JP2010123497A - Electric insulating multilayer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moistureproof and electric insulating multilayer protection sheet which is suitable for a protection sheet for a solar cell module and can be manufactured by melt extrusion molding. <P>SOLUTION: This electric insulating multilayer sheet is a ring-opened polymer hydride of 2-norbornene and a substituting group-containing norbornene-based monomer which is obtained by ring-opening polymerizing 2-norbornene and the substituting group-containing norbornene-based monomer such that the existence ratio of a repeating unit (a) derived from 2-norbornene to all the repeating units is 90-100 wt.% and the existence ratio of a repeating unit (b) derived from the substituting group-containing norbornene-based monomer to all the repeating units is 10-0 wt.%, and by hydrogenating 80% or more of main chain carbon-carbon double bonds in the obtained ring-opening polymer. In this electric insulating multi-layer sheet, a layer A composed of the ring-opening polymer hydride having a melting point is made as an intermediate layer, and a resin layer B of which light beam transmittance in the wavelength 250-365 nm is 50% or less per 100 μm is arranged at both faces of the layer A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrically insulating multilayer sheet suitable for a solar cell back surface protective sheet excellent in weather resistance and moisture resistance that can withstand a harsh natural environment over a long period of time.

  In recent years, interest in global warming issues has increased. Carbon dioxide emissions are cited as a cause of global warming, and various efforts are being made to suppress carbon dioxide emissions to prevent global warming. There is an increasing expectation for photovoltaic power generation as a clean energy source that does not generate carbon dioxide. A solar cell constitutes the heart of a photovoltaic power generation system that converts sunlight energy directly into electricity. A cell that is a power generation element is made of a semiconductor. The structure of a solar cell does not use a power generation element as it is, and generally several to several tens of power generation elements are wired in series and in parallel, over a long period (about 20 years). In order to protect the element, various kinds of parsing are performed and unitized. The unit incorporated in this package is called a solar cell module. Generally, the surface exposed to sunlight is covered with glass, the gap between the power generation elements is filled with a filler made of thermoplastic plastic, and the back surface is moisture-proof and weather-resistant plastic material. The structure is protected by a sheet.

  Since these solar cell modules are used outdoors, sufficient durability and weather resistance are required in their configuration, material structure, and the like. In particular, the back protective sheet is required to have a weather resistance and a low water vapor transmission rate. This is because the moisture absorption may cause the filler to absorb moisture and cause corrosion of the wiring, or the power generation element may deteriorate, affecting the output of the module itself.

Conventionally, as this back surface protection sheet for solar cells, a back surface protection sheet having a laminated structure in which an aluminum foil is sandwiched with a polyvinyl fluoride film has been used in addition to glass. However, higher mechanical strength and higher heat resistance have been demanded in order to suppress damage and thermal denaturation during module production. In addition, when a protective sheet having a metal layer is used to suppress moisture absorption, when the protective sheet is damaged, the solar cell element and the metal layer are short-circuited, which adversely affects battery performance. In addition, the formation of the metal layer is a cause of reducing productivity.
Patent Document 1 proposes a protective sheet having a layer made of a cyclic olefin ring-opening polymer or a hydrogenated product of a cyclic olefin ring-opening polymer. The structure of the protective sheet specifically disclosed herein includes a cyclic olefin-based ring-opening polymer or a layer formed of a hydrogenated product of a cyclic olefin-based ring-opening polymer, a fluororesin, an acrylic resin, and a polyolefin-based polymer. Examples are a layer made of a polymer, a polystyrene polymer, a polyether polymer, polycarbonate, polyamide, and other plastics. In the examples, the weather resistance and moisture resistance of the two-layer protective sheet in which the sheet made of the hydrogenated cyclic olefin ring-opening polymer and the sheet made of the fluororesin are stacked one by one were confirmed. Yes.

  By the way, it is known in Patent Document 2 that when the surface of an article is protected using a resin solution containing a hydride of norbornene-based ring-opening polymer having a melting point, water vapor barrier properties, flexibility, oil resistance and the like can be improved. . Here, specifically, the effect of a multilayer film obtained by applying a norbornene-based ring-opening polymer hydride solution having a melting point to a high-density polyethylene film and drying it has been confirmed.

JP 2000-106450 A JP 2008-111033 A

  An object of the present invention is to provide an inexpensive moisture-proof, electrically insulating multilayer protective sheet suitable for a solar cell module protective sheet, which can be produced by melt extrusion molding.

As a result of the study of the born norbornene ring-opening polymer hydride having a melting point as described in Patent Document 2 as a protective sheet material for a solar cell module, the present inventors have found that the norbornene ring-opening polymer hydride having a melting point has been obtained. It was found that the protective layer made of oxidatively deteriorated by light irradiation.
Based on this knowledge, the present inventor is excellent in light irradiation as long as it is an electrically insulating multilayer protective sheet in which both sides of a layer composed of a hydride of norbornene-based ring-opening polymer having a melting point are sandwiched between light shielding layers. In addition, the present invention has been found to be useful as a protective sheet for a solar cell module that maintains water vapor barrier properties.

  Thus, according to the present invention, 2-norbornene and a substituent-containing norbornene-based monomer are present in a proportion of 90 to 100% by weight based on the total repeating units of the repeating unit (a) derived from 2-norbornene, and the substituent-containing norbornene. 80% or more of the main chain carbon-carbon double bond of the ring-opening polymer obtained by ring-opening polymerization at a ratio of 10 to 0% by weight of the repeating unit (b) derived from the monomer based on all repeating units A ring-opening polymer hydride of 2-norbornene and a substituent-containing norbornene-based monomer obtained by hydrogenation, the 2-norbornene and substituent-containing norbornene-based monomer having a melting point of 110 to 145 ° C A layer A comprising a ring-opened polymer hydride (hereinafter, sometimes referred to as “norbornene-based ring-opened polymer hydride having a melting point”) and an intermediate layer having a wavelength of 250 Light transmittance at 365nm is, the resin layer B is 50% or less per 100 [mu] m, the electrically insulating multilayer sheet is disposed on both surfaces of the layer A - DOO is provided.

