KR20150095635A - Laminated sheet and method for manufacturing same, solar cell back sheet, solar cell module, and method for manufacturing solar cell back sheet - Google Patents

Abstract

The present invention relates to a laminated sheet having a layer mainly composed of a polybutylene terephthalate resin (P1 layer) and a layer mainly composed of a polyolefin resin (P3 layer). (G / m2 / day) at 85 占 폚 and a water vapor transmission rate Pw (g / m2 / day) at 40 占 폚 and 90% RH satisfy the following relationships: 200? Pa and Pw? 2.5 Of the back sheet for a solar cell. Provided is a laminated sheet which is capable of achieving compatibility between heat and humidity resistance, heat resistance and adhesion to a sealing material as compared with a laminated sheet using a conventional polybutylene terephthalate resin, and a method of producing the laminated sheet. The present invention also provides a back sheet for a solar cell module capable of preventing discoloration of the current collecting electrode of the solar cell while maintaining power generation characteristics of the solar cell module at low cost and for a long period of time.

Description

TECHNICAL FIELD [0001] The present invention relates to a laminated sheet, a method for producing the same, and a method for manufacturing a back sheet for a solar cell, a solar cell module, and a back sheet for a solar cell }

The present invention relates to a laminated sheet capable of achieving both durability and adhesion to a sealing material. To a laminated sheet which can be preferably used as a solar cell back sheet, and to a method of producing the laminated sheet. Further, the present invention relates to a back sheet contributing to improvement of long-term reliability of a solar cell module.

In recent years, solar power is attracting attention as a next-generation energy source that is semi-permanent and pollution-free, and solar cells are rapidly spreading. In a solar cell, a power generation element is sealed with a transparent sealing material such as an ethylene-vinyl acetate copolymer (EVA), and a transparent substrate such as glass is bonded to a resin sheet called a back sheet. Solar light is introduced into the solar cell through the transparent substrate. Solar light introduced into the solar cell is absorbed by the power generation element, and the absorbed light energy is converted into electric energy. The converted electric energy is taken out to the lead wire connected to the electric power generating element and used for various electric devices. Here, the conventional backsheet has been studied to provide barrier properties and electrical characteristics by bonding various materials to biaxially oriented polyethylene terephthalate (PET), which is inexpensive and high performance, by dry lamination. Further, the polyolefin-based resin is a material generally used as a back sheet because it has good barrier property and good adhesion with the sealing material.

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

Further, it is known that the solar cell module is susceptible to deterioration in a high temperature and high humidity environment, and improvement of the resistance to humidity and humidity has been a priority. Particularly, in the case of a sealing material used for a solar cell module, EVA is often used from the viewpoints of weatherability, transparency, productivity and the like. However, there has been a concern about the generation of acetic acid by high temperature steam.

Accordingly, in the production of a solar cell module, as described in, for example, Patent Document 3, a back sheet having a low water vapor transmission rate is selected so as to suppress the penetration of moisture, thereby suppressing the generation of acetic acid, There have been inventions in which the output characteristics of the solar cell module do not change over a long period of time.

Also, as in Patent Document 4, there has been an invention of a sealing material for a solar cell module in which output characteristics are not changed for a long period of time by suppressing acetic acid generated from EVA.

Japanese Patent Laid-Open No. 2009-141345 International Publication No. 2010/018662 Japanese Patent Laid-Open Publication No. 1-199379 Japanese Patent Application Laid-Open No. 2008-115344

However, the polybutylene terephthalate resin generally has a drawback that the heat and humidity resistance is poor and the adhesion with the sealing material is poor. Further, the back sheet obtained by laminating the polybutylene terephthalate resin and the polycarbonate resin described in Patent Document 1 improves the heat and humidity resistance, but the adhesion with the sealing material is not obtained, and there is a problem of delamination. Also in the back sheet described in Patent Document 2, it is difficult to achieve both adhesion between the heat resistance and the sealing material. Accordingly, the present invention provides a laminated sheet which can be preferably used for a solar cell back sheet having high productivity and having durability and adhesion to a sealing material, in view of the conventional problems.

In Patent Document 3, there is a problem that an inorganic vapor deposition film or the like is often used when the water vapor permeability is made low, and it is very expensive when the inorganic vapor deposition film is used. On the other hand, in the case where the water vapor transmission rate is large, each part of the metal material used in the solar cell is corroded by moisture, and discoloration due to corrosion of the collecting electrode of the solar cell sometimes occurs.

In addition, in Patent Document 4, there is a concern about the influence of adding an additive to the EVA, and in addition, a change of the EVA adjacent to the solar battery cell is verified for modification.

The present invention has been studied in view of the above problems. That is, it is an object of the present invention to provide a back sheet for a solar cell module, which is inexpensive and capable of maintaining power generation characteristics of a solar cell module for a long period of time, thereby preventing discoloration of the current collecting electrode of the solar cell .

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

The first invention is a laminated sheet having a layer mainly composed of a polybutylene terephthalate resin (P1 layer) and a layer mainly composed of a polyolefin resin (P3 layer).

The second invention has a layer (P2 layer) mainly composed of an adhesive polyolefin-based resin, wherein the P1 layer and the P3 layer are in contact with each other through the P2 layer.

The third invention is characterized in that the thickness of the P2 layer is 15 to 50 mu m.

The fourth invention is characterized in that the crystallization parameter? Tcg of the P1 layer measured by differential scanning calorimetry (DSC) is 7 to 30 占 폚.

The fifth invention relates to a resin composition comprising a polybutylene terephthalate resin as a main constituent component of the P1 layer and a polybutylene terephthalate resin as a main constituent component of the P1 layer when the resin obtained by reacting the terminal blocking agent and the polybutylene terephthalate resin is used as the terminal- Is characterized by comprising a terminal-blocked polybutylene terephthalate-based resin.

The sixth invention is characterized in that the P3 layer contains 0.1 to 30 mass% of inorganic particles.

The seventh aspect of the present invention is characterized in that the amount of rigorous non-crystallization of the P1 layer is 30 to 50%.

The eighth invention is characterized in that the P1 layer contains 0.1 to 5% by mass of a nucleating agent.

The ninth invention is characterized in that the P3 layer contains 5 to 30 mass% of inorganic particles having a particle diameter of 3 to 20 탆 and contains 0.5 to 5 mass% of an adhesive polyolefin resin.

The tenth aspect of the present invention is a method for producing a water-absorbent resin composition, comprising the steps of: (1) providing an aqueous solution having a water permeability Pw (g / m 2 / day) at 85 캜, Pa (g / Pw? 2.5.

The eleventh invention is a solar cell back sheet comprising a laminated sheet according to any one of the above inventions.

The twelfth invention is a solar cell using the solar cell back sheet according to the eleventh invention.

The thirteenth invention is the manufacturing method of the laminated sheet according to any one of the second to tenth aspects, wherein the raw material for the P1 layer mainly composed of the polybutylene terephthalate resin as the main component and the adhesive polyolefin resin as the main constituent components , And a raw material for the P3 layer mainly composed of a polyolefin resin are fed to separate extruders, and the P1 layer, the P2 layer and the P3 layer are joined in this order and melted and laminated in this order, And extruding the sheet from the T die into a sheet.

The fourteenth aspect of the present invention is a method for producing a laminated body of a laminated body according to the first aspect of the present invention, wherein an acetic acid permeability Pa (g / m2 / day) at 85 캜 and a water vapor permeability Pw (g / Pw < / = 2.5. ≪ / RTI >

The fifteenth invention is characterized by having a P4 layer in the fourteenth invention when a layer selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin is a main constituent component, and the layer is a P4 layer .

The sixteenth invention is the back sheet for a solar cell having the P4 layer and the P6 layer, wherein the P6 layer contains inorganic particles and the P4 layer contains P4 The thickness of the P4 layer is T4 (占 퐉), the thickness of the P6 layer is T6 (占 퐉), the thickness of the P6 layer is P6 (占 퐉) (3) 0.05? M / T? 6? 0.5, (4) 200? Ta? 500, and (5) 0.3? T4 / Ta? 0.5, where M is the content of the inorganic particles in the layer Both of which are satisfied.

A seventeenth invention is characterized in that the P4 layer according to any one of the fifteenth or sixteenth invention comprises a polyamide resin or polybutylene terephthalate (PBT) as a main component.

The eighteenth invention is characterized in that, in any one of the sixteenth or seventeenth invention, the layer mainly composed of one selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive and an ethylene vinyl acetate copolymer is referred to as a P5 layer , The P5 layer is located between the P4 layer and the P6 layer.

A nineteenth invention is a solar cell module having a solar cell back sheet according to any one of the fourteenth to eighteenth invention.

A twentieth invention is the process for producing the back sheet for a solar cell according to the eighteenth invention, wherein the polyamide resin for the P4 layer or the raw material containing PBT as the main constituent, the low crystalline soft polymer for the P5 layer, the acrylic adhesive and the ethylene- And a raw material mainly composed of an olefin resin for the P6 layer are fed to separate extruders, respectively, and after the respective melts, P4 layer, P5 layer and P6 Layered in this order, and then extruding the sheet from the T-die into a sheet.

According to the first to thirteenth inventions, it is possible to provide a laminated sheet excellent in the level of durability which can be suitably used for a solar cell back sheet, sealing material adhesion, and interlayer adhesion. Such a laminated sheet can be preferably used for a solar cell back sheet, and a high performance solar cell can be provided by using the back sheet.

According to the back sheet for a solar cell according to the fourteenth to twentieth invention, acetic acid generated inside the solar cell module is discharged 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 current collecting electrode of the solar cell, and furthermore, it is possible to provide a back sheet excellent in heat resistance, P6 layer yellowing, partial discharge voltage and adhesion to the sealing material.

1 is a cross-sectional view schematically showing an example of the configuration of a solar cell (solar cell module) using the laminated sheet (back sheet for a solar cell) of the present invention.
2 is a sectional view of the jig for measuring the acetic acid transmittance.
3 is a top view of a jig for measuring acetic acid transmittance.

The first to thirteenth inventions are laminated sheets having a layer mainly composed of a polybutylene terephthalate resin (P1 layer) and a layer mainly composed of a polyolefin resin (P3 layer).

The polybutylene terephthalate resin refers to a polyester resin having terephthalate as a dicarboxylic acid component and butylene terephthalate containing 1,4-butanediol as a diol component as a main repeating unit. The main repeating unit referred to herein is a terephthalate component in which 80 mol% or more and 100 mol% or less of all the dicarboxylic acid components in the polyester resin are 100 mol% %, It is meant that 80 mol% or more and 100 mol% or less are 1,4-butanediol components. The terephthalate component is preferably 90 mol% or more and 100 mol% or less, and more preferably 95 mol% or more and 100 mol%, based on 100 mol% of all the dicarboxylic acid components in the polyester resin. 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, and more preferably 95 mol% or more and 100 mol% or less.

In such a polybutylene terephthalate resin, other components may be copolymerized in addition to terephthalic acid as the dicarboxylic acid component and 1,4-butanediol as the diol component. Specific examples of the dicarboxylic acid component include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimeric acid, eicosanoic acid, pimelic acid, azelaic acid, Alicyclic dicarboxylic acids such as aliphatic dicarboxylic acids such as malonic acid, malonic acid, malonic acid and ethylmalonic acid, adamantanedicarboxylic acid, norbornenedicarboxylic acid, isosorbide, cyclohexanedicarboxylic acid and decalindicarboxylic acid. Naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 4-naphthalene dicarboxylic acid, , 4'-diphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-sodium sulfoisophthalic acid, phenylendodicarboxylic acid, anthracenedicarboxylic acid, phenanthric dicarboxylic acid , Aromatic dicarboxylic acids such as 9,9'-bis (4-carboxyphenyl) fluorenic acid and the like, or ester derivatives thereof Or the like may be copolymerized. Further, the above-mentioned dicarboxylic acid component may be obtained by addition of oxyacids such as 1-lactide, d-lactide, and hydroxybenzoic acid, derivatives thereof, and a plurality of oxyacids, . If necessary, a plurality of these may be used.

Examples of such diol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol and 1,3-butanediol, Alicyclic diols such as methanol, spiroglycol and isosorbide; alicyclic diols such as bisphenol A, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 9,9'-bis (4-hydroxyphenyl) A diol component such as an aromatic diol, and a component having a plurality of the above-mentioned diols, but the present invention is not limited thereto. If necessary, a plurality of these may be used.

The polybutylene terephthalate resin can be obtained by appropriately combining the dicarboxylic acid component and the diol component and polycondensation. 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 preferable to use those having a melting point of 215 ° C or more and 230 ° C or less.

The crystallization parameter? Tcg of the P1 layer measured by differential scanning calorimetry (DSC) is preferably 7 to 30 占 폚. If the? Tcg of the P1 layer is less than 7 占 폚, it tends to be easily crystallized because of crystallization, so that the heat and humidity resistance may be lowered. If the? Tcg of the P1 layer is larger than 30 占 폚, water may easily enter between the layers due to the crystallinity, and the interlayer adhesion may deteriorate. In order to change the crystallization parameter? Tcg of the P1 layer measured by differential scanning calorimetry (DSC) to 7 to 30 占 폚, the polybutylene terephthalate resin as the main constituent of the P1 layer is subjected to differential scanning calorimetry (DSC) The crystallization parameter < RTI ID = 0.0 > Tcg < / RTI >

It is preferable that the rigorous amorphous amount of the P1 layer is 30 to 50%. If it is less than 30%, curl tends to occur. If it is larger than 50%, it tends to be embrittled after the heat treatment and the heat and humidity resistance is deteriorated.

