JP4986392B2 - Ethylene copolymer, resin composition, foamed molded product and multilayer molded product - Google Patents

Description

  The present invention relates to an ethylene copolymer for foam molding, a resin composition for foam molding, a foam molded body, and a multilayer molded body.

  Multi-layer molded products obtained by laminating a foam molded product made of polyethylene resin and a molded product made of non-polyethylene resin are widely used as daily goods, flooring materials, sound insulation materials, heat insulating materials, for example, , A shoe sole formed by laminating an upper bottom (mid sole) and a lower bottom (outer sole) obtained by cutting a molded product obtained by pressure-foaming molding of an ethylene-vinyl acetate copolymer into a desired shape, ethylene- An upper bottom formed by pressure-foaming a member obtained by cutting a molded body obtained by pressure-foaming molding of vinyl acetate copolymer into a desired shape, and a lower bottom made of styrene-butadiene rubber, etc. A shoe sole formed by laminating and the like is known (see, for example, Patent Document 1).

JP-A-11-151101

However, an upper bottom obtained by cutting a molded body obtained by pressure-foaming molding of an ethylene-vinyl acetate copolymer into a desired shape, and a lower bottom made of a material different from the upper bottom (for example, polyvinyl chloride resin). The shoe sole formed by laminating the foamed layer made of an ethylene-vinyl acetate copolymer has a uniform cell property, and thus has an excellent appearance, but in the interlayer adhesion between the foamed layer and the layer made of the different material. It was not satisfactory enough.
Under such circumstances, the problem to be solved by the present invention is to laminate a foam layer made of a member obtained by cutting a pressure-foamed molded article into a desired shape and a layer made of a material different from the member. An ethylene-based copolymer for pressure-foaming molding, which provides a multilayer molded body excellent in interlayer adhesion between the foamed layer and the layer made of the different material and the appearance of the foamed layer, the ethylene-based copolymer RESIN COMPOSITION CONTAINING COPOLYMER AND FLOATING AGENT, PRESSURE FOAM MOLDED BODY FORMED BY PRESSURE FOAM MOLDING OF THE RESIN COMPOSITION, AND FOAM LAYER COMPRISING THE PRESSURE FOAMED MOLDED BODY AND ETHYLENE COPOLYMER An object of the present invention is to provide a multilayer molded body formed by laminating layers made of different materials.

That is, the first of the present invention is an ethylene copolymer having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms, wherein the melt flow rate is This relates to an ethylene copolymer for pressure foam molding having a flow activation energy of 40 kJ / mol or more at 0.05 to 0.8 g / 10 min.
A second aspect of the present invention relates to a pressure foam molding resin composition containing the ethylene copolymer and a foaming agent.
A third aspect of the present invention relates to a pressure foam molded article obtained by pressure foam molding the above resin composition for pressure foam molding.
A fourth aspect of the present invention relates to a multilayer molded body formed by laminating a layer made of the above-mentioned pressure-foamed molded body and a layer made of a material other than the ethylene-based resin.

  According to the present invention, there is provided a multilayer molded body obtained by laminating a foamed layer made of a member obtained by cutting a pressure-foamed molded body into a desired shape, and a layer made of a material different from the member, An ethylene-based copolymer for pressure-foaming molding that provides a multilayer molded article having excellent interlayer adhesion to the layers made of different materials and the appearance of the foamed layer, and a resin composition containing the ethylene-based copolymer and a foaming agent A foamed product formed by pressurizing and foaming the resin composition, and a foamed layer made of the pressured foamed molded product and a layer made of a material different from the ethylene copolymer A multilayer molded body can be provided.

  The ethylene-based copolymer for pressure foam molding of the present invention is an ethylene-based copolymer having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms. . Examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene, and preferably 1-butene and 1-hexene.

