CN1179964C - Monocenedifluoro-alkoxytitanium compound and its preparation method and use - Google Patents

Abstract

The invention relates to a difluorocene-alkoxytitanium compound of the general formula Cp ¹ TiF ₂ (OR) and a preparation method thereof, wherein Cp ¹ is cyclopentadienyl or substituted cyclopentadienyl, and R is C ₁ -C ₂₀ alkyl, C ₆ ~C ₂₀ aryl or aralkyl, the substituent on the substituted cyclopentadienyl is C ₁ ~C ₂₀ alkyl, C ₆ ~C ₂₀ aryl or aralkyl, C ₂ ～C ₂₀ alkenyl group or C ₁ ～C ₂₀ silyl group, and the catalyst containing the compound for olefin polymerization, especially for the synthesis of syndiotactic polystyrene, can obtain higher catalytic activity and higher High syndiotacticity is conducive to industrial production.

Description

Monocenedifluoro-alkoxytitanium compound and its preparation method and use

Technical field

The present invention relates to a difluorocene-alkoxytitanium compound, a preparation method thereof, and a catalyst containing the compound for olefin polymerization, especially for syndiotactic polystyrene synthesis.

Background technique

It is well known that atactic polystyrene (aPS) can be obtained through free radical polymerization of styrene, which has the advantages of hardness, transparency, insulation, and easy processing, and has been widely used in packaging, construction, medicine, electronics, Automobile, daily necessities and other industries. However, due to the randomness of the structure, its softening temperature is about 100°C, which makes it brittle and poor in heat resistance and chemical corrosion resistance.

In 1956, Natta et al. (Angew.Chem., 1956, 68, 393) used the TiCl ₄ /AlEt ₃ catalytic system to obtain isotactic polystyrene (isotactic Polystyrene, iPS), with a melting point of 240°C and high crystallinity, but due to Its crystallization rate is too slow to have much industrial application value.

In 1986, Ishihara et al. used a homogeneous organometallic catalytic system (Macromolecules, 1986, 19, 2464) composed of titanium compounds and methylaluminoxane (MAO) to obtain syndiotactic Polystyrene (sPS), which is A crystalline material with a melting point of about 270°C. It has the advantages of fast crystallization speed, low specific gravity, low dielectric constant, good heat resistance and chemical corrosion resistance, so it has broader industrial prospects.

So far, the catalysts that have been disclosed for the synthesis of syndiotactic polystyrene include titanium halides, tetraalkoxytitaniums, tetraalkyltitaniums, titanates, titanocenes, and corresponding zirconium compounds (Prog.Polym.Sci. 1996, 21, 47; J. Molecular Catalysis A: Chem. 1998, 128, 67).

Among them, titanocene compounds with semi-sandwich structure (referring to compounds containing a cyclopentadienyl group, such as: a trichlorotitanium, a trialkyltitanium, a trialkoxytitanium and various substituted cyclocene compounds) and The catalytic system composed of MAO or B(C ₆ F ₅ ) ₃ has remarkable syndiotactic orientation and high catalytic activity for the catalytic polymerization of styrene monomers. The corresponding patents include US4680353, US4978730, US5252693, EP781783, WO95 /14024, WO97/07141, CN1253957A, CN1340551A). Wherein US5252693 discloses that the structure is CpTiCl ₃ or Cp ^* TiCl ₃ and the situation that the catalyst system that co-catalyst MAO forms is used for styrene syndiotactic polymerization (wherein Cp is cyclopentadienyl, Cp ^* is pentamethylcyclopentadiene base), but its catalytic activity and catalytic efficiency are not high, its stability is poor, and its industrial application value is not large. Patent CN1340551A discloses the compound CpTiCl ₂ (OR), although the catalytic activity has been improved compared with the past, but the Al/Ti is relatively high. Kaminsky et al. reported (Macromolecules, 1997, 30, 7647) that Cp'TiF ₃ catalysts have high catalytic activity, but they use highly toxic substance Me ₃ SnF in the preparation process, which brings inconvenience to industrial production.

