JP2012009688A - Resin composition for solar cell sealing material and solar cell sealing material using the same, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for a solar cell sealing material containing an ethylene α-olefin copolymer, an organic peroxide or the like and excellent in cross-linking characteristics and heat resistance, a solar cell sealing material using the resin composition, and a solar cell module.SOLUTION: There are provided a resin composition for a solar cell sealing material or the like. The resin composition for a solar cell sealing material contains: an ethylene α-olefin copolymer constituent (A) having the following (a1)-(a2) characteristics; and an organic peroxide constituent (B). (a1) A density is 0.860-0.920 g/cm. (a2) A total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene and a tri-substituted-vinylene in the ethylene α-olefin copolymer is 0.22 (piece/total 1000C) or more (where, a number of pieces of vinyl, vinylidene, cis-vinylene, trans-vinylene and a tri-substituted-vinylene is a number per carbon number of the total 1000 pieces of a main chain and a side chain as measured by NMR).

Description

  The present invention relates to a resin composition for a solar cell encapsulant, a solar cell encapsulant using the same, and a solar cell module, and more specifically, contains an ethylene / α-olefin copolymer and an organic peroxide. In addition, the present invention relates to a resin composition for a solar cell encapsulant that is excellent in crosslinking characteristics, heat resistance, and transparency, and a solar cell encapsulant and solar cell module using the same.

As global environmental issues such as an increase in carbon dioxide are highlighted, solar power generation has come into focus again along with the effective use of hydropower, wind power, and geothermal heat.
Photovoltaic power generation generally protects solar cell elements such as silicon, gallium-arsenic, copper-indium-selenium with an upper transparent protective material and a lower substrate protective material, and the solar cell element and the protective material are sealed with resin. It uses solar cell modules that are fixed with materials and packaged, and although it is smaller in scale than hydropower and wind power, it can be distributed and placed in places where power is required. Research and development aimed at lowering the level is being promoted. In addition, the government and local governments are gradually promoting the spread of measures by substituting installation costs as a residential solar power generation system introduction promotion project. However, further cost reduction is necessary for further spread, so that not only the development of solar cell elements using new materials to replace conventional silicon and gallium arsenide, but also the manufacturing cost of solar cell modules Efforts to further reduce this are continuing.

As a condition of the solar cell encapsulant constituting the solar cell module, in order to ensure the incident amount of sunlight so as not to decrease the power generation efficiency of the solar cell, good transparency is required. Moreover, since a solar cell module is usually installed outdoors, it is exposed to sunlight for a long period of time and the temperature rises. Therefore, in order to avoid troubles in which the resin sealing material flows and the module is deformed, it must have heat resistance. Moreover, in order to reduce the material cost of a solar cell element year by year, the thickness has been reduced, and a sealing material with further flexibility is also required.
For example, in solar cell modules, from the viewpoint of price, workability, moisture resistance, etc., as an encapsulating material, an organic peroxide is blended with an ethylene / vinyl acetate copolymer (EVA) having a high vinyl acetate content and crosslinked. A composition having a structure is employed (see, for example, Patent Document 1). However, ethylene / vinyl acetate copolymer (EVA) resin, when used over a long period of time, has deteriorated moisture resistance due to deterioration / deterioration such as yellowing, cracking and foaming, and power generation due to corrosion of solar cells, etc. The amount was reduced. These are considered to be easily affected by sunlight and moisture because the EVA resin has an ester structure with high hydrolyzability.

Therefore, as a sealing material for a solar cell module, a material composed of an amorphous or low crystalline α-olefin copolymer having a crystallinity of 40% or less has been proposed (see Patent Document 2). In this Patent Document 2, it is exemplified that a low crystalline ethylene / butene copolymer is mixed with an organic peroxide and a sheet is produced at a processing temperature of 100 ° C. using a profile extruder. Since processing temperature is low, there exists a problem that productivity cannot be improved.
Moreover, as a sealing material for solar cell modules, (a) a density of less than about 0.90 g / cc, (b) a 2% secant coefficient of less than about 150 megapascals (mPa) as measured by ASTM D-882-02 (C) a melting point of less than about 95 ° C., (d) an α-olefin content of at least about 15 and less than about 50% by weight based on the weight of the polymer, (e) a Tg of less than about −35 ° C., and (f) A polymer material containing a polyolefin copolymer that satisfies one or more conditions of at least about 50 SCBDI has been proposed (see Patent Document 3).
In the solar cell module, the solar cell encapsulant tends to become thinner as the solar cell element becomes thinner. At that time, when an impact is applied from the upper or lower protective material side of the solar cell sealing material, the wiring is likely to be disconnected. In order to improve it, it is required to increase the rigidity of the sealing material. However, in the polymer material of Patent Document 3, if the rigidity is increased, there is a problem that the crosslinking efficiency is deteriorated.

  Thus, according to the conventional technology, a resin composition for a solar cell encapsulant that is excellent in crosslinkability, heat resistance, transparency, and flexibility has not been obtained.

JP 58-023870 A JP 2006-210906 A JP 2010-504647 A

  An object of the present invention is to provide a resin composition for a solar cell encapsulant that contains an ethylene / α-olefin copolymer and an organic peroxide, and is excellent in crosslinkability, heat resistance, transparency, and flexibility. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have obtained ethylene / α-olefins having characteristics such as specific density, molecular weight distribution, number of unsaturated bonds, etc., polymerized using a metallocene catalyst or the like as a resin component. By selecting a copolymer and adding an organic peroxide thereto, a resin composition for a solar cell encapsulant that is excellent in crosslinkability, heat resistance, transparency, and flexibility can be obtained. Obtaining knowledge that the productivity of the battery module is greatly improved, the present invention has been completed.