When the light transmittance at a wavelength of 250 to 365 nm exceeds the light-shielding resin layer B according to the present invention, the moisture-proofness of the layer A composed of a ring-opened polymer hydride is obtained by long-term sunlight irradiation. This is not preferable because the properties are reduced, the amount of moisture that permeates the protective sheet is increased, the wiring is corroded, and the power generation element is deteriorated.
The resin layer B on one side and the resin layer B on the other side arranged in the layer A may be made of the same resin or different resins, and the light transmittance is within the scope of the present application. The two resin layers B may not have the same light transmittance.

  The hydride of norbornene-based ring-opening polymer having a melting point constituting layer A is a ratio of 2-norbornene and a substituent-containing norbornene-based monomer to the total repeating units of the repeating unit (a) derived from 2-norbornene. Is a main chain of a ring-opening polymer obtained by ring-opening polymerization in a proportion of 90 to 100% by weight, and the ratio of the repeating unit (b) derived from the substituent-containing norbornene monomer to the total repeating units is 10 to 0% by weight A ring-opening polymer hydride of 2-norbornene obtained by hydrogenating 80% or more of carbon-carbon double bonds and a substituent-containing norbornene-based monomer, having a melting point of 110 to 145 ° C. 2 -A ring-opening polymer hydride of norbornene and a substituent-containing norbornene-based monomer, and the norbornene-based ring-opening polymer hydride described in detail in Patent Document 2; It can be obtained in the like.

  2-Norbornene or 2-norbornene and a monomer mixture comprising a substituent-containing norbornene-based monomer are subjected to ring-opening polymerization in the presence of a metathesis polymerization catalyst, whereby 2-norbornene homo-ring-opening polymer or 2-norbornene And a ring-opening copolymer of a substituent-containing norbornene-based monomer.

  2-Norbornene is a known compound and can be obtained, for example, by reacting cyclopentadiene with ethylene.

  The substituent-containing norbornene-based monomer is a compound having a norbornene skeleton in the molecule (excluding 2-norbornene). The “substituent-containing norbornene monomer” used in the present invention includes a norbornene compound having a condensed ring in addition to a 2-norbornene derivative having a substituent.

  Examples of the substituent-containing norbornene monomer include a norbornene monomer that does not have a ring condensed with a norbornene ring in the molecule, and a polycyclic norbornene monomer having three or more rings.

  Specific examples of the norbornene-based monomer having no ring condensed with the norbornene ring in the molecule include norbornenes having an alkyl group such as 5-methylnorbornene and 5-ethylnorbornene; 5-ethylidenenorbornene, 5-vinyl Norbornenes having an alkenyl group such as norbornene and 5-propenylnorbornene; norbornenes having an aromatic ring such as 5-phenylnorbornene; 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene, 5-methyl-5-methoxycarbonylnorbornene, 5-methyl-5-ethoxycarbonylnorbornene, norbornenyl-2-methylpropionate, 5,6-di (hydroxymethyl) norbornene, 5,5-di (hydroxymethyl) norbornene, 5-methoxycarbonyl Norbornenes having polar group containing nitrogen atom such as 5-cyano-norbornene; norbornenes having polar groups containing oxygen atoms, such as 6-carboxy-norbornene and the like.

The polycyclic norbornene monomer having three or more rings is a norbornene monomer having a norbornene ring and one or more rings condensed with the norbornene ring in the molecule. Specific examples thereof include cyclopentadiene such as dicyclopentadiene, methyldicyclopentadiene, dimethyldicyclopentadiene, tricyclo [5.2.1.0 ^2,6 ] dec-8-ene; tetracyclo [9.2. 1.0 ^2,10 . 0 ^3,8 ] tetradeca-3,5,7,12-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene), tetracyclo [10.2.1.0 ^{2 , 11} . Norbornene derivatives having an aromatic ring such as 0 ^4,9 ] pentadeca-4,6,8,13-tetraene (also referred to as 1,4-methano-1,4,4a, 9,9a, 10-hexahydroanthracene) Tetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, 8-ethylidenetetracyclododecene, 8-vinyltetracyclododecene, 8-cyclohexenyltetracyclododecene, 8-phenyl Tetracyclododecene, 8-methoxycarbonyltetracyclododecene, 8-hydroxymethyltetracyclododecene, 8-carboxytetracyclododecene, tetracyclododecene-8,9-dicarboxylic acid, 8-cyanotetracyclododecene , 8-chlorotetracyclododecene, 8-trimethoxysilylte Tetracyclododecenes such as lacyclododecene; hexacycloheptadecene, 12-ethylhexacycloheptadecene, 12-cyclohexylhexacycloheptadecene, 12-ethylidenehexacycloheptadecene, 12-vinylhexacycloheptadecene, 12-cyclohexenyl Hexacycloheptadecene, 12-phenylhexacycloheptadecene, 12-methoxycarbonylhexacycloheptadecene, 12-hydroxymethylhexacycloheptadecene, 12-carboxyhexacycloheptadecene, hexacycloheptadecene 12,13-dicarboxylic acid, 12-cyanohexacycloheptadecene, hexacycloheptadecene 12,13-dicarboxylic imide, 12-chlorohexacycloheptadecene, 12-trimethoxysilyl And hexacycloheptadecenes such as ruhexacycloheptadecene. These norbornene monomers can be used alone or in combination of two or more.

  In the present invention, the aforementioned 2-norbornene and / or substituent-containing norbornene-based monomer and other monomers capable of ring-opening copolymerization can be used in combination.

  Examples of other monomers capable of ring-opening copolymerization with 2-norbornene and / or a substituent-containing norbornene-based monomer include, for example, monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; cyclohexadiene, Cyclic dienes such as cycloheptadiene and derivatives thereof; and the like.

  The composition of the monomer is such that 2-norbornene is usually 90 to 100% by weight, preferably 95 to 99% by weight, more preferably 97 to 99% by weight, and the substituent-containing norbornene monomer is usually 0 to 10% by weight, preferably 1 to 5% by weight, more preferably 1 to 3% by weight.

