JP2005139282A - Propylene-ethylene block copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a propylene-ethylene block copolymer having much improved transparency while keeping excellent rigidity, heat resistance and impact resistance of a conventional propylene-ethylene block copolymer. <P>SOLUTION: The propylene-ethylene block copolymer comprises a crystalline polypropylene component [component (A)] and an ethylene-propylene random copolymer component [component (B)] having 70-95 wt.% ethylene content, has 1-200 g/10 minutes MFR and the ratio of intrinsic viscosity [η]<SB>B</SB>of the component (B) to the intrinsic viscosity [η]<SB>A</SB>of the component (A) of 0.5-1.5. The formula (1): X≥Y≥0.75×X-1.0 is established between an ethylene content X in the component (B) and an ethylene content Y in a component soluble in paraxylene at 23°C in the component (B). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a propylene / ethylene block copolymer having good transparency and improved impact resistance at low temperatures.

  Since polypropylene is excellent in heat resistance and rigidity, it is widely used in various fields such as various containers, daily necessities, automobile parts, and electrical parts. In recent years, in the field of foods such as one-hand cups, there has been a demand for materials that are transparent and have impact resistance while maintaining the heat resistance and rigidity of polypropylene.

  However, although propylene homopolymer is excellent in rigidity and heat resistance, transparency and impact resistance at low temperature are inferior, and a random copolymer of propylene and α-olefin is improved in transparency but low in temperature. The impact resistance was insufficient, and the range of use was limited. Further, as a method for improving impact resistance, propylene block copolymers are known. However, although impact resistance is improved, there is a problem that transparency is impaired.

  In order to solve such problems, a propylene block copolymer of a propylene homopolymer or a propylene / α-olefin random copolymer and a propylene / α-olefin random copolymer with a small content difference of α-olefin It is disclosed (see Patent Documents 1 to 3). All of these can obtain a certain degree of transparency and impact resistance, but the balance is still insufficient. Moreover, these are characterized by extremely low rigidity, and high rigidity specific to polypropylene cannot be obtained.

  Moreover, the ethylene content of the propylene / ethylene copolymer is controlled to 40 to 80% by weight as a propylene block copolymer that is transparent and impact resistant but has high rigidity, so that xylene solubles and insolubles can be obtained. The technique which set the viscosity ratio of the polymer to 0.4-2 is disclosed (refer patent document 4). However, this proves that transparency is still insufficient and has not reached a practical level.

JP-A-9-324022 Japanese Patent Laid-Open No. 10-316810 JP 2001-172454 A JP-A-7-286020

  An object of the present invention is to provide a propylene / ethylene block copolymer having improved transparency while maintaining the excellent rigidity, heat resistance, and impact resistance of a conventional propylene / ethylene block copolymer. And

  As a result of intensive studies in view of the above-mentioned object, the present inventors have found that the ethylene content of the ethylene / propylene random copolymer component [component (B)] is in a specific range, and the specific copolymer containing ethylene and propylene. In the case where it has polymerizability, it has been found that transparency is further improved while maintaining the rigidity, heat resistance and impact resistance of the propylene / ethylene block copolymer.

That is, the invention of claim 1 includes a crystalline polypropylene component [component (A)] satisfying the following (A1) and an ethylene / propylene random copolymer component [component (B) satisfying the following (B1) and (B2): Propylene / ethylene block copolymer comprising an intrinsic viscosity [η] of component (A) measured at 230 ° C. and 21.18 N load MFR of 1 to 200 g / 10 min at 135 ° C. using decalin as a solvent. _The propylene / ethylene block copolymer is characterized in that the intrinsic viscosity [η] _B ([η] _B / [η] _A ) of the component (B) with respect to _A is 0.5 to 1.5.
(A1) propylene homopolymer or propylene / ethylene random copolymer having an ethylene content of 5% by weight or less (B1) ethylene / propylene random copolymer (B2) component having an ethylene content of 70 to 95% by weight ( The following formula (A) holds between the ethylene content X (% by weight) in B) and the ethylene content Y (% by weight) in the component (B) soluble in paraxylene at 23 ° C. Ethylene / propylene random copolymer.

      X ≧ Y ≧ 0.75 · X−1.0 (...)

  According to the invention of claim 2, the propylene / ethylene block copolymer of claim 1 wherein the isotactic pentad fraction ([mmmm]) of the component (A) is 97.5 to 99.9%. A polymer is provided.

According to the invention of claim 3, the intrinsic viscosity [η] _B ([η] _B / [η] _A ) of the component (B) with respect to the intrinsic viscosity [η] _A of the component ( _A ) is 0. The propylene / ethylene block copolymer according to claim 1, which is 7 to 1.3.

  According to the invention of claim 4, the ethylene content X (wt%) in the component (B) and the ethylene content Y (in the component soluble in paraxylene at 23 ° C. of the component (B) ( The propylene / ethylene block copolymer according to claim 1, wherein the following formula (c) is established:

      X ≧ Y ≧ 0.75 ・ X + 3.0 ・ ・ ・ ・ （C）

According to the invention of claim 5, the crystalline polypropylene component [component (A) is obtained by homopolymerizing propylene or copolymerizing propylene and 5% by weight or less of ethylene in the presence of an olefin polymerization catalyst. )] And an ethylene / propylene random copolymer containing 70 to 95% by weight of ethylene in the presence of the olefin polymerization catalyst and the component (A) produced in the first stage polymerization step. A propylene / ethylene block copolymer obtained from the second stage polymerization step for producing the polymer component [component (B)], wherein the block copolymer has an MFR of 230 ° C. and a load of 21.18 N. Intrinsic viscosity [η] _B ([η] _B / [η] _A ) of component (B) with respect to intrinsic viscosity [η] _A of component (A) measured at 1300 g / 10 min at 135 ° C. using decalin as a solvent But 0.5 -1.5 and the ethylene content X (wt%) in the component (B) and the ethylene content Y (wt%) in the component (B) soluble in paraxylene at 23C A propylene / ethylene block copolymer is provided in which the following formula (A) is satisfied.

      X ≧ Y ≧ 0.75 · X−1.0 (...)

  In addition, according to the invention of claim 6, the propylene / ethylene block according to claim 1, comprising 50 to 90 parts by weight of component (A) and 50 to 10 parts by weight of component (B). A copolymer is provided.

  Further, according to the invention of claim 7, there is provided the propylene / ethylene block copolymer according to claim 5, wherein the second stage polymerization step is carried out in a gas phase.

  Further, according to the invention of claim 8, the bending elastic modulus of 700 MPa or more obtained by melt-molding the propylene / ethylene block copolymer according to any one of claims 1 to 7, impact strength of 15 kg · cm. As described above, a molded body having a haze value of 70% or less of a 2 mmt test piece prepared by injection molding is provided.

  The propylene / ethylene block copolymer of the present invention has good rigidity, heat resistance and transparency, and excellent impact resistance at low temperatures. Therefore, it is widely used in various fields such as various containers, daily necessities, automobile parts, and electrical parts. In recent years, the use of food products such as one-hand cups is expected to expand.

  The propylene-ethylene block copolymer of the present invention comprises a crystalline polypropylene component [component (A)] and an ethylene / propylene random copolymer component [(component (B)), and has an MFR of 230 ° C. and a load of 21.18 N. Satisfies 1 to 200 g / 10 min. When the MFR is lower than 1 g / 10 minutes, the moldability is deteriorated. When the MFR is higher than 200 g / 10 minutes, the impact strength is decreased, which is not preferable. 5 to 150 g / 10 min is particularly preferable, and 10 to 100 g / 10 min is more preferable.

