JPH04296314A - Production of propylene block copolymer - Google Patents

Abstract

PURPOSE:To prevent adhesion of polymer to inner wall of device, etc., and to reduce operation load of purifying recycling system of unreacted monomer in carrying out a two-stage polymerization using a polymerization catalyst having high stereoregularity by using a specific method. CONSTITUTION:First, a catalyst having high stereoregularity obtained at least from (A) a solid catalytic component containing Mg, Ti and a halogen and (B) an organoaluminum is used and the first-stage polymerization is carried out in a homopolymerization tank to give a crystalline propylene homopolymer or copolymer. Then, when the reaction product is transported from the homopolymerization tank to a random polymerization tank, the reaction product is provided with an electron donative compound in the transportation channel. Finally, in the polymerization tank, an alpha-olefin is randomly copolymerized in the presence of the propylene (co)polymer, namely, the aforesaid reaction product. Preferably the electron donative compound is previously diluted with an inert solvent, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for producing propylene block copolymers using highly stereoregular polymerization catalysts.

0002

[Prior Art] Compositions in which a crystalline propylene polymer or copolymer is produced in the first step, and propylene and other α-olefins are randomly copolymerized in the second step are generally produced by propylene block copolymerization. It is called a polymer. Such a block copolymer has significantly improved low-temperature impact strength without significantly impairing the excellent rigidity and heat resistance that are characteristics of polypropylene. Conventionally, the production of propylene block copolymers has generally used a highly stereoregular catalyst to produce a crystalline propylene polymer or copolymer in an earlier polymerization step in a homopolymerization tank, and then in a random copolymerization tank. This is carried out by random copolymerization of propylene and other α-olefins in the presence of the above polymer or copolymer in the latter polymerization step.

[0003] In this case, in order to improve the impact strength of propylene block copolymers, it is generally effective to increase the proportion of rubber-like copolymers formed, but this also reduces the adhesion of polymer particles to each other. , adhesion of polymer particles to the inner walls of the device, etc. occur, making it difficult to perform stable continuous operation over a long period of time. In contrast, methods have been proposed in which various compounds are added to a random copolymerization tank in order to prevent polymer particles from adhering to each other or to the inner walls of the apparatus. For example, JP-A No. 63-25611 discloses aromatic carboxylic acid esters, JP-A No. 61-69821 discloses active hydrogen compounds, and JP-A No. 61-215613 discloses Si-O-
It has been proposed to supply each silicon compound containing a C bond to a random copolymerization tank, and this method has achieved a certain effect in preventing adhesion of polymer particles to each other and to the inner walls of the apparatus.

0004

[Problems to be Solved by the Invention] However, in the above-mentioned method of directly supplying a specific compound to a random copolymerization tank, it is not possible to provide sufficient contact time for the compound to react with the catalyst component. A part of it inevitably flows out of the random copolymerization tank unreacted. These unreacted compounds are entrained in the monomer purification circulation system along with unreacted monomers, but all of these compounds reduce catalyst activity, so they must be removed in the monomer purification circulation system. . As a result, the operating load on the monomer purification circulation system increases, for example, the frequency of regeneration of the packing in the purification column increases, which is undesirable. The present invention was developed in view of the above circumstances, and aims to prevent polymer particles from adhering to each other and to the inner wall of the equipment, and to reduce the operating load on the purification circulation system for unreacted monomers, thereby improving rigidity and impact strength. An object of the present invention is to provide a method for producing a propylene block copolymer with good productivity and good mechanical properties and product appearance.

[0005]

[Means for Solving the Problem] As a result of intensive research to achieve the above object, the present inventors have developed a homogeneous compound that prevents polymer powder particles from adhering to each other and from adhering to the inner wall of the device. By supplying the compound to the transfer channel from the polymerization tank to the random polymerization tank, the reaction between the above-mentioned compound and the catalyst component can be almost completed in this transfer channel, and unreacted monomers are entrained in the monomer purification circulation system. The present inventors have discovered that it is possible to reduce the amount of the above-mentioned compounds to such an extent that they do not pose a substantial problem, leading to the present invention.

