foam

Abstract

An embodiment of the present invention relates to a foam comprising an ethylene-α-olefin copolymer or a crosslinked product of the copolymer. The foam is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, and includes an ethylene-α-olefin copolymer (A) or a crosslinked product of the copolymer (A) satisfying specific requirements (1) to (4), as well as the following requirement (5). (5) A melting curve obtained by differential scanning calorimetry (DSC) shows multiple peaks, and the heat of fusion at 115°C or higher per 5 mg of a specimen is in the range from 10 mJ to 200 mJ.

Description

foam

[0001] The present invention relates to a foam containing an ethylene-α-olefin copolymer or a crosslinked product of said copolymer.

[0002] Due to their properties such as light weight, water resistance, heat insulation, sound insulation, and heat sealing properties, polyethylene foams are widely used in fields such as thermal insulation for building materials, cushioning materials for automobile interiors, and food packaging materials. Foams using ethylene polymers are broadly classified into non-crosslinked foams produced by extrusion foam molding or the like, and crosslinked foams in which a crosslinked structure has been introduced into the polyethylene component by electron beam crosslinking, peroxide crosslinking, or the like.

[0003] High-pressure low-density polyethylene (HPE) has a long-chain branched structure and exhibits strain hardening properties in extensional viscosity, which inhibits cell breakage during the foaming process, and is therefore often used for polyethylene-based foams. However, while crosslinked foams made from HPE can easily achieve a high expansion ratio, they have the drawback of being poor in mechanical properties such as tensile strength and heat resistance.

[0004] On the other hand, linear low-density polyethylene has excellent mechanical strength, but does not have strain hardening properties of extensional viscosity, so it is difficult to produce foams with high expansion ratios.

[0005] In order to solve these problems, for example, Patent Documents 1 to 6 disclose ethylene polymers into which long-chain branched structures have been introduced by polymerization using specific catalysts, and foams made from compositions containing the ethylene polymers.

[0006] JP 2006-282991 A JP 2008-001792 A JP 2009-132903 A JP 2010-126641 A JP 2011-001545 A JP 2012-136595 A

[0007] However, it is expected that it will be difficult for the ethylene polymers described in Patent Documents 1 to 6 or foams made from compositions containing such ethylene polymers to fully satisfy the required physical properties in applications such as some buffer protective materials and thermal insulating materials, which require particularly high heat resistance and mechanical strength. An object of the present invention is to provide a foam that has a better balance between mechanical strength and heat resistance than foams made from conventionally known ethylene polymers.

[0008] The present inventors have conducted extensive research in light of the above-mentioned circumstances and have found that a foam containing an ethylene polymer having specific melting properties and a specific molecular structure or a crosslinked product of the ethylene polymer has an excellent balance between mechanical strength and heat resistance, thereby completing the present invention. The present invention relates to, for example, the following items <1> to <4>.

[0009] <1> A foamed product, comprising an ethylene-α-olefin copolymer (A) or a crosslinked product of the copolymer (A), which is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and satisfies the following requirements (1) to (5): (1) A density of 900 kg / m ３ More than 935kg / m ３ (2) The melt flow rate (MFR) at 190°C under a load of 2.16 kg is in the range of 0.01 g / 10 min to 10.0 g / 10 min. (3) The ratio [MT / η*(g / P)] of the melt tension [MT(g)] at 190°C to the shear viscosity [η*(P)] at 200°C and an angular velocity of 1.0 rad / sec is 1.20 x 10 －４ Above 4.00 x 10 －４ (4) Zero shear viscosity at 200°C [η ０ (P)] and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1): －１３ ×Mw ３．４ ≦η ０ ≦2.5×10 －１３ ×Mw ３．４...(Eq-1) (5) The melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks, and the heat of fusion at 115°C or higher per 5 mg of the measurement sample is in the range of 10 mJ or more and 200 mJ or less.

[0010] <2> The foam according to <1>, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirements (6) to (7): (6) The intrinsic viscosity [η] (dl / g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-2): 0.70×10 －４ ×Mw ０．７７６ ≦ [η]≦ 1.65×10 －４ ×Mw ０．７７６ ...(Eq-2) (7) １ The total of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin per 1000 carbon atoms (units / 1000C) measured by H-NMR is in the range of 0.1 or more and 1.0 or less.

[0011] <3> The foam according to <1> or <2>, further comprising a thermoplastic resin other than the ethylene-α-olefin copolymer (A).

[0012] <4> The foam according to any one of <1> to <3>, wherein the foam is a crosslinked foam.

[0013] According to one embodiment of the present invention, a foam having a better balance of mechanical strength and heat resistance than conventionally known foams made of ethylene-based polymers is provided.

[0014] FIG. 1 is a schematic diagram of an example of an extrusion foam molding machine.

[0015] Foam The foam of the present invention contains an ethylene-α-olefin copolymer (A) or a crosslinked product of the copolymer (A). <Ethylene-α-olefin copolymer (A)> The ethylene-α-olefin copolymer (A) is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, preferably a copolymer of ethylene and an α-olefin having 6 to 10 carbon atoms. The α-olefin may be one type or two or more types. Examples of the α-olefin having 4 to 10 carbon atoms that can be copolymerized with ethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. The ethylene-α-olefin copolymer (A) has the properties shown in the following requirements (1) to (5).

[0016] <Requirement (1)> (1) Density is 900 kg / m ３ More than 935kg / m ３ or less, preferably 910 kg / m ３ More than 930kg / m ３ or less, more preferably 912 kg / m ３ More than 925kg / m ３ It is in the following range:

[0017] Density is 900 kg / m ３ In the above cases, the ethylene-α-olefin copolymer (A) has good heat resistance and a density of 935 kg / m ３ The ethylene-α-olefin copolymer (A) has good mechanical strength in the following cases:

[0018] The density depends on the α-olefin content of the ethylene-α-olefin copolymer (A): the lower the α-olefin content, the higher the density, and the higher the α-olefin content, the lower the density. The α-olefin content of the ethylene-α-olefin copolymer (A) is determined by the composition ratio of α-olefin to ethylene (α-olefin / ethylene) in the polymerization system (for example, Walter Kaminsky, Macromol. Chem. 193, p. 606 (1992)). Therefore, by increasing or decreasing the α-olefin / ethylene, an ethylene-α-olefin copolymer (A) having a density within the above range can be produced.

[0019] The density is measured as follows: The strand obtained when measuring MFR is heat treated at 100° C. for 30 minutes, and then left at room temperature for 1 hour, after which the density is measured by the density gradient tube method.

[0020] <<Requirement (2)>> (2) The melt flow rate (MFR) at 190°C under a load of 2.16 kg is 0.01 g / 10 min or more and 10.0 g / 10 min or less, preferably 0.05 g / 10 min or more and 5.0 g / 10 min or less, and more preferably 0.1 g / 10 min or more and 5.0 g / 10 min or less.

[0021] When the MFR is 0.01 g / 10 min or more, the shear viscosity of the ethylene-α-olefin copolymer (A) is not too high and the extrusion load is good.When the MFR is 10.0 g / 10 min or less, the mechanical strength of the ethylene-α-olefin copolymer (A) is good.

[0022] The melt flow rate (MFR) is strongly dependent on the molecular weight; the smaller the MFR, the higher the molecular weight, and the higher the MFR, the lower the molecular weight. It is also known that the molecular weight of an ethylene polymer is determined by the composition ratio of hydrogen to ethylene (hydrogen / ethylene) in the polymerization system (see, for example, Kazuo Soga et al., Catalytic Olefin Polymerization, Kodansha Scientific, 1990, p. 376). Therefore, the melt flow rate (MFR) of an ethylene polymer can be increased or decreased by increasing or decreasing the hydrogen / ethylene ratio. The melt flow rate (MFR) is measured in accordance with JIS K 7210 under conditions of 190°C and a load of 2.16 kg.

[0023] <<Requirement (3)>> (3) The melt tension [MT (g)] at 190°C and the shear viscosity [η ＊ (P) (P is Poise) and the ratio [MT / η ＊ (g / P)] is 1.20 × 10 －４ Above 4.00 x 10 －４ The range is preferably 1.30×10 －４ 3.80 x 10－４ or less, more preferably 1.20 × 10 －４ 3.50 x 10 －４ It is in the following range:

[0024] MT / η ＊ is 1.20 x 10 －４ In the above cases, the ethylene-α-olefin copolymer (A) has a high melt tension relative to its molecular weight, and therefore the ethylene-α-olefin copolymer (A) has excellent moldability. ＊ is 4.00 x 10 －４ In the following cases, the ethylene-α-olefin copolymer (A) has excellent mechanical strength.

[0025] MT / η ＊ is dependent on the long chain branch content of the ethylene-α-olefin copolymer (A), and the higher the long chain branch content, the lower the MT / η ＊ is large, and the lower the long chain branch content, the lower the MT / η ＊ Long chain branching is defined as a branch structure having a length equal to or greater than the molecular weight (Me) between entanglement points contained in the ethylene-α-olefin copolymer (A), and it is known that the introduction of long chain branching significantly changes the melt properties and molding processability of ethylene polymers (for example, Kazuo Matsuura et al., "Polyethylene Technology Reader," Kogyo Chosakai, 2001, pp. 32, 36). ＊ can be adjusted by the type of component (T) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when the same olefin polymerization catalyst (X) is used, it can be adjusted by the polymerization conditions or polymerization process. For example, by increasing the ethylene partial pressure, MT / η ＊ The manufacturing conditions of Manufacturing Example 4 described in the Examples below can reduce the －４ Nearby MT / η ＊ was added to 4.00 × 10 －４ Nearby MT / η ＊ can be obtained.

[0026] The melt tension [MT (g)] is measured as follows. The melt tension (MT) (unit: g) of the ethylene-α-olefin copolymer (A) at 190°C is determined by measuring the stress when stretched at a constant speed. A capillary rheometer is used for the measurement (for example, in the examples described below, a capillograph 1D capillary rheometer manufactured by Toyo Seiki Seisaku-sho, Ltd. was used). The measurement conditions are a resin temperature of 190°C, a melting time of 6 minutes, a barrel diameter of 9.55 mmφ, an extrusion speed of 15 mm / min, a take-up speed of 24 m / min (if the molten filament breaks, the take-up speed is reduced by 5 m / min), a nozzle diameter of 2.095 mmφ, and a nozzle length of 8 mm.

[0027] Shear viscosity [η] at 200°C and angular velocity of 1.0 rad / sec ＊ (P)] is measured as follows: Shear viscosity (η ＊ ) is the shear viscosity (η) at a measurement temperature of 200 ° C. ＊ The angular velocity [ω (rad / sec)] dispersion of the strain is measured in the range of 0.01≦ω≦100. A viscoelasticity measuring device is used for the measurement (for example, in the examples described later, a Physica MCR301 viscoelasticity measuring device manufactured by Anton Paar is used), and a parallel plate with a diameter of 25 mm is used as the sample holder, with the thickness of the ethylene-α-olefin copolymer (A) sample being approximately 2.0 mm. Five measurement points are set per ω digit. The strain amount is appropriately selected from the range of 3 to 10% so that the torque can be detected within the measurement range and so that the torque does not exceed the limit.

[0028] The samples used for shear viscosity measurement were prepared using a molding machine (for example, a press molding machine manufactured by Shinto Metal Industries Co., Ltd. was used in the examples described later), with a preheating temperature of 190°C, a preheating time of 5 minutes, a heating temperature of 190°C, a heating time of 2 minutes, and a heating pressure of 100 kgf / cm. ２ , cooling temperature 20°C, cooling time 5 minutes, cooling pressure 100 kgf / cm ２ A measurement sample is prepared by press molding to a thickness of 2 mm under the conditions above.

[0029] <Requirement (4)> (4) Zero shear viscosity at 200°C [η ０(P)] and the weight average molecular weight (Mw) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1): －１３ ×Mw ３．４ ≦η ０ ≦2.5×10 ―１３ ×Mw ３．４ ... (Eq-1)

[0030] Zero shear viscosity [η ０ (P)] and the weight average molecular weight (Mw) preferably satisfy the following relational expression (Eq-1′): －１３ ×Mw ３．４ ≦η ０ ≦2.2×10 －１３ ×Mw ３．４ ... (Eq-1') Zero shear viscosity [η ０ (P)] and the weight average molecular weight (Mw) more preferably satisfy the following relational expression (Eq-1″): 0.10×10 －１３ ×Mw ３．４ ≦η ０ ≦2.0×10 －１３ ×Mw ３．４ ...(Eq-1")

[0031] Zero shear viscosity [η] relative to weight average molecular weight (Mw) ０ When the zero shear viscosity [η (P)] is plotted on a double logarithmic scale, resins that do not exhibit strain hardening in extensional viscosity, such as linear ethylene polymers without long chain branches, follow a power law with a slope of 3.4, whereas resins that exhibit strain rate hardening in extensional viscosity, such as high-pressure low-density polyethylene, show a zero shear viscosity [η (P)] that is lower than the power law. ０ (P)] (C. Gabriel, H. Munstedt, J. Rheol., 47(3), 619 (2003)).

[0032] Zero shear viscosity at 200 ° C [η ０ (P)] is upper limit 2.5 × 10 －１３ ×Mw ３．４ In the following cases, the elongational viscosity of the ethylene-α-olefin copolymer (A) exhibits strain rate hardening, and therefore take-up surging does not occur. ０The relationship between η (P)] and the weight average molecular weight (Mw) is considered to depend on the content and length of long chain branches in the ethylene-α-olefin copolymer (A). The higher the content of long chain branches and the shorter the length of the long chain branches, the lower the η ０ / Mw ３．４ The lower the long-chain branch content and the longer the length of the long-chain branch, the smaller the η ０ / Mw ３．４ is thought to show a large value.