The propylene / ethylene block copolymer of the present invention has a ratio ([η] _B / [η] _A ) of [η] _B to the intrinsic viscosity [η] _A of component (A) measured at 135 ° C. using decalin as a solvent. Is 0.5 to 1.5. If [η] _B / [η] _A is 0.5 or less, the impact resistance at low temperatures is insufficient, and if it exceeds 1.5, the transparency deteriorates. In particular, [η] _B / [η] _A is preferably 0.6 to 1.4, and more preferably 0.7 to 1.3 from the viewpoint of a balance between impact resistance at low temperature and transparency. This is because by maintaining an appropriate viscosity ratio, a polypropylene matrix composed of component (A) (hereinafter referred to as “PP matrix”) and an ethylene / propylene random copolymer particle composed of component (B) at the time of melt-kneading. As a result of receiving the strain of the same magnitude, it seems to promote the miniaturization of the dispersed particles, suppress the dispersed particle size to about the wavelength of light or less, and express transparency by preventing light scattering.

The intrinsic viscosities [η] _A and [η] _B defined in the present invention are values measured by the method described later.

  Component (A) must be (A1) a propylene homopolymer or a propylene / ethylene random copolymer having an ethylene content of 5% by weight or less. When the ethylene content exceeds 5% by weight, rigidity is lowered and heat resistance is also deteriorated, which is not preferable. Further, by copolymerizing a small amount of ethylene with propylene, the transparency is further improved as compared with the case of propylene homopolymer. This is probably because by introducing a small amount of ethylene into the PP matrix, the crystal-amorphous interface of the PP matrix is blurred, and the scattering loss of minute light generated at the interface can be further reduced. Therefore, the ethylene content is preferably 0.5 to 5% by weight, more preferably 0.7 to 1.3% by weight from the viewpoint of the balance between transparency, rigidity, and heat resistance.

  The component (A) is a crystalline polypropylene component, and its isotactic pentad fraction ([mmmm]) is 97.5 to 99.9%. The isotactic pentad fraction ([mmmm]) is preferably 98 to 99.9%, more preferably 98.5 to 99.9%. If it is below the above range, the transparency deteriorates, and if it is above the above range, it is difficult to produce, which is not preferable. This is presumably because the crystallinity increases, the size of the microcrystals becomes uniform, and as a result, the transparency improves.

The isotactic pentad fraction ([mmmm]) is a value measured by ¹³ C-NMR described later.

  The ethylene content of the ethylene / propylene random copolymer component [(component (B)]) needs to be 70 to 95% by weight, preferably more than 70 to 90% by weight, more preferably 75 to 85% by weight. When the content is below the above range, the transparency is deteriorated, and when the content is above the above range, both the impact resistance and the transparency are deteriorated, which is not preferable. It is a parameter that determines the affinity of the interface between the particles and the dispersed particles.If the affinity is too low, the dispersed particles will agglomerate and swell and light scattering will not increase, and if the affinity is too good, it will melt during pelletization and molding. In the process, the dispersed particles that have undergone deformation remain intact at the original size and are designed to have an appropriate interfacial adhesion, effectively resulting in particle fragmentation during kneading and fine dispersion below the wavelength of light. Gain Is, transparency is expected to greatly improve.

  In addition, ethylene content X of a component (B) is a value measured by the method mentioned later.

  Between the ethylene content Y (wt%) of the component (B) soluble in para-xylene at 23 ° C. and the ethylene content X (wt%) of the component (B), the following formula (I) It needs to hold. The following formula (B) is preferable, and the following formula (C) is more preferable.

X ≧ Y ≧ 0.75 · X−1.0 (...)
X ≧ Y ≧ 0.75 ・ X + 1.0 ・ ・ ・ ・ (b)
X ≧ Y ≧ 0.75 ・ X + 3.0 ・ ・ ・ ・ （C）

  When Y is lower than the right side value of the above formulas (A), (B), and (C), the transparency is deteriorated. When Y is higher than the above range, that is, when Y is larger than X, Since manufacturing is difficult, it is not preferable. This relational expression is a measure representing the copolymerizability of ethylene and propylene. As the ethylene content Y (wt%) of the component (B) soluble in para-xylene at 23 ° C. approaches the ethylene content X (wt%) of the component (B), the copolymerizability increases. When the copolymerization is high, the amount of polyethylene crystals inside the dispersed ethylene / propylene random copolymer can be reduced, the dispersion size can be reduced, and the light scattering loss generated inside the dispersed particles is reduced. Transparency is improved.

    In addition, ethylene content Y of a component soluble in 23 degreeC paraxylene among components (B) is a value measured by the method mentioned later.

In the present invention, the intrinsic viscosity [η] _{A of} the component ( _A ), the intrinsic viscosity [η] _{B of} the component (B), the ethylene content X (% by weight) of the component (B), and 23 of the component (B) The ethylene content Y (% by weight) of the component soluble in para-xylene at ° C is determined by the following method.

(i) Definition of each component-Of component (A), component soluble in paraxylene at 23 ° C: A (cxs),
Ingredient (A), at 23 ° C., insoluble in para-xylene: A (cxis),
-Among components (B), components soluble in paraxylene at 23 ° C: B (cxs),
-Among components (B), at 23 ° C., components insoluble in paraxylene: B (cxis),
-Weight fraction of component A (cxs): W [A (cxs)],
-Weight fraction of component A (cxis): W [A (cxis)],
-Weight fraction of component B (cxs): W [B (cxs)],
-Weight fraction of component B (cxis): W [B (cxis)],
-Weight fraction of component (A): W [A] = W [A (cxs)] + W [A (cxis)]
-Weight fraction of component (B): W [B] = W [B (cxs)] + W [B (cxis)],
-Ethylene content (% by weight) of component A (cxs): E [A (cxs)],
-Ethylene content of component A (cxis) (wt%): E [A (cxis)]
-Ethylene content (weight%) of component B (cxs): E [B (cxs)],
-Ethylene content (% by weight) of component B (cxis): E [B (cxis)],

  When the propylene / ethylene block copolymer comprising the component (A) and the component (B) is referred to as “final polymer (F)”, each component constituting these is defined as shown in [Table 1] below.

なお、各成分の重量分率は、その総和が１となるようにしたものであり、すなわち以下の式が成り立つ。

The weight fraction of each component is such that the sum is 1, that is, the following equation holds.

W [A (cxs)] + W [A (cxis)] + W [B (cxs)] + W [B (cxis)] = 1 (1)
The ethylene content Y (wt%) in the component soluble in paraxylene at 23 ° C. among the ethylene content X (wt%) in the component (B) and the component (B) is obtained by the following formula.

X = {E [B (cxs)] × W [B (cxs)] + E [B (cxis)] × W [B (cxis)]} / (W [B (cxs)] + W [B (cxis)] )
Y = E [B (cxs)]
The weight fraction and ethylene content of each component are determined according to the following procedure.

(ii) Extraction of component (A) at 23 ° C. and para-xylene After completion of polymerization of component (A), a part is sampled from the polymerization tank to obtain component (A).
The obtained component (A) is separated into a component A (cxs) soluble in paraxylene at 23 ° C and a component A (cxis) insoluble in paraxylene at 23 ° C by extraction with paraxylene at 23 ° C described later. .
The ratio K of the weight fractions W [A (cxs)] and W [A (cxis)] of the component A (cxs) and the component A (cxis) is obtained.