Here, stiff amorphous refers to an amorphous state in which the molecular motion is frozen even at a temperature higher than the glass transition temperature in an intermediate state between crystals and completely amorphous states. The stiffness non-crystallization amount is obtained from the formula: stiffness non-crystallization amount = 100% - crystallization degree - complete amorphization amount. The crystallinity and the complete amorphous amount can be quantified by the temperature-modulated DSC method described in "Fiber and Industry" Vol. 65, No. 11 (2009) P.428. Specific measurements are described in the Examples.

The main component of the polybutylene terephthalate resin for the P1 layer is that the polybutylene terephthalate resin is contained in an amount of more than 50 mass% and 100 mass% or less in 100 mass% .

The P1 layer constituting the laminated sheet of the present invention preferably contains inorganic particles in a range of 0.1 mass% or more and 30 mass% or less. The content of the inorganic particles in the P1 layer is more preferably 2 mass% or more and 25 mass% or less, and still more preferably 5 mass% or more and 20 mass% or less. The inorganic particles are used for imparting necessary functions to the sheet according to its purpose. If the content of the inorganic particles in the P1 layer exceeds 30 mass%, the handling property may be lowered or the durability may be lowered. If the content of the inorganic particles in the P1 layer is less than 0.1% by mass, the effect due to the inclusion of the inorganic particles can hardly be obtained and yellowing may occur.

Examples of the inorganic particles preferably used for the P1 layer include inorganic particles having an ability to absorb ultraviolet rays, particles having a large difference in refractive index from a polybutylene terephthalate resin, particles having conductivity, and pigments. , Optical properties such as light reflectivity and whiteness, and antistatic properties can be imparted. The term " particles " means primary particles having a diameter of 5 nm or more as a result of the diameter of the projected equivalent equivalent circle. Unless otherwise stated, in the present invention, the particle diameter means the primary particle size, and the particle means the primary particle.

In more detail, the inorganic particles preferably used in the P1 layer of the present invention may be selected from the group consisting of gold, silver, copper, platinum, palladium, rhenium, vanadium, osmium, cobalt, iron, zinc, ruthenium, praseodymium, chromium A metal such as nickel, aluminum, tin, zinc, titanium, tantalum, zirconium, antimony, indium, yttrium and lanthanum, zinc oxide, titanium oxide, cesium oxide, antimony oxide, tin oxide, indium tin oxide, Metal oxides such as lanthanum, zirconium oxide, aluminum oxide and silicon oxide, metal fluorides such as lithium fluoride, magnesium fluoride, aluminum fluoride and cryolite, metal phosphates such as calcium phosphate, carbonates such as calcium carbonate, sulphates such as barium sulfate, And kaolin.

In the present invention, when a metal oxide such as titanium oxide, zinc oxide, or cerium oxide, which is an inorganic particle having an ultraviolet ray absorbing ability, is used as the inorganic particle in the P1 layer, Is advantageous in that it can exhibit the effect of reducing the coloration due to the deterioration of the sheet over a long term. Furthermore, titanium oxide is more preferably used as the inorganic particles in the P1 layer, and rutile titanium oxide is more preferably used because the ultraviolet ray resistance is higher in that high reflection characteristics can be imparted.

The method of containing the polybutylene terephthalate resin and the inorganic particles in the P1 layer is a method of melt-kneading the polybutylene terephthalate resin and the inorganic particles in advance using a vent type 2-axis kneading extruder or a tandem type extruder desirable. Here, when the inorganic particles are contained, the polybutylene terephthalate resin may be deteriorated in a small amount because it receives a thermal history. As a result, a high-concentration master pellet having a larger content of inorganic particles than the amount of the inorganic particles to be contained in the P1 layer is prepared, and the master pellet is mixed with a polybutylene terephthalate resin to be diluted, Is preferable in terms of durability.

As described above, it is important that the P1 layer is composed mainly of a polybutylene terephthalate resin. Among them, the polybutylene terephthalate resin, which is a main constituent component of the P1 layer, is an end-blocked polybutylene terephthalate resin It is more preferable to include a resin. The terminated polybutylene terephthalate resin as used herein means a resin obtained by reacting a terminal blocking agent with a polybutylene terephthalate resin.

That is, when preparing the P1 layer, a terminal blocking agent is added to the polybutylene terephthalate resin to form a carboxyl group located at the terminal of the polybutylene terephthalate resin (hereinafter referred to as a carboxyl group located at the terminal, Short-chain or COOH group) with a terminal blocking agent to eliminate the catalytic activity of the protons of the COOH group of the polybutylene terephthalate resin, and then to form a P1 layer. The terminal blocking agent herein refers to a compound which reacts with the carboxyl terminal group of the polyester to bond to lose the catalytic activity of the protons of the COOH group. Specifically, a substituent such as an oxazoline group, an epoxy group or a carbodiimide group And the like.

The carbodiimide compound having a carbodiimide group preferable as a terminal blocking agent is a monofunctional carbodiimide and a multifunctional carbodiimide. Examples of the monofunctional carbodiimide include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, di Phenylcarbodiimide, di-t-butylcarbodiimide and di- beta -naphthylcarbodiimide. Particularly preferred are dicyclohexylcarbodiimide and diisopropylcarbodiimide. As the polyfunctional carbodiimide, a carbodiimide having a degree of polymerization of 3 to 15 is preferable. Specific examples include 1,5-naphthalene carbodiimide, 4,4'-diphenylmethanecarbodiimide, 4,4'-diphenyldimethylmethanecarbodiimide, 1,3-phenylenecarbodiimide, A mixture of 4-phenylenediisocyanate, 2,4-tolylene carbodiimide, 2,6-tolylene carbodiimide, a mixture of 2,4-tolylene carbodiimide and 2,6-tolylene carbodiimide, Carbodiimide, cyclohexane-1,4-carbodiimide, xylylene carbodiimide, isophoronecarbodiimide, isophoronecarbodiimide, dicyclohexylmethane-4,4'-carbodiimide, methylcyclo Hexamethyldiisopropylbenzene, hexanecarbodiimide, tetramethylxylylene carbodiimide, 2,6-diisopropylphenylcarbodiimide, 1,3,5-triisopropylbenzene-2,4-carbodiimide and the like . The carbodiimide compound is preferably a carbodiimide compound having high heat resistance because an isocyanate-based gas is generated by thermal decomposition. The higher the molecular weight (polymerization degree) is, the better the heat resistance is, and the more preferable the end of the carbodiimide compound is a structure having a higher heat resistance. Further, if pyrolysis is performed once, new pyrolysis easily occurs. Therefore, it is necessary to study the extrusion temperature of polyester (polybutylene terephthalate resin) as low as possible.

Preferable examples of the epoxy compound as a terminal blocking agent include a glycidyl ester compound and a glycidyl ether compound. Specific examples of the glycidyl ester compound include benzoic acid glycidyl ester, t-Bu-benzoic acid glycidyl ester, P-toluic acid glycidyl ester, cyclohexanecarboxylic acid glycidyl ester, pelargonic acid glycidyl Ester, stearic acid glycidyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester, behenic acid glycidyl ester, glycidyl glycidyl ester, oleic acid glycidyl ester, linolic acid glycidyl ester , Linolenic acid glycidyl ester, behenolic acid glycidyl ester, stearic acid glycidyl ester, terephthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalenedicarboxylic acid diglycidyl Diester ester, diglycidyl methylterephthalate ester, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, cyclo Hexanedicarboxylic acid diglycidyl ester, adipic acid diglycidyl ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecanedioic acid diglycidyl ester, octadecanedicarboxylic acid diglycidyl Diester ester, trimellitic acid triglycidyl ester, pyromellitic acid tetraglycidyl ester, etc. These may be used alone or in combination of two or more. Specific examples of the glycidyl ether compound include phenylglycidyl ether, O-phenylglycidyl ether, 1,4-bis (?,? - epoxypropoxy) butane, 1,6-bis (?,? (?,? - epoxypropoxy) benzene, 1- (?,? - epoxypropoxy) -2-ethoxyethane, 1- (?,? - epoxypropoxy) Propane and 2,2-bis- (4-hydroxyphenyl) propane or 2,2-bis- [? -,? - epoxypropoxy) And bisglycidyl polyether obtained by the reaction of bisphenol such as bis (4-hydroxyphenyl) methane with epichlorohydrin. These may be used singly or in combination of two or more.

The oxazoline compound preferably used as a terminal blocking agent is preferably a bisoxazoline compound, specifically 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl- Bis (4,4-dimethyl-2-oxazoline), 2,2'-bis (4-ethyl-2-oxazoline), 2,2'- Bis (4-propyl-2-oxazoline), 2,2'-bis Bis (4-hexyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline), 2,2'- (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'- 2'-o-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'- (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4,4-dimethyl- Zolene), 2,2'-ethylene bis (2-oxazoline), 2,2'-tetramethylene bis (2-oxazoline), 2,2'- Methylene bis (2-oxazoline), 2,2'-octamethylene bis (2-oxazoline), 2,2'-decamethylene bis (2-oxazoline), 2,2'- (2-oxazoline), 2,2'-tetramethylene bis (4,4-dimethyl-2-oxazoline) 2,2'-cyclohexylene bis (2-oxazoline), 2,2'-diphenylenebis (2-oxazoline) and the like. Of these, 2,2'-bis -Oxazoline) is most preferable in view of reactivity with a polyester (polybutylene terephthalate resin). The bisoxazoline compounds exemplified above may be used singly or in combination of two or more as long as the objects of the present invention are exerted. When the terminal blocking agent is reacted with the polybutylene terephthalate resin to obtain the terminally blocked polybutylene terephthalate resin, the addition concentration of the terminal blocking agent to the 100 mass% of the polybutylene terephthalate resin is preferably 0.25 to 5 mass %, More preferably 0.5 to 2% by mass. If it is less than 0.25 mass%, there is a problem that the effect of addition is small and the heat resistance and heat resistance are deteriorated. When the concentration is higher than 5% by mass, carboxyl terminal groups are significantly reduced, and interlayer adhesion is deteriorated.

The P1 layer and the P3 layer of the laminated sheet of the present invention may contain other additives such as a heat stabilizer, an ultraviolet absorber, a weather stabilizer, an organic lubricant, a pigment, A dye, a filler, an antistatic agent, a nucleating agent, etc. However, the inorganic particles in the present invention are not included in the additives mentioned here). For example, when the ultraviolet absorber is selected as an additive and contained in the P1 layer and / or the P3 layer, it is possible to further enhance the ultraviolet ray resistance of the laminated sheet of the present invention. In addition, when an antistatic agent or the like is contained in the P1 layer and / or the P3 layer, an improvement in withstand voltage can be expected.

It is also preferable that the P1 layer contains 0.1 to 5% by mass of a nucleating agent. The crystal nucleating agent can be selected preferably from the group consisting of talc, aliphatic carboxylic acid amide, aliphatic carboxylic acid salt, aliphatic alcohol, aliphatic carboxylic acid ester, sorbitol compound and organic phosphoric acid compound. Among them, in the present invention, it is preferable that the crystal nucleating agent is one type of crystal nucleating agent including an aliphatic carboxylic acid amide, an aliphatic carboxylic acid salt and a sorbitol compound. When the amount of the crystal nucleating agent is less than 0.1% by mass, the crystallinity is low and the strength can not be obtained in some cases. If it is more than 5% by mass, crystallinity is high and it becomes easy to be embrittled.

Examples of the aliphatic carboxylic acid amide include aliphatic monocarboxylic acids such as lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinolic acid amide and hydroxystearic acid amide Oleic acid amide, N-oleyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl oleic acid amide, N-stearyl stearic acid amide, N-stearyl erucic acid amide, , N-substituted aliphatic monocarboxylic acid amides such as methylol stearic acid amide and methyl oleic acid amide, aliphatic monocarboxylic acid amides such as methylene bisstearic acid amide, ethylene bislauric acid amide, ethylene biscapric acid amide, ethylene bisoleic acid amide, Stearic acid amide, ethylene bis-erucic acid amide, ethylene bis-behenic acid amide, ethylene bis-isostearic acid amide, ethylene bishydroxystear Amide, butylenebisstearic acid amide, hexamethylenebisoleic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenebihydroxystearic acid amide, m-xylylenebisstearic acid amide, m- N, N'-dioleoyl sebacic acid amide, N, N'-dioleyl adipic acid amide, N, N'-dicaryl adipic acid amide and aliphatic biscarboxylic acid amide such as xylylene bis- Substituted aliphatic carboxylic acids such as distearyl diphthalic acid amide, N, N'-distearyl sebacic acid amide, N, N'-distearyl isophthalic acid amide and N, N'-distearyl terephthalic acid amide. N'-stearyl urea, N-stearyl-N'-stearyl urea, N-phenyl-N'-stearyl urea, A silylenebisstearyl component, a toluylenebisstearyl component, a hexamethylenebistearyl component, a diphenylmethane bis Cetearyl element, diphenylmethane-bis La may be substituted for elements N- acids such us the element. These may be one kind or a mixture of two or more kinds. Of these, aliphatic monocarboxylic acid amides, N-substituted aliphatic monocarboxylic acid amides and aliphatic biscarboxylic acid amides are preferably used, and in particular, palmitic acid amide, stearic acid amide, erucic acid amide, Oleic acid amide, N-stearyl erucic acid amide, ethylene biscarboxylic acid amide, ethylene bis-oleic acid amide, ethylene bislauric acid amide, ethylene Bis-erucic acid amide, m-xylylene bis-stearic acid amide and m-xylylene bis-12-hydroxystearic acid amide are preferably used.

