KR20120132899A

KR20120132899A - A solid catalyst for propylene polymerization and a method for preparation of polypropylene using the same

Info

Publication number: KR20120132899A
Application number: KR1020110051292A
Authority: KR
Inventors: 김상열; 이진우; 김은일; 박준려
Original assignee: 삼성토탈 주식회사
Priority date: 2011-05-30
Filing date: 2011-05-30
Publication date: 2012-12-10
Also published as: KR101251801B1

Abstract

PURPOSE: A propylene polymerization solid catalyst is provided to obtain polypropylene with excellent tacticity with high polymerization activity and yield. CONSTITUTION: A propylene polymerization solid catalyst comprises titanium, magnesium, halogen, and cycloalkane-based internal electron donor indicated in chemical formula 2, 3 or 4. In the chemical formulas, R1 and R2 are the same or different and is a C1-20 linear, branched, or cyclic alkyl group, alkenyl group, aryl group, arylalkyl group or alkylaryl group. The solid catalyst comprises 5-40 weight% of magnesium, 0.5-10 weight% of titanium, halogen, and 2.5-30 weight% of an inner electron donor.

Description

Solid Catalyst for Propylene Polymerization and Polypropylene Production Method Using the Same

The present invention relates to a solid catalyst for propylene polymerization and a polypropylene production method using the same, and more particularly, to a solid catalyst for propylene polymerization and a propylene polymerization method using the same, capable of polymerizing polypropylene having excellent stereoregularity with high yield. It is about.

Polypropylene is an industrially useful material, and has been widely applied to various applications, particularly for materials related to automobiles and electronic products. In order to further expand the application of polypropylene, it is important to improve the stiffness by increasing the crystallinity, and at the same time, to increase the molecular weight distribution to have excellent processability. To this end, the solid catalyst should be designed to exhibit high stereoregularity.

In the polymerization of olefins such as propylene, solid catalysts containing magnesium, titanium, an electron donor and halogen as essential components are known. A catalyst system comprising the solid catalyst and an organoaluminum compound and an organosilicon compound is used to polymerize or copolymerize olefins There are many suggestions to make. However, this method is not satisfactory enough to obtain high stereoregular polymers in high yield, and improvements are required in this respect.

On the other hand, it is generally known to use a diester of an aromatic dicarboxylic acid as an internal electron donor in order to lower the cost by increasing the catalytic activity and to improve the physical properties of the polymer by improving the catalytic performance such as stereoregularity , And patents related thereto were filed. US Pat. No. 4,562,173, US Pat. No. 4,981,930, Korean Patent No. 0072844, and the like can be exemplified, and these patents use high-activity, high stereoregularity by using aromatic dialkyl diesters or aromatic monoalkyl monoesters. The catalyst production method which expresses is introduced.

However, the method of the above patents is not satisfactory enough to obtain high stereoregular polymers in high yield and requires improvement.

Korean Patent No. 0491387 discloses a catalyst preparation method using a non-aromatic diether material, and Korean Patent No. 0572616 a non-aromatic material having both a ketone and an ether functional group as an internal electron donor. However, both methods have room for significant improvement in terms of both activity and stereoregularity.

The present invention has been made to solve the above problems, the problem to be solved of the present invention is to use a polyalkaline-based internal electron donor having two or more rings, high stereoregular polypropylene It is an object of the present invention to provide a solid catalyst for propylene polymerization and a polypropylene production method using the same.

In order to solve the above problems, the solid catalyst of the present invention includes a titanium, magnesium, a halogen and a cycloalkane-based internal electron donor represented by the following general formula (II), general formula (III) or general formula (IV) It is characterized by:

... ... (II)

... ... (III)

... ... (IV)

Here, R ₁ and R ₂ are the same as or different from each other, and are a linear, branched or cyclic alkyl group, alkenyl group, aryl group, arylalkyl group or alkylaryl group having 1 to 20 carbon atoms.