K = W [A (cxis)] / W [A (cxs)] (2)
Further, according to the method described later, the ethylene contents E [A (cxs)] and E [A (cxis)] of the components A (cxs) and A (cxis) are obtained.

(iii) Extraction of final polymer (F) at 23 ° C. and paraxylene After polymerization of component (A), final polymer (F) obtained by polymerizing component (B) is extracted at 23 ° C. by paraxylene. The component F (cxs) soluble in para-xylene at 23 ° C. and the component F (cxis) insoluble in para-xylene at 23 ° C.
The weight fractions W [F (cxs)] and W [F (cxis)] of the component F (cxs) and the component F (cxis) are obtained. At this time, the total weight fraction is set to 1.
Further, E [F (cxs)] and E [F (cixs)], which are ethylene contents of the component F (cxs) and the component F (cxis), are obtained.
Here, the component F (cxs) is equal to the sum of the component A (cxs) and the component B (cxs) defined in [Table 1], and the component F (cxis) is equal to the component A (cxis). It is the sum of component B (cxis), and the weight fraction and ethylene content of each component can be determined according to the following calculation.

(iv) Calculation of weight fraction of each component and ethylene content First, the following relationship holds.

W [A (cxs)] + W [B (cxs)] = W [F (cxs)]
Therefore, W [B (cxs)] = W [F (cxs)] − W [A (cxs)] (3)
W [A (cxis)] + W [B (cxis)] = W [F (cxis)]
Therefore, W [B (cxis)] = W [F (cxis)] − W [A (cxis)]
Furthermore, from equation (2)
W [B (cxis)] = W [F (cxis)] − K × W [A (cxs)] (4)
Further, the ethylene content of component F (cxis) is represented by the following formula.

    E [F (cxis)] = {E [A (cxis)] × W [A (cxis)] + E [B (cxis)] × W [B (cxis)]} / W [F (cxis)]

From equations (2) and (4),
E [F (cxis)] = {E [A (cxis)] × K × W [A (cxs)] + E [B (cxis)] × (W [F (cxis)] − K × W [A (cxs )])} / W [F (cxis)]
Therefore,
W [A (cxs)] = {E [F (cxis)] − E [B (cxis)]} × W [F (cxis)] / {E [A (cxis)] − E [B (cxis)] } / K
Here, all the variables on the right side can be obtained as measured values except for E [B (cxis)].
Further, the component B (cxis) is a component having high crystallinity derived from an ethylene chain, and can be substantially set to E [B (cxis)] = 100.
Therefore, W [A (cxs)] can be calculated.

From the formulas (3), (4) and (1),
W [B (cxs)] = W [F (cxs)] − W [A (cxs)]
W [B (cxis)] = W [F (cxis)] − K × W [A (cxs)]
W [A (cxis)] = 1- {W [A (cxs)] + W [B (cxs)] + W [B (cxis)]}
Thus, the weight fraction can be obtained for all components.

  On the other hand, the ethylene content of component F (cxs) is represented by the following formula.

E [F (cxs)] = {E [A (cxs)] × W [A (cxs)] + E [B (cxs)] × W [B (cxs)]} / W [F (cxs)]
Therefore,
E [B (cxs)] = {E [F (cxs)] × W [F (cxs)] − E [A (cxs)] × W [A (cxs)]} / W [B (cxs)]
Thus, it is possible to calculate E [B (cxs)].

(v) Measurement of Intrinsic Viscosity Intrinsic viscosities [η] _A and [η] _B of component (A) and component (B) are measured at 135 ° C. using decalin as a solvent using an Ubbelohde viscometer.
First, after the polymerization of the component (A), a part is sampled from the polymerization tank to obtain the component (A). The intrinsic viscosity [η] A of the obtained component (A) is measured.
Next, after polymerizing the component (A), the intrinsic viscosity [η] _F of the final polymer (F) obtained by polymerizing the component (B) is measured.
[Η] _B is obtained from the following relationship.

[Η] _F = W [A] × [η] _A + W [B] × [η] _B
W [A] = W [A (cxs)] + W [A (cxis)] (5)
W [B] = W [B (cxs)] + W [B (cxis)] (6)

(vi) Extraction method of paraxylene at 23 ° C. A 2 g sample was dissolved in 300 ml of paraxylene (containing 0.5 mg / ml BHT) at 130 ° C. to obtain a solution, and then left at 23 ° C. for 12 hours. Thereafter, the precipitated polymer is separated by filtration and an insoluble component (cxis component) is recovered. Further, paraxylene is evaporated from the filtrate to recover a soluble component (cxs component). Each component is further dried under reduced pressure at 100 ° C. for 12 hours, and measurement and measurement of ethylene content (described later) are performed.

(vii) Method for Measuring Ethylene Content 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.
(Carbon nuclear resonance frequency of 100 MHz or more)
Solvent: Orthodichlorobenzene: 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 attribution of the spectrum may be performed with reference to, for example, Macromolecules, 17, 1950 (1984). The attribution of spectra measured under the above conditions is as shown in Table 2 below. In Table 2, symbols such as Sαα follow the notation of Carman et al. (Macromolecules, 10,536 (1977)), P represents methyl carbon, S represents methylene carbon, and T represents methine carbon.

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), etc., the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (7) to (12).
[PPP] = k × I (T _ββ ) (7)
[PPE] = k × I (T _βδ ) (8)
[EPE] = k × I (T _δδ ) (9)
[PEP] = k × I (S _ββ ) (10)
[PEE] = k × I (S _βδ ) (11)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (12)
Here, [] 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 (13)
It is. K in the formulas (7) to (12) is a constant. I represents spectral intensity. For example, I (T _ββ ) means the intensity of a peak at 28.7 ppm attributed to T _ββ .

By using the relational expressions (7) to (13) above, the fraction of each triad is obtained, and the ethylene content in mol% units is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100 (14)
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = (28 × X mol / 100) / {28 × X mol + 42 × (1−X mol / 100)} (15)
Here, Xmol is the ethylene content in terms of mol% determined from the equation (8).

The isotactic pentad fraction ([mmmm]) in the present invention is the five consecutive propylene monomer units in the center of a chain in which five propylene monomer units are continuously bonded in the polypropylene molecular chain. This is the percentage of propylene monomer units at the center of the meso-linked chain, and is determined by analyzing the ¹³ C-NMR spectrum measured by the method described in the method for measuring ethylene content.

Spectral assignment is performed with reference to Macromolecules, 8, 687 (1975) and Macromolecules, 17, 1950 (1984), for example, and the isotactic pentad fraction is obtained from the following equation (16).
Isotactic pentad fraction (%) = {I _mmmm / (ΣI _Me −I _PPE −I _EPE
)} × 100 (16)

Here, I _mmmm is the intensity of a peak derived from the methyl group of a propylene monomer unit at the center of a chain in which five propylene monomer units are continuously meso-bonded (occurs in the vicinity of 21.8 ppm when measured under the above conditions). Yes, ΣI _Me is the sum of the peaks derived from the methyl group (occurring in the region of about 19.3 to 21.8 ppm under the above measurement conditions), and I _PPE is the methine carbon derived from the propylene-propylene-ethylene bond. The intensity of the peak (occurs in the vicinity of 30.6 ppm under the above measurement conditions), and I _EPE is the intensity of the peak of methine carbon derived from the ethylene-propylene-ethylene bond (in the vicinity of 32.9 ppm under the above measurement conditions).

