JP2010283314A - Solar panel - Google Patents

Abstract

Provided is a solar cell panel that floats in water, unlike a conventional solar cell panel structure, is light in weight, low in production cost, has a high degree of design freedom with respect to the size of the solar cell panel, and is excellent in wind pressure resistance. That is.
[MEANS FOR SOLVING PROBLEMS] A plate-like base material in which a core material composed of one or two or more combinations selected from polyolefin resins, polyurethane resins, and polyethylene terephthalate resins is sandwiched between thin metal plates and integrated. Single or multiple solar cell elements are encapsulated with urethane resin, and the urethane resin side is used as the light receiving surface, and those containing castor oil-based polyol as urethane resin, those containing hexamethylene diisocyanate as urethane resin, hydrogen It is to include a castor oil-based polyol having a structure that does not include a double bond by addition, and to have a structure in which a plurality of through holes from the light receiving surface to the substrate are provided in the arrangement range of the solar cell elements.
[Selection] Figure 1

Description

  The present invention belongs to the field of solar cell panel manufacturing technology. In particular, the present invention relates to a solar cell element encapsulation technique that is lighter in weight, lower in production cost, has a high degree of design freedom, and can achieve high reliability.

A solar cell panel is a solar cell element made of a plurality of semiconductors such as silicon and sealed with a resin or the like. FIG. 14 shows the most general structure of a conventional solar cell panel. A string 6 in which a plurality of solar cell elements 4 are connected by a wiring member 2 is sealed on a glass substrate 8 with EVA resin (ethylene vinyl acetate) 10 and the back surface is sealed with a PET resin (polyethylene terephthalate) sheet 12. is there. In this structure, sunlight enters from the arrow A side.

  Such a conventional solar cell panel is disclosed, for example, in JP-A-5-121772. However, this conventional solar cell panel has been a common structure in the industry since the 1980s, and there is no patent document relating to only its basic structure.

  In order to produce this structure, an EVA sheet before cross-linking is placed on a glass substrate 8, a string 6 is placed thereon, an EVA sheet before cross-linking is further placed thereon, and finally a laminate is covered with a PET sheet 12. Make things. Next, this laminate is integrated by vacuum lamination while heating. The entire string 6 is integrally enclosed by the EVA resin 10 heated and fluidized in the vacuum lamination. The laminate thus integrally enclosed is heated again to complete the crosslinking treatment.

  The EVA resin 10 is completely cured by the crosslinking treatment, and the reliability as the solar cell panel is obtained. Furthermore, in order to prevent moisture from entering from the end face, the end face is filled with a sealing material 14 such as butyl rubber, and a frame 16 such as aluminum is attached in a frame shape to complete a solar cell panel 18 having a conventional structure. The frame 16 prevents moisture from entering from the end face and functions as a fixture for the solar cell panel 18. The frame 16 has a mounting hole 20 for screwing. This is because a hole in the glass substrate 8 involves a risk of reliability such as generation of a crack, and therefore, the glass substrate 8 cannot normally be provided with a hole. Further, since moisture easily enters from the interface between the EVA resin 10 and the glass substrate 8 or the PET resin sheet 12, the frame 16 is an indispensable member in order to protect the end surface by filling with the sealing material 14. .

  Another conventional structure is shown in FIG. The illustrated solar cell panel 28 is obtained by potting the entire string 6 with a silicone resin 24 in a transparent resin container 22 such as polycarbonate. In this structure, sunlight enters from the arrow A side. The reason for using a silicone resin is that it is excellent in durability against sunlight. In addition, in the usage mode in which sunlight is incident from the transparent resin container 22 side, when the silicone resin 24 is exposed to the outside air, dust and dirt are attached due to its self-adhesiveness, and the silicone resin is water permeable. This is because the solar cell element 4 is corroded by the infiltrated moisture. Here, the string 6 has a structure in which a plurality of solar cell elements 4 are connected by the wiring member 2 as in FIG. When attaching this solar cell panel 28, the method of inserting and fixing a screw etc. to the attachment hole 26 provided in the edge part of the container 22 made of transparent resin is taken similarly to FIG. This structure has been generalized in the industry before the structure of FIG. 14, and the inventor could not find a patent document that discloses only this structure.

  Although the conventional solar cell panel as described above has the following problems, since there is no such alternative structure, it has been established in the industry for many years.