Therefore, the present invention provides a solid catalyst component containing at least (A) magnesium, titanium and halogen;
B) After producing a crystalline homopolymer or copolymer of propylene in the first stage polymerization stage in a homopolymerization tank using a highly stereoregular catalyst obtained using an organoaluminum compound, the second stage stage polymerization stage in a random polymerization tank is used. A method for producing a propylene block copolymer, comprising random copolymerization of propylene and another α-olefin in the presence of the above polymer or copolymer in the polymerization step, the reaction leading from the above homopolymerization tank to the random polymerization tank. A method for producing a propylene block copolymer is provided, which comprises supplying an electron-donating compound to the reaction product in a product transfer channel.

The present invention will be explained in more detail below. In the present invention, a highly stereoregular catalyst containing (A) a solid catalyst component containing at least a magnesium atom, a titanium atom, and a halogen atom, and (B) an organoaluminum compound is used as a polymerization catalyst. Examples of such catalysts include highly stereoregular catalysts obtained using the following components (A) and (B). . (A) A solid catalyst component obtained using (a) a magnesium compound and (b) a titanium compound. Examples include highly stereoregular catalysts obtained using (A) Solid catalyst component obtained using (a) a magnesium compound, (b) a titanium compound, and (c) an electron-donating compound (B) an organoaluminum compound (C) an electron-donating compound

[0008] Here, as each of the above-mentioned compounds, the following can be used. (a) Magnesium Compound The magnesium compound is not particularly limited, but magnesium oxide, magnesium hydroxide, dialkylmagnesium, alkylmagnesium halide, magnesium dihalide, magnesium dialkoxide, etc. are preferred, and specifically magnesium trichloride, magnesium Diethoxide, magnesium dimethoxide, etc. can be suitably used. Moreover, as the magnesium compound, a solid product obtained by reacting metallic magnesium, a halogen, and an alcohol can be suitably used. In this case, the shape of magnesium metal is not particularly limited. Therefore, metallic magnesium of any particle size can be used, for example, metallic magnesium in the form of granules, ribbons, powders, etc. Further, the surface condition of magnesium metal is not particularly limited, but it is preferable that a coating of magnesium oxide or the like is not formed on the surface. Further, as the alcohol, any alcohol can be used, but the number of carbon atoms is 1
It is preferable to use a lower alcohol of 6 to 6. especially,
It is preferable to use ethanol because it provides a solid product (magnesium compound (a)) that significantly improves the performance of the catalyst. The purity and water content of the alcohol are not limited either, but if alcohol with a high water content is used, magnesium hydroxide [Mg(OH)2] will be generated on the surface of magnesium metal, so the water content should be 1% or less, especially 2000 pp.
It is preferable to use an alcohol of m or less. Furthermore, in order to obtain a solid product (a) with better morphology, the lower the water content, the more preferable it is, and generally 200 ppm or less is desirable.

The type of halogen is not particularly limited, but chlorine, bromine or iodine, particularly iodine, is preferably used. Their state, shape, particle size, etc. are not particularly limited and may be arbitrary. For example, they can be used in the form of a solution in an alcoholic solvent (eg, ethanol). Although the amount of alcohol is not limited, it is preferably 2 to 100 mol, particularly preferably 5 to 50 mol, per 1 mol of magnesium metal. If the amount of alcohol is too large, the yield of the solid product (a) with good morphology may decrease, and if it is too small, stirring in the reaction tank may not be carried out smoothly. However, the molar ratio is not limited to this. The amount of halogen used is 0.00 per mole of metal magnesium.
0.01 gram atom or more, preferably 0.0005 gram atom or more, more preferably 0.001 gram atom or more. When the amount is less than 0.0001 gram atom, there is no significant difference from the amount using halogen as a reaction initiator, and when the obtained solid product (a) is used without pulverization, the supported amount, activity, stereoregularity, and formed polymer are It becomes defective in all aspects such as morphology. Therefore, pulverization of the solid product (a) is essential. The upper limit of the amount of halogen used is not particularly limited, but is generally selected within a range of less than 0.06 gram atom. Furthermore, by appropriately selecting the amount of halogen used, it is possible to freely control the particle size of the solid product (a).