Contents of Invention

In order to overcome the shortcomings of high aluminum-titanium ratio (Al/Ti) and low catalytic activity when metallocene compounds in the prior art are used in the syndiotactic polymerization process of styrene, the present invention provides a new type of fluorine-containing Metal titanium compound, the invention also provides a preparation method of the compound. In addition, the present invention also provides a catalyst for olefin polymerization, which contains the fluorine-containing metallocene titanium compound, and the catalyst has very high catalytic activity especially in the process of syndiotactic polymerization of styrene , and maintain high syndiotacticity of polystyrene.

The general formula of the difluoro-alkoxytitanium compound of the present invention is:

Cp ¹ TiF ₂ (OR)

Wherein Cp ¹ is cyclopentadienyl or substituted cyclopentadienyl, R is C ₁ -C ₂₀ alkyl, C ₆ -C ₂₀ aryl or aralkyl. The substituents on the substituted cyclopentadienyl are C ₁ -C ₂₀ alkyl, C ₆ -C ₂₀ aryl or aralkyl, C ₂ -C ₂₀ alkenyl or C ₁ -C ₂₀ silyl.

In the above technical solution, R is preferably a C ₁ -C ₆ linear or branched alkyl group, a C ₆ -C ₁₀ aryl group or an aralkyl group. The substituents on the substituted cyclopentadienyl are preferably C ₁ -C ₆ linear or branched alkyl, C ₆ -C ₁₀ aryl or aralkyl, C ₃ -C ₆ alkenyl such as alkenyl Propyl, allyl, allyl, etc., or C ₁ -C ₆ silyl groups, etc.

Typical examples are:

CpTiF ₂ (OMe), CpTiF ₂ (OEt), CpTiF ₂ (OiPr), CpTiF ₂ (OPh), CpTiF ₂ (OCH ₂ Ph), MeCpTiF ₂ (OMe), MeCpTiF ₂ (OEt), MeCpTiF ₂ (OiPr), MeCpTiF ₂ (OPh), MeCpTiF ₂ (OCH ₂ Ph), 1,3-Me ₂ CpTiF ₂ (OMe), 1,3-Me ₂ CpTiF ₂ (OEt), 1,3-Me ₂ CpTiF ₂ (O ⁱ Pr ), 1,3-Me ₂ CpTiF ₂ (OPh), 1,3-Me ₂ CpTiF ₂ (OCH ₂ Ph), 1,2,3,4-Me ₄ CpTiF ₂ (OMe), 1,2,3, 4-Me ₄ CpTiF ₂ (OEt), 1, 2, 3, 4-Me ₄ CpTiF ₂ (O ⁱ Pr), 1, 2, 3, 4-Me ₄ CpTiF ₂ (OPh), 1, 2, 3, 4-Me ₄ CpTiF ₂ (OCH ₂ Ph), Me ₅ CpTiF ₂ (OMe), Me ₅ CpTiF ₂ (OEt), Me ₅ CpTiF ₂ (O ⁱ Pr), Me ₅ CpTiF ₂ (OPh), Me ₅ CpTiF ₂ ( _OCH2Ph ), _EtCpTiF2 (OMe), _EtCpTiF2 (OEt), ^EtCpTiF2 ( ^OiPr ₎ , _iPrCpTiF2 (OMe), ^iprCpTiF2 ₍ OEt) _, ^iPrCpTiF2 ( ^OiPr ), Me ₃ SiCpTiF ₂ (OMe), Me ₃ SiCpTiF ₂ (OEt), Me ₃ SiCpTiF ₂ (O ⁱ Pr), CH ₂ =CHCH ₂ CpTiF ₂ (OMe), CH ₂ =CHCH ₂ CpTiF ₂ (OEt), CH ₂ = _{CHCH2CpTiF2 (} ^OiPr ₎ , _{CH2 = CHCH2CH2CpTiF2 ( OMe )} , _CH2 = _{CHCH2CH2CpTiF2} (OEt ₎ , _CH2 =CHCH2CH2CpTiF2 ₍ ^OiPr ) , PhCH ₂ CpTiF ₂ (OMe), PhCH ₂ CpTiF ₂ (OEt), PhCH ₂ CpTiF ₂ (O ⁱ Pr).