  Examples of the metathesis polymerization catalyst include Japanese Patent Publication No. 41-20111, Japanese Patent Publication No. 46-14910, Japanese Patent Publication No. 57-17883, Japanese Patent Publication No. 57-61044, Japanese Patent Publication No. 54-86600, A general metathesis polymerization catalyst consisting essentially of (a) a transition metal compound catalyst component and (b) a metal compound co-catalyst component, as described in JP-A-58-127728 and JP-A-1-240517; Schrock type polymerization catalyst (Japanese Patent Application Laid-Open No. 7-179575, Schrock et al., J. Am. Chem. Soc., 1990, Vol. 112, page 3875-) and Grubbs type polymerization catalyst (Fu et al. Nguyen et al., J. Am. Chem., 1993, 115, 9856 et seq., J. Am. . Soc, 1992 years, 114th volume, 3974 pp ~;., And the like; Grubbs et al, living ring-opening metathesis catalyst brochures etc.) and No. WO98 / 21214.

Among these, a metathesis polymerization catalyst comprising (a) a transition metal compound catalyst component and (b) a metal compound promoter component is preferable in order to adjust the molecular weight distribution of the obtained polymer to a suitable range.
Specific examples of the (a) transition metal compound catalyst component include TiCl ₄ , TiBr ₄ , VOCl ₃ , WBr ₃ , WCl ₆ , WOCl ₄ , MoCl ₅ , MoOCl ₄ , WO ₂ and H ₂ WO _4. . Of these, W, Mo, Ti, or V is preferable from the viewpoint of polymerization activity and the like, and these halides, oxyhalides, and alkoxy halides are particularly preferable.

  Specific examples of the metal compound promoter (b) include organoaluminum compounds such as trimethylaluminum, triisobutylaluminum, diethylaluminum monochloride, methylaluminum sesquichloride, ethylaluminum dichloride; tetramethyltin, diethyldimethyltin, tetrabutyltin. Organotin compounds such as tetraphenyltin; organolithium compounds such as n-butyllithium; organosodium compounds such as n-pentyl sodium; organomagnesium compounds such as methylmagnesium iodide; organozinc compounds such as diethylzinc; diethylcadmium Organic cadmium compounds such as; organic boron compounds such as trimethylboron; and the like. Of these, Group 13 metal compounds are preferred, and Al organic compounds are particularly preferred.

  In addition to the components (a) and (b), aliphatic tertiary amines, aromatic tertiary amines, molecular oxygen, alcohols, ethers, peroxides, carboxylic acids, acid anhydrides, acids Third components such as chloride, ester, ketone, nitrogen-containing compound, halogen-containing compound and other Lewis acid can be used in combination.

The compounding ratio of these components is (a) component: (b) component is a molar ratio of metal element, usually 1:
The range is 1-1: 100, preferably 1: 2 to 1:10. Moreover, (a) component: 3rd component is the range of 1: 0.005 to 1:50, preferably 1: 1 to 1:10 by molar ratio.

  The polymerization catalyst is used in a molar ratio of (transition metal in the polymerization catalyst) :( total monomer), usually 1: 100 to 1: 2,000,000, preferably 1: 1,000. ˜1: 20,000, more preferably 1: 5,000 to 1: 8,000. If the amount of the catalyst is too large, it is difficult to remove the catalyst after the polymerization reaction, and the molecular weight distribution may be widened. On the other hand, if the amount is too small, sufficient polymerization activity cannot be obtained.

The ring-opening polymerization can be carried out without a solvent, but is preferably carried out in a suitable solvent.
The organic solvent to be used is not particularly limited as long as the polymer and the polymer hydride are dissolved or dispersed under a predetermined condition and do not affect the polymerization and the hydrogenation reaction. Aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons and ethers are preferred.

In the ring-opening polymerization, an α-olefin molecular weight regulator such as 1-hexene can be added to the reaction system. The molecular weight of the resulting ring-opening polymer can be adjusted by adding a molecular weight regulator.
The molecular weight regulator may be added in an amount sufficient to obtain a polymer having a desired molecular weight, and is usually in a molar ratio of (molecular weight regulator) :( total monomer), usually 1:50 to 1: 1,000,000, preferably 1: 100 to 1: 5,000, more preferably 1: 300 to 1: 3,000.

Ring-opening polymerization is initiated by mixing the monomer and the polymerization catalyst. As the temperature, time, and pressure conditions for performing the ring-opening polymerization, general conditions as described in Patent Document 2 are adopted.
After completion of the reaction, the desired ring-opening polymer can be isolated by ordinary post-treatment operation.

The obtained ring-opening polymer is supplied to the next hydrogenation reaction step.
The hydrogenation reaction of the norbornene ring-opening polymer is a reaction in which the norbornene ring-opening polymer is hydrogenated to a carbon-carbon double bond existing in the main chain and / or side chain of the norbornene ring-opening polymer. This hydrogenation reaction is performed by adding a hydrogenation catalyst to an inert solvent solution of a norbornene-based ring-opening polymer and supplying hydrogen into the reaction system.

  As the hydrogenation catalyst, any one of a homogeneous catalyst and a heterogeneous catalyst can be used as long as it is generally used for hydrogenation of an olefin compound. Considering removal of residual metals in the polymer obtained, nickel / palladium such as nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium / alumina, etc. Platinum, rhodium, ruthenium, or a solid catalyst heterogeneous catalyst in which these metals are supported on a carrier such as carbon, silica, diatomaceous earth, alumina, titanium oxide or the like is preferable.

General conditions such as those described in Patent Document 2 may be adopted for the amount of catalyst used, hydrogenation reaction temperature, hydrogenation reaction time, hydrogen pressure, hydrogenation reaction solvent, and the like.
After completion of the hydrogenation reaction, the hydrogenation catalyst and the like are filtered off from the reaction solution, and a volatile component such as a solvent is removed from the polymer solution after the filtration to obtain a target norbornene-based ring-opening weight having a melting point. A combined hydride can be obtained. As a method for removing volatile components such as a solvent, a known method such as a solidification method or a direct drying method, which is a general resin drying method, as described in Patent Document 2 can be employed.

