JP2837246B2 - New syndiotactic polypropylene - Google Patents

Description

The present invention relates to a novel syndiotactic polypropylene having a high crystallization rate. More specifically, it relates to a novel syndiotactic polypropylene useful for molding and the like.

[Conventional technology]

Syndiotactic polypropylene has long been known to be obtained by a method of polymerizing at a low temperature using a catalyst comprising a vanadium compound and an organoaluminum compound, but in the conventional method, the resulting polymer has a low syndiotacticity. However, it was hard to say that it exhibited the characteristics of the original syndiotactic polypropylene.

In contrast, JP-A-2-41303 discloses the following formula R ″ (CpR _n ) (CpR ′ _m ) MeQ _k (where each Cp is a cyclopentadienyl or substituted cyclopentadienyl ring: R _n may be the same or different and are a hydrocarbyl residue having 1 to 20 carbon atoms: R ″ is a structural bridge between Cp rings that provides tacticity to the catalyst: Me is the period of the element 4b, 5b or 6 of the table
a metal of group b: each Q is a hydrocarbyl residue having 1 to 20 carbon atoms or halogen; 0 ≦ k ≦ 3: 0 ≦ n
≦ 3: and 1 ≦ m ≦ 4, and: R ′ _m is selected such that (CpR _n ) is sterically different from (CpR ′ _m );
Metallocene catalyst used to produce syndiotactic polyolefins represented by

It is described that a poly-α-olefin having good syndiotacticity can be produced by using a catalyst containing as one component.

JP-A-2-41305 discloses a syndiotactic polypropylene obtained using the catalyst described in the above-mentioned JP-A-2-41305.

[Problems to be solved by the invention]

JP-A-2-412303, the syndiotactic polypropylene obtained by the method of JP-A-2-41305 is a syndiotactic polypropylene obtained by a method of polymerizing at a low temperature using a catalyst comprising a vanadium compound and an organoaluminum compound. Syndiotactic polypropylene is a syndiotactic polypropylene with much higher syndiotacticity and superior physical properties than the tic polypropylene, and is expected to be used as a novel resin.

However, in the process of examining the practical use of syndiotactic polypropylene obtained by the method of JP-A-2-41305, JP-A-2-41305, particularly when considering the practical use of processing methods and the like as a resin resin It has been found that there is a drawback that it is difficult to solidify when a molded product is obtained by cooling after melting the molten product, and there is a problem in processing.

For example, when granulating the syndiotactic polypropylene obtained by the above method, the strand is not completely solidified by the usual method and apparatus performed with isotactic polypropylene, so that the strand is cut off. It is difficult to continuously granulate, and syndiotactic polypropylene having good processability has been desired for solving the problem.

[Means for solving the problem]

The inventor of the present application has made intensive studies in order to solve the above problems, and has reached the present invention.

That is, the present invention relates to (A) ¹³ C-NMR spectrum in which the signal intensity of the methyl group belonging to the syndiotactic pentad chain is 0.8 or more of the signal intensity of all the methyl groups, and (B) the measurement in tetralin at 135 ° C. Intrinsic viscosity number [η]
(C) the molecular weight distribution index (Mw / Mn) measured by gel permeation chromatography is in the range of 1.5 to 20, and (D) the melting point measured by a differential scanning calorimeter. (Tm) is 13
(E) The crystallization temperature (Tc) measured by differential scanning calorimetry after complete melting is in the range of 105-125 ° C, and (F) 110 ° C measured by differential scanning calorimetry. Syndiotactic polypropylene characterized in that the isothermal half-crystallization rate (t _1/2 ) is 2 minutes or less, which is a novel syndiotactic polypropylene capable of solving the above problems.

The method for producing the syndiotactic polypropylene is not particularly limited. For example, the syndiotactic polypropylene of the present invention can be easily produced by using a special catalyst system.

Examples of the catalyst for producing the syndiotactic polypropylene of the present invention include, for example, a transition metal compound in a catalyst system comprising a transition metal catalyst and a co-catalyst; (However, A ¹ represents a cyclopentadienyl group or a substituted cyclopentadienyl group, A ² represents a fluorenyl group or a substituted fluorenyl group. A ³ represents a hydrocarbon diylidene group having 4 to 20 carbon atoms, R ¹ , R ² is a halogen atom, a hydrogen atom, an aryl group having 1 to 10 carbon atoms, easily present invention depending on the .M to indicate an alkyl group using titanium, zirconium, a transition metal compound represented by hafnium) New syndiotactic polypropylene can be produced.

