Polymer composition and polymer sheet

Abstract

To provide a polymer composition capable of forming a polymer composition layer that suppresses peeling of a back sheet layer and exhibits a high water-vapor-infiltration barrier property (as a sealing material). Provided is a polymer composition containing the following components: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; (A3) a liquid olefin polymer having neither an acid anhydride group nor a carboxyl group; and (B) a water-absorbing filler, wherein the content of the (A1) liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12 mass% or more relative to 100 mass% of the nonvolatile fraction of the polymer composition and the content of the (A3) liquid olefin polymer having neither an acid anhydride group nor a carboxyl group is 4 mass% or less relative to 100 mass% of the nonvolatile fraction of the polymer composition.

Description

Polymer composition and polymer sheet

[0001] The present invention relates to a polymer composition useful for encapsulating electronic devices and the like, and a polymer sheet having a laminated structure including a polymer composition layer formed from the polymer composition.

[0002] To protect electronic devices, such as organic light-emitting diodes (OLEDs), that are sensitive to moisture, from moisture, there is a demand for encapsulants using resin compositions containing moisture-absorbing materials. While encapsulants can be in liquid or sheet form, sheet-shaped encapsulants are preferred because they can be attached to electronic devices for encapsulation. For example, Patent Document 1 proposes an encapsulating sheet containing a polymer composition layer using calcium oxide as a moisture-absorbing material, claiming that it can suppress horizontal moisture penetration. On the other hand, to prevent vertical moisture penetration, it is preferable to use a backsheet with low water vapor permeability (e.g., glass, inorganic compound-deposited PET, metal PET laminate, etc.). To prevent both horizontal and vertical moisture penetration, it is preferable to laminate a layer formed from an encapsulating resin composition and a backsheet. Patent Document 2 proposes a resin composition containing a polymer-containing resin, moisture-absorbing particles such as calcium oxide, and an organic solvent-soluble dispersant, and a resin film (for encapsulating electronic devices) formed from the resin composition into a film, claiming that it suppresses moisture penetration.

[0003] JP 2022-21714 A Patent No. 7264067 A

[0004] However, if the flexibility of the backsheet and the resin composition layer is low, the electronic device cannot be bent. On the other hand, if the flexibility of the backsheet is too high, the backsheet will warp during a high-temperature, high-humidity resistance test, and the backsheet will likely peel off. Furthermore, if the flexibility of the resin composition layer is too high, the warping of the backsheet will cause the resin composition layer to tear (peel off the backsheet due to cohesive failure). Furthermore, if a large amount of water-absorbent filler such as calcium oxide is added to improve the moisture barrier property of the resin composition layer, the flexibility will likely decrease.

[0005] The present invention has been made in light of the above-mentioned circumstances, and an object of the present invention is to provide a polymer composition that can form a polymer composition layer (as an encapsulant) that is inhibited from peeling off a backsheet layer and exhibits high water vapor barrier properties.

[0006] As a result of intensive investigations aimed at solving the above problems, the present inventors have found that a polymer composition containing the following components (A1), (A2), (A3), and (B) can be obtained that is capable of forming a polymer composition layer (as an encapsulant) that is inhibited from peeling off a backsheet layer and exhibits high water vapor barrier properties, and have thus completed the present invention.

[0007] That is, the present invention has the following features. [1] A polymer composition containing the following components: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; (A3) a liquid olefin polymer having neither an acid anhydride group nor a carboxyl group; and (B) a water-absorbing filler, wherein the content of (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12% by mass or more, based on 100% by mass of the non-volatile content of the polymer composition, and the content of (A3) the liquid olefin polymer having neither an acid anhydride group nor a carboxyl group is 4% by mass or less, based on 100% by mass of the non-volatile content of the polymer composition. [2] The polymer composition according to [1], wherein a polymer composition layer formed from the polymer composition has a storage modulus at 85°C of 0.05 MPa or more. [3] The polymer composition according to [1] or [2], wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group has a number average molecular weight of 950 or more. [4] The polymer composition according to any one of [1] to [3], wherein the content of (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12 to 20 mass% based on 100 mass% of the nonvolatile content of the polymer composition. [5] The polymer composition according to any one of [1] to [4], wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is an acid anhydride-modified liquid olefin polymer. [6] The polymer composition according to any one of [1] to [5], wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is a maleic anhydride-modified liquid olefin polymer. [7] The polymer composition according to any one of [1] to [6], wherein (A2) the solid olefin polymer is an unmodified or epoxy-modified solid olefin polymer. [8] The polymer composition according to any one of [1] to [7], wherein the content of the solid olefin-based polymer (A2) is 2 to 50 mass% relative to 100 mass% of the nonvolatile content of the polymer composition.[9] The polymer composition according to any one of [1] to [8], wherein the content of the liquid olefin polymer having neither an acid anhydride group nor a carboxyl group (A3) is 1 to 4 mass% relative to 100 mass% of the nonvolatile content of the polymer composition.

[10] The polymer composition according to any one of [1] to [9], wherein the median diameter of the water-absorbing filler (B) is 0.3 to 5 μm.

[11] The BET specific surface area of ​​the water-absorbing filler (B) is 1 to 30 m. ２ / g.

[12] A polymer sheet having a laminated structure including a polymer composition layer formed from the polymer composition according to any one of [1] to

[11] .

[13] The polymer sheet according to

[12] , which has a back sheet layer laminated on the polymer composition layer.

[14] The polymer sheet according to

[13] , wherein the back sheet layer has a storage modulus at 85°C of 1,000 MPa or more and 100,000 MPa or less.

[15] The polymer sheet according to any one of

[12] to

[14] , which is used for sealing an electronic device.

[16] An electronic device sealed with the polymer sheet according to any one of

[12] to

[15] .

[0008] The present invention also has the following features. [1] A polymer composition comprising the following components: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; and (B) a water-absorbing filler, wherein a polymer composition layer formed from the polymer composition has a storage modulus of 0.05 MPa or more at 85°C. [2] The polymer composition according to [1], wherein the number-average molecular weight of the liquid olefin polymer having an acid anhydride group and / or a carboxyl group (A1) is 950 or more. [3] The polymer composition according to [1] or [2], wherein the content of the liquid olefin polymer having an acid anhydride group and / or a carboxyl group (A1) is 2 to 20 mass% based on 100 mass% of the nonvolatile content of the polymer composition. [4] The polymer composition according to any one of [1] to [3], wherein the liquid olefin polymer having an acid anhydride group and / or a carboxyl group (A1) is an acid anhydride-modified liquid olefin polymer. [5] The polymer composition according to [4], wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is a maleic anhydride-modified liquid olefin polymer. [6] The polymer composition according to any one of [1] to [5], wherein (A2) the solid olefin polymer is an unmodified or epoxy-modified solid olefin polymer. [7] The polymer composition according to any one of [1] to [6], wherein the content of (A2) the solid olefin polymer is 2 to 50 mass% relative to 100 mass% of the nonvolatile content of the polymer composition. [8] The polymer composition according to any one of [1] to [7], wherein (B) the water-absorbing filler has a median diameter of 0.3 to 5 μm. [9] The water-absorbing filler has a BET specific surface area of ​​1 to 30 m ２ / g.

[10] A polymer sheet having a laminated structure including a polymer composition layer formed from the polymer composition according to any one of [1] to [9].

[11] The polymer sheet according to

[10] , having a back sheet layer laminated on the polymer composition layer.

[12] The polymer sheet according to

[11] , wherein the back sheet layer has a storage modulus at 85°C of 1,000 MPa or more and 100,000 MPa or less.

[13] The polymer sheet according to any one of

[10] to

[12] , which is used for sealing an electronic device.

[14] An electronic device sealed with the polymer sheet according to any one of

[10] to

[13] .

[0009] According to the present invention, it is possible to provide a polymer composition capable of forming a polymer composition layer (as an encapsulant) that is inhibited from peeling off a back sheet layer and that exhibits high water vapor barrier properties, and a polymer sheet having a laminate structure including a polymer composition layer formed from the polymer composition.

[0010] The present invention will be described below with reference to preferred embodiments. [Polymer composition] The polymer composition of the present invention contains the following essential components: (A1) component, (A2) component, (A3) component, and (B) component: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; (A3) a liquid olefin polymer having neither an acid anhydride group nor a carboxyl group; and (B) a water-absorbing filler, wherein the content of (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12% by mass or more, based on 100% by mass of the non-volatile content of the polymer composition, and the content of (A3) the liquid olefin polymer having neither an acid anhydride group nor a carboxyl group is 4% by mass or less, based on 100% by mass of the non-volatile content of the polymer composition.

[0011] The polymer composition of the present invention also contains the following components (A1), (A2), and (B) as essential components: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; and (B) a water-absorbing filler, and a polymer composition layer formed from the polymer composition has a storage modulus at 85°C of 0.05 MPa or more.

[0012] In this specification, "olefin polymer" means a polymer in which structural units derived from olefins (hereinafter sometimes abbreviated as "olefin units") are the main structural units (i.e., the amount of olefin units is the largest among all structural units). Note that, hereinafter, "structural units derived from butene," which are olefin units, may be abbreviated as "butene units," etc.

[0013] The olefin polymer may be an olefin resin (e.g., a propylene-butene copolymer) or an olefin rubber (e.g., a butyl rubber, i.e., an isobutylene-isoprene copolymer). In this specification, "olefin resin" means an olefin polymer that cannot form a rubbery elastomer by crosslinking, and "olefin rubber" means an olefin polymer that can form a rubbery elastomer by crosslinking.