The difluoro-alkoxytitanium compound of the present invention can be prepared by fluorinating the corresponding trialkoxytitanium compound. The preparation method of the trialkoxytitanium compound can be found in Chem.Abstr.68/13138e.

A more preferred scheme is: under the protection of an inert atmosphere, the complex solution of fluoride such as boron trifluoride ether is added to the solution of substituted or unsubstituted titanium trialkoxide, titanium trialkoxide and titanium The molar ratio of boron trifluoride etherate complex is 1:0.5~5, the organic solvent is dichloromethane, ether, tetrahydrofuran, toluene, n-hexane or petroleum ether and their mixtures, and the dropping temperature is -78~0°C. After dripping, the reaction temperature is 10-100°C, and the reaction time is 1-60 hours, and then the conventional drying or concentration method is adopted, such as concentration and vacuum sublimation, etc., to obtain the product difluoro-alkoxytitanium compound.

In the above preparation method, the molar ratio of titanium trialkoxide and boron trifluoride etherate complex preferably ranges from 1:0.6 to 1.5, the preferred range of dropping temperature is -60～-30°C, and the preferred range of reaction temperature is 20°C. ~35°C, the reaction time preferably ranges from 6 to 24 hours, the organic solvent is preferably diethyl ether and tetrahydrofuran, and the gas used in the inert atmosphere can be argon or nitrogen.

The present invention also provides a catalyst for olefin polymerization, which comprises the reaction product of the above-mentioned difluoro-alkoxytitanium compound and a co-catalyst, wherein the co-catalyst can be the difluorocene disclosed in the prior art. The cocatalyst component in the metal catalyst system, such as MAO (methyl aluminoxane) or boron compound BX ₁ X ₂ X ₃ or its salt, wherein X ₁ , X ₂ , X ₃ can be the same or different, representing C ₁ -C ₂₀ fluorohydrocarbon substituent.

The catalysts mentioned above are especially suitable for the syndiotactic polymerization of styrene

The molar ratio of styrene monomer to titanium in the catalyst is 1000:1 to 500000:1, preferably 2000:1 to 300000:1.

In addition, the catalyst may also include alkylaluminum or alkylaluminum hydrogen compound, the alkyl group is C ₁ -C ₆ , such as trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum Aluminum hydride, diisobutylaluminum hydride, etc. The molar ratio of alkylaluminum or alkylaluminum hydrogen to titanium is 0-2000:1, preferably 0-500:1.

The polymerization reaction is solution polymerization or bulk polymerization. In the former case, the solvent is aliphatic hydrocarbon or aromatic hydrocarbon, preferably toluene. The volume ratio of solvent to monomer is 0-10:1.

The polymerization temperature is 20-100°C.

The polymerization time is 0.5 to 10 hours, preferably 0.5 to 2 hours.

Tests prove that the catalytic system containing the difluorocene-alkoxytitanium compound of the present invention has high catalytic activity when used in olefin polymerization, especially for the polymerization of styrene monomers. For example, when it is used for styrene syndiotactic solvent state polymerization, it can obtain up to 97.3% high syndiotactic polystyrene, and its catalytic activity is up to 1.56×10 ⁷ gPS/(molTi·molS·h). Under bulk state polymerization, a maximum of 96.3% high syndiotactic polystyrene can be obtained, and the highest catalytic activity is 1.70×10 ⁷ gPS/(molTi·molS·h). In this way, by adopting the catalytic system containing the difluoro-alkoxytitanium compound of the present invention, the residual metal content in the polymer can be greatly reduced, the properties of the polymer are improved, the subsequent separation process is avoided, and the production capacity is reduced. cost, and achieved good results. At the same time, the preparation method of the difluorocene-alkoxytitanium compound of the present invention also has the advantages of simple synthesis and easy separation and purification.

