TWI604951B - Layered sheet and its manufacturing method, and back sheet for solar cell, solar cell module, and method for manufacturing solar cell back sheet - Google Patents

Description

Laminated sheet and manufacturing method thereof, and solar cell back sheet, solar cell module and solar cell back sheet manufacturing method

The present invention relates to a laminated sheet which is capable of both durability and adhesion to an encapsulating material. In particular, it relates to a laminated sheet which can be suitably used as a solar battery back sheet and a method of manufacturing the laminated sheet. Also, there is a backplane that contributes to the long-term reliability of the solar cell module.

In recent years, as a semi-permanent and pollution-free next-generation energy source, solar power generation is attracting attention, and solar cells are rapidly spreading. The solar cell is formed by encapsulating a power-generating element by a transparent encapsulating material such as an ethylene-vinyl acetate copolymer (EVA), and bonding a transparent substrate such as glass to a resin sheet called a back sheet. The sunlight is introduced into the solar cell through the transparent substrate. The sunlight introduced into the solar cell is absorbed by the power generating element, and the absorbed light energy is converted into electric energy. The converted electric energy is taken out using various wires connected to the power generating element for use in various electric appliances. Here, the conventional backsheet has been proposed to impart barrier properties or electricity by bonding various substrates to a low-cost and high-performance biaxially stretched polyethylene terephthalate (PET) by a dry laminated body. The construction of the characteristics. Further, the polyolefin-based resin is generally used as a substrate for a back sheet because it has good adhesion to the above-mentioned packaging material in addition to barrier properties.

On the other hand, in order to improve the durability and productivity of the back sheet and to apply the resin material other than PET, a back sheet of a laminated polybutylene terephthalate resin and a polycarbonate resin has been developed (Patent Document 1) Or a back sheet using a polybutylene terephthalate resin (Patent Document 2).

Moreover, conventional solar battery modules are prone to deterioration in a high-temperature and high-humidity environment, and improvement in moist heat resistance is an urgent task. In particular, from the viewpoints of weather resistance, transparency, productivity, and the like, the EVA is often used for the packaging material used for the solar cell module, but acetic acid is generated by high-temperature steam.

For this reason, in the production of the solar cell module, for example, the method described in Patent Document 3 has a material having a low water vapor transmission rate selected from the back sheet. There is also an invention which suppresses the infiltration of moisture and suppresses the generation of acetic acid, and the output characteristics of the solar cell module do not change for a long period of time.

Moreover, in the aspect of the patent document 4, the invention of the package material for solar cell modules which does not change the output characteristics for a long period of time by suppressing the acetic acid generate|occur|produced by EVA.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2009-141345

Patent Document 2 International Publication No. 2010/018662

Patent Document 3 Japanese Patent Laid-Open Publication No. 2012-199379

Patent Document 4 Japanese Patent Laid-Open Publication No. 2008-115344

However, polybutylene terephthalate resins generally have the disadvantage of being inferior in moisture and heat resistance and further inferior to the packaging material. Further, in the back sheet of the laminated polybutylene terephthalate resin and the polycarbonate resin described in Patent Document 1, the adhesion to the sealing material having improved moist heat resistance is not obtained, but the interlayer peeling is not obtained. problem. Further, the back sheet described in Patent Document 2 is also difficult to have both the moist heat resistance and the adhesion of the sealing material. Therefore, in the present invention, in view of the conventional problems, there is provided a laminated sheet which can be suitably used for a solar battery back sheet which is high in productivity, has durability, and is in close contact with a packaging material.

Further, in Patent Document 3, when the water vapor transmission rate is lowered, an inorganic vapor deposition film or the like is often used, and in the case of using an inorganic vapor deposition film, there is a problem that the cost is extremely high as compared with the case of not using it. On the other hand, in the case where the water vapor transmission rate is large, there is a case where the metal material used for each part of the solar battery cell is corroded by moisture, especially the discoloration caused by the corrosion of the collector electrode of the solar battery cell.

Further, in Patent Document 4, in addition to the influence of the addition of the additive to the EVA, the EVA change adjacent to the solar battery unit is also complicated by the use of the change verification operation.

The present invention has been made in view of the above problems. That is, an object of the present invention is to provide a back sheet for a solar cell module which is characterized by being inexpensive and capable of maintaining the power generation characteristics of the solar cell module for a long period of time and preventing discoloration of the collector electrode of the solar cell unit.

In order to solve the above problems, the present invention adopts the following configuration.

The invention of the first aspect is a layered sheet having a layer (P1 layer) having a polybutylene terephthalate resin as a main structural component and a layer (P3 layer) having a polyolefin resin as a main structural component.

According to the second aspect of the invention, the layer (P2 layer) having the polyolefin-based resin as a main structural component is adhered, and the P1 layer and the P3 layer are connected via the P2 layer.

The third aspect of the invention is that the P2 layer has a thickness of 15 to 50 μm.

The fourth invention is a crystallization parameter ΔTcg of the P1 layer measured by differential scanning calorimetry (DSC) of 7 to 30 °C.

According to a fifth aspect of the invention, the resin obtained by reacting the terminal blocking agent with the polybutylene terephthalate resin is a terminally blocked polybutylene terephthalate resin, and is a main structural component of the P1 layer. The polybutylene terephthalate resin contains a terminal-terminated polybutylene terephthalate resin.

In the sixth aspect of the invention, the P3 layer contains 0.1 to 30% by mass of inorganic particles.

The invention of the seventh aspect is that the amount of the rigid amorphous material of the P1 layer is from 30 to 50%.

In the eighth aspect of the invention, the P1 layer contains 0.1 to 5% by mass of a crystal nucleating agent.

In the ninth invention, the P3 layer contains 5 to 30% by mass of inorganic particles having a particle diameter of 3 μm or more and 20 μm or less, and contains 0.5 to 5% by mass of an adhesive polyolefin-based resin.

The invention of the tenth is that the acetic acid penetration rate Pa (g/m ² /day) at 85 ° C and the water vapor permeability Pw (g / m ² /day) at 40 ° C 90% RH conform to the formula (1). 200 ≦ Pa, and (2) Pw ≦ 2.5.

The invention of claim 11 is a solar battery back sheet comprising the laminated sheet according to any one of the above inventions.

The invention of the twelfth aspect is a solar battery using the solar battery back sheet of the eleventh invention.

The invention of claim 13 is a method for producing a laminated sheet according to any one of the second to tenth aspects, characterized in that the method comprises the steps of: polybutylene terephthalate The P1 layer raw material which is a main structural component, the P2 layer raw material which adheres a polyolefin resin as a main structural component, and the P3 layer raw material which has a polyolefin resin as a main structural component, and the different raw- After the respective melts, the P1 layer, the P2 layer, and the P3 layer are sequentially joined to form a layer, and are extruded into a sheet shape from the T die.

The invention of claim 14 is a back sheet for a solar cell characterized by an acetic acid transmittance Pa (g/m ² /day) at 85 ° C and a water vapor permeability Pw (g/ at 40 ° C 90% RH). m ² /day) conforms to formula (1) 200 ≦ Pa, and formula (2) Pw ≦ 2.5.

According to a fifteenth aspect of the invention, the layer of a main structural component selected from the group consisting of a polyester resin, a polyamide resin, and a fluororesin has a P4 layer.

According to a fifteenth aspect of the invention, in the fifteenth aspect of the invention, the layer having the structural component of the olefin resin as the P6 layer is a back sheet for a solar cell having a P4 layer and a P6 layer, and the P6 layer contains no Machine particles, P4 layer is located in the surface layer, P6 layer is located on the opposite surface layer of P4 layer, the thickness of the entire backing plate is set to Ta (μm), the thickness of P4 layer is set to T4 (μm), and the layer of P6 is When the thickness is T6 (μm) and the content of the inorganic particles in the P6 layer is M (% by mass), all of the formula (3) is 0.05 ≦M/T6 ≦ 0.5, and the formula (4) is 200 ≦ M/Ta. ≦500, formula (5) 0.3≦T4/Ta≦0.5.

The invention of the 17th or 16th aspect, wherein the P4 layer is a polytheneamine resin or a polybutylene terephthalate resin (PBT) as a main structural component.

The invention of the sixteenth or seventeenth aspect, wherein the one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer is used as a main structural component. The layer acts as a P5 layer and the P5 layer is located between the P4 layer and the P6 layer.

The invention of claim 19 is a solar battery module comprising the solar battery back sheet of the invention of any one of the 14th to 18th.

According to a ninth aspect of the invention, a method for producing a back sheet for a solar cell according to the eighteenth aspect of the invention, characterized in that the method for producing a back sheet for a solar cell according to the invention of the present invention a resin or PBT as a raw material of a main structural component, a raw material selected from the group consisting of a low crystalline soft polymer for a P5 layer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer; The olefin resin used as the main structural component of the P6 layer is supplied to each of the different extruders, and after each melting, the P4 layer, the P5 layer and the P6 layer are sequentially laminated to be laminated, and extruded from the T die. Flaky.

According to the inventions of the first to thirteenth aspects, it is possible to provide a laminated sheet excellent in durability, package adhesion, and interlayer adhesion which can be suitably used for the level of the solar battery back sheet. The related laminated sheet can be suitably used for a solar battery back sheet, and further, by using the back sheet, a high performance solar battery can be provided.

According to the solar cell back sheet according to the invention of claims 14 to 20, the acetic acid generated inside the solar cell module is released to the outside of the module by adjusting the acetic acid transmittance and the water vapor permeability of the back sheet. It is possible to prevent the discoloration of the collector electrode of the solar cell while maintaining the power generation characteristics for a long period of time, and to provide a heat resistance, yellowing of the P6 layer, partial discharge voltage, and adhesion to the package material by a preferable form. All are excellent back panels.

1‧‧‧ Backboard

2‧‧‧Package

3‧‧‧Power generation components (solar cells)

4‧‧‧Transparent substrate

5‧‧‧Face on the side of the package 2 of the solar cell backsheet

6‧‧‧Face on the opposite side of the package 2 of the solar cell backsheet

7‧‧ ‧ upper part of the fixture

8‧‧‧The lower part of the fixture

9‧‧‧ acetic acid

10‧‧‧ sieve

11‧‧‧Clamp

Fig. 1 is a cross-sectional view showing an example of a structure of a solar cell (solar cell module) of a laminated sheet (backsheet for solar cell) of the present invention.

Figure 2 is a cross-sectional view of the fixture used to determine the acetic acid penetration rate.

Figure 3 is a top view of the fixture used to determine the acetic acid penetration.

[Formation of the Invention]

The invention according to any one of the first to thirteenth aspects is a layer (P1 layer) having a polybutylene terephthalate resin as a main structural component and a layer having a polyolefin resin as a main structural component (P3). Floor).

The polybutylene terephthalate resin is a terephthalate containing terephthalic acid ester as a dicarboxylic acid component and 1,4-butanediol as a diol component. The main repeating unit of polyester resin. Here, the main repeating unit means that when all the dicarboxylic acid components in the polyester resin are 100 mol%, 80 mol% or more and 100 mol% or less are terephthalate components; When all the diol components in the ester resin are 100 mol%, 80 mol% or more and 100 mol% or less are 1,4-butanediol components. When the total dicarboxylic acid component in the polyester resin is 100 mol%, the terephthalate component is preferably 90 mol% or more and 100 mol% or less, more preferably 95 mol% or more. Mole% or less. Moreover, when all the diol components in the polyester resin are 100 mol%, the 1,4-butanediol component is preferably 90 mol% or more and 100 mol% or less, more preferably 95 mol%. More than 100% of the above.

In addition to the terephthalic acid ester as the dicarboxylic acid component and the 1,4-butanediol as the diol component, other polybutylene terephthalate-based resins may be copolymerized. ingredient. Specifically, as the dicarboxylic acid component, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimer acid, and hexahydrate may be copolymerized. An aliphatic dicarboxylic acid such as alkanoic acid, pimelic acid, sebacic acid, methylmalonic acid or ethylmalonic acid; adamantane dicarboxylic acid, norbornene dicarboxylic acid, isosorbide nitrate An alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid or decalinyl dicarboxylic acid; isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, sodium isophthalate-5-sulfonate, phenyl Decanedicarboxylic acid, phthalic acid, phenanthroic acid, 9,9'- a component such as a dicarboxylic acid such as an aromatic dicarboxylic acid such as bis(4-carboxyphenyl)decanoic acid; or an ester derivative thereof. Further, an oxo acid such as l-lactide, d-lactide or hydroxybenzoic acid, and a derivative thereof; or a plurality of oxoacids or the like are added to the carboxy terminal of the above dicarboxylic acid component It is also suitable for use as a copolymerization component. Also, a plurality of types may be used as necessary.

Further, examples of the diol component include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, and 1,3-butylene. An alicyclic diol such as an alcohol; an alicyclic diol such as cyclohexanedimethanol, spiro diol or isosorbide; bisphenol A, 1,3-benzenedimethanol, 1,4-benzene A diol component such as dimethanol, 9,9'-bis(4-hydroxyphenyl)fluorene or an aromatic diol; a component in which a plurality of the above diols are linked, and the like are exemplified, but are not limited thereto. Also, a plurality of types can be used as necessary.

A polybutylene terephthalate-based resin can be obtained by polycondensation by appropriately combining the above-mentioned dicarboxylic acid component and diol component. The melting point of the obtained polybutylene terephthalate resin is generally 200 ° C or more and 230 ° C or less. Further, in the present invention, it is more preferred to use a melting point of 215 ° C or more and 230 ° C or less.

The crystallization parameter ΔTcg of the P1 layer measured by differential scanning calorimetry (DSC) is preferably from 7 to 30 °C. When the ΔTcg of the P1 layer is less than 7° C., it is easily emulsified and easily embrittled, and the moist heat resistance is lowered. When the ΔTcg of the P1 layer is higher than 30° C., moisture is likely to permeate into the interlayer due to crystallinity, and interlayer adhesion is deteriorated. In order to use the differential scanning calorimetry (DSC) to determine the crystallization parameter ΔTcg of the P1 layer to be 7 to 30 ° C, it is preferred to use a polybutylene terephthalate resin having a main structural component of the P1 layer. The crystallization parameter ΔTcg obtained by differential scanning calorimetry (DSC) was changed to 7 to 30 °C.

The amount of the rigid amorphous material of the P1 layer is preferably from 30 to 50%. If it is less than 30%, curling easily occurs. When the amount is more than 50%, it is easily embrittled after the wet heat treatment to lower the moist heat resistance.