[0014] The olefin is preferably a monoolefin having one olefinic carbon-carbon double bond and / or a diolefin having two olefinic carbon-carbon double bonds. Examples of monoolefins include α-olefins such as ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Examples of diolefins include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene.

[0015] The olefin-based polymer may be a homopolymer or a copolymer. The copolymer may be a random copolymer or a block copolymer. The olefin-based polymer may also be a copolymer of an olefin and a monomer other than an olefin. Examples of the olefin-based copolymer include an ethylene-non-conjugated diene copolymer, an ethylene-propylene copolymer, an ethylene-propylene-non-conjugated diene copolymer, an ethylene-butene copolymer, an ethylene-propylene-butene copolymer, a propylene-butene copolymer, a propylene-butene copolymer, a propylene-butene-non-conjugated diene copolymer, an isobutylene-isoprene copolymer, a styrene-isobutylene copolymer, a styrene-isobutylene-styrene copolymer, a styrene-butylene-butadiene copolymer, and a styrene-ethylene-butylene copolymer.

[0016] Each component will be described in detail below. Unless otherwise specified in this specification, each component may be used alone or in combination of two or more types.

[0017] <Component (A1)> The component (A1) is a liquid olefin polymer having an acid anhydride group (i.e., a carbonyloxycarbonyl group (—CO—O—CO—)) and / or a carboxyl group. Examples of the acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, and a group derived from glutaric anhydride. The component may have one or more types of acid anhydride groups. By incorporating the component (A1), it is possible to obtain a polymer composition layer that is resistant to deformation and can maintain its shape. Without incorporating the component (A1), film formation is difficult. Furthermore, the component (A1) forms a crosslinked structure through a crosslinking reaction between the acid anhydride group and the carboxyl group, or through coordination of the acid anhydride group and the carboxyl group to a water-absorbing filler (such as calcium oxide), thereby enabling the water-absorbing filler (component (B)) to be dispersed well in the polymer composition and also enabling the component to exhibit water vapor barrier properties.

[0018] In the present invention, the term "liquid" in "liquid olefin polymer" means that the viscosity at 25°C is 5,000 Pa s or less. Furthermore, in the present invention, the term "viscosity at 25°C" means the viscosity calculated by multiplying the kinematic viscosity at 25°C measured with a dynamic viscoelasticity measuring device by the density. Examples of dynamic viscoelasticity measuring devices include a rheometer (product name: DISCOVERY HR-2) manufactured by TA Instruments.

[0019] The viscosity of the component (A1) at 25°C is preferably 5 to 5,000 Pa s, more preferably 10 to 4,000 Pa s, and even more preferably 20 to 3,000 Pa s, from the viewpoints of good adhesion to the backsheet layer and flexibility of the resulting polymer composition layer.

[0020] When a liquid olefin polymer having acid anhydride groups is used as component (A1), the concentration of acid anhydride groups in the polymer is preferably 0.05 to 10 mmol / g, more preferably 0.10 to 5 mmol / g. The concentration of acid anhydride groups is determined from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of polymer, in accordance with JIS K 2501.

[0021] When a liquid olefin polymer having carboxyl groups is used as component (A1), the concentration of carboxyl groups in the polymer is preferably 0.05 to 20 mmol / g, more preferably 0.10 to 10 mmol / g. The concentration of carboxyl groups is determined from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of polymer, in accordance with JIS K 2501.

[0022] When a liquid olefin polymer having an acid anhydride group and a carboxyl group is used as the component (A1), the total concentration of the acid anhydride group and the carboxyl group in the polymer is preferably 0.05 to 20 mmol / g, and more preferably 0.10 to 10 mmol / g.

[0023] The component (A1) can be produced, for example, by (i) graft-modifying an olefin polymer with an unsaturated compound having an acid anhydride group and / or a carboxyl group (e.g., maleic anhydride) under radical reaction conditions, or by (ii) copolymerizing an unsaturated compound having an acid anhydride group and / or a carboxyl group with an α-olefin.

[0024] In one embodiment of the present invention, the component (A1) is liquid, (i) preferably at least one selected from the group consisting of polybutene having acid anhydride groups and / or carboxyl groups, isobutylene-isoprene copolymer having acid anhydride groups and / or carboxyl groups (i.e., butyl rubber), ethylene-propylene copolymer having acid anhydride groups and / or carboxyl groups, propylene-butene copolymer having acid anhydride groups and / or carboxyl groups, ethylene-methyl methacrylate copolymer having acid anhydride groups and / or carboxyl groups, styrene-butylene-butadiene copolymer having acid anhydride groups and / or carboxyl groups, styrene-ethylene-butylene copolymer having acid anhydride groups and / or carboxyl groups, and ethylene-propylene-butene copolymer having acid anhydride groups and / or carboxyl groups, (ii) More preferably, it is at least one selected from the group consisting of polybutene having an acid anhydride group and / or a carboxyl group, isobutylene-isoprene copolymer having an acid anhydride group and / or a carboxyl group, ethylene-propylene copolymer having an acid anhydride group and / or a carboxyl group, styrene-ethylene-butylene copolymer having an acid anhydride group and / or a carboxyl group, and propylene-butene copolymer having an acid anhydride group and / or a carboxyl group; (iii) Even more preferably, it is at least one selected from the group consisting of polybutene having an acid anhydride group, isobutylene-isoprene copolymer having an acid anhydride group, ethylene-propylene copolymer having an acid anhydride group, propylene-butene copolymer having an acid anhydride group, and styrene-ethylene-butylene copolymer having an acid anhydride group; (iv) Particularly preferably, it is at least one selected from the group consisting of polybutene having an acid anhydride group, isobutylene-isoprene copolymer having an acid anhydride group, and ethylene-propylene copolymer having an acid anhydride group.

[0025] In another embodiment of the present invention, the component (A1) is preferably an acid anhydride-modified liquid olefin polymer, more preferably a maleic anhydride-modified liquid olefin polymer. Note that the terms "acid anhydride-modified liquid olefin polymer" and "maleic anhydride-modified liquid olefin polymer" are synonymous with "liquid olefin polymer having an acid anhydride group" and "liquid olefin polymer having a maleic anhydride group."

[0026] The number average molecular weight of the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is not particularly limited, but from the viewpoints of preventing cissing during application of a varnish of the polymer composition, imparting moisture resistance to the formed polymer composition layer, and improving mechanical strength, the number average molecular weight is preferably 950 or more, more preferably 1,200 or more. On the other hand, from the viewpoints of achieving good application properties of a varnish of the polymer composition and good compatibility with other components in the polymer composition, the number average molecular weight is preferably 20,000 or less, more preferably 6,000 or less. The number average molecular weight in the present invention is measured by gel permeation chromatography (GPC) (polystyrene equivalent).

[0027] (GPC measurement conditions) Measuring apparatus: "HLC-8420GPC" manufactured by Tosoh Corporation Column: Guard column "HXL-L" manufactured by Tosoh Corporation + "TSK-GEL SuperHZ2000" manufactured by Tosoh Corporation + "TSK-GEL SuperHZ2000" manufactured by Tosoh Corporation + "TSK-GEL SuperHZ3000" manufactured by Tosoh Corporation + "TSK-GEL SuperHZ4000" manufactured by Tosoh Corporation Detector: RI (differential refractometer) Data processing: "GPC workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation Column temperature: 40°C Developing solvent: tetrahydrofuran Flow rate: 0.35 mL / min Standard: In accordance with the measurement manual for the "GPC workstation EcoSEC-WorkStation", the following monodisperse polystyrene with a known molecular weight is used. TSKgel F-80, F-10, A-5000, A-500 (manufactured by Tosoh Corporation) Sample: 0.2% by mass (in terms of resin solid content) tetrahydrofuran solution filtered through a microfilter (10 μL)

[0028] Next, specific examples of liquid olefin polymers having acid anhydride groups and / or carboxyl groups will be described. Specific examples of polyisobutylene resins or polybutene resins include "HV-300M" (acid value: 65 mg KOH / g, acid anhydride group concentration: 1.16 mmol / g, number average molecular weight: 2,100) manufactured by Toho Chemical Industry Co., Ltd., "HV-100M" (acid value: 82 mg KOH / g, acid anhydride group concentration: 1.46 mmol / g, number average molecular weight: 1,218) manufactured by Toho Chemical Industry Co., Ltd., and "DOVERMULSE H1000" (acid value: 54 mg KOH, acid anhydride group concentration: 0.96 mmol / g, number average molecular weight: 1,204) manufactured by DOVER. A specific example of the ethylene-propylene copolymer is "Lucant A-5260" manufactured by Mitsui Chemicals, Inc. (acid anhydride group concentration: 0.44 mmol / g, number average molecular weight: 5,400).

