Ethylene / α-olefin copolymer, method for producing same, and use thereof

Abstract

[Problem] To provide an ethylene / α-olefin copolymer that is excellent in moldability and crosslinking properties and achieves a good balance therebetween. [Solution] An ethylene / α-olefin copolymer (A) satisfying the following requirements (a1)-(a5). (a1) The density is 0.865-0.885 g / cm3. (a2) The MFR (190°C, 2.16 kgf) is 3.0-40 g / 10 min. (a3) The MFR (190°C, 10 kgf) / MFR (190°C, 2.16 kgf) is 6.8-15. (a4) (Complex viscosity (η*0.1) at 100°C and a shear rate of 0.1 rad / s) / (complex viscosity (η*100) at 100°C and a shear rate of 100 rad / s) is 3.5-30, and η*100 is 3,000 Pa s or less. (a5) The total number of unsaturated groups is 0.45-2.0 / 1,000 C.

Description

Ethylene-α-olefin copolymer, method for producing same, and use thereof

[0001] The present invention relates to an ethylene / α-olefin copolymer, a method for producing the same, and uses thereof.

[0002] Ethylene-α-olefin copolymers have conventionally been used in a variety of applications.

[0003] For example, ethylene-α-olefin copolymers are lightweight and flexible and are therefore used in building exterior and interior materials, automobile parts, packaging materials, daily necessities, etc. Furthermore, ethylene-α-olefin copolymers are sometimes crosslinked before use to improve mechanical strength and heat resistance.

[0004] When crosslinking ethylene-α-olefin copolymers, a crosslinked structure is generally formed through a crosslinking reaction after molding in a molding process such as extrusion molding, film molding, or injection molding. In particular, when crosslinking reactions are performed using organic peroxides as initiators, the initiator is blended into the resin during molding, so it is necessary to control shear heat generation within the molding machine to prevent the crosslinking reaction from progressing during molding. For this reason, from the perspective of productivity, it is necessary to reduce the melt viscosity of the resin, i.e., the molecular weight. However, since the crosslinking reaction is generally more efficient as the molecular weight increases, achieving both moldability and crosslinkability is a challenge.

[0005] In order to solve the above problems, attempts have been made to improve processability by using a polymerization technique using a metallocene compound that can form a long-chain branched structure in the polymer, or by broadening the molecular weight distribution and composition distribution by mixing different polymers or using several types of catalysts (for example, Patent Documents 1 and 2).

[0006] Furthermore, attempts have been made to improve crosslinkability by using a polymerization technique using a metallocene compound that can introduce an unsaturated group into a polymer during an olefin polymerization process (for example, Patent Documents 3 and 4).

[0007] Furthermore, ethylene-α-olefin copolymers in which crosslinking properties are improved by narrowing the molecular weight distribution and adjusting the proportion of vinyl groups in unsaturated groups to a certain range, and ethylene-based copolymers in which crosslinking properties are improved by increasing the vinyl group content are also known (Patent Documents 5 and 6).

[0008] International Publication No. WO 2015 / 152266 JP 2006-509904 A JP 2008-308619 A International Publication No. WO 2019 / 212307 JP 2021-520444 A International Publication No. WO 2008 / 152935

[0009] According to the investigations of the present inventors, there is room for further improvement in conventional polyolefin-based materials from the viewpoint of achieving both moldability and crosslinkability.

[0010] The present invention has been made in view of the problems associated with the prior art, and an object of the present invention is to provide an ethylene / α-olefin copolymer that is excellent in a well-balanced manner between moldability and crosslinkability, and to provide uses of such an ethylene / α-olefin copolymer.

[0011] As a result of extensive investigations aimed at achieving the above object, the present inventors have found that the above object can be achieved by an ethylene / α-olefin copolymer (A) that satisfies certain requirements, and have thus completed the present invention.

[0012] That is, according to the present invention, there are provided, for example, the following ethylene / α-olefin copolymers, methods for producing the same, and uses thereof.

[0013] [1] An ethylene / α-olefin copolymer (A) that satisfies the following requirements (a1) to (a5):

[0014] (a1) A density measured in accordance with ASTM D1505 of 0.865 to 0.885 g / cm 3 is.

[0015] (a2) The melt flow rate measured in accordance with ASTM D1238 under conditions of 190°C and a load of 2.16 kg is 3.0 to 40 g / 10 min.

[0016] (a3) MFR10 / MFR2 is in the range of 6.8 to 15.

[0017] (However, MFR 10 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a load of 10 kg, and MFR2 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a load of 2.16 kg.

[0018] (a4) The ratio (η*0.1 / η*100) of the complex viscosity (η*0.1) at a shear rate of 0.1 rad / s measured at 100°C to the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3.5 to 30, and the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3000 Pa s or less.

[0019] (a5) The ethylene / α-olefin copolymer (A) contains 0.45 to 2.0 unsaturated groups in total per 1,000 carbon atoms.

[0020] [2] An ethylene / α-olefin copolymer (A) that satisfies the following requirements (a1), (a2), (a3′), (a4), and (a5):

[0021] (a1) A density measured in accordance with ASTM D1505 of 0.865 to 0.885 g / cm ３ is.

[0022] (a2) The melt flow rate measured in accordance with ASTM D1238 under conditions of 190°C and a load of 2.16 kg is 3.0 to 40 g / 10 min.

[0023] (a3') MFR 10 / MFR2 satisfies the following formula (1).

[0024] -0.428×ln(MFR2)+7.5≦MFR 10 / MFR2 ≦−0.876×ln(MFR2)+11.2 ...Equation (1) (where MFR 10is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a load of 10 kg, and MFR2 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a load of 2.16 kg.

[0025] (a4) The ratio (η*0.1 / η*100) of the complex viscosity (η*0.1) at a shear rate of 0.1 rad / s measured at 100°C to the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3.5 to 30, and the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3000 Pa s or less.

[0026] (a5) The ethylene / α-olefin copolymer (A) contains 0.45 to 2.0 unsaturated groups in total per 1,000 carbon atoms.

[0027] [3] The ethylene / α-olefin copolymer (A) according to the above [1] or [2], which satisfies the following requirement (a6):

[0028] (a6) The content of structural units derived from ethylene is 80 to 90 mol %, and the content of structural units derived from an α-olefin having 3 to 20 carbon atoms is 10 to 20 mol % (provided that the total of the structural units derived from ethylene and the structural units derived from the α-olefin is 100 mol %).

[0029] [4] The ethylene / α-olefin copolymer (A) according to any one of [1] to [3] above, which satisfies the following requirement (a7):

[0030] (a7) The Shore A hardness measured in accordance with ASTM D2240 is 60 to 85.

[0031] [5] The ethylene / α-olefin copolymer (A) according to any one of [1] to [4] above, which satisfies the following requirement (a8):

[0032] (a8) The ethylene / α-olefin copolymer (A) contains 0.05 to 0.3 vinyl groups per 1,000 carbon atoms.

[0033] [6] The ethylene / α-olefin copolymer (A) according to any one of [1] to [5] above, which satisfies the following requirement (a9):

[0034] (a9) The ethylene / α-olefin copolymer (A) contains less than 0.50 vinyl groups and vinylidene groups in total per 1,000 carbon atoms.

[0035] [7] The ethylene / α-olefin copolymer (A) according to any one of [1] to [6] above, which satisfies the following requirement (a10):

[0036] (a10) The proportion of vinyl groups in the unsaturated groups contained in the ethylene / α-olefin copolymer (A) is less than 50 mol %.

[0037] [8] The ethylene / α-olefin copolymer (A) according to any one of [1] to [7] above, which satisfies the following requirement (a11):

[0038] (a11) The molecular weight distribution (Mw / Mn), which is the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) measured by gel permeation chromatography (GPC), is 2.3 or less.

[0039] [9] The ethylene / α-olefin copolymer (A) according to any one of the above [1] to [8], wherein the α-olefin is 1-butene.

[0040]

[10] A method for producing the ethylene / α-olefin copolymer (A) according to the above [1], comprising a polymerization step of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst comprising: a bridged metallocene compound (I) represented by the following general formula [I]; and at least one compound (II) selected from the group consisting of organoaluminum oxy compounds (II-1) and organoaluminum compounds (II-3).

[0041]

[0042] (In formula [I], R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9and R 12 each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group; R 1 ~R 4 Two adjacent groups may be bonded to each other to form a ring.

[0043] R 6 and R 11 are each independently the same atom or group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and R 7 and R 10 are each independently the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, 6 and R 7 may be bonded to each other to form a ring, and R 10 and R 11 may be bonded to each other to form a ring.

[0044] However, R 6 , R 7 , R 10 and R 11 are not all hydrogen atoms.

[0045] R 13 and R 14 are selected from a hydrogen atom, a hydrocarbon group, and a silicon-containing group, and may be the same or different; R 13 and R 14 may be bonded to each other to form a ring.

[0046] Y represents a carbon atom or a silicon atom.

[0047] n represents an integer of 1 or 2 or more, and when n is an integer of 2 or more, R 13 and R 14 is a hydrogen atom.

[0048] M represents a zirconium atom or a hafnium atom.

[0049] Q represents a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having 4 to 10 carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, j represents an integer of 1 to 4, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

[0050]

[11] In the general formula [I], n is 1, and R 13 and R 14 and each of the groups is a benzyl group.

[0051]

[12] In the general formula [I], n is 1, and R 13 and R 14 and each of the groups is a methyl group.

[0052]

[13] The method for producing the ethylene / α-olefin copolymer (A) according to the above

[10] , wherein in the general formula [I], Y represents a carbon atom and n is 2.

[0053]

[14] The method for producing the ethylene / α-olefin copolymer (A) according to any one of the above

[10] to

[13] , wherein the polymerization temperature in the polymerization step is in the range of 100 to 170°C.

[0054]

[15] A composition comprising the ethylene / α-olefin copolymer (A) according to any one of [1] to [9] above.

[0055]

[16] The composition according to

[15] above, further comprising a crosslinking agent.

[0056]

[17] A crosslinked product obtained by crosslinking the composition of

[16] above.

[0057]

[18] A foam containing the ethylene / α-olefin copolymer (A) according to any one of [1] to [9] above.

[0058]

[19] A laminate comprising a layer made of the foam of

[18] above, and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather.

[0059]

[20] Footwear comprising the foam of

[18] above or the laminate of

[19] above.

[0060] [20a] A footwear component comprising the foam of

[18] above or the laminate of

[19] above.

[0061]

[21] The footwear part according to [20a] above, which is a midsole, an inner sole or a sole.

[0062]

[22] A foam comprising the crosslinked product according to

[17] .

[0063]

[23] A laminate comprising a layer made of the foam of

[22] above, and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather.

[0064]

[24] Footwear comprising the foam of

[22] above or the laminate of

[23] above.

[0065] [24a] A footwear part comprising the foam of

[22] above or the laminate of

[23] above.

[0066]

[25] The footwear part according to [24a] above, which is a midsole, an inner sole or a sole.

[0067]

[26] A molded article comprising the composition of

[15] above.

[0068]

[27] An electric wire or cable having a coating layer containing the composition of

[15] above.

[0069]

[28] A molded article comprising the crosslinked product according to

[17] .

[0070]

[29] An electric wire or cable having a coating layer containing the crosslinked product of

[17] above.

[0071]

[30] A composition for forming a solar cell encapsulant, comprising the composition according to

[15] above. That is, the composition according to

[15] above, which is a composition for a solar cell encapsulant.

[0072]

[31] The composition for forming a solar cell encapsulant according to

[30] , comprising an organic peroxide having a one-minute half-life temperature in the range of 100 to 170°C in an amount of 0.1 to 3 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0073] [31a] The composition for forming a solar cell encapsulant according to the above

[30] or

[31] , which contains a silane coupling agent in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0074]

[32] The composition for forming a solar cell encapsulant according to any one of

[30] ,

[31] and [31a] above, which contains 0.005 to 5 parts by mass of at least one selected from the group consisting of an ultraviolet absorber, a heat stabilizer, and a hindered amine-type light stabilizer, per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0075] [32a] The composition for forming a solar cell encapsulant according to any one of

[30] ,

[31] , [31a] and

[32] above, which contains a crosslinking aid in an amount of 0.05 to 5 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0076]

[33] A solar cell encapsulant comprising an encapsulating layer made of a crosslinked product of the solar cell encapsulant-forming composition according to any one of

[30] ,

[31] , [31a],

[32] and [32a] above.

[0077]

[34] The solar cell encapsulant according to the above

[33] , which has a multilayer structure including at least one encapsulating layer.

[0078]

[35] The solar cell encapsulant according to

[34] , which has a three-layer structure including an intermediate layer and two outer layers formed on both sides of the intermediate layer so as to sandwich the intermediate layer, at least one of the layers being the encapsulating layer.

[0079]

[36] A solar cell module comprising a front-side transparent protective member, a back-side protective member, a solar cell element, and the solar cell encapsulant according to any one of

[33] to

[35] above, which encapsulates the solar cell element between the front-side transparent protective member and the back-side protective member.

[0080]

[37] A film comprising the composition of

[15] above.

[0081]

[38] The film of

[36] above, wherein the film impact strength, which is the impact hole opening strength of the film measured in accordance with the impact hole opening strength measurement method specified in JIS P8134 divided by the film thickness of the film, exceeds 38 kJ / m.

[0082] The ethylene / α-olefin copolymer of the present invention has an excellent balance between molding processability and crosslinkability. Therefore, according to the present invention, it is possible to improve the productivity of the ethylene / α-olefin copolymer during molding process and the performance of the crosslinked product. Furthermore, according to the present invention, uses of the ethylene / α-olefin copolymer having such improved performance are provided.

[0083] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be practiced with appropriate modifications within the scope of the object of the present invention. In the present invention, a numerical range expressed as "lower limit to upper limit" means "not less than the lower limit and not more than the upper limit" unless otherwise specified, and the upper limit or lower limit of the numerical range may be replaced with a numerical value in the examples.

[0084] [Ethylene / α-olefin copolymer (A)] The ethylene / α-olefin copolymer (A) of one embodiment of the present invention is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies all of the following requirements (a1) to (a5):

[0085] <α-Olefin> As the α-olefin constituting the ethylene / α-olefin copolymer (A) (hereinafter, sometimes referred to as "copolymer (A)"), one or more α-olefins having 3 to 20 carbon atoms can usually be used.

[0086] Specific examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, etc. Among these, α-olefins having 10 or less carbon atoms are preferred, α-olefins having 3 to 8 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are more preferred, 1-butene, 1-pentene, and 1-hexene are even more preferred, and 1-butene is particularly preferred from the viewpoint of the low-temperature physical properties and mechanical strength of the ethylene / α-olefin copolymer (A).

[0087] The monomers (ethylene and α-olefin) constituting the copolymer (A) may be derived from any of fossil fuels, biomass and chemically recycled materials.

[0088] Furthermore, as the raw material monomers for copolymer (A), raw materials derived from fossil fuels and biomass may be used in combination, raw materials derived from fossil fuels and chemically recycled may be used in combination, raw materials derived from biomass and chemically recycled may be used in combination, or raw materials derived from fossil fuels, biomass, and chemically recycled may be used in combination.

[0089] The ethylene / α-olefin copolymer (A) may be a random copolymer or a block copolymer, but from the viewpoint of flexibility, a random copolymer is preferred.

[0090] In a preferred embodiment, the ethylene / α-olefin copolymer (A) does not contain any monomer other than ethylene and an α-olefin having 3 to 20 carbon atoms, such as a constituent unit derived from a non-conjugated polyene.

[0091] <Requirement (a1)> Requirement (a1) is that the density measured in accordance with ASTM D1505 is 0.865 to 0.885 g / cm 3 In one aspect of the present invention, the density is preferably 0.866 to 0.880 g / cm 3 , more preferably 0.867 to 0.880 g / cm3 , more preferably 0.868 to 0.880 g / cm 3 In another embodiment of the present invention, for example, when the copolymer (A) is used in footwear or footwear parts, the density is preferably 0.870 to 0.885 g / cm 3 , more preferably 0.871 to 0.885 g / cm 3 , more preferably 0.872 to 0.885 g / cm 3 is.

[0092] The density of the copolymer (A) can be adjusted by balancing the content of ethylene units and the content of α-olefin units. That is, increasing the content of ethylene units increases the crystallinity, and a copolymer (A) with a high density can be obtained. On the other hand, decreasing the content of ethylene units decreases the crystallinity, and a copolymer (A) with a low density can be obtained.

[0093] The density of the ethylene-α-olefin copolymer is 0.880 g / cm 3 Ultra, especially 0.885 cm 3 If the temperature exceeds 100° C., the copolymer will have high crystallinity, making extrusion difficult at low temperatures and requiring high temperatures of, for example, 130° C. or higher. For this reason, when an organic peroxide is kneaded into the ethylene / α-olefin copolymer, a crosslinking reaction will proceed in the extruder, and when the copolymer is processed into a sheet, gel-like foreign matter will be generated in the sheet, tending to deteriorate the appearance of the sheet.

