 20α and is located below the first side 20α. The second side 20β is preferably a side along the longitudinal direction LD of the cultivation rack. In particular, it is preferable that the direction of the second side 20β and the longitudinal direction LD are parallel to each other when seen in a plan view. Further, it is preferable that the direction of the second side 20β and the direction of the first side 20α are parallel. The second region is a region near the second side. Specifically, the second region is the second side (end portion) when the length of the side intersecting the second side 20β of the reflection sheet (for example, the length of the side along the vertical direction in FIG. 4) is X. ) To X/2. FIG. 5 is a schematic plan view of the reflection sheet in FIG. 4, and a region from the second side 20β to X/2 is a second region 20B. The second area may be an area from the second side to X/3.

(1) Weighted portion The reflection sheet has a weighted portion in the second region on the second side side. Further, for example, as shown in FIG. 4, the weight portion 22 has a folding structure in which the reflection sheet 20 is folded along the first direction D ₁ intersecting the first side 20α and the second side 20β. The first direction D ₁ is preferably a direction orthogonal to the first side 20α and the second side 20β. Further, for example, as shown in FIG. 5, when the width of the weight portion 22 is W, W may be, for example, 10 mm or more, 30 mm or more, and 50 mm or more. On the other hand, W is, for example, 100 mm or less.

FIG. 6A is a schematic plan view showing an example of the reflection sheet according to the present disclosure, and FIG. 6B is a sectional view taken along the line AA of FIG. 6A. The reflection sheet 20 illustrated in FIGS. 6A and 6B is a sheet including a base sheet 25 and a reinforcing sheet 26 that reinforces the base sheet 25. Further, in the weight portion 22, the reflection sheet 20 is folded and is positioned so that the reflection sheets 20 (especially, the reinforcement sheets 26 in FIG. 6B) face each other. Further, in FIG. 6B, since the weight portion 22 is manufactured by folding once, the folding structure has one bent portion B. On the other hand, the folded structure may have two or more bent portions B. For example, in FIG. 6C, since the weight portion 22 is manufactured by folding twice, the folding structure has two bent portions B. The number of bent portions is basically the same as the number of folds.

FIG. 7A is a schematic plan view showing an example of the reflection sheet according to the present disclosure, and FIG. 7B is a sectional view taken along the line AA of FIG. 7A. The reflection sheet 20 shown in FIGS. 7A and 7B is a sheet that does not have the reinforcing sheet 26 and has only the base sheet 25, unlike FIGS. 6A and 6B. As described above, in the present disclosure, the reflection sheet may include only the base sheet. Further, as shown in FIG. 7B, the folding structure may have one bent portion B, and as shown in FIG. 7C, the folding structure may have two bending portions B. May be.

When the reflection sheet has a base sheet and a reinforcement sheet, the surface of the reflection sheet on the base sheet side is usually located on the cultivation rack side, and the surface of the reflection sheet on the reinforcement sheet side is opposite to the cultivation rack. It is arranged so as to be located on the side. Specifically, as shown in FIG. 4, the surface of the reflection sheet 20 on the side of the base material sheet 25 is located on the cultivation rack 10 side, and the surface of the reflection sheet 20 on the side of the reinforcing sheet 26 is opposite to the cultivation rack. It is arranged to be located. That is, in the region other than the weight portion 22, the cultivation rack 10, the base sheet 25, and the reinforcing sheet 26 are arranged in this order.

In this case, as shown in FIG. 4 and FIG. 6C, in the folding structure of the weight portion 22, the reflection sheet 20 is folded so that the base sheet 25 is on the outside of the structure and the reinforcing sheet 26 is on the inside of the structure. It is preferable that the structure is a mixed structure. This is because the plant can be efficiently irradiated with artificial light. For example, contrary to FIGS. 4 and 6(c), the folding structure in the weight portion is a structure in which the reflection sheet is folded so that the base sheet is on the inside of the structure and the reinforcing sheet is on the outside of the structure. In this case, in the folded structure, the reinforcing sheet is exposed on the surface on the cultivation rack side. Since the reinforcing sheet usually has lower visible light reflectivity than the base sheet, the irradiation of the plant is reduced. On the other hand, as shown in FIG. 4 and FIG. 6C, in the folded structure of the weight portion 22, the reflection sheet 20 has the base sheet 25 on the outside of the structure and the reinforcing sheet 26 on the inside of the structure. In the folded structure 22, the reflection sheet 20 is exposed on the surface on the cultivation rack side, so that the plant can be efficiently irradiated with artificial light.

In the folded structure, the means for fixing the reflecting sheets facing each other is not particularly limited. Above all, in the folded structure, it is preferable that the reflecting sheets facing each other are fixed by sewing. That is, it is preferable that the reflecting sheets facing each other are sewn together. For example, when algae or the like is generated on the reflection sheet and it becomes dirty, cleaning such as washing with water may be performed, but even in that case, the folded structure is easily maintained without breaking. That is, when the reflecting sheets facing each other are sewn together, excellent durability is obtained. Further, “sewn” means a state in which fibers such as threads are sewn together.

Further, as shown in FIG. 6A, in the folded structure of the weight portion 22, it is preferable that the first end portion 201 along the first direction D ₁ is sewn. This is because the sewing of the first end portion 201 can prevent, for example, the generation (propagation) of harmful insects. For example, when the first end portion 201 is not sewn and the first end portion 201 is open, there is a possibility that pests may enter the interior of the folded structure through the opening, form a nest, and breed. On the other hand, for example, when the first end portion 201 is sewn and the first end portion 201 is closed, it is possible to prevent pests from invading the inside of the folding structure and prevent pests from breeding.

Further, as shown in FIG. 6A, in the folded structure of the weight portion 22, it is preferable that the second end portion 202 along the second direction D ₂ intersecting the first direction D ₁ is sewn. Because the second end 202 is sewn, excellent durability is likely to be exhibited. The second end portion 202 is a portion (side) facing the second side 20β, and is preferably parallel to the second side 20β. In addition, it is preferable that the second direction D ₂ and the longitudinal direction LD of the cultivation rack are parallel to each other when seen in a plan view.

Note that, as a means other than sewing, for example, adhesion can be cited. That is, the reflecting sheets facing each other may be adhered to each other. Examples of means for adhering include heat sealing and double-sided tape.

FIG. 8A is a schematic plan view showing an example of the reflection sheet according to the present disclosure, and FIG. 8B is a cross-sectional view taken along the line AA of FIG. 8A. As shown in FIGS. 8A and 8B, the folding structure of the weight portion 22 preferably has a weight 27 inside. This is because flapping of the reflection sheet and curling or distortion of the reflection sheet can be further suppressed. The material of the weight is not particularly limited, and examples thereof include plastic, metal, magnet, wood, paper and the like. On the other hand, the folded structure of the weight portion 22 may not have a weight inside.

(2) Fixing part The reflecting sheet has a fixing part for fixing the reflecting sheet to the cultivation rack in the first region on the first side side. Examples of the fixing portion include an eyelet, a hook-and-loop fastener, and a magnet. The reflection sheet may have only one fixing part or may have a plurality of fixing parts. The plurality of fixing portions are preferably located along the longitudinal direction of the cultivation rack.

For example, in FIG. 4, the reflection sheet 20 has eyelets as the fixing portion 21. On the other hand, the cultivation rack 10 has a hook 17 as a member for hooking an eyelet. Examples of the eyelet include a metal eyelet using a metal such as aluminum, brass, and stainless, and a resin eyelet using a resin such as polycarbonate. The metal eyelet is obtained, for example, by punching the metal member and the reflection sheet using a punch. Specifically, the metal member is crushed by the punch, and an eyelet integrated with the reflection sheet is obtained. Therefore, an eyelet that is firmly adhered to the reflection sheet can be obtained without using an adhesive.

The size of the eyelet can be appropriately adjusted according to the size of the hook for hooking the eyelet, but it is preferably small. This is because a decrease in reflection efficiency due to eyelets can be suppressed.