  The propylene / ethylene block copolymer is a reaction mixture of a crystalline polypropylene component [component (A)] and an ethylene / propylene random copolymer component [component (B)]. This is obtained by propylene homopolymerization for producing component (A) or propylene / ethylene random copolymer containing propylene and 5% by weight or less of ethylene, and subsequent production steps of component (B). Component (A) is produced by a polymerization process of one stage or two or more stages (reaction conditions of each stage are the same or different), and component (B) is also one or more stages (reaction conditions of each stage are the same or different). ) In the polymerization step. Therefore, the entire production process of the propylene / ethylene block copolymer of the present invention is a multistage polymerization process comprising at least two stages. For example, if the component (A) is produced in one stage and the component (B) is produced in two stages, the polymerization process is a total of three stages. Further, if the component (A) is produced in 2 stages and the component (B) is produced in 3 stages, the polymerization process consists of a total of 5 stages. In this case, the first-stage polymerization step referred to in claim 5 is the first two polymerization steps for producing component (A), and the second-stage polymerization step is the latter step for producing component (B). Means three polymerization steps.

  In addition, the reaction mixture here is not a mere physical mixture of the component (A) and the component (B) but means that the component (A) and the component (B) are mixed through the reaction. However, it does not deny the partial presence of the physical mixture.

  The catalyst used for the polymerization is not particularly limited, and is a so-called combination of an organoaluminum compound component and a solid component essentially comprising a titanium atom, a magnesium atom, a halogen atom and an electron donating compound. In addition to the Ziegler-Natta catalyst, a metallocene catalyst can also be used. When the random copolymerization property of ethylene and propylene is high, the transparency is improved, and therefore a metallocene catalyst that is generally said to have good copolymerizability is more preferable.

As the organoaluminum compound, a general formula R ¹ _m AlX _(3-m) known in this kind of polymerization is used.
(Wherein R ¹ is a hydrocarbon residue having 1 to 12 carbon atoms, X represents a halogen atom, and m is a number from 1 to 3). For example, trimethylaluminum, triethyl Trialkylaluminum such as aluminum, dialkylaluminum halide such as dimethylaluminum chloride, diethylaluminum chloride, alkylaluminum sesquihalide such as methylaluminum sesquichloride, ethylaluminum sesquichloride, alkylaluminum dihalide such as methylaluminum dichloride, ethylaluminum dichloride, Examples thereof include alkylaluminum hydrides such as diethylaluminum hydride.

  In addition, the solid component essentially including a titanium atom, a magnesium atom, a halogen atom and an electron donating compound is a known solid component in this type of polymerization.

Titanium compounds that supply titanium atoms include the general formula Ti (OR ² ) _(4-n) X _n
(Wherein R ² is a hydrocarbon residue having 1 to 10 carbon atoms, X represents a halogen atom, and n is a number from 0 to 4). For example, titanium tetrachloride, Examples include tetraethoxy titanium and tetrabutoxy titanium.

  Examples of the magnesium compound that serves as the supply source of the magnesium atom include dialkyl magnesium, magnesium dihalide, dialkoxy magnesium, alkoxy magnesium halide, and the like, among which magnesium dihalide is preferable.

  Examples of the halogen atom include fluorine, chlorine, bromine, and iodine. Among them, chlorine is preferable, and these are usually supplied from the titanium compound or the magnesium compound, and include aluminum halide, silicon halide, tungsten It may be supplied from other halogen sources such as halides.

Examples of the electron donating compound include alcohols, phenols, ethers, ketones, aldehydes, carboxylic acids, oxygen-containing compounds such as organic acids or inorganic acids and derivatives thereof, ammonia, amines, nitriles, isocyanates, etc. Among them, ethers, inorganic acid esters, organic silicon alkoxides, organic acid esters, organic acid halides, etc. are preferable, diethers, silicic acid esters, phthalic acid esters, acetic acid cellosolve esters, phthalic acid halides. , R ³ R ⁴ _(3-p) Si (OR ⁵ ) _p (wherein R ³ is a branched aliphatic hydrocarbon residue having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, or carbon number) 5 to 20, preferably 6 to 10 cyclic aliphatic hydrocarbon residues, wherein R ⁴ is a branched or linear aliphatic hydrocarbon having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. It indicates Motozanmoto, R ⁵ is 1 to 10 carbon atoms, preferably an aliphatic hydrocarbon residue 1 to 4, p is an organic silicon compound represented by a number of 1-3.) Are More preferably, for example, 2,2-diisopropyl-1,3-dimethoxypropane, 2-t-butyl-2-methyl-1,3-dimethoxypropane, dibutyl phthalate, octyl phthalate, dichloride phthalate, cellosolve ethyl acetate Ester, t-butyl-methyl-dimethoxysilane, t-butyl-methyl-diethoxysilane, cyclohexyl-methyl-dimethoxysilane, cyclohexyl-methyl-diethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, propyl Examples include triethoxysilane and tetraethoxysilane.

The metallocene catalyst is preferably composed of, for example, components (a) and (b) as shown below, and component (c) used as necessary.
Component (a): at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula:
_{Q (C 5 H 4-a} R 1 a) (C 5 H 4-b R 2 b) MeXY ··· (17)
[The significance of Q, Me, X, Y, R ¹ and R ² will be described later]
Component (b): at least one solid component selected from the following (b-1) to (b-4) (b-1) a particulate carrier on which an organoaluminum oxy compound is supported,
(B-2) an ionic compound capable of reacting with component (a) to convert component (a) to a cation or a particulate carrier carrying a Lewis acid,
(B-3) solid acid fine particles,
(B-4) an ion-exchange layered silicate,
Component (c): an organoaluminum compound.

<Component (a)>
As the component (a), at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula can be used.

_{Q (C 5 H 4-a} R 1 a) (C 5 H 4-b R 2 b) MeXY
[Wherein Q represents a divalent linking group that bridges two conjugated five-membered ring ligands, Me represents a metal atom selected from titanium, zirconium, and hafnium, and X and Y represent a hydrogen atom, a halogen atom, An atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group or a silicon-containing hydrocarbon group is shown, and X and Y may be independently, that is, the same or different. R ¹ and R ² are hydrogen atoms, hydrocarbon groups, halogenated hydrocarbon groups, silicon-containing hydrocarbon groups, nitrogen-containing hydrocarbon groups, oxygen-containing hydrocarbon groups, boron-containing hydrocarbon groups, or phosphorus-containing hydrocarbon groups. Indicates. ]
Q represents a divalent linking group that bridges two conjugated five-membered ring ligands, for example, a divalent hydrocarbon group, a silylene group or an oligosilylene group, or a silylene group having a hydrocarbon group as a substituent. Alternatively, an oligosilylene group or a germylene group having a hydrocarbon group as a substituent is exemplified. Among these, a divalent hydrocarbon group and a silylene group having a hydrocarbon group as a substituent are preferable.

  X and Y each represents a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. Atoms, chlorine atoms, methyl groups, isobutyl groups, phenyl groups, dimethylamide groups, diethylamide groups and the like can be exemplified. X and Y may be independent of each other, that is, may be the same or different.