Here, the rigid amorphous phase means that the molecular motion is frozen amorphous even in the intermediate state between the crystal and the completely amorphous state, even at a glass transition temperature or higher. The amount of rigid amorphous is determined by the formula: the amount of rigid amorphous = 100% - crystallinity - the amount of completely amorphous. The degree of crystallinity and the amount of complete amorphousness can be quantified by the temperature-modulating DSC method described in "Fiber and Industry" Vol. 65, No. 11 (2009) P.428. Specific assays are described in the examples.

In addition, the P1 layer is a structural component mainly composed of a polybutylene terephthalate resin, and means that the polymer contains more than 50% by mass and 100% by mass or less of 100% by mass of all the components of the layer. Butylene terephthalate resin.

The P1 layer constituting the laminated sheet of the present invention preferably contains inorganic particles in a range of 0.1% by mass or more and 30% by mass or less. The content of the inorganic particles in the P1 layer is more preferably 2% by mass or more and 25% by mass or less, and still more preferably 5% by mass or more and 20% by mass or less. The inorganic particles are used to impart the necessary functions to the sheet in accordance with the purpose. When the content of the inorganic particles in the P1 layer exceeds 30% by mass, workability will be lowered, or durability will be lowered. When the content of the inorganic particles in the P1 layer is less than 0.1% by mass, it is difficult to obtain yellowing due to the effect caused by the inclusion of the inorganic particles.

Examples of the inorganic particles suitable for use in the P1 layer include inorganic particles having ultraviolet absorbing ability and polybutylene terephthalate. The particles having a large difference in refractive index of the resin, particles having conductivity, and pigments can impart ultraviolet light resistance, light reflectivity, whiteness, and optical properties, and antistatic properties. In addition, the particle means a primary particle diameter of 5 nm or more which is obtained by the diameter of the equivalent conversion circle projected. Further, unless otherwise stated, in the present invention, the particle size means primary particle diameter, and the particle system means primary particles.

Further, when it is described in further detail, inorganic particles suitable for use in the P1 layer of the present invention may, for example, be gold, silver, copper, platinum, palladium, rhodium, vanadium, ruthenium, cobalt, iron, zinc, ruthenium, osmium, chromium. Metals such as nickel, aluminum, tin, zinc, titanium, lanthanum, zirconium, hafnium, indium, lanthanum, cerium, etc.; zinc oxide, titanium oxide, cerium oxide, cerium oxide, tin oxide, indium tin oxide, antimony oxide, antimony oxide a metal oxide such as zirconium oxide, aluminum oxide or cerium oxide; a metal fluoride such as lithium fluoride, magnesium fluoride, aluminum fluoride or cryolite; a metal phosphate such as calcium phosphate; and a carbonate such as calcium carbonate; Sulfate such as barium sulfate; talc and kaolin.

In the present invention, in the case where the metal oxide such as titanium oxide, zinc oxide or cerium oxide having inorganic particles having ultraviolet absorbing ability is used as the inorganic particles in the P1 layer, it is used in the present invention. It is preferable from the viewpoint of activating the ultraviolet ray resistance by the inorganic particles and reducing the effect of coloring due to deterioration of the back sheet over a long period of time. Further, it is more preferable to use titanium oxide as the inorganic particles in the P1 layer from the viewpoint of imparting high reflection characteristics, and it is more preferable to use rutile-type titanium oxide from the viewpoint of higher ultraviolet resistance.

The method of containing the polybutylene terephthalate resin and the inorganic particles in the P1 layer is preferably a melt-kneading poly(terephthalic acid) by using a ventilating biaxial kneading extruder or a tandem extruder. A method of a butylene ester-based resin and inorganic particles. Here, when the inorganic particles are contained, a large amount of the polybutylene terephthalate resin is deteriorated due to the heat history. Therefore, in comparison with the amount of inorganic particles contained in the P1 layer, it is preferred to prepare a high-concentration masterbatch pellet having a large content of inorganic particles from the viewpoint of durability, and to form it with polybutylene terephthalate. The resin is mixed and diluted to form a predetermined inorganic particle content of the P1 layer.

As described above, it is important that the P1 layer is composed of a polybutylene terephthalate resin as a main structural component, and the polybutylene terephthalate resin having a main structural component of the P1 layer preferably contains an end seal. Polybutylene terephthalate resin. Here, the end-capped polybutylene terephthalate resin means a resin obtained by reacting a terminal blocking agent with a polybutylene terephthalate resin.

That is, when the P1 layer is preferably produced, the terminal blocking agent is added to the polybutylene terephthalate resin to form a carboxyl group at the end of the polybutylene terephthalate resin (hereinafter, it will be located). The carboxyl group at the terminal is called a carboxyl terminal group or a COOH group, and reacts with a terminal blocking agent to remove the proton catalyst activity of the COOH group of the polybutylene terephthalate resin, and then forms a P1 layer. Here, the terminating terminal blocking agent refers to a compound which reacts with a carboxyl terminal group of a polyester to bond and a proton catalyst activity of a COOH group disappears, and specifically, A compound such as an oxazolyl group, an epoxy group or a substituent such as a carbodiimide group.

The carbodiimide compound having a suitable carbodiimide group as a terminal blocking agent is a functional carbodiimide and a polyfunctional carbodiimide. Examples of the monofunctional carbodiimide include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, and diisobutylcarbodiimide. , dioctylcarbodiimide, t-butylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide Amines, etc. Particularly preferred is dicyclohexylcarbodiimide or diisopropylcarbodiimide. The polyfunctional carbodiimide is preferably a carbodiimide having a degree of polymerization of from 3 to 15. Specific examples thereof include 1,5-naphthalene carbodiimide, 4,4'-diphenylmethane carbodiimide, and 4,4'-diphenyldimethylmethane carbodiimide. , 1,3-phenylene carbodiimide, 1,4-phenylene diisocyanate, 2,4-toluene carbodiimide, 2,6-toluene carbodiimide, 2,4- a mixture of toluene carbodiimide and 2,6-toluene carbodiimide, hexamethylene carbodiimide, cyclohexane-1,4-carbodiimide, xylene carbodiimide Amine, isophorone carbodiimide, dicyclohexylmethane-4,4'-carbodiimide, methylcyclohexanecarbodiimide, tetramethylxylene carbodiimide, 2 , 6-diisopropylphenylcarbodiimide, 1,3,5-triisopropylbenzene-2,4-carbodiimide, and the like. Since the carbodiimide compound generates an isocyanate-based gas by thermal decomposition, it is preferably a carbodiimide compound having high heat resistance. In order to improve heat resistance, the higher the molecular weight (degree of polymerization), the better, and the end of the carbodiimide compound is preferably a structure having high heat resistance. In addition, when thermal decomposition is caused, it is necessary to further thermally decompose, and it is necessary to design the extrusion temperature of the polyester (polybutylene terephthalate resin) to be as low as possible.

Further, preferred examples of the epoxy compound which is suitable as the terminal blocking agent include a glycidyl ester compound or a glycidyl ether compound. Specific examples of the glycidyl ester compound include epoxypropyl benzoate, glycidyl butyl benzoate, glycidyl p-phenylacetate, and propylene glycol cyclohexanecarboxylate. Base ester, glycidyl phthalate, glycidyl stearate, glycidyl laurate, glycidyl palmitate, glycidyl behenate, propylene carbonate Base ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, glycerol linoleic acid glycidyl ester, behenic acid glycidyl ester, stearyl oxypropyl acrylate, Di-epoxypropyl terephthalate, diepoxypropyl isophthalate, diepoxypropyl phthalate, diepoxypropyl naphthalate, methyl terephthalate Epoxypropyl ester, diglycidyl hexahydrophthalate, diepoxypropyl tetrahydrophthalate, diepoxypropyl cyclohexanedicarboxylate, diepoxide of adipic acid Propyl ester, diepoxypropyl succinate, diepoxypropyl sebacate, diepoxypropyl dodecanedione, diepoxypropyl octadecandicarboxylate, partial Trisepoxypropyl trimellitate Pyromellitic acid tetraglycidyl-ester and the like. These can be used alone or in combination of two or more. Specific examples of the glycidyl ether compound include phenylepoxypropyl ether, O-phenylepoxypropyl ether, and 1,4-bis(β,γ-glycidoxy)butane. 1,6-bis(β,γ-glycidoxy)hexane, 1,4-bis(β,γ-glycidoxy)benzene, 1-(β,γ-glycidoxy) )-2-ethoxyethane, 1-(β,γ-glycidoxy)-2-benzyloxyethane, 2,2-bis-[p-(β,γ-glycidoxy) a bisepylene obtained by the reaction of bisphenol with epichlorohydrin, such as phenyl]propane and 2,2-bis-(4-hydroxyphenyl)propane or 2-bis-(4-hydroxyphenyl)methane For the propyl polyether or the like, one type or two or more types can be used.

Also suitable as an end capping agent The oxazoline compound is preferably double The oxazoline compound, specifically, 2,2'-bis(2- Oxazoline), 2,2'-bis(4-methyl-2- Oxazoline), 2,2'-bis(4,4-dimethyl-2- Oxazoline), 2,2'-bis(4-ethyl-2- Oxazoline), 2,2'-bis(4,4'-diethyl-2- Oxazoline), 2,2'-bis(4-propyl-2- Oxazoline), 2,2'-bis(4-butyl-2- Oxazoline), 2,2'-bis(4-hexyl-2- Oxazoline), 2,2'-bis(4-phenyl-2- Oxazoline), 2,2'-bis(4-cyclohexyl-2- Oxazoline), 2,2'-bis(4-benzyl-2- Oxazoline), 2,2'-p-phenylene bis(2- Oxazoline), 2,2'-inter-phenylene bis(2- Oxazoline), 2,2'-o-phenylene bis(2- Oxazoline), 2,2'-p-phenylene bis(4-methyl-2- Oxazoline), 2,2'-p-phenylene bis(4,4'-dimethyl-2- Oxazoline), 2,2'-inter-phenylene bis(4-methyl-2- Oxazoline), 2,2'-meta-phenyl bis(4,4'-dimethyl-2- Oxazoline), 2,2'-extended ethyl bis (2- Oxazoline), 2,2'-tetramethylene double (2- Oxazoline), 2,2'-hexamethylene double. (2- Oxazoline), 2,2'-octamethylene double (2- Oxazoline), 2,2'-decamethylene double (2- Oxazoline), 2,2'-extended ethyl bis(4-methyl-2- Oxazoline), 2,2'-tetramethylenebis(4,4'-dimethyl-2- Oxazoline), 2,2'-9,9'-diphenoxyethane bis (2- Oxazoline), 2,2'-diphenylene bis(2- Among these, from the viewpoint of reactivity with polyester (polybutylene terephthalate resin), 2,2'-bis(2- Oxazoline). Also, as long as the above mentioned double The oxazoline compound can achieve the object of the present invention, and one type of them may be used alone or two or more types may be used in combination. When the terminal blocking agent is reacted with a polybutylene terephthalate resin to obtain a terminally-terminated polybutylene terephthalate resin, 100% by mass relative to the polybutylene terephthalate resin. The concentration of the terminal blocking agent is preferably from 0.25 to 5% by mass, more preferably from 0.5 to 2% by mass. When it is less than 0.25 mass%, there is a problem that the effect of addition is small and the heat and humidity resistance is lowered. When the concentration is more than 5% by mass, there is a problem in that the carboxyl terminal group is relatively small and the interlayer adhesion is lowered.

Further, in the P1 layer and the P3 layer of the laminated sheet of the present invention, other additives may be contained in the range which does not impair the effects of the present invention (for example, a heat-resistant stabilizer, an ultraviolet absorber, and a weather-resistant stabilizer) An organic slip agent, a pigment, a dye, a filler, an antistatic agent, a nucleating agent, etc. However, the so-called inorganic particles in the present invention are not included in the so-called additive herein. For example, when the ultraviolet absorber is selected as an additive and is contained in the P1 layer and/or the P3 layer, the ultraviolet absorbing property of the laminated sheet of the present invention can be further improved. Further, when an antistatic agent or the like is contained in the P1 layer and/or the P3 layer, it is expected to increase the withstand voltage.

Further, the P1 layer preferably contains 0.1 to 5% by mass of a crystal nucleating agent. The crystal nucleating agent is preferably selected from the group consisting of talc, an aliphatic carboxylic acid decylamine, an aliphatic carboxylic acid salt, an aliphatic alcohol, an aliphatic carboxylic acid ester, a sorbitol-based compound, and an organic phosphoric acid compound. In the present invention, the crystal nucleating agent preferably contains one crystal nucleating agent of an aliphatic carboxylic acid decylamine, an aliphatic carboxylic acid salt, and a sorbitol-based compound. When the crystal nucleating agent is less than 0.1% by mass, the crystallinity is low and the strength is not obtained. When the amount is more than 5% by mass, the crystallinity is high and the embrittlement is easy.

Here, as the aliphatic carboxylic acid guanamine, for example, decyl laurate, decyl palmitate, decyl oleate, decylamine stearate, erucamide, crotonate, ricinoleate An amine, an amine monocarboxylic acid amide of hydroxystearate; such as N-oleyl palmitate, N-oleyl oleic acid Guanamine, N-stearyl decyl oleate, N-stearyl decyl stearate, N-stearyl erucamide, hydroxymethyl stearate, hydroxymethyl N-substituted aliphatic monocarboxylic acid decyl amines of decanoic acid decylamine; such as methylene bis-stearate decylamine, ethyl bis-laurate decylamine, ethyl bis-decanoate decylamine, ethyl bis-ethyl Oleic acid decylamine, ethyl bis-stearate decylamine, ethyl erucic acid decylamine, ethyl bis-decanoic acid decylamine, ethyl bis-isostearic acid decylamine, ethyl bishydroxyl Indole stearate, decyl butyl bis-isostearate, decyl hexamethylene bisoleate, decyl hexamethylene bis-stearate, hexamethylene bis-decanoic acid decylamine, six An aliphatic dicarboxylic acid decylamine of methylene bishydroxystearate decylamine, m-xylene bis-stearate decylamine, m-xylene bis-12-hydroxystearic acid decylamine; such as N, N'- Dienyl decyl sebacate, N, N'-dioleyl adipic acid decylamine, N, N'-distearyl decyl adipate, N, N'-distearate N-substituted lipids based on decylamine diamine, N,N'-distearyl decyl isophthalate, N,N'-distearyl decyl phthalate Group of carboxylic acid biguanide; such as N-butyl-N'-stearylcarbazine, N-propyl-N'-stearylcarbazine, N-stearyl-N'-stearin Base urea, N-phenyl-N'-stearyl sulfhydryl urea, xylene bis-stearyl sulfhydryl urea, toluene bis-stea sulphonyl urea, hexamethylene bis-stearyl sulfhydryl urea, diphenylmethane double N-substituted urea of stearyl sulfhydryl urea and diphenylmethane dilauryl urea. These may be one type or a mixture of two or more types. Among them, aliphatic monocarboxylic acid decylamines, N-substituted aliphatic monocarboxylic acid decylamines, and aliphatic dicarboxylic acid decylamines are suitably used, and it is particularly suitable to use decyl palmitate, decylamine stearate, erucic acid. Indamine, behenic acid decylamine, ricinoleic acid decylamine, hydroxystearic acid decylamine, N-oleyl palmitate decylamine, N-stearyl erucyl erucamide, ethyl bis-decanoic acid Indoleamine, ethyl bis-oleate, Ethyl bis-laurate decylamine, ethyl erucic acid decylamine, meta-xylene bis-stearate decylamine, m-xylene bis-12-hydroxystearic acid decylamine.

