JP4910364B2 - Resin composition, foamed molded article and multilayer molded article - Google Patents

Description

  The present invention relates to a resin composition, a foamed molded product, and a multilayer molded product.

  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 member obtained by cutting a molded body formed by pressure-foaming molding of an ethylene-vinyl acetate copolymer into a desired shape is formed from an upper bottom formed by pressure-foaming molding again, styrene-butadiene rubber, etc. A shoe sole formed by laminating a lower bottom is known (for example, see Patent Document 1).

JP-A-11-151101

However, the above multilayer molded product is not sufficiently satisfactory in the strength of the foamed layer.
Under such circumstances, the problem to be solved by the present invention is a multilayer molded article obtained by laminating a foam layer and a layer made of a material different from the foam layer, and the multilayer mold is excellent in the strength of the foam layer. A resin composition from which the body is obtained, a pressure foam molded body obtained by pressure foam molding of the resin composition, and a foamed layer comprising the pressure foam molded body and the ethylene copolymer are made of different materials. An object of the present invention is to provide a multilayer molded body obtained by laminating layers.

That is, the first of the present invention contains the following components (A) and (B), the total amount of the components (A) and (B) is 100% by weight, and the content of the component (A) is 98 to 50% by weight. %, And the content of the component (b) is 2 to 50% by weight.
(A) having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms, having a melt flow rate of 0.01 to 5 g / 10 min, A monomer unit based on at least one unsaturated ester selected from ethylene-α-olefin copolymer (ro) carboxylic acid vinyl ester and unsaturated carboxylic acid alkyl ester having an activation energy of 30 kJ / mol or more; Ethylene-unsaturated having a monomer unit based on ethylene, a content of monomer unit based on the unsaturated ester of 5 to 45% by weight, and a melt flow rate of 4 to 100 g / 10 min Ester copolymer The second of the present invention relates to a pressure foam molded article obtained by pressure foam molding of the resin composition.
A third 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 article obtained by laminating a foam layer and a layer made of a material different from the foam layer, and a resin composition from which a multilayer molded article having excellent foam layer strength is obtained, and the resin composition And a multi-layer molded article obtained by laminating a foam layer made of the pressure foam molded article and a layer made of a different material from the ethylene copolymer. Can be provided.

  The component (a) ethylene-α-olefin copolymer 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. is there. 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-α-olefin copolymer of component (a) include ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, 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 can be used, and from the viewpoint of strength, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-butene-1-hexene are preferable. More preferably, it is an ethylene-1-butene-1-hexene copolymer or an ethylene-1-hexene copolymer.

  The ethylene-α-olefin copolymer of component (a) contains 50% by weight or more of monomer units based on ethylene, where the content of all monomer units in the copolymer is 100% by weight. It is preferable.

  The melt flow rate (MFR) of the ethylene-α-olefin copolymer of component (a) is 0.01 to 5 g / 10 min. When the MFR is too small, the expansion ratio may be decreased, and is preferably 0.05 g / 10 min or more, more preferably 0.1 g / 10 min or more. On the other hand, if the MFR is too large, the interlayer adhesion of the multilayer molded article may be lowered, preferably 2 g / 10 min or less, more preferably 0.8 g / 10 min or less, and still more preferably 0 .6 g / 10 min 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 component (a) ethylene-α-olefin copolymer is a copolymer having a flow activation energy (Ea) of 30 kJ / mol or more. If the Ea is too low, the bubble properties become non-uniform and the appearance may be inferior. From the viewpoint of improving the bubble property, Ea is preferably 40 kJ / mol or more, more preferably 50 kJ / mol or more, and further 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 angular frequency is rad / sec.) For each melt complex viscosity-angular frequency curve at each temperature (T) on the basis of the temperature-time superposition principle. The shift factor (a _T ) at each temperature (T) obtained when superimposed on the melt complex viscosity-angular frequency curve of the olefin copolymer is obtained, and at each temperature (T) and each temperature (T). From the shift factor (a _T ), a first-order approximation (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-α-olefin copolymer of component (a) is preferably 890 kg / m ³ from the viewpoint of improving the secondary workability such as the rigidity of the pressure foam molded article and the cut of the pressure foam molded article. or more, more preferably 900 kg / m ³ or more, still more preferably 905 kg / m ³ or more. Further, from the viewpoint of improving the lightness 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 the ethylene-α-olefin copolymer of component (i), the following promoter support (A), crosslinked bisindenyl zirconium complex (B) and organoaluminum compound (C) are contacted. And a method of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of the catalyst.