Specific examples of the aliphatic carboxylic acid salt include sodium acetate, potassium acetate, magnesium acetate, acetic acid salts such as calcium acetate, sodium laurate, potassium laurate, potassium laurate, magnesium laurate, calcium laurate, Zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, zinc stearate, A salt such as a salt of a palmitic acid such as lithium salt, lithium salt of palmitic acid, potassium palmitate, magnesium palmitate, calcium palmitate, zinc palmitate, copper palmitate, lead palmitate, palmitic thallium, cobalt palmitate , Oleic acid salts such as sodium oleate, potassium oleate, magnesium oleate, calcium oleate, zinc oleate, lead oleate, thallium oleate, copper oleate and nickel oleate, sodium stearate, lithium stearate, , Stearates such as calcium stearate, barium stearate, aluminum stearate, thallium stearate, lead stearate, nickel stearate, beryllium stearate, sodium isostearate, potassium isostearate, magnesium isostearate, isostearic acid Isostearic acid salts such as calcium, barium isostearate, aluminum isostearate, zinc isostearate and nickel isostearate, sodium behenate, potassium behenate, magnesium behenate, calcium behenate, barium behenate, aluminum behenate , Behenic acid salts such as zinc behenate and nickel behenate, montanic acid salts such as sodium montanate, potassium montanate, magnesium montanate, calcium montanate, barium montanate, aluminum montanate, zinc montanate and nickel montanate . These may be one kind or a mixture of two or more kinds. Particularly, salts of stearic acid or salts of montanic acid are preferably used, and sodium stearate, potassium stearate, zinc stearate, barium stearate, sodium montanate and the like are preferably used.

Specific examples of the aliphatic alcohol include aliphatic monohydric alcohols such as pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecyl alcohol, eicosyl alcohol, ceryl alcohol and melissyl alcohol; aliphatic monohydric alcohols such as 1,6- , Aliphatic polyhydric alcohols such as 7-heptanediol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol, cyclopentane-1,2-diol, cyclohexane- , Cyclohexane-1,4-diol, and other cyclic alcohols. These may be one kind or a mixture of two or more kinds. Particularly, aliphatic monoalcohols are preferably used, and stearyl alcohol is particularly preferably used.

Specific examples of such aliphatic carboxylic acid esters include lauric acid cetyl ester, lauric acid phenacyl ester, myristic acid cetyl ester, myristic acid pentacyl ester, palmitic acid isopropylidene ester, palmitic acid dodecyl ester, Palmitic acid tetradodecyl ester, palmitic acid pentadecyl ester, palmitic acid octadecyl ester, palmitoic acid ester, palmitic acid phenyl ester, palmitic acid penneacyl ester, stearic acid ethyl ester, behenic acid ethyl ester, etc. Aliphatic monocarboxylic acid esters of aliphatic monocarboxylic acid esters, monolauric acid glycol, monopalmitic acid glycol, monoester of ethylene glycol such as monostearic acid glycol, dilauric acid glycol, dipalmitic acid glycol, distearic acid glycol and the like Diesters of ethylene glycol, monolauric acid glycerin esters, monomyristic acid glycerin esters, Monoesters of glycerin such as glycerin monostearate and glycerin monostearate, glycerine diesters such as glycerin dilaurate, dimeric lysine glycerin ester, dipelmitic acid glycerin ester and distearic acid glycerin ester; Triesters of glycerin such as trilauric acid glycerin ester, trimyristic acid glycerin ester, tripalmitic acid glycerin ester, tristearic acid glycerin ester, palmito diolane, palmito distearin and oleo stearin, etc. . These may be one kind or a mixture of two or more kinds.

As specific examples of such aliphatic / aromatic carboxylic acid hydrazides, specific examples of sebacic acid dibenzoic acid hydrazide and melamine-based compounds include melamine cyanurate, melamine polyphosphate, and phenylphosphonic acid metal salts, Potassium salt, phenylphosphonic acid magnesium salt, phenylphosphonic acid magnesium salt, and the like can be used.

Examples of the sorbitol compound include 1,3-di (P-methylbenzylidene) sorbitol, 2,4-di (P-methylbenzylidene) sorbitol, 1,3-dibenzylidene sorbitol, , 1,3-di (P-ethyl dibenzylidene) sorbitol, 2,4-di (P-ethyl dibenzylidene) sorbitol and the like.

Examples of the organophosphorus compound include sodium bis (4-t-butylphenyl) phosphate, sodium 2,2'-methylenebis (4,6-di-t-butylphenyl) phosphate, cyclic organic phosphate ester basic multivalent metal salt An alkali metal? -Diketonate, and an alkali metal? -Ketoacetic acid ester salt; and an organic carboxylic acid metal salt.

Above all, sodium montanate is preferably used from the viewpoint of strength.

In the present invention, it is preferable that the substrate has a layer (P2 layer) mainly composed of an adhesive polyolefin-based resin, and further the P1 layer and the P3 layer described later are in contact with each other through the P2 layer. Here, the P1 layer and the P3 layer are in contact with each other through the P2 layer, which means that the P1 layer, the P2 layer and the P3 layer are directly stacked in this order.

Further, since the 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, the layer (P2 layer) comprising the adhesive polyolefin resin as a main constituent , A low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer. The main component of the P2 layer is selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer, and it means that in the 100 mass% Means that it contains not less than 50 mass% and not more than 100 mass% of one selected from the group consisting of a soft polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer.

Examples of the low crystalline soft polymer which is one of the main constituents of the P2 layer include acid-modified polyolefins and unsaturated polyolefins. Examples of acrylic adhesives which are one of the main constituents of the P2 layer include ethylene-acrylic acid ester-maleic anhydride terpolymer. Among them, from the viewpoint of adhesion to both the P1 layer and the P3 layer, it is preferable that the P2 layer contains an acid-modified polyolefin as a main constituent component. As the acid-modified polyolefin, there may be mentioned, for example, "ADMER" manufactured by Mitsui Chemical Industry Co., Ltd., "MODIC" manufactured by Mitsubishi Chemical Corporation, "BENEL" manufactured by DuPont Co., .

It is preferable that the P2 layer further contains a polyolefin-based elastomer in addition to the adhesive polyolefin-based resin. The polyolefin-based elastomer generally refers to a product obtained by finely dispersing an ethylene-propylene rubber in a polypropylene, or a product obtained by copolymerizing an? -Olefin with a polypropylene. These polyolefin elastomers are preferably contained in a proportion of from 0.1 mass% to 20 mass% with respect to 100 mass% of the total components of the P2 layer. By including the polyolefin-based elastomer, tackiness can be imparted to the P2 layer, and the adhesion between the P1 layer and the P2 layer and the adhesion between the P1 layer and the P2 layer are improved. The content of the polyolefin-based elastomer in the P2 layer is preferably 5 mass% or more and 20 mass% or less. The polyolefin elastomer may be a commercially available product, and examples thereof include "Thermorun", "Gelas" manufactured by Mitsubishi Chemical Corporation, "Excelene", "Thafselen", " Esophren "manufactured by Mitsui Chemicals, Inc.," Hi Bra "manufactured by Kuraray Co., Ltd.," Septon ", and" Nothio "manufactured by Mitsui Chemicals, Inc. are preferably used.

The P3 layer in the present invention is a layer mainly composed of a polyolefin resin. Examples of the polyolefin resin in the present invention include polyethylene, polypropylene, polybutene, polymethylpentene, polycycloolefin, polyhexene, polyoctene, polydecene, and polydodecene. Here, it is assumed that the bonded polyolefin-based resin which is the main component of the P2 layer does not correspond to the polyolefin-based resin which is the main constituent component of the P3 layer. Of these, polyethylene resins and polypropylene resins are preferable as the polyolefin resins that are the main constituent components of the P3 layer, because they are easy to process and relatively inexpensive. These polyolefin resins may be mixed and copolymerized with other olefin components. For example, an ethylene-propylene copolymer or an ethylene-propylene-butene copolymer can lower the melting point of the resin and improve adhesion with the sealing material .

Further, the polyolefin-based resin as a main component for the P3 layer means that the polyolefin-based resin is contained in an amount of 50 mass% or more and 100 mass% or less in 100 mass% of the total components of the layer.

The P3 layer constituting the laminated sheet of the present invention preferably contains inorganic particles in a range of 0.1 mass% or more and 30 mass% or less. The content of the inorganic particles in the P3 layer is more preferably 2 mass% or more and 25 mass% or less, and still more preferably 5 mass% or more and 20 mass% or less. The inorganic particles are used for imparting necessary functions to the sheet according to its purpose. If the content of the inorganic particles in the P3 layer exceeds 30 mass%, the adhesion with the sealing material may be deteriorated. If the content of the inorganic particles in the P3 layer is less than 0.1% by mass, the effect due to the inclusion of the inorganic particles is hardly obtained, and yellowing may occur.

It is also preferable that the P3 layer contains 5 to 30 mass% of inorganic particles having a particle diameter of 3 占 퐉 to 20 占 퐉. Here, the particle diameter refers to an average particle size at an integrated value of 50% in the particle size distribution by determining the particle size distribution by laser analysis / scattering method. When the inorganic particles having a particle size of 3 mu m or more and 20 mu m or less are contained in an amount of less than 5 mass%, the mechanical strength may be decreased. If the inorganic particles having a particle size of more than 3 μm and not more than 20 μm are contained in an amount of more than 30% by mass, the surface may become coarse and the adhesion with the sealing agent may be deteriorated. It is also preferable that the P3 layer contains 0.5 to 5% by mass of an adhesive polyolefin resin. The bonded polyolefin resin sometimes acts as a dispersing aid for inorganic particles having a diameter of 3 to 20 탆. When the amount is less than 0.5% by mass, the mechanical strength may be lowered due to dispersion failure of inorganic particles having a diameter of 3 to 20 탆 . If it is larger than 5% by mass, the heat resistance may be lowered. The adhesive polyolefin resin referred to herein is the same as that defined by the bonded 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 transmittance of acetic acid when acetic acid is in a saturated vapor pressure state (85 ° C). In the laminated sheet of the present invention, it is preferable that the acetic acid transmittance Pa at 85 캜 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 sealing material is positively released from the back sheet before the solar battery cell is affected. From the viewpoint of suppressing the power generation performance during the constant temperature and humidity test, It is important that the acetic acid transmittance Pa of the laminated sheet of the present invention is 200 g / m < 2 > / day or more. From the viewpoint of suppressing lowering of power generation performance, the acetic acid permeation rate Pa of the laminated sheet of the present invention is preferably 800 g / m 2 / day or more. On the other hand, it is preferable that the acetic acid permeability Pa is as large as possible, but it is preferable that the acetic acid permeation rate Pa is 1500 g / m < 2 > / day or less considering not only the formula (1) but also the formula (2) concerning the water vapor permeability Pw described later simultaneously.

The water vapor permeability Pw (g / m 2 / day) in the laminated sheet of the present invention means the permeability of water vapor in an environment of 40 ° C and 90% RH. In the laminated sheet of the present invention, it is preferable that the water vapor permeability Pw (g / m 2 / day) at 40 ° C and 90% RH satisfies the following formula (2).

(2) Pw? 2.5

The vapor permeability Pw of the laminated sheet of the present invention is preferably 2.5 g / m2 / m < 2 > day or less. From the viewpoint of suppressing the discoloration of the collector electrode of the far-field cell, it is preferably 2.0 g / m 2 / day or less. On the other hand, it is preferable that the water vapor permeability Pw is as small as possible, but it is preferable that the water vapor permeability Pw is 0.5 g / m 2 / day or more in consideration of not only the equation (2) but also the equation (1) concerning the above- .

The thickness of the P1 layer constituting the laminated sheet of the present invention is preferably 80 mu m or more. If it is less than 80 탆, the heat resistance may be lowered. The thickness of the P2 layer constituting the laminated sheet of the present invention is preferably 15 占 퐉 or more and 50 占 퐉 or less. If it is less than 15 mu m, adhesion between layers may be deteriorated. If the thickness of the P2 layer is larger than 50 占 퐉, the heat resistance may be lowered. The thickness of the P3 layer constituting the laminated sheet of the present invention is preferably 50 mu m or more. If it is less than 50 탆, the adhesion with the sealing material may be deteriorated.

It is important for the laminated sheet of the present invention to have a P1 layer and a P3 layer. In the laminated structure of the laminated sheet of the present invention, it is preferable that at least the P1 layer is located on the surface layer and the P3 layer is located on the reverse surface layer from the P1 layer. Here, the presence of the P3 layer in the reverse surface layer from the P1 layer means that the P1 layer is located on one of the outermost layers of the laminated sheet and the P3 layer is located on the other outermost layer.

