WO2010050343A1 - Solar battery rear surface protection sheet and solar battery module - Google Patents

Solar battery rear surface protection sheet and solar battery module Download PDF

Info

Publication number
WO2010050343A1
WO2010050343A1 PCT/JP2009/067403 JP2009067403W WO2010050343A1 WO 2010050343 A1 WO2010050343 A1 WO 2010050343A1 JP 2009067403 W JP2009067403 W JP 2009067403W WO 2010050343 A1 WO2010050343 A1 WO 2010050343A1
Authority
WO
WIPO (PCT)
Prior art keywords
resin
solar cell
solar battery
film
layer
Prior art date
Application number
PCT/JP2009/067403
Other languages
French (fr)
Japanese (ja)
Inventor
當間　恭雄
泰光 藤野
Original Assignee
コニカミノルタホールディングス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by コニカミノルタホールディングス株式会社 filed Critical コニカミノルタホールディングス株式会社
Publication of WO2010050343A1 publication Critical patent/WO2010050343A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/049—Protective back sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/30—Properties of the layers or laminate having particular thermal properties
    • B32B2307/306—Resistant to heat
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • B32B2457/10—Batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Definitions

  • the present invention relates to a back surface protection sheet for solar cells and a solar cell module using the same.
  • a solar cell module uses a sealing material such as ethylene-vinyl acetate (EVA) or silicon to sandwich a solar cell that generates electricity by receiving sunlight between the front and back protective members.
  • EVA ethylene-vinyl acetate
  • the structure is In these solar cell modules, since an electromotive force is insufficient in one cell, it is rarely configured from a single cell, and usually a plurality of solar cells are connected in series or series-parallel. That is, as shown in FIG. 1, the electrodes (surface electrode 11 and back electrode 12) between solar cells 1 are connected using a wiring 3 such as a conductive material, and these solar cells 1 and a wiring that is a conductive material. 3 is sandwiched between protective members (light incident side transparent protective member 41 and back surface protective sheet 42) made of glass, a resin plate, a resin film, metal, or the like using a sealing material (sealing agent layer 2). ing.
  • protective members light incident side transparent protective member 41 and back surface protective sheet 42
  • a sealing material
  • a sealing material and a back surface protection sheet made of a resin material are repeatedly expanded in the daytime due to a temperature rise due to heating by incident sunlight, and are cooled and contracted at night when sunlight is not applied. Yes.
  • solar cells there is an increasing supply of silicon wafers used for solar cells and demands for cost reduction.
  • a thin solar battery module manufactured using such a thin-layer solar battery cell is more susceptible to thermal shrinkage due to the temperature rise of the sealing material on the back surface side of the solar battery cell and the back surface protection member. Therefore, problems such as cracking of the solar battery cell and peeling of the back electrode, and peeling between the sealing material and the back surface protection material occur, and moisture enters the gap to deteriorate the solar battery cell. There is a problem.
  • Patent Document 4 It has also been proposed to use a transparent multilayer sheet having a layer with an average linear expansion coefficient of 50 ppm for a solar cell (for example, see Patent Document 4).
  • Patent Document 4 does not specifically describe which member of the solar cell the transparent multilayer sheet is used for.
  • these conventionally known resin materials containing reinforcing fibers do not provide a low linear expansion film of 30 ppm / ° C. or less, and the low linear expansion material as in the present invention is used as a back protective sheet for solar cells.
  • an object of the present invention is to provide a back sheet for a solar battery that can be used stably for a long period of time even if thin solar cells are used, and a solar battery module using the same.
  • a back protective sheet for a solar cell in which resin layers are laminated on both sides of a barrier film, wherein a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less is laminated on at least one side of the barrier film.
  • the back surface protection sheet for solar cells characterized.
  • a solar cell module using thin-layer solar cells can provide a solar cell back surface protection sheet that is stable against heating and cooling during use and can be used for a long period of time.
  • FIG. 1 and FIG. 2 are a part of a schematic cross-sectional view showing an example of a general solar battery module.
  • FIG. 1 is a schematic diagram showing a state in which adjacent solar battery cells 1 are connected by wiring 3. is there.
  • the solar cells 1 connected in this way are sandwiched between the light incident side transparent protective member 41 and the back surface protective sheet 42 via the sealing material layer 2.
  • the present invention relates to the back surface protection sheet 42, and as shown in FIG. 3, a barrier film 51, a cell side resin layer 52 (cell side film 52) and a back surface side resin layer 53 disposed on both surfaces thereof. It is a laminate composed of (back side film 53), and either one or both of the cell side resin layer 52 and the back side resin layer 53 is a resin material having a linear expansion coefficient of 30 ppm / ° C. or less. . In the present invention, it is particularly preferable that at least the cell-side resin layer 52 is made of a resin material having a linear expansion coefficient of 30 ppm / ° C. or less from the viewpoint that the object and effects of the present invention can be exhibited. Furthermore, an adhesive layer can be provided between the barrier film 51 and the cell-side resin layer 52 and the back-side resin layer 53.
  • At least one outermost layer is preferably made of a resin material having a linear expansion coefficient of 30 ppm / ° C. or less.
  • the barrier film used in the present invention is a film having at least a gas barrier property, and a metal thin film such as an aluminum foil and a copper foil, a film in which an inorganic oxide layer is laminated on a base film, and the like can be used. However, a film obtained by laminating an inorganic oxide layer on a base film is preferable.
  • the barrier film according to the present invention has a water vapor transmission rate of 0.01 g / m 2 / day or less, more preferably 1 ⁇ 10 ⁇ 3 g / m 2 as gas barrier properties, measured according to JIS K7129 B method.
  • Water vapor permeability (25 ⁇ 0.5 ° C., relative humidity (90 ⁇ 2)% RH) measured by a method according to JIS K 7129-1992 is 1 ⁇ 10 ⁇ 3 g / (m 2 ⁇ 24 h) or less
  • the oxygen permeability measured by a method according to JIS K 7126-1987 is preferably 1 ⁇ 10 ⁇ 3 ml / m 2 ⁇ 24 h ⁇ atm or less.
  • the barrier film preferably has a water vapor permeability (25 ⁇ 0.5 ° C., relative humidity (90 ⁇ 2)% RH) of 1 ⁇ 10 ⁇ 3 g / (m 2 ⁇ 24 h) or less.
  • a cell-side resin layer and a back-side resin layer are provided on both surfaces of a barrier film in which an inorganic oxide layer is formed on one surface side of a base film.
  • the cell-side resin layer is formed on the inorganic oxide layer, and the cell-side resin layer is a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less and is in contact with the sealing material layer.
  • linear expansion coefficient referred to in the present invention was specifically measured according to the method shown below.
  • a resin layer having a film thickness of 100 ⁇ m and a width of 4 mm was fixed at a distance between chucks of 20 mm, and once the temperature was raised from room temperature to 180 ° C. to remove residual strain, room temperature to 10 ° C. / Min. The temperature was raised to 250 ° C., a temperature-strain curve was taken, and the linear expansion coefficient was determined according to the method specified in ASTM D 696.
  • the base film applicable to the present invention is formed with a synthetic resin as a main component and is not particularly limited.
  • a synthetic resin for example, a polyethylene-based resin, a polypropylene-based resin, a cyclic polyolefin-based resin, a polystyrene-based resin, acrylonitrile- 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 Resins, polyimide resins, polyamideimide resins, polyarylphthalate resins, silicon resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins, acetal resins, cellulose resins, etc.
  • polyester resins include polyethylene terephthalate, polyethylene naphthalate, etc.
  • polyethylene terephthalate is particularly well-balanced in terms of various functions such as heat resistance, weather resistance, and price. preferable.
  • the thickness of the base film is preferably 7 to 20 ⁇ m, particularly preferably 10 to 15 ⁇ m.
  • the thickness of the base film is less than 7 ⁇ m, the curling is likely to occur during the vapor deposition process for forming the inorganic oxide layer, and disadvantages such as difficulty in handling occur.
  • the thickness exceeds 20 ⁇ m, it is contrary to the demand for reduction in thickness and weight of the solar cell module.
  • the inorganic oxide layer formed on the base film is a layer for expressing a gas barrier property against oxygen, water vapor and the like, and is formed by depositing an inorganic oxide on the surface of the base film.
  • the vapor deposition means for forming this inorganic oxide layer is not particularly limited as long as the inorganic oxide can be vapor deposited on the synthetic resin base film without causing deterioration such as shrinkage and yellowing.
  • A Physical vapor deposition methods (Physical Vapor Deposition method; PVD method) such as vacuum deposition method, sputtering method, ion plating method, ion cluster beam method, (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method, A chemical vapor deposition method (Chemical Vapor Deposition method; CVD method) such as a photochemical vapor deposition method is employed.
  • PVD method Physical Vapor Deposition method
  • CVD method Chemical Vapor Deposition method
  • the vacuum vapor deposition method and the ion plating method are preferable from the viewpoint of high productivity and formation of a high-quality inorganic oxide layer.
  • the inorganic oxide constituting the inorganic oxide layer is not particularly limited as long as it has gas barrier properties.
  • aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, magnesium oxide Among them, aluminum oxide or silicon oxide having a good balance between gas barrier properties and price is particularly preferable.
  • the lower limit of the thickness (average thickness) of the inorganic oxide layer is preferably 0.3 nm, and particularly preferably 40 nm.
  • the upper limit of the thickness of the inorganic oxide layer is preferably 300 nm, and particularly preferably 80 nm. If the thickness of the inorganic oxide layer is smaller than the above lower limit, the gas barrier property may be lowered. On the other hand, when the thickness of the inorganic oxide layer exceeds the above upper limit, the flexibility of the inorganic oxide layer is reduced, and defects such as cracks are likely to occur.
  • the inorganic oxide layer may have a single layer structure or a multilayer structure of two or more layers.
  • 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 base film, the thickness of the inorganic oxide layer, and the like.
  • an adhesion improving surface treatment for example, corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, primer coating treatment, An undercoat process, an anchor coat process, a vapor deposition anchor coat process, etc. are mentioned.
  • the resin layer laminated on at least one side of the barrier film has a linear expansion coefficient of 30 ppm / ° C. or less, and preferably 20 ppm / ° C. or less.
  • the resin layer is not particularly limited as long as the linear expansion coefficient is a resin material in the range of 30 ppm / ° C. or less, but generally it is difficult to achieve such low linear expansion with a resin alone.
  • a resin material containing inorganic fine particles and reinforcing fibers is preferably used.
  • the inorganic fine particles include clay compounds such as carbon black and talc, which are generally used as a reinforcing material for resins, glass beads, carbonate fine particles such as calcium carbonate, and oxide fine particles such as alumina.
  • the reinforcing fiber include glass fiber, carbon fiber, and resin fiber.
  • the thickness of the resin layer formed on the barrier film or the resin layer having a linear expansion coefficient of 30 ppm / ° C. or less according to the present invention is 50 ⁇ m or more and 200 ⁇ m or less. A range is preferable.
  • At least one of the resin layers formed on the barrier film is a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less, and the method of achieving the linear expansion coefficient defined in the present invention
  • the fiber applicable in the present invention is preferably a fiber having a ratio of fiber length to fiber diameter of 25 or more, particularly an average fiber diameter of 4 nm or more and 200 nm or less, and an average fiber length of 100 nm or more and 20 ⁇ m or less. It is preferable to be within the range.
  • a content rate with respect to the resin material of a fiber it is preferable that it is 0.1 to 30 mass%.
  • fibers having a fiber diameter of less than 4 nm or exceeding 200 nm may be contained in the fiber, but the ratio is preferably 30% by mass or less, and desirably the fiber diameter of all fibers. Is preferably 4 nm or more and 200 nm or less, particularly 100 nm or less, particularly 60 nm or less.
  • the fiber is observed with a transmission electron microscope at a magnification of 100,000 times, the short axis of 100 or more fibers is measured as the fiber diameter, and the arithmetic average value is calculated as the fiber.
  • the average fiber diameter is calculated as the fiber diameter.
  • the fiber used in the present invention is preferably a cellulose fiber.
  • Cellulose fibers refer to cellulose microfibrils constituting the basic skeleton of plant cell walls or the like or constituent fibers thereof, and are usually aggregates of unit fibers having an average fiber diameter of about 4 nm.
  • the cellulose fiber contains a crystal structure of 40% or more.
  • Cellulose fibers used in the present invention may be those isolated from plants, but bacterial cellulose produced by bacteria is preferred, and in particular, the product from bacteria is treated with alkali to dissolve and remove the bacteria. It is suitable to use what is obtained without disaggregation.
  • the fibers may be ones in which the single fibers are not sufficiently aligned and are sufficiently separated so that the matrix material enters between them.
  • the average fiber diameter is the average diameter of single fibers.
  • the fiber according to the present invention may be one in which a plurality of (may be many) single fibers are gathered into a bundle to form one yarn.
  • the fiber diameter is defined as the average value of the diameter of one yarn.
  • Bacterial cellulose consists of the latter yarn.
  • the length of the fiber applied to the present invention is not particularly limited, but an average length of 100 nm or more is preferable. When the average length of the cellulose fiber is shorter than 100 nm, the reinforcing effect is low, and the strength of the fiber-reinforced composite material may be insufficient. In addition, although a fiber length less than 100 nm may be contained in the fiber, it is preferable that the ratio is 30 mass% or less.
  • a resin material obtained by impregnating a matrix resin material into an aggregate of cellulose fibers described in JP-A-2007-51266 can also be used. Furthermore, a resin material obtained by dispersing cellulose fibers and then kneading the matrix resin can also be used.
  • the matrix resin material is not particularly limited.
  • a resin material having a linear expansion coefficient of 30 ppm or less is used for forming the cell side resin layer or the back side resin layer.
  • a resin layer having a linear expansion coefficient of 30 ppm or less is used as the cell-side resin layer, it is preferable to add a silane coupling agent or the like in order to improve the adhesion with the sealing material.
  • a ultraviolet absorber is not particularly limited as long as it is a compound that absorbs ultraviolet rays and can be efficiently converted into heat energy, and is stable to light, and a known one can be used.
  • salicylic acid-based UV absorbers have a high UV-absorbing function, good compatibility with the above-mentioned base polymer, and exist stably in the base polymer.
  • An acrylate ultraviolet absorber is preferable, and one or more selected from these groups may be used.
  • a polymer having an ultraviolet absorbing group in the molecular chain for example, “Hals Hybrid UV-G” series of Nippon Shokubai Co., Ltd.
  • a polymer having an ultraviolet absorbing group in such a molecular chain By using a polymer having an ultraviolet absorbing group in such a molecular chain, the compatibility with the polymer constituting the synthetic resin layer is high, and deterioration of the ultraviolet absorbing function due to bleeding out of the ultraviolet absorbent can be prevented.
  • the solar battery cell is conventionally thinned, and the back surface side sealing material layer 2, which is a low linear expansion resin material, is enclosed between the back surface of the solar battery cell 1 and the back surface side protection member 42 in the sealing material layer 2.
  • the solar cell module shown in FIG. 2 can be preferably used. Furthermore, in order to improve the adhesiveness of the back surface side sealing material layer which is said low linear expansion resin material, and a back surface side protection member, an adhesive layer can also be inserted among them.
  • the solar cell used in the present invention has a semiconductor junction such as a PN junction or a PIN junction inside, a silicon semiconductor material such as single crystal silicon, polycrystalline silicon, or amorphous silicon, or a compound semiconductor material such as GaAs or CuInSe.
  • a general solar cell material such as an organic material such as a dye-sensitized system can be used.
  • a crystal material such as single crystal silicon, polycrystalline silicon, GaAs, or CuInSe is used.
  • the solar cell used is preferably used.
  • the thickness of the solar cell according to the present invention may be about 200 to 300 ⁇ m, which is conventionally used for crystalline silicon, but a thin solar cell of 150 ⁇ m or less is preferable because the high effect of the present invention can be obtained.
  • a solar cell having a thickness of 30 to 150 ⁇ m using a thin silicon wafer is preferable.
  • ethylene-vinyl acetate EVA
  • polyvinyl butyral PVB
  • silicon resin urethane resin
  • acrylic resin fluorine resin
  • Resin materials such as ionomer resins, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, polyethylene resins, polypropylene resins, acid-modified polyolefin resins, and epoxy resins are used.
  • EVA having high adhesiveness is preferred.
  • the front surface electrode, the back surface electrode, and the wiring are formed of a conductive material such as silver, aluminum, copper, nickel, tin, gold, or an alloy thereof.
  • the electrode may have a single layer structure containing a conductive material or a multilayer structure.
  • SnO 2, ITO, IWO it may have a layer including a translucent conductive oxide such as ZnO.
  • the light incident side transparent protective member is usually a glass substrate such as silicate glass.
  • the thickness of the glass substrate is generally from 0.1 to 10 mm, and preferably from 0.3 to 5 mm.
  • the glass substrate may generally be chemically or thermally strengthened.
  • a resin material can also be used to reduce the weight of the solar cell module.
  • the resin material used as the light incident side transparent protective member is not particularly limited as long as the light receiving surface side of the solar cell is translucent.
  • an inorganic filler such as aluminum hydroxide or calcium hydroxide, a flame retardant, or the like may be sewn to provide nonflammability or flame retardancy. Further, it may be foamed by adding a foaming agent or the like, and may further be added with a plasticizer, a stabilizer, a foaming aid, an ultraviolet absorber, a pigment, or the like, and a metal foil is bonded thereto. It may be a thing.
  • Example 1 Preparation of back protection sheet ⁇ [Production of resin film]
  • a bacterial cellulose sheet having an acetyl group introduced therein was prepared in the same manner as described in JP-A-2007-51266, impregnated with an ultraviolet curable acrylic resin monomer TCDDMA (manufactured by Mitsubishi Chemical Corporation), and then irradiated with ultraviolet rays.
  • the resin film 1 having a thickness of 125 ⁇ m was produced.
  • the obtained resin film 1 was 18 ppm / degrees C.
  • the production conditions of the bacterial cellulose sheet are appropriately changed, and the resin film 2 having an average fiber diameter of 40 nm used, the resin film 3 having the same 8 nm, and Similarly, a resin film 4 having a thickness of 250 nm was produced.
  • the linear expansion coefficient of each obtained resin film they were 10 ppm / ° C., 4 ppm / ° C., and 25 ppm / ° C., respectively.
  • a resin film 5 having a thickness of 125 ⁇ m was prepared by mixing 0.075 g of Lucirin TPO (manufactured by BASF) and irradiating with ultraviolet rays. It was 32 ppm / degrees C as a result of measuring the linear expansion coefficient of the obtained resin film 5 by the same method.
  • Solar cell modules 1 to 13 having the configuration shown in FIG. 1 were produced.
  • the light incident side transparent protective member 41 composed of a glass plate (thickness 3 mm) and the back surface protective sheet 42 produced above.
  • two EVAs are connected.
  • a solar cell module was produced by sandwiching between sealing films.
  • the solar cell module was placed on a hot plate, and the solar cell module was subjected to a heating cycle test, with 6 hours as one cycle after the hot plate was operated at 100 ° C. for 3 hours and then stopped for 3 hours. And the nominal maximum output [W] in the time of 200 cycles, 400 cycles, and 600 cycles was calculated
  • the solar cell module of the present invention has a small output decrease in the heat cycle test, and a stable output can be obtained even after long-term use.
  • Example 2 In the production of the respective back surface protective sheets described in Example 1, resin films 1 to 5 and a commercially available low-density film were formed on a 12 ⁇ m thick PET film obtained by depositing 40 nm thick aluminum oxide by a vacuum deposition method as a barrier film. Each resin component constituting the linear expansion film MHD (manufactured by Nippon Steel Chemical Co., Ltd.) and polyethylene terephthalate (PET) film was dissolved in a solvent as appropriate, and then subjected to wet coating method (Wyer bar coating method). Each backside protective sheet was produced in the same manner except that the surface side resin layer and the backside resin layer were formed by coating and drying so as to have the same film thickness as that of each backside protective sheet produced in 1.
  • MHD manufactured by Nippon Steel Chemical Co., Ltd.
  • PET polyethylene terephthalate

Abstract

Provided is a solar battery rear surface protection sheet which can be stably used for a long period of time even when a thin solar battery cell is used.  Provided is also a solar battery module using the protection sheet.  The solar battery rear surface protection sheet is formed by layering a resin layer on both surfaces of a barrier film.  A resin layer having a linear expansion coefficient of 30 ppm/degrees C or below is layered on at least one side of the barrier film.

