CN100528907C - Process for producing polyolefin and vapor phase polymerization apparatus therefor - Google Patents

Abstract

A process for producing polyolefins by continuous vapor phase polymerization in the presence of an olefin polymerization catalyst is provided, comprising the steps of: feeding a cooling circulating medium into the polymerization container from at least one position of the bottom wall and the side wall of the polymerization container. A polyolefin vapor phase polymerization apparatus is also provided, comprising: a polymerization container equipped with a monomer feeding pipe, a polymer discharge pipe and an optional stirring paddle, and a mechanical device for feeding a cooling circulating medium into the polymerization container from at least one position of the bottom wall and the side wall of the polymerization container.

Description

Process for producing polyolefin and its vapor phase polymerization unit

technical field

The present invention relates to a process for the production of polyolefins, in particular polyolefins such as propylene block copolymers, and more particularly to a process for the production of polyolefins by a vapor phase polymerization process in the presence of an olefin polymerization catalyst, the The method has no worry about the polymer sticking to the wall of the polymerization vessel or the stirring paddle used together with it, and can carry out the polyolefin production continuously, stably and for a long time; and relates to a vapor phase polymerization device used in the process.

Background technique

Polyolefins such as polypropylene and propylene block copolymers have experienced a rapid increase in polymer yield per catalyst weight due to the high activity and high stereoregularity achieved by improved Ziegler-Natta catalysts, And thus its stereoregularity is also improved. As a result, the content of metal components such as transition metal catalyst components and atactic polypropylene components of the produced polymer can be reduced. Therefore, the vapor phase polymerization method has attracted attention as a polymerization method for producing polyolefins because it has advantages such as the following compared with conventional methods such as solution polymerization, slurry polymerization and bulk polymerization, namely, No need for solvent recovery and purification steps, easy recovery of monomers, easy drying of the resulting polymers, and applicability of various products.

For example, propylene block copolymers have been produced by a process wherein a crystalline propylene homopolymer or copolymer is produced in a pre-polymerization vessel in the presence of a highly stereoregular olefin polymerization catalyst, and rubbery propylene is then combined with Random copolymers of other alpha-olefins such as ethylene are produced in post-polymerization vessels. The resulting propylene block copolymer is a composition whose excellent properties lie not only in the inherent strength, hardness and heat resistance of crystalline polypropylene, but also in the inherent impact resistance of rubbery random copolymers, especially Low temperature impact. Therefore, the propylene block copolymer has been widely used in various applications such as automobile parts such as exterior trims such as car door panels, or interior trims such as instrument panels and doors, containers, and sheets.

Therefore, the process of producing polyolefins by vapor phase polymerization is a very good process. However, in the vapor phase polymerization method, the inside of the vapor phase polymerization vessel used therein is divided into a polymer powder portion and a vapor phase portion, regardless of whether the polymerization vessel is a vapor phase fluidized bed type or a stirring fluidized bed type, so, in In the polymerization vessel, fluidization, agitation and homogeneity were generally insufficient. Therefore, the vapor phase polymerization method tends to be unsatisfactory in terms of stirring effect and uniformity effect as compared with the solution polymerization method and the slurry polymerization method. In particular, in the third polymerization vessel for producing random copolymers in the above-mentioned process for producing propylene block copolymers, since the produced random copolymers are rubber-like highly viscous substances, there is a possibility that polymers such as or the tendency of problems such as adhesion between copolymer particles, adhesion of polymer or copolymer particles to polymerization vessel walls and stirring paddles.

The above-mentioned sticking makes it difficult for the process to achieve stable continuous production of the target product, and in addition, the deposited material causes an objectionable increase in molecular weight and gel, leading to problems such as poor quality of the finally obtained molded product. In addition, the small lumps produced by the adhesion of polymer particles tend to cause troubles such as clogging of polymer powder delivery pipes, which further may lead to clogging of filters located in cooling monomer circulation pipes. Here, the so-called "inferior quality" means that the polymer or copolymer stays in the polymerization container for a long time due to adhesion to the polymerization container, gels, and forms an infusible or refractory component, thereby causing the resulting molded product to suffer from performance and industrial value. deterioration, such as poor appearance and the starting point for breakage.