The laminated sheet of the present invention may be a laminate obtained by laminating with another film or the like. Also in such a laminate, it is preferable that the P1 layer has a laminated structure provided on one of the surface layers. Examples of other films include a polyester layer for increasing mechanical strength, an antistatic layer, a close contact layer with other materials, an inner ultraviolet layer for further improving the resistance to ultraviolet rays, a flame retardant layer for imparting flame retardancy, A hard coating layer for increasing the thickness of the coating layer, and the like. When the laminated sheet of the present invention is used as a laminated sheet obtained by laminating a laminated sheet with another film or the like, when the laminated sheet of the present invention is used as a solar cell back sheet, other sheet materials, An adhesive layer, an ultraviolet ray layer, and a flame retardant layer, in order to further improve the adhesion with a sealing material (for example, ethylene vinyl acetate) And the like.

Next, a manufacturing method of the laminated sheet of the present invention will be described by way of example. As a method for laminating the P1 layer, the P2 layer and the P3 layer in the laminated sheet of the present invention, for example, a raw material for the P1 layer mainly composed of a polybutylene terephthalate resin as a main constituent, and a bonded polyolefin resin And a raw material for the P3 layer mainly composed of a polyolefin-based resin are fed to separate extruders, respectively, and the P1 layer, the P2 layer and the P3 layer are joined in this order after melting, (Co-extrusion method) including a step of extruding a sheet from a T die into a sheet, a method of laminating a coat layer raw material into an extruder by melt extrusion, Melt laminate method), a method of separately preparing each film, thermocompression bonding by a heated roll or the like (thermal lamination method), bonding by means of an adhesive A coating method, a coating method, a coating method, a coating method, and a combination thereof. Among them, the co-extrusion method is preferable in that the production process is short and the adhesiveness between the layers is good. Hereinafter, the production method in the co-extrusion method will be described in detail.

When the laminated sheet of the present invention is produced by a co-extrusion method, a raw material for a P1 layer mainly comprising a dry polybutylene terephthalate resin as a main component, a raw material for a P2 layer mainly comprising an adhesive polyolefin resin, The raw material for the P3 layer mainly composed of a polyolefin resin is supplied to three extruders heated in a nitrogen stream at 240 DEG C to 300 DEG C for the P1 layer and 180 DEG C to 250 DEG C for the P2 layer and the P3 layer And then melted. Subsequently, the P1 layer, the P2 layer and the P3 layer are joined and laminated in this order using a multi-manifold die, a feed block, a static mixer, a phenol, or the like, and co-extruded from the T die into the sheet. When the difference in melt viscosity of each layer is large, it is preferable to use a multi-manifold die from the viewpoint of suppressing the unevenness of lamination.

The laminated sheet ejected from the T die by the above method is extruded and cooled and solidified on a cooling body such as a casting drum to obtain the laminated sheet of the present invention.

The laminated sheet of the present invention obtained by the above method may be subjected to a heat treatment or aging treatment, if necessary, within a range in which the effect of the present invention is not impaired. By heat treatment, the thermal dimensional stability of the laminated sheet of the present invention can be improved. Further, in order to improve the adhesion of the laminated sheet of the present invention obtained by the above-described method, corona treatment and plasma treatment may be carried out.

The solar cell back sheet of the present invention includes the laminated sheet of the present invention. That is, the laminated sheet of the present invention can be preferably used as a solar cell back sheet. The solar cell of the present invention is characterized by using the solar cell back sheet of the present invention. The use of the laminated sheet of the present invention in a solar cell makes it possible to increase the durability or to make it thinner than the conventional solar cell. A solar cell configuration example of the present invention is shown in Fig. In Fig. 1, a power generation element in which a lead wire (not shown in Fig. 1) for drawing electricity is connected is sealed with a transparent sealing material 2 such as an EVA resin. A transparent substrate 4, The laminated sheet of the present invention is bonded as the solar cell backsheet 1, but the solar cell configuration example of the present invention is not limited to this and can be used in an arbitrary configuration. 1 shows an example of the laminated sheet of the present invention alone, but it is also possible to use a composite sheet of the laminated sheet of the present invention and another film according to the required properties required in the present invention.

Examples of the method of laminating the laminated sheet of the present invention with other films include a method of co-extruding the sheet into a sheet form (co-extrusion method), a method of putting the coat layer raw material into an extruder, A lamination method (melt lamination method) in which the films are extruded from a crotch member, a method in which each of the films is separately prepared and thermocompression is performed with a heated roll or the like (thermal lamination method) A method of coating and drying (dissolution) in a solvent, a coating method, and a combination of these methods.

In the solar cell of the present invention, the above-described solar cell back sheet 1 is provided on the back surface of the sealing material 2 sealing the power generation elements. Here, it is preferable that the solar cell back sheet of the present invention has an asymmetrical structure and that the P3 layer is disposed on the side of the sealing material 2 from the viewpoint that the adhesion with the sealing material can be further enhanced. Further, since the structure is arranged so that the P1 layer of the laminated sheet of the present invention is disposed on the side opposite to the sealing material 2, the resistance against ultraviolet rays reflected from the ground can be enhanced, , The thickness can be reduced.

The power generation element 3 converts the light energy of the sunlight into electric energy and may be any of various types such as a crystal silicon type, a polycrystalline silicon type, a microcrystalline silicon type, an amorphous silicon type, a copper indium selenide type, a compound semiconducting system, A plurality of devices can be connected in series or in parallel depending on a desired voltage or current. Since the transparent substrate 4 having a light-transmitting property is located at the outermost layer of the solar cell, a transparent material having high weatherability, high internal stain resistance and high mechanical strength characteristics is used in addition to high transmittance. In the solar cell of the present invention, any material may be used as long as the transparent substrate 4 having a light-transmitting property satisfies the above characteristics. Examples of the material include glass, tetrafluoroethylene-ethylene copolymer (ETFE), polyvinyl fluoride ), Polyvinylidene fluoride resin (PVDF), polysulfafluoroethylene resin (TFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polytrifluoroethylene resin (CTFE) A fluororesin, a polyolefin resin, an acrylic resin, and a mixture thereof. In the case of glass, it is more preferable to use one reinforced. In the case of using a light-transmitting base made of a resin, it is also preferable to use a resin obtained by stretching the resin in one or two axes from the viewpoint of mechanical strength.

In addition, these substrates are preferably subjected to a corona treatment, a plasma treatment, an ozone treatment, and an adhesion facilitating treatment on the surface thereof in order to give adhesiveness to an EVA resin or the like which is a sealing material of a power generation element.

A sealing material (2) for sealing a power generating element is formed by covering and fixing the unevenness of the surface of a power generating element with a resin to protect the power generating element from the external environment and for the purpose of electric insulation, A material having high transparency, high weather resistance, high adhesion, and high heat resistance is used. Examples thereof include an ethylene-vinyl acetate copolymer (EVA), an ethylene-methyl acrylate copolymer (EMA), an ethylene-ethyl acrylate copolymer (EEA) resin, an ethylene-methacrylic acid copolymer (EMAA) , A polyvinyl butyral resin, a mixture thereof and the like are preferably used.

As described above, by embedding the solar cell back sheet using the laminated sheet of the present invention in a solar cell, it becomes possible to provide a solar cell of high durability and / or thinness compared to a conventional solar cell. INDUSTRIAL APPLICABILITY The solar cell of the present invention can be suitably used for various applications such as a photovoltaic power generation system, a power source for small electronic components, and the like, not limited to outdoor use and indoor use.

Next, embodiments of the solar cell back sheet according to the fourteenth to twentieth inventions, the manufacturing method thereof, and the solar cell module will be described. This embodiment is merely a detailed description for the purpose of better understanding the spirit of the invention, and the present invention is not limited to this embodiment.

The acetic acid transmittance Pa (g / m 2 / day) in the back sheet of the present invention means the transmittance of acetic acid when acetic acid is in a saturated vapor pressure state (85 ° C). In the back sheet of the present invention, it is important that the acetic acid transmittance Pa at 85 캜 satisfies the following formula (1).

(1) 200? Pa

It is important for the back sheet of the present invention that the acetic acid generated from the sealing material actively escapes from the back sheet before the solar cell is affected by the back sheet. From the viewpoint of suppressing the power generation performance deterioration during the constant temperature and humidity test, the back sheet acetic acid transmittance Pa Is not less than 200 g / m 2 / day. From the viewpoint of suppressing lowering of power generation performance, the back sheet acetic acid permeation rate Pa of the present invention is preferably 800 g / m 2 / day or more. On the other hand, it is preferable that the acetic acid permeability Pa is as large as possible, but it is preferable that the acetic acid permeation rate Pa is 1500 g / m < 2 > / day or less considering not only the formula (1) but also the formula (2) concerning the water vapor permeability Pw described later simultaneously.

The water vapor permeability Pw (g / m 2 / day) in the back sheet of the present invention means the water vapor permeability in an environment of 40 ° C and 90% RH. In the back sheet of the present invention, it is important that the water vapor permeability Pw (g / m 2 / day) at 40 ° C and 90% RH satisfies the following formula (2).

(2) Pw? 2.5

The back sheet water vapor transmittance Pw of the present invention is preferably 2.5 g / m 2 / day or less in view of suppressing corrosion inside the solar cell module due to moisture, in particular discoloration due to corrosion of the collecting electrode portion of the solar cell, Or less. From the viewpoint of suppressing the discoloration of the collector electrode of the far-field cell, it is preferably 2.0 g / m 2 / day or less. On the other hand, it is preferable that the water vapor permeability Pw is as small as possible, but it is preferable that the water vapor permeability Pw is 0.5 g / m 2 / day or more in consideration of not only the equation (2) but also the equation (1) concerning the above- .

In order that the acetic acid permeability Pa of the back sheet satisfies the formula (1) and the water vapor permeability Pw satisfies the formula (2), it is preferable that the back sheet has a P4 layer. Here, the P4 layer means a layer mainly composed of one selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin. The layer mainly composed of one selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin refers to a resin selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin, Refers to a layer containing 50% by mass or more and 100% by mass or less of 100% by mass of the whole components.

The polyester resin preferably used as the main constituent component of the P4 layer in the present invention is a resin obtained by polycondensation of a dicarboxylic acid and a dialcohol. These polyester resins may be used alone or in combination with other resins.

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

Specific examples of the dialcohol used for obtaining the polyester resin include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and the like.

Of these, polyethylene terephthalate and / or polybutylene terephthalate are preferable as polyester resins in view of price, water vapor permeability, strength, heat resistance, and the like.

The polyamide resin preferably used as the main constituent component of the P4 layer in the present invention is a resin obtained by ring-opening polymerization of a compound having 1) a lactam skeleton, 2) condensation of an amino acid component having an amino group and a carboxyl group in one molecule , 3) a polycondensation of a diamine component and a dicarboxylic acid component, and a copolymerization of 1) to 3). The polyamide resin may be used alone or in combination with another resin.

Examples of the compound having a lactam skeleton used in 1) include ε-caprolactam (nylon 6 is obtained by ring-opening polymerization), ω-undecane lactam (nylon 11 is obtained by ring-opening polymerization) And lactam (nylon 12 is obtained by ring-opening polymerization).

Examples of the amino acid component having an amino group and a carboxyl group in one molecule used in 2) include amino acids such as? -Aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

Examples of the diamine component used in 3) include tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 1,2,2,4-tetramethylhexamethylenediamine, 2,4,4-trimethylhexa Methylene diamine, methylene diamine, 5-methyl nonanemethylene diamine, m-xylylenediamine, p-xylylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, bis- Hexyl methane, 2,2-bis-p-aminocyclohexylpropane, and isophoronediamine. As the dicarboxylic acid component used in 3), adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid Terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, dimeric acid, and other dicarboxylic acids.

The present invention relates to a composition comprising the following components: 1) a compound having a lactam skeleton; 2) an amino acid component alone or a mixture of amino acid components; or 3) a mixture of a diamine and a dicarboxylic acid. The amide resin may be used in the present invention in the form of a polymer alone, or a copolymer containing two or more components thereof. Among them, examples of the polyamide resin to be used as a main component of the P4 layer include polycaproamide (nylon 6), polyhexamethyleneadipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), polyhexamethylene (Nylon 612), polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I), polyundecanamide (nylon 11), and polydodecanamide (nylon 12) are preferable.

In the back sheet of the present invention, the polyamide resin preferably used as a main constituent component of the P4 layer is preferably a nylon 6, nylon 66, nylon 610, nylon 11 and nylon 11 in terms of crystallinity, strength, heat resistance, 12, and more preferably at least one resin selected from the group consisting of

The fluororesin preferably used as the main constituent component of the P4 layer in the present invention is a polymer of 1) hydrogen atoms partially or wholly substituted with fluorine atoms in the hydrocarbon, 2) hydrogen atoms of a part or all of the hydrocarbon And 3) a copolymer of a hydrogen atom partially or entirely substituted with a fluorine atom in a part or all of the hydrocarbon and a hydrogen atom partially or wholly substituted with a fluorine atom in the hydrocarbon, 4) a copolymer of 1) to 3), a polymer or copolymer in which a hydrogen atom or a part of a fluorine atom is substituted with a chlorine atom, and a polymer or copolymer in which at least one fluorine atom exists even after being substituted with a chlorine atom.