Below by embodiment the present invention will be further elaborated.

【Example 1】

Preparation of compound CpTiF ₂ (OMe):

Under the protection of argon, slowly add 0.25ml (2.0mmol) BF ₃ ·OEt ₂ in 10ml of ether solution to 0.55g (2.7mmol) CpTi(OMe) ₃ solution in 20ml ether at -30°C, dropwise, Naturally rise to 25°C, stir and react for 12 hours, and drain the solvent. The obtained solid is vacuum sublimated (110°C/0.1mmHg) to obtain 0.37g of CpTiF ₂ (OMe) yellow product, the yield is 76%, mp=130～132°C . The analysis test results are as follows

Molecular formula: C ₆ H ₈ F ₂ OTi;

Mass spectrum showed molecular ion peak, MS (EI): 182 (M ⁺ , 80).

¹ H NMR (CDCl ₃ ): δ 4.11 (br.s, 3H, OCH ₃ ), 6.71 (s, 5H, Cp). ¹⁹ F NMR (CDCl ₃ ): δ 20.87 (s).

Elemental Analysis (E.A.): Measured, C: 39.60% H: 4.43%

Computing, C: 39.52% H: 4.40%

[Example 2]

Preparation of compound MeCpTiF ₂ (OMe):

All operations were the same as in Example 1, except that MeCpTi(OMe) ₃ was used instead of CpTi(OMe) ₃ , and MeCpTiF ₂ (OMe) was finally obtained as a bright yellow product with mp=107-109°C. The analysis test results are as follows

Molecular formula: C ₇ H ₁₀ F ₂ OTi; MS (EI): 196 (M ⁺ , 17).

¹ H NMR (CDCl ₃ ): δ 2.38 (s, 3H, CH ₃ ), 4.05 (br.s, 3H, OCH ₃ ), 6.39 (s, 2H, Cp), 6.59 (s, 2H, Cp).

E.A.: Measured, C: 42.89% H: 5.14%

Computing, C: 42.77% H: 5.01%

[Example 3]

Preparation of Compound ⁱ PrCpTiF ₂ (OMe):

All operations were the same as in Example 1, except that ⁱ PrCpTi(OMe) ₃ was used instead of CpTi(OMe) ₃ , and ⁱ prCpTiF ₂ (OMe) yellow product was finally obtained, mp=78-80°C. The analysis test results are as follows

Molecular formula: C ₉ H ₁₄ F ₂ OTi;

MS (EI): 224 (M ⁺ , 3).

¹ H NMR (CDCl ₃ ): δ1.30 (d, J=6.9Hz, 6H, CH ₃ ), 3.11 (m, 1H, CH), 4.12 (br.s, 3H, OCH ₃ ), 6.46 (s, 2H, Cp), 6.56(s, 2H, Cp).

E.A.: Measured, C: 48.24% H: 6.30%

Computing, C: 47.98% H: 6.19%

【Example 4】

Preparation of compound CH ₂ =CHCH ₂ CpTiF ₂ (OMe):

All operations are the same as in Example 1, except that CH ₂ =CHCH ₂ CpTi(OMe) ₃ is used instead of CpTi(OMe) ₃ , and finally CH ₂ =CHCH ₂ CpTiF ₂ (OMe) orange product is obtained, mp=82～84°C . The analysis test results are as follows

Molecular formula: C ₉ H ₁₂ F ₂ OTi;

MS (EI): 222 (M ⁺ , 3).

¹ H NMR (CDCl ₃ ): δ3.49 (d, J=6.6Hz, 2H, CH ₂ ), 4.04 (br.s, 3H, OCH ₃ ), 5.13-5.19 (m, 2H, CH ₂ =), 5.93-6.06 (m, 1H, CH=), 6.41 (s, 2H, Cp), 6.59 (s, 2H, Cp).