  Examples of the ethylene copolymer of the present invention include an ethylene-1-butene copolymer, an ethylene-4-methyl-1-pentene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-octene copolymer. Ethylene-1-decene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-1-octene copolymer From the viewpoint of strength, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-butene-1-hexene copolymer are preferable. More preferred are ethylene-1-butene-1-hexene copolymers and ethylene-1-hexene copolymers.

  The ethylene-based copolymer of the present invention preferably contains 50% by weight or more of monomer units based on ethylene, with the content of all monomer units in the copolymer being 100% by weight.

  The melt flow rate (MFR) of the ethylene-based copolymer of the present invention is 0.05 to 0.8 g / 10 min. If the MFR is too small, the expansion ratio may decrease, and is preferably 0.1 g / 10 min or more. Moreover, when this MFR is too large, interlayer adhesiveness may fall, Preferably it is 0.6 g / 10min or less. The MFR is measured by the A method according to JIS K7210-1995 under conditions of a temperature of 190 ° C. and a load of 21.18N.

  The ethylene-based copolymer of the present invention is a copolymer having a flow activation energy (Ea) of 40 kJ / mol or more. The Ea of a conventionally known ethylene-α-olefin copolymer is lower than 40 kJ / mol, and the pressure-foamed molded product made of the copolymer has a non-uniform cell shape and may have a poor appearance. From the viewpoint of enhancing the bubble property, Ea is preferably 50 kJ / mol or more, and more preferably 55 kJ / mol or more. The Ea is preferably 100 kJ / mol or less, and more preferably 90 kJ / mol or less, from the viewpoint of making the surface of the pressure foam molded article smoother.

The flow activation energy (Ea) is a master curve showing the dependence of the melt complex viscosity (unit: Pa · sec) at 190 ° C. on the angular frequency (unit: rad / sec) based on the temperature-time superposition principle. Is a numerical value calculated by the Arrhenius equation from the shift factor (a _T ) at the time of creating the value, and is a value obtained by the following method. That is, the melt complex viscosity-angular frequency curve of the ethylene-α-olefin copolymer at temperatures of 130 ° C., 150 ° C., 170 ° C. and 190 ° C. (T, unit: ° C.) (the unit of melt complex viscosity is Pa · sec. The unit of the angular frequency is rad / sec.), Based on the temperature-time superposition principle, for each melt complex viscosity-angular frequency curve at each temperature (T), The shift factor (a _T ) at each temperature (T) obtained when superposed on the melt complex viscosity-angular frequency curve of the coalescence is obtained, and each temperature (T) and the shift factor at each temperature ( _T ) are obtained. From (a _T ), a first-order approximate expression (formula (I) below) of [ln (a _T )] and [1 / (T + 273.16)] is calculated by the method of least squares. Next, Ea is obtained from the slope m of the linear expression and the following expression (II).
ln (a _T ) = m (1 / (T + 273.16)) + n (I)
Ea = | 0.008314 × m | (II)
a _T : Shift factor Ea: Activation energy of flow (unit: kJ / mol)
T: Temperature (unit: ° C)
For the calculation, commercially available calculation software may be used. As the calculation software, Rheos V. manufactured by Rheometrics is used. 4.4.4.
The shift factor (a _T ) is obtained by moving the logarithmic curve of the melt complex viscosity-angular frequency at each temperature (T) in the log (Y) = − log (X) axis direction (however, the Y axis Is the complex viscosity of the melt, and the X axis is the angular frequency.), And the amount of movement when superposed on the melt complex viscosity-angular frequency curve at 190 ° C., in the superposition, melting at each temperature (T) The logarithmic curve of complex viscosity-angular frequency shifts the angular frequency by a _T times and the melt complex viscosity by 1 / a _T times for each curve. Moreover, the correlation coefficient when calculating | requiring (I) Formula by the least squares method from the value of four points | pieces, 130 degreeC, 150 degreeC, 170 degreeC, and 190 degreeC is usually 0.99 or more.

