KR19990000189A - Catalysts for styrene polymerisation and the process of preparation thereof - Google Patents

Abstract

The polymer-catalysts of the present invention are used in the cyanide group of an irregular copolymer SAN (poly (styrene-co-acrylronitrile) of styrene and acrylronitrile). The polymer-catalyst includes a neutral polymer-catalyst and a cationic polymer-catalyst compound by reacting a compound of Group VIa, VIIa or VIIIa to form a complex. Dissolves the SAN in an organic solvent, reacts the solution with a transition metal compound of group IVa, Va, VIa, VIIa or VIIIa of the periodic table, separates the reaction solution into a solid layer and a liquid layer, and separates the separated solid layer into an organic solvent. And the washed catalyst is vacuum dried.

Description

[Name of invention]

Styrene polymerization catalyst and preparation method thereof

Detailed description of the invention

[Field of Invention]

The present invention relates to a compound of group IIIa, Va, VIa, VIIa or VIIIa of the periodic table with SAN (poly (styrene-co-acrylronitrile)), an irregular copolymer of styrene and acrylronitrile, for the polymerization of olefins. The present invention relates to polymer-catalysts prepared from the reaction More specifically, the present invention relates to an irregular copolymer of styrene and acrylronitrile for preparing syndiotactic polystyrene. The present invention relates to a process for preparing polymer-catalysts made from a reaction of a polystyrene-co-acrylronitrile (SAN) with a compound of group IVa, Va, VIa, VIIa or VIIIa of the periodic table and polymerization of styrene using the same.

[Background of invention]

Metallocene catalysts have been developed to prepare polyolefins having improved physical properties or polystyrenes having stereoregularity. Metallocene-based catalysts are metallized compounds consisting of transition metals of the Group IVb of the periodic table (eg titanium, zirconium, hafnium) and one or two cycloalkanedienyl groups [example : Cyclopentadienyl group (cyclopentadienyls), indenyl (indenyls), fluorenyl (fluorenyls)] ligand consisting of a sandwich structure. This type of metallocene catalyst is used in conjunction with a promoter. Cocatalysts used are, in addition to those used in conventional Ziegler-Natta catalysts, alkylaluminum oxane (eg, methylaluminum oxane), which is a reaction product of water and an alkylaluminum compound. The use of such metallocene catalysts has made it possible to produce stereoregular polystyrenes (e.g., syndiotactic polystyrenes or isotactic polystyrenes) and polypropylenes (isotactic polystyrenes), which have been impossible to date, and have very high molecular weight distribution. Narrow and improved properties of polyethylene can also be produced. In particular, Sandiotactic polystyrene is a structure in which the benzene rings in the polymer main chain are alternately positioned, unlike the conventional amorphous general purpose atactic polystyrene, and has a melting point of 270 ° C, which is excellent in heat resistance and mechanical properties. It has been a target.

European Patent Publication Nos. 210615 (1986) and 224096 (1986), US Patent Publication Nos. 5066741 (1991), 5237069 (1993), and 5206167 (1993), and PCT in particular Publication No. 88/10275 and 93/03067 disclose syndiotactic polystyrenes having stereoregularity, and cyclopentadienyl titanium trichloride and alkyl-substituted cyclopentadienyl titanium trichloride, i.e., pentamethylcyclo Pentadienyl titanium trichloride (pentamethylcyclopentadienyltrichlorotitanium) is disclosed.

However, current metallocene catalysts are not only very difficult to manufacture catalysts because they are manufactured through various organizations, but they are also expensive due to the need for many process equipment, and most catalysts are sensitive to air and moisture, making them difficult to handle. It has

In order to overcome the above problems, the present inventors have developed a novel polymer-catalyst capable of preparing styrene, particularly syndiotactic polystyrene.

[Purpose of invention]

An object of the present invention is to provide a catalyst for styrene polymerization having good catalytic activity.

Another object of the present invention is to provide a novel polymer-catalyst capable of producing syndiotactic polystyrene.

