JPS6169821A - Production of block propylene copolymer - Google Patents

Abstract

PURPOSE:To obtain the titled copolymer excellent in rigidity, etc., in good yields, by adding an active hydrogen compound to a random copolymerization system is the production of a block propylene copolymer in the presence of a highly stereoregular polymerization catalyst by a multistage polymerization process. CONSTITUTION:In the first stage, a crystalline propylene (co)polymer is produced in the presence of a highly stereoregular polymerization catalyst. In the second stage, propylene is random-copolymerized with other alpha-olefins (e.g., ethylene) at a molar ratio 10/90-90/10 in the presence of said (co)polymer and 0.001-1mol, per g.atom of aluminum in the highly stereoregular polymerization catalyst, of an active hydrogen compound (e.g., methanol or phenol) to obtain the purpose block propylene copolymer. In this way, cohesion of polymer particles among themselves and adhesion thereof to the walls of apparatuses in the polymerization process can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a propylene block copolymer with excellent rigidity, impact resistance, fluidity, and heat sealability with good operability.

[Conventional technology]

Conventionally, crystalline polymers or copolymers of propylene (hereinafter referred to as
(Both are sometimes referred to collectively as simply polypropylene.)
and/or producing a rubbery copolymer of propylene by copolymerizing propylene and other α-olefins in the presence of the polypropylene and/or crystallinity of other α-olefins. It is known to produce polymers or copolymers, especially ethylene or ethylene-based crystalline polymers or copolymers. It is known that such a multi-stage polymerization method can yield a composition that maintains the excellent rigidity of polypropylene and has improved impact resistance at low temperatures.

The composition is usually an intimate mixture of polymers or copolymers produced in each step and is commonly referred to as a block copolymer. Such block copolymers are often used, for example, in containers, automobile parts, easily heat-sealable films, and the like.

Generally, in order to further improve the impact strength of the above-mentioned block copolymers, it is effective to increase the proportion of rubber-like copolymers produced, but this may also increase the tendency of the polymer particles to stick. , difficult to avoid. As a result, polymer particles may adhere to each other or to the inner wall of the device.
This often involves troubles that make stable long-term continuous operation difficult.

Particularly in gas phase polymerization, deterioration in fluidity due to polymer particle adhesion is a fatal defect in operation. In addition, in slurry polymerization, the amount of solvent-soluble polymer increases, and the viscosity of the slurry unreasonably increases, which not only causes problems such as making the polymerization operation difficult, but the amount of rubbery polymer incorporated into the solid polymer is not as high as desired. There is also the problem of not increasing. The polymer particles obtained by such unsatisfactory polymerization have low bulk density, poor flowability, and are accompanied by many defects during post-processing operations such as transportation and melt processing.

For the purpose of reducing the tendency of the polymer particles to adhere, there is a method in which an alkoxyaluminum compound is added in the propylene/α-olefin copolymerization step during block copolymerization, such as in JP-A-56-151713 and JP-A-58-58.
It is proposed in No. 213012. However, these conventionally proposed methods have the disadvantage that it is difficult to achieve the desired effect unless a fairly large amount of the alkoxyaluminum compound is added to the alkylaluminum compound catalyst component used for polymerization.

[Problems to be solved by the present invention]

The present inventors have avoided the disadvantage of requiring the addition of a substantial amount of alkoxyaluminum compound as in the above-mentioned conventional proposal, and solved the problem of the tendency of polymer particles to adhere to each other and to the inner wall of the apparatus. We have been conducting research and development on methods that can reduce this.

[Means, actions and effects for solving the problems] As a result, the present inventors have realized that by supplying an active hydrogen compound to a random copolymerization reaction system in a controlled and specific range of addition amount, Surprisingly, it has been discovered that a significant improvement in the avoidance of the problems associated with deposition 1 can be achieved without any substantial and undesirable reduction in polymerization activity.