[0033] Zero shear viscosity [η ０ (P)] can be adjusted by the type of component (T) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when the same olefin polymerization catalyst (X) is used, it can be adjusted by the polymerization conditions or polymerization process. For example, the zero shear viscosity [η ０ The lower limit of 0.01 × 10 (P) can be increased by the production conditions of Production Example 6 described in the Examples below. －１３ Nearby η ０ / Mw ３．４ Under the manufacturing conditions of Manufacturing Example 4, the upper limit is 2.5 × 10 －１３ Nearby η ０ / Mw ３．４ can be obtained.

[0034] Zero shear viscosity at 200 ° C [η ０ (P)] is measured as follows: Shear viscosity (η ＊The angular velocity ω (rad / sec) dispersion of the ethylene-α-olefin copolymer (A) is measured in the range of 0.01≦ω≦100. For the measurement, a viscoelasticity measuring device (for example, in the examples described later, a Physica MCR301 viscoelasticity measuring device manufactured by Anton Paar) is used, a 25 mmφ parallel plate is used as a sample holder, and the thickness of the ethylene-α-olefin copolymer (A) sample is approximately 2.0 mm. Five measurement points are set per ω digit. The strain amount is appropriately selected within the range of 3 to 10% so that the torque can be detected within the measurement range and does not exceed the torque. The ethylene-α-olefin copolymer (A) sample used for shear viscosity measurement is prepared using a molding machine (for example, in the examples described later, a press molding machine manufactured by Shinto Metal Industries Co., Ltd. was used) under the following conditions: preheating temperature 190°C, preheating time 5 minutes, heating temperature 190°C, heating time 2 minutes, and heating pressure 100 kgf / cm. ２ , cooling temperature 20°C, cooling time 5 minutes, cooling pressure 100 kgf / cm ２ A measurement sample is prepared by press molding to a thickness of 2 mm under the conditions above.

[0035] Zero shear viscosity (η ０ ) is calculated by fitting the Carreau model of the following formula to the measured rheology curve [shear viscosity (η ＊ ) angular velocity (ω) variance]. ＊ =η ０ [1 + (λω) ａ 〕 （ｎ－１）／ａ [λ is a parameter having a time dimension, a is a fitting parameter, and n is a power law index of the material.] Note that fitting by the nonlinear least squares method is performed so that d in the following formula is minimized.

[0036]

[0037] [η ｅｘｐ (ω) represents the measured shear viscosity, and η ｃａｌｃ (ω) represents the shear viscosity calculated from the Carreau model.

[0038] Weight-average molecular weight (Mw) and other parameters are measured by gel permeation chromatography (GPC) as follows. A differential refractometer and a capillary viscometer are used as detectors, the column temperature is 145°C, o-dichlorobenzene is used as the mobile phase, the flow rate is 1.0 mL / min, the sample concentration is 0.1% by mass, and polystyrene is used as the standard polymer. In the examples described below, an Agilent GPC-viscometer (GPC-VISCO) PL-GPC220 is used as the measuring device, two Agilent PLgel Olexis analytical columns are used, and a Tosoh Corporation polystyrene standard is used. The molecular weight is calculated by calculating the actual viscosity using a viscometer and a refractometer, and then the number-average molecular weight (Mn), weight-average molecular weight (Mw), Z-average molecular weight (Mz), and molecular weight distribution (Mw / Mn and Mz / Mw) are determined by actual universal calibration.

[0039] <<Requirement (5)>> (5) The melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks, and the heat of fusion at 115°C or higher per 5 mg of the measurement sample is in the range of 10 mJ to 200 mJ, preferably 55 mJ to 200 mJ, more preferably 80 mJ to 200 mJ, and even more preferably 120 mJ to 200 mJ. When the melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks, even a relatively low-density polyethylene contains a high-melting-point component. Furthermore, the heat of fusion at 115°C or higher corresponds to the amount of unmelted components under temperature conditions around 115°C. When the heat of fusion at 115°C or higher per 5 mg of a measurement sample of the ethylene-α-olefin copolymer (A) is 10 mJ or more, the ethylene-α-olefin copolymer (A) has good heat resistance, and when the heat of fusion at 115°C or higher per 5 mg of a measurement sample of the ethylene-α-olefin copolymer (A) is 200 mJ or less, the ethylene-α-olefin copolymer (A) has good mechanical strength.

[0040] Differential scanning calorimetry (DSC) is performed using a differential scanning calorimeter (for example, a Diamond DSC manufactured by PerkinElmer was used in the examples described below) as follows. Approximately 5 mg of a sample is placed in an aluminum pan, heated to 200°C at 10°C / min, held at 200°C for 10 minutes, cooled to -30°C at 10°C / min, and then heated to 200°C at 10°C / min, to obtain an endothermic curve. The presence of two or more peaks in this endothermic curve means that the melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks. The heat of fusion at 115°C or higher is calculated by drawing a baseline passing through two points, 100°C and 160°C, on the endothermic curve, and then calculating based on the integrated value obtained from the baseline and the endothermic curve in the temperature range of 115°C or higher.

[0041] The number of peaks in the melting curve in DSC and the heat of fusion at 115°C or higher can be adjusted by the type of component (T) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when the same olefin polymerization catalyst (X) is used, these can be adjusted by increasing or decreasing the composition ratio of α-olefin to ethylene in the polymerization system.

[0042] The ethylene-α-olefin copolymer (A) preferably further has the properties as specified in the following requirements (6) and (7).

[0043] <<Requirement (6)>> (6) The intrinsic viscosity [η] (dl / g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-2): 0.70×10 －４ ×Mw ０．７７６ ≦[η]≦1.65×10 －４ ×Mw ０．７７６ The intrinsic viscosity [η] (dl / g) and the weight average molecular weight (Mw) preferably satisfy the following relational expression (Eq-2′): 0.70×10 －４ ×Mw ０．７７６ ≦[η]≦1.40×10 －４ ×Mw ０．７７６...(Eq-2') The above-mentioned intrinsic viscosity [[η] (dl / g)] and weight average molecular weight (Mw) more preferably satisfy the following relational expression (Eq-2''): 0.70×10 －４ ×Mw ０．７７６ ≦[η]≦1.30×10 －４ ×Mw ０．７７６ ...(Eq-2")

[0044] It is known that when long chain branches are introduced into an ethylene polymer, the intrinsic viscosity [η] (dL / g)] relative to the molecular weight becomes smaller than that of a linear ethylene polymer without long chain branches (for example, Walther Burchard, ADVANCES IN POLYMER SCIENCE, 143, Branched Polymer II, p. 137 (1999)). －４ ×Mw ０．７７６ In the following cases, the ethylene-α-olefin copolymer (A) has many long chain branches and is excellent in moldability and flowability.

[0045] The intrinsic viscosity [η] (dl / g)] can be adjusted by the type of component (T) or solid support (S) of the olefin polymerization catalyst (X) described later. Even when the same olefin polymerization catalyst (X) is used, the intrinsic viscosity [η] (dl / g)] can be adjusted by the polymerization conditions or polymerization process. For example, the intrinsic viscosity [η] (dl / g)] can be increased by increasing the ethylene partial pressure. The lower limit of 0.70×10 can be achieved by the production conditions of Production Example 6 described in the Examples below. －４ ×Mw ０．７７６ The intrinsic viscosity [[η] (dl / g)] in the vicinity of 1.65 × 10 －４ ×Mw ０．７７６ The intrinsic viscosity [η] (dl / g) can be measured using decalin as a solvent as follows.

[0046] Approximately 20 mg of the measurement sample is dissolved in 15 mL of decalin, and the specific viscosity ηsp is measured in an oil bath at 135 ° C. 5 mL of decalin solvent is added to this decalin solution to dilute it, and the specific viscosity ηsp is measured in the same manner. This dilution procedure is repeated two more times, and the value of ηsp / C when the concentration (C) is extrapolated to 0 as shown in the following formula is calculated as the limiting viscosity [η] (unit: dl / g). [η] = lim(ηsp / C) (C → 0) The weight average molecular weight (Mw) is measured by the method described in the above requirement (4).

[0047] <<Requirement (7)>> (7) １ The total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins measured by H-NMR (hereinafter also simply referred to as "total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins") is in the range of 0.1 to 1.0. The total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins preferably satisfies the following relational formula (Eq-3'): 0.2≦total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins≦1.0 (Eq-3') The total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins more preferably satisfies the following relational formula (Eq-3"): 0.3≦total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins≦1.0 (Eq-3")

[0048] The number of vinyl, vinylidene, disubstituted internal olefin, and trisubstituted internal olefin in the polymer is １The number per 1,000 carbon atoms contained in a polymer is measured by H-NMR. It is known that the production ratio and number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins increase or decrease depending on the transition metal compound used (H. Saiki, S. Makoto, T. Masao, S. Morihiko, Y. Akihiro, J. Polym. Sci., A: Polym. Chem., 38, 4641 (2000)). These can be adjusted by the type of component (T) or solid support (S) of the olefin polymerization catalyst (X) described below. Furthermore, even when the same olefin polymerization catalyst (X) is used, they can be adjusted by the polymerization conditions or polymerization process, and can be increased or decreased, for example, by increasing or decreasing the ethylene partial pressure.

[0049] When the total number of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin is 0.1 or more, long chain branches are likely to be formed in the ethylene-α-olefin copolymer (A), and a resin composition containing the ethylene-α-olefin copolymer (A) has excellent moldability. When the total number of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin is 1.0 or less, a resin composition containing the ethylene-α-olefin copolymer (A) has excellent heat-sealability, is less susceptible to oxidation of a molten film during molding, and provides a foam with excellent transparency and mechanical strength.

[0050] １ The total number of vinyl, vinylidene, disubstituted internal olefins, and trisubstituted internal olefins measured by H-NMR (500 MHz) is measured using a nuclear magnetic resonance spectrometer (for example, in the examples described later, a Bruker AVANCE III (Cryoprobe) nuclear magnetic resonance spectrometer) as follows: The measurement mode is single pulse, with a pulse width of 45°. The number of points is 32k, the observation range is 20 ppm (-6 to 14 ppm), the repetition time is 7 seconds, and the number of accumulations is 64. 20 mg of a sample is dissolved in 40.6 mL of orthodichlorobenzene-d, and then the measurement is performed at 120°C. １ ​In the H-NMR spectrum, the number of double bonds and the total number of double bonds calculated from the signal integral values ​​derived from various double bonds (vinyl, vinylidene, internal olefin) at 4.5 ppm to 5.8 ppm were １ The relative value of the total number of carbon atoms calculated from the total integrated value of the H signals is determined, and the number of various double bonds per 1,000 carbon atoms in the polymer is calculated.

[0051] The ethylene-α-olefin copolymer (A) may contain biomass-derived monomers (ethylene, α-olefin). The monomers constituting the ethylene-α-olefin copolymer (A) may be only biomass-derived monomers, only fossil fuel-derived monomers, or both biomass-derived monomers and fossil fuel-derived monomers. The biomass-derived monomers are monomers derived from any renewable natural raw material or residue thereof, such as plant-derived or animal-derived, including fungi, yeast, algae, and bacteria, and contain, as carbon, １４ C isotope 1×10 －１２ The ethylene-α-olefin copolymer (A) contains a biomass-derived monomer in a proportion of about 100 pMC, and has a biomass carbon concentration (pMC) of about 100 pMC as measured in accordance with ASTM D 6866. The biomass-derived monomer can be obtained by a conventionally known method. It is preferable that the ethylene-α-olefin copolymer (A) contains a biomass-derived monomer from the viewpoint of reducing the environmental load (mainly reducing greenhouse gases). If the polymer production conditions, such as the polymerization catalyst and the polymerization temperature in the polymerization process, are the same, even if the raw material monomer contains a biomass-derived monomer, １４ C isotope 1×10 －１２ ~1 x 10 －１４ Other than the proportion of ethylene-α-olefin copolymers, the molecular structure is the same as that of ethylene-α-olefin copolymers made from fossil fuel-derived monomers, and therefore the performance is said to be the same.

[0052] The ethylene-α-olefin copolymer (A) may contain a chemically recycled monomer (e.g., ethylene, an α-olefin, etc.). The monomers constituting the ethylene-α-olefin copolymer (A) may consist solely of chemically recycled monomers, or may consist solely of fossil fuel-derived monomers, or may contain a chemically recycled monomer together with a fossil fuel-derived monomer and / or a biomass-derived monomer. The chemically recycled monomers can be obtained by conventionally known methods. It is preferable for the ethylene-α-olefin copolymer (A) to contain a chemically recycled monomer from the viewpoint of reducing the environmental load (mainly waste reduction). Chemically recycled monomers are monomers obtained by depolymerizing or pyrolyzing polymers such as waste plastics back into monomer units such as ethylene, or monomers produced using such monomers as raw materials. Therefore, even if a chemically recycled monomer is contained as a raw material monomer for the ethylene-α-olefin copolymer (A), the molecular structure will be equivalent to that of an ethylene-α-olefin copolymer composed of a fossil fuel-derived monomer, provided that the polymer production conditions, such as the polymerization catalyst, polymerization process, and polymerization temperature, are equivalent. Therefore, the performance is also considered to be unchanged.

[0053] <Method for producing ethylene-α-olefin copolymer (A)> From the viewpoint of efficient polymerization, the method for producing the ethylene-α-olefin copolymer (A) is preferably a method of polymerizing ethylene and an α-olefin having 4 to 10 carbon atoms in the presence of an olefin polymerization catalyst (X) comprising the following components: Hereinafter, the olefin polymerization catalyst (X) used in the method for producing the ethylene-α-olefin copolymer (A) will be described in detail.

[0054] <Olefin Polymerization Catalyst (X)> The olefin polymerization catalyst (X) comprises the following component (T) and solid support (S).

[0055] [Component (T)] Component (T) is a transition metal compound represented by the following formula (1) (hereinafter also referred to as "transition metal compound (1)"). The olefin polymerization catalyst (X) contains at least one transition metal compound (1). That is, one or more transition metal compounds (1) may be used as component (T).