  The hydride of norbornene-based ring-opening polymer having a melting point has a hydrogenation rate of carbon-carbon double bonds in the polymer of 80% or more, preferably 90% or more, more preferably 95% or more, and further preferably 99%. Thus, the content is particularly preferably 99.9% or more. It is excellent in the light resistance of a resin layer as it exists in said range, and it is preferable.

The hydrogenation rate of the norbornene-based ring-opened polymer hydride obtained as described above (hereinafter sometimes referred to as “ring-opened polymer hydride”) is determined by ¹ H-NMR using deuterated chloroform as a solvent. It can be determined by measurement.

  The proportion of the norbornene-based ring-opening polymer hydride having a melting point with respect to all repeating units of the repeating unit (A) derived from 2-norbornene is 90 to 100% by weight, preferably 95 to 99% by weight, more preferably 97 to 99% by weight. 99% by weight, and the ratio of the repeating unit (B) derived from the substituent-containing norbornene monomer to the entire repeating unit is 0 to 10% by weight, preferably 1 to 5% by weight, more preferably 1 to 3%. % By weight.

  If the proportion of the repeating unit (B) is too large, the heat resistance and water vapor barrier property of the multilayer sheet may be deteriorated. When the proportion of the repeating unit (B) is within the above range, the water vapor barrier property is excellent, and the mechanical properties of the multilayer sheet are also excellent and preferable. Moreover, when there are too few repeating units (B), there exists a possibility that mechanical characteristics may fall.

  The weight average molecular weight (Mw) of the norbornene ring-opening polymer hydride having a melting point is preferably in terms of standard polystyrene by gel permeation chromatography (GPC) using 1,2,4-trichlorobenzene as an eluent. Is 50,000 to 200,000, more preferably 60,000 to 180,000, still more preferably 70,000 to 150,000.

  When the Mw of the norbornene-based ring-opening polymer hydride having a melting point is in this range, the solubility of the 2-norbornene ring-opening polymer hydrogenated product in the solvent is good, so that the polymer productivity is excellent. It is preferable because it is easy to purify and easy to mold, and the resulting multilayer sheet has good mechanical properties and heat resistance. On the other hand, if the Mw is too high, the melt viscosity becomes too high and the filterability is lowered, so that the productivity may be deteriorated. Also, when the resin is formed into a sheet, the film thickness accuracy of the sheet is increased. There is a need to increase the resin temperature, and die lines due to resin burning may occur. In addition, if Mw is too small, the mechanical properties and heat resistance of the molded product may be reduced, and the polymer hydrogenated product may be difficult to dissolve in the solution because of its crystallinity. Purification may be difficult.

The molecular weight distribution (Mw / Mn) of the norbornene-based ring-opening polymer hydride having a melting point is preferably 1.5 to 5.0, more preferably 2.0 to 4.5, and still more preferably 2.5 to 4. 0.0, particularly preferably 2.5 to 3.5.
When Mw / Mn is too narrow, the polymer is not easily dissolved in an organic solvent and may be precipitated. Moreover, when Mw / Mn is too wide, the mechanical properties of the multilayer sheet may be deteriorated.

The melting point (Tm) of the norbornene-based ring-opening polymer hydride having a melting point is usually 110 to 145 ° C, preferably 120 to 145 ° C, more preferably 130 ° C to 145 ° C.
A melting point in the above range is preferable because the heat resistance of the multilayer sheet is excellent.
The melting point of the hydride of norbornene-based ring-opening polymer having a melting point varies depending on the molecular weight, molecular weight distribution, isomerization rate, composition ratio, and the like.

  The isomerization rate of the norbornene-based ring-opening polymer hydride having a melting point is usually 0 to 40%, preferably 0 to 20%, more preferably 1 to 10%, and further preferably 3 to 9%. The isomerization rate can be measured by the method described in the examples below.

  If the isomerization rate of the norbornene-based ring-opening polymer hydride having a melting point is too high, the heat resistance may be lowered. On the other hand, if the isomerization rate is too low, the solubility of the polymer in the solution becomes poor, and the productivity of the polymer may be deteriorated. Therefore, the isomerization rate of the ring-opened polymer hydride may be 0%, but preferably exhibits a certain degree of isomerization within a range of 10% or less.

  In order to make the isomerization ratio within the above range, in the hydrogenation reaction of the ring-opening polymer, the reaction temperature is preferably 120 to 220 ° C, more preferably 160 to 200 ° C, and the use of a hydrogenation catalyst to be used. The amount is preferably 0.1 to 5 parts by weight, more preferably 0.1 to 1 part by weight with respect to 100 parts by weight of the ring-opening polymer.

Norbornene-based ring-opening polymer hydrides having a melting point can be used singly or in combination of two or more.
Furthermore, in the norbornene-type ring-opening polymer hydride having a melting point, various compounding agents (compounding agents usually used in the resin industry) can be used alone or in admixture as necessary.
Other compounding agents are not particularly limited as long as they are usually used in thermoplastic resin materials. For example, antioxidants, ultraviolet absorbers, light stabilizers, near infrared absorbers, dyes and pigments, etc. And colorants, plasticizers, antistatic agents, fluorescent whitening agents, and the like. Moreover, when a nucleating agent is blended, it becomes easy to control the crystal size.

Antiaging agents include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants are preferred, and alkyl-substituted phenolic antioxidants are particularly preferred. preferable. Antioxidants can be used alone or in combination of two or more. The blending amount of the antioxidant is appropriately selected within a range not impairing the object of the present invention. 5 parts by weight, preferably in the range of 0.01 to 1 part by weight.
In the present invention, the above components are mixed and used as necessary.
Each compounding agent is independently compounded in advance with a norbornene-based ring-opening polymer hydride having a melting point.
The mixing method is not particularly limited as long as the compounding agent is sufficiently dispersed in the polymer. For example, a method of kneading a resin in a molten state with a mixer, a single-screw kneader, a twin-screw kneader, a roll, a brabender, an extruder, etc., a solidifying method, a casting method, or direct drying by dissolving and dispersing in an appropriate solvent There is a method of removing the solvent by a method.
When a biaxial kneader is used, after kneading, it is usually extruded in a rod shape in a molten state, cut into an appropriate length with a strand cutter, and pelletized in many cases.