Examples of the fluororesin include polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, ethylene chlorotrifluoroethylene, Ethylene copolymer and the like. The fluororesin preferably used as the main component of the P4 layer in the back sheet of the present invention is polyvinyl fluoride, polyvinylidene fluoride, ethylene tetrafluoroethylene, polytetrafluoroethylene, polytetrafluoroethylene, polyvinylidene fluoride, Ethylene tetrafluoride · hexafluoropropylene copolymer is particularly preferable.

As described above, the P4 layer is a layer mainly composed of one selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin. The P4 layer is a layer mainly composed of a polyamide resin or polybutylene terephthalate It is particularly preferable to use a constitutional component.

When the backsheet of the present invention has a P4 layer, it is preferable that the P4 layer contains 0.1 mass% or more and 30 mass% or less of the inorganic particles in 100 mass% of the total components of the P4 layer. The content of the inorganic particles in the P4 layer is more preferably 2 mass% or more and 25 mass% or less, and still more preferably 5 mass% or more and 20 mass% or less. The inorganic particles are used for imparting necessary functions to the backsheet according to the purpose. If the content of the inorganic particles in the P4 layer exceeds 30 mass%, the handling property may deteriorate or the durability may deteriorate. When the content of the inorganic particles in the P4 layer is less than 0.1% by mass, the effect of containing the inorganic particles is hardly obtained, and yellowing may occur.

Examples of the inorganic particles preferably used for the P4 layer include inorganic particles having ultraviolet ray absorbing ability, particles having a large difference in refractive index from a polyester resin, a polyamide resin and a fluorine resin, particles having conductivity, and pigments Optical properties such as ultraviolet light resistance, light reflectivity, whiteness, and antistatic properties can be imparted. In the present invention, the term " particles " means primary particles having a diameter of 5 nm or more according to the projected equivalent equivalent diameter. Unless otherwise stated, in the present invention, the particle diameter means the primary particle size, and the particle means the primary particle.

More specifically, the inorganic particles preferably used in the P4 layer of the present invention include inorganic particles such as gold, silver, copper, platinum, palladium, rhenium, vanadium, osmium, cobalt, iron, zinc, ruthenium, praseodymium, A metal such as nickel, aluminum, tin, zinc, titanium, tantalum, zirconium, antimony, indium, yttrium and lanthanum, zinc oxide, titanium oxide, cesium oxide, antimony oxide, tin oxide, indium tin oxide, Metal oxides such as lanthanum, zirconium oxide, aluminum oxide and silicon oxide, metal fluorides such as lithium fluoride, magnesium fluoride, aluminum fluoride and cryolite, metal phosphates such as calcium phosphate, carbonates such as calcium carbonate, sulphates such as barium sulfate, And kaolin.

In the present invention, in the case where a metal oxide such as titanium oxide, zinc oxide, or cerium oxide, which is an inorganic particle having an ultraviolet ray absorbing ability, is used as the inorganic particles in the P4 layer, Is advantageous in that it can exert the effect of reducing the coloration due to deterioration of the back sheet over a long period of time. Furthermore, titanium oxide is more preferably used as the inorganic particles in the P4 layer, and rutile titanium oxide is more preferably used because the ultraviolet ray resistance is higher because it can impart high reflection characteristics.

The method of containing a polyester resin, a polyamide resin, a fluororesin or an inorganic particle in the P4 layer is preferably a method in which the resin and inorganic particles are melt-kneaded in advance by using a vent type 2-axis kneading extruder or a tandem type extruder . Here, when the inorganic particles are contained, since they receive thermal history, the resin sometimes deteriorates. Therefore, it is preferable to prepare a high-concentration master pellet having a larger content of inorganic particles than the amount of the inorganic particles to be contained in the P4 layer, and mix it with the resin to dilute it to obtain the content of inorganic particles of the predetermined P4 layer .

The back sheet P4 layer and the P6 layer (the P6 layer will be described later) of the present invention may contain other additives (for example, heat stabilizers, ultraviolet absorbers, weathering stabilizers, Pigments, dyes, fillers, antistatic agents, nucleating agents and the like. However, the inorganic particles mentioned in the present invention are not included in the additives mentioned here). For example, when the ultraviolet absorber is selected as an additive and contained in the P4 layer and / or the P6 layer, it is possible to further enhance the ultraviolet ray resistance of the back sheet of the present invention. In addition, if an antistatic agent or the like is contained in the P4 layer and / or the P6 layer, an increase in withstand voltage can be expected.

It is important that the P4 layer in the present invention is located on the surface layer of the back sheet from the viewpoint of flame retardancy. Here, the presence of the P4 layer on the surface layer means that the P4 layer is located on the outermost surface layer of one back sheet of the present invention.

In the present invention, it is preferable that the P5 layer is located between the P4 layer and the P6 layer described later. Here, the P5 layer is a layer mainly composed of one selected from the group consisting of low crystalline soft polymer, acrylic adhesive and ethylene vinyl acetate copolymer. Further, with respect to the P5 layer, one of the main constituent components selected from the group consisting of a low crystalline soft polymer, an acrylic adhesive and an ethylene vinyl acetate copolymer is referred to as a low crystalline soft Polymer, an acrylic adhesive, and an ethylene-vinyl acetate copolymer is contained in an amount of 50% by mass or more and 100% by mass or less.

The P5 layer is preferably located between the P4 layer and the P6 layer. The reason why the P5 layer is located between the P4 layer and the P6 layer is that when the P4 layer is located on the surface layer and the P6 layer is located on the opposite surface layer to the P4 layer in the back sheet of the present invention, Means that the two layers, that is, the P5 layer, is located in the inner layer.

It is preferable that the P5 layer has a function of bonding to both the P4 layer and the P6 layer. The low crystalline soft polymer which is one of the main constituent components of the P5 layer preferably has a crystallinity of 50% or less and a melting point of 170 캜 or less, and examples thereof include an acid-modified olefin and an unsaturated polyolefin. Examples of the acrylic adhesive which is one of the main components of the P5 layer include an ethylene-acrylic acid ester-maleic anhydride terpolymer. Among them, from the standpoint of adhesion to both the P4 layer and the P6 layer, it is preferable that the P5 layer contains an acid-modified polyolefin as a main constituent component. As the acid-modified polyolefin, for example, "ADMER" (registered trademark) manufactured by Mitsui Chemical Industry Co., Ltd. and "MODIC" (registered trademark) manufactured by Mitsubishi Chemical Corporation are commercially available.

The layer mainly composed of an olefin resin is referred to as a P6 layer. Examples of the olefin resin used for the P6 layer include polyethylene, polypropylene, polybutene, polymethylpentene, polycycloolefin, polyhexene, polyoctene, polydecene, and polydodecene. Of these, polyethylene resins and polypropylene resins are preferable as the olefin resin which is the main constituent component of the P6 layer in terms of ease of processing and relatively low cost. These olefin resins may be mixed and copolymerized with other olefin components. For example, an ethylene-propylene copolymer or an ethylene-propylene-butene copolymer may lower the melting point of the resin.

The olefin resin is the main constituent component for the P6 layer means that the olefin resin is contained in an amount of 50% by mass or more and 100% by mass or less in 100% by mass of the total components of the layer.

The melting point (hereinafter also referred to as a melting endothermic peak temperature) of the olefin resin, which is the main constituent of the P6 layer in the present invention, is preferably 120 ° C or more and 170 ° C or less. If the melting point of the olefin resin in the P6 layer is less than 120 캜, there is a possibility that the heat resistance is lowered. On the other hand, if the melting point of the olefin resin in the P6 layer is higher than 170 DEG C, the adhesion with the sealing material may be lowered.

It is preferable that the back sheet of the present invention 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 reverse surface layer to the P4 layer. (%) Of the inorganic particles in the P6 layer, and the thickness of the P4 layer is T4 (mu m), the thickness of the P6 layer is T6 (mu m), and the content of the inorganic particles in the P6 layer is M It is more preferable that all of the expressions (3) to (5) are satisfied.

(3) 0.05? M / T? 6? 0.5

(4) 200? Ta? 500

(5) 0.3? T4 / Ta? 0.5

By satisfying the equations (3) to (5) at the same time, it is possible to obtain a back sheet having both heat resistance and sealing property, water vapor permeability and electrical characteristics.

When the back sheet of the present invention has a plurality of P4 layers or P6 layers, T4 is determined using only the P4 layer in the surface layer, and T6 and M are determined using only the P6 layer in the reverse surface layer, (5) at the same time.

The expression (3) is an expression of the amount of the inorganic particles per a thickness. In order to manifest the effect of the inorganic particles, it is important to make the concentration of the inorganic particles thicker as the thickness becomes thicker. In the formula (3), when M / T6 is less than 0.05, the P6 layer tends to become yellow due to deterioration. If M / T6 is larger than 0.5, the adhesion with EVA may be lowered.

The P6 layer preferably contains inorganic particles. The inorganic particles in the P6 layer are used to impart necessary functions to the backsheet depending on the purpose. As the inorganic particles in the P6 layer, the same inorganic particles as the inorganic particles exemplified as the above-mentioned P4 layer can be used. In view of the fact that the inorganic particles in the P6 layer are often used outdoors in the present invention, when metal oxides such as titanium oxide, zinc oxide, and cerium oxide having ultraviolet absorbing ability are used, It is preferable from the viewpoint that the ultraviolet ray property can be utilized and the effect of reducing the coloring due to deterioration of the back sheet over a long term can be exhibited. Furthermore, from the viewpoint of being able to impart high reflection characteristics, it is more preferable to use titanium oxide as the inorganic particles in the P6 layer and more preferably to use rutile titanium oxide in view of higher ultraviolet ray resistance.

Equation (4) indicates the thickness range of the entire backsheet. When Ta is less than 200 mu m, heat resistance and water vapor permeability may be inferior. If Ta is larger than 500 mu m, processability is poor and transportation is difficult, resulting in poor processability. In addition, a solar cell module requiring light weight and space saving may become too thick.

Equation (5) shows the ratio of the thickness of the P4 layer to the total thickness. The thicker the P4 layer, the better the heat resistance. If the value of T4 / Ta is less than 0.3, the heat resistance may decrease. The larger the value of T4 / Ta is, the higher the durability is. However, since the P4 layer is often expensive compared to the P6 layer, the P4 layer is preferably 0.5 or less from the viewpoint of reducing the product cost.

The thickness T5 (mu m) of the P5 layer is preferably 15 to 50 mu m. When a plurality of P5 layers are present, it is preferable that the thickness T5 (占 퐉) of each P5 layer is 15 to 50 占 퐉. If T5 is less than 15 占 퐉, the adhesion to the P4 layer and the P6 layer may be deteriorated and interlayer peeling may occur. When T5 is larger than 50 탆, deterioration of the flame retardancy tends to occur when the combustibility of the back sheet is confirmed. T5 is more preferably 20 占 퐉 or more and 40 占 퐉 or less. Here, the delamination refers to peeling between the P4 layer and the P5 layer and between the P5 layer and the P6 layer.

The laminated structure of the back sheet in the present invention is such that at least the P4 layer is located on the surface layer and the P6 layer is located on the reverse surface layer from the P4 layer. Here, the P6 layer is located on the reverse surface layer from the P4 layer, which means that the P4 layer is located on the outermost surface layer of the back sheet, and thus the P6 layer is positioned on the outermost surface layer. From this point of view, the layer constitution (sequence of layers) of the back sheet of the present invention is preferably P4 layer / P5 layer / P6 layer.

Next, the method of producing the back sheet of the present invention will be described in detail with reference to the form having the P4 layer, the P5 layer and the P6 layer. As a method for laminating the P4 layer, the P5 layer and the P6 layer in the back sheet of the present invention, for example, a method of laminating a polyamide resin for P4 layer or a raw material containing polybutylene terephthalate as a main constituent, A raw material mainly composed of one selected from the group consisting of a crystalline soft polymer, an acrylic adhesive, and an ethylene vinyl acetate copolymer, and a raw material containing an olefin resin for a P6 layer as a main constituent are supplied to separate extruders (Co-extrusion method) comprising a step of joining the P4 layer, the P5 layer and the P6 layer in this order and melting them, and then laminating them and extruding them from the T-die into a sheet, (Melt lamination method) in which each sheet is separately prepared, and the sheet is heated (Coating method), a combination of these methods, or the like can be used, which is a method of thermocompression bonding (thermal lamination method) using a roll group or the like have. Among them, the co-extrusion method is preferable in that the production process is short and the adhesiveness between the layers is good. Hereinafter, the production method in the co-extrusion method will be described in detail.

When the back sheet of the present invention is produced by a co-extrusion method, a polyamide resin for a P4 layer or a raw material mainly composed of polybutylene terephthalate, a low crystalline soft polymer for a P5 layer, an acrylic adhesive, An ethylene vinyl acetate copolymer, and a raw material mainly composed of an olefin resin for a P6 layer, in a nitrogen stream, at a temperature of not less than 240 ° C and not more than 300 ° C , The raw material for the P5 layer and the raw material for the P6 layer are supplied to three extruders heated to 180 DEG C or more and 250 DEG C or less and melted. Subsequently, the P4 layer, the P5 layer and the P6 layer are joined and laminated in this order using a multi-manifold die, a feed block, a static mixer, a phenol, or the like, and co-extruded from the T die into the sheet. When the difference in melt viscosity of each layer is large, it is preferable to use a multi-manifold die from the viewpoint of suppressing the unevenness of lamination.