The reaction itself between magnesium metal, alcohol and halogen can be carried out in the same manner as known methods. That is, a method of obtaining solid product (a) by reacting metallic magnesium, alcohol, and halogen under reflux (about 79°C) until no hydrogen gas is generated (usually for about 20 to 30 hours). It is. in particular,
For example, when using iodine as a halogen, there is a method in which solid iodine is poured into metallic magnesium and alcohol, and then heated and refluxed, or an alcoholic solution of iodine is dropped into metallic magnesium and alcohol, and then heated and refluxed. Examples include a method of dropping an alcoholic solution of iodine while heating a metallic magnesium or alcoholic solution. Both methods are preferably carried out under an inert gas (eg, nitrogen gas, argon gas) atmosphere, optionally using an inert organic solvent (eg, a saturated hydrocarbon such as n-hexane). Regarding the charging of metallic magnesium, alcohol, and halogen, it is not necessary to charge the entire amount of each into the reaction tank from the beginning, and they may be charged in portions. A particularly preferred method is to add the entire amount of alcohol from the beginning, and then add metallic magnesium in several portions. In this case, it is possible to prevent temporary generation of a large amount of hydrogen gas, which is very desirable from a safety standpoint. Furthermore, the reaction tank can also be downsized. Furthermore, it is also possible to prevent entrainment of alcohol and halogen droplets caused by the temporary generation of a large amount of hydrogen gas. The number of times of division may be determined by taking into account the scale of the reaction tank and is not particularly limited, but in view of the complexity of the operation, 5 to 10 times is usually suitable.

[0011] It goes without saying that the reaction itself may be carried out either batchwise or continuously.Furthermore, as a modified method, a small amount of metallic magnesium is first added to the alcohol, which has been entirely added from the beginning, and the product produced by the reaction is It is also possible to repeat the operation of separating the substances into another tank and removing them, and then adding a small amount of metallic magnesium again. When the solid product thus obtained is used for the next synthesis of a solid catalyst composition, it may be dried or washed with an inert solvent such as heptane after filtration. In either case, the obtained solid product (a) can be used in the following steps without pulverization or classification operations to make the particle size distribution uniform.

(b) Titanium compound In the present invention, any titanium compound can be used as a titanium compound (b)
) can be used as Those titanium compounds, for example, have the general formula (I) TiX1n(OR1)4-n...(I
) (wherein, X1 is a halogen atom, especially a chlorine atom,
R1 is a hydrocarbon group having 1 to 10 carbon atoms, especially a straight-chain or branched alkyl group, and when a plurality of groups R1 are present, they may be the same or different. n is an integer from 0 to 4. ) is a titanium compound represented by Specifically, Ti(O-i-C3H7)4, Ti(O-
C4H9)4, TiCl(O-C2H5)3, TiCl
(O-i-C3H7)3, TiCl(O-C4H9)3
, TiCl2(O-C4H9)2, TiCl2(O-i
-C3H7)2, TiCl4, and the like.

(c) Electron-donating compound In the solid catalyst component (A) of the present invention, any electron-donating compound (c) can be used as required. These electron-donating compounds (c) are usually organic compounds containing oxygen, nitrogen, phosphorus or sulfur. Specifically, amines, amides, ketones, nitriles, phosphines, fosmylamides, esters, ethers, thioethers, alcohols, thioesters, acid anhydrides, acid halides, aldehydes, organic acids, S
Examples include organosilicon compounds having an i-O-C bond, and more specifically the following compounds.

