WO2012050093A1 - Resin composition having excellent transparency and moisture prevention properties, and sheet obtained by molding same - Google Patents

Abstract

To provide a novel resin composition which is capable of providing a sheet that is obtained by molding the resin composition with sufficient transparency and moisture prevention properties. The resin composition contains a metallocene ethylene polymer (A) that has a density of 0.936-0.948 g/cm³ and a crystal melting enthalpy of 150-200 J/g and a crystal nucleator (B), and is characterized in that the ratio of the component (B) in the total amount of the components (A) and (B) contained therein is 0.01-3% by mass.

Description

Resin composition excellent in transparency and moisture resistance, and sheet formed by molding the same

The present invention relates to a resin composition that can be suitably used for applications requiring transparency and moisture resistance, and a sheet formed by molding the resin composition.

Conventionally, polyvinyl chloride (hereinafter sometimes referred to as “PVC”) is mainly used as the main material for sheets that require thermoformability, rigidity, impact resistance, moisture resistance, and transparency. I came. However, PVC is considered to be an alternative material for PVC because hydrogen chloride gas generated during combustion may deteriorate the combustion furnace or the hydrogen chloride gas may pollute the environment.

As such an alternative material for PVC, linear low density polyethylene, high density polyethylene, polypropylene and the like have been proposed.
However, although the linear low density polyethylene is excellent in transparency, the moisture resistance is not sufficient, and it is difficult to say that it is an optimal resin from the viewpoint of the stability of the contents during long-term storage.
Although polypropylene is superior in moisture resistance as compared to linear low density polyethylene, it has a problem that it does not have sufficient moisture resistance for use in applications where higher moisture resistance is required.

On the other hand, high-density polyethylene has a problem that it is inferior in transparency although it is superior in moisture-proofing properties to linear low-density polyethylene and polypropylene.
Therefore, in order to improve the transparency of the high density polyethylene, Patent Document 1 discloses a resin composition obtained by blending a high density polyethylene having a density of 0.942 to 0.965 g / cm ³ with a nucleating agent. It is disclosed. Patent Document 2 discloses a resin composition comprising a high density polyethylene having a density of 0.94 to 0.97 g / cm ³ and an alicyclic saturated hydrocarbon resin containing no polar group. ing.

JP 2001-192513 A JP 2007-137968 A

As in Patent Document 1, even when a nucleating agent is blended with high-density polyethylene, it is difficult to obtain sufficient transparency when the sheet is molded.
In addition, as described in Patent Document 2, by blending high-density polyethylene with an alicyclic saturated hydrocarbon resin that does not contain a polar group, moisture resistance is slightly improved, but sufficient transparency is obtained when the sheet is molded. It was difficult to get.

Accordingly, an object of the present invention is to provide a new resin composition capable of imparting sufficient transparency and moisture resistance when formed into a sheet, in view of such problems of the prior art.

The present invention relates to a resin composition comprising a metallocene ethylene polymer (A) having a density of 0.936 to 0.948 g / cm ³ and a heat of crystal fusion of 150 to 200 J / g, and a crystal nucleating agent (B). The present invention proposes a resin composition characterized in that the ratio of (B) in the total content of (A) and (B) is 0.01 to 3.0% by mass.

According to the resin composition of the present invention, sufficient transparency and moisture resistance can be imparted when the sheet is molded. Therefore, transparency and moisture resistance are required, for example, for packaging materials such as pharmaceuticals and sweets. It can be used as a packaging material. Further, it can be particularly suitably used as a protective material for an electronic device such as a solar cell encapsulant that requires high transparency and moisture resistance.

<This resin composition>
Hereinafter, a resin composition (referred to as “the present resin composition”) as an example of an embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.

This resin composition is a resin composition containing a metallocene ethylene-based polymer (A) and a crystal nucleating agent (B). If necessary, an olefin-compatible resin (C), an olefin-based resin ( It is a resin composition containing D).

[Metalocene ethylene polymer (A)]
It is important that the ethylene polymer used in the resin composition is a metallocene ethylene polymer (A), that is, an ethylene polymer that is polymerized using a metallocene catalyst.

Examples of the metallocene catalyst include a single site catalyst in which a metallocene compound and methylaluminoxane are combined.
Features of an ethylene polymer that is polymerized using a metallocene catalyst, that is, a metallocene ethylene-based polymer, include a narrow molecular weight distribution and a low heat of crystal melting even at the same density.

From these characteristics, the metallocene ethylene polymer (A) has a molecular weight distribution index (Mw / Mn) of 2.5 to 4.5, particularly 2.6 or more, 4.3 or less, especially 3.0 or more or It is preferably 4.0 or less. Thus, by adding a nucleating agent to an ethylene polymer having a narrow molecular weight distribution, the transparency and moisture resistance when the sheet is formed can be further increased.

The lower limit of the density of the metallocene ethylene polymer (A) is 0.932 g / cm ³ , preferably 0.936 g / cm ³ , more preferably 0.938 g / cm ³ , and more preferably 0.8. It is 940 g / cm ³ , more preferably 0.941 g / cm ³ . The upper limit is preferably 0.948 g / cm ³ , more preferably 0.947 g / cm ³ , and still more preferably 0.942 g / cm ³ . From the above, the density of the metallocene ethylene-based polymer (A) in the present invention is preferably 0.936 ~ 0.948g / cm ^3, particularly preferably 0.941 ~ 0.948g / cm ³ .
It is important that the heat of crystal melting of the metallocene ethylene polymer (A) is 150 to 200 J / g, particularly 155 J / g or more or 190 J / g or less, and among them, 160 J / g or more or 185 J / g. It is preferable that:
If the density and heat of crystal fusion of the metallocene ethylene polymer (A) are within such ranges, both transparency and moisture resistance can be improved when the sheet is formed.

The crystallization peak temperature (Tc) of the metallocene ethylene polymer (A) is preferably 105 to 130 ° C., more preferably 110 ° C. or more and 125 ° C. or less, particularly 112 ° C. or more and 120 ° C. or less. Is preferred.
When the crystallization peak temperature (Tc) of the metallocene ethylene polymer (A) is within the above range, the crystallization rate is sufficiently high, fine crystals can be formed, and a resin composition excellent in transparency can be obtained. Therefore, it is preferable.

The metallocene ethylene polymer (A) may be an ethylene homopolymer, or may be a copolymer of ethylene and an α-olefin. Moreover, these mixtures can be used. Among these, an ethylene homopolymer or a copolymer of ethylene with at least one α-olefin of butene-1, hexene-1 and octene-1, specifically ethylene Copolymer of butene-1, copolymer of ethylene and hexene-1, copolymer of ethylene and octene-1, copolymer of ethylene, butene-1 and hexene-1, ethylene and butene- It is preferable to use a copolymer of 1 and octene-1, a copolymer of ethylene, hexene-1 and octene-1, or a copolymer of ethylene, butene-1, hexene-1 and octene-1. preferable.

When a copolymer of ethylene and α-olefin is used, the total content of butene-1, hexene-1 and octene-1 in the metallocene ethylene polymer (A) is 0.1 to 3.0. It is preferable that it is mass%, and it is more preferable that it is 0.3 mass% or more or 2.8 mass% or less among these, and 0.5 mass% or more or 2.6 mass% or less is especially preferable. If the α-olefin is within such a range, a resin composition having excellent transparency and moisture resistance can be provided.
A preferred example of the metallocene ethylene polymer (A) is a polymer composed of ethylene, butene-1 and octene-1, and the proportion of butene-1 in the metallocene ethylene polymer (A) is 0.00. 1 to 2.0% by mass, a polymer having a ratio of octene-1 of 0.1 to 2.0% by mass, or a polymer composed of ethylene, hexene-1 and octene-1, and A polymer in which the proportion of hexene-1 in the metallocene ethylene polymer (A) is 0.1 to 2.0% by mass and the proportion of octene-1 is 0.1 to 2.0% by mass is given. be able to.

[Crystal nucleating agent (B)]
The kind of the crystal nucleating agent (B) used in the resin composition is not particularly limited as long as the effect of improving the transparency of the metallocene ethylene polymer (A) is recognized. For example, dibenzylidene sorbitol (DBS) compound, 1,3-O-bis (3,4 dimethyl benzylidene) sorbitol, dialkyl benzylidene sorbitol, diacetal of sorbitol having at least one chlorine or bromine substituent, di (methyl or ethyl substituted benzylidene) ) Sorbitol, bis (3,4-dialkylbenzylidene) sorbitol having substituents forming a carbocycle, aliphatic, alicyclic, and aromatic carboxylic acids, dicarboxylic acids or polybasic polycarboxylic acids, corresponding anhydrides Metal salts of organic acids such as organic and metal salts, bicyclic dicarboxylic acids and salt compounds such as cyclic bis-phenol phosphate, disodium bicyclo [2.2.1] heptene dicarboxylic acid, bicyclo [2.2 .1] Heptane-dicarboxylate Bicyclic dicarboxylate saturated metal or organic salt compounds such as 1,3: 2,4-O-dibenzylidene-D-sorbitol, 1,3: 2,4-bis-O- (m- Methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-ethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-isopropylbenzylidene)- D-sorbitol, 1,3: 2,4-bis-O- (mn-propylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (mn-butylbenzylidene)- D-sorbitol, 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- p-isopropylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-propylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p- n-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,3-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2, 4-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,5-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3 4-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,5-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2, 3-Diethylbenzylidene) -D-sorbite 1,3: 2,4-bis-O- (2,4-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,5-diethylbenzylidene) -D -Sorbitol, 1,3: 2,4-bis-O- (3,4-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,5-diethylbenzylidene) -D -Sorbitol, 1,3: 2,4-bis-O- (2,4,5-trimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4,5-trimethyl Benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,4,5-triethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4 , 5-triethylbenzylidene) -D-sorbitol, 1,3: 2, -Bis-O- (p-methyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4 -Bis-O- (p-isopropyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (on-propyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2 , 4-Bis-O- (on-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-chlorobenzylidene) -D-sorbitol, 1,3: 2,4 -Bis-O- (p-chlorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O-[(5,6,7,8, -tetrahydro-1-naphthalene) -1-methylene] - -Sorbitol, 1,3: 2,4-bis-O-[(5,6,7,8, -tetrahydro-2-naphthalene) -1-methylene] -D-sorbitol, 1,3-O-benzylidene- 2,4-Op-methylbenzylidene-D-sorbitol, 1,3-Op-methylbenzylidene-2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4- Op-ethylbenzylidene-D-sorbitol, 1,3-Op-ethylbenzylidene-2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-Op- Chlorbenzylidene-D-sorbitol, 1,3-Op-chlorobenzylidene-2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (2,4-dimethyl Nylidene) -D-sorbitol, 1,3-O- (2,4-dimethylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (3 , 4-Dimethylbenzylidene) -D-sorbitol, 1,3-O- (3,4-dimethylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-Op-methyl-benzylidene- 2,4-Op-ethylbenzylidenesorbitol, 1,3-p-ethyl-benzylidene-2,4-p-methylbenzylidene-D-sorbitol, 1,3-Op-methyl-benzylidene-2,4 Dia such as —Op-chlorobenzylidene-D-sorbitol, 1,3-Op-chloro-benzylidene-2,4-Op-methylbenzylidene-D-sorbitol Tar compounds, sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate, aluminum bis [2,2'-methylene-bis- (4-6-di-tert-butylphenyl) ) Phosphate], sodium 2,2-methylenebis (4,6-di-tert-butylphenyl) phosphate, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic Acids, fatty acids such as pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, montanic acid, fatty acid amides such as oleic acid amide, erucic acid amide, stearic acid amide, hebenic acid amide, stearin Magnesium oxide, zinc stearate, calcium stearate Fatty acid metal salts such beam, silica, talc, kaolin, inorganic particles such as calcium carbonate, glycerol, can be mentioned higher fatty acid esters such as glycerin monoesters, and the like.