E.A.: Measured, C: 48.68% H: 5.45%

Compute, C: 48.60% H: 5.50%

【Example 5】

Preparation of compound Me ₃ SiCpTiF ₂ (OMe):

All the operations were the same as in Example 1, except that CpTi(OMe) ₃ was replaced by CpTi(OMe) ₃ , and a yellow product of Me ₃ SiCpTiF ₂ (OMe) was finally obtained, mp=73-75°C. The analysis test results are as follows

Molecular formula: C ₉ H ₁₆ F ₂ OSiTi;

MS (EI): 278 (M ⁺ , 6).

¹ H NMR (CDCl ₃ ): δ0.33 (s, 9H, SiMe ₃ ), 4.17 (br.s, 9H, OCH ₃ ), 6.82 (d, J=8.4Hz, 4H, Cp).

E.A.: Measured, C: 42.53% H: 6.34%

Compute, C: 42.41% H: 6.45%

[Example 6]

Preparation of Compound PhCH ₂ CpTiF ₂ (OMe):

All the operations were the same as in Example 1, except that PhCH ₂ CpTi(OMe) ₃ was used instead of CpTi(OMe) ₃ , and PhCH ₂ CpTiF ₂ (OMe) orange product was finally obtained. The analysis test results are as follows

Molecular formula: C ₁₃ H ₁₄ F ₂ OTi;

MS (EI): 253 (M ⁺ -F, 6).

¹ H NMR (CDCl ₃ ): δ4.07 (br.s, 5H, OCH ₃ , CH ₂ ), 6.36 (s, 2H, Cp), 6.56 (s, 2H, Cp), 7.23～7.34 (m, 5H , Ph).

E.A.: Measured, C: 57.38% H: 5.19%

Computing, C: 56.95% H: 5.11%

[Example 7]

Polymerizations were carried out in a baked argon-filled ampule three times. 2ml styrene, 8.5ml toluene, 0.99ml concentration of 1.53M MAO toluene solution, and 0.5ml concentration of 0.01M CpTiF ₂ (OMe) (prepared in Example 1) toluene solution were injected into the ampoule successively, placed in Polymerization was carried out in an oil bath whose temperature was previously adjusted to 50° C. for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtering and washing, the obtained polymer was vacuum-dried to constant weight at 100°C to obtain 1.363g polystyrene with a yield of 75.0% and a catalytic activity of 1.56×10 ⁷ gPS/(molTi molS h).

Reflux in methyl ethyl ketone for 4 hours to remove atactic polystyrene, and the measured syndiotactic polystyrene content is 93.9%.

The resulting polymer had a melting point of 258.9°C.

[Embodiment 8]

2ml styrene, 8.5ml toluene, 0.99ml concentration is the MAO toluene solution of 1.53M, and the toluene solution of 0.5ml concentration is 0.01M MeCpTiF ₂ (OMe) (prepared in Example 2) is injected into the ampoule successively, at 50 Polymerize in an oil bath at °C for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtration and washing treatment, the obtained polymer was vacuum-dried to constant weight at 100°C to obtain 1.2143g polystyrene with a yield of 66.8% and a catalytic activity of 1.39×10 ⁷ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 97.2%.

The resulting polymer had a melting point of 266.1°C.

[Example 9]

2ml styrene, 8.5ml toluene, 0.5ml concentration of 1.53M MAO toluene solution, and 0.5ml concentration of 0.01M MeCpTiF ₂ (OMe) (prepared in Example 2) toluene solution were injected into the ampoule successively, at 50°C polymerized in an oil bath for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtering and washing, the resulting polymer was vacuum-dried to constant weight at 100°C to obtain 1.3468g polystyrene with a yield of 74.1% and a catalytic activity of 1.543×10 ⁷ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 96.0%.

【Example 10】

2ml styrene, 8.5ml toluene, 0.99ml concentration of 1.53M MAO toluene solution, and 0.5ml concentration of 0.01M ^iprCpTiF ₂ (OMe) (prepared in Example 3) toluene solution were injected into the ampoule successively, placed in Polymerization was carried out in an oil bath whose temperature was previously adjusted to 50° C. for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtering and washing, the obtained polymer was vacuum-dried to constant weight at 100°C to obtain 1.0329g polystyrene with a yield of 56.8% and a catalytic activity of 1.184×10 ⁷ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 97.3%.