Aromatic carboxylic acids such as benzoic acid, p
- oxybenzoic acid; acid anhydrides, such as succinic anhydride;
Benzoic anhydride, p-toluic anhydride; carbon origin index 3-1
Ketones of 5, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, benzoquinone; Aldehydes having 2 to 15 carbon atoms, such as acetaldehyde, propionaldehyde, octyl aldehyde, benzaldede, naphthaldehyde; 2 carbon atoms -18 esters, such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl butyrate,
Ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, benzoate Octyl acid, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, p-butoxybenzoic acid Ethyl, ethyl o-chlorobenzoate, ethyl naphthoate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, ethylene carbonate; mono- and diesters of aromatic dicarboxylic acids, such as mono- and diesters of phthalic acid, are preferred, e.g. , monomethyl phthalate, dimethyl phthalate, monomethyl terephthalate, dimethyl terephthalate, monoethyl phthalate, diethyl phthalate, monoethyl terephthalate, diethyl terephthalate, monopropyl phthalate, dipropyl phthalate, monopropyl terephthalate, dipropyl terelate, monobutyl phthalate, dibutyl phthalate , monobutyl terephthalate, dibutyl terephthalate, monoisobutyl phthalate, diisobutyl phthalate, monoamyl phthalate, diamyl phthalate, monoisoamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate, ethylpropyl phthalate,

Acid halides having 2 to 20 carbon atoms;
The acid moiety (acyl group moiety) of this acid halide is a monobasic, dibasic, or tribasic aliphatic (including those having rings such as alicyclics) having about 2 to 20 carbon atoms. Monovalent to trivalent acylic acid obtained by extracting each hydroxyl group from an acid, or aromatic (alkali) having about 7 to 20 carbon atoms.
It also includes le-type and aralkyl-type. ) is preferably a monovalent to trivalent acyl group obtained by extracting each hydroxyl group from a monobasic, dibasic or tribasic acid. Further, as the halogen atom in the acid halide, chlorine atom,
A bromine atom is preferred, and a chlorine atom is particularly preferred. In the present invention, acid halides that can be suitably used include, for example, acetyl chloride, acetyl bromide, propionyl chloride, butyryl chloride, isobutyryl chloride, 2-methylpropionyl chloride, valeryl chloride, isovaleryl Chloride, hexanoyl chloride, methylhexanoyl chloride, 2-ethylhexanoyl chloride, octanoyl chloride, decanoyl chloride, undecanoyl chloride, hexadecanoyl chloride, octadecanoyl chloride, henzyl carbonyl chloride, dichlorohexane carbonyl chloride , malonyl dichloride, succinyl dichloride, pentanedioyl dichloride, hexanedioyl dichloride, dichlorohexane dicarbonyl dichloride, benzoyl chloride, benzoyl bromide, methylbenzoyl chloride, phthaloyl chloride, isophthaloyl chloride,
Examples include terephthaloyl chloride and benzene-1,2,4-tricarbonyl trichloride. Among these, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, etc. are particularly preferred.
Particularly preferred is phthaloyl chloride. In addition, these acid halides may be used individually by 1 type, and may use 2 or more types together.

Ethers having 2 to 20 carbon atoms, such as methyl ether, ethyl ether, isopropyl ether, n-butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether, ethylene glycol butyl ether; acid amides, such as acetate amide, benzoic Acid amide, toluic acid amide; Amines, such as tributylamine, N,N'-dimethylpiperazine, tribenzylamine, aniline, pyridine, pyrroline, tetramethylethylenediamine; Nitriles,
For example, acetonitrile, benzonitrile, tolnitrile; tetramethylurea, nitrobenzene, lithium butyrate; organosilicon compounds having Si-O-C bonds,
For example, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane,
Phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane,
γ-aminopropyltriethoxysilane, chlortriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate,
Trimethylphenoxysilane, methyltriaryloxysilane, vinyltris(β-methoxyethoxy)silane,
Examples include vinyltriacetoxysilane and dimethyltetraethoxydisiloxane. Of these,
Preferred are esters, ethers, ketones,
acid anhydrides, etc.