[0094] On the other hand, the density of ethylene-α-olefin copolymer is 0.865 g / cm 3 If the temperature is less than 100°C, the crystallization rate of the ethylene / α-olefin copolymer tends to be slow. Therefore, when the copolymer is processed into a sheet using an extruder, the extruded sheet becomes sticky, making it difficult to peel the sheet with the first cooling roll after extrusion (hereinafter also referred to as the "first cooling roll"), and it tends to be difficult to obtain the sheet. Furthermore, since the sheet becomes sticky, blocking tends to occur, and the sheet's payout ability tends to deteriorate. Furthermore, crosslinking may be insufficient, which may reduce heat resistance.

[0095] <Requirement (a2)> Requirement (a2) is that the melt flow rate (MFR2) of the ethylene / α-olefin copolymer (A) measured in accordance with ASTM D 1238 at 190°C under a load of 2.16 kg is in the range of 3.0 to 40 g / 10 min. The MFR is preferably in the range of 3.0 to 35 g / 10 min, more preferably 3.0 to 31 g / 10 min, and even more preferably 3.5 to 25 g / 10 min.

[0096] The MFR2 of the copolymer (A) can be adjusted by adjusting the polymerization temperature and polymerization pressure during the polymerization reaction described below, as well as the molar ratio of the ethylene and α-olefin monomer concentrations and the hydrogen concentration in the polymerization system.

[0097] If the MFR2 is less than 3.0 g / 10 min, the fluidity of the ethylene-α-olefin copolymer decreases, and when the copolymer is processed into a sheet, it may not be possible to extrude it within the preferred temperature range for sheet extrusion molding. Furthermore, the copolymer is prone to gelation due to shear heat generated during sheet extrusion molding. This may increase the torque of the extruder, making sheet molding difficult. Even if a sheet is obtained, the gel generated in the extruder may cause unevenness on the surface of the sheet, resulting in a poor appearance.

[0098] On the other hand, if the MFR2 exceeds 40 g / 10 min, when the copolymer is processed into a sheet, the sheet may adhere to the surface of a roll such as a chill roll, requiring peeling, which may make it difficult to form a sheet of uniform thickness. Furthermore, the copolymer loses stiffness, making it difficult to form a sheet of 0.3 mm or more. In addition, crosslinkability (particularly crosslinking rate) tends to decrease, making it difficult to obtain a sufficient crosslinked product, and reducing heat resistance.

[0099] On the other hand, when the MFR2 is 40 g / 10 min or less, necking can be suppressed when the copolymer (A) is molded into a sheet, a wide sheet can be molded, and a good crosslinked sheet having particularly excellent crosslinking properties and heat resistance can be obtained.

[0100] <Requirement (a3)> Requirement (a3) ​​is the melt flow rate (MFR) measured at 190°C under a load of 10 kg in accordance with ASTM D1238. 10 and the ratio of MFR2, which is the melt flow rate measured at 190°C under a load of 2.16 kg in accordance with ASTM D1238 (MFR 10 / MFR2) is in the range of 6.8 to 15. 10 / MFR2) is preferably in the range of 6.8 to 12, more preferably 6.9 to 11, even more preferably 6.9 to 10, and most preferably in the range of 7.0 or more and 10 or less.

[0101] MFR 10 / MFR2 is an index of the degree of long chain branching of the copolymer, and MFR 10 If the MFR2 is less than 6.8, the long chain branching is low, and when the copolymer is processed into a sheet, edge vibration is likely to occur during sheet molding, which may result in reduced productivity.

[0102] MFR 10 If MFR2 exceeds 15, the amount of long chain branching increases, and the gelation rate during crosslinking may decrease.

[0103] MFR 10 The value of / MFR2 can be increased or decreased by adjusting, for example, the molecular weight or the degree of long chain branching, and the molecular weight or the degree of long chain branching can be adjusted by the polymerization temperature, the amount of hydrogen, and the selection of the metallocene compound in the production method of the ethylene / α-olefin copolymer (A) described below.

[0104] <Requirement (a4)> Requirement (a4) is that the ratio (η*0.1 / η*100) of the complex viscosity (η*0.1) at a shear rate of 0.1 rad / s measured at 100°C to the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is in the range of 3.5 to 30. The ratio (η*0.1 / η*100) is preferably in the range of 3.5 to 25, more preferably 3.5 to 20, even more preferably 3.7 to 20, still more preferably 4.0 to 20, and most preferably 4.0 to 15, and η*100 is 3000 Pa s or less, preferably 2990 Pa s or less, more preferably 2950 Pa s or less, and the lower limit may be, for example, 1000 Pa s. These can be measured by the methods employed in the examples described below or equivalent methods.

[0105] η*0.1 / η*100 is an index of workability.

[0106] If η*0.1 / η*100 is less than 3.5, the shear rate dependency of the melt viscosity is small, which may result in poor kneading in an extruder when the copolymer is processed into a sheet, flow of the copolymer when laminating the sheet, etc. Furthermore, the shear rate dependency of the melt viscosity is small, which may result in poor extrusion moldability of the copolymer at low temperatures (for example, below 130°C) (hereinafter also referred to as "low-temperature extrusion moldability").

[0107] If η*0.1 / η*100 exceeds 30, the shear rate dependency of the melt viscosity is large, which may cause non-uniformity in the thickness of the sheet when the copolymer is processed into a sheet.

[0108] Furthermore, if η*100 exceeds 3000 Pa·s, the low-temperature extrusion moldability of the copolymer may be poor, and shear heat may occur due to kneading in the extruder, resulting in the formation of gel.

[0109] The value of η*0.1 / η*100 can be increased or decreased by adjusting, for example, the molecular weight or the degree of long chain branching, and the value of η*0.1 / η*100 increases as the molecular weight increases or the degree of long chain branching increases.

[0110] The value of η*100 can be increased or decreased by adjusting, for example, the molecular weight or the degree of long chain branching, and the value of η*0.1 / η*100 increases as the molecular weight increases or the degree of long chain branching increases.

[0111] <Requirement (a5)> Requirement (a5) is that the total number of unsaturated groups contained in the copolymer (A) per 1,000 carbon atoms is 0.45 to 2.0. The total number is preferably 0.45 to 1.8, more preferably 0.45 to 1.6, even more preferably 0.5 to 1.5, and particularly preferably 0.5 to 1.3. The total number of unsaturated groups means: １ It is the total amount of vinyl groups, vinylidene groups, di-substituted internal olefins, and tri-substituted internal olefins in an ethylene-α-olefin copolymer, as determined by H-NMR spectroscopy.

[0112] The amount and type of unsaturated groups can be determined by the method employed in the examples described below.

[0113] If the polymer produced in the production process of the ethylene / α-olefin copolymer (A) has many unsaturated groups, a reaction to form a long-chain branched structure is more likely to occur, increasing the degree of long-chain branching and resulting in an ethylene / α-olefin copolymer (A) with improved melt viscosity characteristics. The ethylene / α-olefin copolymer (A) thus obtained may also contain many unsaturated groups, and the amount thereof may be, for example, within the range described above.

[0114] If the total number of the above-mentioned unsaturated groups is less than 0.45, the formation of a long chain branched structure may be insufficient, resulting in poor low-temperature extrusion moldability of the copolymer.

[0115] If the total number of the above-mentioned unsaturated groups exceeds 2.0, the gelation rate during crosslinking may decrease due to excessive long chain branches.

[0116] The amount of unsaturated groups can be increased or decreased by, for example, adjusting the polymerization temperature, the amount of hydrogen or the amount of organoaluminum oxy compound in the production process for the ethylene / α-olefin copolymer (A) described below, or by selecting the metallocene compound.

[0117] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a6):

[0118] <Requirement (a6)> Requirement (a6) is that the content of structural units derived from ethylene constituting the copolymer (A) (hereinafter may be referred to as "ethylene units") is 80 to 90 mol%, and the content of structural units derived from an α-olefin having 3 to 20 carbon atoms constituting the copolymer (A) (hereinafter may be referred to as "α-olefin units") is 10 to 20 mol% (where the total of the ethylene units and the α-olefin units is 100 mol%). The content of the ethylene units is preferably 81 to 89 mol%, more preferably 82 to 88 mol%, and even more preferably 83 to 87 mol%, and the content of the α-olefin units is preferably 11 to 19 mol%, more preferably 12 to 18 mol%, and even more preferably 13 to 17 mol%.

[0119] From the viewpoint that the copolymer (A) has low crystallinity and can be extruded at a low temperature rather than at a high temperature (for example, 130° C. or higher), it is preferable that the content of ethylene units is equal to or less than the above upper limit. The ability to perform extrusion at a low temperature is preferable from the viewpoint that when an organic peroxide is kneaded into the copolymer (A) and the copolymer (A) is processed into a sheet, the progress of a crosslinking reaction in the extruder is prevented, thereby preventing deterioration of the sheet appearance due to the generation of gel-like foreign matter.

[0120] From the viewpoint of crystallizing the copolymer (A) at an appropriate rate that is not too slow, it is preferable that the content of ethylene units is equal to or greater than the above-mentioned lower limit. Crystallizing the copolymer (A) at an appropriate rate is preferable from the viewpoints of preventing the sheet from becoming sticky when the copolymer (A) is processed into a sheet using an extruder, the ease of feeding the sheet, and the heat resistance of the crosslinked product of the copolymer (A).

[0121] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a7):

[0122] <Requirement (a7)> Requirement (a7) is that the Shore A hardness measured in accordance with ASTM D2240 is in the range of 60 to 85. The Shore A hardness is preferably in the range of 62 to 83, more preferably 62 to 80, and even more preferably 65 to 80.

[0123] The Shore A hardness of the ethylene-α-olefin copolymer (A) can be adjusted by controlling the ethylene unit content and density of the copolymer (A) within the above-mentioned ranges. That is, a copolymer (A) having a high ethylene unit content and a high density has a high Shore A hardness. On the other hand, a copolymer (A) having a low ethylene unit content and a low density has a low Shore A hardness.

[0124] From the viewpoint of crystallizing the copolymer (A) at an appropriate rate that is not too slow, it is preferable that the Shore A hardness is equal to or greater than the above lower limit. Crystallizing the copolymer (A) at an appropriate rate is preferable from the viewpoints of preventing the sheet from becoming sticky when the copolymer (A) is processed into a sheet using an extruder, the ease of feeding the sheet, and the heat resistance of the crosslinked product of the copolymer (A).

[0125] On the other hand, from the viewpoint that the copolymer (A) has low crystallinity and can be extruded at a low temperature rather than at a high temperature (for example, 130° C. or higher), it is preferable that the Shore A hardness is equal to or less than the upper limit. The ability to perform extrusion at a low temperature is preferable from the viewpoint that when an organic peroxide is kneaded into the copolymer (A) and the copolymer (A) is processed into a sheet, the progress of a crosslinking reaction in the extruder is prevented, thereby preventing deterioration of the sheet appearance due to the generation of gel-like foreign matter.

[0126] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a8):

[0127] <Requirement (a8)> Requirement (a8) is that the number of vinyl groups contained in the copolymer (A) per 1000 carbon atoms is 0.05 to 0.3. The number of vinyl groups is preferably 0.06 to 0.3, more preferably 0.08 to 0.3, even more preferably 0.08 to 0.27, and particularly preferably 0.10 to 0.25.

[0128] When the amount of vinyl groups is within the above range, the degree of gelation and the gelation rate during crosslinking can be improved.

[0129] The amount of vinyl groups can be increased or decreased by, for example, adjusting the polymerization temperature, the amount of hydrogen or the amount of organoaluminum oxy compound in the production process for the ethylene / α-olefin copolymer (A) described below, or by selecting the metallocene compound.

[0130] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a9):

[0131] <Requirement (a9)> Requirement (a9) is that the total number of vinyl groups and vinylidene groups contained in the ethylene / α-olefin copolymer (A) per 1,000 carbon atoms is less than 0.50, more preferably 0.05 to 0.49, even more preferably 0.10 to 0.49, and particularly preferably 0.13 to 0.49.

[0132] When the total amount of vinyl groups and vinylidene groups is within the above range, the degree of gelation and the gelation rate during crosslinking can be improved.

[0133] The total amount of vinyl groups and vinylidene groups can be increased or decreased by, for example, adjusting the polymerization temperature, the amount of hydrogen or the amount of organoaluminum oxy compound in the production process for the ethylene / α-olefin copolymer (A) described below, or by selecting the metallocene compound.

[0134] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a10):

[0135] <Requirement (a10)> Requirement (a10) is that the proportion of vinyl groups in the unsaturated groups (i.e., the proportion of vinyl groups relative to the total amount of unsaturated groups; hereinafter, this may be referred to as "vinyl group selectivity") is less than 50 mol%. The vinyl group selectivity is preferably 45 mol% or less, more preferably 40 mol% or less. The lower limit is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and particularly preferably 20 mol% or more.

[0136] When the vinyl group selectivity is within the above range, the copolymer (A) has excellent melt viscosity characteristics and crosslinking characteristics in a well-balanced manner.

[0137] The vinyl group selectivity can be adjusted, for example, by adjusting the polymerization temperature, the amount of hydrogen or the amount of organoaluminum oxy compound when producing the copolymer (A).

[0138] In addition to the above requirements (a1) to (a5), the copolymer (A) preferably satisfies the following requirement (a11):

[0139] <Requirement (a11)> Requirement (a11) is that the molecular weight distribution (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer (A) measured by gel permeation chromatography (GPC), is 2.3 or less. The molecular weight distribution (Mw / Mn) is preferably 2.2 or less. There is no particular restriction on the lower limit of Mw / Mn, but it is usually 1.5.

[0140] The copolymer (A) having a molecular weight distribution within the above range exhibits good crosslinkability and mechanical properties after crosslinking.

[0141] The Mw is preferably 50,000 to 200,000, more preferably 60,000 to 18,000, even more preferably 70,000 to 170,000, and particularly preferably 80,000 to 160,000.

[0142] Mn is preferably 30,000 to 100,000, more preferably 35,000 to 90,000, still more preferably 40,000 to 85,000, and particularly preferably 42,000 to 80,000.

[0143] Specific methods for measuring Mw, Mn and Mw / Mn will be described in detail in the examples below.

[0144] The ethylene / α-olefin copolymer (A) of another embodiment of the present invention satisfies the following requirement (a3′) in addition to the above requirements (a1), (a2), (a4), and (a5), and preferably further satisfies one or more of the above requirements (a6) to (a11):

[0145] <Requirement (a3')> Requirement (a3') is the melt flow rate (MFR) measured at 190°C under a load of 10 kg in accordance with the method of ASTM D1238. 10 and the ratio of MFR2, which is the melt flow rate measured at 190°C under a load of 2.16 kg in accordance with ASTM D1238 (MFR 10 / MFR2) satisfies the following formula (1):

[0146] -0.428×ln(MFR2)+7.5≦MFR 10 / MFR2 ≦-0.876×ln(MFR2)+11.2 ...Formula (1) MFR 10 / MFR2 is an index of the degree of long chain branching of the copolymer, and its value depends on MFR2. The lower the MFR2, the higher the MFR 10 It is known that the ratio of MFR2 to MFR2 increases. 10 The relationship of / MFR2 can provide a specific index of the degree of long chain branching.

[0147] MFR 10 When / MFR2 is -0.428 × ln(MFR2) + 7.5 or more as defined by the formula (1), there is a large amount of long chain branching, and when the copolymer is processed into a sheet, edge vibration during sheet molding can be suppressed, which tends to improve productivity. 10When / MFR2 is not more than -0.876 x ln(MFR2) + 11.2 as defined in formula (1), there is a tendency to suppress the decrease in gelation rate during crosslinking of the copolymer.

[0148] The MFR can be controlled by adjusting the polymerization temperature, the amount of hydrogen or the amount of organoaluminum oxy compound in the production process of the ethylene / α-olefin copolymer (A) described below, or by selecting the metallocene compound. 10 By increasing or decreasing the value of / MFR2, an ethylene / α-olefin copolymer (A) that satisfies formula (1) can be obtained.

[0149] <Method for Producing Ethylene / α-olefin Copolymer (A)> The ethylene / α-olefin copolymer (A) can be produced, for example, by a method including a polymerization step of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene compound (I0).

[0150] As the metallocene compound (I), various metallocene compounds can be used, including, for example, the metallocene compounds described in JP-A Nos. 2006-077261, 2008-231265, and 2005-314680. However, metallocene compounds having structures different from those described in these patent documents may also be used, and two or more metallocene compounds may be used in combination.

[0151] As the metallocene compound (I0), a bridged metallocene compound (I) represented by the following general formula [I] can be preferably used.

[0152]

[0153] (In formula [I], R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group; R 1 ~R 4Two adjacent groups may be bonded to each other to form a ring.