[0056]

[0057] In the above formula (1), M is a zirconium atom or a hafnium atom, preferably a zirconium atom.

[0058] In the above formula (1), n ​​is an integer of 1 to 4 selected so that the transition metal compound (1) is electrically neutral, and preferably 2. In the above formula (1), each X is independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, an oxygen-containing group, a nitrogen-containing group, or a conjugated diene derivative group, and preferably a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

[0059] The halogen atom includes fluorine, chlorine, bromine and iodine, with chlorine being particularly preferred.

[0060] Examples of the hydrocarbon group having 1 to 20 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, isopropyl, sec-butyl (butan-2-yl), tert-butyl (2-methylpropan-2-yl), isobutyl (2-methylpropyl), pentan-2-yl, 2-methylbutyl, isopentyl (3-methylbutyl), neopentyl (2,2-dimethylpropyl), cyamyl (1,2-dimethylpropyl), isohexyl (4-methylpentyl), 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, thexyl (2,3-dimethylbut-2-yl), and 4,4-dimethylpentyl; linear or branched alkenyl groups or unsaturated double bond-containing groups such as a vinyl group, an allyl group, a propenyl group (prop-1-en-1-yl group), an iso-propenyl group (prop-1-en-2-yl group), an allenyl group (prop-1,2-dien-1-yl group), a but-3-en-1-yl group, a crotyl group (but-2-en-1-yl group), a but-3-en-2-yl group, a methallyl group (2-methylallyl group), a buta-1,3-dienyl group, a pent-4-en-1-yl group, a pent-3-en-1-yl group, a pent-2-en-1-yl group, an iso-pentenyl group (3-methylbut-3-en-1-yl group), a 2-methylbut-3-en-1-yl group, a pent-4-en-2-yl group, or a prenyl group (3-methylbut-2-en-1-yl group); linear or branched alkynyl groups or unsaturated triple bond-containing groups such as ethynyl, prop-2-yn-1-yl, and propargyl (prop-1-yn-1-yl); linear or branched alkyl groups and unsaturated double bond-containing groups containing aromatic groups such as benzyl, 2-methylbenzyl, 4-methylbenzyl, 2,4,6-trimethylbenzyl, 3,5-dimethylbenzyl, cuminyl (4-isopropylbenzyl), 2,4,6-tri-isopropylbenzyl, 4-tert-butylbenzyl, 3,5-di-tert-butylbenzyl, 1-phenylethyl, and benzhydryl (diphenylmethyl);Examples of suitable aromatic substituents include cyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cycloheptatrienyl, norbornyl, norbornenyl, 1-adamantyl, and 2-adamantyl groups; and aromatic substituents such as phenyl, tolyl (methylphenyl), xylyl (dimethylphenyl), mesityl (2,4,6-trimethylphenyl), cumenyl (isopropylphenyl), duryl (2,3,5,6-tetramethylphenyl), 2,6-di-isopropylphenyl, 2,4,6-tri-isopropylphenyl, 4-tert-butylphenyl, 3,5-di-tert-butylphenyl, naphthyl, biphenyl, ter-phenyl, binaphthyl, acenaphthalenyl, phenanthryl, anthracenyl, pyrenyl, and ferrocenyl groups. Among these, a methyl group, an isobutyl group, a neopentyl group, a cyamyl group, a benzyl group, a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group are preferred.

[0061] The hydrocarbon group having 1 to 20 carbon atoms may be a halogen-substituted hydrocarbon group in which some or all of the hydrogen atoms of the hydrocarbon group having 1 to 20 carbon atoms have been substituted with halogen atoms. Examples of such a group include a fluoromethyl group, a trifluoromethyl group, a trichloromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a pentachloroethyl group, a pentafluorophenylmethyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a tetrafluorophenyl group, a pentafluorophenyl group, a trifluoromethylphenyl group, and a bistrifluoromethylphenyl group, with a pentafluorophenyl group being preferred.

[0062] Examples of the silicon-containing group include a trimethylsilyl group, a triethylsilyl group, a tri-isopropylsilyl group, a diphenylmethylsilyl group, a tert-butyldimethylsilyl group, a tert-butyldiphenylsilyl group, a triphenylsilyl group, a tris(trimethylsilyl)silyl group, and a trimethylsilylmethyl group, and preferably a trimethylsilylmethyl group.

[0063] Examples of the oxygen-containing group include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an allyloxy group, an n-butoxy group, a sec-butoxy group, an iso-butoxy group, a tert-butoxy group, a benzyloxy group, a methoxymethoxy group, a phenoxy group, a 2,6-dimethylphenoxy group, a 2,6-di-iso-propylphenoxy group, a 2,6-di-tert-butylphenoxy group, a 2,4,6-trimethylphenoxy group, a 2,4,6-tri-iso-propylphenoxy group, an acetoxy group, a pivaloyloxy group, a benzoyloxy group, a trifluoroacetoxy group, a perchlorate anion, and a periodate anion, and preferably a methoxy group, an ethoxy group, an iso-propoxy group, or a tert-butoxy group.

[0064] Examples of the nitrogen-containing group include an amino group, a cyano group, a methylamino group, a dimethylamino group, an ethylamino group, a diethylamino group, an allylamino group, a diallylamino group, a benzylamino group, a dibenzylamino group, a pyrrolidinyl group, a piperidinyl group, a morpholyl group, a pyrrolyl group, and a bistriflylimide group.

[0065] Examples of the conjugated diene derivative group include a 1,3-butadienyl group, an isoprenyl group (2-methyl-1,3-butadienyl group), a piperylenyl group (1,3-pentadienyl group), a 2,4-hexadienyl group, a 1,4-diphenyl-1,3-pentadienyl group, and a cyclopentadienyl group, and preferably a 1,3-butadienyl group and a 1,3-pentadienyl group. In the above formula (1), Q represents a carbon atom or a silicon atom, and preferably a silicon atom.

[0066] In the above formula (1), R １ ~R １４ are each independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group having 1 to 20 carbon atoms, an oxygen-containing group having 1 to 20 carbon atoms, or a nitrogen-containing group having 1 to 20 carbon atoms, and are preferably a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or an oxygen-containing group having 1 to 20 carbon atoms.

[0067] R １ ~R １４Examples of the hydrocarbon group having 1 to 20 carbon atoms as the alkyl group include linear or branched alkyl groups such as methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, isopropyl, sec-butyl (butan-2-yl), tert-butyl (2-methylpropan-2-yl), isobutyl (2-methylpropyl), pentan-2-yl, 2-methylbutyl, isopentyl (3-methylbutyl), neopentyl (2,2-dimethylpropyl), cyamyl (1,2-dimethylpropyl), isohexyl (4-methylpentyl), 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, thexyl (2,3-dimethylbut-2-yl), and 4,4-dimethylpentyl; linear or branched alkenyl groups or unsaturated double bond-containing groups such as a vinyl group, an allyl group, a propenyl group (prop-1-en-1-yl group), an iso-propenyl group (prop-1-en-2-yl group), an allenyl group (prop-1,2-dien-1-yl group), a but-3-en-1-yl group, a crotyl group (but-2-en-1-yl group), a but-3-en-2-yl group, a methallyl group (2-methylallyl group), a buta-1,3-dienyl group, a pent-4-en-1-yl group, a pent-3-en-1-yl group, a pent-2-en-1-yl group, an iso-pentenyl group (3-methylbut-3-en-1-yl group), a 2-methylbut-3-en-1-yl group, a pent-4-en-2-yl group, or a prenyl group (3-methylbut-2-en-1-yl group); a straight-chain or branched alkynyl group or an unsaturated triple bond-containing group such as an ethynyl group, a prop-2-yn-1-yl group, or a propargyl group (prop-1-yn-1-yl group);linear or branched alkyl groups and unsaturated double bond-containing groups containing aromatic groups, such as benzyl, 2-methylbenzyl, 4-methylbenzyl, 2,4,6-trimethylbenzyl, 3,5-dimethylbenzyl, cuminyl (4-isopropylbenzyl), 2,4,6-tri-isopropylbenzyl, 4-tert-butylbenzyl, 3,5-di-tert-butylbenzyl, 1-phenylethyl, benzhydryl (diphenylmethyl), and pentafluorophenylmethyl; cyclic saturated hydrocarbon groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cycloheptatrienyl, norbornyl, norbornenyl, 1-adamantyl, and 2-adamantyl; aromatic substituents such as a phenyl group, a tolyl group (methylphenyl group), a xylyl group (dimethylphenyl group), a mesityl group (2,4,6-trimethylphenyl group), a cumenyl group (isopropylphenyl group), a duryl group (2,3,5,6-tetramethylphenyl group), a 2,6-di-isopropylphenyl group, a 2,4,6-tri-isopropylphenyl group, a 4-tert-butylphenyl group, a 3,5-di-tert-butylphenyl group, a naphthyl group, a biphenyl group, a ter-phenyl group, a binaphthyl group, an acenaphthalenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, and a ferrocenyl group; halogen-substituted hydrocarbon groups in which some or all of the hydrogen atoms of the above-mentioned hydrocarbon groups having 1 to 20 carbon atoms have been substituted with halogen atoms, such as a fluoromethyl group, a trifluoromethyl group, a trichloromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a pentachloroethyl group, a pentafluorophenylmethyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a tetrafluorophenyl group, a pentafluorophenyl group, a trifluoromethylphenyl group, and a bistrifluoromethylphenyl group;and preferably a methyl group, an ethyl group, a 1-propyl group, a 1-butyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, an isopropyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an allyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclooctenyl group, a norbornyl group, a bicyclo[2.2.2]octan-1-yl group, a 1-adamantyl group, a 2-adamantyl group, or a benzyl group. , benzhydryl group, cumyl group, 1,1-diphenylethyl group, trityl group, 2-phenylethyl group, 3-phenylpropyl group, cinnamyl group, phenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, 2,6-di-iso-propylphenyl group, 2,4,6-tri-iso-propylphenyl group, 4-tert-butylphenyl group, 3,5-di-tert-butylphenyl group, 4-adamantylphenyl group, naphthyl group, biphenyl group, tert-phenyl group, binaphthyl group, phenanthryl group, anthracenyl group, ferrocenyl group, and pentafluorophenyl group;

[0068] R １ ~R １４ Preferred examples of the silicon-containing group having 1 to 20 carbon atoms as the aryl group include a trimethylsilyl group, a triethylsilyl group, a tri-iso-propylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, a cyclopentadienyldimethylsilyl group, a cyclopentadienyldiphenylsilyl group, an indenyldimethylsilyl group, a fluorenyldimethylsilyl group, a 4-trimethylsilylphenyl group, a 4-triethylsilylphenyl group, a 4-tri-iso-propylsilylphenyl group, and a 3,5-bis(trimethylsilyl)phenyl group, and examples thereof include a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a 4-trimethylsilylphenyl group, a 4-triethylsilylphenyl group, a 4-tri-iso-propylsilylphenyl group, and a 3,5-bis(trimethylsilyl)phenyl group.

[0069] R １ ~R １４Examples of the oxygen-containing group having 1 to 20 carbon atoms as the alkyl group include a methoxy group, an ethoxy group, an isopropoxy group, an allyloxy group, an n-butoxy group, a tert-butoxy group, a prenyloxy group, a benzyloxy group, a phenoxy group, a naphthoxy group, a toluyloxy group, an isopropylphenoxy group, an allylphenoxy group, a tert-butylphenoxy group, a methoxyphenoxy group, a biphenyloxy group, a binaphthyloxy group, an allyloxymethyl group, a benzyloxymethyl group, a phenoxymethyl group, a methoxyethyl group, a methoxyallyl group, a benzyloxyallyl group, a phenoxyallyl group, a dimethoxymethyl group, a dioxolanyl group, a tetramethyldioxolanyl group, a dioxanyl group, a dimethyldioxanyl group, a methoxyphenyl group, an isopropoxyphenyl group, an aryloxy group, an aryloxymethyl group, a phenyl ... Examples of the alkyl group include an alkyloxyphenyl group, a phenoxyphenyl group, a methylenedioxyphenyl group, a 3,5-dimethyl-4-methoxyphenyl group, a 3,5-di-tert-butyl-4-methoxyphenyl group, a furyl group, a methylfuryl group, a tetrahydropyranyl group, a furofuryl group, a benzofuryl group, and a dibenzofuryl group, and preferred are a methoxy group, an iso-propoxy group, a tert-butoxy group, an allyloxy group, a phenoxy group, a dimethoxymethyl group, a dioxolanyl group, a methoxyphenyl group, an iso-propoxyphenyl group, an allyloxyphenyl group, a phenoxyphenyl group, a 3,5-dimethyl-4-methoxyphenyl group, a 3,5-di-tert-butyl-4-methoxyphenyl group, a furyl group, a methylfuryl group, a benzofuryl group, and a dibenzofuryl group.

[0070] R １ ~R １４Examples of the nitrogen-containing group having 1 to 20 carbon atoms as the nitrogen-containing group include an amino group, a dimethylamino group, a diethylamino group, an allylamino group, a benzylamino group, a dibenzylamino group, a pyrrolidinyl group, a piperidinyl group, a morpholyl group, a dimethylaminomethyl group, a benzylaminomethyl group, a pyrrolidinylmethyl group, a dimethylaminoethyl group, a pyrrolidinylethyl group, a dimethylaminopropyl group, a pyrrolidinylpropyl group, a dimethylaminoallyl group, a pyrrolidinylallyl group, an aminophenyl group, a dimethylaminophenyl group, a 3,5-dimethyl-4-dimethylaminophenyl group, a 3,5-di-iso-propyl-4-dimethylaminophenyl group, a julolidinyl group, a tetramethyljulolidinyl group, a pyrrolidinylphenyl group, a pyrrolylphenyl group, a carbazolylphenyl group, a di-tert-butylcarbazolyl group, a Examples of the alkyl group include a zolylphenyl group, a pyrrolyl group, a pyridyl group, a quinolyl group, a tetrahydroquinolyl group, an iso-quinolyl group, a tetrahydro-iso-quinolyl group, an indolyl group, an indolinyl group, a carbazolyl group, a di-tert-butylcarbazolyl group, an imidazolyl group, a dimethylimidazolidinyl group, a benzimidazolyl group, an oxazolyl group, an oxazolidinyl group, and a benzoxazolyl group, and preferred are an amino group, a dimethylamino group, a diethylamino group, a pyrrolidinyl group, a dimethylaminophenyl group, a 3,5-dimethyl-4-dimethylaminophenyl group, a 3,5-di-iso-propyl-4-dimethylaminophenyl group, a julolidinyl group, a tetramethyljulolidinyl group, a pyrrolidinylphenyl group, a pyrrolyl group, a pyridyl group, a carbazolyl group, and an imidazolyl group.

