JP2008208224A - Propylene-ethylene random copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propylene-ethylene random copolymer that contains relatively many different kinds of insertions and has suppressed spreading of crystalline distribution even when it has a low melting point. <P>SOLUTION: The propylene-ethylene random copolymer is comprised of 94-84 mol% of propylene and 6-16 mol% of ethylene and has properties (a)-(d) below. (a) A weight-average molecular weight (Mw) of 100,000-500,000. (b) A melt peak temperature (Tm) of 90-115°C. (c) The difference between an elution end temperature and an elution peak temperature of at most 7°C and the amount eluted before 0°C of at most 1 wt.% of the whole in the TREF elusion curve. (d) A propylene unit chain portion having a head-to-tail linkage having an isotactic triad fraction of at least 97%, an area fraction of regioregularity based on 2.1-insertion of 0.15-1.0% and an area fraction of regioregularity based on 1.3-insertion of at least 0.05%, each measured by<SP>13</SP>C-NMR. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a propylene / ethylene random copolymer obtained by copolymerizing ethylene as a comonomer with propylene, and more specifically, although a melting point is low by copolymerizing a relatively large amount of ethylene, a crystalline distribution, In particular, the present invention relates to a novel propylene / ethylene random copolymer in which the spread of crystallinity distribution to the high crystal side is suppressed and the generation of soluble components is extremely small and has a specific propylene heterogeneous insertion.

Conventionally, propylene / ethylene random copolymers have excellent transparency, and among polypropylene resins, their melting points are relatively low, and heat sealability of films, etc. is excellent. Widely used in fields such as the body.
Conventionally, Ziegler-Natta catalysts have been widely used for the production of these propylene / ethylene random copolymers. However, it has been difficult to obtain a propylene / ethylene random copolymer having a lower melting point.
This is because there are multiple types of active sites in the catalyst system, and there is a difference in ethylene copolymerizability, so even if the total ethylene content is increased, at the active sites with low ethylene copolymerizability, This is due to the low crystallinity of the melting point due to the formation of a component with low ethylene content and high crystallinity. However, in the high active site, a lot of amorphous components containing a large amount of ethylene are produced, which causes stickiness and is extremely difficult to produce. It had the problem of causing many problems such as poor appearance due to bleeding out.

  In recent years, metallocene catalysts using transition metal compounds have been developed, proposals for various complexes have been made, and since the active sites are uniform, the crystal melting temperature can be increased by increasing the ethylene content. It has been disclosed that a propylene / ethylene random copolymer having a narrow molecular weight and composition distribution and a small amount of xylene solubles can be obtained even if the content of the transition metal is lowered. Specifically, a transition metal having a specific structure is disclosed. There has been proposed a method for obtaining a propylene / ethylene random copolymer with a small amount of xylene extract which deteriorates blocking resistance using a metallocene catalyst using a compound (see, for example, Patent Document 1).

On the other hand, with the increasing use of polypropylene resins in the industry in recent years, improvement in productivity and quality has always been demanded, but propylene / ethylene random copolymers having a lower melting point are used as heat seal temperatures in the sealant field. Improvement of moldability such as further lowering of the temperature and improvement of mechanical properties such as transparency, elongation and strength are expected, and development thereof is desired.
Here, several proposals have been made in recent years for propylene / ethylene random copolymers having a lower crystal melting temperature such that the melting point is less than 120 ° C. Specifically, a propylene / ethylene random copolymer (see Patent Document 2) containing a relatively large amount of ethylene at 10 to 70 mol% and having a low melting point of 40 ° C. to 140 ° C. has been proposed. The polymer obtained in (1) has a small decrease in crystal melting temperature despite having a high ethylene content, and has a relatively broad crystallinity distribution, leaving room for improvement in transparency and heat seal characteristics.
This means that even with the metallocene catalyst, the crystalline distribution tends to broaden as the ethylene content is increased, and similar behavior is typically obtained with the metallocene catalyst. In the proposal regarding a molded body such as a film obtained from a propylene-based random copolymer having a high molecular weight and a low normal decane content and a film obtained from the copolymer (see Patent Document 3), many more examples are given. It is disclosed. In this proposal, the lowering of the melting point when the ethylene content is increased becomes gentler as the ethylene content is increased, and it cannot be said that the broadening of the crystalline distribution that occurs when the melting point is lowered is not eliminated. .

Although the spread of such crystallinity distribution is smaller than that obtained with Ziegler-Natta type catalysts, the low-temperature heat sealability and transparency are deteriorated, and the stickiness is not sufficiently improved. Leaving room for improvement.
In addition, it is well known to those skilled in the art that polypropylene-based resins produced using metallocene-based catalysts contain position irregular units such as 2,1-insertion or 1,3-insertion of propylene monomer. .
Specifically, a proposal relating to a propylene / ethylene random copolymer containing a relatively large amount of ethylene at 5 to 50 mol% and having a 2,1-insertion of 0.05 to 0.5% (see Patent Document 4). It is obtained by copolymerizing propylene with at least one α-olefin selected from the group consisting of ethylene and an α-olefin having 4 to 20 carbon atoms using a specific catalyst. Proposals related to propylene / ethylene random copolymers containing 0.21-% or less of 2,1-insertion (see Patent Document 5) have also been made, and in these proposals, a relatively large amount of ethylene is contained. A propylene random copolymer having an amount is shown.

Here, the more heterogeneous insertions are included, the lower the crystallinity of the propylene-based resin. In particular, when 1,3-insertion increases, the glass transition temperature of the propylene-based resin decreases, and the transparency and strength are excellent. It is expected. Moreover, the higher the stereoregularity, the higher the ethylene content at the same crystallinity, and the higher the impact resistance. In the propylene / ethylene random copolymers shown in Patent Documents 4 and 5, although stereoregularity is high, there is little 1,3-insertion and there is room for improvement.
In addition, propylene / ethylene random copolymer having high stereoregularity and including 1,3-insertion has specific MFR and memory effect, exhibits specific DSC behavior, and is 0.5 to 2.0%. The proposal regarding a propylene-based resin film having 2,1-insertion of 0.06 to 0.4% of 1,3-insertion (Patent Document 6) is shown. In such a propylene / ethylene random copolymer having a very low melting point, the problem that the crystallinity distribution is widespread has not been recognized, and no suggestion has been made for its solution.
JP-A-1-266116 Japanese Patent Laid-Open No. 62-119215 JP 9-176222 A JP-A-7-149833 JP 7-196734 A JP-A-11-302470

  An object of the present invention is to provide a propylene / ethylene random copolymer that contains a relatively large number of different types of insertions and suppresses the spread of crystallinity distribution even at a low melting point, in view of the problems of the prior art. It is in.

  In order to solve the above problems, the present inventors have conducted extensive research on a propylene random copolymer having a high degree of stereoregularity, a relatively large number of different insertions, and a low melting point. However, when increasing the ethylene content and lowering the melting point, it was recognized that there was a problem of inhibiting transparency and heat sealability by spreading the crystallinity distribution particularly on the high crystal side. In spite of having a low crystal melting temperature of 90-115 ° C. due to the inclusion of a specific heterogeneous insertion, the crystallinity distribution is kept narrow and the crystal melting temperature is greatly reduced when the ethylene content is increased. New propylene random copolymers in a specific range are found, and the transition metal having a specific structure is used for the production of these new propylene random copolymers. Using a metallocene catalyst comprising a compound, from the viewpoint of productivity and the like may be gas phase polymerization under specific conditions, found to be very effective, and have completed the present invention.

That is, according to the first invention of the present invention, propylene / ethylene random copolymer consisting of propylene 94 to 84 mol% and ethylene 6 to 16 mol% and having the following physical properties (a) to (d) Coalescence is provided.
(A) The weight average molecular weight (Mw) obtained by GPC measurement is in the range of 100,000 to 500,000.
(B) The melting peak temperature (Tm) measured by DSC is in the range of 90 to 115 ° C.
(C) TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. The difference [T (99) −T (P)] between the elution end temperature [T (99)] and the elution peak temperature [T (P)] is 7 ° C. or less and the amount [W ( 0)] is 1 wt% or less of the whole.
(D) The propylene unit chain portion composed of a head-to-tail bond has an isotactic triad fraction measured by ¹³ C-NMR of 97% or more and a regioregular area based on 2.1-insertion. The rate is in the range of 0.15 to 1.0%, and the area fraction of the positional regularity based on 1.3-insertion is 0.05% or more.

According to the second invention of the present invention, there is further provided a propylene / ethylene random copolymer having the following physical property (e) in the first invention.
(E) The melting peak temperature (Tm) and the ethylene content ([E] (mol%)) satisfy the following formula (i).
Formula (i): 155-5 × [E] ≧ Tm ≧ 140−5 × [E]

  According to a third invention of the present invention, in the first or second invention, propylene / ethylene is obtained by gas phase polymerization using a transition metal compound represented by the following general formula (I): A random copolymer is provided.

(In the formula, A and A ′ are optionally substituted cyclopentadienyl groups. Q is a binding group that bridges two conjugated five-membered ring ligands at an arbitrary position. M is a metal atom of a transition metal selected from Groups 4 to 6 in the periodic table X and Y are auxiliary ligands, each of which is a hydrogen atom, a halogen atom, a hydrocarbon group, or hetero (It is a hydrocarbon group which may have an atom.)
According to a fourth invention of the present invention, in the first or second invention, propylene characterized by being vapor-phase polymerized using a transition metal compound represented by the following general formula (II) An ethylene random copolymer is provided.

(In formula, R < ¹ >, R < ² >, R < ⁴ > and R < ⁵ > are respectively independently a hydrogen atom, a C1-C10 hydrocarbon group, a C1-C18 silicon-containing hydrocarbon group, or C1. Represents a halogenated hydrocarbon group of ˜18, and R ³ and R ⁶ each independently represents a saturated or unsaturated group having 3 to 10 carbon atoms that forms a condensed ring with respect to the five-membered ring to which it is bonded. A condensed hydrocarbon group in which at least one of R ³ and R ⁶ has 5 to 8 carbon atoms and has a unsaturated bond derived from R ³ or R ^6. R ⁷ and R ⁸ are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, C1-C20 oxygen-containing hydrocarbon group, amino group, C1-C20 nitrogen-containing carbon A hydrogen group or a sulfur-containing hydrocarbon group having 1 to 20 carbon atoms, m and n each independently represents an integer of 0 to 20. However, m and n are not 0 at the same time. When m or n is 2 or more, R ⁷ or R ⁸ may be linked to each other to form a new ring structure, Q is a bridging group that links two cyclopentadienyl rings. X and Y represent a σ covalent bond auxiliary ligand that reacts with a cocatalyst to develop olefin polymerization ability, and M represents a transition metal of Groups 4 to 6 in the periodic table.
Furthermore, according to the fifth invention of the present invention, in the third or fourth invention, an olefin polymerization catalyst comprising the following components (A) and (B) or components (A), (B) and (C): A propylene / ethylene random copolymer characterized by being vapor-phase polymerized using is provided.
Component (A): Transition metal compound represented by general formula (I) or (II) Component (B): At least one compound selected from ion-exchange layered silicate Component (C): Organoaluminum compound

As described above, the present invention relates to a propylene / ethylene random copolymer, and preferred embodiments thereof include the following.
(1) In the general formula (I) or (II), M is a transition metal belonging to Group 4 of the periodic table.
(2) In the general formula (I) or (II), M is zirconium or hafnium, and the propylene / ethylene random copolymer according to the above (1).
(3) The propylene / ethylene random copolymer as described above, wherein in the general formula (I), A and A ′ are an indenyl group or an azulenyl group.
(4) The ion-exchange layered silicate of the component (B) is a spherical particle having an average particle size of 50 μm or more and / or a water content of 3% by weight or less. Random copolymer.

