JP2014028875A - Ethylene-1-butene copolymer, ethylene-1-butene copolymer composition and foamed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene-1-butene copolymer capable of melt mixing at a temperature at which forming agent is not decomposed and giving a foamed body having high hardness, and to provide an ethylene-1-butene copolymer composition and the formed body having high hardness.SOLUTION: An ethylene-1-butene copolymer has density of 921 to 930 kg/m, a melt flow rate of 0.1 to 5.0 g/10 minutes, a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 5 to 15, an activation energy of flow of 50 to 100 kJ/mol, a swell ratio of 1.10 to 1.60, only one melting peak in a melting curve at 25°C to 150°C obtained by a differential scanning calorimetry, and a melting peak temperature of 100°C to 109°C.

Description

  The present invention relates to an ethylene-1-butene copolymer, an ethylene-1-butene copolymer composition, and a foam.

Foams made of an ethylene-α-olefin copolymer are excellent in flexibility and heat insulating properties, and thus are used for various applications such as buffer materials and heat insulating materials. For example, Patent Document 1, the density and the ethylene-1-hexene copolymer 907 kg / m ^3, foam, wherein the density containing ethylene-1-octene copolymer 870~890kg / m ³ Has been.

JP 2012-107223 A

Although high hardness is calculated | required for a foam depending on a use, the hardness of the foam described in patent document 1 was not enough. In general, the higher the density of the ethylene-α-olefin copolymer, the higher the hardness of the resulting foam. However, the conventional high-density ethylene-α-olefin copolymer will melt unless the temperature is high. Therefore, the foaming agent was decomposed when the resin and the foaming agent were melt-kneaded, and sufficient foaming was not performed at the time of foam molding, so that a foam with a high expansion ratio could not be obtained.
Under such circumstances, the problem to be solved by the present invention is that an ethylene-1-butene copolymer, ethylene, which can be melt-kneaded at a temperature at which the foaming agent does not decompose and can obtain a foam having high hardness, ethylene It is in providing a -1-butene copolymer composition and a foam with high hardness.

That is, the first of the present invention has a density of 921 to 930 kg / m ³ , a melt flow rate of 0.1 to 5.0 g / 10 min, and a weight average molecular weight (Mw) with respect to the number average molecular weight (Mn). The ratio (Mw / Mn) is 5 to 15, the flow activation energy is 50 to 100 kJ / mol, the swell ratio is 1.10 to 1.60, and from 25 ° C. obtained by differential scanning calorimetry. In the melting curve up to 150 ° C., only one melting peak is shown, and the melting peak temperature relates to an ethylene-1-butene copolymer having a melting point of 100 ° C. to 109 ° C.

  INDUSTRIAL APPLICABILITY According to the present invention, an ethylene-1-butene copolymer, an ethylene-1-butene copolymer composition, and a hardness that can be melt-kneaded at a temperature at which the foaming agent is not decomposed and a foam having high hardness can be obtained. High foam can be provided.

It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene copolymer (PE-1) of Example 1. It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene copolymer (PE-2) of Example 2. It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene copolymer (PE-3) of Example 3. It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene-1-hexene copolymer (PE-4) of the comparative example 1. It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene-1-hexene copolymer (PE-5) of the comparative example 2. It is the figure which showed the melting curve obtained by the differential scanning calorimetry of the ethylene-1-butene-1-hexene copolymer (PE-6) of the polymerization example 1.

[Ethylene-1-butene copolymer (A)]
The ethylene-1-butene copolymer used in the present invention is an ethylene-1-butene copolymer having a monomer unit based on ethylene and a monomer unit based on 1-butene.

  The amount of ethyl branching in the ethylene-1-butene copolymer used in the present invention is 10 or more and 25 or less per 1000 carbons as measured by NMR. From the viewpoint of the hardness of the foam obtained using the ethylene-1-butene copolymer of the present invention, it is preferably 22 or less per 1000 carbons, more preferably 20 or less. Moreover, from the viewpoint that the ethylene-1-butene copolymer of the present invention is easily melt-kneaded at a lower temperature, it is preferably 12 or more per 1000 carbons, more preferably 14 or more.

The density of ethylene-1-butene used in the present invention (hereinafter sometimes referred to as “d”) is 921 to 930 kg / m ³ , preferably from the viewpoint of increasing the hardness of the obtained foam. It is 922 kg / m ³ or more. From the viewpoint of increasing the tensile strength of the obtained foam, it is preferably 928 kg / m ³ or less, more preferably 926 kg / m ³ or less. The density is measured according to the method defined in Method A of JIS K7112-1980 after annealing described in JIS K6760-1995. When the content of monomer units based on ethylene in the ethylene-1-butene copolymer is increased, an ethylene-1-butene copolymer having a low density can be obtained.

  The melt flow rate (hereinafter sometimes referred to as “MFR”) of the ethylene-1-butene polymer used in the present invention is 0.1 to 5.0 g / 10 minutes. The melt flow rate is preferably 0.15 g / 10 min or more, more preferably 0.3 g / 10 min or more, from the viewpoint of improving molding processability, particularly from the viewpoint of reducing the extrusion load. Moreover, from a viewpoint of raising the mechanical strength of the foam obtained, Preferably it is 4.0 g / 10min or less. The melt flow rate is a value measured by Method A under the conditions of a temperature of 190 ° C. and a load of 21.18 N in the method defined in JIS K7210-1995. In the measurement of the melt flow rate, usually, an ethylene-1-butene copolymer previously blended with about 1000 ppm of an antioxidant is used. Further, the melt flow rate of the ethylene-1-butene copolymer can be changed by, for example, the hydrogen concentration or the polymerization temperature in the production method described later. When the hydrogen concentration or the polymerization temperature is increased, the melt flow rate is increased. An ethylene-1-butene copolymer can be obtained.

The swell ratio (hereinafter sometimes referred to as “SR”) of the ethylene-1-butene copolymer used in the present invention is 1.10 or more, and a foam having a high foaming ratio or a foam having a large thickness is used. In order to obtain a body, it is preferably 1.20 or more, more preferably 1.30 or more. The swell ratio is 1.60 or less, preferably 1.58 or less, more preferably 1.55 or less, and still more preferably from the viewpoint of difficulty in cracking of the resin when foaming due to mold opening. Is 1.50 or less. The swell ratio is obtained by measuring a strand of an ethylene-α-olefin copolymer extruded at a length of about 15 to 20 mm from an orifice under the conditions of a temperature of 190 ° C. and a load of 21.18 N when measuring the melt flow rate. About the solid strand obtained by cooling in air, the diameter D (unit: mm) of the strand at a position of about 5 mm from the upstream end of extrusion was measured, and the diameter D was determined to be 2.095 mm (D ₀ )) (D / D ₀ ). Further, the swell ratio can be changed by, for example, the hydrogen concentration or the electron donating compound concentration in the production method described later.

  Molecular weight distribution (the ratio of the weight average molecular weight (hereinafter referred to as “Mw”) to the number average molecular weight (hereinafter referred to as “Mn”) of the ethylene-1-butene copolymer used in the present invention ( Hereinafter, it is described as “Mw / Mn”). Mw / Mn is preferably 5.5 or more, more preferably 6.0 or more, from the viewpoint of reducing the extrusion load during molding. Mw / Mn is preferably 13 or less, more preferably 11 or less, from the viewpoint of increasing the mechanical strength of the foam obtained. The Mw / Mn is determined by measuring Mn and Mw by gel permeation chromatography (GPC) method and dividing Mw by Mn. The Mw / Mn can be changed by, for example, the hydrogen concentration or the polymerization temperature in the production method described later. When the hydrogen concentration or the polymerization temperature is increased, the ethylene-1-butene copolymer having a large Mw / Mn. Can be obtained.