  The melt complex viscosity-angular frequency curve is measured using a viscoelasticity measuring apparatus (for example, Rheometrics Mechanical Spectrometer RMS-800 manufactured by Rheometrics), and usually geometry: parallel plate, plate diameter: 25 mm, plate interval: 1. It is performed under the conditions of 5 to 2 mm, strain: 5%, angular frequency: 0.1 to 100 rad / sec. The measurement is performed in a nitrogen atmosphere, and it is preferable that an appropriate amount (for example, 1000 ppm) of an antioxidant is added to the measurement sample in advance.

The density of the ethylene-based copolymer of the present invention is preferably 890 kg / m ³ or more, more preferably 900 kg / m ³ or more, from the viewpoint of enhancing secondary processability such as cutting of a pressure-foamed molded article. More preferably, it is 905 kg / m ³ or more. Further, from the viewpoint of increasing the flexibility of the pressure foam molded article, the density is preferably 930 kg / m ³ or less, more preferably 925 kg / m ³ or less. The density is measured by an underwater substitution method described in JIS K7112-1980 after annealing described in JIS K6760-1995.

  As the method for producing an ethylene-based copolymer of the present invention, in the presence of a catalyst obtained by contacting the following promoter support (A), the crosslinked bisindenyl zirconium complex (B) and the organoaluminum compound (C), Examples thereof include a method of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.

The above promoter support (A) comprises (a) diethylzinc, (b) fluorinated phenol, (c) water, (d) silica and (e) trimethyldisilazane (((CH ₃ ) ₃ Si) ₂ NH ).

The amount of each component (a), (b), (c) used is not particularly limited, but the molar ratio of the amount of each component used is the component (a): component (b): component (c) = 1: When y: z, y and z preferably satisfy the following formula.
| 2-y-2z | ≦ 1
Y in the above formula is preferably a number of 0.01 to 1.99, more preferably a number of 0.10 to 1.80, and still more preferably a number of 0.20 to 1.50. Most preferably, the number is 0.30 to 1.00.

  The amount of component (d) used relative to component (a) is such that the number of moles of zinc atoms contained in the particles obtained by contacting component (a) and component (d) is 1 g of the particles. The amount is preferably 0.1 mmol or more, and more preferably 0.5 to 20 mmol. The amount of the component (e) to be used with respect to the component (d) is preferably an amount that makes the component (e) 0.1 mmol or more per 1 g of the component (d), and an amount that becomes 0.5 to 20 mmol. More preferably.

  The cross-linked bisindenyl zirconium complex (B) is preferably racemic-ethylenebis (1-indenyl) zirconium dichloride or racemic-ethylenebis (1-indenyl) zirconium diphenoxide.

  The organoaluminum compound (C) is preferably triisobutylaluminum or trinormaloctylaluminum.

The amount of the bridged bisindenyl zirconium complex (B) used is preferably 5 × 10 ^{−6 to} 5 × 10 ⁻⁴ mol per 1 g of the promoter support (A). The amount of the organoaluminum compound (C) used is preferably such that the aluminum atom of the organoaluminum compound (C) is 1 to 2000 moles per mole of zirconium atoms in the cross-linked bisindenyl zirconium complex (B). is there.

  The polymerization method is preferably a continuous polymerization method involving the formation of ethylene copolymer particles, for example, continuous gas phase polymerization, continuous slurry polymerization, continuous bulk polymerization, and preferably continuous gas phase polymerization. . The gas phase polymerization reaction apparatus is usually an apparatus having a fluidized bed type reaction tank, and preferably an apparatus having a fluidized bed type reaction tank having an enlarged portion. A stirring blade may be installed in the reaction vessel.