As a specific example of the aliphatic carboxylate, an acetate such as sodium acetate, potassium acetate, magnesium acetate or calcium acetate; sodium laurate, potassium laurate, potassium hydrogen laurate, magnesium laurate, calcium laurate, and laurel can be used. a laurate of zinc citrate or silver laurate; a meat of lithium myristate, sodium myristate, potassium hydrogen myristate, magnesium myristate, calcium myristate, zinc myristate, silver myristate, etc. Myristic acid salt; palmitate of lithium palmitate, potassium palmitate, magnesium palmitate, calcium palmitate, zinc palmitate, copper palmitate, lead palmitate, barium palmitate, cobalt palmitate, etc.; sodium oleate, oil Acid acid potassium salt, magnesium oleate, calcium oleate, zinc oleate, lead oleate, barium oleate, copper oleate, nickel oleate, etc.; sodium stearate, lithium stearate, magnesium stearate , stearic acid calcium, barium stearate, aluminum stearate, barium stearate, lead stearate, nickel stearate, barium stearate, etc.; sodium isostearate, iso-hard Lithium oleate, magnesium isostearate, calcium isostearate, barium isostearate, aluminum isostearate, zinc isostearate, nickel isostearate, etc.; Sodium citrate, sodium behenate, magnesium behenate, calcium behenate, bismuth behenate, aluminum behenate, zinc behenate, nickel behenate, etc.; sodium montanate, montanic acid Potassium, magnesium montanate, calcium montanate, barium montanate, aluminum montanate, zinc montanate, nickel montanate, etc. These may be one type or a mixture of two or more types. It is particularly suitable to use a salt of stearic acid or a salt of montanic acid, and it is particularly suitable to use sodium stearate, lithium stearate, potassium stearate, zinc stearate, barium stearate, sodium montanate or the like.

As a specific example of the aliphatic alcohol, a pentadecyl alcohol, a hexadecyl alcohol, a heptadecyl alcohol, an octadecyl alcohol, a nonadecyl group can be used. An aliphatic monoalcohol of an alcohol, an eicosyl alcohol, a hexadecyl alcohol or a triacontanol; 1,6-hexanediol, 1,7-heptanediol, 1,8-octane An aliphatic polyol such as an alcohol, 1,9-nonanediol or 1,10-decanediol; cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane A cyclic alcohol such as an alkane-1,4-diol or the like. These may be one type or a mixture of two or more types. It is particularly suitable for the use of aliphatic monoalcohols, and more particularly for the use of stearyl alcohol.

Further, as a specific example of the related aliphatic carboxylic acid ester, cetyl laurate, benzoyl laurate, cetyl myristate, phenyl myristate, and methylene palmitate can be used. Propyl ester, lauryl palmitate, myristyl palmitate, pentadecyl palmitate, octadecyl palmitate, cetyl palmitate, phenyl palmitate, benzoyl palmitate, An aliphatic monocarboxylic acid ester such as cetyl stearate or ethyl behenate; ethylene glycol monolaurate, ethylene glycol monopalmitate, ethylene glycol monostearate, etc. Glycol monoesters; ethylene glycol diesters such as ethylene glycol dilaurate, ethylene glycol dipalmitate, ethylene glycol distearate; glycerol monolaurate, glycerol Glycerol monoesters such as monomyristate, glycerol monopalmitate, glycerol monostearate; glycerol dilaurate, glycerol dimyristate, C Glycerol diesters such as alcohol dipalmitate, glycerol distearate; glycerol trilaurate, glycerol trimidolide, glycerol tripalmitate, C Alcohol three Aliphatic esters, palmitate dioleate, palmitate distearate, oleic acid esters of glycerol triesters distearate. These may be one type or a mixture of two or more types.

Further, as a specific example of the related aliphatic/aromatic carboxylic acid hydrazine, hydrazine benzoic acid benzoate can be used; as a melamine-based compound As a specific example of the substance, melamine tripolyisocyanate or polymelamine melamine can be used; as a specific example of the phenyl sulfonic acid metal salt, zinc phenylsulfonate, calcium phenylsulfonate or magnesium phenylsulfonate can be used. Wait.

Examples of the sorbitol-based compound include 1,3-bis(P-methylbenzylidene)sorbitol and 2,4-di(P-methylbenzylidene)sorbitol; 3-dibenzylidene sorbitol, 2,4-dibenzylidene sorbitol, 1,3-bis(P-ethyldiphenylmethylene)sorbitol, 2,4-di ( P-ethyldibenzylidene) sorbitol or the like.

Further, examples of the organic phosphoric acid compound include bis(4-tert-butylphenyl)phosphate and 2,2'-methylenebis(4,6-di(t-butyl)benzene. Sodium, cyclic organophosphate base polyvalent metal salt with alkali metal carboxylate, alkali metal-β-diketonate and alkali metal-β-keto acetate salt organic carboxylic acid metal salt 1 Kind of mixture, etc.

Among the above, sodium montanate is preferably used from the viewpoint of strength.

In the present invention, it is preferable to have a layer (P2 layer) having a polyolefin-based resin as a main structural component, and it is more preferable to connect the P1 layer and a P3 layer to be described later via a P2 layer. Here, the connection of the P1 layer and the P3 layer via the P2 layer means that the layers are directly laminated in the order of the P1 layer, the P2 layer, and the P3 layer.

In addition, the term "adhesive polyolefin resin" means one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer, and is a resin-based polyolefin resin. The layer of the main structural component (P2 layer) is selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and ethylene vinyl acetate. A layer of a group of copolymers as a major structural component. In addition, as for the P2 layer, one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer is a main structural component, and means all components of the layer. 100% by mass contains one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer in an amount of more than 50% by mass and 100% by mass or less.

The low crystalline soft polymer which is one of the main structural components of the P2 layer may, for example, be an acid-modified polyolefin or an unsaturated polyolefin. Moreover, the acrylic adhesive which is one of the main structural components of the P2 layer may, for example, be an ethylene-acrylate-maleic anhydride ternary copolymer. Among them, from the viewpoint of adhesion to the two layers of the P1 layer and the P3 layer, the P2 layer is preferably made of an acid-modified polyolefin as a main structural component. Here, as the acid-modified polyolefin, for example, "Admer" manufactured by Mitsui Chemicals Co., Ltd. or "Modic" manufactured by Mitsubishi Chemical Corporation, manufactured by DuPont Co., Ltd." Bynel".

Further, in addition to the polyolefin resin, the P2 layer further preferably contains a polyolefin elastomer. The polyolefin-based elastomer generally means a method in which an ethylene-propylene rubber is finely dispersed in polypropylene, or another α-olefin is copolymerized with polypropylene. The polyolefin-based elastomer is preferably contained in an amount of 0.1% by mass or more and 20% by mass or less based on 100% by mass of all the components of the P2 layer. By containing a polyolefin-based elastomer, adhesion to the P2 layer can be imparted, and the adhesion between the P1 layer and the P2 layer and the adhesion between the P3 layer and the P2 layer can be improved. The content of the polyolefin-based elastomer in the P2 layer is preferably 5% by mass or more and 20% by mass or less. Polyolefin bomb The physique may also be a commercially available product, for example, "Thermorun" manufactured by Mitsubishi Chemical Corporation, "Zelas"; "Exellen", "Tafcelene", "Esprene" manufactured by Sumitomo Chemical Co., Ltd.; "Hybrar", "Septon"; "Notio" made by Mitsui Chemicals Co., Ltd., etc.

The P3 layer of the present invention is a layer having a polyolefin resin as a main structural component. The polyolefin-based resin of the present invention may, for example, be polyethylene, polypropylene, polybutene, polymethylpentene, polycycloolefin, polyhexene, polyoctene, polydecene or polydodecene. . Here, the adhesive polyolefin resin which is a main structural component of the P2 layer is a polyolefin resin which does not apply the main structural component of the P3 layer. Among them, the polyolefin-based resin which is a main structural component of the P3 layer is preferably polyethylene or polypropylene because it is easy to process and relatively inexpensive. These polyolefin-based resins can be mixed and copolymerized with other olefin components. For example, when an ethylene-propylene copolymer or an ethylene-propylene-butene copolymer is produced, the melting point of the resin can be lowered, and it is preferable to improve the tightness of the package. Sticky.

In the P3 layer, the polyolefin-based resin is used as the main structural component, and the polyolefin-based resin is contained in an amount of more than 50% by mass and 100% by mass or less based on 100% by mass of all the components.

The P3 layer constituting the laminated sheet of the present invention preferably contains inorganic particles in a range of 0.1% by mass or more and 30% by mass or less. The content of the inorganic particles in the P3 layer is more preferably 2% by mass or more and 25% by mass or less, and still more preferably 5% by mass or more and 20% by mass or less. The inorganic particles are used to impart the necessary functions to the sheet in accordance with the purpose. If the content of the inorganic particles in the P3 layer exceeds 30% by mass, it will be lowered with the packaging material. Closeness. When the content of the inorganic particles in the P3 layer is less than 0.1% by mass, it is difficult to obtain yellowing due to an effect caused by the inclusion of the inorganic particles.

Further, the P3 layer preferably contains 5 to 30% by mass of inorganic particles having a particle diameter of 3 μm or more and 20 μm or less. Here, the so-called particle size refers to the analysis by laser. The particle size distribution was determined by the scattering method, and the average particle diameter of the cumulative value of the particle size distribution was 50%. When the inorganic particles of 3 μm or more and 20 μm or less are less than 5% by mass, the mechanical strength is reduced. When the inorganic particles of 3 μm or more and 20 μm or less are more than 30% by mass, the surface is roughened and the adhesion to the sealing material is lowered. Further, in the P3 layer, it is preferable to contain 0.5 to 5% by mass of the adhesive polyolefin-based resin. The adhesive polyolefin-based resin has a function as an inorganic particle dispersing aid of 3 μm or more and 20 μm or less. When the amount is less than 0.5% by mass, the mechanical strength is lowered due to poor dispersion of inorganic particles of 3 μm or more and 20 μm or less. When the amount is more than 5% by mass, the heat resistance is lowered. Here, the adhesive polyolefin-based resin is the same as defined by the adhesive polyolefin resin of the P2 layer.

The acetic acid transmittance Pa (g/m ² /day) in the laminated sheet of the present invention means the acetic acid transmittance when the acetic acid is in a saturated vapor pressure state (85 ° C). Further, the laminated sheet of the present invention has an acetic acid transmittance Pa at 85 ° C which satisfies the following formula (1): (1) 200 ≦ Pa.

When the laminated sheet of the present invention is used as a back sheet, it is important that the acetic acid generated from the packaging material is actively removed from the back sheet before the influence on the solar battery unit, and the power generation in the constant temperature and humidity test is suppressed. From the viewpoint of performance degradation, it is important that the laminated sheet of the present invention has an acetic acid transmittance Pa of 200 g/m ² /day or more. Moreover, from the viewpoint of further suppressing the decrease in power generation performance, the laminated sheet of the present invention preferably has an acetic acid transmittance Pa of 800 g/m ² /day or more. On the other hand, although the acetic acid transmittance Pa is preferably as large as possible, the acetic acid transmittance Pa is preferably determined in consideration of the formula (2) which satisfies not only the formula (1) but also the water vapor permeability Pw described later. 1500g/m ² /day or less.

The water vapor permeability Pw (g/m ² /day) in the laminated sheet of the present invention means the water vapor transmission rate in an environment of 40 ° C and 90% RH. Further, the water vapor permeability Pw (g/m ² /day) of the laminated sheet of the present invention at 90 ° C 90% RH preferably conforms to the following formula (2): (2) Pw ≦ 2.5.

The laminated sheet of the present invention has a water vapor transmission rate Pw of the laminated sheet of the present invention from the viewpoint of suppressing corrosion inside the solar cell module due to moisture, especially due to corrosion caused by corrosion of the collector electrode portion of the solar cell unit. Preferably, it is 2.5 g/m ² /day or less. Further, from the viewpoint of further suppressing discoloration of the collector electrode of the unit, it is preferably 2.0 g/m ² /day or less. On the other hand, although the water vapor transmission rate Pw is as small as possible, the water vapor permeability Pw is compared when considering the formula (1) which satisfies not only the formula (2) but also the above-mentioned acetic acid permeability Pa. Preferably, it is 0.5 g/m ² /day or more.

The thickness of the P1 layer constituting the laminated sheet of the present invention is preferably 80 μm or more. If it is less than 80 μm, the heat resistance will be lowered. The thickness of the P2 layer constituting the laminated sheet of the present invention is preferably 15 μm or more and 50 μm or less. If it is less than 15 μm, the interlayer adhesion will be lowered. If the thickness of the P2 layer is larger than 50 μm, the heat resistance will be lowered. The thickness of the P3 layer constituting the laminated sheet of the present invention is preferably 50 μm or more. If it is less than 50 μm, the adhesion to the packaging material will be lowered.

It is important that the laminated sheet of the present invention has a P1 layer and a P3 layer. Further, in the laminated structure of the laminated sheet of the present invention, it is preferable that at least the P1 layer is located in the surface layer, and the P3 layer is located in the surface layer opposite to the P1 layer. Here, the fact that the P3 layer is located opposite to the P1 layer means that the P1 layer is located on the outermost layer on the side of the laminate sheet, and the P3 layer is located on the outermost layer on the other side.

Further, the laminated sheet of the present invention can be laminated with another film or the like. In such a laminate, the P1 layer is preferably a laminate structure provided on either side surface layer. As an example of another film, a polyester layer for improving mechanical strength, an antistatic layer, an adhesion layer with another substrate, and an ultraviolet ray resistant layer for further improving ultraviolet resistance can be arbitrarily selected according to the use. It is used for imparting a flame retardant layer which is flame retardant, a hard coating layer for improving impact resistance or abrasion resistance, and the like. As a specific example of the case where the laminated sheet of the present invention is formed as a laminate with another film or the like, a case where the laminated sheet of the present invention is used as a solar battery back sheet is used in addition to further forming other sheet materials or embedding power generation. In addition to the easy-adhesion layer, the ultraviolet-resistant layer, and the flame-retardant layer, which are improved in the adhesion of the component (for example, ethylene-vinyl acetate), the conductive layer in which the voltage of the partial discharge phenomenon of the insulating property is increased is improved. .