[0029] The content of component (A1) in the polymer composition of the present invention is not particularly limited. However, from the viewpoint of imparting good coatability and moldability and ensuring ease of handling (suppression of tack), the content is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to 100% by mass of the nonvolatile content of the polymer composition. On the other hand, from the viewpoint of ensuring good wet heat resistance and dispersibility of the water-absorbing filler (component (B)), the content is preferably 2% by mass or more, more preferably 9% by mass or more, and particularly preferably 16% by mass or more, relative to 100% by mass of the nonvolatile content of the polymer composition. In one embodiment of the present invention, the content of component (A1) is preferably 2 to 40% by mass, more preferably 9 to 30% by mass, and even more preferably 16 to 20% by mass, relative to 100% by mass of the nonvolatile content of the polymer composition. In another embodiment of the present invention, the content of component (A1) is preferably 2 to 20% by mass, relative to 100% by mass of the nonvolatile content of the polymer composition. In yet another embodiment of the present invention, the content of the component (A1) is 12% by mass or more, preferably 13% by mass or more, more preferably 14% by mass or more, even more preferably 15% by mass or more, and still more preferably 16% by mass or more, based on 100% by mass of the nonvolatile content of the polymer composition. In yet another embodiment of the present invention, the content of the component (A1) is preferably 12 to 20% by mass, based on 100% by mass of the nonvolatile content of the polymer composition.

[0030] <Component (A2)> The component (A2) is a solid olefin-based polymer. By incorporating the component (A2), the water vapor barrier property, mechanical strength, and elastic modulus of the resulting polymer composition layer can be improved. In the present invention, the term "solid" in the term "solid olefin-based polymer" means that the viscosity at 25°C exceeds 5,000 Pa s.

[0031] In the present invention, the component (A2) is not particularly limited as long as it is a solid olefin polymer, and may be either unmodified or epoxy-modified.

[0032] When an unmodified solid olefin polymer is used as the component (A2), its number average molecular weight is preferably 20,000 or more, more preferably 50,000 or more, and even more preferably 100,000 or more, from the viewpoint of improving the mechanical strength and elastic modulus of the resulting polymer composition layer.

[0033] As the unmodified solid olefin polymer, commercially available products can be used, such as "HYBRAR7311F" (styrene-ethylene-ethylene-propylene-styrene copolymer) manufactured by Kuraray Co., Ltd.

[0034] The unmodified solid olefin polymer as component (A2) is preferably a styrene-ethylene-ethylene-propylene-styrene copolymer.

[0035] When an epoxy-modified solid olefin polymer is used as component (A2), the term “epoxy-modified solid olefin polymer” is synonymous with “solid olefin polymer having epoxy groups.” The epoxy groups of the epoxy-modified solid olefin polymer form a crosslinked structure by reacting with the acid anhydride groups / carboxyl groups in the liquid olefin polymer (component (A1)) having acid anhydride groups and / or carboxyl groups, thereby improving the water vapor barrier property, mechanical strength, and elastic modulus of the resulting polymer composition layer.

[0036] The epoxy group concentration in the epoxy-modified solid olefin polymer is preferably 0.05 to 10 mmol / g, more preferably 0.10 to 5 mmol / g, and is determined from the epoxy equivalent weight according to JIS K 7236-1995.

[0037] The epoxy-modified solid olefin polymer preferably has a number average molecular weight of 1,000 to 1,000,000, more preferably 2,000 to 500,000, and even more preferably 2,000 to 200,000, from the viewpoints of achieving good coatability of the varnish of the polymer composition and improving the sealing performance, mechanical strength, and elastic modulus of the formed polymer composition layer.

[0038] The epoxy-modified solid olefin polymer can be obtained, for example, by (i) graft-modifying an olefin polymer with an unsaturated compound having an epoxy group (e.g., glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether) under radical reaction conditions, or by (ii) copolymerizing an unsaturated compound having an epoxy group with an α-olefin.

[0039] Commercially available epoxy-modified solid olefin polymers can be used. Examples of such commercially available products include "ER829" (glycidyl methacrylate-modified propylene-butene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 400,000) manufactured by Seiko PMC Co., Ltd., "T-YP276" (glycidyl methacrylate-modified propylene-butene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 57,000) manufactured by Seiko PMC Co., Ltd., and "ER850" (glycidyl methacrylate-modified isobutylene-isoprene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 57,000) manufactured by Seiko PMC Co., Ltd. random copolymer, epoxy group concentration: 0.654 mmol / g, number average molecular weight: 99,200), "ER899" manufactured by Seiko PMC Corporation (glycidyl methacrylate modified butyl rubber, isobutene unit / isoprene unit: 98.9% / 1.1%, epoxy group concentration: 1.63 mmol / g, number average molecular weight: 102,000 (non-volatile content: 28%)), and "BF-7M" manufactured by Sumitomo Chemical Co., Ltd. (ethylene-glycidyl methacrylate-methyl acrylate copolymer, melt flow rate: 7 g / 10 min).

[0040] The epoxy-modified solid olefin polymer is a solid: (i) preferably at least one selected from the group consisting of ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, propylene-butene copolymer having epoxy groups, isobutylene-isoprene copolymer having epoxy groups (i.e., butyl rubber), and ethylene-methyl methacrylate copolymer having epoxy groups; (ii) more preferably at least one selected from the group consisting of propylene-butene copolymer having epoxy groups, isobutylene-isoprene copolymer having epoxy groups, and ethylene-methyl methacrylate copolymer having epoxy groups; (iii) still more preferably propylene-butene copolymer having epoxy groups and / or isobutylene-isoprene copolymer having epoxy groups; and (iv) particularly preferably propylene-butene copolymer having epoxy groups, or isobutylene-isoprene copolymer having epoxy groups.

[0041] When a propylene-butene copolymer having an epoxy group is used as the epoxy-modified solid olefin polymer, the amount of butene units in the copolymer is preferably 1 to 50 mass %, more preferably 2 to 45 mass %, and even more preferably 3 to 40 mass %, based on the total of propylene units and butene units. The amount of butene units is based on the propylene units and butene units excluding modified portions (for example, portions derived from glycidyl (meth)acrylate for introducing epoxy groups).

[0042] When an isobutylene-isoprene copolymer having epoxy groups (i.e., butyl rubber) is used as the epoxy-modified solid olefin polymer, the amount of isoprene units in the copolymer is preferably 0.1 to 20 mass%, more preferably 0.3 to 15 mass%, and even more preferably 0.5 to 10 mass%, based on the total of isobutylene units and isoprene units, from the viewpoint of yellowing resistance of the polymer composition layer, etc. The amount of isoprene units is based on the isobutylene units and isoprene units excluding modified portions (e.g., portions derived from glycidyl (meth)acrylate for introducing epoxy groups).

[0043] The content of component (A2) in the polymer composition of the present invention is not particularly limited. However, from the viewpoints of the water vapor barrier property, mechanical strength, and elastic modulus of the formed polymer composition layer, the content is preferably 1% by mass or more, more preferably 1.5% by mass or more, and particularly preferably 2% by mass or more, relative to 100% by mass of the nonvolatile content of the polymer composition. On the other hand, from the viewpoints of good adhesion and flexibility of the formed polymer composition layer to the backsheet layer, and of ensuring handleability (suppression of tack), the content is preferably 50% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less, relative to 100% by mass of the nonvolatile content of the polymer composition. In one embodiment of the present invention, the content of component (A2) is preferably 1 to 50% by mass, more preferably 2 to 20% by mass, and even more preferably 2 to 10% by mass, relative to 100% by mass of the nonvolatile content of the polymer composition. In another embodiment of the present invention, the content of component (A2) is preferably 2 to 50% by mass, relative to 100% by mass of the nonvolatile content of the polymer composition.

[0044] The total content of the components (A1) and (A2) in the polymer composition of the present invention is not particularly limited, but from the viewpoint of ensuring good wet heat resistance and adhesiveness, the total content is preferably 5 to 55 mass%, more preferably 10 to 50 mass%, and even more preferably 15 to 45 mass%, based on 100 mass% of the nonvolatile content of the polymer composition.

[0045] <Component (B)> The component (B) is a water-absorbing filler. By adding the component (B), it is possible to impart water vapor barrier properties to the formed polymer composition layer.

[0046] The water-absorbing filler is not particularly limited as long as it is a filler capable of absorbing moisture, and examples thereof include metal oxides such as calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, barium oxide, calcined hydrotalcite, and calcined dolomite, metal hydroxides such as calcium hydroxide, magnesium hydroxide, strontium hydroxide, aluminum hydroxide, barium hydroxide, and semi-calcined hydrotalcite, and molecular sieves. Among these, calcium oxide and semi-calcined hydrotalcite are preferred from the viewpoint of water absorbency, and semi-calcined hydrotalcite is preferred from the viewpoint of transparency, and calcium oxide is preferred from the viewpoint of water vapor barrier properties. Only one type of water-absorbing filler may be used, or two or more types may be used in combination.

[0047] The median diameter (D50) of component (B) is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less to prevent the water-absorbing filler from damaging the electronic device during the encapsulation process. From the viewpoint of dispersibility of component (B) in the polymer composition, the median diameter (D50) is preferably 0.2 μm or more, more preferably 0.3 μm or more, and even more preferably 0.4 μm or more. In one embodiment of the present invention, the median diameter of component (B) is preferably 0.2 to 20 μm, more preferably 0.3 to 10 μm, and even more preferably 0.4 to 5 μm. The median diameter of component (B) can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the measurement can be performed by creating a particle size distribution of component (B) on a volume basis using a laser diffraction particle size distribution analyzer. A measurement sample prepared by dispersing component (B) in ethanol using ultrasonic waves can be preferably used. As the laser diffraction scattering particle size distribution measuring device, an LA-500 manufactured by Horiba Ltd. or the like can be used.