As a method of supplying each component of the metallocene olefin polymerization catalyst used in the production of the ethylene polymer of the present invention to the reaction vessel, usually, using an inert gas such as nitrogen or argon, hydrogen, ethylene or the like, A method of supplying in a state free from moisture and a method of supplying each component in a solution or slurry after dissolving or diluting each component in a solvent are used. Each component of the catalyst may be supplied individually, or arbitrary components may be supplied in contact in advance in an arbitrary order.
Moreover, it is preferable to carry out prepolymerization before carrying out the main polymerization and to use the prepolymerized prepolymerized catalyst component as a catalyst component or catalyst for the main polymerization.

The polymerization temperature is usually below the temperature at which the ethylene copolymer melts, preferably 0 to 150 ° C, more preferably 30 to 100 ° C.
Further, hydrogen may be added as a molecular weight regulator for the purpose of regulating the melt fluidity of the copolymer. An inert gas may coexist in the mixed gas.

  The ethylene-based copolymer of the present invention is used for the production of a pressure foam molded article. As a method for producing a pressure-foamed molded article using the copolymer, for example, the ethylene copolymer and the foaming agent are melt-mixed by a mixing roll, a kneader, an extruder, or the like at a temperature at which the foaming agent is not decomposed. The composition thus obtained is filled into a mold by an injection molding machine or the like, foamed in a pressurized (holding pressure) / heated state, then cooled, and the pressurized foamed molded product is taken out, and then melt mixed. Examples thereof include a method in which the composition obtained in this manner is placed in a mold and foamed in a pressurized (holding) / heated state with a pressure press or the like, and then cooled to take out the pressurized foamed molded article.

  Examples of the foaming agent that can be used in the present invention include a thermally decomposable foaming agent having a decomposition temperature equal to or higher than the melting temperature of the copolymer. For example, azodicarbonamide, barium azodicarboxylate, azobisbutylnitrile, nitrodiguanidine, N, N-dinitrosopentamethylenetetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, P— Toluenesulfonyl hydrazide, P, P′-oxybis (benzenesulfonylhydrazide) azobisisobutyronitrile, P, P′-oxybisbenzenesulfonyl semicarbazide, 5-phenyltetrazole, trihydrazinotriazine, hydrazodicarbonamide, etc. Which can be used singly or in combination of two or more. Among these, azodicarbonamide or sodium hydrogen carbonate is preferable. The blending ratio of the foaming agent is usually 1 to 50 parts by weight, preferably 1 to 15 parts by weight with respect to 100 parts by weight of the ethylene copolymer.

  You may mix | blend a foaming adjuvant with the composition obtained by said melt-mixing as needed. Examples of the foaming aid include compounds mainly composed of urea; metal oxides such as zinc oxide and lead oxide; higher fatty acids such as salicylic acid and stearic acid; and metal compounds of the higher fatty acids. The amount of the foaming aid used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, with the total of the foaming agent and the foaming aid being 100% by weight.

  Further, the composition obtained by the above melt mixing may be blended with a crosslinking agent as necessary, and the composition blended with the crosslinking agent may be heat-crosslinked and foamed to form a crosslinked pressure-foamed molded article. . As the crosslinking agent, an organic peroxide having a decomposition temperature equal to or higher than the flow start temperature of the copolymer is preferably used. For example, dicumyl peroxide, 1,1-ditertiary butyl peroxy-3,3 , 5-trimethylcyclohexane, 2,5-dimethyl-2,5-ditertiary butyl peroxyhexane, 2,5-dimethyl-2,5-ditertiary butyl peroxyhexine, α, α-ditertiary butyl peroxy Examples thereof include isopropylbenzene, tertiary butyl peroxyketone, and tertiary butyl peroxybenzoate. In addition, when using the pressure foaming molding of this invention for a shoe sole or a shoe sole member, it is preferable to make a pressure foaming molding into a bridge | crosslinking pressure foaming molding.