The propylene / ethylene random copolymer of the present invention has high stereoregularity, contains a relatively large number of heterogeneous insertions, and has a crystallinity distribution, particularly on the high crystal side, despite a very low melting point of 90-115 ° C. In addition, the low-molecular-weight component is suppressed, and the low-temperature heat-sealing property, flexibility, and transparency are extremely excellent, and it has the effect of having improved strength without causing bleed-out and blocking. Play.
The propylene / ethylene random copolymer of the present invention can be produced under industrially easy conditions by employing specific polymerization conditions using a catalyst made of a specific metallocene compound.

  The present invention relates to a novel propylene-based random copolymer having the following characteristics, that is, a propylene / ethylene random copolymer. The propylene / ethylene random copolymer of the present invention and the production method thereof will be described in detail below for each item.

1. Propylene / ethylene random copolymer The propylene / ethylene random copolymer of the present invention comprises propylene 94 to 84 mol% and ethylene 6 to 16 mol%, and has the following physical properties (a) to (d) or physical properties (a ) To (e).

(1) Physical properties (a): Weight average molecular weight (Mw)
The propylene / ethylene random copolymer of the present invention has a weight average molecular weight Mw measured by gel permeation chromatography (GPC) in the range of 100,000 to 500,000. In the case where the weight average molecular weight Mw is 100,000 or less, there arises a problem that the molding raw material is lowered in various moldings and the strength is also inferior. On the other hand, in the case of 500,000 or more, the load at the time of shaping | molding increases remarkably and is not practical.

(2) Physical property (b): Melting peak temperature (Tm)
The propylene / ethylene random copolymer of the present invention has a melting peak temperature (hereinafter referred to as melting point or Tm (° C.)) measured by DSC in the range of 90 to 115 ° C. A propylene random copolymer having a melting point higher than this range is inferior in strength, and low-temperature heat sealability is not sufficient. On the other hand, if it is lower than this range, the crystallinity is extremely low, and problems are likely to occur during molding.
As a DSC measurement method, a commercially available differential scanning calorimeter is used, a sample of 5.0 mg is taken, held at 200 ° C. for 5 minutes, and then crystallized at a rate of temperature decrease of 10 ° C./min up to 40 ° C. The melting peak temperature when melted at a heating rate of 10 ° C./min is defined as Tm (unit: ° C.).

(3) Physical property (c): Crystalline distribution by TREF measurement The crystalline distribution of the propylene-ethylene random copolymer was measured using a temperature rising elution fractionation method (or temperature rising elution fractionation method) (hereinafter, referred to as “temperature rising elution fractionation method”). The technique evaluated by TREF) is well known to those skilled in the art, and for example, the detailed measurement method is shown in the following document.
(I) G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Polym. Symp. 45, 1-24 (1990)
(Ii) L. Wild, Adv. Polym. Sci. 98, 1-47 (1990)
(Iii) J. Org. B. P. Soares, A .; E. Hamielec, Polymer; 36, 8, 1639-1654 (1995)

  The propylene / ethylene random copolymer of the present invention is an elution amount (dWt% / dT) with respect to temperature by a temperature rising elution fractionation method (TREF) in a temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. ), The difference between the elution end temperature T (99) and the elution peak temperature T (P) (= T (99) −T (P)) is 7 ° C. or less and 0 ° C. The amount [W (0)] eluted up to 1% is 1 wt% or less.

As described above in the above [Technical Background], it is a fact well known to those skilled in the art that propylene copolymers obtained by conventional metallocene catalysts have a narrow molecular weight and composition distribution.
However, the propylene / ethylene random copolymer having an ethylene content of 6 to 16 mol%, a melting peak temperature of 90 to 115 ° C. and a relatively low melting point as in the present invention has a crystalline property. Distribution tends to spread.
As a result, in the TREF measurement for evaluating the crystallinity distribution, the elution end temperature becomes higher as the higher crystallinity component is included with respect to the elution peak temperature T (P).
Then, when the elution end temperature is the temperature T (99) at which 99 wt% of the entire elution is taken into account based on the accuracy of TREF measurement, the temperature difference from the elution peak temperature T (P) to the elution end temperature T (99) The crystallinity distribution can be evaluated by (= T (99) −T (P)).

Here, the temperature difference of the propylene / ethylene random copolymer of the present invention is as small as 7 ° C. or less, and the crystallinity distribution to the high crystal side is suppressed.
When this temperature difference is 7 ° C. or more, the highly crystalline component adversely affects transparency and heat sealability. In addition, the spread of the crystallinity distribution toward the high crystal side usually expands the distribution toward the low crystal side, so that the non-crystalline component increases, thereby worsening stickiness and blocking.
However, in the present invention, the crystallinity distribution to the low crystal side is suppressed as well as the crystallinity distribution to the high crystal side, so that almost no component is eluted by 0 ° C., and the amount [W (0)] is 1 wt% or less.

(4) Physical Property (d): Isotactic Triad Fraction of Propylene Unit Chain Part and Heterogeneous Insertion The propylene / ethylene random copolymer of the present invention is a ¹³ C- The isotactic triad fraction measured by NMR is 97% or more, and the area fraction of regioregularity based on 2.1-insertion is in the range of 0.15% or more and 1.0% or less; and 1.3- The area fraction of positional regularity based on insertion is 0.05% or more.
When the isotactic triad fraction is low, the amount of copolymer incorporated in the melting point region of the present invention is greatly reduced. At this time, since the higher the ethylene content, the lower the impact resistance at a low temperature associated with the lowering of the glass transition temperature cannot be exhibited, in the present invention, an isotactic triad is used so that a sufficient copolymer can be copolymerized. The fraction needs to be 97% or more.

In addition, it is well known to those skilled in the art that metallocene-based catalysts contain regioregular units based on 2,1-insertions and / or regioregular units based on 1,3-insertions. Therefore, it is expected to be excellent in transparency and strength.
In addition, the isotactic triad fraction (area fraction derived from the mm peak) and the position regularity area fraction in the present invention are obtained by analyzing a ¹³ C-NMR spectrum measured by a proton complete decoupling method. Ask.

¹³ C-NMR measurement:
An isotactic triad fraction is calculated | required by a following formula from a < ¹³ > C-NMR spectrum.

As a measurement method, the ¹³ C-NMR spectrum was obtained by measuring about 0.05 ml of 50 to 70 mg of a sample in about 0.5 ml of hexachlorobutadiene, o-dichlorobenzene or 1,2,4-trichlorobenzene in an NMR sample tube (5 mmφ). The solution was completely dissolved in a solvent to which deuterated benzene, which is a rock solvent, was added, and then measured at 120 ° C. by a proton complete decoupling method.
As measurement conditions, a flip angle of 45 ° and a pulse interval of 3.4 T or more (T is the longest value among spin lattice relaxation times of methyl groups) are selected. Since T of the methylene group and methine group is shorter than that of the methyl group, the recovery of magnetization is 99% or more under this condition. The chemical shift was set so that the methyl group of the 3rd unit of 5 units of propylene units bonded head-to-tail was 21.59 ppm.
The spectrum relating to the methyl carbon region (19 to 23 ppm) has peak regions of the first region (21.2 to 21.9 ppm), the second region (20.3 to 21.0 ppm), and the third region (19.5 to 59.5 ppm). 20.3 ppm). Each peak in the spectrum was assigned with reference to literature (Polymer, 30 (1989) 1350).

In the first region, the methyl group of the second unit in the three propylene unit chains represented by PPP (mm) resonates. In the second region, the methyl group of the second unit of the three-chain propylene unit represented by PPP (mr) and the methyl group of the propylene unit (PPE-methyl group) in which the adjacent units are a propylene unit and an ethylene unit resonate. (Around 20.7 ppm). In the third region, the methyl group of the second unit of the three propylene units chain represented by PPP (rr) and the methyl group of the propylene unit (EPE-methyl group) in which the adjacent units are all ethylene units are resonant ( 19.8 ppm).
As a partial structure including the position irregular unit, the following structures (i) and (ii) are included.

Among these, the carbon A peak and the carbon A ′ peak appear in the second region, and the carbon B peak and the carbon B ′ peak appear in the third region. Thus, among the peaks appearing in the first to third regions, the peaks not based on the head-to-tail bonded propylene unit three chain are PPE-methyl group, EPE-methyl group, carbon A, carbon A ′, carbon B and carbon. It is a peak based on B ′.
The peak area based on the PPE-methyl group can be evaluated from the peak area of the PPE-methine group (resonance at around 30.6 ppm), and the peak area based on the EPE-methyl group is resonant at about 32.9 ppm. ) Peak area.
The peak area based on carbon A can be evaluated from twice the peak area of methine carbon (resonant at around 33.6 ppm) to which the methyl group of carbon B is directly bonded, and the peak area based on carbon A ′ is that of carbon B ′. It can be evaluated by the peak area of the adjacent methine carbon (resonance near 33.2 ppm) of the methyl group.
The peak area based on carbon B can be evaluated by the peak area of the adjacent methine carbon (resonant at around 33.6 ppm), and the peak area based on carbon B ′ is also similar to the adjacent methine carbon (resonated at around 33.2 ppm). The peak area can be evaluated.
Therefore, when these peak areas are subtracted from the peak areas of the second region and the third region, the peak area based on the head-to-tail three-linked propylene units (PPP (mr) and PPP (rr)) can be obtained. .
By the above, since the peak areas of PPP (mm), PPP (mr) and PPP (rr) can be evaluated, the isotactic triad fraction of the propylene unit chain part consisting of a head-to-tail bond is determined according to the above formula. Can be requested.

During the polymerization, the propylene monomer undergoes 1,2-insertion (methylene side binds to the catalyst), but rarely 2,1-insertion. 2,1-inserted monomers form regiorandom units in the polymer. The ratio of 2,1-insertion in the total propylene insertion was calculated | required from the following formula using ¹³ C-NMR with reference to literature (Polymer, 30 (1989) 1350).