According to the above-mentioned conventional proposal for adding an alkoxyaluminum compound, it has been shown that the alkoxyaluminum compound can be prepared by mixing an alkylaluminum compound and an alcohol in advance. However, quite unexpectedly, compared to using an alkoxyaluminum compound prepared in advance in the form of an alkoxyaluminum compound, introducing an active hydrogen compound such as an alcohol into the random copolymerization reaction system is more effective. It has been discovered that even when compared on the basis of alkoxy groups, a small supply amount is extremely effective in preventing the troubles caused by the first adhesion, and moreover, it exhibits an improving effect of improving -N. Furthermore,
It has been found that in addition to alcohol, other active hydrogen compounds that are inexpensive and easily available can also be used.

Thus, according to the research of the present inventors, a crystalline polymer or copolymer of propylene is produced in the previous step in the presence of a highly stereoregular polymerization catalyst, and the polymer or copolymer is produced in the later polymerization step. Polymerization ratio (molar ratio) of propylene and other α-olefins in the presence of the copolymer: 10/90 to 90/1
In a method for producing a propylene block copolymer comprising random copolymerization in a proportion of 0, 1 g of aluminum in a highly stereoregular polymerization catalyst is
By supplying the active hydrogen compound to the random copolymerization reaction system at a ratio of 0.01 to 1 mole per atom, the drawbacks of conventional proposals can be overcome by utilizing an inexpensive and easily available active hydrogen compound. However, it has been found that the problem of the adhesion tendency can be industrially advantageously avoided.

The active hydrogen compound can be supplied to the random copolymerization reaction system by directly or indirectly adding it to the cough system.

Although the details of the mechanism of action of achieving the unexpected and excellent improvement effect by the above-mentioned method of the present invention are not yet clear, as will be shown experimentally later using Examples and Comparative Examples, clearly different effects were achieved. In view of this, the unexpected and excellent improvement effect of the method of the present invention obtained by supplying an active hydrogen compound, such as alcohol, in the controlled and small amount to the random copolymerization reaction system is due to the fact that the alcohol is It is presumed that the mechanism of action is clearly different from that of simply converting an alkyl aluminum compound into an alkoxy aluminum compound. Of course, it should be understood that the method of the present invention is not limited in any way by such speculation about the mechanism of action.

According to the method of the present invention, in the above method for producing a propylene block copolymer, during the random copolymerization, the active hydrogen compound is contained at a ratio of 0.01 to 1 mole per 1 g atom of aluminum in the highly stereoregular polymerization catalyst. Then, it is supplied to the random copolymerization reaction system.

Many catalysts that can be used in the present invention are already known, and are capable of highly stereoregular polymerization of propylene. Typically, it consists of a titanium catalyst component and an organoaluminum compound catalyst component, but an electron donor catalyst component may be used if necessary for the purpose of improving stereoregularity.

Typical titanium catalyst components are titanium trichloride catalyst components or magnesium compound-supported halogen-containing titanium catalyst components containing as essential components an interaction product of a magnesium compound, a titanium compound, and an electron donor. Although they can be used in the present invention, the latter type is preferred because of its significantly higher activity.

The titanium trichloride catalyst component is titanium tetrachloride reduced with a reducing agent such as aluminum, titanium, hydrogen, or an organoaluminum compound, or mechanically pulverized such as ball milling and/or solvent washed [inert A cleaning treatment with a solvent and/or a polar compound such as ether] and/or a treatment with titanium tetrachloride can be used.

Further, a halogen-containing titanium catalyst component containing as an essential component an interaction product of a magnesium compound, a titanium compound, and an electron donor can be used, for example, by reacting a magnesium compound (or magnesium metal), a titanium compound, and an electron donor in any order. Alternatively, in addition to the above raw materials, a reaction aid such as a halogenating agent and/or an organoaluminum compound is used to react in any order, or the products obtained by each of the above methods are further washed with a solvent. be able to. This type of catalyst component, in the absence of an inert diluent, usually has a specific surface area of 3 rd/g or more, e.g. 30 to 100 rd/g.
0rd/g, halogen/Ti (atomic ratio) is, for example, 4 to 100, preferably 6 to 70, Mg/T
i (atomic ratio) is in the range of, for example, 2 to 100, preferably 4 to 70, and the electron donor/titanium (molar ratio) is in the range of, for example, O to 10, preferably 0.2 to 6. It is usually in a highly amorphous state compared to magnesium chloride. Typical examples of the electron donor are esters, ethers, acid anhydrides, alkoxy silicon compounds, and the like.