Description

太陽電池用裏面保護シート及び太陽電池モジュールSolar cell back surface protection sheet and solar cell module
　本発明は、太陽電池用裏面保護シートと、それを用いた太陽電池モジュールに関する。 The present invention relates to a back surface protection sheet for solar cells and a solar cell module using the same.
　近年、資源の有効利用や環境汚染防止等の観点から、太陽光を直接電気エネルギーに変換する太陽電池が注目され、開発が進められている。 In recent years, solar cells that directly convert sunlight into electrical energy have attracted attention and are being developed from the viewpoint of effective use of resources and prevention of environmental pollution.
　太陽電池モジュールは、一般的には、太陽光を受けて発電する太陽電池セルを、エチレン－ビニルアセテート（ＥＶＡ）やシリコン等の封止材を用い、表面および裏面の保護部材との間に挟持させた構造になっている。これらの太陽電池モジュールでは、セル１個体では起電力が不足するため、単独のセルから構成されることは少なく、通常は複数の太陽電池セルが直列または直並列に接続されて構成される。すなわち、図１に示すように、太陽電池セル１の電極間（表面電極１１と裏面電極１２）が、導電材料等の配線３を用いて接続され、これら太陽電池セル１と導電材料である配線３が、封止材（封止剤層２）を用いて、ガラスや樹脂板、樹脂フィルム、金属等からなる保護部材（光入射側透明保護部材４１と裏面保護シート４２）の間に挟持されている。 In general, a solar cell module uses a sealing material such as ethylene-vinyl acetate (EVA) or silicon to sandwich a solar cell that generates electricity by receiving sunlight between the front and back protective members. The structure is In these solar cell modules, since an electromotive force is insufficient in one cell, it is rarely configured from a single cell, and usually a plurality of solar cells are connected in series or series-parallel. That is, as shown in FIG. 1, the electrodes (surface electrode 11 and back electrode 12) between solar cells 1 are connected using a wiring 3 such as a conductive material, and these solar cells 1 and a wiring that is a conductive material. 3 is sandwiched between protective members (light incident side transparent protective member 41 and back surface protective sheet 42) made of glass, a resin plate, a resin film, metal, or the like using a sealing material (sealing agent layer 2). ing.
　一般的に樹脂材料からなる封止材や裏面保護シートは、昼間は入射した太陽光による加熱による温度上昇により膨張し、太陽光の当たらない夜間には冷却されて収縮するということが繰り返されている。一方、太陽電池の普及に伴い、太陽電池セルに用いられるシリコンウエハの供給不足や、コストダウン要求が高まってきており、最近では太陽電池セルを薄くする検討が進められている。このような薄層太陽電池セルを用いて作製した薄い太陽電池モジュールは、太陽電池セルの裏面側の封止材や裏面保護部材の温度上昇による熱収縮の影響をより受け易い。従って、太陽電池セルの割れや裏面電極のはがれ等の配線不良を起こすといった問題や、封止材と裏面保護材間の剥離が生じ、その隙間から水分が浸入して太陽電池セルを劣化させるといった問題が生じている。 In general, a sealing material and a back surface protection sheet made of a resin material are repeatedly expanded in the daytime due to a temperature rise due to heating by incident sunlight, and are cooled and contracted at night when sunlight is not applied. Yes. On the other hand, with the widespread use of solar cells, there is an increasing supply of silicon wafers used for solar cells and demands for cost reduction. Recently, studies have been conducted to make solar cells thinner. A thin solar battery module manufactured using such a thin-layer solar battery cell is more susceptible to thermal shrinkage due to the temperature rise of the sealing material on the back surface side of the solar battery cell and the back surface protection member. Therefore, problems such as cracking of the solar battery cell and peeling of the back electrode, and peeling between the sealing material and the back surface protection material occur, and moisture enters the gap to deteriorate the solar battery cell. There is a problem.
　これに対し、太陽電池セルの表面側と裏面側で接着力が異なる封止材を用いて太陽電池セルの反りを抑制する方法が提案されている（例えば、特許文献１参照）。しかしながら、提案されている方法では、接着力の差が時間経過とともに小さくなってしまうため、長期間にわたって効果を維持することが難しかった。 On the other hand, a method of suppressing the warpage of the solar battery cell using a sealing material having different adhesive strengths on the front surface side and the back surface side of the solar battery cell has been proposed (for example, see Patent Document 1). However, in the proposed method, the difference in adhesive strength becomes smaller with time, and it is difficult to maintain the effect over a long period of time.
　太陽電池の保護シートについては、従来から様々な検討が行われており、剛性を向上させる目的で、強化繊維としてガラス繊維等の無機繊維や、合成樹脂繊維等の有機繊維を含有した有機樹脂層を有する保護シートが提案されている（例えば、特許文献２、３参照）。これら提案されている方法は、いずれも加工寸法安定性や表面硬度の改良を目的としたものであり、上記の如き裏面保護シートの加熱による劣化に対して改良するものではない。 Various studies have been made on solar cell protective sheets, and an organic resin layer containing inorganic fibers such as glass fibers or organic fibers such as synthetic resin fibers as reinforcing fibers for the purpose of improving rigidity. The protection sheet which has this is proposed (for example, refer patent document 2, 3). All of these proposed methods are aimed at improving the dimensional stability and surface hardness of the process, and do not improve against the deterioration of the back surface protective sheet as described above due to heating.
　また、平均線膨張率が５０ｐｐｍである層を有する透明多層シートを太陽電池に用いることが提案されている（例えば、特許文献４参照）。しかしながら、特許文献４には、透明多層シートを太陽電池のどこの部材に用いるか具体的な記載はされていない。さらに、これら従来から知られている強化繊維を含有した樹脂材料では、３０ｐｐｍ／℃以下の低線膨張フィルムは得られず、本発明の如き低線膨張の材料を太陽電池の裏面保護シートとして使用することはこれまでなかった。 It has also been proposed to use a transparent multilayer sheet having a layer with an average linear expansion coefficient of 50 ppm for a solar cell (for example, see Patent Document 4). However, Patent Document 4 does not specifically describe which member of the solar cell the transparent multilayer sheet is used for. Furthermore, these conventionally known resin materials containing reinforcing fibers do not provide a low linear expansion film of 30 ppm / ° C. or less, and the low linear expansion material as in the present invention is used as a back protective sheet for solar cells. Never before.
　一方、線膨張率３０ｐｐｍ／℃以下の樹脂材料として、セルロース繊維の集合体にマトリクス樹脂材料を含浸したものが最近報告されている（例えば、特許文献５参照）。しかしながら、これらの材料をバリア性フィルムと貼合し、太陽電池用裏面保護シートとして用いることはこれまで知られていなかった。 On the other hand, as a resin material having a linear expansion coefficient of 30 ppm / ° C. or less, a cellulose fiber aggregate impregnated with a matrix resin material has recently been reported (for example, see Patent Document 5). However, it has not been known until now that these materials are bonded to a barrier film and used as a back protective sheet for solar cells.
特開２００７－２９４８６９号公報JP 2007-294869 A 特開２００４－２２８３８８号公報JP 2004-228388 A 特開２００１－６８６９５号公報JP 2001-68695 A 特開２００７－２９８７３２号公報JP 2007-298732 A 特開２００７－５１２６６号公報JP 2007-51266 A
　上記の通り、太陽電池セルを薄くすることが求められているものの、従来と同様のモジュール構成で薄層太陽電池セルを使用した場合には、特に裏面シートの熱収縮による封止材との剥離が生じ易く、耐久性の点で課題があった。従って、本発明の目的は、薄型太陽電池セルを用いても長期間安定して使用可能な太陽電池用裏面シートと、それを用いた太陽電池モジュールを提供することである。 As described above, it is required to make the solar cell thinner, but when the thin-layer solar cell is used in the same module configuration as the conventional one, the separation from the sealing material due to thermal contraction of the back sheet in particular. Is likely to occur, and there is a problem in terms of durability. Accordingly, an object of the present invention is to provide a back sheet for a solar battery that can be used stably for a long period of time even if thin solar cells are used, and a solar battery module using the same.
　本発明の上記目的は、以下の構成により達成することができる。 The above object of the present invention can be achieved by the following configuration.
　１．バリア性フィルムの両面に樹脂層を積層した、太陽電池用裏面保護シートであって、該バリア性フィルムの少なくとも片面側に、線膨張率が３０ｐｐｍ／℃以下の樹脂層が積層されていることを特徴とする太陽電池用裏面保護シート。 1. A back protective sheet for a solar cell in which resin layers are laminated on both sides of a barrier film, wherein a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less is laminated on at least one side of the barrier film. The back surface protection sheet for solar cells characterized.
　２．前記樹脂層が、樹脂フィルムを積層して形成されることを特徴とする前記１記載の太陽電池用裏面保護シート。 2. 2. The back protective sheet for solar cell according to 1 above, wherein the resin layer is formed by laminating a resin film.
　３．前記線膨張率が３０ｐｐｍ／℃以下の樹脂層が、平均繊維径が４ｎｍ以上、２００ｎｍ以下の繊維を含有する樹脂層であることを特徴とする前記１または２記載の太陽電池用裏面保護シート。 3. 3. The solar cell back surface protective sheet according to 1 or 2, wherein the resin layer having a linear expansion coefficient of 30 ppm / ° C. or less is a resin layer containing fibers having an average fiber diameter of 4 nm to 200 nm.
　４．前記１から３のいずれか１項に記載の太陽電池用裏面保護シートを用いて作製したことを特徴とする太陽電池モジュール。 4. A solar cell module produced using the solar cell back surface protective sheet according to any one of 1 to 3 above.
　本発明によれば、薄層太陽電池セルを用いた太陽電池モジュールにおいて、使用時の加熱冷却に対して安定で長期間使用可能な太陽電池用裏面保護シートを提供できる。 According to the present invention, a solar cell module using thin-layer solar cells can provide a solar cell back surface protection sheet that is stable against heating and cooling during use and can be used for a long period of time.
一般的な太陽電池モジュールの断面の一例を示す概略図である。It is the schematic which shows an example of the cross section of a common solar cell module. 一般的な太陽電池モジュールの他の態様を示す概略断面図である。It is a schematic sectional drawing which shows the other aspect of a common solar cell module. 本発明の太陽電池用裏面保護シートの態様を示す概略断面図である。It is a schematic sectional drawing which shows the aspect of the back surface protection sheet for solar cells of this invention.