First, with respect to the structure of FIG. 14, the problem of productivity by using a technique called vacuum lamination, the problem of weight by using a glass substrate, the problem of cost, etc. can be mainly pointed out.
The method of vacuum laminating uses the pressure when a laminated body of glass substrate / EVA sheet / string / EVA sheet / PET sheet is heated in a chamber that is depressurized to vacuum, and the chamber is opened to atmospheric pressure. In a single unit. Therefore, it becomes a bottleneck in productivity because it is always batch processing.

Moreover, since the glass substrate is used, the weight of the solar cell panel is inevitably increased. If the glass substrate is made thin in order to reduce the weight, the impact resistance against dropping of the heel or the like is lowered, which is not preferable. However, such a large weight is not a problem for solar panels installed on the roof of a detached house. This is because it is incorporated into a building as a building material.
On the other hand, when it becomes small things, such as a solar cell for road signs, a glass substrate will become relatively thick for the size of a solar cell panel, and the problem of weight cannot be ignored. Since the thickness of the glass substrate is determined by the impact resistance against dropping of the bag, etc., even if the size of the solar cell panel is reduced, it cannot be reduced proportionally. Furthermore, even if a small amount of solar panels are installed on the veranda of an apartment depending on the residents' preferences, it cannot be installed as a building material like a detached house. Become.

  In addition, as already described, a frame must be provided in order to prevent moisture from entering from the interface between the glass substrate and EVA resin, and between the EVA resin and the PET sheet, which is negative in terms of cost. In addition, since the solar cell panel is plate-shaped, the installation struts and the like must be made thicker in consideration of the wind pressure load after installation, which also causes an increase in cost.

  Next, the structure shown in FIG. 15 is problematic in terms of cost and design freedom because a transparent resin container must be used. That is, the transparent resin container is a resin molded product using a mold, and the mold must be manufactured for each string size. The solar cell panel having the structure shown in FIG. 15 is currently widely used as a power source for road signs. Such road signs using solar panels are LED light emitting signs such as stop signs, curve signs in mountainous areas, and display of shoulders in snowy areas, and their power consumption varies widely. The difference in power consumption is adjusted by the area of the solar cell (string size), but in order to cope with various types of power consumption with the minimum economical solar cell size, there are various corresponding It is necessary to prepare a transparent resin container of a large size. Therefore, it is necessary to manufacture various molds for that purpose, which leads to an increase in production cost.

  Furthermore, recently, as a safety measure for water purification plants and the like, cases of installing solar cells for the purpose of protecting the water surface of water storage tanks are increasing. By covering the water tank surface of the water purification plant with a solar cell panel, it aims at the effect of two birds with one stone to cover part of the required power with solar cells, while preventing disturbing acts such as throwing in dangerous goods. However, since the solar cell is heavy, it is impossible to float on the water surface, and it is common to install a frame over the water surface of the water storage tank and attach the solar cell on the frame. Therefore, the current installation structure causes an increase in construction costs. If the solar cell can be floated on the water surface, this extra cost is not necessary.

  The present invention solves the problems of the solar cell panel having such a conventional structure, is light in weight and low in production cost, has a high degree of design freedom with respect to the size of the solar cell panel, has excellent wind pressure resistance, A solar cell panel that can be installed in a floating state is provided.

  The present invention provides a plate-like base material in which a core material composed of one or two or more combinations selected from polyolefin resins, polyurethane resins, and polyethylene terephthalate resins is sandwiched between thin metal plates and integrated. It can be realized by encapsulating a single or a plurality of solar cell elements with urethane resin and forming a solar cell panel with the urethane resin side as a light receiving surface.

  When the urethane resin contains a castor oil-based polyol, particularly preferable performance with respect to water resistance can be obtained.

  When the urethane resin contains hexamethylene diisocyanate, particularly preferable performance with respect to light resistance can be obtained.

  When the urethane resin contains a castor oil-based polyol having a structure that does not contain a double bond by hydrogenation, preferable performance can be obtained as it can achieve both water resistance and light resistance. In particular, the combination with hexamethylene diisocyanate is such that both the polyol and the isocyanate do not contain a double bond, so that both water resistance and light resistance can be achieved at an extremely high level.

  If the solar cell panel has a structure in which a plurality of through holes from the light receiving surface to the base material are provided at least within the arrangement range of the solar cell elements, the wind passes through the solar cell panel when the wind hits the solar cell panel. The load applied to the panel support material can be reduced.