[0048] The BET specific surface area of ​​the component (B) is preferably 1 m² from the viewpoint of the water vapor barrier properties of the polymer composition layer to be formed. ２ / g or more, more preferably 1.5m ２ / g or more, and more preferably 2m ２ On the other hand, from the viewpoint of dispersibility of the component (B) in the polymer composition, it is preferably 50 m / g or more. ２ / g, and more preferably 30m ２ / g or less, and particularly preferably 25m ２ In one embodiment of the present invention, the BET specific surface area of ​​component (B) is preferably 1 to 50 m ２ / g, more preferably 1.5 to 30m ２ / g, and more preferably 2 to 25m ２ The BET specific surface area of ​​component (B) can be calculated according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountech Co., Ltd.) and then using the BET multipoint method.

[0049] The content of the (B) component is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on 100% by mass of the nonvolatile content of the polymer composition, from the viewpoint of the water vapor barrier property of the polymer composition layer, and is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, based on 100% by mass of the nonvolatile content of the polymer composition. In one embodiment of the present invention, the content of the (B) component is preferably 5 to 80% by mass, more preferably 10 to 75% by mass, and even more preferably 15 to 70% by mass, based on 100% by mass of the nonvolatile content of the polymer composition.

[0050] In the polymer composition of the present invention, in dynamic viscoelasticity measured with a rheometer, the storage modulus of a polymer composition layer formed from the polymer composition at a frequency of 1 Hz and 85°C is preferably 0.05 MPa or more, more preferably 0.06 MPa or more from the viewpoint of high-temperature, high-humidity durability of the formed polymer composition layer, and is preferably 100,000 MPa or less, more preferably 50,000 MPa or less, from the viewpoint of ensuring good flexural resistance. It has been experimentally shown that there is a correlation between the storage modulus in dynamic viscoelasticity measured with a rheometer and the presence or absence of peeling of the backsheet layer in a high-temperature, high-humidity environment. By setting the storage modulus at a frequency of 1 Hz and 85°C to 0.05 MPa or more, peeling of the backsheet layer in a high-temperature, high-humidity environment can be suppressed. A storage modulus of 0.05 MPa or more at a frequency of 1 Hz at 85°C can be achieved, for example, by setting the content of the (A1) component, the content of the (A2) component, and the total content of the (A1) component and the (A2) component within the above ranges, or by setting the content of the (A3) component, the total content of the (A1) component and the (A3) component, the total content of the (A2) component and the (A3) component, and the total content of the (A1) component, the (A2) component and the (A3) component within the ranges described below, specifically, for example, by using 2 to 20% by weight of the (A1) component having a number average molecular weight of 950 or more, relative to 100% by weight of the nonvolatile content of the polymer composition. The storage modulus at 85°C at a frequency of 1 Hz can be measured by the method described in the examples below.

[0051] <Other Components> The polymer composition of the present invention may contain components other than the component (A1), the component (A2), and the component (B) (hereinafter, these may be referred to as "other components"), provided that the effects of the present invention are not impaired. Examples of other components include a liquid olefin polymer other than the component (A1) (component (A3)), a tackifier, an antioxidant, a curing accelerator, a plasticizer, etc. These may be used alone or in combination of two or more.

[0052] Component (A3) is a liquid olefin polymer other than component (A1), i.e., a liquid olefin polymer having neither an acid anhydride group nor a carboxyl group. By incorporating component (A3), the adhesiveness of the polymer composition can be improved. In one embodiment of the present invention, the polymer composition of the present invention contains component (A3) as an essential component.

[0053] There are no particular limitations on the number average molecular weight of the component (A3). From the viewpoint of the adhesiveness of the polymer composition, however, this number average molecular weight is preferably at least 950, more preferably at least 1,200, and is preferably at most 20,000, more preferably at most 6,000.

[0054] Commercially available products can be used for component (A3). Examples of such commercially available products include ENEOS "HV-100" (liquid polybutene), ENEOS "HV-300" (liquid polybutene), ENEOS "HV-1900" (liquid polybutene), ENEOS "HV-50" (liquid polybutene), ENEOS "HV-35" (liquid polybutene), Kothari "950MW" (liquid polybutene), Kothari "2400MW" (liquid olefin polymer), INEOS "H-1900" (liquid polybutene), and INEOS " H-6000 (liquid polybutene), INEOS "H-18000" (liquid polybutene), NOF Corporation "200N" (liquid polybutene), Nippon Soda "BI-2000" (liquid hydrogenated polybutadiene), Nippon Soda "BI-3000" (liquid hydrogenated polybutadiene), Nippon Soda "GI-3000" (liquid hydrogenated polybutadiene), Mitsui Chemicals "Lucant LX100" (liquid olefin polymer), Mitsui Chemicals "Lucant LX400" (liquid olefin polymer), Idemitsu Showa Shell "Poly bd R-45HT" (liquid butadiene rubber), Idemitsu Showa Shell "Poly bd R-15HT" (liquid butadiene rubber), Idemitsu Showa Shell "Poly ip" (liquid polyisoprene), Nippon Soda's "B-1000" (liquid polybutadiene), Nippon Soda's "B-3000" (liquid polybutadiene), Nippon Soda's "G-3000" (liquid polybutadiene), Kuraray's "LIR-30" (liquid polyisoprene), Kuraray's "LIR-390" (liquid polyisoprene), Kuraray's "LIR-290" (liquid polyisoprene), Kuraray's "LBR-302" (liquid polybutadiene), Kuraray's "LBR-305" (liquid polybutadiene), Kuraray's "LBR-361" (liquid polybutadiene), Kuraray's "L-SBR-820" (liquid styrene-butadiene random copolymer), CRAY VALLEY's "Ricon" 154" (liquid butadiene), and CRAY VALLEY's "Ricon 184" (liquid styrene-butadiene random copolymer).

[0055] From the viewpoint of adhesiveness of the polymer composition, the content of the component (A3) is preferably 1 to 25% by mass, more preferably 2 to 15% by mass, based on 100% by mass of the nonvolatile content of the polymer composition. In one embodiment of the present invention, the content of the component (A3) is 4% by mass or less, preferably 1 to 4% by mass, based on 100% by mass of the nonvolatile content of the polymer composition.

[0056] The total content of the components (A1) and (A3) in the polymer composition of the present invention is not particularly limited, but from the viewpoint of ensuring good wet heat resistance and handleability (suppression of tack), the total content is preferably 5 to 35% by mass, more preferably 10 to 30% by mass, and even more preferably 15 to 25% by mass, based on 100% by mass of the nonvolatile content of the polymer composition.

[0057] The total content of the components (A2) and (A3) in the polymer composition of the present invention is not particularly limited, but from the viewpoint of ensuring good wet heat resistance and adhesiveness, the total content is preferably 1 to 50 mass%, more preferably 1.5 to 45 mass%, and even more preferably 2 to 40 mass%, relative to 100 mass% of the nonvolatile content of the polymer composition.

[0058] The total content of the components (A1), (A2), and (A3) in the polymer composition of the present invention is not particularly limited, but from the viewpoint of ensuring good wet heat resistance, adhesiveness, and handleability (suppression of tack), the total content is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, and even more preferably 15 to 50% by mass, based on 100% by mass of the nonvolatile content of the polymer composition.

[0059] (Tackifier) ​​A tackifier is also called a tackifier, and is a resin that is blended with a plastic polymer to impart tackiness. The tackifier is not particularly limited, and preferred examples include terpene resins, modified terpene resins (hydrogenated terpene resins, terpene-phenol copolymer resins, aromatic modified terpene resins, etc.), coumarone resins, indene resins, and petroleum resins (aliphatic petroleum resins, hydrogenated alicyclic petroleum resins, aromatic petroleum resins, aliphatic-aromatic copolymer petroleum resins, alicyclic petroleum resins, dicyclopentadiene petroleum resins and their hydrogenated products, etc.).

[0060] Examples of commercially available products that can be used as tackifiers include the following: Terpene resins include YS Resin PX and YS Resin PXN (both manufactured by Yasuhara Chemical Co., Ltd.), aromatic modified terpene resins include YS Resin TO and TR series (both manufactured by Yasuhara Chemical Co., Ltd.), hydrogenated terpene resins include Clearon P, Clearon M, and Clearon K series (both manufactured by Yasuhara Chemical Co., Ltd.), terpene phenol copolymer resins include YS Polystar 2000, Polystar U, Polystar T, Polystar S, and Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.), and hydrogenated alicyclic petroleum resins include Examples of suitable petroleum resins include Escorez 5300 series and 5600 series (both manufactured by ExxonMobil Corporation), aromatic petroleum resins include ENDEX 155 (manufactured by Eastman Co.), aliphatic aromatic copolymer petroleum resins include Quintone D100 (manufactured by Zeon Corporation), alicyclic petroleum resins include Quintone 1325 and Quintone 1345 (both manufactured by Zeon Corporation), and saturated hydrocarbon resins include Arkon P100, Arkon P125, Arkon P140 and TFS13-030 (all manufactured by Arakawa Chemical Industries, Ltd.).

[0061] The softening point of the tackifier is preferably 50 to 200° C., more preferably 90 to 180° C., and even more preferably 100 to 150° C., from the viewpoint of softening the polymer composition sheet in the lamination step and having the desired heat resistance. The softening point is measured by the ring and ball method in accordance with JIS K2207.