Next, a method of manufacturing the laminated sheet of the present invention will be described by way of example. In the laminated sheet of the present invention, as a method of laminating the P1 layer, the P2 layer, and the P3 layer, for example, the following method or the like can be used: a P1 layer containing a polybutylene terephthalate resin as a main structural component The raw material, the P2 layer raw material containing the polyolefin-based resin as a main structural component, and the P3 layer raw material containing the polyolefin-based resin as a main structural component are supplied to different extruders, and after each melting, sequentially P1 layer, P2 layer and P3 layer are combined to form a layer, which is extruded into a sheet shape from a T die, and then processed into a sheet form (coextrusion method); the coated material is poured into an extruder And melt-extruding onto a sheet made of a single film, and extruding a layer of a layer from a nozzle (melt layering method); each film is produced differently, and is heat-pressed by a heated roll group or the like The method (heat layer method); the method of bonding by means of an adhesive (adhesive method); in addition, coating. A method of drying (a coating method) in which it has been dissolved in a solvent; a method of combining the methods, and the like. Among these, a coextrusion method is preferred from the viewpoint that the production steps are short and the interlayer adhesion is good. Hereinafter, the production method using the coextrusion method will be described in detail.

When the laminated sheet of the present invention is produced by a co-extrusion method, first, the raw materials for each layer are separately supplied to three extruders to be melted under a nitrogen stream: the P1 layer will be dried with polybutylene terephthalate. The P1 layer raw material containing the ester resin as a main structural component is supplied to an extruder which has been heated to 240 ° C or more and 300 ° C or less; the P 2 layer and the P 3 layer are used as the P 2 layer which is a main structural component of the adhesive polyolefin resin. The raw material and the raw material for the P3 layer containing the polyolefin-based resin as a main structural component are respectively supplied to an extruder which has been heated to 180 ° C or more and 250 ° C or less. Next, the P1 layer, the P2 layer, and the P3 layer are sequentially combined by a multi-manifold die or a feed section or a static mixer, a sleeve (PINOL), etc., and laminated, and coextruded into a sheet shape from the T die. . In the case where the difference in the melt viscosity of each layer is large, a multi-manifold die is preferably used from the viewpoint of suppressing unevenness in lamination.

The laminated sheet of the present invention can be obtained by extruding a laminated sheet discharged from a T die by the above method onto a cooling body such as a casting reel and cooling and solidifying it.

The processing of heat treatment or aging of the laminated sheet of the present invention obtained by the above method may be increased as necessary within the range not impairing the effects of the present invention. The thermal dimensional stability of the laminated sheet of the present invention can be improved by heat treatment. Further, in order to improve the adhesion of the laminated sheet of the present invention obtained by the above method, corona treatment or plasma treatment may be performed.

The solar battery back sheet of the present invention is composed of the laminated sheet of the present invention. That is, the laminated sheet of the present invention can be suitably used as a solar battery back sheet. The solar cell of the present invention is characterized by using the solar cell back sheet of the present invention. Compared with the conventional solar cell, by using the laminated sheet of the present invention in a solar cell, durability or thinning can be further improved. A structural example of the solar cell of the present invention is shown in Fig. 1. In the first embodiment, the transparent substrate 4 such as glass is bonded to the transparent battery 2 of the EVA resin or the like by using the laminated sheet of the present invention as the solar battery back sheet 1 (in the first embodiment). The power generating element (not shown in Fig. 1) is configured. However, the structural example of the solar cell of the present invention is not limited thereto and can be used in any structure. Further, in the first drawing, an example in which the laminated sheet monomer of the present invention is used, and a composite sheet of the laminated sheet of the present invention and another film can be used in accordance with other required characteristics.

In the laminated sheet of the present invention, as a method of laminating with another film or the like, for example, a method of co-extruding into a sheet form (coextrusion method) can be used; and the coating material is poured into an extruder. a method of melt-extruding onto a sheet made of a single film and extruding a layer of a layer from a nozzle (melt layering method); each film is separately produced by heating A method of hot pressing and bonding of a reel group (heat lamination method); a method of bonding by an adhesive (adhesive method); in addition, coating. A method of drying (a coating method) in which it has been dissolved in a solvent; a method of combining the methods, and the like.

In the solar cell of the present invention, the solar battery back sheet 1 described above is provided on the back surface of the package 2 for encapsulating the power generating element. Here, the solar battery back sheet of the present invention has an asymmetrical structure, and the P3 layer is disposed on the side of the package 2, and is preferable from the viewpoint of further improving the adhesion to the package. In addition, in order to provide a structure in which the P1 layer of the laminated sheet of the present invention is disposed on the side opposite to the sealing material 2, the durability against ultraviolet rays or the like from the ground can be improved, so that it can be made highly durable. Solar cells or thinned thickness.

The power generation element 3 converts light energy of sunlight into electric energy, and can be a crystalline lanthanide, a polycrystalline lanthanide, a microcrystalline lanthanum, an amorphous lanthanum, a copper indium selenium system, a compound semiconductor system, or a dye sensitization system. According to any component of the purpose, and connected in series or in parallel according to the desired voltage or current, a plurality of components are used. Since the transparent substrate 4 having light transmissivity is located at the outermost layer of the solar cell, in addition to high transmittance, a transparent material having high weather resistance, high contamination resistance, and high mechanical strength characteristics is also used. In the solar cell of the present invention, if the transparent substrate 4 having light transmittance satisfies the above characteristics, any material can be used, and examples thereof include glass, tetrafluoroethylene-ethylene copolymer (ETFE), and poly Fluorinated vinyl resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene resin (CTFE), poly A fluorine-based resin such as a vinylidene fluoride resin; a polyolefin-based resin, an acrylic resin, and the like. In the case of glass, Better use has been enhanced. Further, in the case of using a light-transmitting substrate made of a resin, it is preferred to use a uniaxially or biaxially stretched resin as described above from the viewpoint of mechanical strength.

Moreover, in order to impart adhesion to the EVA-based resin or the like of the power-generating element package, the surface is preferably subjected to corona treatment, plasma treatment, ozone treatment, and easy adhesion treatment.

In addition to resin coating and fixing the surface unevenness of the power generating element, the package material 2 for encapsulating the power generating element is also used to adhere the light transmissive substrate or the back sheet, in addition to the purpose of external environmental protection power generation elements and electrical insulation. A material having high transparency, high weather resistance, high adhesion, and high heat resistance is used for the power generation element. As an example thereof, ethylene-vinyl acetate copolymer (EVA), ethylene-alkyl methacrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA) resin, ethylene-methacrylic acid are preferably used. Copolymer (EMAA), ionic polymer resin, polyvinyl butyral resin, mixtures of these, and the like.

As described above, by assembling the solar cell back sheet using the laminated sheet of the present invention into a solar cell, it is possible to produce a highly durable and/or thin solar cell as compared with the conventional solar cell. The solar cell of the present invention is not limited to outdoor applications such as solar power generation systems and power sources for small electronic components, and can be suitably used for various purposes in indoor applications.

Next, an embodiment of a solar cell backsheet, a method for producing the same, and a solar cell module according to the inventions of the fourteenth to twenty-fifth embodiments will be described. It is to be noted that the present invention is specifically described in order to better understand the meaning of the invention, and the present invention is not limited by the embodiment.

The acetic acid transmittance Pa (g/m ² /day) in the back sheet of the present invention means the acetic acid transmittance when acetic acid is brought into a saturated vapor pressure state (85 ° C). Moreover, it is important that the back sheet of the present invention has an acetic acid transmittance Pa at 85 ° C in accordance with the following formula (1): (1) 200 ≦ Pa.

What is important is that the back sheet of the present invention is actively extracted from the back sheet before the acetic acid generated from the package material is affected by the solar cell unit, and is important from the viewpoint of suppressing the decrease in power generation performance in the constant temperature and humidity test. The back sheet of the present invention has an acetic acid transmittance Pa of 200 g/m ² /day or more. Moreover, from the viewpoint of further suppressing the decrease in power generation performance, the acetic acid transmittance Pa of the back sheet of the present invention is preferably 800 g/m ² /day or more. On the other hand, although the acetic acid transmittance Pa is preferably as large as possible, the acetic acid transmittance Pa is preferably determined in consideration of the formula (2) which satisfies not only the formula (1) but also the water vapor permeability Pw described later. 1500g/m ² /day or less.

The water vapor permeability Pw (g/m ² /day) in the back sheet of the present invention means the water vapor transmission rate in an environment of 40 ° C and 90% RH. Moreover, it is important that the water vapor permeability Pw (g/m ² /day) of the back sheet of the present invention at 90 ° C 90% RH preferably conforms to the following formula (2): (2) Pw ≦ 2.5.

The back sheet of the present invention is important for suppressing the internal corrosion of the solar cell module caused by moisture, especially the discoloration caused by the corrosion of the collector electrode portion of the solar cell unit, and it is important that the water vapor of the back sheet of the present invention penetrates. The rate Pw is 2.5 g/m ² /day or less. Further, from the viewpoint of further suppressing discoloration of the collector electrode of the unit, it is preferably 2.0 g/m ² /day or less. On the other hand, although the water vapor transmission rate Pw is as small as possible, the water vapor permeability Pw is compared when considering the formula (1) which satisfies not only the formula (2) but also the above-mentioned acetic acid permeability Pa. Preferably, it is 0.5 g/m ² /day or more.

In order to make the acetic acid transmittance Pa of the back sheet conform to the formula (1) while making the water vapor permeability Pw conform to the formula (2), the back sheet is preferably formed into a form having a P4 layer. Here, the P4 layer means a layer selected from the group consisting of a polyester resin, a polyamide resin, and a fluororesin as a main structural component. Further, the layer selected from the group consisting of a polyester resin, a polyamide resin, and a fluororesin as a main structural component means that more than 50% by mass of 100% by mass of all components of the layer is 100% by mass. The layer below one selected from the group consisting of a polyester resin, a polyamide resin, and a fluororesin.

The polyester resin suitable for use as the main structural component of the P4 layer of the present invention is a resin obtained by polycondensing a dicarboxylic acid and a diol. Further, the polyester resin may be used singly or in combination with other resins.

Specific examples of the dicarboxylic acid used for obtaining the polyester resin include terephthalic acid or 2,6-naphthalene dicarboxylic acid.

Moreover, as a specific example of the diol used for obtaining a polyester resin, ethylene glycol, 1,3-propanediol, 1,4-butanediol, etc. are mentioned.

Among these, from the viewpoints of price, water vapor permeability, strength, heat resistance and the like, the polyester resin is preferably polyethylene terephthalate and/or polybutylene terephthalate.

The polyamidamide resin which is suitable for use as a main structural component of the P4 layer of the present invention includes 1) a compound which has a ring-opening polymerization of a compound having an indoleamine skeleton, and 2) an amine having an amine group and a carboxyl group in a molecule of a polycondensation polymerization. The acid component, 3) the polydiamine component and the dicarboxylic acid component, and the copolymers 1) to 3). Further, the polyamide resin may be used singly or in combination with other resins.

Examples of the compound having the indoleamine skeleton used in 1) include ε-caprolactam (Nylon 6 can be obtained by ring-opening polymerization), and ω-undecane decylamine (by The ring-opening polymerization can obtain an internal guanamine compound such as nylon 11) or ω-dodecane decylamine (Nylon 12 can be obtained by ring-opening polymerization).

Further, examples of the amino acid component having an amine group and a carboxyl group in one molecule used in 2) include ε-aminohexanoic acid, 11-aminoundecanoic acid, and 12-amino 12 An amino acid such as an alkanoic acid.

Further, examples of the diamine component used in 3) include butanediamine, hexamethylenediamine, undecanediamine, dodecanediamine, and 1,2,2,4-tetramethylhexamethylenediamine. , 2,4,4-trimethylhexamethylenediamine, 5-methylnonanediamine, m-xylylenediamine, p-xylenediamine, 1,3-diaminomethylcyclohexane, 1,4 - bisaminomethylcyclohexane, bis-aminocyclohexylmethane, 2,2-bis-p-aminocyclohexylpropane, isophorone diamine, and the like. Further, examples of the dicarboxylic acid component used in 3) include adipic acid, suberic acid, sebacic acid, sebacic acid, dodecanedioic acid, and 1,4-cyclohexanedicarboxylic acid; a dicarboxylic acid such as 3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid or dimer acid.

For the structural components, the polymerization is provided in the form of 1) a compound having an internal guanamine skeleton, 2) a mixture of a single amino acid or an amino acid, or 3) a mixture of a diamine and a dicarboxylic acid, etc. The obtained polyamine resin can be used in the present invention to separately polymerize the component. A polymer containing any one of copolymers of two or more components. Among these, the polyamine resin used as the main structural component of the P4 layer is preferably polyhexylamine (Nylon 6), polyhexamethylenediamine (Nylon 66), polyfluorene hexamethylenediamine. (Nylon 610), polydodecane dimercaptohexane (Nylon 612), poly(p-phenylene hexamethylene diamine (Nylon 6T), poly-m-phenylene hexamethylene diamine (Nylon 6I), poly Undecyl decylamine (Nylon 11), polydodecyl decylamine (Nylon 12).

Further, in the back sheet of the present invention, the polyamine resin suitable for use as the main structural component of the P4 layer of the present invention is more preferably selected from the group consisting of nylon based on the height or strength of crystallinity, heat resistance and rigidity. 6. At least one resin of the group of nylon 66, nylon 610, nylon 11, and nylon 12.

Further, the fluororesin which is preferably used as the main structural component of the P4 layer may be a polymer obtained by substituting a fluorine atom for a part or all of a hydrogen atom of a hydrocarbon; and 2) replacing a part or all of a hydrocarbon with a fluorine atom. a hydrogen atom or a copolymer with a hydrocarbon; 3) a copolymer in which a fluorine atom is substituted for a part or all of a hydrogen atom of a hydrocarbon, and a fluorine atom is substituted for a part or all of a hydrogen atom of a hydrocarbon; 4) 1 a polymer or copolymer of a polymer or a copolymer of 3) which is a part of a hydrogen atom or a fluorine atom substituted by a chlorine atom, and substituted with a chlorine atom, at least one polymer or copolymer having a fluorine atom. Wait.