Here, the peak was named according to the method of Carman et al. (Rubber Chem. Technol., 44 (1971), 781). Iαβ and the like indicate peak areas such as αβ peaks. In addition, when it is difficult to obtain an area such as Iαβ directly from the spectrum due to overlapping peaks, a carbon peak having a corresponding area can be substituted.
The amount of three linkages based on 1,2-, 1,3-, 1,2-insertion of propylene is half the area of the βγ peak (resonance near 27.4 ppm), and 1 of all methyl group peaks and βγ peaks. By dividing by the sum of / 2 and multiplying by 100, the percentage was determined in%.

(5) Physical property (e): Relationship between melting peak temperature (Tm) and ethylene content [E] In the propylene / ethylene random copolymer in the present invention, ethylene content [E] (measured by ¹³ C-NMR) ( mol%) and the melting peak temperature Tm (° C.) satisfy the following formula (i).
Formula (i): 155-5 × [E] ≧ Tm ≧ 140−5 × [E]

Here, the formula (i) shows the relationship between the melting peak temperature and the ethylene content. That is, it is well known to those skilled in the art that in a propylene / ethylene random copolymer, the crystallinity decreases as the ethylene content increases and the crystal melting temperature tends to decrease accordingly.
In this case, the relationship between the ethylene content [E] and the melting peak temperature Tm is almost linear when the propylene / ethylene random copolymer has no crystallinity distribution, and the composition distribution as in the present invention is narrow. In the propylene / ethylene random copolymer, the decrease in melting peak temperature Tm per 1 mol% of ethylene content [E] is about 5 ° C.
On the other hand, when the crystallinity distribution is wide, the decrease in melting peak temperature Tm per mol of ethylene content [E] is small, and in the region of ethylene content of 6 to 16 mol% in the present invention, the melting peak temperature Tm is sufficiently decreased. Since it cannot be achieved, the range of formula (i) cannot be taken.

Further, when the ethylene content of the propylene / ethylene random copolymer is 0, that is, the melting peak temperature Tm in the propylene homopolymer becomes higher as the stereoregularity and the positional regularity are higher. Here, the left side 155 and the right side 145 in the formula (i) indicate the melting peak temperature range when the ethylene content is 0, and indicate that a specific amount of position irregular units is included.
Therefore, when it has a high isotactic triad fraction and no position irregular units are included, it exceeds 155 ° C., so it cannot satisfy the scope of the present invention. If the rate is low, it is often below 140 ° C.
As in the present invention, when the isotactic triad fraction is high and an appropriate position irregular unit is included, the relationship of the formula (i) can be satisfied.
The positioning of the propylene / ethylene random copolymer in the present invention and the conventional propylene / ethylene random copolymer having a wide crystallinity distribution is apparent from Table 1 showing the objects of Examples and Comparative Examples described later.
In addition, the copolymer content in this invention is calculated | required by analyzing the ¹³ C-NMR spectrum measured by the proton complete decoupling method. Spectral assignment may be performed with reference to Macromolecules, 17 , 1950 (1984), for example.

2. Propylene / ethylene random copolymer production method The method of producing the propylene / ethylene random copolymer of the present invention provides a propylene / ethylene random copolymer satisfying the above physical properties (a) to (e). Although there is no particular limitation as long as it is present, among them, a suitable catalyst system for producing the propylene / ethylene random copolymer of the present invention is a metallocene catalyst, and it is preferable to use a specific metallocene catalyst.
For example, as shown in the following (I) or (II), component (A): transition metal compound, component (B): at least one compound selected from ion-exchanged layered silicates, if necessary, component (C): Can be produced using an olefin polymerization catalyst containing an organoaluminum compound.

(1) Catalyst component (A) Transition metal compound (A) The transition metal compound that forms a preferred polymerization catalyst for producing the propylene / ethylene random copolymer in the present invention is represented by the following general formula (I) or (II). It is a transition metal compound represented.

  In the general formula (I), A and A ′ are cyclopentadienyl groups which may have a substituent. An example of this substituent is a hydrocarbon group having 1 to 30 carbon atoms (which may contain a hetero atom such as halogen, silicon, oxygen or sulfur). Even if this hydrocarbon group is bonded to the cyclopentadienyl group as a monovalent group, and when there are a plurality of these, two of them are bonded at the other end (ω-end). A ring may be formed together with a part of cyclopentadienyl. Other examples include an indenyl group, a fluorenyl group, or an azulenyl group. These groups may further have a substituent on the side ring. Among these, an indenyl group or an azulenyl group is preferable.

Q represents a binding group that bridges between two conjugated five-membered ring ligands at an arbitrary position, and specifically, is preferably an alkylene group, a silylene group, a silafluorene group, or a germylene group.
M is a metal atom of a transition metal selected from Groups 4 to 6 of the periodic table, preferably titanium, zirconium, hafnium or the like. In particular, zirconium and hafnium are preferable.
X and Y are auxiliary ligands that generate an active metallocene having olefin polymerization ability. Therefore, as long as this object is achieved, X and Y are not limited in the type of ligand, and each may have a hydrogen atom, a halogen atom, a hydrocarbon group, or a hetero atom. Examples are groups. Among these, a hydrocarbon group having 1 to 10 carbon atoms or a halogen atom is preferable.

(In Formula (II), R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms, or A halogenated hydrocarbon group having 1 to 18 carbon atoms, each of R ³ and R ⁶ independently represents a saturated or unsaturated group having 3 to 10 carbon atoms that forms a condensed ring with respect to the five-membered ring to which it is bonded; A saturated divalent hydrocarbon group, provided that at least one of R ³ and R ⁶ has 5 to 8 carbon atoms and has a unsaturated bond derived from R ³ or R ^6. R ⁷ and R ⁸ are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, or a silicon-containing carbon atom having 1 to 20 carbon atoms. Hydrogen group, C1-C20 oxygen-containing hydrocarbon group, amino group, C1-C20 nitrogen And a sulfur-containing hydrocarbon group having 1 to 20 carbon atoms, m and n each independently represent an integer of 0 to 20, provided that m and n are not 0 at the same time. When m or n is 2 or more, R ⁷ or R ⁸ may be linked to each other to form a new ring structure, Q is a bridge that connects two cyclopentadienyl rings. And X and Y represent a σ covalent bond auxiliary ligand that reacts with a cocatalyst to develop an olefin polymerization ability, and M represents a transition metal of Groups 4 to 6 in the periodic table.)

In general formula (II), R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a silicon-containing hydrocarbon group having 1 to 18 carbon atoms. Or a C1-C18 halogenated hydrocarbon group is shown.
Specific examples of the hydrocarbon group having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, and n. Preferred are alkyl groups such as hexyl, cyclopropyl, cyclopentyl and cyclohexyl, alkenyl groups such as vinyl, propenyl and cyclohexenyl, as well as phenyl groups.

  Specific examples of the silicon-containing hydrocarbon group having 1 to 18 carbon atoms include trialkylsilyl groups such as trimethylsilyl, triethylsilyl and t-butyldimethylsilyl, and alkylsilylalkyl groups such as bis (trimethylsilyl) methyl. Can be mentioned.

In the halogenated hydrocarbon group having 1 to 18 carbon atoms, preferred examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated hydrocarbon group is a compound in which, when the halogen atom is, for example, a fluorine atom, the fluorine atom is substituted at an arbitrary position of the hydrocarbon group.
Specific examples include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, iodomethyl, 2,2,2-trifluoroethyl, 2,2,1 , 1-tetrafluoroethyl, pentafluoroethyl, pentachloroethyl, pentafluoropropyl, nonafluorobutyl, trifluorovinyl, 2-, 3-, 4-substituted fluorophenyl, 2-, 3-, 4-substituted Each of chlorophenyl, 2-, 3-, 4-substituted bromophenyl, 2,4-, 2,5-, 2,6-, 3,5-substituted difluorophenyl, 2,4-, 2, 5-, 2,6-, 3,5-substituted dichlorophenyl, 2,4,6-trifluorophenyl, 2,4,6-trichlorophenyl Cycloalkenyl, pentafluorophenyl and pentachlorophenyl and the like.
Among these, as R ¹ and R ⁴ , a hydrocarbon group having 1 to 6 carbon atoms is preferable, and an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, and butyl is particularly preferable, and R ² and R ⁵ is particularly preferably a hydrogen atom.

In the general formula (II), each of R ³ and R ⁶ independently represents a saturated or unsaturated divalent carbon atom having 3 to 10 carbon atoms that forms a condensed ring with respect to the five-membered ring to which R ³ and R ⁶ are bonded. Indicates a hydrogen group. Provided that at least one of the carbon atoms of ^{R 3} and ^{R 6} are 5-8, to form a condensed ring consisting of 7-10 membered rings having an unsaturated bond derived from ^{R 3} or ^{R 6.}
Preferable examples of the bonding parts R ³ and R ⁶ are saturated or unsaturated divalent hydrocarbon bonding groups having 3 to 10 carbon atoms, and specific examples thereof include trimethylene, tetramethylene, pentamethylene, hexamethylene and the like. Divalent saturated hydrocarbon group, propenylene, 2-propen-1-ylidene, 1-butenylene, 2-butenylene, 1,3-butadienylene, 1-pentenylene, 2-pentenylene, 1,3-pentadienylene, 1,4- Pentadienylene, 1-hexenylene, 2-hexenylene, 3-hexenylene, 1,3-hexadienylene, 1,4-hexadienylene, 1,5-hexadienylene, 2,4-hexadienylene, 2,5-hexadienylene, 1,3,5- Divalent unsaturated hydrocarbon groups such as hexatrienylene are preferred, and among these, Preferably, the divalent unsaturated group having 4 or 5 carbon atoms such as 1,3-butadienylene (that is, when a 6-membered ring is formed) or 1,3-hexadienylene (that is, when a 7-membered ring is formed) It is a hydrocarbon, and a 1,3-hexadienylene group is a more preferable linking group.

R ⁷ and R ⁸ are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, or 1 to 1 carbon atoms. 20 oxygen-containing hydrocarbon groups, amino groups, nitrogen-containing hydrocarbon groups having 1 to 20 carbon atoms or sulfur-containing hydrocarbon groups having 1 to 20 carbon atoms are shown.

  Specific examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n -Alkyl groups such as hexyl, cyclopropyl, cyclopentyl, cyclohexyl, and methylcyclohexyl; alkenyl groups such as vinyl, propenyl, and cyclohexenyl; arylalkyl groups such as benzyl, phenylethyl, and phenylpropyl; and arylalkenyl groups such as trans-styryl; Examples include aryl groups such as phenyl, tolyl, dimethylphenyl, ethylphenyl, trimethylphenyl, 1-naphthyl, 2-naphthyl, acenaphthyl, phenanthryl and anthryl. Among these, alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclopropyl, phenyl, tolyl, An aryl group having 6 to 20 carbon atoms such as dimethylphenyl, ethylphenyl, trimethylphenyl, 1-naphthyl and 2-naphthyl is preferred.