R ¹ and R ² are a hydrogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon. Represents a group. Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a phenyl group, a naphthyl group, a butenyl group, and a butadienyl group. In addition, as halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group, or phosphorus-containing hydrocarbon group, methoxy group, ethoxy group, phenoxy group Typical examples include trimethylsilyl group, diethylamino group, diphenylamino group, pyrazolyl group, indolyl group, dimethylphosphino group, diphenylphosphino group, diphenylboron group, dimethoxyboron group, and the like. Among these, a hydrocarbon group having 1 to 20 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, and a butyl group are particularly preferable. By the way, adjacent R ¹ and R ² may combine to form a ring, on which a hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing You may have a substituent which consists of a hydrocarbon group, a boron containing hydrocarbon group, or a phosphorus containing hydrocarbon group.

  Me is a metal atom selected from titanium, zirconium and hafnium, preferably zirconium and hafnium.

  Among the components (a) described so far, preferred for the production of the propylene / ethylene block copolymer of the present invention is a substituted cyclopenta crosslinked with a silylene group, a germylene group or an alkylene group having a hydrocarbon substituent. It is a transition metal compound composed of a ligand having a dienyl group, a substituted indenyl group, a substituted fluorenyl group, or a substituted azulene group, and particularly preferably a 2,2 crosslinked with a silylene group having a hydrocarbon substituent or a germylene group. It is a transition metal compound comprising a ligand having a 4-position substituted indenyl group and a 2,4-position substituted azulene group.

  Non-limiting specific examples include dimethylsilylene bis (2-methyl, 4-phenylindenyl) zirconium dichloride, diphenylsilylene bis (2-methyl, 4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl). Benzoindenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl, 4- (3,5-diisopropylphenyl) indenyl) zirconium dichloride, dimethylsilylenebis (2-propyl, 4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylenebis (2-methyl, 4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-methyl, 4- (4-chlorophenyl) azurenyl) zirconium dichloride, dimethylsilylenebi (2-Ethyl, 4-phenylazurenyl) zirconium dichloride, dimethylsilylene bis (2-isopropyl, 4-phenylazurenyl) zirconium dichloride, dimethylsilylene bis (2-ethyl, 4- (2-fluorobiphenyl) azurenyl) zirconium Examples thereof include dichloride, dimethylsilylene bis (2-ethyl, 4- (4-t-butyl, 3-chlorophenyl) azurenyl) zirconium dichloride, and the like.

  As described above, compounds in which the silylene group is replaced with a germylene group and zirconium is replaced with hafnium in the compounds of these specific examples are also exemplified as suitable compounds.

<Component (b)>
As the component (b), at least one solid component selected from the components (b-1) to (b-4) described above is used. Each of these components is known and can be used by appropriately selecting from known techniques. Specific examples and manufacturing methods thereof are described in detail in JP-A No. 2002-284808, JP-A No. 2002-53609, JP-A No. 2002-69116, JP-A No. 2002-105015, and the like.

  Here, as the fine particle simple substance used for component (b-1) and component (b-2), inorganic oxides such as silica, alumina, magnesia, silica alumina, silica magnesia, magnesium chloride, magnesium oxychloride, chloride Examples thereof include inorganic halides such as aluminum and lanthanum chloride, and organic simple substances such as porous polypropylene, polyethylene, polystyrene, styrene divinyl benzene copolymer and acrylic acid copolymer.

  Further, as a non-limiting specific example of the component (b), as a component (b-1), a particulate carrier on which methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, aluminum butylboronate tetraisobutyl and the like are supported As component (b-2), triphenylborane, tris (3,5-difluorophenyl) borane, tris (pentafluorophenyl) borane, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N, N-dimethyl A particulate carrier on which anilinium tetrakis (pentafluorophenyl) borate, etc. are supported, as component (b-3), alumina, silica alumina, magnesium chloride, etc., as component (b-4), montmorillonite, zakonite, Beidellite, nontronite, Ponaito, hectorite, stevensite, bentonite, smectite group such as taeniolite, vermiculite group, mica group, and the like. These may form a mixed layer.

  Particularly preferable among the above components (b) are component (b-4) ion-exchange layered silicates, and more preferable ones are subjected to chemical treatment such as acid treatment, alkali treatment, salt treatment, and organic matter treatment. Ion exchange layered silicate.

<Component (c)>
Examples of organoaluminum compounds used as component (c) as needed are those of the general formula AlR _a P _3-a
(Wherein R is a hydrocarbon group having 1 to 20 carbon atoms, P is hydrogen, halogen, alkoxy group, a is a number of 0 <a ≦ 3), trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutyl Trialkylaluminum such as aluminum or halogen- or alkoxy-containing alkylaluminum such as diethylaluminum monochloride or diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Of these, trialkylaluminum is particularly preferred.

<Catalyst formation>
Component (a), component (b) and, if necessary, component (c) are brought into contact to form a catalyst. The contact method is not particularly limited, but can be contacted 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.
1) Contact component (a) and component (b) 2) Add component (c) after contacting component (a) and component (b) 3) Contact component (a) and component (c) 4) Add component (b) after contact 4) Add component (a) after contacting component (b) and component (c), or contact three components simultaneously.

  The amount of components (a), (b) and (c) used in the present invention is arbitrary. For example, the usage-amount of a component (a) becomes like this. Preferably it is 0.1-1000 micromol with respect to 1 g of component (b), Most preferably, it is the range of 0.5-500 micromol. The usage-amount of a component (c) is 1-100000 with respect to the transition metal of a component (a), Preferably it is 10-10000.

  Prior to using the catalyst of the present invention in the first stage polymerization step, the catalyst is preferably subjected to a prepolymerization treatment comprising contacting an olefin with this to polymerize in a small amount. Although the olefin to be used is not particularly limited, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene, and the like can be used. It is possible to use, and it is particularly preferable to use propylene. The olefin feed method may be any method such as a feed method for maintaining the olefin at a constant rate or a constant pressure in the reaction tank, a combination thereof, or a stepwise change. The prepolymerization temperature and time are not particularly limited, but are preferably in the range of −20 ° C. to 100 ° C. and 5 minutes to 24 hours, respectively. The amount of prepolymerization is preferably 0.01 to 100, more preferably 0.1 to 50 with respect to the component (B). After completion of the prepolymerization, the catalyst can be used as it is, depending on the usage form of the catalyst. However, if necessary, drying can be performed.

  In the sequential multi-stage polymerization step of at least two steps, propylene, and optionally ethylene are supplied in the first-stage polymerization step, and the temperature is 50 to 50 in the presence of the catalyst (preferably the prepolymerized catalyst). Propylene homopolymerization or ethylene / propylene random copolymerization is carried out under conditions of 150 ° C., preferably 50 to 70 ° C., and a partial pressure of propylene of 0.5 to 4.5 MPa, preferably 1.0 to 3.5 MPa. (A) is manufactured.

  Subsequently, in the second stage polymerization step, propylene and ethylene are supplied, and a temperature of 50 to 150 ° C., preferably 70 to 120, is present in the presence of the catalyst (the catalyst used in the first stage polymerization step). C., propylene and ethylene partial pressures of 0.3 to 4.5 MPa, preferably 0.5 to 3.5 MPa, random copolymerization of propylene and ethylene to produce component (B), and finally As a product, a propylene / ethylene block copolymer is obtained.

  The polymerization at that time may be any of batch, continuous, and semi-batch, and the polymerization in the first stage polymerization step may be carried out in the gas phase or liquid phase, or after the second stage polymerization step. The polymerization is also preferably carried out in the gas phase or liquid phase, particularly in the gas phase, and the residence time of each stage is preferably 0.5 to 10 hours, preferably 1 to 5 hours.