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-α-olefin copolymer particles, for example, continuous gas phase polymerization, continuous slurry polymerization, continuous bulk polymerization, and preferably continuous gas polymerization. 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 for supplying each component of the metallocene olefin polymerization catalyst used for the production of the component (a) ethylene-α-olefin copolymer to the reaction vessel, usually, an inert gas such as nitrogen or argon, hydrogen , A method of supplying ethylene or the like without water, or a method of dissolving or diluting each component in a solvent and supplying in a solution or slurry state. 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-α-olefin 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.

  Component (b), an ethylene-unsaturated ester copolymer, is a monomer unit based on at least one unsaturated ester selected from carboxylic acid vinyl esters and unsaturated carboxylic acid alkyl esters, and a monomer based on ethylene. A copolymer having units. Examples of the carboxylic acid vinyl ester include vinyl acetate and vinyl propionate. The unsaturated carboxylic acid alkyl ester includes methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylic N-butyl acid, t-butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, etc. can give.

  The component (b) ethylene-unsaturated ester copolymer is preferably an ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, or an ethylene-acrylic acid. Ethyl copolymers are used.

  The melt flow rate (MFR) of the ethylene-unsaturated ester copolymer of component (b) is 4 to 100 g / 10 min. If the MFR is too high, the strength of the pressure-foamed molded product may decrease. Preferably it is 50 g / 10 minutes or less, More preferably, it is 20 g / 10 minutes or less, More preferably, it is 10 g / 10 minutes or less. Moreover, when this MFR is too low, it may be difficult to obtain a molded article having a high expansion ratio. Preferably it is 5 g / 10min or more, More preferably, it is 6 g / 10min or more. 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.

  In the ethylene-unsaturated ester copolymer of component (b), the total content of the monomer units based on the carboxylic acid vinyl ester and the monomer units based on the unsaturated carboxylic acid alkyl ester is within the copolymer. The content of all the monomer units is 5 to 45% by weight based on 100% by weight. If the content is too high, the strength of the pressure-foamed molded article may decrease. Preferably it is 40 weight% or less, More preferably, it is 35 weight% or less. Moreover, when this content is too small, the interlayer adhesiveness of a multilayer molded object may fall. Preferably it is 10 weight% or more, More preferably, it is 15 weight% or more. The content is measured by a known method. For example, the content of monomer units based on vinyl acetate is measured according to JIS K6730-1995.

  The component (b) ethylene-unsaturated ester copolymer is produced by a known polymerization method using a known olefin polymerization catalyst. Examples thereof include a bulk polymerization method using a radical initiator and a solution polymerization method.

  The resin composition of the present invention is a resin composition containing the component (a) and the component (b), and the total content of the component (a) and the component (b) is 100% by weight. Is 98 to 50% by weight, and the content of component (b) is 2 to 50% by weight. If the content of component (a) is too small (the content of component (b) is too large), the strength of the pressure-foamed molded article may be reduced. Preferably, the content of component (a) is 60% by weight or more, the content of component (b) is 40% by weight or less, and more preferably, the content of component (a) is 70% by weight or more. Yes, the content of component (b) is 30% by weight or less. Moreover, when there is too much content of a component (I) (content of a component (B) is too little), the interlayer adhesiveness of a multilayer molded body may fall. Preferably, the content of component (a) is 95% by weight or less, the content of component (b) is 5% by weight or more, and more preferably the content of component (a) is 90% by weight or less. Yes, the content of component (b) is 10% by weight or more.

  In the resin composition of the present invention, the total content of the monomer unit based on the carboxylic acid vinyl ester and the monomer unit based on the unsaturated carboxylic acid alkyl ester of the component (b) is as follows. From the viewpoint of enhancing the strength of the pressure-foamed molded article and the interlayer adhesion of the multilayer molded article, the total amount of b) is preferably 100% by weight. The content is preferably 10% by weight or less from the viewpoint of further increasing the strength of the pressure-foamed molded body, and preferably 2% by weight or more from the viewpoint of further improving the interlayer adhesion of the multilayer molded body. .

  If necessary, the resin composition of the present invention includes a crosslinking aid, a heat stabilizer, a weathering agent, a lubricant, an antistatic agent, a filler and a pigment (zinc oxide, titanium oxide, calcium oxide, magnesium oxide, silicon oxide). Various additives such as metal oxides such as magnesium carbonate, carbonates such as calcium carbonate; fiber materials such as pulp) may be blended, and if necessary, high pressure method low density polyethylene, high density polyethylene, Resin / rubber components such as polypropylene and polybutene may be blended.

  The resin composition of this invention is used suitably for manufacture of a pressurization foaming molding. Examples of a method for producing a pressure-foamed molded article using the resin composition include, for example, a mixing roll, a kneader, an extruder, etc., at a temperature at which the foaming agent is not decomposed. A composition obtained by melting and mixing in a mold by an injection molding machine or the like, foamed in a pressurized (holding) / heated state, and then cooled to take out a pressurized foamed molded article, The composition obtained by melt-mixing is put into a mold, foamed in a pressurized (holding) / heated state with a pressure press, etc., and then cooled to take out a pressure-foamed molded article. It is done.

