KR20030025391A - A process for polymerization of olefin - Google Patents

Abstract

PURPOSE: A method for preparing an olefin and a polypropylene resin prepared by the method are provided, to improve the stiffness, the impact resistance and the heat resistance of a polyolefin. CONSTITUTION: The method comprises the steps of surface treating a solid titanium catalyst for polymerization of olefin with a silane compound having at least two vinyl groups; and total polymerizing an olefin monomer and at least one diene compound selected from the group consisting of 1,3-butadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene and 1,13-tetradecadiene, by using the surface-treated solid titanium catalyst. Preferably the solid titanium catalyst is prepared by dissolving a magnesium compound having no reducing property into an electron donor to prepare a magnesium compound solution; reacting the magnesium compound solution with a transition metal compound, a silicon compound, a tin compound or their mixtures to precipitate solid particles; and reacting the precipitated particles with a titanium compound and an electron donor.

Description

Polymerization method of olefin with excellent rigidity, impact resistance and heat resistance {A PROCESS FOR POLYMERIZATION OF OLEFIN}

The present invention relates to an olefin polymerization method. Specifically, rigidity, impact resistance and heat resistance are achieved by using a prepolymerization catalyst in which a macromonomer is encapsulated around an optimum catalyst for alpha olefin polymerization. A method of polymerizing an improved polyolefin.

Conventionally, in order to improve the rigidity, impact resistance, and heat resistance of polypropylene, a method of reinforcing by mixing an inorganic filler with a polypropylene resin has been proposed (Japanese Patent Nos. 53-64256, 53-64257). Problems such as defects and cost incurred due to the increase in specific gravity of materials occur. In addition, when the inorganic filler is generally added, the fluidity of the resin may be deteriorated during molding, which may cause problems such as poor dispersion of pigments and unmolding of complex products.

In order to solve this disadvantage, there is a method (European Patent No. 562119) to improve the rigidity and heat resistance by adding a phosphorus-based nucleating agent, but has a disadvantage inferior in heat resistance.

An object of the present invention is to prepare a polyolefin having excellent rigidity, impact resistance, and heat resistance in a polymerization step, to synthesize a polymerization catalyst having a functionalized active point in a polymer and containing a high molecular weight monomer, and using the same for olefin polymerization. To provide.

In the present invention, "polymerization" is meant to include not only olefin homopolymerization but also copolymerization of olefins with other alpha olefins. In addition, "polymer" is meant to include not only olefin homopolymers but also copolymers with other alphaolefins.

The olefin polymerization method of the present invention is characterized by using a catalyst (hereinafter referred to as "prepolymerization catalyst") in which a high molecular weight monomer is encapsulated around a catalyst prepared by a process comprising the following steps:

(i) surface treating the solid titanium catalyst for olefin polymerization with a silane compound having two or more vinyl groups;

(ii) prepolymerizing the surface-treated solid titanium catalyst with an olefin monomer and at least one diene compound.

As the solid titanium catalyst used in the preparation of the prepolymerization catalyst of the present invention, all of the conventional solid titanium catalysts for olefin polymerization may be used, which may be prepared by various methods. For example, in the presence of an electron donor without active hydrogen, a magnesium compound having no reducing ability in the liquid state may be prepared by direct contact reaction with the liquid titanium compound, that is, by directly contacting each other in the liquid state. It is also possible to produce a solid catalyst with a magnesium compound and a titanium compound without contact with an electron donor, without an electron donor having no electron donor.

Among the various methods for preparing the solid titanium catalyst used in the preparation of the prepolymerization catalyst of the present invention, the most common method is to contact a magnesium compound with a titanium compound containing at least one halogen and, if necessary, the product. Various methods are known for treating N with an electron donor. Some of these methods are described in JP 2,230,672, 2,504,036, 2,553,104 and 2,605,922 and JP 51-28189, 51-136625 and 52-87486. . Further, Japanese Laid-Open Patent Publication No. 79-40293 describes a method for producing a solid titanium compound containing an electron donor from a liquid titanium compound derived from liquid magnesium.

