JP2006169511A - Method for producing propylene-based block copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a propylene-based block copolymer, having good economical efficiency and capable of producing the copolymer decreased in a number of fish eyes. <P>SOLUTION: This method for producing the propylene-based block copolymer comprises conducting a polymerization process (I) for producing a polymer component (X) comprising propylene units in an amount of ≥95 wt% and then conducting a polymerization process (II) for producing a polymer component (Y) comprising the propylene units in an amount of 90-10 wt%, wherein the polymer component (X) is produced by (a) a batch polymerization procedure and/or a continuous polymerization procedure by a reactor of extrusion-flowing type and (b) a continuous polymerization procedure by a reactor of non-extrusion-flowing type and an amount of a polymer component produced in the continuous polymerization procedure (b) by the reactor of non-extrusion-flowing type is made to be 50 wt% or less in the polymerization process (I) and the polymer component (Y) is produced by (c) a batch polymerization procedure and/or a continuous polymerization procedure by a reactor of extrusion-flowing type in the polymerization process (II). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a propylene-based block copolymer.

  Polypropylene resins used in automobile parts, home appliance parts, etc. are required to have high rigidity and high impact resistance, so generally, a crystalline propylene polymer part and an amorphous propylene polymer part are included. Propylene-based block copolymer is used. As a method for producing the propylene-based block copolymer, there are many methods of performing a second polymerization step of copolymerizing propylene and ethylene after performing a first polymerization step of homopolymerizing propylene, for example, , A method of performing the first polymerization step and the second polymerization step by batch polymerization (see, for example, Patent Document 1), the first polymerization step is performed by continuous polymerization using a non-extrusion flow reactor, and the second polymerization step is batch-processed. A method of performing polymerization (for example, refer to Patent Document 2), a method of performing the first polymerization step and the second polymerization step by continuous polymerization using a non-extrusion flow reactor (for example, refer to Patent Document 3), and the like are known. ing.

Japanese Patent Laid-Open No. 6-136018 JP 61-101511 A JP-A-10-168142

However, in the above production method, from the viewpoint of economy, a production method in which the first polymerization step and the second polymerization step are performed by continuous polymerization using a non-extrusion flow reactor is preferable, but propylene produced by the method is used. The block copolymer may be deteriorated in appearance and mechanical strength due to the fish eye in the propylene block copolymer, and the first polymerization step and the second polymerization step are performed by batch polymerization. In the method, the propylene-based block copolymer produced by the method has a good fish eye, but the method is not sufficiently satisfactory in terms of economy.
Under such circumstances, the present inventors have earnestly developed a method for producing a propylene-based block copolymer having good economic efficiency and a method for producing a propylene-based block copolymer having a reduced number of fish eyes. As a result of studies, the present invention has been completed.

  In the present invention, propylene is homopolymerized or copolymerized with propylene and an olefin (excluding propylene) in the presence of an addition polymerization catalyst, and the content of monomer units based on propylene is 95% by weight or more. The polymerization step (I) for producing the polymer component (X) is carried out, followed by copolymerization of propylene and olefin (excluding propylene), and the content of monomer units based on propylene is A method for producing a propylene-based block copolymer for carrying out a polymerization step (II) for producing a polymer component (Y) of 90 to 10% by weight, wherein in the polymerization step (I), (a) a batch polymerization method And / or polymer component (X) is produced by continuous polymerization using an extrusion flow reactor and (b) continuous polymerization using a non-extrusion flow reactor, and (b) continuous polymerization using a non-extrusion flow reactor. In the polymerization step (II), the production amount of the polymer component in the polymerization method is 50% by weight or less (however, the production amount of the polymer component in the polymerization step (I) is 100% by weight). c) A method for producing a propylene-based block copolymer, characterized in that the polymer component (Y) is produced by a batch polymerization method and / or a continuous polymerization method using an extrusion flow reactor.

  According to the present invention, it is a method for producing a propylene-based block copolymer having a reduced number of fish eyes, and a production method having good economic efficiency can be provided.

  As the addition polymerization catalyst used in the present invention, a known addition polymerization catalyst used for olefin polymerization can be used. For example, a solid catalyst component (hereinafter referred to as catalyst) containing titanium, magnesium, halogen and an electron donor. And a catalyst for addition polymerization formed by contacting an organoaluminum compound component and an electron donor component.

  The catalyst component (A) can be used as a catalyst generally called a titanium / magnesium composite type and a catalyst, and is obtained by contacting a titanium compound, a magnesium compound, and an electron donor as described below. Can do.

Examples of the titanium compound used for adjusting the catalyst component (A) include the general formula Ti (OR ¹ ) _a X _4-a (R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, and X is a halogen atom. , A represents a number of 0 ≦ a ≦ 4)). Specifically, tetrahalogenated titanium compounds such as titanium tetrachloride; trihalogenated alkoxytitanium compounds such as ethoxytitanium trichloride and butoxytitanium trichloride; dihalogenated dialkoxytitanium such as diethoxytitanium dichloride and dibutoxytitanium dichloride Compounds; monohalogenated trialkoxytitanium compounds such as triethoxytitanium chloride and tributoxytitanium chloride; and tetraalkoxytitanium compounds such as tetraethoxytitanium and tetrabutoxytitanium. These titanium compounds may be used alone or in combination of two or more.