On the other hand, the member for hooking the eyelet is not particularly limited, but for example, a hook can be used. Examples of the hook include a U-shaped hook 17 as shown in FIG. 9A and an S-shaped hook 17 as shown in FIG. 9B. Note that FIG. 9B shows an example in which the S-shaped hook 17 is hung on the bar 18 provided on the second member 13, but in addition to this, for example, the S-shaped hook is opened on the second member. It may be hooked in the hole. The cultivation rack may have only one hook or a plurality of hooks. The plurality of hooks are preferably located along the longitudinal direction of the cultivation rack.

FIG. 10A is a schematic plan view showing an example of the reflection sheet according to the present disclosure, and FIG. 10B is a cross-sectional view taken along the line AA of FIG. 10A. As shown in FIGS. 10A and 10B, the reflection sheet 20 is provided in the first region 20A on the first side 20α side along the first direction D ₁ intersecting the first side 20α and the second side 20β. The reflection sheet 20 may have a folded structure (first region side folded structure). Since the reflection sheet has the first region side folded structure, it is possible to further suppress the flapping of the reflection sheet and the curling or distortion of the reflection sheet. Further, the reflection sheet 20 may have a fixing portion 21 at a position at least overlapping with the first region side folding structure. In particular, as shown in FIGS. 10(a) and 10(b), when the fixing portion 21 is an eyelet, the first region side folding structure facilitates the adjustment of the thickness and obtains an eyelet that firmly adheres to the reflection sheet. Be done.

On the other hand, another example of the fixing portion is a surface fastener. FIG. 11A is a schematic plan view showing an example of the reflection sheet in the present disclosure, and FIG. 11B is a sectional view taken along the line AA of FIG. 11A. In FIGS. 11A and 11B, the reflection sheet 20 has a surface fastener as the fixing portion 21. On the other hand, although not shown, the cultivation rack also usually has a hook-and-loop fastener that can be attached to and detached from the fixing portion 21 (hook-and-loop fastener). Examples of the surface fastener include a surface fastener having hook-shaped raised fibers and a surface fastener having loop-shaped raised fibers. Usually, the hook-and-loop raised hook-and-loop fastener and the loop-like raised hook-and-loop fastener are used in combination to be detachable. A general surface fastener can be used as the surface fastener.

The reflective sheet may have only one surface fastener or may have a plurality of surface fasteners. It is preferable that the plurality of hook-and-loop fasteners are located along the longitudinal direction of the cultivation rack. Moreover, examples of the shape of the surface fastener include a square and a rectangle. Further, the surface fastener may be a long surface fastener extending along the second direction of the reflection sheet.

Examples of the method of attaching the surface fastener to the reflection sheet include a method of attaching the surface fastener to the reflection sheet using an adhesive and a method of sewing the surface fastener to the reflection sheet.

Moreover, a magnet is mentioned as another example of a fixed part. FIG. 12A is a schematic plan view showing an example of the reflection sheet in the present disclosure, and FIG. 12B is a sectional view taken along the line AA of FIG. 12A. In FIGS. 12A and 12B, the reflection sheet 20 has a magnet as the fixing portion 21. A general magnet can be used as the magnet. On the other hand, although not shown, the cultivation rack also usually has a magnetic member. The member having magnetism may be a magnet or a metal sheet. Further, for example, if the structure of the cultivation rack (for example, the second member) is made of metal, the structure itself functions as a member having magnetism.

The reflection sheet may have only one magnet or may have a plurality of magnets. The plurality of magnets are preferably located along the longitudinal direction of the cultivation rack. Moreover, examples of the shape of the magnet include a square and a rectangle. The magnet may be a long magnet extending along the second direction of the reflection sheet.

As shown in FIG. 12B, when the reflection sheet is arranged on the cultivation rack, the fixing portion 21 (magnet) may be located on the surface on the cultivation rack side. On the other hand, when the fixed portion is a magnet, since the magnetic force is used, the installation position of the magnet on the reflection sheet has a high degree of freedom. For example, as shown in FIG. 13A, when the reflection sheet is arranged on the cultivation rack, the fixing portion 21 (magnet) may be located on the surface opposite to the cultivation rack. Furthermore, as shown in FIG. 13B, the fixing portion 21 (magnet) may be located inside the folding structure.

As a method of attaching the magnet to the reflection sheet, for example, a method of attaching the magnet to the reflection sheet using an adhesive agent can be mentioned.

Further, FIG. 14A is a schematic plan view showing an example of the reflection sheet according to the present disclosure, and FIG. 14B is a sectional view taken along the line AA of FIG. 14A. As shown in FIGS. 14A and 14B, the reflection sheet 20 may have a fixing portion 221 for temporarily folding the reflection sheet at a position overlapping the folding structure of the weight portion 22. Examples of such a fixing portion include an eyelet, a hook-and-loop fastener, and a magnet. When the reflection sheet 20 has the fixed portion 21 and the fixed portion 221, as shown in FIG. 15( a ), as shown in FIG. 15( b ), the cultivation rack is provided in the penetrating portion formed by folding the reflection sheet 20. Can be hooked (not shown). If the reflection sheet can be partially folded when performing maintenance of the plant during cultivation, it is not necessary to remove the reflection sheet, and the plant can be efficiently irradiated with artificial light. 16A is a schematic plan view showing an example of the reflection sheet in the present disclosure, and FIG. 16B is a sectional view taken along the line AA of FIG. 16A. As shown in FIGS. 16A and 16B, the fixing portion 221 may be a surface fastener. Similarly, as shown in FIGS. 17A and 17B, the fixed portion 221 may be a magnet. Although two fixing parts are shown in FIG. 17, the fixing part on the upper side of the drawing is a fixing part 21 for fixing the reflection sheet 20 to a cultivation rack (not shown) and a reflection sheet temporarily. It also has a fixing portion 221 for folding the sheet. In addition, in FIGS. 17A and 17B, the fixing portion 221 (magnet) is located inside the folding structure. However, as in FIGS. 12B and 13A, the fixing rack 221 is located on the cultivation rack side. The fixed portion 221 (magnet) may be located on the surface, and the fixed portion 221 (magnet) may be located on the surface opposite to the cultivation rack.

(3) Layer Configuration of Reflective Sheet The reflective sheet according to the present disclosure is not particularly limited, but preferably has at least a base material sheet containing a polyolefin resin. The base sheet is a sheet mainly responsible for the reflection function. Further, the reflection sheet preferably has a reinforcing sheet on one surface side of the base material sheet.

(I) Base Material Sheet The base material sheet preferably contains at least a polyolefin resin. Further, the base sheet preferably contains an inorganic filler. Further, the base sheet may contain additives such as a light stabilizer, an antioxidant and an ultraviolet absorber. The base sheet may be a non-stretched sheet or a stretched sheet (uniaxially stretched sheet, biaxially stretched sheet, etc.).

(Polyolefin resin)
The base sheet preferably contains a polyolefin resin. Examples of the polyolefin resin include homopolymers of olefins, copolymers of two or more kinds of olefins, copolymers of one or more kinds of olefins, and one or more kinds of polymerizable monomers capable of being polymerized with olefins. Can be mentioned. Examples of the olefin (monomer unit) include ethylene, propylene, butene, and hexene. The copolymer may be binary, ternary or quaternary. Further, the copolymer may be a random copolymer or a block copolymer.

Examples of the polyolefin resin include polyethylene resin and polypropylene resin. Examples of the polyethylene-based resin include high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and ultra-low-density polyethylene (VLDPE). These may be used alone or in combination of two or more.

Among these, high density polyethylene and linear low density polyethylene are preferable, and high density polyethylene is more preferable. This is because the high-density polyethylene is excellent in weather resistance and tensile strength, and the sheet containing the high-density polyethylene has no slack even in the case of a long roll and is unlikely to cause a defective appearance due to whitening during bending. Further, high-density polyethylene is opaque, and the addition of titanium oxide and calcium carbonate contributes to increase the whiteness of the film and, as a result, to high reflectivity.