Among these, fatty acid amides such as oleic acid amide, erucic acid amide, stearic acid amide and hebenic acid amide, and fatty acid metal salts such as magnesium stearate, zinc stearate and calcium stearate are particularly preferable.

As specific examples of the crystal nucleating agent (B), the product name “Gelall D” series of Shin Nippon Rika Co., Ltd., the product name “Adeka Stub” series of ADEKA Co., Ltd., the product name “Millad” series of Milliken Chemical Co., Ltd., "Hyperform" series, BASF's product name "IRGACLEAR" series, etc., and as a master batch of crystal nucleating agent, Riken Vitamin Co., Ltd. product name "Rike Master CN" series, Miliken Chemical's product name " HL3-4 "and the like. Among these, the products with the highest effect of improving the transparency are the product names of Milliken Chemicals “HYPERFORM HPN-20E” and “HL3-4”, and the product names of Riken Vitamin Co., Ltd. “Rike Master CN-001” “Rike Master CN-002 ”.

Regarding the content of the crystal nucleating agent (B), the proportion of (B) in the total content of the metallocene ethylene polymer (A) and the crystal nucleating agent (B) is 0.01 to 3.0% by mass. Of these, 0.03% by mass or more or 2.0% by mass or less is more preferable, and among them, 0.05% by mass or more or 1.0% by mass or less is even more preferable. By blending the crystal nucleating agent (B) within such a range, the transparency and moisture resistance can be effectively further improved without causing a decrease in transparency due to excessive addition of the crystal nucleating agent.

[Olefin compatible resin (C)]
The moisture-proof property can be further improved by blending the olefin-compatible resin (C) with the resin composition.

The olefin compatible resin (C) is preferably a resin that is compatible with an olefin resin, particularly a metallocene ethylene polymer (A) and has a glass transition temperature higher than that of the metallocene ethylene polymer (A). . Examples thereof include one resin or two or more resins selected from the group consisting of petroleum resins, terpene resins, coumarone-indene resins, rosin resins, and hydrogenated derivatives thereof.

Examples of the petroleum resin include alicyclic petroleum resin from cyclopentadiene or its dimer, aromatic petroleum resin from C9 component, and the like.
Examples of the terpene resin include terpene-phenol resin from β-pinene.
Examples of the coumarone-indene resin include a coumarone-indene copolymer and a coumarone-indene-styrene copolymer.
Examples of the rosin resin include rosin resins such as gum rosin and wood rosin, and esterified rosin resins modified with glycerin, pentaerythritol, and the like.

The olefin-compatible resin (C) is a hydrogenated derivative, particularly a hydrogenation rate (hereinafter referred to as “water”) from the viewpoint of compatibility, color tone, thermal stability and the like when mixed with the metallocene ethylene polymer (A). The ratio of the unsaturated double bond of the conjugated diene based on the phenyl group, which may be abbreviated as “addition rate”, which is sometimes abbreviated as “addition rate”) is 95% or more, and is a hydroxyl group, carboxyl group, halogen It is preferable to use a hydrogenated petroleum resin or a hydrogenated terpene resin that substantially does not contain an unsaturated bond such as a polar group or a double bond.

In this resin composition, the softening temperature Ts (C) measured in accordance with JIS K2207 of the olefin compatible resin (C) is a differential measured in accordance with JIS K7121 of the metallocene ethylene polymer (A). The crystallization peak temperature Tc (A) measured at a cooling rate of 10 ° C./min in scanning calorimetry Tc (A) + 30 ° C. or less, that is, if the crystallization peak temperature Tc (A) is 100 ° C., it is preferably 130 ° C. or less. The Tc (A) + 20 ° C. or lower is more preferable, the Tc (A) + 10 ° C. or lower is more preferable, and the Tc (A) + 5 ° C. or lower is particularly preferable. The lower limit of Ts (C) is preferably 80 ° C.
Since the upper limit of the softening temperature Ts (C) satisfies this condition, the olefin-compatible resin (C) has a high degree of molecular chain freedom in the crystallization process of the metallocene ethylene-based polymer (A). It is preferable because crystallization of the polymer (A) is hardly inhibited, fine crystals are formed, and a resin composition excellent in moisture resistance and transparency can be obtained.
Further, when the softening temperature Ts (C) of the olefin compatible resin (C) is 80 ° C. or higher, preferably 90 ° C. or higher, blocking of raw materials during molding, secondary processing, transportation, use Is preferable because bleeding out to the surface of the resin composition hardly occurs.
The softening temperature Ts (C) of the olefin-compatible resin (C) can be obtained mainly by selecting the molecular weight.

Specific examples of the olefin compatible resin (C) include, for example, Mitsui Chemical Co., Ltd., trade names “Hi-Lets” series, “Petrogin” series, Arakawa Chemical Industries, Ltd., trade names “Arcon” series, Yasuhara Chemical Co., Ltd. ) Product name “Clearon” series, Idemitsu Kosan Co., Ltd. product name “Imabe” series, Tonex Co., Ltd. product name “Escollet” series.

The content of the olefin compatible resin (C) is preferably 5 to 30% by mass in the present resin composition, more preferably 10% by mass or more and 25% by mass or less, and more preferably 15% by mass or more. Or it is still more preferable that it is a ratio of 20 mass% or less. By blending the (C) within such a range, moisture resistance can be further improved without causing bleeding of the surface of the molded product of the (C), a decrease in mechanical properties, and the like.

[Olefin resin (D)]
Transparency can be further improved by blending the specific olefin resin (D) with the resin composition.

As the olefin resin (D), from the viewpoint of improving transparency, an olefin resin having a heat of crystal fusion of 0 to 100 J / g, particularly 80 J / g or less, and more preferably 50 J / g or less is preferable.

Examples of the olefin resin (D) include linear low density polyethylene made of a copolymer of ethylene and α-olefin, polypropylene resin, and cyclic olefin resin. Among these, it is particularly preferable to use a cyclic olefin resin. By using a cyclic olefin resin as the olefin resin (D), the transparency can be improved without substantially reducing the moisture resistance.

Examples of the cyclic olefin-based resin include (i) a polymer obtained by hydrogenating a ring-opening (co) polymer of a cyclic olefin as necessary, (ii) an addition (co) polymer of a cyclic olefin, and (iii) a cyclic olefin Random copolymers with α-olefins such as ethylene and propylene, (iv) The above (i) to (iii) are unsaturated such as maleic anhydride, maleic acid, itaconic anhydride, itaconic acid, (meth) acrylic acid, etc. Examples thereof include graft copolymers modified with a carboxylic acid or anhydride modifier. These may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the cyclic olefin resin is preferably 50 to 110 ° C., more preferably 60 to 90 ° C., and further preferably 65 to 85 ° C. Here, it is preferable that the glass transition temperature (Tg) is within the above range because the transparency of the resin composition of the present invention can be improved without significantly reducing the heat resistance and workability.

Since the cyclic olefin-based resin has low compatibility with the metallocene ethylene-based polymer (A), in consideration of transparency, the average refractive index at room temperature is preferably 1.510 to 1.540. The absolute value of the difference from the average refractive index of the metallocene ethylene polymer (A) used is preferably 0.010 or less, more preferably 0. 0.005 or less, and more preferably 0.003 or less.
If the absolute value of the average refractive index difference is within this range, it is preferable because the transparency can be improved without being greatly influenced by the dispersion diameter of the cyclic olefin resin in the resin composition. The average refractive index can be measured using a known method, for example, an Abbe refractometer.

As specific examples of the olefin resin (D), as the linear low density polyethylene, Ube Maruzen Polyethylene Co., Ltd. trade name “Umerit” series, Nihon Unicar Co., Ltd. trade name “NUC polyethylene” series, etc. Can be mentioned.
Examples of the polypropylene resin include a trade name “Novatech PP” series of Nippon Polypro Co., Ltd. and a trade name “Nobrene” series of Sumitomo Chemical Co., Ltd.
Examples of the cyclic olefin-based resin include the product name “TOPAS” series of Polyplastics Co., Ltd., the product name “Apel” series of Mitsui Chemicals, Inc., and the product name “ZEONOR” series of Nippon Zeon Co., Ltd. be able to.
The olefin-based resin (D) may be either a single resin or a mixture of a plurality of resins.

The content of the olefin resin (D) is preferably 10 to 50% by mass in the resin composition from the viewpoint of further improving transparency without impairing moisture resistance. It is more preferably 20% by mass or more or 45% by mass or less, and more preferably 25% by mass or more or 30% by mass or less.

[Other ingredients]
In addition, the resin composition includes additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial / antifungal agent, an antistatic agent, and a lubricant as long as the effects of the present invention are not impaired. Can be blended.

[Sheet using the present resin composition]
Next, the manufacturing method of the sheet | seat using this resin composition is demonstrated.

The method for forming a sheet using the resin composition is not particularly limited. For example, metallocene ethylene polymer (A), crystal nucleating agent (B), olefin-compatible resin (C), olefin resin (D) and other additives, if necessary, uniaxial or biaxial extrusion An unstretched sheet can be produced by melt-mixing with a machine or the like, extruding with a T-die, quenching with a cast roll, and solidifying.
Here, the unstretched sheet means a sheet that is not actively stretched for the purpose of increasing the strength of the sheet. For example, a sheet that has been stretched to less than 2 times by a stretching roll during extrusion molding is included in the unstretched sheet. Shall be.

At this time, the thickness of the sheet is not particularly limited, but considering workability and practicality, it is preferably 0.01 mm or more and 3 mm or less, and 0.05 mm or more and 2.5 mm or less. More preferably, it is 0.1 mm or more and 2.0 mm or less. Within such a range, the rigidity of the sheet can be made necessary and sufficient, the secondary workability is not inferior, and the handling property when used as various packaging materials does not become a problem, and the transparency. Can also be secured.

In addition, for the purpose of further improving the heat resistance, various mechanical properties, and moisture resistance of the unstretched sheet, a plurality of sheets made of the resin composition are laminated by a method such as coextrusion, extrusion lamination, thermal lamination, and dry lamination. Or resin compositions other than the resin composition of the present invention (for example, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polypropylene resins, mixtures of polypropylene resins and petroleum resins, polystyrene resins) One or more layers can be laminated on one or both sides of a sheet formed by molding the resin composition. In addition, for the purpose of further improving the heat resistance and moisture resistance of the non-stretched sheet or the laminated sheet, it can be stretched uniaxially or biaxially using a roll method, a tenter method, a tubular method, or the like.

When this resin composition is used for various packaging materials, the internal haze is measured based on JIS K7105 when it is formed into a sheet with a thickness of 0.1 mm from the viewpoints of design properties, contents visibility, and the like. Is preferably 10% or less, more preferably 9% or less, and even more preferably 8% or less. If it is the range which concerns on an internal haze, sufficient visibility will be acquired and the product excellent in the designability can be obtained.

Sheets formed by molding this resin composition can be formed into molded products of various shapes by vacuum molding, pressure molding, pressure vacuum molding, press molding, and other thermoforming, and other resins, metals, glass, etc. It can also be used in multiple layers. Since the sheet formed by molding the resin composition has excellent transparency and moisture resistance, it is used in applications requiring transparency and moisture resistance in various fields, for example, medical, food, electronic equipment and energy fields. It can be preferably used.

In addition, for the purpose of improving the designability and secondary processability of the product, the sheet surface may be processed such as embossing or matting. In this case, even if a mirror-like sheet is once produced and processed with an embossing roll or a matte roll, the cast roll is changed to an embossing roll or a matte roll during extrusion molding. May be. As long as the gist of the present invention is not impaired, the surface of the sheet may be coated with an antistatic agent, silicone, wax, etc., a film may be formed using a surface protective sheet for the purpose of preventing the adhesion of scratches, or a printing layer may be provided. Is also possible. In addition, a well-known arbitrary means is employable as a formation means of a printing layer.