[0062] The tackifier may be used alone or in combination of two or more. The content of the tackifier in the polymer composition is not particularly limited. However, from the viewpoint of maintaining good moisture permeation resistance of the polymer composition, when a tackifier is used, the content is preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less, relative to 100% by mass of the nonvolatile content of the polymer composition. On the other hand, from the viewpoint of having sufficient adhesiveness, when a tackifier is used, the content is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the nonvolatile content of the polymer composition.

[0063] Among these, petroleum resins are preferred from the viewpoints of adhesiveness, moisture resistance, transparency, etc. of the polymer composition. Examples of petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, aliphatic-aromatic copolymer petroleum resins, and alicyclic petroleum resins. Among these, aromatic petroleum resins, aliphatic-aromatic copolymer petroleum resins, and alicyclic petroleum resins are more preferred from the viewpoints of adhesiveness, moisture resistance, compatibility, etc. of the polymer composition. Furthermore, alicyclic petroleum resins are particularly preferred from the viewpoint of improving transparency. As the alicyclic petroleum resin, aromatic petroleum resins that have been subjected to hydrogenation treatment can also be used. In this case, the hydrogenation rate of the alicyclic petroleum resin is preferably 30 to 99%, more preferably 40 to 97%, and even more preferably 50 to 90%. If the hydrogenation rate is too low, there is a tendency for problems such as reduced transparency due to coloration to occur, and if the hydrogenation rate is too high, there is a tendency for production costs to increase. The hydrogenation rate is determined by the ratio of hydrogen on the aromatic ring before and after hydrogenation. １ It can be determined from the ratio of H-NMR peak intensities. As alicyclic petroleum resins, cyclohexane ring-containing hydrogenated petroleum resins and dicyclopentadiene-based hydrogenated petroleum resins are particularly preferred. One or more types of petroleum resins may be used in combination. The number average molecular weight Mn of the petroleum resin is preferably 100 to 2,500, more preferably 200 to 2,000, and even more preferably 300 to 1,500.

[0064] (Antioxidant) In the present invention, there are no particular limitations on the antioxidant, and known antioxidants can be used. By incorporating an antioxidant, the light resistance of the formed polymer composition layer can be improved. For example, "Irganox 1010" (hindered phenol-based antioxidant) manufactured by BASF can be mentioned. When an antioxidant is used, the content thereof is preferably 0.01 to 5 mass %, more preferably 0.05 to 2.5 mass %, and even more preferably 0.10 to 2 mass %, relative to 100 mass % of the nonvolatile content of the polymer composition.

[0065] (Curing Accelerator) In the present invention, a curing accelerator may be used to open the acid anhydride group of the component (A1) to promote the chelate crosslinking reaction and to disperse the water-absorbing filler well in the polymer composition. Examples of the curing accelerator include imidazole compounds, tertiary and quaternary amine compounds, dimethylurea compounds, and organic phosphine compounds.

[0066] Examples of the imidazole compound include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-phenyl-4,5-bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, 2-dodecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Specific examples of the imidazole compound include Curesol 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemicals Corporation).

[0067] The tertiary and quaternary amine compounds are not particularly limited, and examples thereof include quaternary ammonium salts such as tetramethylammonium bromide, tetrabutylammonium bromide, and triethylmethylammonium 2-ethylhexanoate; diazabicyclo compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenolate, DBU-octylate, DBU-p-toluenesulfonate, DBU-formate, and DBU-phenol novolac resin salt; and tertiary amines or salts thereof such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP).

[0068] Examples of the organic phosphine compound include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphine triphenylborane, etc. Specific examples of the organic phosphine compound include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, TPP-S (all manufactured by Hokko Chemical Industry Co., Ltd.), etc.

[0069] When a curing accelerator is used, the content thereof is preferably 0.001 to 5% by mass, more preferably 0.001 to 2.5% by mass, and even more preferably 0.001 to 1% by mass, relative to 100% by mass of the nonvolatile content of the polymer composition, in order to promote the crosslinking reaction of the acid anhydride groups and / or carboxyl groups of the component (A1).

[0070] (Plasticizer) The use of a plasticizer can improve the flexibility and moldability of the polymer composition. The plasticizer is not particularly limited, but materials that are liquid at room temperature are preferably used. Specific examples of plasticizers include mineral oils such as paraffinic process oil, naphthenic process oil, liquid paraffin, polyethylene wax, polypropylene wax, and petrolatum; vegetable oils such as castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, and olive oil; and liquid poly-α-olefins such as liquid polybutene, hydrogenated liquid polybutene, liquid polybutadiene, and hydrogenated liquid polybutadiene. Liquid poly-α-olefins are preferred as the plasticizer used in the present invention, with liquid polybutadiene being particularly preferred. Furthermore, from the standpoint of adhesiveness, liquid poly-α-olefins with low molecular weights are preferred, with weight-average molecular weights in the range of 500 to 5,000, and preferably 1,000 to 3,000, being more preferred. These plasticizers may be used alone or in combination of two or more. Here, "liquid" refers to the state of the plasticizer at room temperature (25° C.) When a plasticizer is used, the content thereof is preferably 50% by mass or less relative to 100% by mass of the nonvolatile content of the polymer composition, from the viewpoint of not adversely affecting the electronic device.

[0071] <Method for Producing Polymer Composition> The method for producing the polymer composition of the present invention is not particularly limited, and examples thereof include a method in which the blending components are mixed using a kneading roller, a rotary mixer, or the like, with the addition of a solvent or the like as necessary, and the resulting mixture is dried.

[0072] The mixture can be dried conveniently by heating. Heating may be carried out under normal pressure or under reduced pressure. The heating temperature and heating time may vary depending on the components used. Those skilled in the art can appropriately set the heating temperature and heating time depending on the components used.

[0073] <Polymer Sheet and Manufacturing Method Thereof> The present invention also provides a polymer sheet having a laminated structure including a polymer composition layer formed from the polymer composition of the present invention.

[0074] The polymer composition layer of the polymer sheet may be formed by a method known to those skilled in the art. For example, the polymer composition layer may be formed by preparing a varnish by dissolving the above-mentioned components in an organic solvent, and then applying and drying the varnish onto a support. The non-volatile content of the varnish is preferably 20 to 80% by mass, more preferably 30 to 70% by mass.

[0075] Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, etc., acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, etc., cellosolves such as cellosolve, carbitols such as butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. Only one organic solvent may be used, or two or more organic solvents may be used in combination.

[0076] The varnish can be dried conveniently by heating. Heating may be performed under normal pressure or under reduced pressure. The heating temperature and heating time may vary depending on the components and organic solvent used. Those skilled in the art can appropriately set the heating temperature and heating time depending on the components and organic solvent used.

[0077] When a polymer sheet is prepared using a polymer composition containing a liquid olefin polymer having an acid anhydride group and an epoxy-modified solid olefin polymer, the acid anhydride group is reacted with the epoxy group to form a crosslinked structure, thereby increasing the moisture resistance of the polymer composition layer and providing a polymer sheet with higher sealing performance (such as blocking performance against moisture and oxygen in the air).

[0078] The thickness of the polymer composition layer in the polymer sheet is preferably 1 to 200 μm, more preferably 2 to 180 μm.

[0079] Examples of supports used for the polymer sheet include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; cycloolefin polymers; polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate; polycarbonate; and plastic films such as polyimide. The surface of the support that is bonded to the polymer composition layer may be subjected to a release treatment. Examples of release treatments include release treatments using a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, or a fluororesin-based release agent.

[0080] The thickness of the support is not particularly limited, but from the viewpoint of ease of handling of the polymer sheet, it is preferably 10 to 150 μm, more preferably 20 to 100 μm.

[0081] The support used for the polymer sheet is preferably a support having a barrier layer (e.g., a plastic film having a barrier layer). By using a support with low moisture permeability, moisture absorption by the polymer composition layer can be prevented during storage of the polymer sheet. Examples of the barrier layer include inorganic films such as silica vapor deposition films, silicon nitride films, and silicon oxide films. The barrier layer may be composed of multiple layers of multiple inorganic films (e.g., silica vapor deposition films). Furthermore, the barrier layer may be composed of an organic material and an inorganic material, or may be a composite multilayer of an organic layer and an inorganic film.

[0082] The support having a barrier layer is, for example, a support having a water vapor transmission rate (WVTR) of 0.0005 (g / m ２ A high-barrier plastic film having a water vapor permeability (g / m / 24 hr) or less can be used. ２ / 24hr) refers to the time it takes for an area of ​​1m to be measured under the specified temperature and humidity conditions described below. ２This refers to the amount (g) of water vapor that permeates a film of this type over 24 hours. Examples of high-barrier plastic films include those manufactured by laminating a single layer or multiple layers of inorganic films, such as silicon oxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon nitride oxide, SiCN, or amorphous silicon, onto the surface of a plastic film using chemical vapor deposition (e.g., chemical vapor deposition using heat, plasma, ultraviolet light, vacuum heat, vacuum plasma, or vacuum ultraviolet light) or physical vapor deposition (e.g., vacuum deposition, sputtering, ion plating, laser deposition, or molecular beam epitaxy) (see, for example, JP 2016-185705 A, Japanese Patent No. 5719106 A, Japanese Patent No. 5712509 A, Japanese Patent No. 5292358 A, etc.). To prevent cracking of the inorganic film, it is preferable to alternately laminate the inorganic film and a transparent, flat layer (e.g., a transparent plastic layer).