  The activation energy (hereinafter sometimes referred to as “Ea”) of the flow of the ethylene-1-butene copolymer used in the present invention is 50 kJ / mol from the viewpoint of reducing the extrusion load during the molding process. ˜100 kJ / mol. From the viewpoint of fluidity, Ea of the ethylene-1-butene copolymer of the present invention is preferably 55 kJ / mol or more, more preferably 60 kJ / mol or more, and further preferably 65 kJ / mol or more. From the viewpoint of increasing the mechanical strength of the foam, the Ea of the ethylene-1-butene copolymer of the present invention is preferably 90 kJ / mol or less, more preferably 80 kJ / mol or less, and even more preferably. Is 75 kJ / mol or less. In the production method described later, the flow activation energy can be changed, for example, depending on polymerization conditions such as hydrogen concentration, organoaluminum compound concentration, ethylene pressure, and polymerization temperature.

The activation energy (Ea) of the flow is dependent on the angular frequency (unit: rad / second) dependence of the melt complex viscosity (unit: Pa · second) at 190 ° C. based on the temperature-time superposition principle. It is a numerical value calculated by the Arrhenius type equation from the shift factor (a _T ) when creating the master curve shown, and is a value obtained by the method shown below. First, the melt complex viscosity-angular frequency curve of the ethylene-1-butene copolymer at temperatures of 130 ° C., 150 ° C., 170 ° C. and 190 ° C. (T, unit: ° C.) (the unit of melt complex viscosity is Pa · second). The unit of angular frequency is rad / sec.). Next, based on the temperature-time superposition principle, the melt complex viscosity-angular frequency curve at each temperature (T) is changed to a melt complex viscosity-angular frequency curve of the ethylene-1-butene copolymer at 190 ° C. The shift factor (a _T ) at each temperature (T) is obtained by superposition. A respective temperature (T), from a shift factor (a _T) at each temperature (T), by the method of least squares [ln (a _T)] and [1 / (T + 273.16) ] and the primary approximate expression (Equation (II) below) is calculated. Next, Ea is obtained from the slope m of the linear expression and the following expression (III).
ln (a _T ) = m (1 / (T + 273.16)) + n (II)
Ea = | 0.008314 × m | (III)
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 (II) 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 ethylene-1-butene copolymer used in the present invention is melted from 25 ° C. to 150 ° C. obtained by differential scanning calorimetry from the viewpoint of suppressing foaming due to decomposition of the foaming agent during melt kneading of the resin and the foaming agent. In the curve, only one melting peak is shown.
Here, the melting peak means a point where the peak height (heat flow) shows a maximum value in the melting curve or a point where the peak height (heat flow) shows the following shoulder.
A shoulder means that there is no local maximum between two inflection points, and the melting curve between the two inflection points is convex upward, the inflection point on the low temperature side and the high temperature side inflection point. It is a convex vertex that connects inflection points with a straight line to form a base line, and the base line is the base.
The inflection point is a point at which the tangent slope at a certain point of the melting curve starts from increasing to decreasing, or a tangential slope from the decreasing to increasing point.
The melting curve of PE-1 of Example 1 showing only one melting peak is shown in FIG. In addition, FIG. 6 shows a melting curve of PE-6 of Polymerization Example 1 in which two melting peaks are shown, and one of the melting peaks shows the shoulder.

  In addition, the melting curve of the ethylene-1-butene copolymer is measured using, for example, an aluminum pan in which about 10 mg of a sample is sealed with a differential scanning calorimeter (for example, a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer). (1) held at 150 ° C. for 5 minutes, (2) lowered from 150 ° C. to 20 ° C. at 5 ° C./minute, (3) held at 20 ° C. for 2 minutes, and (4) 20 at 5 ° C./minute. It is obtained from the differential scanning calorimetry curve obtained in (4) by raising the temperature from 0 ° C. to the melting end temperature + about 20 ° C. (usually about 150 ° C.).

  The melting peak temperature of the ethylene-1-butene copolymer used in the present invention is 100 ° C to 109 ° C. In the melting curve of the ethylene-1-butene copolymer of the present invention, a temperature showing only one melting peak is defined as a melting peak temperature. The temperature is preferably 108 ° C. or less from the viewpoint of suppressing foaming due to decomposition of the foaming agent during melt kneading of the resin and the foaming agent and shortening the kneading time. Moreover, from the viewpoint of suppressing the sticky component of the obtained foam, the temperature is preferably 105 ° C or higher.

Production method of ethylene-1-butene copolymer Examples of the production method of the ethylene-1-butene copolymer of the present invention include diethyl zinc (hereinafter referred to as component (a)), 3, 4, and 5. -Toluene solvent containing trifluorophenol (hereinafter referred to as component (b)), water (hereinafter referred to as component (c)), and inorganic compound particles (hereinafter referred to as component (d)). A solid particulate promoter support (hereinafter referred to as “component (A)”) obtained by contacting the catalyst and two ligands having a cyclopentadienyl skeleton, A metallocene complex (hereinafter referred to as component (B)) having a structure bonded with a crosslinking group such as an alkylene group or a silylene group and an organoaluminum compound (hereinafter referred to as component (C)) are used as catalyst components. In the presence of a polymerization catalyst A method of copolymerizing a α- olefin.

Component (d) is 1,1,1,3,3,3-hexamethyldisilazane (((CH ₃ ) ₃ Si) ₂ NH) (hereinafter referred to as component (e)) as necessary. You may carry out contact processing with.

  The inorganic compound particles of component (d) are preferably silica gel.

The amount of component (a), component (b), and component (c) used is not particularly limited, but the molar ratio of the amount of each component used is component (a): component (b): component (c) = 1: When the molar ratio of y: z is used, it is preferable that y and z substantially satisfy the following formula (1).
0.5 <y + 2z <5 (1)
In the above formula (1), y is preferably a number of 0.5 to 4, more preferably a number of 0.6 to 3, further preferably a number of 0.8 to 2.5, and most preferably. Is a number from 1 to 2. Z in the above formula (1) is a positive number larger than 0, and can arbitrarily take a range determined by y and the above formula (1).

Examples of the order in which the component (a), the component (b), the component (c), the component (d), and the component (e) are brought into contact include the following orders.
<1> After contacting component (d) and component (e), contact component (b), then contact component (a), and then contact component (c).
<2> After contacting component (d) and component (e), contact component (a), then contact component (b), and then contact component (c).
<3> Component (d) and component (a) are contacted, then component (b) is contacted, and then component (c) is contacted.
<4> Component (d) and component (b) are contacted, then component (a) is contacted, and then component (c) is contacted.
The contact order is preferably <1>.

  The contact treatment of component (a), component (b), component (c), component (d) and component (e) is preferably carried out in an inert gas atmosphere. The treatment temperature is usually −100 to 300 ° C., preferably −80 to 200 ° C. The treatment time is usually 1 minute to 200 hours, preferably 10 minutes to 100 hours.