<Encapsulant for solar cell>
The sheet | seat using this resin composition can be used as a sealing material for solar cells.
The solar cell encapsulant in the present invention can be used as a single layer of a sheet using the present resin composition or as a multilayer body laminated with other layers.
When used as a multilayer body, the other layers laminated with the sheet made of the resin composition (hereinafter sometimes referred to as the resin layer (II)) are not particularly limited, but have sealing properties, heat resistance, and transparency. Therefore, the resin layer (I) containing an ethylene-based resin is preferable.
In particular, the resin layer (I) containing an ethylene-based resin is preferably the following resin layer (I) -1 and / or the following resin layer (I) -2, and has this as at least one of the outermost layers. It is preferable to use as a solar cell sealing multilayer body.
Resin layer (I) -1: an ethylene-α-olefin random copolymer (P) that satisfies the following conditions (a) and an ethylene-α-olefin block copolymer that satisfies the following conditions (b) ( Resin layer containing Q) Resin layer (I) -2: Resin layer containing silane-modified ethylene resin (X) (a): Heat of crystal melting measured at a heating rate of 10 ° C./min in differential scanning calorimetry 0 ~ 70J / g
(B): The crystal melting peak temperature measured at a heating rate of 10 ° C./min in differential scanning calorimetry is 100 to 145 ° C., and the crystal melting heat amount is 5 to 70 J / g.

Due to the above multi-layer structure, the present invention provides moisture resistance sufficient for protection of solar cell elements, excellent transparency and heat resistance, and excellent sealing properties when manufacturing solar cell modules, and handling properties at room temperature. It is possible to provide a solar cell sealing multi-layer body having rigidity for imparting a solar cell module and a solar cell module manufactured using the same.

[Resin layer (I) -1]
Resin layer (I) -1 includes an ethylene-α-olefin random copolymer (P) satisfying the condition (a) and an ethylene-α-olefin block copolymer satisfying the condition (b). (Q) is contained, and the role which expresses the outstanding transparency for providing the outstanding sealing performance, heat resistance for protecting mainly a solar cell element (cell), and sufficient power generation efficiency to a solar cell. Have

(Ethylene-α-olefin random copolymer (P))
The ethylene-α-olefin random copolymer (P) used in the present invention is not particularly limited as long as the above condition (a) is satisfied. Usually, ethylene and an α-olefin having 3 to 20 carbon atoms are used. These random copolymers are preferably used. Examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 3-methyl-butene. -1,4-methyl-pentene-1, etc. In the present invention, propylene, 1-butene, 1-hexene, and 1-octene are preferably used as the α-olefin copolymerized with ethylene from the viewpoints of industrial availability, various characteristics, and economical efficiency. It is done. The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

Further, the content of the α-olefin copolymerized with ethylene is not particularly limited as long as the above condition (a) is satisfied. However, the content of all units in the ethylene-α-olefin random copolymer (P) is not limited. It is usually 2 mol% or more, preferably 40 mol% or less, more preferably 3 to 30 mol%, still more preferably 5 to 25 mol%, based on the monomer unit. Within this range, the crystallinity is reduced by the copolymerization component, so that the transparency is improved and problems such as blocking of the raw material pellets are less likely to occur. The type and content of the α-olefin copolymerized with ethylene can be qualitatively and quantitatively analyzed by a known method, for example, a nuclear magnetic resonance (NMR) measuring device or other instrumental analyzer.

The ethylene-α-olefin random copolymer (P) may contain monomer units based on monomers other than α-olefin as long as the condition (a) is satisfied. Examples of the monomer include cyclic olefins, vinyl aromatic compounds (such as styrene), polyene compounds, and the like. The content of the monomer units is 20 mol% or less and 15 mol% or less, assuming that all monomer units in the ethylene-α-olefin random copolymer (P) are 100 mol%. It is preferable. Further, the steric structure, branching, branching degree distribution and molecular weight distribution of the ethylene-α-olefin random copolymer (P) are not particularly limited as long as the above condition (a) is satisfied. A copolymer having a branch generally has good mechanical properties, and has an advantage that the melt tension (melt tension) at the time of molding a sheet is increased and the calendar moldability is improved. A copolymer having a narrow molecular weight distribution polymerized using a single site catalyst has advantages such as a low molecular weight component and a relatively low blocking of raw material pellets.

The melt flow rate (MFR) of the ethylene-α-olefin random copolymer (P) used in the present invention is not particularly limited, but is usually MFR (JIS K7210, temperature: 190 ° C., load: 21. 18N) is about 0.5 to 100 g / 10 min, more preferably 2 to 50 g / 10 min, still more preferably 3 to 30 g / 10 min. Here, the MFR may be selected in consideration of molding processability when molding a sheet, adhesion when sealing a solar cell element (cell), a wraparound condition, and the like. For example, when calendering a sheet, the MFR is preferably a relatively low value, specifically about 0.5 to 5 g / 10 minutes, because of the handling properties when the sheet is peeled off from the forming roll. When extrusion is performed using a die, the MFR is preferably 2 to 50 g / 10 min, more preferably 3 to 30 g / 10 min, from the viewpoint of reducing the extrusion load and increasing the extrusion rate. Good. Furthermore, from the viewpoint of adhesion when sealing solar cell elements (cells) and ease of wrapping, the MFR is preferably 2 to 50 g / 10 minutes, more preferably 3 to 30 g / 10 minutes. Use it.

The production method of the ethylene-α-olefin random copolymer (P) used in the present invention is not particularly limited, and a known polymerization method using a known olefin polymerization catalyst can be employed. For example, slurry polymerization method, solution polymerization method, bulk polymerization method, gas phase polymerization method using multi-site catalyst represented by Ziegler-Natta type catalyst, single site catalyst represented by metallocene catalyst and post metallocene catalyst And a bulk polymerization method using a radical initiator. In the present invention, since the ethylene-α-olefin random copolymer (P) is a relatively soft resin, it has a low molecular weight from the viewpoint of ease of granulation after pelletization and prevention of blocking of raw material pellets. A polymerization method using a single site catalyst capable of polymerizing a raw material with few components and a narrow molecular weight distribution is suitable.

The ethylene-α-olefin random copolymer (P) used in the present invention satisfies the above condition (a), that is, the crystal melting calorie measured at a heating rate of 10 ° C./min in the differential scanning calorimetry is 0 to It is necessary to be 70 J / g, preferably 5 to 70 J / g, more preferably 10 to 65 J / g. If it is in the range of 0 to 70 J / g, flexibility and transparency (total light transmittance) of the multilayer body for sealing solar cells is preferable. In particular, if the heat of crystal fusion is 5 J / g or more, it is preferable because problems such as blocking of raw material pellets hardly occur. Here, as reference values for the heat of crystal melting, general-purpose high-density polyethylene (HDPE) is about 170 to 220 J / g, and low-density polyethylene resin (LDPE) and linear low-density polyethylene (LLDPE) are 100 to 160 J. / G or so. The heat of crystal melting can be measured at a heating rate of 10 ° C./min according to JIS K7122 using a differential scanning calorimeter.

In addition, the crystal melting peak temperature of the ethylene-α-olefin random copolymer (P) used in the present invention is not particularly limited, but is usually less than 100 ° C. and is often 30 to 90 ° C. . Here, as reference values for the crystal melting peak temperature, general-purpose high-density polyethylene (HDPE) is about 130 to 145 ° C., and low-density polyethylene resin (LDPE) and linear low-density polyethylene (LLDPE) are 100 to 125. It is about ℃. That is, with the ethylene-α-olefin random copolymer (P) used alone in the present invention, the crystal melting peak temperature measured at a heating rate of 10 ° C./min in differential scanning calorimetry is 100 ° C. or higher, and It is difficult to achieve a heat of crystal melting of 5 to 70 J / g. The crystal melting peak temperature can be measured at a heating rate of 10 ° C./min according to JIS K7121 using a differential scanning calorimeter.

Specific examples of the ethylene-α-olefin random copolymer (P) used in the present invention include trade names “Engage”, “Affinity” manufactured by Dow Chemical Co., Ltd., Mitsui Chemicals, Inc. The product name “TAFMER A”, “TAFMER 、 P”, and the product name “Kernel” manufactured by Nippon Polyethylene Co., Ltd. can be exemplified.

(Ethylene-α-olefin block copolymer (Q))
The ethylene-α-olefin block copolymer (Q) used in the present invention is not particularly limited as long as the above condition (b) is satisfied. Usually, ethylene and an α-olefin having 3 to 20 carbon atoms are used. These block copolymers are preferably used. Examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 3-methyl-butene. -1,4-methyl-pentene-1, etc. In the present invention, propylene, 1-butene, 1-hexene, and 1-octene are preferably used as the α-olefin copolymerized with ethylene from the viewpoints of industrial availability, various characteristics, and economical efficiency. It is done. The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

Further, the ethylene-α-olefin block copolymer (Q) may contain monomer units based on monomers other than α-olefin as long as the condition (b) is satisfied. Examples of the monomer include cyclic olefins, vinyl aromatic compounds (such as styrene), polyene compounds, and the like. The content of the monomer units is 20 mol% or less and 15 mol% or less, assuming that all monomer units in the ethylene-α-olefin block copolymer (Q) are 100 mol%. It is preferable.

The block structure of the ethylene-α-olefin block copolymer (Q) used in the present invention is not particularly limited as long as the condition (b) is satisfied, but the balance of flexibility, heat resistance, transparency, etc. Multi-block containing two or more, preferably three or more segments or blocks having different comonomer contents, crystallinity, density, crystal melting peak temperature (melting point Tm), or glass transition temperature (Tg) A structure is preferred. Specific examples include a completely symmetric block, an asymmetric block, and a tapered block structure (a structure in which the ratio of the block structure gradually increases in the main chain). Regarding the structure and production method of the copolymer having the multi-block structure, International Publication No. 2005/090425 (WO2005 / 090425), International Publication No. 2005/090426 (WO2005 / 090426), and International Publication No.2005. / 090427 pamphlet (WO2005 / 090427) or the like can be employed.

In the present invention, the ethylene-α-olefin block copolymer having the multi-block structure will be described in detail below.
The ethylene-α-olefin block copolymer having a multiblock structure can be suitably used in the present invention, and an ethylene-octene multiblock copolymer having 1-octene as a copolymerization component as an α-olefin is preferable. As the block copolymer, an almost non-crystalline soft segment copolymerized with a large amount of octene component (about 15 to 20 mol%) relative to ethylene and a small amount of octene component (about 2 mol% relative to ethylene). Less) a multiblock copolymer in which two or more highly crystalline hard segments each having a copolymerized crystal melting peak temperature of 100 to 145 ° C. are present. By controlling the chain length and ratio of these soft segments and hard segments, both flexibility and heat resistance can be achieved. As a specific example of the copolymer having the multi-block structure, trade name “Infuse” manufactured by Dow Chemical Co., Ltd. may be mentioned.

The melt flow rate (MFR) of the ethylene-α-olefin block copolymer (Q) used in the present invention is not particularly limited, but is usually MFR (JIS K7210, temperature: 190 ° C., load: 21. 18N) is about 0.5 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, still more preferably 1 to 30 g / 10 min, and particularly preferably 1 to 10 g / 10 min.
Here, the MFR may be selected in consideration of molding processability when molding a sheet, adhesion when sealing a solar cell element (cell), a wraparound condition, and the like. Specifically, when calendering the sheet, the MFR is preferably relatively low, specifically about 0.5 to 5 g / 10 minutes, because of the handling properties when the sheet is peeled off from the forming roll. Further, when extrusion is performed using a T die, an MFR of 1 to 30 g / 10 minutes is preferably used from the viewpoint of reducing the extrusion load and increasing the extrusion amount. Further, from the viewpoint of adhesion and ease of wrapping when sealing the solar cell element (cell), those having an MFR of 3 to 50 g / 10 min are preferably used.