  Here, the polyurethane-based resin is a name of an ordinary two-component curable urethane resin and a foamed urethane resin regardless of whether it is transparent or opaque, colored or non-colored, and the urethane resin is an ordinary two-component curable type. Among the urethane resins, it is used as a name for those excluding foamed urethane resins and opaque ones.

According to claim 1, a plate-like base material obtained by laminating and integrating a core material composed of one or more kinds selected from polyolefin resin, polyurethane resin, and polyethylene terephthalate resin between thin metal plates is provided. Since the solar cell element can be encapsulated with only urethane resin, it is possible to realize a solar cell panel that is light in weight, low in cost, and high in design freedom. In particular, urethane resin is widely used as a mold and a flooring material for electric parts, and is a very inexpensive material. Furthermore, since a plate-like base material in which a core material is sandwiched between thin metal plates and integrated is used, a solar cell floating on the water surface can be realized. Such plate-like base materials are often used for soundproof walls on roads, blindfolds for building emergency staircases, decorative boards for condominium verandas, and the like, and can directly impart a power generation function to these plate materials.
Conventionally, a solar cell panel in which a solar cell element is encapsulated with epoxy, acrylic resin or the like on a substrate has existed. However, epoxy resins and acrylic resins are highly influenced by their high hardness and expansion / contraction, and it has not been possible to achieve long-term reliability as a solar cell panel due to physical factors such as the occurrence of cracks in the solar cell element. Therefore, these solar cell panels are limited to uses such as teaching materials and experiments.
On the other hand, production of solar cell panels with urethane resin has never been performed in the industry. The reason for this is that the urethane resin is feared to turn yellow by light irradiation, and the present inventor analogizes that the physical characteristics may be inferior to epoxy resins and acrylic resins. . However, even if yellowing occurs, the decrease in the output of the solar cell is about 5% and its effect is low, and the urethane resin is easy to control the hardness, and it can be physically controlled by following the expansion and contraction of the solar cell element. It was found that it was possible to realize that it was not affected by the factors. Specifically, as a result of performing a moisture resistance test and an outdoor exposure test on a plurality of the products of the present invention having the structure described later, there was certainly some yellowing, but the output was 95% of the initial characteristics. The above was maintained. As a result of such a reliability test, if 95% or more of the initial characteristics can be maintained, there is no practical problem.

  In addition, as hardness of urethane resin preferable by this invention, it is 40-95 in A hardness (65 degreeC), and is about 10-80 in D hardness (20 degreeC). However, the hardness for obtaining the effect of the present invention is not limited to this range.

According to claim 2, high water resistance can be obtained. The water resistance is an indispensable performance for solar cells used outdoors. The reason why the water resistance performance is improved by the constitution of claim 2 is due to the effect of the castor oil-based polyol which is the urethane raw material of the present invention. Castor oil is an oil obtained from the seeds of a plant called Castor (Coleoptera). This oil is an ester of fatty acid and glycerin, and about 90% of the fatty acid is ricinoleic acid. Shows different properties. The feature is particularly excellent in water resistance.
Specifically, castor oil-based polyurethane is superior in water resistance, hydrolysis resistance, and electrical insulation compared to polypropylene glycol-based and polyester-based polyols compared to polypropylene glycol-based, polyester-based, and polybutadiene-based polyurethanes. ing. These are all the reliability characteristics required for solar cells. In addition, since it has a lower viscosity than polybutadiene-based and polyester-based polyols, it is excellent in productivity and workability.

  According to the third aspect, high light resistance can be obtained. Isocyanate is the main raw material of urethane resin together with polyol, but hexamethylene diisocyanate is an aliphatic isocyanate, and unlike aromatic isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate, it has a characteristic that yellowing hardly occurs. . This is considered to be due to the fact that the chemical structure does not contain a double bond.

  According to the fourth aspect, since the double bond of castor oil is removed by hydrogenation as the polyol, high light resistance can be obtained in addition to the high water resistance of castor oil. The reason why the urethane resin turns yellow due to light irradiation or the influence of high temperature is that the double bond is cut by these external energies. Therefore, if there is no double bond, yellowing can be prevented even if intense light over all wavelengths such as sunlight is irradiated. In particular, the combination with hexamethylene diisocyanate has an effect that both water resistance and light resistance can be achieved at an extremely high level since both the polyol and isocyanate do not contain a double bond.