[0083] Furthermore, the support having a barrier layer may be, for example, a support having a WVTR of 0.005 (g / m ２ / 24hr) or more 1 (g / m ２ / 24 hr) or less. Examples of medium-barrier plastic films include those produced by vapor-depositing an inorganic film containing an inorganic substance such as silicon oxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon nitride oxide, SiCN, or amorphous silicon onto the surface of a substrate as a barrier layer, or by applying a coating liquid containing a metal oxide and an organic resin having barrier properties to the substrate and drying it (see, for example, JP 2013-108103 A and JP 4028353 A).

[0084] The water vapor transmission rate can be measured using a water vapor transmission rate measuring device, PERMATRAN series (manufactured by MOCON Corporation) (in accordance with ISO 15106-2 and JIS K7129B). ２ The specimen is cut into pieces, set in a jig using silicone grease, and then adjusted to a temperature of 40° C. and a humidity of 90% RH using ultrapure water, and the water vapor permeability is measured until it reaches a steady state.

[0085] Commercially available products may be used as the support having a barrier layer. Examples of commercially available medium-barrier plastic films include "Kurarista CI" manufactured by Kuraray Co., Ltd., "Techbarrier HX," "Techbarrier LX," and "Techbarrier L" manufactured by Mitsubishi Plastics, Inc., "IB-PET-PXB" manufactured by Dai Nippon Printing Co., Ltd., "GL, GX Series" manufactured by Toppan Printing Co., Ltd., and "Belear" manufactured by Reikosha Co., Ltd., while examples of commercially available high-barrier plastic films include "X-BARRIER" manufactured by Mitsubishi Plastics, Inc.

[0086] It is preferable that the polymer composition layer provided on the support is protected with a protective film. The protective film can be laminated on the polymer composition layer using a known device. Examples of devices used for laminating the protective film include a roll laminator, a press, and a vacuum pressure laminator.

[0087] Examples of the protective film include the above-mentioned plastic films. It is preferable that the surface of the protective film that is to be bonded to the polymer composition layer is subjected to a release treatment. Examples of the release treatment include a release treatment using a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, or a fluororesin-based release agent.

[0088] The thickness of the protective film is not particularly limited, but from the viewpoint of ease of handling of the polymer sheet, it is preferably 10 to 150 μm, more preferably 20 to 100 μm.

[0089] It is preferable to use a protective film having a barrier layer to prevent the polymer composition layer from absorbing moisture after drying. Examples of protective films having a barrier layer include the above-mentioned plastic films having a barrier layer. From the viewpoint of cost, etc., it is preferable to use the above-mentioned medium-barrier plastic film as the plastic film having a barrier layer used for the protective film.

[0090] The polymer sheet of the present invention may have a backsheet layer laminated on the polymer composition layer.

[0091] The "backsheet layer" is a member that remains without being peeled off even after the electronic device is sealed, i.e., a member that is disposed on the opposite side of the light-emitting / light-receiving surface of the electronic device, unlike a "support" (which is peeled off after the electronic device is sealed) that is used to coat the polymer composition to form a film when forming the polymer composition layer. Examples of the backsheet layer include the same supports as those described above, except that the surface that is to be bonded to the polymer composition layer has not been subjected to a release treatment.

[0092] The storage modulus of the backsheet layer at 85°C at a frequency of 1 Hz is preferably 1,000 MPa or more, more preferably 2,000 MPa or more, and preferably 100,000 MPa or less, more preferably 50,000 MPa or less, from the viewpoint of flexural resistance. The storage modulus of the backsheet layer can be measured using a dynamic mechanical analyzer (DMA). This measurement can be performed at a frequency of 1 Hz, starting at a temperature of 25°C to 240°C, at a heating rate of 5°C / min. Specific measurement procedures can be employed as described in the "Method for Evaluating Storage Modulus" in the Examples.

[0093] The backsheet layer can be laminated on the polymer composition layer using, for example, a known device such as a roll laminator, a press, or a vacuum pressure laminator, in the same manner as the protective film.

[0094] <Uses> The polymer composition and polymer sheet of the present invention can be suitably used for sealing electronic devices that are sensitive to moisture, such as organic EL devices, organic light-emitting diodes (OLEDs), solar cells, and organic thin film transistors (OTFTs).

[0095] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples and can be practiced with appropriate modifications within the scope of the above and below aims, all of which are included within the technical scope of the present invention. Note that "parts" and "%" in the amounts of components and copolymerized units mean "parts by mass" and "% by mass," respectively, unless otherwise specified.

[0096] <Components> The components used in the examples and comparative examples are as follows: Component (A1): liquid olefin polymer having an acid anhydride group and / or a carboxyl group "Lucant A-5260" (manufactured by Mitsui Chemicals, Inc.): maleic anhydride-modified liquid polyolefin, number average molecular weight: 5,400 "HV-100M" (manufactured by Toho Chemical Industry Co., Ltd.): maleic anhydride-modified liquid polybutene, acid anhydride group concentration: 1.46 mmol / g, number average molecular weight: 1,218

[0097] Component (A2): Solid olefin polymer "HYBRAR7311F" (manufactured by Kuraray Co., Ltd.): styrene-ethylene-ethylene-propylene-styrene copolymer, number average molecular weight: 130,000 "ER6003" (manufactured by Seiko PMC Co., Ltd.): maleic anhydride-butyl methacrylate random copolymer-modified butyl rubber, isobutene unit / isoprene unit: 98.9% / 1.1%, butyl methacrylate unit concentration: 0.32 mmol / g, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 32,000 (non-volatile content: 39%) "ER899" (manufactured by Seiko PMC Co., Ltd.): glycidyl methacrylate-modified butyl rubber, isobutene unit / isoprene unit: 98.9% / 1.1%, epoxy group concentration: 1.63 mmol / g, number average molecular weight: 102,000 (non-volatile content: 28%) "BF-7M" (Sumitomo Chemical Co., Ltd.): ethylene-glycidyl methacrylate-methyl acrylate copolymer, melt flow rate: 7 g / 10 min, number average molecular weight: 85,000

[0098] Component (A3): Liquid olefin polymer other than (A1) "HV-1900" (manufactured by ENEOS Corporation): Liquid polybutene, number average molecular weight: 2,900, viscosity at 25°C: 460 Pa·s "BI-3000" (manufactured by Nippon Soda Co., Ltd.): Liquid hydrogenated polybutadiene, number average molecular weight: 3,300, viscosity at 25°C: 50 Pa·s

[0099] (B) Component: Water-absorbent filler Calcium oxide A (manufactured by Yoshizawa Lime Industry Co., Ltd.): D50: 1.6 μm, BET specific surface area: 20 m ２ / g Calcium oxide B (manufactured by Inoue Lime Industry Co., Ltd.): D50: 2.6 μm, BET specific surface area: 2.2 m ２ / g "DHT-4C" (Kyowa Chemical Industry Co., Ltd.): semi-calcined hydrotalcite, D50: 400 nm, BET specific surface area: 15 m ２ / g

[0100] (Other Components): <Tackifier> - "Arcon P-125" (manufactured by Arakawa Chemical Industries, Ltd., hydrogenated petroleum resin, softening point: 125°C) <Antioxidant> - "Irganox 1010" (manufactured by BASF): hindered phenol-based antioxidant <Cure Accelerator> - 2,4,6-tris(dimethylaminomethyl)phenol (manufactured by Kayaku Nouryon, hereinafter abbreviated as "TAP")

[0101] <Backsheet layer> Composite film comprising aluminum foil and polyethylene terephthalate film "PET-Tuki AL1N30" (aluminum foil thickness: 30 μm, polyethylene terephthalate film thickness: 25 μm, manufactured by Tokai Toyo Aluminium Sales Co., Ltd.) Medium-barrier plastic film "Belear 38M006" (thickness: 38 μm, manufactured by Reikosha Co., Ltd.) Aluminum foil (thickness: 50 μm; hereinafter and in Table 1, referred to as "Al (3005-H38)")

[0102] Example 1 A varnish having the blending ratio shown in the table below was prepared by the following procedure, and a polymer sheet was prepared using the obtained varnish. The amount (parts) of each component used in the table below indicates the amount of non-volatile content of each component in the varnish.

[0103] Specifically, a mixture was obtained by dispersing maleic anhydride-modified liquid polyolefin (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.), styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.), liquid polybutene (HV-1900, manufactured by ENEOS Corporation), and calcium oxide A (manufactured by Yoshizawa Lime Industry Co., Ltd.) in an Ipzole solution (non-volatile content 60%) of hydrogenated petroleum resin (tackifier: Alcon P-125, manufactured by Arakawa Chemical Industries, Ltd.) using a triple roll roller.

[0104] To the resulting mixture, a hindered phenol-based antioxidant (Irganox 1010, manufactured by BASF), a curing accelerator (TAP, manufactured by Kayaku Nouryon Co., Ltd.), and toluene were added, and the resulting mixture was uniformly dispersed in a high-speed rotating mixer to obtain a varnish of a polymer composition.