The transition metal compound (I) is a novel metallocene compound having two transition metal atoms in one molecule.

A ¹ may be either from unsubstituted cyclopentadienyl group to 4-substituted cyclopentadienyl group, A ² may be either up to 8 substituted fluorenyl group from unsubstituted fluorenyl group.

A ³ represents a hydro carbon diisopropyl isopropylidene group having 4 to 20 carbon atoms.

Specific examples of A ^3, for example, 2,3-Butanjiiriden group, 2,4-pentane diisopropyl alkylidene group, 1,3-cyclopentane diisopropyl isopropylidene group, 4-cyclopentene-1,3 Jiiriden group, 2,5 -Hexanediylidene group, 1,4-cyclohexanediylidene group, 6-methyl-2,4-heptanediylidene group, bicyclo [3,3,0] octane-3,7-diylidene group, bicyclo [3,3 , 1] nonane-3,7-diylidene group, 9,
Examples thereof include a 10-anthracene diylidene group.

R ¹ and R ² are a halogen atom such as fluorine, chlorine, bromine or iodine, a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an aryl group having 1 to 10 carbon atoms such as a phenyl group, or an alkyl group. And preferably a chlorine atom or a methyl group.

R ¹ and R ² may be the same or different from each other.

M is titanium, zirconium, hafnium, preferably zirconium, hafnium, which may be the same or different.

The synthetic route of the novel transition metal compound (I) of the present invention is, for example, as follows in the case of 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dihalolide]. .

C ₆ H ₈ O ₂ +2 C ₅ H ₆ → C ₆ H ₈ (= C ₅ H ₄ ) ₂ + 2H ₂ OC ₆ H ₈ (= C ₅ H ₄ ) ₂ + 2LiC ₁₃ H ₉ + 2HCl → C ₆ H ₈ [(C ₅ H ₅ ) C ₁₃ H ₉ ] ₂ + 2LiCl C ₆ H ₈ [(C ₅ H ₅ ) C ₁₃ H ₉ ] ₂ +4 nBuLi → C ₆ H ₈ [(LiC ₅ H ₄ ) LiC ₁₃ H _{8] 2 + 4C 4 H 10 C 6} H 8 _{[(LiC 5 H 4) LiC 13} H 8 ] _{2 + 2ZrX 4 → C 6 H} 8 _{[(C 5 H 5) (C} 13 H 8) ZrX 2 ] ₂ + 4LiX (X is a halogen atom) Further, the above C ₆ H ₈ [(C ₅ H ₅ ) (C ₁₃ H ₈ ) ZrX ₂ ] ₂ is RLi or R
Periodic table such as MgCl (R is an alkyl group having 1 to 10 carbon atoms)
By reacting with a metal alkyl compound of Group IA or Group IIA of the periodic table, a compound in which at least one of X is substituted with R can be obtained.

Specific examples of the novel transition metal compound (I) of the present invention include, for example, 2,3-butanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium chloride], 2,3-butanediylidenebis [ (Cyclopentadienyl-9-fluorenyl) hafnium dichloride],
2,3-butanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl], 2,3-
Butanediylidenebis [(cyclopentadienyl-9-
Fluorenyl) hafnium dimethyl], 2,5-hexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride], 2,5-hexanediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride ], 2,5-hexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl], 2,5-hexanediylidenebis [(cyclopentadienyl-9-fluorenyl)
Hafnium dimethyl], 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl)
Zirconium dichloride], 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride], 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl], 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dimethyl], 6-methyl-2,4-heptanediylidenebis [(cyclopentadienyl-9-
Fluorenyl) zirconium dichloride], 6-methyl-2,4-heptanediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride], 6
-Methyl-2,4-heptanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl], 6-methyl-2,4-heptanediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium Dimethyl], bicyclo [3,3,0] octane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride], bicyclo [3,3,0]
Octane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride], bicyclo [3,3,0] octane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl ], Bicyclo [3,3,0] octane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dimethyl], bicyclo [3,3,1] nonane-3,7-diylidenebis [(cyclo Pentadienyl-9
-Fluorenyl) zirconium dichloride], bicyclo [3,3,1] nonane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride], bicyclo [3,3,1] nonane-3,7 -Diylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl], bicyclo [3,3,1] nonane-3,7-diylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dimethyl], 9,10 -Anthracene diylidene bis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride], 9,10-anthracene diylidene bis [(cyclopentadienyl-9-fluorenyl) hafnium dichloride], 9,10-anthracene diylidene Bis [(cyclopentadienyl-9-fluorenyl) zirconium dimethyl] , 9,10-anthracenediylidenebis [(cyclopentadienyl-9-fluorenyl) hafnium dimethyl].

