JP2011213038A - Cylindrical mold, optical reuse sheet and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical mold S for forming a sheet to condense light efficiently in a solar cell 30, a sheet molded by the mold S, and a solar cell module 200 using the sheet.SOLUTION: The mold S includes a cylindrical mold body S1 provided with a molding section having an irregular shape in the surface. The irregular shape formed in the molding section includes pleat portions P1 having two or more grooves extending in the axial direction and arranged along the circumference, and two or more belt-like grooves B1 extending in the direction of the circumference and arranged along the axial direction. The sheet is molded by using the mold S, to be used in the solar cell module 200.

Description

  The present invention relates to a cylindrical mold for transferring an uneven shape, a light reuse sheet having an uneven shape transferred to the surface of the cylindrical mold, and a solar cell module using the light reuse sheet. .

In recent years, the widespread use of solar cell modules has expanded greatly, from relatively small ones mounted on small electronic devices such as calculators to large areas used for solar cell modules installed in homes and large-scale power generation facilities The use of solar cell power generation systems and power supplies for artificial satellites has been promoted in various fields (see, for example, Patent Document 1).
In such a solar cell, the amount of power generation increases mainly in proportion to the area irradiated with light. Therefore, in order to improve the power generation efficiency, in addition to improving the manufacturing technology such as sealing technology and film forming technology, how to increase the aperture ratio of the solar cell module (the ratio of the area capable of power generation to the total area) Is an important issue.

In particular, a solar cell module using single crystal silicon or polycrystalline silicon has a problem that the cost of the silicon is high. Moreover, the cost for attaching it also costs.
In view of this, the amount of silicon that is a constituent member of a solar cell is small, and a thin-film silicon solar cell that can be formed by a technique such as CVD has been used.

However, the above-described one has a low light absorptivity because infrared light easily passes through thin-film silicon solar cells. Therefore, in order to increase the light utilization efficiency, it has been considered that the incident light is intentionally scattered to increase the light utilization efficiency by increasing the distance through which the thin film silicon solar cells are transmitted.
In general, there are two types of amorphous silicon solar cells (also referred to as amorphous Si solar cells). First, a transparent conductive film such as SnO ₂ or ITO is formed on a light-transmitting substrate such as glass, and an amorphous semiconductor (Si) p-layer, i-layer, and n-layer are stacked in this order. It is of the structure which is made. The other is an amorphous semiconductor (Si) n-layer, i-layer, and p-layer stacked in this order on a metal substrate electrode to form a photoelectric conversion active layer, and a transparent conductive film is further formed thereon. It has a laminated structure.

In particular, in the amorphous silicon solar cell having the former structure, a transparent insulating substrate can also serve as a solar cell surface cover glass in order to form amorphous semiconductors in the order of pin layers. Since a plasma-resistant transparent conductive film such as SnO ₂ has been developed, it has become possible to form an amorphous semiconductor photoelectric conversion active layer thereon by a plasma CVD method. .

For the formation of the amorphous semiconductor photoelectric conversion active layer, a plasma CVD method using glow discharge decomposition of a source gas or a vapor phase growth method using a photo CVD method can be used. There is also an advantage that it can be formed.
The amorphous Si solar cell can be formed at a relatively low temperature of about 100 ° C. to 200 ° C. For this reason, although substrates of various materials can be used as the substrate for forming the amorphous Si solar cell, glass substrates and stainless steel substrates are commonly used.

  In addition, since the film thickness of the silicon light absorption layer when the conversion efficiency for converting light into electricity is maximum is about 500 nm, the amorphous Si solar cell has a light absorption layer to improve the conversion efficiency. It is important to increase the amount of light absorption within the film thickness. Therefore, the optical path length of light in the light absorption layer is increased by forming a transparent conductive film with unevenness on the surface of the glass substrate or forming a metal film with unevenness on the surface of the stainless steel substrate. It has been performed conventionally.

  In the case of the solar cell in which the optical path length in the light absorption layer is increased by such a method, the light is compared with the case where the amorphous Si solar cell is formed on a flat substrate having no irregularities on the surface. The utilization efficiency of is significantly improved.

By the way, as a general method of forming irregularities on the surface of the glass substrate, there is a method of forming a SnO ₂ film which is a transparent electrode by an atmospheric pressure CVD method. In addition, as a method of forming irregularities on a metal substrate such as stainless steel, a method of adjusting the formation conditions when Ag is formed by a vapor deposition method or a sputtering method, or performing a heat treatment after the formation of Ag is used. It was done.

  This thin-film solar cell has a transparent conductive film, a hydrogenated amorphous silicon carbide (a-SiC H) p layer, a hydrogenated amorphous silicon (a-Si H) i layer, a hydrogenated amorphous silicon on a translucent insulating substrate. The (a-SiH) n layer, the transparent conductive film, and the back electrode are sequentially formed. Then, as described above, a concavo-convex shape is formed on the surface of the transparent conductive film, whereby each layer formed on the top has a concavo-convex structure.

Moreover, when forming semiconductor elements, such as a thin film solar cell, on a flexible substrate or a lightweight substrate, the polyimide resin with high heat resistance has been used. A method for forming irregularities in such a resin is disclosed in Patent Document 2 and the like.
Further, Patent Document 3 discloses a patent that retroreflects light by the periodic structure of the V-groove to increase the light utilization efficiency, and that the V-groove apex angle is desirably 50 to 90 degrees. There is a description. Further, there is a description that the pitch of the period of the V groove is preferably 10 μm to 20 μm.

  A crystalline solar cell module is configured by connecting small-sized cells with a plurality of electrodes. In the crystalline solar cell module, there is some space between adjacent cells. Moreover, in order to prevent the erosion of rainwater or the like at the end portion of the solar cell module, a blank portion where no cell is arranged is provided from several millimeters to several tens of millimeters.

  Since there are no cells in these gaps and blank portions, even if light is applied to these regions, power generation is not achieved and loss occurs. Conventionally, the following countermeasures have been proposed for such a loss of light that pours into the gaps and margins of the cells.

  For example, in a crystalline solar cell module, a reflection protection sheet disposed on the back surface is used as a light reflecting material, light is returned to the cell side again, is totally reflected by a glass plate as a front plate, and is re-applied to the light receiving surface of the cell. There are those that increase the efficiency by injecting light.

  Furthermore, there is a structure in which a concavo-convex structure is provided on the reflection protection sheet disposed on the back surface, the light reflected on the concavo-convex structure is easily scattered, and the probability of leading to the light receiving surface of the cell is improved to increase efficiency (Patent Document 1) And 2). In addition, there is a configuration in which light is scattered by forming irregularities on the reflection protection sheet on the back surface, and the efficiency is increased by using a cell in which both surfaces of the cell are light receiving surfaces (see Patent Document 3).