Examples of such a fluororesin include polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, and ethylene-chlorine. Trifluoroethylene copolymer and the like. From the viewpoints of price, water vapor permeability, and acetic acid penetration, Among the back sheets of the present invention, a fluororesin suitable for use as a main structural component of the P4 layer is particularly preferably a polyvinyl fluoride, a polyvinylidene fluoride, an ethylene-tetrafluoroethylene or a tetrafluoroethylene-hexafluoropropylene copolymer.

As described above, the P4 layer is a layer mainly composed of a polyester resin, a polyamide resin, and a fluororesin, and the P4 layer is particularly preferably a polyamine resin or a poly pair. A butyl phthalate-based resin is a main structural component.

In the case where the back sheet of the present invention contains a P4 layer, the P4 layer preferably contains 0.1% by mass or more and 30% by mass or less of inorganic particles in 100% by mass of all the components of the P4 layer. The content of the inorganic particles in the P4 layer is more preferably 2% by mass or more and 25% by mass or less, and still more preferably 5% by mass or more and 20% by mass or less. The inorganic particles are used to impart the necessary functions to the back sheet in accordance with the purpose. When the content of the inorganic particles in the P4 layer exceeds 30% by mass, workability will be lowered, or durability will be lowered. When the content of the inorganic particles in the P4 layer is less than 0.1% by mass, it is difficult to obtain an effect due to the inclusion of the inorganic particles, which causes yellowing.

Examples of the inorganic particles suitable for use in the P4 layer include inorganic particles having an ultraviolet absorbing ability; particles having a large difference in refractive index from a polyester resin, a polyamide resin, and a fluororesin; particles having conductivity; and pigments. In view of this, it is possible to impart optical properties such as ultraviolet resistance, light reflectivity, and whiteness, and antistatic properties. Further, in the present invention, the term "particles" means that the primary particle diameter obtained by the diameter of the equivalent conversion circle projected is 5 nm or more. Further, unless otherwise stated, in the present invention, the particle size means primary particle diameter, and the particle system means primary particles.

Further, as described in detail, the inorganic particles suitable for use in the P4 layer of the present invention include, for example, gold, silver, copper, platinum, palladium, rhodium, vanadium, ruthenium, cobalt, iron, zinc, ruthenium, osmium. Metals such as chromium, nickel, aluminum, tin, titanium, lanthanum, zirconium, hafnium, indium, lanthanum, cerium, etc.; zinc oxide, titanium oxide, cerium oxide, cerium oxide, tin oxide, indium tin oxide, antimony oxide, antimony oxide a metal oxide such as zirconia, aluminum oxide or cerium oxide; a metal fluoride such as lithium fluoride, magnesium fluoride, aluminum fluoride or cryolite; a metal phosphate such as calcium phosphate; a carbonate such as calcium carbonate; Sulfate such as barium sulfate; talc and kaolin.

In the present invention, in the case where the metal oxide such as titanium oxide, zinc oxide or cerium oxide having inorganic particles having ultraviolet absorbing ability is used as the inorganic particles in the P4 layer, It is preferable to activate the ultraviolet ray resistance by the inorganic particles and to reduce the coloring effect caused by the deterioration of the back sheet over a long period of time. Further, from the viewpoint of imparting high reflection characteristics, it is more preferable to use titanium oxide as the inorganic particles in the P4 layer, and it is more preferable to use rutile-type titanium oxide from the viewpoint of higher ultraviolet resistance.

The method of including the polyester resin, the polyamide resin, the fluororesin, or the inorganic particles in the P4 layer is preferably a method of melt-kneading using a vented biaxial kneading extruder or a tandem extruder. Here, when it contains inorganic particles, many resin will deteriorate due to a heating process. Therefore, in comparison with the amount of inorganic particles contained in the P4 layer, it is preferred to produce a high-concentration masterbatch pellet having a large content of inorganic particles from the viewpoint of durability, and mixing it with the resin and diluting it to form a predetermined The inorganic particle content of the P4 layer.

Further, in the P4 layer and the P6 layer (described later in the P6 layer) of the back sheet of the present invention, other additives may be contained in the range which does not impair the effects of the present invention (for example, heat-resistant stability may be mentioned). Agent, ultraviolet absorber, weathering stabilizer, organic slip agent, pigment, dye, filler, antistatic agent, nucleating agent, etc. However, the so-called inorganic particles in the present invention are not included herein. In the additive). For example, when the ultraviolet absorber is selected as an additive and is contained in the P4 layer and/or the P6 layer, the ultraviolet absorbing property of the back sheet of the present invention can be further improved. Further, when an antistatic agent or the like is contained in the P4 layer and/or the P6 layer, it is expected to increase the withstand voltage.

Further, from the viewpoint of flame retardancy, it is important that the P4 layer of the present invention is located on the surface layer of the back sheet. Here, the fact that the P4 layer is located on the surface layer of the back sheet means that the P4 layer is located at the outermost layer on the side of the back sheet of the present invention.

In the present invention, the P5 layer is preferably located between the P4 layer and the P6 layer described later. Here, the P5 layer is a layer selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer as a main structural component. In addition, as for the P5 layer, one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer as a main structural component means that all components in the layer are 100. The mass% contains more than 50% by mass and 100% by mass or less of one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer.

The P5 layer is preferably located between the P4 layer and the P6 layer. The fact that the P5 layer is located between the P4 layer and the P6 layer means, for example, the back sheet of the present invention. In the case where the P4 layer is located in the surface layer and the P6 layer is located in the opposite layer to the P4 layer, the P5 layer is located between the two layers, that is, the inner layer.

Further, the P5 layer preferably has a function of adhering to two layers of the P4 layer and the P6 layer. In addition, the low crystalline soft polymer which is one of the main structural components of the P5 layer preferably has a crystallinity of 50% or less and a melting point of preferably 170 ° C or less. For example, an acid-modified olefin or an unsaturated group is mentioned. Polyolefins, etc. Moreover, the acrylic adhesive which is one of the main structural components of the P5 layer may, for example, be an ethylene-acrylate-maleic anhydride ternary copolymer. Among them, from the viewpoint of adhering to the two layers of the P4 layer and the P6 layer, the P5 layer is preferably an acid-modified polyolefin as a main structural component. Here, as the acid-modified polyolefin, for example, "Adomer" (registered trademark) manufactured by Mitsui Chemicals Co., Ltd. or "Modic" (registered trademark) manufactured by Mitsubishi Chemical Corporation can be cited as a commercial product.

The layer in which the olefin resin is the main structural component is referred to as a P6 layer. The olefin resin used in the P6 layer may, for example, be polyethylene, polypropylene, polybutene, polymethylpentene, polycycloolefin, polyhexene, polyoctene, polydecene or polydodecene. Among them, the olefin resin which is a main structural component of the P6 layer is preferably polyethylene or polypropylene because it is easy to process and relatively inexpensive. These olefin resins can be mixed and copolymerized with other olefin components. For example, when an ethylene-propylene copolymer or an ethylene-propylene-butene copolymer is produced, the melting point of the resin can be lowered.

In addition, the olefin resin is a main structural component of the P6 layer, and means an olefin resin containing more than 50% by mass and 100% by mass or less in 100% by mass of all the components of the layer.

The melting point (hereinafter also referred to as melting endothermic peak temperature) of the olefin resin of the main structural component of the P6 layer of the present invention is preferably from 120 ° C to 170 ° C. When the melting point of the olefin resin in the P6 layer is less than 120 ° C, there is a possibility that heat resistance is deteriorated. On the other hand, when the melting point of the olefin resin in the P6 layer exceeds 170 ° C, the adhesion to the packaging material will become low.

The back sheet of the present invention preferably has a P4 layer and a P6 layer, the P6 layer contains inorganic particles, the P4 layer is located on the surface layer, and the P6 layer is located on the surface layer opposite to the P4 layer. Further, the back sheet of the present invention has the thickness of the entire back sheet. When Ta (μm), the thickness of the P4 layer is T4 (μm), the thickness of the P6 layer is T6 (μm), and the content of the inorganic particles in the P6 layer is M (% by mass), Preferably, all of the formulas (3) to (5) are met: (3) 0.05 ≦ M / T6 ≦ 0.5; (4) 200 ≦ M / Ta ≦ 500; (5) 0.3 ≦ T4 / Ta ≦ 0.5.

By conforming to the formulas (3) to (5), it is possible to form a back sheet having heat resistance and package adhesion, water vapor permeability, and electrical characteristics.

Further, in the case where the back sheet of the present invention is a P4 layer or a P6 layer having a plurality of layers, T4 is obtained using only the P4 layer of the surface layer, and T6 and M are obtained by using only the P6 layer of the opposite surface layer. It is also that these also conform to equations (3) to (5).

Formula (3) mathematically quantifies the amount of inorganic particles per unit thickness. In order to find the effect of inorganic particles, it is important to show that the thicker the thickness, the more concentrated the concentration of inorganic particles. In the formula (3), if the M/T is smaller than 0.05, the P6 layer is liable to yellow due to deterioration. If the M/T is greater than 0.5, the adhesion to the EVA will be reduced.

Further, the P6 layer preferably contains inorganic particles. The inorganic particles in the P6 layer are used for the purpose of imparting the necessary functions to the back sheet in accordance with the purpose. As the inorganic particles in the P6 layer, the same inorganic particles as those used for the P4 layer can be used. Further, in the present invention, in the case where the inorganic particles in the P6 layer are used as a metal oxide such as titanium oxide, zinc oxide or cerium oxide having ultraviolet absorbing ability, the inorganic particles in the P6 layer can be used. It is preferable from the viewpoint of activating the ultraviolet ray resistance by the inorganic particles and reducing the coloring effect caused by the deterioration of the back sheet over a long period of time. Further, from the viewpoint of imparting high reflection characteristics, titanium oxide is more preferably used as the inorganic particles in the P6 layer, and rutile-type titanium oxide is more preferably used from the viewpoint of higher ultraviolet resistance.

Formula (4) shows the thickness range of the entire back sheet, and if Ta is smaller than 200 μm, heat resistance and water vapor permeability will be deteriorated. When Ta is larger than 500 μm, the processability is poor and it is difficult to carry it, so that the step suitability is poor and the weight is reduced. The space-saving solar cell module has become too thick.

The formula (5) indicates the ratio of the thickness of the P4 layer to the entire thickness. The thicker the thickness of the P4 layer, the higher the heat resistance. When the value of T4/Ta is smaller than 0.3, the heat resistance is lowered. If the value of T4/Ta is larger, the heat resistance will be increased. In contrast to the P6 layer, since the P4 layer is often expensive, it is preferably 0.5 or less from the viewpoint of reducing the cost of the product.

The thickness T5 (μm) of the P5 layer is preferably 15 to 50 μm. Also, in the case where a plurality of P5 layers are present, the thickness of the respective P5 layers T5 (μm) is preferably 15 to 50 μm. If T5 is smaller than 15 μm, the adhesion to the P4 layer or the P6 layer will be lowered to cause interlayer peeling. When T5 is larger than 50 μm, when the combustibility of the back sheet is confirmed, the deterioration of flame retardancy is likely to occur. T5 is preferably 20 μm or more and 40 μm or less. Here, the interlayer peeling means that the interface peeling occurs between the P4 layer and the P5 layer and between the P5 layer and the P6 layer.

At least in the laminated structure of the back sheet of the present invention, the P4 layer is located on the surface layer, and the P6 layer is located on the surface layer opposite to the P4 layer. Here, the fact that the P6 layer is located opposite to the P4 layer means that the P4 layer is located on the outermost layer on the side of the backing plate, and the P6 layer is located on the outermost layer on the other side. From such a viewpoint, the layer structure (layer order) of the back sheet of the present invention is preferably a P4 layer/P5 layer/P6 layer.

Next, the method for producing the back sheet of the present invention will be specifically described with respect to the form having the P4 layer, the P5 layer, and the P6 layer. As a method of laminating the P4 layer, the P5 layer, and the P6 layer on the back sheet of the present invention, for example, the following method or the like can be used: a polyphthalamide resin or a polybutylene terephthalate resin to be used as the P4 layer is used. A raw material of a main structural component, a raw material selected from the group consisting of a low crystalline soft polymer for a P5 layer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer, and a P6 layer. The olefin resin is supplied as a raw material of the main structural component to each of the different extruders, and after the respective melting, the P4 layer, the P5 layer, and the P6 layer are sequentially laminated to be laminated, and the step of extruding into a sheet shape from the T die is carried out. Manufacturing method (co-extrusion method); a method in which a coating material is poured into an extruder and melt-extruded onto a sheet made of a single film, and one layer is extruded from a nozzle (melt layering method); each A method in which each sheet is produced differently, which is heat-pressed by a heated roll group or the like (heat lamination method); a method of bonding by an adhesive (adhesive method); and, in addition, coating. A method of drying the solvent in a solvent (coating method); a method of combining the methods, and the like. Among these, a coextrusion method is preferred from the viewpoint that the production steps are short and the interlayer adhesion is good. Hereinafter, the production method using the coextrusion method will be described in detail.

When the back sheet of the present invention is produced by a co-extrusion method, the raw materials for each layer are first supplied to three extruders and melted under a nitrogen stream: the raw material for the P4 layer is used for the dried P4 layer. The polyamide resin or the polybutylene terephthalate resin is supplied as a raw material of the main structural component to an extruder which has been heated to 240 ° C or more and 300 ° C or less; the raw material for the P 5 layer and the P 6 layer is selected from the group consisting of A raw material containing a low crystalline soft polymer for a P5 layer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer as a main structural component, and an olefin resin for a P6 layer as a main structural component. They are supplied separately to an extruder that has been heated to a temperature below 180 ° C and below 250 ° C. Next, the P4 layer, the P5 layer, and the P6 layer are sequentially laminated by a multi-manifold die or a feed section or a static mixer, a sleeve (PINOL), etc., and are laminated to form a sheet from the T die. . In the case where the difference in the melt viscosity of each layer is large, a multi-manifold die is preferably used from the viewpoint of suppressing unevenness in lamination.

The back sheet of the present invention can be obtained by extruding a back sheet ejected from a T die by the above method onto a cooling body such as a casting reel and cooling and solidifying.

The heat treatment or aging of the back sheet of the present invention obtained by the above method may be increased as necessary within the range not impairing the effects of the present invention. Processing. The thermal dimensional stability of the back sheet of the present invention can be improved by performing heat treatment. Further, in order to improve the adhesion of the back sheet of the present invention obtained by the above method, corona treatment or plasma treatment may be performed.

The solar cell module of the present invention is characterized by having the back sheet for a solar cell of the present invention. Compared with the conventional solar cell module, by using the back sheet of the present invention in a solar cell module, it is possible to maintain power generation characteristics for a long period of time. A structural example of the solar cell of the present invention is shown in Fig. 1. In the first embodiment, the transparent substrate 4 such as glass is bonded to the solar cell back sheet 1 of the present invention, and the conductive lead wire is packaged by the transparent encapsulating material 2 such as EVA resin (in the first drawing). The solar cell of the solar cell of the present invention is not limited to the solar cell of the present invention, and can be used in any structure.