That is, according to 1st invention of this invention, the resin composition for solar cell sealing materials characterized by containing the following component (A) and component (B) is provided.
Component (A): ethylene / α-olefin copolymer (a1) having the following characteristics (a1) to (a2): Density of 0.860 to 0.920 g / cm ³
(A2) The total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted-vinylene in the ethylene / α-olefin copolymer is 0.22 (total / total 1000 C) or more (however, vinyl, vinylidene, cis -The number of vinylene, trans-vinylene, and tri-substituted vinylene is the number per 1000 carbon atoms in total of the main chain and side chain measured by NMR.
Component (B): Organic peroxide

According to a second aspect of the present invention, in the first aspect, the component (A) is an ethylene / α-olefin copolymer further having the following property (a3): A battery encapsulant composition is provided.
(A3) The ratio (Mz / Mn) of the Z average molecular weight (Mz) and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC) is 8.0 or less.

According to the third aspect of the present invention, in the first or second aspect, the content of the component (B) is 0.2 to 5 parts by weight with respect to 100 parts by weight of the component (A). The resin composition for solar cell sealing materials characterized by this is provided.
According to the fourth invention of the present invention, there is provided a resin composition for a solar cell encapsulant, characterized in that in any one of the first to third inventions, the composition further comprises the following component (C): Provided.
Component (C): Hindered amine light stabilizer Moreover, according to 5th invention of this invention, in 4th invention, content of a component (C) is 100 weight part of component (A), Provided is a resin composition for a solar cell sealing material, which is 0.01 to 2.5 parts by weight.
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the component (A) is ethylene / 1-butene or an ethylene / 1-hexene copolymer. A resin composition for a solar cell encapsulant is provided.
On the other hand, according to the seventh invention of the present invention, there is provided a solar cell encapsulant comprising the resin composition for solar cell encapsulant according to any one of the first to sixth inventions.
Moreover, according to the 8th invention of this invention, it is related with the 7th invention, The solar cell module using a solar cell sealing material is provided.

  The resin composition for a solar cell encapsulant of the present invention is mainly composed of an ethylene / α-olefin copolymer having specific density, molecular weight distribution, number of unsaturated bonds, etc., and an organic peroxide. Therefore, when this resin composition is made into a sheet, the ethylene / α-olefin copolymer is crosslinked in a relatively short time, and the balance between rigidity and crosslinking efficiency is well balanced. The module can be easily formed as a material, and the manufacturing cost can be reduced. Moreover, the obtained solar cell module becomes excellent in transparency, flexibility, weather resistance, etc., and it can be expected to maintain stable conversion efficiency for a long period of time.

1. Resin composition for solar cell encapsulant The resin composition for solar cell encapsulant of the present invention (hereinafter also simply referred to as a resin composition) comprises the following ethylene / α-olefin copolymer component (A) and organic peroxide. It contains an oxide (B).

(1) Component (A)
Component (A) used in the present invention is an ethylene / α-olefin copolymer having the following properties (a1) to (a2).
(A1) Density is 0.860-0.920 g / cm ³
(A2) The total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted-vinylene in the ethylene / α-olefin copolymer is 0.22 (total / total 1000 C) or more (however, vinyl, vinylidene, cis -The number of vinylene, trans-vinylene, and tri-substituted vinylene is the number per 1000 carbon atoms in total of the main chain and side chain measured by NMR.
(A3) The ratio (Mz / Mn) of the Z average molecular weight (Mz) and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC) is 8.0 or less.

(I) Monomer structure of component (A) The ethylene / α-olefin copolymer used in the present invention is a random copolymer of ethylene and α-olefin, the main component of which is a structural unit derived from ethylene. .
The α-olefin used as a comonomer is preferably an α-olefin having 3 to 12 carbon atoms. Specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene- 1 etc. can be mentioned. Specific examples of such ethylene / α-olefin copolymers include ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-octene copolymers, ethylene -4-methyl-pentene-1 copolymer etc. are mentioned. Of these, ethylene / 1-butene copolymer and ethylene / 1-hexene copolymer are preferable. Moreover, 1 type, or 2 or more types of combination may be sufficient as an alpha olefin. When combining two kinds of α-olefins to form a terpolymer, ethylene / propylene / 1-hexene terpolymer, ethylene / 1-butene / 1-hexene terpolymer, ethylene / propylene -1-octene terpolymer, ethylene / 1-butene / 1-octene terpolymer, etc. are mentioned.
As a comonomer, a small amount of a diene compound such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, and 1,9-decadiene may be added to the α-olefin. When these diene compounds are blended, long-chain branching is possible, so that the crystallinity of the ethylene / α-olefin copolymer is lowered, transparency, flexibility, adhesiveness, etc. are improved, and it becomes an intermolecular crosslinking agent. So the mechanical strength increases. Moreover, since the terminal group of the long chain branch is an unsaturated group, it can easily undergo a crosslinking reaction with an organic peroxide, a copolymerization reaction with an acid anhydride group-containing compound or an epoxy group-containing compound, and a graft reaction. it can.