　本発明を更に詳しく説明する。 The present invention will be described in more detail.
　以下本発明を実施するための最良の形態について詳細に説明するが、本発明はこれらに限定されるものではない。 Hereinafter, the best mode for carrying out the present invention will be described in detail, but the present invention is not limited thereto.
　以下、図面を参照しながら本発明の好ましい実施形態について説明する。 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
　図１および図２は、一般的な太陽電池モジュールの一例を示す概略断面図の一部であり、図１では隣接する太陽電池セル１を配線３で接続している様子を示した概略図である。 FIG. 1 and FIG. 2 are a part of a schematic cross-sectional view showing an example of a general solar battery module. FIG. 1 is a schematic diagram showing a state in which adjacent solar battery cells 1 are connected by wiring 3. is there.
　このように接続された太陽電池セル１は、封止材層２を介して光入射側透明保護部材４１と裏面保護シート４２に挟持されている。 The solar cells 1 connected in this way are sandwiched between the light incident side transparent protective member 41 and the back surface protective sheet 42 via the sealing material layer 2.
　本発明は、この裏面保護シート４２に関するものであり、図３に示す様に、バリア性フィルム５１と、その両面に配置されたセル側樹脂層５２（セル側フィルム５２）と裏面側樹脂層５３（裏面側フィルム５３）から構成される積層体であり、セル側樹脂層５２または裏面側樹脂層５３のいずれか一方または両方が線膨張率３０ｐｐｍ／℃以下の樹脂材料であることを特徴とする。本発明においては、本発明の目的効果をいかんなく発揮できる観点から、少なくともセル側樹脂層５２が線膨張率３０ｐｐｍ／℃以下の樹脂材料で構成されていることが、特に好ましい。さらに、バリア性フィルム５１と該セル側樹脂層５２および該裏面側樹脂層５３との間には、接着材層を有すこともできる。 The present invention relates to the back surface protection sheet 42, and as shown in FIG. 3, a barrier film 51, a cell side resin layer 52 (cell side film 52) and a back surface side resin layer 53 disposed on both surfaces thereof. It is a laminate composed of (back side film 53), and either one or both of the cell side resin layer 52 and the back side resin layer 53 is a resin material having a linear expansion coefficient of 30 ppm / ° C. or less. . In the present invention, it is particularly preferable that at least the cell-side resin layer 52 is made of a resin material having a linear expansion coefficient of 30 ppm / ° C. or less from the viewpoint that the object and effects of the present invention can be exhibited. Furthermore, an adhesive layer can be provided between the barrier film 51 and the cell-side resin layer 52 and the back-side resin layer 53.
　また、バリア性フィルム上に複数層の樹脂層が形成された構成の場合には、少なくも最表層の１層が、線膨張率３０ｐｐｍ／℃以下の樹脂材料で構成されていることが好ましい。 Further, in the case where a plurality of resin layers are formed on the barrier film, at least one outermost layer is preferably made of a resin material having a linear expansion coefficient of 30 ppm / ° C. or less.
　本発明で用いられるバリア性フィルムとは、少なくともガスバリア性を備えたフィルムであり、アルミ箔、銅箔等の金属薄膜や、基材フィルムに無機酸化物層を積層したフィルム等を用いることができるが、好ましくは、基材フィルムに無機酸化物層を積層したフィルムである。本発明に係るバリア性フィルムとしては、ガスバリア性として、ＪＩＳ　Ｋ７１２９　Ｂ法に従って測定した水蒸気透過率が、０．０１ｇ／ｍ２／ｄａｙ以下であり、より好ましくは１×１０－３ｇ／ｍ２／ｄａｙ以下であり、ＪＩＳ　Ｋ　７１２９－１９９２に準拠した方法で測定した水蒸気透過度（２５±０．５℃、相対湿度（９０±２）％ＲＨ）が、１×１０－３ｇ／（ｍ２・２４ｈ）以下のバリア性フィルムであることが好ましく、さらには、ＪＩＳ　Ｋ　７１２６－１９８７に準拠した方法で測定された酸素透過度が、１×１０－３ｍｌ／ｍ２・２４ｈ・ａｔｍ以下、水蒸気透過度（２５±０．５℃、相対湿度（９０±２）％ＲＨ）が、１×１０－３ｇ／（ｍ２・２４ｈ）以下のバリア性フィルムであることが好ましい。 The barrier film used in the present invention is a film having at least a gas barrier property, and a metal thin film such as an aluminum foil and a copper foil, a film in which an inorganic oxide layer is laminated on a base film, and the like can be used. However, a film obtained by laminating an inorganic oxide layer on a base film is preferable. The barrier film according to the present invention has a water vapor transmission rate of 0.01 g / m 2 / day or less, more preferably 1 × 10 −3 g / m 2 as gas barrier properties, measured according to JIS K7129 B method. Water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method according to JIS K 7129-1992 is 1 × 10 −3 g / (m 2 · 24 h) or less, and the oxygen permeability measured by a method according to JIS K 7126-1987 is preferably 1 × 10 −3 ml / m 2 · 24 h · atm or less. The barrier film preferably has a water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) of 1 × 10 −3 g / (m 2 · 24 h) or less.
　本発明の太陽電池用裏面保護シートにおける特に好ましい態様としては、基材フィルムの一方の面側に無機酸化物層を形成したバリア性フィルムの両面に、セル側樹脂層および裏面側樹脂層を設け、無機酸化物層にセル側樹脂層を形成し、このセル側樹脂層が線膨張率３０ｐｐｍ／℃以下の樹脂層で、封止材層と接している構成である。 As a particularly preferred embodiment of the back surface protection sheet for solar cells of the present invention, a cell-side resin layer and a back-side resin layer are provided on both surfaces of a barrier film in which an inorganic oxide layer is formed on one surface side of a base film. The cell-side resin layer is formed on the inorganic oxide layer, and the cell-side resin layer is a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less and is in contact with the sealing material layer.
　本発明でいう線膨張率は、具体的には下記に示す方法に従って測定した。 The linear expansion coefficient referred to in the present invention was specifically measured according to the method shown below.
　セイコーインスツルメンツ社製のＴＭＡ－ＳＳ６１００を用い、膜厚１００μｍ、幅４ｍｍの樹脂層を、チャック間距離２０ｍｍで固定し、室温から１８０℃まで一旦昇温し残留歪みを取った後、室温から１０℃／Ｍｉｎ．で２５０℃まで昇温し、温度－歪み曲線をとり、ＡＳＴＭ　Ｄ　６９６に規定された方法に従って線膨張率を求めた。 Using a TMA-SS6100 manufactured by Seiko Instruments Inc., a resin layer having a film thickness of 100 μm and a width of 4 mm was fixed at a distance between chucks of 20 mm, and once the temperature was raised from room temperature to 180 ° C. to remove residual strain, room temperature to 10 ° C. / Min. The temperature was raised to 250 ° C., a temperature-strain curve was taken, and the linear expansion coefficient was determined according to the method specified in ASTM D 696.
　本発明に適用可能な基材フィルムは、合成樹脂を主成分として形成され、特に限定されるものではないが、例えば、ポリエチレン系樹脂、ポリプロピレン系樹脂、環状ポリオレフィン系樹脂、ポリスチレン系樹脂、アクリロニトリル－スチレン共重合体（ＡＳ樹脂）、アクリロニトリル－ブタジエン－スチレン共重合体（ＡＢＳ樹脂）、ポリ塩化ビニル系樹脂、フッ素系樹脂、ポリ（メタ）アクリル系樹脂、ポリカーボネート系樹脂、ポリエステル系樹脂、ポリアミド系樹脂、ポリイミド系樹脂、ポリアミドイミド系樹脂、ポリアリールフタレート系樹脂、シリコン系樹脂、ポリスルホン系樹脂、ポリフェニレンスルフィド系樹脂、ポリエーテルスルホン系樹脂、ポリウレタン系樹脂、アセタール系樹脂、セルロース系樹脂等が挙げられる。上記樹脂の中でも、高い耐熱性、強度、耐候性、耐久性、水蒸気等に対するガスバリア性等を有するポリエステル系樹脂、フッ素系樹脂及び環状ポリオレフィン系樹脂が好ましい。 The base film applicable to the present invention is formed with a synthetic resin as a main component and is not particularly limited. For example, a polyethylene-based resin, a polypropylene-based resin, a cyclic polyolefin-based resin, a polystyrene-based resin, acrylonitrile- 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 Resins, polyimide resins, polyamideimide resins, polyarylphthalate resins, silicon resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins, acetal resins, cellulose resins, etc. BeAmong the above resins, polyester resins, fluorine resins and cyclic polyolefin resins having high heat resistance, strength, weather resistance, durability, gas barrier properties against water vapor and the like are preferable.
　特に、ポリエステル系樹脂として、例えば、ポリエチレンテレフタレート、ポリエチレンナフタレート等が挙げられ、これらのポリエステル系樹脂の中でも、耐熱性、耐候性等の諸機能面及び価格面のバランスが良好なポリエチレンテレフタレートが特に好ましい。 In particular, examples of polyester resins include polyethylene terephthalate, polyethylene naphthalate, etc. Among these polyester resins, polyethylene terephthalate is particularly well-balanced in terms of various functions such as heat resistance, weather resistance, and price. preferable.
　上記基材フィルムの厚さは、７～２０μｍが好ましく、１０～１５μｍが特に好ましい。基材フィルムの厚さが７μｍ未満であると、無機酸化物層を形成するための蒸着加工の際にカールが発生しやすくなり、取扱いが困難になる等の不都合が発生する。逆に、２０μｍを超えると、太陽電池モジュールの薄型化及び軽量化の要請に反することになる。 The thickness of the base film is preferably 7 to 20 μm, particularly preferably 10 to 15 μm. When the thickness of the base film is less than 7 μm, the curling is likely to occur during the vapor deposition process for forming the inorganic oxide layer, and disadvantages such as difficulty in handling occur. On the other hand, when the thickness exceeds 20 μm, it is contrary to the demand for reduction in thickness and weight of the solar cell module.
　また、基材フィルム上に形成する無機酸化物層は、酸素、水蒸気等に対するガスバリア性を発現するための層であり、基材フィルムの表面に無機酸化物を蒸着することで形成される。この無機酸化物層を形成する蒸着手段としては、合成樹脂製の基材フィルムに収縮、黄変等の劣化を招来することなく無機酸化物が蒸着できれば特に限定されるものではなく、（ａ）真空蒸着法、スパッタリング法、イオンプレーティング法、イオンクラスタービーム法等の物理気相成長法（Ｐｈｙｓｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ法；ＰＶＤ法）、（ｂ）プラズマ化学気相成長法、熱化学気相成長法、光化学気相成長法等の化学気相成長法（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ法；ＣＶＤ法）が採用される。これらの蒸着法の中でも、生産性が高く良質な無機酸化物層が形成できる観点から、真空蒸着法やイオンプレーティング法が好ましい。 Further, the inorganic oxide layer formed on the base film is a layer for expressing a gas barrier property against oxygen, water vapor and the like, and is formed by depositing an inorganic oxide on the surface of the base film. The vapor deposition means for forming this inorganic oxide layer is not particularly limited as long as the inorganic oxide can be vapor deposited on the synthetic resin base film without causing deterioration such as shrinkage and yellowing. (A) Physical vapor deposition methods (Physical Vapor Deposition method; PVD method) such as vacuum deposition method, sputtering method, ion plating method, ion cluster beam method, (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method, A chemical vapor deposition method (Chemical Vapor Deposition method; CVD method) such as a photochemical vapor deposition method is employed. Among these vapor deposition methods, the vacuum vapor deposition method and the ion plating method are preferable from the viewpoint of high productivity and formation of a high-quality inorganic oxide layer.