  In the halogenated hydrocarbon group having 1 to 20 carbon atoms, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated hydrocarbon group is a compound in which, when the halogen atom is, for example, a fluorine atom, the fluorine atom is substituted at an arbitrary position of the hydrocarbon group. Specifically, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, iodomethyl, 2,2,2-trifluoroethyl, 2,2,1 , 1-tetrafluoroethyl, pentafluoroethyl, pentachloroethyl, pentafluoropropyl, nonafluorobutyl, trifluorovinyl, 1,1-difluorobenzyl, 1,1,2,2-tetrafluorophenylethyl, o-, m-, p-fluorophenyl, o-, m-, p-chlorophenyl, o-, m-, p-bromophenyl, 2,4-, 3,5-, 2,6-, 2,5-difluorophenyl 2,4-, 3,5-, 2,6-, 2,5-dichlorophenyl, 2,4,6-trifluorophen 2,4,6-trichlorophenyl, pentafluorophenyl, pentachlorophenyl, 4-fluoronaphthyl, 4-chloronaphthyl, 2,4-difluoronaphthyl, heptafluoro-1-naphthyl, heptachloro-1-naphthyl, o- , M-, p-trifluoromethylphenyl, o-, m-, p-trichloromethylphenyl, 2,4-, 3,5-, 2,6-, 2,5-bis (trifluoromethyl) phenyl, 2,4-, 3,5-, 2,6-, 2,5-bis (trichloromethyl) phenyl, 2,4,6-tris (trifluoromethyl) phenyl, 4-trifluoromethylnaphthyl, 4-trichloro Examples thereof include a methyl naphthyl group and a 2,4-bis (trifluoromethyl) naphthyl group.

  Specific examples of the silicon-containing hydrocarbon group having 1 to 20 carbon atoms include 2-, 3-, 4-trimethylsilylphenyl, 2-, 3-, 4-t-butyldimethylsilylphenyl, 2-, 3- 4-diphenylmethylsilylphenyl, 2-, 3-, 4-dimethylphenylsilylphenyl, trimethylsilyltolyl, 4-trimethylsilyl-1-naphthyl, 6-trimethylsilyl-1-naphthyl, 4-trimethylsilyl-2-naphthyl, 6- Trimethylsilyl-2-naphthyl, 4-t-butyldimethylsilyl-2-naphthyl, 6-t-butyldimethylsilyl-2-naphthyl, 4-diphenylmethylsilyl-2-naphthyl, 6-diphenylmethylsilyl-2-naphthyl, 4-dimethylphenylsilyl-2-naphthyl, 6-dimethylphenylsilyl-2-naphth 3-trimethylsilylbiphenyl, 4'-trimethylsilylbiphenyl, 4-methyl-6-trimethylsilyl-1-naphthyl, 4-methyl-6-trimethylsilyl-2-naphthyl, 6-trimethylsilyl-2-anthryl, 7-trimethylsilyl-2 -Phenanthryl, 7-trimethylsilyl-9,10-dihydro-2-phenanthryl and the like.

Specific examples of the oxygen-containing hydrocarbon group having 1 to 20 carbon atoms include alkoxy groups such as methoxy, ethoxy, propoxy, cyclopropoxy and butoxy, allyloxy groups such as phenoxy, methylphenoxy, dimethylphenoxy and naphthoxy, phenylmethoxy And oxygen-containing heterocyclic groups such as arylalkoxy groups such as naphthylmethoxy and furyl groups.
Specific examples of the nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms include alkylamino groups such as methylamino, dimethylamino, ethylamino and diethylamino, arylamino groups such as phenylamino and diphenylamino, (methyl And (alkyl) (aryl) amino groups such as (phenyl) amino, and nitrogen-containing heterocyclic groups such as pyrazolyl and indolyl.

In general formula (II), m and n each independently represent an integer of 0 to 20. However, m and n are not 0 simultaneously. when m or n is 2 or more, respectively, they may form a new ring structure linked is R ⁷ s or R ⁸ together. Preferably, m = n = 1.

In general formula (II), Q is a bridging group that connects two cyclopentadienyl rings. As the type of Q, a crosslinking group in a known bridged metallocene transition metal compound can be used.
Specific examples of Q include an alkylene group, an arylalkylene group, an alkylsilylene group, an (alkyl) (aryl) silylene group, and an arylsilylene group. These hydrocarbon groups may contain heteroatoms such as N, P, O, Si or halogen. Further, it may be a crosslinking group in which the above silicon is replaced with germanium. When two hydrocarbon groups are present on the above-mentioned silylene group or the like, they may be bonded to each other to form a ring structure.
Among the above-mentioned crosslinking groups, dimethylsilylene, dimethylgermylene, and silafluoroolenyl groups are particularly preferable.

X and Y are σ covalent bond auxiliary ligands that react with a cocatalyst to develop olefin polymerization ability, specifically, independently of each other, a hydrogen atom, a halogen atom, or a carbon number of 1 to 20 Hydrocarbon group, halogenated hydrocarbon group having 1 to 20 carbon atoms, silicon-containing hydrocarbon group having 1 to 20 carbon atoms, oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, amino group or nitrogen having 1 to 20 carbon atoms The containing hydrocarbon group is shown.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
X and Y are preferably a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or A nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms is more preferable, and a chlorine atom, a methyl group, an i-butyl group, a phenyl group, a benzyl group, a dimethylamino group or a diethylamino group is particularly preferable.

  M represents a transition metal of Groups 4 to 6 of the periodic table, preferably Titanium, zirconium or hafnium of Group 4 of the periodic table, particularly preferably zirconium or hafnium.

  Specific examples of the compound represented by the general formula (II) include the following compounds. However, in the following specific examples, titanium or zirconium instead of hafnium, other X and Y compounds instead of dichloride, and other substituents in the ring structure can be said to be exemplified. .

(1) Dichloro {1,1′-dimethylsilylenebis (2-methyl-4-phenyl-4H-azulenyl)} zirconium (2) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2 -Methylphenyl) -4H-azurenyl}] zirconium (3) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-methylphenyl) -4H-azurenyl}] zirconium (4) dichloro [1 , 1′-dimethylsilylenebis {2-methyl-4- (4-methylphenyl) -4H-azulenyl}] zirconium (5) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (2, 6-dimethylphenyl) -4H-azurenyl}] zirconium (6) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-trifluoro) Tilphenyl) -4H-azurenyl}] zirconium (7) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] zirconium (8) dichloro [1,1 ′ -Dimethylsilylenebis {2-methyl-4- (4-fluorophenyl) -4H-azulenyl}] zirconium (9) dichloro [1,1'-dimethylsilylenebis {2-methyl-4- (3-chlorophenyl)- 4H-azulenyl}] zirconium (10) dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (3-fluorophenyl) -4H-azurenyl}] zirconium (11) dichloro [1,1′-dimethyl Silylenebis {2-methyl-4- (4-trimethylsilylphenyl) -4H-azurenyl}] zirconium (12 ) Dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-t-butylphenyl) -4H-azulenyl}] zirconium (13) dichloro [1,1′-dimethylsilylenebis {2-methyl -4- (1-naphthyl) -4H-azurenyl}] zirconium (14) dichloro {1,1′-dimethylsilylenebis (2-ethyl-4-phenyl-4H-azurenyl)} zirconium (15) dichloro [1, 1'-dimethylsilylenebis {2-ethyl-4- (2-methylphenyl) -4H-azurenyl}] zirconium (16) dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (3-methyl) Phenyl) -4H-azulenyl}] zirconium (17) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-methylphenyl) -4H-azurenyl}] zirconium (18) dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (2,6-dimethylphenyl) -4H-azurenyl}] zirconium (19) dichloro [1,1 '-Dimethylsilylenebis {2-ethyl-4- (4-trifluoromethylphenyl) -4H-azulenyl}] zirconium (20) dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4- Chlorophenyl) -4H-azurenyl}] zirconium

(21) Dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-fluorophenyl) -4H-azulenyl}] zirconium (22) dichloro [1,1′-dimethylsilylenebis {2-ethyl -4- (3-chlorophenyl) -4H-azurenyl}] zirconium (23) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (3-fluorophenyl) -4H-azurenyl}] zirconium (24 ) Dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilylphenyl) -4H-azulenyl}] zirconium (25) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4 -(4-Trimethylsilyl-3-chlorophenyl) -4H-azurenyl}] hafnium (26) dichloro [1,1′-di Tylsilylenebis {2-ethyl-4- (4-trimethylsilyl-3-methylphenyl) -4H-azurenyl}] hafnium (27) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilyl-) 3-fluorophenyl) -4H-azurenyl}] hafnium (28) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilyl-3,5-dichlorophenyl) -4H-azurenyl}] hafnium (29) Dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilyl-3,5-dimethylphenyl) -4H-azulenyl}] hafnium (30) dichloro [1,1′-dimethyl Silylene bis {2-ethyl-4- (4-trimethylsilyl-3,5-diethylphenyl) -4 -Azulenyl}] hafnium (31) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilyl-3-chloro-5-methylphenyl) -4H-azurenyl}] hafnium (32) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-trimethylsilyl-3-chloro-5-fluorophenyl) -4H-azulenyl}] hafnium (33) dichloro [1,1′-dimethylsilylenebis {2-Ethyl-4- (4-trimethylsilyl-3-chloro-5-ethylphenyl) -4H-azurenyl}] hafnium (34) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4 -T-butylphenyl) -4H-azulenyl}] zirconium (35) dichloro [1,1′-dimethylsilylenebis {2-e Tyl-4- (4-t-butyl-3-chlorophenyl) -4H-azulenyl}] zirconium (36) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-t-butyl-3) -Methylphenyl) -4H-azurenyl}] zirconium (37) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-tert-butyl-3-fluorophenyl) -4H-azurenyl}] zirconium (38) Dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (1-naphthyl) -4H-azulenyl}] zirconium (39) Dichloro [1,1′-dimethylsilylenebis {2-ethyl- 4- (4-Chloro-1-naphthyl) -4H-azurenyl}] zirconium (40) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- ( - fluoro-1-naphthyl) -4H- azulenyl}] zirconium