The ethylene-α-olefin block copolymer (Q) used in the present invention satisfies the condition (b), that is, the crystal melting peak temperature measured at a heating rate of 10 ° C./min in differential scanning calorimetry is 100. It is necessary that the temperature is ˜145 ° C. and the heat of crystal fusion is 5 to 70 J / g. The crystal melting peak temperature is preferably 105 ° C. or higher, more preferably 110 ° C. or higher, and the upper limit is usually 145 ° C. The heat of crystal fusion is preferably 10 to 60 J / g, more preferably 15 to 55 J / g. The method for measuring the crystal melting peak temperature and the crystal melting heat amount is as described above.

In general, a solar cell module is heated to about 85 to 90 ° C. by heat generated during power generation or radiant heat of solar light. If the crystal melting peak temperature is 100 ° C. or higher, the multilayer body for sealing solar cells of the present invention is used. On the other hand, if the upper limit is 145 ° C., it is preferable because it can be sealed without excessively high temperature in the sealing step of the solar cell element. If the heat of crystal fusion is in the range of 5 to 70 J / g, the flexibility and transparency (total light transmittance) of the solar cell sealing multilayer body of the present invention are ensured, and the raw material pellets are blocked. It is preferable because problems such as these are unlikely to occur.

(Resin layer (I) -1)
The resin layer (I) -1 is a resin layer containing the ethylene-α-olefin random copolymer (P) and the ethylene-α-olefin block copolymer (Q). Here, the types of α-olefins used in each of the copolymer (P) and the copolymer (Q) may be the same or different, but in the present invention, It is preferable that they are the same because the compatibility when mixed and the transparency of the solar cell sealing multilayer body are improved, that is, the photoelectric conversion efficiency of the solar cell is improved.

Next, the contents of the ethylene-α-olefin random copolymer (P) and the ethylene-α-olefin block copolymer (Q) in the resin layer (I) -1 are flexible, heat resistant, and transparent. From the viewpoint of having an excellent balance such as, it is preferably 50 to 99% by mass, 1 to 50% by mass, more preferably 60 to 98% by mass, and 2 to 40% by mass, and still more preferably. 70 to 97% by mass, and 3 to 30% by mass. The mixing (containing) mass ratio of the ethylene-α-olefin random copolymer (P) and the ethylene-α-olefin block copolymer (Q) is not particularly limited, but preferably (P) / (Q) = 99 to 50/1 to 50, more preferably 98 to 60/2 to 40, more preferably 97 to 70/3 to 30, more preferably 97 to 80/3 to 20, Preferably, it is 97 to 90/3 to 10. However, the total of (P) and (Q) is 100 parts by mass. Here, it is preferable that the mixed (contained) mass ratio is in the above range because a solar cell sealing multilayer body excellent in balance of flexibility, heat resistance, transparency and the like can be easily obtained.

[Resin layer (I) -2]
Resin layer (I) -2 is a resin layer mainly composed of silane-modified ethylene resin (X) or a resin layer mainly composed of a mixture of silane-modified ethylene resin (X) and polyethylene resin (F). It doesn't matter. As described above, the silane-modified ethylene-based resin (X) can be usually obtained by melt-mixing a polyethylene-based resin, a vinyl silane compound, and a radical generator at a high temperature, and performing graft polymerization. When the polyethylene resin used for using the radical generator is partially crosslinked, gel or fish eye may be mixed in, or the vinylsilane compound or radical generator used may remain unreacted. Therefore, in this invention, it is more preferable that it is a resin layer which has as a main component the mixture of silane modification ethylene-type resin (X) and polyethylene-type resin (F). It is preferable to use the mixture because it improves economic efficiency and relatively easily adjusts various properties such as flexibility, transparency and heat resistance.

Here, the polyethylene resin (F) is not particularly limited, but is mixed with the silane-modified ethylene resin (X), and the silane-modified ethylene resin (X) in the resin layer (I) -2. In addition to adjusting the content, the resin layer (I) -2 is adjusted for various properties such as flexibility, transparency, sealing properties and heat resistance. Specifically, the same resin as the polyethylene resin used for obtaining the silane-modified ethylene resin (X), that is, low density polyethylene, medium density polyethylene, high density polyethylene, very low density polyethylene, or linear Low density polyethylene is mentioned. These may be used alone or in combination of two or more.

The melt flow rate (MFR) of the polyethylene resin (F) used in the present invention is not particularly limited, but usually MFR (JIS K7210, temperature: 190 ° C., load: 21.18 N) is 0.1. What is about 5 to 100 g / 10 min, more preferably 2 to 50 g / 10 min, still more preferably 3 to 30 g / 10 min is used. Here, the MFR may be selected in consideration of molding processability when molding a sheet, adhesion when sealing a solar cell element (cell), a wraparound condition, and the like. For example, when calendering a sheet, the MFR is preferably relatively low, specifically about 0.5 to 5 g / 10 min from the handling property when the sheet is peeled off from the forming roll. In the case of extrusion molding using a, MFR is preferably 2 to 50 g / 10 min, more preferably 3 to 30 g / 10 min, from the viewpoint of reducing the extrusion load and increasing the extrusion rate. Further, from the viewpoint of adhesion and ease of wraparound when sealing a solar cell element (cell), the MFR is preferably 2 to 50 g / 10 min, more preferably 3 to 30 g / 10 min. Good.

In the present invention, the polyethylene resin (F) may be the same resin as the polyethylene resin used when obtaining the silane-modified ethylene resin (X) or a different resin. It is preferable that they are the same resin from the viewpoints of compatibility and transparency when mixed. Moreover, in this invention, since transparency and a softness | flexibility become favorable, a polyethylene-type resin with a low density is used suitably. Specifically, the polyethylene resin is preferably a density of 0.850 ~ 0.920g / cm ^3, the density is more preferably a linear low density polyethylene 0.860 ~ 0.880g / cm ^3. Further, in the linear low density polyethylene, it is particularly preferable that the type of α-olefin as a copolymerization component is the same as that of the polyethylene resin used for obtaining the silane-modified ethylene resin (X).

In the present invention, specific examples of polyethylene resins having a low density that are preferably used include trade names “Engage”, “Affinity”, and “Infuse” manufactured by Dow Chemical Co., Ltd. ”, Trade names“ TAFMER A ”,“ TAFMER P ”manufactured by Mitsui Chemicals, Inc., and“ kernel ”manufactured by Nippon Polyethylene Co., Ltd. it can.

The mixing mass ratio when the resin layer (I) -2 is a resin layer mainly composed of a mixture of the silane-modified ethylene resin (X) and the polyethylene resin (F) is not particularly limited. The silane-modified ethylene resin (X) / polyethylene resin (F) ratio is 1 to 99/99 to 1, preferably 2 to 70/98 to 30, more preferably 3 to 40/97 to 60. Within this range, the content of the silane-modified ethylene resin (X) in the resin layer (I) -2, that is, the silane-modified group concentration can be easily adjusted, and the main role of the resin layer (I) -2 While maintaining the function as an adhesive layer, it is preferable because various properties such as flexibility, transparency, sealing properties and heat resistance as a surface layer and a sealing layer can be adjusted relatively easily.

The resin layer (I) -2 has a role of mainly expressing functions as a surface layer, a sealing layer and an adhesive layer in the solar cell multilayer body of the present invention. For this reason, it is preferable that the resin used for the resin layer (I) -2 has flexibility. On the other hand, the resin layer (I) -2 is also required to prevent blocking due to softening as a surface layer. In the present invention, although not particularly limited, the Vicat softening temperature of the resin layer (I) -2 is preferably 60 ° C. or less, more preferably 30 ° C. or more and less than 60 ° C., 35 More preferably, it is not lower than 55 ° C. and not higher than 55 ° C. Within this range, the flexibility of the resin layer (I) -2 is sufficiently secured, and it is difficult to block in a normal storage environment (temperature 30 ° C., humidity 50%), which is preferable. The Vicat softening temperature can be measured according to JIS K7206. Specifically, the heat transfer medium is raised at a rate of 50 ° C./hour while applying a total load of 10 N (A method) through a needle-like indenter with a tip cross-sectional area of 1 mm ² placed perpendicular to the test piece in the heating bath. This is the temperature when the tip of the indenter penetrates 1 mm into the test piece.

The mixing method in the case of using a mixture of the silane-modified ethylene resin (X) and the polyethylene resin (F) for the resin layer (I) -2 is not particularly limited. May be supplied to the hopper, or may be supplied after melting and mixing all materials in advance to produce pellets. In the present invention, as described above, since the vinylsilane compound and radical generator added when obtaining the silane-modified ethylene resin (X) may remain without reacting, the silane-modified ethylene resin When mixing (X) and a polyethylene-type resin (F), it is preferable to remove a volatile matter with a vacuum vent.

The thickness of the resin layer (I) is not particularly limited, but is preferably 0.02 to 0.7 mm from the viewpoint of sealing performance and economic efficiency of the solar cell element (cell), More preferably, the thickness is from 05 to 0.6 mm.

[Resin layer (II)]
The resin layer (II) includes the above-described resin composition, that is, a metallocene ethylene polymer (A) having a density of 0.936 to 0.948 g / cm ³ and a crystal melting heat of 150 to 200 J / g, It consists of the sheet | seat which consists of a resin composition containing a crystal nucleating agent (B). Thereby, the moisture-proof property and transparency which were excellent in the multilayer body for solar cells of this invention, heat resistance, and rigidity can be provided with sufficient balance.

[Other ingredients]
In addition, the resin layer (I) constituting the solar cell multilayer body of the present invention has various characteristics (flexibility, rigidity, heat resistance, transparency, adhesiveness, etc.) and the like within a range not departing from the gist of the present invention. Other resins can be mixed for the purpose of further improving the molding processability or economy. Here, as other resins, for example, other polyolefin resins and various elastomers (olefins, styrenes, etc.), polar groups such as carboxyl groups, amino groups, imide groups, hydroxyl groups, epoxy groups, oxazoline groups, thiol groups, etc. Examples thereof include a resin modified with a group.

Further, various additives can be added to the resin layer (I) as necessary. Examples of the additive include a silane coupling agent, an antioxidant, an ultraviolet absorber, a weathering stabilizer, a light diffusing agent, a nucleating agent, a pigment (for example, a white pigment), a flame retardant, and a discoloration preventing agent. . In the present invention, it is preferable that at least one additive selected from an antioxidant, an ultraviolet absorber, and a weathering stabilizer is added for reasons described later.

Silane coupling agents are useful for improving adhesion to protective materials for sealing materials (glass, resin front sheets, back sheets, etc.) and solar cell elements, such as vinyl groups, acryloxy groups, Examples thereof include compounds having a hydrolyzable group such as an alkoxy group together with an unsaturated group such as a methacryloxy group, an amino group, and an epoxy group. Specific examples of the silane coupling agent include N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxy. Examples thereof include silane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane. When added, γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane are preferably used because of good adhesiveness and little discoloration such as yellowing. The addition amount of the silane coupling agent is usually about 0.0 to 5.0 parts by mass with respect to 100 parts by mass of the resin composition constituting each resin layer. Similarly to the silane coupling agent, A coupling agent such as an organic titanate compound can also be used effectively, but it is preferably not added in the present invention.

As the antioxidant, various commercially available products can be applied, and various types such as monophenol type, bisphenol type, polymer type phenol type, sulfur type and phosphite type can be mentioned. Examples of monophenols include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and the like. Examples of bisphenols include 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4 '-Thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 3,9-bis [{1,1-dimethyl- 2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,9,10-tetraoxaspiro] 5,5-undecane.