　無機酸化物層を構成する無機酸化物としては、ガスバリア性を有するものであれば特に限定されるものではなく、例えば酸化アルミニウム、酸化珪素、酸化チタン、酸化ジルコニウム、酸化亜鉛、酸化スズ、酸化マグネシウム等が用いられ、中でもガスバリア性及び価格面のバランスが良好な酸化アルミニウム又は酸化珪素が特に好ましい。 The inorganic oxide constituting the inorganic oxide layer is not particularly limited as long as it has gas barrier properties. For example, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, magnesium oxide Among them, aluminum oxide or silicon oxide having a good balance between gas barrier properties and price is particularly preferable.
　無機酸化物層の厚さ（平均厚さ）の下限としては、０．３ｎｍが好ましく、４０ｎｍが特に好ましい。一方、無機酸化物層の厚さの上限としては、３００ｎｍが好ましく、８０ｎｍが特に好ましい。無機酸化物層の厚さが上記下限より小さいと、ガスバリア性が低下するおそれがある。一方、無機酸化物層の厚さが上記上限を超えると、無機酸化物層のフレキシビリティーが低下し、クラック等の欠陥が発生しやすくなる。 The lower limit of the thickness (average thickness) of the inorganic oxide layer is preferably 0.3 nm, and particularly preferably 40 nm. On the other hand, the upper limit of the thickness of the inorganic oxide layer is preferably 300 nm, and particularly preferably 80 nm. If the thickness of the inorganic oxide layer is smaller than the above lower limit, the gas barrier property may be lowered. On the other hand, when the thickness of the inorganic oxide layer exceeds the above upper limit, the flexibility of the inorganic oxide layer is reduced, and defects such as cracks are likely to occur.
　無機酸化物層は、単層構造でもよく、２層以上の多層構造でもよい。このように無機酸化物層を多層構造とすることで、蒸着の際に懸かる熱負担の軽減により基材フィルムの劣化が低減され、さらに基材フィルムと無機酸化物層との密着性等を改善することができる。また、上記物理気相成長法及び化学気相成長法における蒸着条件は、基材フィルムの樹脂種類、無機酸化物層の厚さ等に応じて適宜設計される。 The inorganic oxide layer may have a single layer structure or a multilayer structure of two or more layers. By making the inorganic oxide layer into a multilayer structure in this way, the deterioration of the base film is reduced by reducing the thermal burden applied during vapor deposition, and the adhesion between the base film and the inorganic oxide layer is further improved. can do. 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 base film, the thickness of the inorganic oxide layer, and the like.
　また、基材フィルムと無機酸化物層との密接着性等を向上させるため、基材フィルムの蒸着面に表面処理を施すと良い。このような密着性向上表面処理としては、例えばコロナ放電処理、オゾン処理、酸素ガス若しくは窒素ガス等を用いた低温プラズマ処理、グロー放電処理、化学薬品等を用いた酸化処理や、プライマーコート処理、アンダーコート処理、アンカーコート処理、蒸着アンカーコート処理などが挙げられる。 In addition, in order to improve the close adhesion between the base film and the inorganic oxide layer, it is preferable to perform a surface treatment on the deposition surface of the base film. As such an adhesion improving surface treatment, for example, corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, primer coating treatment, An undercoat process, an anchor coat process, a vapor deposition anchor coat process, etc. are mentioned.
　本発明においては、上記バリア性フィルムの少なくとも片面側に積層された樹脂層が、線膨張率３０ｐｐｍ／℃以下であることを特徴とし、２０ｐｐｍ／℃以下であることが好ましい。該樹脂層としては、線膨張率が３０ｐｐｍ／℃以下の範囲樹脂材料であれば特に限定はされないが、一般的に樹脂単独でこのような低線膨張を達成することは難しいため、補強材として無機微粒子や強化繊維を含有した樹脂材料が好ましく用いられる。該無機微粒子としては、一般的に樹脂の補強材として用いられるカーボンブラック、タルク等の粘土化合物、ガラスビーズ、炭酸カルシウム等の炭酸塩微粒子、アルミナ等の酸化物微粒子等が挙げられる。また、該強化繊維としては、ガラス繊維、炭素繊維、樹脂繊維等が挙げられる。 In the present invention, the resin layer laminated on at least one side of the barrier film has a linear expansion coefficient of 30 ppm / ° C. or less, and preferably 20 ppm / ° C. or less. The resin layer is not particularly limited as long as the linear expansion coefficient is a resin material in the range of 30 ppm / ° C. or less, but generally it is difficult to achieve such low linear expansion with a resin alone. A resin material containing inorganic fine particles and reinforcing fibers is preferably used. Examples of the inorganic fine particles include clay compounds such as carbon black and talc, which are generally used as a reinforcing material for resins, glass beads, carbonate fine particles such as calcium carbonate, and oxide fine particles such as alumina. Examples of the reinforcing fiber include glass fiber, carbon fiber, and resin fiber.
　また、本発明の太陽電池用裏面保護シートにおいて、バリア性フィルム上に形成する樹脂層あるいは、本発明に係る線膨張率３０ｐｐｍ／℃以下の樹脂層の厚さとしては、５０μｍ以上、２００μｍ以下の範囲であることが好ましい。 Moreover, in the back surface protection sheet for solar cells of the present invention, the thickness of the resin layer formed on the barrier film or the resin layer having a linear expansion coefficient of 30 ppm / ° C. or less according to the present invention is 50 μm or more and 200 μm or less. A range is preferable.
　本発明においては、バリア性フィルム上に形成する樹脂層の少なくとも１層は線膨張率３０ｐｐｍ／℃以下の樹脂層であることを特徴とするが、本発明で規定する線膨張率を達成する方法としては、特に制限はないが、繊維を含有する樹脂材料を用いることが好ましい。本発明で適用可能な繊維としては、繊維の長さと繊維径の比が２５以上の繊維であることが好ましく、特に平均繊維径が４ｎｍ以上、２００ｎｍ以下で、平均繊維長が１００ｎｍ以上２０μｍ以下の範囲内であることが好ましい。また、繊維の樹脂材料に対する含有率としては、０．１質量％以上、３０質量％以下であることが好ましい。本発明においては、繊維中に４ｎｍ未満、あるいは２００ｎｍを越える繊維径のものが含まれていても良いが、その割合は３０質量％以下であることが好ましく、望ましくは、すべての繊維の繊維径が４ｎｍ以上で、かつ２００ｎｍ以下、特に１００ｎｍ以下、とりわけ６０ｎｍ以下であることが望ましい。 In the present invention, at least one of the resin layers formed on the barrier film is a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less, and the method of achieving the linear expansion coefficient defined in the present invention Although there is no restriction | limiting in particular, It is preferable to use the resin material containing a fiber. The fiber applicable in the present invention is preferably a fiber having a ratio of fiber length to fiber diameter of 25 or more, particularly an average fiber diameter of 4 nm or more and 200 nm or less, and an average fiber length of 100 nm or more and 20 μm or less. It is preferable to be within the range. Moreover, as a content rate with respect to the resin material of a fiber, it is preferable that it is 0.1 to 30 mass%. In the present invention, fibers having a fiber diameter of less than 4 nm or exceeding 200 nm may be contained in the fiber, but the ratio is preferably 30% by mass or less, and desirably the fiber diameter of all fibers. Is preferably 4 nm or more and 200 nm or less, particularly 100 nm or less, particularly 60 nm or less.
　本発明において、繊維の繊維径の測定方法としては、繊維を透過型電子顕微鏡にて１０万倍で観察し、１００個以上の繊維の短軸を繊維径として測定し、その算術平均値を繊維の平均繊維径とした。 In the present invention, as a method for measuring the fiber diameter of the fiber, the fiber is observed with a transmission electron microscope at a magnification of 100,000 times, the short axis of 100 or more fibers is measured as the fiber diameter, and the arithmetic average value is calculated as the fiber. The average fiber diameter.
　さらに、本発明で用いる繊維としては、セルロース繊維であることが好ましい。セルロース繊維とは、植物細胞壁の基本骨格等を構成するセルロースのミクロフィブリル又はこれの構成繊維をいい、通常、平均繊維径が４ｎｍ程度の単位繊維の集合体である。このセルロース繊維は、結晶構造を４０％以上含有するものが、高い強度と低い線膨張率を得る上で好ましい。 Furthermore, the fiber used in the present invention is preferably a cellulose fiber. Cellulose fibers refer to cellulose microfibrils constituting the basic skeleton of plant cell walls or the like or constituent fibers thereof, and are usually aggregates of unit fibers having an average fiber diameter of about 4 nm. In order to obtain a high strength and a low linear expansion coefficient, it is preferable that the cellulose fiber contains a crystal structure of 40% or more.
　本発明において用いるセルロース繊維としては、植物から分離されるものであってもよいが、バクテリアによって作り出されるバクテリアセルロースが好適であり、特にバクテリアからの産生物をアルカリ処理してバクテリアを溶解除去して得られるものを離解処理することなく用いるのが好適である。 Cellulose fibers used in the present invention may be those isolated from plants, but bacterial cellulose produced by bacteria is preferred, and in particular, the product from bacteria is treated with alkali to dissolve and remove the bacteria. It is suitable to use what is obtained without disaggregation.
　この繊維は、単繊維が、引き揃えられることなく、且つ相互間にマトリクス材料が入り込むように十分に離隔して存在するものであってもよい。この場合、平均繊維径は単繊維の平均径となる。また、本発明に係る繊維は、複数（多数であってもよい）本の単繊維が束状に集合して１本の糸条を構成しているものであってもよく、この場合、平均繊維径は１本の糸条の径の平均値として定義される。バクテリアセルロースは、後者の糸条よりなるものである。 The fibers may be ones in which the single fibers are not sufficiently aligned and are sufficiently separated so that the matrix material enters between them. In this case, the average fiber diameter is the average diameter of single fibers. Further, the fiber according to the present invention may be one in which a plurality of (may be many) single fibers are gathered into a bundle to form one yarn. The fiber diameter is defined as the average value of the diameter of one yarn. Bacterial cellulose consists of the latter yarn.
　本発明に適用する繊維の長さについては、特に限定されないが、平均長さで１００ｎｍ以上が好ましい。セルロース繊維の平均長さが１００ｎｍより短いと、補強効果が低く、繊維強化複合材料の強度が不十分となるおそれがある。なお、繊維中には繊維長さ１００ｎｍ未満のものが含まれていても良いが、その割合は３０質量％以下であることが好ましい。 The length of the fiber applied to the present invention is not particularly limited, but an average length of 100 nm or more is preferable. When the average length of the cellulose fiber is shorter than 100 nm, the reinforcing effect is low, and the strength of the fiber-reinforced composite material may be insufficient. In addition, although a fiber length less than 100 nm may be contained in the fiber, it is preferable that the ratio is 30 mass% or less.