[0071] In the above formula (1), R １ ~R ６ Adjacent substituents (e.g., R １ and R ２ , R ２ and R ３ , R ３ and R ４ , R ４ and R ５ , and R ５ and R ６) may be bonded to each other to form a ring which may have a substituent. In this case, the ring formed is preferably a 5- to 8-membered ring which is fused to the indenyl ring moiety and which is made of a saturated hydrocarbon (excluding the hydrocarbon of the indenyl ring moiety) or an unsaturated hydrocarbon which may have a substituent. When multiple rings are present, these may be the same or different. Although not particularly limited as long as the effects of the present invention are achieved, the ring is more preferably a 5- or 6-membered ring. In this case, examples of the structure formed by combining the ring and the indenyl ring moiety of the mother nucleus include a benzoindenyl ring, a tetrahydroindacene ring, and a cyclopentatetrahydronaphthalene ring, with a benzoindenyl ring and a tetrahydroindacene ring being preferred. These rings may have a substituent.

[0072] In the above formula (1), R ７ ~R １２ Adjacent substituents (e.g., R ７ and R ８ , R ８ and R ９ , R ９ and R １０ , R １０ and R １１ , and R １１ and R １２ ) may be bonded to each other to form a ring which may have a substituent. In this case, the ring formed is preferably a 5- to 8-membered ring which is fused to the indenyl ring moiety and which is made of a saturated hydrocarbon (excluding the hydrocarbon of the indenyl ring moiety) or an unsaturated hydrocarbon which may have a substituent. When multiple rings are present, these may be the same or different. Although not particularly limited as long as the effects of the present invention are achieved, the ring is more preferably a 5- or 6-membered ring. In this case, examples of the structure formed by combining the ring and the indenyl ring moiety of the mother nucleus include a benzoindenyl ring, a tetrahydroindacene ring, a cyclopentatetrahydronaphthalene ring, a tetrahydrofluorene ring, and a fluorene ring, with a benzoindenyl ring and a tetrahydroindacene ring being preferred. These rings may have a substituent.

[0073] In the above formula (1), R １３ and R １４may be bonded to each other to form a ring containing Q, and these rings may have a substituent. In this case, the ring formed preferably forms a 3- to 8-membered saturated or unsaturated ring which may have a substituent. Although there are no particular limitations as long as the effects of the present invention are achieved, a 4- to 6-membered ring is preferred. In this case, examples of the structure combined with Q include a cyclobutane ring, a cyclopentane ring, a fluorene ring, a silacyclobutane (siletane) ring, a silacyclopentane (silorane) ring, a silacyclohexane (silinane) ring, and a silafluorene ring, and a cyclopentane ring, a silacyclobutane ring, or a silacyclopentane ring are preferred. These rings may have a substituent.

[0074] Specific examples of the transition metal compound (1) are shown below, but the scope of the present invention is not particularly limited by these. For convenience, the ligand structure of the transition metal compound (1) excluding the portion represented by MXn (metal portion) is referred to as a 2-indenyl ring portion, a 1-indenyl ring portion, an indenyl ring portion R １ , R ６ and R ８ Substituent, indenyl ring moiety R ２ , R ５ , R ９ and R １２ Substituent, indenyl ring moiety R ３ , R ４ , R １０ and R １１ Substituent, 1-indenyl ring moiety R ７ The abbreviation for the 2-indenyl ring portion is α, the abbreviation for the 1-indenyl ring portion is β, and the abbreviation for the indenyl ring portion R １ , R ６ and R ８ The abbreviation of the substituent is γ, and the indenyl ring portion R ２ , R ５ , R ９ and R １２ The abbreviation of the substituent is δ, and the indenyl ring portion is R ３ , R ４ , R １０ and R １１ The abbreviation of the substituent is ε, and the 1-indenyl ring moiety R ７The abbreviation for the substituent is ζ, the abbreviation for the structure of the crosslinked portion is η, and the abbreviations for each substituent are shown in [Table 1] to [Table 7].

[0075]

[0076]

[0077] The wavy lines in Tables 1 and 2 above indicate the bonding sites with the crosslinked moieties.

[0078]

[0079] R in Table 3 above １ , R ６ and R ８ The substituents in any combination may be the same or different from one another.

[0080]

[0081] R in Table 4 above ２ , R ５ , R ９ and R １２ The substituents in any combination may be the same or different from one another.

[0082]

[0083] R in Table 5 above ３ , R ４ , R １０ and R １１ The substituents in any combination may be the same or different from one another.

[0084]

[0085]

[0086] Specific examples of the metal moiety MXn include ZrF ２ , ZrCl ２ , ZrBr ２ , ZrI ２ , Zr(Me) ２ , Zr(Bn) ２ , Zr(Allyl) ２ , Zr(CH ２ -tBu) ２, Zr(1,3-butadienyl), Zr(1,3-pentadienyl), Zr(2,4-hexadienyl), Zr(1,4-diphenyl-1,3-pentadienyl), Zr(CH ２ -Si(Me) ３ ) ２ , Zr(OMe) ２ , Zr(OiPr) ２ , Zr(NMe ２ ) ２ , Zr(OMs) ２ , Zr(OTs) ２ , Zr(OTf) ２ , HfF ２ , HfCl ２ , HfBr ２ , HfI ２ , Hf(Me) ２ , Hf(Bn) ２ , Hf(Allyl) ２ , Hf(CH ２ -tBu) ２ , Hf(1,3-butadienyl), Hf(1,3-pentadienyl), Hf(2,4-hexadienyl), Hf(1,4-diphenyl-1,3-pentadienyl), Hf(CH ２ -Si(Me) ３ ) ２ , Hf(OMe) ２ , Hf(OiPr) ２ , Hf(NMe ２ ) ２ , Hf(OMs) ２ , Hf(OTs) ２ , Hf(OTf) ２ Me is a methyl group, Bn is a benzyl group, tBu is a tert-butyl group, Si(Me) ３ is a trimethylsilyl group, OMe is a methoxy group, OiPr is an iso-propoxy group, NMe ２ is a dimethylamino group, OMs is a methanesulfonate group, OTs is a p-toluenesulfonate group, and OTf is a trifluoromethanesulfonate group.

[0087] According to the above notation, the 2-indenyl ring moiety is α-1 in [Table 1], the 1-indenyl ring moiety is β-5 in [Table 2], and the indenyl ring moiety R １ , R ６and R ８ All of the substituents are the γ-1,2-indenyl ring moiety R ２ and R ５ The substituents are all the δ-1,2-indenyl ring moiety R in [Table 4]. ３ and R ４ The substituents are all the ε-1,1-indenyl ring moiety R ７ The substituent is the ζ-30,1-indenyl ring moiety R ９ The substituent is δ-38, 1-indenyl ring moiety R in [Table 4] １２ The substituent is composed of δ-3 in [Table 4] and the bridging portion is composed of η-20 in [Table 7], and the metal portion MXn is ZrCl ２ In this case, the compound represented by the following formula [6] is exemplified.

[0088]

[0089] The 2-indenyl ring moiety is α-1 in Table 1, the 1-indenyl ring moiety is β-2 in Table 2, and the indenyl ring moiety R １ , R ６ and R ８ All of the substituents are the γ-1,2-indenyl ring moiety R ２ and R ５ All of the substituents are the δ-2,2-indenyl ring moiety R in Table 4. ３ and R ４ The substituents are all the ε-1,1-indenyl ring moiety R ７ The substituent is composed of ζ-1 in [Table 6], the bridging portion is composed of η-4 in [Table 7], and the metal portion MXn is Zr (NMe ２ ) ２ In this case, the compound represented by the following formula [7] is exemplified.

[0090]

[0091] In addition, the α-3,1-indenyl ring moiety in [Table 1] corresponds to the β-1,2-indenyl ring moiety R in [Table 2]. １ and R ６ The substituents are all γ-2 in Table 3, the indenyl ring moiety R ２ , R ５ and R１２ All of the substituents are the δ-1,1-indenyl ring moiety R in Table 4. ７ The substituent is the ζ-12,1-indenyl ring moiety R ８ The substituent is the γ-1,1-indenyl ring moiety R ９ The substituent is δ-42 in Table 4, 1-indenyl ring moiety R １０ The substituent is the ε-3,1-indenyl ring moiety R １１ The substituent is composed of ε-12 in [Table 5], the bridging portion is composed of a combination of η-31 in [Table 7], and the metal portion MXn is HfMe ２ In this case, the compound represented by the following formula [8] is exemplified.

[0092]

[0093] In addition, the α-1,1-indenyl ring moiety in [Table 1] corresponds to the β-1,2-indenyl ring moiety R １ and R ６ All of the substituents are the γ-1,2-indenyl ring moiety R ２ The substituent is the δ-7,2-indenyl ring moiety R in [Table 4] ３ , R ４ , R １０ and R １１ The substituents are all the ε-1,2-indenyl ring moiety R ５ The substituent is the δ-2,1-indenyl ring moiety R in [Table 4] ７ The substituent is the ζ-1,1-indenyl ring moiety R ８ The substituent is the γ-9,1-indenyl ring moiety R ９ and R １２ In the case where the substituents are all composed of a combination of δ-1 in [Table 4], the bridging portion is composed of a combination of η-29 in [Table 7], and the metal portion MXn is Zr(1,3-pentadienyl), a compound represented by the following formula [9] is exemplified.

[0094]

[0095] The transition metal compound (1) can be produced by a conventionally known method, and the production method is not particularly limited. The substituted indene compound, which is the starting material, can be produced by a conventionally known method, and the production method is not particularly limited. Known production methods include those described in, for example, "Organometallics 1994, 13, 954.", "Organometallics 2006, 25, 1217.", JP-T-2006-509059, "Bioorg. Med. Chem. 2008, 16, 7399.", WO2009 / 080216, "Organometallics 2011, 30, 5744.", JP-T-2011-500800, "Organometallics 2012, 31, 4962.", and "Chem. Eur. J. 2012,18,4174.", JP 2012-012307 A, JP 2012-121882 A, JP 2014-196319 A, JP 2014-513735 A, JP 2015-063495 A, JP 2016-501952 A, JP 2019-059933 A, and the like.

[0096] Known methods for producing the transition metal compound (1) and its precursor compound (ligand) are described, for example, in "Macromolecules 2001, 34, 2072," "Macromolecules 2003, 36, 9325," "Organometallics 2004, 23, 5332," "Eur. J. Inorg. Chem. 2005, 1003," and "Eur. J. Inorg. Chem. 2009, 1759." Furthermore, the transition metal compound (1) has two faces (front and back) of the indenyl ring moiety that bond to the central metal across the bridge. Therefore, when the 2-indenyl ring moiety does not have a plane of symmetry, two structural isomers, as shown, for example, in the following general formula [10a] or [10b], exist:

[0097] ...[10a] ...[10b]

[0098] Similarly, the substituent R １３ and R１４ are not identical, there exist two structural isomers represented by the following general formula [11a] or [11b], for example.

[0099] ...[11a] ...[11b]

[0100] Purification and separation of these structural isomer mixtures, or selective production of structural isomers, can be performed by known methods, and the production method is not particularly limited. Known production methods include those exemplified as the production method for the transition metal compound (1) above, as well as production methods disclosed in JP-A-10-109996, "Organometallics 1999, 18, 5347," "Organometallics 2012, 31, 4340," and JP-A-2011-502192.

[0101] Within the scope of the transition metal compound (1), the transition metal compound may be used alone or in combination of two or more, or a structural isomer mixture may be used, or a structural isomer may be used alone or in combination of two or more. When the transition metal compound (1) is used as the transition metal compound constituting the olefin polymerization catalyst, an ethylene polymer having many long-chain branches introduced therein can be produced with high catalytic activity. Furthermore, as long as this effect is not impaired, one or more transition metal compounds other than the transition metal compound (1) may be used in combination as the transition metal compound. In this case, the transition metal compound (1) may be in any of the above-mentioned forms.

[0102] [Solid Support (S)] The solid support (S) contained in the olefin polymerization catalyst (X) is an inorganic or organic compound, and is a granular or fine particle solid.

[0103] Examples of inorganic compounds used as the solid support (S) include porous oxides, solid aluminoxane compounds, inorganic chlorides, clays, clay minerals, and ion-exchange layered compounds.

[0104] The porous oxide may be SiO ２ , Al ２ O３ , MgO, ZrO, TiO ２ , B ２ O ３ , CaO, ZnO, BaO and ThO ２ etc., or composites or mixtures containing these, specifically natural or synthetic zeolites, SiO ２ -MgO, SiO ２ -Al ２ O ３ , SiO ２ -TiO ２ , SiO ２ -V ２ O ５ , SiO ２ -Cr ２ O ３ and SiO ２ -TiO ２ Among these, SiO ２ The porous oxide preferably contains a small amount of Na. ２ CO ３ , K. ２ CO ３ , CaCO ３ , MgCO ３ , Na ２ SO ４ , Al ２ (SO ４ ) ３ , BaSO ４ , KNO ３ , Mg(NO ３ ) ２ , Al(NO ３ ) ３ , Na ２ O.K. ２ O, Li ２ It may contain carbonates, sulfates, nitrates, and oxides such as O.