Examples of the magnesium compound used for adjusting the catalyst component (A) include a magnesium compound having a magnesium-carbon bond or magnesium-hydrogen bond and having a reducing ability, or a magnesium compound having no reducing ability. . Specific examples of magnesium compounds having reducing ability include dialkyl magnesium compounds such as dimethyl magnesium, diethyl magnesium, dibutyl magnesium, and butyl ethyl magnesium; alkyl magnesium halide compounds such as butyl magnesium chloride; alkyl alkoxy magnesium compounds such as butyl ethoxy magnesium; Examples thereof include alkyl magnesium hydrides such as butyl magnesium hydride. These magnesium compounds having a reducing ability may be used in the form of a complex compound with an organoaluminum compound.
On the other hand, specific examples of magnesium compounds having no reducing ability include magnesium halide compounds such as magnesium dichloride; alkoxymagnesium halide compounds such as methoxymagnesium chloride, ethoxymagnesium chloride and butoxymagnesium chloride; diethoxymagnesium and dibutoxymagnesium. Dialkoxymagnesium compounds such as magnesium; carboxylates of magnesium such as magnesium laurate and magnesium stearate; These magnesium compounds having no reducing ability may be synthesized in advance by a known method from a magnesium compound having reducing ability at the time of preparing the catalyst component (A).

  The electron donor used for the preparation of the catalyst component (A) includes alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, acid anhydrides. Oxygen-containing electron donors such as ammonia; nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates; and organic acid halides. Of these electron donors, inorganic acid esters, organic acid esters and ethers are preferably used.

The inorganic acid ester is preferably a general formula R ² _n Si (OR ³ ) _4-n (R ² represents a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, and R ³ has 1 to 20 carbon atoms. And n represents a number of 0 ≦ n <4). Specifically, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane; methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, t-butyltrimethoxysilane, methyl Alkyltrialkoxysilanes such as triethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, t-butyltriethoxysilane; dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diisobutyldimethoxysilane, di- t-butyldimethoxysilane, butylmethyldimethoxysilane, butylethyldimethoxysilane, t-butylmethyldimethoxysilane, dimethyldiethoxysilane Dialkyldialkoxy such as diethyldiethoxysilane, dibutyldiethoxysilane, diisobutyldiethoxysilane, di-t-butyldiethoxysilane, butylmethyldiethoxysilane, butylethyldiethoxysilane, t-butylmethyldiethoxysilane Examples thereof include silane.

  As the organic acid esters, mono- and polyvalent carboxylic acid esters are preferably used, and examples thereof include aliphatic carboxylic acid esters, alicyclic carboxylic acid esters, and aromatic carboxylic acid esters. Specific examples include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, ethyl valerate, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl benzoate, butyl benzoate, methyl toluate, Ethyl toluate, ethyl anisate, diethyl succinate, dibutyl succinate, diethyl malonate, dibutyl malonate, dimethyl maleate, dibutyl maleate, diethyl itaconate, dibutyl itaconate, diethyl phthalate, di-n-phthalate Examples thereof include butyl and diisobutyl phthalate. Preferred are unsaturated aliphatic carboxylic acid esters such as methacrylic acid esters and phthalic acid esters such as maleic acid esters, and more preferred are phthalic acid diesters.

  Examples of ethers include dialkyl ethers such as diethyl ether, dibutyl ether, diisobutyl ether, diamyl ether, diisoamyl ether, methyl butyl ether, methyl isoamyl ether, and ethyl isobutyl ether. Dibutyl ether and diisoamyl ether are preferred.

  Examples of the organic acid halides include mono- and polyvalent carboxylic acid halides, and examples thereof include aliphatic carboxylic acid halides, alicyclic carboxylic acid halides, and aromatic carboxylic acid halides. Specific examples include acetyl chloride, propionic acid chloride, butyric acid chloride, valeric acid chloride, acrylic acid chloride, methacrylic acid chloride, benzoyl chloride, toluic acid chloride, anisic acid chloride, succinic acid chloride, malonic acid chloride, maleic acid chloride, Examples thereof include itaconic acid chloride and phthalic acid chloride. Aromatic carboxylic acid chlorides such as benzoyl chloride, toluic acid chloride, and phthalic acid chloride are preferable, and phthalic acid chloride is more preferable.

Examples of the method for adjusting the catalyst component (A) include the following methods.
(1) A method in which a liquid magnesium compound or a complex compound comprising a magnesium compound and an electron donor is reacted with a precipitating agent and then treated with a titanium compound, or a titanium compound and an electron donor.
(2) A method of treating a solid magnesium compound or a complex compound comprising a solid magnesium compound and an electron donor with a titanium compound or a titanium compound and an electron donor.
(3) A method in which a liquid magnesium compound and a liquid titanium compound are reacted in the presence of an electron donor to precipitate a solid titanium composite.
(4) A method in which the reaction product obtained in (1), (2) or (3) is further treated with a titanium compound, or an electron donor and a titanium compound.
(5) A method of treating a solid product obtained by reducing an alkoxytitanium compound with an organomagnesium compound such as a Grignard reagent in the presence of an organosilicon compound having a Si—O bond with an ester compound, an ether compound and titanium tetrachloride. .
(6) A solid product obtained by reducing a titanium compound with an organomagnesium compound in the presence of an organosilicon compound or an organosilicon compound and an ester compound is converted into a mixture of an ether compound and titanium tetrachloride, and then an organic acid halide compound. And then treating the treated solid with a mixture of an ether compound and titanium tetrachloride or a mixture of an ether compound, titanium tetrachloride and an ester compound.
(7) A method of contacting a contact reaction product of a metal oxide, dihydrocarbylmagnesium and a halogen-containing alcohol with an electron donor and a titanium compound after or without treatment with a halogenating agent.
(8) A method in which a magnesium compound such as a magnesium salt of an organic acid or alkoxymagnesium is contacted with an electron donor and a titanium compound after or without treatment with a halogenating agent.
(9) A method of treating the compound obtained in (1) to (8) with any one of a halogen, a halogen compound and an aromatic hydrocarbon.
Of these methods for adjusting the catalyst component (A), the methods (1) to (6) are preferred. These adjustments are usually performed under an inert gas atmosphere such as nitrogen or argon.