Various solar cell condensing systems are known in order to increase the efficiency by concentrating sunlight on expensive solar cells.
However, when a lens or the like is used as the light condensing system, there is a problem that installation on a roof of a house is difficult and the installation place is limited.
In view of this, a structure in which a large amount of light is incident on a cell in the same form as a normal solar cell module is known. The back material used in such a solar cell module can be produced by forming a concavo-convex shape on the surface of a cylindrical mold, and transferring the concavo-convex shape to a sheet and molding it.

Japanese Utility Model Publication No. 62-101247 JP-A-10-284747 Japanese Patent No. 3670835

  However, in the conventional technique, the cylindrical mold for producing the prism-like shape has only a mold having grooves in the circumferential direction, and a sheet that can sufficiently reuse light is produced. I can't. In order to sufficiently reuse light, it is preferable to enclose the prism reflection structure in a concentric rectangle around the element. However, at that time, when a cylindrical mold having the same circumference as the module size is produced, the size of the module is usually from 800 mm to 1600 mm, and the diameter of the roll for producing the film is 250 mm. To 500 mm. Similarly, since the roll length is from 800 mm to 1600 mm, the weight of the iron roll reaches 25 t. Further, when the film is cut, the gap between the film pattern and the cutting position is accumulated, so that the drawing position is shifted, and the original performance cannot be obtained.

  The present invention has been made in view of the above points, and is a cylindrical mold capable of forming a light reuse sheet that can be efficiently collected on a solar battery cell, and light formed by the mold. An object of the present invention is to provide a recycling sheet and a solar cell module using the light recycling sheet.

  In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention includes a cylindrical mold body having a concavo-convex shape formed on a surface thereof, and the groove extending in the axial direction is a circle as the concavo-convex shape. Provided is a cylindrical mold characterized by having a plurality of pleats formed along the circumferential direction and a strip-shaped groove formed with a plurality of grooves extending in the circumferential direction along the axial direction. is there.

  Next, the invention described in claim 2 is the configuration described in claim 1, wherein the formation position of the belt-like groove portion is smaller than the formation position of the pleat portion, and the belt-like groove portion and the pleat portion are formed. In the meantime, it has an inclined part whose diameter changes stepwise or continuously from the belt-like groove part to the pleat part.

Next, in the invention described in claim 3, in the configuration described in claim 2, a plurality of grooves extending in the circumferential direction with respect to the inclined portion are formed in the axial direction, and the groove is interposed between the inclined portion and the pleated portion. The groove extending in the axial direction and the groove extending in the circumferential direction have an intersection formed by intersecting.
Next, the invention described in claim 4 is the configuration described in claim 3, wherein the plurality of grooves formed in the inclined portion include a step Tg at the apex of adjacent grooves and an axial distance Tp between the apexes. The ratio (Tg / Tp) satisfies the following formula.

          1/300 ≦ (Tg / Tp) ≦ 1/3

  Next, the invention described in claim 5 is laminated on the structure layer molded using the cylindrical mold according to any one of claims 1 to 4 and the uneven surface of the structure layer. A light reuse sheet comprising a reflective layer is provided.

  Next, the invention described in claim 6 is laminated on the structure layer formed by using the cylindrical mold according to any one of claims 1 to 4 and the uneven surface of the structure layer. A light reuse sheet comprising a reflective layer and a protective layer laminated on the reflective layer via an adhesive / adhesive layer is provided.

Next, the invention described in claim 7 is a pleated portion in which a plurality of grooves extending in the axial direction are formed along the circumferential direction and a plurality of grooves extending in the circumferential direction are formed along the axial direction on the surface. And a light reuse sheet characterized by having a belt-like groove portion.
Next, the invention described in claim 8 is a solar battery module in which the light reuse sheet described in any one of claims 5 to 7 is disposed on the back side of the solar battery cell. It is to provide.

  According to the mold of the present invention, the occurrence of scratches during storage is suppressed, and the sheet-like member molded by the present mold is suppressed from shifting at the film end when stored in a roll shape. In addition, scratches are prevented when a metal reflective layer is formed on the molded film. By disposing the light regeneration sheet molded by the mold or the like on the back surface of the solar battery cell, it is possible to reuse the light not incident on the solar battery cell and increase the power generation amount of the solar battery cell.

That is, it is possible to provide a solar cell module capable of obtaining a large amount of power generation with a small number of solar cells by efficiently concentrating light incident on the solar cell module on the solar cells.
In addition, by using the light reuse sheet and reusing light from a light emitting element such as an LED or an EL element, the light utilization efficiency can be improved and a light emitting element with high light emission efficiency can be provided.

It is a perspective view which shows an example of the metal mold | die which concerns on embodiment based on this invention. It is a perspective view which shows the storage method of the metal mold | die which concerns on embodiment based on this invention. It is sectional drawing which shows an example of the metal mold | die which concerns on embodiment based on this invention. It is a figure explaining shaping | molding of the light reuse sheet | seat (sheet-like member) using the metal mold | die which concerns on embodiment based on this invention. It is sectional drawing which shows an example of the light reuse sheet | seat which concerns on embodiment based on this invention. It is sectional drawing which shows an example which bonded the light reuse sheet | seat which concerns on embodiment based on this invention. It is a perspective view which shows the uneven | corrugated shape of the metal mold | die which concerns on embodiment based on this invention. It is sectional drawing which shows the solar cell module which concerns on embodiment based on this invention. It is a layout at the time of arrange | positioning a photovoltaic cell to the light reuse sheet | seat which concerns on embodiment based on this invention. It is sectional drawing which shows the structure of the solar cell module which concerns on embodiment based on this invention, Comprising: It is a figure of the solar cell module using the light reuse sheet | seat with a reflective surface which has a strip | belt-shaped groove part and the adjacent inclination part. It is a graph which shows the change of the relative incident light quantity to the photovoltaic cell in the solar cell module shown in FIG. It is a figure of the solar cell module using the light reuse sheet | seat with a reflective surface which has a substantially saw-shaped inclination part. It is a figure of the solar cell module using the light reuse sheet | seat with a reflective surface which has a belt-shaped groove part with a hollow. It is sectional drawing which shows an example of a light reuse sheet | seat. It is sectional drawing which shows an example of a light reuse sheet | seat. It is sectional drawing which shows an example in a solar cell module. It is sectional drawing which shows an example of a light reuse sheet | seat. It is sectional drawing of the example which applied the light reproduction sheet | seat with respect to the light emitting element.

Next, embodiments of the present invention will be described with reference to the drawings.
First, the roll metal mold | die which comprises the cylindrical metal mold | die which concerns on this invention is demonstrated using FIG.