In particular, when the resin component is only a polyethylene resin, it is preferable to use at least one of high density polyethylene and linear low density polyethylene. Further, since high-density polyethylene has excellent heat resistance and processability during processing, it is particularly suitable for sheet forming by calendering.

The polyethylene resin preferably has a melt flow rate (temperature 230° C., load 2.16 kg) measured according to JIS K 7210 of 0.1 g/10 min or more and 4.0 g/10 min or less, and 0. More preferably, it is not less than 0.4 g/10 min and not more than 2.0 g/10 min. When the melt flow rate (MFR) is within the above range, it is particularly suitable for sheet formation by calendering.

The base material sheet may contain a polyethylene resin as a main component of the resin component. The ratio of the polyethylene resin to the total amount of the resin components is, for example, 50% by mass or more, and may be 70% by mass or more.

On the other hand, examples of the polypropylene resin include homopolymer polypropylene (h-PP), random copolymer polypropylene (r-PP), block copolymer polypropylene (b-PP), and metallocene polypropylene. These may be used alone or in combination of two or more. Of these, random copolymer polypropylene is preferred. This is because the random copolymer polypropylene has flexibility as compared with the homopolymer polypropylene and the block copolymer polypropylene.

The polypropylene-based resin may be a copolymer of propylene and another α-olefin. Examples of other α-olefins include at least one of ethylene, butene-1, hexene-1, and heptene-1,4-methylpentene-1. The polypropylene resin preferably contains propylene as the main component of the monomer unit.

The polypropylene resin preferably has a melt flow rate (temperature 230° C., load 2.16 kg) measured according to JIS K 7210 of, for example, 0.1 g/10 min or more and 4.0 g/10 min or less. More preferably 0.4 g/10 min or more and 2.0 g/10 min or less. When the melt flow rate (MFR) is within the above range, it is particularly suitable for sheet formation by calendering.

The base material sheet may contain a polypropylene resin as the main component of the resin component. The ratio of the polypropylene resin to the total amount of the resin components is, for example, 50% by mass or more, and may be 70% by mass or more. The base material sheet may contain both a polypropylene resin and a polyethylene resin as a resin component.

Examples of the other polyolefin-based resin include a copolymer having at least one of an ethylene-propylene copolymer component and a polybutylene component, and a polypropylene component (so-called reactor TPO).

(Inorganic filler)
The base sheet preferably contains an inorganic filler. Examples of the inorganic filler include calcium carbonate, titanium oxide, talc, titanium oxide, titanium oxide/antimony oxide/nickel oxide solid solution, and the like. The base sheet preferably contains at least one of calcium carbonate and titanium oxide as an inorganic filler.

The content of the inorganic filler in the base material sheet is, for example, 30% by mass or more, 40% by mass or more, or 50% by mass or more, based on the polyolefin resin. If the content of the inorganic filler is too low, the whiteness and light reflectivity of the base sheet may be lowered. On the other hand, the content of the inorganic filler is, for example, 80% by mass or less, 75% by mass or less, or 70% by mass or less, based on the polyolefin resin. If the content of the inorganic filler is too large, the flexibility of the base sheet may be reduced.

(Additive)
The base sheet preferably contains at least one of a light stabilizer, an antioxidant and an ultraviolet absorber as an additive.

Examples of the light stabilizer include hindered amine light stabilizers, and among them, NOR hindered amine light stabilizers are preferable. The NOR-type hindered amine light stabilizer has good acid resistance and greatly improves weather resistance.

Specific examples of the NOR-type hindered amine light stabilizers include, for example, ADEKA STAB LA-81 manufactured by ADEKA and TINUVIN 123 (bis(2,2,6,6-tetramethyl-1-(octyloxy)decanedioate) manufactured by BASF. )-4-Piperidinyl)ester) and the like.

The content of the light stabilizer in the substrate sheet is, for example, 0.05% by mass or more, may be 0.1% by mass or more, and is 0.4% by mass or more, based on the polyolefin resin. Good. If the content of the light stabilizer is too small, the weather resistance of the base sheet may not be improved. On the other hand, the content of the light stabilizer in the base material sheet is, for example, 3.0% by mass or less, may be 1.0% by mass or less, or 0.5% by mass or less, based on the polyolefin resin. It may be. When the content of the light stabilizer is too large, the production unit price may increase.

Examples of antioxidants include phenolic antioxidants and phosphorus antioxidants. Examples of the phenolic antioxidant include pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propinate], 2,6-di-t-butyl-4-methylphenol, 4,4'-methylene-bis(2,6-di-t-butyl)phenol, 4,4'-butylidene-bis(6-t-butyl-3-methyl)phenol, 2,2-methylene-bis( 6-t-butyl-3-methyl)phenol, 2,2-methylene-bis(4-methyl-6-t-butyl)phenol, 4,4'-thiobis(2-methyl-6-t-butyl)phenol , 4,4'-thiobis(3-methyl-2-t-butyl)phenol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4hydroxybenzyl) Examples thereof include benzene, 3,5-t-butyl-4-hydroxy-α-hydroxybenzene, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate.

On the other hand, examples of the phosphorus-based antioxidant include trisnonylphenyl phosphite, tris(2,4-ditert-butylphenyl)phosphite, tris[2-tert-butyl-4-(3-tert-butyl-phosphite). 4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tridecylphosphite, octyldiphenylphosphite, di(decyl)monophenylphosphite, di(tridecyl)pentaerythritol diphosphite, distearyl Pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) ) Pentaerythritol diphosphite, bis(2,4,6-tritert-butylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidene diphenol diphosphite, tetra(tridecyl)-4,4'-n -Butylidene bis(2-tert-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, tetrakis( 2,4-ditert-butylphenyl)biphenylene diphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris(2-[(2,4,8,10 -Tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine and the like.

The content of the antioxidant in the base material sheet is, for example, 0.05% by mass or more, may be 0.1% by mass or more, and is 0.4% by mass or more with respect to the polyolefin resin. Good. If the content of the antioxidant is too low, the weather resistance of the base sheet may not be improved. On the other hand, the content of the antioxidant in the base material sheet is, for example, 5.0% by mass or less, may be 3.0% by mass or less, and is 1.0% by mass or less with respect to the polyolefin resin. It may be. If the content of the antioxidant is too large, it may lead to poor appearance due to bleed-out.

Examples of the UV absorber include benzotriazole UV absorbers, triazine UV absorbers, benzophenone UV absorbers, salicylate UV absorbers, and cyanoacrylate UV absorbers. Furthermore, examples of the benzotriazole-based ultraviolet absorber include 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-ditert-butylphenyl)benzotriazole, 2- (2-Hydroxy-3,5-ditert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2-( 2-Hydroxy-3-tert-butyl-5-carboctoxyethylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dioctane) Examples thereof include 2-hydroxyphenylbenzotriazole compounds such as milphenyl)benzotriazole and 2,2′-methylenebis(4-tertiaryoctyl-6-benzotriazolylphenol).

The content of the ultraviolet absorber in the base material sheet is, for example, 0.05% by mass or more, may be 0.1% by mass or more, and is 0.4% by mass or more, based on the polyolefin resin. Good. If the content of the ultraviolet absorber is too low, the weather resistance of the base sheet may not be improved. On the other hand, the content of the ultraviolet absorber in the base material sheet is, for example, 5.0% by mass or less, may be 3.0% by mass or less, and is 1.0% by mass or less with respect to the polyolefin resin. It may be. If the content of the ultraviolet absorber is too large, it may lead to poor appearance due to bleed-out and, depending on the type of the ultraviolet absorber, poor appearance due to coloring.

The base sheet may contain a heavy metal deactivator. When the base sheet comes into contact with, for example, an iron pipe or the like, the polyolefin-based resin may be decomposed due to the influence of a heavy metal element (for example, Fe element) contained in the iron pipe. Specifically, the heavy metal element forms an oxide, and the catalytic action of the oxide may decompose the polyolefin resin. Examples of the heavy metal element include Fe element, Cu element, Mn element, and Zn element.