　本発明においては、特開２００７－５１２６６号公報に記載されたセルロース繊維の集合体にマトリクス樹脂材料を含浸した樹脂材料を用いることもできる。さらに、セルロース繊維を分散した後、マトリクス樹脂に混練して得られた樹脂材料を用いることもできる。該マトリクス樹脂材料としては、特に限定されるものではないが、例えば、ポリエチレン系樹脂、ポリプロピレン系樹脂、環状ポリオレフィン系樹脂、ポリスチレン系樹脂、アクリロニトリル－スチレン共重合体（ＡＳ樹脂）、アクリロニトリル－ブタジエン－スチレン共重合体（ＡＢＳ樹脂）、ポリ塩化ビニル系樹脂、フッ素系樹脂、ポリ（メタ）アクリル系樹脂、ポリカーボネート系樹脂、ポリエステル系樹脂、ポリアミド系樹脂、ポリイミド系樹脂、ポリアミドイミド系樹脂、ポリアリールフタレート系樹脂、シリコン系樹脂、ポリスルホン系樹脂、ポリフェニレンスルフィド系樹脂、ポリエーテルスルホン系樹脂、ポリウレタン系樹脂、アセタール系樹脂、セルロース系樹脂等が挙げられる。これらのうち、セルロース繊維との親和性が高く、さらに高い耐熱性、強度、耐候性、耐久性を有するアクリル系樹脂とポリエステル系樹脂が好ましい。 In the present invention, a resin material obtained by impregnating a matrix resin material into an aggregate of cellulose fibers described in JP-A-2007-51266 can also be used. Furthermore, a resin material obtained by dispersing cellulose fibers and then kneading the matrix resin can also be used. The matrix resin material is not particularly limited. For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-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, polyaryl Examples thereof include phthalate resins, silicon resins, polysulfone resins, polyphenylene sulfide resins, polyether sulfone resins, polyurethane resins, acetal resins, and cellulose resins. Of these, acrylic resins and polyester resins having high affinity with cellulose fibers and higher heat resistance, strength, weather resistance, and durability are preferred.
　本発明においては、線膨張率が３０ｐｐｍ以下の樹脂材料を、セル側樹脂層あるいは裏面側樹脂層の形成用いることを特徴とする。線膨張率が３０ｐｐｍ以下の樹脂層を、セル側樹脂層として用いる場合は、封止材との密着性を高めるために、シランカップリング剤等を添加することが好ましい。また、裏面側樹脂層として用いる場合には、耐候性を付与するために紫外線吸収剤を添加することが好ましい。この紫外線吸収剤としては、紫外線を吸収し、効率よく熱エネルギーに変換できるもので、かつ光に対して安定な化合物であれば特に限定されるものではなく公知のものを使用することができる。中でも、紫外線吸収機能が高く、上記基材ポリマーとの相溶性が良好で、基材ポリマー中に安定して存在するサリチル酸系紫外線吸収剤、ベンゾフェノン系紫外線吸収剤、ベンゾトリアゾール系紫外線吸収剤及びシアノアクリレート系紫外線吸収剤が好ましく、これらの群より選択される１種又は２種以上のものを用いるとよい。また、紫外線吸収剤としては、分子鎖に紫外線吸収基を有するポリマー（例えば、（株）日本触媒の「ハルスハイブリッドＵＶ－Ｇ」シリーズなど）も好適に使用される。かかる分子鎖に紫外線吸収基を有するポリマーを用いることで、合成樹脂層を構成するポリマーとの相溶性が高く、紫外線吸収剤のブリードアウト等による紫外線吸収機能の劣化を防止することができる。 In the present invention, a resin material having a linear expansion coefficient of 30 ppm or less is used for forming the cell side resin layer or the back side resin layer. In the case where a resin layer having a linear expansion coefficient of 30 ppm or less is used as the cell-side resin layer, it is preferable to add a silane coupling agent or the like in order to improve the adhesion with the sealing material. Moreover, when using as a back surface side resin layer, in order to provide a weather resistance, it is preferable to add a ultraviolet absorber. The ultraviolet absorber is not particularly limited as long as it is a compound that absorbs ultraviolet rays and can be efficiently converted into heat energy, and is stable to light, and a known one can be used. Among them, salicylic acid-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, and cyano have a high UV-absorbing function, good compatibility with the above-mentioned base polymer, and exist stably in the base polymer. An acrylate ultraviolet absorber is preferable, and one or more selected from these groups may be used. Further, as the ultraviolet absorber, a polymer having an ultraviolet absorbing group in the molecular chain (for example, “Hals Hybrid UV-G” series of Nippon Shokubai Co., Ltd.) is also preferably used. By using a polymer having an ultraviolet absorbing group in such a molecular chain, the compatibility with the polymer constituting the synthetic resin layer is high, and deterioration of the ultraviolet absorbing function due to bleeding out of the ultraviolet absorbent can be prevented.
　この太陽電池セルを従来から薄くするとともに、封止材層２のうち、太陽電池セル１の裏面と裏面側保護部材４２の間に低線膨張樹脂材料である裏面側封止材層２を封入した図２に示した太陽電池モジュールが好ましく使用できる。さらに、上記の低線膨張樹脂材料である裏面側封止材層と裏面側保護部材との接着性を高めるために、その間に接着層を挿入することもできる。 The solar battery cell is conventionally thinned, and the back surface side sealing material layer 2, which is a low linear expansion resin material, is enclosed between the back surface of the solar battery cell 1 and the back surface side protection member 42 in the sealing material layer 2. The solar cell module shown in FIG. 2 can be preferably used. Furthermore, in order to improve the adhesiveness of the back surface side sealing material layer which is said low linear expansion resin material, and a back surface side protection member, an adhesive layer can also be inserted among them.
　本発明に用いられる太陽電池セルは、内部にＰＮ接合やＰＩＮ接合等の半導体接合を有す、単結晶シリコンや多結晶シリコン、アモルファスシリコン等のシリコン半導体材料、ＧａＡｓやＣｕＩｎＳｅ等の化合物系半導体材料、色素増感系等の有機系材料など一般的な太陽電池材料を用いることができるが、本発明の太陽電池モジュール構成においては、単結晶シリコン、多結晶シリコン、ＧａＡｓ、ＣｕＩｎＳｅ等の結晶材料を用いた太陽電池セルが好ましく用いられる。 The solar cell used in the present invention has a semiconductor junction such as a PN junction or a PIN junction inside, a silicon semiconductor material such as single crystal silicon, polycrystalline silicon, or amorphous silicon, or a compound semiconductor material such as GaAs or CuInSe. A general solar cell material such as an organic material such as a dye-sensitized system can be used. In the solar cell module configuration of the present invention, a crystal material such as single crystal silicon, polycrystalline silicon, GaAs, or CuInSe is used. The solar cell used is preferably used.
　本発明に係る太陽電池セルの厚みは、結晶シリコン系で従来から用いられている２００～３００μｍ程度でも良いが、１５０μｍ以下の薄型太陽電池セルが本発明の高い効果が得られるために好ましい。特に、薄型のシリコンウエハを使用した厚み３０～１５０μｍの太陽電池セルが好ましい。 The thickness of the solar cell according to the present invention may be about 200 to 300 μm, which is conventionally used for crystalline silicon, but a thin solar cell of 150 μm or less is preferable because the high effect of the present invention can be obtained. In particular, a solar cell having a thickness of 30 to 150 μm using a thin silicon wafer is preferable.
　本発明の太陽電池モジュールでは、封止層として一般的に透明封止材として用いられているエチレン－ビニルアセテート（ＥＶＡ）やポリビニルブチラール（ＰＶＢ）、シリコン樹脂、ウレタン樹脂、アクリル樹脂、フッ素系樹脂、アイオノマー樹脂、エチレン－アクリル酸共重合体、エチレン－メタクリル酸共重合体、ポリエチレン系樹脂、ポリプロピレン系樹脂、酸変性ポリオレフィン系樹脂、エポキシ系樹脂等の樹脂材料が用いられ、特に透光性と接着性が高いＥＶＡが好ましい。 In the solar cell module of the present invention, ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), silicon resin, urethane resin, acrylic resin, fluorine resin, which are generally used as a transparent sealing material as a sealing layer Resin materials such as ionomer resins, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, polyethylene resins, polypropylene resins, acid-modified polyolefin resins, and epoxy resins are used. EVA having high adhesiveness is preferred.
　表面電極、裏面電極、および配線は、銀やアルミ、銅、ニッケル、錫、金等、もしくはこれらの合金等の導電性材料を含んだもので形成される。なお、電極は導電性材料を含んだ単層構造であってもよいし、多層構造であってもよい。また、これらの導電性材料を含む層に加えて、ＳｎＯ２、ＩＴＯ、ＩＷＯ、ＺｎＯ等の透光性導電酸化物を含む層を有していてもよい。 The front surface electrode, the back surface electrode, and the wiring are formed of a conductive material such as silver, aluminum, copper, nickel, tin, gold, or an alloy thereof. Note that the electrode may have a single layer structure containing a conductive material or a multilayer structure. In addition to the layer containing these conductive materials, SnO 2, ITO, IWO, it may have a layer including a translucent conductive oxide such as ZnO.
　光入射側透明保護部材は、通常珪酸塩ガラスなどのガラス基板であるのがよい。ガラス基板の厚さは、０．１～１０ｍｍが一般的であり、０．３～５ｍｍが好ましい。ガラス基板は、一般に、化学的に、或いは熱的に強化させたものであってもよい。また、太陽電池モジュールを軽量化するために樹脂材料を用いることもできる。 The light incident side transparent protective member is usually a glass substrate such as silicate glass. The thickness of the glass substrate is generally from 0.1 to 10 mm, and preferably from 0.3 to 5 mm. The glass substrate may generally be chemically or thermally strengthened. A resin material can also be used to reduce the weight of the solar cell module.
　光入射側透明保護部材として用いられる樹脂材料は、太陽電池セルの受光面側が透光性のものであれば、特に限定されるものではなく、例えばポリカーボネート、アクリル樹脂、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリ塩化ビニル、ポリエチレン、ポリプロピレン、ポリスチレン、ポリ酢酸ビニル、ポリ塩化ビニリデン、ポリフェニレンサルファイド、ポリアミド、ポリウレタン、ポリメタクリレート、ポリアクリロニトリル、ＡＢＳ，フェノール樹脂、メラミン樹脂、ホルムアルデヒド樹脂、尿素樹脂、不飽和ポリエステル樹脂、エポキシ樹脂、天然ゴムやその誘導体から成るものでも良く、または前記樹脂の２種類以上から成るものでもよいし、２種類以上の樹脂板を貼り合わせたものでもよい。また、水酸化アルミニウムや水酸化カルシウム等の無機フィラーや難燃剤等を縫合して、不燃性、難燃性を具備させてもよい。また、発泡剤等を添加して発泡させたものでもよく、さらには可塑剤、安定剤、発泡助剤、紫外線吸収剤、顔料などが添加されているものでも良く、金属箔が貼り合わされているものでもよい。 The resin material used as the light incident side transparent protective member is not particularly limited as long as the light receiving surface side of the solar cell is translucent. For example, polycarbonate, acrylic resin, polyethylene terephthalate, polybutylene terephthalate, Polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinylidene chloride, polyphenylene sulfide, polyamide, polyurethane, polymethacrylate, polyacrylonitrile, ABS, phenol resin, melamine resin, formaldehyde resin, urea resin, unsaturated polyester resin, It may be composed of an epoxy resin, natural rubber or a derivative thereof, or may be composed of two or more kinds of the above resins, or may be composed of two or more kinds of resin plates bonded together. In addition, an inorganic filler such as aluminum hydroxide or calcium hydroxide, a flame retardant, or the like may be sewn to provide nonflammability or flame retardancy. Further, it may be foamed by adding a foaming agent or the like, and may further be added with a plasticizer, a stabilizer, a foaming aid, an ultraviolet absorber, a pigment, or the like, and a metal foil is bonded thereto. It may be a thing.