In addition, as a solid titanium catalyst used in the preparation of the prepolymerization catalyst of the present invention, U.S. Patent Nos. 4,482,687, 4,277,372, 3,642,746, 3,642,772, 4,158,642, 4,148,756, 4,477,639, and Conventional Ziegler-Natta catalysts described in 4,518,706, 4,946,816, 4,866,022, 5,013,702, 5,124,297, 4,330,649, European Patent 131,832, JP-A-63-54004 and the like can be used.

A preferred example of the method for preparing the solid titanium catalyst is prepared by the method comprising the following steps, in the embodiment of the present invention was prepared by using a magnesium-supported solid complex titanium catalyst in this way:

(a) dissolving a non-reducing magnesium compound in an electron donor to prepare a magnesium compound solution;

(b) reacting the magnesium compound solution with a transition metal compound, silicon compound, tin compound or a mixture thereof to precipitate solid particles; And

(c) reacting the precipitated solid particles with the titanium compound and the electron donor.

After washing the solid particles reacted in the step (c) with a hydrocarbon solvent, it is possible to produce a solid catalyst particles having a controlled particle shape.

Non-reducing magnesium compounds used in the preparation of such solid titanium catalysts include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide and magnesium fluoride, methoxymagnesium chloride, ethoxymagnesium chloride and isopropoxy Alkoxymagnesium halides such as magnesium chloride, butoxymagnesium chloride and octoxymagnesium chloride, and aryloxymagnesium halides, ethoxymagnesium, isopropoxymagnesium, butoxymagnesium and oxy such as phenoxymagnesium chloride and methylphenoxymagnesium chloride Magnesium salts of alkoxy magnesium, such as methoxymagnesium, and aryloxy magnesium, such as phenoxyshima magnesium and dimethylphenoxy magnesium, and carboxylic acid, such as lauryl magnesium and magnesium stearate, are mentioned.

The magnesium compound may be used in the form of a complex with another metal or in combination with another metal, or may be used as a mixture of two or more magnesium compounds. Preferred magnesium compounds are hydrogen-containing magnesium compounds, magnesium chloride, alkoxymagnesium chlorides, preferably those having C ₁ to C ₁₄ alkoxy and aryloxymagnesium chlorides, preferably C ₅ to C ₂₀ aryloxy.

Usually, the above-listed compounds may be represented by simple chemical formulas, but sometimes they may not be expressed by simple formulas depending on the preparation method of the magnesium compound. These are generally regarded as mixtures of the aforementioned compounds. For example, a method of reacting magnesium metal with an alcohol or a phenol in the presence of halosilane, phosphorus pentachloride, or thionyl chloride, and pyrolysis of Grignard reagent or hydroxyl group, carbonyl group ester bond, ether bond, or the like Compounds obtained by the decomposition method using the same are considered to be a mixture of various compounds according to the reagent or the reactivity thereof, and these compounds may also be used in the present invention.

The magnesium compound solution is prepared by reacting the aforementioned magnesium compound with at least one electron donor selected from the group consisting of alcohols, organic carboxylic acids, aldehydes, amines and mixtures thereof in the presence or absence of a hydrocarbon solvent. Magnesium compound solutions can be prepared by mixing and heating a hydrocarbon solvent and an electron donor. Examples of hydrocarbon solvents used for these purposes include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane and kerosene, cycloaliphatic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane and methylcyclohexane, benzene And aromatic hydrocarbons such as toluene, xylene, ethylbenzene, cumene and cymene and halogenated hydrocarbons such as dichloroethane, dichloropropane, dichloroethylene, trichloroethylene, carbon tetrachloride and chlorobenzene.

In the case of dissolving a hydrogen-containing magnesium compound in a hydrocarbon solvent using alcohol as an electron donor in the preparation of the magnesium compound solution in step (a), the amount does not vary depending on the amount and type of the magnesium compound and the hydrocarbon solvent. However, it is preferred to use a minimum amount of alcohol per mole of magnesium compound, preferably about 1.0 to 20 moles, more preferably about 2.0 to about 10 moles.