The ethylene / α-olefin copolymer used in the present invention has an α-olefin content of 5 to 40% by weight, preferably 10 to 35% by weight, and more preferably 15 to 30% by weight. Within this range, flexibility and heat resistance are good.
Here, the content of α-olefin is a value measured by a 13C-NMR method under the following conditions.
Device: JEOL-GSX270 manufactured by JEOL
Concentration: 300 mg / 2 mL
Solvent: Orthodichlorobenzene

(Ii) Polymerization catalyst and polymerization method of component (A) The ethylene / α-olefin copolymer used in the present invention is a Ziegler catalyst, vanadium catalyst or metallocene catalyst, preferably a vanadium catalyst or metallocene catalyst, more preferably a metallocene catalyst. Can be manufactured using. Examples of the production method include a high-pressure ion polymerization method, a gas phase method, a solution method, and a slurry method. In particular, it is preferable to use a high-pressure method such as a high-pressure ion polymerization method.
Although it does not necessarily limit as a metallocene catalyst, The catalyst which uses a metallocene compound, such as a zirconium compound coordinated with the group which has a cyclopentadienyl skeleton, etc., and a promoter as a catalyst component is mentioned. In particular, it is preferable to use a metallocene compound such as a zirconium compound in which a group having a cyclopentadienyl skeleton is coordinated. Commercially available products include Harmolex (registered trademark) series, Kernel (registered trademark) series manufactured by Japan Polyethylene, Evolue (registered trademark) series manufactured by Prime Polymer, Exelen (registered trademark) GMH series manufactured by Sumitomo Chemical, Exelen (registered trademark) FX series may be mentioned. Examples of the vanadium catalyst include a catalyst having a soluble vanadium compound and an organic aluminum halide as catalyst components.

(Iii) Characteristics of component (A) (a1) Density The ethylene / α-olefin copolymer used in the present invention has a density of 0.860 to 0.920 g / cm ³ , preferably 0.870 to 0.8. It is 915 g / cm ³ , more preferably 0.875 to 0.910 g / cm ³ . When the density of the ethylene / α-olefin copolymer is less than 0.860 g / cm ³ , the processed sheet is blocked, and when the density exceeds 0.920 g / cm ³ , the processed sheet has too high rigidity. Thus, the handling property is lacking.

  In order to adjust the density of the polymer, for example, a method of appropriately adjusting the α-olefin content, the polymerization temperature, the catalyst amount and the like is employed. The density of the ethylene / α-olefin copolymer is measured according to JIS-K6922-2: 1997 appendix (in the case of low density polyethylene) (23 ° C.).

(A2) Vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted vinylene The ethylene / α-olefin copolymer used in the present invention is vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted-vinylene. The total amount must be in a certain range. Here, the number of vinyl, vinylidene, cis-vinylene, trans-vinylene, and tri-substituted vinylene is the number per 1000 carbon atoms in total of the main chain and side chain measured by NMR.
That is, in the present invention, the total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, and tri-substituted vinylene in the ethylene / α-olefin copolymer is 0.22 (pieces / total 1000C) or more. use. The total amount is preferably 0.25 or more, more preferably 0.30 or more, further preferably 0.40 or more, and particularly preferably 0.50 or more.

The amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, tri-substituted vinylene is not particularly limited. For example, vinyl is preferably 0.05 or more, vinylidene is preferably 0.05 or more, and cis-vinylene. And the total amount of trans-vinylene is preferably 0.10 or more, and tri-substituted vinylene is preferably 0.10 or more.
Since these groups have an unsaturated bond, the crosslinkability can be enhanced by a total of 0.22 or more in the ethylene / α-olefin copolymer. This effect is not greatly different depending on the type of unsaturated bond in the molecular chain, but if the amount of trisubstituted vinylene in the molecular chain is large, it can be expected that the crosslinking efficiency is further improved.

Here, the number of unsaturated bonds can be measured by H-NMR method.
The total of vinyl, vinylidene, cis-trans-vinylene, and tri-substituted vinylene in the polymer is measured by H-NMR, and is determined by the number per 1000 carbons in total of the main chain and side chain.
Specifically, the vinylidene number per 1000 carbon atoms was calculated from the ratio of the peak area derived from the saturated alkyl chain appearing between chemical shifts of 0.4 to 2.8 ppm and the peak area derived from vinylidene near 4.7 ppm. In addition, the intensity of each characteristic peak is used around 4.9 ppm for vinyl, around 5.2 ppm for trisubstituted vinylene, and around 5.4 ppm for cis and trans-vinylene.

(A3) Ratio (Mz / Mn) of Z average molecular weight (Mz) to number average molecular weight (Mn)
The ethylene / α-olefin copolymer used in the present invention has a ratio (Mz / Mn) of Z average molecular weight (Mz) to number average molecular weight (Mn) determined by gel permeation chromatography (GPC) of 8.0. Or less, preferably 5.0 or less, more preferably 4.0 or less. Moreover, Mz / Mn is 2.0 or more, preferably 2.5 or more, more preferably 3.0 or more. However, when Mz / Mn exceeds 8.0, transparency deteriorates. In order to adjust Mz / Mn to a predetermined range, a method of selecting an appropriate catalyst system can be used.

In addition, the measurement of Mz / Mn is performed by gel permeation chromatography (GPC), and the measurement conditions are as follows.
Apparatus: Waters GPC 150C type detector: MIRAN 1A infrared spectrophotometer (measurement wavelength: 3.42 μm)
Column: Showa Denko AD806M / S 3 (column calibration was measured by Tosoh monodisperse polystyrene (0.5 mg / ml solution of each of A500, A2500, F1, F2, F4, F10, F20, F40, and F288) The logarithmic value of the elution volume and molecular weight was approximated by a quadratic equation, and the molecular weight of the sample was converted to polyethylene using the viscosity equation of polystyrene and polyethylene, where the coefficient of the viscosity equation of polystyrene is α = 0.723, log K = -3.967, polyethylene is α = 0.733, log K = -3.407.)
Measurement temperature: 140 ° C
Concentration: 20 mg / 10 mL
Injection volume: 0.2ml
Solvent: Orthodichlorobenzene Flow rate: 1.0 ml / min

  Since the Z average molecular weight (Mz) greatly contributes to the average molecular weight of the high molecular weight component, Mz / Mn is easier to confirm the presence of the high molecular weight component than Mw / Mn. The high molecular weight component is a factor that affects the transparency, and when the high molecular weight component is large, the transparency is deteriorated. Moreover, the tendency for a crosslinking efficiency to deteriorate is seen. Therefore, a smaller Mz / Mn is preferable.