Many methods for producing the titanium catalyst component as described above are already known and can be used in the present invention.

The titanium catalyst component preferably has a narrow particle size distribution and is spherical, ellipsoidal, or similar in shape.

As the organoaluminum compound catalyst component used in block copolymerization, compounds having at least one Al-carbon bond in the molecule can be used, such as (i) a compound having the general formula R'mA1 (OR'')I%IIPXQ (Here R
1 and R2 are hydrocarbon groups containing usually 1 to 15 carbon atoms, preferably [ to 4 carbon atoms, such as an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, etc., and these R1 and R2 may be the same as each other or It's okay to be different. X is halogen, m is 0<m≦3, n is O≦n<3, p
is a number such that 0≦p<3, q is a number such that 0≦q<3, and m
+ n + p + q = 3), (ii) general formula M'AIR
Examples include complex alkylated products of Group 1 metals and aluminum represented by 4 (here, Ml is Li, Na, or K, and R is the same as above).

Examples of the organoaluminum compounds belonging to (i) above include the following. General formula R'mAI (OR”
)3-g (Here, R1 and R2 are the same as above.m
is preferably a number of 1.5≦m≦3).

General formula R'ra A I
), the general formula R'-%A I II ? -% (here, R1 is the same as above. m is preferably 2≦m<3), general formula R', , Al (OR2), , XqC, -Fl'Oyohi R2 is the same as above. X is halogen, Q<m≦3, Q
5n<3.0≦q<3, m + n + q = 3
) can be exemplified.

Specific examples of aluminum compounds belonging to (1) include:
Trialkylaluminum such as triethylaluminum and tributylaluminium; trialkenylaluminum such as triisoprenylaluminum; alkyl such as butylkylaluminum alkoxide such as diethylaluminum chloride and dibutylaluminum ptoxide; ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide; Aluminum sesquialkoxide; R↓, s Al (OR2'). , etc.; dialkyl aluminum halides such as diethylaluminum chloride, dibutyl aluminum chloride, diethylaluminum bromide; ethyl aluminum sesquichloride, butyl aluminum sesquichloride, Alkylaluminum sesquihalogenides such as ethylaluminum sesquipromide; partially halogenated alkylaluminums such as alkylaluminum halides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum bromide, etc.; diethylaluminum hydride, dibutyl dialkylaluminum hydrides such as aluminum hydride; partially hydrogenated alkylaluminums such as alkylaluminum halides such as ethylaluminum dihydride, pro-aluminum dihydride: ethylaluminum ethoxy chloride, butylaluminum sesquichloride, ethylaluminum Examples include partially alkoxylated and halogenated alkyl aluminums such as ethoxybromide. Moreover, as a compound similar to (i), an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom may be used. Examples of compounds such as ε include (C2115)2 Al0AI (C
21k)2, (C4119)2 to AIO (CaH
g), y, (C211 da)2 AlNAl (C, It
Examples include S)2. Said C, H.

As a compound belonging to (ii), LiA1 (CZ
Examples include II Yuhato, LiAl (C7t]15)4, and the like. Among these, preferred ones vary depending on the type of titanium catalyst component. For example, when using a titanium trichloride catalyst component, it is preferable to use a dialkyl aluminum halide, and when using a magnesium compound-supported titanium catalyst component, a trialkyl aluminum or an alkyl aluminum compound having two or more aluminum atoms, Alternatively, it is preferable to use a mixture of these trialkylaluminum and the like and alkyl aluminum halide.

In addition to the titanium catalyst component and the organoaluminum compound catalyst component described above, an electron donor catalyst component may be used to form the highly stereoregular catalyst. Such electron donor catalyst components include organic acid esters, inorganic acid esters, alkoxy silicon compounds, carboxylic acid anhydrides, sterically hindered amines,
Examples include complexes of these and aluminum chloride.