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

The backsheet of the present invention obtained by the above-described method may be subjected to a heat treatment or aging treatment as necessary insofar as the effect of the present invention is not impaired. By heat treatment, the thermal dimensional stability of the back sheet of the present invention can be improved. Further, in order to improve the adhesion of the back sheet of the present invention obtained by the above-described method, corona treatment or plasma treatment may be carried out.

The solar cell module of the present invention is characterized by having a back sheet for a solar cell of the present invention. By using the back sheet of the present invention in the solar cell module, it becomes possible to maintain power generation characteristics for a long period of time as compared with the conventional solar cell module. An example of the solar cell module configuration of the present invention is shown in Fig. In Fig. 1, a solar cell having a lead wire (not shown in Fig. 1) connected with a lead wire for taking out electricity is sealed with a transparent sealing material 2 such as EVA resin, And the back sheet 1 for a solar cell according to the present invention are bonded to each other. However, the solar cell module configuration example of the present invention is not limited to this and can be used in an arbitrary configuration.

In the solar cell module of the present invention, the above-described solar cell back sheet 1 is provided on the back surface of the sealing material 2 sealing the solar cell. Here, it is preferable that the solar cell back sheet of the present invention is asymmetric, and the P6 layer is disposed so as to be located on the sealing material 2 side in that the adhesion with the sealing material can be further enhanced. In addition, since the P4 layer of the back sheet of the present invention is disposed on the opposite side of the sealing material 2, resistance against ultraviolet rays reflected from the ground can be enhanced, and a highly durable solar cell module Or the thickness can be reduced.

The solar cell 3 is a solar cell that converts the light energy of the sunlight into electric energy and can be arbitrarily selected according to purposes such as a polycrystalline silicon system, a polycrystalline silicon system, a microcrystalline silicon system, an amorphous silicon system, a copper indium selenide system, A plurality of elements may be connected in series or in parallel depending on a desired voltage or current. Since the transparent substrate 4 having a light-transmitting property is located at the outermost layer of the solar cell module, a transparent material having high weatherability, high internal stain resistance and high mechanical strength characteristics is used in addition to high transmittance. In the solar cell module of the present invention, any material may be used as long as the transparent substrate 4 having transparency satisfies the above characteristics. Examples of the material include glass, ethylene tetrafluoroethylene (ETFE), polyvinyl fluoride (PVF) Based resin such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (TFE), tetrafluoroethylene-propylene hexafluoride (FEP), polytetrafluoroethylene chloride (CTFE) and polyvinylidene fluoride, an olefin resin, an acrylic resin , And mixtures thereof. In the case of glass, it is more preferable to use one reinforced. In the case of using a light-transmitting base made of a resin, it is also preferable to use a resin obtained by stretching the resin in one or two axes from the viewpoint of mechanical strength.

In addition, these substrates are preferably subjected to a corona treatment, a plasma treatment, an ozone treatment, and an adhesion facilitating treatment on the surface in order to give adhesiveness to an EVA resin or the like which is a sealing material of a solar battery cell.

The sealing member 2 for sealing the solar cell is formed by covering and fixing the unevenness of the surface of the solar cell with a resin to protect the solar cell from the external environment and to provide a light- A material having high transparency, high weatherability, high adhesion, and high heat resistance is used in order to adhere to the solar cell. Examples thereof include an ethylene-vinyl acetate copolymer (EVA), an ethylene-methyl acrylate copolymer (EMA), an ethylene-ethyl acrylate copolymer (EEA) resin, an ethylene-methacrylic acid copolymer (EMAA) , A polyvinyl butyral resin, a mixture thereof and the like are preferably used.

As described above, by embedding the back sheet for a solar cell of the present invention in a solar cell module, it becomes possible to provide a solar cell of high durability and / or thinness compared to a conventional solar cell. The solar cell module of the present invention can be suitably used for various applications such as a photovoltaic power generation system, a power source for small electronic parts, and the like, not limited to outdoor use and indoor use.

Example

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereto. The various characteristics described in this specification were evaluated as follows.

[Evaluation method of characteristics]

(1) layer thicknesses T1, T2, T3, T4, T5, T6, Ta, lamination ratio T4 / Ta

(A1) to (A4). The average value of the thickness T1 (占 퐉) of the P1 layer, the thickness T2 (占 퐉) of the P2 layer, the thickness T3 (占 퐉) of the P3 layer and the thickness T4 (占 퐉) of the P4 layer were measured. The thickness T5 (占 퐉) of the P5 layer, the thickness T6 (占 퐉) of the P6 layer, and the thickness Ta (占 퐉) of the entire sheet. Further, T4 and T6 obtained here were used to obtain a lamination ratio T4 / T6.

(A1) Using a microtome, the cross section of the laminated sheet (back sheet) is cut perpendicularly to the surface direction of the laminated sheet (back sheet) without crushing in the thickness direction.

(A2) Subsequently, the cut section is observed using an electron microscope, and an image enlarged and observed at 500 times is obtained. In addition, the observation place is determined at random, and the vertical direction of the image is made parallel to the thickness direction of the laminated sheet (back sheet) and the lateral direction of the image are respectively parallel to the surface direction of the laminated sheet (back sheet). In the case where the entire thickness direction is not included in one image, an image is prepared which can observe the entire thickness by observing the observation position in a direction away from the thickness direction and combining the plurality of images.

(A3) The thickness T1 of the P1 layer, the thickness T2 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, the thickness T6 of the P6 layer, The total thickness Ta was obtained.

(A4) T4 was divided by Ta to calculate the layer ratio T4 / Ta.

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

The P1 layer, the P3 layer, the P4 layer and the P6 layer were removed or peeled from the laminated sheet (back sheet) to separate the P1 layer and the P3 layer, the P4 layer and the P6 layer, Was calculated.

The mass wa (g) of the removed substance was measured. Subsequently, ortho-cresol, P3 layer and P6 layer were dissolved in ortho-dichlorobenzene (100 deg. C) and P4 layer was dissolved in formic acid. , The inorganic particles were collected. The obtained inorganic particles were washed with ortho-cresol, ortho-dichlorobenzene and formic acid, and centrifuged. Further, the cleaning operation was repeated until ethanol was added to the cleaning liquid after centrifugal separation until it was no longer cloudy. The mass wa '(g) of the obtained inorganic particles was determined, and the content of inorganic particles was calculated from the following equation.

Content of inorganic particles (% by mass) Wa1 = (wa '/ wa) x100.

(3) Crystallization parameters

{Glass transition temperature Tg, crystallization temperature Tc, crystallization parameter? Tcg}

The glass transition temperature (Tg) and the crystallization temperature (Tc) at the time of heating were measured according to JIS-K7121 (1987) using a differential scanning calorimeter DSCII manufactured by Seiko Instrument Co., . First, 5 mg of a sample was sampled and the temperature was raised from 25 DEG C to 300 DEG C at a heating rate of 20 DEG C / min to obtain Tg and Tc, and the crystallization parameter DELTA Tcg was obtained from the following formula.

? Tcg = Tc-Tg

Further, when a plurality of Tg and Tc are observed,? Tcg is calculated using all the Tc and Tg having a relation of Tc> Tg, and the smallest value among them is defined as? Tcg.

(4) Measurement of fracture elongation and fracture strength

Based on ASTM-D882 (1997), the sample was cut into a size of 1 cm x 20 cm, and the elongation at break and the breaking strength at the time of stretching at 5 cm in the chuck and at a tensile speed of 300 mm / min were measured. For each of the lengthwise and widthwise directions of the film, the number of samples was measured as n = 5, and the average value thereof was defined as the elongation at break and the breaking strength.

When 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 among them.

(5) Humidity resisting property (elongation retention after moisture heat resistance test)

The sample was cut into the shape of a measuring piece (1 cm x 20 cm), and then subjected to 1000 hours of treatment under the conditions of a temperature and humidity of 85% RH and a constant temperature and humidity chamber PR-1 KPH manufactured by Espec Co., The elongation at break was measured according to 4). The measurement was carried out for five samples each in the longitudinal direction and the lateral direction of the laminated sheet with n = 5, and the average value thereof was taken as the elongation at break E1. For the laminated sheet before the treatment, the elongation at break E0 was measured in accordance with the above item (4), and the elongation retention was calculated by the following equation using the obtained elongation at break E0, E1.

Elongation Retention Rate (%) = (E1 / E0) x100

The obtained elongation retention ratios were determined as follows.

When the elongation retention rate is 50% or more: S

When the elongation retention rate is 40% or more and less than 50%: A

When the elongation retention rate is 30% or more and less than 40%: B

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

If the retention rate is less than 20%: D

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

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

The sample was cut into the shape of a measuring piece (1 cm x 20 cm), and then subjected to a treatment for 2000 hours under the condition of a temperature of 140 캜 with a heat treatment machine GPHH-102 manufactured by Espec Co., The elongation was measured. The measurement was carried out for five samples each in the longitudinal direction and the lateral direction of the laminated sheet with n = 5, and the average value thereof was taken as the elongation at break E1. For the laminated sheet before the treatment, the elongation at break E0 was measured in accordance with the above item (4), and the elongation retention was calculated by the following equation using the obtained elongation at break E0, E1.

Elongation Retention Rate (%) = (E1 / E0) x100

The obtained elongation retention ratios were determined as follows.

When the elongation retention rate is 50% or more: S

When the elongation retention rate is 40% or more and less than 50%: A

When the elongation retention rate is 30% or more and less than 40%: B

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

If the retention rate is less than 20%: D

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

(7) Weatherability of P1 layer surface (change in color tone after UV irradiation)

(Light source: metal halide lamp, wavelength range: 295 to 450 nm, peak wavelength: 365 nm) at a temperature of 60 캜, a relative humidity of 50%, and a intensity of 100 mW / cm 2 with an eye Super Ultraviolet Tester S- W131 manufactured by Iwasaki Denki Co., Under the conditions of < RTI ID = 0.0 > P1 < / RTI > The sample before and after irradiation was measured for a sample in the reflection mode according to JIS Z-8722 (2000) using a spectroscopic colorimeter Model SE-2000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) The b value at the P1 layer side before and after the irradiation was measured and the average value was calculated to obtain the b value before and after the irradiation. The difference (the b value before irradiation from the b value after irradiation) was determined as the hue change? B1 after ultraviolet irradiation.

The obtained color tone change? Bl was determined as follows.

When the color tone change? B1 is 1 or less: S

When the color tone change? B1 is greater than 1 and less than or equal to 3: A

When the color tone change? B1 is greater than 3 and less than or equal to 6: B

If the color change? B1 is greater than 6 and less than or equal to 9: C

When the hue change? B1 is larger than 9: D

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

(8) Weatherability of P3 layer surface (change in color tone after UV irradiation)

(Light source: metal halide lamp, wavelength range: 295 to 450 nm, peak wavelength: 365 nm) at a temperature of 60 캜, a relative humidity of 50%, and a intensity of 100 mW / cm 2 with an eye Super Ultraviolet Tester S- W131 manufactured by Iwasaki Denki Co., Under the condition of the following conditions. The sample before and after irradiation was measured for a sample in the reflection mode according to JIS Z-8722 (2000) using a spectroscopic colorimeter Model SE-2000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) The b value at the P3 layer side before and after the irradiation was measured and the average value was calculated to obtain the b value before and after the irradiation. The difference (b value before irradiation from the b value after irradiation) was determined as the color tone change? B2 after ultraviolet irradiation.

The obtained color tone change (? B2) was determined as follows.

When the color tone change? B2 is 1 or less: S

When the color tone change? B2 is greater than 1 and less than or equal to 3: A

If the color change? B2 is greater than 3 and less than or equal to 6: B

If the color change? B2 is greater than 6 and less than or equal to 9: C

When the color change? B2 is larger than 9: D

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

(9) Adhesion to sealant

Based on JIS K6854 (1994), the adhesion of the sealing material was evaluated from the peel strength of the EVA sheet (sealing material) and the P3 layer. The test specimens were prepared by superimposing a 500 mu m-thick EVA sheet manufactured by Sankibiku Co., Ltd. and semi-tempered glass having a thickness of 3 mm and a laminated sheet of Examples and Comparative Examples in which the corona treatment was carried out and using a commercially available glass laminator, And then subjected to a pressing treatment at a load of 29.4 N / cm 2 for 15 minutes under a heating condition of 140 캜. The width of the test piece of the peel strength test was set to 10 mm, and two test pieces were prepared. Each of the test pieces was transferred to three places, and the average value of the obtained measured values was taken as the value of peel strength.

From the obtained peel strength, adhesion to the sealing material was evaluated as follows.

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

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

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

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

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

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

(10) Interlayer adhesion

The interlaminar adhesion was evaluated from the interlaminar peeling strength after treatment at 85 DEG C and 85% RH for 1000 hours. Here, the interlaminar peeling strength was the strength at the time of peeling in T-shape measured according to JIS K6854-3 (1999). Here, the interlayer spacing is defined as the interlayer separable between the P1 layer and the P2 layer and between the P2 layer and the P3 layer. The width of the test piece of the interlaminar peel strength test was set to 15 mm and two test pieces were prepared and transferred to each test piece at three places and the average value of the obtained measured values was taken as the interlaminar peel strength, ≪ / RTI >

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

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

When the peel strength is less than 3N / 15mm and less than 6N / 15mm: B

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

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

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

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

The water vapor permeability under the environment of a measurement area of 50 cm 2 and a temperature of 40 캜 and a relative humidity of 90% RH was measured in accordance with the infrared sensor method of JIS K7129 (2008).