  In the solar cell module, the solar cell encapsulant tends to become thinner as the solar cell element becomes thinner. In the solar cell encapsulating material having a reduced thickness, when an impact is applied from the upper or lower protective material side, the wiring is easily disconnected, so that the rigidity of the encapsulating material is required to be increased. When the rigidity is increased, the crosslinking efficiency is deteriorated. Therefore, a copolymer having a high degree of branching of the polymer chain is used to improve the fluidity of the copolymer before crosslinking and to be used as a material having excellent moldability. There is a need. In the present invention, the ethylene / α-olefin copolymer has a polymer structure in which the number of unsaturated bonds is 0.22 (units / total 1000 C) or more, so that the crosslinkability is large and good.

  The ethylene / α-olefin copolymer according to the present invention can be produced by a copolymerization reaction using a catalyst as described above, but the composition ratio of raw material monomers to be copolymerized and the type of catalyst to be used are selected. Thus, the number of unsaturated bonds in the polymer chain can be easily adjusted. The use of a metallocene compound such as a zirconium compound coordinated with a group having a cyclopentadienyl skeleton or the like is preferable because a large amount of unsaturated bonds such as a terminal vinyl group and a terminal vinylidene group can be left. In order for the number of unsaturated bonds of the ethylene / α-olefin copolymer used in the present invention to be 0.22 (unit / total 1000 C) or more, the comonomer in the ethylene / α-olefin copolymer is propylene, 1- It is preferred to select from butene or 1-hexene. Moreover, it is preferable to produce using a vapor phase method or a high pressure method, and it is more preferable to select a high pressure method.

(2) Component (B)
The organic peroxide of component (B) in the present invention is mainly used for crosslinking component (A).
As the organic peroxide, an organic peroxide having a decomposition temperature (temperature at which the half-life is 1 hour) is 70 to 180 ° C., particularly 90 to 160 ° C. can be used. Examples of such organic peroxides include t-butyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-butyl peroxyacetate, t-butyl peroxybenzoate, dicumyl peroxide, 2 , 5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 1 , 1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-butylperoxy) cyclohexane, methyl ethyl ketone peroxide, 2,5-dimethylhexyl-2,5- Diperoxybenzoate, t-butyl hydroperoxide, p-menthane hydroperoxy Id, benzoyl peroxide, p- chlorobenzoyl peroxide, t- butyl peroxy isobutyrate, hydroxyheptyl peroxide, such as di-cyclohexanone peroxide.

(4) Mixing ratio of component (B) The mixing ratio of component (B) is preferably 0.2 to 5 parts by weight, more preferably 0, when component (A) is 100 parts by weight. 0.5-3 parts by weight, more preferably 1-2 parts by weight. When the blending ratio of component (B) is less than the above range, crosslinking is not performed or it takes time for crosslinking. Moreover, when larger than the said range, dispersion | distribution will become inadequate and it will be easy to become non-uniform | crosslinked.

(5) Hindered amine light stabilizer (C)
In the present invention, it is preferable to blend a hindered amine light stabilizer in the resin composition. The hindered amine light stabilizer captures radical species harmful to the polymer and prevents generation of new radicals. There are many types of hindered amine light stabilizers ranging from low molecular weight compounds to high molecular weight compounds, but any conventionally known compounds can be used without particular limitation.

  Low molecular weight hindered amine light stabilizers include decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl hydroperoxide and Consists of 70% by weight of a reaction product of octane (molecular weight 737) and 30% by weight of polypropylene; bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1 -Dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate (molecular weight 685); bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6 6-pentamethyl-4-piperidyl sebacate mixture (molecular weight 509); bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate ( 481); tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (molecular weight 791); tetrakis (1,2,2,6, 6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (molecular weight 847); 2,2,6,6-tetramethyl-4-piperidyl-1,2,3,4-butane Mixture of tetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate (molecular weight 900); 1,2,2,6,6-pentamethyl-4-piperidyl-1,2,3,4-butane Examples thereof include a mixture (molecular weight 900) of tetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate.

  As the high molecular weight hindered amine light stabilizer, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2, 2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (molecular weight 2,000-3,100); succinic acid Polymer of dimethyl and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (molecular weight 3,100 to 4,000); N, N ′, N ″, N ″ ′-tetrakis- ( 4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10- Diamine (molecular weight 2,286) and above A mixture of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol; dibutylamine, 1,3,5-triazine, N, N′-bis (2,2 , 6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (molecular weight 2,600-3) 400) and 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-acryloyloxy-1-ethyl -2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-1-propyl-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy 1-butyl-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6-pentamethyl Peridine, 4-methacryloyloxy-1-ethyl-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1-butyl-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy Examples include copolymers of cyclic aminovinyl compounds such as -2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-1-propyl-2,2,6,6-tetramethylpiperidine and ethylene. The above-mentioned hindered amine light stabilizers may be used alone or in combination of two or more.