In order to solve these problems, a method for producing polyolefins, especially propylene block copolymers, in which an alkoxy aluminum compound is added to the reaction system to prevent the adhesion of polymer particles (for example, see JP 56-151713A and JP 58-213012A). However, since it is necessary to add a large amount of alkoxyaluminum compound in order to exhibit a sufficient degree of anti-adhesion effect, it is difficult to apply this method to a vapor phase polymerization method due to an increase in the aluminum content in the resulting polymer.

Also, a production method is disclosed, wherein an active hydrogen compound is added to a reaction system for producing a random copolymer in an amount of 0.001 to 1 mole per gram atom of aluminum contained in a high stereoregularity polymerization catalyst (e.g. , see JP 61-69821A). However, in JP 61-69821A, the continuous polymerization method is not exemplified, only the batch polymerization method is described. Therefore, in JP 61-69821A, although a specific method of feeding an active hydrogen compound and a high bulk density of the resulting polymer are described, there is no specific description about the effect of preventing sticking. This is because a batch polymerization system necessarily requires good uniformity.

In addition, specifically disclosed is a method wherein, in a vapor phase polymerization reaction system, alcohol is fed to a cooling single circulation system, and is transferred between a polymerization vessel for producing crystalline polypropylene and a polymerization vessel for producing propylene random copolymer Fluids (for example, see JP 63-225613A, JP 4-296313A, JP 4-296314A and JP 11-71415A). In any of these methods, the catalyst activation inhibitor with respect to the olefin polymerization catalyst is not directly added to the polymerization vessel. In these methods, catalyst activation inhibitors are fed into polymer powder delivery lines or monomer feed lines to enhance their dispersibility. However, these methods are considered to be superior methods because the catalyst activity inhibitor is ultimately fed into the polymerization vessel.

Furthermore, in the embodiment of the above-mentioned JP 11-71415A, it is described that the heptane solution containing 17% (by mass) isopropanol is metered into the delivery pipe connecting the two reactors, that is, each other is the front stage reactor and subsequent reactor, and in its comparative example, the metering of the same solution directly into the subsequent reactor is described. As a result, after operating for 3 weeks in the embodiment, compared with after the same operation for 3 weeks in the comparative example, the amount of lumps and agglomerates in the powder bed formed in the latter stage reactor of the former decreased by 45 to 35%. %, while the amount of film and deposits on the reactor wall or on the surface of the baffle is reduced by 25-35%. In JP 11-71415A, although the effect of reduction was quantitatively evaluated, it is obvious that the improved method only has a limited effect of reducing lumps, agglomerates or deposits, so it is still unsatisfactory.

In addition, there is disclosed a process for producing polyolefins by a continuous vapor phase polymerization process in the presence of an olefin polymerization catalyst, characterized in that a catalyst activation inhibitor is fed into the vapor phase portion in the polymerization vessel from the side wall of the polymerization vessel and Further feed the powder portion therein (for example, see JP 2001-261720A). This method is also limited in its effectiveness in preventing the polymer from adhering to the upper part of the paddle. Therefore, a large amount of lumps and agglomerates, depending on the type of polymerization vessel and polymerization conditions, may still remain in the reaction system, causing problems such as its adhesion to the walls of the polymerization vessel and stirring paddles and clogging of the polymer particle discharge pipe. and the like. Therefore, the method must be further improved in order to solve these problems.

Contents of the invention

The present invention has solved the above-mentioned problems. The object of the present invention is to provide a process for the production of polyolefins by a continuous vapor phase polymerization process in the presence of an olefin polymerization catalyst, which does not form lumps or agglomerates, sticking of the polymer to the walls of the polymerization vessel or to the stirring blades The present invention provides a vapor-phase polymerization device for the above-mentioned process and the worry of clogging pipes, and the ability to carry out stable and continuous polyolefin production without deterioration of its quality.

After extensive research, the inventors have found that, in the process of producing polyolefins by continuous vapor phase polymerization method using olefin polymerization catalysts, the above object can be achieved by passing the cooling circulating medium from the bottom wall of the polymerization vessel and its At least one point of the side wall feeds the polymerization vessel. The present invention achieves its object on the basis of the above findings.