  Furthermore, in the composition obtained by the above melt mixing, if necessary, a crosslinking aid, a heat stabilizer, a weathering agent, a lubricant, an antistatic agent, a filler or a pigment (zinc oxide, titanium oxide, Various additives such as metal oxides such as calcium oxide, magnesium oxide, and silicon oxide; carbonates such as magnesium carbonate and calcium carbonate; fiber materials such as pulp) may be blended. Resin / rubber components such as low density polyethylene, high density polyethylene, polypropylene, polyvinyl acetate, and polybutene may be blended.

  The multilayer laminate of the present invention is a multilayer laminate obtained by laminating a foam layer formed by pressure foam molding of the ethylene copolymer of the present invention and a layer made of a material other than an ethylene resin. Materials other than the ethylene resin include vinyl chloride resin material, styrene copolymer rubber material, olefin copolymer rubber material (ethylene copolymer rubber material, propylene copolymer rubber material, etc.), natural A leather material, an artificial leather material, a cloth material, and the like can be mentioned, and at least one kind of material is used as these materials.

  As a method for producing the multilayer laminate of the present invention, for example, a pressure-foamed molded body obtained by pressure-foaming molding of the ethylene-based copolymer of the present invention is molded by the above-described method, and then cut into a desired shape. Then, a member made of a pressure-foamed molded body is prepared, and then the member and a molded body made of a non-ethylene resin material that is separately molded are bonded together by heat bonding or chemical adhesive, etc. can give. Known chemical adhesives can be used. Of these, urethane chemical adhesives and chloroprene chemical adhesives are particularly preferable. Moreover, you may apply | coat the top coat called a primer beforehand in the case of bonding by these chemical adhesives.

  The pressure foam molded article of the present invention is suitably used for a shoe sole or a shoe sole member, and is suitably used as an upper sole (midsole) as a shoe sole member. The upper bottom is used as a shoe sole or a shoe sole member by being laminated with a lower bottom (outer sole) made of a non-ethylene resin material. In addition to the shoe sole, the multilayer molded body of the present invention is also used for building materials such as a heat insulating material and a cushioning material.

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples.
[I] Physical property measurement method (1) Melt flow rate (MFR)
According to JIS K7210-1995, it measured by A method on the conditions with a temperature of 190 degreeC and a load of 21.18N.
(2) Density After performing the annealing described in JIS K6760-1995, the density was measured by the underwater substitution method described in JIS K7112-1980.
(3) Flow activation energy (Ea)
Using a viscoelasticity measuring device (Rheometrics Mechanical Spectrometer RMS-800 manufactured by Rheometrics), dynamic viscosity-angular frequency curves at 130 ° C, 150 ° C, 170 ° C and 190 ° C were measured under the following measurement conditions. From the obtained dynamic viscosity-angular velocity curve, Rheometrics R. The activation energy (Ea) of the flow was determined using 4.4.4.
<Measurement conditions>
Geometry: Parallel plate Plate diameter: 25mm
Plate spacing: 1.5-2mm
Strain: 5%
Angular frequency: 0.1 to 100 rad / sec Measurement atmosphere: Under nitrogen

(4) Interlaminar Adhesion A test piece of 10 cm long × 2 mm wide × 1 cm thick was cut out from the foamed molded article, and a primer (“PE-120” manufactured by No-Tape Kogyo Co., Ltd.) was placed on the 3 cm end in the longitudinal direction of the 10 cm long × 2 mm wide surface. ”), And after drying for 30 minutes, an adhesive (“ 9640 ”manufactured by the company) is applied, and a vinyl chloride resin sheet (applied with an adhesive (“ 2400 ”manufactured by the company)) is bonded and pressed. Then, the laminate was dried at 50 ° C. for 10 minutes to obtain a multilayer laminate having a foam layer and a vinyl chloride resin layer. By peeling the foamed layer and the vinyl chloride resin layer of the multilayer laminate at a peeling rate of 50 mm / min using a 180 degree peel tester (UTM-1-2500 manufactured by TENSILON), the foamed layer and the chloride layer are peeled off. The adhesive strength of the vinyl resin layer was measured. The adhesive strength was determined as follows.
○: Adhesive strength is 15 N / 20 mm width or more.
Δ: Adhesive strength is 12 N / 20 mm width or more and less than 15 N / 20 mm width.
X: Adhesive strength is less than 12N / 20mm width.
(5) Appearance of multilayer molded body The appearance of the foamed layer of the multilayer foam was visually evaluated as follows.
○: The bubble shape is uniform.
Δ: The bubble shape is slightly non-uniform.
X: The bubble shape is non-uniform.