  Among these, as the hindered amine light stabilizer, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2 , 2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (molecular weight 2,000-3,100); Polymer of dimethyl acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (molecular weight 3,100 to 4,000); N, N ′, N ″, N ″ ′-tetrakis- (4,6-Bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10 -Diamine (molecular weight 2,286) A mixture of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol; dibutylamine, 1,3,5-triazine, N, N′-bis (2 , 2,6,6-Tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (molecular weight 2,600) ~ 3,400) It is preferable to use a copolymer of a cyclic aminovinyl compound and ethylene, because the hindered amine light stabilizer is prevented from bleeding out over time when the product is used. An agent having a melting point of 60 ° C. or higher is preferably used from the viewpoint of easy preparation of the composition.

In the present invention, the content of the hindered amine light stabilizer is 0.01 to 2.5 parts by weight, preferably 0.01 to 1 part by weight based on 100 parts by weight of the ethylene / α-olefin copolymer. 0 parts by weight, more preferably 0.01 to 0.5 parts by weight, still more preferably 0.01 to 0.2 parts by weight, and most preferably 0.03 to 0.1 parts by weight.
When the content is 0.01 parts by weight or more, a sufficient stabilizing effect is obtained, and when the content is 2.5 parts by weight or less, the resin is discolored due to excessive addition of a hindered amine light stabilizer. In the present invention, the weight ratio (B: C) of the organic peroxide (B) to the hindered amine light stabilizer (C) is 1: 0.01 to 1:10. , Preferably 1: 0.02 to 1: 6.5. Thereby, it becomes possible to remarkably suppress yellowing of the resin.

(6) Crosslinking aid Further, a crosslinking aid can be blended in the resin composition of the present invention. The crosslinking aid is effective in promoting the crosslinking reaction and increasing the degree of crosslinking of the ethylene / α-olefin copolymer. Specific examples thereof include polyaryl compounds and poly (meth) acryloxy compounds. Saturated compounds can be exemplified.
More specifically, polyallyl compounds such as triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl fumarate, diallyl maleate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, etc. Examples include poly (meth) acryloxy compounds and divinylbenzene. A crosslinking adjuvant can be mix | blended in the ratio of about 0-5 weight part with respect to 100 weight part of component (A).

(7) Ultraviolet absorber An ultraviolet absorber can be mix | blended with the resin composition of this invention. Examples of the ultraviolet absorber include various types such as benzophenone, benzotriazole, triazine, and salicylic acid ester.
Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, and 2-hydroxy-4. -N-dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone 2,2-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, etc. To mention Can.

The benzotriazole ultraviolet absorber is a hydroxyphenyl-substituted benzotriazole compound, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) Benzotriazole, 2- (2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-methyl-5-t- Butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, and the like. Can be mentioned. Examples of triazine ultraviolet absorbers include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- ( And 4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol. Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate.
These ultraviolet absorbers are blended in an amount of 0 to 2.0 parts by weight, preferably 0.05 to 2.0 parts by weight, more preferably 0.1 to 1. part by weight based on 100 parts by weight of the ethylene / α-olefin copolymer. 0 parts by weight, more preferably 0.1 to 0.5 parts by weight, and most preferably 0.2 to 0.4 parts by weight.

In the resin composition of the present invention, a silane coupling agent can be used mainly for the purpose of improving the adhesive strength between the solar cell upper protective material and the solar cell element.
Examples of the silane coupling agent in the present invention include γ-chloropropyltrimethoxysilane; vinyltrichlorosilane; vinyltriethoxysilane; vinyltrimethoxysilane; vinyl-tris- (β-methoxyethoxy) silane; γ-methacryloxypropyl. Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; γ-glycidoxypropyltrimethoxysilane; vinyltriacetoxysilane; γ-mercaptopropyltrimethoxysilane; γ-aminopropyltrimethoxysilane; N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane and the like can be mentioned. Vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane are preferable.
These silane coupling agents are used in an amount of 0 to 5 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the ethylene / α-olefin copolymer. More preferably, it is used at 0.05 to 1 part by weight.

(8) Other additive components In the resin composition of the present invention, other additional optional components can be blended within a range that does not significantly impair the object of the present invention. As such optional components, antioxidants, crystal nucleating agents, clearing agents, lubricants, colorants, dispersants, fillers, fluorescent whitening agents, UV absorbers used in ordinary polyolefin resin materials, A light stabilizer etc. can be mentioned.

  Further, in order to impart flexibility and the like to the resin composition of the present invention, a crystalline ethylene / α-olefin copolymer polymerized by a Ziegler-based or metallocene-based catalyst within a range not impairing the object of the present invention. And / or rubber compounds such as ethylene / α-olefin elastomers such as EBR and EPR, or styrene elastomers such as SEBS and hydrogenated styrene block copolymers may be blended in an amount of 3 to 75 parts by weight. Furthermore, in order to give melt tension etc., 3-75 weight part of high pressure process low density polyethylene can also be mix | blended.

2. Solar cell encapsulant The solar cell encapsulant of the present invention (hereinafter also simply referred to as encapsulant) is a pelletized or sheeted product of the resin composition.
If this solar cell sealing material is used, a solar cell module can be manufactured by fixing a solar cell element with upper and lower protective materials. Examples of such solar cell modules include various types. For example, the upper transparent protective material / encapsulant / solar cell element / encapsulant / lower protective material sandwiched between the solar cell elements from both sides, formed on the inner peripheral surface of the lower substrate protective material A solar cell element formed on the inner peripheral surface of the upper transparent protective material, for example, a fluororesin-based transparent protective material. The thing of the structure which forms a sealing material and a lower protective material on what created the amorphous solar cell element by sputtering etc. can be mentioned.

  The solar cell element is not particularly limited, and is based on silicon such as single crystal silicon, polycrystalline silicon, amorphous silicon, III-V group or II-VI group such as gallium-arsenic, copper-indium-selenium, cadmium-tellurium. Various solar cell elements such as compound semiconductors can be used. In the present invention, those using glass as the substrate are preferred.