  In preparing the catalyst component (A), the titanium compound, the organosilicon compound and the ester compound are preferably used after being dissolved or diluted in a suitable solvent. Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, octane, and decane; aromatic hydrocarbons such as toluene and xylene; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and decalin; diethyl ether, And ether compounds such as dibutyl ether, diisoamyl ether, and tetrahydrofuran.

  In the adjustment of the catalyst component (A), the temperature of the reduction reaction using the organomagnesium compound is usually −50 to 70 ° C., and preferably −30 to 50 ° C., particularly preferably from the viewpoint of increasing the catalyst activity and cost. -25 to 35 ° C. The dropping time of the organomagnesium compound is not particularly limited, but is usually about 30 minutes to 12 hours. Further, after the reduction reaction, a post-reaction may be performed at a temperature of 20 to 120 ° C.

In the adjustment of the catalyst component (A), a porous material such as an inorganic oxide or an organic polymer may coexist in the reduction reaction, and the porous product may be impregnated with the porous product. As such a porous substance, those having a pore volume at a pore radius of 20 to 200 nm of 0.3 ml / g or more and an average particle diameter of 5 to 300 μm are preferable. Examples of the porous inorganic oxide include SiO ₂ , Al ₂ O ₃ , MgO, TiO ₂ , ZrO ₂ , and composite oxides thereof. In addition, examples of the porous polymer include polystyrene-based porous polymers such as polystyrene and styrene-divinylbenzene copolymer; polyethyl acrylate, methyl acrylate-divinylbenzene copolymer, polymethyl methacrylate, methyl methacrylate-divinyl. Examples thereof include polyacrylic ester porous polymers such as benzene copolymers; polyolefin porous polymers such as polyethylene, ethylene-methyl acrylate copolymers, and polypropylene. Among these porous materials, preferably SiO _2, Al ₂ O _3, a styrene - divinylbenzene copolymer.

  The catalyst component (A) may be used as a prepolymerization catalyst component by polymerizing a small amount of olefin (hereinafter referred to as prepolymerization) before being subjected to polymerization. The amount of the olefin to be prepolymerized is usually 0.1 to 200 g per 1 g of the catalyst component (A). Examples of the prepolymerization method include known methods. For example, the catalyst component (A) and There is a method in which a small amount of propylene is supplied in the presence of an organoaluminum compound and a slurry is used in a solvent. Examples of the solvent used for the prepolymerization include propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, and other inert saturated hydrocarbons and liquid propylene. You may mix and use. Moreover, the slurry concentration in prepolymerization is 1-500g normally as a weight of the catalyst component (A) contained per 1L of solvents, Preferably it is 3-150g.

  The amount of the organoaluminum compound used in the prepolymerization is 0.1 to 700 mol, preferably 0.2 to 200 mol, more preferably 0.2, per 1 mol of titanium atoms contained in the catalyst component (A). ~ 100 moles. In the prepolymerization, an electron donor may coexist if necessary, and the amount of the electron donor used is preferably 0.01 to 400 mol per 1 mol of titanium atoms contained in the catalyst component (A). More preferably, it is 0.02-200 mol, More preferably, it is 0.03-100 mol. In the prepolymerization, a chain transfer agent such as hydrogen may be used.

  The prepolymerization temperature is usually -20 to 100 ° C, preferably 0 to 80 ° C. The prepolymerization time is usually 2 minutes to 15 hours.

The organoaluminum compound component used for the preparation of the catalyst for addition polymerization has at least one Al-carbon bond in the molecule, and a typical one is shown below by a general formula.
R ⁴ _m AlY _3-m
R ⁵ R ⁶ Al—O—AlR ⁷ R ⁸
(R ^{4 to} R ⁸ represent a hydrocarbon group having 1 to 8 carbon atoms, Y represents a halogen atom, hydrogen or an alkoxy group. R ^{4 to} R ⁸ may be the same or different. M is a number represented by 2 ≦ m ≦ 3.)

  Specific examples of the organic aluminum compound component include trialkylaluminum such as triethylaluminum and triisobutylaluminum; dialkylaluminum hydride such as diethylaluminum hydride and diisobutylaluminum hydride; dialkylaluminum halide such as diethylaluminum chloride and diisobutylaluminum chloride; triethylaluminum And a mixture of a trialkylaluminum and a dialkylaluminum halide such as a mixture of sodium and diethylaluminum chloride; an alkylalumoxane such as tetraethyldialumoxane and tetrabutyldialumoxane. Of these organoaluminum compounds, preferably trialkylaluminum, a mixture of trialkylaluminum and dialkylaluminum halide, alkylalumoxane, more preferably triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, or Tetraethyl dialumoxane is preferred.