  According to the fifth aspect, the wind blown to the solar cell panel surface passes through the through hole, so that the load load on the construction member such as the column supporting the solar cell panel is reduced. As a result, the total cost of the solar cell system is reduced. It can be greatly reduced. This effect appears as an effect equivalent to the weight reduction of the solar cell panel as a whole of the solar cell system. In addition, since a urethane resin with reasonable hardness characteristics is used, this through hole can be opened without any cracks in post-processing, so even if it is necessary to install it in an area where the assumed wind speed is high It can respond to changes and contribute to productivity improvement.

  In FIG. 1, the example of the form of the base material for implementing this invention is shown. The illustrated example is a plate-like substrate 1 in which a core material 1a made of one or a combination of two or more selected from polyolefin resins, polyurethane resins, and polyethylene terephthalate resins is sandwiched between metal thin plates 1b and laminated together. It is. In order to more surely prevent insulation failure due to contact with the solar cell element on the surface of the metal thin plate 1b, it is also considered to apply a protective coating such as a baking coating of a polyester resin. It goes without saying that this protective coat can be applied in various ways other than this example.

FIG. 2 shows the best mode for carrying out the present invention. The illustrated example is a solar cell panel in which a plurality of solar cell elements 3 are encapsulated with a urethane resin 5 on a substrate 1 and the urethane resin 5 side is a light receiving surface. The plurality of solar cell elements 3 are connected in series by the wiring material 7 to form a string 9, and both ends of the wiring material 7 are taken out to the back surface side of the substrate 1 as extraction electrodes 11 and 13. As the wiring member 7, a solder-coated copper foil or the like can be used. In addition, taking out to the back surface side is through the through-hole 21 of the base material 1. The inside of the through hole 21 is also filled with the urethane resin 5.
In the case of the solar cell element 3 using a p-type silicon wafer, the extraction electrode 11 on the front surface side is a negative electrode, and the extraction electrode 13 on the back surface side is a positive electrode. A gap is provided between the substrate 1 and the solar cell element 3 by a putty 15 such as a silicone resin so that the urethane resin also wraps around the back surface side of the solar cell element 3. Although not shown in the figure, an insulating coat may be applied to the surface of the substrate 1 so that the extraction electrodes 11 and 13 are not short-circuited.

  FIG. 3 shows an example in which a lower layer urethane resin (underlayer) 17 is provided in place of the putty 15 in FIG. 2 in order to increase productivity and reduce production costs. Although not shown, an insulating coat may be applied to the surface of the substrate 1 so that the extraction electrodes 11 and 13 are not short-circuited. For this description, first, the production process for the structure of FIG. 2 will be described below.

  First, the putty 15 is disposed at a predetermined position of the base material 1, and then the string 9 is disposed thereon, and the extraction electrodes 11 and 13 are taken out to the back side of the base material 1. At this time, the string 9 (each solar cell element 3) is temporarily fixed by the adhesive force of the putty 15 while maintaining a gap between the string 9 and the base material 1. Next, a urethane resin raw material mixed with polyol and isocyanate and vacuum degassed is dropped on the entire surface, and the entire workpiece is heated to about 50 ° C. The viscosity of the urethane resin raw material dropped by this heating is lowered and goes around to the back surface of the solar cell element 3. Thereafter, the whole is heated to about 70 ° C. to 100 ° C., the urethane resin raw material is reacted and cured, and the solar cell panel enclosed with the urethane resin 5 is completed.

  In contrast to the manufacturing of the solar cell panel of FIG. 2, in FIG. 3, first, a urethane resin raw material to be the base layer 17 is applied to the entire surface of the base material 1, and the string 9 is disposed thereon, The extraction electrodes 11 and 13 are extracted on the back side of the substrate 1. In this state, the string 9 is temporarily fixed by the viscosity of the urethane resin raw material and the rigidity of the wiring member 7 and the extraction electrodes 11 and 13 on the back surface. Then, the urethane resin raw material which mixed the polyol and isocyanate and vacuum-defoamed was dripped on the whole surface, the urethane resin raw material was reaction-cured by heating the whole to about 70 to 100 degreeC, and was enclosed with the urethane resin 5 A solar panel is completed. The lower urethane resin 17 and the encapsulating urethane resin 5 may be the same material, and after completion, the boundary between the lower urethane resin 17 and the encapsulating urethane resin 5 is integrated so that it cannot be distinguished. Here, it is divided into two layers for convenience of explanation. In this case, since it is not necessary to wrap the urethane resin material around the back surface side of the solar cell element 3, there is no need to take a temperature holding time for reducing the viscosity.