Examples of the upper protective material constituting the solar cell module include glass, acrylic resin, polycarbonate, polyester, and fluorine-containing resin.
The lower protective material is a single or multilayer sheet such as a metal or various thermoplastic resin films, for example, a metal such as tin, aluminum or stainless steel, an inorganic material such as glass, polyester, an inorganic vapor-deposited polyester, or fluorine. Examples of the protective material include a single layer or a multilayer such as a containing resin and polyolefin. Such an upper and / or lower protective material can be subjected to a primer treatment in order to enhance the adhesion to the sealing material. In the present invention, glass is preferred as the upper protective material.

  The solar cell encapsulant of the present invention may be used as a pellet, but is usually used after being formed into a sheet having a thickness of about 0.1 to 1 mm. If the thickness is less than 0.1 mm, the strength is low, and the adhesion is insufficient. A preferred thickness is 0.1 to 0.8 mm.

  The sheet-like solar cell encapsulant can be produced by a known sheet molding method using a T-die extruder, a calendar molding machine, or the like. For example, a cross-linking agent is added to an ethylene / α-olefin copolymer, and if necessary, a hindered amine light stabilizer, a cross-linking aid, a silane coupling agent, an ultraviolet absorber, an antioxidant, a light stabilizer. An additive such as an agent can be dry-blended in advance and supplied from a hopper of a T-die extruder, and extruded into a sheet at an extrusion temperature of 80 to 150 ° C. In these dry blends, some or all of the additives can be used in the form of a masterbatch. In addition, in T-die extrusion and calendering, some or all of the additive is previously melt-mixed into the amorphous α-olefin copolymer using a single screw extruder, twin screw extruder, Banbury mixer, kneader, etc. Thus obtained resin composition can also be used.

  In manufacturing the solar cell module, the sheet of the sealing material of the present invention is prepared in advance, and the above-described method is performed by pressure bonding at a temperature at which the resin composition of the sealing material melts, for example, 150 to 200 ° C. A module having a simple structure can be formed. Moreover, if the method of laminating with the solar cell element, the upper protective material or the lower protective material by extrusion coating the sealing material of the present invention is adopted, the solar cell module can be manufactured in one step without bothering to form a sheet. Is possible. Therefore, if the sealing material of this invention is used, the productivity of a module can be improved markedly.

On the other hand, when the solar cell module is manufactured, the sealing material is temporarily applied to the solar cell element or the protective material at a temperature at which the organic peroxide is not substantially decomposed and the sealing material of the present invention is melted. Adhesion is then carried out to raise the temperature, and sufficient adhesion and crosslinking of the ethylene / α-olefin copolymer can be carried out. In this case, the gel in the encapsulant layer is used in order to obtain a solar cell module with good heat resistance having a melting point (DSC method) of the encapsulant layer of 85 ° C. or higher and a storage elastic modulus of 150 ° C. of 10 ³ Pa or higher. Fraction (1 g of sample is immersed in 100 ml of xylene, heated at 110 ° C. for 24 hours, then filtered through a 20 mesh wire net and the mass fraction of unmelted portion is measured) is 50 to 98%, preferably about 70 to 95% It is better to crosslink so that

  In Patent Document 2, 100 parts by weight of an amorphous or low crystalline ethylene / butene copolymer is added to 2,5-dimethyl-2,5-di (t-butylperoxy) hexane as an organic peroxide. A mixture of 1.5 parts by weight and 2 parts by weight of triallyl isocyanurate as a crosslinking aid was produced using a profile extruder at a processing temperature of 100 ° C. and a thickness of 0.5 mm (Example 3). ). However, when such a composition is selected, sufficient productivity cannot be obtained because the processing temperature is low.

  In the sealing operation of the solar cell element, after covering the solar cell element with the sealing material of the present invention, the solar cell element is temporarily bonded by heating to a temperature at which the organic peroxide is not decomposed for several minutes to 10 minutes, In addition, there is a method in which the organic peroxide is decomposed in the oven at a high temperature of about 150 to 200 ° C. for 5 to 30 minutes to be bonded.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The evaluation methods and resins used in the examples and comparative examples are as follows.

1. Evaluation method of resin physical properties (1) Melt flow rate (MFR): MFR of ethylene / α-olefin copolymer is measured according to JIS-K6922-2: 1997 appendix (190 ° C., 21.18 N load). did.
(2) Density: As described above, the density of the ethylene / α-olefin copolymer was measured according to JIS-K6922-2: 1997 appendix (23 ° C., in the case of low density polyethylene).
(3) Mz / Mn: Measured by GPC as described above.
(4) Melt viscosity: In accordance with JIS-K-7199-1999, using Capillograph 1-B manufactured by Toyo Seiki Seisakusho, using a capillary with set temperature: 100 ° C., D = 1 mm, L / D = 10, melt viscosity at a shear rate of _{^{2.43 × 10sec -1 (η * 1}} ), to measure the melt viscosity at a shear rate of ^{2.43 × 10 2 sec -1 (η} * 2).