Method for preparing solid catalyst component (A) Solid catalyst component (A) is prepared using a magnesium compound (a), a titanium compound (b) and, if necessary, an electron-donating compound (c). It can be prepared by the following method. For example, it is preferable to bring the magnesium compound (a) into contact with the electron-donating compound (c) and then bring them into contact with the titanium compound (b). The conditions for bringing the electron donating compound (c) into contact with the magnesium compound (a) are not particularly limited and may be appropriately determined depending on various circumstances. Usually, magnesium compound (a) 1 in terms of magnesium atom
Add 0.01 to 10 mol, preferably 0.05 to 5 mol, of the electron donating compound (c) per mol, and heat at 0 to 200°C.
for 5 minutes to 10 hours, preferably at 30 to 150°C.
The contact reaction may be carried out for 30 minutes to 3 hours. Incidentally, an inert hydrocarbon such as pentane, hexane, heptane or octane can also be added to this reaction system as a solvent. There are no particular restrictions on the conditions under which the titanium compound (b) is brought into contact with the magnesium compound (a) or the contact product of it and the electron-donating compound (c), but usually the magnesium 1 in the product is 1 to 50 mol, preferably 2 to 20 mol of titanium compound (b) per mol
Add in a molar range and heat at 0 to 200°C for 5 minutes to 10 hours.
Preferably, the reaction is carried out at 30 to 150°C for 30 minutes to 5 hours. The liquid titanium compound (e.g., titanium tetrachloride) is brought into contact with the titanium compound (b) alone, and the other titanium compounds are brought into contact with any inert hydrocarbon solvent (e.g.,
It can be carried out in a state dissolved in hexane, heptane, kerosene). In addition, a magnesium compound (a), a titanium compound (b), and an electron donating compound (c) as needed.
) The magnesium compound (a) can also be brought into contact with, for example, a halogenated hydrocarbon, a halogen-containing silicon compound, a halogen gas, hydrogen chloride, hydrogen iodide, etc., before the above-mentioned contact with the magnesium compound (a). In addition, after the reaction is completed, it is preferable to wash the product with an inert hydrocarbon (for example, n-hexane, n-heptane).

(B) Organic aluminum compound The organic aluminum compound (B) is not particularly limited, but has the following general formula (II) AlR2mX23-m
...(II) (wherein R2 is an alkyl group, cycloalkyl group, or aryl group having 1 to 10 carbon atoms, m
is an integer from 1 to 3, and X2 is a halogen atom, such as a chlorine atom or a bromine atom), which is widely used. Specifically, trialkylaluminium compounds, such as trimethylaluminum, triethylaluminum, triisopropylaluminium, triisobutylaluminum or trioctylaluminum;
Alternatively, dialkyl aluminum monohalide compounds such as diethylaluminum monochloride, dipropylaluminum monochloride or dioctyl aluminum monochloride can be mentioned.

(C) Electron-donating compound In the production method of the present invention, an electron-donating compound (C) can be used in combination, if necessary. In this case, the electron donating compound (C) is the solid catalyst component (A).
The same electron-donating compound (c) used in the preparation of can be used. At this time, an electron-donating compound (
C) may be the same as or different from the electron-donating compound (c) used in preparing the solid catalyst component (A). Preferred electron donating compound (C)
is a silane compound having a Si--OC bond, particularly a compound represented by the following formula (III). R3pSi(OR4)4-p
...(III) (wherein R3 is selected from linear or branched hydrocarbon residues, aromatic hydrocarbon residues, or cyclic saturated hydrocarbon residues, and when p≧2, the above (III) (R4 is a linear or branched hydrocarbon residue; p is 0≦p≦3), specifically, tert-butylcyclohexyldimethoxysilane, methylcyclohexyldimethoxysilane, di-tert-butyldimethoxysilane,
Examples include dicyclohexyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, and methylphenyldimethoxysilane.

In the present invention, the above-mentioned highly stereoregular catalyst is used, and as illustrated in FIG. Supplying the product with an electron-donating compound. Examples of the electron-donating compound supplied to the transfer channel include the electron-donating compound (c) used in preparing the solid catalyst component (A) and the electron-donating compound (c) used in preparing the catalyst.
The same one as C) can be used. At this time, the electron-donating compound supplied to the transfer channel may be the same as or different from the electron-donating compound (c) or (C).