During the polymerization, as the co-catalyst used together with the transition metal compound of the present invention, in addition to known aluminoxanes, JP-A-1-501950, JP-A-1-502036, etc. Although a boron compound can be used as a co-catalyst, aluminoxanes are preferred from the viewpoint of activity and availability.

General formulas for aluminoxanes And / or Wherein R is a hydrocarbon group having 1 to 3 carbon atoms and n is an integer of 2 or more. In particular, methyl is aluminoxane in which R is a methyl group and n is 5 or more, preferably 10 or more. Is used. The above aluminoxanes may be mixed with some alkylaluminum compounds.

Methods for producing the above aluminoxanes are known. For example, a method of adding a trialkylaluminum to a salt containing water of crystallization (eg, copper sulfate hydrate, magnesium chloride hydrate) in a hydrocarbon solvent and reacting the salt, A method of directly reacting a trialkylaluminum with water in a compound solvent can be exemplified.

The use ratio of the aluminoxane to the transition metal compound in the present invention is 10 to 10,000 mol times, usually 50 to 5000.
It is molar times.

The polymerization method and polymerization conditions carried out by the method of the present invention are not particularly limited, and a known method carried out in the polymerization of α-olefin is used, and a solvent polymerization method using an inert hydrocarbon medium, or a substantially inert carbon method is used. A bulk polymerization method or a gas phase polymerization method without a hydride medium can also be used, and the polymerization is generally performed at a temperature of -100 to 200 ° C and a polymerization pressure of normal pressure to 100 kg / cm ² . Preferably, it is -50 ° C to 100 ° C and normal pressure to 50 kg / cm ² .

As the hydrocarbon medium used in the polymerization, for example, in addition to saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane, and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene are also included. Can be used.

The syndiotactic polypropylene of the present invention is ¹³ C-NM
In the R spectrum, the signal intensity of the methyl group belonging to the syndiotactic pentad chain is 0.8 or more of the signal intensity of all the methyl groups. That is, the syndiotactic pentad fraction (rr measured by ¹³ C-NMR spectrum)
rr) is 0.8 or more syndiotactic polypropylene.

The measurement of the ¹³ C-NMR spectrum was performed by dissolving the sample in a 10% −1,2,4-trichlorobenzene / deuterated benzene solution.
Measured in ° C.

In addition, the syndiotactic polypropylene of the present invention
The limiting viscosity number [η] measured in tetralin at 135 ° C is 0.01
It has a value in the range of 1010 dl / g, preferably in the range of 0.1 to 8.0 dl / g.

Further, the syndiotactic polypropylene of the present invention has a molecular weight distribution index (Mw / Mn) measured by gel permeation chromatography in the range of 1.5 to 20, preferably 2.0.
It is in the range of ~ 10.

The molecular weight distribution index (Mw / Mn) was measured by dissolving the sample in o-dichlorobenzene and performing gel permeation chromatography to calculate the number average molecular weight Mn and weight average molecular weight Mw in terms of polystyrene. The syndiotactic polypropylene has a melting point (Tm) measured by a differential scanning calorimeter (DSC) of 130 to 170 ° C, preferably 140 to 165 ° C.
The crystallization temperature (Tc) measured by a differential scanning calorimeter after complete melting is in the range of 105 to 125 ° C.

Melting point (Tm) and crystallization temperature (Tm) by differential scanning calorimetry
c) The measurement rate is 10 ° C / min
And the peak temperature was measured.

Furthermore, the isothermal half-crystallization rate (t _1/2 ) of the syndiotactic polypropylene measured at 110 ° C. by a differential scanning calorimeter is 2 minutes or less. The measurement of the isothermal half-crystallization rate is performed using a differential scanning calorimeter.
After complete dissolution at 110 ° C., it was defined as the time required for the peak due to crystallization to reach the peak at 110 ° C.

It is a syndiotactic polypropylene characterized by the above.

The poly-α-olefin obtained by the method of the present invention is characterized by a high crystallization temperature and a high crystallization rate.

When the crystallization speed is slow, it is difficult to crystallize when pelletizing the resin, it is difficult to cut the strand into pellets, or it is difficult to take out from the mold when molding the resin, but there is a problem when processing it. The poly-α-olefin obtained by the method can eliminate the conventional disadvantages.