The resulting polymer had a melting point of 269.4°C.

[Example 11]

2ml styrene, 8.5ml toluene, 0.99ml concentration is 1.53M MAO toluene solution, and 0.5ml concentration is 0.01M Me ₃ SiCpTiF ₂ (OMe) (prepared in Example 5) toluene solution is injected into the ampoule successively, place Polymerize for 1 hour in an oil bath whose temperature was previously adjusted to 50°C. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtration and washing treatment, the obtained polymer was vacuum-dried to constant weight at 100°C to obtain 0.6550g polystyrene, the yield was 36.0%, and the catalytic activity was 7.50×10 ⁶ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 94.2%.

The resulting polymer had a melting point of 269.8°C.

[Example 12]

2ml styrene, 8.5ml toluene, 0.99ml concentration of 1.53M MAO toluene solution, and 0.5ml concentration of 0.01M CH ₂ =CHCH ₂ CpTiF ₂ (OMe) (prepared in Example 4) toluene solution were injected into the ampoule in sequence placed in an oil bath whose temperature was previously constant to 50°C for polymerization for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtering and washing, the obtained polymer is vacuum-dried to constant weight at 100°C to obtain 0.4566g polystyrene, the yield is 25.1%, and the catalytic activity is 5.23×10 ⁶ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 95.8%.

The resulting polymer had a melting point of 267.4°C.

[Example 13]

2ml styrene, 8.5ml toluene, 0.99ml concentration of 1.53M MAO toluene solution, and 0.5ml concentration of 0.01M PhCH ₂ CpTiF ₂ (OMe) (prepared in Example 6) toluene solution were injected into the ampoule successively, placed Polymerize for 1 hour in an oil bath whose temperature was previously adjusted to 50°C. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtration and washing treatment, the obtained polymer is vacuum-dried to constant weight at 100°C to obtain 0.2169g polystyrene, the yield is 11.9%, and the catalytic activity is 2.49×10 ⁶ gPS/(molTi molS h).

The measured syndiotactic polystyrene content was 92.4%.

The resulting polymer had a melting point of 264.5°C.

[Comparative Example 1]

2ml styrene, 8.5ml toluene, 0.99ml 1.53M MAO toluene solution, and 0.5ml 0.01M CpTiCl ₃ toluene solution were sequentially injected into the ampoule and polymerized in an oil bath at 50°C for 1 hour. Terminate the polymerization reaction with ethanol containing 10% HCl, after filtration and washing treatment, the obtained polymer was vacuum-dried to constant weight at 100°C to obtain 0.3328g polystyrene with a yield of 18.3% and a catalytic activity of 3.81×10 ⁶ gPS/(molTi molS h).

The measured syndiotactic polystyrene content is 92.5%,

The resulting polymer had a melting point of 257.9°C.

[Example 14]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M CpTiF ₂ (OMe) toluene solution were sequentially injected into the ampoule, polymerized in an oil bath at 50° C. for 1 hour, 4.1231 g of polystyrene was obtained, the yield was 41.2%, and the catalytic activity was 1.70×10 ⁷ gPS/(molTi·molS·h).

The measured syndiotactic polystyrene content was 93.4%.

[Example 15]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M MeCpTiF ₂ (OMe) toluene solution were sequentially injected into the ampoule, polymerized in an oil bath at 50° C. for 1 hour, 3.9404 g of polystyrene was obtained, the yield was 39.4%, and the catalytic activity was 1.63×10 ⁷ gPS/(molTi·molS·h).

The measured syndiotactic polystyrene content was 95.0%.

[Example 16]

11 ml of styrene, 0.5 ml of 1.53 M MAO in toluene, and 0.25 ml of 0.01 M ⁱ prCpTiF ₂ (OMe) in toluene were sequentially injected into the ampoule and polymerized in an oil bath at 50°C for 1 hour , 3.4948g of polystyrene was obtained, the yield was 35.0%, and the catalytic activity was 1.45×10 ⁷ gPS/(molTi·molS·h).