　以下、実施例を挙げて本発明を具体的に説明するが、本発明の態様はこれに限定されない。 Hereinafter, although an Example is given and this invention is demonstrated concretely, the aspect of this invention is not limited to this.
　実施例１
　《裏面保護シートの作製》
　〔樹脂フィルムの作製〕
　特開２００７－５１２６６号公報に記載の方法と同様にして、アセチル基を導入したバクテリアセルロースシートを作製し、紫外線硬化型アクリル樹脂モノマーＴＣＤＤＭＡ（三菱化学（株）社製）を含浸した後、紫外線を照射して厚さ１２５μｍの樹脂フィルム１を作製した。ＴＥＭ観察により用いたアセチル基を導入したバクテリアセルロース繊維の平均繊維径は１８０ｎｍであった。また、得られた樹脂フィルム１をセイコーインスツルメンツ製ＴＭＡ／ＳＳ６１００を用い、ＡＳＴＭ　Ｄ　６９６に規定された方法で線膨張率を測定した結果、１８ｐｐｍ／℃であった。 Example 1
《Preparation of back protection sheet》
[Production of resin film]
A bacterial cellulose sheet having an acetyl group introduced therein was prepared in the same manner as described in JP-A-2007-51266, impregnated with an ultraviolet curable acrylic resin monomer TCDDMA (manufactured by Mitsubishi Chemical Corporation), and then irradiated with ultraviolet rays. The resin film 1 having a thickness of 125 μm was produced. The average fiber diameter of bacterial cellulose fibers introduced with acetyl groups used by TEM observation was 180 nm. Moreover, as a result of measuring the linear expansion coefficient by the method prescribed | regulated to ASTMD696 using the TMA / SS6100 by Seiko Instruments, the obtained resin film 1 was 18 ppm / degrees C.
　また、樹脂フィルム１の作製と同様の方法で、バクテリアセルロースシートの作製条件を適宜変化させ、用いたバクテリアセルロース繊維の平均繊維径が４０ｎｍである樹脂フィルム２、同じく８ｎｍである樹脂フィルム３、および同じく２５０ｎｍである樹脂フィルム４を作製した。得られた各樹脂フィルムの線膨張率を測定した結果、それぞれ１０ｐｐｍ／℃、４ｐｐｍ／℃、２５ｐｐｍ／℃であった。 In addition, in the same manner as the production of the resin film 1, the production conditions of the bacterial cellulose sheet are appropriately changed, and the resin film 2 having an average fiber diameter of 40 nm used, the resin film 3 having the same 8 nm, and Similarly, a resin film 4 having a thickness of 250 nm was produced. As a result of measuring the linear expansion coefficient of each obtained resin film, they were 10 ppm / ° C., 4 ppm / ° C., and 25 ppm / ° C., respectively.
　次に、硬化性樹脂であるジメチロールトリシクロデカンジメタクリレート６０ｇと、無機フィラーであるコロイダルシリカ溶液（日産化学社製　スノーテックＭＥＫ－ＳＰ・固形分３０％）３００ｇと、光重合開始剤であるＬｕｃｉｒｉｎ　ＴＰＯ（ＢＡＳＦ社製）０．０７５ｇとを混合し、紫外線を照射して厚さ１２５μｍの樹脂フィルム５を作製した。得られた樹脂フィルム５の線膨張率を同様の方法で測定した結果、３２ｐｐｍ／℃であった。 Next, 60 g of dimethylol tricyclodecane dimethacrylate as a curable resin, 300 g of colloidal silica solution (Nissan Chemical Co., Ltd. Snowtech MEK-SP, solid content 30%) as an inorganic filler, and a photopolymerization initiator A resin film 5 having a thickness of 125 μm was prepared by mixing 0.075 g of Lucirin TPO (manufactured by BASF) and irradiating with ultraviolet rays. It was 32 ppm / degrees C as a result of measuring the linear expansion coefficient of the obtained resin film 5 by the same method.
　〔裏面保護シートの作製〕
　上記の作製した樹脂フィルム１～５、および市販の低線膨張フィルムであるＭＨＤ（新日鐵化学（株）社製）と、厚さ１２５μｍのポリエチレンテレフタレート（ＰＥＴ）フィルムと、バリア性フィルムとして真空蒸着法により厚さ４０ｎｍの酸化アルミニウムを蒸着した厚さ１２μｍのＰＥＴフィルムを用い、表１に記載した各フィルムの組み合わせでドライラミネート加工により積層接着することで、裏面保護シートＢＳ－１～ＢＳ－１１を作製した。各層の接着には、ポリウレタン系接着剤を適宜使用した。 [Preparation of back protection sheet]
Resin films 1-5 prepared above, and a commercially available low linear expansion film MHD (manufactured by Nippon Steel Chemical Co., Ltd.), a polyethylene terephthalate (PET) film having a thickness of 125 μm, and a vacuum as a barrier film Using a PET film having a thickness of 12 μm obtained by vapor-depositing aluminum oxide having a thickness of 40 nm by a vapor deposition method, the back protection sheets BS-1 to BS- 11 was produced. For adhesion of each layer, a polyurethane-based adhesive was appropriately used.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　《太陽電池モジュールの作製》
　図１に記載の構成からなる太陽電池モジュール１～１３を作製した。ガラス板（厚さ３ｍｍ）で構成される光入射側透明保護部材４１と、上記で作製した裏面保護シート４２との間に太陽電池セル１を４つ直列に接続した状態で、２枚のＥＶＡ封止フィルムで挟んで太陽電池モジュールを製造した。太陽電池セル１は、単結晶シリコンウエハを用い、表面電極１１および裏面電極１２として、それぞれアルミ電極を用いた、厚みが５０μｍ、１５０μｍ、２５０μｍの３種を用いた。なお、封止は、真空ラミネータで、真空下、温度１５０℃で、加熱圧着することにより行った。 << Production of solar cell module >>
Solar cell modules 1 to 13 having the configuration shown in FIG. 1 were produced. In the state where four solar cells 1 are connected in series between the light incident side transparent protective member 41 composed of a glass plate (thickness 3 mm) and the back surface protective sheet 42 produced above, two EVAs are connected. A solar cell module was produced by sandwiching between sealing films. As the solar cell 1, a single crystal silicon wafer was used, and three types having a thickness of 50 μm, 150 μm, and 250 μm, each using an aluminum electrode as the front electrode 11 and the back electrode 12, were used. Sealing was performed by thermocompression bonding with a vacuum laminator at a temperature of 150 ° C. under vacuum.
　《太陽電池モジュールの評価》
　上記で作製した太陽電池モジュール１～１３のそれぞれに、ＡＭ１．５にスペクトル調整したソーラーシミュレータによって、２５℃、照射強度１０００ｍＷ／ｃｍ２の擬似太陽光を照射し、太陽電池の開放電圧［Ｖ］、および、１ｃｍ２当たりの公称最大出力動作電流［Ａ］および公称最大出力動作電圧［Ｖ］を測定し、これらの積から公称最大出力［Ｗ］（ＪＩＳ　Ｃ８９１１　１９９８）を求め、これを各モジュールの基準出力とした。 << Evaluation of solar cell module >>
Each of the solar cell modules 1 to 13 produced above was irradiated with pseudo-sunlight with an irradiation intensity of 1000 mW / cm 2 by a solar simulator whose spectrum was adjusted to AM 1.5, and the open-circuit voltage [V] of the solar cell was irradiated. , And a nominal maximum output operating current [A] and a nominal maximum output operating voltage [V] per cm 2 , and a nominal maximum output [W] (JIS C8911 1998) is obtained from the product of these, and this is calculated for each module. Standard output.
　次に、上記太陽電池モジュールをホットプレート上に設置し、ホットプレートを１００℃設定で３時間運転した後に３時間停止するという６時間を１サイクルとして、太陽電池モジュールの加熱サイクル試験を実施した。そして、２００サイクル、４００サイクル、６００サイクルの時点での公称最大出力［Ｗ］を求め、下式に従って出力比を求めた。 Next, the solar cell module was placed on a hot plate, and the solar cell module was subjected to a heating cycle test, with 6 hours as one cycle after the hot plate was operated at 100 ° C. for 3 hours and then stopped for 3 hours. And the nominal maximum output [W] in the time of 200 cycles, 400 cycles, and 600 cycles was calculated | required, and the output ratio was calculated | required according to the following formula.
　　出力比＝加熱サイクル試験後の公称最大出力／基準出力×１００（％）
　得られた結果を、結果を表２に示す。 Output ratio = nominal maximum output after heating cycle test / reference output x 100 (%)
The results obtained are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に記載の結果より明らかなように、本発明の太陽電池モジュールは、加熱サイクル試験での出力低下が小さく、長期間の使用においても安定した出力が得られることがわかる。 As is clear from the results shown in Table 2, it can be seen that the solar cell module of the present invention has a small output decrease in the heat cycle test, and a stable output can be obtained even after long-term use.
　実施例２
　実施例１に記載の各裏面保護シートの作製において、バリア性フィルムとして真空蒸着法により厚さ４０ｎｍの酸化アルミニウムを蒸着した厚さ１２μｍのＰＥＴフィルム上に、樹脂フィルム１～５、および市販の低線膨張フィルムであるＭＨＤ（新日鐵化学（株）社製）、ポリエチレンテレフタレート（ＰＥＴ）フィルムを構成する各樹脂成分を適宜溶媒に溶解した後、湿式塗布法（ワーヤーバー塗布方法）により実施例１で作製した各裏面保護シートと同様の膜厚になるように塗布、乾燥して表面側樹脂層及び裏面側樹脂層を形成した以外は同様にして各裏面保護シートを作製した。 Example 2
In the production of the respective back surface protective sheets described in Example 1, resin films 1 to 5 and a commercially available low-density film were formed on a 12 μm thick PET film obtained by depositing 40 nm thick aluminum oxide by a vacuum deposition method as a barrier film. Each resin component constituting the linear expansion film MHD (manufactured by Nippon Steel Chemical Co., Ltd.) and polyethylene terephthalate (PET) film was dissolved in a solvent as appropriate, and then subjected to wet coating method (Wyer bar coating method). Each backside protective sheet was produced in the same manner except that the surface side resin layer and the backside resin layer were formed by coating and drying so as to have the same film thickness as that of each backside protective sheet produced in 1.
　次いで、上記塗布法により作製した各裏面保護シートを用い、実施例１に記載の方法と同様にして、太陽電池モジュールを作製し、同様の評価を行った結果、実施例１の表２に記載したのと同様の効果を得ることができた。 Next, solar cell modules were produced in the same manner as in Example 1 using the respective back surface protective sheets produced by the above coating method, and the same evaluation was performed. As a result, the results are shown in Table 2 of Example 1. It was possible to obtain the same effect as that.
　１　太陽電池セル
　２　封止材層
　３　配線
　１１　表面電極
　１２　裏面電極
　４１　光入射側透明保護部材
　４２　裏面保護シート
　５１　バリア性フィルム
　５２　セル側フィルム
　５３　裏面側フィルム DESCRIPTION OF SYMBOLS 1 Solar cell 2 Sealing material layer 3 Wiring 11 Front surface electrode 12 Back surface electrode 41 Light incident side transparent protective member 42 Back surface protection sheet 51 Barrier film 52 Cell side film 53 Back surface side film