(41) Dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4-methyl-1-naphthyl) -4H-azulenyl}] zirconium (42) dichloro [1,1′-dimethylsilylenebis { 2-ethyl-4- (4-biphenyl) -4H-azulenyl}] zirconium (43) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (2-fluoro-4-biphenyl) -4H— Azulenyl}] zirconium (44) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (2-chloro-4-biphenyl) -4H-azurenyl}] zirconium (45) dichloro [1,1′- Dimethylsilylenebis {2-ethyl-4- (2-methyl-4-biphenyl) -4H-azulenyl}] zirconium (46) dichloro [1,1'-dimethyl Rylenebis {2-ethyl-4- (2-ethyl-4-biphenyl) -4H-azulenyl}] zirconium (47) dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (2,6-dimethyl) -4-biphenyl) -4H-azurenyl}] zirconium (48) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (2-chloro-6-methyl-4-biphenyl) -4H-azurenyl} Zirconium (49) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (2′-chloro-4-biphenyl) -4H-azulenyl}] zirconium (50) dichloro [1,1′-dimethyl Silylene bis {2-ethyl-4- (2'-methyl-4-biphenyl) -4H-azulenyl}] zirconium (51) dichloro [1,1'-dimethylsilyl Bis {2-ethyl-4- (2 ′, 6′-dimethyl-4-biphenyl) -4H-azulenyl}] zirconium (52) dichloro [1,1′-dimethylsilylenebis {2-ethyl-4- (4 '-Chloro-4-biphenyl) -4H-azurenyl}] zirconium (53) dichloro [1,1'-dimethylsilylenebis {2-ethyl-4- (4'-methyl-4-biphenyl) -4H-azurenyl} ] Zirconium (54) dichloro {1,1'-dimethylsilylenebis (2-i-propyl-4-phenyl-4H-azulenyl)} zirconium (55) dichloro [1,1'-dimethylsilylenebis {2-i- Propyl-4- (2-methylphenyl) -4H-azulenyl}] zirconium (56) dichloro [1,1′-dimethylsilylenebis {2-i-propyl-4- 4-trifluoromethylphenyl) -4H-azurenyl}] zirconium (57) dichloro [1,1′-dimethylsilylenebis {2-i-propyl-4- (4-t-butylphenyl) -4H-azurenyl}] Zirconium (58) dichloro [1,1′-dimethylsilylenebis {2-i-propyl-4- (4-trimethylsilylphenyl) -4H-azulenyl}] zirconium (59) dichloro [1,1′-dimethylsilylenebis { 2-i-propyl-4- (1-naphthyl) -4H-azulenyl}] zirconium (60) dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4-phenyl- 4H-azulenyl}] zirconium

(61) Dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (2-methylphenyl) -4H-azurenyl}] zirconium (62) dichloro [1,1 ′ -Dimethylsilylenebis {2- (5-methyl-2-furyl) -4- (4-trifluoromethylphenyl) -4H-azulenyl}] zirconium (63) dichloro [1,1'-dimethylsilylenebis {2- (5-Methyl-2-furyl) -4- (4-chlorophenyl) -4H-azulenyl}] zirconium (64) dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl)- 4- (4-t-butylphenyl) -4H-azulenyl}] zirconium (65) dichloro [1,1′-dimethylsilylenebis {2- (5-methyl-2-furyl) -4- ( -Naphthyl) -4H-azurenyl}] zirconium (66) dichloro {1,1'-dimethylgermylenebis (2-methyl-4-phenyl-4H-azurenyl)} zirconium (67) dichloro {1,1'-ethylene Bis (2-methyl-4-phenyl-4H-azurenyl)} zirconium (68) dichloro {1,1′-silafluorenebis (2-methyl-4-phenyl-4H-azurenyl)} zirconium (69) dichloro {1 , 1′-dimethylsilylenebis (2-methyl-4-phenyl-4H-5,6,7,8-tetrahydro-azulenyl)} zirconium

(B) At least one compound selected from ion-exchange layered silicate In the preferred catalyst according to the present invention, at least one compound selected from component (B) ion-exchange layered silicate is an ionic bond or the like. Is a silicate compound having a crystal structure in which the surfaces constituted by are stacked in parallel with each other with a weak binding force, and the ions contained therein are exchangeable. Most ion-exchange layered silicates are naturally produced mainly as the main component of clay minerals, but these ion-exchange layered silicates are not limited to natural ones, but are artificially synthesized. There may be.

  Specific examples of the ion-exchange layered silicate are known layered silicates described in, for example, Haruo Shiramizu, “Clay Mineralogy” Asakura Shoten (1995), etc. Smectites such as tronite, saponite, hectorite, stevensite, bentonite and teniolite, vermiculite and mica are preferred.

  Moreover, although a component (B) can be used as it is, without performing a process in particular, it is also preferable to perform a chemical process to a component (B). Here, as the chemical treatment, any of a surface treatment for removing impurities adhering to the surface and a treatment affecting the crystal structure of the clay can be used. Specifically, acid treatment, alkali treatment, salt treatment, organic matter treatment and the like can be mentioned.

In the present invention, 40% or more, preferably 60% or more, of the exchangeable group 1 metal cation contained in the ion-exchangeable layered silicate before being treated with salts is dissociated from the salts shown below. It is preferable to ion exchange with cations.
The salt used in the salt treatment for the purpose of ion exchange is a group consisting of a cation containing at least one atom selected from the group consisting of group 1 to 14 atoms, a halogen atom, an inorganic acid and an organic acid. A compound comprising at least one anion selected from the group consisting of at least one anion selected from the group consisting of group 2 to 14 atoms and Cl, Br, I, F, PO. ₄ , SO ₄ , NO ₃ , CO ₃ , C ₂ O ₄ , ClO ₄ , OOCCH ₃ , CH ₃ COCHCOCH ₃ , OCl ₂ , O (NO ₃ ) ₂ , O (ClO ₄ ) ₂ , O (SO ₄ ), At least one anion selected from the group consisting of OH, O ₂ Cl ₂ , OCl ₃ , OOCH, OOCCH ₂ CH ₃ , C ₂ H ₄ O ₄ and C ₅ H ₅ O ₇ It is the compound which consists of.

_{Specifically, LiF, LiCl, LiBr, LiI} , Li 2 SO 4, Li (CH 3 COO), LiCO 3, Li (C 6 H 5 O 7), LiCHO 2, LiC 2 O 4, LiClO 4, Li ₃ PO ₄ CaCl ₂ , CaSO ₄ , CaC ₂ O ₄ , Ca (NO ₃ ) ₂ , Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , MgCl ₂ , MgBr ₂ , MgSO ₄ , Mg (PO ₄ ) ₂ , Mg (ClO ₄ ) ₂ , MgC ₂ O ₄ , Mg (NO ₃ ) ₂ , Mg (OOCCH ₃ ) ₂ , MgC ₄ H ₄ O ₄ , Ti (OOCCH ₃ ) ₄ , Ti (CO ₃ ) ₂ , Ti (NO ₃₎ ) ₄ , Ti (SO ₄ ) ₂ , TiF ₄ , TiCl ₄ , Zr (OOCCH ₃ ) ₄ , Zr (CO ₃ ) ₂ , Zr (NO ₃ ) ₄ , Zr (SO ₄ ) ₂ , ZrF ₄ , ZrCl ₄ , ZrOCl ₂ , ZrO (NO ₃ ) ₂ , ZrO (ClO ₄ ) ₂ , ZrO (SO ₄ ), HF (OOCCH ₃ ) ₄ , HF (CO ₃ ) ₂ , HF (NO ₃ ) ₄ , HF ( _{SO 4) 2, HFOCl 2,} HFF 4, HFCl 4, V (CH 3 COCHCOCH 3) 3, VOSO 4, VOCl 3, VCl 3, VCl 4, VBr 3, Cr (CH 3 COCHCOCH 3) 3, Cr (OOCCH ₃ ) ₂ OH, Cr (NO ₃ ) ₃ , Cr (ClO ₄ ) ₃ , CrPO ₄ , Cr ₂ (SO ₄ ) ₃ , CrO ₂ Cl ₂ , CrF ₃ , CrCl ₃ , CrBr ₃ , CrI ₃ , Mn (OOCCH _{3) 2, Mn (CH 3} COCHCOCH 3) 2, MnCO 3, Mn (NO 3) 2, MnO, Mn (ClO _{) 2, MnF 2, MnCl 2} , Fe (OOCCH 3) 2, Fe (CH 3 COCHCOCH 3) 3, FeCO 3, Fe (NO 3) 3, Fe (ClO 4) 3, FePO 4, FeSO 4, Fe 2 (SO ₄ ) ₃ , FeF ₃ , FeCl ₃ , FeC ₆ H ₅ O ₇ , Co (OOCCH ₃ ) ₂ , Co (CH ₃ COCHCOCH ₃ ) ₃ , CoCO ₃ , Co (NO ₃ ) ₂ , CoC ₂ O ₄ , Co (ClO ₄ ) ₂ , Co ₃ (PO ₄ ) ₂ , CoSO ₄ , CoF ₂ , CoCl ₂ , NiCO ₃ , Ni (NO ₃ ) ₂ , NiC ₂ O ₄ , Ni (ClO ₄ ) ₂ , NiSO ₄ , NiCl _{2, NiBr 2, Zn (OOCCH} 3) 2, Zn (CH 3 COCHCOCH 3) 2, ZnCO 3, Zn (NO 3) _{, Zn (ClO 4) 2,} Zn 3 (PO 4) 2, ZnSO 4, ZnF 2, ZnCl 2, AlF 3, AlCl 3, AlBr 3, AlI 3, Al 2 (SO 4) 3, Al 2 (C 2 O ₄ ) ₃ , Al (CH ₃ COCHCOCH ₃ ) ₃ , Al (NO ₃ ) ₃ , AlPO ₄ , GeCl ₄ , GeBr ₄ , GeI ₄ and the like.

In addition to removing impurities on the surface, the acid treatment can elute part or all of cations such as Al, Fe, Mg, etc. having a crystal structure.
The acid used in the acid treatment is preferably selected from hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, and oxalic acid.
Two or more salts and acids may be used in the treatment. The conditions for treatment with salts and acids are not particularly limited. Usually, the salt and acid concentrations are selected from 0.1 to 50% by weight, the treatment temperature is from room temperature to boiling point, and the treatment time is from 5 minutes to 24 hours. Thus, it is preferable to carry out the reaction under the condition that at least a part of the substance constituting at least one compound selected from the ion-exchange layered silicate is eluted. In addition, salts and acids are generally used in an aqueous solution.

  These ion-exchange layered silicates usually contain adsorbed water and interlayer water. In the present invention, it is preferable to remove these adsorbed water and interlayer water and use them as the component (B).

  The heat treatment method of the adsorbed layered silicate adsorbed water and interlayer water is not particularly limited, but it is necessary to select conditions so that interlayer water does not remain and structural destruction does not occur. The heating time is 0.5 hour or longer, preferably 1 hour or longer. At that time, the water content of the component (B) after removal is 3% by weight or less, preferably 0% by weight when the water content is 0% by weight when dehydrated for 2 hours under the conditions of a temperature of 200 ° C. and a pressure of 1 mmHg. Is preferably 1% by weight or less.