(Mold configuration)
The roll mold S of the present embodiment includes a mold body S1 formed of a cylindrical body, and a shaft portion S3 for attaching to a molding apparatus. Of the surface of the mold main body S1, a portion excluding the left and right end portions is a molding portion. As will be described later, an uneven shape as a mold is formed in the molding portion. The shaft portion S3 protrudes coaxially with the mold body S1 from both end faces of the mold body S1.

In the mold S, iron, stainless steel, aluminum, aluminum alloy, or the like can be used as the core material, and further, copper or nickel formed thereon by plating or the like can be used.
The uneven shape formed on the surface of the mold body S1 can be formed by plating copper or nickel on the base metal to form a cutting base layer and cutting the base layer. Further, chrome plating can be applied after the cutting in order to improve the scratch resistance and the release property.

The concavo-convex shape includes a pleat portion P1 in which a plurality of grooves extending in the axial direction are formed along the circumferential direction, and a strip-shaped groove portion B1 in which a plurality of grooves extending in the circumferential direction are formed along the axial direction. The pleat portions P1 and the strip-shaped groove portions B1 are alternately formed along the axial direction of the mold body S1.
Here, in this embodiment, the groove portion is formed with a V-groove periodic structure so that the groove to be transferred has a prism shape, and the V-groove apex angle is preferably 50 degrees or more and 90 degrees or less.

Further, as shown in FIG. 3, the diameter of the formation position of the belt-like groove B1 is smaller than the diameter of the formation position of the pleat portion P1.
As shown in FIG. 3, there is an inclined portion T1 whose diameter changes stepwise or continuously from the strip groove portion B1 toward the pleat portion P1 between the strip groove portion B1 and the pleat portion P1.
As shown in FIG. 7, a plurality of grooves extending in the circumferential direction may be formed along the axial direction with respect to the inclined portion T1.

  Furthermore, as shown in FIG. 7, it is preferable to form an intersecting portion X1 formed by intersecting a plurality of axial grooves and a plurality of circumferential grooves between the inclined portion T1 and the pleat portion P1. As shown in FIG. 7, for example, as shown in FIG. 7, the grooves provided in the intersection portion X1 are formed with a plurality of grooves extending in the circumferential direction as grooves of the pleat portions P1 along the axial direction. It is provided by forming an axial groove so as to extend in the direction.

In the plurality of grooves formed in the inclined portion T1, it is preferable that the ratio (Tg / Tp) between the step Tg at the apex of the adjacent grooves and the axial distance Tp between the apexes satisfies the following formula.
1/300 ≦ (Tg / Tp) ≦ 1/3

  The sheet-like member 60 to which the concavo-convex shape is transferred is molded using the mold S in which the concavo-convex shape as described above is formed. For example, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or the like is applied or injected onto the concave and convex shape of the mold S, and a base material is disposed thereon. By releasing the mold, a sheet-like member 60 having a concavo-convex shape can be formed as shown in FIG. In the present specification, the sheet shape includes a film shape and a plate shape. FIG. 4 is a diagram in which the inclined portion T1 is omitted.

  Alternatively, by using the roll mold S for at least one of the pair of rolls, and pressing the sheet-like molten resin extruded from the T die with the pair of rolls, the sheet-like member 60 having the uneven shape is formed. It may be molded.

(Mold functions and others)
Since the mold S is normally used a plurality of times, there is a storage period between the use period and the use period. During storage, a cover C0 such as a soft wrapping material is wound on the mold S as shown in FIG. 2 so as not to damage the uneven shape on the surface of the mold S during this storage period. Further, as shown in FIG. 2, the rack 500 is hung with the shaft portion S <b> 3 so as to be horizontally mounted, and stored so that no load is applied to the uneven shape.

Further, when the mold S is moved, the mold S is moved so as to roll on the rack 500. During this movement, the cover C0 is easily slipped in the circumferential direction on the mold S, and the top of the groove formed in the mold S and the cover C0 are in sliding contact, so that the top of the groove is likely to be damaged.
In order to prevent this, in the present embodiment, the pleated portion P1 is formed on the surface of the mold S, so that an axial groove is formed and the cover C0 is prevented from slipping in the circumferential direction.

  Here, when the pitch of the groove of the pleat portion P1 is smaller than 10 μm, the pressure applied to the top portion of the groove of the pleat portion P1 is dispersed too much, and the cover C0 may slide in the circumferential direction. On the other hand, when the pitch of the groove of the pleat portion P1 is larger than 200 μm, too much pressure is applied to the top portion of the groove of the pleat portion P1, and the top portion of the groove may be damaged. From the above, the groove pitch of the pleat portion P1 is preferably 10 μm or more and 200 μm or less.

  Further, the pleat portion P1 described above can prevent the cover C0 from sliding in the circumferential direction, but cannot prevent the cover C0 from shifting in the axial direction. In rare cases, the cover C0 may be displaced in the axial direction. In contrast, in the present embodiment, this is dealt with by providing the belt-like groove B1. That is, since the cover C0 is caught at the boundary between the pleat portion P1 and the belt-like groove portion B1, it is possible to suppress the cover C0 from sliding in the axial direction.

  The ratio of the width of the belt-like groove B1 and the width of the pleat P1 is preferably in the range of 1: 9 to 5: 5. If the ratio of the width of the belt-like groove B1 is smaller than 1: 9, the axial slip may not be prevented. On the other hand, if it is larger than 5: 5, there is a possibility that slip in the circumferential direction cannot be sufficiently prevented. Moreover, it is preferable that this strip-shaped groove part B1 is 10 micrometers or more and 200 micrometers or less recessed from the pleat part P1, that is, it becomes a small diameter and is offset in radial direction. If the dent is smaller than 10 μm, the cover C0 is not easily caught and the cover C0 may slip. On the other hand, if it is larger than 200 μm, the molding material is clogged in the molding process described later, which is not preferable.

  In addition, as a diameter of the metal mold | die S, 100 mm or more and 500 mm or less are preferable. When it is smaller than 100 mm, the roll is bent in the molding process of the sheet, and the molding rate differs between the center and the end of the sheet-like member 60 to be molded. On the other hand, if the roll is larger than 500 mm, the roll is too heavy, and when the roll is rotated, unevenness may occur when cutting the mold S due to uneven rotation.

(Relationship with sheet-like members such as film to be molded)
As described above, by using the above-described mold S as shown in FIG. 4, an ultraviolet curable resin or a thermosetting resin can be molded into a sheet shape. Since the concavo-convex shape of the sheet-like member 60 such as a molded film is opposite to the concavo-convex shape of the mold S, the concave belt-like groove B1 in the mold S is a convex belt-like shape in the sheet-like member 60. It becomes groove part B2. The sheet-like member 60 shown in FIG. 4 has a structure in which the structural layer 3 is laminated on a transparent substrate.