Claims (4)

  1. バリア性フィルムの両面に樹脂層を積層した、太陽電池用裏面保護シートであって、該バリア性フィルムの少なくとも片面側に、線膨張率が３０ｐｐｍ／℃以下の樹脂層が積層されていることを特徴とする太陽電池用裏面保護シート。 A back protective sheet for a solar cell in which resin layers are laminated on both sides of a barrier film, wherein a resin layer having a linear expansion coefficient of 30 ppm / ° C. or less is laminated on at least one side of the barrier film. The back surface protection sheet for solar cells characterized.
  2. 前記樹脂層が、樹脂フィルムを積層して形成されることを特徴とする請求項１記載の太陽電池用裏面保護シート。 The back protective sheet for a solar cell according to claim 1, wherein the resin layer is formed by laminating a resin film.
  3. 前記線膨張率が３０ｐｐｍ／℃以下の樹脂層が、平均繊維径が４ｎｍ以上、２００ｎｍ以下の繊維を含有する樹脂層であることを特徴とする請求項１または２記載の太陽電池用裏面保護シート。 The back protective sheet for solar cells according to claim 1 or 2, wherein the resin layer having a linear expansion coefficient of 30 ppm / ° C or less is a resin layer containing fibers having an average fiber diameter of 4 nm or more and 200 nm or less. .
  4. 請求項１から３のいずれか１項に記載の太陽電池用裏面保護シートを用いて作製したことを特徴とする太陽電池モジュール。 A solar cell module produced using the back surface protective sheet for solar cell according to any one of claims 1 to 3.
PCT/JP2009/067403 2008-10-29 2009-10-06 Solar battery rear surface protection sheet and solar battery module WO2010050343A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008278002 2008-10-29
JP2008-278002 2008-10-29