Heavy metal deactivators are known as copper damage inhibitors. The heavy metal deactivator is not particularly limited, and examples thereof include an oxalic acid derivative, a salicylic acid derivative, and a hydrazide derivative, and more specifically, trade names Eastman Inhibitor OAB H (manufactured by Eastman Kodak Co., Ltd.), Adekastab CDA-1 , CDA-6 (manufactured by ADEKA CORPORATION), Chel-180, Inganox MD 1024 (manufactured by BASF Corporation) and the like. Further, JP-B-37-14484, JP-B-39-9072, JP-B-39-12454, JP-B-39-19541, JP-B-40-12293, and JP-B-40-18852, JP-B-42-4356, JP-B-42-4596, JP-B-42-13247, JP-B-43-6538, JP-B-43-18606, JP-B-47-27624, JP-B-47-24 48-36837, JP-B-49-15466, JP-B-52-22834, JP-B-54-43537, JP-B-54-90143, US Pat. No. 3,357,944, US Pat. It may be exemplified by the specification, French Patent No. 1481105, French Patent No. 1495830, and the like.

The content of the heavy metal deactivator in the base material sheet is, for example, 0.05 mass% or more, may be 0.1 mass% or more, and is 0.4 mass% or more with respect to the polyolefin resin. May be. If the content of the heavy metal deactivator is too low, copper damage may not be sufficiently suppressed. On the other hand, the content of the heavy metal deactivator in the base material sheet is, for example, 5.0 mass% or less, may be 3.0 mass% or less, and is 1.0 mass% or less with respect to the polyolefin resin. May be If the content of the heavy metal deactivator is too large, it may lead to poor appearance due to poor dispersion.

The base sheet may contain an appropriate amount of known additives such as a lubricant, a heat stabilizer, a pigment, a modifier, a flame retardant, an antistatic agent, a reinforcing agent and an antifungal agent.

(Base material sheet)
The substrate sheet may be a sheet having no voids inside or a sheet having voids inside (a porous substrate sheet). The base sheet may have a single-layer structure or a multi-layer structure. When the substrate sheet has a multilayer structure, the resin components contained in each layer may be the same or different. As an example of the base material sheet having a multi-layer structure, an inner layer and two outer layers located on both sides of the inner layer are included, and the resin components contained in the two outer layers are the same, and the resin components contained in the outer layer are the same. Examples of the base sheet include different resin components contained in the inner layer.

The base sheet preferably has a high visible light reflectance. The average reflectance of visible light (wavelength 380 nm or more and 780 nm or less) is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more. The visible light reflectance was measured using an ultraviolet/visible/near-infrared spectrophotometer (Shimadzu UV-3600) and an integrating sphere accessory (ISR-3100) at an incident angle of 8° in the visible range of 380 nm to 780 nm. It is obtained by measuring the reflectance (total reflectance) and determining the average reflectance.

The thickness of the base sheet is not particularly limited, but may be, for example, 25 μm or more, 30 μm or more, or 40 μm or more. On the other hand, the thickness of the base material sheet is, for example, 90 μm or less, and may be 80 μm or less. When the thickness of the base material sheet is within the above range, for example, when the base material sheet is produced by calendering, a sheet having excellent surface smoothness and high thickness accuracy can be obtained.

(Method for manufacturing base material sheet)
The method for producing the substrate sheet is not particularly limited as long as it is a method for obtaining the desired substrate sheet, for example, a step of producing a resin composition containing at least a polyolefin resin, and the resin composition sheet And a film forming process to produce a base material sheet.

The method for producing the resin composition is not particularly limited, but a method for producing a resin composition by melting and kneading a predetermined amount of each raw material is preferable. Examples of the apparatus used for melt-kneading include a continuous kneader, a Banbury mixer, a kneader, and an extruder. The heating temperature at the time of melt-kneading is, for example, 150° C. or higher and 200° C. or lower.

Examples of the method for forming the resin composition into a sheet include known molding methods such as calendering and extrusion molding, and calendering is particularly preferable. This is because, for example, when the sheet is thin, it is suitable for producing a sheet having a uniform thickness. In addition, the calender molding is suitable because it is easy to cope with the size and the kind of the resin due to the structure of the molding machine, and it is easy to deal with a small lot. Furthermore, in the present disclosure, when a resin composition having a high content of an inorganic filler is used, it is preferable to mold it by calendering. When a large amount of an inorganic filler is contained, for example, when it is molded by extrusion molding, the surface of the obtained sheet is rough, and the sheet is likely to tear, but molding by calendering does not cause such an inconvenience, A smooth sheet can be manufactured. Furthermore, the superiority of calendering when a resin composition having a high content of an inorganic filler is used is particularly noticeable when the thickness of the substrate sheet is as thin as 30 μm or more and 70 μm or less.

In calendering, for example, the resin composition obtained by melt-kneading is supplied to a heated calender roll and rolled to obtain a base sheet. The heating temperature of the calender roll is, for example, 150° C. or higher and 220° C. or lower, and preferably 160° C. or higher and 190° C. or lower. As the calender device, an appropriate one such as a three-type, a four-L type, a four-sided L-type, a four-Z type, and a six-type may be used.

After forming the resin composition into a sheet, various surface treatments may be performed as necessary. Examples of the surface treatment include corona treatment (corona discharge treatment), plasma treatment, ultraviolet treatment, electron beam treatment (electron beam radiation treatment), and the like.

(Ii) Reinforcing Sheet The reflecting sheet may have a reinforcing sheet on one surface side of the base material sheet. The reinforcing sheet is a sheet that reinforces the base sheet. The reflection sheet may have another layer between the base sheet and the reinforcing sheet, or may not have the other layer.

Examples of the reinforcing sheet include non-woven fabric and woven fabric. Among the thermoplastic resins, the material of the non-woven fabric or the woven fabric is preferably a polyolefin resin, an ester resin or an amide resin. Further, as the non-woven fabric, for example, fiber orthogonal non-woven fabric, long fiber non-woven fabric, short fiber non-woven fabric, wet non-woven fabric, dry non-woven fabric, air-laid non-woven fabric, card type non-woven fabric, parallel non-woven fabric, cross non-woven fabric, random non-woven fabric, spun bond non-woven fabric, melt blown non-woven fabric , Flash spun nonwoven fabric, chemical bond nonwoven fabric, hydroentangled nonwoven fabric, needle punched nonwoven fabric, stitch bond nonwoven fabric, thermal bond nonwoven fabric, burst fiber nonwoven fabric, tow opening nonwoven fabric, split fiber nonwoven fabric, composite nonwoven fabric, laminated nonwoven fabric, coated nonwoven fabric, laminated nonwoven fabric, etc. Is mentioned.

The fiber-orthogonal nonwoven fabric is a nonwoven fabric in which two or more stretched films are laminated so that the stretching directions are orthogonal to each other, and examples thereof include Wallif (registered trademark) manufactured by JX ANCI Corporation. The basis weight of the fiber-orthogonal nonwoven fabric is preferably 5 g/m ² or more and 100 g/m ² or less, and more preferably 20 g/m ² or more and 50 g/m ² or less. When the basis weight of the fiber-orthogonal nonwoven fabric has the above lower limit, a reinforcing sheet having sufficient strength can be obtained. The fiber diameter of the long-fiber nonwoven fabric is preferably, for example, 3 μm or more and 20 μm or less. On the other hand, the fiber diameter of the short fiber nonwoven fabric is preferably less than 3 μm, for example.

On the other hand, as another example of the reinforcing sheet, a cloth-type nonwoven fabric may be mentioned. Examples of the cloth-type nonwoven fabric include the polyolefin mesh cloth disclosed in JP-A 2007-259734. The polyolefin mesh cloth is preferably polyethylene mesh cloth. Polyethylene mesh cloth is preferably used in consideration of adhesiveness in extrusion molding, for example. The cross-type nonwoven fabric preferably has a thickness of 30 μm or more and 100 μm or less, and more preferably 50 μm or more and 80 μm or less.