  Further, when problems such as stickiness occur in the powder particles of the composition produced by the successive multistage polymerization process of at least two stages, the first stage polymerization process is performed for the purpose of imparting fluidity to the powder particles. After the polymerization in step 2, before or during the polymerization in the second stage polymerization step, the active hydrogen-containing compound is added in an amount of 100 to 1000 times moles of titanium atoms in the solid component of the catalyst, and the organic of the catalyst. It is preferable to add in the range of 2 to 5 moles relative to the aluminum compound.

  Here, examples of the active hydrogen-containing compound include water, alcohols, phenols, aldehydes, carboxylic acids, acid amides, ammonia, amines, and the like.

  Further, the propylene block copolymer of the present invention has various additives such as a heat stabilizer, an antioxidant, a weather stabilizer, an ultraviolet absorber, and a crystal nucleating agent as long as the object of the present invention is not impaired. Copper damage prevention agents, antistatic agents, flame retardants, hydrophilizing agents, slip agents, antiblocking agents, antifogging agents, colorants, fillers, elastomers, petroleum resins and the like can be blended.

  In the present invention, the propylene / ethylene block copolymer and, if necessary, these various additives are heated and melt-kneaded at 180 to 300 ° C. in a dry blend state or using a melt-kneader and cut into granules. Provided in pellet form.

  Further, the propylene / ethylene block copolymer of the present invention has properties excellent in fluidity, heat resistance, flexural modulus, low temperature impact properties, and transparency, and preferably the following (a) to (f): It has the physical properties of

(A) Melt flow rate (MFR)
It is 1 to 200 g / 10 minutes, preferably 5 to 150 g / 10 minutes, and more preferably 10 to 100 g / 10 minutes.

(B) Heat resistance (melting point)
Preferably it is 120 degreeC or more, More preferably, it is 125 degreeC or more, More preferably, it is 130 degreeC or more.

(C) Flexural modulus Preferably it is 700 MPa or more, More preferably, it is 700-2000 MPa, More preferably, it is 800-1500 MPa.

(D) Low temperature surface impact strength It is preferably 15 kg · cm or more, more preferably 20 kg · cm or more, and further preferably 25 kg · cm or more.

(E) Transparency (haze value)
The haze value of a 2 mmt test piece prepared by injection molding is preferably 70% or less, more preferably 60% or less, and even more preferably 50% or less.

(F) ΔHaze Preferably it is 30% or less, more preferably 20% or less, and even more preferably 10% or less.

  EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

1. Physical property measurement method:
(A) MFR
Based on JIS K-7210-1995, it measured at the temperature of 230 degreeC by 21.18N load.

(B) Heat resistance (melting point)
Using a DSC7 differential scanning calorimeter manufactured by PerkinElmer, the position of the peak of the maximum endothermic peak temperature indicating melting, which was melted at 230 ° C. for 10 minutes and measured at a heating rate of 10 ° C./min, was determined. .

(C) Flexural modulus Measured according to JIS K-7203-1982 at a bending speed of 2 mm / min at 23 ° C. As an evaluation sample, an 80 × 120 × 2 mm sheet-like test piece prepared by injection molding at a molding temperature of 200 ° C. using an EC100 type injection molding machine manufactured by Toshiba Machine was used.

(D) Low-temperature surface impact strength Using a EC100-type injection molding machine manufactured by Toshiba Machine, a dart with a diameter of 20 mm and a load of 3 kg is applied to an 80 × 120 × 2 mm sheet-shaped test piece prepared by injection molding at a molding temperature of 200 ° C. It was dropped from 2.5 m, and the absorbed energy at that time was measured. At that time, the ambient temperature is 0 ° C.

(E) Transparency (haze value)
Based on JIS K-7105, it measured with the test piece of thickness 2mm created by injection molding.

(F) haze haze value of the propylene / ethylene block copolymer finally obtained through the second stage polymerization step and crystalline polypropylene component [component (A)] obtained in the first stage polymerization step It calculated | required as a difference with a single haze value.

2. Materials Used (1) Propylene / ethylene block copolymer The propylene / ethylene block copolymers (PP-1 to PP-12) obtained in Production Example 1-12 below were used.

<Production Example 1>
(I) Production of solid catalyst component (a) 20 liters of dehydrated and deoxygenated n-heptane was introduced into a tank equipped with a stirrer with an internal volume of 50 liters purged with nitrogen, and then 10 moles of magnesium chloride and 20 moles of tetrabutoxytitanium And then reacting at 95 ° C. for 2 hours, lowering the temperature to 40 ° C., introducing 12 liters of methylhydropolysiloxane (viscosity 20 centistokes) and further reacting for 3 hours, then taking out the reaction solution The resulting solid component was washed with n-heptane.

  Subsequently, 5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank equipped with a stirrer, and then 3 mol of the solid component synthesized above was introduced in terms of magnesium atom. Next, 5 liters of silicon tetrachloride was mixed with 2.5 liters of n-heptane and introduced at 30 ° C. for 30 minutes. The temperature was raised to 70 ° C. and reacted for 3 hours. Then, the reaction solution was taken out, The resulting solid component was washed with n-heptane.

  Subsequently, 2.5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank equipped with a stirrer, 0.3 mol of phthalic acid chloride was mixed and introduced at 90 ° C. for 30 minutes, The reaction was carried out at 95 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 2 liters of titanium tetrachloride was added at room temperature, and the temperature was raised to 100 ° C., followed by reaction for 2 hours. After completion of the reaction, washing with n-heptane was performed. Further, 0.6 liters of silicon tetrachloride and 8 liters of n-heptane were introduced, reacted at 90 ° C. for 1 hour, and sufficiently washed with n-heptane to obtain a solid component. This solid component contained 1.30% by weight of titanium.

  Next, 8 liters of n-heptane, 400 g of the solid component obtained above, 0.27 mol of t-butyl-methyl-dimethoxysilane and 0.27 mol of vinyltrimethylsilane were introduced into the tank equipped with a stirrer substituted with nitrogen. And contacted at 30 ° C. for 1 hour. Next, the mixture was cooled to 15 ° C., 1.5 mol of triethylaluminum diluted in n-heptane was introduced over 15 minutes under 15 ° C., and after the introduction, the temperature was raised to 30 ° C. and reacted for 2 hours. The solid catalyst component (a) (390 g) was obtained by washing with heptane.

  The obtained solid catalyst component (a) contained 1.22% by weight of titanium. This is called “Ziegler catalyst synthesis product I”.

  Furthermore, 6 liters of n-heptane and 1 mol of triisobutylaluminum diluted in n-heptane were introduced over 30 minutes at 15 ° C., and then about 0.4 kg / kg of propylene was controlled so as not to exceed 20 ° C. Preliminarily polymerized by introducing for 1 hour. As a result, a polypropylene-containing solid catalyst component (a) in which 0.9 g of propylene was polymerized per 1 g of solid was obtained.