In addition, when aliphatic hydrocarbons or alicyclic hydrocarbons are used as hydrocarbon solvents, the alcohols are used in the above-mentioned amounts, but when using alcohols having 6 or more carbon atoms among these alcohols, at least 0.5 mole per mole of magnesium compound, Preferably, when 1.0 mole or more is used, the halogen-containing magnesium compound may be dissolved, and a catalyst component having high activity may be obtained using a small amount of alcohol. In this case, when only alcohol having 5 or less carbon atoms is used, the total amount of alcohol should be at least about 15 moles per mole of halogen-containing magnesium compound, and the resulting catalyst component also has lower catalytic activity than when alcohol is used in the above-described method. On the other hand, when an aromatic hydrocarbon is used as the hydrocarbon solvent, the hydrogen-containing magnesium compound can be dissolved by using about 20 moles, preferably about 12 to 12 moles of alcohol, regardless of the type of alcohol.

The contact reaction between the magnesium compound and the alcohol which is the electron donor is preferably carried out in a hydrocarbon medium. The contact reaction is about 15 minutes to about 5 hours, preferably about 30 minutes to about room temperature or high temperature, for example, about 30 to 200 ° C, preferably about 60 to 150 ° C, depending on the type of magnesium compound and alcohol. It is carried out for 3 hours.

The alcohol used as the electron donor in step (a) is 2-methylpentanol, 2-ethylbutanol, n-heptanol, n-octanol, having at least 6 carbon atoms, preferably 6 to 20 carbon atoms, Aliphatic alcohols such as 2-ethylhexanol, decanol, dodecanol, tetradecyl alcohol, undecenol, oleyl alcohol and stearyl alcohol, alicyclic alcohols such as cyclohexanol and methylcyclohexanol and benzyl alcohol, methyl Aromatic alcohols such as benzyl alcohol, isopropylene benzyl alcohol, α-methylbenzyl alcohol and α, α-dimethylbenzyl alcohol. Alcohols having 5 or less carbon atoms include methanol, ethanol, propanol, butanol, ethylene glycol and methylcarbitol.

The magnesium compound solution prepared as described above is reacted with a transition metal compound such as a titanium compound, a silicon compound, a tin compound, or a mixture thereof to crystallize into a spherical solid (step b). It can be added as appropriate. For example, an appropriate amount of the transition metal compound, silicon compound, tin compound, or a mixture thereof per mole of magnesium compound is 0.1 to 20 moles, preferably 0.1 to 10 moles, more preferably 0.2 to 2 moles. .

When crystallizing the liquid magnesium compound in step (b), the shape and size of the magnesium carrier vary depending on the reaction conditions, and the preferred contact reaction temperature is in the range of about -70 ° C to 200 ° C. In general, however, in order to obtain the form of granular or spherical particles, it is preferable to avoid high temperatures during mixing, and if the contact temperature is too low, precipitation of the solid product does not occur, so the reaction is carried out at a temperature of about 20 ° C to 150 ° C. It is desirable to.