As an example of a highly active and highly stereoregular catalyst using a magnesium compound-supported titanium catalyst component, for example, JP-A-52
-151691, JP 53-21093°C, JP 55-135102-3, JP 56-811, JP 57-63310-2, JP 58-83006
The highly active and highly stereoregular catalyst systems described in JP-A-58-138705-12 and the like can be mentioned, and can be used in the present invention.

In the present invention, a propylene crystalline polymer or copolymer is produced in the preliminary step. At this stage, the polymerization may be carried out in two steps. Furthermore, prior to full-scale polymerization, a prepolymerization treatment may be performed in which the catalyst is brought into contact with a small amount of propylene in order to improve catalyst activity, bulk density, fluidity, and the like. An example of the prepolymerization treatment is the treatment disclosed in Japanese Patent Publication No. 57-45244.

The pre-polymerization can be carried out in the liquid or gas phase in the presence or absence of an inert solvent. The appropriate amount of each catalyst component to be used can be appropriately selected depending on the type thereof. For example, when using a typical titanium trichloride catalyst component as the titanium catalyst component, the reaction volume l! For example, about 0.01 to about 30 mmol, preferably about 0.01 to about 10 mmol, of the titanium catalyst component in terms of titanium atoms,
The organoaluminum compound catalyst component is, for example, At/Ti (
atomic ratio) from about 0.1 to about 50, preferably about 0.5
An example may be an embodiment in which the proportion is from about 10 to about 10. In addition, when using a highly active catalyst supported on a magnesium compound as a titanium catalyst component, the titanium catalyst component is, for example, approximately 0.0 in terms of titanium atoms per 1 p of reaction volume.
01 to about 0.5 mmol, preferably about 0.005
from about 0.5 mmol to about 0.5 mmol of the organoaluminum compound catalyst component, for example, with an At/Ti (atomic ratio) of from about 1 to about 2.
000, preferably from about 1 to about 500, and the electron donor catalyst component can be appropriately selected depending on the type thereof, but the amount is, for example, about 0.000 per mole of the organoaluminum compound catalyst component.
0.001 to about 50 moles, preferably about 0.005 to about 50 moles.

In the pre-stage polymerization, a crystalline propylene polymer or copolymer is produced in order to obtain a highly rigid block copolymer. Copolymerization components for producing a copolymer include α-olefins other than propylene, such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, Examples include those having 2 to 10 carbon atoms such as 1-decene. The proportion of propylene component units in the copolymer is adjusted to be, for example, about 90 mol % or more, preferably about 95 mol % or more.

Preferably, a highly crystalline propylene polymer or copolymer having a crystallinity of 40% or more as measured by X-rays is produced. As the polymer or copolymer, 1
The intrinsic viscosity [η] measured in decalin at 35°C is, for example, about 1 to about 10 d! /g, especially about 1 to about 5
It is preferable to produce a polymer with a molecular weight of about dl/g, and for this purpose, a molecular weight regulator, preferably hydrogen, may be present in the polymerization system. The polymerization temperature can be selected as appropriate, for example, about 50 to about 100°C, preferably about 60 to about 90°C. Further, the polymerization pressure can be appropriately selected, for example, about 1 to about 200 kg/cnl-G.
, preferably about 1 to about 100 kg/cJA-G.

When carrying out liquid phase polymerization, propylene may be used as a liquid medium, or an inert solvent may be used as a liquid medium. Examples of such inert solvents include e.g. evapropane, butane, pentane, hexane, heptane, octane, decane,
A typical example is kerosene.

In the present invention, in the later polymerization step, propylene and other α-olefins are mixed at a polymerization ratio (
Molar ratio) Random copolymerization is carried out at a ratio of 10/90 to 90/10. This random copolymerization is usually carried out subsequent to the previous polymerization step to produce a crystalline propylene polymer or copolymer, but if desired, the random copolymerization can be carried out after the previous step. Before this, a step of producing another α-olefin crystalline polymer or copolymer as described later may be provided in advance. However, other α
- When the above-mentioned step of producing a crystalline polymer of olefin is provided, it is preferable from the viewpoint of the process to provide it after the above-mentioned random copolymerization step.