[0105] The properties of such porous oxides vary depending on the type and production method, but as a solid support (S), the particle size is usually 0.2 to 300 μm, preferably 1 to 200 μm, and the specific surface area is usually 50 to 1200 m. ２ / g, preferably 100 to 1000m ２ / g, and the pore volume is usually 0.3 to 30 cm ３ / g. Such a carrier is preferably calcined, as necessary, at, for example, 100 to 1000°C, preferably 150 to 700°C, before use. Examples of the solid aluminoxane compound include aluminoxanes having a structure represented by the following general formula (S-a), aluminoxanes having a structure represented by the following general formula (S-b), and aluminoxanes having a structure comprising a repeating unit represented by the following general formula (Sc) and a repeating unit represented by the following general formula (S-d).

[0106] ... (S-a) ... (S-b) ... (Sc) ... (S-d)

[0107] In the above formulas (S-a) to (S-d), R ｅ are each independently a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms, and specific examples thereof include hydrocarbon groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an isopropenyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, a cyclohexyl group, a cyclooctyl group, a phenyl group, a tolyl group, and an ethylphenyl group, with a methyl group, an ethyl group, and an isobutyl group being preferred, and a methyl group being particularly preferred. ｅ is partly substituted with halogen atoms such as chlorine and bromine, and the halogen content is R ｅ In the above formulas (Sc) and (Sd), a line that is not connected to an atom on one side represents a bond to another atom that is not shown.

[0108] In the above formulas (S-a) and (S-b), r represents an integer of 2 to 500, preferably 6 to 300, and particularly preferably 10 to 100. In the above formulas (Sc) and (S-d), s and t each represent an integer of 1 or greater. r, s, and t are selected so that the aluminoxane can be maintained in a substantially solid state in the reaction environment in which it is used.

[0109] The solid aluminoxane compound differs from conventionally known olefin polymerization catalyst supports in that it does not contain inorganic solid components such as silica or alumina, or organic polymer components such as polyethylene or polystyrene, but is a solidified product of an alkylaluminum compound as the main component. The term "solid" means that the aluminoxane component maintains a substantially solid state under the reaction environment in which it is used. More specifically, this means that the aluminoxane component maintains a substantially solid state when the component (T) is brought into contact with the aluminoxane component to prepare an olefin polymerization catalyst (e.g., an ethylene polymerization catalyst) as described below, and when the prepared olefin polymerization catalyst is used to polymerize an olefin (e.g., ethylene) (e.g., suspension polymerization).

[0110] The simplest method for determining whether the aluminoxane component is in a solid state is visual confirmation, but visual confirmation is often difficult, for example, during polymerization. In such cases, it is possible to determine whether the aluminoxane component is in a solid state based on, for example, the properties of the polymer powder obtained after polymerization or the state of adhesion to the reactor. Conversely, if the properties of the polymer powder are good and adhesion to the reactor is low, it may be acceptable to assume that some of the aluminoxane component eluted in the polymerization environment. Indicators for determining the properties of the polymer powder include bulk density, particle shape, surface shape, and the presence of amorphous polymers, but polymer bulk density is preferred from the viewpoint of quantitative determination. The bulk density is usually 0.01 to 0.9, preferably 0.05 to 0.6, and more preferably 0.1 to 0.5.

[0111] The solubility of the solid aluminoxane compound in n-hexane maintained at 25° C. is usually in the range of 0 to 40 mol %, preferably 0 to 20 mol %, and particularly preferably 0 to 10 mol %.

[0112] The dissolution rate can be determined by adding 2 g of the solid aluminoxane compound carrier to 50 mL of n-hexane maintained at 25°C, stirring for 2 hours, separating the solution using a G-4 glass filter, and measuring the aluminum concentration in the filtrate. Therefore, the dissolution rate is determined as the ratio of aluminum atoms present in the filtrate to the amount of aluminum atoms equivalent to 2 g of the aluminoxane used.

[0113] As the solid aluminoxane compound, known solid aluminoxanes can be used without limitation, and for example, the solid polyaluminoxane composition described in International Publication No. 2014 / 123212 can also be used. Known production methods include those described in JP-B No. 7-42301, JP-A No. 6-220126, JP-A No. 6-220128, JP-A No. 11-140113, JP-A No. 11-310607, JP-A No. 2000-38410, JP-A No. 2000-95810, and WO 2010 / 55652.

[0114] The average particle diameter of the solid aluminoxane compound is generally in the range of 0.01 to 50,000 μm, preferably 0.1 to 1,000 μm, and particularly preferably 1 to 200 μm. The average particle diameter of the solid aluminoxane compound is determined by observing the particles with a scanning electron microscope, measuring the particle diameters of 100 or more particles, and averaging the weight values. First, the particle diameter d of each particle is determined by measuring the length of the particle image between two parallel lines in the horizontal and vertical directions, and then using the following formula: Particle diameter d = ((horizontal length) ２ + (vertical length) ２ ) ０．５

[0115] Next, the weight average particle diameter of the solid aluminoxane compound is calculated by the following formula using the particle diameter d calculated above and the number of particles n: Average particle diameter = Σnd ４ / Σnd ３ The solid aluminoxane compound has a specific surface area of ​​50 to 1,000 m ２ / g, preferably 100 to 800 m ２ / g, and the pore volume is 0.1 to 2.5 cm ３ It is desirable that the saturation coefficient be 1 / g.

[0116] Examples of the inorganic halide include MgCl ２ , MgBr ２ , MnCl ２ , MnBr ２ The inorganic halide may be used as it is, or may be used after being pulverized using a ball mill or a vibration mill. Alternatively, the inorganic halide may be dissolved in a solvent such as alcohol and then precipitated into fine particles using a precipitating agent.

[0117] Clay is usually composed mainly of clay minerals. Ion-exchangeable layered compounds are compounds with a crystalline structure in which planes formed by ionic bonds or the like are stacked parallel to one another with weak bonding forces, and the ions they contain are exchangeable. Most clay minerals are ion-exchangeable layered compounds. These clays, clay minerals, and ion-exchangeable layered compounds are not limited to natural products, and synthetic compounds can also be used.

[0118] Further, as the clay, clay mineral or ion-exchangeable layered compound, clay, clay mineral, hexagonal close packing type, antimony type, CdCl ２ Type, CdI ２ Examples include ionic crystalline compounds having a layered crystal structure such as the crystalline type.

[0119] Examples of such clays and clay minerals include kaolin, bentonite, kibushi clay, gairome clay, allophane, hisingerite, pyrophyllite, ummo group, montmorillonite group, vermiculite, ryokudeite group, palygorskite, kaolinite, nacrite, dickite, halloysite, and the like. Examples of ion-exchange layered compounds include α-Zr(HAsO ４ ) ２ ・H ２ O, α-Zr(HPO ４ ) ２ , α-Zr(KPO ４ ) ２ ・3H ２ O, α-Ti(HPO ４ )２ , α-Ti(HAsO ４ ) ２ ・H ２ O, α-Sn(HPO ４ ) ２ ・H ２ O, γ-Zr(HPO ４ ) ２ , γ-Ti(HPO ４ ) ２ , γ-Ti(NH ４ P.O. ４ ) ２ ・H ２ Examples of suitable salts include crystalline acid salts of polyvalent metals such as 0.

[0120] Such clays, clay minerals, or ion-exchangeable layered compounds preferably have a pore volume of 0.1 cc / g or more, particularly preferably 0.3 to 5 cc / g, having a pore radius of 20 Å or more as measured by mercury intrusion porosimetry. Here, the pore volume is measured by mercury intrusion porosimetry using a mercury porosimeter, and is preferably 0.1 cc / g or more, particularly preferably 0.3 to 5 cc / g. ４ When a carrier having a pore volume of less than 0.1 cc / g with a radius of 20 Å or more is used, it tends to be difficult to obtain high polymerization activity.

[0121] It is also preferable to subject clay and clay minerals to chemical treatment. Examples of chemical treatments that can be used include surface treatments that remove impurities attached to the surface and treatments that affect the crystalline structure of the clay. Specific examples of chemical treatments include acid treatment, alkali treatment, salt treatment, and organic treatment. Acid treatment not only removes surface impurities but also increases the surface area by eluting cations such as Al, Fe, and Mg in the crystalline structure. Alkali treatment destroys the crystalline structure of the clay, resulting in structural changes. Furthermore, salt treatment and organic treatment form ionic complexes, molecular complexes, organic derivatives, etc., which can change the surface area and interlayer distance.

[0122] The ion-exchangeable layered compound may be a layered compound in which the interlayer spacing is expanded by utilizing the ion exchange property and exchanging the exchangeable ions between the layers with other large, bulky ions. Such bulky ions play a role of supporting the layered structure and are usually called pillars. The introduction of another substance between the layers of a layered compound in this way is called intercalation. Examples of the guest compound to be intercalated include TiCl. ４ , ZrCl ４ cationic inorganic compounds such as Ti(OR) ４ , Zr(OR) ４ , PO(OR) ３ , B(OR) ３ metal alkoxides (R is a hydrocarbon group, etc.), [Al １３ O ４ (OH) ２４ ] ７＋ , [Zr ４ (OH) １４ ] ２＋ , [Fe ３ O (OCOCH ３ ) ６ ] ＋ These compounds may be used alone or in combination of two or more. When these compounds are intercalated, Si(OR) ４ , Al(OR) ３ , Ge(OR) ４ Polymers obtained by hydrolysis of metal alkoxides such as SiO ２ It is also possible to allow the pillars to coexist with colloidal inorganic compounds such as those mentioned above. Examples of the pillars include oxides produced by intercalating the metal hydroxide ions between layers and then dehydrating them by heating.

[0123] The clay, clay mineral, and ion-exchangeable layered compound may be used as is, or may be used after treatment such as ball milling or sieving. Furthermore, they may be used after newly adding and adsorbing water or after heat dehydration treatment. Furthermore, they may be used alone or in combination of two or more.

[0124] Examples of organic compounds used as the solid support (S) include granular or particulate solids with particle sizes in the range of 10 to 300 μm. Specific examples of the organic compound include polymers produced primarily from olefins having 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, or polymers or reactants produced primarily from vinylcyclohexane, styrene, and divinylbenzene, as well as granular or particulate solids formed from modified products thereof. Porous oxides are preferred as the solid support (S) from the viewpoint of preventing foreign matter during molding.

[0125] [Component (C)] The olefin polymerization catalyst (X) may preferably further contain component (C), which is at least one compound selected from the group consisting of organometallic compounds (c-1) represented by the following general formulas (3) to (5), organoaluminum oxy compounds (c-2), and compounds (c-3) that react with component (T) to form an ion pair:

[0126] R ａ ｍ Al (OR ｂ ) ｎ H ｐ X ｑ ...(3) In formula (3), R ａ and R ｂ each independently represents a hydrocarbon group having 1 to 15 carbon atoms, X represents a halogen atom, m is a number that satisfies 0<m≦3, n is a number that satisfies 0≦n<3, p is a number that satisfies 0≦p<3, and q is a number that satisfies 0≦q<3, and m+n+p+q=3.

[0127] M ａ AlR ａ ４ ...(4) In formula (4), M ａ represents Li, Na or K, and R ａ represents a hydrocarbon group having 1 to 15 carbon atoms.

[0128] R ａ ｒ M ｂ R ｂ ｓ X ｔ...(5) In formula (5), R ａ and R ｂ each independently represents a hydrocarbon group having 1 to 15 carbon atoms; 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.

[0129] Among the organometallic compounds (c-1), those represented by the above formula (3) are preferred, and specific examples thereof include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum; dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, and dimethylaluminum bromide; alkylaluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide; alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, and ethylaluminum dibromide; Examples of the aluminum hydride include alkyl aluminum hydrides such as dimethyl aluminum hydride, diethyl aluminum hydride, dihydrophenyl aluminum hydride, diisopropyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, diisohexyl aluminum hydride, diphenyl aluminum hydride, dicyclohexyl aluminum hydride, di-sec-heptyl aluminum hydride, and di-sec-nonyl aluminum hydride; and dialkyl aluminum alkoxides such as dimethyl aluminum ethoxide, diethyl aluminum ethoxide, diisopropyl aluminum methoxide, and diisobutyl aluminum ethoxide.

[0130] Examples of the above formula (4) include lithium aluminum hydride, and examples of the above formula (5) include dialkylzinc compounds described in JP-A-2003-171412, etc., which can also be used in combination with a phenol compound, etc.

[0131] The organoaluminum oxy compound (c-2) is preferably an organoaluminum oxy compound prepared from trialkylaluminum or tricycloalkylaluminum, and particularly preferably an aluminoxane prepared from trimethylaluminum or triisobutylaluminum, such as methylaluminoxane. Such organoaluminum oxy compounds may be used alone or in combination of two or more.

[0132] Examples of the compound (c-3) that reacts with the component (T) to form an ion pair include Lewis acids, ionic compounds, borane compounds, and carborane compounds, as well as heteropoly compounds and isopoly compounds, as described in, for example, JP-T-1-501950, JP-T-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, and U.S. Pat. No. 5,321,106.

[0133] In the olefin polymerization catalyst (X), when an organoaluminum oxy compound such as methylaluminoxane is used in combination as a co-catalyst component, not only does the catalyst exhibit extremely high polymerization activity for olefin compounds, but also a solid support component containing the co-catalyst component can be easily prepared by reaction with active hydrogen in the solid support. For this reason, it is preferable that component (C) contains at least an organoaluminum oxy compound (c-2).