  The electron donor component used for adjusting the catalyst for addition polymerization includes alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic acids or inorganic acids, ethers, acid amides, acid anhydrides. Commonly used ones such as oxygen-containing electron donors such as ammonia; nitrogen-containing electron donors such as ammonia, amines, nitriles and isocyanates can be used. Of these electron donor components, esters of inorganic acids and ethers are preferred.

The inorganic acid ester is preferably a general formula R ⁹ _n Si (OR ¹⁰ ) _4-n (wherein R ⁹ is a hydrocarbon group or hydrogen atom having 1 to 20 carbon atoms, and R ¹⁰ is 1 to 1 carbon atom). 20 is a silicon compound represented by the following formula: n is 0 ≦ n <4. Specific examples include tetrabutoxysilane, butyltrimethoxysilane, tert-butyl-n-propyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylethyldimethoxysilane, and the like.

（式中、Ｒ¹¹〜Ｒ¹⁴は炭素数１〜２０の線状または分岐状のアルキル基、脂環式炭化水素基、アリール基、またはアラルキル基であり、Ｒ¹¹またはＲ¹²は水素原子であってもよい。）で表されるジエーテル化合物があげられる。具体例としては、ジブチルエーテル、ジアミルエーテル、２，２−ジイソブチル−１，３−ジメトキシプロパン、２，２−ジシクロペンチル−１，３−ジメトキシプロパン等をあげることができる。 The ethers are preferably dialkyl ethers, general formula

(Wherein R ^{11 to} R ¹⁴ are linear or branched alkyl groups, alicyclic hydrocarbon groups, aryl groups, or aralkyl groups having 1 to 20 carbon atoms, and R ¹¹ or R ¹² is a hydrogen atom. May be present). Specific examples include dibutyl ether, diamyl ether, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, and the like.

Of these electron donor components, an organosilicon compound represented by the general formula R ¹⁵ R ¹⁶ Si (OR ¹⁷ ) ₂ is particularly preferably used. Here, in the formula, R ¹⁵ is a hydrocarbon group having 3 to 20 carbon atoms in which the carbon atom adjacent to Si is secondary or tertiary, specifically, isopropyl group, sec-butyl group, tert-butyl. Group, branched alkyl groups such as tert-amyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; cycloalkenyl groups such as cyclopentenyl group; aryl groups such as phenyl group and tolyl group. In the formula, R ¹⁶ is a hydrocarbon group having 1 to 20 carbon atoms, specifically, a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group; isopropyl group, sec -Branched alkyl groups such as butyl group, tert-butyl group, tert-amyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; cycloalkenyl groups such as cyclopentenyl group; aryls such as phenyl group and tolyl group Group and the like. Further, in the formula, R ¹⁷ is a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms. Specific examples of the organosilicon compound used as such an electron donor component include tert-butyl-n-propyldimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylethyldimethoxysilane, and the like.

  In the preparation of the catalyst for addition polymerization, the amount of the organoaluminum compound component used is usually 1 to 1000 mol, preferably 5 to 800 mol, per 1 mol of titanium atoms contained in the catalyst component (A). The amount of the electron donor component used is usually 0.1 to 2000 mol, preferably 0.3 to 1000 mol, more preferably 0.5 to 1 mol per mol of titanium atoms contained in the catalyst component (A). 800 moles.

  In the polymerization step (I), propylene is homopolymerized or copolymerized with propylene and an olefin (excluding propylene), and the content of monomer units (propylene units) based on propylene is 95% by weight or more. This is a step of producing a certain polymer component (X) (provided that the content of all monomer units in the polymer component (X) is 100% by weight). Examples of the olefin include olefins having 2 to 8 carbon atoms (excluding propylene) such as ethylene, 1-butene, 1-hexene, and 1-octene. It is used in combination of more than one species, preferably ethylene. The content of the propylene unit is measured by infrared spectroscopy.

  The polymerization step (I) includes a polymerization method having a narrow residence time distribution in the reactor, that is, (a) a continuous polymerization method using a batch polymerization method and / or an extrusion flow reactor, and a residence time distribution in the reactor. The polymer component (X) is produced by a wide polymerization method, that is, (b) a continuous polymerization method using a non-extrusion flow reactor. Examples of the batch polymerization method include a batch bulk polymerization method, a batch slurry polymerization method, and a batch gas phase polymerization method. The continuous polymerization method using an extrusion flow type reactor is one in which continuous polymerization is carried out in a polymerization reactor having a residence time distribution corresponding to a complete tank series model of 10 tanks or a residence time distribution narrower than the residence time distribution. Examples of the reactor include a tube reactor, a moving bed reactor, and a multi-chamber reactor. As the continuous polymerization method using an extrusion flow type reactor, continuous polymerization using a polymerization reactor having a residence time distribution corresponding to a complete tank series model of 12 tanks or a residence time distribution narrower than the residence time distribution is preferable.

  (B) The continuous polymerization method using a non-extrusion flow type reactor is a method in which continuous polymerization is carried out by a polymerization reactor having a residence time distribution wider than the residence time distribution corresponding to a 10-mixing tank model. Examples of the reactor include a stirred tank reactor and a fluidized bed reactor.

  In the polymerization step (I), (b) the production amount of the polymer component in the continuous polymerization method using a non-extrusion flow type reactor is set to 100% by weight based on the production amount of the polymer component in the polymerization step (I). From the viewpoint of reducing the number of eyes, it is 50% by weight or less.