(5) Number of unsaturated bonds:
The total of vinyl, vinylidene, cis-trans-vinylene, and tri-substituted vinylene in the polymer was measured by H-NMR, and the total number of main chains and side chains per 1000 carbon atoms was determined.
Specifically, the vinylidene number per 1000 carbon atoms was calculated from the ratio of the peak area derived from the saturated alkyl chain appearing between chemical shifts of 0.4 to 2.8 ppm and the peak area derived from vinylidene near 4.7 ppm. The intensity of each characteristic peak was about 4.9 ppm for vinyl, about 5.2 ppm for trisubstituted vinylene, and about 5.4 ppm for cis and trans-vinylene.
Apparatus: Bruker BioSpin Corporation AVANCE III cryo-400MHz
Solvent: o-dichlorobenzene / deuterated bromobenzene = 8/2 mixed solution A 10 mmφ NMR sample tube was used, and the concentration was 460 mg / 2.3 ml.
<H-NMR measurement conditions>
Integration count: 1400scan
Flip angle: 1.03 °
AQ (loading time) = 1.8 s D1 (waiting time) = 0.01 s

2. Method for evaluating extruded product (sheet) (1) HAZE
It measured based on JIS-K7136-2000 using the press sheet of thickness 0.7mm. The press sheet piece was set in a glass cell containing special liquid paraffin made by Kanto Chemical Co., Ltd. and measured. The press sheet was stored in a hot press machine at 160 ° C. for 30 minutes, and prepared by crosslinking. The smaller the HAZE value, the better.

(2) Light transmittance It measured based on JIS-K7361-1-1997 using the press sheet of thickness 0.7mm. The press sheet piece was set in a glass cell containing special liquid paraffin made by Kanto Chemical Co., Ltd. and measured. The press sheet was stored in a hot press machine at 160 ° C. for 30 minutes, and prepared by crosslinking.
The light transmittance is 80% or more, preferably 85% or more, and more preferably 90% or more.

(3) Tensile modulus Measured according to ISO 1184-1983 using a press sheet having a thickness of 0.7 mm crosslinked at 160 ° C. for 30 minutes. The tensile elastic modulus was determined when the tensile rate was 1 mm / min, the test piece width was 10 mm, the distance between grips was 100 mm, and the elongation was 1%. It shows that it is excellent in the softness, so that this value is small.

(4) Heat resistance It evaluated by the gel fraction of the sheet | seat bridge | crosslinked at 160 degreeC and the sheet | seat bridge | crosslinked at 150 degreeC for 30 minutes. It can be evaluated that the higher the gel fraction, the more the crosslinking proceeds and the higher the heat resistance. A gel fraction having a gel fraction of 70 wt% or more was designated as a heat resistance evaluation “◯”. As for the gel fraction, about 1 g of the sheet is cut out and weighed accurately, immersed in 100 cc of xylene, treated at 110 ° C. for 24 hours, the residue after filtration is dried and weighed, and divided by the weight before treatment. Calculate the gel fraction.

3. Raw Material Used (1) Component (A): Ethylene / α-Olefin Copolymer Ethylene and 1-hexene copolymer (PE-1) polymerized in the following <Production Example 1>, polymerized in <Production Example 2> Copolymer of ethylene and 1-hexene (PE-2), commercially available ethylene / 1-butene copolymer “Tafmer A35070S manufactured by Mitsui Chemicals” (PE-3), ethylene / 1-octene copolymer “Dow” Engage 8400 "(PE-4) manufactured by the company was used. The physical properties are shown in Table 1.
(2) Organic peroxide: 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (manufactured by Arkema Yoshitomi, Luperox 101)
(3) Hindered amine light stabilizer: polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (manufactured by BASF, TINUVIN 622LD)
(4) UV absorber: 2-hydroxy-4-n-octoxybenzophenone (manufactured by Sun Chemical Co., Ltd., CYTEC UV531)

<Production Example 1>
(I) Preparation of catalyst A catalyst for producing a copolymer of ethylene and 1-hexene was prepared by the method described in JP-T-7-508545. That is, to the complex dimethylsilylene bis (4,5,6,7-tetrahydroindenyl) hafnium dimethyl 2.0 mmol, tripentafluorophenyl boron is added in an equimolar amount to the complex, and diluted to 10 liters with toluene. A catalyst solution was prepared.
(Ii) Polymerization Using a stirred autoclave type continuous reactor having an internal volume of 1.5 liters, maintaining the pressure in the reactor at 130 MPa, a mixture of ethylene and 1-hexene has a composition of 1-hexene of 75% by weight. The raw material gas was continuously supplied at a rate of 40 kg / hour. Further, the catalyst solution was continuously supplied, and the supply amount was adjusted so that the polymerization temperature was maintained at 150 ° C. The polymer production per hour was about 4.3 kg. After completion of the reaction, an ethylene / 1-hexene copolymer (PE-) having a 1-hexene content of 24% by weight, an MFR of 35 g / 10 min, a density of 0.880 g / cm ³ , and Mz / Mn of 3.7. 1) was obtained.
Furthermore, PE-1 to 160 ℃ -0kg / cm ^{3 3} minutes preheat, 160 ℃ -100kg / cm ³ 5 min pressure, then under the conditions of 100 kg / cm ³ to a cooling press set to 30 ° C., 10 minutes A 0.7 mm thick press sheet was obtained by cooling. The tensile elastic modulus was measured according to ISO 1184-1983, and as a result, it was 17 MPa.
The characteristics of this ethylene / 1-hexene copolymer (PE-1) are shown in Table 1.

<Production Example 2>
In Production Example 1, polymerization was carried out by the same production method as in Production Example 1 except that the composition of 1-hexene at the time of polymerization was 71% by weight and the polymerization temperature was changed to 157 ° C. The polymer production per hour was about 4.0 kg. After completion of the reaction, an ethylene / 1-hexene copolymer (PE-) having 1-hexene content = 19 wt%, MFR = 30 g / 10 min, density = 0.890 g / cm ³ , and Mz / Mn = 3.7 2) was obtained. As a result of measuring the tensile modulus in the same manner as in Production Example 1, it was 34 MPa. The characteristics of this ethylene / 1-hexene copolymer (PE-2) are shown in Table 1.