The cloth-type non-woven fabric has excellent mechanical properties such as tear strength and is preferably used as a reinforcing sheet, and has an advantage that it is easy to control tension during lamination by the roll-to-roll method and curl is small. Furthermore, the cloth-type nonwoven fabric has a strength that allows edge processing, and for example, eyelets can be provided in the edge processing portion.

As the woven structure of the cross-type non-woven fabric, various shapes such as plain weave, twill weave, entangled weave, and dummy weave are used, but the plain weave is preferable from the viewpoint of smoothness.

The cross-type nonwoven fabric can be formed by weaving drawn yarns as warp and weft yarns. In the present disclosure, the cross-type nonwoven fabric has 5 or more fibers along the first fiber direction in the area of 1 inch square and 5 or more along the second fiber direction intersecting the first fiber direction. It is preferable to have fibers of If this is expressed by the shot density, it can be expressed as “5×5 lines/inch or more”. The implantation density can be, for example, 5×5 lines/inch or more, preferably 6×5 lines/inch or more, and particularly preferably 8×8 lines/inch or more. The implantation density can be, for example, 10×10/inch or less. When the implantation density has the upper limit, it is possible to suppress an increase in manufacturing cost and prevent a problem that the curl of the laminated product becomes too large.

The mesh in the cross-type nonwoven fabric is preferably 0.3 mm or more in both the first fiber direction (for example, the longitudinal direction) and the second fiber direction (for example, the lateral direction), and more preferably 0.4 mm or more. .. Further, the mesh in the cloth-type nonwoven fabric is preferably, for example, 3 mm or less in both the first fiber direction (for example, the longitudinal direction) and the second fiber direction (for example, the lateral direction), and particularly preferably 2 mm or less. Here, the mesh means the width of the space between adjacent fibers in the first fiber direction or the second fiber direction of the mesh. When the mesh in the cloth-type nonwoven fabric has the above lower limit, it is possible to suppress an increase in the light blocking rate. Further, when the mesh in the cloth-type nonwoven fabric has the above-mentioned upper limit, it is possible to suppress the decrease in the strength of the cloth-type nonwoven fabric.

The cloth-type nonwoven fabric can be manufactured by using, for example, a monofilament or a flat yarn. The cloth-type nonwoven fabric obtained by using the monofilament has high strength and good air permeability, and the cloth-type nonwoven fabric obtained by using the flat yarn is easy to form a cloth having a smooth surface and has good coverage. In addition, the cloth-type nonwoven fabric can be preferably obtained by heat-bonding a core-sheath composite monofilament or a multilayer composite flat yarn. The cross-type nonwoven fabric obtained by using the core-sheath composite monofilament or the multi-layer composite flat yarn is, for example, a relatively low-temperature polyolefin whose surface is coated, is softened and melted by heating, and is cross-bonded to each other at the cross-bonded portion of the warp and weft yarns. It is obtained by heat fusion. By such a sealing process, it is possible to prevent the misalignment with durability.

The core-sheath composite monofilament preferably has a structure in which a high melting point polyolefin having a relatively high melting point is used as a core layer and a polyolefin having a lower melting point is coated on the surface of the core layer to form a sheath layer. As the core/sheath combination of the core-sheath composite monofilament, propylene homopolymer/propylene-ethylene block copolymer, propylene homopolymer/propylene-ethylene random copolymer, propylene homopolymer/high density polyethylene, propylene homopolymer Polymer/low-density polyethylene, propylene homopolymer layer/linear low-density polyethylene, propylene-ethylene block copolymer/linear low-density polyethylene, propylene-ethylene random copolymer/low-density polyethylene, high-density polyethylene/ Examples thereof include low density polyethylene and high density polyethylene/linear low density polyethylene. A more preferable combination of core layer/sheath layer is, for example, a combination of high-density polyethylene/low-density polyethylene and high-density polyethylene/linear low-density polyethylene from the viewpoints of heat-sealing property, strength, recycling and the like. Be done.

The core-sheath composite monofilament is, for example, melt-kneaded with a polyolefin-based resin of each layer of the core layer and the sheath layer by an extruder, and for example, while supplying a core layer made of a high-melting point polyolefin at a melting temperature of 160° C. or higher and 300° C. or lower, It can be produced by coating the outer surface with a sheath layer made of a low-melting point polyolefin, cooling and solidifying the product, stretching the product, and then performing a relaxation heat treatment. The draw ratio may be, for example, 3 times or more and 12 times or less, and preferably 5 times or more and 10 times or less.

The core-sheath composite monofilament preferably has a fineness of, for example, 30 dt or more, and more preferably 50 dt or more. The fineness of the core-sheath composite monofilament is preferably 3000 dt or less, and more preferably 2000 dt or less. When the fineness of the core-sheath composite monofilament has the above lower limit, it is possible to suppress the occurrence of the problem that the fibers become too thin and the durability decreases. Further, it is possible to suppress deterioration of mechanical properties such as tear strength of the reinforcing sheet. On the other hand, when the fineness of the core-sheath composite monofilament has the above upper limit, good weaving becomes possible. Also, good flexibility is obtained, and sufficient adhesion with the adhesive layer is possible.

The sectional area ratio (sheath layer/core layer) of the sheath layer and the core layer of the core-sheath composite filament is, for example, preferably 1/9 or more, and more preferably 2/8 or more. The cross-sectional area ratio (sheath layer/core layer) between the sheath layer and the core layer of the core-sheath composite filament is preferably 6/4 or less, and more preferably 5/5 or less. When the cross-sectional area ratio of the sheath layer to the core layer of the core-sheath composite filament has the above lower limit, the sheath component can cover the entire cross section of the core layer, and the decrease in adhesive strength can be suppressed. On the other hand, when the cross-sectional area ratio between the sheath layer and the core layer of the core-sheath composite filament has the above upper limit, it is possible to suppress the decrease in the tensile strength of the filament yarn.

The multilayer composite flat yarn preferably has a multilayer structure in which a high melting point polyolefin is used as an inner base layer and a low melting point polyolefin having a lower melting point is sandwiched between outer surface layers. Examples of the combination of the multi-layer composite flat yarn include a low density polyethylene layer/high density polyethylene layer/low density polyethylene layer composite, and a linear low density polyethylene layer/high density polyethylene layer/linear low density polyethylene layer. Examples thereof include a composite and a combination of a propylene-ethylene random copolymer layer/a polypropylene homopolymer layer/a propylene-ethylene random copolymer layer composite. As a more preferable combination of the multilayer composite flat yarn, from the viewpoint of recycling, a composite of a low density polyethylene layer/a high density polyethylene layer/a low density polyethylene layer, a linear low density polyethylene layer/a high density polyethylene layer/a straight chain Examples thereof include a composite of a low density polyethylene layer.

The multilayer composite flat yarn is, for example, a base material made of a high-melting polyolefin at a melting temperature of, for example, 160° C. or higher and 300° C. or lower by melt-kneading the polyolefin-based resin of each layer of the inner base layer and the outer surface layer with an extruder. It can be manufactured by supplying a layer, coating the surface layer made of low melting point polyolefin on both upper and lower surfaces of the base material layer, cooling and solidifying, then slitting, further stretching treatment, and then performing relaxation heat treatment. .. The stretching ratio is preferably, for example, 3 times or more and 12 times or less.

The fineness of the multilayer composite flat yarn is, for example, preferably 100 dt or more, and more preferably 200 dt or more. The fineness of the multilayer composite flat yarn is preferably 4000 dt or less, and more preferably 3000 dt or less. When the fineness of the multilayer composite flat yarn has the above lower limit, it is possible to suppress the occurrence of the problem that the fiber becomes too thin and the durability decreases. On the other hand, when the fineness of the multilayer composite flat yarn has the above upper limit, good weaving becomes possible.