Example 1
(1) Preparation of promoter support Solid product (hereinafter referred to as promoter support (A1)) in the same manner as component (A) in Example 10 (1) and (2) of JP-A No. 2003-171415 Was prepared.

(2) Preliminary polymerization In an autoclave with a stirrer having an internal volume of 210 liters, which was previously purged with nitrogen, 0.6 kg of the above promoter support (A1), 80 liters of butane, 0.03 kg of 1-butene, and 11 hydrogen as normal temperature and normal pressure After charging the liter, the autoclave was heated to 40 ° C. Further, ethylene was charged by 0.2 MPa for the gas phase pressure in the autoclave, and after the system was stabilized, 210 mmol of triisobutylaluminum and 70 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide were added to initiate polymerization. . While raising the temperature to 45 ° C. and continuously supplying ethylene and hydrogen, preliminary polymerization was carried out at 49 ° C. for a total of 4 hours. After the polymerization was completed, ethylene, butane, hydrogen gas and the like were purged, and the remaining solid was vacuum-dried at room temperature, whereby 14 g of ethylene-1-butene copolymer was prepolymerized per 1 g of the promoter support (A1). A prepolymerized catalyst component was obtained.

(3) Continuous gas phase polymerization Using the above prepolymerization catalyst component, ethylene and 1-hexene were copolymerized in a continuous fluidized bed gas phase polymerization apparatus. The polymerization conditions were a temperature of 75 ° C., a total pressure of 2 MPa, a hydrogen molar ratio to ethylene of 0.31%, a 1-hexene molar ratio to ethylene of 1.2%, ethylene to maintain a constant gas composition during the polymerization, 1-hexene and hydrogen were continuously supplied. Furthermore, the pre-polymerization catalyst component and triisobutylaluminum were continuously supplied at a constant ratio so that the total powder weight of the fluidized bed was maintained at 80 kg and the average polymerization time was 4 hours. By polymerization, a powder of an ethylene-1-hexene copolymer (hereinafter referred to as PE (1)) was obtained with a production efficiency of 22 kg / hr.

(4) Granulation of ethylene-1-hexene copolymer powder Using the LCM50 extruder manufactured by Kobe Steel, the PE (1) powder obtained above was fed at a feed rate of 50 kg / hr, a screw rotation speed of 450 rpm, Pelletizing PE (1) was obtained by granulation under conditions of a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 215 ° C. PE (1) had an MFR of 0.1 g / 10 min, a density of 909 kg / m ³ , and a flow activation energy of 70.5 kJ / mol.

(5) Foam molding PE (1) 100 parts by weight, heavy calcium carbonate 50 parts by weight, stearic acid 1 part by weight, zinc oxide 0.9 part by weight, chemical foaming agent (manufactured by Sankyo Kasei Co., Ltd. Cel weight CE ”)) and 6.4 parts by weight of dicumyl peroxide were kneaded using a roll kneader at a roll temperature of 120 ° C. for 5 minutes to obtain a resin composition. The resin composition was filled in a 10 cm × 10 cm × 1 cm mold and foamed under pressure under the conditions of a temperature of 150 ° C., a time of 10 minutes, and a pressure of 1 MPa to obtain a foamed molded article. Table 1 shows the physical property evaluation results of the obtained foamed molded article.