Examples of the cycloalkane-based compounds having two or more rings represented by the general formulas (II), (III) and (IV) include dimethyl decahydronaphthalene-2,3-dicarboxylate. , Diethyl decahydronaphthalene-2,3-dicarboxylate, dipropyldecahydronaphthalene-2,3-dicarboxylate, dibutyldecahydronaphthalene-2,3-dicarboxylate, dihexyldecahydro Naphthalene-2,3-dicarboxylate, dioctyldecahydronaphthalene-2,3-dicarboxylate, diisopropyldecahydronaphthalene-2,3-dicarboxylate, diisobutyldecahydronaphthalene-2 , 3-dicarboxylate, dimethyl bicyclo [4.1.0] heptane-3,4-dicarboxylate, diethyl bicyclo [4.1.0] heptane-3,4-dicarboxylate, dipropyl bike Rho [4.1.0] heptane-3,4-dicarboxylate, dibutyl bicyclo [4.1.0] heptane-3,4-dicarboxylate, dihex Bicyclo [4.1.0] heptane-3,4-dicarboxylate, dioctyl bicyclo [4.1.0] heptane-3,4-dicarboxylate, diisopropyl bicyclo [4.1.0] heptane- 3,4-dicarboxylate, diisobutyl bicyclo [4.1.0] heptan-3,4-dicarboxylate, dimethyl tricyclooctane-3,4-dicarboxylate, diethyl tricyclooctane- 3,4-dicarboxylate, dipropyl tricyclooctane-3,4-dicarboxylate, dibutyl tricyclooctane-3,4-dicarboxylate, dihexyl tricyclooctane-3,4-dica Carboxylate, dioctyl tricyclooctane-3,4-dicarboxylate, diisopropyl tricyclooctane-3,4-dicarboxylate, diisobutyl tricyclooctane-3,4-dicarboxylate Etc.

The solid catalyst of the present invention as described above may be prepared by a manufacturing method preferably comprising the following steps:

(1) reacting a dialkoxymagnesium with a titanium halide in the presence of an organic solvent;

(2) having two or more rings represented by the general formula (II), general formula (III) or general formula (IV) in the resultant of step (1) while heating up at a temperature of 60-150 ° C; Reacting by adding at least one selected from a cycloalkane compound; And

(3) reacting the result of step (2) with titanium halide at a temperature of 60 to 150 ° C, and washing the resultant.

As the organic solvent used in the step (1), there is no particular limitation on the kind, and C6-C12 aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, etc. may be used, and more preferably C7-C10 saturated aliphatic compounds. Or aromatic hydrocarbons or halogenated hydrocarbons, and specific examples thereof may be used alone or in combination of one or more selected from octane, nonane, decane, toluene and xylene, chlorobutane, chlorohexane, chloroheptane and the like. have.

The dialkoxymagnesium used in the step (1) is spherical particles having an average particle size of 10 to 200 탆 obtained by reacting metallic magnesium with anhydrous alcohol in the presence of magnesium chloride and having a smooth surface, If the average particle diameter is less than 10 mu m, the fine particles of the prepared catalyst are undesirably increased. When the average particle diameter exceeds 200 mu m, the apparent density tends to be small, which is not preferable.

The use ratio of the organic solvent to the dialkoxymagnesium is preferably 1: 5 to 50, more preferably 1: 7 to 20, by weight of dialkoxymagnesium weight: organic solvent, : If the ratio is less than 5, the viscosity of the slurry increases sharply, which makes uniform stirring difficult, which is undesirable. When the ratio exceeds 1:50, the bulk density of the resulting carrier decreases rapidly or the particle surface becomes rough.

The titanium halide used in step (1) in the production of the solid catalyst is preferably represented by the following general formula (I)

Ti (OR) _a X _(4-a) ‥‥‥ (I)

Here, R is an alkyl group of 1 to 10 carbon atoms, X is a halogen element, and a is an integer of 0 to 3 for matching the valency of the general formula. As the titanium halide, titanium tetrachloride is preferably used.

The reaction in step (1) of the solid catalyst production process is preferably carried out by slowly adding a titanium halide in the temperature range of -20 ~ 50 ℃.

The amount of titanium halide used at this time is preferably 0.1 to 10 moles, more preferably 0.3 to 2 moles with respect to 1 mole of dialkoxymagnesium. If it is less than 0.1 mole, the reaction of dialkoxymagnesium to magnesium chloride is smooth. It is not preferable because it does not proceed, and exceeding 10 moles is not preferable because excessively many titanium components are present in the catalyst.

In the step (2), the temperature of the resultant product of step (1) is gradually raised to 60 to 150 ° C, preferably 80 to 130 ° C, and the internal electron donor is added during the temperature raising process to react for 1 to 3 hours If the temperature is less than 60 ° C or the reaction time is less than 1 hour, the reaction is difficult to be completed. If the temperature exceeds 150 ° C or the reaction time exceeds 3 hours, the polymerization reaction of the resultant catalyst Or the stereoregularity of the polymer may be lowered.

As long as the internal electron donor is charged during the temperature raising process, the charging temperature and the number of times of charging are not limited, and the total amount of the internal electron donor is 0.1 to 1.0 mol based on 1 mol of dialkoxymagnesium used However, if it is outside the above range, the polymerization activity of the resultant catalyst or the stereoregularity of the polymer may be lowered, which is not preferable.