〔Example〕

 Hereinafter, the present invention will be described specifically with reference to Examples.

Example 1 Synthesis of Metallocene Compound [1,4-biscyclopentadienylidenecyclohexane] In a 500 ml four-necked flask sufficiently purged with nitrogen, 15 g of 1,4-cyclohexanedione and 36 g of cyclopentadiene were dissolved in 200 ml of methanol. 34 ml of pyrrolidine is added to this solution at 0 ° C.
, And the mixture was returned to room temperature and stirred for 30 minutes. Acetic acid
The reaction was stopped by adding 28 ml, the solid was filtered off,
Further washed with methanol. Dry brown 1,
39 g of 4-biscyclopentadienylidenecyclohexane was obtained.

[1,4-biscyclopentadienyl-1,4-bifluorenylcyclohexane] Fluorene is placed in a 500 ml four-necked flask sufficiently purged with nitrogen.
16.6 g was dissolved in 150 ml of tetrahydrofuran and lithiated with methyllithium to obtain a solution of fluorenyllithium in tetrahydrofuran. A solution obtained by diluting 1,4 g of 1,4-biscyclopentadienylidenecyclohexane synthesized above with 200 ml of tetrahydrofuran was added to this solution.
It was added dropwise at 0 ° C. over 30 minutes. After completion of the dropwise addition, the reaction temperature was raised to room temperature, and stirring was continued for another 15 hours. The reaction was stopped by charging 200 ml of 3.6% aqueous hydrochloric acid, and the formed solid was separated by filtration and washed with ether. By drying, 18.5 g of 1,4-biscyclopentadienyl-1,4-bifluorenylcyclohexane as a white powder was obtained.

[1,4-Cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride] 1,4-biscyclopentadienyl-1,4-
By lithifying bifluorenylcyclohexane with n-butyllithium, a tetralithium salt of 1,4-biscyclopentadienyl-1,4-bifluorenylcyclohexane was prepared. Next, 6.1 g of zirconium tetrachloride was suspended in 100 ml of methylene chloride in a 500 ml glass flask which had been sufficiently purged with nitrogen. 0.013 mol of 1,4-biscyclopentadienyl-1,4- dissolved in this suspension at −78 ° C.
300 ml of a tetralithium salt of bifluorenylcyclohexane in methylene chloride were introduced. After stirring at −78 ° C. for 4 hours, the temperature was raised to room temperature, and the reaction was continued at that temperature for another 15 hours. The reddish-brown solution containing a white precipitate of lithium chloride was filtered off, concentrated, and cooled at −30 ° C. for 24 hours to give orange 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride. 3.1 g was obtained.

 The elemental analysis values of the product are shown below.

C wt% H wt% Clwt% Zr wt% Analytical value 58.6 3.72 16.5 21.2 Calculated value 58.1 3.78 16.7 20.4 The measurement results of ¹ H-NMR spectrum of this product are shown in FIG.

Polymerization method A 2-liter SUS autoclave was purged with nitrogen, charged with toluene, and the above-prepared 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride] 3.0 mg, Tosoh Akzo 0.4 g of a methylaluminoxane (polymerization degree: 17.7) manufactured by the Company was added. Add propylene and keep the system at 3kg / cm ² G while keeping
Polymerization was carried out at 0 ° C. for 1 hour.

After the polymerization, the slurry was taken out and filtered. After drying, 100.0 g of syndiotactic polypropylene powder was obtained. Further, the toluene soluble in the filtrate is distilled off under reduced pressure to remove toluene.
1 g was obtained.

The intrinsic viscosity (hereinafter abbreviated as η) measured with a tetralin solution of powder at 135 ° C. was 0.60 dl / g, and the molecular weight distribution index (Mw / Mn) measured by GPC (gel permeation chromatography) was 2.7. Was. ¹³ C-NMR was measured and about 2
The syndiotactic pentad fraction determined from the peak attributed to the 0.2 ppm methyl group was 0.91. Further, the obtained syndiotactic polypropylene was melted at 230 ° C. and cooled to 110 ° C., and the isothermal half-crystallization rate (t 1/2) was 1 minute and 22 seconds, the melting point was 149 ° C., and the crystallization temperature was 10 ° C.
7 ° C.

Example 2 Example 2 after replacing a 2 l SUS autoclave with nitrogen.
2.0 mg of 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride] synthesized in 1 above and 0.13 g of methylaluminoxane were added. 400 g of liquid propylene was introduced into the system, and polymerization was performed at 50 ° C. for 1 hour. Unreacted propylene was purged and dried under reduced pressure to obtain 197.0 g of syndiotactic polypropylene powder.