In the present invention, the resin layer B has a light transmittance at a wavelength of 250 to 365 nm adjusted to 50% or less, preferably 40% or less, more preferably 30% or less per 100 μm by blending a light-shielding substance with the resin. It is a thing.
There are no particular restrictions on the resin, but polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyamide, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, polyarylate, polyethersulfone, polysulfone , Amorphous cyclic olefin ring-opening polymer hydride, addition copolymer of cyclic olefin and α-olefin, and the like. Among these, polyethylene, amorphous cyclic olefin ring-opening polymer hydride, cyclic olefin and α-olefin addition copolymer are preferable in terms of low moisture permeability, excellent adhesion with layer A, and sheet productivity. In view of this, an amorphous cyclic olefin ring-opened polymer hydride or an addition copolymer of a cyclic olefin and an α-olefin is particularly preferable, and an amorphous cyclic olefin ring-opened polymer hydride is particularly preferable.

  Examples of the light shielding substance include pigments, dyes, inorganic fillers, carbon, and ultraviolet absorbers. Among these, an ultraviolet absorber is preferable because it does not increase the weight of the sheet but also has excellent light resistance of the resin layer and does not cause the resin layer to have conductivity. Although it does not specifically limit as an ultraviolet absorber, It is preferable that it is at least 1 type chosen from a benzotriazole type | system | group, a benzoate type | system | group, a benzophenone type | system | group, an acrylic type, and a metal complex type | system | group.

  Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole and 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro. -2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxy Phenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2) -Hydroxyphenyl) -2H-benzotriazole and the like.

  Examples of the benzoate ultraviolet absorber include 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate, 2,4-di-t-butylphenyl-3,5-di-t-butyl- 4-hydroxybenzoate, hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5,6- Tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole, and the like.

  Examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy-4- Octyloxybenzophenone, 4-dodecaloxy-2-hodoxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′- Examples include dimethoxybenzophenone.

  Examples of the acrylic ultraviolet absorber include ethyl-2-cyano-3,3-diphenyl acrylate, 2'-ethylhexyl-2-cyano-3,3-diphenyl acrylate, and the like.

  Examples of the metal complex ultraviolet absorber include [2,2'-thiobis (4-t-octylphenolate)]-2-ethylhexylamine nickel.

  These ultraviolet absorbers can be used alone or in combination of two or more.

  The blending amount of the ultraviolet absorber preferable as the light-shielding substance is 0.01 to 20 parts by weight, preferably 0.02 to 15 parts by weight, more preferably 100 parts by weight of the resin used for the resin layer B having the light-shielding property. Is 0.05 to 10 parts by weight.

There is no particular limitation on the method of blending the resin and the light-shielding substance, and a general method of mixing the compounding agent with the resin may be employed. Specifically, a method of kneading a resin in a molten state with a mixer, a single-screw kneader, a twin-screw kneader, a roll, a brabender, an extruder, etc., a solidifying method by dissolving and dispersing in an appropriate solvent, a casting method, Alternatively, there is a method of removing the solvent by a direct drying method.
When a biaxial kneader is used, after kneading, it is usually extruded in a rod shape in a molten state, cut into an appropriate length with a strand cutter, and pelletized in many cases.

  In the resin constituting the resin layer B, an additive can be blended in the same manner as the hydride of norbornene-based ring-opening polymer having a melting point.

  In the multilayer sheet of the present invention, for example, the resin layer B is disposed on both sides of the layer A. There is no particular restriction on the method for producing such a multilayer sheet, such as a method of laminating a sheet corresponding to the layer A and a sheet corresponding to the resin layer B, such as a dry laminating method and a heat laminating method, a melt extrusion method, etc. Is mentioned. A melt extrusion method is preferable. Specifically, the polymer and / or polymer mixture that forms the multilayer sheet is melted in an extruder, then the melt is extruded from a flat film extrusion die, and the resulting film is drawn into one or more rolls to cool and solidify. Then, if appropriate, the film is treated by known stretching methods, and / or thermosetting methods, and / or surface treatment methods.

    The melt discharged from the extruder is extruded from an annular die, and the resulting film is processed into an inflated film system to be filmed, crushed by a roll, and heat cured and / or surface treated as appropriate.

Moreover, the obtained multilayer sheet can be thermoset (heat treatment), and the multilayer sheet is held at a temperature of 100 to 160 ° C. for 0.5 to 10 seconds. Next, the multilayer sheet is wound up by a winding device in a conventional manner. One or more take-up rolls of the winding device are kept at a temperature of 20 to 90 ° C. when they have a function of cooling and solidifying the multilayer sheet.
Furthermore, one side or both sides of the multilayer sheet can be corona-treated or flame-treated by a known method.
The thickness of the multilayer sheet is preferably 10 to 1000 μm, more preferably 100 to 800 μm. When the thickness of the multilayer sheet is too thick, it is not preferable because the weight increases when used as a solar battery back sheet. If it is too thin, moisture permeability deteriorates, which is not preferable.
The thickness of the layer A is preferably 30% to 80% with respect to the total thickness. If the thickness of the layer A is too thick, the light resistance is lowered, which is not preferable. If it is too thin, the moisture permeability deteriorates, which is not preferable. The resin layers B arranged on both surfaces of the layer A are 1% or more, preferably 5% or more of the total thickness of the multilayer sheet from the viewpoint of light resistance, and both may be the same thickness or different thicknesses.