There is no particular restriction on the method of supplying the electron-donating compound to the transfer channel. For example, a method of directly supplying the electron-donating compound to the transfer channel can be adopted; Particularly preferred is a method in which the solution is supplied diluted in an inert solvent. The amount of electron-donating compound added is 0.000000000000000 yen per 1 mol of organoaluminum compound.
01-1.5 mol, preferably 0.1-1.3 mol
It is. If it is less than 0.01 mol, the effect of preventing adhesion of polymer particles may not be obtained, and if it is more than 1.5 mol, the activity of the catalyst may be reduced too much.

In the present invention, a propylene crystalline polymer or copolymer is produced in the preliminary step, but the polymerization may be carried out in two or more steps in this step. Further, 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 advance for the purpose of improving 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-stage polymerization is carried out in the presence or absence of an inert solvent,
It can be carried out in liquid phase or gas phase. A suitable amount of each catalyst component to be used can be appropriately selected depending on the type thereof. In the pre-stage polymerization, a crystalline propylene polymer or copolymer is produced in order to obtain a highly rigid block copolymer. As a copolymerization component when producing a copolymer, α-olefins other than propylene, such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1- Examples include those having 2 to 10 carbon atoms such as decene.

[0023] As the polymer or copolymer, 135
For example, if the intrinsic viscosity [η] measured in decalin at ℃ is about 1
to about 10 dl/g, particularly about 1 to about 5 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 appropriately, for example, about 50 to about 100°C, preferably about 60 to about 90°C. In addition, the polymerization pressure can be selected appropriately, for example, about 1
Examples include polymerization pressures of from about 1 to about 200 Kg/cm2G, preferably from about 1 to about 100 Kg/cm2G. 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, for example, propane, butane, pentane, hexane, heptane, octane, decane,
A typical example is kerosene.

In the present invention, in the subsequent polymerization step, propylene and other α-olefins are randomly copolymerized in the presence of the catalyst-containing propylene crystalline polymer or copolymer obtained in the previous step. This random copolymerization is usually carried out following a previous polymerization step to produce a crystalline propylene polymer or copolymer. 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, resulting in a high yield relative to the consumed olefin, 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 1-decene. Preferably ethylene or ethylene and C4 to C8 α-
It is a combination with olefin. The copolymerization ratio of propylene and other α-olefins is 10/90 to 90/
10, preferably 20/80 to 80/20.

[0025]

[Examples] The present invention will be explained in more detail with reference to Examples below, but these are not intended to limit the scope of the present invention. In addition, in the following examples, the following reagents were used. Ethanol: Manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent. Iodine: Manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent. Metallic magnesium: granular (average particle size 350 μm). Example 1 (1) Preparation of magnesium compound (a) A glass reactor (inner volume: about 12 liters) equipped with a stirrer was sufficiently purged with nitrogen gas, and about 4,860 g of ethanol, 32 g of iodine, and 320 g of metallic magnesium were charged. The reaction was carried out under heating under reflux conditions with stirring until no hydrogen gas was generated from the system, to obtain a solid reaction product. The reaction solution containing this solid product was dried under reduced pressure to obtain a magnesium compound (solid product) (a). (2) Preparation of solid catalyst component (A) The magnesium compound (a) (
(unpulverized) 160g, purified heptane 800m
1, 24 ml of silicon tetrachloride, and 23 ml of diethyl phthalate.
ml was added. The inside of the system was kept at 90°C, and 770ml of titanium tetrachloride was added while stirring, and the mixture was reacted at 110°C for 2 hours.The solid components were separated and washed with purified heptane at 80°C. Furthermore, 1220 ml of titanium tetrachloride was added, and 11
After reacting at 0° C. for 2 hours, the mixture was thoroughly washed with purified heptane to obtain a solid catalyst component (A).