Random copolymerization can also be carried out in the liquid or gas phase. In particular, if gas phase polymerization is employed, all of the copolymer is incorporated into the block copolymer, so the yield relative to the consumed olefin is high, which is industrially advantageous.

Examples of other α-olefins used in random copolymerization include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and -decene. Preferred is ethylene or a combination of ethylene and a C4 to C6 α-olefin. The copolymerization ratio of propylene and other α-olefins is 10 in molar ratio.
/90 to 90/10, preferably 20/80 to 80/20, more preferably 30/70 to 70/3
It is 0.

In random copolymerization, the active hydrogen compound is added in an amount of 0.01 to 1 g atom per g atom of aluminum in the catalyst,
Preferably it is used in a proportion of 0.02 to 0.8 g atom, more preferably 0.02 to 0.6 g atom.

Examples of the active hydrogen compound include water, alcohol, phenol, carboxylic acid, sulfonic acid, primary amine, secondary amine, and the like. -More specifically, alcohols include methanol, ethanol, isopropanol, n-propanol, tert-butanol,
Saturated or saturated alcohols having about 1 to 18 carbon atoms, such as n-hexanol, n-occuenol, n-dodecanol, oleyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, methoxyethanol, cyclohexanol, benzyl alcohol, isopropylbenzyl alcohol, and phenylethyl alcohol. Unsaturated aliphatic, alicyclic or aromatic alcohols; phenols include phenol, cresol, xylenol,
ethylphenol, isopropylphenol, tert
-Butylphenol, nonylphenol, etc.; carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, acrylic acid, cyclohexanecarboxylic acid, benzoic acid, salicylic acid,
Aliphatic, alicyclic or aromatic carboxylic acids such as stearic acid; sulfonic acids such as mekunsulfonic acid, ecunsulfonic acid, benzenesulfonic acid, toluenesulfonic acid; primary amines such as methylamine, ethylamine, isopropylamine, Examples of secondary amines include cyclohexylamine, aniline, etc.; dimethylamine, dibutylamine, dihenzylamine, etc.

Among these, it is particularly preferable to use alcohols, particularly alcohols having 1 to 10 carbon atoms, since they are highly effective. Two or more of these active hydrogen compounds may be used in combination.

In order to supply an active hydrogen compound to a random copolymerization system, it is possible to use a mode in which it is directly introduced into the system, but it is effective to mix it with an inert gas or gaseous polymerization raw material in advance and then introduce it. . It is also possible to adopt a supply method in which it is directly introduced into the random copolymerization system or diluted with butane, hexane, etc. (solvent D).

The amount of copolymerization in random copolymerization can be selected and changed as appropriate depending on the physical properties of the target block copolymer.
For example, about 5 to about 60 parts by weight, preferably about 5 to about 5 parts by weight, per 100 parts by weight of the crystalline polymer of propylene.
An example of -2: polymerization amount of 0 parts by weight. In general, when the amount of copolymerization is small, the tendency for the flowability of the resulting block copolymer to deteriorate is small, and therefore the effect of adopting the present invention is not as great as that on the left. However, as the amount of copolymerization increases, the tendency of the present invention to be adopted is The benefits increase.

In random copolymerization, the intrinsic viscosity [η] measured in decalin at 135°C is, for example, about 1 to about 15 d1.
/g, preferably about 1 to about 10 d1/g, and for this purpose, molecular weight regulators such as hydrogen may be used as appropriate. Although [η] of the random copolymer cannot be directly measured, it can be estimated from [η] of the block copolymer and [η] of the crystalline propylene (co)polymer, assuming that additivity holds.

In the block copolymerization of the present invention, as mentioned above, crystalline polymers (or copolymers) of other α-olefins are produced for the purpose of improving impact resistance, rigidity, whitening resistance, etc. A process may be provided.

Most typical are homopolymers of ethylene or copolymers of ethylene with small proportions, eg up to 5 mole percent, of other α-olefins. It is preferable to provide such a step after the random copolymerization.

The random copolymerization may be, for example, about 40 to about 150
'C1 is preferably carried out at a temperature of about 50 to about 100° C. and a pressure of, for example, about 1 to about 200 kg/cal-G, especially about 1 to about 100 kg/cal-G.