Examples of the high molecular phenolic group include 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 , 5-di-tert-butyl-4-bidoxybenzyl) benzene, tetrakis- {methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate} methane, bis { (3,3′-bis-4′-hydroxy-3′-tert-butylphenyl) butyric acid} glycol ester, 1,3,5-tris (3 ′, 5′-di-tert-butyl-4 '-Hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, triphenol (vitamin E) and the like.

Examples of sulfur-based compounds include dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiopropionate.

Examples of phosphites include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, Crick neopentanetetrayl bis (octadecyl phosphite), tris (mono and / or di) phenyl phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10 -Dihydro-9-oxa-10- Sphaphenanthrene, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite, 2 , 2-methylenebis (4,6-tert-butylphenyl) octyl phosphite.

In the present invention, phenol-based and phosphite-based antioxidants are preferably used in view of the effect of the antioxidant, thermal stability, economy and the like, and it is more preferable to use a combination of both. The addition amount of the antioxidant is usually about 0.1 to 1.0 part by mass with respect to 100 parts by mass of the resin composition constituting each resin layer, and 0.2 to 0.5 part by mass is added. It is preferable.

Examples of ultraviolet absorbers include various types such as benzophenone-based, benzotriazole-based, triazine-based, salicylic acid ester-based, and various commercially available products can be applied. Examples of benzophenone ultraviolet absorbers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n. -Dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorochlorophenone, 2, , 4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. It is.

Examples of the benzotriazole ultraviolet absorber include hydroxyphenyl-substituted benzotriazole compounds such as 2- (2-hydroxy-5-methylphenyl) benzotriazole and 2- (2-hydroxy-5-tert-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, etc. It is done. Examples of triazine ultraviolet absorbers include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- ( 4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol and the like. Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate.

The addition amount of the ultraviolet absorber is usually about 0.01 to 2.0 parts by mass with respect to 100 parts by mass of the resin composition constituting each resin layer, and 0.05 to 0.5 parts by mass is added. It is preferable.

Hindered amine light stabilizers are preferably used as the weather stabilizer for imparting weather resistance in addition to the above ultraviolet absorbers. A hindered amine light stabilizer does not absorb ultraviolet rays like an ultraviolet absorber, but exhibits a remarkable synergistic effect when used together with an ultraviolet absorber. There are some which function as a light stabilizer other than hindered amines, but they are often colored and are not preferable for the multilayer body for solar cell of the present invention.

Examples of hindered amine light stabilizers include dimethyl-1- (2-hydroxyethyl) succinate-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, 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}], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2, 6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3 , 5-Di-tert-4 Hydroxybenzyl) -2-n-butyl malonic acid bis (1,2,2,6,6-pentamethyl-4-piperidyl) and the like.

The amount of the hindered amine light stabilizer added is usually about 0.01 to 0.5 parts by mass and 0.05 to 0.3 parts by mass with respect to 100 parts by mass of the resin composition constituting each resin layer. It is preferable to add a part.

[Multilayer for sealing solar cells]
It is preferable to use the sheet | seat which consists of this resin composition for the sealing material for solar cells, and it is preferable to use it for the multilayer body for sealing for solar cells.
The multilayer for sealing solar cells is excellent in moisture resistance, and has a water vapor transmission rate of 3.0 g / (m ² · 24 hours) or less measured at a total thickness of 0.3 mm, a temperature of 40 ° C., and a relative humidity of 90%. It is preferable that In the present invention, it is more preferably 2.0 g / (m ² · 24 hours) or less from the viewpoint of durability and long-term reliability of the solar cell module produced using the multilayer body for sealing solar cells. 1.0 g / (m ² · 24 hours) or less, more preferably 0.5 g / (m ² · 24 hours) or less. Such excellent moisture resistance in the present invention is mainly due to the combination of the ethylene resin (A) and the crystal nucleating agent (B), and also the olefin compatible resin (C) and / or the cyclic olefin resin. It can be achieved by adding an olefin resin (D) such as The water vapor transmission rate can be measured by various known methods. In the present invention, the temperature is 40 ° C. using PERMATRAN W 3/31 manufactured by MOCON in accordance with JIS K7129B. The water vapor transmission rate of a multilayer sheet having a total thickness of 0.3 mm was measured under the condition of 90% relative humidity.

The multi-layer body for solar cell sealing can appropriately adjust its flexibility and rigidity in consideration of the shape and thickness of the solar cell to be applied, the installation location, and the like. For example, handling property when a solar cell sealing multilayer body is collected in the form of a sheet, prevention of blocking between sheet surfaces, or weight reduction in a solar cell module (usually about 3 mm, thin film glass (about 1.1 mm) ) Is applicable, or a glass-less configuration is applicable), and the storage elastic modulus (E ′) at a vibration frequency of 10 Hz and a temperature of 20 ° C. in the dynamic viscoelasticity measurement is preferably 100 to 1000 MPa, More preferably, it is 250 to 900 MPa, more preferably 300 to 700 MPa, and particularly preferably 400 to 600 MPa. The storage elastic modulus (E ′) can be obtained by measuring a predetermined temperature range at a vibration frequency of 10 Hz using a dynamic viscoelasticity measuring apparatus and obtaining a value at a temperature of 20 ° C.

Since the multilayer body for solar cell sealing has a multilayer structure having the resin layer (I) and the resin layer (II) as at least one of the outermost layers, the characteristics required for the surface layer such as adhesion and flexibility It is possible to balance the properties required for the entire multilayer body such as moisture resistance and handling properties (rigidity) in a well-balanced manner.

For example, to explain flexibility and handling properties (rigidity) as an example, the solar cell sealing multilayer body employs a soft layer as the resin layer (I) and a hard layer as the resin layer (II). By appropriately adjusting, flexibility and handling properties (rigidity) can be achieved in a well-balanced manner. The solar cell sealing multilayer body may have a laminated structure of two or more layers of the resin layer (I) and the resin layer (II), but the curling prevention (maintaining flatness) and film-forming property as the multilayer body. From such viewpoints, a symmetrical configuration such as a resin layer (I) / resin layer (II) / resin layer (I), in other words, a soft layer / a hard layer / a soft layer, two-layer / three-layer configuration is preferable.

The soft layer is not particularly limited, but is a layer having a storage elastic modulus (E ′) at a vibration frequency of 10 Hz and a temperature of 20 ° C. in dynamic viscoelasticity measurement of preferably 100 MPa or less, more preferably 5 to 50 MPa. The hard layer is a layer having a storage elastic modulus (E ′) preferably exceeding 100 MPa, more preferably 200 to 3000 MPa, and still more preferably 500 to 2000 MPa. By adopting such a laminated structure, when the solar cell sealing multilayer body is used as, for example, a solar cell sealing material, the protection property (cushioning property) of the solar cell element and the handling property as a whole sealing material ( It is preferable that both the elastic modulus at room temperature and the like can be realized relatively easily.

The total light transmittance at a total thickness of 0.3 mm of the solar cell sealing multilayer body is applied to the type of solar cell to be applied, for example, an amorphous thin-film silicon type or a portion that does not block sunlight reaching the solar electronic element. In some cases, it may not be considered as important, but it is preferably 85% or more, more preferably 88% or more in consideration of the photoelectric conversion efficiency of the solar cell and workability when stacking various members. Preferably, it is 90% or more. The total light transmittance can be measured by various known methods. In the present invention, the “reflection / transmittance” manufactured by Murakami Color Research Laboratory Co., Ltd. is used in accordance with JIS K7105. The total light transmittance of a multilayer sheet having a total thickness of 0.3 mm was measured using a “meter”.

The solar cell sealing multilayer body is a solar cell encapsulant that is easy to form a solar cell module, can omit the cross-linking step, and has excellent transparency, moisture resistance, sealing properties, handling properties (rigidity), etc. Is preferably used. In order to satisfy these characteristics at the same time, when a solar cell sealing multilayer body having a total thickness of 0.3 mm is measured, the storage elastic modulus (E ′) at a vibration frequency of 10 Hz and a temperature of 20 ° C. in dynamic viscoelasticity measurement is 300. It is preferable that the water vapor transmission rate measured at ˜700 MPa, temperature 40 ° C. and relative humidity 90% is 3.0 g / (m ² · 24 hours) or less and the total light transmittance is 85% or more. More preferably, the water vapor permeability measured at a vibration frequency of 10 Hz, a storage elastic modulus (E ′) at a temperature of 20 ° C. of 400 to 600 MPa, a temperature of 40 ° C. and a relative humidity of 90% in the dynamic viscoelasticity measurement is 2.0 g / ( m ² · 24 hours) and the total light transmittance is 87% or more, and more preferably, the storage elastic modulus (E ′) at a vibration frequency of 10 Hz and a temperature of 20 ° C. in the dynamic viscoelasticity measurement is 400 to 600 MPa, The water vapor transmission rate measured at a temperature of 40 ° C. and a relative humidity of 90% is 1.0 g / (m ² · 24 hours) or less, and the total light transmittance is 88% or more.

The heat resistance of the solar cell sealing multilayer body is affected by various properties (crystal melting peak temperature, crystal melting heat amount, MFR, molecular weight, etc.) of the resin used for the resin layer (I) and the resin layer (II). Generally, a solar cell module is heated to about 85 to 90 ° C. due to heat generated during power generation or radiant heat of sunlight, but if the crystal melting peak temperature is 100 ° C. or higher, the heat resistance of the multilayer body for solar cell sealing Can be secured.

The total thickness of the solar cell sealing multilayer body is not particularly limited, but is usually about 0.03 to 1.0 mm, preferably from the viewpoint of transparency, moisture resistance, handling properties, and the like. Is used in the form of a sheet of 0.10 to 0.75 mm.

Next, the manufacturing method of the multilayer body for solar cell sealing is demonstrated.
As a method for forming a sheet-like multilayer for sealing solar cells, a known method, for example, a single-screw extruder, a multi-screw extruder, a Banbury mixer, a kneader or other melt mixing equipment, and extrusion using a T die A casting method, a calendar method, an inflation method, and the like can be employed, and are not particularly limited, but in the present invention, an extrusion casting method using a T die is preferably used from the viewpoint of handling properties, productivity, and the like. It is done. The molding temperature in the extrusion casting method using a T-die is appropriately adjusted according to the flow characteristics and film forming properties of the resin composition constituting each resin layer, but is generally 130 to 280 ° C., preferably 150 to 250 ° C. It is. In addition, as a multilayering method, a known method such as a co-extrusion method, an extrusion lamination method, a heat lamination method, a dry lamination method, or the like can be used, but in the present invention, handling property, productivity, etc. From the viewpoint of the above, a coextrusion method is preferably used. In the coextrusion method, various multilayer die can be selected, and examples thereof include a feed block method and a multi-manifold method. In addition, a dumbbell base, a capsule base, or the like can be used as appropriate for the purpose of preventing the trimming efficiency of each resin layer and the decrease in transparency during regeneration addition.

In the multilayer body for sealing a solar cell produced by the above production method, the thickness ratio to the total thickness of the resin layer (II) is preferably 10% or more and 90% or less, and 20% or more and 60% or less. More preferably, it is 25% or more and 45% or less. Here, if the thickness ratio of the resin layer (II) is within this range, a solar cell sealing multilayer body excellent in balance between moisture resistance, rigidity and transparency is preferable. Further, since the solar cell sealing multilayer body is excellent in rigidity at room temperature, for example, when used for a flexible type solar cell module, rigidity (waistness) can be imparted, and also used for a rigid type solar cell module. And thin glass (for example, 1.1 mm) can be applied, or a structure such as glassless can be applied, and weight reduction can be expected.