Example 2
(1) Preparation of promoter support In the same manner as component (A) in Example 10 (1) and (2) of JP-A No. 2003-171415, it is referred to as a solid product (hereinafter referred to as promoter support (A2)). ) Was prepared.

(2) Prepolymerization Into an autoclave with a stirrer having an internal volume of 210 liters that has been previously purged with nitrogen, 0.7 kg of the above promoter support (A2), 80 liters of butane, 0.02 kg of 1-butene, and 11 hydrogen as normal temperature and pressure. After charging the liter, the autoclave was heated to 40 ° C. Further, ethylene was charged for 0.2 MPa at the gas phase pressure in the autoclave, and after the system was stabilized, 315 mmol of triisobutylaluminum and 105 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide were added to initiate polymerization. . While raising the temperature to 47 ° C. and supplying ethylene and hydrogen continuously, prepolymerization was carried out at 50 ° C. for a total of 4 hours. After the polymerization was completed, ethylene, butane, hydrogen gas and the like were purged, and the remaining solid was vacuum-dried at room temperature, so that 13 g of ethylene-1-butene copolymer was prepolymerized per 1 g of the promoter support (A2). A prepolymerized catalyst component was obtained.

(3) Continuous gas phase polymerization Using the above prepolymerization catalyst component, ethylene and 1-butene were copolymerized in a continuous fluidized bed gas phase polymerization apparatus. The polymerization conditions were a temperature of 75 ° C., a total pressure of 2 MPa, a hydrogen molar ratio to ethylene of 0.6%, a 1-butene molar ratio to ethylene of 7.5%, ethylene to maintain a constant gas composition during the polymerization, 1-butene and hydrogen were continuously supplied. Furthermore, the pre-polymerization catalyst component and triisobutylaluminum were continuously supplied at a constant ratio so that the total powder weight of the fluidized bed was maintained at 80 kg and the average polymerization time was 4 hours. By polymerization, a powder of ethylene-1-butene copolymer (hereinafter referred to as PE (2)) was obtained with a production efficiency of 22 kg / hr.

(4) Granulation of ethylene-1-butene copolymer powder Using the LCM50 extruder manufactured by Kobe Steel, the PE (2) powder obtained above was fed at a feed rate of 50 kg / hr, a screw rotation speed of 450 rpm, By pelletizing under the conditions of a gate opening degree of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 215 ° C., PE (2) pellets were obtained. PE (2) had an MFR of 0.3 g / 10 min, a density of 902 kg / m ³ , and a flow activation energy of 67.4 kJ / mol.

(5) Foam molding Foam molding was performed according to Example 1 except that PE (2) was used instead of PE (1). Table 1 shows the physical property evaluation results of the obtained foamed molded article.

Comparative Example 1
Instead of PE (1), a commercially available ethylene-vinyl acetate copolymer (Evatate H2020 manufactured by Sumitomo Chemical Co., Ltd. [MFR = 1.3 g / 10 min, density = 936 kg / m ³ , flow activation energy = 63 0.2 kJ / mol]; hereinafter referred to as EVA), and foam molding was performed according to Example 1 except that 1.0 part by weight of dicumyl peroxide was used. Table 1 shows the physical property evaluation results of the obtained foamed molded article.

Comparative Example 2
Instead of PE (1), commercially available high-pressure radical polymerization method low-density polyethylene (Sumitomo Chemical Co., Ltd. Sumikasen G201 [MFR = 2 g / 10 min, density = 919 kg / m ³ , flow activation energy = 66.0 kJ / Mol]; hereinafter referred to as LD), foam molding was performed according to Example 1. Table 2 shows the physical property evaluation results of the obtained foamed molded article.

Comparative Example 3
Instead of PE (1), a commercially available ethylene-1-hexene copolymer (Sumikasen E FV401 manufactured by Sumitomo Chemical Co., Ltd. [MFR = 4 g / 10 min, density = 905 kg / m ³ , flow activation energy = 33) .2 kJ / mol]; hereinafter referred to as LL), foam molding was performed according to Example 1, but cracking occurred in the foamed molded product due to foam breakage.