  In the polymerization step (I), the polymerization temperature in each polymerization method is usually 0 to 150 ° C, preferably 30 to 80 ° C, more preferably 50 to 70 ° C.

  In the polymerization step (II), propylene and an olefin (excluding propylene) are copolymerized to obtain a polymer component (Y) having a content of monomer units based on propylene of 90 to 10% by weight. (However, the content of all monomer units of the polymer component (Y) is 100% by weight). Examples of the olefin include olefins having 2 to 8 carbon atoms (excluding propylene) such as ethylene, 1-butene, 1-hexene, and 1-octene. It is used in combination of more than one species, preferably ethylene. The content of the propylene unit is measured by infrared spectroscopy.

  In the polymerization step (II), in the presence of the polymer component (X), the transition metal-containing catalyst component used in the production of the polymer component (X) (in the above addition polymerization catalyst, the catalyst component (A) Copolymerization under the action of The polymerization step (II) is performed by (c) a batch polymerization method and / or a continuous polymerization method using an extrusion flow reactor, following the polymerization step (I), and as the batch polymerization method, a batch bulk polymerization method, Examples thereof include a batch slurry polymerization method and a batch gas phase polymerization method. The continuous polymerization method using an extrusion flow type reactor is one in which continuous polymerization is carried out in a polymerization reactor having a residence time distribution corresponding to a complete tank series model of 10 tanks or a residence time distribution narrower than the residence time distribution. Examples of the reactor include a tube reactor, a moving bed reactor, and a multi-chamber reactor. As the continuous polymerization method using an extrusion flow type reactor, continuous polymerization using a polymerization reactor having a residence time distribution corresponding to a complete tank series model of 12 tanks or a residence time distribution narrower than the residence time distribution is preferable.

  In the polymerization step (II), the polymerization temperature in each polymerization method is usually from 0 to 100 ° C, preferably from 30 to 100 ° C, more preferably from 50 to 90 ° C.

  The bulk polymerization method is a method of performing polymerization using a liquid olefin as a medium, and the slurry polymerization method is a polymerization in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, and octane. The gas phase polymerization method is a method in which a gaseous monomer is used as a medium and the gaseous monomer is polymerized in the medium, and the solution polymerization method is a method in which the monomer is polymerized. This is a method in which a monomer is polymerized in a dissolved solvent as a medium. These polymerization methods may be performed in multiple stages, and these polymerization methods may be arbitrarily combined. In these polymerization methods, a chain transfer agent such as hydrogen can be used to adjust the molecular weight of the polymer.

  In the production of the propylene-based block copolymer, the production amount of the polymer component in the polymerization step (I) is 90 to 60% by weight, and the production amount of the polymer component in the polymerization step (II) is 10 to 40%. It is preferable that it is weight%. However, the total of the production amount of the polymer component in the polymerization step (I) and the production amount of the polymer component in the polymerization step (II) is 100% by weight.

  Since the propylene block copolymer obtained by this production method has a reduced number of fish eyes, it has excellent appearance and impact resistance, and is suitably used for automobile parts, household appliance parts, and the like.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
Measurement of physical properties and evaluation in the examples were performed by the following methods.
(1) Intrinsic viscosity (unit: dl / g)
Using an Ubbelohde viscometer, reduced viscosities were measured at three points of concentrations of 0.1, 0.2, and 0.5 g / dl under the conditions of a tetralin solvent and a temperature of 135 ° C. Next, according to the calculation method described in “Polymer Solution, Polymer Experimental 11” (published by Kyoritsu Shuppan Co., Ltd., 1982), page 491, extrapolation to plot the reduced viscosity against the concentration and extrapolate the concentration to zero The intrinsic viscosity was determined by the method.

(2) Ethylene unit content (unit:% by weight)
It was determined by the infrared absorption spectrum method.

(3) Proportion of polymer component production in each polymerization step (unit:% by weight)
Production rate ratio W _P1 (% by weight) of the polymer component in the continuous polymerization method using the non-extrusion flow reactor in the polymerization step (I), Production rate rate of the polymer component in the batch polymerization method in the polymerization step (I) W _P2 (% by weight) and the production amount ratio W _EP (% by weight) of the polymer component in the polymerization step (II) were calculated by the following formula.
W _P1 = Production amount of polymer component in continuous polymerization method by non-extrusion flow type reactor in polymerization step (I) / Total polymer production amount × 100
W _P2 = (Production amount of polymer component in polymerization step (I) −Production amount of polymer component in continuous polymerization method by non-extrusion flow reactor in polymerization step (I)) / Total polymer production amount × 100
W _EP = 100−W _P1 −W _P2

(4) In the production amount of the polymer component in the polymerization step (I), the proportion of the production amount of the polymer component in the continuous polymerization method using a non-extrusion flow reactor (unit:% by weight)
In the production amount of the polymer component in the polymerization step (I), the production amount ratio (unit:% by weight) M _r (unit:% by weight) of the polymer component in the continuous polymerization method using a non-extrusion flow reactor is It is a value obtained from the following formula (1).
M _r = W _P1 / (W _P1 + W _P2 ) × 100 (1)