When the multilayer sheet has a thickness of 100 μm, the moisture permeability is preferably 0.5 g / m ² · 24 hr or less, more preferably 0.2 g / m ² · 24 hr or less, and particularly preferably 0.1 g / m ² · 24 hr or less. is there. If the moisture permeability is too high, the amount of moisture that permeates the protective sheet increases, which causes corrosion of the wiring and deterioration of the power generation element. In order to obtain a sheet (film) having low moisture permeability using a norbornene-based ring-opening polymer hydride having a melting point, slow cooling treatment or annealing treatment may be performed, but the cycle time becomes long. When another layer is formed on both sides of a layer made of a born norbornene-based ring-opening polymer hydride having a melting point, a layer A made of a norbornene-based ring-opening polymer hydride having a melting point is arranged on the inner layer. When it is taken up by the roll, the inner layer does not directly contact the roll, and is gradually cooled without a long cycle time. Therefore, the moisture permeability can be increased without performing an annealing treatment, so that a film excellent in moisture resistance and productivity can be provided.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited only to these examples. In the following examples and comparative examples, “part” or “%” is based on weight unless otherwise specified.

In the following Examples and Comparative Examples, various physical properties are measured as follows.
(1) The weight average molecular weight (Mw) and number average molecular weight (Mn) of the ring-opening polymer were measured as standard polystyrene conversion values by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as an eluent. .

  GPC-8020 series (DP8020, SD8022, AS8020, CO8020, RI8020, manufactured by Tosoh Corporation) was used as a measuring apparatus. As standard polystyrene, standard polystyrene (Mw is 500, 2630, 10200, 37900, 96400, 427000, 1090000, 5480000, a total of 8 points, manufactured by Tosoh Corporation) was used.

  The sample was prepared by dissolving the measurement sample in THF and filtering it with a cartridge filter (PTFE 0.5 μm) so that the sample concentration was 1 mg / ml.

  The measurement was performed using two TSKgel GMHHR · H (manufactured by Tosoh Corporation) connected in series to the column under the conditions of a flow rate of 1.0 ml / min, a sample injection amount of 100 μml, and a column temperature of 40 ° C.

(2) The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the ring-opened polymer hydride are standard by gel permeation chromatography (GPC) using 1,2,4-trichlorobenzene as an eluent. It measured as a polystyrene conversion value.

As a measuring device, HLC8121GPC / HT (manufactured by Tosoh Corporation) was used. As standard polystyrene, standard polystyrene (Mw is 988, 2580, 5910, 9010, 18000, 37700, 95900, 186000, 351000, 88
9000, 1050000, 2770000, 5110000, 7790,000, 20000000 in total, 16 points, manufactured by Tosoh Corporation) were used.

  The sample was prepared by heating and dissolving the measurement sample in 1,2,4-trichlorobenzene at 140 ° C. so that the sample concentration was 1 mg / ml.

  The measurement was performed using three TSKgel GMHHR · H (20) HT (manufactured by Tosoh Corporation) connected in series to the column under the conditions of a flow rate of 1.0 ml / min, a sample injection amount of 300 μml, and a column temperature of 140 ° C.

(3) The hydrogenation rate of the ring-opening polymer hydride was measured by 1H-NMR using deuterated chloroform as a solvent.

(4) The melting point was measured by using a differential scanning calorimeter (DSC 6220SII, manufactured by Nanotechnology) based on JIS K7121, after heating the sample to 30 ° C. or higher from the melting point to room temperature at a cooling rate of −10 ° C./min. After cooling, it was measured at a temperature elevation rate of 10 ° C./min.

(5) The glass transition temperature was measured based on JIS K 6911 using a differential scanning calorimeter (DSC6220SII, manufactured by Nanotechnology Inc.).
(6) The light transmittance (%) of the resin layer B is a spectrophotometer (V-570) prepared separately from the following examples and comparative examples by producing a single-layer sheet having a thickness of 100 μm, which is only the resin used for the layer B. , Manufactured by JASCO Corporation) at a wavelength of 250 to 365 nm.
(7) The moisture permeability of the multilayer sheet is measured under the conditions of temperature: 40 ° C., humidity:% RH based on JIS K 7129 (Method A) using a water vapor transmission tester (L80-5000 type, manufactured by LYSSY). did. The measurement was performed twice before and after irradiation for 500 hours using a fade meter (U48, manufactured by Suga Test Instruments Co., Ltd.) with an ultraviolet long life carbon arc lamp at an ultraviolet illuminance of ² mJ / m ² . The smaller the change in moisture permeability before and after UV irradiation, the better the light resistance.
(8) Dielectric breakdown voltage was measured in silicon oil at a temperature of 23 ° C. based on ASTM D 149 using a dielectric breakdown test apparatus (YST-243-100RHO, manufactured by Yamayo Tester). The measurement was performed twice before and after irradiation for 500 hours using a fade meter (U48, manufactured by Suga Test Instruments Co., Ltd.) with an ultraviolet long life carbon arc lamp at an ultraviolet illuminance of ² mJ / m ² . The smaller the change in moisture permeability before and after UV irradiation, the better the light resistance.

[Example 1]
(Ring-opening polymerization)
In a nitrogen atmosphere, 500 parts by weight of dehydrated cyclohexane, 0.55 parts by weight of 1-hexene, 0.30 parts by weight of diisopropyl ether, 0.20 parts by weight of triisobutylaluminum, and 0.075 parts by weight of isobutyl alcohol were reacted at room temperature. Then, while maintaining at 55 ° C., 250 parts by weight of 2-norbornene and 15 parts by weight of a 1.0 wt% toluene solution of tungsten hexachloride were continuously added over 2 hours for polymerization. The resulting ring-opening polymer (A) had a weight average molecular weight (Mw) of 83,000 and a molecular weight distribution (Mw / Mn) of 1.8.