Comparative Example 4
(1) Preparation of promoter support In the same manner as the synthesis of component (A) described in Example 10 (1) and (2) of JP-A No. 2003-171415, a solid product (hereinafter referred to as promoter support) (Referred to as (A3)).

(2) Prepolymerization Into an autoclave with a stirrer having an internal volume of 210 liters, which was previously purged with nitrogen, 0.7 kg of the above promoter support (A3), 100 liters of butane, 0.02 kg of 1-butene, 12 hydrogen as normal temperature and normal pressure After charging the liter, the autoclave was heated to 42 ° C. Further, ethylene was charged by 0.1 MPa as the gas phase pressure in the autoclave, and after the system was stabilized, 225 mmol of triisobutylaluminum and 75 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide were added to initiate polymerization. . While raising the temperature to 50 ° C. and continuously supplying ethylene and hydrogen, preliminary polymerization was carried out at 50 ° C. for a total of 6 hours. After the polymerization was completed, ethylene, butane, hydrogen gas and the like were purged, and the remaining solid was vacuum-dried at room temperature, so that 13 g of ethylene-1-butene copolymer was prepolymerized per 1 g of the promoter support (A3). A prepolymerized catalyst component was obtained.

(3) Continuous gas phase polymerization Using a continuous fluidized bed gas phase polymerization apparatus, the polymerization temperature is 85 ° C., the polymerization pressure is 2 MPa, the pre-polymerization catalyst component, triisobutylaluminum, ethylene, 1-butene, 1-hexene. And hydrogen are continuously fed into the reactor, the molar ratio of hydrogen to ethylene in the reaction gas is 1.53%, and the molar ratios of 1-butene and 1-hexene to ethylene are 2.5% and 0%, respectively. The copolymerization of ethylene, 1-butene and 1-hexene was carried out under the conditions of 0.3% and an average polymerization time of 5 hours. By polymerization, a powder of an ethylene-1-butene-1-hexene copolymer (hereinafter referred to as PE (3)) was obtained.

(4) Granulation of ethylene-1-butene-1-hexene copolymer powder Using the LCM50 extruder manufactured by Kobe Steel, the powder of PE (3) obtained above was fed at a feed rate of 50 kg / hr, screw Granulation was performed under the conditions of a rotation speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 215 ° C., thereby obtaining PE (3) pellets. PE (3) had an MFR of 1.3 g / 10 min, a density of 923 kg / m ³ , and a flow activation energy of 71.0 kJ / mol.

(5) Foam molding Foam molding was performed according to Example 1 except that PE (3) was used instead of PE (1). Table 2 shows the physical property evaluation results of the obtained foamed molded article.

Claims (7)

An ethylene copolymer having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms, and having a melt flow rate of 0.05 to 0.8 g / 10 A resin composition comprising an ethylene copolymer having a flow activation energy of 40 to 90 kJ / mol and a foaming agent.   The resin composition according to claim 1, comprising 1 to 50 parts by weight of a foaming agent per 100 parts by weight of the ethylene copolymer.   A pressure foam molded article obtained by pressure foam molding of the resin composition according to claim 1.   A shoe sole comprising the pressure-foamed molded article according to claim 3.   The multilayer laminated body formed by laminating | stacking the foaming layer which consists of a pressurization foaming molding of Claim 3, and the layer which consists of materials other than ethylene-type resin.   The layer made of a material other than ethylene-based resin is at least selected from the group consisting of vinyl chloride resin material, styrene-based copolymer rubber material, olefin-based copolymer rubber material, natural leather material, artificial leather material, and cloth material The laminate according to claim 5, which is a layer containing one kind of material.   A shoe sole comprising the multilayer laminate according to claim 5 or 6.