[0105] A low-moisture permeable polyethylene terephthalate "HX" (trade name: PET: 12 μm: manufactured by Mitsubishi Chemical Corporation) was laminated to the other surface of a polyethylene terephthalate (PET) film "SP3000" (trade name: PET: 50 μm: manufactured by Toyo Cross Co., Ltd.) treated with a silicone-based release agent on one side. A laminate film was produced and used as a support. In addition, a low-moisture permeable polyethylene terephthalate "HX" (trade name: PET: 12 μm: manufactured by Mitsubishi Chemical Corporation) was laminated to the other surface of a polyethylene terephthalate (PET) film "SP8002K2" (trade name: PET: 25 μm: manufactured by Toyo Cross Co., Ltd.) treated with a silicone-based release agent on one side. A laminate film was produced and used as a protective film. The obtained varnish was uniformly applied to the release-treated surface of the support using a die coater and heated at 150 ° C. for 10 minutes to form a polymer composition layer. Thereafter, a polymer composition layer was laminated on the release-treated surface of the protective film to obtain a polymer sheet having a polymer composition layer with a thickness of 50 μm.

[0106] Example 2 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the maleic anhydride-modified liquid polyolefin (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.) of the component (A1) was changed to maleic anhydride-modified liquid polybutene (HV-300M, manufactured by Toho Chemical Industry Co., Ltd.).

[0107] Example 3 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of component (A2) was changed to a maleic anhydride-butyl methacrylate random copolymer-modified butyl rubber (ER6003, manufactured by Seiko PMC Corporation).

[0108] Example 4 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of the component (A2) was changed to a glycidyl methacrylate-modified butyl rubber (ER899, manufactured by Seiko PMC Corporation).

[0109] Example 5 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) used as component (A2) was changed to an ethylene-glycidyl methacrylate-methyl acrylate copolymer (BF-7M, manufactured by Sumitomo Chemical Co., Ltd.).

[0110] Example 6 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the amount of styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of component (A2) was changed from 4 parts to 1 part.

[0111] Example 7 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the amount of styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of component (A2) was changed from 4 parts to 2 parts.

[0112] Example 8 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the amount of styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of component (A2) was changed from 4 parts to 11 parts.

[0113] Example 9 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the amount of styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) of component (A2) was changed from 4 parts to 15 parts.

[0114] Example 10 A polymer sheet having a polymer composition layer with a thickness of 50 μm was obtained in the same manner as in Example 1, except that calcium oxide A (manufactured by Yoshizawa Lime Industry Co., Ltd.) in component (B) was changed to calcium oxide B (manufactured by Inoue Lime Industry Co., Ltd.).

[0115] Example 11 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that calcium oxide A (manufactured by Yoshizawa Lime Industry Co., Ltd.) as component (B) was changed to semi-calcined hydrotalcite (DHT-4C, manufactured by Kyowa Chemical Industry Co., Ltd.).

[0116] Example 12 The (A1) component, 19 parts of maleic anhydride-modified liquid polyolefin (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.) was changed to 15 parts of maleic anhydride-modified liquid polybutene (HV-300M, manufactured by Toho Chemical Industry Co., Ltd.), the (A2) component, 4 parts of styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) was changed to 12 parts of maleic anhydride-butyl methacrylate random copolymer-modified butyl rubber (ER6003, manufactured by Seiko PMC Co., Ltd.) and 12 parts of glycidyl methacrylate-modified butyl rubber (ER899, manufactured by Seiko PMC Co., Ltd.), and the (A2) component, 19 parts of maleic anhydride-modified liquid polyolefin (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.) was changed to 15 parts of maleic anhydride-modified liquid polybutene (HV-300M, manufactured by Toho Chemical Industry Co., Ltd.). A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the curing accelerator (TAP, manufactured by Nouryon Chemical Industries, Ltd.) and the curing accelerator (BASF 1010) were not added.

[0117] Comparative Example 1 An attempt was made to prepare a polymer sheet having a 50 μm-thick polymer composition layer in the same manner as in Example 1, except that the maleic anhydride-modified liquid polyolefin (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.) of component (A1) was not blended.

[0118] Comparative Example 2 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.), component (A2), was not blended.

[0119] Comparative Example 3 A polymer sheet having a 50 μm thick polymer composition layer was obtained in the same manner as in Example 1, except that calcium oxide A (manufactured by Yoshizawa Lime Industry Co., Ltd.), component (B), was not blended.

[0120] Comparative Example 4 A polymer sheet having a 50 μm thick polymer composition layer was obtained in the same manner as in Example 1, except that the (A1) component maleic anhydride-modified liquid polyolefin (LUCANT A-5260, manufactured by Mitsui Chemicals, Inc.) was changed from 19 parts to 25 parts, the (A2) component styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) was changed from 4 parts to 2 parts, the (A3) component liquid polybutene (HV-1900, manufactured by ENEOS Corporation) was changed from 3 parts to 7 parts, and the (A3) component hydrogenated petroleum resin (tackifier: ALCON P-125, manufactured by Arakawa Chemical Industries, Ltd.) was changed from 24 parts to 30 parts.

[0121] Comparative Example 5 A polymer sheet having a 50 μm-thick polymer composition layer was obtained in the same manner as in Example 1, except that the (A1) component maleic anhydride-modified liquid polyolefin (LUCANT A-5260, manufactured by Mitsui Chemicals, Inc.) was changed from 19 parts to 10 parts, the (A2) component styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR 7311F, manufactured by Kuraray Co., Ltd.) was changed from 4 parts to 1 part, and the (A2) component hydrogenated petroleum resin (tackifier: ALCON P-125, manufactured by Arakawa Chemical Industries, Ltd.) was changed from 24 parts to 30 parts.

[0122] Comparative Example 6 A polymer sheet having a 50 μm thick polymer composition layer was obtained in the same manner as in Example 1, except that the (A1) component maleic anhydride-modified liquid polyolefin (LUCANT A-5260, manufactured by Mitsui Chemicals, Inc.) was changed from 19 parts to 10 parts, the (A2) component styrene-ethylene-ethylene-propylene-styrene copolymer (HYBRAR7311F, manufactured by Kuraray Co., Ltd.) was changed from 4 parts to 2 parts, the (A3) component liquid polybutene (HV-1900, manufactured by ENEOS Corporation) was changed from 3 parts to 6 parts, and the (A3) component hydrogenated petroleum resin (tackifier: ALCON P-125, manufactured by Arakawa Chemical Industries, Ltd.) was changed from 24 parts to 20 parts.

[0123] <Method for evaluating film-forming properties> The state of the polymer sheets produced in the examples and comparative examples was evaluated according to the following criteria: ◯ (Good): Film formation was good and usable as a pressure-sensitive adhesive sheet. × (Poor): Poor dimensional stability due to shrinkage when heated at 150°C for 10 minutes, or film formation was not possible.

[0124] <Method for evaluating storage modulus> Storage modulus can be obtained by dynamic viscoelasticity measurement. The principle of measuring dynamic viscoelasticity is to apply sinusoidal periodic vibration to an object, and calculate the mechanical properties from the load and phase difference δ detected as a response to this stimulus. When deforming an object, an object that requires a large load is said to be hard, while an object that can be deformed with a small load is said to be soft.

[0125] A 50 μm-thick polymer composition layer prepared in each of the Examples and Comparative Examples was folded twice and cut out with a circular cutter to prepare a circular sample (diameter: 8 mm, thickness: 200 μm) for measuring dynamic viscoelasticity. The obtained circular sample was loaded into a TA Discovery HR2 (rheometer), and the elastic modulus was measured at a frequency of 1 Hz and a temperature range of −40 to 160°C (heating rate of 6°C / min), and the storage modulus at 85°C was obtained. The obtained storage modulus was evaluated according to the following criteria: ◯ (Good): 0.05 MPa or more; × (Poor): Less than 0.05 MPa.

[0126] In addition, the backsheet layers used in the examples and comparative examples were processed into strips of 7 mm x 20 mm, and the elastic modulus was measured using a dynamic mechanical analyzer (DMA) (Hitachi High-Tech Corporation, DMA7100) at a frequency of 1 Hz and in a temperature range of 25 to 240°C (heating rate of 5°C / min) to obtain the storage elastic modulus at 85°C.

[0127] <Method for Evaluating Edge Peeling> The protective film was peeled off from the polymer sheets (50 mm square) produced in the Examples and Comparative Examples, and the exposed polymer composition layer was laminated onto the aluminum foil side of "PET-attached AL1N30" (backsheet layer) using a batch-type vacuum laminator (Morton-724, manufactured by Nichigo-Morton Co., Ltd.). Lamination was performed under conditions of a temperature of 80°C, a time of 30 seconds, and a pressure of 0.3 MPa. Next, the support was peeled off, and a glass plate (50 mm square, 1.2 mm thick) was further laminated onto the exposed polymer composition layer under the same conditions as above. The resulting laminate was placed in a thermo-hygrostat chamber set at a temperature of 85°C and a humidity of 85% RH for 500 hours to perform an accelerated test. The laminate was removed from the thermo-hygrostat chamber, and the peripheral edge, including the four corners, was observed. Peeling of the backsheet layer was evaluated according to the following criteria. Similarly, for the polymer sheet produced in Example 1, a laminate was produced using "Belear 38M006" as the backsheet layer, and the peeling of the backsheet layer was evaluated according to the following criteria (Example 13). Furthermore, similarly, for the polymer sheet produced in Example 1, a laminate was produced using "Al (3005-H38)" as the backsheet layer, and the peeling of the backsheet layer was evaluated according to the following criteria (Example 14). ◯ (Good): No peeling was observed at the four corners. △ (Fair): Minor peeling was observed at only one of the four corners. Minor means a lift of 1 mm or less. × (Poor): Peeling was observed at two or more of the four corners.