[0134] [Method of Use and Order of Addition of Each Component] The olefin polymerization catalyst (X) can be prepared by mixing and contacting component (T) and component (S), and optionally component (C), in an inert hydrocarbon. Focusing on the order of contacting, examples of methods for contacting each component include: (i) a method of contacting component (S) with component (T); (ii) a method of contacting component (S) with component (C), and then with component (T); (iii) a method of contacting component (T) with component (C), and then with component (S); (iv) a method of contacting component (S) with component (C), and then with a mixture of component (T) and component (C); and (v) a method of contacting component (S) with component (C), and then with component (C), and then with a mixture of component (T) and component (C). When a plurality of components (C) are used, the components (C) may be the same or different. Of the above methods, (i), (ii) and (iii) are preferred.

[0135] In each of the methods showing the contact order form described above, in the step including contact of component (S) with component (C) and the step including contact of component (S) with component (T), the coexistence of component (G) suppresses fouling during the polymerization reaction and improves the particle properties of the resulting polymer. As component (G), a compound having a polar functional group can be used, and nonionic surfactants are preferred, with polyalkylene oxide blocks, higher aliphatic amides, polyalkylene oxides, polyalkylene oxide alkyl ethers, alkyldiethanolamines, polyoxyalkylene alkylamines, glycerin fatty acid esters, and N-acylamino acids being more preferred. These may be used alone or in combination of two or more.

[0136] The solvent used in preparing the olefin polymerization catalyst (X) may be an inert hydrocarbon solvent. Specific examples thereof include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane; and mixtures thereof.

[0137] When components (C) and (S) are contacted, a reactive site in component (C) reacts with a reactive site in component (S) to chemically bond them, forming a contact product of components (C) and (S). The contact time between components (C) and (S) is typically 1 minute to 20 hours, preferably 30 minutes to 10 hours, and the contact temperature is typically −50 to 200°C, preferably −20 to 120°C. If the initial contact between components (C) and (S) is carried out too quickly, the heat generated by the reaction and the reaction energy can cause component (S) to disintegrate, deteriorating the morphology of the resulting solid catalyst component. When this solid catalyst component is used in polymerization, poor polymer morphology often makes continuous operation difficult. Therefore, it is preferable to initially contact components (C) and (S) at a lower temperature to suppress the heat generated by the reaction, or to control the heat generated by the reaction and react at a rate that maintains the initial contact temperature. The same applies when components (C) and (S) are contacted first, followed by component (C). The contact mass ratio between component (C) and component (S) (mass of component (C) / mass of component (S)) can be selected arbitrarily, but a higher contact mass ratio allows a larger amount of component (T) to be contacted, thereby improving the catalytic activity per mass of the solid catalyst component.

[0138] The contact mass ratio of component (C) to component (S) [= mass of component (C) / mass of component (S)] is preferably 0.05 to 3.0, particularly preferably 0.1 to 2.0. When the contact product of component (C) and component (S) is contacted with component (T), the contact time is usually 1 minute to 20 hours, preferably 1 minute to 10 hours, and the contact temperature is usually within the range of −50 to 200° C., preferably −50 to 100° C.

[0139] Component (C-1) is used in an amount such that the molar ratio of component (C-1) to the total transition metal atoms (M) in component (T) [(C-1) / M] is generally 0.01 to 100,000, preferably 0.05 to 50,000.

[0140] Component (C-2) is used in an amount such that the molar ratio [(C-2) / M] of component (C-2) (in terms of aluminum atoms) to the total transition metal atoms (M) in component (T) is generally 10 to 500,000, preferably 20 to 100,000.

[0141] Component (C-3) is used in an amount such that the molar ratio of component (C-3) to the total transition metal atoms (M) in component (T) [(C-3) / M] is generally 1 to 10, preferably 1 to 5.

[0142] The ratio of component (C) to the total transition metal atoms (M) in component (T) can be determined by inductively coupled plasma atomic emission spectrometry (ICP analysis). For ethylene polymerization, the olefin polymerization catalyst (X) can be used as is, but it can also be used after prepolymerizing an olefin on this olefin polymerization catalyst to form a prepolymerization catalyst (XP).

[0143] The prepolymerized catalyst (XP) can be prepared by prepolymerizing ethylene or the like in the presence of the olefin polymerization catalyst (X), usually in an inert hydrocarbon solvent, and can be carried out in any of a batch system, a semi-continuous system, or a continuous system, and can be carried out under reduced pressure, normal pressure, or increased pressure. Furthermore, it is desirable to produce the prepolymerized catalyst (XP) by prepolymerization in an amount of 0.01 to 1000 g, preferably 0.1 to 800 g, and more preferably 0.2 to 500 g, per gram of the solid catalyst component.

[0144] The prepolymerized catalyst (XP) produced in the inert hydrocarbon solvent may be separated from the suspension and then resuspended in the inert hydrocarbon, and ethylene may be introduced into the resulting suspension. Alternatively, the suspension may be dried and then ethylene may be introduced.

[0145] The prepolymerization temperature is −20 to 80° C., preferably 0 to 60° C., and the prepolymerization time is about 0.5 to 100 hours, preferably about 1 to 50 hours. For the prepolymerization, an olefin containing ethylene as a main component is preferably used.

[0146] The form of the solid catalyst component used in the prepolymerization can be any of those already mentioned above, without any limitations. If necessary, component (C) is used, and the organometallic compound (c-1) represented by the above formula (3) is preferably used. When component (C) is used, component (C) is used in an amount such that the molar ratio (Al / M) of the aluminum atom (Al) in component (C) to the transition metal atom (M) in component (T) is 0.1 to 10,000, preferably 0.5 to 5,000.

[0147] The concentration of the olefin polymerization catalyst (X) in the prepolymerization system is usually 1 to 1,000 g / L, preferably 10 to 500 g / L, in terms of the olefin polymerization catalyst / polymerization volume ratio. During the prepolymerization, the above-mentioned component (G) may be present together for the purpose of suppressing fouling or improving particle properties.

[0148] Furthermore, for the purpose of improving the fluidity of the prepolymerized catalyst (XP) and suppressing the occurrence of heat spots, sheeting, and polymer lumps during polymerization, the prepolymerized catalyst (XP) may be brought into contact with the component (G) once produced by prepolymerization.

[0149] The temperature when component (G) is contacted is usually −50 to 50° C., preferably −20 to 50° C., and the contact time is usually 1 minute to 20 hours, preferably 5 minutes to 10 hours. When the olefin polymerization catalyst (X) is contacted with component (G), component (G) is used in an amount of 0.1 to 20 parts by mass, preferably 0.3 to 10 parts by mass, and more preferably 0.4 to 5 parts by mass, per 100 parts by mass of the olefin polymerization catalyst (X).

[0150] The olefin polymerization catalyst (X) and component (G) can be mixed and contacted in an inert hydrocarbon solvent, and examples of the inert hydrocarbon solvent include those similar to those described above. In the production method for ethylene-α-olefin copolymer (A) described below, a dried prepolymerized catalyst (XP) (hereinafter also referred to as a "dried prepolymerized catalyst") can be used as the olefin polymerization catalyst (X). Drying of the prepolymerized catalyst (XP) is usually carried out after removing the hydrocarbon dispersant from the obtained suspension of the prepolymerized catalyst by filtration or the like.

[0151] The prepolymerized catalyst (XP) is dried by maintaining the prepolymerized catalyst (XP) at a temperature of 70°C or less, preferably in the range of 20 to 50°C, under a flow of inert gas. The amount of volatile components in the obtained dried prepolymerized catalyst is desirably 2.0% by mass or less, preferably 1.0% by mass or less. The amount of volatile components in the dried prepolymerized catalyst is better as small as possible, and there is no particular lower limit, but in practice it is 0.001% by mass. The drying time is usually 1 to 48 hours, depending on the drying temperature.

[0152] The dry prepolymerized catalyst has excellent fluidity and can be stably supplied to a polymerization reactor. Furthermore, the use of the dry prepolymerized catalyst can stably carry out polymerization because it is not necessary to entrain the solvent used for suspension in the gas-phase polymerization system.

[0153] A preferred method for producing the ethylene-α-olefin copolymer (A) is to obtain the ethylene-α-olefin copolymer (A) by polymerizing (homopolymerization or copolymerization) ethylene in the presence of the above-mentioned olefin polymerization catalyst (X). By using the olefin polymerization catalyst (X), it is possible to efficiently produce a low-density ethylene polymer having numerous long-chain branches, which has high polymerization activity and is excellent in moldability and mechanical strength. The ethylene-α-olefin copolymer (A) preferably has an ethylene content of 10 mol % or more, more preferably 50 mol % or more.

[0154] The polymerization method for the ethylene-α-olefin copolymer (A) can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization, or a gas phase polymerization method, but in the suspension polymerization method and the gas phase polymerization method, it is preferable to use the above-mentioned prepolymerization catalyst (XP).

[0155] Specific examples of inert hydrocarbon solvents used in liquid phase polymerization include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, kerosene, etc.; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, etc.; aromatic hydrocarbons such as benzene, toluene, xylene, etc.; halogenated hydrocarbons such as ethylene chloride, chlorobenzene, dichloromethane, etc.; and mixtures thereof. In liquid phase polymerization, the olefin itself can also be used as the solvent.

[0156] When ethylene is polymerized using the above-mentioned olefin polymerization catalyst, the component (T) of the olefin polymerization catalyst (X) is usually used in an amount of 1×10 per liter of reaction volume. －１２ ~1 x 10 －１ mole, preferably 1 x 10 －８ ~1 x 10 －２ The olefin polymerization catalyst (X) preferably contains the component (C), and more preferably contains an organoaluminum compound represented by the formula (3) in (c-1).

[0157] The polymerization temperature of ethylene using the prepolymerization catalyst (XP) is usually in the range of −50 to +200° C., preferably 0 to 170° C., and particularly preferably 60 to 170° C. The polymerization pressure is usually in the range of atmospheric pressure to 100 kgf / cm. ２ , preferably atmospheric pressure to 50 kgf / cm ２The polymerization reaction is carried out under the conditions of (a) and (b) above, and can be carried out by any of batch, semi-continuous, and continuous methods. Furthermore, the polymerization can be carried out in two or more stages with different reaction conditions. The molecular weight of the resulting polymer can be adjusted by adding hydrogen to the polymerization system or by changing the polymerization temperature. Generally, the more low-molecular-weight components there are, the more they adhere to the walls and agitator blades of the polymerization reactor, which can increase the burden on the cleaning process and lead to reduced productivity. During polymerization, component (G) can be present in the olefin polymerization catalyst (X) to suppress fouling or improve particle properties.

[0158] The α-olefin monomer supplied together with ethylene to the copolymerization reaction is an α-olefin having 4 to 10 carbon atoms, and is preferably one or more monomers selected from α-olefins having 6 to 10 carbon atoms. Specific examples of the α-olefin having 4 to 10 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. Monomers other than ethylene and α-olefins having 4 to 10 carbon atoms may or may not be supplied within a range that does not impair the effects of the present invention.

[0159] <Other Thermoplastic Resins> The foam of the present invention may contain a thermoplastic resin other than the ethylene-α-olefin copolymer (A) (hereinafter referred to as "other thermoplastic resin"). Examples of other thermoplastic resins include crystalline thermoplastic resins such as polyolefins other than the ethylene-α-olefin copolymer (A) (hereinafter also referred to as "other polyolefins"), ethylene-unsaturated ester copolymers, polyamides, polyesters, and polyacetals; and non-crystalline thermoplastic resins such as polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS), polycarbonates, polyphenylene oxides, and polyacrylates. Polyvinyl chloride is also preferred. The other thermoplastic resin may be polyester, polyamide, polyurethane, polylactic acid, or polycarbonate containing a biomass-derived monomer or a chemically recycled monomer.

[0160] Examples of the other polyolefins include ethylene-α-olefin copolymers other than the ethylene-α-olefin copolymer (A), propylene polymers, high-density polyethylene, amorphous or low-crystalline α-olefin copolymers, etc., and among these, amorphous or low-crystalline α-olefin copolymers, ethylene-α-olefin copolymers other than the ethylene-α-olefin copolymer (A), and high-density polyethylene are preferred. Examples of the amorphous or low-crystalline α-olefin copolymers include ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, propylene-1-butene copolymers, and ethylene-propylene-1-butene copolymers. Among these, ethylene-propylene copolymers, ethylene-1-butene copolymers, and ethylene-propylene-1-butene copolymers are particularly preferred.

[0161] The amorphous or low-crystalline α-olefin copolymer may be a synthetic product or a commercially available product. Commercially available amorphous or low-crystalline α-olefin copolymers include the Tafmer (registered trademark) P series, Tafmer A series, Tafmer DF series, Tafmer PN series, and Tafmer BL series manufactured by Mitsui Chemicals, Inc. The ethylene-α-olefin copolymer other than the ethylene-α-olefin copolymer (A) may be a synthetic product or a commercially available product. Commercially available ethylene-α-olefin copolymers other than the ethylene-α-olefin copolymer (A) include the Evolue (registered trademark) series, Ultzex ​​(registered trademark) series, and Neozex (registered trademark) series manufactured by Prime Polymer Co., Ltd. The high-density polyethylene may be a synthetic product or a commercially available product. Commercially available high-density polyethylene products include the Hi-Zex (registered trademark) series and Evolue (registered trademark) H series manufactured by Prime Polymer Co., Ltd.

[0162] Each of the other polyolefins may be a polyolefin containing a biomass-derived monomer. The monomers constituting the other polyolefins may be only biomass-derived monomers, only fossil fuel-derived monomers, or may contain both biomass-derived monomers and fossil fuel-derived monomers. Each of the other polyolefins may be a polyolefin containing a chemically recycled monomer. The monomers constituting the other polyolefins may be only chemically recycled monomers, only fossil fuel-derived monomers, or may contain chemically recycled monomers, fossil fuel-derived monomers, and / or biomass-derived monomers.