In the solar cell module of the present invention, the solar cell backsheet 1 described above is provided with a solar cell unit disposed on the back surface of the package 2 of the packaged solar cell. Here, the solar battery back sheet of the present invention has an asymmetric structure, and the P6 layer is disposed on the side of the package 2, and is preferable from the viewpoint of further improving the adhesion to the package. Moreover, in order to provide a structure in which the P4 layer of the back sheet of the present invention is disposed on the opposite side of the package 2, it is possible to improve the durability against ultraviolet rays or the like from the ground, so that it can be made highly durable. Solar cell module or thinned thickness.

The solar battery unit 3 is capable of converting solar light energy into electric energy, and is capable of crystallization lanthanide, polycrystalline lanthanide, microcrystalline lanthanide, amorphous lanthanide, copper indium selenium, compound semiconductor, dye sensitization, and the like. , According to any component of the purpose, and connected in series or in parallel according to the desired voltage or current, a plurality of components are used. Since the transparent substrate 4 having light transmissivity is located at the outermost layer of the solar cell module, in addition to high transmittance, a transparent material having high weather resistance, high contamination resistance, and high mechanical strength characteristics is also used. In the solar battery module of the present invention, any material having a light-transmissive transparent substrate 4 can be used, and examples thereof include glass, ethylene-tetrafluoroethylene (ETFE), and polyfluoride. Fluorine systems such as ethylene oxide (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (TFE), tetrafluoroethylene-hexafluoropropylene (FEP), polychlorotrifluoroethylene (CTFE), and polyvinylidene fluoride Resin; olefin resin, acrylic resin, and the like. In the case of glass, better use has been strengthened. Further, in the case of using a light-transmitting substrate made of a resin, it is preferred to use a uniaxially or biaxially stretched resin as described above from the viewpoint of mechanical strength.

Moreover, in order to impart adhesion to the EVA-based resin or the like of the solar cell package, the surface is preferably subjected to corona treatment, plasma treatment, ozone treatment, and easy adhesion treatment.

In addition to coating and fixing the surface irregularities of the solar cell unit by resin, the package material 2 for encapsulating the solar cell unit is also used to adhere the substrate having light transmissivity or the purpose of externally protecting the solar cell unit and electrically insulating. A material having high transparency, high weather resistance, high adhesion, and high heat resistance is used for the back sheet and the solar cell unit. As an example thereof, ethylene-vinyl acetate copolymer (EVA), ethylene-alkyl methacrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA) resin, ethylene-methacrylic acid are preferably used. Copolymer (EMAA), ionic polymer resin, polyvinyl butyral resin, mixtures of these, and the like.

As described above, by assembling the solar cell back sheet using the present invention into a solar cell module, it is possible to produce a highly durable and/or thin solar cell as compared with a conventional solar cell. The solar cell module of the present invention is not limited to outdoor applications such as solar power generation systems and power sources for small electronic components, and can be suitably used for various purposes in indoor applications.

Example

Hereinafter, the present invention will be described by way of examples, but the present invention is not necessarily limited thereto. Further, the evaluation of various characteristics described in the present specification is carried out in the following manner. Among them, Examples 30 to 34, 57, and 60 are reference examples.

[Method of evaluation of characteristics]

(1) Layer thickness T1, T2, T3, T4, T5, T6, Ta, laminate ratio T4/Ta

It is obtained in the order of (A1) to (A4) below. Further, the measurement system was measured at 10 positions, and the average value thereof was defined as the thickness T1 (μm) of the P1 layer, the thickness T2 (μm) of the P2 layer, the thickness T3 (μm) of the P3 layer, and the thickness T4 of the P4 layer. (μm), the thickness T5 (μm) of the P5 layer, the thickness T6 (μm) of the P6 layer, and the thickness Ta (μm) of the entire sheet. Further, the layer ratio T4/T6 was obtained by using T4 and T6 obtained here.

(A1) The slice cutter is used to cut the laminated sheet (back sheet) in the thickness direction, but is cut perpendicularly to the surface of the laminated sheet (back sheet).

(A2) Next, the cut cross section was observed using an electron microscope, and an image observed by magnification up to 500 times was obtained. Further, although the observation position is arbitrarily set, the upper and lower directions of the image are parallel to the thickness direction of the laminated sheet (back sheet), and the left and right directions of the image are parallel to the product. The direction of the surface of the layer (backsheet) is carried out. Further, in the case where the entire thickness direction cannot be accommodated in one image, the image is observed by shifting the observation position in the thickness direction, and a plurality of images are combined to prepare an image in which the entire thickness can be confirmed.

(A3) Determine the thickness of the P1 layer in the image obtained in (A2), the thickness T1 of the P2 layer, the thickness T3 of the P3 layer, the thickness T4 of the P4 layer, the thickness T5 of the P5 layer, and the thickness T6 of the P6 layer. The thickness of the whole sheet Ta.

(A4) The layer ratio T4/Ta is calculated by dividing Ta by T4.

(2) Content of inorganic particles (% by mass)

The P1 layer, the P3 layer, the P4 layer, and the P6 layer are separated or peeled off from the laminated sheet (back sheet) to separate the P1 layer, the P3 layer, the P4 layer, and the P6 layer, and the inorganic particles are calculated by the following methods. The content.

The mass wa(g) of the cut material is measured, and then the P1 layer is dissolved in o-cresol, the P3 layer and the P6 layer are dissolved in o-dichlorobenzene (100 ° C), and the P4 layer is dissolved in formic acid. The inorganic particles among the insoluble components are equally divided by centrifugation. The obtained inorganic particles were washed with o-cresol, o-dichlorobenzene, and formic acid, followed by centrifugation. Further, in the washing operation, ethanol was added to the washing liquid after centrifugation, and it was repeated until it became cloudy. The mass wa' (g) of the obtained inorganic particles was determined, and the content of the inorganic particles was calculated from the following formula: . The content (% by mass) of the inorganic particles Wa1 = (wa' / wa) × 100.

(3) Crystallization parameters

{glass transition temperature Tg, crystallization temperature Tc, crystallization parameter ΔTcg}

The glass transition temperature (Tg) and the crystallization temperature (Tc) at the time of temperature rise were measured in accordance with JIS-K7121 (1987) using a differential scanning calorimeter DSCII type manufactured by Seiko Instrument Co., Ltd. First, 5 mg of the sample was weighed and heated from 25 ° C to 300 ° C at a temperature increase rate of 20 ° C /min to obtain Tg and Tc. The crystallization parameter ΔTcg was obtained by the following formula: ΔTcg=Tc-Tg.

Further, in the case where a plurality of Tg and Tc were observed, ΔTcg was calculated using all of Tc and Tg which are Tc>Tg relationships. Among them, the minimum value is set to ΔTcg of the present application.

(4) Determination of elongation at break and determination of fracture strength

According to ASTM-D882 (1997), the sample was cut into a size of 1 cm × 20 cm, and the elongation at break and the breaking strength at a tensile speed of 300 mm/min were measured at 5 cm between the chucks. Further, the number of samples in the longitudinal direction and the broad side direction of each of the films was measured by n = 5, and the average value of the samples was defined as elongation at break and breaking strength.

The case where the breaking strength is 80 MPa or more: S

When the breaking strength is 40 MPa or more and less than 80 MPa: A

When the breaking strength is 30 MPa or more and less than 40 MPa: B

When the breaking strength is 20 MPa or more and less than 30 MPa: C

When the breaking strength is less than 20 MPa: D

S to C are acceptable, and S is the most excellent.

(5) Moisture and heat resistance (extension retention after damp heat test)

After cutting the sample into the shape of the measuring piece (1 cm × 20 cm), the constant temperature and humidity device manufactured by Espec Co., Ltd. was used. PR-1KPH was treated at a temperature of 85 ° C and a relative humidity of 85% RH for 1,000 hours, and then the elongation at break was measured in accordance with the above item (4). In addition, the measurement system was set to n=5, and after measuring the 5 samples in the longitudinal direction and the horizontal direction of the laminated sheet, the average value was made into the fracture elongation E1. Further, for the laminated sheet before the treatment, the elongation at break E0 was measured in accordance with the above item (4), and the elongation at break was calculated by the following formula using the obtained elongation at break E0 and E1: The elongation retention ratio (%) = (E1/E0) × 100.

The obtained elongation retention ratio was determined as follows.

The case where the elongation retention rate is 50% or more: S

The case where the elongation retention rate is 40% or more and less than 50%: A

The case where the elongation retention rate is 30% or more and less than 40%: B

The elongation retention rate is 20% or more and less than 30%: C

Case where the elongation retention rate is less than 20%: D

S to C are acceptable, and S is the most excellent.

(6) Heat resistance (extension retention after heat resistance test)

After the sample was cut into a shape of a measuring piece (1 cm × 20 cm), it was treated by a thermostat humidifier GPHH-102 manufactured by Espec Co., Ltd. at a temperature of 140 ° C for 2000 hours, and then according to the above item (4). The elongation at break was measured. In addition, the measurement system was set to n=5, and after measuring the five samples in the longitudinal direction and the horizontal direction of the laminated sheet, the average value was made into the fracture elongation E1. Moreover, the elongation at break E0 was measured in accordance with the above item (4) for the laminated sheet before the treatment, and the elongation retention ratio was calculated by the following formula using the obtained elongation at break E0 and E1: . The elongation retention ratio (%) = (E1/E0) × 100.

The obtained elongation retention ratio was determined as follows.

The case where the elongation retention rate is 50% or more: S

The case where the elongation retention rate is 40% or more and less than 50%: A

The case where the elongation retention rate is 30% or more and less than 40%: B

The elongation retention rate is 20% or more and less than 30%: C

Case where the elongation retention rate is less than 20%: D

S to C are acceptable, and S is the most excellent.

(7) Weather resistance on the P1 level (tone change after ultraviolet irradiation △ b)

Use the Eye Super UV Tester S-W131 manufactured by Iwasaki Electric Co., Ltd. at a temperature of 60 ° C, a relative humidity of 50%, and a strength of 100 mW/cm ² (light source: metal halide lamp, wavelength range: 295 to 450 nm, peak wavelength: 365 nm) Under the conditions of the P1 side, it was irradiated for 48 hours. For the sample before and after the irradiation, the number of samples was set to n=5, and the spectroscopic color difference meter SE-2000 type (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the irradiation mode in reflection mode according to JIS Z-8722 (2000). The b value on the P1 layer side is calculated as an average value, and the b value before and after the irradiation is obtained. The difference (b value after irradiation and b value before irradiation) was set as the color tone change Δb1 after ultraviolet irradiation.

The judgment was made as follows in accordance with the obtained color tone change (?b1).

The case where the hue change Δb1 is 1 or less: S

The case where the color tone change Δb1 is larger than 1 and is less than 3: A

The change in hue Δb1 is greater than 3 and is less than 6: B

The change in hue Δb1 is greater than 6 and is 9 or less: C

The case where the hue change Δb1 is larger than 9: D

S to C are acceptable, and S is the most excellent.

(8) Weather resistance at the P3 level (tone change after ultraviolet irradiation △ b)

Use the Eye Super UV Tester S-W131 manufactured by Iwasaki Electric Co., Ltd. at a temperature of 60 ° C, a relative humidity of 50%, and a strength of 100 mW/cm ² (light source: metal halide lamp, wavelength range: 295 to 450 nm, peak wavelength: 365 nm) Under the conditions of the P3 side, it was irradiated for 48 hours. For the sample before and after the irradiation, the number of samples was set to n=5, and the spectroscopic color difference meter SE-2000 type (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the irradiation mode in reflection mode according to JIS Z-8722 (2000). The b value on the P3 layer side is calculated as an average value, and the b value before and after the irradiation is obtained. The difference (b value after irradiation and b value before irradiation) was set to change in color tone Δb2 after ultraviolet irradiation.

The judgment was made as follows in accordance with the obtained color tone change (?b2).

The case where the hue change Δb2 is 1 or less: S

The case where the color tone change Δb2 is larger than 1 and is less than 3: A

The change in hue Δb2 is greater than 3 and is less than 6: B

The change in hue Δb2 is greater than 6 and is 9 or less: C

The case where the hue change Δb2 is larger than 9: D

S to C are acceptable, and S is the most excellent.

(9) Adhesion to packaging materials

The adhesion of the package material was evaluated from the peel strength of the EVA sheet (package material) and the P3 layer in accordance with JIS K6854 (1994). For the measurement test piece, a 500 μm-thick EVA sheet manufactured by Sanvic Co., Ltd., and a laminated sheet of the examples and comparative examples subjected to corona treatment were superposed on a semi-tempered glass having a thickness of 3 mm, and used commercially. After the glass laminate was evacuated, it was subjected to a compression treatment at a temperature of 140 ° C for 15 minutes under a load of 29.4 N/cm ² . The width of the test piece prepared for the peel strength test was set to 10 mm, and two test pieces were prepared. Three positions were measured for each test piece, and the average value of the obtained measurement values was defined as the value of the peel strength.

The adhesion to the package material was judged from the obtained peel strength as follows.

When the peel strength is 50N/10mm or more: S

When the peel strength is 40N/10mm or more and less than 50N/10mm: A

When the peeling strength is 30N/10mm or more and less than 40N/10mm: B

When the peeling strength is 20N/10mm or more and less than 30N/10mm: C

When the peel strength is less than 20N/10mm: D

S to C are acceptable, and S is the most excellent.

(10) Interlayer adhesion

The interlayer adhesion was evaluated from the interlayer peel strength after treatment at 85 ° C 85% RH for 1000 hours. Here, the interlayer peel strength is the strength at the time of T-peel peeling measured in accordance with JIS K6854-3 (1999). Here, the interlayer system is an interlayer between the P1 layer and the P2 layer and between the P2 layer and the P3 layer. The width of the test piece for the interlayer peel strength test was set to 15 mm, and two test pieces were prepared for each. In the test piece, three positions were measured by changing the position, and the average value of the obtained measurement values was defined as the interlayer peel strength. The determination of the interlayer adhesion is performed as follows.

When the peel strength is 10N/15mm or more: S

When the peel strength is 6N/15mm or more and less than 10N/15mm: A

When the peeling strength is 3N/15mm or more and less than 6N/15mm: B

When the peeling strength is 1N/15mm or more and less than 3N/15mm: C

When the peel strength is less than 1N/15mm: D

S to C are acceptable, and S is the most excellent.