Therefore, the present invention provides:

(1) A process for producing polyolefins by means of continuous vapor phase polymerization in the presence of an olefin polymerization catalyst, comprising the steps of: feeding the cooling circulating medium from the bottom wall of the polymerization vessel and from at least one position on the side wall thereof to the the aggregation container, and

(2) A polyolefin vapor-phase polymerization device, comprising: a polymerization container equipped with a monomer feeding pipe, a polymer discharge pipe and an optional stirring paddle, and a cooling circulation medium from the bottom wall of the polymerization container and from its side wall At least one location feeds into the polymerization vessel mechanism.

Brief description of the drawings

Fig. 1 is a schematic diagram showing an embodiment of a post-stage polymerization vessel applied to an apparatus for producing a propylene-ethylene block copolymer as an example of a vapor phase polymerization apparatus for producing polyolefin according to the present invention.

Reference numeral 1 denotes a post-stage polymerization vessel; 2, a monomer feeding pipe; 3, a polymer discharge pipe; 4, a cooling circulation medium feeding device; 5, a stirring blade; and 6, a vapor phase portion.

Detailed ways

In general, the present invention can be applied to a process for the production of polyolefins by a continuous vapor phase polymerization process using an olefin polymerization catalyst, in particular, it is preferably applied to a process for the production of propylene block copolymers. There is no particular limitation on the monomers used in the production of polyolefins in the present invention. Examples of the monomer include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 4-methyl-pentene-1, 1-hexene, 1-octene, 1-nonene and 1-Decene. These α-olefins may be homopolymerized separately, or two or more α-olefins may be copolymerized with each other. In addition, alpha-olefins can be copolymerized with other copolymerizable monomers such as vinyl acetate and acrylic acid.

The olefin polymerization catalyst used in the process for producing polyolefin according to the present invention is not particularly limited, and various known catalysts can be used. Examples of olefin polymerization catalysts include those employed in known vapor phase polymerization processes, for example, Ziegler-Natta catalysts comprising a solid catalyst component derived from halides or alkoxides of trivalent or tetravalent titanium , alkoxytitanium halide, and magnesium chloride, alkoxymagnesium, etc., and a solid catalyst supported on a carrier, which contains, as a catalyst component, a metallocene-based compound such as a cyclopentadiene group-containing Ti ^- , Zr ^- and Hf ^- compounds. Examples of these catalyst components include those produced by using organoaluminum compounds such as alkylaluminums and aluminoxanes, known cocatalysts such as ion complexes and Lewis acids, and electron donors. In addition, electron-donating compounds can be applied upon polymerization.

The vapor phase polymerization vessel used in the process for producing polyolefin by a vapor phase method according to the present invention is not particularly limited, and various known equipment can be used. Examples of the vapor phase polymerization vessel applied to the present invention include those described in Japanese "Chemical Apparatus" Vol. 41, No. 12, pp. 62-74 (1999). Specific examples of the vapor phase polymerization vessel include: a fluidized bed type polymerization vessel (for example, JP 4-234409A, etc.), a vertical polymerization vessel with stirring paddles (for example, JP 53-123487A, JP 54-23258A, etc.) The horizontal polymerization container of paddle (for example, JP 63-223001A etc.).

Also, in the process of the present invention, there may be a single-stage polymerization vessel, ie, a single polymerization vessel, or two or more stages of polymerization vessels, ie, a plurality of polymerization vessels. Vapor phase polymerization vessels are generally constructed so that solid catalyst and monomer are continuously fed thereinto, and polymer particles produced by polymerization of the monomers are continuously or intermittently discharged therefrom. In addition, a method may also be adopted in which the monomer gas discharged from the polymerization vessel is cooled by an external compressor or an external condenser, and then the cooled liquid monomer is sprayed into the polymerization vessel, thereby removing the monomer gas by latent heat of monomer evaporation. The heat of polymerization generated.

In particular, in the process for producing polyolefins according to the present invention, it is preferred to use two or more polymerization vessels, usually two polymerization vessels. More precisely, the preceding and subsequent polymerization vessels are used so that two types of polymers (copolymers) different in properties from each other are produced in the respective polymerization vessels. For example, in the subsequent polymerization vessel, a rubbery random copolymer is produced in the presence of crystalline polyolefin produced in the preceding polymerization vessel. As a result, the process of the present invention is suitable for the production of polyolefins in the form of mixtures of the two types of polyolefins so produced.