Another object of the present invention is to provide a method for preparing a novel polymer-catalyst and a method for polymerizing styrene using the same.

These and other objects can be achieved by the present invention described in detail below.

[Summary of invention]

The polymer-catalysts of the present invention are used in the cyanide group of an irregular copolymer SAN (poly (styrene-co-acrylronitrile) of styrene and acrylronitrile). , VIa, VIIa, or VIIIa compounds react to form a complex The polymer-catalyst includes a neutral polymer-cationic, cationic polymer-catalyst compound.

The polymer-catalyst of the present invention dissolves SAN in an organic solvent, reacts the solution with a transition metal compound of group IVa, Va, VIa, VIIa or VIIIa of the periodic table, and separates the reaction solution into a solid layer and a liquid layer, and The solid layer is prepared by washing with an organic solvent and vacuum drying the washed catalyst.

Detailed Description of the Invention

The transition metal compound of group IVa, Va, VIa, VIIa or VIIIa of the periodic table reacts with the cyanide group of the polymer-catalyst SAN [poly (styrene-co-acrylronitrile)] of the present invention. II) has a complex structure such as:

Where M is the periodic table IVa, (Ti, Zr, Hf), Va (V, Nb, Ta), VIa (Cr, Mo, W), VIIa (Mn Tc, Re) or VIIIa (Fe, Ru, Os, Rh , Ir, Ni, Pd, Pt), a transition metal, X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, or a combination thereof, m is an integer of 1 to 4 , N is an integer of 2 to 4, p and q are integers representing the statistical distribution according to the relative reactivity of the styrene and acrylonitrile monomers, Z is a non-coordinating anion, cyanide group Is an anion that is not coordinating or very weakly coordinating to the metal cation moiety included in the c), and thus preventing other Lewis bases from interacting with the metal part comprising the cyanide group of the cation. It is represented by ^{_{- [BQ 1 Q 2 Q 3}} Q 4]. Wherein B is boron in the valence trivalent state, and Q1, Q2, Q3, and Q4 are independently of each other a radical selected from the group consisting of hydrides, dialkylamido, alkoxides, aryloxides, hydrocarbonyls to be.

SAN which can be used in the present invention has a molecular weight of the polymer backbone range of 1,000 to 1,000,000, preferably 10,000 to 300,000. Or SAN is in the range of 1 to 99% by weight of acrylonitrile, preferably 5 to 50% by weight.

The polymer-catalyst of the present invention is prepared by the following method.

The polymer-catalyst of the present invention dissolves SAN in an organic solvent, reacts the solution with a transition metal compound of group IVa, Va, VIa, VIIa or VIIIa of the periodic table, and separates the reaction solution into a solid layer and a liquid layer, and The solid layer is prepared by washing with an organic solvent and vacuum drying the washed catalyst.

The reaction scheme wherein the SAN dissolved in the organic solvent reacts with the transition metal compound is represented by the following (III):

Wherein M, X, m, n, p and q are as defined above.

Examples of transition metal compounds when the transition metal is Group IVa include titanium tetrachloride (TiCl ₄ ), zirconium tetrachloride (ZrCl ₄ ), hafnium tetrachloride (HfCl ₄ ), and tetrafluorotitanium (chlorine or fluorine bonded to titanium, zirconium or hafnium). TiF ₄ ), tetrafluorozirconium (ZrF ₄ ), tetrafluorohafnium (HfF ₄ ), and the like.

The product produced in the reaction formula (III) is the catalyst of the formula (I), a non-coordinating anion Z is bonded to the compound of the formula (I) to prepare a catalyst of the formula (II).

When dissolving SAN in an organic solvent, representative examples of organic solvents that can be used are toluene and dichloromethane. When the SAN is reacted with the transition metal compound, a solid layer and a liquid layer are formed, at which time the liquid layer is separated and the solid layer is washed again with an organic solvent. Representative organic solvents that can be used at this time are hexane and toluene. The solvent washed with the organic solvent is vacuum dried to obtain a polymer-catalyst according to the present invention.