Publications (1)

Publication Number Publication Date
WO2010050343A1 true WO2010050343A1 (en) 2010-05-06

Family

ID=42128709

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/067403 WO2010050343A1 (en) 2008-10-29 2009-10-06 Solar battery rear surface protection sheet and solar battery module

Country Status (1)

Country Link
WO (1) WO2010050343A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5273313B2 (en) * 2010-09-29 2013-08-28 Ｄｉｃ株式会社 Method for refining cellulose, cellulose nanofiber, master batch, and resin composition
JP2014045177A (en) * 2012-07-31 2014-03-13 Mitsubishi Plastics Inc Solar cell module and solar cell sealing material used for the same
EP2680317A4 (en) * 2011-02-23 2015-10-07 Mitsubishi Rayon Co Solar cell module
CN112582490A (en) * 2020-12-17 2021-03-30 苏州中来光伏新材股份有限公司 Photovoltaic backboard resisting mechanical impact, preparation process and photovoltaic module

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09148606A (en) * 1995-11-29 1997-06-06 Sanyo Electric Co Ltd Foldable film-shaped solar cell
JP2001053306A (en) * 1999-08-16 2001-02-23 Kanegafuchi Chem Ind Co Ltd Solar battery module and manufacture thereof
WO2006082964A1 (en) * 2005-02-07 2006-08-10 Kyoto University Fiber-reinforced composite material and method for production thereof, and precursor for producing fiber-reinforced composite material
JP2006316253A (en) * 2005-03-31 2006-11-24 Asahi Kasei Chemicals Corp Cellulose-containing resin composite
WO2008010462A1 (en) * 2006-07-19 2008-01-24 Pioneer Corporation Nanofiber sheet, process for producing the same, and fiber-reinforced composite material
JP2008053470A (en) * 2006-08-24 2008-03-06 Toyo Aluminium Kk Rear face protection sheet for solar battery module and solar battery module equipped therewith

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09148606A (en) * 1995-11-29 1997-06-06 Sanyo Electric Co Ltd Foldable film-shaped solar cell
JP2001053306A (en) * 1999-08-16 2001-02-23 Kanegafuchi Chem Ind Co Ltd Solar battery module and manufacture thereof
WO2006082964A1 (en) * 2005-02-07 2006-08-10 Kyoto University Fiber-reinforced composite material and method for production thereof, and precursor for producing fiber-reinforced composite material
JP2006316253A (en) * 2005-03-31 2006-11-24 Asahi Kasei Chemicals Corp Cellulose-containing resin composite
WO2008010462A1 (en) * 2006-07-19 2008-01-24 Pioneer Corporation Nanofiber sheet, process for producing the same, and fiber-reinforced composite material
JP2008053470A (en) * 2006-08-24 2008-03-06 Toyo Aluminium Kk Rear face protection sheet for solar battery module and solar battery module equipped therewith

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5273313B2 (en) * 2010-09-29 2013-08-28 Ｄｉｃ株式会社 Method for refining cellulose, cellulose nanofiber, master batch, and resin composition
US8735470B2 (en) 2010-09-29 2014-05-27 Dic Corporation Method for fibrillating cellulose, cellulose nanofiber, masterbatch, and resin composition
EP2680317A4 (en) * 2011-02-23 2015-10-07 Mitsubishi Rayon Co Solar cell module
JP2014045177A (en) * 2012-07-31 2014-03-13 Mitsubishi Plastics Inc Solar cell module and solar cell sealing material used for the same
CN112582490A (en) * 2020-12-17 2021-03-30 苏州中来光伏新材股份有限公司 Photovoltaic backboard resisting mechanical impact, preparation process and photovoltaic module

Similar Documents

Publication Publication Date Title
JP5115777B2 (en) Surface protection sheet for solar cell module
WO2010126088A1 (en) Sheet for solar cell, and solar cell module
US20060166023A1 (en) Backside protective sheet for solar battery module and solar battery module using the same
JP2002083988A (en) Rear surface protection sheet for solar cell module and solar cell module using the same
KR20080112283A (en) Backside protective sheet for solar battery module
EP2800148B1 (en) Protective sheet
JP2004247390A (en) Rear face protecting sheet for solar cell module, and solar cell module using it
JP2011014559A (en) Protective film for solar cell module, and solar cell module using the same
JP4992530B2 (en) Back protection sheet for solar cells
JP2004200322A (en) Rear surface protective sheet for solar cell module and solar cell module using the same
JP2010287682A (en) Back protective sheet for solar cell module
JP2001119051A (en) Rear-surface protecting sheet for solar cell module and solar cell module using the same
WO2010050343A1 (en) Solar battery rear surface protection sheet and solar battery module
JP6035818B2 (en) Back surface protection sheet for solar cell module and solar cell module
JP5109273B2 (en) Surface protection sheet for solar cell module
JP5136937B2 (en) Film for back surface protection sheet for solar cell module, and solar cell module using the same
JP2000307137A (en) Solar cell cover film and solar cell module using the same
JP2001044481A (en) Potecion sheet for solar battery module and the solar battery module using the same
JP2001068701A (en) Protective sheet for solar cell module and solar cell module using the same
EP3686938A1 (en) Solar cell module
JP4478250B2 (en) Protective sheet for solar cell module and solar cell module using the same
JP4757364B2 (en) Solar cell module
JP2011044690A (en) Sheet for solar cell, and solar cell module
JP2017139285A (en) Rear surface protective sheet for solar cell module and method of manufacturing the sane, and method of manufacturing solar cell module
CN220086060U (en) Light photovoltaic module and photovoltaic system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09823456

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: JP

122 Ep: pct application non-entry in european phase

Ref document number: 09823456

Country of ref document: EP

Kind code of ref document: A1