As a metal atom (M) of the metallocene complex of the said component (B), a periodic table group IV atom is preferable, and a zirconium atom and a hafnium atom are more preferable.
The ligand having a cyclopentadienyl skeleton of the metallocene complex of the component (B) is preferably an indenyl group, a methylindenyl group, a methylcyclopentadienyl group, or a dimethylcyclopentadienyl group.

  As a crosslinking group of the metallocene complex of the said component (B), a methylene group, a dimethylmethylene group, and an ethylene group are preferable, More preferably, it is an ethylene group.

As the remaining substituents that the metal atom of the metallocene complex of the component (B) has, a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 20 carbon atoms, a carbon atom number of 3 10 cycloalkyl groups, aralkyl groups having 7 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aralkyloxy groups having 7 to 20 carbon atoms, carbon atoms 6-20 aryloxy group, silyl group optionally having 1-20 carbon atoms hydrocarbyl group as a substituent, hydrocarbyl group having 1-20 carbon atoms as a substituent The amino group which may be sufficient is mentioned. Preferably, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, or an alkyl group having 1 to 6 carbon atoms An amino group optionally having a hydrocarbyl group as a substituent, particularly preferably a chlorine atom, a bromine atom, an iodine atom, an alkoxy group having 1 to 10 carbon atoms, or an aryl having 6 to 10 elementary atoms An amino group which may have an oxy group or a hydrocarbyl group having 1 to 6 carbon atoms as a substituent. Specifically, phenoxy group, 4-methylphenoxy group, 2,3,4-trimethylphenoxy group, 2,3,5-trimethylphenoxy group, 2,3,6-trimethylphenoxy group, 2,4,6- Examples include trimethylphenoxy group, 3,4,5-trimethylphenoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, isobutoxy group, dimethylamino group, and diethylamino group. Particularly preferred are a phenoxy group and a dimethylamino group.
Preferred examples of the component (B) metallocene complex include ethylene bis (1-indenyl) hafnium dichloride, ethylene bis (1-indenyl) zirconium dichloride, and ethylene bis (1-indenyl) zirconium diphenoxide.

  The organoaluminum compound of component (C) is preferably triisobutylaluminum, trinormal octylaluminum, triethylaluminum, or trimethylaluminum.

The amount of the metallocene complex used as the component (B) is preferably 5 × 10 ^{−6 to} 5 × 10 ⁻⁴ mol with respect to 1 g of the promoter support of the component (A). The amount of the organoaluminum compound used as the component (C) is preferably a ratio of the number of moles of aluminum atoms in the organoaluminum compound as the component (C) to the number of moles of metal atoms in the metallocene complex as the component (B) (Al / M ) And 1 to 5000.

  In the polymerization catalyst obtained by contacting the promoter support (A), the metallocene complex (B) and the organoaluminum compound (C), the promoter support (A), the metallocene complex (B), and It is good also as a polymerization catalyst which makes an electron-donating compound (D) contact an organoaluminum compound (C). Specific examples of the electron donating compound (D) include tertiary amines and secondary amines. Tertiary amines are preferable, and specific examples include triethylamine and trinormaloctylamine.

  From the viewpoint of increasing the molecular weight distribution of the resulting ethylene-1-butene copolymer, the electron donating compound (D) is preferably used, and the amount of the electron donating compound (D) used is an organoaluminum compound. The amount is more preferably 0.1 mol% or more, still more preferably 1 mol% or more, relative to the number of moles of aluminum atoms in (C). In addition, from the viewpoint of increasing the polymerization activity, the amount used is preferably 30 mol% or less, and more preferably 20 mol% or less.

  The ethylene-1-butene copolymer used in the present invention can be polymerized by a continuous gas phase polymerization method. The gas phase polymerization reaction apparatus used in the polymerization method 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 polymerization catalyst used in the production of the ethylene-1-butene copolymer used in the present invention to the reaction vessel, usually, an inert gas such as nitrogen or argon, hydrogen, ethylene or the like is used. Then, a method of supplying in a state free from moisture, or a method of supplying each component in a solution or slurry after dissolving or diluting each component in a solvent is used. Each component of the catalyst may be supplied individually, or arbitrary components may be supplied in contact in advance in an arbitrary order. In the production of the ethylene-1-butene copolymer used in the present invention, it is preferable to carry out prepolymerization and use the prepolymerized catalyst component as a catalyst component or catalyst for the main polymerization.

  The polymerization temperature of the ethylene-1-butene copolymer used in the present invention is preferably 60 to 100 ° C, more preferably 65 to 90 ° C, still more preferably 70 to 90 ° C, and particularly preferably 75 to 90 ° C. Yes, most preferably 80-90 ° C. By increasing the polymerization temperature, the molecular weight distribution can be narrowed.

  In order to adjust the melt fluidity of the ethylene-1-butene copolymer used in the present invention, hydrogen may be added to the polymerization reactor as a molecular weight regulator.

  In order to widen the molecular weight distribution of the ethylene-1-butene copolymer used in the present invention, multistage polymerization may be performed.

[Foaming agent]
The ethylene-1-butene copolymer composition of the present invention comprises 0.1 to 30 parts by weight of a blowing agent with respect to 100 parts by weight of the ethylene-1-butene copolymer and the ethylene-1-butene copolymer. contains. The content of the foaming agent is preferably 1 part by weight or more. Examples of the foaming agent include pyrolytic foaming agents and physical foaming agents.
The ethylene-1-butene copolymer composition of the present invention may contain a plurality of foaming agents.

Examples of the pyrolytic foaming agent include inorganic foaming agents such as ammonium carbonate, sodium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, anhydrous monosodium citrate; azodicarbonamide, barium azodicarboxylate, Azobisbutyronitrile, nitrodiguanidine, N, N'-dinitropentamethylenetetramine, N, N'-dimethyl-N, N'-dinitrosotephthalamide, p-toluenesulfonyl hydrazide, 4-toluenesulfonyl cellcarbazide 4,4′-oxybisbenzenesulfonyl hydrazide, azobisisobutyronitrile, 4,4′-oxybisbenzenesulfonyl semicarbazide, 5-phenyltetrazole, trihydrazinotriazine, hydrazodicarbonamide, etc. Such as foaming agents That. Among these, azodicarbonamide, sodium hydrogen carbonate, and 4,4′-oxybisbenzenesulfonyl hydrazide are preferably used from the viewpoint of economy. It is more preferable to use a foaming agent containing azodicarbonamide or sodium hydrogen carbonate since a molding temperature range is wide and a foam having fine bubbles is obtained.
When the foaming agent contained in the ethylene-1-butene copolymer composition of the present invention is a thermal decomposition type foaming agent, the content of the thermal decomposition type foaming agent is 100 parts by weight of the ethylene-1-butene copolymer. On the other hand, it is preferably 1 to 30 parts by weight.

  The foaming agent in the present invention is preferably a thermally decomposable foaming agent having a decomposition temperature of 120 to 240 ° C. The decomposition temperature of the thermally decomposable foaming agent can be determined by a method based on JIS K0064. The thermal decomposition type foaming agent can be used by lowering the decomposition temperature by using a foaming aid in combination. As foaming aids, metal oxides such as zinc oxide and lead oxide; metal carbonates such as zinc carbonate; metal chlorides such as zinc chloride; urea; zinc stearate, lead stearate, dibasic lead stearate, Metal soap such as zinc laurate, zinc 2-ethylhexoate, and dibasic lead phthalate; Organotin compounds such as dibutyltin dilaurate and dibutyltin dimale; Tribasic lead sulfate, dibasic lead phosphite, basic Examples thereof include inorganic salts such as lead sulfite. Among these, it is preferable to use urea and zinc oxide from the viewpoint of lowering the decomposition temperature of the blowing agent. Moreover, it is preferable to use zinc stearate from the viewpoint of improving the releasability during kneading. Foaming aids may be used alone or in combination of two or more.