  As described above, in the present invention, particularly preferable as the component (B) is an ion-exchange layered silicate having a water content of 3% by weight or less obtained by performing a salt treatment and / or an acid treatment. is there.

The component (B) is preferably a spherical particle having an average particle size of 5 μm or more. If the particle shape is spherical, a natural product or a commercially available product may be used as it is, or a particle whose particle shape and particle size are controlled by granulation, sizing, fractionation, or the like may be used.
More preferably, spherical particles having an average particle diameter of 50 μm or more are used. In order to produce a polymer having a very low melting point in the present invention, it is important to prevent fusion between polymer particles during production. In order to reduce the contact area between the polymer particles, such average particles are used. It is particularly important to use one having a large diameter.

Examples of the granulation method used here include a stirring granulation method and a spray granulation method, but commercially available products can also be used. Moreover, you may use organic substance, an inorganic solvent, inorganic salt, and various binders in the case of granulation.
The spherical particles obtained as described above desirably have a compressive fracture strength of 0.2 MPa or more, particularly preferably 0.5 MPa or more, in order to suppress crushing and generation of fine powder in the polymerization process. In the case of such particle strength, the effect of improving the particle properties is effectively exhibited especially when prepolymerization is performed.

(C) Organoaluminum compound In the preferred polymerization catalyst of the present invention, component (C) an organoaluminum compound is used as necessary. Examples of component (C) include compounds represented by general formula (III).
AlR _a P _3-a (III)
(In the formula, R is a hydrocarbon group having 1 to 20 carbon atoms, P is a hydrogen, halogen or alkoxy group, and a is a number of 0 <a ≦ 3.)

  Specific examples of the compound represented by the general formula (III) include trialkylaluminum such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, or halogen or alkoxy such as diethylaluminum monochloride, diethylaluminum monomethoxide. Containing alkylaluminum. In addition, aluminoxanes such as methylaluminoxane can also be used. Of these, trialkylaluminum is particularly preferable.

(2) Preparation of catalyst Preparation of the preferable polymerization catalyst based on this invention makes the said component (A), a component (B), and a component (C) as needed to make a catalyst.
Although the contact method is not specifically limited, Contact can be made in the following order. Further, this contact may be performed not only at the time of catalyst preparation but also at the time of prepolymerization with olefin or at the time of polymerization of olefin.
(I) The component (A) is contacted with the component (B).
(Ii) Component (A) and component (B) are contacted, and then component (C) is added.
(Iii) After contacting the component (A) and the component (C), the component (B) is added.
(Iv) Component (A) is added after contacting component (B) and component (C).
(V) contacting the three components simultaneously.

When the catalyst components are brought into contact with each other or after the contact, polymers such as polyethylene and polypropylene, and solids of inorganic oxides such as silica and alumina may be present together or brought into contact with each other. The contact may be performed in an inert gas such as nitrogen or in an inert hydrocarbon solvent such as pentane, hexane, heptane, toluene, xylene. The contact temperature is between −20 ° C. and the boiling point of the solvent, particularly preferably between room temperature and the boiling point of the solvent.
The catalyst thus obtained may be used after preparation without washing with an inert solvent, particularly hydrocarbons such as hexane, heptane, etc., or after washing with the solvent.

  Moreover, you may use it combining the said component (C) newly as needed. The amount of the component (C) used at this time is selected so that the atomic ratio of aluminum in the component (C) to the transition metal in the component (A) is 1: 0 to 10,000.

  Prior to polymerization, olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane and styrene are preliminarily polymerized. It is also possible to use a washed catalyst as necessary.

  This preliminary polymerization is preferably carried out under mild conditions in an inert solvent so that 0.01 to 1000 g, preferably 0.1 to 100 g, of polymer is produced per 1 g of the solid catalyst. Is desirable.

(3) Polymerization Since it is desirable that the polymerization process according to the present invention does not elute in a solvent, it is necessary to carry out the polymerization by gas phase polymerization.
A known gas phase polymerization process can be used as the gas phase polymerization process, but a vertical or horizontal gas phase polymerization process that is mechanically stirred is preferable.

The polymerization temperature in the polymerization step is a temperature range in which the polymer to be produced does not melt, and is specifically 30 to 115 ° C, preferably about 50 to 80 ° C. More preferably, it is 50-65 degreeC.
When producing a polymer having a very low melting point in the present invention, a high polymerization temperature is not preferable because the possibility of the polymer melting increases. On the other hand, when the polymerization temperature is greatly lowered, there is a problem that productivity is lowered due to a decrease in activity. It is important to determine the polymerization temperature in consideration of these balances.

  The polymerization pressure is 0.1 to 5 MPa, preferably 0.5 to 4 MPa. Although it is known that when the polymerization pressure is too high, the supercritical state is known, but the gas phase polymerization in the present invention does not include such a supercritical state.

In addition, the presence of hydrogen as a molecular weight regulator in the polymerization system makes it possible to obtain a desired polymer by controlling the molecular weight and molecular weight distribution.
In the present invention, when the metallocene complex of the component (A) and the montmorillonite of the component (B) are combined in the above catalyst system, the activity is low in hydrogen responsiveness compared to the normal metallocene active site. Points are also generated, and high molecular weight components are generated. Even in the presence of hydrogen, which is a molecular weight regulator, the weight average molecular weight can be adjusted while maintaining the abundance of the high molecular weight component, and the molecular weight distribution Q value is suitable for resin processing moldability. Can do.
Furthermore, since the Q value depends on the polymerization temperature and the polymerization pressure, the Q value can be kept at a desired value by optimizing these conditions.

The change with time in the hydrogen concentration in the polymerization system has a great influence not only on the molecular weight of the produced polymer but also on its distribution. For example, in the case of hydrogen batch feed, in order to obtain a desired MFR, it is necessary to determine the initial condition of the hydrogen feed amount by taking into account the deviation of the molecular weight of the polymer produced with the consumption of hydrogen over time. In some cases, the MFR can be adjusted, but a large amount of low molecular weight polymer is produced, which adversely affects the physical properties of the product.
Therefore, in the present invention, it is preferable to continuously introduce the hydrogen so that the hydrogen concentration becomes constant during the polymerization. When the batch polymerization method is used, the control range of the hydrogen concentration in the autoclave can be set to any value from 1 ppm to 10,000 ppm.

Moreover, it is preferable to use the same method when using the continuous polymerization method. The concentration setting range can also be arbitrarily set within the hydrogen concentration range of 1 ppm to 10,000 ppm.
By these methods, a desired propylene / ethylene random copolymer having the physical properties of the present invention can be obtained.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples, unless it deviates from the summary.

The measuring method of various physical properties of the propylene / ethylene random copolymer obtained by the following production examples is as follows.
[Physical property measurement method]
(1) GPC measurement In this invention, a weight average molecular weight (Mw) and a number average molecular weight (Mn) say what was measured by the gel permeation chromatography (GPC) method.
Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene.
The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000

A calibration curve is created by injecting 0.2 mL of a solution dissolved in o-dichlorobenzene (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL.
The calibration curve uses a cubic equation obtained by approximation by the least square method. The following numerical values are used for [η] = K × M ^α in the viscosity formula used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ α = 0.7
PE: K = 3.92 × 10 ⁻⁴ α = 0.733
PP: K = 1.03 × 10 ⁻⁴ α = 0.78

The measurement conditions for GPC are as follows.
Apparatus: GPC manufactured by WATERS (ALC / GPC 150C)
Detector: MIRAN1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 ° C
Flow rate: 1.0 ml / min Injection volume: 0.2 ml
Sample preparation: Prepare a 1 mg / mL solution using o-dichlorobenzene (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.

(2) Melting peak temperature (Tm)
Using a Seiko DSC, take 5.0 mg of sample, hold at 200 ° C. for 5 minutes, crystallize to 40 ° C. at a rate of temperature decrease of 10 ° C./min, and further melt at a rate of temperature increase of 10 ° C./min. The melting peak temperature was Tm (unit: ° C.).
DHm was determined from the area of the endothermic curve at the time of temperature increase.

(3) MFR
In accordance with Method A and Condition M of JIS K7210 “Plastics—Test Methods for Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Thermoplastic Plastics”, measurement was performed under the following conditions.
Test temperature: 230 ° C
Nominal load: 2.16kg
Die shape: 2.095mm diameter, 8.00mm length

(4) Measurement of ethylene content by ¹³ C-NMR The ethylene content is determined by analyzing a ¹³ C-NMR spectrum measured according to the following conditions by a proton complete decoupling method.
Model: GSX-400 manufactured by JEOL Ltd. or equivalent device (carbon nuclear resonance frequency of 100 MHz or more)
Solvent: o-dichlorobenzene / heavy benzene = 4/1 (volume ratio)
Concentration: 100 mg / mL
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more

  The spectrum may be assigned with reference to, for example, Macromolecules 17 1950 (1984). The attribution of spectra measured under the above conditions is as shown in the table below. Symbols such as Sαα in the table are in accordance with the notation of Carman et al. (Macromolecules 10 536 (1977)), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

Chemical shift (ppm) attribution
45-48 Sαα
37.8-37.9 Sαγ
37.4-37.5 Sαδ
33.1 Tδδ
30.9 Tβδ
30.6 Sγγ
30.2 Sγδ
29.8 Sδδ
28.7 Tββ
27.4-27.6 Sβδ
24.4 to 24.7 Sββ
19.1-22.0 P

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six kinds of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. As described in Macromolecules 15 1150 (1982) and the like, the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (Tββ) (1)
[PPE] = k × I (Tβδ) (2)
[EPE] = k × I (Tδδ) (3)
[PEP] = k × I (Sββ) (4)
[PEE] = k × I (Sβδ) (5)
[EEE] = k × {I (Sδδ) / 2 + I (Sγδ) / 4} (6)
Here, [ABC] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore,
[PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is.
Further, k is a constant, I indicates the spectral intensity, and for example, I (Tββ) means the intensity of the 28.7 ppm peak attributed to Tββ.

By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
The propylene random copolymer of the present invention contains a small amount of propylene heterogeneous bonds (2,1-bonds and / or 1,3-bonds), thereby producing the following minute peaks.

Chemical shift (ppm) attribution
42.0 Sαα
38.2 Tαγ
37.1 Sαδ
34.1-35.6 Sαβ
33.7 Tγγ
33.3 Tγδ
30.8-31.2 Tβγ
30.5 Tβδ
30.3 Sαβ
27.3 Sβγ

  In order to obtain an accurate ethylene content, it is necessary to include these peaks derived from heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds. Since the ethylene content according to the present invention is a small amount, the relational expressions (1) to (7) are the same as the analysis of the copolymer produced with the Ziegler-Natta catalyst that does not substantially contain a heterogeneous bond. It will be obtained using.