(12) Acetic acid transmittance at 85 캜 Pa (g / m 2 / day)

A cross-sectional view is shown in Fig. 2 and a top view is shown in Fig. 3 with respect to the jig 11 used for measuring the acetic acid transmittance. The jig 11 includes a jig upper part 7 having a circular opening of 65 cm 2 made of stainless steel and a jig lower part 8 as a container containing acetic acid having the same shape as the jig 7 on the upper surface of the container , And the acetic acid stock solution (9) is placed in the lower jig (8).

The mesh sheet 10 having a wire diameter of 0.29 mm and a mesh size of 0.98 mm made of stainless steel was sandwiched between the jig lower portion 8 and the jig upper portion 7 on the side of the jig upper portion 7, And the jig upper portion 7 and the jig lower portion 8 are fixed by a screw so that the vapor of the acetic acid does not escape. The mass W1 at room temperature after the back sheet 1 and the acetic acid solution 9 having the measurement area of 65 cm2 satisfied the jig 11 prepared in this state was left at 85 占 폚 for 1 hour. After the W1 measurement, the mass W2 at room temperature after being left at 85 DEG C for another hour was measured. In the same manner, the mass W4 at room temperature and the mass W4 at room temperature after 1 hour from the measurement of W3 after 1 hour of measurement after W2 measurement were measured. The obtained W1 to W4 were calculated according to the following equations and Pa was calculated.

Pa (g / m 2 / day) = {W 1 -W 2 + W 2 -W 3 + W 3 -W 4} / 3 24 /

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

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

When the maximum output retention rate is 75% or more: S

If the maximum output retention rate is 50% or more and less than 75%: A

When the maximum power retention rate is 25% or more and less than 50%: B

If the maximum output retention is less than 25%: C

S and A are acceptable, and S is the most excellent among them.

(14) Confirmation of discoloration of cell collecting electrode portion (discoloration of cell collecting electrode)

The surface-side current collecting electrode included in the solar cell of the solar cell module was subjected to a deterioration acceleration test at 85 ° C and 85% RH for 5000 hours using a constant-temperature and constant-humidity test tank "Constant Temperature and Humidity Test Tester of Manufactured by Especa" Subsequent discoloration was visually confirmed for the number of samples n = 5. From the number of discolored samples obtained, discoloration of the cell current collector electrode portion was determined as follows.

When the number of discolored samples is n = 0: S

When the number of discolored samples is n = 1 or 2: A

If the number of discolored samples is n = 3 or 4: B

When the number of discolored samples is n = 5: C

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

(15) P6 layer sulfur

The back sheet was cut into the shape of a measurement piece (3 cm x 3 cm), and then treated with a hot air oven PV (H) -212 manufactured by Espec Co., Ltd. at 120 ° C for 72 hours. The samples before and after the treatment were subjected to measurement in a reflection mode according to JIS Z-8722 (2000) using a spectroscopic colorimeter Model SE-2000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) , The b value at the P6 layer side was measured with a sample measurement diameter of 30 mm phi, and the average value was calculated to determine the difference in b value before and after the treatment. That is,? B was obtained by subtracting the b value before the processing from the b value after the processing, and the determination was made as follows.

When the color change? B is less than 3: S

When the color tone change Δb is 3 or more and less than 5: A

When the color change? B is 5 or more and less than 8: B

When the color change? B is 8 or more and 10 or less: C

When the hue change? B is more than 10: D

(16) Heat resistance (130 캜)

The back sheet was cut into a size of 1 cm x 20 cm based on ASTM-D882 (1997), and the temperature was measured before and after 1000 hours of standing in a hot air oven PV (H) -212 manufactured by SPEC , The distance between the chucks was 5 cm, and the tensile speed was 300 mm / min. The rate of decrease in elongation at break was determined as an average value after measurement of the number of samples with n = 5 for each of the longitudinal direction and the width direction of the film. From the obtained rate of decrease in elongation at break, it was judged as follows.

When the elongation at break is 70% or more: S

When the retention of elongation at break is 50% or more and less than 70%: A

When the retention of elongation at break is 30% or more and less than 50%: B

When the elongation at break is less than 30%: C

(17) partial discharge voltage

The partial discharge voltage of the back sheet was determined using a partial discharge tester KPD2050 (manufactured by Kikuchi Denshi Kogyo Co., Ltd.). The test conditions are as follows.

The output voltage application pattern in the output sheet is a pattern for simply raising the voltage from 0 V to a predetermined test voltage in the first stage, a pattern for holding the predetermined test voltage in the second stage, And a pattern for simply lowering the voltage from the test voltage of 0 V to 0 V is selected.

· The frequency shall be 50Hz. The test voltage shall be 1 kV.

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

• The pulse count sheet count method is "+" (plus), and the detection level is 50%.

· The amount of charge in the range sheet should be 1,000 pcs.

• On the protection sheet, check the voltage check box and enter 2 kV. The pulse count is set to 100,000.

• The start voltage and the extinction voltage in the measurement mode shall be 1.0pc and 1.0pc, respectively.

Further, the measurement was carried out at arbitrary 10 places within the film plane, and the average value was set as the partial discharge voltage V0. In addition, the measurement samples were left overnight in a room at 23 캜 and 65% RH, and measurement was carried out.

When the partial discharge voltage is 1,050 V or more: S

When the partial discharge voltage is 950 V or more and less than 1,050 V: A

If the partial discharge voltage is higher than 700 V and lower than 950 V: B

When the partial discharge voltage is higher than 300V and lower than 700V: C

When the partial discharge voltage is less than 300 V: D

(18) Adhesion to the sealing material (135 占 폚 vacuum laminate)

Based on JIS K6854 (1994), the adhesion between the EVA sheet (sealing material) and the sealing material was evaluated from the peel strength of the P6 layer of the back sheet. The test specimens were prepared by superimposing a 500 탆 thick EVA sheet manufactured by Sankibik Co., Ltd., and semi-tempered glass having a thickness of 3 mm, and a back sheet of Examples and Comparative Examples in which the corona treatment was performed, And then subjected to a pressing treatment at a load of 29.4 N / cm 2 for 15 minutes under a 135 ° C heating condition. The width of the test piece of the peel strength test was set to 10 mm, and two test pieces were prepared. Each of the test pieces was transferred to three places, and the average value of the obtained measured values was taken as the value of peel strength. From the obtained peel strength, the adhesion of the sealing material was determined as follows. In the case of the back sheet having no P6 layer, the evaluation is carried out in the same manner.

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

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

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

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

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

(19) Flatness (Curl)

The laminated sheet was cut into 100 mm wide and 100 mm wide and allowed to be concave as viewed from the side in a no-load state on the plane, and the height of the four corners of the sheet was measured. The total value at that time was used as the curl height, and the following judgment was made.

If the total height of the four corners of the curl is less than 20 mm: S

If the sum of the four corner heights of the curl is 20mm or more and less than 50mm: A

If the sum of the four corner heights of the curl is 50 mm or more and less than 80 mm: B

If the sum of the four corner heights of the curl is 80 mm or more and less than 100 mm: C

If the sum of the four corner heights of the curl is more than 100mm: D

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

(20) Rigid amorphous quantities

("Fiber and Industry", Vol. 65, No. 11 (2009) P.428) by performing the differential scanning calorimetry (DSC) and the temperature-modulated DSC under the following conditions and apparatus under the following conditions: The hardness non-crystallization amount was calculated.

<DSC method>

Apparatus: DSC Q1000 manufactured by TA Instruments

Atmosphere: Nitrogen flow (50 mL / min)

Temperature and calorimetric correction: High purity indium

Temperature range: 0-250 ° C

Heating rate: 10 ° C / min

Sample weight: 10 mg

Sample container: Standard container made of aluminum

<Temperature Modulation DSC Method>

Device: DSC Q1000 manufactured by TE Instruments

Atmosphere: Nitrogen flow (50 mL / min)

Temperature and calorimetric correction: High purity indium

Nonthermal correction: Sapphire

Temperature range: 0-300 ° C

Heating rate: 2 캜 / min

Sample weight: 5 mg

Sample container: Standard container made of aluminum

The rigid amorphous amount: χra (%) was calculated by the following formula.

? c (%) = (? Hm -? Hc) /? Hm ⁰ ? 100

χma (%) = ΔCp / ΔCp ⁰ × 100

χra (%) = 100- (χc + χma)

χra: Rigid amorphous

χc: crystallinity

χma: movable amorphous amount

ΔHm: Heat of fusion

? Hc: cold crystallization calorie

? Hm ⁰ : total crystal melting heat amount (145.3 J / g)

ΔCp: non-train

ΔCp ⁰ : a completely amorphous train (0.3497 J / (g · ° C))

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

The P3 layer is removed or peeled off from the laminated sheet, and the mass W (g) is measured. Dissolved in ortho-dichlorobenzene (100 DEG C), and inorganic particles were collected from insoluble components by centrifugation. The obtained inorganic particles are further washed with a solvent, centrifuged, and the mass Wt of the obtained inorganic particles is measured. In addition, the cleaning operation was repeated until ethanol was added to the cleaning liquid after centrifugal separation until it was not cloudy.

The obtained inorganic particles were filtered with a quantitative filter paper grade 44 manufactured by Whatman, and the particle size distribution at the integrated value of 50% in the particle size distribution was determined by the laser analysis and scattering method with respect to the components remaining as the residue Average particle diameter. The particle size distribution referred to herein is the particle size distribution measured by the laser diffraction / scattering method particle size distribution measuring apparatus LS series (Beckman Coulter Co.), and Toyoda Mayumi (Measurement of particle size distribution) (Beckmann Coulter Co., Ltd.) Respectively. In addition, the measurement solution was prepared such that inorganic particles were added to pure water and dispersion treatment was performed for 1 minute with a homogenizer, and an indication of the concentration adjustment window of the apparatus included 45 to 55%.

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

(Raw material)

· Polybutylene terephthalate resin

(Registered trademark) 1200M (manufactured by Toray Industries, Inc.) was used as the polybutylene terephthalate resin (PBT) constituting the P1 layer in Examples 1 to 26, 57 to 72 and Comparative Example 1 Respectively.

· Polyolefin resin

As a polyolefin resin constituting the P3 layer in Examples 1 to 26, 57 to 72, and Comparative Example 2, "Nobleen " WF345S (ethylene 3.5 mass%, butene 4.0 Mass%) was used as EPBC1.

For Example 25, "Nobleen" (registered trademark) FLX80E4 manufactured by Sumitomo Chemical Co., Ltd. was used as PP1.

· Acid-modified polyolefin

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

· Polyolefinic elastomer

"NOTIO " PN2060 manufactured by Mitsui Chemicals, Inc. was used as the elastomer 1 as the polyolefin-based elastomer.

· Inorganic particles

Titanium dioxide was used as the inorganic particles of the P1 layer of Examples 1 to 5, 7 to 26, 57 to 72, Comparative Example 1 and the P3 layer of Examples 1 to 9, 11 to 26 and Comparative Example 2. For the titanium dioxide of the P1 layer, a master batch produced in a ratio of 50 mass% / 50 mass% of the resin used as the main constituent component of the P1 layer and titanium dioxide in each of the Examples and Comparative Examples was added so as to have a desired concentration . For the titanium dioxide of the P3 layer, a master batch prepared at a ratio of 30 mass% / 70 mass% of the resin used as the main constituent component of the P3 layer and titanium dioxide in each of the Examples and Comparative Examples was added so as to have a desired concentration.

· End blocker

P-400 manufactured by Rinkemisa Co., Ltd. was used as the end blocker used in the P1 layer of Examples 1, 3 to 25, 57 to 72, and Comparative Example 1. "Carbodilite" (registered trademark) HMV-15CA manufactured by Nisshinbo Chemical Co., Ltd. was used for Example 26. [

· Crystal nucleating agent

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

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

Talc having an average particle size of 5 占 퐉 was used as the inorganic particles having a particle size of 3 占 퐉 to 20 占 퐉 in the P3 layer of Examples 64 to 72.

(Examples 1 to 26, 61 to 72)

Using the extruder 1, the extruder 2 and the extruder 3, the raw materials shown in Tables 1 and 5 were supplied to the respective extruders at a desired mixing ratio. Subsequently, the layer melt-extruded from the extruder 1 was a P1 layer, the extruder 2 was a P2 layer, Each layer was joined with a multi-manifold so that the extruder 3 was laminated in the order of P1 layer / P2 layer / P3 layer as the P3 layer, and the resin discharged from the separating member was cooled and solidified on a casting drum at 25 deg. . P1 layer, P2 layer and P3 layer had the thicknesses shown in Tables 1 and 5. The obtained laminated sheet was subjected to evaluation shown in Tables 2 and 6. As a result, as shown in Tables 2 and 6, it was found that the examples were excellent laminated sheets.

Further, in Example 24, since the P2 layer contains an elastomer, interlaminar adhesion is extremely excellent.