  The molded sheet-like member 60 can be made into a form suitable for transportation or the like by making it into a take-up roll shape. When the molded sheet-like member 60 is rolled, the belt-like groove B2 of the sheet-like member 60 becomes a convex groove extending in a direction intersecting with the width direction of the sheet-like member 60. Therefore, the sheet-like member 60 Prevents sliding in the width direction. Thereby, it is possible to prevent the form of the roll around which the sheet-like member 60 is wound from collapsing during transportation.

  In order to prevent the shape of the roll from collapsing during transportation or the like, the step between the pleat portion P2 transferred to the sheet-like member 60 and the belt-like groove portion B2 is preferably 5 μm or more and 100 μm or less. If it is smaller than 5 μm, it may not be possible to prevent slipping sufficiently. On the other hand, if it is larger than 100 μm, slipping can be prevented, but distortion may occur when the film is wound, and there is a possibility that it cannot be wound well.

Furthermore, as shown in FIG. 5, the reflective layer 4 may be formed by vapor-depositing a metal on the sheet-like member 60 formed with the uneven shape. FIG. 5A shows an example in which no groove is formed in the inclined portion T2, and FIG. 5B shows an example in which a groove is formed in the inclined portion T2 and an intersecting portion X2 is provided.
Although the reflective layer 4 is very easily damaged, the reflective surface can be protected by sealing with another base material (protective layer 6) with an adhesive / adhesive layer 5 as shown in FIG. . If the depth of the groove is larger than 30 μm at this time, the sticky / adhesive constituting the sticky / adhesive layer 5 does not enter the groove well and causes floating.

  Further, as shown in FIG. 6, there is a possibility that floating occurs between the adhesive / adhesive material and the reflective layer 4 at the boundary between the pleat portion P <b> 2 and the strip-shaped groove portion B <b> 2. In order to prevent this, it is preferable to form an inclined portion T2 at the boundary between the pleat portion P2 and the strip-like groove portion B2, and further to provide a groove portion in the inclined portion T2. Each groove formed in the inclined portion T2 is a plurality of grooves extending in the circumferential direction having different heights.

This inclination of the inclined portion T2 is not preferable because the ratio of the step difference Tg between the vertices of adjacent grooves and the distance Tp between the vertices is larger than 1/3, which causes floating. If it is smaller than 1/300, it is not preferable because the depth of the groove tends to vary. For this reason, in the plurality of grooves formed in the inclined portion T1, it is preferable that the ratio (Tg / Tp) between the step Tg at the apex of the adjacent grooves and the axial distance Tp between the apexes satisfies the following formula.
1/300 ≦ (Tg / Tp) ≦ 1/3

  Further, by providing the mold S with the intersecting portion X1 as shown in FIG. 7 between the inclined portion T1 and the pleat portion P1, the sheet-like member 60 is further improved in sticking of the adhesive / adhesive material, and the adhesion force. Therefore, it is more preferable to provide a cross-shaped groove.

(About light reuse sheet)
The sheet-like member 60 constitutes the light reuse sheet 20.

Further, the reflective layer 4 may be laminated on the uneven surface of such a sheet-like member 60.
Further, a protective layer may be laminated on the reflective layer 4 via an adhesive / adhesive layer.
The light reuse sheet 20 of FIG. 8 includes a transparent base material, a structural layer composed of a sheet-like member 60 molded using the cylindrical mold S, a reflective layer 4, an adhesive / adhesive layer, and a protective layer. This is an example in which layers are sequentially stacked.

FIG. 8 shows an example of a cross-sectional view of the solar cell module 200.
As shown in FIG. 8, by disposing the light reuse sheet 20 on the back surface (opposite side of the light source) of the solar battery cell 30, the light that does not enter the solar battery cell 30 is reused by the solar battery cell 30. Is possible. That is, by arranging the light reuse sheet 20 on the back surface of the solar battery cell 30, the light incident on the periphery of the solar battery cell 30 can be incident again in the direction of the solar battery cell 30. The power generation amount of 30 can be increased.

In FIG. 8, L is a light source, 22 is a front plate, and 21 is a filling layer.
Here, when such a light reuse sheet 20 is disposed on the back surface of the solar battery cell 30 and light that does not enter the solar battery cell 30 is reused by the solar battery cell 30, as shown in FIG. It is necessary to match the position of the groove of the sheet-like member 60 with the position of the solar battery cell 30. At this time, the groove is continuously formed in the longitudinal direction of the sheet-like member 60, so that alignment is not necessary, but alignment is necessary in the width direction.

  At this time, as shown in FIG. 9A, it is preferable that the cells are connected in advance so that the distance between the cells is constant, and the wiring is arranged in the width direction of the sheet-like member 60. In this case, as shown in FIG. 9B, even if the longitudinal direction of the sheet-like member 60 is shifted, it is possible to prevent the solar battery cell 30 from shifting in the width direction. In addition, the position of the cell is easy to shift in the direction orthogonal to the wiring 32, but since the groove is continuously arranged in that direction, the groove always surrounds the periphery of the cell to suppress the shift. Can do.

Here, the pitch of the plurality of grooves of the pleat portion P2 of the sheet-like member 60 and the strip-like groove portion B2 is preferably 1 μm or more. A pitch smaller than 1 μm is not preferable because the reflection surface appears rainbow-colored due to diffraction and the appearance is impaired.
Further, since the belt-like groove B2 has the inclined part T2 in which the groove is formed, not only the bottom part of the groove but also the light of the inclined part T2 can be used effectively, so that the light can be used more effectively.

Furthermore, with reference to FIG. 10, the effect of the inclined part T2 adjacent to the strip-shaped groove part B2 will be described.
The inclined portion T2 has a surface that rises to the right or rises to the left, but as a whole, is inclined in one direction and is in contact with the strip-shaped groove portion B2. For this reason, part of the light H2 reflected by the inclined portion T2 becomes light H4 that becomes a loss, but part of the light H2 is reflected by the incident surface 110 of the solar cell module 200 and enters the solar battery cell 30. It becomes light H3. For this reason, as compared with the case of only the strip-shaped groove B1, only the solar battery cell 30 can receive more light by having the inclined portion T2.

Data when the inclined portion T2 is provided is shown in FIG.
As can be seen from FIG. 11, the light incident on the solar battery cell 30 can be increased up to 2.6 times by setting the width of the inclined portion T2 to 5 mm. Furthermore, when the width of the inclined portion T2 is 10 mm, the light incident on the solar battery cell 30 can be increased up to 3.2 times.

As described above, by providing the strip-shaped groove B <b> 2 as the uneven shape and further providing the inclined portion T <b> 2 as described above, more light can be incident on the solar cells 30.
The inclined portion T2 has a saw-like shape as shown in FIG.
Further, the belt-like groove B2 may have a recess B12 as shown in FIG.
As shown in FIG. 14, the light reuse sheet 20 having the uneven shape described above can be composed of the reflective layer 4, the structural layer 3, and the base material 2.