The magnesium compound in the solid particle state obtained above is reacted with a titanium compound and an electron donor to prepare a solid complex titanium catalyst (step c). Examples of electron donors used in this step are generally oxygen-containing electron donors such as water, alcohols, phenols, ketones, aldehydes, carboxylic acids, esters, ethers and acid amides, and ammonia, amines and nitriles. And nitrogen-containing electron donors such as isocyanates, specific examples of which include methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol and iso Alcohols containing 1 to 18 carbon atoms, such as propylbenzyl alcohol, and 6 to 15 carbon atoms, which may contain lower alkyl groups, such as phenol, cresol, xylene, ethylphenol, propylphenol, cumylphenyl, and naphthol Like ketones, acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde and naphtholaldehyde Aldehydes containing 2 to 15 carbon atoms, methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valeric acid, methyl chloroacetate, dichloro Ethyl acetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylic acid, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl aniseate, aniseic acid Ethyl, Ethoxy Benzoate, γ-Butyrolactone, δ-Valerolactone, Coumarin, Phthalide, Cyclohexyl Acetate, Ethyl Propionate, Methyl Butyrate, Methyl Barate, Methyl Chloroacetate, Ethyl Dichloro Acetate, Methyl Meta Acrylate, ethylcycloate, phenylbenzoate, methyltoluate, ethyltoluate, propylbenzoate, butylbenzoate, cyclohexylbenzoate Organic esters containing 2 to 18 carbon atoms, such as amyltoluate, ethylene carbonate and ethylene carbonate, and containing 2 to carbon atoms, such as acetyl chloride, benzyl chloride, toluic acid chloride and anisonic chloride Acid halides and acid amides such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, anisole and diphenyl ether, methylamine, ethylamine, diethylamine, tributyl Aluminum containing amines such as amines, piperidine, tribenzylamine, aniline, pyridine, pinolin and tetramethylethylenediamine, nitriles such as acetonitrile, benzonitrile and tolunitrile and the aforementioned functional groups in the molecule, There are compounds such as silicon and tin. Also as ester derivatives of monoethylene glycol (MEG), diethylene glycol (DEG), triethylene glycol (TEG), polyethylene glycol (PEG), monopropylene glycol (MPG) and dipropylene glycol (DPG) acetate, propionate , n- and iso-butyrate, benzoate, toluate and the like may be preferably used. Examples of such benzoate include monoethylene glycol monobenzoate, monoethylene glycol dibenzoate, diethylene glycol monobenzoate, Diethylene glycol dibenzoate, triethylene glycol monobenzoate, triethylene glycol dibenzoate, monopropylene glycol monobenzoate, dipropylene glycol monobenzoate, dipropylene glycol dibenzoate, tripropylene glycol monobenzoate, and the like. have. These electron donors can be used as mixtures of two or more, with aromatic esters in particular being suitable. However, such electron donors are not always necessary as starting materials and may be used in the form of adducts or complexes of other compounds. The amount of the electron donor may be appropriately changed, and about 0.01 to about 5 mol, preferably about 0.01 to 5 mol, more preferably 0.05 to about 1 mol, per mol of the magnesium compound.

As the titanium compound in the liquid state to react with the magnesium compound in the solid particle state in step (c), a _tetravalent titanium compound having the general formula Ti (OR) _m X _4-m (wherein R is an alkyl group having 1 to 10 carbon atoms, X represents a halogen atom, and m is a number of 0 ≦ m ≦ 4). Examples of such titanium compounds include titanium tetrahalides such as TiCl ₄ , TiBr ₄ and TiI ₄ , Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (OC ₄ H ₉ ) Cl ₃ , Ti ( Trihalogenated alkoxytitanium such as OC ₂ H ₅ ) Br ₃ and Ti (O (iC ₂ H ₅ )) Br ₃ , Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (OC ₄ H _{9) 2} Cl ₂ and Ti (OC ₂ H _{5) 2} is halogenated alkoxy titanium such as _{Br 2, Ti (OCH 3)} 3 Cl, Ti (OC 2 H 5) 3 Cl, Ti (OC 4 H 9) Monohalogenated alkoxytitaniums such as ₃ Cl and Ti (OC ₂ H ₅ ) ₃ Br, tetraalkoxytitanium mixtures such as Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (OC ₄ H ₉ ) ₄ , etc. There is this. Among these halogen-containing titanium compounds, titanium halides are preferred, and titanium tetrachloride is particularly preferred among titanium tetrahalides.

Such titanium compounds are used in an amount of at least 1 mole, typically 3 to about 200 moles, preferably about 5 to 100 moles, per mole of magnesium compound. When contacting the magnesium compound with the liquid titanium compound, it is advisable to mix at a low temperature and then slowly increase the reaction temperature. For example, the two compounds are brought into contact with each other at -70 ° C to about 50 ° C to prevent them from reacting rapidly.The reaction is slowly raised to a sufficient time at a temperature of 50 to 150 ° C. Wash with free hydrocarbons until no free titanium is detected. By the catalyst production method, a solid titanium catalyst having excellent performance can be prepared.

The solid titanium catalyst used in the present invention preferably has a molar ratio of halogen / titanium of about 4 or more and substantially does not liberate the titanium compound by hexane washing at room temperature. Preferred examples of solid titanium catalysts are those in which the molar ratio of halogen / titanium is at least about 4, more preferably at least about 5 and most preferably at least about 8. The molar ratio of magnesium / titanium is about 3 or more, preferably about 5 to about And a molar ratio of electron donor / titanium is from about 0.2 to about 6, preferably from about 0.4 to about 3, more preferably from about 0.8 to about 2. Furthermore, the specific surface area of the solid is at least 10 m 2 / g, preferably at least about 50 m 2 / g, more preferably at least 100 m 2 / g.