(5) Isotactic triad fraction, 2,1-bond content, and 1,3-bond content measurement by ¹³ C-NMR The measurement was performed by the method of the above paragraphs [0026] to [0036]. Specifically, it was integrated 6000 times by using JSX-400FT-NMR (resonance frequency of carbon nucleus is 100 MHz).

(6) Temperature rising elution fractionation (TREF)
A sample is dissolved in o-dichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to prepare a solution. This is introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, subsequently cooled to −15 ° C. at a rate of 4 ° C./min, and held for 60 minutes. Thereafter, o-dichlorobenzene as a solvent (containing 0.5 mg / mL BHT) is allowed to flow through the column at a flow rate of 1 mL / min, and components dissolved in o-dichlorobenzene at −15 ° C. in the TREF column. Elution is performed for 10 minutes, and then the column is linearly heated to 140 ° C. at a temperature increase rate of 100 ° C./hour to obtain an elution curve.

〔apparatus〕
(TREF part):
TREF column: 4.3 mmφ × 150 mm stainless steel column Column packing material: 100 μm surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation, digital program controller KP1000 (valve oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C
Valve: 6-way valve, 4-way valve

(Sample injection part):
Injection method: Loop injection method Injection amount: Loop size 0.1ml
Inlet heating method: Aluminum heat block Measurement temperature: 140 ° C

(Detection unit):
Detector: Fixed wavelength infrared detector, MIRAN 1A manufactured by FOXBORO
Detection wavelength: 3.42 μm
High-temperature flow cell: LC-IR micro flow cell, optical path length 1.5 mm, window shape 2φ × 4 mm oval, synthetic sapphire window Measurement temperature: 140 ° C.
(Pump part):
Liquid feed pump: manufactured by Senshu Kagaku Co., SSC-3461 pump

〔Measurement condition〕:
Solvent: o-dichlorobenzene (containing 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

[Production Example 1]
The catalyst synthesis process and the polymerization process are shown below. The following steps were all performed under a purified nitrogen atmosphere. The solvent used was dehydrated with molecular sieve MS-4A.

・ Catalyst synthesis:
(1) Synthesis of metallocene complex (1-a) Synthesis of dichloro {1,1′-dimethylsilylenebis [2-methyl-4- (4-chlorophenyl) -4H-azurenyl]} zirconium.
The compound was synthesized by the method described in JP-A-11-240909.

(2) Preparation of cocatalyst 1,700 g of pure water was put into a 5 L separable flask equipped with a stirring blade and a reflux device, and 500 g of 98% sulfuric acid was added dropwise. Further, 300 g of commercially available granulated montmorillonite (Mizusawa Chemical Co., Ltd., Benclay SL, average particle size: 19.5 μm) was added and stirred. Thereafter, the mixture was reacted at 90 ° C. for 2 hours. This slurry was washed with an apparatus in which an aspirator was connected to Nutsche and a suction bottle. A 900 mL aqueous solution of 325 g of lithium sulfate monohydrate was added to the recovered cake and reacted at 90 ° C. for 2 hours. This slurry was washed to pH> 4 with an apparatus in which an aspirator was connected to Nutsche and a suction bottle. The collected cake was dried at 120 ° C. overnight. As a result, 270 g of a chemically treated product was obtained. To 516 mg of montmorillonite, 1.8 ml of a toluene solution of triisopropylaluminum having a concentration of 0.72 mol / L was added and stirred at room temperature for 1 hour. Then, it wash | cleaned with toluene and prepared the montmorillonite-toluene slurry (concentration 25 mg / mL). This was used as a cocatalyst.

(3) Preparation of Prepolymerization Catalyst (3-a) Prepolymerization Catalyst Using Metallocene A 2.13 mL (1504 μmol) of a triisobutylaluminum heptane solution was added to the triisobutylaluminum-treated montmorillonite heptane slurry prepared in (2) above. And stirred at room temperature for 10 minutes. In another flask (volume 200 mL), toluene (60 mL) was added to metallocene A (299 μmol) to form a slurry, which was then added to the 1 L flask and stirred at room temperature for 60 minutes.
Next, 340 mL of heptane was further added to the montmorillonite heptane slurry and introduced into a 1 L stirred autoclave, and propylene was added at 40 ° C. at a constant rate of 238.1 mmol / hr (10 g / hr) for 120 minutes. Supplied. After the completion of the propylene supply, the temperature was raised to 50 ° C. and maintained for 2 hours, after which the remaining gas was purged and the prepolymerized catalyst slurry was recovered from the autoclave.
The recovered prepolymerized catalyst slurry was allowed to stand, and the supernatant liquid was extracted. To the remaining solid, 8.5 mL (6.0 mmol) of a heptane solution of triisobutylaluminum was added at room temperature, stirred at room temperature for 10 minutes, and then dried under reduced pressure to recover a solid catalyst. The prepolymerization ratio (a value obtained by dividing the amount of the prepolymerized polymer by the amount of the solid catalyst) was 1.98.

·polymerization:
A horizontal reactor (L / D = 6, internal volume 100 liters) having a stirring blade was sufficiently dried, and the inside was sufficiently replaced with nitrogen gas. While stirring at a rotation speed of 30 rpm in the presence of a polypropylene powder bed, 0.321 g / hr of the prepolymerized catalyst prepared in (3) above (as the amount of solid catalyst excluding the prepolymerized powder) was placed upstream of the reactor. Triisobutylaluminum was continuously supplied at 15.0 mmol / hr. The monomer mixed gas is continuously reacted so that the temperature of the reactor is maintained at 60 ° C., the pressure is 2.14 MPa, the ethylene / propylene molar ratio in the gas phase in the reactor is 0.155, and the hydrogen concentration is 142 ppm. It was made to distribute | circulate in a container and vapor phase polymerization was performed.
The polymer powder produced by the reaction was continuously extracted from the downstream portion of the reactor so that the amount of the powder bed in the reactor was constant. At this time, the amount of the polymer extracted when the steady state was reached was 7.0 kg / hr.

The propylene / ethylene random copolymer obtained in Production Example 1 was blended with the following additives, and granulated under the following conditions to form pellets (PP-1).
・ Additives:
Antioxidant: Tetrakis {methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate} methane 500 ppm
Tris (2,4-di-t-butylphenyl) phosphite 500ppm
Neutralizer: Calcium stearate 500ppm
・ Granulation conditions:
Extruder: KZW-15-45MG twin screw extruder manufactured by Technobel Co., Ltd. Screw: 15 mm in diameter, L / D = 45
Extruder set temperature: (from below the hopper) 40, 80, 160, 200, 200, 200 (die temperature)
Screw rotation speed: 400rpm
Discharge amount: Adjusted to about 1.5 kg / hr with a screw feeder Die: 3 mm diameter, strand die, 2 holes

  The obtained PP-1 raw material pellets were subjected to various analyzes by the methods described in the above [Physical property measurement method]. The results are shown in Table 3.

[Production Examples 2 to 8]
As in Production Example 1, polymerization pressure, polymerization temperature, supply amount of prepolymerization catalyst (as solid catalyst amount excluding prepolymerization powder), ethylene / propylene molar ratio in the reactor gas phase, hydrogen concentration A continuous gas phase polymerization was carried out in the same manner as in Production Example 1 except that was changed. The polymerization conditions and polymerization results are shown in Table 1.
The obtained propylene / ethylene random copolymer was granulated under the same additive composition and conditions as in Production Example 1 to form PP-2 to 8 pellets.
The obtained PP-2 to 8 raw material pellets were analyzed in the same manner as in Production Example 1. The results are shown in Table 3.

[Production Example 9]
After fully replacing the autoclave with a stirrer with an internal volume of 200 L with propylene gas, 45.0 kg of propylene was added. Next, 0.12 mol of triisobutylaluminum was added and stirring was started. While maintaining the temperature at 30 ° C., 2.03 kg of ethylene and 4.5 NL of hydrogen were added, and 0.399 g of the prepolymerized catalyst prepared in Production Example 1 (as the amount of solid catalyst excluding the prepolymerized powder) was added. After raising the temperature to 62 ° C., polymerization was carried out for 60 minutes while continuously supplying hydrogen at 0.27 g / hr. As a result, 18.1 kg of polymer could be obtained.
The resulting propylene / ethylene random copolymer was granulated with the same additive formulation and conditions as in Production Example 1 to form PP-9 pellets.
Various analyzes were performed on the obtained PP-9 raw material pellets in the same manner as in Production Example 1. The results are shown in Table 3.

[Production Examples 10 and 11]
The same polymerization as in Production Example 9 except that the amount of ethylene, the amount of hydrogen, the amount of prepolymerization catalyst, the polymerization temperature, the amount of hydrogen supplied during polymerization, and the polymerization time were changed in advance as in Production Example 9. Went. The polymerization conditions and polymerization results are shown in Table 2.
The resulting propylene / ethylene random copolymer was granulated with the same additive formulation and conditions as in Production Example 1 to form PP-10 and 11 pellets.
Various analyzes were performed on the obtained PP-10 and 11 raw material pellets in the same manner as in Production Example 1. The results are shown in Table 3.

[Example 1]
Using PP-1 pellets as raw materials, injection molding was performed under the following conditions to obtain test pieces for evaluating physical properties.
·(injection molding):
Standard number: Compliant with JIS K7152 (ISO294-1) “Plastic-Thermoplastic material injection molding test piece” Reference molding machine: EC20P injection molding machine manufactured by Toshiba Machine Co., Ltd. Molding machine set temperature: (from under hopper) 80, 210, 210, 200, 200 ° C
Mold temperature: 40 ℃
Injection speed: 52 mm / s (screw speed)
Holding pressure: 30 MPa
Holding time: 8 seconds Mold shape: Two flat plates (thickness 4 mm, width 10 mm, length 80 mm) and flat plate (thickness 2 mm, width 30 mm, length 90 mm)
About the obtained test piece, the physical property of the following item was evaluated. The results are shown in Table 4.