  In the production of a pressure-foamed molded article, the pressure-foamed molded article obtained by the above method may be cut into a desired shape, or the member obtained by cutting may be further heat-shaped. Further, buffing may be performed.

  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. Further, the blending ratio of the foaming agent is usually 1 to 50 parts by weight, preferably 1 to 15 parts by weight, with the total amount of the component (A) and the component (B) being 100 parts by weight.

  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.

  The expansion ratio of the pressure foam molded article is appropriately set depending on the use of the pressure foam molded article, but is usually 3 to 16 times, preferably 5 to 13 times.

  The multilayer molded body of the present invention is a multilayer molded body formed by laminating a foam layer formed by pressure foam molding of the resin composition of the present invention and a layer made of a material other than an ethylene-based 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 molded body of the present invention, for example, a pressure foam molded body obtained by pressure foam molding of the resin composition of the present invention is molded by the method described above, and then the pressure foam molded body is formed. And a method of bonding a molded body made of a non-ethylene resin material that has been separately molded with heat bonding or a chemical adhesive. 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 excellent in strength. Therefore, for example, the pressure foam molded article of the present invention is suitably used for a shoe sole or a shoe sole member. Moreover, since the adhesiveness with non-ethylene resin material is also favorable, it is preferably used by laminating with various non-ethylene resin materials. For example, the pressure-foamed molded article of the present invention is suitably used as an upper bottom (midsole), and the upper bottom is laminated with a lower bottom (outer sole) made of a non-ethylene resin material. And used as a sole member. 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, unit: g / 10 min)
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 (Unit: kg / m ³ )
After annealing described in JIS K6760-1995, the measurement was performed by an underwater substitution method described in JIS K7112-1980.
(3) Flow activation energy (Ea, unit: kJ / mol)
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) 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) Vinyl acetate unit amount (unit:% by weight)
It measured according to JIS K6730-1995.

(5) Strength of foam molded product (unit: kg / cm)
The tear strength of the foamed molded product was measured according to ASTM-D642. Specifically, the foamed molded body was sliced to a thickness of 10 mm, and then punched into the shape of No. 3 dumbbell to prepare a test piece. The test piece was pulled at a speed of 500 mm / min, and the maximum load F (kg) when the test piece broke was divided by the sample piece thickness of 1 cm to determine the tear strength. The greater this value, the better the strength.

(6) Interlayer Adhesiveness of Multilayer Molded Body A test piece having a length of 10 cm × width 2 mm × thickness 1 cm is formed from the secondary molded body so that the surface of the secondary molded body is one vertical 10 cm × width 2 mm surface of the test piece. Cut out, a primer (“GE-320A” manufactured by Daito Resin, Taiwan) was applied to a 3 cm portion in the longitudinal direction of the 10 cm long × 2 mm wide surface, and dried at 60 ° C. for 5 minutes. Next, a mixed solution of an adhesive (“GE-420” manufactured by the same company) and a curing agent (“348” manufactured by the same company; 4 wt% of the adhesive) is applied, and a rubber sheet (primer (“GE manufactured by Daito Resin, Taiwan”) is applied. -310A ") is applied and dried, and then an adhesive (a" GE-420 "manufactured by the company) and a mixed solution of a curing agent (" 348 "manufactured by the company) are applied) and bonded to each other at 60 ° C. Was dried for 5 minutes to form a multilayer molded body having a foam layer and a rubber layer. The adhesive strength between the foamed layer and the rubber layer was measured by peeling off the foamed layer and the rubber layer of the multilayer molded body using a 180 degree peel tester at a peel rate of 50 mm / min. The adhesive strength was determined as follows.
A: Adhesive strength is 3 Kg / cm width or more.
○: Adhesive strength is 2 kg / cm width or more and less than 3 kg / cm width.
X: Adhesive strength is less than 2 kg / cm width.

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

(2) Prepolymerization In an autoclave with a stirrer having an internal volume of 210 liters, which was previously purged with nitrogen, 0.68 kg of the above promoter support (A), 80 liters of butane, 0.02 kg of 1-butene, 3 hydrogen as normal temperature and pressure After charging the liter, the autoclave was heated to 30 ° C. Further, ethylene was charged by 0.03 MPa as the gas phase pressure in the autoclave, and after the system was stabilized, 216 mmol of triisobutylaluminum and 70 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide were added to initiate polymerization. . While raising the temperature to 50 ° 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 14 g of ethylene-1-butene copolymer was prepolymerized per 1 g of the promoter support (A). 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 mole ratio to ethylene of 0.77%, a 1-hexene mole ratio to ethylene of 1.98%, 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 0.5 g / 10 min, a density of 912 kg / m ³ , and an activation energy of 73 kJ / mol.