(Ii) Production of Propylene / Ethylene Block Copolymer (PP-1) Polymerization was carried out using a continuous reaction apparatus formed by connecting two fluidized bed reactors having an internal volume of 230 liters. First, in the first reactor, the polymerization temperature is 65 ° C., the propylene partial pressure is 18 kg / cm ² (absolute pressure), ethylene is ethylene / propylene molar ratio is 0.027, hydrogen as the molecular weight control agent is hydrogen / propylene mole In addition to continuously supplying the ratio to 0.050, triethylaluminum is 5.25 g / hr, and the polymer polymerization rate of “Ziegler catalyst synthesis product I” is 16 kg / hr as the solid catalyst component (a). Supplied to be. The powder polymerized in the first reactor (crystalline propylene / ethylene random copolymer) was continuously withdrawn so that the amount of powder held in the reactor was 40 kg, and continuously transferred to the second reactor ( First stage polymerization step).

  Propylene and ethylene are continuously supplied at a polymerization temperature of 90 ° C. and a pressure of 2.0 MPa so that the molar ratio of ethylene / propylene is 3.0, and hydrogen as a molecular weight control agent is In addition to continuously supplying 1.2 molar ratio of / propylene, ethyl alcohol was supplied as an active hydrogen compound so as to be 2.6-fold mol with respect to triethylaluminum. The powder polymerized in the second reactor is continuously extracted into the vessel so that the amount of powder held in the reactor becomes 50 kg, and the reaction is stopped by supplying nitrogen gas containing moisture. A polymer (PP-1) was obtained (second stage polymerization step).

  Table 3 shows the reaction conditions of the first stage polymerization step and the second stage polymerization step. The crystalline polypropylene component [component (A)] obtained in the first stage polymerization step and the ethylene / propylene random copolymer component [component (B)] obtained in the second stage polymerization step are also various. The physical properties are shown in Table 4.

<Production Examples 2-4, 8, 9>
Using the catalyst alignment polymerization method used in Production Example 1, the supply amount and hydrogen amount of propylene and ethylene in the first stage polymerization, the supply amount and hydrogen amount of propylene and ethylene in the second stage polymerization, polymerization in each stage The time and polymerization temperature were changed as shown in Table 3, and propylene / ethylene block copolymers (PP-2 to PP-4, PP-8, PP-9) were produced. Table 4 shows the physical properties of the component (A) and the component (B) obtained in the first stage polymerization and the second stage polymerization.

<Production Examples 5-7, 10>
Using the catalyst (Ziegler catalyst synthesis product I) used in Production Example 1, in a first reactor having an internal volume of 400 liters, a temperature of 70 ° C. and a pressure corresponding to the vapor pressure of liquid propylene at the operating temperature (70 The solid catalyst component (a) in such a ratio that the propylene is continuously fed at about 3.2 MPa at a temperature of 10 ° C., triethylaluminum is 10 g / hr, and the polymer production rate is 20 kg / hour. (Average 0.7 g / hr) is continuously supplied, and hydrogen as a molecular weight control agent is continuously supplied so that the molar ratio of hydrogen / propylene is 0.042, and polymerization is performed in the liquid phase. And a propylene homopolymer was produced with an average residence time of 60 minutes (first stage polymerization).

  Subsequently, the produced polymer was introduced into a fluidized bed type second reactor having an internal volume of 780 liters via a propylene purge tank, and propylene and ethylene were brought to a pressure of 2.0 MPa at a polymerization temperature of 90 ° C. Is continuously supplied so that the molar ratio of ethylene / propylene is 3.0, and further, hydrogen as a molecular weight control agent is continuously supplied so that the molar ratio of hydrogen / propylene is 1.2. At the same time, ethyl alcohol was supplied as an active hydrogen compound so as to be 2.4 moles relative to triethylaluminum. The powder polymerized in the second reactor is continuously withdrawn into the vessel so that the amount of powder in the reactor is 60 kg, and the reaction is stopped by supplying nitrogen gas containing moisture. A polymer (PP-5) was obtained (second stage polymerization). PP-6, 7 and 10 use the catalyst alignment polymerization method used in this production example, supply amount and hydrogen amount of propylene and ethylene in the first stage polymerization, and propylene and ethylene in the second stage polymerization. The amount of hydrogen and the amount of hydrogen, the polymerization time at each stage, and the polymerization temperature were changed as shown in Table 3.

  Table 3 shows the polymerization conditions at each stage, and Table 4 shows the physical properties of the components (A) and (B) obtained by the first stage polymerization and the second stage polymerization.

<Production Example 11>
(I) Production of solid catalyst component (a) In a 100 liter reaction vessel having a reflux condenser, 830 g of chip-shaped magnesium metal (purity 99.5%, average particle size 1.6 mm) in a nitrogen gas atmosphere and After adding 25 liters of n-hexane and stirring at 68 ° C. for 1 hour, the metallic magnesium was taken out and dried under reduced pressure at 65 ° C. to obtain a preactivated metallic magnesium.

  Next, 14 liters of n-butyl ether and 50 milliliters of an n-butyl ether solution of n-butyl magnesium chloride (1.75 mol / liter) are added to the magnesium metal and stirred to form a suspension. Maintained at 55 ° C. Further, a solution prepared by dissolving 3.85 liters of n-butyl chloride in 5 liters of n-butyl ether was added dropwise over 50 minutes. Thereafter, the reaction was carried out at 70 ° C. for 4 hours with stirring, and then the reaction solution was kept at 25 ° C.

Next, 5.57 liters of triethoxymethane HC (OC ₂ H ₅ ) ₃ was added to this reaction solution over 1 hour, and after the addition was completed, the reaction was performed at 60 ° C. for 15 minutes, and the resulting reaction product solid was obtained. Was washed 6 times with 30 liters of n-hexane. Thereafter, it was dried under reduced pressure at room temperature for 1 hour to obtain 3.16 kg of a magnesium-containing solid containing 19.0% by weight of magnesium and 28.9% by weight of chlorine.

  In a 30 liter reaction vessel having a reflux condenser and a stirrer, 63 g of the magnesium-containing solid obtained previously and 5 liters of n-heptane were put in a nitrogen gas atmosphere, and this was stirred to form a suspension. A mixture of 2,2,2-trichloroethanol (2 liters (20 mol)) and n-heptane (1.1 liters) was added to the turbid liquid over 30 minutes while continuing stirring at room temperature, and further at 80 ° C. for 1 hour. Stir. This suspension was filtered, and the resulting solid was washed 4 times with 10 liters of each n-hexane at room temperature, and further twice with 10 liters of toluene to obtain a solid component.

4 liters of toluene was added to the solid component thus obtained, and titanium tetrachloride was further added at a ratio such that titanium tetrachloride / toluene (volume ratio) was 3/2, and the temperature was raised to 90 ° C. . Next, a mixture of 200 ml of di-n-butyl phthalate and 500 ml of toluene was added dropwise to the mixture over 5 minutes with stirring, and the mixture was stirred at 120 ° C. for 2 hours. The mixture was filtered at 90 ° C. to obtain a solid material. This solid material was washed twice at 90 ° C. with 10 l each of toluene. Furthermore, the same amount of titanium tetrachloride and toluene as before were added and stirred at 120 ° C. for 2 hours. The mixture was filtered at 110 ° C. to obtain a solid material. This solid material was washed seven times with 10 liters of each n-hexane at room temperature. In this way, 550 g of a solid component was obtained.
This is called “Ziegler catalyst synthesis product II”.

  A 10-liter reaction vessel was charged with 4 liters of hexane and 13.7 g of triethylaluminum, cooled to 0 ° C., and 100 g of the solid component was added thereto. Subsequently, propylene was supplied at a rate of 5 g / min for 1 hour with stirring to perform prepolymerization. Stirring was continued for another 15 minutes after the propylene supply was stopped. The solid was washed 3 times with 3 liters of hexane and then dried to obtain 382 g of a solid catalyst component (a).