The measured syndiotactic polystyrene content was 90.6%.

[Example 17]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M Me ₃ SiCpTiF ₂ (OMe) toluene solution were injected into the ampoule in sequence, and polymerized in an oil bath at 50°C for 1 After 1 hour, 2.9177 g of polystyrene was obtained, with a yield of 29.2%, and a catalytic activity of 1.21×10 ⁷ gPS/(molTi·molS·h).

The measured syndiotactic polystyrene content was 93.2%.

[Example 18]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M CH ₂ =CHCH ₂ CpTiF ₂ (OMe) toluene solution were injected into the ampoule in sequence, and placed in an oil bath at 50° C. Medium polymerization was carried out for 1 hour to obtain 3.9339 g polystyrene with a yield of 39.3% and a catalytic activity of 1.63×10 ⁷ gPS/(molTi·molS·h).

The syndiotactic polystyrene content was measured to be 92.3%.

【Comparative example 2】

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M _CpTiCl3 toluene solution were sequentially injected into the ampoule and polymerized in an oil bath at 50°C for 1 hour to obtain 0.8056 g Polystyrene, the yield is 8.1%, and the catalytic activity is 3.33×10 ⁶ gPS/(molTi·molS·h).

The syndiotactic polystyrene content was measured to be 82.3%.

[Example 19]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M CpTiF ₂ (OMe) toluene solution were sequentially injected into the ampoule, and polymerized in an oil bath at 30° C. for 1 hour. 1.8829 g of polystyrene was obtained, the yield was 18.8%, and the catalytic activity was 7.78×10 ⁶ gPS/(molTi·molS·h).

The measured syndiotactic polystyrene content was 96.3%.

[Example 20]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M CpTiF ₂ (OMe) toluene solution were sequentially injected into the ampoule, and polymerized in an oil bath at 70° C. for 1 hour. 4.0215 g of polystyrene was obtained, the yield was 40.2%, and the catalytic activity was 1.66×10 ⁷ gPS/(molTi·molS·h).

The syndiotactic polystyrene content was measured to be 92.0%.

[Example 21]

11 ml of styrene, 0.5 ml of 1.53 M MAO toluene solution, and 0.25 ml of 0.01 M CpTiF ₂ (OMe) toluene solution were sequentially injected into the ampoule, and polymerized in an oil bath at 90° C. for 1 hour. 2.9899 g of polystyrene was obtained, the yield was 29.9%, and the catalytic activity was 1.24×10 ⁷ gPS/(molTi·molS·h).

The syndiotactic polystyrene content was measured to be 88.8%. Example Types of titanocenes Al/Ti ratio (mmol/mmol) Catalytic activity×10 ⁷ gPS/(molTi·molS·h) Syndiotactic styrene content (wt%) Example 7 CpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 1.56 93.9 Example 8 MeCpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 1.39 97.2 Example 9 MeCpTiF ₂ (OMe) 0.5×1.53/0.5×0.01 1.543 96.0 Example 10 ⁱ PrCpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 1.184 97.3 Example 11 Me ₃ SiCpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 0.75 94.2 Example 12 CH ₂ =CHCH ₂ CpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 0.523 95.8 Example 13 PhCH ₂ CpTiF ₂ (OMe) 0.99×1.53/0.5×0.01 0.249 92.4 Compare 1 CpTiCl ₃ 0.99×1.53/0.5×0.01 0.381 92.5 Example 14 CpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.70 93.4 Example 15 MeCpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.63 95.0 Example 16 ⁱ PrCpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.45 90.6 Example 17 Me ₃ SiCpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.21 93.2 Example 18 CH ₂ =CHCH ₂ CpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.63 92.3 Compare 2 CpTiCl ₃ 0.5×1.53/0.25×0.01 0.333 82.3 Example 19 CpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 0.778(30℃) 96.3 Example 20 CpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.66(70℃) 92.0 Example 21 CpTiF ₂ (OMe) 0.5×1.53/0.25×0.01 1.24(90℃) 88.8 Compare 3 CpTiCl ₂ (OMeOEt) 6.6×1.53/0.1×0.05 0.35 95.1 Compare 4 CpTiCl ₂ (OphOMe) 0.5×1.53/0.05×0.05 1.92 86.2