(11) Water vapor permeability Pw (g/m ² /day) at 40 ° C 90% RH

The measurement of the water vapor permeability of the measurement area of 50 cm ² and the environment of 40 ° C and 90% RH was carried out in accordance with the infrared sensing method of JIS K7129 (2008).

(12) Acetate penetration rate at 85 ° C Pa (g / m ² / day)

The cross-sectional view of the jig 11 used for measuring the acetic acid transmittance is shown in Fig. 2, and the plan view is shown in Fig. 3. The jig 11 includes a jig upper portion 7 having a circular opening portion of 65 cm ² made of stainless steel, and a jig lower portion 8 having an acetic acid-containing container having the same shape as the jig 7 on the container, and pouring the acetic acid stock solution 9 into it. In the lower part 8 of the clamp.

The laminated sheet and the back sheet 1 to be measured are placed between the lower portion 8 of the jig and the upper portion 7 of the jig, so that the stainless steel wire having a diameter of 0.29 mm and a mesh size of 0.98 mm is overlapped on the upper portion 7 side of the jig, and acetic acid is allowed to be mixed. The vapor does not escape in such a manner as to be sandwiched by the O-ring provided on the lower portion 8 of the jig, and the upper portion 7 of the jig and the lower portion 8 of the jig are fixed by the pins. In this state, the mass W1 at room temperature after the backing plate 1 filled with the measurement area of 65 cm ² and the jig 11 prepared with the acetic acid 9 were left at 85 ° C for 1 hour was measured. After the measurement by W1, the mass W2 at room temperature after standing for 1 hour was measured again at 85 °C. In the same manner, the mass W3 at room temperature after standing for 1 hour was measured, and the mass W4 at room temperature 1 hour after the measurement of W3 was measured. For the obtained W1 to W4, Pa is calculated according to the following formula: Pa(g/m ² /day)={(W1-W2)+(W2-W3)+(W3-W4)}/3×24/0.065.

(13) Evaluation of power generation characteristics of solar cell modules

The initial maximum output measured according to the reference state of JIS C8914 (2005) and the acceleration of 85 ° C 85% RH for 5000 hours using the constant temperature and humidity test tank "Conservative constant temperature and humidity test tank PL-4KT" The maximum output after the deterioration test was calculated, and the maximum output retention after the test was calculated. From the maximum output retention obtained, the power generation characteristics were determined as follows.

Maximum output retention is 75% or more: S

Maximum output retention is 50% or more and less than 75%: A

Maximum output retention is 25% or more and less than 50%: B

Maximum output retention is less than 25%: C

S and A are qualified, and S is the most excellent.

(14) Confirmation of discoloration of the unit collector electrode section (unit collector electrode discoloration)

For the surface side collector electrode included in the solar cell module of the solar cell module, the number of samples n=5 was used, and it was visually confirmed that the constant temperature and humidity test tank "Espec constant temperature and humidity test tank PL-4KT" was used. The discoloration after accelerated deterioration test at 85 ° C 85% RH for 5000 hours was carried out. From the obtained number of samples which have been discolored, the discoloration of the unit collector electrode portion was determined as follows.

The case where the number of samples that have changed color is n=0: S

The case where the number of samples that have been discolored is n = 1 or 2: A

The case where the number of samples that have been discolored is n=3 or 4: B

The case where the number of samples that have changed color is n=5: C

S to A are acceptable, and S is the most excellent.

(15) P6 layer yellowing

After the back sheet was cut into the shape of the measurement piece (3 cm × 3 cm), it was treated at 120 ° C for 72 hours using a hot air oven PV (H)-212 manufactured by Espec Co., Ltd. For the sample before and after the treatment, by setting the number of samples n=5, a spectroscopic color difference meter SE-2000 type (manufactured by Nippon Denshoku Industries Co., Ltd.) was used, and in a reflection mode according to JIS Z-8722 (2000) The sample was measured to have a diameter of 30 mmφ, and the b value on the side of the P6 layer was measured, and an average value was calculated to obtain a b value before and after the treatment. That is, Δb is obtained by subtracting the b value before the processing from the b value after the processing, and the determination is performed as follows.

The case where the hue change Δb is less than 3: S

The case where the color tone change Δb is 3 or more and less than 5: A

The case where the color tone change Δb is 5 or more and less than 8: B

The case where the color tone change Δb is 8 or more and 10 or less: C

The case where the hue change Δb exceeds 10: D.

(16) Heat resistance (130 ° C)

According to ASTM-D882 (1997), the back sheet was cut into a size of 1 cm × 20 cm, and a hot air oven PV (H)-212 manufactured by Espec Co., Ltd. was used to measure 5 cm between the chucks placed at 130 ° C for 1000 hours. The elongation at break at a tensile speed of 300 mm/min when stretched. In addition, the rate of decrease in elongation at break was set to the longitudinal direction and the broad side direction of each of the films, and the number of samples was set to an average value measured by n=5. The rate of decrease in elongation at break was determined as follows.

The case where the elongation at break is 70% or more: S

The elongation at break is 50% or more and less than 70%: A

The elongation at break is 30% or more and less than 50%: B

Case where the elongation at break is less than 30%: C.

(17) Partial discharge voltage

A partial discharge voltage of the backing plate was obtained using a partial discharge tester KPD2050 (manufactured by Kikusui Electronics Co., Ltd.). Also, the test conditions are as follows.

. The pattern of the output voltage of the output sheet is selected to include the following three-stage pattern: the first stage is a pattern in which the voltage is simply raised from 0 V up to a predetermined test voltage, and the second stage is a pattern in which a predetermined test voltage is maintained. The 3 stage is a pattern that simply drops from the established test voltage up to 0V.

. The frequency is set to 50 Hz. The test voltage was set to 1 kV.

. The time T1 of the first stage is 10 sec, the time T2 of the second stage is 2 sec, and the time T3 of the third stage is 10 sec.

. The counting method of the pulse counting piece is set to "+" (positive), and the detection level is set to 50%.

. The charge amount in the range piece was set to the range of 1,000 pc.

. In the protective sheet, enter 2kV on the check box of the check input voltage. Also, the pulse count is set to 100,000.

. The initial voltage in the measurement mode was set to 1.0 pc, and the extinction voltage was set to 1.0 pc.

Further, the measurement was carried out at any ten places in the film surface, and the average value thereof was defined as a partial discharge voltage V0. Further, the measurement sample was measured by using a nightly object placed in a room at 23 ° C and 65% RH.

Partial discharge voltage is above 1,050V: S

Partial discharge voltage is 950V or more and less than 1,050V: A

Partial discharge voltage is 700V or more and less than 950V: B

Partial discharge voltage is 300V or more and less than 700V: C

The case where the partial discharge voltage is less than 300V: D.

(18) Adhesion to packaging materials (135 ° C vacuum laminate)

According to JIS K6854 (1994), the adhesion to the package material was evaluated from the peel strength of the E6 sheet (package material) and the P6 layer of the back sheet. For the measurement test piece, a 500 μm-thick EVA sheet manufactured by Sanvic Co., Ltd., and a corona-treated example and a back sheet of a comparative example were superposed on a semi-tempered glass having a thickness of 3 mm, and were used commercially. After the glass laminate was evacuated, the glass laminate was subjected to a compression treatment at a temperature of 135 ° C for 15 minutes under a load of 29.4 N/cm ² . The width of the test piece of the peel strength test was set to 10 mm, and two test pieces were prepared, and the position of each test piece was changed, and three points were measured, and the average value of the obtained measured value was made into the value of peeling intensity. The adhesion to the package material was judged from the obtained peel strength as follows. Also, the case where the backing plate of the P6 layer is not provided is also evaluated in the same manner.

When the peel strength is 50N/10mm or more: S

When the peel strength is 40N/10mm or more and less than 50N/10mm: A

When the peeling strength is 30N/10mm or more and less than 40N/10mm: B

When the peeling strength is 20N/10mm or more and less than 30N/10mm: C

Case where the peel strength is less than 20 N/10 mm: D.

(19) Planarity (crimpness)

The laminated sheet was cut into a size of 100 mm × a width of 100 mm, and the laminated sheet was placed in a concave manner in a state where there was no load on the plane, and the height of the four corners of the sheet was measured. The total value at this time is set to the crimp height, and is determined as follows.

The case where the total height of the curled four corners is less than 20 mm: S

The case where the total height of the curled four corners is 20 mm or more and less than 50 mm: A

The case where the curling height of the four corners is 50 mm or more and less than 80 mm: B

The case where the total height of the curled four corners is 80 mm or more and less than 100 mm: C

The case where the total height of the curled four corners is 100 mm or more: D

S to C are good, and S is the most excellent.

(20) rigid amorphous quality

The P1 layer was cut from the laminated sheet, and the differential scanning calorimetry (DSC) and temperature-modulated DSC method were carried out by the following apparatus and conditions, using "Fiber and Industry" Vol. 65, No. 11 (2009) P.428. The method calculates the rigid amorphous mass.

<DSC method>

Device: DSC Q1000 manufactured by TA Instruments

Gas environment: nitrogen flow (50mL/min)

temperature. Calorie correction: high purity indium

Temperature range: 0 to 250 ° C

Heating rate: 10 ° C / min

Sample weight: 10mg

Sample container: aluminum standard container

<temperature modulation DSC method>

Device: DSC Q1000 manufactured by TA Instruments

Gas environment: nitrogen flow (50mL/min)

temperature. Calorie correction: high purity indium

Specific heat correction: sapphire

Temperature range: 0 to 300 ° C

Heating rate: 2 ° C / min

Sample weight: 5mg

Sample container: aluminum standard container

Further, the rigid amorphous mass: χra (%) is calculated by the following formula: χc (%) = (ΔHm - ΔHc) / ΔHm ⁰ × 100; χma (%) = ΔCp / ΔCp ⁰ ×100; χra(%)=100-(χc+χma).

Χra: straight amorphous quality

Χc: crystallinity

Χma: movable amorphous mass

△Hm: melting heat

△Hc: cold crystallization heat

△Hm ⁰ : complete crystal melting heat (145.3J/g)

△Cp: specific heat difference

ΔCp ⁰ : complete amorphous specific heat difference (0.3497 J/(g. ° C)).

(21) Particle size (average particle diameter) of inorganic particles

The P3 layer was peeled off or peeled off from the laminated sheet and separated, and the mass W (g) was measured. This was dissolved in o-dichlorobenzene (100 ° C), and inorganic particles were equally dispersed from the insoluble components by centrifugation. The obtained inorganic particles were further washed with a solvent, and after centrifugation, the mass Wt of the obtained inorganic particles was measured. Further, in the washing operation, ethanol was added to the washing liquid after centrifugation, and it was repeated until it became cloudy.

The obtained inorganic particles were filtered by a quantitative filter paper grade 44 manufactured by Whatman, and analyzed by laser for the components remaining as residues. The particle size distribution was determined by the scattering method, and the particle diameter of 50% of the cumulative value of the particle size distribution was defined as the average particle diameter. Here, the particle size distribution is based on the "laser diffraction. Scattering method particle size distribution measuring device LS series" (Beckmann Coulter Co., Ltd.) and Toyota True Bow "measuring particle size distribution" (Beckmann Coulter Co., Ltd. And find it. Also, the measurement solution is to add inorganic particles to water. The homogenizer was used to perform the dispersion treatment for 1 minute, and the concentration adjustment window display of the device was adjusted to 45 to 55%.

First, the inventions of the first to thirteenth embodiments will be described by way of Examples 1 to 26, 57 to 72, and Comparative Examples 1 and 2.

(raw material) . Polybutylene terephthalate resin

"Toraycon" (registered trademark) 1200M (manufactured by Toray Co., Ltd.) was used as the polybutylene terephthalate resin (PBT) constituting the P1 layer in Examples 1 to 26, 57 to 72, and Comparative Example 1. .

. Polyolefin resin

"Noblen" (registered trademark) WF345S manufactured by Sumitomo Chemical Co., Ltd. (3.5% by mass of ethylene, butene 4.0) was used as the polyolefin resin constituting the P3 layer in Examples 1 to 26, 57 to 72, and Comparative Example 2. Mass %) is used as EPBC1.

In the case of Example 25, "Noblen" (registered trademark) FLX80E4 manufactured by Sumitomo Chemical Co., Ltd. was used as PP1.

. Acid modified polyolefin

In the resins constituting the P2 layer of Examples 1 to 26 and 57 to 72, "Modic" (registered trademark) P553A manufactured by Mitsubishi Chemical Corporation was used as the resin 1.

. Polyolefin elastomer

As a polyolefin-based elastic system of Example 24, "Notio" (registered trademark) PN2060 manufactured by Mitsui Chemicals, Inc. was used as the elastomer 1.

. Inorganic particles

Titanium dioxide was used as the inorganic particles of the P1 layers of Examples 1 to 5, 7 to 26, 57 to 72, Comparative Example 1, and the P3 layers of Examples 1 to 9, 11 to 26 and Comparative Example 2. Further, the titanium dioxide produced by the ratio of the resin used as the main structural component of the P1 layer and the titanium dioxide in the ratio of 50% by mass to 50% by mass of the P1 layer in each of the examples and the comparative examples was added to the titanium dioxide of the P1 layer. material. The parent compound prepared by adding the ratio of the resin which is the main structural component of the P3 layer and the titanium dioxide in the ratio of 30 mass% / 70 mass% of the P3 layer main structural component of each Example and the comparative example was added to the P3 layer.

. End capping agent

In Examples 1, 3 to 25, 57 to 72, and the terminal blocking agent for the P1 layer of Comparative Example 1, P-400 manufactured by Rhein Chemie Co., Ltd. was used. For Example 26, "Carbodilite" (registered trademark) HMV-15CA manufactured by Nissin Textile Chemical Co., Ltd. was used.

. Crystal nucleating agent

Sodium montanate was used as a crystal nucleating agent for the P1 layer of Examples 61 to 63.

. Inorganic particles (3 μm or more and 20 μm or less)

The talc having an average particle diameter of 5 μm was used as the inorganic particles of 3 μm or more and 20 μm or less of Examples 64 to 72.

(Examples 1 to 26, 61 to 72)

The extruder 1, the extruder 2, and the extruder 3 were used to supply the raw materials shown in Tables 1 and 5 to each extruder in such a manner as to achieve the desired blend ratio, and then, from the extruder. 1 melt extruded layer as In the P1 layer, the extruder 2 is used as the P2 layer, and the extruder 3 is used as the P3 layer. The layers are laminated in the order of the P1 layer/P2 layer/P3 layer, and the layers are merged by the manifold, and are ejected from the nozzles. The resin was cooled and solidified on a casting reel at 25 ° C to obtain a laminated sheet. The P1 layer, the P2 layer, and the P3 layer are shown in the thicknesses of Tables 1 and 5. The evaluations shown in Table 2 and Table 6 were carried out for the obtained laminated sheets. As a result, as shown in Table 2 and Table 6, it was found that the laminate sheet was excellent in the examples.