The cross-sectional area ratio (surface layer/base material layer) of the surface layer and the base material layer of the multilayer composite flat yarn is, for example, preferably 1/9 or more, and more preferably 2/8 or more. The cross-sectional area ratio between the surface layer and the base material layer of the multilayer composite flat yarn is, for example, preferably 6/4 or less, and more preferably 5/5 or less. When the cross-sectional area ratio between the surface layer and the base material layer of the multilayer composite flat yarn has the above lower limit, the surface layer can sufficiently cover the base material layer, and the decrease in adhesive strength can be suppressed. it can. On the other hand, when the cross-sectional area ratio between the surface layer and the base material layer of the multilayer composite flat yarn has the above upper limit, it is possible to suppress the decrease in the tensile strength of the filament yarn. Here, the cross-sectional area of the surface layer in the above cross-sectional area ratio is the sum of the cross-sectional areas of the surface layers on both sides.

The reinforcing sheet preferably contains a resin. The resin may be a thermoplastic resin or a thermosetting resin, but the former is preferable. Examples of the thermoplastic resin include a polyolefin resin, an acrylic resin, a styrene resin, a vinyl fluoride resin, an amide resin, and a saturated ester resin. Among them, the polyolefin resin is preferable. In the present disclosure, the reinforcing sheet is preferably a fiber orthogonal nonwoven fabric containing a polyolefin resin. This is because it has excellent heat resistance, water resistance, chemical resistance, and cost.

Specific examples of the polyolefin-based resin include, for example, polyethylene-based resin, polypropylene-based resin and the like, and among them, the polyethylene-based resin is preferable. Examples of the polyolefin-based resin include the polyolefin-based resins described in the above “(i) Substrate sheet”.

As described above, acrylic resin, styrene resin, vinyl fluoride resin, amide resin, ester resin or the like can be used as the thermoplastic resin. Examples of the acrylic resin include polymethyl acrylate, polymethyl methacrylate, ethylene-ethyl acrylate copolymer and the like. Examples of the styrene resin include butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polystyrene, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-acrylic acid copolymer and the like. Is mentioned. Examples of the vinyl fluoride resin include vinyl chloride resin, polyvinyl fluoride, polyvinylidene fluoride and the like. Examples of the amide-based resin include 6-nylon, 6,6-nylon, 12-nylon and the like. Examples of the ester-based resin include polyethylene terephthalate and polyprebutylene terephthalate. Further, as the thermoplastic resin, polycarbonate, polyphenylene oxide, polyacetal, polyphenylene sulfide, silicone resin, thermoplastic urethane resin, polyether ether ketone, polyether imide, thermoplastic elastomer or the like may be used.

Further, it is preferable that both the reinforcing sheet and the base sheet contain a polyethylene resin. This is because, for example, when an adhesive layer described below is provided, the polyethylene-based resin has the same adhesiveness to the adhesive, so that a strongly adhered reflective sheet can be obtained. Also, since the degree of expansion and contraction due to heat, moisture, etc. is close, warpage is less likely to occur, and adhesion is less likely to peel off. As a result, the reflective sheet has high durability. Further, by using the polyethylene resin, the reflection sheet having high water resistance can be obtained. Further, when both the reinforcing sheet and the base sheet contain a polyethylene resin, the reflective sheet becomes recyclable, and the environmental load at the time of disposal is small. In particular, it is preferable that all layers of the reflection sheet contain a polyethylene resin.

Further, it is preferable that the reinforcing sheet contains a polypropylene resin and the base sheet contains a polyethylene resin. This is because the workability of the reflection sheet is improved. Specifically, polypropylene-based resin is a relatively hard resin and therefore difficult to process. On the other hand, since the polyethylene resin is a relatively soft resin, the workability of the reflection sheet is improved by combining the polyethylene resin.

The reinforcing sheet may have a single-layer structure or a multi-layer structure. Examples of the reflection sheet having a single-layer structure reinforcing sheet include a reflection sheet having a base sheet, an adhesive layer, and a single-layer structure reinforcing sheet in this order.

On the other hand, examples of the reflection sheet having a reinforcing sheet having a multilayer structure include a reflecting sheet having a base sheet, an adhesive layer, and a reinforcing sheet having a multilayer structure in this order. The reinforcing sheet having a multilayer structure preferably has a first reinforcing sheet layer, a reinforcing sheet adhesive layer, and a second reinforcing sheet layer in this order. In addition, the plurality of reinforcing sheet layers may be in contact (for example, fused) without an adhesive layer. Further, the type of the adhesive layer for the reinforcing sheet is not particularly limited.

The reinforcing sheet may be a porous reinforcing sheet. When the reinforcing sheet has a multi-layer structure, at least one layer constituting the reinforcing sheet may be a porous reinforcing layer.

The thickness of the reinforcing sheet is not particularly limited, but is, for example, 10 μm or more and 150 μm or less, and preferably 20 μm or more and 100 μm or less. When the reinforcing sheet has a multi-layer structure, the thickness of each layer forming the reinforcing sheet is preferably within the above range. Further, the reflection sheet may have the reinforcing sheet on the outermost surface or may have the reinforcing sheet inside.

(Iii) Adhesive Layer When the reflective sheet has a reinforcing sheet on one surface side of the base sheet, the reflective sheet may have an adhesive layer between the base sheet and the reinforcing sheet, and does not have an adhesive layer. You don't have to. In the latter case, it is preferable that the base sheet and the reinforcing sheet are in direct contact with each other. The adhesive layer preferably contains a resin such as a polyolefin resin. Such an adhesive layer can be obtained by, for example, extrusion coating a resin.

In extrusion coating, resins that can be melted by heat and fused to each other can be used. Examples of such resins include polyethylene resins such as low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene resins such as polypropylene, and ethylene-vinyl acetate copolymer. Coal, ionomer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, Acid-modified polyolefin resin obtained by modifying polyolefin resin such as polybutene polymer, polyethylene or polypropylene with unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid or itaconic acid, polyvinyl acetate resin , Poly(meth)acrylic resin, and polyvinyl chloride resin can be used.

These may be used alone or in combination of two or more. Among these, polyethylene resins are suitable, low density polyethylene and linear low density polyethylene are preferable, and low density polyethylene is more preferable. Low-density polyethylene is excellent in processability, has excellent adhesiveness to a polyethylene non-woven fabric, and is inexpensive.

The polyethylene resin preferably has a melt flow rate (temperature 230° C., load 2.16 kg) measured according to JIS K 7210 of 0.1 g/10 min or more and 4.0 g/10 min or less, and 0. More preferably, it is not less than 0.4 g/10 min and not more than 2.0 g/10 min. A melt flow rate (MFR) within the above range is particularly suitable for extrusion coating.

Further, in order to enhance the adhesiveness between the base sheet and the reinforcing sheet, for example, an anchor coating agent may be coated on the base sheet to provide an anchor coating layer. Examples of the anchor coating agent that forms the anchor coating agent layer include organic titanium-based anchor coating agents such as alkyl titanates, isocyanate-based anchor coating agents, polyethyleneimine-based anchor coating agents, and polybutadiene-based anchor coating agents. In the present disclosure, similarly to the above, the anchor coating agent is coated by, for example, roll coating, gravure coating, knife coating, dip coating, spray coating, or other coating method, and drying the solvent, the diluent, etc. An anchor coat agent layer can be formed. In the above, the application amount of the anchor coating agent is preferably 0.1 g/m ² or more and 5 g/m ² or less (dry state).

In the present disclosure, as an adhesive for laminating to form an anchor coating agent, for example, an aromatic polyisocyanate such as tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, or hexamethylene diisocyanate. , Polyfunctional isocyanates such as aliphatic polyisocyanates such as xylylene diisocyanate, and polyether polyurethane-based resins and polyesters obtained by the reaction of hydroxyl group-containing compounds such as polyether-based polyols, polyester-based polyols and polyacrylate polyols It is preferable to use a laminating adhesive containing a polyurethane polyurethane resin or a polyacrylate polyurethane resin as a main component.