[0154] R 6 and R 11 are each independently the same atom or group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and R 7 and R 10 are each independently the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, 6 and R 7 may be bonded to each other to form a ring, and R 10 and R 11 may be bonded to each other to form a ring.

[0155] However, R 6 , R 7 , R 10 and R 11 are not all hydrogen atoms.

[0156] R 13 and R 14 are selected from a hydrogen atom, a hydrocarbon group, and a silicon-containing group, and may be the same or different; R 13 and R 14 may be bonded to each other to form a ring.

[0157] Y represents a carbon atom or a silicon atom.

[0158] n represents an integer of 1 or 2 or more. When n is 2 or more, R 13 and R 14 is a hydrogen atom.

[0159] M represents a zirconium atom or a hafnium atom.

[0160] Q represents a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having 4 to 10 carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, j represents an integer of 1 to 4, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

[0161] The bridged metallocene compound (I) has the following structural features [m1] and [m2].

[0162] [m1] Of the two ligands, one is a cyclopentadienyl group which may have a substituent, and the other is a fluorenyl group which has a substituent (hereinafter also referred to as a "substituted fluorenyl group").

[0163] [m2] Two ligands are bonded together by a bridge portion (hereinafter also referred to as "bridge portion") consisting of a carbon atom or silicon atom having a hydrocarbon group.

[0164] The optionally substituted cyclopentadienyl group, the substituted fluorenyl group, the crosslinking moiety and other features of the bridged metallocene compound (I) will be explained below in order.

[0165] (Optionally substituted cyclopentadienyl group) In formula [I], R 1 , R 2 , R 3 and R 4 are each independently a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group, and R 1 , R 2 , R 3 and R 4 are all hydrogen atoms, or R 1 , R 2 , R 3 and R 4 is a methyl group and the others are all hydrogen atoms, 1 , R 2 , R 3 and R 4 is more preferably a structure in which all of are hydrogen atoms.

[0166] (substituted fluorenyl group) In formula [I], R 5 , R 8 , R 9 and R 12each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group, and preferably represents a hydrogen atom, a hydrocarbon group, or a silicon-containing group.

[0167] R 6 and R 11 are the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and are preferably selected from a hydrogen atom, a hydrocarbon group, and a silicon-containing group; R 7 and R 10 are the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and are preferably selected from a hydrogen atom, a hydrocarbon group, and a silicon-containing group; R 6 and R 7 may be bonded to each other to form a ring, and R 10 and R 11 may be bonded to each other to form a ring. 6 , R 7 , R 10 and R 11 are not all hydrogen atoms.

[0168] From the viewpoint of polymerization activity, R 6 and R 11 is preferably not a hydrogen atom; 6 , R 7 , R 10 and R 11 It is more preferable that none of R 6 and R 11 are the same group selected from hydrocarbon groups and silicon-containing groups, and R 7 and R 10 It is particularly preferred that are the same group selected from hydrocarbon groups and silicon-containing groups.

[0169] Also, R 6 and R 7 are bonded to each other to form an alicyclic or aromatic ring, and R 10 and R 11 are also preferably bonded to each other to form an alicyclic or aromatic ring.

[0170] R 5 ~R 12 Examples of the group (f1) include a hydrocarbon group (preferably a hydrocarbon group having 1 to 20 carbon atoms, hereinafter sometimes referred to as a "hydrocarbon group (f1)") and a silicon-containing group (preferably a silicon-containing group having 1 to 20 carbon atoms, hereinafter sometimes referred to as a "silicon-containing group (f2)").

[0171] R 1 ~R 4 Examples of the heteroatom-containing group include hydrogen atoms, hydrocarbon groups, and silicon-containing groups, as well as heteroatom-containing groups (excluding the silicon-containing group (f2)) such as halogenated hydrocarbon groups, oxygen-containing groups, and nitrogen-containing groups.

[0172] Specific examples of the hydrocarbon group (f1) include linear hydrocarbon groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decanyl, and allyl groups; branched hydrocarbon groups such as isopropyl, isobutyl, sec-butyl, t-butyl, amyl, 3-methylpentyl, neopentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl, 1,1-dimethyl-2-methylpropyl, and 1-methyl-1-isopropyl-2-methylpropyl groups; and cyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, and adamantyl groups. Examples include cyclic unsaturated hydrocarbon groups such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, and an anthracenyl group, and their nuclear alkyl-substituted derivatives; and saturated hydrocarbon groups in which at least one hydrogen atom has been substituted with an aryl group, such as a benzyl group and a cumyl group.

[0173] R 5 ~R 12The silicon-containing group (f2) in the formula (I) is preferably a silicon-containing group having 1 to 20 carbon atoms, and examples thereof include groups in which a silicon atom is directly covalently bonded to a ring carbon of a cyclopentadienyl group, and specific examples thereof include alkylsilyl groups (e.g., trimethylsilyl group) and arylsilyl groups (e.g., triphenylsilyl group).

[0174] Specific examples of the heteroatom-containing group (excluding the silicon-containing group (f2)) include a methoxy group, an ethoxy group, a phenoxy group, an N-methylamino group, a trifluoromethyl group, a tribromomethyl group, a pentafluoroethyl group, and a pentafluorophenyl group.

[0175] Among the hydrocarbon groups (f1), preferred examples include linear or branched aliphatic hydrocarbon groups having 1 to 20 carbon atoms, specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, neopentyl, and n-hexyl groups.

[0176] R 6 and R 7 (R 10 and R 11 ) are bonded to each other to form an alicyclic or aromatic ring, the substituted fluorenyl group preferably being a group derived from a compound represented by any of the following formulae:

[0177]

[0178] (Crosslinking part) In formula [I], R 13 and R 14 preferably each independently represents a hydrogen atom or a hydrocarbon group.

[0179] Y represents a carbon atom or a silicon atom.

[0180] n is an integer of 1 or 2 or more (for example, 2 to 4), and when n is an integer of 2 or more, R 13 and R 14 is a hydrogen atom.

[0181] From the viewpoint of ease of manufacturing, R 13 and R 14 are preferably the same as each other.

[0182] An embodiment in which Y represents a carbon atom and n is 2 is also preferred.

[0183] R 13 and R 14 The hydrocarbon group as is preferably a benzyl group or an aliphatic hydrocarbon group, more preferably an alkyl group having 10 or less carbon atoms, and even more preferably a methyl group.

[0184] As the crosslinking portion, n=1 and R 13 and R 14 In a particularly preferred embodiment, all of the above are methyl groups.

[0185] (Q) As described above, Q represents a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having 4 to 10 carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

[0186] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0187] Examples of the hydrocarbon group include the hydrocarbon group (f1) described above. More specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a 2-methylpropyl group, a 1,1-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1,1-diethylpropyl group, a 1-ethyl-1-methylpropyl group, a 1,1,2,2-tetramethylpropyl group, a sec-butyl group, a tert-butyl group, a 1,1-dimethylbutyl group, a 1,1,3-trimethylbutyl group, a neopentyl group, a cyclohexylmethyl group, a cyclohexyl group, and a 1-methyl-1-cyclohexyl group.

[0188] Examples of halogenated hydrocarbon groups include trifluoromethyl groups, pentafluorophenyl groups, and chlorophenyl groups.

[0189] The neutral conjugated or non-conjugated dienes include, for example, s-cis- or s-trans-η 4-1,3-butadiene, s-cis- or s-trans-η 4 -1,4-diphenyl-1,3-butadiene, s-cis- or s-trans-η 4 -3-methyl-1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-dibenzyl-1,3-butadiene, s-cis- or s-trans-η 4 -2,4-hexadiene, s-cis- or s-trans-η 4 -1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-ditolyl-1,3-butadiene, and s-cis- or s-trans-η 4 and 1,4-bis(trimethylsilyl)-1,3-butadiene.

[0190] Examples of neutral ligands capable of coordinating with lone electron pairs include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine; and ethers such as tetrahydrofuran, dioxane, diethyl ether, and 1,2-dimethoxyethane.

[0191] Examples of the anionic ligand include alkoxy groups such as methoxy and tert-butoxy; aryloxy groups such as phenoxy; substituted aryloxy groups; carboxylate groups such as acetate and benzoate; sulfonate groups such as mesylate and tosylate; and thioalkoxy groups such as methylthio and thiophenoxy.

[0192] The substituted aryloxy group is represented by O-subAr, where subAr is an aryl group in which at least one hydrogen atom is substituted with a substituent, and the substituent includes at least one group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryl(1 to 20 carbon atoms) alkyl group (having 6 to 20 carbon atoms), an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, and an arylthio group having 6 to 20 carbon atoms, and subAr has 14 or more carbon atoms. Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a tetracenyl group, and a tetraphenyl group.

[0193] Specific examples of the substituted aryloxy group include a 4-dodecylphenoxy group, a 3-pentadecylphenoxy group, a 4-pentadecylphenoxy group, and a 4-t-octylphenoxy group.

[0194] Specific examples of the metallocene compound (I0) include dimethylmethylene(cyclopentadienyl)(2,7-di-t-butylfluorenyl)zirconium dichloride and dimethylmethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dimethyl.

[0195] As a polymerization reaction using a metallocene compound, for example, the following embodiments can be mentioned as suitable examples.

[0196] Ethylene and an α-olefin are supplied in the presence of an olefin polymerization catalyst comprising a metallocene compound (I) and at least one compound (II) (also referred to as a co-catalyst) selected from the group consisting of an organoaluminum oxy compound (II-1), a compound (II-2) that reacts with the metallocene compound (I) to form an ion pair, and an organoaluminum compound (II-3).

[0197] Examples of the organoaluminum oxy compound (II-1), the compound (II-2) that reacts with the metallocene compound (I) to form an ion pair, and the organoaluminum compound (II-3) include those described in JP-A Nos. 2006-077261, 2008-231265, and 2005-314680. These compounds and the metallocene compound (I) may be introduced into the polymerization atmosphere individually or after contacting each other in advance. Furthermore, they may be supported on a fine particle inorganic oxide support, as described in JP-A No. 2005-314680.

[0198] Preferably, the ethylene / α-olefin copolymer (A) can be obtained by producing the copolymer without substantially using the compound (II-2) that reacts with the metallocene compound (I) to form an ion pair.

[0199] The organoaluminum oxy compound (II-1) (hereinafter also referred to as "component (II-1)") and the organoaluminum compound (II-3) (hereinafter also referred to as "component (II-3)") will be described in detail below.

[0200] (Component (II-1)) Component (II-1) is not particularly limited as long as it is a compound other than component (II-3), but is preferably at least one compound selected from the group consisting of organoaluminum compounds (II-1a) represented by the following formula (II-1a): compounds of Group 1 metals and aluminum (II-1b) represented by the following formula (II-1b): and compounds of Group 2 or Group 12 metals (II-1c) represented by the following formula (II-1c):

[0201] Among these, compound (II-1a) is preferred.

[0202] The component (II-1) may be used alone or in combination of two or more.

[0203] R ａ ｍ Al (OR ｂ ) ｎ H ｐ X ｑ ...(II-1a) [In formula (II-1a), Rａ and R ｂ each independently represent a hydrocarbon group having 1 to 15 carbon atoms and may be the same or different, X independently represents a halogen atom, m is 0<m≦3, n is 0≦n<3, p is 0≦p<3, q is 0≦q<3, and m+n+p+q=3.] Examples of compound (II-1a) include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, dialkylaluminum hydrides such as diisobutylaluminum hydride, and tricycloalkylaluminums.

[0204] M ａ AlR ａ ４ ...(II-1b) [In formula (II-1b), M ａ represents Li, Na or K, and R ａ are independently a hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 4 carbon atoms).] Examples of the compound (II-1b) include LiAl(C2H5)4, LiAl(C7H 15 ) 4 are listed.

[0205] R ａ ｒ M ｂ R ｂ ｓ X ｔ ...(II-1c) [In formula (II-1c), R ａ and R ｂ each independently represents a hydrocarbon group having 1 to 15 carbon atoms, and may be the same or different; M ｂ is selected from Mg, Zn and Cd, X represents a halogen atom, r is 0<r≦2, s is 0≦s≦1, t is 0≦t≦1, and r+s+t=2.] Examples of compound (II-1c) include dimethylmagnesium, diethylmagnesium, di-n-butylmagnesium, ethyl-n-butylmagnesium, diphenylmagnesium, dimethylzinc, diethylzinc, di-n-butylzinc, and diphenylzinc.

[0206] (Component (II-3)) Component (II-3) may be, for example, a conventionally known aluminoxane, or an organoaluminum oxy compound that is insoluble or slightly soluble in benzene, as exemplified in JP-A-2-78687. Conventionally known aluminoxanes can be produced, for example, by the following methods (1) to (4), and are usually obtained as a solution in a hydrocarbon solvent.

[0207] The component (II-3) may be used alone or in combination of two or more.

[0208] (1) A method in which an organoaluminum compound such as trialkylaluminum is added to a hydrocarbon medium suspension of a compound containing adsorbed water or a salt containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, or cerous chloride hydrate, to react the adsorbed water or water of crystallization with the organoaluminum compound.

[0209] (2) A method in which water, ice or water vapor is directly reacted with an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, diethyl ether or tetrahydrofuran.

[0210] (3) A method in which an organoaluminum compound such as trialkylaluminum is reacted with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene, or toluene.

[0211] (4) A method in which a compound produced by reacting an organoaluminum such as trialkylaluminum with an organic compound having a carbon-oxygen bond such as a tertiary alcohol, a ketone, or a carboxylic acid is subjected to a non-hydrolytic conversion such as thermal decomposition reaction.

[0212] The aluminoxane may contain a small amount of an organometallic component. After the solvent or unreacted organoaluminum compound is removed from the recovered aluminoxane solution by distillation or the like, the aluminoxane may be redissolved in a solvent or suspended in a poor solvent for the aluminoxane.

[0213] Specific examples of organoaluminum compounds used in preparing aluminoxane include the same organoaluminum compounds as those exemplified above as compound (II-1a). Among these, trialkylaluminum and tricycloalkylaluminum are preferred, and trimethylaluminum is particularly preferred.

[0214] Other examples of component (II-3) include modified methylaluminoxane. Modified methylaluminoxane is an aluminoxane prepared using trimethylaluminum and an alkylaluminum other than trimethylaluminum. Such a compound is generally called MMAO. MMAO can be prepared by the methods described in U.S. Pat. Nos. 4,960,878 and 5,041,584. Also commercially produced by Tosoh Finechem Corporation and other companies under the names MMAO and TMAO are those prepared using trimethylaluminum and triisobutylaluminum.

[0215] Such MMAO is an aluminoxane with improved solubility in various solvents and improved storage stability. Specifically, unlike the organoaluminum oxy compounds described above that are insoluble or poorly soluble in benzene, MMAO is characterized by its solubility in aliphatic hydrocarbons and alicyclic hydrocarbons.

[0216] The polymerization of the ethylene / α-olefin copolymer (A) can be carried out by any of the conventionally known gas phase polymerization methods and liquid phase polymerization methods such as slurry polymerization and solution polymerization. Liquid phase polymerization methods such as solution polymerization are preferred. When the ethylene / α-olefin copolymer (A) is produced by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms using the above metallocene compound, the metallocene compound (I) is usually used in an amount of 1×10 per liter of reaction volume. -9 ~1 x 10 -1 mole, preferably 1 x 10 -8 ~1 x 10 -2 It is used in molar amounts.

[0217] The organoaluminum oxy compound (II-1) is used in such an amount that the molar ratio [(II-1) / M] of the organoaluminum oxy compound (II-1) to the total transition metal atoms (M) in the metallocene compound (I) is usually 1 to 10,000, preferably 10 to 5,000.

[0218] The compound (II-2) which reacts with the metallocene compound (I) to form an ion pair is used in such an amount that the molar ratio of the compound (II-2) to the total transition metal atoms (M) in the metallocene compound (I), [(II-2) / M], is usually 50 or less, preferably 20 or less.

[0219] The organoaluminum compound (II-3) is used in an amount of usually 0 to 5 millimoles, preferably about 0 to 2 millimoles, calculated as aluminum atoms per liter of polymerization volume.

[0220] In the polymerization step, the polymerization temperature is preferably 100 to 170°C.

[0221] In the polymerization step, the polymerization pressure is usually from atmospheric pressure to 10 MPa gauge pressure, preferably from atmospheric pressure to 5 MPa gauge pressure, and the polymerization time is usually 1 hour or less, preferably 40 minutes or less.

[0222] The copolymerization reaction can be carried out in any of batch, semi-continuous and continuous systems. Furthermore, the copolymerization can be carried out in two or more stages with different reaction conditions.

[0223] Hydrogen may be added to the polymerization system. In this case, the hydrogen (H ２ The molar ratio of hydrogen to ethylene supplied to the polymerization system (moles of hydrogen / moles of ethylene) is preferably less than 0.020, more preferably 0.001 or more and less than 0.020.