As an embodiment of the two-stage polymerization process, the following process and a combination of these processes may be selectively used, that is, a process of performing polymerization reactions in separate polymerization vessels to produce two types of polyolefins having different molecular weights from each other, in each The process of carrying out (co)polymerization of two types of different monomers in a separate polymerization vessel, the process of carrying out the copolymerization reaction in separate polymerization vessels to produce two types of copolymers with different copolymerization formulas, and carrying out (co)polymerization in separate polymerization vessels ) Polymerization to produce two types of polyolefins with different degrees of crystallinity from each other.

The process for producing polyolefins according to the present invention is characterized in that in the process for producing polyolefins by a continuous vapor phase polymerization process using an olefin polymerization catalyst, the cooling circulating medium is transferred from the bottom wall of the polymerization vessel and from at least one position on the side wall thereof The polymerization vessel is fed, and the medium can be mainly applied to the subsequent polymerization vessel applied in the above-mentioned two-stage polymerization process. Among them, the cooling circulation medium is not particularly limited as long as the heat of polymerization is effectively removed. Examples of cooling circulating media include liquids, gases, and mixtures of gases and liquids. Among these cooling circulation media, liquid is preferably used because the cooling effect of liquid is excellent.

Furthermore, according to the structure of the vapor phase polymerization device for producing polyolefins according to the present invention, comprising: a polymerization vessel equipped with a monomer feeding pipe, a polymer discharge pipe and an optional stirring paddle, and cooling circulation medium from the polymerization vessel bottom wall and a mechanical arrangement for feeding the polymerization vessel from at least one point of its side wall. The device of the present invention is illustrated by taking a process for producing a propylene-ethylene block copolymer as an example. Fig. 1 is a schematic diagram showing an embodiment of a post-stage polymerization vessel applied to an apparatus for producing a propylene-ethylene block copolymer. This is an example of a vapor phase polymerization plant for producing polyolefins according to the present invention. The post-stage polymerization vessel 1 includes a monomer feed pipe 2 , a polymer discharge pipe 3 , a cooling circulation medium feed device 4 and an optional stirring blade 5 . The interior of the polymerization vessel is divided into a vapor phase part (upper part) 6 and a powder part (lower part) 7 . The cooling circulation medium usually consists of 0.01-1% (by mass) hydrogen, 5-40% (by mass) ethylene, 40-90% (by mass) propylene, 4-20% (by mass) propane, 0 ~1% (by mass) nitrogen and 0.01-5% (by mass) methane. In the present invention it is important that the cooling circulating medium is fed into the powder part of the polymerization vessel not only from the bottom wall of the polymerization vessel but also from its side walls. Preferably, the cooling circulation medium is fed at 1/2 or more of the height of the powder part. The cooling circulation medium can be fed at many positions on the side wall of the polymerization vessel, but the number of feeding positions varies according to the structure of the polymerization vessel and the conditions for forming the powder fraction. The amount of the cooling circulation medium fed from the side wall of the polymerization vessel is usually 0.05 to 0.5 times (by mass) the amount of the cooling circulation medium fed from the bottom wall. Among them, the nozzle can usually be used as the cooling circulation medium to feed the equipment.

The process for the production of polyolefins according to the present invention can be adapted, in particular, to such a process for the production of block polypropylene (propylene block copolymer) by multistage polymerization, wherein propylene homopolymer or self-propylene with 5% (by mass) or less crystalline polypropylene in the form of a copolymer of other α-olefins is produced in a first polymerization vessel, then propylene is randomized with other α-olefins in the presence of crystalline polypropylene in a second polymerization vessel Copolymerization in which the cooling circulating medium is fed into the second polymerization vessel not only from the bottom wall of the second polymerization vessel but also from one or more points on its side walls.