  As described above, the structure of FIG. 3 increases the productivity because the cost of the putty 15 and the trouble of providing the putty 15 and the temperature holding for making the urethane resin raw material wrap around the back surface of the solar cell element 3 are unnecessary. Cost can be reduced. In the structure of FIG. 3, it is sufficient that the thickness of the underlayer 17 is such that the solar cell element 3 gets wet with the urethane resin raw material, and the amount used is very small. Therefore, even when compared with the structure of FIG. 2, the amount of the urethane resin raw material used is almost the same.

  Next, FIG. 4 will be described. FIG. 4 shows the structure of the solar cell panel of FIGS. 2 and 3 as viewed from the light receiving surface side, in which four solar cell elements 3 are arranged in series. In addition, mounting holes 19 are provided at four corners of the substrate 1. This mounting hole 19 is omitted in FIGS.

FIG. 5 shows an example in which the base material 1 is formed by bending a container shape. The illustrated example uses a solar cell panel in which a base material 1 is formed into a container shape by bending, and a plurality of solar cell elements 3 are sealed with urethane resin 5 inside thereof, and the urethane resin 5 side is a light receiving surface. is there. The plurality of solar cell elements 3 are connected in series by the wiring material 7 to form a string 9, and both ends of the wiring material 7 are taken out to the back surface side of the substrate 1 as extraction electrodes 11 and 13. In addition, taking out to the back surface side is through the through-hole 21 of the base material 1.
The inside of the through hole 21 is also filled with the urethane resin 5. Although not shown in the figure, an insulating coat may be applied to the surface of the substrate 1 so that the extraction electrodes 11 and 13 are not short-circuited.
In this structure as well as in FIG. 2, a gap is provided between the base material 1 and the solar cell element 3 by a putty 15 such as a silicone resin so that the urethane resin also wraps around the back surface side of the solar cell element 3. .

  FIG. 6 shows the structure of FIG. 3 in which only the base material 1 is an aluminum container. Similar to FIG. 3, in order to increase productivity and reduce production costs, an example in which a lower urethane resin 17 is provided in place of the putty 15. Although not shown, an insulating coat may be applied to the surface of the substrate 1 so that the extraction electrodes 11 and 13 are not short-circuited.

  Next, FIG. 7 is an example of an end face external view of the solar cell panel of the present invention. 2 to 6 are illustrated as structures for which no special coating is provided on the extraction electrodes 11 and 13 as illustrations. In general, in order to prevent moisture from entering the solar cell panel, the extraction electrode is usually molded with a silicone resin or encapsulated with a terminal box or the like. Similarly, in the structure of FIG. 7, extraction electrodes 11 and 13 are provided via a terminal box 23. In FIG. 7, the extraction electrodes 11 and 13 are illustrated as an example of the covered electric wire, but the covered electric wire and the wiring material drawn from the solar cell element are connected inside the terminal box 23 (the connection portion is illustrated in FIG. 7). Not shown).

  FIG. 8 shows a structural example of claim 5. In the illustrated example, a plurality of through holes 25 from the light receiving surface to the base material are provided in the arrangement range of the solar cell elements 3. With such a structure, when the wind hits the solar cell panel, the wind passes through the solar cell panel, so that the load applied to the support member of the solar cell panel can be reduced. The solar cell panel is more affected by the wind when the area becomes larger. Therefore, this figure shows a structure in which two strings 9 in which four solar cell elements 3 are connected in series are connected in parallel, which is larger than that shown in FIG.