The X-ray spectrum of the solid titanium catalyst preferably exhibits amorphous properties irrespective of the starting magnesium, or is more amorphous than the commercial grade of conventional magnesium halides.

In order to prepare the prepolymerization catalyst used in the present invention, the above-mentioned solid complex titanium catalyst is first surface treated with a silane compound having two or more vinyl groups. Examples of the divinyl silane compound used at this time include divinyl dimethyl silane, divinyl diphenyl silane, divinyl diethyl silane, divinyl diisobutyl silane, divinyl dihydride silane and the like. In the case of surface treatment, these materials use an amount of 2 to 200 moles per mole of magnesium compound. The reaction of the solid titanium catalyst with these surface treatment materials is carried out by contacting the two compounds between -50 and 50 ° C., and the two materials can be reacted with or without a solvent.

In order to manufacture the prepolymerization catalyst used in the present invention, prepolymerization is performed on the solid titanium catalyst surface-treated as described above. In the prepolymerization step, when the olefin monomer and the diene compound are reacted at -50 to 50 ° C in the presence of the surface-treated solid titanium catalyst, aluminum alkyl and electron donor, the double-bonded compounds and olefin monomer surface-treated on the catalyst And diene compounds react together to polymerize high molecular weight monomers on the surface of the catalyst. These high molecular weight monomers consist of olefins, double bond-containing silane-based materials and diene compounds, which encapsulate the catalyst surface. The composition of the olefin, diene, and silane-based materials in the high molecular weight monomer thus produced is 1 to 99% by weight of olefin, 0.01 to 10% by weight of diene, and 0.001 to 1% by weight of silane material. Among these, it is preferable that 70 to 95 weight% of olefins, 0.1 to 5 weight% of dienes, and 0.01 to 1 weight% of silane materials. In this case, at least one selected from ethylene, propylene, 1-butene, 1-hexene, and 1-octene is used as the olefin monomer, and as the diene-based material, 1,3-butadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 1,13- tetradecadiene, etc. are mentioned.

The molecular weight of the high molecular weight monomer is preferably in the range of 500 to 100,000. Among them, the polymer having excellent polymerization capacity in the main polymerization is in the range of 1,000 to 10,000 molecular weight.

The prepolymerization catalyst of the present invention prepared as above is advantageous for the polymerization of olefins such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, vinylcycloalkane or cycloalkene Used. In particular, these catalysts are suitable for the polymerization of α-olefins having three or more carbon atoms, copolymerization of each other, copolymerization of these with less than 20 mol% of ethylene, and those having polyunsaturated compounds such as conjugated or unconjugated dienes. It is advantageously applied to the copolymerization of.

The prepolymerization catalyst for olefin polymerization of the present invention has excellent catalytic activity compared to the conventional titanium catalyst, has a wide molecular weight distribution, enables the polymerization of polymers having high stereoregularity, and forms long branches in polyolefins. There is a characteristic.

The olefin polymerization process according to the invention is characterized in that the olefin is polymerized or copolymerized in the presence of a catalyst system consisting of the following components (A), (B) and (C):

(A) A high molecular weight monomer obtained by prepolymerization of an olefin and a diene compound with the above-mentioned prepolymerization catalyst, ie, a solid titanium catalyst having as its essential component a magnesium compound, a titanium compound, an electron donor and a silane compound having two or more double bonds. Encapsulated prepolymerization catalyst

(B) organometallic compounds of Group I or Group III metals of the periodic table; and

(C) External electron donor.

As the organometallic compound (B) used as a promoter in the polymerization method of the present invention, specifically, trialkylaluminum such as triethylaluminum and tributylaluminum, trialkylaluminum such as triisoprenylaluminum, partially alkoxylated Alkyl aluminum such as dialkyl aluminum alkoxide such as diethyl aluminum ethoxide and dibutyl aluminum butoxide, alkyl aluminum sesquihalide and ethyl such as ethyl aluminum sesquiethoxide and butyl aluminum sesquiethoxide Alkyl aluminum dihalides such as aluminum dichloride, propyl aluminum dichloride and butyl aluminum dibromide, partially halogenated aluminum, for example aluminum hydride and dibutyl aluminum hydride such as diethyl aluminum hydride or dibutyl aluminum hydride Dialkylaluminum Particularly alkoxylated and halogenated alkylaluminums such as dry, ethylaluminum ethoxychloride, butylaluminum butoxychloride and ethylaluminum ethoxybromide belong.