[0128] <Method for evaluating water vapor barrier properties> A composite film "PET-Tuki AL1N30" (aluminum foil thickness: 30 μm, polyethylene terephthalate film thickness: 25 μm, manufactured by Tokai Toyo Aluminum Sales Co., Ltd.) comprising an aluminum foil and a polyethylene terephthalate film was prepared as a support film. A polymer composition layer was formed on the aluminum foil side of the support film in the same manner as in the polymer sheet manufacturing method in each Example and Comparative Example, except that this support film was used instead of a support. In this way, a test sheet comprising a support film and a polymer composition layer was obtained.

[0129] A 50 mm x 50 mm square glass plate made of alkali-free glass was prepared, washed with boiled isopropyl alcohol for 5 minutes, and dried at 150°C for 30 minutes or more.

[0130] Calcium was vapor-deposited onto one surface of the glass plate using a mask that covered the peripheral area 0 mm to 1 mm from the edge of the glass plate, thereby forming a calcium film (purity 99.8%) with a thickness of 200 nm on the central portion of one surface of the glass plate, excluding the peripheral area 0 mm to 1 mm from the edge of the glass plate.

[0131] In a nitrogen atmosphere, the polymer composition layer of the test sheet and the calcium film side of the glass plate were bonded together using a thermal laminator (Fujipla Lamipacker DAiSY A4 (LPD2325)) to obtain a laminate.

[0132] Generally, calcium becomes transparent when it comes into contact with water and becomes calcium oxide. Furthermore, in the evaluation sample, since the glass plate and aluminum foil have sufficiently high water vapor barrier properties, moisture usually migrates in the in-plane direction (perpendicular to the thickness direction) through the edge of the polymer composition layer and reaches the calcium film. Therefore, when moisture penetrates the evaluation sample, the calcium film gradually oxidizes from the edge and becomes transparent, and shrinkage of the calcium film is observed. Therefore, moisture penetration into the evaluation sample can be evaluated by measuring the sealing distance [mm] from the edge of the evaluation sample to the calcium film. Therefore, the evaluation sample containing the calcium film can be used as a model for a lead-containing electronic device.

[0133] First, the sealing distance X2 [mm] from the edge of the evaluation sample to the edge of the calcium film was measured using a microscope (Measuring Microscope MF-U, manufactured by Mitutoyo Corporation). Hereinafter, this sealing distance X2 may be referred to as the initial sealing distance X2.

[0134] Next, the evaluation sample was placed in a thermo-hygrostat chamber set at a temperature of 85°C and a humidity of 85% RH. When the sealing distance X1 (mm) between the end of the evaluation sample placed in the thermo-hygrostat chamber and the end of the calcium film increased by 0.1 mm from the initial sealing distance X2, the evaluation sample was removed from the thermo-hygrostat chamber. The time from when the evaluation sample was placed in the thermo-hygrostat chamber to when the evaluation sample was removed from the thermo-hygrostat chamber was calculated as the decrease start time t [hours]. This decrease start time t was calculated from the time T when the evaluation sample was placed in the thermo-hygrostat chamber. Ｐ１ From the time T, the sealing distance X1 [mm] between the end of the evaluation sample stored in the thermo-hygrostat and the end of the calcium film becomes "X2 + 0.1 mm". Ｐ２ corresponds to the time until

[0135] The sealing distance X1 and the decrease start time t were applied to the Fick diffusion equation of formula (1) to calculate a constant K as a water vapor barrier property parameter.

[0136]

[0137] Using the obtained constant K, the water vapor barrier property, which is the ability of the polymer composition layer to suppress the penetration of moisture, was evaluated according to the following criteria. The smaller the value of the constant K, the higher the water vapor barrier property. "h" means "hours."

[0138] (Criteria for water vapor barrier properties) ◯ (Good): Constant K is 0.0075 cm / h ０．５ Less than △ (Acceptable): Constant K is 0.0075 cm / h ０．５ Above, 0.025cm / h ０．５ x (bad): Constant K is less than 0.025 cm / h ０．５ That's all.

[0139] <Method for evaluating flexibility> The protective film (PET film) was peeled off from the polymer sheet produced in the Examples and Comparative Examples, and the backsheet layer (in the case of "PET-attached AL1N30", the aluminum foil side) was attached to the polymer composition layer by vacuum lamination (80°C, 0.3 MPa, 30 seconds). Furthermore, the support (PET film) was also peeled off, and a polyimide film (manufactured by Unitika Ltd., thickness 25 μm) was attached to the polymer composition layer by vacuum lamination (80°C, 0.3 MPa, 30 seconds) to produce an evaluation sample having a structure of "backsheet layer / polymer composition layer / polyimide (PI) film".

[0140] The obtained evaluation sample was placed in a clamshell-type bending tester "CL40R type-E02" (manufactured by Yuasa System Co., Ltd.), and the evaluation sample was bent 10 times under the conditions of a temperature of 23°C, a humidity of 50% RH, a radius of curvature (R) of 2.0 mm, and a speed of 60 rpm. After bending, the evaluation sample was observed using a Keyence Corporation digital microscope "VHX-5000" (magnification: 20x), and the bending resistance was evaluated according to the following criteria. (Evaluation criteria for bending resistance) ○ (Good): No peeling of the backsheet layer, no crease, or slight crease. △ (Fair): No peeling of the backsheet layer, but strong crease. × (Unacceptable): Peeling of the backsheet layer.

[0141]

[0142]

[0143] The results in Table 1 show that the polymer sheets of Examples 1 to 12 were good in the evaluations of film-forming ability, storage modulus, flexibility, edge peeling, and water vapor barrier property. On the other hand, the results in Table 2 show that in Comparative Example 1, which did not contain the (A1) component, film formation was impossible and no polymer sheet was obtained, the polymer sheet of Comparative Example 2, which did not contain the (A2) component, was poor in the evaluations of storage modulus and edge peeling, the polymer sheet of Comparative Example 3, which did not contain the (B) component, was poor in the evaluations of water vapor barrier property, the polymer sheet of Comparative Example 4, which contained more than 4% by mass of the (A3) component, was poor in the evaluations of storage modulus and edge peeling, the polymer sheet of Comparative Example 5, which contained less than 12% by mass of the (A1) component, was poor in the evaluations of storage modulus and edge peeling, and the polymer sheet of Comparative Example 6, which contained less than 12% by mass of the (A1) component and more than 4% by mass of the (A3) component, was poor in the evaluation of storage modulus.

[0144] The polymer composition of the present invention can form a polymer composition layer (as an encapsulant) that is inhibited from peeling off a backsheet layer and exhibits high water vapor barrier properties, and can be suitably used for encapsulating electronic devices that are sensitive to moisture, such as organic EL devices, organic light-emitting diodes (OLEDs), solar cells, and organic thin film transistors (OTFTs).

[0145] This application is based on patent application No. 2024-052475 filed in Japan, the contents of which are incorporated in their entirety herein.

Claims

1. A polymer composition comprising the following components: (A1) a liquid olefin polymer having an acid anhydride group and / or a carboxyl group; (A2) a solid olefin polymer; (A3) a liquid olefin polymer having neither an acid anhydride group nor a carboxyl group; and (B) a water-absorbing filler, wherein the content of (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12% by mass or more based on 100% by mass of the non-volatile content of the polymer composition, and the content of (A3) the liquid olefin polymer having neither an acid anhydride group nor a carboxyl group is 4% by mass or less based on 100% by mass of the non-volatile content of the polymer composition.

2. The polymer composition according to claim 1, wherein the storage modulus of the polymer composition layer formed from the polymer composition at 85°C is 0.05 MPa or more.

3. The polymer composition according to claim 1, wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group has a number average molecular weight of 950 or more.

4. The polymer composition according to claim 1, wherein the content of (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is 12 to 20% by mass relative to 100% by mass of the nonvolatile content of the polymer composition.

5. The polymer composition according to claim 1, wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is an acid anhydride-modified liquid olefin polymer.

6. The polymer composition according to claim 4, wherein (A1) the liquid olefin polymer having an acid anhydride group and / or a carboxyl group is a maleic anhydride-modified liquid olefin polymer.

7. The polymer composition according to claim 1, wherein the solid olefin polymer (A2) is an unmodified or epoxy-modified solid olefin polymer.

8. The polymer composition according to claim 1, wherein the content of the solid olefin polymer (A2) is 2 to 50% by mass relative to 100% by mass of the nonvolatile content of the polymer composition.

9. The polymer composition according to claim 1, wherein the content of (A3) the liquid olefin polymer having neither an acid anhydride group nor a carboxyl group is 1 to 4 mass % relative to 100 mass % of the nonvolatile content of the polymer composition.

10. The polymer composition according to claim 1, wherein the median diameter of the water-absorbing filler (B) is 0.3 to 5 μm.

11. (B) The BET specific surface area of ​​the water-absorbing filler is 1 to 30 m ２ The polymer composition of claim 1, wherein the molecular weight of the polymer composition is 1 / g.

12. A polymer sheet having a laminated structure comprising a polymer composition layer formed from the polymer composition of claim 1.

13. The polymer sheet of claim 12, having a backsheet layer laminated onto the polymer composition layer.

14. The polymer sheet according to claim 13, wherein the storage modulus of the backsheet layer at 85°C is 1,000 MPa or more and 100,000 MPa or less.

15. The polymer sheet of claim 12, which is used to encapsulate electronic devices.

16. An electronic device encapsulated with the polymer sheet of claim 12.

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