  The ethylene-1-butene copolymer composition of the present invention preferably contains 1 to 5 parts by weight of a foaming aid, more preferably a foaming aid, relative to 100 parts by weight of the ethylene-1-butene copolymer. Is preferably contained in an amount of 1.5 to 4 parts by weight.

  In order to obtain a foam having finer bubbles, it is preferable to use a foam nucleating agent in combination. Foam nucleating agents include talc, silica, mica, zeolite, calcium carbonate, calcium silicate, magnesium carbonate, aluminum hydroxide, barium sulfate, aluminosilicate, clay, quartz powder, diatomaceous earth inorganic fillers; polymethyl methacrylate, polystyrene Examples of beads having a particle diameter of 100 μm or less; metal salts such as calcium stearate, magnesium stearate, zinc stearate, sodium benzoate, calcium benzoate, aluminum benzoate, magnesium oxide, etc., may be used alone Two or more of these may be combined.

[Crosslinking agent]
The composition of the present invention preferably contains a crosslinking agent from the viewpoint of increasing the expansion ratio and obtaining a foam having excellent strength. As the crosslinking agent, an organic peroxide having a 1-minute half-life temperature equal to or higher than the melting point of the ethylene-1-butene copolymer is preferably used, and examples thereof include dicumyl peroxide and 1,1-ditertiary butyl peroxide. Oxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-ditertiary butyl peroxyhexane, 2,5-dimethyl-2,5-ditertiary butyl peroxyhexine, α, α- Examples include ditertiary butyl peroxyisopropylbenzene, tertiary butyl peroxyketone, and tertiary butyl peroxybenzoate. The crosslinking agent is preferably an organic peroxide having a 1 minute half-life temperature of 120 to 220 ° C, more preferably an organic peroxide having a temperature of 140 to 190 ° C.
These crosslinking agents may be used alone or in combination of two or more.

  The content of the cross-linking agent is based on 100 parts by weight of the ethylene-1-butene copolymer contained in the ethylene-1-butene copolymer composition from the viewpoint that the foam diameter of the obtained foam tends to be uniform. It is preferable that it is 0.01-4 weight part. More preferably, it is 0.1-4 weight part, More preferably, it is 0.3-2.5 weight part.

  The ethylene-1-butene copolymer composition of the present invention may contain a crosslinking aid. As the crosslinking aid, a compound having a plurality of double bonds in the molecule is preferably used. Specifically, for example, N, N'-m-phenylene bismaleimide, toluylene bismaleimide, triallyl isocyanurate, triallyl cyanurate, p-quinone dioxime, nitrobenzene, diphenylguanidine, divinylbenzene, ethylene glycol di Examples include methacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, and allyl methacrylate. Moreover, these crosslinking adjuvants may be used independently and may be used combining plurality.

  The addition amount of the crosslinking aid is preferably 0.01 to 4 parts by weight with respect to 100 parts by weight of the ethylene-1-butene copolymer contained in the ethylene-1-butene copolymer composition. 0.1-3 parts by weight is more preferable, and 0.5-2 parts by weight is still more preferable.

  The ethylene-1-butene copolymer composition of the present invention may contain additives such as a heat stabilizer, a weather stabilizer, a pigment, a filler, a lubricant, an antistatic agent, and a flame retardant as necessary. Good.

The ethylene-1-butene copolymer composition of the present invention may contain a thermoplastic resin or a thermoplastic elastomer different from the ethylene-1-butene copolymer, if necessary. The thermoplastic resin or thermoplastic elastomer, high-pressure low-density polyethylene, high density polyethylene, medium-density polyethylene, the density is 865kg ^{/ m 3} ~909kg ^/ m 3 ultra low density polyethylene, the activation energy of flow 40kJ Ethylene-α-olefin copolymer, ethylene- (meth) acrylic acid copolymer, metal salt of ethylene- (meth) acrylic acid copolymer, polypropylene, polystyrene, ABS resin, styrene-butadiene block Copolymers and hydrogenated products thereof, styrene polymers such as styrene / isoprene block copolymers and hydrogenated products thereof, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, nylon 66, nylon 11 and nylon 12 , Na Polyamides such as Ron 6 and 66, polycarbonate, polymethyl methacrylate, polyacetal, polyphenylene sulfide, ethylene / propylene copolymer rubber, styrene thermoplastic elastomer, olefin thermoplastic elastomer, polyester thermoplastic elastomer, polyurethane thermoplastic elastomer And polyamide-based thermoplastic elastomers.

  The ethylene-1-butene copolymer composition comprises an ethylene-1-butene copolymer, a foaming agent, and, if necessary, other components at a temperature lower than the decomposition temperature of the foaming agent, and ethylene-1-butene. It is preferable to manufacture by melting and kneading with a mixing roll, kneader, extruder, or the like at a temperature equal to or higher than the melting point of the copolymer. Moreover, when the said composition contains a crosslinking agent, it is below the decomposition temperature of a foaming agent, is more than melting | fusing point of an ethylene-1-butene copolymer, and is below 1 minute half life temperature of a crosslinking agent. It is preferable to manufacture by melt-kneading at a temperature. The melt kneading temperature is preferably 100 to 140 ° C, more preferably 105 to 120 ° C, and still more preferably 110 to 115 ° C.

[Method for producing foam]
The foam of the present invention is obtained by foam-molding the ethylene-1-butene copolymer composition. The obtained foam may be a crosslinked foam or an uncrosslinked foam.
Specifically, as a foam molding method for obtaining a crosslinked foam, for example, an ethylene-1-butene copolymer composition containing a crosslinking agent is supplied into a mold, and the composition in the mold is heated and pressurized. In some cases, the composition is crosslinked and foamed to obtain a crosslinked foam.

The cross-linked foam can be produced using a pressure press.
An example of a method for producing a crosslinked foam using a pressure press machine is a production method including the following steps.
Supplying the ethylene-1-butene copolymer composition containing a crosslinking agent into a mold of a pressure press,
Pressing and heating the composition in the mold to form a plasticized and crosslinked intermediate (i); and
The step of foaming the intermediate (i) by opening the mold to form a crosslinked foam

The composition supplied into the mold is preferably a composition obtained by the following treatment in advance.
First, a mixture of an ethylene-1-butene copolymer, a cross-linking agent, a foaming agent, and other components as required is a half-life temperature of the cross-linking agent of 1 minute or less and below the decomposition temperature of the foaming agent. In addition, it is preferable that plasticization is performed by a mixing roll, a kneader, an extruder, or the like at a temperature equal to or higher than the melting point of the ethylene-1-butene copolymer. The temperature for plasticizing the mixture is preferably 100 to 140 ° C, more preferably 105 to 120 ° C, and still more preferably 110 to 115 ° C. The plasticized mixture is cooled to obtain a composition. The resulting composition is fed into a mold.