Further, in Example 24, the P2 layer contained an elastomer, and the interlayer adhesion was extremely excellent.

(Examples 57 to 60)

The same procedure as in Example 1 was carried out except that the temperature of the casting reel was changed to 15 ° C (Example 57), 20 ° C (Example 58), 40 ° C (Example 59), and 50 ° C (Example 60). Layered film. The evaluation shown in Table 6 was carried out for the obtained laminate. As a result, as shown in Table 6, it was found to be an excellent laminated sheet for the examples.

(Comparative Example 1)

The raw material shown in Table 1 was supplied to the extruder by using the extruder 1 in such a manner as to achieve the desired blend ratio, and then the resin discharged from the extruder 1 from the melt-extruded nozzle was used. Cooling and solidifying on a casting reel to obtain a single layer sheet. Since there is no polyolefin-based resin layer, the adhesion to the packaging material is deteriorated.

(Comparative Example 2)

The raw material shown in Table 1 was supplied to the extruder by using the extruder 3 in such a manner as to achieve the desired blend ratio, and then the resin discharged from the extruder 3 from the melt-extruded nozzle was used. Cooling and solidifying A single layer of sheet is obtained by casting on a roll. Since there is no polybutylene terephthalate-based resin, it is deteriorated in heat resistance and heat resistance.

In comparison with the laminated sheet using the conventional polybutylene terephthalate resin, it is possible to provide a laminated sheet which can have both moist heat resistance, heat resistance and adhesion to a packaging material. In addition to the solar cell backsheet, the related laminated sheet can also be suitably used for reflective panels for liquid crystal displays, automotive materials, and building materials, such as heat and humidity resistance, UV resistance, and light reflectivity. use. In particular, it is possible to provide a laminated sheet which can be suitably used as a solar battery back sheet, and a method of producing the laminated sheet.

Next, the inventions of the 14th to 20th are explained by the examples 27 to 56 and the comparative examples 3 to 5.

(Examples 27 to 56, Comparative Example 5) (raw material) . Polyamide resin

A nylon 6 resin "Amilan" (registered trademark) CM1021T (TORAY Co., Ltd.) as a polyamide resin (PA6) constituting the P4 layers of Examples 27, 34 to 39, 41 to 49, and Comparative Examples 4 and 5 was used. System, Tm: 225 ° C).

Regarding Example 50, a nylon 66 resin "Amilan" (registered trademark) CM3001 (PA66) was used; with respect to Example 51, Nylon 610 resin "Amilan" (registered trademark) CM2001 (PA610) was used; with respect to Example 52, Nylon 11 resin "Rilsan" BESN-O-TL (PA11) was used; with respect to Example 53, Nylon 12 resin was used" Rilsan" AESN-TL (PA12).

. Polybutylene terephthalate

"Toraycon" (registered trademark) 1200M (manufactured by Toray Co., Ltd., Tm: 224 ° C) was used as the polybutylene terephthalate (PBT) of the P4 layer of Examples 29 and 54.

. Polyethylene terephthalate

A film of 25 μm "Lumirror" (registered trademark) S10 (manufactured by Toray Co., Ltd.) was used as the polyethylene terephthalate (PET) constituting the P4 layer of Example 28.

. Polyfluorinated ethylene

A film of 38 μm "Tedlar" (registered trademark) (manufactured by Dupont Co., Ltd.) was used as the polyvinyl fluoride (PVF) constituting the P4 layer of Example 30.

. Ethylene-tetrafluoroethylene

A film of "Toyoflon" (registered trademark) EL (manufactured by Toray Film Processing Co., Ltd.) of 50 μm was used as the ethylene-tetrafluoroethylene (ETFE) constituting the P4 layer of Example 31.

. Tetrafluoroethylene-hexafluoropropylene

A film of "Toyoflon" (registered trademark) FL (manufactured by Toray Film Processing Co., Ltd.) of 25 μm was used as the tetrafluoroethylene-hexafluoropropylene (FEP) constituting the P4 layer of Example 32.

. Polyvinylidene fluoride

A film of 30 μm of Kynar Film 302 PGM TR (manufactured by ARK EMA Co., Ltd.) was used as the polyvinylidene fluoride (PVDF) constituting the P4 layer of Example 33.

. Olefin resin

In Examples 27 to 45, 50 to 54, and Comparative Example 5, "Noblen" (registered trademark) WF345S (3.5% by mass of ethylene and 4.0% by mass of butene) manufactured by Sumitomo Chemical Co., Ltd. was used as EPBC1.

Regarding Example 46, "Evolue" (registered trademark) SP2530 manufactured by Sumitomo Chemical Co., Ltd. was used as LLDPE1.

Regarding Example 47, "Evolue" (registered trademark) SP2540 manufactured by Sumitomo Chemical Co., Ltd. was used as LLDPE2.

For Example 48, an ethylene mass 1% copolymerized polypropylene was used as EPC1.

In the case of Example 49, "Noblen" (registered trademark) FLX80E4 manufactured by Sumitomo Chemical Co., Ltd. was used as PP1.

. Acid modified olefin

"Modic" (registered trademark) P553A manufactured by Mitsubishi Chemical Corporation was used as the resin 1 as the resin constituting the P5 layer of Examples 34 to 39, 41 to 54, and Comparative Example 5.

. Ethylene-vinyl acetate copolymer

"Modic" (registered trademark) A515 manufactured by Mitsubishi Chemical Corporation was used as the resin 2 as the resin constituting the P5 layer of Example 55.

. Acrylic adhesive

In the resin constituting the P5 layer of the example 56, "Bondfast" (registered trademark) 7L manufactured by Sumitomo Chemical Co., Ltd. was used as the resin 3.

. Inorganic particles

The inorganic particles used in the P4 layers of Examples 27, 29, 34 to 39, 41 to 54, and Comparative Example 5 and the P6 layers of Examples 27 to 54 and Comparative Example 5 were titanium dioxide having an average particle diameter of 0.25 μm.

Further, the titanium dioxide of the P4 layer was added to the resin having a ratio of 50% by mass to 50% by mass of the main structural component of the P4 layer in each of the examples and the comparative examples. The titanium dioxide of the P6 layer was added to the resin having a ratio of 30% by mass to 70% by mass of the main structural component of the P6 layer in each of the examples and the comparative examples.

(layered)

The raw materials shown in Tables 3-1 and 3-2 were supplied to the respective extruders by using the extruder 4, the extruder 5, and the extruder 6 so as to have a desired blend ratio, and then, from The layer melt-extruded in the extruder 4 is a P4 layer, the extruder 5 is a P5 layer, and the extruder 6 is a P6 layer, and the multi-manifold is used in a layered manner in the order of the P4 layer/P5 layer/P6 layer. The layers are joined together, and the resin ejected from the nozzle is cooled and solidified on the casting reel to obtain a back sheet.

Among the back sheets without the P5 layer, the examples 27 and 29 used the extruder 4 and the extruder 6 to make the desired blending ratio. The raw materials shown in Table 3-1 were supplied to each extruder, and then the layer melt-extruded from the extruder 4 was designated as a P4 layer, and the extruder 6 was designated as a P6 layer in the order of the P4 layer/P6 layer. In a layered manner, the manifolds are used to join the layers, and the resin ejected from the nozzles is cooled and solidified on the casting reel to obtain a back sheet.

Among the back sheets having no P5 layer, Examples 28, 30 to 33, and Comparative Example 3 were used as the structures of Tables 3-1 and 3-2, and the dry layer method was used as the adhesion system between the layers. The polyurethane adhesive is laminated as an adhesive. At this time, the EPBC1 used in Examples 28, 30 to 33 was supplied to the extruder 6 in such a manner that it was made into a desired blend ratio, and then, the extruder 6 was melt-extruded from the extruder 6 and passed from the nozzle. The ejected resin is cooled and solidified on a casting reel to obtain a single layer sheet.

In the embodiment 39, the raw material is supplied to the extruder 6 in such a manner that it is a desired blend ratio, and then the resin which is melt-extruded from the extruder 6 and ejected from the nozzle is cooled and solidified on the casting reel. Obtain a single layer.

(Solar battery moduleization)

The flux "H722 manufactured by HOZAN Co., Ltd." was applied to the silver electrode portion on the front and back surfaces of the solar cell "Q6LPT-G2 manufactured by Qcells Co., Ltd." by a dispenser, and the back surface side was formed on the silver electrodes on the front and back surfaces. The wiring material cut into a length of 155 mm "copper foil SSA-SPS 0.2 × 1.5 (20) made by Hitachi Cable Co., Ltd." was placed at a distance of 10 mm from the end of the surface side unit, and the soldering iron was used to remove the unit. On the back side, the soldering iron is brought into contact while soldering the surface and the back surface to form a 1-cell strip.

In the longitudinal direction of the wiring material which protruded from the unit of the one-piece strip produced, the long-side direction of the extraction electrode "Aluminum foil A-SPS 0.23 × 6.0 made by Hitachi Cable Co., Ltd." which was cut into 180 mm was The flux is applied in a vertical manner, and the flux is applied to a portion where the wiring member and the extraction electrode overlap, and soldering is performed to form a strip with the extraction electrode.

Then, a glass of 190 mm × 190 mm, a 3.2 mm thick white plate heat-treated glass for a solar cell made by Asahi Glass Co., Ltd., and an ethylene-vinyl acetate product of 190 mm × 190 mm, a 0.5 mm thick package made of Sanvic Co., Ltd., were produced. Each of the strips with the extracted electrodes, 190 mm × 190 mm of ethylene-vinyl acetate "0.5 mm thick made of Sanvic company's packaging material", and 190 mm × 190 mm of each of the back sheets of the table 3-1, 3-2 The hot lamination of the vacuum laminator was set in such a manner that the hot plate temperature was 145 ° C, the vacuum was applied for 4 minutes, the pressurization was performed for 1 minute, and the holding time was 10 minutes. At this time, the strip with the extraction electrode is provided such that the glass surface becomes the unit surface side.

The thicknesses of the P4 layer, the P5 layer, and the P6 layer, the acetic acid transmittance Pa, and the water vapor transmission rate Pw are shown in Tables 3-1 and 3-2. The evaluations shown in Tables 4-1 and 4-2 were carried out for the use of the obtained back sheet and the solar cell module using the back sheet. As a result, as shown in Tables 4-1 and 4-2, it was found to be an excellent back sheet for the examples.

In Comparative Example 5, the Pw was larger than 2.5, and the discoloration of the unit collecting electrode was poor.

(Comparative Example 3)

By the dry lamination method, a polyurethane adhesive is used as an adhesive for the adhesion between the layers, and 125 μm of white polyethylene terephthalate "Lumirror" E20F (manufactured by Toray Co., Ltd.) is sequentially laminated. And a backing plate of 12 μm polyethylene terephthalate "Barrialox" (registered trademark) EG-C2 (manufactured by Toray Film Processing Co., Ltd.) having an inorganic compound vapor-deposited layer made of alumina, if acetic acid is measured In the case of the permeability and the water vapor transmission rate, Pa is 10 g / 24 hr / m ² for the acetic acid transmittance, and Pw is 0.2 g / 24 hr / m ² for the water vapor transmission rate. Moreover, the solar cell module was fabricated using the back sheet, and compared with the maximum output retention ratio of 85 ° C 85% RH 5000 hours before and after, the maximum output retention ratio was 10%, and since the Pa was smaller than 200, the power generation characteristics were Poor.

(Comparative Example 4)

The raw material shown in Table 3-2 was supplied to the extruder using the extruder 4 in such a manner as to achieve the desired blend ratio, and then, it was melt extruded from the extruder 4 and ejected from the nozzle. The resin is cooled and solidified on a casting reel to obtain a single layer sheet. Since the Pw is larger than 2.5, the discoloration of the unit collector electrode is poor.

Claims (12)

A laminated sheet characterized in that a layer (P1 layer) having a polybutylene terephthalate resin as a main structural component and a layer (P3 layer) having a polyolefin resin as a main structural component, and a layer P1 The amount of rigid amorphous is 30 to 50%, the acetic acid penetration rate of Pa (g/m ² /day) at 85 ° C, and the water vapor transmission rate Pw (g/ at 90 ° C 90 ° C). m ² /day) conforms to formula (1) and formula (2): (1) 200 ≦ Pa; (2) Pw ≦ 2.5. The laminate sheet of claim 1, which has a layer (P2 layer) having a polyolefin-based resin as a main structural component, and a P1 layer and a P3 layer via a P2 layer. The laminate of claim 2, wherein the thickness of the P2 layer is 15 to 50 μm. The laminate sheet according to any one of claims 1 to 3, which has a crystallization parameter ΔTcg of the P1 layer measured by differential scanning calorimetry (DSC) of 7 to 30 °C. The laminated sheet according to any one of claims 1 to 3, wherein the polybutylene terephthalate resin which is a main structural component of the P1 layer contains a terminally-terminated polybutylene terephthalate resin, The end-capped polybutylene terephthalate resin is obtained by reacting a terminal blocking agent with a polybutylene terephthalate resin. The laminate of any one of claims 1 to 3, wherein the P3 layer contains 0.1 to 30% by mass of inorganic particles. The laminate of any one of claims 1 to 3, wherein the layer P1 contains 0.1 to 5% by mass of a crystallization nucleating agent. The laminated sheet according to any one of claims 1 to 3, wherein the P3 layer contains 5 to 30% by mass of inorganic particles having a particle diameter of 3 μm or more and 20 μm or less, and contains 0.5 to 5% by mass of the adhesive polyolefin-based resin. A solar battery back sheet comprising the laminated sheet according to any one of claims 1 to 8. A solar cell using the solar cell backsheet of claim 9. A method for producing a laminated sheet according to any one of claims 2 to 8, characterized by comprising the step of using a polybutylene terephthalate resin as a main structural component The P1 layer raw material, the P2 layer raw material containing the polyolefin resin as a main structural component, and the P3 layer raw material containing the polyolefin resin as a main structural component are supplied to different extruders, and after melting each The P1 layer, the P2 layer, and the P3 layer are sequentially joined to form a layer, and are extruded into a sheet shape from the T die. A back sheet for a solar cell characterized by an acetic acid transmittance Pa (g/m ² /day) at 85 ° C and a water vapor transmission rate Pw (g/m ² /day) at 40 ° C 90% RH A P4 layer conforming to the formula (1) and the formula (2) and having any of a polyester resin and a polyamide resin as a main structural component: (1) 200 Å Pa; (2) Pw ≦ 2.5.