(5) Intrinsic viscosity of polymer component produced in each polymerization step (unit: dl / g)
Intrinsic viscosity [η] _P1 (dl / g) of a polymer component produced by a continuous polymerization method using a non-extrusion flow reactor in the polymerization step (I), a polymer component produced by a batch polymerization method in the polymerization step (I) The intrinsic viscosity [η] _P2 (dl / g) and the intrinsic viscosity [η] _EP (dl / g) of the polymer component produced in the polymerization step (II) were calculated according to the following formula.
[Η] _P1 = [η] ₁
[Η] _P2 = ([η] ₂ − [η] _P1 × W _P1 / (W _P1 + W _P2 )) × (W _P1 + W _P2 ) / W _P2
[Η] _EP = ([η] ₃ − [η] _P1 × W _P1 / 100− [η] _P2 × W _P2 / 100) × 100 / W _EP
[Η] ₁ : Intrinsic viscosity (dl / g) of the polymer component after continuous polymerization in the non-extrusion flow type reactor in the polymerization step (I)
[Η] ₂ : Intrinsic viscosity (dl / g) of the polymer component after the polymerization step (I)
[Η] ₃ : Intrinsic viscosity (dl / g) of the polymer after the polymerization step (II)

(6) Ethylene unit content of polymer component produced in each polymerization step (unit: wt%)
Polymer unit content E _P1 (unit:% by weight) of the polymer component produced by the continuous polymerization method in the non-extrusion flow type reactor in the polymerization step (I), polymer produced by the batch polymerization method in the polymerization step (I) The ethylene unit content E _P2 (unit: wt%) of the component and the ethylene unit content E _EP (unit: wt%) of the polymer component produced in the polymerization step (II) were calculated by the following formula.
E _P1 = E ₁
E _P2 = (E ₂ −E _P1 × W _P1 / (W _P1 + W _P2 )) × (W _P1 + W _P2 ) / W _P2
E _EP = (E ₃ −E _P1 × W _P1 / 100−E _P2 × W _P2 / 100) × 100 / W _EP
E ₁ : ethylene unit content (unit:% by weight) of the polymer component after continuous polymerization in the non-extrusion flow reactor in the polymerization step (I)
E ₂ : ethylene unit content of polymer component after polymerization step (I) (unit: wt%)
E ₃ : ethylene unit content of the polymer after the polymerization step (II) (unit:% by weight)

(7) Number of fish eyes (unit: pieces / 100cm ² )
The obtained polymer was molded into a film having a thickness of 80 μm at a temperature of 220 ° C. using a T-die film molding machine (20 mmφ extruder manufactured by Tanabe Plastics Co., Ltd., 100 mm width T-die). The image of the film is taken into a computer using a scanner (manufactured by Seiko Epson Corporation), and then the image is analyzed using an image analysis program (manufactured by Asahi Engineering Co., Ltd.). The number of was measured. The number of fish eyes was expressed as the amount per 100 cm ^{2 of} film.

Example 1
[Preparation of solid catalyst components]
After replacing the SUS reaction vessel with an internal volume of 200 L with a stirrer with nitrogen, 80 L of hexane, 6.55 mol of tetrabutoxytitanium, 2.8 mol of diisobutyl phthalate, and 98.9 mol of tetraethoxysilane were added to form a homogeneous solution. did. Next, 51 L of a diisobutyl ether solution of butyl magnesium chloride having a concentration of 2.1 mol / L was gradually added dropwise over 5 hours while maintaining the temperature in the reaction vessel at 5 ° C. After completion of the dropping, the mixture was stirred at room temperature for 1 hour, separated into solid and liquid at room temperature, and then washed with 70 L of toluene three times. Next, toluene was added so that the slurry concentration became 0.2 kg / L, 47.6 mol of diisobutyl phthalate was added, and the reaction was performed at 95 ° C. for 30 minutes. After the reaction, it was separated into solid and liquid and washed twice with toluene. Next, 3.13 mol of diisobutyl phthalate, 8.9 mol of butyl ether and 274 mol of titanium tetrachloride were added, and the reaction was carried out at 105 ° C. for 3 hours. After completion of the reaction, solid-liquid separation was performed at the same temperature, and washing was performed twice with 90 L of toluene at the same temperature. Next, after adjusting the slurry concentration to 0.4 kg / L, 8.9 mol of butyl ether and 137 mol of titanium tetrachloride were added, and the reaction was carried out at 105 ° C. for 1 hour. After completion of the reaction, solid-liquid separation was performed at the same temperature, followed by washing with 90 L of toluene three times at the same temperature, then further washing with 70 L of hexane three times and drying under reduced pressure to obtain 11.4 kg of a solid catalyst component.

[Preliminary polymerization]
To a 3 L SUS autoclave with a stirrer, add 1.5 L of fully dehydrated and degassed n-hexane, 37.5 mmol of triethylaluminum, 3.75 mmol of cyclohexylethyldimethoxysilane and 15 g of the above solid catalyst component. Then, while maintaining the temperature in the autoclave at about 10 ° C., 15 g of propylene was continuously supplied over about 30 minutes to perform prepolymerization, and then the prepolymerized slurry was transferred to an SUS autoclave with a stirrer having an internal volume of 150 L Then, 100 L of liquid butane was added to prepare a slurry of a prepolymerized catalyst component.