  The composition in the mold is pressed and heated by a pressure press or the like to form a plasticized and crosslinked intermediate (i). The temperature at which the composition is heated is equal to or higher than the one minute half-life temperature of the crosslinking agent, equal to or higher than the decomposition temperature of the blowing agent, and equal to or higher than the melting peak temperature of the ethylene-1-butene copolymer. It is preferable. It is preferable that the temperature which heats a composition is 130-200 degreeC, More preferably, it is 140-190 degreeC, More preferably, it is 140-180 degreeC.

The mold clamping pressure is preferably 3 to 20 MPa, and the pressure holding time is preferably about 30 to 60 minutes.
Next, when the mold is opened, the intermediate (i) foams and a crosslinked foam can be obtained.

  A cross-linked foam obtained using the pressure press may be referred to as a single-stage foam. It is also possible to obtain a two-stage foam by supplying the single-stage foam into a mold of a pressure press, heating and pressurizing the single-stage foam in the mold, and then opening the mold. The two-stage foam is a composition containing two or more types of foaming agents having different decomposition temperatures. The decomposition temperature of the foaming agent having a higher decomposition temperature is higher than the decomposition temperature of the lower foaming agent. After obtaining a single-stage foam by heating and pressurizing at a lower temperature, it can be obtained by heating and pressurizing at a temperature higher than the decomposition temperature of the foaming agent having a higher decomposition temperature. By performing two-stage foaming, a foam having an expansion ratio of 20 times or more can be obtained without cracking the foam.

  The cross-linked foam of ethylene-1-butene copolymer used in the present invention is formed by cross-linking foam molding by irradiating ionizing radiation such as an electron beam in addition to the above-mentioned cross-linking foam molding method using a pressure press. A crosslinked foam can also be obtained by a method or a normal pressure crosslinked foaming method using a chemical crosslinking agent.

By using the ethylene-1-butene copolymer of the present invention, an uncrosslinked foam can be produced by the following method.
In this method, an ethylene-1-butene copolymer or composition is melt-kneaded in an extruder, a physical foaming agent is injected into the ethylene-1-butene copolymer or the composition, and the mixture is further kneaded and then extruded under a low pressure condition from the extruder to be foamed. Here, “under low pressure than the extruder” is, for example, atmospheric pressure conditions. Further, an uncrosslinked foam can be produced by injection molding using an ethylene-1-butene copolymer or composition and a physical foaming agent in combination.
Physical foaming agents include vapors of low-boiling organic solvents such as methanol, ethanol, propane, butane and pentane; vapors of halogen-based inert solvents such as dichloromethane, chloroform, carbon tetrachloride, chlorofluorocarbon and nitrogen trifluoride; carbon dioxide , Inert gases such as nitrogen, argon, helium, neon, and astatine.
When the foam is produced by the above-described method using the physical foaming agent of the present invention, the amount of the physical foaming agent contained in the composition is 0.1% with respect to 100 parts by weight of the resin component contained in the composition. It is preferably ˜5 parts by weight.

  The foam obtained by the present invention is suitably used for a buffer material, a heat insulating material, a sound insulating material, a heat insulating and cold insulating material, and the like.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
The physical properties in Examples and Comparative Examples were measured according to the following methods.

(1) Density of ethylene-α-olefin copolymer (d, unit: kg / m ³ )
The density of the ethylene-α-olefin copolymer was measured according to the method defined in Method A of JIS K7112-1980. The sample was annealed according to JIS K6760-1995.

(2) Melt flow rate of ethylene-α-olefin copolymer (MFR, unit: g / 10 min)
In the method specified in JIS K7210-1995, the melt flow rate of the ethylene-α-olefin copolymer was measured by the method A under the conditions of a load of 21.18 N and a temperature of 190 ° C.

(3) Swell ratio (SR)
In the measurement of the melt flow rate in (2), an ethylene-α-olefin copolymer strand extruded at a length of about 15 to 20 mm from an orifice under conditions of a temperature of 190 ° C. and a load of 21.18 N Cooled to obtain a solid strand. Next, the diameter D (unit: mm) of the strand at a position of about 5 mm from the upstream end of extrusion of the strand was measured, and the value obtained by dividing the diameter D by the orifice diameter 2.095 mm (D ₀ ) (D / D ₀ ) was calculated and used as the swell ratio.

(4) Molecular weight distribution of ethylene-α-olefin copolymer (Mw / Mn)
Using a gel permeation chromatograph (GPC) method, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are measured under the following conditions (1) to (8) to obtain Mw / Mn. It was. The baseline on the chromatogram is a stable horizontal region with a sufficiently long retention time than the appearance of the sample elution peak and a stable horizontal region with a sufficiently long retention time than the solvent elution peak was observed. A straight line formed by connecting the points.
(1) Equipment: Waters 150C manufactured by Waters
(2) Separation column: TOSOH TSKgelGMH6-HT
(3) Measurement temperature: 140 ° C
(4) Carrier: Orthodichlorobenzene
(5) Flow rate: 1.0 mL / min
(6) Injection volume: 500 μL
(7) Detector: Differential refraction
(8) Molecular weight reference material: Standard polystyrene

(5) Activation energy of flow of ethylene-α-olefin copolymer (Ea, unit: kJ / mol)
Using a viscoelasticity measuring device (Rheometrics Mechanical Spectrometer RMS-800 manufactured by Rheometrics), a melt complex viscosity-angular frequency curve at 130 ° C., 150 ° C., 170 ° C. and 190 ° C. was measured under the following measurement conditions. From the obtained melt complex viscosity-angular frequency curve, calculation software Rhios V. Using 4.4.4, a master curve of the melt complex viscosity-angular frequency curve at 190 ° C. was created, and the activation energy (Ea) of the flow was determined.
<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: Nitrogen

(6) Differential scanning calorimetry The ethylene-α-olefin copolymer was pressed for 5 minutes at a pressure of 10 MPa with a hot press at 150 ° C and then cooled for 5 minutes with a cooling press at 30 ° C to obtain a thickness of about The sheet was molded into a 100 μm sheet, and a sample of about 10 mg was cut out from the sheet and sealed in an aluminum pan. Next, the aluminum pan in which the sample was sealed was held at a differential scanning calorimeter (differential scanning calorimeter DSC-7 manufactured by Perkin Elmer Co., Ltd.) (1) at 150 ° C. for 5 minutes, and (2) 5 ° C. (3) Hold at 20 ° C. for 2 minutes, (4) Increase the temperature from 20 ° C. to 150 ° C. at 5 ° C./minute, and calculate the melting curve in (4) It was measured. From the obtained melting curve, the temperature showing the melting peak having the highest peak height among melting peaks existing in the range from 25 ° C. to 150 ° C. was determined and used as the melting peak temperature. In addition, when there were a plurality of melting peaks, a temperature showing a melting peak different from the maximum melting peak was also obtained.