[0224] The ethylene / α-olefin copolymer obtained by this production method may be subjected to known post-treatment steps such as a catalyst deactivation step, a catalyst residue removal step, and a drying step, if necessary, after synthesis by the above-mentioned method.

[0225] The α-olefin to be supplied to the polymerization reaction is an α-olefin having 3 to 20 carbon atoms, the details of which are as described above.

[0226] As the monomers (i.e., ethylene and α-olefins) supplied to the polymerization reaction, a combination of fossil fuel-derived and biomass-derived monomers may be used, a combination of fossil fuel-derived and chemically recycled monomers may be used, a combination of biomass-derived and chemically recycled monomers may be used, or a combination of fossil fuel-derived, biomass-derived and chemically recycled monomers may be used.

[0227] Ethylene and the α-olefin having 3 to 20 carbon atoms are supplied so that the proportion of structural units derived from ethylene and the proportion of structural units derived from the α-olefin having 3 to 20 carbon atoms in the resulting ethylene / α-olefin copolymer (A) are as described above.

[0228] [Composition] The composition (X) according to the present invention contains the copolymer (A) and a component other than the copolymer (A).

[0229] The composition (X) may contain, as a component other than the copolymer (A), a resin other than the copolymer (A). Examples of resins other than the copolymer (A) include amorphous α-olefin polymers such as polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-butene-1-ethylene-terpolymer, propylene-hexene-1-octene-1-terpolymer, propylene-hexene-1-4-methylpentene-1-terpolymer, polybutene-1, butene-1-ethylene copolymer, butene-1-propylene copolymer, butene-1-propylene-ethylene-terpolymer, butene-1-hexene-1-octene-1-terpolymer, and butene-1-hexene-1-4-methylpentene-1-terpolymer; crystalline α-olefin polymers such as polyolefins and copolymers thereof, including polyethylene, polypropylene, and polybutene; ethylene-vinyl acetate copolymer; styrene-based polymers and hydrogenated products thereof, such as polystyrene and acrylonitrile-styrene copolymer; polyvinyl chloride, polyvinylidene chloride; Examples of the polymer include vinyl carboxylic acid polymers and vinyl carboxylic acid ester polymers such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate, and polyethyl methacrylate; ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, and ethylene-vinyl alcohol copolymer; polyesters such as polycarbonate, polyethylene terephthalate, and polybutylene terephthalate; polyamides such as nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon MXD6, wholly aromatic polyamides, and semi-aromatic polyamides; and polyacetal.

[0230] The composition (X) may contain various additives depending on the purpose. The amount of the additives added is appropriately selected depending on the application within a range that does not impair the object of the present invention.

[0231] Examples of the additives include one or more additives selected from the group consisting of radical polymerization initiators, elastomers, heat stabilizers, weather stabilizers, radiation resistant agents, plasticizers, lubricants, release agents, nucleating agents, friction and wear improvers, flame retardants, foaming agents, antistatic agents, colorants, antifogging agents, antiblocking agents, impact resistance agents, surface wetting improvers, fillers, hydrochloric acid absorbers, and metal deactivators.

[0232] <Crosslinking of Ethylene / α-olefin Copolymer (A)> One embodiment of the composition (X) is a composition containing the ethylene / α-olefin copolymer (A) and an organic peroxide.

[0233] The ethylene / α-olefin copolymer (A) can be crosslinked by using an organic peroxide as a radical initiator.

[0234] The organic peroxide is not particularly limited as long as it can crosslink the copolymer (A). However, an organic peroxide having a one-minute half-life temperature in the range of 100 to 190°C, preferably 100 to 180°C, is preferred, as it provides a good balance between formability when processing the copolymer (A) into a sheet by extrusion molding and crosslinking rate.

[0235] Known organic peroxides can be used, and specific examples thereof include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, dibenzoyl peroxide, cyclohexanone peroxide, di-t-butylperphthalate, t-butyl hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, 1,1-di(t-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-amylperoxy)cyclohexane, t-amylperoxyisononanoate, t-amylperoxynormaloctoate, 1,1-di(t- butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-amyl peroxybenzoate, t-butylperoxyacetate, t-butylperoxyisononanoate, t-butylperoxybenzoate, 2,2-di(butylperoxy)butane, n-butyl-4,4-di(t-butylperoxy)butyrate, methyl ethyl ketone peroxide, ethyl-3,3-di(t-butylperoxy)butyrate, dicumyl peroxide, t-butylcumyl peroxide, t-butylperoxybenzoate, and acetylacetone peroxide. Preferred examples include dilauroyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, t-butylperoxyacetate, t-butylperoxyisononanoate, t-butylperoxy-2-ethylhexyl carbonate, and t-butylperoxybenzoate.

[0236] The organic peroxide may be used alone or in combination of two or more kinds.

[0237] The amount of the organic peroxide to be added is preferably 0.1 to 3 parts by mass, more preferably 0.2 to 2.5 parts by mass, based on 100 parts by mass of the copolymer (A).

[0238] [Uses] The composition (X) of the present invention can be used for a wide range of applications, from household goods to industrial goods, to molded articles, adhesives, and sealants. That is, the composition (X) can be used as a raw material for molded articles, adhesives, or sealants, and all of such raw materials for molded articles, adhesives, and sealants contain the composition (X).

[0239] When the composition (X) is used as a raw material for a molded body, the composition (X) can be crosslinked to form a molded body. That is, one embodiment of the molded body of the present invention is obtained by crosslinking the composition (X), and can be said to include a crosslinked product of the composition (X).

[0240] The copolymer (A) of the present invention is an ethylene-α-olefin copolymer that has a good balance between moldability and crosslinkability, but may also be useful in applications that do not require crosslinking.

[0241] Examples of major applications of the composition (X) include electrical and electronic components, automotive parts, mechanical parts, food containers, films, sheets, fibers, etc. Specific examples include office and OA equipment such as printers, personal computers, word processors, keyboards, PDAs (personal digital assistants), telephones, mobile phones, smartphones, tablet devices, Wi-Fi routers, facsimiles, copiers, ECRs (electronic cash registers), calculators, electronic organizers, electronic dictionaries, cards, holders, and stationery; home appliances such as washing machines, refrigerators, vacuum cleaners, microwave ovens, lighting fixtures, game consoles, irons, and kotatsu tables; audio-visual equipment such as TVs, VTRs, video cameras, digital cameras, single-lens reflex cameras, portable audio terminals, radio-cassette players, tape recorders, minidiscs, CD players, speakers, and liquid crystal displays; electrical and electronic components and communication devices such as connectors, relays, capacitors, switches, printed circuit boards, coil bobbins, electric wires, cables, transformers, deflection yokes, distribution boards, and clocks; semiconductor encapsulation materials, solar cell encapsulation materials, etc.

[0242] Examples of applications also include automobile, vehicle, ship, aircraft and construction materials such as seats (padding, outer material, etc.), belts, ceiling coverings, convertible tops, armrests, door trims, rear package trays, carpets, mats, sun visors, wheel covers, tires, mattress covers, airbags, insulation materials, hand straps, hand straps, wire covering materials, electrical insulation materials, paints, coating materials, upholstery materials, flooring materials, corner walls, deck panels, covers, plywood, ceiling boards, partition boards, side walls, carpets, wallpaper, wall coverings, exterior materials, interior materials, roofing materials, soundproofing boards, heat insulating boards, window materials, etc.; and lifestyle and sporting goods such as clothing, curtains, sheets, plywood, synthetic fiber boards, rugs, entrance mats, sheets, buckets, hoses, containers, eyeglasses, bags, cases, goggles, skis, rackets, tents, musical instruments, etc.

[0243] Further examples of uses include bottles for shampoo, detergent, cosmetics, etc., seasoning bottles for cooking oil, soy sauce, etc., beverage bottles for mineral water, juice, etc., lunch boxes, heat-resistant food containers such as bowls for chawanmushi, tableware such as plates and chopsticks, various other food containers, packaging films, packaging bags, toothbrush and knife handles, etc.

[0244] Further examples of applications include adhesives, hot melt adhesives, heat sealing materials, primers, sealants, covering materials for electric wires, wires, cables, wire harnesses, etc., linings, hoses, tubes, pipes, bottles, separators, molding materials, mandrels, belts, shock absorbing pads, protective equipment such as protectors, helmets and guards, various grip materials for golf clubs, tennis rackets, bats, tools, etc., mouth guards, various balls such as baseballs, tennis balls and golf balls, vibration-damping pallets, shock absorbing dampers, insulators, shock absorbing materials for footwear, shock absorbing foams, toothbrushes, flooring materials, power tool components, agricultural machinery components, heat dissipation materials, transparent substrates, soundproofing materials, cushioning materials, gaskets, caps, medicine stoppers, packing materials, cap liners, shoe soles, shoe midsoles, inner soles, shoe and sandal components such as soles, leather, nonwoven fabrics, fabric materials, Examples include films and sheets used for various purposes such as packaging, optics, mold release, heat transfer, conductivity, dust prevention, transfer, protection, and impact absorption; bumpers, rear package trim, seatback garnishes, instrument panels; masterbatches such as pellets, powders, and pastes containing fillers, pigments, oils, fibers, etc.; industrial materials; clothing materials; everyday goods materials; and kitchenware materials.

[0245] It should be noted that some of the above uses may overlap with each other.

[0246] <Molded Article> The molded article of the present invention contains the copolymer (A) or the composition (X), or a crosslinked product thereof. The molded article can be produced by molding the copolymer (A) or the composition (X) by a conventionally known molding method, such as blow molding, injection molding, press molding, extrusion molding, inflation molding, extrusion blow molding, injection blow molding, vacuum molding, calendar molding, or melt T-die casting.

[0247] Specific examples of the molded article include films, sheets, injection molded articles, blow molded articles, automobile interior and exterior parts, etc. More specific examples include civil engineering and building materials such as multi-layer hoses, tubes, decorative sheets, and flooring mats, covering materials for electric wires and cables (e.g., insulating layers, sheath layers), nonwoven fabrics, stretch films, food packaging films, packaging sheets, food packaging trays and beverage cups obtained by thermoforming the sheet, and plastic containers obtained by folding the sheet.

[0248] <Coating Material for Electric Wire or Cable> The coating material for an electric wire or cable of the present invention contains the composition (X) or a crosslinked product thereof.

[0249] The electric wire or cable of the present invention has a coating layer made of the above-mentioned coating material.

[0250] One embodiment of the composition (X) used for a covering material for an electric wire or cable may contain, in addition to the ethylene / α-olefin copolymer (A), a flame retardant, the above-mentioned "resin other than the copolymer (A)", or a crosslinking agent.

[0251] Examples of the flame retardant include conventionally known flame retardants such as phosphorus-based flame retardants (for example, aluminum diethylphosphinate).

[0252] The proportion of the flame retardant is, for example, 30 to 100 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0253] As the resin other than the copolymer (A), preferred examples include crystalline α-olefin polymers such as polyolefins such as polyethylene, polypropylene, and polybutene, and copolymers thereof.

[0254] When a resin other than the copolymer (A) is contained, the proportion thereof is, for example, 50 to 200 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0255] Examples of the crosslinking agent include conventionally known crosslinking agents such as organic peroxides (e.g., dicumyl peroxide).

[0256] When the crosslinking agent is used, the proportion thereof is, for example, 0.1 to 3 parts by mass relative to 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0257] <Foam, Laminate> The foam of the present invention contains the ethylene / α-olefin copolymer (A).

[0258] The foam of the present invention can be produced by a conventional method for producing a foam containing an ethylene / α-olefin copolymer, except that the ethylene / α-olefin copolymer (A) is used as the ethylene / α-olefin copolymer.

[0259] Examples of the method for producing a foam include: a method for producing a foam comprising a step of physically or chemically foaming the copolymer (A); a method for producing a foam comprising a step of physically or chemically foaming the composition (X) containing the copolymer (A) and a component other than the crosslinking agent; a method for producing a foam comprising a step of physically or chemically foaming the composition (X) containing the copolymer (A) and a crosslinking agent; a method for producing a foam comprising a step of impregnating the copolymer (A) with a supercritical fluid; a method for producing a foam comprising a step of impregnating the composition (X) containing the copolymer (A) and a component other than the crosslinking agent with a supercritical fluid; and a method for producing a foam comprising a step of impregnating the composition (X) containing the copolymer (A) and a crosslinking agent with a supercritical fluid.

[0260] One embodiment of the composition (X) used for the foam may contain, in addition to the ethylene / α-olefin copolymer (A), an ethylene / polar monomer copolymer, a physical foaming agent, a chemical foaming agent, or a crosslinking agent.

[0261] Specific examples of the ethylene-polar monomer copolymer include conventionally known ethylene-polar monomer copolymers such as ethylene-vinyl acetate copolymer.

[0262] When the ethylene-polar monomer copolymer is used, the proportion thereof is, for example, 50 to 200 parts by mass per 100 parts by mass of the ethylene-α-olefin copolymer (A).

[0263] When the composition (X) contains an ethylene-polar monomer copolymer, when the foam is used as one layer of a laminate described later, the foam layer tends to have excellent adhesion to other layers made of polyurethane, rubber, leather, etc.

[0264] Examples of the physical foaming agent include conventionally known physical foaming agents such as carbon dioxide.

[0265] Examples of the chemical foaming agent include conventionally known chemical foaming agents such as azodicarbonamide (ADCA).

[0266] When the chemical foaming agent is used, the proportion thereof is, for example, 0.5 to 5 parts by mass per 100 parts by mass of the total of the ethylene / α-olefin copolymer (A) and the ethylene / polar monomer copolymer.

[0267] When a chemical foaming agent is used, a foaming assistant may be used in combination. Specific examples of the foaming assistant include conventionally known foaming assistants such as zinc oxide (ZnO), titanium oxide, and stearic acid.

[0268] When the foaming aid is used, the proportion thereof is, for example, 1 to 10 parts by mass per 100 parts by mass of the total of the ethylene / α-olefin copolymer (A) and the ethylene / polar monomer copolymer.

[0269] Examples of the crosslinking agent include conventionally known crosslinking agents such as organic peroxides (e.g., dicumyl peroxide).

[0270] When the crosslinking agent is used, the proportion thereof is, for example, 0.1 to 3 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A) and the ethylene / polar monomer copolymer combined.

[0271] When a crosslinking agent is used, a crosslinking aid may be used in combination. Specific examples of the crosslinking aid include conventionally known crosslinking aids such as triisocyanurate.

[0272] When the crosslinking aid is used, the crosslinking aid is used in an amount such that the mass ratio of the crosslinking aid to the crosslinking agent [mass of crosslinking aid / mass of crosslinking agent] is, for example, 1 / 30 to 1 / 0.2.

[0273] The laminate of the present invention has a layer made of the foam of the present invention described above and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather. The polyolefin, polyurethane, rubber, leather, and artificial leather are not particularly limited, and any conventionally known polyolefin, polyurethane, rubber, leather, or artificial leather can be used.

[0274] The laminate of the present invention is particularly suitable for use in footwear or footwear parts.

[0275] <Footwear and Footwear Components> The footwear and footwear components of the present invention both use the foam or laminate of the present invention. That is, it can be said that the footwear and footwear components of the present invention both include the foam or laminate of the present invention. Examples of footwear components include soles, midsoles, innersoles, soles, and sandals. Among these, the foam or laminate is preferably used as a midsole, innersole, or sole.

[0276] <<Composition for forming a solar cell encapsulant>> The composition for forming a solar cell encapsulant of the present invention includes the composition (X). In other words, one embodiment of the composition (X) is a composition for forming a solar cell encapsulant.

[0277] The composition for forming a solar cell encapsulant may contain a silane coupling agent such as an ethylenically unsaturated silane compound. When the composition contains a silane coupling agent, the amount thereof is usually 0.1 to 5 parts by mass, and preferably 0.1 to 3 parts by mass, per 100 parts by mass of the copolymer (A).

[0278] The composition for forming a solar cell encapsulant may contain an organic peroxide having a 1-minute half-life temperature in the range of 100 to 170°C. When the composition contains an organic peroxide, the amount thereof is usually 0.1 to 3 parts by mass, and preferably 0.2 to 2.5 parts by mass, per 100 parts by mass of the copolymer (A).

[0279] The composition for forming a solar cell encapsulant preferably contains 0.1 to 5 parts by mass of a silane coupling agent such as an ethylenically unsaturated silane compound and 0.1 to 3 parts by mass of a crosslinking agent such as an organic peroxide, relative to 100 parts by mass of the copolymer (A).

[0280] The composition for forming a solar cell encapsulant more preferably contains 0.1 to 4 parts by mass of the ethylenically unsaturated silane compound and 0.2 to 3 parts by mass of the organic peroxide, and particularly preferably contains 0.1 to 3 parts by mass of the ethylenically unsaturated silane compound and 0.2 to 2.5 parts by mass of the organic peroxide, relative to 100 parts by mass of the copolymer (A).