(3) Polymerization/pretreatment 230 liters of n-heptane was charged into a reaction tank with stirring blades having an internal volume of 500 liters, and the solid catalyst component was heated to 25K.
g, triethylaluminum at 0.6 mol/1g atom per Ti atom in the solid catalyst component, and diphenyldimethoxysilane at 0.4 mol/1g atom per Ti atom in the solid catalyst component.
After supplying at a rate of 1 g atom, propylene was introduced until the propylene partial pressure reached 0.3 Kg/cm2G, and the mixture was heated at 55°C.
The mixture was allowed to react for 4 hours. After the reaction is completed, the solid catalyst component is
Washed several times with heptane, supplied with carbon dioxide and stirred for 24 hours.・As the first stage of main polymerization, a polymerization tank with an internal volume of 200 liters and equipped with stirring blades (
The treated solid catalyst component was fed into the homopolymerization tank at a rate of 3 mmol/Hr, triethylaluminum at a rate of 600 mmol/Hr, and diphenyldimethoxysilane at a rate of 15 mmol/Hr in terms of Ti atoms in the component, and the polymerization temperature was 70℃, propylene pressure 28Kg/cm2G
I reacted with At this time, hydrogen was used to adjust the molecular weight to a predetermined value. Then, the powder is continuously extracted from the homopolymerization tank and transferred to a random copolymerization tank. At this time,
700 mmol of ethanol diluted with n-heptane was supplied to the powder extraction pipe (transfer channel). The amount supplied was 1.17 mol/mol as an ethanol/organoaluminum compound molar ratio. In the random copolymerization tank, propylene and ethylene were supplied at a polymerization temperature of 55° C. to perform random copolymerization. At this time, in order to achieve the specified ethylene content,
The feed ratio of propylene and ethylene was adjusted. The powder continuously extracted from the random copolymerization tank was granulated and evaluated. In addition, gas was collected from the unreacted monomer circulation line in the random polymerization tank, and the amount of the added electron-donating compound contained therein was measured. The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that ethanol was supplied at 120 mmol/Hr as an electron-donating compound to the powder extraction pipe. This supply amount is 0.2 mol/as an ethanol/organoaluminum compound molar ratio.
It is mol. The results are shown in Table 1. Example 3 The same procedure as in Example 1 was conducted except that methanol was supplied as an electron-donating compound to the powder extraction pipe at a rate of 400 mmol/Hr. This supply amount is 0.67 mol as methanol/organoaluminum compound molar ratio.
/mol. The results are shown in Table 1. Example 4 The same procedure as in Example 1 was conducted except that isopropyl alcohol was supplied as an electron donating compound to the powder extraction pipe at a rate of 700 mmol/Hr. This supply amount is 1 as an ethanol/organoaluminum compound molar ratio.
．． It is 17 mol/mol. The results are shown in Table 1. Comparative Example 1 The same procedure as in Example 1 was carried out except that the electron-donating compound was directly supplied to the random copolymerization tank. The results are shown in Table 1. In addition, in both the above examples and comparative examples, there was no problem in continuous operation of the apparatus.

In Table 1, MI(1) is the melt index of the product in the first polymerization stage, and MI(2) is the melt index of the propylene block copolymer produced in the second stage. Further, other physical properties are those of the propylene block copolymer produced in the latter stage. Moreover, each physical property in Table 1 was measured by the following method. Tensile modulus: Measured according to JIK K 6738. Izod impact strength: Measured according to JISK 6738. However, the measurement temperature was -20°C.

[0029]

[Table 1]

[0030]

As explained above, according to the production method of the present invention, it is possible to effectively prevent polymer particles from adhering to each other and to the inner wall of the apparatus, and to purify and circulate unreacted monomers. The operating load on the system can be reduced, and therefore a propylene block copolymer with excellent mechanical properties such as rigidity and impact strength, and a good product appearance can be produced with high productivity.

[0031]

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the manufacturing method of the present invention.

Claims (1)

[Claims] Claim 1: Using a highly stereoregular catalyst obtained using at least (A) a solid catalyst component containing magnesium, titanium, and a halogen and (B) an organoaluminum compound, propylene is After producing a crystalline homopolymer or copolymer, propylene and another α-olefin are randomly copolymerized in the presence of the above polymer or copolymer in a subsequent polymerization step in a random polymerization tank. A method for producing a propylene block copolymer, the method comprising supplying an electron-donating compound to the reaction product in a flow path for transferring the reaction product from the homopolymerization tank to the random polymerization tank. manufacturing method.