Examples of processes and polymerization plants for producing polyolefins according to the present invention include those used for producing propylene block copolymers. Here, the propylene block copolymer is produced by a process in which propylene homopolymer or from the copolymerization of propylene with 5% by mass or less of other α-olefins such as ethylene and 1-butene A crystalline polypropylene-based resin in the form of a solid is produced in a pre-stage vapor-phase polymerization vessel in the presence of a stereoregular polymerization catalyst, and, subsequently, while continuously feeding the crystalline polypropylene-based resin to a subsequent-stage polymerization vessel , Propylene is randomly copolymerized with other α-olefins such as ethylene in the post-stage polymerization vessel to produce rubber-like metatactic copolymers. As a result, it is possible to produce a propylene block copolymer composed of a continuous phase composed of crystalline polypropylene and a dispersed phase composed of rubbery particles (including polyethylene), and, therefore, the copolymer has excellent impact resistance, especially at low temperature Impact resistance. According to the above-mentioned production process, by controlling the copolymerization formulation, molecular weight and random copolymer content, it is possible to produce block polypropylene copolymers whose properties are as required for their application. Here, the monomers used to produce the random copolymer in the subsequent polymerization vessel include combinations of propylene and other α-olefins such as ethylene and 1-butene. The copolymerization ratio (mass ratio) of propylene to other α-olefins is usually 10-90 to 90-10, preferably 20-85 to 80-15. In addition, the content of the random copolymer produced in the post-stage polymerization vessel is generally 3 to 60% by mass and preferably 5 to 50% by mass, based on the propylene block copolymer.

An example of a polymerization catalyst is a high stereoregularity catalyst obtained from (A) a solid catalyst component containing at least a magnesium atom, a titanium atom and a halogen atom, and (B) an organoaluminum compound. Such catalysts include, for example, highly stereoregular catalysts obtained from the following components (A) and (B), that is, obtained from (A) produced by using (a) a magnesium compound and (b) a titanium compound A solid catalyst component and (B) a highly stereoregular catalyst of an organoaluminum compound, and is preferably produced by using the following components (A), (B) and (C).

(A) a solid catalyst component produced by using (a) a magnesium compound and (b) a titanium compound;

(B) organoaluminum compounds; and

(C) Electron donating compounds.

The following compounds can be used as the above-mentioned respective compounds.

(a) Magnesium compounds

The magnesium compound is not particularly limited. Examples of magnesium compounds include magnesium oxide, magnesium hydroxide, dialkylmagnesium, alkylmagnesium halides, magnesium halides and magnesium dihydrocarbyloxides. Specific examples of magnesium compounds include magnesium chloride, diethoxymagnesium and dimethoxymagnesium. In addition, as the magnesium compound, a known solid product obtained by reacting metallic magnesium, a halogen, and an alcohol with each other can also be suitably used. Examples of alcohols include methanol and ethanol. The use of such alcohols readily produces solid products with good morphology having a water content of 200 ppm or less. Additionally, examples of suitable halogens include chlorine, bromine and iodine. Among these halogens, iodine is preferably used.

(b) Titanium compounds

As the titanium compound, optional titanium compounds can be used. Examples of titanium compounds include compounds represented by the following general formula (1),

TiX ¹ n(OR ¹ ) _4-n (1)

Wherein, X ¹ is a halogen atom, especially a chlorine atom; R ¹ is a hydrocarbon group containing 1 to 10 carbon atoms, especially a linear or branched chain alkyl group, but most of the R ¹ groups, if any words, may be the same or different; and n is an integer of 0-4.

Specific examples of titanium compounds include Ti(OiC ₃ H ₇ ) ₄ , Ti(O·C ₄ H ₉ ) ₄ , TiCl(OC ₂ H ₅ ) ₃ , TiCl(OiC ₃ H ₇ ) ₃ , TiCl(OC ₄ H ₉ ) ₃ , TiCl ₂ (OC ₄ H ₉ ) ₂ , TiCl ₂ (OiC ₃ H ₇ ) ₂ and TiCl ₄ .

(c) Electron-donating compounds

The solid catalyst component (A) may also contain, if desired, optionally electron-donating compounds (C). Electron donating compounds are usually organic compounds containing oxygen, nitrogen, phosphorus or sulfur. Examples of electron-donating compounds include amines, amides, ketones, nitriles, phosphines, esters, ethers, thioethers, alcohols, thioesters, acid anhydrides, acid halides, aldehydes, organic acids, and organosilicon compounds having Si-O-C bonds.

Specific examples of electron-donating compounds include aromatic phthalate diesters such as diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and dihexyl phthalate; and Silicone compounds such as dimethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, di-tert-butyldimethoxysilane , Diisobutyldimethoxysilane, Diisopropyldimethoxysilane, Dicyclohexyldimethoxysilane and Dicyclopentyldimethoxysilane.