As a method for forming the concavo-convex shape on the structure layer 3, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or the like is applied or injected onto the surface of the mold reflecting surface 100 on which the concavo-convex shape is formed. The method of arrange | positioning the base material 2 and releasing from the metal mold | die S after a hardening process is mentioned.
Further, as a method for producing the light reuse sheet 20 made of only the structural layer 3 without using the base material 2 as shown in FIG. And a method of integrally molding with. According to the above-described method, the uneven shape can be formed simultaneously with the sheet formation.

As a mold for forming the reflective surface 100, a mold produced by mechanical cutting can be used. At this time, the tip of the concavo-convex shape is preferably rounded to prevent the shape from being scratched.
Furthermore, the thickness of the structural layer 3 is not particularly limited, but is, for example, 3 μm or more and 500 μm or less.
The above-described production method may be appropriately selected depending on suitability for the following materials.

(About sheet materials and others)
In the polymer composition forming the structural layer 3, in addition to the polymer composition, for example, a scattering reflector, a curing agent, a plasticizer, a dispersant, various leveling agents, an ultraviolet absorber, an antioxidant, a viscosity modifier, A lubricant, a light stabilizer and the like may be appropriately blended.

  The above-mentioned polymer composition is not particularly limited. For example, poly (meth) acrylic resin, polyurethane resin, fluorine resin, silicone resin, polyimide resin, epoxy resin, polyethylene resin, Polystyrene resins such as polypropylene resin, methacrylic resin, polymethylpentene resin, cyclic polyolefin resin, acrylonitrile- (poly) styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin). Polyvinyl chloride resin, polycarbonate resin, polyester resin, polyamide resin, polyamideimide resin, polyaryl phthalate resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyethylene naphtha Over preparative resin, polyether imide resin, acetal resin, cellulose resin and the like, can be used as a mixture of these polymers alone or in combination.

  Examples of the polyol that is a raw material for the polyurethane resin include a polyol obtained by polymerizing a monomer component containing a hydroxyl group-containing unsaturated monomer, a polyester polyol obtained under conditions of excess hydroxyl group, and the like. These can be used alone or in admixture of two or more.

  Examples of the hydroxyl group-containing unsaturated monomer include (a) 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, allyl alcohol, homoallyl alcohol, Keihi Hydroxyl-containing unsaturated monomers such as alcohol and crotonyl alcohol, (b) for example, ethylene glycol, ethylene oxide, propylene glycol, propylene oxide, butylene glycol, butylene oxide, 1,4-bis (hydroxymethyl) cyclohexane, phenylglycidyl Dihydric alcohols or epoxy compounds such as ether, glycidyl decanoate, Plaxel FM-1 (manufactured by Daicel Chemical Industries, Ltd.) and, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, Tonsan, and the like hydroxyl group-containing unsaturated monomers obtained by reaction of an unsaturated carboxylic acid such as itaconic acid. One or more selected from these hydroxyl group-containing unsaturated monomers can be polymerized to produce a polyol.

  The polyols described above are ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, ethyl hexyl acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, N-butyl methacrylate, tert-butyl methacrylate, ethyl hexyl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, styrene, vinyl toluene, 1-methylstyrene, acrylic acid, methacrylic acid, acrylonitrile, vinyl acetate, vinyl propionate, stearin Vinyl acid, allyl acetate, diallyl adipate, diallyl itaconate, diethyl maleate, vinyl chloride, vinylidene chloride, acrylamide, N-methylol acrylamide, N-butyl One or more ethylenically unsaturated monomers selected from xymethyl acrylamide, diacetone acrylamide, ethylene, propylene, isoprene and the like, and a hydroxyl group-containing non-functional group selected from the above (a) and (b) It can also be produced by polymerizing a saturated monomer.

The number average molecular weight of a polyol obtained by polymerizing a monomer component containing a hydroxyl group-containing unsaturated monomer is from 1,000 to 500,000, preferably from 5,000 to 100,000. The hydroxyl value is 5 or more and 300 or less, preferably 10 or more and 200 or less, more preferably 20 or more and 150 or less.
The polyester polyol obtained under the condition of excess hydroxyl group is (c), for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl. Glycol, hexamethylene glycol, decamethylene glycol, 2,2,4-trimethyl-1,3-pentanediol, trimethylolpropane, hexanetriol, glycerin, pentaerythritol, cyclohexanediol, hydrogenated bisphenol A, bis (hydroxymethyl) Polyhydric alcohols such as cyclohexane, hydroquinone bis (hydroxyethyl ether), tris (hydroxyethyl) isosinurate, xylylene glycol, and (d) maleic acid, for example. Polybasic acids such as fumaric acid, succinic acid, adipic acid, sebacic acid, azelaic acid, trimetic acid, terephthalic acid, phthalic acid, isophthalic acid, and other polyvalent acids such as propanediol, hexanediol, polyethylene glycol, and trimethylolpropane It can be produced by reacting under conditions where the number of hydroxyl groups in the alcohol is greater than the number of carboxyl groups in the polybasic acid.

  The number average molecular weight of the polyester polyol obtained under the above hydroxyl group-excess conditions is 500 or more and 300,000 or less, preferably 2000 or more and 100,000 or less. The hydroxyl value is 5 or more and 300 or less, preferably 10 or more and 200 or less, more preferably 20 or more and 150 or less.

  The polyol used as the polymer material of the polymer composition is obtained by polymerizing the above-described polyester polyol and a monomer component containing the above-mentioned hydroxyl group-containing unsaturated monomer, and is a (meth) acryl unit. Etc. are preferred. If such polyester polyol or acrylic polyol is used as a polymer material, the weather resistance is high, and yellowing of the structural layer 3 can be suppressed. In addition, any one of this polyester polyol and acrylic polyol may be used, and both may be used.

  The number of hydroxyl groups in the above-described polyester polyol and acrylic polyol is not particularly limited as long as it is 2 or more per molecule, but if the hydroxyl value in the solid content is 10 or less, the number of crosslinking points decreases, and the solvent resistance Film properties such as heat resistance, water resistance, heat resistance and surface hardness tend to decrease.

A scattering reflector may be contained in the polymer composition forming the structural layer 3 in order to improve reflection performance and heat resistance performance. By including a scattering reflector in the polymer composition, the heat resistance of the structural layer 3 and thus the light reuse sheet 20 can be improved, and if the refractive index is significantly different from that of the polymer composition, light can be emitted. Can be reflected. In addition, when sufficient reflectivity is obtained by this, the metal reflective layer 4 does not need to be provided as shown in FIGS. The inorganic material constituting the scattering reflector agent is not particularly limited, and an inorganic oxide is preferable. As the inorganic oxide, silica or the like can be used, but a metal compound such as ZnS can also be used, but metal oxides such as TiO ₂ , ZrO, and Al ₂ O ₃ are particularly desirable. Silica hollow particles can also be used. Of these, TiO ₂ is preferable because of its high refractive index and easy dispersibility. The shape of the scattering reflector may be any particle shape such as a spherical shape, a needle shape, a plate shape, a scale shape, and a crushed shape, and is not particularly limited.