In addition, the multilayer structure for solar cell sealing preferably uses the above-described two-layer / three-layer structure of the resin layer (I) / resin layer (II) / resin layer (I), but has improved characteristics as a solar cell module. It is also possible to employ other laminated structures for the purpose of adjusting the appearance and improving the warp and curl. For example, resin layer (I) (with additive) / resin layer (I) (without additive) / resin layer (II), resin layer (I) (with additive A) / resin layer (I) ( (Including additive B) (additives A and B have different additive formulations) / resin layer (II), resin layer (I) ′ / resin layer (I) ″ (resin layer (I) ′ and (I ) '' Is different in storage modulus (E ') and mixing ratio of additives) / resin layer (II), resin layer (I) / resin layer (II)' / resin layer (II) '' (resin layer) (II) 'and (II)' 'differ in storage modulus (E') and mixing ratio of additives) 3 types, 3 layers configuration, resin layer (I) / adhesive layer / resin layer (II) / adhesion Layer / resin layer (II) (adhesive layer is an adhesive layer of resin layer (I) and resin layer (II)), resin layer (I) / recycled layer / resin layer (II) / recycled layer / resin layer ), And three types and five layers of resin layer (I) / recycled layer / resin layer (II) / recycled layer / resin layer (II) Etc. Here, the playback layer can be added with scrolls generated by trimming the ears or adjusting the width of the product that are produced when the solar cell sealing multilayer body is formed. In the present invention, the resin layer (II) does not deteriorate moisture resistance, transparency, rigidity, etc., which are the main functions of the resin layer (II). It is preferable to set and add a reproduction layer without adding as much as possible the scroll generated by the width adjustment (slit).

The method of mixing various additives such as antioxidants, ultraviolet absorbers, weathering stabilizers, etc. used for the solar cell sealing multilayer body may be dry blended with the resin in advance and then supplied to the hopper. Pellets may be supplied after melting and mixing the materials, or a master batch in which only the additive is previously concentrated in the resin may be prepared and supplied. Moreover, on the surface and / or the back surface of the solar cell sealing multilayer body obtained in the form of a sheet, if necessary, it is possible to prevent blocking between sheets when the sheet is used as a scroll or to seal a solar cell element. Embossing and various irregularities (cone, pyramid shape, hemispherical shape, etc.) may be performed for the purpose of improving the ease of handling and air bleeding.

Furthermore, when producing a multilayer body for solar cell sealing, another base film (for example, stretched polyester film (OPET), stretched polypropylene film (OPP) or ETFE (tetrafluoroethylene / ethylene copolymer), PVF (polyvinyl fluoride), PVDF (polyvinylidene fluoride) and various weathering films such as acrylic) and the like may be laminated by methods such as extrusion lamination, coextrusion and sand lamination. By laminating the solar cell sealing multilayer body and various substrate films, it is possible to relatively easily adjust the required characteristics and economy according to the improvement in handling properties and the lamination ratio.

[Solar cell module]
The solar cell sealing multilayer body is used as a solar cell member, and the portion thereof is not particularly limited, but is mainly a portion as a solar cell sealing material that adheres and protects the solar cell element. In addition, the solar cell module is also used for a portion that is not in close contact with the solar cell element for the purpose of adjusting the flexibility, rigidity, curl, thickness and dielectric breakdown voltage of the entire solar cell module. Here, as a specific example of the portion that is not in close contact with the solar cell element, for example, the constituent layer of the upper protective material of the solar cell module such as the upper protective material / sealing material / solar cell element / sealing material / lower protective material As the outermost surface layer / multilayer for solar cell sealing / barrier layer, outermost surface layer / barrier layer / multilayer for solar cell sealing, outermost surface layer / multilayer for solar cell sealing, outermost surface layer / sun Battery sealing multilayer / barrier layer / solar battery sealing multilayer, and the like. As a constituent layer of the lower protective material, solar cell sealing multilayer / barrier layer / backmost layer, other polyolefins Layer (such as CPP) / multilayer body for solar cell sealing / barrier layer / outermost back layer, other polyolefin layer (such as CPP) / barrier layer / multilayer body for solar cell sealing / outermost back surface layer and other polyolefin layers ( CPP etc.) / Multilayer for solar cell sealing / outermost layer etc. It is below. In addition, when the solar cell sealing multilayer body is used in a portion that does not adhere to the solar cell element, the solar cell sealing material that adheres to and protects the solar cell element includes a solar cell sealing multilayer body, or Commercially available EVA or ionomer type solar cell encapsulant can be used. Here, a solar cell module manufactured using a solar cell sealing multilayer body as a solar cell sealing material that adheres to and protects a solar cell element will be described.

A solar cell module can be manufactured by fixing a solar cell element with a front sheet and a back sheet, which are upper and lower protective materials, using a multilayer body for encapsulating solar cells. As such a solar cell module, various types can be exemplified, and preferably a solar cell sealing multilayer body is used as a sealing material, and an upper protective material, a solar cell element, and a lower protective material are used. The solar cell module produced using the material, specifically, the solar cell from both sides of the solar cell element such as upper protective material / sealing material / solar cell element / sealing material / lower protective material. A structure that is sandwiched between sealing multilayers, a structure that forms a sealing material and an upper protective material on a solar cell element formed on the inner peripheral surface of the lower protective material, and an upper protective material A solar cell element formed on the inner peripheral surface, for example, a structure in which an amorphous solar cell element is formed on a fluororesin transparent protective material by sputtering or the like, and a sealing material and a lower protective material are formed. Is mentioned. In the solar cell module using the solar cell sealing multilayer body, when the sealing material is used in two or more parts, the solar cell sealing multilayer body may be used in all parts. A solar cell sealing multilayer body may be used in only one part. When the sealing material is used in two or more parts, the resin layer (I) and the resin layer (II) constituting the solar cell sealing multilayer body used in each part are constituted. The composition of the resin composition and the thickness ratio of the resin layer (I) and the resin layer (II) in the multilayer body may be the same or different. In any case, the solar cell module is produced so that the resin layer (I) side of the solar cell sealing multilayer body is in contact with the solar cell element side, which is sufficient for sealing the solar cell element. It is preferable because excellent adhesiveness and sealing properties can be obtained.

Examples of the solar cell element arranged and wired between the sealing materials include, for example, III-type such as single crystal silicon type, polycrystalline silicon type, amorphous silicon type, gallium-arsenic, copper-indium-selenium, cadmium-tellurium, etc. Examples include group V and II-VI compound semiconductor types, dye sensitized types, and organic thin film types.

About each member which comprises the solar cell module produced using the multilayer body for solar cell sealing, although it does not specifically limit, For example, glass, an acrylic resin, polycarbonate, polyester, Examples thereof include a plate material such as a fluorine-containing resin and a single layer or multilayer protective material for a film. The lower protective material is a single layer or multilayer sheet such as metal or various thermoplastic resin films, for example, metals such as tin, aluminum and stainless steel, inorganic materials such as glass, polyester, inorganic vapor deposition polyester, fluorine-containing resin. And a single-layer or multilayer protective material such as polyolefin. The surface of the upper and / or lower protective material can be subjected to a known surface treatment such as a primer treatment or a corona treatment in order to improve adhesion to the solar cell sealing multilayer body or other members. .

The upper protective material / sealing material (resin layer (I) / resin layer (II) / resin layer (I)) / solar cell element / described above for a solar cell module produced using a multilayer body for encapsulating solar cells As an example, a sealing material (resin layer (I) / resin layer (II) / resin layer (I)) / lower protective material is sandwiched from both sides of the solar cell element with a sealing material. . In order from the solar light receiving side, a transparent substrate, a sealing material A using a multilayer body for sealing a solar cell (resin layer (I) / resin layer (II) / resin layer (I)), solar cell element, solar cell A sealing material B using a multilayer body for sealing (resin layer (I) / resin layer (II) / resin layer (I)) and a back sheet are laminated, and a junction box ( A terminal box for connecting wiring for taking out electricity generated from the solar cell element to the outside is bonded. The solar cell elements are connected by wiring in order to conduct the generated current to the outside. The wiring is taken out through a through hole provided in the backsheet and connected to the junction box.

As a manufacturing method of the solar cell module, a known manufacturing method can be applied, and it is not particularly limited, but in general, an upper protective material, a sealing material, a solar cell element, a sealing material, a lower protective material. And a step of vacuum-sucking them and heat-pressing them. Also, batch type manufacturing equipment, roll-to-roll type manufacturing equipment, and the like can be applied.

The solar cell module manufactured using the multilayer body for solar cell sealing of the present invention is installed on a small solar cell represented by a mobile device, a roof or a roof, depending on the type and module shape of the applied solar cell. It can be applied to various applications such as large solar cells, both indoors and outdoors.

Examples are shown below, but the present invention is not limited to the following examples.
(1) Molecular weight distribution index (Mw / Mn)
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured using a high temperature GPC system manufactured by Nippon Water Co., and the molecular weight distribution index (Mw / Mn) was calculated.

(2) Transparency (internal haze)
“Internal haze” means a value obtained by subtracting the external haze value from the haze value of the entire film.
The internal haze was measured by applying dioctyl phthalate (DOP) to both surfaces of a 0.1 mm thick sheet (sample) and adjusting the external haze to zero based on JIS K7105. Those having an internal haze of 10% or less were accepted.

(3) Moisture resistance (water vapor transmission rate)
Based on JIS K7129B, the water vapor transmission rate at a thickness of 0.1 mm was measured in an atmosphere of 40 ° C. and 90% RH using PERMATRAN W 3/31 manufactured by MOCON. A water vapor transmission rate of 1.20 g / (m ² · 24 hours) or less was accepted.

(4) Heat of crystal melting (ΔHm)
Using a differential scanning calorimeter “DSC-7” (manufactured by PerkinElmer), according to JIS K7122, about 10 mg of a sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. After holding for 1 minute, the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min, and again from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min (ΔHm) (J / G).

(5) Crystallization peak temperature (Tc)
Using a differential scanning calorimeter “DSC-7” (manufactured by PerkinElmer), according to JIS K7121, about 10 mg of the sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. After holding for 1 minute, the crystallization peak temperature (Tc) (° C.) was determined from the thermogram measured when the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min.

(6) Softening temperature (Ts)
Based on JIS K2207, the softening temperature (° C.) of the olefin compatible resin (C) was determined.

(7) Average refractive index For a sample molded to a thickness of 0.1 mm, using an Abbe refractometer manufactured by Atago Co., Ltd., using sodium D line (589 nm) as the light source, and n = 5 at an ambient temperature of 23 ° C. based on JIS K7124 Measurement was performed, and the average value of the refractive index was calculated as the average refractive index.

[Resin (A)]
(A) -1: Metallocene ethylene polymer (each mass ratio in resin (A) -1: ethylene / butene-1 / octene-1 = 97.7 / 1.1 / 1.2 mass%, density = 0.941 g / cm ³ , heat of crystal fusion = 183 J / g, crystallization peak temperature (Tc (A)) = 114 ° C., Mw / Mn = 3.12, average refractive index = 1.527)
(A) -2: Metallocene ethylene polymer (Each mass ratio in resin (A) -2: ethylene / butene-1 / octene-1 = 97.9 / 0.8 / 1.3 mass%, density = 0.947 g / cm ³ , heat of crystal fusion = 181 J / g, crystallization peak temperature (Tc (A)) = 113 ° C., Mw / Mn = 2.87, average refractive index = 1.530)
(A) -3: Metallocene ethylene polymer (each mass ratio in resin (A) -3: ethylene / hexene-1 / octene-1 = 97.6 / 1.4 / 1.0 mass%, density = 0.940 g / cm ³ , heat of crystal fusion = 180 J / g, crystallization peak temperature (Tc (A)) = 113 ° C., Mw / Mn = 2.90, average refractive index = 1.526)

[Crystal nucleating agent (B)]
(B) -1: fatty acid metal salt (zinc stearate / 1,2-cyclohexanedicarboxylic acid calcium salt = 34/66 mass%)

[Olefin compatible resin (C)]
(C) -1: Hydrogenated petroleum resin (trade name Alcon P115, Arakawa Chemical Industries, Ltd., softening temperature (Ts (C)) = 115 ° C.)
(C) -2: Hydrogenated petroleum resin (trade name Alcon P140, Arakawa Chemical Industries, Ltd., softening temperature (Ts (C)) = 140 ° C.)