(7) Quantification of short-chain branched species by NMR (unit: pieces / 1000 carbons)
The number of short-chain branches per 1000 carbon atoms was determined by measuring the carbon nuclear magnetic resonance (13C-NMR) spectrum of the polymer under the following measurement conditions by the carbon nuclear magnetic resonance (13C-NMR) method. From the method, the number of short chain branches per 1000 carbon atoms in the polymer was determined.
(Measurement condition)
Apparatus: AVANCE600 manufactured by Bruker
Measurement probe: 10 mm cryoprobe Measurement solvent: 1,2-dichlorobenzene / 1,2-dichlorobenzene-d4 = 75/25 (volume ratio) liquid mixture Measurement temperature: 130 ° C.
Measurement method: proton decoupling method Pulse width: 45 degrees Pulse repetition time: 4 seconds Measurement standard: Tetramethylsilane window function: Exponential or Gaussian integration number: 2500

<Method for calculating the number of ethyl branches>
Derived from methine carbon to which a branch having 2 carbon atoms is bonded, when the sum of the peak areas of all peaks having a peak top at 5 to 50 ppm is 1000 in the NMR spectrum obtained by treating the window function with an exponential. The number of short chain branches was calculated from the peak area. Under the present measurement conditions, the number of ethyl branches was determined from the peak area of 39.5 to 40.0 ppm.
<Calculation method of butyl branch>
Derived from methine carbon having 4 carbon atoms combined when the sum of the peak areas of all peaks having a peak top at 5 to 50 ppm is 1000 in the NMR spectrum obtained by treating the window function with an exponential. The number of short chain branches was calculated from the peak area. Under these measurement conditions, the number of butyl branches was determined from the total value of the peak area of 38.0 to 38.21 ppm and the peak area of 35.85 to 36.00 ppm.

(8) Evaluation of kneadability of composition The following kneadability evaluation was performed to determine whether melt kneading is possible at a temperature lower than the decomposition temperature of a general pyrolytic foaming agent, that is, 115 ° C.
Using a roll kneader, kneading was performed under conditions of a roll temperature of 115 ° C. and a kneading time of 5 minutes, and the kneadability of the composition was evaluated. The case where the pellets were completely melted after 5 minutes was marked as ◯, and the case where unmelted pellets remained was marked as x. When unmelted pellets remain, cross-linking unevenness and non-uniform cell diameter of the produced cross-linked foam are generated.

(9) Foam density (d, unit: Kg / m ³ )
The density of the foam was measured according to the method defined in Method A of JIS K7112-1980. Note that the foam sample was not annealed.

(10) Foaming ratio (unit: times)
The density was calculated from the density of the ethylene-α-olefin copolymer determined by the above (1) density method and the foam density determined in (8) by the following formula.
Foaming ratio = ethylene-α-olefin copolymer density / foam density

(11) Hardness of crosslinked foam (unit: none)
The hardness of the surface (mold installation surface) of the obtained crosslinked foam was measured with a C method hardness tester in accordance with ASTM-D2240.

[Example 1]
(1) Treatment of silica In a reactor equipped with a nitrogen-replaced stirrer, 500 ml of toluene as a solvent and silica heat-treated at 300 ° C. under a nitrogen stream (Sypolol 948 manufactured by Devison; average particle size = 55 μm; pore volume) = 1.67 ml / g; specific surface area = 325 m ² / g) was added and stirred. Then, after cooling to 5 ° C., a mixed solution of 28.5 ml of 1,1,1,3,3,3-hexamethyldisilazane and 38.3 ml of toluene was maintained while keeping the temperature in the reactor at 5 ° C. It was dripped in 30 minutes. After completion of the dropping, the mixture was stirred at 5 ° C. for 1 hour and then at 95 ° C. for 3 hours and filtered. The obtained solid component was washed 6 times with 500 ml of toluene and twice with 500 ml of hexane. Thereafter, the solid component was dried at 23 ° C. under reduced pressure for 1 hour to obtain 52.2 g of surface-treated silica gel.

(2) Preparation of promoter support (A1) After drying under reduced pressure, in a 300 ml four-necked flask purged with nitrogen, 16.2 g of the surface-treated silica gel obtained in Example 1 (1) above and toluene 112 .5 ml was added. Next, 40.5 ml of a diethylzinc hexane solution having a diethylzinc concentration of 2 mmol / ml was added and stirred. Then, after cooling to 5 ° C., 16.7 ml of a 3,4,5-trifluorophenol toluene solution having a concentration of 3,4,5-trifluorophenol of 2.42 mmol / ml was added to the reactor. While maintaining the temperature at 5 ° C., the solution was added dropwise over 180 minutes. After completion of dropping, the mixture was stirred at 5 ° C. for 1 hour and at 40 ° C. for 1 hour. Thereafter, 1.08 ml of water was added dropwise over 4.5 hours while maintaining the temperature in the reactor at 5 ° C. After completion of dropping, the mixture was stirred at 5 ° C for 1.5 hours, at 40 ° C for 2 hours, and further at 80 ° C for 2 hours. After the stirring was stopped, the mixture was allowed to stand, 90 ml of the supernatant liquid was extracted, 90 ml of toluene was added, the temperature was raised to 95 ° C., the mixture was stirred for 4 hours, and after stirring, the supernatant liquid was extracted to obtain a solid component. The obtained solid component was washed 4 times with 90 ml of toluene and 3 times with 90 ml of hexane. Thereafter, the solid component (hereinafter referred to as a promoter support (A1)) was obtained by drying.

(3) Preparation of pre-polymerization catalyst component (B1) 80 liters of butane was added to an autoclave with an internal volume of 210 liters previously purged with nitrogen, and then 101 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide was added. The autoclave was heated to 50 ° C. and stirred for 2 hours. Next, after the temperature of the autoclave was lowered to 30 ° C. and the system was stabilized, ethylene was charged in an amount of 0.03 MPa at the gas phase pressure in the autoclave, and 0.7 kg of the promoter support (A1) was added, and then triisobutyl was added. Polymerization was started by charging 158 mmol of aluminum. After 30 minutes while continuously supplying ethylene at 0.7 kg / hour, the temperature was raised to 50 ° C., and ethylene and hydrogen were supplied at 3.5 kg / hour and 5.5 liters (room temperature and normal pressure volume) / hour, respectively. A total of 4 hours of prepolymerization was carried out by continuous feeding. After completion of the polymerization, the remaining solids purged with ethylene, butane, hydrogen gas and the like are vacuum-dried at room temperature, and the prepolymerized catalyst component (B1) in which 20 g of polyethylene is prepolymerized per 1 g of the promoter support (A1). Got.

(4) Production of ethylene-1-butene copolymer (PE-1) Using the prepolymerized catalyst component (B1) obtained above, ethylene and 1-butene are copolymerized in a continuous fluidized bed gas phase polymerization apparatus. This was carried out to obtain a polymer powder. As polymerization conditions, the polymerization temperature was 86 ° C., the polymerization pressure was 2 MPa, the hydrogen molar ratio to ethylene was 1.39%, and the 1-butene molar ratio to the total of ethylene and 1-butene was 4.25%. During the polymerization, ethylene, 1-butene and hydrogen were continuously supplied in order to keep the gas composition constant. Moreover, the said prepolymerization catalyst component (B1), triisobutylaluminum, and triethylamine (3% of molar ratio with respect to triisobutylaluminum) were supplied continuously, and the total powder weight of 80 kg of the fluidized bed was kept constant. The average polymerization time was 4 hours. The obtained polymer powder was fed using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg / hour, a screw speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 230 ° C. By granulating under the conditions, an ethylene-1-butene copolymer (PE-1) was obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

(2) Molding of cross-linked foam 100 parts by weight of the copolymer PE-1, and azodicarbonamide <ADCA> (Eiwa Chemical Co., Ltd.), which is a thermal decomposition foaming agent, with respect to 100 parts by weight of PE-1. Product name: VINYHALL AC # 3 Decomposition temperature: 208 ° C) 5 parts by weight, dicumyl peroxide as a cross-linking agent (trade name: Park Mill D, manufactured by NOF Corporation), urea as a foaming aid ( Eiwa Chemical Co., Ltd. product name Cell paste 101) 0.5 parts by weight, zinc stearate 1.0 parts by weight and zinc oxide 2.0 parts by weight, using a roll kneader, at a roll temperature of 115 ° C. Kneading was performed for 5 minutes to obtain a composition. The above composition was filled in a 12 cm × 12 cm × 2.0 cm mold, the composition filled under the conditions of a temperature of 154 ° C., a time of 40 minutes, and a pressure of 20 MPa was heated and pressurized, and then the mold was opened to form a crosslinked foam. Got. The physical property evaluation results of the obtained crosslinked foam are shown in Table 2.