Process for producing solid catalyst component (A)

The solid catalyst component (A) can be produced by known methods from the magnesium compound (a), the titanium compound (b) and, if desired, the electron donating compound (c). For example, after contacting the magnesium compound (a) with the electron-donating compound (c), the resulting contact product of these compounds is then contacted with the titanium compound (b). Although there are no special restrictions on the contact conditions, the addition amount of the electron-donating compound (c) is usually 0.01 to 10 mol, preferably 0.05 to 5 mol, and based on 1 mol of the magnesium compound (a) in terms of magnesium atoms, these compounds are in the range of 0 to 10 mol. Contact each other at 200°C for 5 minutes to 10 hours, preferably at 30 to 150°C for 30 minutes to 3 hours. Depending on the production of the contact product, inert hydrocarbons such as pentane, hexane and heptane may also be added.

The magnesium compound (a) or the product from the contact of the magnesium compound (a) with the electron-donating compound (c) is subsequently contacted with the titanium compound (b). There are no particular limitations on the contact conditions between the magnesium compound (a) or the contact product from the compounds (a) and (c) and the titanium compound (b). Generally speaking, the addition amount of titanium compound is 1-50 mol, preferably 2-20 mol, based on 1 mol of magnesium, and these compounds are contacted with each other at 0-200°C for 5min-10hr, more preferably at 30-150°C for 30min-5hr. The titanium compound (b) to be contacted, when it is in a liquid state (e.g., titanium tetrachloride), can be used alone, or, when its form is different from a liquid state, can be prepared by dissolving the titanium compound in an optional inert hydrocarbon used in the form of a solution. In addition, the magnesium compound (a), before being contacted with the electron-donating compound (c) (if necessary), may be contacted with, for example, a halogenated hydrocarbon, a halogen-containing silicon compound, a halogen gas, hydrogen chloride, hydrogen iodide, or the like. Meanwhile, after completion of the contacting, it is preferred that the resulting contacted product is washed with an inert hydrocarbon.

(B) Organoaluminum compound

The organoaluminum compound (B) is not particularly limited, and a compound represented by the following general formula (2) can be used,

AlR ² mX ² _3-m (2)

Wherein, R ² is an alkyl, cycloalkyl or aryl group containing 1 to 10 carbon atoms; m is an integer of 1 to 3; and X ² is a halogen atom, that is, a chlorine atom or a bromine atom.

Specific examples of the organoaluminum compound include: trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisopropylaluminum and triisobutylaluminum; and monochlorodialkylaluminum such as monochlorodiethylaluminum and Aluminum Dipropyl Chloride.

(C) electron donating compound

In the process of producing block polypropylene, electron donating compounds (C) can also be used, if desired. In this case, the electron donating compound (C) may be the same compound as that used for the electron donating compound (c) in the production of the solid catalyst component (A). Also, in this case, the electron donating compound (c) may be the same as or different from the electron donating compound (c) used in the production of the solid catalyst component. Examples of suitable electron-donating compounds (C) include silane compounds having SiO—C bonds, especially, those represented by the following general formula (3):

R ³ _p Si(OR ⁴ ) _4-p (3)

Wherein, R ³ is a linear or branched hydrocarbon group, an aromatic hydrocarbon group or a cyclic saturated hydrocarbon group, and when p is 2 or greater (p≥2), an optional combination of these groups can be applied; R ⁴ is a linear hydrocarbon group or a branched hydrocarbon group; and p is an integer 0-3.

Specific examples of the compound represented by the general formula (3) include t-butylcyclohexyldimethoxysilane, methylcyclohexyldimethoxysilane, di-t-butyldimethoxysilane, dicyclohexyldimethoxysilane , Diphenyldimethoxysilane, Dimethyldiethoxysilane, Trimethylethoxysilane and Methylphenyldimethoxysilane.

In addition, in order to stabilize the polymerization reaction in the polymerization vessel, a catalyst activation inhibitor may also be applied. More specifically, the catalyst activation inhibitor may be suitably selected from alcohols, phenols, carboxylic acids, sulfonic acids, amines, amides, esters, ethers, phosphines, water, carbon monoxide and carbon dioxide. Among these catalyst activation inhibitors, compounds containing active hydrogen are preferred. Specific examples of compounds containing active hydrogen include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butanol and n-hexanol, phenols such as phenol, cresol and xylenol, carboxylic acids such as formic acid, acetic acid , propionic and benzoic acids, sulfonic acids such as sulfonic acid, benzenesulfonic acid and toluenesulfonic acid, amines such as ethylamine and isopropylamine, and water. Among these active hydrogen-containing compounds, linear or branched alcohols having 1 to 20 carbon atoms are preferred, and those having 1 to 10 carbon atoms such as methanol, ethanol, n-propanol and isopropanol are preferred. These catalyst activation inhibitors may be used alone or in admixture of any two or more thereof.