(Hydrogenation reaction)
The polymerization reaction liquid containing the ring-opening polymer (A) obtained above was transferred to a pressure-resistant hydrogenation reactor, to which a diatomaceous earth-supported nickel catalyst (T8400, nickel support rate 58% by weight, manufactured by Nissan Zudhemy) 1 0.0 part by weight was added and reacted at 200 ° C. and hydrogen pressure 4.5 MPa for 6 hours. This solution was filtered through a filter equipped with a stainless steel wire mesh using diatomaceous earth as a filter aid to remove the catalyst. The obtained reaction solution was poured into 3000 parts by weight of isopropyl alcohol with stirring to precipitate a hydride and collected by filtration. Further, after washing with 500 parts by weight of acetone, it was dried in a vacuum drier set at 0.13 × 10 ³ Pa or less and 100 ° C. for 48 hours to obtain a norbornene-based ring-opening polymer hydride (A) having a melting point. 190 parts by weight were obtained.

(Polymer physical properties)
The hydrogenation rate of the obtained ring-opened polymer hydride (A) was 99.9%, the weight average molecular weight (Mw) was 82,200, the molecular weight distribution (Mw / Mn) was 2.9, and the isomerization rate was It was 5% and the melting point was 140 ° C.

(Preparation of resin composition for inner layer)
A biaxial kneading machine (TEM35, Toshiba Machine) was added to 0.1 parts by weight of a hindered phenolic antioxidant (IRGANOX 1010, manufactured by Ciba Geigy) to 100 parts by weight of a norbornene ring-opening polymer hydride (A) having a melting point. And pelletized resin A1 was obtained.

(Preparation of resin composition for outer layer)
100 parts by weight of ZEONOR 1410R (manufactured by Nippon Zeon Co., Ltd., hydrogenated amorphous cyclic olefin ring-opening polymer) is added with a benzotriazole-based UV absorber (TINUVIN 329, manufactured by Ciba Specialty Chemicals Co., Ltd., hereinafter referred to as “UV absorber A”). .) 0.5 parts by weight, 6 parts by weight of a hindered amine light stabilizer (CHIMASSORB 2020FDL, manufactured by Ciba Specialty Chemicals, hereinafter referred to as “light stabilizer A”) was added, and a twin-screw kneader (TEM35, Toshiba Machine) To obtain pelletized resin A2.

(Sheet molding)
Using these pellets, a hanger manifold type T-die film melt extrusion molding machine (stationary type, manufactured by GSI Creos) equipped with a screw with a screw diameter of 20 mmφ, a compression ratio of 3.1, and L / D = 30, T-die molding was performed under the following conditions to obtain a multilayer sheet (1) of resin A1 (thickness 300 μm) on the inner layer and resin A2 (thickness 50 μm each) on both sides.

Die lip: 0.8mm,
Molten resin temperature: Resin A1 210 ° C., Resin A2 260 ° C.,
T die width: 300mm,
Cooling roll temperature: 95 ° C
Cast roll temperature: 95 ° C.

  Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (1).

[Example 2]
Norbornene-based ring-opening polymer hydrogen having a melting point by performing ring-opening polymerization and hydrogenation reaction in the same manner except that 250 parts by weight of 2-norbornene was changed to 245 parts by weight of 2-norbornene and 5 parts by weight of dicyclopentadiene. 190 parts by weight of the compound (B) was obtained.

(Polymer physical properties)
The hydrogenation rate of the obtained norbornene-based ring-opening polymer hydride (B) having the melting point was 99.9%, the weight average molecular weight (Mw) was 80,500, and the molecular weight distribution (Mw / Mn) was 2.7. The isomerization rate was 5% and the melting point was 134 ° C.

(Preparation of resin composition for inner layer)
Using the norbornene-based ring-opening polymer hydride (B) having a melting point, a pelletized resin B1 was obtained in the same manner as in Example 1.

(Sheet molding)
Except for using pelletized resin B1 instead of pelletized resin A1, T-die molding was performed in the same manner as in Example 1, resin B1 (thickness 300 μm) on the inner layer, and resin A2 (thickness 50 μm each) on both sides A multilayer sheet (2) was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (2).

[Example 3]
(Preparation of resin composition for inner layer)
Instead of the pelletized resin A1, 70 parts by weight of pelletized resin A1 and 30 parts by weight of ZEONOR 1020R (manufactured by Nippon Zeon Co., Ltd., amorphous cyclic olefin ring-opened polymer hydride) Kneaded with TEM35 (manufactured by Toshiba Machine Co., Ltd.) to obtain pelletized resin C1.

(Sheet molding)
Except for using pelletized resin C1 instead of pelletized resin A1, T-die molding was performed in the same manner as in Example 1, resin C1 (thickness 300 μm) on the inner layer, and resin A2 (thickness 50 μm each) on both sides A multilayer sheet (3) was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (3).

[Example 4]
(Preparation of resin composition for outer layer)
Add 0.5 parts by weight of UV absorber A and 6 parts by weight of light stabilizer A to 100 parts by weight of Prime Polypro F109V (manufactured by Prime Polymer Co., Ltd., polypropylene) and knead with a twin screw kneader (TEM35, manufactured by Toshiba Machine Co., Ltd.) A pelletized resin B2 was obtained.

(Sheet molding)
T-die molding is performed in the same manner as in Example 1 except that the pelletized resin B2 is used instead of the pelletized resin A2 and the molten resin temperature on the outer layer side is changed from 260 ° C. to 220 ° C. A multilayer sheet (4) of A1 (thickness 300 μm) and resin B2 (thickness 50 μm each) on both sides thereof was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (4).

[Example 5]
(Preparation of resin composition for outer layer)
Add 0.5 parts by weight of UV absorber A and 6 parts by weight of light stabilizer A to 100 parts by weight of NOVAPEX GS400 (manufactured by Mitsubishi Chemical Corporation, polyethylene terephthalate), and knead with a biaxial kneader (TEM35, manufactured by Toshiba Machine Co., Ltd.). A pelletized resin C2 was obtained.

(Sheet molding)
T-die molding was performed in the same manner as in Example 1 except that the pelletized resin C2 was used instead of the pelletized resin A2, and the molten resin temperature on the outer layer side was changed from 260 ° C to 290 ° C. A multilayer sheet (5) of resin A1 (thickness 300 μm) and resin C2 (thickness 50 μm each) on both sides was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (5).