Note: comparison 3 is example 5 in the CN1340551A specification

Comparison 4 is the example 7 in the CN1340551A specification

As can be seen from the above table, compared with the prior art, the titanocene compound of the present invention has very high catalytic activity and high syndiotacticity of higher polystyrene in the syndiotactic polymerization process of styrene . At the same time, the ratio of aluminum to titanium can be reduced, thereby reducing the amount of aluminoxane and reducing the cost of the catalyst.

Claims (10)

1, a cyclopentadienyl difluoro alkoxy titanium compound has following general formula:

Cp ¹TiF ₂(OR) Cp wherein ¹Be cyclopentadienyl or substituted cyclopentadienyl, R is C ₁～C ₂₀Alkyl, C ₆～C ₂₀Aryl or C ₆～C ₂₀Aralkyl, the substituting group on the cyclopentadienyl of replacement are C ₁～C ₂₀Alkyl, C ₆～C ₂₀Aryl or C ₆～C ₂₀Aralkyl, C ₂～C ₂₀Alkenyl or C ₁～C ₂₀Silylation.

2, a cyclopentadienyl difluoro alkoxy titanium compound according to claim 1 is characterized in that, R is C ₁～C ₆The alkyl of straight or branched, C ₆～C ₁₀Aryl or C ₆～C ₁₀Aralkyl.

3, a cyclopentadienyl difluoro alkoxy titanium compound according to claim 1 is characterized in that, the substituting group on the substituted cyclopentadienyl is C ₁～C ₆The alkyl of straight or branched, C ₆～C ₁₀Aryl or C ₆～C ₁₀Aralkyl, C ₃～C ₆Alkenyl or C ₁～C ₆Silylation.

4, a cyclopentadienyl difluoro alkoxy titanium compound according to claim 1 is selected from following compound

CpTiF ₂(OMe)，MeCpTiF ₂(OMe)， ⁱPrCpTiF ₂(OMe)，Me ₃SiCpTiF ₂(OMe)，CH ₂＝CHCH ₂CpTiF ₂(OMe)，PhCH ₂CpTiF ₂(OMe)。

5, the preparation method of the described cyclopentadienyl difluoro alkoxy titanium compound of claim 1 under inert atmosphere, joins Cp with fluoride aqueous solution ¹Ti (OR) ₃Solution in, Cp wherein ¹Define as claim 1 Cp with R ¹Ti (OR) ₃With the mol ratio of fluorochemical be 1: 0.5～5, dropping temperature is-78～0 ℃, dripping a complete afterreaction temperature is 10～100 ℃, the reaction times is to react under the condition in 1～60 hour, filters then, concentrates, and obtains product one cyclopentadienyl difluoro alkoxy titanium compound.

6, the preparation method of a cyclopentadienyl difluoro alkoxy titanium compound according to claim 5, wherein fluoride aqueous solution is the complex solution of boron trifluoride diethyl etherate.

7, the preparation method of a cyclopentadienyl difluoro alkoxy titanium compound according to claim 5 is characterized in that Cp ¹Ti (OR) ₃With the mol ratio of fluorochemical be 1: 0.6～1.5.

8, the catalyzer that is used for olefinic polyreaction comprises the reaction product of the described cyclopentadienyl difluoro alkoxy titanium compound of claim 1 and methylaluminoxane or boron compound, and wherein boron compound is BX ₁X ₂X ₃, X wherein ₁, X ₂, X ₃Can be identical, also can be different, represent C ₁～C ₂₀The fluorinated hydrocarbon substituting group.

9, catalyzer according to claim 8 also comprises aluminum alkyls or alkyl hydrogen aluminum compound, and alkyl is C ₁～C ₆

10, the described catalyzer of claim 8 is used for styrene catalyzed syndiotactic polymerization.