[0281] (Ethylenically unsaturated silane compound) When the amount of the ethylenically unsaturated silane compound is equal to or greater than the lower limit, the solar cell encapsulant-forming composition has excellent adhesiveness. On the other hand, when the amount of the ethylenically unsaturated silane compound is equal to or less than the upper limit, the solar cell encapsulant-forming composition has a good balance between cost and performance, and the amount of organic peroxide added for grafting the ethylenically unsaturated silane compound to the copolymer (A) contained in the solar cell encapsulant-forming composition during lamination with the solar cell module can be reduced.

[0282] Specific examples of the ethylenically unsaturated silane compound include conventionally known ethylenically unsaturated silane compounds such as γ-methacryloxypropyltrimethoxysilane.

[0283] (Organic Peroxide) The organic peroxide is used as a radical initiator during the graft modification of an ethylenically unsaturated silane compound with the copolymer (A) contained in the solar cell encapsulant-forming composition, and also as a radical initiator during the crosslinking reaction during lamination molding of the solar cell encapsulant-forming composition and a solar cell module. By graft-modifying the copolymer (A) contained in the solar cell encapsulant-forming composition with an ethylenically unsaturated silane compound, a solar cell module with good adhesion to glass, a backsheet, a cell, and an electrode can be obtained. Furthermore, by crosslinking the copolymer (A) that forms the solar cell encapsulant-forming composition, a solar cell module with excellent heat resistance and adhesion can be obtained.

[0284] The organic peroxide may be any organic peroxide capable of graft-modifying the copolymer (A) contained in the solar cell encapsulant-forming composition with an ethylenically unsaturated silane compound or crosslinking the copolymer (A) contained in the solar cell encapsulant-forming composition. In order to balance the productivity in extrusion sheet molding and the crosslinking rate during lamination with a solar cell module, the organic peroxide preferably has a one-minute half-life temperature of 100 to 170°C. When the one-minute half-life temperature of the organic peroxide is equal to or greater than the lower limit, gel formation in the sheet-shaped solar cell encapsulant obtained from the copolymer (A) containing the organic peroxide during extrusion sheet molding can be prevented. When the one-minute half-life temperature of the organic peroxide is equal to or less than the upper limit, the crosslinking rate during lamination with a solar cell module is appropriate, resulting in good productivity of the solar cell module.

[0285] Known organic peroxides can be used. Specific examples of organic peroxides having a one-minute half-life temperature in the range of 100 to 170°C include the above-mentioned organic peroxides having a one-minute half-life temperature in the range of 100 to 170°C, such as t-butylperoxy-2-ethylhexyl carbonate.

[0286] (Crosslinking Aid) The composition for forming a solar cell encapsulant may contain a crosslinking aid.

[0287] When the composition for forming a solar cell encapsulant contains a crosslinking aid, the blending amount of the crosslinking aid is preferably 0.05 to 5 parts by mass relative to 100 parts by mass of the copolymer (A), because this allows an appropriate crosslinked structure to be formed and improves heat resistance, mechanical properties, and adhesiveness.

[0288] Specific examples of the crosslinking aid include conventionally known crosslinking aids that are generally used for olefin resins, such as triisocyanurate.

[0289] (Ultraviolet Absorber, Light Stabilizer, Heat Stabilizer) The composition for forming a solar cell encapsulant preferably contains at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and a heat stabilizer.

[0290] The blending amount of these additives is preferably 0.005 to 5 parts by mass per 100 parts by mass of copolymer (A). When the blending amount of the additives is within the above range, the effects of improving resistance to high temperatures and humidity, resistance to heat cycles, weather resistance, and heat resistance can be sufficiently ensured, and a decrease in the transparency of the composition for forming a solar cell encapsulant and in the adhesion to glass, a backsheet, a cell, an electrode, and aluminum can be prevented, which is preferable.

[0291] Specific examples of the light stabilizer include hindered amine light stabilizers such as bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, and hindered piperidine light stabilizers.

[0292] (Other Additives) The solar cell encapsulant-forming composition may contain various other components in addition to those described above, as long as the components do not impair the objectives of the present invention. Examples of such components include various polyolefins other than copolymer (A), styrene-based and ethylene-based block copolymers, and propylene-based polymers. The content of these components may be 0.0001 to 100 parts by mass, preferably 0.001 to 50 parts by mass, per 100 parts by mass of copolymer (A). The solar cell encapsulant-forming composition may also contain one or more additives selected from various resins other than polyolefins and / or various rubbers, plasticizers, fillers, pigments, dyes, antistatic agents, antibacterial agents, antifungal agents, flame retardants, crosslinking aids, and dispersants.

[0293] The composition for forming a solar cell encapsulant contains, for example, 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more of the copolymer (A). The upper limit of the content of the copolymer (A) depends on the content of the additives.

[0294] The solar cell encapsulant of the present invention includes an encapsulating layer made of a crosslinked product of the solar cell encapsulant-forming composition of the present invention.

[0295] The solar cell encapsulant of the present invention may have a single layer structure or a multilayer structure of two or more layers. More specifically, the solar cell encapsulant of the present invention may be a single-layer film consisting of one layer (also referred to as an "encapsulating layer") composed of the crosslinked product of the solar cell encapsulant-forming composition, a multilayer film consisting of two or more layers composed of the crosslinked product of the solar cell encapsulant-forming composition, or a multilayer film having at least one layer composed of the crosslinked product of the solar cell encapsulant-forming composition and at least one layer other than the layer composed of the crosslinked product of the solar cell encapsulant-forming composition.

[0296] When the solar cell encapsulant of the present invention has a multilayer structure, the layer formed of the crosslinked product of the composition for forming a solar cell encapsulant may be used as an outer layer or an intermediate layer.

[0297] When the solar cell encapsulant of the present invention has a multilayer structure, the solar cell encapsulant preferably has a two-layer structure in which two outer layers (hereinafter also referred to as "adhesive layers") are laminated, at least one of the outer layers being made of a crosslinked product of the solar cell encapsulant-forming composition of the present invention, or a three-layer structure including an intermediate layer and two outer layers formed on both sides of the intermediate layer so as to sandwich the intermediate layer, at least one layer, preferably the intermediate layer, being made of a crosslinked product of the solar cell encapsulant-forming composition of the present invention.

[0298] In a multilayer structure having a plurality of layers each composed of a crosslinked product of the composition for forming a solar cell encapsulant, the composition or type of the copolymer (A) or the composition for forming a solar cell encapsulant in each layer may be the same or different.

[0299] The thickness of the solar cell encapsulant of the present invention is, for example, 0.1 mm or more and 10 mm or less, preferably 0.2 mm or more and 5 mm or less, and more preferably 0.3 mm or more and 2 mm or less.

[0300] When the thickness of the solar cell encapsulant is equal to or greater than the above lower limit, the mechanical strength of the solar cell encapsulant can be improved, and when the thickness of the solar cell encapsulant is equal to or less than the above upper limit, the optical properties and interlayer adhesion of the solar cell encapsulant can be improved.

[0301] When the solar cell encapsulant of the present invention includes an outer layer and an intermediate layer, the thickness of the outer layer is arbitrary, but the thickness a of the outer layer is preferably in the range of 1 μm to 500 μm, more preferably in the range of 10 μm to 500 μm, and particularly preferably in the range of 20 μm to 300 μm.

[0302] When the thickness a is 1 μm or more, the adhesive strength can be further improved, and when it is 500 μm or less, the transparency is further improved.

[0303] Furthermore, when the solar cell encapsulant according to the present invention includes an outer layer and an intermediate layer, the thickness of the intermediate layer relative to the total layer thickness may be large from the viewpoint of transparency. Specifically, the thickness b of the intermediate layer can be freely set within the range obtained by subtracting the preferred thickness a of the outer layer from the preferred total thickness range of 0.1 mm to 10 mm.

[0304] Furthermore, when the solar cell encapsulant of the present invention includes an outer layer and an intermediate layer, the thickness ratio (a / b) of the outer layer (thickness a) to the intermediate layer (thickness b) is preferably 1 / 20 to 5 / 1, more preferably 1 / 15 to 3 / 1, and even more preferably 1 / 10 to 3 / 1. When the solar cell encapsulant of the present invention includes two outer layers, the thickness a of the outer layer is the average value of the thicknesses of the two outer layers.

[0305] When the thickness ratio (a / b) of the outer layer to the intermediate layer is within the above range, the adhesiveness and transparency are further improved.

[0306] <<Solar Cell Module>> The solar cell encapsulant is used in a solar cell module. Examples of the solar cell module include a crystalline solar cell module in which a solar cell element formed of polycrystalline silicon or the like is sandwiched and laminated between solar cell encapsulant sheets or crosslinked products thereof, and further covered on both the front and back sides with protective sheets. That is, a typical example of the configuration of a solar cell module includes a solar cell module protective sheet (surface protective member) / a sheet made of the solar cell encapsulant-forming composition or its crosslinked product / a solar cell element / a sheet made of the solar cell encapsulant-forming composition or its crosslinked product / a solar cell module protective sheet (rear protective member).

[0307] One example is a solar cell module including a front-side transparent protective member, a back-side protective member, a solar cell element, and a sealing layer formed by crosslinking the solar cell encapsulant-forming composition, which seals the solar cell element between the front-side transparent protective member and the back-side protective member.

[0308] The solar cell module is not limited to the above configuration, and some of the above layers may be omitted or other layers may be provided as appropriate, provided that the object of the present invention is not impaired. Examples of other layers include an adhesive layer, an impact absorbing layer, a coating layer, an anti-reflection layer, a rear surface reflection layer, and a light diffusion layer. These layers are not particularly limited, and can be provided in appropriate positions taking into account the purpose and characteristics of each layer.

[0309] (Method for manufacturing solar cell module) The method for manufacturing the solar cell module includes, for example, (i) a step of laminating a front-side transparent protective member, the solar cell encapsulant-forming composition, a solar cell element (cell), a solar cell encapsulant-forming composition, and a back-side protective member in this order to form a laminate, and (ii) a step of applying pressure and heating to integrate the obtained laminate.

[0310] In step (i), when the surface of the sheet-shaped solar cell encapsulant-forming composition is embossed, it is preferable to arrange the solar cell encapsulant-forming composition so that the surface on which the uneven shape (embossed shape) is formed faces the solar cell element.

[0311] In step (ii), the laminate obtained in step (i) is integrated (sealed) by heating and pressing using a vacuum laminator or a heat press according to a conventional method. During sealing, the solar cell encapsulant has high cushioning properties, which can prevent damage to the solar cell element. In addition, its excellent degassing properties prevent air entrapment, allowing high-quality products to be produced with a high yield.

[0312] When producing a solar cell module, the ethylene / α-olefin copolymer (A) constituting the composition for forming a solar cell encapsulant is crosslinked and cured. This crosslinking step may be carried out simultaneously with step (ii) or after step (ii).

[0313] When the crosslinking step is carried out after step (ii), the laminate is vacuum-heated for 3 to 6 minutes at a temperature of 125 to 160°C and a vacuum pressure of 10 Torr or less in step (ii), and then pressurized at atmospheric pressure for about 1 to 15 minutes to integrate the laminate. The crosslinking step carried out after step (ii) can be carried out by a conventional method, for example, using a tunnel-type continuous crosslinking furnace or a tray-type batch crosslinking furnace. The crosslinking conditions are typically 130 to 155°C and about 20 to 60 minutes.

[0314] On the other hand, when the crosslinking step is carried out simultaneously with the step (ii), the crosslinking step can be carried out in the same manner as when the crosslinking step is carried out after the step (ii), except that the heating temperature in the step (ii) is set to 145 to 170°C and the pressurization time at atmospheric pressure is set to 6 to 30 minutes.

[0315] In the production of the solar cell module, the solar cell encapsulant-forming composition is temporarily bonded to a solar cell element or a protective material at a temperature at which the crosslinking agent does not substantially decompose and the solar cell encapsulant-forming composition melts, and then the temperature is raised to achieve sufficient adhesion and crosslinking of the solar cell encapsulant-forming composition. An additive formulation that satisfies various conditions may be selected, and for example, the types and impregnation amounts of the crosslinking agent and crosslinking aid may be selected.

[0316] <Film> The film of the present invention contains the copolymer (A) or composition (X) of the present invention.

[0317] One embodiment of the composition (X) used for the film may contain, in addition to the ethylene / α-olefin copolymer (A), the above-mentioned "resin other than the copolymer (A)."

[0318] As the resin other than the copolymer (A), preferred examples include crystalline α-olefin polymers such as polyolefins such as polyethylene, polypropylene, and polybutene, and copolymers thereof.

[0319] When a resin other than the copolymer (A) is used, the proportion thereof is, for example, 100 to 500 parts by mass per 100 parts by mass of the ethylene / α-olefin copolymer (A).

[0320] The film is not particularly limited, and its shape, size (thickness), etc. may be appropriately selected depending on the desired application. The film may be a single layer or a multilayer. In the case of a multilayer film, at least one layer of the film may contain the copolymer (A) or composition (X) of the present invention.

[0321] The thickness of the film (total thickness if multi-layered) is preferably 5 μm or more, more preferably 10 μm or more, and is preferably 150 μm or less, more preferably 100 μm or less.

[0322] The film impact strength, which is the impact puncture strength of the film measured in accordance with the method for measuring impact puncture strength specified in JIS P8134 divided by the film thickness, is preferably greater than 38 kJ / m, more preferably 39 to 80 kJ / m, even more preferably 40 to 70 kJ / m, and particularly preferably 40 to 50 kJ / m.

[0323] Specific applications of the film include, for example, packaging films for packaging foods, liquids, medicines, and the like.

[0324] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the measurement methods, compounds used, methods for preparing test pieces, and evaluation methods are as follows.

[0325] <Methods for Measuring Physical Properties of Ethylene / α-olefin Copolymer> [Density] The density of the ethylene / α-olefin copolymer was measured in accordance with ASTM D1505.

[0326] [Content (Composition) of Each Structural Unit] The ethylene-derived structural units and the α-olefin-derived structural units in the ethylene / α-olefin copolymer were determined by analyzing the nuclear magnetic resonance spectrum of the polymer by the following method.

[0327] (Measurement conditions) Apparatus: JEOL ECX400P nuclear magnetic resonance apparatus Measurement nuclei: 1 H (400MHz); 13 C (125 MHz) Measurement mode: Single pulse Pulse width: 45° (5.25 μsec) Number of points: 32k Measurement range: 20 ppm (-4 to 16 ppm) Repetition time: 7.0 seconds Number of accumulations: 64 Measurement solvent: orthodichlorobenzene-d4 Sample concentration: ca. 20 mg / 0.6 mL Measurement temperature: 120°C Window function: exponential (BF: 0.12 Hz) Chemical shift reference: orthodichlorobenzene (7.1 ppm)

[0328] The repeating units derived from the ethylene and α-olefin copolymer monomers of the ethylene / α-olefin copolymer (A) obtained by the process described in Example 1 below have a frequency of 125 MHz. 13 The amount was measured and quantified based on the intensity ratio (integral value) of the peak derived from ethylene and the peak derived from α-olefin obtained by C-NMR (JEOL ECX400P).

[0329] [Unsaturation Amount] The amount of unsaturated groups per 1000 carbon atoms contained in the ethylene / α-olefin copolymer, specifically the amount of vinyl groups, the amount of vinylidene groups, the amount of di-substituted internal olefins, the amount of tri-substituted internal olefins, and the total amount of these (also referred to as the "total amount of unsaturated groups"), was determined by analyzing the nuclear magnetic resonance spectrum of the aforementioned polymer.

[0330] Here, the following vinyl double bonds, vinylidene double bonds, di-substituted olefin double bonds, and tri-substituted olefin double bonds are observed as signals derived from double bonds in unsaturated groups. The amount of double bonds was quantified from the integrated intensity of each signal. The main chain methylene signal of the ethylene-α-olefin copolymer was used as the chemical shift reference (1.2 ppm).

[0331]

[0332] [In each formula, * represents a bond to an atom other than a hydrogen atom.] The peaks of the hydrogen atoms a to e are observed near the following positions.

[0333] Peak of hydrogen atom a: 4.60 ppm Peak of hydrogen atom b: 4.85 ppm Peak of hydrogen atom c: 5.10 ppm Peak of hydrogen atom d: 5.25 ppm Peak of hydrogen atom e: 5.70 ppm The quantitative formula for the amount of double bonds is as follows:

[0334] Amount of vinyl double bonds = {(integrated intensity of signal b) + (integrated intensity of signal e)} / 3 Amount of vinylidene double bonds = (integrated intensity of signal a) / 2 Amount of disubstituted olefinic double bonds = (integrated intensity of signal d) / 2 Amount of trisubstituted olefinic double bonds = (integrated intensity of signal c)

[0335] From these results, the amount of double bonds of each type (vinyl type, vinylidene type, di-substituted olefin type, tri-substituted olefin type) per 1000 carbon atoms (1000C) of the ethylene-α-olefin copolymer was determined, and these were taken as the amount of vinyl groups, the amount of vinylidene groups, the amount of di-substituted internal olefins, and the amount of tri-substituted internal olefins, respectively. Furthermore, the sum of these amounts was taken as the total amount of unsaturated groups. In addition, the total amount of vinyl groups and vinylidene groups and the vinyl group selectivity (amount of vinyl groups / total amount of unsaturated groups) were calculated.