[Olefin resin (D)]
(D) -1: Cyclic olefin resin (trade name TOPAS 9506F-04 of Polyplastics Co., Ltd., glass transition temperature = 68 ° C., heat of crystal fusion = 0 J / g, average refractive index = 1.529)
[Ethylene-α-olefin random copolymer (P)]
(P) -1: ethylene-octene random copolymer (manufactured by Dow Chemical Co., Ltd., trade name: engage 8200, ethylene / octene = 76/24 mass% (93/7 mol%), crystal melting peak temperature = 65 ° C., heat of crystal fusion = 53 J / g)
(P) -2: ethylene-propylene-hexene random copolymer (manufactured by Nippon Polyethylene Co., Ltd., trade name: kernel KJ640T, ethylene / propylene / hexene = 80/10/10% by mass (89/7/4 mol%) ), Crystal melting peak temperature = 53 ° C., crystal melting heat amount = 58 J / g)

[Ethylene-α-olefin block copolymer (B)]
(Q) -1: ethylene-octene block copolymer (manufactured by Dow Chemical Co., Ltd., trade name: Infuse 9000, ethylene / octene = 65/35 mass% (88/12 mol%), crystal melting peak temperature = 122 ° C., heat of crystal fusion = 44 J / g)

[Additive (G)]
(G) -1: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM503, γ-methacryloxypropyltrimethoxysilane)

[Silane-modified ethylene resin (X)]
(X) -1; Silane-modified ethylene-octene random copolymer (manufactured by Mitsubishi Chemical Corporation, trade name: Linkron SL800N, density: 0.868 g / cm ³ , crystal melting peak temperature: 54 ° C. and 116 ° C., Heat of crystal fusion: 22 J / g and 4 J / g, storage elastic modulus (E ′) at 20 ° C .: 15 MPa, average refractive index: 1.4857, MFR (temperature: 190 ° C., load: 21.18 N): 1.7 g / 10min)
(X) -2; Silane-modified ethylene-hexene random copolymer (manufactured by Mitsubishi Chemical Corporation, trade name: Linkron XLE815N, density: 0.915 g / cm ³ , crystal melting peak temperature: 121 ° C., heat of crystal melting) : 127 J / g, storage elastic modulus at 20 ° C. (E ′): 398 MPa, average refractive index: 1.5056, MFR (temperature: 190 ° C., load: 21.18 N): 0.5 g / 10 min)

[Ethylene resin (F)]
(F) -1; ethylene-octene random copolymer (manufactured by Dow Chemical Co., Ltd., trade name: affinity EG8200G, density: 0.870 g / cm ³ , ethylene / 1-octene = 68/32% by mass (89 / 11 mol%), crystal melting peak temperature: 59 ° C., crystal melting heat amount: 49 J / g, Vicat softening temperature: 45 ° C., storage elastic modulus (E ′) at 20 ° C .: 14 MPa, average refractive index: 1.4856, MFR (temperature: 190 ° C., load: 21.18 N): 5 g / 10 min)

Example 1
After dry blending (A) -1 and (B) -1 at a mixing mass ratio of 99.95: 0.05 to obtain a resin composition, 230A was used using a 40 mmφ co-directional twin screw extruder. After kneading at 0 ° C. and then extruding from a T-die, it was quenched with a casting roll at about 50 ° C. to prepare a sheet (sample) having a thickness of 0.1 mm.
The obtained sheet (sample) was evaluated for transparency and moisture resistance. The results are shown in Table 1.

(Example 2)
A resin composition and a sheet (sample) were prepared in the same manner as in Example 1 except that the mixing mass ratio of (A) -1 and (B) -1 was 99.9: 0.1. Evaluation was performed in the same manner. The results are shown in Table 1.

(Example 3)
A resin composition and a sheet (sample) were prepared in the same manner as in Example 1 except that the mixing mass ratio of (A) -1 and (B) -1 was 99.8: 0.2. Evaluation was performed in the same manner. The results are shown in Table 1.

Example 4
Examples were obtained except that (A) -1, (B) -1, and (C) -1 were dry blended at a mixing mass ratio of 79.9: 0.1: 20 to obtain a resin composition. A sheet (sample) was prepared in the same manner as in No. 1 and evaluated in the same manner. The results are shown in Table 1.

(Example 5)
A resin composition obtained by dry blending (A) -1, (B) -1, (C) -1, and (D) -1 at a mixing mass ratio of 49.9: 0.1: 20: 30 A sheet (sample) was prepared in the same manner as in Example 1 except that the evaluation was performed, and the evaluation was performed in the same manner. The results are shown in Table 1.

(Example 6)
A sheet (A) -2 and (B) -1 were prepared in the same manner as in Example 1 except that a resin composition was obtained by dry blending at a mixing mass ratio of 99.9: 0.1. Sample) was prepared and evaluated in the same manner. The results are shown in Table 1.

(Example 7)
A sheet (A) -3 and (B) -1 were prepared in the same manner as in Example 1 except that a resin composition was obtained by dry blending at a mixing mass ratio of 99.9: 0.1. Sample) was prepared and evaluated in the same manner. The results are shown in Table 1.

(Example 8)
Examples were obtained except that (A) -1, (B) -1, and (C) -2 were dry blended at a mixing mass ratio of 79.9: 0.1: 20 to obtain a resin composition. A sheet (sample) was prepared in the same manner as in No. 1 and evaluated in the same manner. The results are shown in Table 1.

(Comparative Example 1)
Using (A) -1 alone, a sheet was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
A sheet (sample) was prepared in the same manner as in Example 1 except that (A) -1 and (C) -1 were dry blended at a mixing mass ratio of 80:20 to obtain a resin composition. The same evaluation was made. The results are shown in Table 1.

(Comparative Example 3)
Instead of resin (A), trade name of HYZEX 3600F (Prime Polymer Co., Ltd.) (high density polyethylene, density = 0.958 g / cm ³ , heat of crystal fusion = 195 J / g, crystallization peak temperature (Tc) = 116 ° C. Mw / Mn = 4.72), and the resin composition was obtained by dry blending Hi-Zex 3600F and (B) -1 at a mixing mass ratio of 99.9: 0.1. Sheets (samples) were prepared in the same manner as in Example 1, and evaluated in the same manner. The results are shown in Table 1.

(Comparative Example 4)
Trade name Umerit 2040FC (linear low density polyethylene, density = 0.918 g / cm ³ , heat of crystal fusion = 134 J / g, crystallization peak temperature (Tc) instead of resin (A) ) = 105 ° C., Mw / Mn = 2.80), and Umelite 2040FC and (B) -1 were dry blended at a mixing mass ratio of 99.9: 0.1 to obtain a resin composition. Except for the above, a sheet (sample) was prepared in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

From these results and the previous test results, as in Examples 1 to 8, a metallocene ethylene polymer having a density of 0.936 to 0.948 g / cm ³ and a heat of crystal melting of 150 to 200 J / g. It was found that when a sheet was formed from a resin composition containing (A) and the crystal nucleating agent (B), a sheet excellent in both moisture resistance and transparency could be obtained.
At this time, it is important to adjust the ratio of (B) in the total content of the metallocene ethylene polymer (A) and the crystal nucleating agent (B) to a range of 0.01 to 3.0% by mass. I understood. In Examples 1 to 8, the ratio of (B) is in the range of 0.05 to 0.2% by mass, but from the test results so far, in the range of 0.01 to 3.0% by mass ( It can be considered that the same effect can be expected even when B) is blended.

It was also found that moisture resistance and transparency can be further improved by further blending an olefin-compatible resin (C) that is compatible with the metallocene ethylene polymer (A) (see Examples 4 and 8). .
Furthermore, it was also found that moisture resistance and transparency can be further improved by further blending an olefin resin (D) having a heat of crystal melting of 0 to 100 J / g (see Example 5).

Examples of multilayer bodies using the present resin composition are shown below. In the following examples, the following evaluation was performed in addition to the above evaluation.
(8) Crystal melting peak temperature (Tm)
Using a differential scanning calorimeter manufactured by PerkinElmer Co., Ltd., trade name “Pyris1 DSC”, according to JIS K7121, about 10 mg of sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. After holding at 200 ° C. for 1 minute, the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min, and again from the thermogram measured from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min. (Tm) (° C.) was determined.

(9) Transparency (total light transmittance)
Using a “reflection / transmittance meter” manufactured by Murakami Color Research Laboratory Co., Ltd., the total light transmittance of a multilayer sheet having a total thickness of 0.3 mm was measured according to JIS K7105. The results were described, and the results evaluated according to the following criteria were also shown.
(○) Total light transmittance is 85% or more (×) Total light transmittance is less than 85%

(10) Moisture resistance (water vapor transmission rate)
Measurement was performed according to the method of (3) above, and evaluation was performed according to the following criteria.
(◎) Water vapor transmission rate is 1.0 g / (m ² · 24 hours) or less (○) Water vapor transmission rate exceeds 1.0 g / (m ² · 24 hours) and 3.0 g / (m ² · ² hours) 24 hours) or less (x) Water vapor transmission rate exceeds 3.0 g / (m ² · 24 hours)

(11) Vicat softening temperature Measured according to JIS K7206. That is, the temperature of the heat transfer medium is increased at a rate of 50 ° C./hour while applying a total load of 10 N (A method) through a needle-like indenter having a tip cross-sectional area of 1 mm ² placed perpendicular to the test piece in the heating bath, The temperature when the tip of the indenter entered 1 mm into the test piece was measured.

(12) Rigidity (Storage elastic modulus (E ′))
Using a dynamic viscoelasticity measuring device manufactured by IT Measurement Co., Ltd., trade name “Viscoelastic Spectrometer DVA-200”, a sample (4 mm long, 60 mm wide) was subjected to a vibration frequency of 10 Hz, a strain of 0.1%, and a temperature increase. Measurement was made from −150 ° C. to 150 ° C. in the transverse direction at a speed of 3 ° C./min and 25 mm between chucks, and the storage elastic modulus (E ′) at 20 ° C. was determined from the obtained data. The results were described, and the results evaluated according to the following criteria were also shown.
(◎) The storage elastic modulus (E ′) at 20 ° C. is 300 MPa or more and 700 MPa or less (◯) The storage elastic modulus (E ′) at 20 ° C. is 100 MPa or more and less than 300 MPa, or more than 700 MPa and 1000 MPa or less. Yes (×) Storage elastic modulus (E ′) at 20 ° C. exceeds 1000 MPa

(13) Sealing property Using a vacuum laminator manufactured by NPC Co., Ltd., trade name “LM30 × 30”, hot plate temperature: 150 ° C., processing time: 20 minutes (breakdown, vacuuming: 5 minutes) , Press: 5 minutes, pressure retention: 10 minutes), pressure bonding speed: under rapid conditions, in order from the hot plate side, 3 mm thick white plate glass (trade name: Solite, manufactured by Asahi Glass Co., Ltd.), 0.3 mm thick Multilayer sheet (sealing material), solar cell element (cell) having a thickness of 0.4 mm (manufactured by France Photowatt Co., Ltd., product name: 101 × 101 MM), multilayer sheet having a thickness of 0.3 mm (sealing material), thickness The appearance of a solar cell module (size: 150 mm × 150 mm) produced by vacuum pressing 5 layers of 125 mm weather-resistant PET film (trade name: Lumirror X10S, manufactured by Toray Industries, Inc.) Evaluated by criteria.
(○) Multi-layer sheet is sufficiently wrapped around the solar cell element without any gaps (×) The multilayer sheet is not sufficiently wrapped around the solar cell element, and bubbles and floats are generated