  Then, the example of the installation mode of the solar cell panel of the structure of FIG. 8 is demonstrated using FIGS. 9-11. FIG. 9 is an example of a fixture 27 for attaching the solar cell panel of FIG. This attachment 27 is an example in which attachment stays 31 having attachment holes 29 are provided at four corners of a frame such as metal. FIG. 10 is a view in which the solar cell panel 35 of claim 5 is fitted into the opening 33 of FIG. 9 and the solar cell panel 35 and the fixture 27 are screwed through the attachment holes 29. Further, the mounting bracket 37 is integrally fastened together with the solar cell panel 35 and the mounting tool 27 through the mounting hole 29. FIG. 11 shows a state in which the one shown in FIG. 10 is attached to a column or the like (not shown). Solar cell panels are usually installed with an inclination toward the south as shown in the figure in order to receive sunlight more efficiently. In such an attachment form, when wind hits the solar cell panel, the wind is received over the entire area, so that a large load is applied to the root portion B of the mounting bracket 37. However, in the present invention, since the wind (indicated by the dotted line arrow in the figure) passes through the solar cell panel 35 as shown in the figure, a large load is not applied to the root portion B of the mounting bracket 37. Therefore, since structural members, such as a support | pillar, can be made thin, it can contribute to the cost reduction as the whole solar cell system.

Hereinafter, specific examples will be described.
Example 1
As an embodiment of claim 1, a polyolefin resin core material 1 a is sandwiched between two aluminum thin plates 1 b having a thickness of 0.2 mm, and is laminated and integrated into a thickness of 3 mm to have a size of 60 mm and 75 mm. A road sign having the structure of FIG. 2 using a base material 1 (“Plametal” manufactured by Sekisui Jushi Plastic Metal Co., Ltd.) and a string in which single crystal solar cell elements cut to 8 mm × 52 mm are connected in series by solder coated copper foil. A solar cell panel was prepared. The urethane resin raw material used was 100 parts by weight of a polyester polyol having a hydroxyl value of 300 (KOHmg / g) (manufactured by Nippon Polyurethane Industry Co., Ltd.) and diphenylmethane diisocyanate having an NCO content of 29% (Millionate series manufactured by Nippon Polyurethane Industry Co., Ltd.). An NCO index = 1.05 is 74 parts by weight, and an appropriate amount of a catalyst and an antifoaming agent are mixed and vacuum degassed. The curing condition was 30 ° C. for 30 minutes. Thereafter, curing was performed for 24 hours, and complete curing was confirmed. This solar cell panel was subjected to 10 cycles of a temperature and humidity cycle test of 80 ° C. to 85% to −40 ° C. and a humidity resistance test of 1000 hours for 80 ° C. and 85%. As a result, although the urethane resin was slightly yellowed, the electrical characteristics as a solar cell panel maintained 95% or more of the initial value.

(Example 2)
As an embodiment of claim 2, a polyolefin resin core 1a is sandwiched between two aluminum thin plates 1b having a thickness of 0.2 mm, and is laminated and integrated into a thickness of 3 mm so as to have a size of 180 mm / 320 mm. 2 using a string in which the base material 1 (“Plametal” manufactured by Sekisui Plastic Plametal Co., Ltd.) and a single crystal solar cell element cut into 15 mm × 78 mm are connected in series in 34 rows of two rows by solder-coated copper foil. A solar cell panel for road sign having a structure was prepared. The urethane resin raw material used was 100 parts by weight of castor oil-based polyol having a hydroxyl value of 220 to 240 (KOHmg / g) (URIC-F series manufactured by Ito Oil Co., Ltd.), diphenylmethane diisocyanate having an NCO content of 29% (Nippon Polyurethane Industrial Co., Ltd.) Company Millionate series) was NCO index = 1.05, 60 parts by weight, and an appropriate amount of catalyst and antifoaming agent were mixed and vacuum degassed. Curing conditions were 70 ° C. for 60 minutes. Thereafter, curing was performed for 24 hours, and complete curing was confirmed. This solar cell panel was subjected to 10 cycles of a temperature and humidity cycle test of 80 ° C. to 85% to −40 ° C. and a humidity resistance test of 1000 hours for 80 ° C. and 85%. As a result, although the urethane resin was slightly yellowed, the electrical characteristics as a solar cell panel maintained 95% or more of the initial value.