The anchor coat agent layer can form a thin film that is soft, highly flexible, and highly flexible, and can improve its tensile elongation. Further, it acts as a coating film having flexibility, flexibility, etc. on the base material sheet to improve the suitability for processing the base material sheet at the time of laminating and prevent peeling defects during use.

The anchor coating agent layer in the present disclosure preferably has a tensile elongation of 100% or more and 300% or less based on JIS K7113. The tensile elongation of the anchor coat agent layer can improve the tight adhesion between the base sheet and the reinforcing sheet. Therefore, the laminating strength and the like of the base sheet and the reinforcing sheet can be increased.

On the other hand, the adhesive layer in the present disclosure may be a layer containing an adhesive. Such an adhesive layer can be obtained, for example, by applying an adhesive composition containing an adhesive. The type of adhesive is not particularly limited, and examples thereof include polyether adhesives, polyester adhesives, polyurethane adhesives, vinyl adhesives, (meth)acrylic adhesives, polyamide adhesives, epoxy adhesives. Agents, rubber-based adhesives, and the like. The adhesive may be a one-component curing type or a two-component curing type.

(Iv) Reflective Sheet The reflective sheet may or may not have a light reflecting layer. When the light reflecting layer is provided, the visible light reflectance can be further increased. The light reflecting layer contains, for example, a white powder and a resin component. Examples of the white powder include anatase type or rutile type titanium oxide, titanium oxide whose surface is treated with a metal oxide such as Al and Si, calcium carbonate, barium sulfate and the like. Examples of the resin component include polyurethane resin and polyester resin. Examples of polyurethane resins include polyester polyurethane, polyether polyurethane, polyether polyester polyurethane, polycarbonate polyurethane, and polycaprolactam polyurethane. The location of the light reflecting layer is not particularly limited, and may be the outermost surface or the inside of the reflecting sheet. Moreover, it is preferable that the light reflection layer is provided on the opposite side of the reinforcing sheet with respect to the base sheet. The thickness of the light reflecting layer is, for example, 0.5 μm or more and 4 μm or less.

The reflective sheet preferably has a high visible light reflectance. The average reflectance of visible light (wavelength 380 nm or more and 780 nm or less) is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more. The total reflectance of the reflection sheet at a wavelength of 600 nm is, for example, 70% or more, 80% or more, or 90% or more.

The thickness of the reflection sheet is not particularly limited, but is, for example, 50 μm or more and 300 μm or less, and preferably 80 μm or more and 250 μm or less. If the thickness of the reflection sheet is too large, it becomes difficult to produce a folded structure. In particular, it becomes difficult to manufacture a folded structure by sewing. Further, if the thickness of the reflection sheet is too large, the operability may decrease. The moisture permeability of the reflection sheet may be, for example, 10 g/m ² ·day or more, and may be 20 g/m ² ·day or more.

2. Cultivation rack The cultivation rack in the present disclosure provides a first member on which a cultivation tank can be placed, a second member provided with a space for the first member, and a space for the first member. And a plurality of pillar members for fixing the positions of the first member and the second member, and a lighting member arranged on the first member side with respect to the second member. .. In addition, "the cultivation tank can be mounted" means that the first member can be mounted directly or through another member. Further, the first member does not necessarily have to be able to mount the cultivation tank alone. For example, the cultivation tank may be connected to a pillar member or the like, and the weight of the cultivation tank may be dispersed by the above connection so that the first member can be placed on the cultivation tank.

(1) First member, second member and pillar member The skeleton of the cultivation rack is formed by the first member, the second member and the plurality of pillar members. The materials of the first member, the second member, and the plurality of pillar members are not particularly limited, but examples thereof include metals such as stainless steel, iron, and aluminum. The first member and the second member may have a plate shape or a mesh shape, for example. Further, the plan-view shapes of the first member and the second member are not particularly limited, and examples thereof include a square and a rectangle. Examples of the cross-sectional shape of the pillar member include a circle, a square, and a rectangle. The number of the pillar members is preferably such that the first member and the second member can be stably fixed, and is, for example, 3 or more, 4 or more, or 8 or more. It is preferable that the first member and the second member are connected to the pillar member using a known connecting tool.

The shape of the cultivation tank placed on the first member is not particularly limited, and examples thereof include a pot shape, a bag shape, and a bed shape. Further, hydroponics (submerged hydroponics, NFT hydroponics) may be performed using a cultivation tank, or soil culture may be performed. Alternatively, a rock wool mat may be laid on the first member, and a rock wool pot may be placed on the mat to perform rock wool cultivation. Further, instead of rock wool, coco bag cultivation may be performed using coco peat, which is easy to dispose after use, as a medium.

(2) Illumination member The illumination member is arranged with a space provided with respect to the first member, and is arranged closer to the first member than the second member. The lighting member may be directly arranged on the surface of the second member, or may be arranged with a space provided for the second member via another member. Further, the lighting member may also have the function of the second member. In that case, the illumination member is arranged with a space provided with respect to the first member.

The lighting member has at least a light source. Examples of the light source include an LED and a fluorescent lamp, and among them, an LED is preferable. This is because the power consumption is low. The color of the light source is not particularly limited and is appropriately selected according to the plant to be cultivated. Further, it is preferable that the light source is arranged on the substrate directly or via another layer. A refrigerant pipe may be connected to the base body. This is because the heat generated from the light source can be removed. Examples of the material of the base include aluminum and copper. Examples of the refrigerant include ammonia and water.

Further, a reflector may be arranged between the light source and the base. This is because even if the light emitted from the light source is reflected by the surface of the culture medium in the cultivation tank and returns to the light source, the reflected light can be emitted to the plant again by providing the reflection plate.

Further, the number of light sources may be changed according to the growth of plants. This is because the amount of light required for plants differs depending on the growth stage. That is, it is preferable to reduce the amount of light in a plant that has a thick leaf and is close to the harvest time, in a case where the plant has a large amount of light, and a plant that has just emerged and has small leaves still has a small amount of light. By setting an appropriate amount of light in this way, the number of light sources can be reduced as a result, and the facility cost and the running cost can be reduced.

(3) Cultivation Rack The cultivation rack has a structure having a first member, a second member, a lighting member, and a plurality of pillar members. The cultivation rack may have one structure or a plurality of the structures. For example, the cultivation rack 10 in FIGS. 1 and 2 has a structure in which the structures 16 are stacked in four stages. When the cultivation rack has a plurality of structures, the second member may also have the function of the first member. For example, in FIG. 2, the second member 13 of the second structure 16 from the top has the lighting member 14 arranged on one surface side and the cultivation tank 11 placed on the other surface side. That is, the second member 13 also has the function of the first member 12.

The cultivation rack may be a fixed type or a movable type. Further, the cultivation rack may be a hanging type.

3. Plant cultivation device A plant cultivation device in the present disclosure includes at least the above-described cultivation rack and reflection sheet. The plant cultivation device may have a culture solution supply device that supplies the culture solution to the cultivation tank. As the culture solution supply device, for example, a storage section that stores the culture solution, a pipe section and a pump section that circulate the culture solution in the storage section, and a culture solution that is connected to each cultivation tank and supplies the culture solution in the piping section to the cultivation tank A device having a supply unit for In addition, the plant cultivation device further includes at least one of a CO ₂ supply device, a blower, an air purifier, a dehumidifier, a humidifier, a heater, and a cooler for increasing the CO ₂ concentration in the cultivation rack, if necessary. May be.

The use of the plant cultivation device is not particularly limited, but it is preferably used for artificial light type cultivation that does not use sunlight. Moreover, you may use a plant cultivation apparatus as a seedling raising apparatus. The plant cultivated by the plant cultivating device may be a long-day plant (a plant that responds to long days to regulate flower bud formation) or a short-day plant (a plant that responds to short days to regulate flower bud formation). It may be a neutral plant (a plant that does not react to the photoperiod). Specific examples include leaf vegetables, fruit vegetables, flowers and the like. Examples of the leaf vegetables include lettuce, bok choy, arugula, coriander, basil, celery, kale, perilla, ice plant, saffron, and the like. Examples of the fruit and vegetables include tomato, okra, squash, cucumber and the like.