[0336] [Melt flow rate (MFR): MFR2, MFR 10 , MFR 10 / MFR2] MFR2 and MFR2 are melt flow rates of ethylene-α-olefin copolymers measured under a temperature condition of 190°C and a load of 2.16 kg and 10 kg, respectively, in accordance with ASTM D1238. 10 The MFR was also calculated. 10 The value of / MFR2 was calculated.

[0337] [Shore A Hardness] Ethylene-α-olefin copolymers were sheet-molded using a Shinto Metal Industrial Co., Ltd. hydraulic heat press (NS-50) set to 190°C at a gauge pressure of 10 MPa. For 2 mm-thick sheets (spacer shape: 200 x 200 x 0.5-2 mm on a 240 x 240 mm plate), the sheets were preheated for approximately 4-7 minutes, pressed at a gauge pressure of 10 MPa for 1-2 minutes, and then compressed at a gauge pressure of 10 MPa using another Shinto Metal Industrial Co., Ltd. hydraulic heat press set to 20°C and cooled for approximately 4-5 minutes. A 5 mm-thick brass plate was used as the hot plate. The Shore A hardness of the ethylene-α-olefin copolymers was measured using the sheets prepared by the above method in accordance with ASTM D2240.

[0338] [Melt Viscoelasticity] The melt viscoelasticity was measured using Discovery HR-3 manufactured by TA Instruments.

[0339] The ethylene-α-olefin copolymer was sheet-molded at a gauge pressure of 10 MPa using a hydraulic hot press (NS-50) manufactured by Shinto Metal Industries Co., Ltd. set at 190°C. A 25 mmφ disk was punched out of the resulting 2 mm-thick sheet and used as a measurement sample. The frequency dependence of the complex viscosity (η*) at 100°C was measured under conditions of a shear rate of 0.1 to 100 rad / s and a strain of 5%. The value of η*0.1 / η*100 was calculated from the complex viscosity at 100 rad / s (η*100) and the complex viscosity at 0.1 rad / s (η*0.1).

[0340] [Weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn)] The weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the ethylene-α-olefin copolymer are values ​​measured by GPC in terms of polystyrene. The measuring apparatus and conditions are as follows. The molecular weight was calculated based on a calibration curve prepared using commercially available monodisperse polystyrene and converted into a polystyrene equivalent.

[0341] Apparatus: Gel permeation chromatograph Alliance GP2000 (manufactured by Waters) Analytical device: Empower2 (manufactured by Waters) Column: TSKgel GMH6-HT x 2 + TSKgel GMH6-HTL x 2 (both 7.5 mm I.D. x 30 cm, manufactured by Tosoh Corporation) Column temperature: 140°C Mobile phase: o-dichlorobenzene (containing 0.025% by mass of BHT) Detector: Differential refractometer (RI) Flow rate: 1.0 mL / min Injection volume: 400 μL Sampling time interval: 1 s Column calibration: Monodisperse polystyrene (manufactured by Tosoh Corporation) Molecular weight conversion: Polystyrene conversion / calibration method taking viscosity into consideration

[0342] [Molding processability / heat generation amount] In the examples described later, the heat generation amount was measured when the blend was melt-kneaded using a Labo Plastomill. Specifically, the resin temperature was monitored, and the difference in the resin temperature at the start and end of melt-kneading was taken as the heat generation amount.

[0343] A low calorific value means that shear heat generation during kneading is low, and the generation of gel due to reaction of peroxides is suppressed, and further means that molding processability is excellent.

[0344] The evaluation criteria for moldability are as follows:

[0345] Rating A (Excellent): Heat generation is 7°C or less Rating B: Heat generation is more than 7°C and less than 11°C Rating C (Poor): Heat generation is 11°C or more

[0346] [Gel Fraction] The crosslinked sheet prepared in the Examples described below was cut into small pieces. Approximately 100 mg of the cut pieces was weighed, wrapped in a 325-mesh stainless steel screen, and immersed in 30 ml of p-xylene at 140°C for 3 hours in a sealed container. The screen was then removed and dried at 80°C for 2 hours or more until a constant weight was reached. That is, after heating at 80°C for 2 hours or more, the sheet was repeatedly weighed, heated at 80°C, and weighed again until the mass no longer changed by 0.01 g or more, and it was confirmed that the sheet had reached a constant weight. The gel fraction (% by mass) is expressed by the following formula:

[0347] Gel fraction (mass%) = 100 × (W3 - W2) / (W1 - W2) (W1: mass of the screen and sample before the test, i.e., before immersion; W2: mass of the screen; W3: mass of the screen and sample after the test, i.e., after immersion and drying)

[0348] [Evaluation of Crosslinkability] Using the uncrosslinked copolymers used in the examples, etc., a cure meter test was carried out using a measuring device: MDR2000P (manufactured by ALPHA TECHNOLOGIES) under measurement conditions of a temperature of 160°C and a time of 20 minutes, and S'Max - S'Min was measured as follows.

[0349] The sample was placed in a measuring device and the torque change obtained under conditions of a constant temperature and a constant shear rate was measured to obtain a vulcanization curve. The minimum and maximum torque values ​​S'Min and S'Max were determined from the vulcanization curve, and the progress of crosslinking was confirmed based on the increase in torque.

[0350] The evaluation criteria for crosslinkability are as follows:

[0351] Rating A (Excellent): S'Max - S'Min is 5.0 or more Rating B: S'Max - S'Min is more than 2.5 and less than 5.0 Rating C (Poor): S'Max - S'Min is 2.5 or less

[0352] Example 1 Synthesis of Ethylene-α-Olefin Copolymer (A-1) A 2-L stainless steel autoclave that had been thoroughly purged with nitrogen was charged with 490 mL of hexane, 410 mL of 1-butene, and 500 mL of hydrogen. The temperature inside the system was raised to 115°C, and ethylene was then supplied to adjust the total pressure to 3.0 MPa-G. Next, 0.2 mmol of triisobutylaluminum (TIBAL) was injected into the autoclave with nitrogen, and then a premix catalyst prepared by mixing 0.0004 mmol of dimethylmethylene(cyclopentadienyl)(2,7-di-t-butylfluorenyl)zirconium dichloride, the main catalyst, and 0.1 mmol (in terms of Al atom) of MMAO (modified methylaluminoxane, manufactured by Tosoh Finechem Corporation) at room temperature for 15 minutes was injected with nitrogen, and polymerization was initiated by increasing the stirring speed to 250 rpm. Thereafter, the total pressure was maintained at 3.0 MPa-G by continuously supplying only ethylene, and polymerization was carried out at 115°C for 9 minutes. Next, a small amount of methanol was added to the system to terminate the polymerization, and unreacted ethylene and 1-butene were purged. The obtained polymer solution was poured into a large excess of a methanol / acetone mixed solution to precipitate the polymer. The precipitated polymer was recovered by filtration and dried overnight under reduced pressure at 120°C, yielding 35.0 g of ethylene-1-butene copolymer (A-1). The polymerization activity was 580 kg / mmol-Zr h.

[0353] <Preparation of Crosslinked Sheet> 100 parts by mass of the produced ethylene / 1-butene copolymer (A-1) was blended with 1.0 part by mass of t-butylperoxy-2-ethylhexyl carbonate having a one-minute half-life temperature of 166°C as an organic peroxide.

[0354] The compound was melt-kneaded at 90°C, a screw rotation speed of 30 rpm, and a kneading time of 5 minutes using a Laboplastomill (two-screw batch melt-kneader) manufactured by Toyo Seiki Co., Ltd., to obtain a resin composition. After preheating for 3 minutes using a hydraulic heat press set at 160°C, the mixture was molded under a pressure of 10 MPa for 10 minutes and then cooled at 20°C under a pressure of 10 MPa for 4 minutes to produce a crosslinked sheet having a thickness of 0.5 mm.

[0355] The physical properties of the copolymer (A-1) and the sheet were measured and the results are shown in Table 1.

[0356] Example 2 Synthesis of Ethylene / 1-Butene Copolymer (A-2) The procedure was the same as in Example 1, except that the main catalyst was changed to 0.0004 mmol of dimethylmethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dimethyl, the polymerization temperature was changed to 130°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 400 mL, and the amount of hydrogen was changed to 300 mL. An ethylene / 1-butene copolymer (A-2) was obtained in a yield of 42.0 g, and a crosslinked sheet having a thickness of 0.5 mm was prepared. The physical properties are shown in Table 1.

[0357] Example 3 Synthesis of Ethylene / 1-Butene Copolymer (A-3) The procedure was the same as in Example 1, except that the main catalyst was changed to 0.0003 mmol of ethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz[b,h]-fluorenyl)zirconium dichloride, the polymerization temperature was changed to 140°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 710 mL, and the amount of hydrogen was changed to 600 mL. An ethylene / 1-butene copolymer (A-3) was obtained in a yield of 38.0 g and a crosslinked sheet having a thickness of 0.5 mm was prepared. The physical properties are shown in Table 1.

[0358] Example 4 Synthesis of Ethylene / 1-Butene Copolymer (A-4) The procedure of Example 1 was repeated, except that the main catalyst was changed to 0.0004 mmol of diphenylmethylene(cyclopentadienyl)(2,7-di-t-butylfluorenyl)zirconium dichloride, the polymerization temperature was changed to 130°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 510 mL, and the amount of hydrogen was changed to 1500 mL. An ethylene / 1-butene copolymer (A-4) was obtained in a yield of 32.0 g and a crosslinked sheet having a thickness of 0.5 mm was produced. The physical properties are shown in Table 1.

[0359] Example 5 Synthesis of Ethylene / 1-Butene Copolymer (A-5) The procedure of Example 1 was repeated, except that the main catalyst was changed to 0.0004 mmol of dimethylmethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dimethyl, the polymerization temperature was changed to 140°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 400 mL, and the amount of hydrogen was changed to 100 mL. An ethylene / 1-butene copolymer (A-5) was obtained in a yield of 32.0 g and a crosslinked sheet having a thickness of 0.5 mm was prepared. The physical properties are shown in Table 1.

[0360] Example 6 Synthesis of Ethylene / 1-Butene Copolymer (A-6) The procedure of Example 1 was repeated, except that the main catalyst was changed to 0.0004 mmol of ethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz[b,h]-fluorenyl)zirconium dichloride, the polymerization temperature was changed to 130°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 710 mL, and the amount of hydrogen was changed to 300 mL. An ethylene / 1-butene copolymer (A-6) was obtained in a yield of 42.0 g and a crosslinked sheet having a thickness of 0.5 mm was prepared. The physical properties are shown in Table 1.

[0361] Example 7 Synthesis of Ethylene / 1-Butene Copolymer (A-7) The procedure of Example 1 was repeated, except that the main catalyst was changed to diphenylmethylene(cyclopentadienyl)(2,7-di-t-butylfluorenyl)zirconium dichloride, the polymerization temperature was changed to 130°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 510 mL, and the amount of hydrogen was changed to 500 mL. An ethylene / 1-butene copolymer (A-7) was obtained in a yield of 50.0 g and a crosslinked sheet having a thickness of 0.5 mm was produced. The physical properties are shown in Table 1.

[0362] Comparative Example 1 Synthesis of Ethylene / 1-Butene Copolymer (a-8) To a 100 L stainless steel polymerization vessel equipped with a stirring blade (stirring rotation speed=250 rpm), dehydrated hexane was continuously supplied at a rate of 23 L / hr, a toluene solution of methylaluminoxane as a cocatalyst at a rate of 8 mmol / hr, and bis(1,3-dimethylcyclopentadienyl)zirconium dichloride as a main catalyst at a rate of 0.025 mmol / hr and triisobutylaluminum at a rate of 0.6 mmol / hr. Simultaneously, ethylene was continuously supplied at a rate of 3.0 kg / hr, 1-butene at a rate of 15 kg / hr, and hydrogen at a rate of 1.5 NL / hr to another supply port of the polymerization vessel, and continuous solution polymerization was carried out under the conditions of a polymerization temperature of 90°C and a residence time of 1.0 hour. The normal hexane / toluene mixed solution of ethylene / 1-butene copolymer produced in the polymerization reactor was continuously discharged through an outlet provided at the bottom of the polymerization reactor, and the jacket was pressurized at 3 to 25 kgf / cm so that the normal hexane / toluene mixed solution of ethylene / 1-butene copolymer was maintained at 150 to 190°C. 2The resulting mixture was introduced into a connecting pipe heated with steam. Just before reaching the connecting pipe, a feed port for injecting methanol, a catalyst deactivator, was provided, and methanol was injected at a rate of approximately 0.75 L / hr to join the normal-hexane / toluene mixed solution of ethylene-1-butene copolymer. The normal-hexane / toluene mixed solution of ethylene-1-butene copolymer, maintained at approximately 190°C in the steam-jacketed connecting pipe, was continuously fed to a flash tank by adjusting the aperture of a pressure control valve provided at the end of the connecting pipe so as to maintain a pressure of approximately 4.3 MPaG. During transfer into the flash tank, the solution temperature and the aperture of the pressure control valve were set so as to maintain the pressure in the flash tank at approximately 0.1 MPaG and the temperature of the steam portion in the flash tank at approximately 180°C. The mixture was then passed through a single-screw extruder with a die temperature set to 180°C, and the strands were cooled in a water tank and cut with a pellet cutter to obtain ethylene-1-butene copolymer (a-8) in the form of pellets. The yield was 2.0 kg / hr.

[0363] <Preparation of Crosslinked Sheet> A crosslinked sheet having a thickness of 0.5 mm was prepared in the same manner as in Example 1, except that the ethylene / 1-butene copolymer (A-1) was changed to the ethylene / 1-butene copolymer (a-8). The physical properties are shown in Table 1.

[0364] Comparative Example 2 Synthesis of Ethylene-1-Butene Copolymer (a-9) An ethylene-1-butene copolymer (a-9) was obtained at a yield of 2.0 kg / hr in the same manner as in Comparative Example 1, except that ethylene, 1-butene, and hydrogen were supplied at rates of 3.0 kg / hr, 15 kg / hr, and 0.5 NL / hr, and a crosslinked sheet having a thickness of 0.5 mm was produced. The physical properties are shown in Table 1.

[0365] Comparative Example 3 Synthesis of Ethylene / 1-Butene Copolymer (a-10) To a 100 L stainless steel polymerization vessel equipped with a stirring blade (stirring rotation speed=250 rpm), the dehydrated hexane was continuously supplied at a rate of 23 L / hr, a toluene solution of methylaluminoxane as a cocatalyst at a rate of 8 mmol / hr, bis(p-tolyl)methylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dichloride as a main catalyst at a rate of 0.0053 mmol / hr, and triisobutylaluminum at a rate of 0.6 mmol / hr. Simultaneously, ethylene was continuously supplied at a rate of 4.3 kg / hr, 1-butene at a rate of 9.0 kgf / hr, and hydrogen at a rate of 8 NL / hr to another supply port of the polymerization vessel, and continuous solution polymerization was carried out under the conditions of a polymerization temperature of 130°C and a residence time of 1.0 hour. The normal hexane / toluene mixed solution of ethylene / 1-butene copolymer produced in the polymerization reactor was continuously discharged through an outlet provided at the bottom of the polymerization reactor, and the jacket was pressurized at 3 to 25 kgf / cm so that the normal hexane / toluene mixed solution of ethylene / 1-butene copolymer was maintained at 150 to 190°C. 2 The resulting mixture was introduced into a connecting pipe heated with steam. Just before reaching the connecting pipe, a feed port for injecting methanol, a catalyst deactivator, was provided, and methanol was injected at a rate of approximately 0.75 L / hr to join the normal-hexane / toluene mixed solution of ethylene-1-butene copolymer. The normal-hexane / toluene mixed solution of ethylene-1-butene copolymer, kept at approximately 190°C in the steam-jacketed connecting pipe, was continuously fed to a flash tank by adjusting the aperture of a pressure control valve provided at the end of the connecting pipe so as to maintain a pressure of approximately 4.3 MPaG. During transfer into the flash tank, the solution temperature and the aperture of the pressure control valve were set so as to maintain the pressure in the flash tank at approximately 0.1 MPaG and the temperature of the steam portion in the flash tank at approximately 180°C. The mixture was then passed through a single-screw extruder with a die temperature set to 180°C, and the strands were cooled in a water tank and cut with a pellet cutter to obtain ethylene-1-butene copolymer (a-10) in the form of pellets. The yield was 5.0 kg / hr.

[0366] <Preparation of Crosslinked Sheet> A crosslinked sheet having a thickness of 0.5 mm was prepared in the same manner as in Example 1, except that the ethylene / 1-butene copolymer (A-1) was changed to the ethylene / 1-butene copolymer (a-10). The physical properties are shown in Table 1.