Step (3) of the production of the solid catalyst is a step of reacting the resultant of step (2) with titanium halide in a second order at a temperature of 60 to 150 ° C, preferably 80 to 130 ° C. An example of the titanium halide to be used at this time is titanium halide of the above-mentioned general formula (I).

In the production process of the solid catalyst, the reaction in each step is preferably carried out in a reactor equipped with a stirrer in which water and the like are sufficiently removed in a nitrogen gas atmosphere.

The solid catalyst of the present invention prepared by the above method comprises magnesium, titanium, halogen and internal electron donor, and considering the catalytic activity, 5 to 40% by weight magnesium, 0.5 to 10% by weight titanium %, 50 to 85% by weight of halogen and 2.5 to 30% by weight of internal electron donor.

The solid catalyst of the present invention may be suitably used in the production method of polypropylene, and the polypropylene production method using the solid catalyst prepared according to the present invention may polymerize propylene in the presence of the solid catalyst, the promoter and the external electron donor. Copolymerizing propylene with other alphaolefins.

The solid catalyst can be used in the prepolymerized state with ethylene or alpha olefin before being used as a component of the polymerization reaction.

The prepolymerization reaction can be carried out in the presence of a hydrocarbon solvent (e.g. hexane), the catalyst component and an organoaluminum compound (e.g. triethylaluminum) at sufficiently low temperatures and under ethylene or alpha olefin pressure conditions. Pre-polymerization helps encapsulate the catalyst particles in the polymer to maintain the shape of the catalyst to improve the shape of the polymer after polymerization. The weight ratio of polymer / catalyst after prepolymerization is preferably about 0.1 to 20: 1.

In the polypropylene production method of the present invention, as the cocatalyst component, an organometallic compound of Group II or Group III of the periodic table may be used. As an example, an alkylaluminum compound is preferably used. The alkylaluminum compound is represented by general formula (V):

AlR ₃ ‥‥‥ (Ⅴ)

Here, R is a C1-C6 alkyl group.

Specific examples of the alkylaluminum compound include trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, triisobutylaluminum and trioctylaluminum.

The ratio of the promoter component to the solid catalyst component is somewhat different depending on the polymerization method, but the molar ratio of metal atoms in the promoter component to titanium atoms in the solid catalyst component is preferably in the range of 1 to 1000, More preferably, it is good that it is the range of 10-300. If the molar ratio of the metal atom in the cocatalyst component to the titanium atom in the solid catalyst component, for example, the aluminum atom, is out of the above range of 1 to 1000, the polymerization activity is greatly reduced.

In the polypropylene production method of the present invention, one or more of the alkoxysilane compounds represented by the following general formula (VI) may be used as the external electron donor.

R ¹ _m R ² _n Si (OR ³ ) _(4-mn) ‥‥‥ (Ⅵ)

Wherein R ¹ and R ² may be the same or different and are a linear or branched or cyclic alkyl group or an aryl group having 1 to 12 carbon atoms, R ³ is a linear or branched alkyl group having 1 to 6 carbon atoms, and m , n is 0 or 1, respectively, and m + n is 1 or 2.

Specific examples of the external electron donor include, but are not limited to, n-propyltrimethoxysilane, dinormalpropyldimethoxysilane, isopropyltrimethoxysilane, diisopropyldimethoxysilane, n-butylbutyltrimethoxysilane, dinormalbutyldimethoxy Silane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, tertiarybutyltrimethoxysilane, ditertiarybutyldimethoxysilane, n-pentyltrimethoxysilane, dinormalpentyldimethoxysilane, cyclopentyltrimethoxy Silane, dicyclopentyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylpropyldimethoxysilane, cyclohexyltrimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldimethoxysilane, , Cyclohexylethyldimethoxysilane, cyclohexylpropyldimethoxysilane, cycloheptyltrimethoxysilane, dicycloheptyldimethoxysilane, cycloheptyl Methyldimethoxysilane, cycloheptylethyldimethoxysilane, cycloheptyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, phenylethyldimethoxysilane, phenylpropyldimethoxysilane, nalmal Propyltriethoxysilane, dinormalpropyldiethoxysilane, isopropyltriethoxysilane, diisopropyldiethoxysilane, n-butylbutyltriethoxysilane, dinormalbutyldiethoxysilane, isobutyltriethoxysilane, diisobutyl Diethoxy silane, tertiary butyl triethoxy silane, ditertiary butyl diethoxy silane, normal pentyl triethoxy silane, dinormal pentyl diethoxy silane, cyclopentyl triethoxy silane, dicyclopentyl diethoxy silane, cyclopentyl methyl Diethoxysilane, cyclopentylethyldiethoxysilane, cyclopentylpropyldiethoxysilane, cyclohexyltriethoxysilane, dicyclohexyldiethoxysilane , Cyclohexyl methyl diethoxy silane, cyclohexyl ethyl diethoxy silane, cyclohexyl propyl diethoxy silane, cycloheptyl triethoxy silane, dicycloheptyl diethoxy silane, cycloheptyl methyl diethoxy silane, cycloheptyl ethyl diethoxy silane, Cycloheptylpropyl diethoxysilane, phenyltriethoxysilane, diphenyl diethoxysilane, phenylmethyl diethoxysilane, phenylethyl diethoxysilane and phenylpropyl diethoxysilane, and the like. Can be.