(Example 3)
As an embodiment of claim 3, a polyolefin resin core 1 a is sandwiched between two aluminum thin plates 1 b having a thickness of 0.2 mm, and is laminated and integrated into a thickness of 3 mm to have a size of 110 mm and 175 mm. Base material 1 ("Plametal" manufactured by Sekisui Plastic Plametal Co., Ltd.) is bent into a 3mm deep container and single crystal solar cell elements cut to 8mm x 51mm are composed of two rows of solder-coated copper foil Thus, a road sign solar battery panel having the structure shown in FIG. 5 was produced. The urethane resin raw material used is 100 parts by weight of a polyester polyol having a hydroxyl value of 200 to 250 (KOHmg / g) (manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diisocyanate having an NCO content of 21% (coronate series manufactured by Nippon Polyurethane Industry). NCO index = 1.05, 85 parts by weight, an appropriate amount of a catalyst and an antifoaming agent were mixed and vacuum degassed. The curing condition was 30 ° C. for 30 minutes. Thereafter, curing was performed for 24 hours, and complete curing was confirmed. This solar cell panel was subjected to 10 cycles of a temperature and humidity cycle test of 80 ° C. to 85% to −40 ° C. and a humidity resistance test of 1000 hours for 80 ° C. and 85%. As a result, the yellowing of the urethane resin was less than in Example 1 and Example 2, and the electrical characteristics as a solar cell panel maintained 95% or more of the initial value.

Example 4
As an embodiment of claim 4, a polyethylene terephthalate resin core material 1a is sandwiched between two aluminum thin plates 1b having a thickness of 0.2 mm, and is laminated and integrated to a thickness of 4 mm to have a size of 240 mm / 450 mm. The solar cell panel for a solar street light having the structure shown in FIG. 2 is prepared using a string in which a single crystal solar cell element cut into 51 mm × 51 mm is connected in series of 32 in a four-row configuration with a solder-coated copper foil. did. The urethane resin raw material used was a castor oil-based polyol 100 parts by weight (URIC-Y series manufactured by Ito Oil Co., Ltd.) having a hydroxyl value of 110 to 120 (KOHmg / g) and removing double bonds by hydrogenation, an NCO content of 21 % Hexamethylene diisocyanate (Coronate series manufactured by Nippon Polyurethane Industry Co., Ltd.) with an NCO index = 1.05, 40 parts by weight, an appropriate amount of a catalyst and an antifoaming agent were mixed, and vacuum degassed. The curing conditions were 80 ° C. and 60 minutes. Thereafter, curing was performed for 24 hours, and complete curing was confirmed. This solar cell panel was subjected to 10 cycles of a temperature and humidity cycle test of 80 ° C. to 85% to −40 ° C. and a humidity resistance test of 1000 hours for 80 ° C. and 85%. As a result, no yellowing of the urethane resin was observed, and the electrical characteristics of the solar cell panel maintained 95% or more of the initial value. Moreover, yellowing was not seen in the outdoor exposure test for 1000 hours.

(Example 5)
Using the same urethane resin raw material with the same structure as the solar cell panels of Examples 1 to 4 above, the solar cell panel is thinned out, and a solar cell panel in which two through holes are provided in the thinned portion is manufactured. Then, the temperature and humidity cycle test and the moisture resistance test performed in Examples 1 to 4 were performed. In addition, the through hole was provided as a post-processing after complete curing of the urethane resin. As a result, 95% or more of the initial characteristics was maintained, and no effect on the characteristics of the solar cell panel such as moisture intrusion from the opening portion of the through hole was confirmed.

(Example 6)
As another embodiment of claim 4, a polyolefin resin core material 1a is sandwiched between two aluminum thin plates 1b having a thickness of 0.2 mm, and is laminated and integrated to a thickness of 4 mm to have a size of 1220 mm and 1220 mm. A string 9 in which 35 base-shaped base materials 1 ("Plametal" manufactured by Sekisui Jushi Plastic Metal Co., Ltd.) and 156 mm x 156 mm polycrystalline solar cell elements 3 are connected in series in 35 rows of 5 layers by solder-coated copper foil, A soundproof panel for road with solar cell having a structure of 12 was produced. “Plametal” is a standard product used for soundproof walls and the like, and the embodiment of FIG. The urethane resin raw material used was a castor oil-based polyol 100 parts by weight (URIC-Y series manufactured by Ito Oil Co., Ltd.) having a hydroxyl value of 110 to 120 (KOHmg / g) and removing double bonds by hydrogenation, an NCO content of 21 % Hexamethylene diisocyanate (Coronate series manufactured by Nippon Polyurethane Industry Co., Ltd.) with an NCO index = 1.05, 40 parts by weight, an appropriate amount of a catalyst and an antifoaming agent were mixed, and vacuum degassed. The curing conditions were 80 ° C. and 60 minutes. Thereafter, curing was performed for 24 hours, and complete curing was confirmed. This solar cell panel was subjected to 10 cycles of a temperature and humidity cycle test of 80 ° C. to 85% to −40 ° C. and a humidity resistance test of 1000 hours for 80 ° C. and 85%. As a result, no yellowing of the urethane resin was observed, and the electrical characteristics of the solar cell panel maintained 95% or more of the initial value. Moreover, yellowing was not seen in the outdoor exposure test for 1000 hours.