Example 1
2,5-dimethyl-2,5-di (t-butylperoxy) hexane (Arkema Yoshitomi Co., Ltd.) as an organic peroxide with respect to 100 parts by weight of a copolymer of ethylene and 1-hexene (PE-1) Manufactured by Lupelox 101) and a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (BASF) as a hindered amine light stabilizer. 0.05% by weight of TINUVIN 622LD). This was thoroughly mixed and pelletized using a 40 mmφ single screw extruder under conditions of a set temperature of 130 ° C. and an extrusion rate (17 kg / hour).
The resulting sheets, at the 160 ℃ -0kg / cm ² conditions, after 3 minutes preheat, 160 ℃ -100kg / cm (30 minutes press molding at 160 ° C.) 27 minutes pressurization at ² conditions, and then, A sheet having a thickness of 0.7 mm was produced by cooling for 10 minutes in a cooling press set to 30 ° C. under a pressure of 100 kg / cm ² . The sheet was measured for HAZE, light transmittance, tensile modulus, and heat resistance.
Separately for evaluation of heat resistance, under the condition of 150 ℃ -0kg / cm ^2, after 3 minutes preheat, 150 ℃ -100kg / cm (30 minutes press molding at 0.99 ° C.) in 27 min pressurized ^second condition and Then, a sheet having a thickness of 0.7 mm was prepared by cooling for 10 minutes on a cooling press set to 30 ° C. under a pressure of 100 kg / cm ² .
The evaluation results are shown in Table 2.

(Example 2)
In Example 1, a sheet was produced in the same manner as in Example 1 except that PE-2 was used instead of PE-1. The sheet was measured for HAZE, light transmittance, tensile modulus, and heat resistance. The evaluation results are shown in Table 2.

(Example 3)
In Example 1, a sheet was prepared in the same manner as in Example 1 except that 0.3 part of 2-hydroxy-4-n-octoxybenzophenone (CYTEC UV531 manufactured by Sun Chemical Co., Ltd.) was further added as an ultraviolet absorber. did. The sheet was evaluated for HAZE, light transmittance, tensile modulus, and heat resistance. The evaluation results are shown in Table 2.

(Comparative Example 1)
Example 3 was used in the same manner as in Example 1 except that PE-3 (ethylene / 1-butene copolymer, Tuffmer A35070S manufactured by Mitsui Chemicals, Inc.) was used instead of the copolymer of ethylene and 1-hexene (PE-1). A sheet was produced. The sheet was evaluated for HAZE, light transmittance, tensile modulus, and heat resistance. The evaluation results are shown in Table 2.

(Comparative Example 2)
A sheet was prepared in the same manner as in Example 1 except that PE-4 (ethylene / 1-octene copolymer, Dow Engage 8400) was used instead of PE-1. The sheet was evaluated for HAZE, light transmittance, tensile modulus, and heat resistance. The evaluation results are shown in Table 2.

"Evaluation"
As a result, as is apparent from Table 2, in Examples 1 to 3, since the resin composition of the present invention was used, the sheet obtained by extrusion molding had good cross-linking properties and HAZE Small, high light transmittance, and excellent heat resistance.
On the other hand, in Comparative Example 1, unlike the present invention, an ethylene / 1-butene copolymer having a total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, and tri-substituted vinylene of less than 0.22 is used. Since the containing resin composition was used, the crosslinking efficiency was poor, and the obtained sheet was inferior in heat resistance. Since the comparative example 2 also used the resin composition containing the ethylene / 1-octene copolymer deviating from the present invention, the crosslinking efficiency was poor, and the resulting sheet was inferior in heat resistance.

The resin composition for a solar cell encapsulant of the present invention is preferably used as a solar cell encapsulant because it has high crosslinking properties and is excellent in transparency, flexibility, heat resistance and the like. It is particularly useful as a sealing material for thin film solar cells, ICs (integrated circuits), and solar cell modules.

Claims (8)

The resin composition for solar cell sealing materials characterized by containing the following component (A) and a component (B).
Component (A): ethylene / α-olefin copolymer (a1) having the following characteristics (a1) to (a2): Density of 0.860 to 0.920 g / cm ³
(A2) The total amount of vinyl, vinylidene, cis-vinylene, trans-vinylene, trisubstituted-vinylene in the ethylene / α-olefin copolymer is 0.22 (total / total 1000 C) or more (however, vinyl, vinylidene, cis -The number of vinylene, trans-vinylene, and tri-substituted vinylene is the number per 1000 carbon atoms in total of the main chain and side chain measured by NMR.
Component (B): Organic peroxide The resin composition for a solar cell sealing material according to claim 1, wherein the component (A) is an ethylene / α-olefin copolymer further having the following property (a3).
(A3) The ratio (Mz / Mn) of the Z average molecular weight (Mz) and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC) is 8.0 or less.   Content of a component (B) is 0.2-5 weight part with respect to 100 weight part of a component (A), The resin composition for solar cell sealing materials of Claim 1 or 2 characterized by the above-mentioned. object. Furthermore, the following component (C) is contained, The resin composition for solar cell sealing materials in any one of Claims 1-3 Component (C): A hindered amine light stabilizer   Content of a component (C) is 0.01-2.5 weight part with respect to 100 weight part of components (A), The resin composition for solar cell sealing materials of Claim 4 characterized by the above-mentioned. object.   The resin composition for a solar cell encapsulant according to any one of claims 1 to 5, wherein the component (A) is ethylene / 1-butene or ethylene / 1-hexene copolymer.   The solar cell sealing material which consists of a resin composition for solar cell sealing materials in any one of Claims 1-6.   The solar cell module using the solar cell sealing material of Claim 7.