(14) Heat resistance A multilayer sheet having a total thickness of 0.3 mm is stacked between a white sheet glass (size: 75 mm length, 25 mm width) and an aluminum plate (size: length 120 mm, width 60 mm) having a thickness of 3 mm, and vacuum is applied. Using a press machine, a sample which was laminated and pressed at 150 ° C. for 15 minutes was prepared, and the sample was installed at an inclination of 60 ° C. in a constant temperature and humidity chamber of 85 ° C. and 85% RH. Was observed and evaluated according to the following criteria.
(○) Glass did not deviate from the initial reference position (×) Glass deviated from the initial reference position, or the sheet melted

Example 9
After dry blending (P) -1, (Q) -1, and (G) -1 at a mixing mass ratio of 94.5: 5: 0.5, using a φ40 mm co-directional twin screw extruder Extrusion was carried out at a set temperature of 190 to 200 ° C. as a resin layer (I) serving as both outer layers from a two-type, three-layer multi-manifold die. At the same time, after dry blending (A) -1 and (B) -1 at a mixing mass ratio of 99.9: 0.1, an intermediate layer is formed from the same die using a φ40 mm co-directional twin screw extruder. The resulting resin layer (II) was extruded at a set temperature of 200 to 220 ° C. At this time, the thickness of each layer is such that the resin layer (I) / resin layer (II) / resin layer (I) is 0.1 / 0.1 / 0.1 (mm). Adjusted. Next, this coextruded sheet was quenched with a cast roll of about 20 ° C. to obtain a multilayer sheet having a thickness of 0.3 mm. The obtained multilayer sheet was evaluated for transparency, water vapor transmission rate, and heat resistance. The results are shown in Table 2.

(Example 10)
In Example 9, (A) -1, (B) -1 and (C) -1 were mixed in a resin mass (79.9: 0.1: 20) constituting the resin layer (II). A multilayer sheet was prepared and evaluated by the same method and thickness structure as in Example 9 except that the mixture was mixed at a ratio. The results are shown in Table 2.

(Example 11)
In Example 9, as the resin composition constituting the resin layer (II), (A) -1, (B) -1, (C) -1 and (D) -1 were mixed in a mass ratio of 49.9: A multilayer sheet was prepared and evaluated in the same manner and thickness as in Example 9 except that the mixture was changed to a mixture of 0.1: 20: 30. The results are shown in Table 2.

(Example 12)
Production and evaluation of a multilayer sheet with the same method and thickness as in Example 11 except that (A) -1 in the resin composition constituting the resin layer (II) was changed to (A) -2 in Example 11. Went. The results are shown in Table 2.

(Example 13)
In Example 11, a multilayer sheet was produced by the same method and thickness as in Example 9 except that (P) -1 in the resin composition constituting the resin layer (I) was changed to (P) -2. Evaluation was performed. The results are shown in Table 2.

(Example 14)
In Example 11, a multilayer sheet was produced by the same method and thickness as in Example 11 except that (C) -1 in the resin composition constituting the resin layer (II) was changed to (C) -2. And evaluated. The results are shown in Table 2.

(Example 15)
After dry blending (P) -1, (Q) -1, and (G) -1 at a mixing mass ratio of 94.5: 5: 0.5, using a φ40 mm co-directional twin screw extruder The resin layer (I) was extruded from a two-type two-layer multi-manifold die at a set temperature of 190 to 200 ° C. At the same time, after dry blending (A) -1, (B) -1, (C) -1, and (D) -1 at a mixing mass ratio of 49.9: 0.1: 20: 30 The resin layer (II) was extruded from the same die at a set temperature of 200 to 220 ° C. using a φ40 mm same-direction twin screw extruder. At this time, the discharge amount of the molten resin was adjusted so that the thickness of each layer would be 0.15 / 0.15 (mm) of resin layer (I) / resin layer (II). Next, this coextruded sheet was quenched with a cast roll of about 20 ° C. to obtain a multilayer sheet having a thickness of 0.3 mm. Evaluation similar to Example 9 was performed about the obtained multilayer sheet. The results are shown in Table 2.

(Example 16)
Using a vacuum laminator LM30 × 30 manufactured by NPC, hot plate temperature: 150 ° C., processing time: 20 minutes (breakdown, evacuation: 5 minutes, press: 5 minutes, pressure retention: 10 minutes), pressure bonding Speed: Under rapid conditions, in order from the hot plate side, a white sheet glass having a thickness of 3 mm (made by Asahi Glass Co., Ltd., trade name: Solite) as an upper protective material, a multilayer sheet having a thickness of 0.3 mm collected in Example 11 (Sealant, resin layer (I) is solar cell element side), solar cell element (cell) having a thickness of 0.4 mm (manufactured by Photowatt, model: 101 × 101 MM), the thickness collected in Example 11 0.3 mm multilayer sheet (sealing material, resin layer (I) is solar cell element side), weather-resistant PET film having a thickness of 0.125 mm as a lower protective material (trade name: Lumirror X10S manufactured by Toray Industries, Inc.) 5 layers are vacuum pressed and solar cells Jules: to prepare a (size 150mm × 150mm). The obtained solar cell module was excellent in transparency and appearance.

(Example 17)
(X) -1 and (F) -1 are mixed at a ratio of 30:70 by using a φ40 mm same-direction twin screw extruder, and a resin layer (both outer layers) from a two-kind, three-layer multi-manifold die ( Extrusion was performed at a set temperature of 180 to 200 ° C. as I). At the same time, a resin layer (II) which is an intermediate layer from the same die using (A) -1 and (B) -1 at a mixing mass ratio of 99.9: 0.1 using a φ40 mm co-directional twin-screw extruder. ) At a set temperature of 200 to 230 ° C. Next, the amount of molten resin discharged is adjusted, and the coextruded sheet is quenched with a cast roll of about 20 ° C., so that the thickness of each layer is resin layer (I) / resin layer (II) / resin layer (I) = 0.1 / 0.1 / 0.1 (mm) and a multilayer sheet having a total thickness of 0.3 mm was obtained. The obtained multilayer sheet was evaluated for transparency, moisture resistance, heat resistance, and the like. The results are shown in Table 3.

(Example 18)
In Example 17, the resin composition constituting the resin layer (II) was prepared by mixing (A) -1, (B) -1, and (C) -1 in a mixing mass ratio of 79.9: 0.1: 20. A multilayer sheet was obtained by the same method and thickness as in Example 17 except for the change. The obtained multilayer sheet was evaluated for transparency, moisture resistance, heat resistance, and the like. The results are shown in Table 3.

(Example 19)
In Example 18, a multilayer sheet was obtained by the same method and thickness as in Example 17 except that (C) -1 in the resin composition constituting the resin layer (II) was changed to (C) -2. . The obtained multilayer sheet was evaluated for transparency, moisture resistance, heat resistance, and the like. The results are shown in Table 3.

(Example 20)
In Example 17, the resin composition constituting the resin layer (II) was prepared by mixing (A) -1, (B) -1, (C) -1 and (D) -1 with a mixing mass ratio of 49.9: 0. A multilayer sheet was obtained by the same method and thickness as in Example 17 except that the ratio was changed to 1:20:30. The obtained multilayer sheet was evaluated for transparency, moisture resistance, heat resistance, and the like. The results are shown in Table 3.

(Example 21)
In Example 20, a multilayer sheet was obtained by the same method and thickness as in Example 20 except that (A) -1 in the resin composition constituting the resin layer (II) was changed to (A) -2. It was. The obtained multilayer sheet was evaluated for transparency, moisture resistance, heat resistance, and the like. The results are shown in Table 3.

(Example 22)
Using a vacuum laminator manufactured by NPC Corporation, product name “LM30 × 30”, hot plate temperature: 150 ° C., processing time: 20 minutes (breakdown, vacuuming: 5 minutes, press: 5 minutes , Pressure retention: 10 minutes), pressure bonding speed: obtained under the conditions of rapid, white plate glass (made by Asahi Glass Co., Ltd., trade name: Solite) having a thickness of 3 mm as an upper protective material in order from the hot plate side, in each example. Multi-layer sheet (encapsulant) having a total thickness of 0.3 mm, solar cell element (cell) having a thickness of 0.4 mm (manufactured by Photowatt Co., Ltd., trade name: 101 × 101 MM), the total thickness obtained in the examples is 0 .5mm multilayer sheet (sealing material) and 0.125mm thick weather-resistant PET film (product name: Lumirror X10S) as a lower protective material are vacuum-pressed to form a solar cell module ( Size: 150mm x 150mm) It was. The obtained solar cell modules were excellent in transparency and appearance.

Claims (14)

A resin composition comprising a metallocene ethylene polymer (A) having a density of 0.936 to 0.948 g / cm ³ and a heat of crystal fusion of 150 to 200 J / g, and a crystal nucleating agent (B), A resin composition, wherein the proportion of (B) in the total content of (A) and (B) is 0.01 to 3.0 mass%. Further contains an olefin compatible resin (C) consisting of one kind of resin or two or more kinds of resins selected from the group consisting of petroleum resins, terpene resins, coumarone-indene resins, rosin resins, and hydrogenated derivatives thereof. The resin composition according to claim 1. A crystal whose softening temperature Ts (C) of the olefin-compatible resin (C) is 80 ° C. or more and which is measured at a cooling rate of 10 ° C./min in the differential scanning calorimetry of the ethylene resin (A). The resin composition according to claim 2, which has a crystallization peak temperature Tc (A) + 30 ° C. or lower. The resin composition according to any one of claims 1 to 3, wherein the metallocene ethylene polymer (A) has a molecular weight distribution index of 2.5 to 4.5. The metallocene ethylene polymer (A) contains at least one α-olefin of butene-1, hexene-1 and octene-1 as a component other than ethylene, and the metallocene ethylene polymer. 5. The total content of butene-1, hexene-1 and octene-1 in (A) is 0.1 to 3.0% by mass. The resin composition as described. The resin composition according to any one of claims 1 to 5, further comprising an olefin resin (D) having a crystal heat of fusion of 0 to 100 J / g. The olefin resin (D) is one resin selected from the group consisting of linear low density polyethylene, polypropylene resin, and cyclic olefin resin, or a mixed resin of two or more kinds. 7. The resin composition according to any one of 1 to 6. The resin composition according to any one of claims 1 to 7, wherein an internal haze measured based on JIS K7105 when the resin composition is formed to a thickness of 0.1 mm is 10% or less. A sheet formed by molding the resin composition according to any one of claims 1 to 8. A solar cell encapsulant comprising the resin composition according to any one of claims 1 to 8. A solar cell encapsulant comprising a multilayer body having a resin layer (I) containing an ethylene-based resin in the layer (II) having the resin composition according to any one of claims 1 to 8. The resin layer (I) containing the ethylene-based resin has an ethylene-α-olefin random copolymer (P) that satisfies the following condition (a) and an ethylene-α- that satisfies the following condition (b): The sealing material for solar cells according to claim 11, which is a resin layer containing an olefin block copolymer (Q).
(A): Heat of crystal melting measured at a heating rate of 10 ° C./min in differential scanning calorimetry is 0 to 70 J / g
(B): The crystal melting peak temperature measured at a heating rate of 10 ° C./min in differential scanning calorimetry is 100 to 145 ° C., and the crystal melting heat is 5 to 70 J / g. The solar cell encapsulant according to claim 11, wherein the resin layer (I) containing the ethylene resin is a resin layer containing a silane-modified ethylene resin (X). A solar cell module produced using the solar cell encapsulant according to any one of claims 11 to 13, an upper protective material, a solar battery cell, and a lower protective material.