These catalyst activation inhibitors can be used alone, or can be fed with a carrier fluid, such as an inert hydrocarbon solvent such as monomer and heptane, hydrogen, nitrogen, and the like.

The polymerization reaction can be carried out at 40-100°C, preferably at 50-90°C, under a pressure of about 0.1-10 MPa, while using hydrogen or the like to control the molecular weight of the resulting polymer so that the intrinsic viscosity [η] of the polymer is 1-10 dL /g, and preferably 1 to 6 dL/g, measured in tetralin at 135°C.

According to the present invention, in a process for producing polyolefin by a continuous vapor phase polymerization method using an olefin polymerization catalyst, it is possible to effectively prevent the polymer from sticking to the Polymerization vessel walls and stirring paddles. As a result, polyolefins without deterioration in quality can be produced.

The present invention will now be described in more detail with reference to the following examples, but it should be noted that these examples are illustrative only and are not intended to limit the scope of the present invention therein.

Embodiment 1: the production of propylene-ethylene block copolymer

(1) Production of magnesium compound (a)

A glass reactor (capacity: about 12 L) equipped with a stirrer was sufficiently purged with nitrogen, and then charged with 4860 g of ethanol, 32 g of iodine and 320 g of metallic magnesium. The contents of the reactor were heated to react with each other while stirring under reflux until no hydrogen gas was generated from the reaction system to obtain a solid reaction product. The solid reaction product thus obtained was dried under reduced pressure to obtain a magnesium compound (a) [solid product].

(2) Preparation of solid catalyst component (A)

Into a three-neck glass Erlenmeyer flask (volume: 5 L) which was sufficiently purged with nitrogen gas, 160 g of the above-mentioned unpulverized magnesium compound (a), 80 ml of purified heptane, 24 ml of silicon tetrachloride and 23 ml of diethyl phthalate were charged. ester. While maintaining the reaction system at 90°C, 770 ml of titanium tetrachloride was added to the flask while stirring, and the contents of the flask were allowed to react with each other at 110°C for 2 hr. The solid component was separated from the resulting reaction mixture, and then washed with pure heptane at 80°C. Further, after adding 1220 ml of titanium tetrachloride, the reaction mixture was reacted at 110° C. for 2 hrs, and then sufficiently washed with pure heptane to obtain a solid catalyst component (A).

(3) Polymerization

preprocessing

230ml normal heptane and 25kg above-mentioned solid catalyst component (A) are loaded into the reaction vessel that 500L is equipped with stirring paddle, then feed triethylaluminum and diphenyldimethoxysilane in reaction vessel, its amount is respectively It is 0.6 mol/1 gram atom and 0.4 mol/1 gram atom based on the Ti atom contained in the solid catalyst component (A). Thereafter, propylene was added to the reaction vessel until the partial pressure of propylene therein reached 0.03 MPa (gauge pressure), and then reacted at 55° C. for 4 hr. After the reaction was completed, the obtained solid catalyst component was washed several times with n-heptane, and stirred for 24 hr while feeding carbon dioxide thereto.

Specific Polymerization Reaction

To the 200L polymerization container (homopolymerization container) that agitator paddle is equipped with as front stage reactor, the solid catalyst component that above has been processed is loaded into, and its amount is 3mmol/hr in terms of Ti atom contained therein, triethylaluminum, The amount is 600 mmol/hr, and diphenyldimethoxysilane is 15 mmol/hr. The polymerization reaction of propylene was carried out at 70° C. and a propylene pressure of 2.7 MPa (gauge pressure). At the same time, the molecular weight of the obtained product is controlled to a predetermined value with hydrogen. Next, the resulting polymer powder is continuously discharged from the previous-stage polymerization vessel, and sent to the subsequent-stage polymerization vessel (random copolymerization vessel). In the subsequent polymerization vessel (random copolymerization vessel), propylene and ethylene were fed thereinto, and random copolymerization was performed. At the same time, the feed ratio of propylene and ethylene is controlled so that the resulting polymer has a predetermined ethylene unit content.