[Example 2]
(1) Production of ethylene-1-butene copolymer (PE-2) Using a prepolymerization catalyst component (B1) obtained by the same method as in Example 1, ethylene and 1- Butene was copolymerized to obtain a polymer powder. As polymerization conditions, the polymerization temperature was 86 ° C., the polymerization pressure was 2 MPa, the hydrogen molar ratio to ethylene was 2.16%, and the 1-butene molar ratio to the total of ethylene and 1-butene was 4.85%. During the polymerization, ethylene, 1-butene and hydrogen were continuously supplied in order to keep the gas composition constant. Moreover, the said prepolymerization catalyst component (B1), triisobutylaluminum, and triethylamine (3% of molar ratio with respect to triisobutylaluminum) were continuously supplied, and the total powder weight of 80 kg of the fluidized bed was maintained constant. The average polymerization time was 4 hours. The obtained polymer powder was fed using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg / hour, a screw speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 230 ° C. By granulating under the conditions, an ethylene-1-butene copolymer (PE-2) was obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

(2) Molding of cross-linked foam A cross-linked foam was obtained in the same manner as in Example 1 except that PE-2 was used instead of PE-1. Table 2 shows the physical properties of the obtained crosslinked foam.

Example 3
(1) Production of ethylene-1-butene copolymer (PE-3) Using a prepolymerization catalyst component (B1) obtained by the same method as in Example 1, ethylene and 1- Butene was copolymerized to obtain a polymer powder. As polymerization conditions, the polymerization temperature was 87 ° C., the polymerization pressure was 2 MPa, the hydrogen molar ratio to ethylene was 1.14%, and the 1-butene molar ratio to the total of ethylene and 1-butene was 4.13%. During the polymerization, ethylene, 1-butene and hydrogen were continuously supplied in order to keep the gas composition constant. Moreover, the said prepolymerization catalyst component (B1), triisobutylaluminum, and triethylamine (3% of molar ratio with respect to triisobutylaluminum) were continuously supplied, and the total powder weight of 80 kg of the fluidized bed was maintained constant. The average polymerization time was 4 hours. The obtained polymer powder was fed using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg / hour, a screw speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 230 ° C. By granulating under the conditions, an ethylene-1-butene copolymer (PE-3) was obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

(2) Production of cross-linked foam A cross-linked foam was obtained in the same manner as in Example 1 except that PE-3 was used instead of PE-1. Table 2 shows the physical properties of the obtained crosslinked foam.

[Comparative Example 1]
(1) Preparation of solid catalyst component In a reactor equipped with a nitrogen-replaced stirrer, silica heat-treated at 300 ° C. under nitrogen flow (Sypolol 948 manufactured by Devison; 50% volume average particle size = 55 μm; 1.67 ml / g; specific surface area = 325 m ² / g) 2.8 kg and 24 kg of toluene were added and stirred. Thereafter, after cooling to 5 ° C., a mixed solution of 0.9 kg of 1,1,1,3,3,3-hexamethyldisilazane and 1.4 kg of toluene was maintained for 30 minutes while maintaining the reactor temperature at 5 ° C. It was dripped at. After completion of dropping, the mixture was stirred at 5 ° C. for 1 hour, then heated to 95 ° C., stirred at 95 ° C. for 3 hours, and filtered. The obtained solid product was washed 6 times with 20.8 kg of toluene. Thereafter, 7.1 kg of toluene was added to form a slurry, which was allowed to stand overnight.

To the slurry obtained above, 1.73 kg of diethylzinc in hexane (diethylzinc concentration: 50 mass%) and 1.02 kg of hexane were added and stirred. Then, after cooling to 5 ° C., a mixed solution of 0.78 kg of 3,4,5-trifluorophenol and 1.44 kg of toluene was added dropwise over 60 minutes while maintaining the temperature of the reactor at 5 ° C. After completion of dropping, the mixture was stirred at 5 ° C. for 1 hour, then heated to 40 ° C. and stirred at 40 ° C. for 1 hour. Then cooled to 22 ° C., was added dropwise for 1.5 hours while maintaining the H ₂ O0.11kg the temperature of the reactor 22 ° C.. After completion of dropping, the mixture was stirred at 22 ° C. for 1.5 hours, then heated to 40 ° C., stirred at 40 ° C. for 2 hours, further heated to 80 ° C., and stirred at 80 ° C. for 2 hours. After stirring, at room temperature, the supernatant was withdrawn to a residual amount of 16 L, charged with 11.6 kg of toluene, then heated to 95 ° C. and stirred for 4 hours. After stirring, the supernatant liquid was extracted at room temperature to obtain a solid product. The obtained solid product was washed 4 times with 20.8 kg of toluene and 3 times with 24 liters of hexane. Then, the solid catalyst component was obtained by drying.

(2) Preparation of pre-polymerization catalyst component (B2) 80 liters of butane was charged into an autoclave with an internal volume of 210 liters that had been previously purged with nitrogen, and then 34.5 mmol of racemic-ethylenebis (1-indenyl) zirconium diphenoxide. The autoclave was heated to 50 ° C. and stirred for 2 hours. Next, after the temperature of the autoclave is lowered to 30 ° C. and the system is stabilized, 0.03 MPa of ethylene is charged at the gas phase pressure in the autoclave, and 0.7 kg of the solid catalyst component described in (1) is added. Polymerization was started by adding 140 mmol of triisobutylaluminum. After 30 minutes while continuously supplying ethylene at 0.7 kg / hour, the temperature was raised to 50 ° C., and ethylene and hydrogen were supplied at 3.5 kg / hour and 10.2 liters (room temperature and normal pressure volume) / hour, respectively. A total of 4 hours of prepolymerization was carried out by continuous feeding. After the polymerization was completed, ethylene, butane, hydrogen gas and the like were purged, and the remaining solid was vacuum dried at room temperature to obtain a prepolymerized catalyst component (B2) in which 15 g of polyethylene was prepolymerized per 1 g of the solid catalyst component. .