B. Reflective sheet The reflective sheet in the present disclosure is used to be arranged on the side surface of the cultivation rack, and is a reflective sheet having visible light reflectivity, in the first region on the first side, the reflective sheet is cultivated as described above. Having a fixing portion for fixing to a rack, in a second region on the second side opposite to the first side, has a weight portion, the weight portion, the reflection sheet is along the second side. It has a folding structure folded along the first direction.

According to the present disclosure, since the reflection sheet has the specific weight portion, it is possible to prevent the reflection sheet from fluttering and curling or distorting in the reflection sheet when the reflection sheet is placed on the cultivation rack. The reflection sheet may be arranged on the side surface in the longitudinal direction of the cultivation rack or may be arranged on the side surface in the lateral direction of the cultivation rack, but the former is preferable. Further, since the details of the reflection sheet can be the same as those described in the above “A. Plant cultivation device 1. Reflection sheet”, the description thereof is omitted here.

Note that the present disclosure is not limited to the above embodiment. The above-described embodiment is an exemplification, has substantially the same configuration as the technical idea described in the claims of the present disclosure, and has any similar effects to the present invention. It is included in the technical scope in the disclosure.

[Example 1]
(Preparation of base material sheet)
100 parts by mass of linear low-density polyethylene (L-LDPE, melting point 125° C., MFR (190° C., 2160 g): 2.0 g/10 min) as a polyethylene resin, and 2(2′-hydroxy-5′) as an ultraviolet absorber. 0.1 parts by mass of -tert-octylphenyl)benzotriazole, NOR-type hindered amine light stabilizer (Adeka Stab LA-81 manufactured by ADEKA CORPORATION) (bis(1-undecaneoxy-2,2,6,6-tetramethylpiperidine) -4-yl)carbonate) 0.4 part by mass, as a phenolic antioxidant, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propinate] 0.1 part by mass, 20 parts by mass of calcium carbonate as an inorganic filler 1 (heavy calcium carbonate (PE masterbatch with a filling rate of 60%): PE content 8 parts by mass), 40 parts by mass of a titanium pigment as an inorganic filler 2 (filling ratio of 80%) PE masterbatch (content of PE: 8 parts by mass) was mixed and melt-kneaded at 180° C. using a Banbury mixer.

The total amount of the polyethylene-based resin contained in the obtained kneaded product was 116 parts by mass, and the content of the NOR-type hindered amine-based light stabilizer was 0.34% by mass with respect to the polyethylene-based resin. Further, the content of the inorganic fillers 1 and 2 is 51.7% by mass based on the polyethylene resin.

Next, the obtained kneaded product is supplied to a 12-inch diameter×30-liter common head type mixing roll (rotation speed: 18 rpm) and rolled at a roll temperature of 165° C. or higher and 190° C. or lower to obtain a base sheet having a thickness of 60 μm. (Polyethylene sheet) was obtained.

(Production of reflective sheet)
A base sheet and a reinforcing sheet were prepared. A polyethylene cloth made of polyethylene resin is prepared as a reinforcing sheet, and then a urethane-based anchor coating agent is coated on the base material sheet to form an anchor coating agent layer having a thickness of 0.5 g/m ² (dry state). Formed. Further, low density polyethylene (LDPE, MI=8.0, density=0.92) was melt-extruded (extrusion coating) with a thickness of 15 μm on the above anchor coat agent layer while performing ozone treatment, A reflection sheet was produced by bonding the reinforcing sheet. The molten resin temperature of LDPE was 320°C.

The obtained reflection sheet was subjected to visible light reflectance measurement, smoothness evaluation, and antifouling evaluation. In the visible light reflectance measurement, using an ultraviolet/visible/near-infrared spectrophotometer (Shimadzu UV-3600) and an integrating sphere accessory (ISR-3100), the incident angle was 8° and the visible region was 380 nm or more and 780 nm or less. The reflectance (total reflectance) was measured, and the average reflectance was calculated. As a standard plate, Spectralon (made by Teflon (registered trademark)) manufactured by Lovesphere, Inc. in the United States was used. The measurement surface was the surface of the base sheet of the reflection sheet. As a result, the visible light reflectance was 94%. Further, in the evaluation of antifouling property, the pollution grade was evaluated based on JIS-L-1919. As a result, the pollution grade was 3.0.

(Grommet processing)
One side of the obtained reflection sheet was diffracted twice with a width of 35 mm, sewing was performed with a sewing machine, and eyelets were formed as fixed portions at 40 cm intervals in the sewn portion. It should be noted that these eyelets are arranged so as to equally divide the area of the reflection sheet in the vertical direction when the reflection sheet is arranged on the side surface of the cultivation rack. On the other hand, the side opposite to the above-mentioned one side was similarly dipped twice in a width of 35 mm and sewn with a sewing machine to form a weight portion. As a result, a reflection sheet having a fixed portion and a weight portion was obtained.

[Example 2]
A reflective sheet was obtained in the same manner as in Example 1 except that a polypropylene sheet having a width of 25 mm and a thickness of 1 mm was placed inside when forming the weight portion.

[Evaluation]
The reflection sheet obtained in each of Examples 1 and 2 was placed on the side surface of the cultivation rack in the longitudinal direction, and a plant was cultivated for one month. As a result, it was confirmed that curling did not occur and a stable reflection function was maintained at a fixed position.

10... Cultivation rack 11... Cultivation tank 12... First member 13... Second member 14... Illumination member 15... Pillar member 16... Structure 17... Hook 18... Bar 20... Reflection sheet 21... Fixing part 22... Weight part 25... Base material sheet 26... Reinforcement sheet 27... Weight 100... Plant cultivation device

Claims (8)

A first member on which a cultivation tank can be placed, a second member provided with a space provided for the first member, a second member provided with a space provided for the first member, and the second member A lighting member arranged on the side of the first member rather than a member, and a cultivation rack having a structure having a plurality of pillar members for fixing the positions of the first member and the second member,
Arranged on the side surface in the longitudinal direction of the cultivation rack, a reflective sheet having visible light reflectivity,
Equipped with
The reflection sheet, in the first region on the first side, has a fixing portion for fixing the reflection sheet to the cultivation rack, and, facing the first side, below the first side. In the second region on the second side located on the side, has a weight portion,
The plant cultivation device, wherein the weight portion has a folding structure in which the reflection sheet is folded along a first direction intersecting the first side and the second side. The reflection sheet has a base sheet, and a reinforcing sheet located on one surface side of the base sheet,
The reflection sheet, the surface of the base material sheet side is located on the cultivation rack side, the surface of the reinforcing sheet side is arranged so as to be located on the opposite side to the cultivation rack,
The plant cultivating apparatus according to claim 1, wherein the folding structure is a structure in which the reflection sheet is folded such that the base sheet is on the outside of the structure and the reinforcing sheet is on the inside of the structure. The plant cultivation device according to claim 1 or 2, wherein in the folded structure, a first end portion along the first direction is sewn. The plant cultivation device according to any one of claims 1 to 3, wherein in the folded structure, a second end portion along a second direction intersecting the first direction is sewn. The plant cultivation device according to any one of claims 1 to 4, wherein the folding structure has a weight inside. The plant cultivation device according to any one of claims 1 to 5, wherein the fixing portion is an eyelet, a hook-and-loop fastener, or a magnet. The reflection sheet, in the first region, has a first region side folding structure in which the reflection sheet is folded along the first direction,
The plant cultivation device according to any one of claims 1 to 6, wherein the reflection sheet has the fixing portion at a position at least overlapping with the first region side folding structure. A reflective sheet used to be placed on the side surface of a cultivation rack and having visible light reflectivity,
In the first region on the first side, has a fixing portion for fixing the reflection sheet to the cultivation rack,
In a second region on the second side facing the first side, a weight portion is provided,
The reflection sheet, wherein the weight portion has a folding structure in which the reflection sheet is folded along a first direction intersecting the first side and the second side.