The polymer-catalyst of the above formula (I) prepared according to the present invention is usually used as a catalyst for polymerizing olefins on a support. In other words, the catalyst is prepared by directly supporting the compound of formula (I) on a dehydrated support. Examples of supports include silica, alumina, MgR ₂ , where R is alkyl, allyl, alkoxy, or halogen. MgRX [where R is alkyl, aryl or X Halogen, zeolite, aluminum phosphate, zirconia, and the like.

As a method of supporting the catalyst of the structural formula (I), the method of directly supporting the catalyst of the structural formula (I) and the surface of the carrier with aluminum, non-aluminum cocatalyst, or organometallic compound There is a method of supporting the catalyst of (I). In a non-aluminum co-catalyst used herein is _{[R 7 R 8 R 9 C} ] + [BQ 1 Q 2 Q 3 Q 4] - or _{[HNR 10 R 11 R 12 C} ] + [BQ 1 Q 2 Q 3 Q 4 ^- and a, R ₇ ~ R ₁₂ is hydrogen, alkyl, aryl, alkoxy, silyl or siloxy, as defined earlier, B and Q ₁ ~ Q _4.

The polymer-catalyst according to the present invention can be used together with an organometallic compound as a cocatalyst. Organometallic compounds that can be used here include alkylaluminoxanes or organoaluminum compounds. Representative examples of the alkylaluminoxane include methylaluminoxane (MAO) and modified methylaluminoxane (MMAO), and the organoaluminum compound is AlR _n X _3-n (where R is C _1-10) . Alkyl or aryl, X is halogen, n is an integer of 1, 2 or 3).

The polymer-catalyst of the present invention can be used as a catalyst for homopolymerization, copolymerization or trimer polymerization of styrene. Here, homopolymerization of styrene means polymerization by using monomers of styrene or styrene derivatives alone. Examples of styrene derivatives include α-methylstyrene, para-methylstyrene, α-chlorostyrene, para-chlorostyrene and the like. Copolymerization of styrene means the polymerization of two kinds of monomers selected from styrene, styrene derivatives, α-olefin monomers, and polar monomers. Examples of the α-olefin monomers include ethylene, propylene, butene, butadiene, polybutadiene, hexene and octene, and polar monomers include methyl methacrylate (MMA), acetonitrile (AN), vinyl acetate (VA), Vinyl chloride monomer (VCM) and the like. Trimer polymerization selects and polymerizes 3 types of monomer from a styrene, a styrene derivative, an alpha-olefin type monomer, and a polar monomer.

The amount of the polymerization catalyst is preferably 10 ^-7 to 10 ^-2 moles per liter of solvent, more preferably 10 ^-5 to 10 ^-4 moles. Styrene polymerization temperature is 0-100 degreeC, Preferably it is 30-80 degreeC.

The polymer-catalyst of the present invention can be more clearly understood by the following examples, which are only illustrative purposes of the present invention and are not intended to limit the scope of the invention.

EXAMPLE

Example 1 below is an example according to the present invention, and Comparative Examples 1-3 below are examples for comparison with Examples of the present invention.

Example 1

Representative of the polymer-catalysts according to the invention, for example, will be described as follows.

(1) Synthesis of SAN-TiCl ₄ Catalyst

SAN containing about 23% acrylonitrile

[Poly (styrene-co-acrylronitrile] compound (2 g, 4.335 mmol / g) was dissolved in an organic solvent (toluene; 200 mL), and the titanium tetrachloride (TiCl ₄ ) [16.5 mmol] compound was reacted at low temperature for about 10 hours. The liquid and solid phases were separated, and only the solid phase was taken up, washed with an organic solvent [toluene (100 mL × 2) and hexane (100 mL × 3), and vacuum dried to prepare a SAN-TiCl ₄ catalyst.