  The lower limit of the average particle diameter of the scattering reflector is preferably 0.1 μm, and the upper limit is preferably 30 μm. If the average particle diameter is smaller than 0.1 μm, light is not sufficiently reflected. Further, if the average particle size is larger than 30 μm, the moldability is poor.

  The lower limit of the amount of the scattering reflector to 100 parts of the polymer composition is preferably 30 parts in terms of solid content. On the other hand, the upper limit of the amount of the scattering reflector described above is preferably 100 parts. This is because when the amount of the inorganic filler is less than 30 parts, the light H1 incident on the structural layer 3 from the filler layer 21 cannot be sufficiently reflected. On the contrary, if the blending amount exceeds the above range, the moldability is poor.

  As the above-mentioned scattering reflector, one having an organic polymer fixed on its surface may be used. Thus, by using the scattering reflector fixed to the organic polymer, the dispersibility in the polymer composition and the affinity with the polymer composition can be improved. The organic polymer is not particularly limited with respect to its molecular weight, shape, composition, presence or absence of a functional group, and any organic polymer can be used. Moreover, about the shape of an organic polymer, the thing of arbitrary shapes, such as a linear form, a branched form, and a crosslinked structure, can be used.

  Specific resins constituting the above-mentioned organic polymer include, for example, (meth) acrylic resin, polystyrene, polyvinyl acetate, polyolefin such as polyethylene and polypropylene, polyester such as polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, and the like. And a resin partially modified with a functional group such as an amino group, an epoxy group, a hydroxyl group, or a carboxyl group. Among them, those having an organic polymer containing a (meth) acryl unit such as a (meth) acrylic resin, a (meth) acrylic-styrene resin, and a (meth) acrylic-polyester resin have a film forming ability. Is preferred. On the other hand, a resin having compatibility with the above-described polymer composition is preferable, and therefore, a resin having the same composition as the polymer composition is most preferable.

  As the above-mentioned polymer composition, a polyol having a cycloalkyl group is preferable. By introducing a cycloalkyl group into the polyol as the polymer composition, the polymer composition becomes highly hydrophobic, such as water repellency and water resistance, and the structural layer 3 and thus the light reuse sheet 20 under high temperature and high humidity conditions. The bending resistance, dimensional stability, etc. are improved. In addition, the basic properties of the coating layer such as weather resistance, hardness, feeling of holding, and solvent resistance of the structural layer 3 are improved. Furthermore, the affinity with the scattering reflector having the organic polymer fixed on the surface and the dispersibility of the scattering reflector are further improved.

  Moreover, it is good to contain isocyanate as a hardening | curing agent in a polymer composition. Thus, by containing an isocyanate hardening | curing agent in a polymer composition, it becomes a much stronger crosslinked structure and the film physical property of the structural layer 3 further improves. As this isocyanate, the same substance as the above-mentioned polyfunctional isocyanate compound is used. Of these, aliphatic isocyanates that prevent yellowing of the coating are preferred.

The scattering reflector may contain an organic polymer inside. Thereby, moderate softness and toughness can be imparted to the inorganic material that is the core of the scattering reflector.
As the above-mentioned organic polymer, one containing an alkoxy group may be used, and the content thereof is not particularly limited, but is preferably 0.01 mmol or more and 50 mmol or less per 1 g of the scattering reflector. The alkoxy group can improve the affinity with the polymer composition and the dispersibility in the polymer composition.

  The above-described alkoxy group represents an RO group bonded to a metal element that forms a fine particle skeleton. R is an alkyl group which may be substituted, and the RO groups in the fine particles may be the same or different. Specific examples of R include methyl, ethyl, n-propyl, isopropyl, n-butyl and the like. The same metal alkoxy group as the metal constituting the scattering reflector is preferably used. When the scattering reflector is colloidal silica, it is preferable to use an alkoxy group having silicon as a metal.

The organic polymer content of the scattering reflector to which the organic polymer is fixed is not particularly limited, but is preferably 0.5% by mass or more and 50% by mass or less based on the scattering reflector.
When the reflective layer 4 is used in the light reuse sheet 20, surface treatment may be performed on the deposition target surface of the reflective layer 4 (the surface of the structural layer 3) in order to improve the tight adhesion and the like (not shown). ). Examples of such surface treatment include (a) corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, and (b) primer. Examples of the coating treatment include undercoating, anchor coating, vapor deposition anchor coating, and the like. Among these surface treatments, a corona discharge treatment and an anchor coat treatment that improve adhesion strength with the reflective layer 4 and contribute to the formation of a dense and uniform reflective layer 4 are preferable.

  Examples of the anchor coating agent used in the above-described anchor coating treatment include a polyester anchor coating agent, a polyamide anchor coating agent, a polyurethane anchor coating agent, an epoxy anchor coating agent, a phenol anchor coating agent, and a (meth) acrylic anchor. Examples thereof include a coating agent, a polyvinyl acetate anchor coating agent, a polyolefin anchor coating agent such as polyethylene aly polypropylene, and a cellulose anchor coating agent. Among these anchor coating agents, polyester anchor coating agents that can further improve the adhesive strength of the reflective layer 4 are particularly preferable.

The coating amount (in terms of solid content) of the above-described anchor coating agent is preferably 1 g / m ² or more and 3 g / m ² or less. When the coating amount of the anchor coating agent is less than 1 g / m ^{2, the} effect of improving the adhesion of the reflective layer 4 becomes small. On the other hand, when the coating amount of the anchor coating agent is more than 3 g / m ² , the strength, durability, etc. of the light reuse sheet 20 may be lowered.

  In the above-mentioned anchor coating agent, various additives such as a silane coupling agent for improving tight adhesion, an anti-blocking agent for preventing blocking, and an ultraviolet absorber for improving weather resistance, etc. It can mix suitably. The amount of the additive to be mixed is preferably 0.1% by weight or more and 10% by weight or less from the balance between the effect expression of the additive and the function inhibition of the anchor coating agent. If the above-mentioned additive is less than 0.1% by weight, blocking cannot be sufficiently prevented and sufficient weather resistance cannot be obtained, and if it is more than 10% by weight, the function of the topcoat agent is inhibited.