[0163] The blend ratio of the ethylene-α-olefin copolymer (A) to the other thermoplastic resin is not particularly limited, but the mass fraction (W Ａ ) and the mass fraction (W Ｂ ) is 100% by mass, and preferably W Ａ is in the range of 50 to 99 mass %, and more preferably W Ａ When the blend ratio of the ethylene-α-olefin copolymer (A) to the other thermoplastic resin is within the above range, the foam of the present invention has a good balance between mechanical strength and heat resistance.

[0164] <Additives> The foam of the present invention may contain, as necessary, additives such as a crosslinking agent, a crosslinking aid, a foaming agent, a foaming aid, a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an antislip agent, an antiblocking agent, an antifogging agent, a lubricant, a pigment, a dye, a plasticizer, an antioxidant, a hydrochloric acid absorber, an antioxidant, etc. These additives may be used alone or in combination of two or more.

[0165] The total amount of the additives is generally 20 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the ethylene-α-olefin copolymer (A).

[0166] The foam of the present invention may contain a crosslinking agent, if necessary. Examples of crosslinking agents include sulfur-based compounds, organic peroxides, phenolic resins, hydrosilicone-based compounds, amino resins, quinone or its derivatives, amine-based compounds, azo-based compounds, epoxy-based compounds, isocyanates, and quinone dioxime-based crosslinking agents such as p-quinone dioxime. Among these crosslinking agents, sulfur-based compounds, organic peroxides, and phenolic resins are preferred.

[0167] When the crosslinking agent is an organic peroxide, examples thereof include dicumyl peroxide, di-tert-butyl peroxide, 2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

[0168] The foam of the present invention may contain a crosslinking aid, if necessary. The crosslinking aid is a compound that acts as a crosslinking reaction catalyst when blended together with the crosslinking agent when the ethylene copolymer is crosslinked by heating.

[0169] Examples of the crosslinking aid include acrylic crosslinking aids such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate, allyl crosslinking aids such as diallyl phthalate and triallyl isocyanurate, other maleimide crosslinking aids, and divinylbenzene. Among these, allyl crosslinking aids are preferred, and triallyl isocyanurate is more preferred.

[0170] Specific examples of the foaming agent include the foaming agents described in the foam production method described below.

[0171] The foam of the present invention may contain a foaming aid together with the foaming agent, if necessary. The foaming aid has the effect of lowering the decomposition temperature of the foaming agent, accelerating decomposition, and homogenizing the bubbles. Examples of the foaming aid include zinc oxide, zinc stearate, organic acids such as salicylic acid, phthalic acid, stearic acid, and oxalic acid, urea, and derivatives thereof.

[0172] [Foam] The foam of the present invention can be produced by foaming the ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A). The foam may be a non-crosslinked foam or a crosslinked foam, but is preferably a crosslinked foam.

[0173] <Method of Manufacturing Foam> Any method may be used to manufacture the foam as long as it can produce a foam. For example, the following manufacturing method may be used.

[0174] (1) Extrusion Foaming Method The ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A) is placed in the hopper of an extruder and extruded at a temperature near its melting point. A physical foaming agent is injected through a pressure hole provided midway through the extruder, and the extruded material is extruded through a die having a desired shape, thereby continuously producing a foam. Examples of physical foaming agents that can be used include volatile foaming agents such as chlorofluorocarbons, butane, pentane, hexane, and cyclohexane, and inorganic gas foaming agents such as nitrogen, air, water, and carbon dioxide. Furthermore, a bubble nucleating agent such as calcium carbonate, talc, clay, or magnesium oxide may be added during extrusion foaming.

[0175] The blending ratio of the physical blowing agent is typically 0.5 to 60 parts by mass, preferably 0.5 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A). If the blending ratio of the physical blowing agent is below this range, the expansion ratio of the foam tends to decrease, while if it exceeds this range, the strength of the foam tends to decrease. The blending ratio of the bubble nucleating agent is typically 0.5 to 60 parts by mass, preferably 0.5 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A). If the blending ratio of the bubble nucleating agent is below this range, the expansion ratio of the foam tends to decrease, while if it exceeds this range, the strength of the foam tends to decrease.

[0176] (2) Foaming Method Using a Thermally Decomposable Foaming Agent The ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A), a thermally decomposable foaming agent, and, if necessary, other additives are melt-kneaded at a temperature below the decomposition temperature of the thermally decomposable foaming agent using a kneading device such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader mixer, or a roll, and then the mixture is generally molded into a sheet.

[0177] The sheet is then heated to a temperature equal to or higher than the decomposition temperature of the foaming agent to produce a foam. There are no particular restrictions on the thermally decomposable foaming agent, as long as it decomposes to generate gas when the resin is heated and melted, and general organic or inorganic chemical foaming agents can be used.

[0178] Specific examples include azo compounds such as azodicarbonamide, 2,2'-azobisisobutyronitrile, azohexahydrobenzonitrile, and diazoaminobenzene; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, benzene-1,3-sulfonyl hydrazide, diphenylsulfone-3,3'-disulfonyl hydrazide, diphenyloxide-4,4'-disulfonyl hydrazide, 4,4'-oxybis(benzenesulfonyl hydrazide), and p-toluenesulfonyl hydrazide; nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dinitroso-N,N'-dimethylphthalamide; azide compounds such as terephthalazide and p-t-butylbenzazide; and carbonate compounds such as sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate, and at least one of these is used. Among these, azodicarbonamide, 4,4'-oxybis(benzenesulfonylhydrazide) and carbonic acid compounds are preferred.

[0179] The blending ratio of the thermally decomposable foaming agent is usually 1 to 50 parts by mass, and preferably 2 to 25 parts by mass, per 100 parts by mass of the ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A). If the blending ratio of the thermally decomposable foaming agent is below the above range, the expansion ratio of the foam tends to decrease, whereas if it exceeds the above range, the strength of the foam tends to decrease.

[0180] (3) Foaming method in a pressure vessel The ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A) is molded into a shape such as a sheet or block using a press or extruder. The molded product is then placed in a pressure vessel, and the physical blowing agent is thoroughly dissolved in the molded product, followed by depressurization to produce a foam. Alternatively, the pressure vessel containing the molded product may be filled with a physical blowing agent at room temperature, pressurized, and after depressurization, removed from the vessel and heated in an oil bath or oven to foam the product.

[0181] (4) Foaming Method Using a Crosslinking Agent In the present invention, a crosslinked foam can be obtained by crosslinking the ethylene-α-olefin copolymer (A) or a resin composition containing the copolymer (A) in advance. Common crosslinking methods include crosslinking by thermal decomposition of a crosslinking agent such as an organic peroxide in the resin, crosslinking by irradiation with ionizing radiation, crosslinking by irradiation with ionizing radiation in the presence of a polyfunctional monomer, and silane crosslinking. There are no particular limitations on the method for producing the crosslinked foam, but it can be produced, for example, by the following method.

[0182] First, a resin composition comprising the ethylene-α-olefin copolymer (A), a blowing agent, and a crosslinking agent such as an organic peroxide is formed into a sheet using a calendar molding machine, a press molding machine, or a T-die extruder. During this sheet molding, it is preferable to mold the sheet at a temperature equal to or lower than the decomposition temperature of the blowing agent and the crosslinking agent such as an organic peroxide, and specifically, it is preferable to mold the sheet under temperature conditions, for example, 100 to 130°C, at which the resin components are in a molten state.

[0183] The resin composition sheet obtained by the above method is cut into pieces in the range of 1.0 to 1.2 volume % relative to the volume of the mold, and inserted into a mold maintained at 130 to 200°C, and the mold clamping pressure is set to 30 to 300 kgf / cm. ２ A primary foam (crosslinked foam) is produced under the conditions of a holding time of 10 to 90 minutes. Note that the holding time depends on the thickness of the mold, and can be increased or decreased beyond this range as appropriate.

[0184] The shape of the mold for the crosslinked foam is not particularly limited, but a mold having a shape that can produce a sheet is usually used. This mold preferably has a completely sealed structure so that gas generated during decomposition of the molten resin and the foaming agent does not escape. Furthermore, a mold frame with a tapered inner surface is preferred from the viewpoint of mold releasability of the resin.

[0185] In addition to the above-mentioned method, the crosslinked foam according to one embodiment of the present invention can also be produced by an extrusion foaming method in which a resin composition containing the ethylene-α-olefin copolymer (A) is extruded from an extruder and released into the atmosphere to simultaneously foam.

[0186] Another example is a method (injection foaming method) in which a resin composition containing the ethylene-α-olefin copolymer (A) is injected into a mold at a temperature equal to or lower than the decomposition temperature of the foaming agent and the crosslinking agent, and crosslinked and foamed while maintaining the temperature in the mold at, for example, about 130°C to 200°C.

[0187] Furthermore, to obtain a crosslinked foam by a crosslinking method using ionizing radiation, for example, a resin composition containing an organic pyrolytic foaming agent and an ethylene-α-olefin copolymer (A) is melt-kneaded at a temperature below the decomposition temperature of the organic pyrolytic foaming agent, and the resulting kneaded mixture is molded into, for example, a sheet to obtain an uncrosslinked sheet-like foam. The resulting uncrosslinked sheet-like foam is then irradiated with a predetermined amount of ionizing radiation to crosslink the sheet-like foam, and the resulting crosslinked sheet-like foam is then further heated to a temperature equal to or higher than the decomposition temperature of the organic pyrolytic foaming agent, as necessary, to obtain a crosslinked sheet-like foam. In other words, a foam can be produced by heat treatment. Examples of ionizing radiation that can be used include α-rays, β-rays, γ-rays, electron beams, neutron beams, and X-rays. Among these, γ-rays of cobalt-60 and electron beams are preferably used.

[0188] Examples of the product shape of the foam include a sheet, a thick board, a net, and a molded product. The crosslinked foam obtained as described above can be given a predetermined shape by compression molding to produce a secondary foam. The compression molding conditions are, for example, a mold temperature of 130 to 200°C and a mold clamping pressure of 30 to 300 kgf / cm. ２ The compression time is in the range of 5 to 60 minutes, and the compression ratio is in the range of 1.1 to 3.0.

[0189] Among the above-mentioned production methods, the foam of the present invention is preferably a crosslinked foam.

[0190] The foam of the present invention is suitably used for flooring materials, building materials, packaging materials, automobile interior materials, daily necessities, mats, seats, sporting goods, and the like.

[0191] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples.

[0192] [Measurement and Evaluation of Physical Properties of Raw Materials] In the following examples, various physical properties of the ethylene-α-olefin copolymer (A) were measured by the methods described in [Mode for Carrying Out the Invention].

[0193] [Measurement of Foam] <Expansion Ratio> The specific gravity of the foam was measured according to JIS K7222, and the expansion ratio of each foam was calculated by dividing the specific gravity of the ethylene-α-olefin copolymer (A) used in the foam by the specific gravity of the foam. For crosslinked foams described below, samples were taken from 20 mm or more inward from each of the four sides of the plane of the largest area, and from the surface of the parallel planes with the skin remaining. For foams molded into a sheet by extrusion foaming (non-crosslinked foams), samples were taken from 20 mm or more inward from both ends of the sheet.

[0194] <Tear Strength> Tear strength was measured at a test speed of 500 mm / min in an environment of 23° C. in accordance with JIS K 6252. For foams (non-crosslinked foams) molded into sheets by extrusion foaming, tear strength was measured in both the take-up direction (MD) and the transverse direction (TD).

[0195] <Tensile Breaking Stress> Tensile breaking stress was measured at a test speed of 200 mm / min in an environment of 23° C. in accordance with JIS K 6301. For foams (non-crosslinked foams) molded into sheets by extrusion foaming, the tensile breaking stress was measured in both the take-up direction (MD) and the transverse direction (TD).

[0196] <Heat shrinkage (110°C x 22h)> The molded foam (crosslinked foam) was heat-treated in a 110°C environment for 22 hours, removed from a 23°C environment, and measured 30 minutes later. The heat shrinkage (Sh) (%) was calculated using the following formula: Sh = s1 / s0 x 100, where s0 is the longitudinal length of the sample before heat treatment (mm), and s1 is the longitudinal length of the sample after heat treatment (mm).

[0197] <Heat shrinkage (110°C x 30 min)> A foam (non-crosslinked foam) molded into a sheet by the extrusion foaming method was cut into strips of 10 mm width x 100 mm length to obtain MD test pieces and TD test pieces. Each test piece was placed in an air oven at 110°C and heated for 30 minutes, and the length of the test piece was confirmed. The heat shrinkage in the MD direction and the TD direction was calculated based on the following formula: Heat shrinkage in the MD direction (%) = {length of the MD test piece before heating (100 mm) - length of the MD test piece after heating (mm)} / 100 mm x 100 Heat shrinkage in the TD direction (%) = {length of the TD test piece before heating (100 mm) - length of the TD test piece after heating (mm)} / 100 mm x 100

[0198] [Raw Materials Used] The transition metal compound (T) and component (G) used in the examples are as follows: Transition metal compound (T-1): dimethylsilylene(2-indenyl)(4-(3,5-di-tert-butyl-4-methoxyphenyl)-7-methoxy-1-indenyl)zirconium dichloride [synthesized by the method described in JP 2019-059933 A] Component (G-1): lauryldiethanolamine (manufactured by Kao Corporation)

[0199] <Synthesis of Prepolymerized Catalyst (XP-1)> A 270 L reactor equipped with a stirrer was charged with silica (average particle size: 70 μm, specific surface area: 340 m) manufactured by Fuji Silysia Ltd. as a solid carrier (S) under a nitrogen atmosphere. ２ / g, pore volume 1.3cm ３10 kg of the resulting methylaluminoxane (10 kg / g, calcined at 250°C) was suspended in 77 L of toluene and then cooled to 0-5°C. To this suspension, 20.4 L of a toluene solution of methylaluminoxane (3.5 mol / L in terms of Al atoms) was added dropwise over 30 minutes. The temperature in the system was maintained at 0-5°C. After reacting for 30 minutes at 0-5°C, the temperature was raised to 95-100°C over approximately 1.5 hours and then reacted for 4 hours at 95-100°C. The temperature was then lowered to room temperature, the supernatant was removed by decantation, and the mixture was washed twice with toluene to prepare a toluene slurry with a total volume of 58.0 L. A portion of the resulting slurry component was sampled and its concentration was examined; the slurry concentration was 248.0 g / L and the Al concentration was 1.21 mol / L.