In addition, when producing a crystalline (co)polymer of the other α-olefin, for example, at a temperature of about 40 to about 150° C.
In particular, at a temperature of about 50 to about 100"C, about 1 to about 200 kg/c+d-G, especially about 1
Preferably, the pressure is from about 100 kg/cnl-G to about 100 kg/cnl-G.

According to the present invention, a block copolymer having excellent rigidity and induction impact resistance can be produced with good operability.

Particularly in the random copolymerization process, adhesion of polymers to each other and adhesion to walls can be significantly reduced or avoided, so long-term continuous operation is possible. Furthermore, the resulting block copolymer has a high bulk density and excellent fluidity, so it is easy to transport and has good extrusion characteristics.

Example 1 (Preparation of titanium catalyst component) Anhydrous magnesium chloride 7.41 g (75 mmol)
, 37 m +2 decane and 35.1 ml (225 mmol) of 2-ethylhexyl alcohol at 130°C.
After a heating reaction was carried out for 2 hours to form a homogeneous solution, 1.11 g (7.5 mmol) of phthalic anhydride was added to this solution, and stirring and mixing was performed at 130°C for an additional 1 hour to form a homogeneous solution of phthalic anhydride. Dissolve in solution. After cooling the homogeneous solution thus obtained to room temperature, the total M was added dropwise over 1 hour to 200 ml of titanium tetrachloride maintained at -20"C. The temperature of the liquid was raised to 110°C over 4 hours, and when it reached 110°C, diisobutyl phthalate, OmN (18.8 mmo+) was added, and from this point on, the stirring ball was kept at the same temperature for 2 hours. do.

After 2 hours of reaction, the solid part was collected by hot filtration, and this solid part was re-turbidized with 275 ml of TiCl4.
The heating reaction is carried out again at 110°C for 2 hours. After completion of the reaction, the solid portion is again collected by hot filtration and thoroughly washed with decane and hexane at 110° C. until no free titanium compound is detected during washing. The titanium catalyst component synthesized by the above production method is stored as a hexane slurry, and a portion of this is dried for the purpose of examining the catalyst composition.

The composition of the titanium catalyst component (A) thus obtained was 2.7% by weight of titanium, 63.0% by weight of chlorine, and 17% by weight of magnesium. Owe% and diisobutyl phthalate-1-14,
It was 5% by weight.

The titanium catalyst component was a granular catalyst with an average particle size of 15.1 μm and a geometric standard deviation (σg) of particle size distribution of 1.2.

(Prepolymerization with α-olefin) 0.96 mmol of triethylaluminum and 0.32 mmol of the titanium-containing catalyst component described above in terms of titanium atoms are added to 150 ml of sufficiently purified hexane.

1.70 g of propylene was fed into the system at 20°C over 60 minutes. The supernatant was sufficiently replaced with fresh hexane to obtain a titanium catalyst component.

(Polymerization) An autoclave with an internal volume of 50'/cm was sufficiently replaced with propylene. 13.5 kg of propylene and 15 mmol of triethylaluminum and 2.1 mmol of diphenyldimethoxysilane
mmol and the above-mentioned Ti catalyst component were added to the system in an amount of Q, 08 mg atoms in terms of Ti atoms. Hydrogen 36N
After adding 6, the mixture was stirred at 70°C for 1 hour. After removing liquid propylene for 1 hour, 1.6 mmol of ethanol was added at 60 °C, and ethylene/propylene mixed gas (composition 40/60 M/M) was immediately supplied, 3 k
While maintaining g/cot G, polymerization was carried out until the polymerization V in the copolymerization stage reached 18.8 wt%.

(wt%) The yield of the obtained block copolymer was 6.4 kg, M F
R is 1.0g/10 minutes Bulk specific gravity is 0.48g/me
, the ethylene content was 711°C%, the falling time was 7.0 seconds, the amount of rubbery polymer was 12.5wt% as n-decane soluble part,
Its [η] was 3.504/g.