  The reflective layer 4 reflects light incident on the light reuse sheet 20. When the reflective layer 4 is formed, the reflective layer 4 is formed by vapor-depositing a metal along the surface on which the uneven shape of the structural layer 3 is formed. The means for depositing the reflective layer 4 is not particularly limited as long as a metal can be deposited without causing deterioration of the structural layer 3 such as shrinkage and yellowing. (A) Vacuum deposition method, sputtering method, ion plate Chemical vapor deposition methods (Physical Vapor Deposition method; PVD method), (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method, photochemical vapor deposition method, etc. A phase growth method (Chemical Vapor Deposition method; CVD method) is employed. Among these vapor deposition methods, a vacuum vapor deposition method and an ion plating method that can form a high-quality reflective layer 4 with high productivity are preferable.

  The metal used for the reflective layer 4 is not particularly limited as long as it has a metallic luster and can be deposited. For example, aluminum (Al), silver (Ag), gold (Au), nickel (Ni) , Tin (Sn), zirconium (Zr) and the like. Among these, aluminum (Al), which has high reflectivity and allows the dense reflective layer 4 to be formed relatively easily, is preferable.

  The reflective layer 4 may have a single layer structure or a multilayer structure of two or more layers. Thus, by making the reflective layer 4 into a multi-layer structure, the deterioration of the structural layer 3 is reduced by reducing the thermal burden during vapor deposition, and the adhesion between the structural layer 3 and the reflective layer 4 is further improved. Can do. At this time, a metal oxide layer may be provided on the metal film. The vapor deposition conditions in the physical vapor deposition method and the chemical vapor deposition method are appropriately designed according to the resin type of the structural layer 3 and the base material 2, the thickness of the reflective layer 4, and the like.

  As a minimum of the thickness of the reflection layer 4, 10 nm is preferable and 20 nm is especially preferable. On the other hand, the upper limit of the thickness of the reflective layer 4 is preferably 200 nm, and particularly preferably 100 nm. If the thickness of the reflective layer 4 is less than 10 nm, the light incident on the reflective layer 4 from the filling layer 21 cannot be sufficiently reflected. Further, even if the thickness is 20 nm or more, the light reflected by the reflection layer 4 does not increase. On the other hand, if the thickness of the reflective layer 4 exceeds the upper limit of 200 nm, cracks that can be visually confirmed occur in the reflective layer 4, and cracks that cannot be visually confirmed occur if the thickness is 100 nm or less.

  Further, the outer surface of the reflective layer 4 is preferably subjected to a top coat treatment (not shown). By performing the top coat treatment on the outer surface of the reflective layer 4 in this manner, the reflective layer 4 is sealed and protected, and as a result, the handleability of the light reuse sheet 20 is improved. Moreover, the aged deterioration of the reflective layer 4 is also suppressed.

  Examples of the topcoat agent used in the above-described topcoat treatment include a polyester topcoat agent, a polyamide topcoat agent, a polyurethane topcoat agent, an epoxy topcoat agent, a phenol topcoat agent, and a (meth) acrylic top. Examples thereof include a coating agent, a polyvinyl acetate top coating agent, a polyolefin top coating agent such as polyethylene aly polypropylene, and a cellulose top coating agent. Among such topcoat agents, a polyester-based topcoat agent that has high adhesive strength with the reflective layer 4 and contributes to surface protection of the reflective layer 4, sealing of defects, and the like is particularly preferable.

The coating amount (in terms of solid content) of the above-mentioned topcoat agent is preferably 3 g / m ² or more and 7 g / m ² or less. If the coating amount of the top coat agent is less than 3 g / m ² , the effect of sealing and protecting the reflective layer 4 may be reduced. On the other hand, even if the coating amount of the topcoat agent exceeds 7 g / m ² , the sealing and protecting effect of the reflective layer 4 does not increase so much, and the thickness of the light reuse sheet 20 increases instead. .

  In addition, in the above-mentioned top coat agent, various additives such as a silane coupling agent for improving tight adhesion, an ultraviolet absorber for improving weather resistance and the like, an inorganic filler for improving heat resistance and the like Can be mixed as appropriate. The amount of the additive to be mixed is preferably 0.1% by weight or more and 10% by weight or less from the balance between the effect expression of the additive and the function inhibition of the topcoat agent. If the above-mentioned additive is less than 0.1% by weight, close adhesion, weather resistance and heat resistance cannot be sufficiently obtained, and if it is more than 10% by weight, the function of the topcoat agent is inhibited.

  The base material 2 constituting the light reuse sheet 20 is formed by sheet molding using a synthetic resin as a material. As the synthetic resin used for the base material 2, in view of being installed outdoors, it is desirable to have water resistance, weather resistance such as durability against ultraviolet rays, for example, polyethylene terephthalate resin (PET resin), etc. Polyethylene resin, polypropylene resin, methacrylic resin, polymethylpentene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile- (poly) styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, Silicone resin, polysulfo System resin, polyphenylene sulfide resins, polyether sulfone resins, triethylene naphthalate resins, polyether imide resins, Epokishin resins, polyurethane resins, acetal resins, cellulose resins and the like.

Among the above-mentioned resins, polyimide resins, polycarbonate resins, polyester resins, fluorine resins, polylactic acid resins are those having high heat resistance, strength, weather resistance, durability, gas barrier properties against water vapor and the like. preferable.
Examples of the polyester-based resin include polyethylene terephthalate and polyethylene naphthalate. Among these polyester-based resins, polyethylene terephthalate is particularly preferable because it has a good balance between various functions such as heat resistance and weather resistance, and price.

  Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, and a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP). ), Copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene resin (PCTFE), ethylene and chlorotrifluoroethylene Copolymer (ECTFE), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), and the like. Among these fluororesins, polyvinyl fluoride resin (PVF) and a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE) which are excellent in strength, heat resistance, weather resistance and the like are particularly preferable.

  Examples of the above-mentioned cyclic polyolefin-based resin include polymerizing cyclic dienes such as a) cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof), cyclohexadiene (and derivatives thereof), norbornadiene (and derivatives thereof), and the like. And b) a copolymer obtained by copolymerizing the cyclic diene with one or more olefinic monomers such as ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. It is done. Among these cyclic polyolefin resins, cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof) or norbornadiene (and derivatives thereof) such as polymers having excellent strength, heat resistance, and weather resistance are particularly preferred. preferable.

  In addition, as a formation material of the base material 2, the above-mentioned synthetic resin can be used 1 type or in mixture of 2 or more types. In addition, various additives and the like can be mixed in the forming material of the base material 2 for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, and the like. Examples of the additive include a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing fiber, a reinforcing agent, an antistatic agent, a flame retardant, a flame retardant, a foaming agent, and an antifungal agent. And pigments. The method for forming the substrate 2 is not particularly limited, and known methods such as an extrusion method, a cast forming method, a T-die method, a cutting method, and an inflation method are employed.