(5) Pressurized foam molding PE (1) 80 parts by weight and ethylene-vinyl acetate copolymer (Sumitomo Chemical Co., Ltd. Sumitate KA-31 [MFR = 7 g / 10 min, density = 940 kg / m ³ , vinyl acetate Unit amount = 28 wt%]; hereinafter referred to as EVA (1).) 20 parts by weight was melt-blended using a single-screw kneader at a temperature of 150 ° C. and a screw speed of 80 rpm to obtain a resin composition. Obtained. Next, 100 parts by weight of the resin composition, 10 parts by weight of heavy calcium carbonate, 0.5 parts by weight of stearic acid, 1.5 parts by weight of zinc oxide, 3.5 parts by weight of chemical foaming agent, 1.0 part by weight of mill peroxide was kneaded using a roll kneader under conditions of a roll temperature of 120 ° C. and a kneading time of 5 minutes to obtain a resin composition. The resin composition is filled into a 22.8 cm × 15 cm × 1.2 cm mold and subjected to pressure foaming under the conditions of a temperature of 160 ° C., an hour of 11 minutes, and a pressure of 150 kg / cm ² to obtain a primary foamed molded article. It was. Next, the obtained primary foam sliced to 1 cm thickness was filled in a 26 cm × 18 cm × 1 cm mold, heated and pressed for 210 seconds under conditions of a temperature of 150 ° C. and a pressure of 150 kg / cm ² , and then for 600 seconds. A secondary molded body was obtained by cooling. Table 1 shows the physical property evaluation results of the obtained secondary molded body.

Comparative Example 1
In the pressure foam molding, instead of EVA (1), an ethylene-vinyl acetate copolymer (Evalate K2010 manufactured by Sumitomo Chemical Co., Ltd. [MFR = 3 g / 10 min, density = 940 kg / m ³ , vinyl acetate unit amount = 25 wt%]; hereinafter referred to as EVA (2)), and the same procedure as in Example 1 except that PE (1) was 60 parts by weight and EVA (2) was 40 parts by weight. Table 1 shows the physical property evaluation results of the obtained secondary molded body.

Comparative Example 2
Ethylene-vinyl acetate copolymer (Cosmocene H2181 manufactured by The Polyolefin Company, Ltd. [MFR = 2 g / 10 min, density = 940 kg / m ³ , vinyl acetate unit amount = 18 wt%]; hereinafter referred to as EVA (3) .) 100 parts by weight, heavy calcium carbonate 10 parts by weight, stearic acid 0.5 parts by weight, zinc oxide 1.5 parts by weight, chemical blowing agent 3.0 parts by weight, dicumyl peroxide 0. 7 parts by weight were kneaded using a roll kneader under conditions of a roll temperature of 120 ° C. and a kneading time of 5 minutes to obtain a resin composition. The resin composition is filled into a 22.8 cm × 15 cm × 1.2 cm mold and subjected to pressure foaming under the conditions of a temperature of 160 ° C., an hour of 11 minutes, and a pressure of 150 kg / cm ² to obtain a primary foamed molded article. It was. Next, the obtained primary foam sliced to 1 cm thickness was filled in a 26 cm × 18 cm × 1 cm mold, heated and pressed for 210 seconds under conditions of a temperature of 150 ° C. and a pressure of 150 kg / cm ² , and then for 600 seconds. A secondary molded body was obtained by cooling. Table 1 shows the physical property evaluation results of the obtained secondary molded body.

Claims (6)

The following components (a) and (b) are contained, the total amount of components (a) and (b) is 100% by weight, and the content of the component (a) is 98 to 70 % by weight. A resin composition having a content of 2 to 30 % by weight.
(A) having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms, having a melt flow rate of 0.01 to 5 g / 10 min, An unsaturated ester having a monomer unit based on an ethylene-α-olefin copolymer (ro) carboxylic acid vinyl ester having an activation energy of 55 to 100 kJ / mol and a monomer unit based on ethylene Ethylene-unsaturated ester copolymer having a monomer unit content of 5 to 45% by weight and a melt flow rate of 5 to 100 g / 10 min 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 2. A multilayer molded body obtained by laminating a foam layer made of the pressure foam molded body according to claim 2 and a layer made of a material other than an ethylene-based 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 multilayer molded article according to claim 4, which is a layer containing one kind of material. A shoe sole comprising the multilayer molded article according to claim 4 or 5.