(1) Transparency:
The transparency of the test piece was evaluated under the following conditions.
Standard number: JIS K7136 (ISO14782) "Plastics-Determination of haze of transparent materials" and JIS K7361-1 "Plastics-Test method for total light transmittance of transparent materials-Part 1: Single beam method" Measuring instrument : Haze meter NDH2000 (Nippon Denshoku Industries Co., Ltd.)
Test piece thickness: 2 mm
Preparation of test piece: Injection molded flat plate Condition adjustment: After molding, left in a constant temperature room adjusted to room temperature 23 ° C and humidity 50% Number of test pieces: 3
Evaluation item: Haze

(2) Bending characteristic test The bending characteristic of the test piece was evaluated under the following conditions.
Standard number: Compliant with JIS K7171 (ISO178) "Plastics-Testing method for bending properties" Testing machine: Fully automatic bending testing machine, Bendgraph (manufactured by Toyo Seiki Seisakusho Co., Ltd.)
Specimen sampling direction: Flow direction Specimen shape: Thickness 4.0 mm, width 10.0 mm, length 80.0 mm
Condition adjustment: left in a temperature-controlled room adjusted to room temperature 23 ° C. and humidity 50% for 24 hours or more Test room: temperature-controlled room temperature adjusted to 23 ° C. and humidity 50% Number of test pieces: 5
Distance between fulcrums: 64.0mm
Test speed: 2.0 mm / min Evaluation item: Flexural modulus

(3) Charpy impact strength The impact resistance of the test piece was evaluated under the following conditions.
Test standard: JIS K7111 "Plastics-How to determine Charpy impact properties"
Measuring machine: Automatic Charpy testing machine with thermostatic chamber (Toyo Seiki Seisakusho Co., Ltd.)
Test specimen dimensions: 4 mm thickness, 10 mm width, 80 mm length
Notch type: Edgewise, A type (radius 0.25mm, notch depth 2mm, angle 45 °)
Hammer capacity: 4J
Lifting angle: 150 °
Measurement temperature: 23 ° C, 0 ° C
Number of specimens: 5

[Examples 2 to 5]
Except having used PP-2-5 pellets as a raw material, it shape | molded similarly to Example 1 and evaluated the physical property. The results are shown in Table 4.

[Comparative Examples 1-6]
Except having used PP-6-11 pellet as a raw material, it shape | molded similarly to Example 1 and evaluated the physical property. The results are shown in Table 4.

[Example 6]
Using PP-1 pellets as a raw material, film forming was performed under the following conditions, and the heat seal characteristics of the obtained film were evaluated as follows. The results are shown in Table 5.
(Film forming):
Extruder: 35 mm diameter, L / D = 24, full flight screw Die: Coat hanger type single layer T die, width 300 mm, lip width 1 mm
Cooling: Cooling roll (semi-matt with a surface roughness of 2 μm) + air knife Molding conditions: extrusion temperature 230 ° C., cooling roll temperature 35 ° C., film take-up speed 20 m / min Corona treatment: 42 mN / m on one side
Film thickness: 25 μm

(Heat seal property evaluation):
A film left for 24 hours or longer in a temperature-controlled room controlled at 23 ° C. and 50% humidity is cut out to 10 × 15 cm, the non-treated surfaces are put together, pressure is 0.2 MPa in the TD direction, and the heat seal time is 1 second. Heat sealing was performed every 5 ° C. from the start of sealing to the temperature at which yielding occurred on the film.
After leaving the film after heat sealing in a temperature-controlled room adjusted to 23 ° C. and 50% humidity for 24 hours or more, it is cut out at a width of 15 mm and pulled away in the MD direction at a tensile speed of 500 mm / min using a shopper type tester. The load was read.
Table 5 shows the peel load (g / 15 mm) of the film heat-sealed at each heat-sealing temperature.

[Examples 7 and 8]
A film was formed in the same manner as in Example 6 except that PP-2 and 4 pellets were used as raw materials, and the heat seal characteristics were evaluated in the same manner as in Example 6. The results are shown in Table 5.

[Comparative Examples 7 to 11]
A film was formed in the same manner as in Example 6 except that PP-6, 7, and 9-11 pellets were used as raw materials, and the heat seal characteristics were evaluated in the same manner as in Example 6. The results are shown in Table 5.

[Consideration by comparison between Example and Comparative Example]
As is clear from Table 3 among PP-1 to 11, PP-1 to 5 are propylene / ethylene random copolymers that satisfy all the essential requirements in the present invention.
On the other hand, since PP-6 to 8 have a high melting peak temperature, they are inferior in mechanical properties such as transparency and strength, or low-temperature heat seal characteristics in film applications.
PP-9 to 10 have not only a high melting peak temperature, but also a large T (99) -T (P) and a wide crystallinity distribution, so that the transparency is further deteriorated and the low-temperature heat seal characteristics are also inferior. .
Furthermore, although PP-11 has the melting peak temperature satisfying the necessary requirements of the present invention, T-11 has a large T (99) -T (P), and therefore has poor transparency and heat seal characteristics.
Specifically, the mechanical properties by injection molding are compared in Examples 1 to 5 and Comparative Examples 1 to 6. That is, it is well known to those skilled in the art that the physical properties of polypropylene resins are affected by the molecular weight. Here, Examples 1, 2, and 4 in which the weight average molecular weight Mw is at the same level as 200,000. As is clear from the comparison between Comparative Examples 1 and 2 and the comparison between Examples 3 and 5 and Comparative Example 3 in which Mw is at the same level as about 160,000, the melting peak temperature Tm which is a necessary requirement in the present invention. Is inferior in mechanical properties such as transparency and Charpy impact strength, as compared with Example in which the melting peak temperature Tm is 115 ° C. or higher.
Furthermore, in Comparative Examples 4 to 6, the difference between the elution end temperature T (99) and the elution peak temperature T (P) in TREF measurement, which is one of the necessary requirements of the present invention (= T (99) −T (P Comparative Example 1 and Examples 1 and 2 having the same molecular weight and ethylene content when T (99) -T (P) is 7 ° C. or less. In comparison, the melting peak temperature Tm decrease corresponding to the ethylene content is small, the transparency is remarkably deteriorated, and the physical property deterioration due to the wide crystallinity distribution is clear.

Moreover, regarding the heat seal characteristic in a film use, the comparison is performed in Examples 6-8 and Comparative Examples 7-11. Here, in comparison with Examples where the melting peak temperature Tm, which is a necessary requirement in the present invention, is in the range of 90 to 115 ° C., Comparative Examples 7 and 8 where the melting peak temperature Tm is 115 ° C. or higher are heat sealing properties. The starting temperature is high, welding at low temperature is impossible, and the superiority of the present invention, which is excellent in heat seal characteristics at low temperature, is highlighted.
Further, the difference between the elution end temperature T (99) and the elution peak temperature T (P) in TREF measurement (= T (99) −T (P)) is 7 ° C. or more, and Comparative Examples 9 to 9 exhibit a broadening in crystallinity. In No. 11, the heat seal temperature is widened, but this is a result of the crystallinity distribution being widened, and at low temperatures, the films are blocked due to stickiness, which causes a problem when used as a film. Cheap.
As described above, the quality of the propylene / ethylene random copolymer that does not satisfy the requirements of the present invention is various in terms of the propylene / ethylene random copolymer in the present invention, which is superior in mechanical properties and heat seal characteristics. It is inferior and highlights the superiority of the present invention.

(reference):
As the relationship between the ethylene content (mol%) and the melting peak temperature Tm (° C.) in the prior art, the data of Examples 1 to 30 in Patent Document 3 are shown in FIG. 1 together with the examples in the present invention.

  The propylene / ethylene random copolymer of the present invention is excellent in low-temperature heat sealability, flexibility and transparency, does not cause bleed-out and blocking, and has a high quality with improved strength. It can be suitably used for applications and has high industrial applicability.

It is a plot figure explaining the relationship between the ethylene content (mol%) and the melting peak temperature (Tm) (° C.) of the propylene / ethylene random copolymer of the present invention in comparison with the prior art (Patent Document 3). .

Claims (5)

A propylene / ethylene random copolymer comprising 94 to 84 mol% of propylene and 6 to 16 mol% of ethylene and having the following physical properties (a) to (d).
(A) The weight average molecular weight (Mw) obtained by GPC measurement is in the range of 100,000 to 500,000.
(B) The melting peak temperature (Tm) measured by DSC is in the range of 90 to 115 ° C.
(C) TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. The difference [T (99) −T (P)] between the elution end temperature [T (99)] and the elution peak temperature [T (P)] is 7 ° C. or less and the amount [W ( 0)] is 1 wt% or less of the whole.
(D) The propylene unit chain portion composed of a head-to-tail bond has an isotactic triad fraction measured by ¹³ C-NMR of 97% or more and a regioregular area based on 2.1-insertion. The rate is in the range of 0.15 to 1.0%, and the area fraction of the positional regularity based on 1.3-insertion is 0.05% or more. Furthermore, it has the following physical property (e), The propylene-ethylene random copolymer of Claim 1 characterized by the above-mentioned.
(E) The melting peak temperature (Tm) and the ethylene content ([E] (mol%)) satisfy the following formula (i).
Formula (i): 155-5 × [E] ≧ Tm ≧ 140−5 × [E] 3. The propylene / ethylene random copolymer according to claim 1, wherein the propylene / ethylene random copolymer is gas phase polymerized using a transition metal compound represented by the following general formula (I):

(In the formula, A and A ′ are optionally substituted cyclopentadienyl groups. Q is a binding group that bridges two conjugated five-membered ring ligands at an arbitrary position. M is a metal atom of a transition metal selected from Groups 4 to 6 in the periodic table X and Y are auxiliary ligands, each of which is a hydrogen atom, a halogen atom, a hydrocarbon group, or hetero (It is a hydrocarbon group which may have an atom.) 3. The propylene / ethylene random copolymer according to claim 1, wherein the propylene / ethylene random copolymer is gas phase polymerized using a transition metal compound represented by the following general formula (II):

(In formula, R < ¹ >, R < ² >, R < ⁴ > and R < ⁵ > are respectively independently a hydrogen atom, a C1-C10 hydrocarbon group, a C1-C18 silicon-containing hydrocarbon group, or C1. Represents a halogenated hydrocarbon group of ˜18, and R ³ and R ⁶ each independently represents a saturated or unsaturated group having 3 to 10 carbon atoms that forms a condensed ring with respect to the five-membered ring to which it is bonded. A condensed hydrocarbon group in which at least one of R ³ and R ⁶ has 5 to 8 carbon atoms and has a unsaturated bond derived from R ³ or R ^6. R ⁷ and R ⁸ are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, C1-C20 oxygen-containing hydrocarbon group, amino group, C1-C20 nitrogen-containing carbon A hydrogen group or a sulfur-containing hydrocarbon group having 1 to 20 carbon atoms, m and n each independently represents an integer of 0 to 20. However, m and n are not 0 at the same time. When m or n is 2 or more, R ⁷ or R ⁸ may be linked to each other to form a new ring structure, Q is a bridging group that links two cyclopentadienyl rings. X and Y represent a σ covalent bond auxiliary ligand that reacts with a cocatalyst to develop olefin polymerization ability, and M represents a transition metal of Groups 4 to 6 in the periodic table. The composition according to claim 3, wherein the gas phase polymerization is performed using an olefin polymerization catalyst comprising the following components (A) and (B), or components (A), (B) and (C): 4. The propylene / ethylene random copolymer according to 4.
Component (A): Transition metal compound represented by general formula (I) or (II) Component (B): At least one compound selected from ion-exchange layered silicate Component (C): Organoaluminum compound

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