[Comparative Example 1]
(Preparation of resin composition for outer layer)
Pellets were produced in the same manner as in Example 1 except that ZEONOR 1410R (manufactured by Nippon Zeon Co., Ltd., amorphous cyclic olefin ring-opened polymer hydride) was not kneaded with UV absorber A and light stabilizer A. Resin D1 was obtained.

(Sheet molding)
T-die molding was performed in the same manner as in Example 1 except that pelletized resin D1 was used instead of pelletized resin A2, resin A1 (thickness 300 μm) on the inner layer, and resin D1 (thickness 50 μm each) on both sides Multilayer sheet (6) was obtained.
Table 1 shows the water vapor permeability and dielectric breakdown voltage of the obtained multilayer sheet (6) before and after ultraviolet irradiation.

[Comparative Example 2]
(Preparation of resin composition for outer layer)
Pellets were produced in the same manner as in Comparative Example 1 except that Kureha KF polymer (manufactured by Kureha, vinylidene fluoride resin) was used instead of ZEONOR 1410R (manufactured by Nippon Zeon Co., Ltd., hydrogenated amorphous cyclic olefin ring-opening polymer). Resin D2 was obtained.

(Sheet molding)
Instead of the pelletized resin A1, the pelletized resin D1 is used. Instead of the pelletized resin A2, the pelletized resin D2 is used. The molten resin temperature on the inner layer side is 210 ° C. to 260 ° C. T-die molding was performed in the same manner as in Example 1 except that the molten resin temperature was changed from 260 ° C. to 300 ° C., and a multilayer sheet of resin D1 (thickness 300 μm) on the inner layer and resin D2 (thickness 50 μm each) on both sides ( 7) was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after the ultraviolet irradiation of the obtained multilayer sheet (7).

[Comparative Example 3]
(Preparation of resin composition for outer layer)
Pelletization was carried out in the same manner as in Comparative Example 1 except that Hi-Zex 5000SF (manufactured by Prime Polymer Co., Ltd., high-density polyethylene) was used instead of ZEONOR 1410R (manufactured by ZEON Corporation, hydrogenated amorphous cyclic olefin ring-opening polymer). Resin E2 was obtained.

(Sheet molding)
T-die molding was performed in the same manner as in Comparative Example 2 except that pelletized resin E2 was used instead of pelletized resin D2, and the molten resin temperature on the outer layer side was changed from 260 ° C. to 220 ° C., and resin D1 was formed on the inner layer. A multilayer sheet (8) of resin E2 (thickness 50 μm each) was obtained (thickness 300 μm) on both sides thereof.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained multilayer sheet (8).

[Comparative Example 4]
(Sheet molding)
T-die molding was performed in the same manner as in Example 1 except that the pelletized resin D1 was used instead of the pelletized resins A1 and A2, and the molten resin temperature on the inner layer side was changed from 210 ° C. to 260 ° C. A multilayer sheet (9) of resin D1 (thickness 300 μm) and resin D1 (thickness 50 μm each) on both sides was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained single-layer film (9).

[Comparative Example 5]
(Sheet molding)
T-die molding is performed in the same manner as in Example 1 except that the pelletized resin A1 is used instead of the pelletized resin A2 and the molten resin temperature on the outer layer side is changed from 260 ° C. to 210 ° C. A multilayer sheet (10) of A1 (thickness 300 μm) and resin A1 (thickness 50 μm each) on both sides was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained single layer film (10).

[Comparative Example 6]
(Sheet molding)
T-die molding was performed in the same manner as in Example 1 except that the pelletized resin C1 was used instead of the pelletized resins A1 and A2, and the molten resin temperature on the inner layer side was changed from 210 ° C. to 260 ° C. A multilayer sheet (11) of resin C1 (thickness 300 μm) and resin C1 (thickness 50 μm each) on both sides was obtained.
Table 1 shows the water vapor permeability and breakdown voltage before and after ultraviolet irradiation of the obtained single layer film (11).

(Discussion)
The table shows the following.
In the multilayer sheet of the present invention, the layer A is prepared using a hydride of norbornene-based ring-opening polymer having a specific melting point, and the light transmittance at a wavelength of 250 to 365 nm is 50% or less per 100 μm. However, since it is arrange | positioned on both surfaces of the layer A, it turns out that the change of the water vapor transmission rate before and behind a light resistance test and a dielectric breakdown voltage is very small (Examples 1-5).
On the other hand, it can be seen that a film made of a resin layer having a light transmittance at a wavelength of 250 to 365 nm of the resin layer B of 50% or more per 100 μm has a large change in moisture permeability and dielectric breakdown voltage before and after the light resistance test (comparison). Example 1, 3).
Moreover, since the norbornene-type ring-opening polymer hydride which does not have melting | fusing point is used for the resin layer A, it turns out that moisture permeability is high (comparative example 2).
Furthermore, it turns out that the change of the moisture permeability before and behind a light resistance test and a dielectric breakdown voltage is large for the single layer film which consists of resin layer A and resin layer B from the same resin (Comparative Examples 4-6).

Claims (1)

2-norbornene and a substituent-containing norbornene-based monomer are 90 to 100% by weight of the repeating unit (a) derived from 2-norbornene based on all repeating units, and a repeating unit derived from a substituent-containing norbornene-based monomer ( It is obtained by hydrogenating 80% or more of the main chain carbon-carbon double bond of the ring-opening polymer obtained by ring-opening polymerization in a proportion of 10 to 0% by weight with respect to all repeating units of b). Ring-opening polymer hydride of 2-norbornene and a substituent-containing norbornene-based monomer, which is a ring-opening polymer hydrogen of 2-norbornene and a substituent-containing norbornene-based monomer having a melting point of 110 to 145 ° C. The resin layer B having a layer A made of a chemical compound as an intermediate layer and having a light transmittance at a wavelength of 250 to 365 nm of 50% or less per 100 μm is disposed on both sides of the layer A. Electrical insulating properties are multi-layer sheet - door.