  When the substrate 2 is used, the thickness is preferably 25 μm or more and 500 μm or less, and particularly preferably 250 μm. When the thickness of the base material 2 is less than 25 μm, curling occurs during the coating process of the structural layer 3 due to the effect of curing shrinkage of an ultraviolet curable resin or the like, and problems occur when it is incorporated into the solar cell module 200. . Conversely, when the thickness of the base material 2 exceeds 500 μm, the weight of the sheet-like member 60 increases, and the weight of the solar cell module 200 also increases. If it is 250 micrometers or less, the lighter-weight solar cell module 200 is realizable.

  Further, the base material 2, the structural layer 3, and the base material 2 may contain an ultraviolet stabilizer or a polymer in which an ultraviolet stabilizing group is bonded to a molecular chain. By this ultraviolet stabilizer or ultraviolet stabilizer, radicals generated by ultraviolet rays, active oxygen, etc. are inactivated, and the ultraviolet stability, weather resistance, etc. of the light reuse sheet 20 can be improved. As the UV stabilizer or UV stabilizer, a hindered amine UV stabilizer or a hindered amine UV stabilizer having high stability to UV is preferably used.

(Operation of solar cell module 200)
According to the solar cell module 200 using the light reuse sheet 20 having such characteristics, the light incident on the region R1 between the adjacent solar cells 30 is reflected by the reflection surface 100 of the light reuse sheet 20, The light can enter the solar battery cell 30. Thereby, the light incident on the region R1 between the adjacent solar cells 30 can also be used, and the power generation efficiency of the solar cell module 200 can be improved.

(Modifications and others)
The light reuse sheet 20 can also be arranged with the back surface of the reflection surface 100 of the light reuse sheet 20 facing the filling layer side 21 as shown in FIG.
Further, as shown in FIG. 17, the light reuse sheet 20 having a protective layer 40 made of a metal layer of 10 μm to 30 μm and a silica layer of 10 nm to 100 nm can be used. In order to increase the durability, PVF (polyvinyl fluoride resin) may be applied or the sheet-like member 60 having the polyvinyl fluoride resin may be bonded to protect the solar cell module 200. By doing in this way, the solar cell module 200 can also be used as a back sheet.

In addition, as shown in FIG. 18, the light reuse sheet 20 can be used for reusing light from a solid light emitting element 50 such as an EL.
FIG. 18 shows a sectional view of a uniform state according to the light source module 210 of the present invention. The light source module 210 includes the filling layer 21, the light emitting element 50, and the light reuse sheet 20.
The light emitting element 50 has a function of converting electricity into light by electroluminescence, and is emitted from the light receiving and emitting surface 160. The light emitting element 50 is preferably a solid light emitting diode such as an LED, an organic EL, or an inorganic EL.

  The filling layer 21 seals the light emitting element 50. The light M3 emitted from the light emitting element 50 is transmitted through the filling layer 21, partly becomes light H <b> 30 emitted from the emission surface 150, and part becomes light M <b> 31 reflected by the emission surface 150. As the material of the filling layer 21, a material having a high light transmittance is used to transmit the light M3 incident on the filling layer 21, and an acrylic resin having a high transmittance is preferably used.

  Of the light emitted from the light emitting element 50, the light M <b> 31 reflected by the emission surface 150 is reflected by the emission surface 150 and enters the reflection surface 100 of the light reuse sheet 20. The light M <b> 2 that enters the reflecting surface is reflected by the reflecting surface 100 and then enters the exit surface 150. The reflected light M1 that is reflected by the reflecting surface 100 and incident on the exit surface 150 exits from the exit surface 150 to the outside. Thereby, compared with the structure without the light reuse sheet | seat 20, there exists an effect which light utilization efficiency improves.

  The traveling direction of the reflected light M1 can be controlled by the uneven shape of the reflective surface 100 of the present invention, and the reflective surface 100 can emit a lot of light from the exit surface by having the above-described band-shaped groove B1.

The present invention relates to a mold S that can be easily stored by preventing generation of scratches. Moreover, the sheet-like member 60 molded using the mold S is also excellent in stability when formed into a roll. Furthermore, by using this sheet-like member 60, the power generation efficiency is remarkably improved by using it for solar power generation that generates power using sunlight.
Further, by using it for a light emitting element such as an LED or an EL element, the light emission efficiency can be increased, so that power consumption can be suppressed.

3 Structural Layer 4 Reflective Layer 5 Adhesive / Adhesive Layer 6 Protective Layer 20 Light Reuse Sheet 21 Filling Layer 30 Solar Cell 40 Protective Layer 50 Light Emitting Element 60 Sheet Member 200 Solar Cell Module B1 Strip Groove B2 Strip Groove S Mold S1 Mold body T1 Inclined portion T2 Inclined portion Tg Step Tp Distance X1 Intersection

Claims (8)

Provided with a cylindrical mold body with an uneven shape on the surface,
The concavo-convex shape includes a pleat portion in which a plurality of grooves extending in the axial direction are formed along the circumferential direction, and a belt-like groove portion in which a plurality of grooves extending in the circumferential direction are formed along the axial direction. A cylindrical mold. The formation position of the band-shaped groove part is smaller in diameter than the formation position of the pleat part,
2. The cylindrical mold according to claim 1, further comprising an inclined portion whose diameter changes stepwise or continuously from the strip-shaped groove portion to the pleat portion between the strip-shaped groove portion and the pleat portion. . A plurality of grooves extending in the circumferential direction with respect to the inclined portion are formed in the axial direction,
3. The cylindrical mold according to claim 2, further comprising an intersecting portion formed by intersecting an axially extending groove and a circumferentially extending groove between the inclined portion and the pleat portion. . The plurality of grooves formed in the inclined portion have a ratio (Tg / Tp) between a step Tg at the apex of adjacent grooves and an axial distance Tp between the apexes satisfying the following expression. The cylindrical mold described in 1.
1/300 ≦ (Tg / Tp) ≦ 1/3   5. An optical recycle comprising: a structural layer molded using the cylindrical mold according to claim 1; and a reflective layer laminated on an uneven surface of the structural layer. Use sheet.   A structural layer molded using the cylindrical mold according to any one of claims 1 to 4, a reflective layer laminated on an uneven surface of the structural layer, and an adhesive / adhesive layer on the reflective layer The light reuse sheet | seat characterized by including the protective layer laminated | stacked through.   A pleated portion in which a plurality of grooves extending in the axial direction are formed along the circumferential direction and a strip-shaped groove portion in which a plurality of grooves extending in the circumferential direction are formed along the axial direction with respect to the surface. Light reuse sheet.   A solar battery module, wherein the light reuse sheet according to any one of claims 5 to 7 is disposed on a back surface side of the solar battery cell.

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