(2) Homopolymerization, copolymerization and trimer polymerization of styrene

Styrene polymerization was carried out in a glass reactor with an external thermostat, a magnetic stirrer and a valve capable of supplying monomers and nitrogen. After adding styrene to the nitrogen-substituted glass reactor, the required amount of cocatalyst MMAO was added, and then the required amount of catalyst was injected to carry out polymerization. After some time, a little methanol was added to terminate the polymerization. The resulting mixture was poured into a large amount of methanol added with hydrochloric acid to obtain a polymer, washed with water and methanol and dried in vacuo.

Other polymerizations were carried out under [Al] / [Ti] = 1000, 60 ° C., 2hrs, 50 mL of styrene for homopolymerization, 50 mL of styrene for copolymerization, 6.6 wt% of styrene in para-methylstyrene, In the case of trimer polymerization, 50 mL of styrene was polymerized, para-methylstyrene was 6.6 wtmℓ of styrene, and polybutadiene was polymerized under 2 wt% of styrene.

In the case of homopolymerization of the catalyst prepared according to Example 1, the catalytic activity and polystyrene stereoregularity, melting temperature, molecular weight and molecular weight distribution are shown in Table 1, and in case of copolymerization and trimer polymerization, catalytic activity and melting temperature, molecular weight molecular weight The distributions are shown in Tables 2 and 3.

Comparative Example 1

The polymerization was carried out under the same conditions as in Example 1 except that pentamethylcyclopentadienyltitanium trichloride (CpTiCl ₃ ) was used as the styrene polymerization catalyst.

In the case of styrene homopolymerization according to Comparative Example 1, catalytic activity and polystyrene stereoregularity, melting temperature, molecular weight and molecular weight distribution are shown in Table 1, and in case of copolymerization and trimer polymerization, catalytic activity and melting temperature, molecular weight and molecular weight The distributions are shown in Tables 2 and 3.

Comparative Example 2

The polymerization was carried out under the same conditions as in Example 1, except that indenyl titanium trichloride (IndTiCl ₃ ) was used as the styrene polymerization catalyst.

In the case of styrene homopolymerization according to Comparative Example 3, catalytic activity and polystyrene stereoregularity, melting temperature, molecular weight and molecular weight distribution are shown in Table 1, and in the case of copolymerization and trimer polymerization, catalytic activity and melting temperature, molecular weight and molecular weight distribution Are shown in Table 2 and Table 3.

Comparative Example 3

The polymerization was carried out under the same conditions as in Example 1 except that pentamethylcyclopentadienyltitanium trichloride (Cp * TiCl ₃ ) was used as the styrene polymerization catalyst.

The catalytic activity and polystyrene stereoregularity, melting temperature, molecular weight, and molecular weight distribution for styrene homopolymerization by comparative chamber 1 are shown in Table 1, and catalytic activity and melting temperature, molecular weight and molecular weight distribution for copolymerization and trimer polymerization. Are shown in Table 2 and Table 3.

TABLE 1

TABLE 2

TABLE 3

The structures of the catalysts shown in Tables 1, 2, and 3 were examined by hydrogen and carbon nuclear magnetic resonance analyzers (H-NMR and C-NMR), and the catalyst components and compositions were analyzed by inductive plasma spectroscopy (ICP).

The catalytic activity of Tables 1, 2, and 3 was expressed by kg Polymer / (mol-Ti) · hr by measuring the weight of the polymer in the polymerization.

In order to measure the syndiotacticity (S.I.) of the obtained polystyrene, the stereoregularity of the polymers obtained in the polymerization of Table 1 was extracted with methyl ethyl ketone, and the weight of the polymer remaining after extraction was obtained to express S.I. as a percentage.

The melting points of Tables 1, 2, and 3 were measured by differential thermal analyzer (DSC), and the specimen was heated to 200 ° C. for 5 minutes, cooled and warmed, and the temperature rising rate was 10 ° C./min.