[0200] Next, 6.1 L of the toluene slurry obtained above and 21.9 L of toluene were charged into a 114 L reactor equipped with a stirrer and thoroughly purged with nitrogen, and 5.4 L of an 8 mM toluene solution of transition metal compound (T-1) was added. After contact for 1 hour at a system temperature of 20 to 25°C, the supernatant was removed by decantation and the mixture was washed twice with hexane to prepare a slurry with a total volume of 30.9 L. While adjusting the temperature of the resulting slurry to 10 to 15°C, 3.1 L of a 0.92 M hexane solution of diisobutylaluminum hydride was added, and the supply of ethylene gas was started at a flow rate of 0.74 kg / h. After adding 34.3 mL of 1-hexene, the temperature was increased, and while adjusting the system temperature to 32 to 38°C, 34.3 mL of 1-hexene was added every hour for a total of five times. Six hours after the start of ethylene supply, when the ethylene supply amount reached 4.5 kg, the ethylene supply was stopped. Thereafter, the system was thoroughly purged with nitrogen, the supernatant was removed by decantation, and the mixture was washed four times with hexane to prepare a slurry with a total volume of 21.9 L. While maintaining the obtained slurry at 35 to 40°C, 6.1 L of a 10 g / L hexane solution of component (G-1) was added and the mixture was allowed to come into contact for 2 hours. The entire amount of the obtained slurry was placed in an evaporative dryer equipped with a stirrer and having an internal volume of 43 L under a nitrogen atmosphere, and the pressure inside the dryer was reduced to -68 kPaG over approximately 60 minutes. Once the pressure reached -68 kPaG, the mixture was vacuum dried for approximately 4.3 hours to remove hexane and volatiles from the prepolymerized catalyst components. The pressure was further reduced to -100 kPaG, and once the pressure reached -100 kPaG, the mixture was vacuum dried for 8 hours to obtain 6.2 kg of prepolymerized catalyst (XP-1). A portion of the resulting prepolymerized catalyst (XP-1) was sampled and its composition was examined, revealing that it contained 0.56 mg of Zr atoms per 1 g of the prepolymerized catalyst component.

[0201] <Production of Ethylene-α-Olefin Copolymer (A)> [Production Example 1] (Production of Ethylene-α-Olefin Copolymer (A-1)) An ethylene polymer (ethylene-α-olefin copolymer (A-1)) was produced by a gas-phase polymerization process using a fluidized-bed gas-phase polymerization reactor. 24 kg of spherical ethylene polymer particles having an average particle size of 900 μm were previously introduced into the reactor, and nitrogen was supplied to form a fluidized bed. After that, ethylene, hydrogen, 1-hexene, a prepolymerization catalyst (XP-1), Electrostripper (registered trademark) EA (manufactured by Kao Corporation), and the like were continuously supplied so as to reach a steady state under the polymerization conditions shown in Table 8. The polymerization product was continuously withdrawn from the reactor and dried in a dryer to obtain a powder of ethylene-α-olefin copolymer (A-1). To the obtained powder of copolymer (A-1), 850 ppm of Sumilizer GP (manufactured by Sumitomo Chemical Co., Ltd.) and 210 ppm of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd.) were added as heat stabilizers, and the mixture was melt-kneaded using a 46 mmφ twin-screw co-rotating extruder manufactured by Ikegai Corporation at a set temperature of 200°C and a screw rotation speed of 300 rpm. The mixture was then extruded into a strand shape and cut to prepare pellets.

[0202] [Production Examples 2 to 6] (Production of ethylene-α-olefin copolymers (A-2) to (A-6)) Powders of ethylene-α-olefin copolymers (A-2) to (A-6) were obtained in the same manner as in Production Example 1, except that the polymerization conditions were changed as shown in Table 8. Pellets were prepared using the obtained powders of copolymers (A-2) to (A-6) in the same manner as in Production Example 1. Table 8 lists Chemistat (registered trademark) 2500 (manufactured by Sanyo Chemical Industries, Ltd.) as a component that was not used in Production Example 1.

[0203] Production Examples 7 and 8 Production of Ethylene-α-olefin Copolymers (A-7) to (A-8) Powders of ethylene-α-olefin copolymers (A-7) to (A-8) were obtained in the same manner as in Production Example 1, except that the polymerization conditions were changed as shown in Table 8. The obtained powder of copolymer (A-7) was melt-kneaded using a 100 mmφ twin-screw counter-rotating extruder manufactured by Kobe Steel, Ltd. at an extrusion rate of 364 kg / h and a screw rotation speed of 351 rpm, and then extruded into a strand shape and cut to prepare pellets. Pellets were also prepared from the powder of copolymer (A-8) in the same manner as above.

[0204] [Production Examples 9 and 10] (Production of ethylene-α-olefin copolymers (A-9) to (A-10)) Powders of ethylene-α-olefin copolymers (A-9) to (A-10) were obtained in the same manner as in Production Example 1, except that the polymerization conditions were changed as shown in Table 8. Pellets were prepared using the obtained powders of copolymers (A-9) to (A-10), respectively, in the same manner as in Production Example 1.

[0205]

[0206] <Measurement of Physical Properties of Polymer> [Ethylene-α-olefin Copolymers (A-1) to (A-10)] The pellets prepared above were used to measure the physical properties. The measurement results are shown in Table 9.

[0207] [Ethylene-based polymer (a-11)] High-pressure low-density polyethylene ("Suntech M1820" manufactured by Asahi Kasei Corporation) was used as the ethylene-based polymer (a-11). The measurement results of the ethylene-based polymer (a-11) are shown in Table 9.

[0208]

[0209] In Table 9 above, the total heat of fusion of the melting peak is shown as "heat of fusion_total", and the heat of fusion at 115°C or higher is shown as "heat of fusion ≥ 115°C".

[0210] <Foam Evaluation> Crosslinked Foam [Example 1] A crosslinking agent containing 1.05 parts by mass of dicumyl peroxide (DCP), a crosslinking aid containing 0.1 parts by mass of triallyl isocyanurate (TAIC) [product name M-60 (TAIC content 60%), manufactured by Nippon Kasei Co., Ltd.], a foaming agent containing 2.5 parts by mass of azodicarbonamide (ADCA), and a foaming agent containing titanium oxide (TiO ２ A resin composition obtained by blending 3 parts by mass of PEG-100 (aluminum phosphate copolymer), 3 parts by mass of zinc oxide (ZnO), and 1 part by mass of stearic acid (St) was kneaded with a roll at a roll surface temperature of 120°C for 10 minutes and formed into a sheet.

[0211] The obtained 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 A crosslinked foam was obtained by applying pressure and heating for 15 minutes under conditions of 170° C. The crosslinked foam expanded when the pressure was released, and had a thickness of 15 mm or more.

[0212] The expansion ratio, heat shrinkage (110°C x 22 h), tear strength and tensile breaking stress of the resulting crosslinked foam were measured according to the above-mentioned methods. The results are shown in Table 10.

[0213] [Example 2] Except for using 5.0 parts by mass of azodicarbonamide (ADCA), a crosslinked foam was produced and its physical properties were measured in the same manner as in Example 1. The results are shown in Table 10.

[0214] [Example 3] A crosslinked foam was produced and its physical properties were measured in the same manner as in Example 1, except that 100 parts by mass of ethylene-α-olefin copolymer (A-8) pellets were used instead of 100 parts by mass of ethylene-α-olefin copolymer (A-7) pellets. The results are shown in Table 10.

[0215] [Example 4] A crosslinked foam was produced and its physical properties were measured in the same manner as in Example 2, except that 100 parts by mass of ethylene-α-olefin copolymer (A-8) pellets were used instead of 100 parts by mass of ethylene-α-olefin copolymer (A-7) pellets. The results are shown in Table 10.

[0216] [Example 5] A crosslinked foam was produced and its physical properties were measured in the same manner as in Example 2, except that 100 parts by mass of ethylene-α-olefin copolymer (A-10) pellets were used instead of 100 parts by mass of ethylene-α-olefin copolymer (A-7) pellets. The results are shown in Table 10.

[0217] A crosslinked foam was produced and its physical properties were measured in the same manner as in Example 1, except that 100 parts by mass of ethylene polymer (a-11) pellets were used instead of 100 parts by mass of ethylene-α-olefin copolymer (A-7) pellets and 0.75 parts by mass of dicumyl peroxide (DCP). The results are shown in Table 10.

[0218] [Comparative Example 2] Except for using 5.0 parts by mass of azodicarbonamide (ADCA), a crosslinked foam was produced and its physical properties were measured in the same manner as in Comparative Example 1. The results are shown in Table 10.

[0219]

[0220] Non-crosslinked foam [Example 6] 20 parts by mass of a calcium carbonate masterbatch [trade name MFP-CLLAR (calcium carbonate content 80%), manufactured by Sanfuku Kogyo Co., Ltd.] as a bubble nucleating agent and 2 parts by mass of an inorganic gas-based blowing agent masterbatch [trade name Polythrene EE205, manufactured by Eiwa Chemical Industry Co., Ltd.] as a foaming agent were blended with 100 parts by mass of the ethylene-α-olefin copolymer (A-7) pellets prepared above, and the mixture was dry-blended to obtain a resin composition. The resulting resin composition was subjected to extrusion foaming using the apparatus shown in Figure 1 under the following conditions to produce a sheet-like non-crosslinked foam. The expansion ratio, heat shrinkage (110°C x 30 min), tear strength, and tensile stress at break of the resulting non-crosslinked foam were measured according to the methods described above. The results are shown in Table 11. (Conditions) Extruder: Twin-screw extruder TEM-41SS (product name) manufactured by Shibaura Machine Co., Ltd. Die shape: Annular die Die dimensions: 65 mm Extrusion rate: 40 kg / h Screw rotation speed: 100 rpm Cylinder set temperature: 160°C Die set temperature: 160°C Carbon dioxide gas supply rate: 150 g / h

[0221] [Example 7] A non-crosslinked foam was produced and its physical properties were measured in the same manner as in Example 6, except that the carbon dioxide gas supply rate was changed to 200 g / h. The results are shown in Table 11.

[0222] [Example 8] A non-crosslinked foam was produced and its physical properties were measured in the same manner as in Example 6, except that the carbon dioxide gas supply rate was changed to 250 g / h. The results are shown in Table 11.

[0223] A non-crosslinked foam was produced and its physical properties were measured in the same manner as in Example 8, except that 100 parts by mass of ethylene polymer (a-11) pellets were used instead of 100 parts by mass of ethylene-α-olefin copolymer (A-7) pellets, and the cylinder temperature and die temperature were set to 130° C. The results are shown in Table 11.

[0224]

[0225] The ethylene polymer (a-11) used in Comparative Examples 1 to 3 was a high-pressure low-density polyethylene. The melting curve of the polymer (a-11) obtained by differential scanning calorimetry (DSC) showed a single peak, and the heat of fusion at 115°C or higher per 5 mg of the measurement sample was outside the range of "10 mJ or more and 200 mJ or less" specified in requirement (5).

[0226] As shown in Table 10, the crosslinked foams containing the ethylene-α-olefin copolymers of Examples 1 to 5 have a better balance of mechanical strength and heat resistance than the crosslinked foams containing the ethylene polymer (a-11) of Comparative Examples 1 and 2. Furthermore, as shown in Table 11, the non-crosslinked foams containing the ethylene-α-olefin copolymers of Examples 6 to 8 have a better mechanical strength and heat resistance than the non-crosslinked foam of Comparative Example 3 containing the ethylene polymer (a-11).

[0227] The foam of the present invention is suitably used for flooring materials, building materials, packaging materials, automobile interior materials, daily necessities, mats, seats, sporting goods, and the like.

[0228] REFERENCE SIGNS LIST 100 Extrusion foam molding machine 110 Hopper 120 Cylinder 130 Carbon dioxide gas introduction path 140 Foam 150 Mandrel 160 Cutting member 170 Winding roller

Claims

1. A foam comprising an ethylene-α-olefin copolymer (A) or a crosslinked product of said copolymer (A), which is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and satisfies the following requirements (1) to (5): (1) A density of 900 kg / m ３ More than 935kg / m ３ (2) The melt flow rate (MFR) at 190°C under a load of 2.16 kg is in the range of 0.01 g / 10 min to 10.0 g / 10 min. (3) The melt tension [MT (g)] at 190°C and the shear viscosity [η * (P)] and the ratio [MT / η * (g / P)] is 1.20 × 10 －４ Above 4.00 x 10 －４ (4) Zero shear viscosity at 200°C [η ０ (P)] and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1): －１３ ×Mw ３．４ ≦η ０ ≦2.5×10 －１３ ×Mw ３．４ ...(Eq-1) (5) The melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks, and the heat of fusion at 115°C or higher per 5 mg of the measurement sample is in the range of 10 mJ or more and 200 mJ or less.

2. The foam according to claim 1, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirements (6) and (7): (6) The intrinsic viscosity [η] (dl / g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-2): 0.70×10 －４ ×Mw ０．７７６ ≦ [η]≦ 1.65×10 －４ ×Mw ０．７７６ ...(Eq-2) (7) １ The total of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin per 1000 carbon atoms (units / 1000C) measured by H-NMR is in the range of 0.1 or more and 1.0 or less.

3. The foam according to claim 1 or 2, further comprising a thermoplastic resin other than the ethylene-α-olefin copolymer (A).

4. The foam of claim 1 or 2, wherein the foam is a crosslinked foam.

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