[0367]

[0368] (Comparison between Examples and Comparative Examples) As shown in Table 1 above, the ethylene / α-olefin copolymers (A) (ethylene / 1-butene copolymers (A-1) to (A-7)) produced in the Examples were excellent in terms of moldability (sheet formability) and crosslinkability in a well-balanced manner.

[0369] On the other hand, the crosslinked sheet of Comparative Example 1 using the ethylene / 1-butene copolymer (a-8) had a significantly low S'Max-S'Min value, and was therefore significantly inferior in crosslinking properties.

[0370] Furthermore, the crosslinked sheets of Comparative Examples 2 and 3, which used the ethylene-1-butene copolymers (a-9) and (a-10), generated a significantly large amount of heat during melt-kneading, and therefore were significantly inferior in low-temperature extrusion moldability.

[0371] Example 8 Synthesis of Ethylene / 1-Butene Copolymer (A-8) The procedure was the same as in Example 1, except that the main catalyst was changed to 0.0004 mmol of dimethylmethylene(cyclopentadienyl)(1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dimethyl, the polymerization temperature was changed to 130°C, the amount of hexane was changed to 500 mL, the amount of 1-butene was changed to 400 mL, and the amount of hydrogen was changed to 30 mL. An ethylene / 1-butene copolymer (A-8) was obtained in a yield of 42.0 g, and a crosslinked sheet having a thickness of 0.5 mm was prepared. The physical properties are shown in Table 2.

[0372] Example 9 Synthesis of Ethylene / 1-Butene Copolymer (A-9) Ethylene / 1-butene copolymer (A-9) was obtained in a yield of 47.0 g in the same manner as for ethylene / 1-butene copolymer (A-2), except that the amount of 1-butene was changed to 250 mL, and a crosslinked sheet having a thickness of 0.5 mm was prepared from the obtained copolymer. The physical properties are shown in Table 2.

[0373] Comparative Example 4 Synthesis of Ethylene-1-Butene Copolymer (a-11) An ethylene-1-butene copolymer (a-11) was obtained at a yield of 2.0 kg / hr in the same manner as in Comparative Example 1, except that ethylene, 1-butene, and hydrogen were supplied at rates of 3.0 kg / hr, 15 kg / hr, and 0.9 NL / hr, and a crosslinked sheet having a thickness of 0.5 mm was produced. The physical properties are shown in Table 2.

[0374] Comparative Example 5 Synthesis of Ethylene-1-Butene Copolymer (a-12) An ethylene-1-butene copolymer (a-12) was obtained at a yield of 5.0 kg / hr in the same manner as in Comparative Example 3, except that ethylene, 1-butene, and hydrogen were supplied at rates of 4.3 kg / hr, 9.0 kgf / hr, and 2.0 NL / hr, respectively, and a crosslinked sheet having a thickness of 0.5 mm was produced. The physical properties are shown in Table 2.

[0375] Comparative Example 6 A commercially available ethylene-1-octene copolymer (Engage EG8200 manufactured by DuPont Dow Elastomers, having an MFR of 5.0 g / 10 min and a density of 870 kg / m, measured at 190°C and 2.16 kgf) was used as a comparative copolymer. ３ )) was prepared.

[0376]

[0377] Furthermore, compositions containing the ethylene / 1-butene copolymers produced in the above-mentioned Examples and Comparative Examples were produced and evaluated, as described in detail below.

[0378] <Evaluation of Resin Compositions 1 - Evaluation of Compositions for Footwear or Footwear Parts> In the following Examples and Comparative Examples, the resin compositions were evaluated as follows.

[0379] [Melt Viscoelasticity] The melt viscoelasticity of the resin composition was measured using ARES-G2 manufactured by TA Instruments.

[0380] The resin composition pellets were molded into a 2 mm thick sheet using a press set at 190°C. A 25 mm diameter disk was punched out of the sheet and used as a measurement sample. The frequency dependence of the complex viscosity (η*) at 120°C was measured under conditions of a shear rate of 0.1 to 200 rad / s and a strain of 1%. The complex viscosity value at 200 rad / s was calculated.

[0381] [Evaluation of Physical Properties of Crosslinked Foam] In the following examples and comparative examples, various physical properties of the crosslinked foam were measured and evaluated as follows.

[0382] [Specific Gravity] The specific gravity of the crosslinked foam was measured in accordance with JIS K 7222:2005.

[0383] The samples used for measuring the specific gravity were taken from a portion of the crosslinked foam that was 20 mm or more inward from each of the four sides of the crosslinked foam having the largest area and 2.5 mm or more inward from the surface of the crosslinked foam. Samples were prepared from five positions on the crosslinked foam, and the specific gravity was measured and the average value was used.

[0384] [Asker C Hardness] The Asker C hardness was measured in a 23°C environment according to the "Spring Hardness Test Type C Test Method" described in JIS K 7312:1996, Appendix 2.

[0385] [Rebound resilience] Rebound resilience was measured in accordance with JIS K 6255: 2013. Samples prepared in the same manner as the samples used for the compression set (CS) described below were used, and the measurement was carried out in an atmosphere of 23°C.

[0386] [Compression Set (CS)] The compression set (CS) was measured in accordance with JIS K 6262: 2013. The sample was prepared by cutting a crosslinked foam into a cylindrical shape with a diameter of 30 mm and a thickness of 15 mm or more, and cutting one of two parallel flat surfaces of the cylinder to make it 10 mm thick.

[0387] A cylindrical dumbbell cutter was used to cut out a cylindrical shape from the foam and to cut out a foam from the surface of a parallel plane.

[0388] The thickness of the obtained sample was measured, and the thickness of the sample was measured 30 minutes after the sample was left standing in a 50°C environment under a 50% compression for 6 hours and then the pressure was released. The compression set (CS) (%) was calculated using the following formula.

[0389] CS = (t ０ -t １ ) / (t ０ -t ２ ) x 100 t ０ t: thickness of sample used for measurement (mm) １ t: Thickness of sample (mm) 30 minutes after removing the sample from the compression device ２ : Spacer thickness (mm)

[0390] [Interlaminar Tear Strength] Interlaminar tear strength was measured in accordance with ASTM D3574 at a test temperature of 23°C using a 205X ​​universal testing machine (manufactured by Intesco Co., Ltd.).

[0391] Specifically, a crosslinked foam was cut into a strip of 90 mm in length, 25 mm in width, and 15 mm in thickness, and a 30 mm incision was made horizontally (in the lengthwise direction) from one end of the sample to form a tab. The tab was held in a testing machine chuck (distance between chucks: 30 mm) and torn in the thickness direction at a testing speed of 50 mm / min. The interlaminar tear strength S (kgf / cm) was calculated using the following formula.

[0392] S = S0 / S1, S0: tear stress (kgf), S1: sample width (cm)

[0393] Example 11 Production of Resin Composition and Crosslinked Foam 50 parts by mass of ethylene-1-butene copolymer (A-8) and 50 parts by mass of ethylene-vinyl acetate copolymer (B-1) (VA content = 25% by mass, MFR (190°C, 2.16 kg load) = 2 g / 10 min, trade name: Evaflex EV360, manufactured by Dow Mitsui Polychemicals Co., Ltd.) were kneaded and granulated at 200°C in a single-screw extruder to obtain resin composition pellets. The complex viscosity at 200 rad / s of the obtained resin pellets was calculated according to the method described above.

[0394] A mixture of the obtained resin pellets, 3.0 parts by mass of zinc oxide, 1.0 part by mass of stearic acid, 3.0 parts by mass of titanium oxide, 0.1 part by mass of triallyl isocyanurate (TAIC) (trade name: M-60 [TAIC content: 60% by mass], manufactured by Nippon Kasei Chemical Co., Ltd.), 0.7 part by mass of dicumyl peroxide (DCP), and 2.6 parts by mass of azodicarbonamide (ADCA) was kneaded with a roll at a surface temperature of 120°C for 10 minutes and then formed into a sheet, thereby obtaining a sheet-like composition.

[0395] The obtained composition sheet was filled into a press mold (mold size: length 140 mm, width 65 mm, thickness 10 mm) and subjected to a pressure of 180 kgf / cm ２ The crosslinked foam was then pressurized and heated at 170°C for 15 minutes to obtain a crosslinked foam. The crosslinked foam expanded upon depressurization, and its thickness reached 15 mm or more. The specific gravity, Asker C hardness, rebound resilience, compression set, and interlaminar tear strength of the crosslinked foam were measured according to the methods described above. The results are shown in Table 3.

[0396] [Example 12] A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 1.0 part by mass and 3.25 parts by mass, respectively. The results are also shown in Table 3.

[0397] [Example 13] A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that (A-9) was used as the ethylene-1-butene copolymer, and the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 1.0 part by mass and 2.8 parts by mass, respectively. The results are also shown in Table 3.

[0398] Comparative Example 11 A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that the ethylene-1-butene copolymer was not used and 100 parts by mass of ethylene-vinyl acetate copolymer (B-1) was used, and the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 1.0 part by mass and 2.8 parts by mass, respectively. The results are also shown in Table 3.

[0399] Comparative Example 12 A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that (a-9) was used as the ethylene-1-butene copolymer, and the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 1.0 part by mass and 2.4 parts by mass, respectively. The results are also shown in Table 3.

[0400] Comparative Example 13 A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that (a-9) was used as the ethylene-1-butene copolymer, and the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 1.3 parts by mass and 2.8 parts by mass, respectively. The results are also shown in Table 3.

[0401] Comparative Example 14 A resin composition and a crosslinked foam were produced and their physical properties were evaluated in the same manner as in Example 11, except that (a-12) was used as the ethylene-1-butene copolymer, and the amounts of dicumyl peroxide (DCP) and azodicarbonamide (ADCA) were changed to 0.7 parts by mass and 3.15 parts by mass, respectively. The results are also shown in Table 3.

[0402]

[0403] Comparison of Examples and Comparative Examples The resin compositions of the Examples had low complex viscosities at 200 rad / s and exhibited good fluidity. Furthermore, the crosslinked foams of the Examples had low C hardness and high impact resilience. Therefore, when the crosslinked foams of the Examples are used in footwear or footwear components, the footwear provides good comfort and cushioning. Furthermore, the excellent compression set and interlaminar tear strength result in excellent durability and mechanical strength.

[0404] The crosslinked foam of Comparative Example 11 has high C hardness and low impact resilience, resulting in poor comfort and cushioning when used in footwear or footwear parts. The resin compositions of Comparative Examples 12 and 13 have high compression set or low interlaminar tear strength, resulting in poor durability and mechanical strength. The resin composition of Comparative Example 14 has high complex viscosity at 200 rad / s, resulting in poor fluidity.

[0405] Therefore, the crosslinked foams of Examples 11 to 13 can be preferably used for footwear and footwear parts.

[0406] <<Evaluation of Resin Compositions 2: Evaluation of Wire Coating Compositions>> In the following Examples and Comparative Examples, the resin compositions were evaluated as follows.

[0407] [Kneading Torque] When obtaining the compositions of the Examples and Comparative Examples, kneading was carried out using a Laboplastomill (two-screw batch melt kneader) manufactured by Toyo Seiki Seisaku-Sho, Ltd., at a temperature of 100°C or 140°C, a screw rotation speed of 60 rpm, and a kneading time of 5 minutes, and the average value of the kneading torque measured during this process was used.

[0408] [Tensile elongation at break, tensile modulus] Measurements were performed in accordance with JIS K7113. The compositions obtained in the examples and comparative examples were preheated for 5 minutes using a hydraulic hot press set at 100°C or 140°C, pressed at 10 MPa for 2 minutes, and then pressed at 10 MPa for 4 minutes at 20°C to produce a 0.5 mm thick sheet. For Example 22, the composition was preheated at 160°C for 1 minute, pressed at 10 MPa for 17 minutes, and then pressed at 10 MPa for 4 minutes at 20°C to produce a 0.5 mm thick sheet. Test specimens were cut from the obtained sheets in the shape of JIS K7113, 2(1 / 2) type small test specimens, and the tensile elongation at break and tensile modulus were measured using a precision universal testing machine AG-X-5 manufactured by Shimadzu Corporation at a tensile speed of 100 mm / min.

[0409] [Melt Viscosity] The melt viscosity was measured in accordance with JIS K7199. The compositions obtained in the examples and comparative examples were subjected to a 1.2×10 melt viscosity test using a Capillograph 1D manufactured by Toyo Seiki Seisaku-sho, Ltd. under the conditions of a temperature of 140° C. and a capillary diameter of 1×30 mm. １ / s to 6.1 x 10 ３ The melt viscosity was measured for shear rates in the range of 1 / s to determine whether it was measurable.

[0410] [Crosslinking Torque] The vulcanization curve of the composition obtained in the Examples before crosslinking was measured using an MDR2000P manufactured by ALPHA TECHNOLOGIES under the conditions of a temperature of 160°C and a time of 20 minutes, and the maximum torque MH was determined.

[0411] [Oxygen Index] The compositions obtained in the examples or comparative examples were preheated for 5 minutes using a hydraulic hot press set to a predetermined temperature (Example 21: 100 ° C., Comparative Example 21: 140 ° C.), pressed at 10 MPa for 2 minutes, and then pressed at 10 MPa for 4 minutes at 20 ° C. to produce a 0.5 mm thick sheet. The composition obtained in Example 22 was preheated at 160 ° C. for 1 minute, pressed at 10 MPa for 17 minutes, and then pressed at 10 MPa for 4 minutes at 20 ° C. to produce a 0.5 mm thick sheet. Test pieces measuring 3 × 3 × 0.5 mm were cut from the obtained sheet and conditioned at a temperature of 23 ° C. and a humidity of 50% RH for 24 hours or more. Thereafter, the oxygen index was measured using an oxygen index flammability tester ON-2M manufactured by Suga Test Instruments Co., Ltd., with a flame exposure time of 90 seconds.

[0412] <Raw Materials> The raw materials used in the examples and comparative examples are as follows.

[0413] [Ethylene-based polymer (b-1)] The ethylene-based polymer (b-1) was ULTZEX 4050, an LLDPE manufactured by Prime Polymer Co., Ltd. (MFR measured at 190°C and 2.16 kgf was 6 g / 10 min, and density was 937 kg / m ３ ) was used.

[0414] [Phosphorus-Based Flame Retardant (B)] As the phosphorus-based flame retardant (B), Exolit OP1230, an aluminum salt of diethylphosphinic acid manufactured by Clariant, was used.

[0415] [Peroxide (C)] Percumyl D (one minute half-life temperature: 175.2°C), a dicumyl peroxide manufactured by NOF Corporation, was used as peroxide (C).

[0416] Example 21 A resin composition was obtained by kneading 100 parts by mass of the ethylene-1-butene copolymer (A-2) and 60 parts by mass of the phosphorus-based flame retardant (B) using a Laboplastomill (two-screw batch melt kneader) manufactured by Toyo Seiki Seisaku-Sho, Ltd., at a temperature of 100°C, a screw rotation speed of 60 rpm, and a kneading time of 5 minutes.

[0417] Example 22 A resin composition was obtained in the same manner as in Example 21, except that 1 part by mass of the peroxide (C) was added.

[0418] Example 23 A resin composition was obtained in the same manner as in Example 21, except that 100 parts by mass of the ethylene / 1-butene copolymer (A-2) was changed to 100 parts by mass of the ethylene / 1-butene copolymer (A-5).

[0419] Example 24 A resin composition was obtained in the same manner as in Example 21, except that 100 parts by mass of the ethylene / 1-butene copolymer (A-2) was changed to 100 parts by mass of the ethylene / 1-butene copolymer (A-9).

[0420] Example 25 A resin composition was obtained in the same manner as in Example 21, except that the 100 parts by mass of the ethylene-1-butene copolymer (A-2) was replaced with 50 parts by mass of the ethylene-1-butene copolymer (A-2) and 50 parts by mass of the ethylene-based polymer (b-1), and the kneading temperature was changed to 140°C.

[0421] Comparative Example 21 A resin composition was obtained in the same manner as in Example 21, except that 100 parts by mass of the ethylene-1-butene copolymer (A-2) was replaced with 100 parts by mass of the ethylene polymer (b-1) and the kneading temperature was changed to 140°C.

[0422] Comparative Example 22 A resin composition was obtained in the same manner as in Example 21, except that 100 parts by mass of the ethylene / 1-butene copolymer (A-2) was changed to 100 parts by mass of the ethylene / 1-butene copolymer (a-11).

[0423] Comparative Example 23 A resin composition was obtained in the same manner as in Example 21, except that 100 parts by mass of the ethylene / 1-butene copolymer (A-2) was replaced with 100 parts by mass of the ethylene / 1-butene copolymer (a-11), and 1 part by mass of the peroxide (C) was added.

[0424] The composition and evaluation results of each resin composition are shown in Table 4.