[Polymerization step (I)]
(Continuous polymerization with non-extrusion flow reactor)
In a bulk polymerization tank in the preceding stage of an apparatus in which two cylindrical bulk polymerization tanks with an internal volume of 298 L and a gas phase fluidized bed reactor with an internal volume of 1440 L connected with a stirrer are connected, propylene, hydrogen, triethylaluminum, cyclohexylethyldimethoxysilane and A slurry of a prepolymerization catalyst component is continuously supplied, polymerization temperature: 70 ° C., polymerization pressure: 2.6 MPaG, propylene concentration in the reactor: 53.3% by volume, hydrogen concentration: 24.2% by volume, triethylaluminum Feed rate: 31.1 mmol / hr, cyclohexylethyldimethoxysilane feed rate: 4.58 mmol / hr, pre-polymerization catalyst component slurry feed rate: 0.423 g / hr in terms of solid catalyst component, average residence time Continuous bulk polymerization was performed for 1.1 hours at a produced polymer particle amount of 8.3 kg / hour. Polymer particles obtained by continuous bulk polymerization were continuously fed to the gas phase fluidized bed reactor, and the feeding was stopped when the amount of polymer particles in the gas phase fluidized bed reactor reached 18.8 kg.

(Batch polymerization)
The gas phase portion in the gas phase fluidized bed reactor into which the polymer particles were fed was replaced with nitrogen and maintained at a temperature of 70 ° C. and a pressure of 0.3 MPaG. Thereafter, propylene: 25 kg / hour, hydrogen: 1100 NL / hour were supplied, and the temperature inside the reactor was increased to 70 ° C. and 1.8 MPaG. After the pressure increase, propylene: 15 kg / hour and hydrogen: 1300 NL / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 40.7 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did.

[Polymerization step (II)]
Propylene: 30 kg / hour, ethylene: 9.5 kg / hour are supplied to the gas phase fluidized bed reactor filled with polymer particles in the polymerization step (I), and the inside of the reactor becomes 70 ° C. and 1.0 MPaG. The temperature was increased and the pressure was increased. After the pressure increase, propylene: 15 kg / hour and ethylene: 5.5 kg / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 61.5 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did. The polymer particles were extracted to obtain propylene-ethylene block copolymer particles. Table 1 shows the evaluation results of the propylene-ethylene block copolymer particles and the polymer particles obtained in the polymerization step (I).

Example 2
[Polymerization step (I)]
(Continuous polymerization with non-extrusion flow reactor)
Continuous bulk polymerization was carried out in the same manner as in the continuous polymerization using the non-extrusion flow reactor in the polymerization step (I) of Example 1. The polymer particles obtained by continuous bulk polymerization were continuously fed to the gas phase fluidized bed reactor, and the feeding was stopped when the amount of polymer particles in the gas phase fluidized bed reactor reached 15.6 kg.

(Batch polymerization)
The gas phase portion in the gas phase fluidized bed reactor into which the polymer particles were fed was replaced with nitrogen and maintained at a temperature of 70 ° C. and a pressure of 0.3 MPaG. Thereafter, propylene: 25 kg / hour, hydrogen: 1100 NL / hour were supplied, and the temperature inside the reactor was increased to 70 ° C. and 1.8 MPaG. After the pressure increase, propylene: 15 kg / hour and hydrogen: 1300 NL / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 34.8 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did.

[Polymerization step (II)]
Propylene: 30 kg / hour, ethylene: 9.5 kg / hour are supplied to the gas phase fluidized bed reactor filled with polymer particles in the polymerization step (I), and the inside of the reactor becomes 70 ° C. and 1.0 MPaG. The temperature was increased and the pressure was increased. After the pressure increase, propylene: 15 kg / hour and ethylene: 5.6 kg / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 57.8 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did. The polymer particles were extracted to obtain propylene-ethylene block copolymer particles. Table 1 shows the evaluation results of the propylene-ethylene block copolymer particles and the polymer particles obtained in the polymerization step (I).

Comparative Example 1
[Polymerization step (I)]
(Continuous polymerization with non-extrusion flow reactor)
Using the same apparatus as in Example 1, a slurry of propylene, hydrogen, triethylaluminum, cyclohexylethyldimethoxysilane and the prepolymerized catalyst component prepared in Example 1 was continuously supplied to the previous bulk polymerization tank, and the polymerization temperature was : 60 ° C., polymerization pressure: 2.94 MPaG, propylene concentration in the reactor: 67.8% by volume, hydrogen concentration: 19.51% by volume, feed amount of triethylaluminum: 32.8 mmol / hour, cyclohexylethyldimethoxysilane Feed rate: 4.83 mmol / hr, pre-polymerization catalyst component slurry feed rate: 1.541 g / hr in terms of solid catalyst component, average residence time 1.82 hr, product polymer particle volume 15.8 kg / hr The continuous bulk polymerization was carried out. The polymer particles obtained by continuous bulk polymerization were continuously fed into the gas phase fluidized bed reactor, and the feeding was stopped when the amount of polymer particles in the gas phase fluidized bed reactor reached 30.4 kg.

[Polymerization step (II)]
The gas phase portion in the gas phase fluidized bed reactor into which the polymer particles were fed was replaced with nitrogen, and the temperature was kept at 65 ° C. and the pressure was 0.3 MPaG. Thereafter, propylene: 15 kg / hour and ethylene: 7.5 kg / hour were supplied, and the temperature was raised and raised until the inside of the reactor reached 65 ° C. and 1.0 MPaG. After the pressure increase, propylene: 15 kg / hour and ethylene: 7.5 kg / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 48.7 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did. The polymer particles were extracted to obtain propylene-ethylene block copolymer particles. Table 1 shows the evaluation results of the propylene-ethylene block copolymer particles and the polymer particles obtained in the polymerization step (I).