(Examples 57 to 60)

A laminated sheet was produced in the same manner as in Example 1 except that the cast drum temperature was changed to 15 ° C (Example 57), 20 ° C (Example 58), 40 ° C (Example 59), and 50 ° C (Example 60) Respectively. The obtained laminated sheet was subjected to the evaluation shown in Table 6. As a result, as shown in Table 6, it was found that the examples were excellent laminated sheets.

(Comparative Example 1)

Using the extruder 1, the raw materials shown in Table 1 were fed to the extruder so as to have a desired blending ratio, and then the resin extruded from the extruder 1 and discharged from the cementing member was cooled and solidified on the casting drum to obtain a single-layer sheet. Since the polyolefin-based resin layer was not present, the adhesion with the sealing material was poor.

(Comparative Example 2)

Using the extruder 3, the raw materials shown in Table 1 were fed to the extruder at a desired mixing ratio, and the resin extruded from the extruder 3 and then discharged from the cementing unit was cooled and solidified on the casting drum to obtain a single-layer sheet. Since the polybutylene terephthalate-based resin layer is not present, the heat resistance and heat resistance are poor.

It is possible to provide a laminated sheet capable of achieving compatibility between heat and humidity resistance, heat resistance and adhesion to a sealing material as compared with a laminated sheet using a conventional polybutylene terephthalate resin. Such a laminated sheet can be suitably used for applications such as reflectors for liquid crystal displays, automobile materials, building materials, and other applications in which humidity resistance, resistance to ultraviolet rays, and light reflectivity are important in addition to solar cell back sheets. Particularly a laminated sheet which can be preferably used as a solar cell back sheet, and a method for producing the laminated sheet.

[Table 1]

[Table 2]

[Table 5]

[Table 6]

Next, the fourteenth to twentieth inventions will be described with reference to Examples 27 to 56 and Comparative Examples 3 to 5.

(Examples 27 to 56, Comparative Example 5)

(Raw material)

· Polyamide resin

(Manufactured by Toray Industries, Inc.) as the polyamide resin (PA6) constituting the P4 layer in Examples 27, 34 to 39, 41 to 49 and Comparative Examples 4 and 5, , Tm; 225 占 폚) was used.

Nylon 610 resin "Amilan " CM2001 (PA610) for Example 51, Nylon 11 resin (PA610) for Example 52, Nylon 66 resin" Nylon 12 resin "Ric acid" AESN-TL (PA12) was used for Example 53 in terms of "acid" BESN-O-TL (PA11).

· Polybutylene terephthalate

"Torecon" (registered trademark) 1200M (Tm; 224 ° C, manufactured by Toray Industries, Inc.) was used as the polybutylene terephthalate (PBT) constituting the P4 layer in Examples 29 and 54.

· Polyethylene terephthalate

As the polyethylene terephthalate (PET) constituting the P4 layer in Example 28, a film of 25 mu m "RUMIRER" S10 (manufactured by Toray Industries, Inc.) was used.

· Polyvinyl fluoride

As the polyvinyl fluoride (PVF) constituting the P4 layer in Example 30, 38 占 퐉 "Tedlar" (trade name) (manufactured by DuPont) was used.

· Ethylene tetrafluoroethylene

As the ethylene tetrafluoroethylene (ETFE) constituting the P4 layer in Example 31, a 50 mu m film of "Toyoflon" (registered trademark) EL (manufactured by Toray Film Processing Co., Ltd.) was used.

· Ethylene tetrafluoride · Propylene hexafluoride

As the tetrafluoroethylene hexafluoropropylene (FEP) constituting the P4 layer in Example 32, a film of "Toyoflon" (registered trademark) FL (manufactured by Toray Film Processing Co., Ltd.) of 25 m was used.

· Polyvinylidene fluoride

As the polyvinylidene fluoride (PVDF) constituting the P4 layer in Example 33, a film of 30 μm Kynar Film 302 PGM TR (manufactured by ARKEMA) was used.

· Olefin resin

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

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

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

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

For Example 49, "Nobleen " (trade name) FLX80E4 manufactured by Sumitomo Chemical Co., Ltd. was used as PP1.

· Acid-modified olefins

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

· Ethylene vinyl acetate copolymer

As the resin constituting the P5 layer in Example 55, "Mordic" (registered trademark) A515 manufactured by Mitsubishi Chemical Corporation was used as Resin 2.

· Acrylic adhesive

As the resin constituting the P5 layer in Example 56, "Bond Fast" (registered trademark) 7L manufactured by Sumitomo Chemical Co., Ltd. was used as Resin 3.

· Inorganic particles

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

For the titanium dioxide of the P4 layer, the resin used as the main constituent component of the P4 layer and the resin mastered at a ratio of 50 mass% / 50 mass% of the titanium dioxide to each of the examples and the comparative examples were adjusted so that the desired concentration . For the titanium dioxide of the P6 layer, the resin used as the main constituent component of the P6 layer and the resin mastered at a ratio of 30 mass% / 70 mass% of titanium dioxide were added to the respective Examples and Comparative Examples so as to have a desired concentration.

(Lamination)

Using the extruder 4, the extruder 5 and the extruder 6, the raw materials shown in Tables 3-1 and 3-2 were supplied to respective extruders so that the layer melt-extruded from the extruder 4 was a P4 layer, the extruder 5 P5 layer and the extruder 6 are laminated in the order of P4 layer / P5 layer / P6 layer as the P6 layer, and the resin discharged from the separating member is cooled and solidified on the casting drum to form a back sheet .

Of the backsheets having no P5 layer, in Examples 27 and 29, the raw materials shown in Table 3-1 were fed to respective extruders using the extruder 4 and the extruder 6, and then melt extruded from the extruder 4 The layers were joined together in the multi-manifold so that the layer P4, the extruder 6, and the P4 layer / the P6 layer were stacked in this order, and the resin discharged from the separating member was cooled and solidified on the casting drum to obtain a back sheet .

Of the backsheets having no P5 layer, Examples 28, 30 to 33, and Comparative Example 3 were prepared by dry lamination so as to have the desired configurations shown in Tables 3-1 and 3-2, The adhesive was used as an adhesive to perform lamination. At this time, the EPBC1 used in Examples 28 and 30 to 33 was supplied with the raw material so as to have a desired blending ratio in advance in the extruder 6, and subsequently the resin discharged from the cementing member was melt-extruded from the extruder 6 and cooled and solidified on the casting drum The resulting single-layer sheet was used.

In Example 39, a single-layer sheet obtained by supplying a raw material so as to have a desired blending ratio to the extruder 6, and subsequently melt-extruded from the extruder 6 to cool and solidify the resin discharged from the cementing unit onto the casting drum was used.

(Solar cell module)

A flux "H722" manufactured by HOZAN Co., Ltd. was applied to the silver electrode portions on the front and rear surfaces of the Q6LPT-G2 made by Qcells, a solar cell, The copper foil SSA-SPS 0.2 x 1.5 (20) manufactured by Hitachi, Ltd., which was cut to a length of 155 mm, was placed at a position 10 mm away from one side of the cell on the front surface side to the end portion of the wiring material, And soldering iron was used to bring the soldering iron into contact with the back surface of the cell so that the front surface and the back surface were simultaneously solder-welded to produce a one-cell string.

The longitudinal direction of the wiring member protruding from the cell of the produced one-cell string was perpendicular to the longitudinal direction of the extraction electrode "copper foil A-SPS 0.23 × 6.0" manufactured by Hitachi, Ltd., cut to 180 mm, The flux was applied to a portion where the extraction electrode overlapped, and solder welding was performed to fabricate a string having the extraction electrode.

Then, a glass having a size of 190 mm x 190 mm, a heat-treated glass having a thickness of 3.2 mm for a solar cell manufactured by Asahi Glass Co., Ltd., ethylene vinyl acetate having a size of 190 mm x 190 mm, 190 mm × 190 mm ethylene vinyl acetate "seal material 0.5 mm thick manufactured by Sanbixa", 190 mm × 190 mm, and the back sheets of Tables 3-1 and 3-2 were laminated in this order, and the glass was brought into contact with the nirvana of the vacuum laminator Vacuum laminating was carried out under the conditions of a heating temperature of 145 占 폚, 4 minutes of vacuuming, 1 minute of pressing and 10 minutes of holding time. At this time, the string with the extraction electrode was set so that the glass surface was on the cell surface side.

The thicknesses of the P4 layer, the P5 layer, and the P6 layer, the acetic acid permeability Pa, and the water vapor permeability Pw were as shown in Tables 3-1 and 3-2. The obtained back sheet and the solar cell module using the back sheet were subjected to the evaluation shown in Tables 4-1 and 4-2. As a result, as shown in Tables 4-1 and 4-2, it was found that the examples were excellent backsheets.

In Comparative Example 5, since Pw was larger than 2.5, the discoloration of the cell current collecting electrode was lowered.

(Comparative Example 3)

A 125 占 퐉 white polyethylene terephthalate film "Lumirror" E20F (manufactured by Toray Industries, Inc.) and an inorganic compound containing aluminum oxide (trade name, manufactured by Toray Industries, Inc.) were laminated by a dry lamination method using a polyurethane- A 12 占 퐉 polyethylene terephthalate film "Barryrox" (registered trademark) EG-C2 (manufactured by Toray Film Processing Co., Ltd.) having a vapor-deposited layer was laminated in this order to obtain a back sheet, and the transmittance of acetic acid and the vapor permeability , The Pa was 10 g / 24 hr / m &lt; 2 &gt; with respect to the acetic acid transmittance, and Pw was 0.2 g / 24 hr / m & The solar cell module was manufactured using this backsheet, and the maximum output retention ratio was compared with that at 85 ° C and 85% RH for 5000 hours. The maximum output retention was 10%, and since Pa was smaller than 200, The power generation characteristics were inferior.

(Comparative Example 4)

Using the extruder 4, the raw materials shown in Table 3-2 were supplied to the extruder at a desired mixing ratio, and the resin extruded from the extruder 4 and then discharged from the cementing unit was cooled and solidified on the casting drum to obtain a single-layer sheet. Pw was larger than 2.5, the discoloration of the cell current collecting electrode was deteriorated.

[Table 3-1]

[Table 3-2]

[Table 4-1]

[Table 4-2]

1: back sheet
2: Seal material
3: Generator (solar cell)
4: transparent substrate
5: The surface of the solar cell back sheet on the side of the sealing material 2
6: a surface opposite to the sealing material 2 of the solar cell back sheet
7: jig top
8: jig bottom
9: Acetic acid
10: Mesh
11: Jig

Claims (15)

A laminate sheet having a layer mainly composed of a polybutylene terephthalate resin (P1 layer) and a layer mainly composed of a polyolefin resin (P3 layer). The laminate according to claim 1, which has a layer (P2 layer) mainly composed of an adhesive polyolefin resin,
And the P1 layer and the P3 layer are in contact with each other through the P2 layer. The laminated sheet according to claim 2, wherein the thickness of the P2 layer is 15 to 50 占 퐉. The laminated sheet according to any one of claims 1 to 3, wherein the crystallization parameter? Tcg of the P1 layer measured by differential scanning calorimetry (DSC) is 7 to 30 占 폚. The resin composition according to any one of claims 1 to 4, wherein when the resin obtained by reacting the terminal blocking agent with a polybutylene terephthalate resin is a terminal-blocked polybutylene terephthalate resin,
A laminated sheet characterized in that the polybutylene terephthalate resin as a main component of the P1 layer comprises a terminally blocked polybutylene terephthalate resin. The laminated sheet according to any one of claims 1 to 5, wherein the P3 layer contains 0.1 to 30 mass% of inorganic particles. The laminated sheet according to any one of claims 1 to 6, wherein the amount of the rigidified amorphous phase of the P1 layer is 30 to 50%. The laminated sheet according to any one of claims 1 to 7, wherein the P1 layer contains 0.1 to 5% by mass of a crystal nucleating agent. The laminate according to any one of claims 1 to 8, wherein the P3 layer contains 5 to 30 mass% of inorganic particles having a particle diameter of 3 m or more and 20 m or less and contains 0.5 to 5 mass% of an adhesive polyolefin resin Sheet. The method according to any one of claims 1 to 9, wherein the acetic acid permeability Pa (g / m2 / day) at 85 占 폚 and the water vapor permeability Pw (g / m2 / day) at 40 占 폚 and 90% ) And (2).
(1) 200? Pa
(2) Pw? 2.5 A solar cell back sheet comprising the laminated sheet according to any one of claims 1 to 10. A solar cell using the solar cell back sheet according to claim 11. The method for producing a laminated sheet according to any one of claims 2 to 10,
A raw material for a P1 layer mainly comprising a polybutylene terephthalate resin as a main constituent component, a raw material for a P2 layer mainly composed of an adhesive polyolefin resin as a main component and a raw material for a P3 layer mainly comprising a polyolefin resin And extruding the laminate from the T die into the sheet in the order of the P1 layer, the P2 layer, and the P3 layer, respectively, after they are melted. (G / m2 / day) at 85 占 폚 and the water vapor transmission rate Pw (g / m2 / day) at 40 占 폚 and 90% RH satisfy the following expressions (1) and Back sheet for battery.
(1) 200? Pa
(2) Pw? 2.5 15. The back sheet for a solar cell according to claim 14, wherein a layer selected from the group consisting of a polyester resin, a polyamide resin and a fluororesin is a main constituent component, and the layer is a P4 layer.

Images