Although the amount of the external electron donor to be used for the solid catalyst varies depending on the polymerization method, the molar ratio of the silicon atoms in the external electron donor to the titanium atom in the catalyst component is preferably in the range of 0.1 to 500, more preferably 1 to 100 Is more preferable. If the molar ratio of the silicon atom in the external electron donor to the titanium atom in the solid catalyst component is less than 0.1, the resulting stereoregularity of the resulting propylene polymer becomes significantly low, and if it exceeds 500, the polymerization activity of the catalyst is significantly reduced .

In the above-mentioned propylene polymerization or copolymerization method, the polymerization reaction temperature is preferably 20 to 120 ° C. If the polymerization reaction temperature is less than 20 ° C, the reaction does not proceed sufficiently, which is not preferable. It is undesirable because it causes considerable deterioration and adversely affects the physical properties of the polymer.

By using the solid catalyst of the present invention and the polypropylene production method using the same, it is possible to produce polypropylene having excellent stereoregularity with high yield.

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

[ Example ]

Example One

1. Preparation of solid catalyst

Into a glass reactor equipped with a 1 liter stirrer sufficiently substituted with nitrogen, 150 ml of toluene and 20 g of diethoxy magnesium (a sphere having an average particle diameter of 20 µm, having a particle size distribution index of 0.86 and an apparent density of 0.35 g / cc) were charged. 40 ml of titanium tetrachloride was diluted in 60 ml of toluene and added over 1 hour while maintaining the temperature at 10 ° C. Then, 6.9 g of dibutyl tricyclooctane-3,4-dicarboxylate was added while raising the temperature of the reactor to 110 ° C. Injected. After holding at 110 ° C. for 2 hours, the temperature was lowered to 90 ° C. to stop stirring, the supernatant was removed, and further washed once with 200 ml of toluene. 150 ml of toluene and 50 ml of titanium tetrachloride were added thereto, and the temperature was raised to 110 ° C. and maintained for 2 hours. The aged slurry mixture thus obtained was washed twice with 200 ml of toluene per one time and washed with n-hexane at 40 ° C for five times with 200 ml each time to obtain a pale yellow solid catalyst component. The titanium content in the solid catalyst component obtained by drying for 18 hours in flowing nitrogen was 2.7% by weight.

2. Polymerization of polypropylene

10 mg of the above solid catalyst, 6.6 mmol of triethylaluminum and 0.66 mmol of cyclohexylmethyldimethoxysilane were charged into a 4-liter high-pressure stainless steel reactor. Subsequently, 1000 ml of hydrogen and 2.4 L of liquid propylene were added in sequence, and then the temperature was raised to 70 ° C to perform polymerization. After 2 hours after the start of the polymerization, the temperature of the reactor was lowered to room temperature, and the valve was opened to completely degas the propylene in the reactor.

The resulting polymer was analyzed and is shown in Table 1.

Here, catalytic activity and stereoregularity were determined by the following method.

① Catalyst activity (kg-PP / g-cat) = amount of polymer produced (kg) ÷ amount of catalyst (g)

(2) Stereoregularity (XI): Weight% of insoluble matter crystallized and crystallized in mixed xylene

Example 2

Example 1 1. In the preparation of the solid catalyst, 5.7 g of diethyl tricyclooctane-3,4-dicarboxylate was used instead of 6.9 g of dibutyl tricyclooctane-3,4-dicarboxylate. Catalyst was prepared. The titanium content in the solid catalyst component was 2.5% by weight. Next, polypropylene polymerization was carried out in the same manner as in Example 1, and the results are shown in Table 1.