Comparative Example 2
[Polymerization step (I)]
(Continuous polymerization with non-extrusion flow reactor)
Continuous bulk polymerization was performed in the same manner as in the continuous polymerization using the non-extrusion flow reactor in the polymerization step (I) of Comparative Example 1. Polymer particles obtained by continuous bulk polymerization were continuously fed to the gas phase fluidized bed reactor, and the feeding was stopped when the amount of polymer particles in the gas phase fluidized bed reactor reached 35.3 kg.

(Batch polymerization)
The gas phase portion in the gas phase fluidized bed reactor that received the polymer particles was replaced with nitrogen, and maintained at a temperature of 65 ° C. and a pressure of 0.3 MPaG. Thereafter, propylene: 20 kg / hour, hydrogen: 517 NL / hour were supplied, and the temperature inside the reactor was increased to 65 ° C. and 1.4 MPaG. After the pressure increase, propylene: 20 kg / hour and hydrogen: 517 NL / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 56.4 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did.

[Polymerization step (II)]
Propylene: 17 kg / hour, ethylene: 5.0 kg / hour are supplied to the gas phase fluidized bed reactor packed with polymer particles in the polymerization step (I), and the inside of the reactor becomes 65 ° C. and 1.0 MPaG. The temperature was increased and the pressure was increased. After the pressure increase, propylene: 17 kg / hour and ethylene: 5.0 kg / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 67.2 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did. The polymer particles were extracted to obtain propylene-ethylene block copolymer particles. Table 1 shows the evaluation results of the propylene-ethylene block copolymer particles and the polymer particles obtained in the polymerization step (I).

Comparative Example 3
[Polymerization step (I)]
(Continuous polymerization with non-extrusion flow reactor)
Using the same apparatus as in Example 1, a slurry of propylene, hydrogen, triethylaluminum, cyclohexylethyldimethoxysilane and the prepolymerized catalyst component prepared in Example 1 was continuously supplied to the previous bulk polymerization tank, and the polymerization temperature was : 55 ° C, polymerization pressure: 2.93 MPaG, propylene concentration in the reactor: 81.0 vol%, hydrogen concentration: 22.03 vol%, supply amount of triethylaluminum: 31.6 mmol / hour, cyclohexylethyldimethoxysilane Feed rate: 4.66 mmol / hr, slurry feed rate of pre-polymerization catalyst component: 0.677 g / hr in terms of solid catalyst component, average residence time 0.78 hr, amount of produced polymer particles 4.7 kg / hr The continuous bulk polymerization was carried out. Polymer particles obtained by continuous bulk polymerization were continuously fed to the gas phase fluidized bed reactor, and the feeding was stopped when the amount of polymer particles in the gas phase fluidized bed reactor reached 20.6 kg.

(Batch polymerization)
The gas phase portion in the gas phase fluidized bed reactor that received the polymer particles was replaced with nitrogen, and maintained at a temperature of 65 ° C. and a pressure of 0.3 MPaG. Thereafter, propylene: 25 kg / hour, hydrogen: 1900 NL / hour were supplied, and the temperature inside the reactor was increased to 65 ° C. and 1.4 MPaG. After the pressure increase, propylene: 15 kg / hour and hydrogen: 925 NL / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 40.1 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did.

[Polymerization step (II)]
Propylene: 30 kg / hour and ethylene: 30 kg / hour are supplied to the gas-phase fluidized bed reactor packed with polymer particles in the polymerization step (I), and the temperature inside the reactor is increased to 65 ° C. and 1.4 MPaG. Hot pressurization was performed. After the pressure increase, propylene: 20 kg / hour and ethylene: 3.5 kg / hour were supplied at a constant pressure, and batch gas phase polymerization was performed until the amount of polymer particles in the reactor reached 60.6 kg. After the polymerization is completed, the supplied propylene and hydrogen are stopped, the gas is purged until the internal pressure of the reactor becomes 0.3 MPaG, and the gas phase is replaced with nitrogen until the hydrogen concentration in the gas in the reactor becomes 1% by volume or less. did. The polymer particles were extracted to obtain propylene-ethylene block copolymer particles. Table 1 shows the evaluation results of the propylene-ethylene block copolymer particles and the polymer particles obtained in the polymerization step (I).

Claims (2)

  A polymer in which the content of monomer units based on propylene is 95% by weight or more by homopolymerizing propylene or copolymerizing propylene and olefins (excluding propylene) in the presence of an addition polymerization catalyst. Polymerization step (I) for producing component (X) is carried out, and then, propylene and olefin (excluding propylene) are copolymerized, and the content of monomer units based on propylene is 90 to 10 wt. % Of a propylene-based block copolymer in which a polymerization step (II) for producing a polymer component (Y) is carried out. In the polymerization step (I), (a) a batch polymerization method and / or extrusion A polymer component (X) is produced by a continuous polymerization method using a flow reactor and (b) a continuous polymerization method using a non-extrusion flow reactor, and (b) a continuous polymerization method using a non-extrusion flow reactor. The production amount of the polymer component is 50% by weight or less (however, the production amount of the polymer component in the polymerization step (I) is 100% by weight). In the polymerization step (II), (c) batch weighting A method for producing a propylene-based block copolymer, wherein the polymer component (Y) is produced by a combination method and / or a continuous polymerization method using an extrusion flow reactor. The production amount of the polymer component (X) in the polymerization step (I) is 90 to 60% by weight, and the production amount of the polymer component (Y) in the polymerization step (II) is 10 to 40% by weight. Item 2. A process for producing a propylene-based block copolymer according to Item 1.