  In this structure, as shown in FIG. 13, the boundary portion A between the urethane resin 5 and the substrate 1 is exposed to the outside air. In such a structure, generally, a “peeling” force is applied, and the reliability is often inferior. However, in this example, since the base 1 is made of a surface of an aluminum thin plate that has been baked with a polyester, it has excellent adhesion to the urethane resin 5 and can maintain high reliability. I think that the. In particular, since the compatibility between the polyester-based baking coating and the urethane resin is excellent, this combination can contribute to maintaining high reliability.

  Each of the solar cell panels shown in Examples 1 to 6 had a specific gravity slightly lower than 1, and it was confirmed that the solar cell panels floated on the water surface in any structure. In addition, it was confirmed that even if it was submerged in water, it floated slowly.

  As described above, the solar cell panel of the present invention can be widely applied to road signs, solar street lights, and other various small to medium solar cell applications, and it is necessary to use glass plates and molds. Therefore, productivity and material cost can be greatly reduced. Therefore, it can be widely deployed in fields where solar cells could not be used due to restrictions on price and shape design. Further, by providing a through hole, it is easy to design the wind pressure resistance, and this point can also contribute to expanding the field of use of solar cells. Thus, in recent years when the energy saving momentum is increasing, the industrial applicability of the present invention is very large.

Explanatory drawing of the cross-section of the base material used for the solar cell panel of this invention Explanatory drawing of the cross-sectional structure example of the solar cell panel of this invention Explanatory drawing of the cross-sectional structure example of the solar cell panel of this invention Explanatory drawing of the light-receiving surface side structural example of the solar cell panel of this invention Explanatory drawing of the cross-sectional structure example of the solar cell panel of this invention Explanatory drawing of the cross-sectional structure example of the solar cell panel of this invention Explanatory drawing of the end face external appearance example of the solar cell panel of the present invention Explanatory drawing of the light-receiving surface side structural example of the solar cell panel of this invention Explanatory drawing of the example of the fixture of the solar cell panel of this invention Explanatory drawing of the example of the attachment aspect of the solar cell panel of this invention Explanatory drawing showing a mode that a wind passes through the solar cell panel of the present invention Explanatory drawing of the whole structural example of the solar cell panel of this invention Structural diagram for explaining the reliability of the solar cell panel of the present invention Explanatory drawing of the sectional structure of a conventional solar cell panel Explanatory drawing of the sectional structure of a conventional solar cell panel

DESCRIPTION OF SYMBOLS 1a Core material 1b Metal thin plate 1 Base material 2,7 Wiring material 3,4 Solar cell element 5 Urethane resin 6,9 String 8 Glass substrate 10 EVA resin 11,13 Extraction electrode 12 PET resin sheet 14 Sealing material 15 Putty 16 Frame 17 Lower layer urethane resin (underlayer)
18, 28 Solar panel 19, 20, 26, 29 having a conventional structure Mounting hole 21, 25 Through hole 22 Transparent resin container 23 Terminal box 24 Silicone resin 27 Mounting tool 31 Mounting stay 33 Opening 35 Solar panel 37 mounting bracket

Claims (5)

  Single or multiple sheets on a plate-like base material obtained by laminating and integrating a core material composed of one or more kinds selected from polyolefin resin, polyurethane resin, and polyethylene terephthalate resin between thin metal plates A solar cell panel in which the solar cell element is encapsulated with urethane resin and the urethane resin side is the light receiving surface.   The solar cell panel according to claim 1, wherein the urethane resin contains a castor oil-based polyol.   The solar cell panel according to claim 1 or 2, wherein the urethane resin contains hexamethylene diisocyanate.   The solar cell panel according to any one of claims 1 to 3, wherein the urethane resin contains a castor oil-based polyol having a structure containing no double bond by hydrogenation.   The solar cell panel of any one of Claims 1-4 which provided the several through-hole from the light-receiving surface to a base material at least in the arrangement | sequence range of a solar cell element.

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