Example 3

Example 1 1. In the preparation of the solid catalyst, diethyl bicyclo [4.1.0] heptane-3,4-dicarboxylate instead of 6.9 g of dibutyl tricyclooctane-3,4-dicarboxylate The catalyst was prepared using 5.4 g. The titanium content in the solid catalyst component was 2.9% by weight. Next, polypropylene polymerization was carried out in the same manner as in Example 1, and the results are shown in Table 1.

Example 4

In polypropylene polymerization of Example 1, polymerization was carried out using 0.66 mmol of dicyclopentyldimethoxysilane instead of 0.66 mmol of cyclohexylmethyldimethoxysilane, and the results are shown in Table 1.

Comparative example One

1. Preparation of solid catalyst

150 ml of toluene, 12 ml of tetrahydrofuran, 20 ml of butanol and 21 g of magnesium chloride were added to a glass reactor equipped with a stirrer having a volume of 1 liter sufficiently substituted with nitrogen, and the temperature was raised to 110 ° C and maintained for 1 hour to obtain a homogeneous solution. The temperature of the solution was cooled to 15 ° C., titanium tetrachloride 25 ml was added, and the temperature of the reactor was raised at 60 ° C. over 1 hour. After aging for 10 minutes, the mixture was left for 15 minutes to settle the carrier, and the upper solution was removed. It was. 200 ml of toluene was added to the slurry remaining in the reactor and washed twice by stirring, standing, and removing the supernatant.

After 150 ml of toluene was poured into the slurry thus obtained, 25 ml of titanium tetrachloride was diluted with 50 ml of toluene at 15 ° C and added over 1 hour. The temperature of the reactor was increased to 30 ° C at a rate of 0.5 ° C per minute. The reaction mixture was kept at 30 ° C. for 1 hour, after which 7.5 ml of diisobutyl phthalate was injected, and the temperature was further raised to 110 ° C. at a rate of 0.5 ° C. per minute.

After maintaining at 110 DEG C for 1 hour, the temperature was lowered to 90 DEG C and stirring was stopped, and the supernatant was removed, and further washed once with 200 mL of toluene in the same manner. 150 ml of toluene and 50 ml of titanium tetrachloride were added thereto, and the temperature was elevated to 110 ° C and maintained for 1 hour. After the aging process, the slurry mixture was washed twice with 200 ml of toluene 매 each time, and washed 5 times with 200 ml of hexane each time at 40 ° C. to obtain a pale yellow solid catalyst component. The titanium content in the solid catalyst component obtained by drying in flowing nitrogen for 18 hours was 3.3% by weight.

2. Polymerization of polypropylene

Polymerization was carried out in the same manner as in Example 1 using 10 mg of the above solid catalyst, and the results are shown in Table 1.

division Active (kg-PP / g-cat) Stereoregularity (wt.%) Example 1 37 97.7 Example 2 36 98.0 Example 3 31 97.4 Example 4 42 98.1 Comparative Example 1 26 97.3

As shown in Table 1, Examples 1 to 4 according to the present invention using a cycloalkane-based internal electron donor containing two or more rings, excellent stereoregularity and activity, while Comparative Example 1 It can be seen that the activity and stereoregularity are inferior.

Claims

A solid catalyst for propylene polymerization comprising titanium, magnesium, halogen and cycloalkane-based internal electron donors represented by the following general formula (II), general formula (III) or general formula (IV):

... ... (II)

... ... (III)

... ... (IV)
Here, R ₁ and R ₂ are the same as or different from each other, and are a linear, branched or cyclic alkyl group, alkenyl group, aryl group, arylalkyl group or alkylaryl group having 1 to 20 carbon atoms.

According to claim 1, wherein the solid catalyst is 5 to 40% by weight of magnesium, 0.5 to 10% by weight of titanium, 50 to 85% by weight of halogen and 2.5 to 30% by weight of the internal electron donor solid for propylene polymerization catalyst.

The solid catalyst according to claim 1 or 2, AlR ₃ (wherein R is an alkyl group having 1 to 6 carbon atoms) as cocatalyst and R ¹ _m R ² _n Si (OR ³ ) as an external electron donor ₍₄ ( _mn) wherein R ¹ and R ² may be the same or different and are linear or branched or cyclic alkyl groups having 1 to 12 carbon atoms, or aryl groups, and R ³ is linear or branched having 1 to 6 carbon atoms Alkyl group, m, n are each 0 or 1, m + n is 1 or 2), or a method for producing polypropylene, comprising copolymerizing propylene or copolymerizing propylene with another alphaolefin.