In addition, a cooling circulating medium having a composition of 0.3% by mass of hydrogen, 38% by mass of ethylene, 58% by mass of propylene and 3.7% by mass of propane was fed into the polymerization vessel , its amount is to feed 110kg/hr from the bottom wall of the polymerization vessel, and feed 50kg/hr from the sidewall of the polymerization vessel, that is, the cooling circulation medium total amount that feeds into the polymerization vessel is 160kg/hr. The cooling circulating medium fed from the side wall of the polymerization vessel was fed at a height of 0.55 m, and the height of the powder layer formed in the polymerization vessel was 0.8 m. Production equipment runs for 6 days. As a result of checking the inside of the polymerization vessel, it was confirmed that no polymer adhesion was found on the surface of the stirring blade.

Comparative example 1

Repeat the same steps as in Example 1, except that the amount of the cooling circulation medium fed from the bottom wall is changed from 110kg/hr to 160kg/hr, and the amount of the cooling circulation medium fed from the side wall is changed from 50kg/hr To 0kg/hr, that is, the cooling circulation medium is only fed from the bottom wall. Production equipment runs for 6 days. As a result of checking the inside of the polymerization vessel, it was confirmed that polymer adhesion was found both on the surface of the stirring blade and on the inner surface of the polymerization vessel.

Possibility of industrial application

According to the present invention, it is possible to provide a polyolefin that does not deteriorate in quality.

Claims (9)

1. One kind in the presence of olefin polymerization catalysis, adopt continuous vapor phase polymerization method to produce polyolefinic technology, it comprises the steps: the liquid cooling circulatory mediator is fed into this aggregation container from the aggregation container diapire with from least one position of its sidewall, be by mass 0.05～0.5 times wherein, and the liquid cooling circulatory mediator feed the powder part of aggregation container from the amount of the liquid cooling circulatory mediator of diapire feeding from the amount of the liquid cooling circulatory mediator of aggregation container sidewall feeding.
2. 2. the polyolefinic technology of the production of claim 1, wherein the liquid cooling circulatory mediator is in 1/2 or the above place feeding of the powder part height of aggregation container.
3. 3. the polyolefinic technology of the production of claim 1, wherein alkene catalyst is the high stereospecicity catalyzer that adopts following component (A), (B) and (C) produce, (A) ingredient of solid catalyst, by adopt (a) magnesium compound and (b) titanium compound produce; (B) organo-aluminium compound; (C) give electron compound.
4. 4. the polyolefinic technology of the production of claim 1, the polyolefinic process application of wherein said production is in the technology of producing propylene-based block copolymer by multistage polymerization, in the technology of producing propylene-based block copolymer, with alfon or from propylene with by mass 5% or the crystalline polypropylene of the multipolymer form of still less other alpha-olefin in the first vapor phase polymerization container, producing in the presence of the stereospecicity polymerizing catalyst, carrying crystalline polypropylene continuously in second aggregation container then, in second aggregation container, in the presence of crystalline polypropylene, make propylene and other alpha-olefin random copolymerization, wherein, the liquid cooling circulatory mediator not only from the second aggregation container diapire and also from its sidewall one or more positions feed second aggregation container.
5. 5. the polyolefinic technology of the production of claim 4, wherein the content of the random copolymers of producing in second aggregation container is by mass 5～50%, is benchmark in the propylene-based block copolymer.
6. 6. the polyolefinic technology of the production of claim 4, wherein propylene is 20～85 to 80～15 with the copolymerization ratio of other alpha-olefin by mass.
7. 7. polyolefine vapor-phase polymerization apparatus therefor, comprise: the aggregation container of monomer feeding pipe, polymkeric substance vent pipe and stirring rake is housed, and the liquid cooling circulatory mediator is fed into equipment this aggregation container from the aggregation container diapire with from least one position of its sidewall.
8. 8. the polyolefine vapor-phase polymerization apparatus therefor of claim 7, wherein this device is equipped with to be used to make from the amount of the cooled circulated medium of aggregation container sidewall feeding and is 0.05～0.5 times the equipment by mass from the amount of the cooled circulated medium of diapire feeding.
9. 9. the polyolefine vapor-phase polymerization apparatus therefor of claim 7, the equipment that wherein is used to feed the liquid cooling circulatory mediator is contained in 1/2 or above place of the powder part height of aggregation container.

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