Η of powder is 0.52dl / g, (Mw / Mn) is 2.6, fraction of syndiotactic pentad is 0.83, t 1/2 is 1 minute 12 seconds,
The melting point was 145 ° C and the crystallization temperature was 106 ° C.

Comparative Example 1 Isopropylidene (cyclopentadienyl-9-fluorenyl) zirconium dichloride synthesized by a conventional method
Polymerization was carried out in the same manner as in [Polymerization method] of Example 1 except that 3.0 mg was used as a metallocene compound component. 126.4 g of the obtained syndiotactic polypropylene powder,
The amount of the soluble matter in toluene was 0.7 g. Η of powder is 1.39dl /
g, (Mw / Mn) is 2.2, syndiotactic pentad fraction is 0.91, t 1/2 is 3 minutes and 42 seconds, melting point 150 ° C., crystallization temperature 92
° C.

Example 3 Synthesis of metallocene compound 1,4-biscyclopentadienyl-1,4-bifluorenylcyclohexane 5 g synthesized in Example 1 was lithiated with n-butyllithium to give 1,4-bis. The tetralithium salt of cyclopentadienyl-1,4-bifluorenylcyclohexane was prepared.

Next, a mixture of 2.2 g of zirconium tetrachloride and 3.0 g of hafnium tetrachloride was suspended in 100 ml of a methylene chloride solution in a 500-ml glass flask sufficiently purged with nitrogen. This suspension was mixed with 1,4-biscyclopentadienyl-1,4- synthesized above.
300 ml of a methylene chloride solution of tetralithium salt of bifluorenylcyclohexane was charged at -78 ° C, and the mixture was stirred at -78 ° C for 4 hours, heated to room temperature, and further reacted at room temperature for 15 hours.

Filtering the reddish-brown solution containing a white precipitate of lithium chloride,
The filtrate was concentrated and cooled at −30 ° C. for 24 hours to precipitate a solid. After filtration and drying, 2.6 g of an orange solid was obtained.

 The elemental analysis of the orange solid was 52.16% for C, 3.21% for H, 14.33% for Cl, 9.04% for Zr, and 20.50% for Hf.

Polymerization test result After replacing 2 L of SUS autoclave with nitrogen, 2.0 mg of the orange solid synthesized above and 0.2 g of methylaluminoxane were added, and then 400 g of liquefied propylene was charged into the autoclave and polymerized at 50 ° C. for 1 hour. did.

Unreacted propylene was purged, and the resulting polymer was dried under reduced pressure to obtain 116.2 g of syndiotactic polypropylene powder.

The η of this powder was 0.93 dl / g, (Mw / Mn) was 6.8, and the syndiotactic pentad fraction was 0.82. Also t
1/2 had a melting point of 145 ° C and a crystallization temperature of 105 ° C for 1 minute and 50 seconds.

〔The invention's effect〕

The syndiotactic polypropylene obtained by the method of the present invention has a high crystallization rate, can improve the moldability, and is extremely valuable industrially.

[Brief description of the drawings]

FIG. 1 shows the result of ¹ H-NMR measurement of 1,4-cyclohexanediylidenebis [(cyclopentadienyl-9-fluorenyl) zirconium dichloride obtained in Example 1 of the present invention. FIG. 2 shows an X-ray diffraction pattern of the syndiotactic polypropylene of the present invention obtained in Example 1. In the figure, θ
Indicates the Bragg angle (°).

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08F 10/06 C08F 110/06 C08F 210/06 C08F 4/60-4/70 CAS ONLINE

Claims (1)

(57) [Claims] (1) The signal intensity of a methyl group belonging to a syndiotactic pentad chain in the ¹³ C-NMR spectrum is 0.8 or more of the signal intensity of all methyl groups, and (B) tetralin at 135 ° C. Measured intrinsic viscosity [η]
(C) gel permeation chromatography (GPC)
The molecular weight distribution index (Mw / Mn) measured in (1) is in the range of 1.5 to 20, and (D) the melting point (Tm) measured by a differential scanning calorimeter is 13
(E) The crystallization temperature (Tc) measured by differential scanning calorimetry after complete melting is in the range of 105-125 ° C, and (F) 110 ° C measured by differential scanning calorimetry. Syndiotactic polypropylene characterized in that the isothermal half-crystallization rate (t _1/2 ) obtained is 2 minutes or less