(3) Production of ethylene-1-butene-1-hexene copolymer (PE-4) Using the prepolymerized catalyst component (B2) obtained above, ethylene and 1-butene were obtained in a continuous fluidized bed gas phase polymerization apparatus. 1-hexene was copolymerized to obtain a polymer powder. As polymerization conditions, the polymerization temperature was 84 ° C., the polymerization pressure was 2 MPa, the hydrogen molar ratio to ethylene was 1.04%, the 1-butene molar ratio to the total of ethylene, 1-butene and 1-hexene was 2.16%, The 1-hexene molar ratio was 0.73%. During the polymerization, ethylene, 1-butene, 1-hexene and hydrogen were continuously supplied in order to keep the gas composition constant. Further, the above prepolymerization catalyst component, triisobutylaluminum and triethylamine (a molar ratio of 3% with respect to triisobutylaluminum) were continuously supplied, and the total powder mass of 80 kg in the fluidized bed was kept constant. The average polymerization time was 4 hours. The obtained polymer powder was fed using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg / hour, a screw speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 230 ° C. By granulating under the conditions, an ethylene-1-butene-1-hexene copolymer (PE-4) was obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

(2) Production of composition When roll kneading was carried out in the same manner as in Example 1 except that PE-4 was used instead of PE-1, unmelted pellets remained after 5 minutes. Could not be manufactured.

[Comparative Example 2]
(1) Production of ethylene-1-butene-1-hexene copolymer (PE-5) Using a prepolymerized catalyst component (B1) obtained by the same method as in Example 1, using a continuous fluidized bed gas phase polymerization apparatus. Copolymerization of ethylene with 1-butene and 1-hexene was performed to obtain a polymer powder. As polymerization conditions, the polymerization temperature was 84 ° C., the polymerization pressure was 2 MPa, the hydrogen molar ratio to ethylene was 1.4%, the 1-butene molar ratio to the total of ethylene, 1-butene and 1-hexene was 2.3%, The 1-hexene molar ratio was 1.0%. During the polymerization, ethylene, 1-butene, 1-hexene and hydrogen were continuously supplied in order to keep the gas composition constant. Further, the above prepolymerization catalyst component, triisobutylaluminum and triethylamine (a molar ratio of 3% with respect to triisobutylaluminum) were continuously supplied, and the total powder mass of 80 kg in the fluidized bed was kept constant. The average polymerization time was 4 hours. The obtained polymer powder was fed using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg / hour, a screw speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 to 230 ° C. By granulating under the conditions, an ethylene-1-butene-1-hexene copolymer (hereinafter referred to as PE-5) was obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

(2) Production of cross-linked foam A cross-linked foam was obtained in the same manner as in Example 1 except that PE-5 was used instead of PE-1. Table 3 shows the physical properties of the obtained crosslinked foam.

[Polymerization Example 1]
(1) Preparation of solid catalyst component Silica (Sypolol 948, manufactured by Devison Corp .; average particle size = 61 μm; pore volume = 1.70 ml) heated at 300 ° C. under nitrogen flow in a nitrogen-substituted three-liter four-necked flask / G; specific surface area = 291 m ² / g) was added in an amount of 203 g, and then 1.2 liters of toluene was added while the silica adhering to the flask wall was washed away. After cooling to 5 ° C., a mixed solution of 84.4 ml of 1,1,1,3,3,3-hexamethyldisilazane and 115 ml of toluene was added dropwise over 25 minutes. After completion of the dropping, the mixture was stirred at 5 ° C. for 1 hour and then at 95 ° C. for 3 hours and filtered. Thereafter, the filter was washed four times with 1.2 liters of toluene at 95 ° C. Then, after adding 1.2 liters of toluene, it was left still overnight.

(2) Synthesis of component (A3) 0.550 liter (1.10 mol) of diethylzinc in hexane (2.00 mol / liter) was added to the slurry obtained in Example 10 (1) and cooled to 5 ° C. did. A solution prepared by dissolving 105 g (0.570 mol) of pentafluorophenol in 173 ml of toluene was added dropwise thereto over 65 minutes. After completion of dropping, the mixture was stirred at 5 ° C. for 1 hour. Then, it heated at 40 degreeC and stirred for 1 hour. After the temperature was adjusted to 5 ° C. with an ice bath, 14.9 g (0.828 mol) of water was added dropwise over 90 minutes. After completion of dropping, the mixture was stirred at 5 ° C. for 1.5 hours and at 40 ° C. for 2 hours. Then, it left still overnight at room temperature. Then, after stirring at 80 ° C. for 2 hours, the mixture is allowed to stand to settle the solid component, and when the interface between the precipitated solid component layer and the upper slurry portion is seen, the upper slurry portion is removed, and then the remaining liquid After filtering the components with a filter, 1.7 liters of toluene was added and stirred at 95 ° C. for 2 hours. Thereafter, the mixture was stirred four times with 1.7 liters of toluene at 95 ° C. and twice with 1.7 liters of hexane at room temperature, and then allowed to stand to precipitate the solid component. When the interface with the slurry portion was seen, the upper slurry portion was removed, and the remaining liquid component was then filtered through a filter. Thereafter, the solid component was dried under reduced pressure at room temperature for 3 hours to obtain 386 g of a solid component (hereinafter referred to as promoter support (A3)). As a result of elemental analysis, they were Zn = 2.4 mmol / g and F = 6.8 mmol / g.

(2) Preparation of pre-polymerization catalyst component (B3) In an autoclave with a stirrer with an internal volume of 210 liters that had been previously purged with nitrogen, 0.7 kg of the above-mentioned promoter support (A3), 100 liters of butane, 0.02 kg of 1-butene, After charging 12 liters of hydrogen at normal temperature and pressure, 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 (B3) was obtained.

(3) Production of ethylene-1-butene-1-hexene copolymer (PE-6) Using a continuous fluidized bed gas phase polymerization apparatus, the polymerization temperature was 85 ° C., the polymerization pressure was 2 MPa, and the prepolymerization catalyst. Component (B3), triisobutylaluminum, ethylene, 1-butene and hydrogen are continuously fed into the reactor so that the molar ratio of hydrogen to ethylene in the reaction gas is 1.12% and 1-butene to ethylene. Copolymerization of ethylene, 1-butene and 1-hexene was carried out under the conditions of a molar ratio of 2.4%, a molar ratio of 1-hexene to ethylene of 0.3% and an average polymerization time of 5 hours. By polymerization, an ethylene-1-butene-1-hexene copolymer powder is fed using a LCM50 extruder manufactured by Kobe Steel, Ltd., at a feed rate of 50 kg / hour, a screw rotation speed of 450 rpm, a gate opening of 50%, and a suction pressure. By pelletizing under conditions of 0.1 MPa and a resin temperature of 200 to 215 ° C., pellets of ethylene-1-butene-1-hexene copolymer (PE-6) were obtained. The results of physical property evaluation of the obtained copolymer are shown in Table 1. The melting curve of the obtained copolymer is shown in FIG.

1 Point indicating shoulder 2 Inflection point 3 Inflection point

Claims (4)

The density is 921 to 930 kg / m ³ , the melt flow rate is 0.1 to 5.0 g / 10 min, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) is 5. In a melting curve from 25 ° C. to 150 ° C. obtained by differential scanning calorimetry, with a flow activation energy of 50 to 100 kJ / mol, a swell ratio of 1.10 to 1.60, An ethylene-1-butene copolymer having only one melting peak and a melting peak temperature of 100 ° C to 109 ° C.   An ethylene-1-butene copolymer containing 0.1 to 30 parts by weight of a blowing agent with respect to 100 parts by weight of the ethylene-1-butene copolymer according to claim 1 and the ethylene-1-butene copolymer. Polymer composition.   The ethylene-1-butene copolymer composition according to claim 2, further comprising 0.01 to 4 parts by weight of a crosslinking agent with respect to 100 parts by weight of the ethylene-1-butene copolymer.   The foam formed by foam-molding the ethylene-1-butene copolymer composition of Claim 2 or 3.

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