As the external electron donor (C) used in the polymerization method of the present invention, an external electron donor material commonly used for olefin polymerization may be used. These external electron donors are mainly used to optimize the activity and stereoregularity of the catalyst in the polymerization of olefins. Examples of external electron donors usable in the present invention include organic acids, organic acid anhydrides, organic acid esters, alcohols, ethers, aldehydes, ketones, silanes, amines, amine oxides, amides, diols, oxygen such as phosphate esters, silicon, nitrogen, sulfur And organic compounds containing phosphorus atoms and mixtures thereof. Particularly preferred external electron donors are organosilicon compounds with alkoxy groups, i.e., alkoxy silane compounds, and their kinds include aromatic silanes such as diphenyldimethoxysilane, phenyltrimethoxysilane, phenylethyldimethoxysilane and phenylmethyldimethoxysilane. , Isobutyltrimethoxysilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane, di-t-butyldimethoxysilane, t-butyltrimethoxysilane, cyclohexylmethyldimethoxysilane, dicyclopentyldimeth Aliphatic silanes such as methoxysilane, dicyclohexyldimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, vinyltriethoxysilane, and mixtures thereof, and particularly the silane compounds described above. Of these, branched alkyl dialkoxysilanes such as diisobutyldimethoxysilane and cycloalkyl dialkoxysilanes such as dicyclopentyldimethoxysilane are effective. The compounds may be used alone or in combination of two or more thereof.

When the polymerization method of the present invention is carried out in a liquid phase, an inert solvent such as hexane, heptane or kerosene may be used as the reaction medium, but the olefin itself may serve as the reaction medium. In the case of liquid phase polymerization, the preferred concentration of prepolymerization catalyst (A) in the polymerization reaction system is from about 0.001 to about 5 mmol, preferably from about 0.001 to about 0.5 mmol, calculated as titanium atoms for 1 L of solvent. In the case of gas phase polymerization, the amount of prepolymerization catalyst (A), calculated as titanium atom, is about 0.001 to about 5 mmol, preferably about 0.001 to about 1.0 mmol, more preferably 0.01 to about 0.5, per liter of the polymerization zone. It is good to set it as mmol. The ratio of organometallic atoms in component (B) is preferably about 1 to 2,000 mol, preferably about 5 to 500 mol, per mole of titanium atoms in catalyst (A), and the proportion of external electron donor component (C) is nitrogen. Or about 0.001 to 10 mol, preferably about 0.01 to 2 mol, particularly preferably 0.05 to 1 mol per mole of organometallic atom in component (B) calculated as silicon atoms.

The polymerization or copolymerization of olefins in the presence of the catalyst system of the present invention proceeds in the same way as in the polymerization of olefins using conventional Ziegler-type catalysts. In particular, it is carried out substantially in the absence of oxygen and water. The polymerization of the olefins may preferably be carried out at a temperature of about 20 to 200 ° C., more preferably at a temperature of about 50 to 180 ° C. and a pressure of atmospheric pressure to 100 atmospheres, preferably at a pressure of about 2 to 50 atmospheres. This polymerization can be carried out batchwise, semibatch or continuously, and it is also possible to carry out the polymerization in two or more stages with different reaction conditions.

Polyolefins, for example, polypropylene prepared according to the present invention generally have a melt index of 0.1 to 50 g / 10 minutes, a molecular weight distribution of 3 to 20 measured by gel permeation chromatography (GPC), and a polypropylene resin. The total polymer content is made from 0.001 to 30 parts by weight based on 100 parts by weight.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, these examples are for illustrative purposes only, and the present invention is not limited to these examples.