[0425]

[0426] <Comparison between Examples and Comparative Examples> Compared to Comparative Example 21, Examples 21, 23, and 24 allow low-temperature kneading and have large tensile elongation at break and low tensile modulus, and therefore are excellent in mechanical properties.

[0427] Compared to Comparative Example 21, Example 25 has a low kneading torque and is capable of measuring the melt viscosity at high shear, so it has excellent moldability. In addition, it has a large tensile elongation at break and a low tensile modulus, so it has excellent mechanical properties.

[0428] Examples 21 and 22 have a higher oxygen index and are more flame retardant than Comparative Example 21.

[0429] Examples 21, 23, and 24 have lower kneading torque and are superior in moldability compared to Comparative Example 22.

[0430] Although Example 22 has a lower kneading torque and is excellent in moldability compared to Comparative Example 23, it exhibits the same crosslinking torque.

[0431] Therefore, the resin compositions of Examples 21 to 25 can be preferably used as compositions for covering electric wires.

[0432] <Evaluation of Resin Composition 3: Evaluation of Composition for Forming Solar Cell Encapsulant> In the following Examples and Comparative Examples, the resin compositions were evaluated as follows.

[0433] [Molding processability / heat generation] In the following examples and comparative examples, the heat generation was measured when the blend was melt-kneaded using a Labo Plastomill. Specifically, the resin temperature was monitored, and the difference in resin temperature between the start and end of melt-kneading was taken as the heat generation.

[0434] A low calorific value means that shear heat generation during kneading is low, and the generation of gel due to reaction of peroxides is suppressed, and further means that molding processability is excellent.

[0435] The evaluation criteria for moldability are as follows:

[0436] Rating A (Excellent): Heat generation is 7°C or less Rating B: Heat generation is more than 7°C and less than 11°C Rating C (Poor): Heat generation is 11°C or more

[0437] [Evaluation of Crosslinkability] The crosslinked sheets prepared in the following Examples and Comparative Examples were cut into small pieces. Approximately 100 mg of each was weighed, wrapped in a 325-mesh stainless steel screen, and immersed in 30 ml of p-xylene at 140°C for 3 hours in a sealed container. The screen was then removed and dried at 80°C for 2 hours or more until a constant weight was reached. That is, after heating at 80°C for 2 hours or more, the sheet was repeatedly weighed, heated at 80°C, and weighed again until the mass no longer changed by 0.01 g or more, and it was confirmed that the sheet had reached a constant weight. The gel fraction (% by mass) is expressed by the following formula:

[0438] Gel fraction (mass%) = 100 × (W ３ -W ２ ) / (W １ -W ２ ) W １ : Mass of the screen and sample before immersion W ２ : Screen mass W ３ : Mass of the screen and sample after immersion and drying The evaluation criteria for crosslinkability are as follows.

[0439] Evaluation A (excellent): Gel fraction is 85% by mass or more. Evaluation B: Gel fraction is more than 75% by mass and less than 85% by mass. Evaluation C (poor): Gel fraction is 75% by mass or less.

[0440] <Preparation of solar cell encapsulant> [Example 31] 0.2 parts by mass of γ-methacryloxypropyltrimethoxysilane as an ethylenically unsaturated silane compound, 1.0 part by mass of t-butylperoxy-2-ethylhexyl carbonate having a one-minute half-life temperature of 166°C as an organic peroxide, 0.6 parts by mass of triallyl isocyanurate as a crosslinking aid, and 0.1 part by mass of bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate as a light stabilizer were blended with 100 parts by mass of the ethylene-α-olefin copolymer (A-2).

[0441] The compound was melt-kneaded and molded using a Toyo Seiki Co., Ltd. Laboplastomill (two-screw batch melt-kneading device) at 90°C, a screw rotation speed of 30 rpm, and a kneading time of 5 minutes to obtain a sheet-like resin composition (uncrosslinked sheet). The uncrosslinked sheet was then preheated for 3 minutes using a hydraulic heat press set at 160°C, molded for 10 minutes under a pressure of 10 MPa, and then cooled for 4 minutes at 20°C under a pressure of 10 MPa to produce a 0.5 mm-thick sheet-like solar cell encapsulant (crosslinked sheet). The physical properties are shown in Table 5.

[0442] Examples 32 to 36, Comparative Examples 31 to 33 Solar cell encapsulant materials were prepared in the same manner as in Example 31, except that the blending amounts of each material were set to the blending amounts shown in Table 5. Table 5 shows the physical properties.

[0443]

[0444] <Comparison between Examples and Comparative Examples> As shown in Table 5 above, the solar cell encapsulant materials using the ethylene / α-olefin copolymers (A) (ethylene / 1-butene copolymers (A-2) to (A-7)) prepared in the Examples were excellent in terms of moldability (sheet formability) and crosslinkability in a well-balanced manner.

[0445] On the other hand, the solar cell encapsulant of Comparative Example 31, which used the ethylene / 1-butene copolymer (a-8), had a low gel fraction value and was therefore inferior in crosslinking properties.

[0446] Furthermore, the crosslinked sheets of Comparative Examples 32 and 33, which used the ethylene-1-butene copolymers (a-9) and (a-10), were significantly inferior in low-temperature extrusion moldability due to the significantly large amount of heat generated during melt-kneading of the encapsulating material raw materials.

[0447] Therefore, the resin compositions of Examples 31 to 36 can be preferably used in the production of solar cell encapsulants.

[0448] <Evaluation of Resin Compositions 4: Evaluation of Packaging Compositions> In the following Examples and Comparative Examples, the resin compositions were evaluated as follows.

[0449] [Moldability (Stability of Film Width)] From the steady-state operating state during molding described in Example 41 below, the take-up speed was changed to 10 m / min and 15 m / min, and resin films were obtained using each resin material so as to have the contents shown in Table 6. The length of the resin film in a direction horizontal to the take-up direction when the molten mixture of the resin material extruded from the T-die came into contact with the chill roll was measured as the film width [mm], and the difference Δ [mm] in the film width of the resin film using each resin material relative to the film width [mm] of Comparative Example 41 below was calculated, and the stability of the film width was evaluated as moldability.

[0450] The evaluation criteria for formability (stability of film width) are as follows:

[0451] Evaluation A (excellent): The film width was wider than that of Comparative Example 41 at both take-up speeds of 10 m / min and 15 m / min. Evaluation B: The film width was equivalent to that of Comparative Example 41 at both take-up speeds of 10 m / min and 15 m / min. Evaluation C (poor): The film width was narrower than that of Comparative Example 41 at at least one of the take-up speeds of 10 m / min and 15 m / min.

[0452] [Impact Resistance] The impact puncture strength [kJ] of the film was measured according to the method for measuring impact puncture strength specified in JIS P8134, and the strength was divided by the film thickness [m] to calculate the film impact strength [kJ / m]. For the measurement, a film impact tester manufactured by Toyo Seiki Seisakusho, Ltd. was used, the impact head spherical shape was 1 inch φ, and the measurement temperature was 23°C.

[0453] The evaluation criteria for impact resistance are as follows:

[0454] Rating A (excellent): Film impact strength is 41 kJ / m or more Rating B: Film impact strength is more than 38 kJ / m and less than 41 kJ / m Rating C (poor): Film impact strength is 38 kJ / m or less

[0455] <Raw Materials> (Ethylene / 1-octene Copolymer (b-1)) The ethylene / 1-octene copolymer (b-1) was prepared using Engage EG8200 (MFR: 5.0 g / 10 min, density: 870 kg / m, measured at 190°C and 2.16 kgf) manufactured by DuPont Dow Elastomers. ３ ) was used.

[0456] (Ethylene-α-olefin copolymer (c-1)) The ethylene-α-olefin copolymer (c-1) was Evolue SP1540, an LLDPE manufactured by Prime Polymer Co., Ltd. (MFR measured at 190°C and 2.16 kgf was 3.8 g / 10 min, density was 913 kg / m ３ ) was used.

[0457] Example 41 Each resin material was charged into the hopper of a Modern Machinery film molding machine equipped with a T-die (lip width 350 mm) and a single-screw extruder with a cylinder inner diameter of 40 mm so as to obtain the content shown in Table 6. The temperature of each part of the cylinder of each extruder was set to 220°C to 230°C, and the die temperature was set to 230°C. The melt-kneaded resin material was extruded from the T-die to a total thickness of 70 μm, cast-molded using a chill roll with a mirror surface set at 20°C, and taken up at a take-up speed of 5 m / min to obtain a resin film. The physical properties are shown in Table 6.

[0458] Examples 42 to 43, Comparative Examples 41 to 43 Resin films were obtained in the same manner as in Example 41, except that each resin material was used so as to have the content shown in Table 6. Table 6 shows the physical properties.

[0459]

[0460] <Comparison between Examples and Comparative Examples> [Moldability (Stability of Film Width)] Compared to Comparative Examples 41 to 43, Examples 41 to 43 showed a small decrease in the film width difference Δ [mm] when the take-up speed was increased, and it was possible to mold a resin film in a stable state.

[0461] [Impact Resistance] Compared to Comparative Example 41, Examples 41 to 43 had high film impact strength at 23° C., and it was possible to provide resin films with excellent impact resistance.

[0462] Therefore, the resin compositions of Examples 41 to 43 can be preferably used as packaging materials.

Claims

1. An ethylene / α-olefin copolymer (A) that satisfies the following requirements (a1) to (a5): (a1) a density of 0.865 to 0.885 g / cm as measured in accordance with ASTM D1505; 3 (a2) The melt flow rate measured in accordance with ASTM D1238 under conditions of 190°C and a load of 2.16 kg is 3.0 to 40 g / 10 min. (a3) ​​MFR 10 / MFR2 is in the range of 6.8 to 15. (However, MFR 10 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a 10 kg load, and MFR2 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a 2.16 kg load.) (a4) The ratio (η*0.1 / η*100) of the complex viscosity (η*0.1) at a shear rate of 0.1 rad / s measured at 100°C to the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3.5 to 30, and the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3000 Pa s or less. (a5) The ethylene / α-olefin copolymer (A) contains a total of 0.45 to 2.0 unsaturated groups per 1000 carbon atoms.

2. An ethylene / α-olefin copolymer (A) that satisfies the following requirements (a1), (a2), (a3'), (a4), and (a5): (a1) a density of 0.865 to 0.885 g / cm as measured in accordance with ASTM D1505; ３ (a2) The melt flow rate measured in accordance with ASTM D1238 under conditions of 190°C and a load of 2.16 kg is 3.0 to 40 g / 10 min. (a3') MFR 10 / MFR2 satisfies the following formula (1): -0.428 × ln(MFR2) + 7.5≦MFR 10 / MFR2 ≦−0.876×ln(MFR2)+11.2 ...Equation (1) (where MFR 10 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a 10 kg load, and MFR2 is the melt flow rate measured in accordance with ASTM D1238 at 190°C under a 2.16 kg load.) (a4) The ratio (η*0.1 / η*100) of the complex viscosity (η*0.1) at a shear rate of 0.1 rad / s measured at 100°C to the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3.5 to 30, and the complex viscosity (η*100) at a shear rate of 100 rad / s measured at 100°C is 3000 Pa s or less. (a5) The ethylene / α-olefin copolymer (A) contains a total of 0.45 to 2.0 unsaturated groups per 1000 carbon atoms.

3. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a6): (a6) the content of structural units derived from ethylene is 80 to 90 mol %, and the content of structural units derived from an α-olefin having 3 to 20 carbon atoms is 10 to 20 mol % (provided that the total of the structural units derived from ethylene and the structural units derived from the α-olefin is 100 mol %).

4. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a7): (a7) the Shore A hardness measured in accordance with ASTM D2240 is 60 to 85; 5. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a8): (a8) The ethylene / α-olefin copolymer (A) contains 0.05 to 0.3 vinyl groups per 1,000 carbon atoms.

6. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a9): (a9) the total number of vinyl groups and vinylidene groups contained in the ethylene / α-olefin copolymer (A) per 1,000 carbon atoms is less than 0.50; 7. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a10): (a10) the proportion of vinyl groups in the unsaturated groups contained in the ethylene / α-olefin copolymer (A) is less than 50 mol %.

8. The ethylene / α-olefin copolymer (A) according to claim 1, which satisfies the following requirement (a11): (a11) the molecular weight distribution (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), measured by gel permeation chromatography (GPC), is 2.3 or less.

9. The ethylene / α-olefin copolymer (A) according to claim 1, wherein the α-olefin is 1-butene.

10. A method for producing the ethylene / α-olefin copolymer (A) according to claim 1, comprising a polymerization step of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst comprising: a bridged metallocene compound (I) represented by the following general formula [I]; and at least one compound (II) selected from the group consisting of organoaluminum oxy compounds (II-1) and organoaluminum compounds (II-3). (In formula [I], R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group; R 1 ~R 4 Two adjacent groups among R may be bonded to each other to form a ring. 6 and R 11 are each independently the same atom or group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and R 7 and R 10 are each independently the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, 6 and R 7 may be bonded to each other to form a ring, and R 10 and R 11 may be bonded to each other to form a ring. 6 , R 7 , R 10 and R 11 are not all hydrogen atoms. 13 and R 14 are selected from a hydrogen atom, a hydrocarbon group, and a silicon-containing group, and may be the same or different; R 13 and R 14 may be bonded to each other to form a ring. Y represents a carbon atom or a silicon atom. n represents an integer of 1 or 2 or more. When n is an integer of 2 or more, R 13 and R 14 is a hydrogen atom. M is a zirconium atom or a hafnium atom. Q is a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having 4 to 10 carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, and j is an integer of 1 to 4, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

11. In the general formula [I], n is 1 and R 13 and R 14 and each of the groups is a benzyl group.

12. In the general formula [I], n is 1 and R 13 and R 14 and each of the groups is a methyl group.

13. The method for producing an ethylene / α-olefin copolymer (A) according to claim 10, wherein in the general formula [I], Y represents a carbon atom and n is 2.

14. The method for producing an ethylene / α-olefin copolymer (A) according to claim 10, wherein the polymerization temperature in the polymerization step is in the range of 100 to 170°C.

15. A composition comprising the ethylene / α-olefin copolymer (A) according to claim 1.

16. The composition of claim 15, further comprising a crosslinking agent.

17. A crosslinked product obtained by crosslinking the composition according to claim 16.

18. A foam comprising the ethylene / α-olefin copolymer (A) according to claim 1.

19. A laminate comprising a layer made of the foam according to claim 18 and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather and artificial leather.

20. Footwear or a footwear component comprising the foam of claim 18 or the laminate of claim 19.

21. Footwear or a footwear component according to claim 20, wherein the footwear component is a midsole, an inner sole, or a sole.

22. A foam comprising the crosslinked product of claim 17.

23. A laminate comprising a layer made of the foam according to claim 22 and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather and artificial leather.

24. Footwear or a footwear component comprising the foam of claim 22 or the laminate of claim 23.

25. Footwear or a footwear component according to claim 24, wherein the footwear component is a midsole, an innersole, or a sole.

26. A molded body comprising the composition of claim 15.

27. An electric wire or cable having a coating layer comprising the composition of claim 15.

28. A molded article comprising the crosslinked article according to claim 17.

29. An electric wire or cable having a coating layer containing the crosslinked product according to claim 17.

30. A composition for forming a solar cell encapsulant, comprising the composition according to claim 15.

31. The composition for forming a solar cell encapsulant according to claim 30, comprising, per 100 parts by mass of the ethylene / α-olefin copolymer (A), 0.1 to 3 parts by mass of an organic peroxide having a 1-minute half-life temperature in the range of 100 to 170°C, and 0.1 to 5 parts by mass of a silane coupling agent.

32. The composition for forming a solar cell encapsulant according to claim 30, comprising, per 100 parts by mass of the ethylene / α-olefin copolymer (A), 0.005 to 5 parts by mass of at least one selected from the group consisting of an ultraviolet absorber, a heat stabilizer, and a light stabilizer, and 0.05 to 5 parts by mass of a crosslinking aid.

33. A solar cell encapsulant comprising an encapsulating layer made of a crosslinked product of the solar cell encapsulant forming composition according to claim 30.

34. The solar cell encapsulant according to claim 33, which has a multi-layer structure including at least one encapsulating layer.

35. The solar cell encapsulant according to claim 34, which has a three-layer structure including an intermediate layer and two outer layers formed on both sides of the intermediate layer so as to sandwich the intermediate layer, at least one of the layers being the encapsulating layer.

36. A solar cell module comprising a front-side transparent protective member, a back-side protective member, a solar cell element, and the solar cell encapsulant according to claim 33, which encapsulates the solar cell element between the front-side transparent protective member and the back-side protective member.

37. A film comprising the composition of claim 15.

38. A film according to claim 37, wherein the film impact strength, calculated by dividing the impact hole opening strength of the film measured in accordance with the method for measuring impact hole opening strength specified in JIS P8134 by the film thickness of the film, exceeds 38 kJ / m.

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