As can be seen from Tables 1, 2, and 3, the polymerization activity of the styrene polymerized using the polymer-catalyst of the present invention was lower than that of CpTiCl ₃ , Cp * TiCl ₃ , IndTiCl ₃ , but the steric rules Synthetic index SI showed almost the same results as CpTiCl ₃ , Cp * TiCl ₃ and IndTiCl ₃ . The melting temperature of homopolymer was about 270 ℃, the melting temperature of copolymer was about 244 ℃, and in the case of trimer polymerization, it did not show a big difference such as CpTiCl ₃ , Cp * TiCl ₃ , IndTiCl _It was about 7-8 wider than all of ₃ , and a polymer having a molecular weight larger than CpTiCl ₃ and smaller than Cp * TiCl ₃ IndTiCl ₃ was obtained.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (9)

A polymer-polymer for styrene polymerization of the following structural formulas (I) or (II) prepared by reacting SAN, an irregular copolymer of styrene and acrylonitrile, with a transition metal compound of group IVa, Va, VIa, VIIa, or VIIIa of the periodic table. -catalyst): Where M is the periodic table IVa, (Ti, Zr, Hf), Va (V, Nb, Ta), VIa (Cr, Mo, W), VIIa (Mn, Tc, Re) or VIIIa (Fe, Ru, Os) , Rh, Ir, Ni, Pd, Pt) is a transition metal, X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen or a combination thereof, m is 1-4 N is an integer of 2 to 4, p and q are integers indicating a statistical distribution according to the relative reactivity of styrene and acrylonitrile monomers, and Z is a non-coordinating anion. is an anion that is not coordinating to the metal cation moiety contained in the cyanide group or very weakly coordination to prevent other Lewis bases from interacting with the metal part comprising the cyanide group of the cation. Advantageously _{[BQ 1 Q 2 Q 3 Q} 4] - shown as (wherein B is a boron atom in a trivalent _{state, Q 1, Q 2, Q} 3, and Q ₄ are each dock Typically radical Im) selected from the group consisting of a hydrogen anion (hydride), even the dialkyl amido, alkoxide, aryl oxide, hydrocarbyl carbonyl. The polymer-catalyst for styrene polymerization according to claim 1, wherein the SAN has a molecular weight in the range of 1,000 to 1,000,000 and an acrylonitrile content of 1 to 99% by weight. Dissolving SAN, an irregular copolymer of styrene and acrylonitrile, in an organic solvent; Reacting the solution with a transition metal compound of group IVa, Va, VIa, VIIa, or VIIIa of the periodic table; Separating the reaction solution into a solid layer and a liquid layer; Washing the separated solid layer with an organic solvent; And Vacuum drying the washed catalyst A process for producing a polymer-catalyst for styrene polymerization of the formula (I) or (II) according to claim 1, characterized in that it comprises a step. The method of claim 3, wherein the method further comprises the step of supporting the compound of formula (I) on a support. The method of claim 4, wherein the support is silica, alumina, MgR ₂ , wherein R is alkyl, aryl, alkoxy or halogen, MgRX where R is alkyl, Aryl (arly) or X = halogen], zeolite, aluminum phosphate and zirconia. A styrene polymerization method for producing syndiotactic polystyrene, wherein the polymer-catalyst for styrene polymerization of claim 1 and an alkylaluminum oxane or organoaluminum compound are used as a promoter. The styrene polymerization method for producing syndiotactic polystyrene according to claim 6, wherein the aluminoxane is methyl aluminum oxane or modified methyl aluminum oxane. The organoaluminum compound of claim 6, wherein the organoaluminum compound is AlRnX _3-n , wherein R is C _1-10 alkyl or aryl, X is halogen and n is an integer of 1, 2 or 3. Process for the polymerization of styrene for producing syndiotactic polystyrene. The method according to claim 6, wherein the polymerization is carried out by homopolymerization of styrene or styrene derivatives, copolymerization of styrene with an α-olefin monomer, a polar monomer or a styrene derivative or with styrene and an α-olefin monomer, a polar monomer and a styrene derivative. Polymerization method of styrene for producing syndiotactic polystyrene, characterized in that the trimer polymerization with two monomers selected from the group consisting of.