Example

Example 1

Preparation of Prepolymerization Catalyst (A)

Step 1: Preparation of Magnesium Compound Solution

A mixture of 15 g of MgCl ₂ , AlCl ₃ , and 550 ml of toluene was added to a 1.0 liter reactor equipped with a mechanical stirrer, which was replaced with a nitrogen atmosphere, stirred at 400 rpm, followed by 30 ml of tetrahydrofuran, 28 ml of butanol, 1.4 ml of ethanol, and silicon. 1.5 mL of tetraethoxide and 3.0 mL of tributyl phosphate were added thereto, and the temperature was raised to 105 ° C to react for 4 hours. The homogeneous solution obtained after the reaction was completed was cooled to room temperature.

Step 2: preparing a solid carrier

The magnesium solution prepared in step 1 was transferred to a 1.6 L reactor maintained at 13 ° C. After stirring was maintained at 350 rpm, 15.5 mL of TiCl ₄ was added thereto, and the temperature of the reactor was raised to 90 ° C. Solid carriers are produced during this process. The reaction was continued at 90 ° C. for 1 hour and then stirring was stopped to allow precipitation of the resulting solid support. After the precipitation was completed, the solid carrier from which the supernatant was separated was washed twice with 75 ml of toluene.

Step 3: Preparation of Solid Titanium Catalyst

100 mL of toluene and 100 mL of TiCl _{4 were} added to the solid carrier, and the temperature of the reactor was raised to 110 ° C. and heated for 1 hour. After the stirring was stopped, the solid carrier was precipitated, the supernatant was separated, 100 ml of toluene and 100 ml of TiCl ₄ were added thereto, and 2.9 ml of diisobutyl phthalate was added at 70 ° C. The temperature of the reactor was again raised to 120 ° C. and stirred for 1 hour. After the stirring was stopped, the supernatant was separated, 100 ml of toluene was injected, and the temperature of the reactor was lowered to 70 ° C. and stirred for 30 minutes. After stopping the reactor stirring and separating the supernatant, 100 ml of TiCl ₄ was injected and stirred at 70 ° C. for 30 minutes to prepare a solid titanium catalyst.

Step 4: surface treatment of solid titanium catalyst

The solid titanium catalyst prepared above was washed five times with 75 ml of purified hexane, and 500 ml of hexane and 50 ml of divinyldimethylsilane were added and reacted at room temperature for 1 hour. The prepared catalyst was stored after drying in a nitrogen atmosphere. The surface treated solid titanium catalyst contained 2.5% by weight of titanium atoms.

Step 5: prepolymerization

After washing the high-pressure reactor with a capacity of 0.5 L with propylene, 2 g of the catalyst obtained in step 4, 300 ml of hexane, 0.5 mmol of cyclohexylmethyldimethoxysilane, 6 mmol of triethylaluminum, and 20 ml of octadiene were added thereto, The pressure was adjusted and polymerization was carried out at 20 ° C. for 5 hours. In the prepolymerization catalyst thus obtained, the amount of the high molecular weight monomer polymerized around the catalyst was 55.0 g per 1 g of the catalyst.

polymerization

The high-pressure reactor with a capacity of 2 L was washed with propylene, and then loaded into the reactor with 20 mg of the prepolymerized catalyst prepared above in a glass bottle, and then the reactor was repeated three times in a nitrogen / vacuum state and brought to atmospheric pressure. 7 mmol of triethylaluminum, 0.5 mmol of dicyclopentyldimethoxysilane and 0.5 mmol of diisopropyldimethoxysilane were injected into the reactor. Again, 300Nml of hydrogen was added, and then 1,200ml of liquid propylene was added, and then the temperature was raised to 65 ° C while the reactor was stirred, and polymerization was performed for 1 hour.

After the polymerization reaction was completed, the unreacted gas was discharged, the temperature was cooled to room temperature, and the reactor was desorbed. The resulting polymer was collected separately and dried in a vacuum oven at 50 ° C. for at least 6 hours to obtain a white polymer.

Property analysis

The polypropylene resin thus obtained was put into a PCG30 twin-screw kneading extruder and injected with Samsung antioxidant in Samsung Kleukner FCM-110 (cutting force = 110 tons) to prepare a specimen specified in the ASTM standards and measured its physical properties. The results are shown in Table 1.