Example 2.3.4 Using the Ti catalyst component of Example 1, polymerization was carried out in the same manner as shown in Table 1 (except that the conditions in the copolymerization stage were changed. The results are shown in the table.

Comparative Example 1 Polymerization was carried out in Example 1 without adding ethanol.

The yield of block copolymer was 6.5 kg, MFR
is 1.7g/10min, bulk specific gravity is 0.38g/me,
The ethylene content was 6.5 wt%, the falling time was 36 seconds, the rubbery polymer was 11.2 wt% including the n-decane soluble part, and its [η] was 2.90 di/g.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 1 except that ethanol 1, 6 mmo I was replaced with diethylaluminum ethoxide 1, 6 mmo +. The MFR of the copolymer is 1.6 g/10 min, the ethylene content is 8 wt%, the falling time is 18 seconds, and the amount of rubbery polymer is H, 6 wt% [η
] was 3.00 J/g.

Example 5 (t of titanium catalyst component)! il) Commercially available magnesium 95.3 g, n-decane 48
8ml and 2-ethylehexanol 464.5ml
After heating and reacting at 130° C. for 2 hours to obtain a homogeneous solution, 22.88 ml of ethyl benzoate was added. This homogeneous solution was added to titanium tetrachloride 41 kept at -20°C for 20 minutes.
After the mixture was added dropwise with stirring for 1 minute, the mixture was further stirred at -20°C for 1 hour. After reaching a temperature of 80°C for removal, further add 4 ethyl benzoate.
Add 8.6ml and mold 1' at 80°C for 2 hours! F-shita. The solid material was collected by filtration, resuspended in 41 titanium tetrachloride and stirred at 90°C for 2 hours.
The solid material was collected by filtration and thoroughly washed with beef sun for purification until no free titanium compounds were detected in the washing solution. The titanium catalyst component contains 3.6% by weight of titanium, 59.0% by weight of chlorine, 17.0% by weight of magnesium, and 15.0% by weight of ethyl benzoate in terms of atoms. Its specific surface was 230 m/g, average particle size was 13 μm, and g was 1.13. 100 g of the above Ti catalyst component was suspended in 41 hexane, and 75.16 mmo of triethylaluminum was added.
l and p-) Methyl ruylate 25.05 mn+ol
was added, and propylene was added so that 300 g of propylene was polymerized at 25°C.

(Polymerization) An autoclave with an internal volume of 50 A was sufficiently replaced with propylene. 13.5 kg of propylene and 15 mmol of t')-n-hexylaluminum, 4 methyl paratoluate
．． 29 mmol and the above Ti catalyst component were added to Ti13H
The amount was added in an amount of 0.15 mg per atomic system. hydrogen 5
After adding so as to give kg/cn+, the mixture was stirred at 75°C for 1 hour. After removing liquid propylene for 1 h, tri-n-hexylaluminum 1,29 mmo 1'
c addition, then 0.3 mmol of ethanol, immediately after adding ethylene/propylene mixed gas (composition 50
/50M/M), and polymerization was carried out at 70'C while maintaining 4 kg/cnlQ until the polymerization amount in the copolymerization stage reached 20.6 wt%.

The yield of the obtained polymer was 3.6 kg, and MFR was 2.
．． 5g/10 minutes, bulk specific gravity is 0.44g/mβ, ethylene content is 7.5wt%, falling time is 8.4 seconds, and the amount of rubbery polymer is 11.7wt% as n-decane soluble part.
Met.

Claims (1)

[Scope of Claims] In the presence of a highly stereoregular polymerization catalyst, a crystalline polymer or copolymer of propylene is produced in the previous step, and in the presence of the polymer or copolymer in the later polymerization step, propylene Polymerization ratio (mole ratio) of and other α-olefins
In a method for producing a propylene block copolymer comprising random copolymerization at a ratio of 10/90 to 90/10, an active hydrogen compound is added per 1 g atom of aluminum in the highly stereoregular polymerization catalyst during the random copolymerization. A method for producing a propylene block copolymer, which comprises supplying the propylene block copolymer to the random copolymerization reaction system in a proportion of 0.001 to 1 mole.