(Ii) Production of propylene / ethylene block copolymer (PP-11) Supply of propylene and ethylene in the first stage polymerization using the solid catalyst component (a) and the same polymerization method as in Production Example 5. Propylene / ethylene block copolymer (PP-11) by changing the amount and hydrogen amount, the supply amount and hydrogen amount of propylene and ethylene in the second stage polymerization, the polymerization time of each stage, and the polymerization temperature as shown in Table 3 Manufactured. Table 4 shows the physical properties of the component (A) and the component (B) obtained in the respective polymerization steps.

<Production Example 12>
(I) Procurement of solid catalyst component (a) A Ziegler catalyst commercial product (manufactured by Tosoh Finechem Co., Ltd., titanium trichloride TSO-0514) was used.
(Ii) Production of propylene / ethylene block copolymer (PP-12) The above commercially available titanium trichloride was used as the solid catalyst component (a), and diethylaluminum chloride was used in place of triethylaluminum. Table 3 shows the amount of propylene and ethylene supplied and the amount of hydrogen in the first stage polymerization, the amount of propylene and ethylene supplied and the amount of hydrogen in the second stage polymerization, the polymerization time at each stage, and the polymerization temperature. Thus, a propylene / ethylene block copolymer (PP-12) was produced. Table 4 shows the physical properties of the component (A) and the component (B) obtained in the respective polymerization steps.

<Examples 1-7, Comparative Examples 1-5>
Tetrakis [methylene-3- (3′5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (IRGANOX1010 manufactured by Ciba Geigy) 0 in 100 parts by weight of the propylene / ethylene block copolymer shown in Table 4 0.05 part by weight, 0.05 part by weight of tris (2,4-di-t-butylphenyl) phosphite (IRGAFOS168 manufactured by Ciba Geigy), bis (2,4,6,8,10-tetra-t as a nucleating agent -Butyl-oxo-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin-6-oxide) aluminum hydroxide salt (NA21 manufactured by Asahi Denka Co., Ltd.) 0.2 parts by weight, magnesium aluminum Mixing 0.05 parts by weight of hydroxoxide carbonate hydrate (DHT4A manufactured by Kyowa Chemical Industry Co., Ltd.) After mixing for 5 minutes at over mixer to obtain a polypropylene resin composition by kneading granulation at a set temperature of 210 ° C. at Kobe Steel Co. twin-screw kneader (2FCM).

  Thereafter, a test piece for measuring physical properties was prepared at a molding temperature of 210 ° C. with an injection molding machine having a clamping pressure of 100 tons, and the measurement was performed according to the above various measuring methods. The evaluation results are shown in Table 5.

  The following can be understood from Tables 3 to 5. That is, Example 1 is the example with the best balance of transparency and impact resistance, Example 2 is the one in which the ethylene content in the first stage of Example 1 is reduced, and Example 3 is in the rubber of Example 2. Example 4 was obtained by changing the ethylene content to 90% by weight, Example 4 was obtained by reducing the ethylene content of the first stage of Example 3, Example 5 was an example where the first stage was homopolypropylene, Example 6 shows an example of an index substantially equivalent to that of Example 2, and Example 7 shows that the [η] of the rubber part of Example 4 is different.

Since Comparative Example 1 is a one-stage polymer, an example in which transparency is good but impact resistance is poor, and Comparative Example 2 is an example in which the ethylene content in the rubber is low, so impact resistance is good but transparency is not achieved. Example 3 is an example in which [η] _B / [η] _A is deviated and no transparency is obtained, and Comparative Example 4 is a random copolymerization property of rubber (X ≧ Y ≧ 0.75 · X−1.0). Comparative example 5 shows an example in which the first stage [mmmm] is low and the transparency is not obtained.

Propylene / ethylene block copolymer with improved rigidity while maintaining rigidity, heat resistance and impact resistance, so it can be widely used in various fields such as various containers, daily necessities, automobile parts, electrical parts, etc. is there.

Claims (8)

Propylene / ethylene block copolymer comprising a crystalline polypropylene component [component (A)] satisfying the following (A1) and an ethylene / propylene random copolymer component [component (B)] satisfying the following (B1) and (B2): The intrinsic viscosity of the component (B) relative to the intrinsic viscosity [η] _A of the component (A) measured at 230 ° C. and an MFR of 21.18 N load of 1 to 200 g / 10 min at 135 ° C. using decalin as a solvent [ η] _B ([η] _B / [η] _A ) is 0.5 to 1.5, and a propylene / ethylene block copolymer.
(A1) propylene homopolymer or propylene / ethylene random copolymer having an ethylene content of 5% by weight or less (B1) ethylene / propylene random copolymer (B2) component having an ethylene content of 70 to 95% by weight ( The following formula (A) holds between the ethylene content X (% by weight) in B) and the ethylene content Y (% by weight) in the component (B) soluble in paraxylene at 23 ° C. Ethylene / propylene random copolymer.
X ≧ Y ≧ 0.75 · X−1.0 (...)   The propylene / ethylene block copolymer according to claim 1, wherein the isotactic pentad fraction ([mmmm]) of component (A) is 97.5 to 99.9%. The intrinsic viscosity [η] _B ([η] _B / [η] _A ) of the component (B) with respect to the intrinsic viscosity [η] _A of the component ( _A ) is 0.7 to 1.3. Propylene / ethylene block copolymer. Between the ethylene content X (wt%) in the component (B) and the ethylene content Y (wt%) in the component (B) soluble in paraxylene at 23 ° C., the following formula (c) The propylene / ethylene block copolymer according to claim 1, wherein:
X ≧ Y ≧ 0.75 ・ X + 3.0 ・ ・ ・ ・ （C） A first stage polymerization step of producing a crystalline polypropylene component [component (A)] by homopolymerizing propylene in the presence of an olefin polymerization catalyst or copolymerizing propylene and 5% by weight or less of ethylene; And an ethylene / propylene random copolymer component [component (B)] containing 70 to 95% by weight of ethylene in the presence of the olefin polymerization catalyst and the component (A) produced in the first stage polymerization step. A propylene / ethylene block copolymer obtained from the second stage polymerization step, wherein the block copolymer has a MFR of 230 ° C., 21.18 N load of 1 to 200 g / 10 min, and decalin at 135 ° C. The intrinsic viscosity [η] _B ([η] _B / [η] _A ) of the component (B) with respect to the intrinsic viscosity [η] _A of the component (A) measured as a solvent is 0.5 to 1.5, And in component (B) The following formula (A) is established between the ethylene content X (wt%) and the ethylene content Y (wt%) in the component (B) soluble in paraxylene at 23 ° C. Propylene / ethylene block copolymer.
X ≧ Y ≧ 0.75 · X−1.0 (...)   The propylene / ethylene block copolymer according to any one of claims 1 to 5, comprising 50 to 90 parts by weight of the component (A) and 50 to 10 parts by weight of the component (B).   The propylene / ethylene block copolymer according to claim 5, wherein the second stage polymerization step is carried out in a gas phase. A haze of a 2 mmt test piece prepared by injection molding, having a flexural modulus of 700 MPa or more and an impact strength of 15 kg · cm or more formed by melt-molding the propylene / ethylene block copolymer according to any one of claims 1 to 7. A molded product having a value of 70% or less.