Test conditions for each test property are as follows.

(1) Melt Index

According to ASTM D1238, it measured by 2.16 kg load at 230 degreeC.

(2) flexural modulus

It measured according to ASTM D790.

(3) Izod impact strength

It measured at 23 degreeC based on ASTMD256.

(4) heat deflection temperature

It was measured under reduced weight (4.6 kg) according to ASTM D648.

Example 2

In preparing the prepolymerization catalyst, the polymerization was carried out in the same manner as in Example 1 except that the polymerization time was 3 hours, and the amount of the high molecular weight monomer polymerized around the catalyst was 30.0 g per 1 g of the catalyst.

Example 3

In preparing the prepolymerization catalyst, the same procedure as in Example 1 was carried out except that the diene material was used in 20 ml of hexadiene.

Comparative Example 1

The physical properties of the prepared polymer were measured in the same manner as in Example 1 except that the prepolymerization process of the high molecular weight monomer was not performed in preparing the catalyst.

Table 1.

Example Comparative example One 2 3 One Properties Melt Index (g / 10 min) 4 3 4 3 Flexural Strength (kgf / cm ² ) 560 555 495 500 Flexural modulus (kgf / cm ² ) 18,500 18,500 16,300 16,500 Izod impact strength (kg cm / cm) 5.8 5.0 4.8 3 Heat deflection temperature (℃) 122 119 118 110 Hardness (R-scale) 99 100 97 95

As can be seen from the above examples and comparative examples, according to the polymerization method using the prepolymerization catalyst of the present invention, compared with the conventional polymerization method using a catalyst, the stiffness, resistance of polypropylene without significant change in polymerization activity It can be confirmed that the result has greatly increased impact resistance and heat resistance.

Claims (10)

An olefin polymerization method characterized in that the polymerization is carried out using a prepolymerization catalyst prepared by a method comprising the following steps, wherein a high molecular weight monomer is encapsulated around a catalyst. (i) surface treating the solid titanium catalyst for olefin polymerization with a silane compound having two or more vinyl groups; (ii) the surface treated solid titanium catalyst in olefin monomer and 1,3-butadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, or 1,13-tetradecadiene Prepolymerizing one or more diene compounds selected. The olefin polymerization method according to claim 1, wherein the solid titanium catalyst is prepared by a method comprising the following steps: (a) dissolving a non-reducing magnesium compound in an electron donor to prepare a magnesium compound solution; (b) reacting the magnesium compound solution with a transition metal compound, silicon compound, tin compound or a mixture thereof to precipitate solid particles; And (c) reacting the precipitated solid particles with the titanium compound and the electron donor. The silane compound having two or more vinyl groups is divinyl dimethyl silane, divinyl diphenyl silane, divinyl diethyl silane, divinyl diisobutyl silane or divinyl dihydride silane. Olefin polymerization method. The method of claim 1, wherein the amount of the silane compound having two or more vinyl groups is used in the olefin polymerization method, characterized in that 2 to 200 moles per one mole of the magnesium compound. The olefin polymerization method according to claim 1, wherein the olefin monomer used in the prepolymerization step is at least one selected from ethylene, propylene, butene, 1-hexene or 1-octene. The high molecular weight monomer encapsulated around the catalyst has a weight average molecular weight in the range of 500 to 100,000, 1 to 99% by weight of olefin, 0.01 to 10% by weight of diene, and 0.001 to 1 of silane-based material. Olefin polymerization method, characterized in that consisting of. The olefin polymerization process according to any one of claims 1 to 6, wherein the following components are used together with the prepolymerization catalyst (A): (B) organometallic compounds of Group I or Group III metals of the periodic table; and (C) External electron donor. The olefin polymerization method according to claim 7, wherein the organometallic compound of component (A) is trialkylaluminum. 8. The method for olefin polymerization according to claim 7, wherein the external electron donor of component (C) is an alkoxysilane compound. It is polymerized by the method of Claim 7, the melt index is 0.1-50 g / 10min, the molecular weight distribution measured by the gel permeation chromatography (GPC) is 3-20, and the total polymer content is 100 parts by weight of polypropylene resin. Polypropylene resin, characterized in that consisting of 0.001 to 30 parts by weight.