JP3489697B2 - Propylene-aromatic vinyl compound copolymer and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel propylene-aromatic vinyl compound copolymer and a method for producing the same, and more particularly to a copolymer having a specific stereoregularity in a propylene chain and an efficient method for producing the same.

[0002]

2. Description of the Related Art Propylene-aromatic vinyl compound copolymers, such as propylene-styrene copolymers, are polymers having excellent thermal oxidation resistance properties (Industrial Chemistry, 66 , 102 (1963), ibid. , 67 , 258 (1964)). Also,
High energy-radiation (electron beam,
It is known to significantly improve resistance to ultraviolet rays and γ rays (J. Appl. Polym. Sci., 9 , 1585 (196
Five) ). Furthermore, propylene-styrene random copolymers have conventionally been attempted to be synthesized by using a so-called heterogeneous Ziegler-Natta type catalyst using titanium trichloride or titanium tetrachloride (for example, Macromolecules, 22 , 2875 (19
89), JP-A-2-206602, JP-B-4-36168,
Japanese Patent Publication No. 1-14247). On the other hand, a propylene-styrene block copolymer is conventionally obtained by a method in which a polystyrene chain block is formed by anionic polymerization, and then a propylene chain is block-copolymerized at −78 ° C. with a vanadium catalyst (JP-A-3- 231706).

[0003]

However, when polypropylene and polystyrene are mixed, since the compatibility of polypropylene and polystyrene is poor, deterioration of physical properties other than the above high energy radiation resistance cannot be avoided. On the other hand, graft polymerization has many problems such as high cost and inability to obtain a uniform composition. Further, the propylene-styrene random copolymer with the above-mentioned heterogeneous Ziegler-Natta type catalyst has low catalyst productivity, the content of styrene is less than a few wt%, and the obtained copolymer is considerable. The amount of styrene homopolymer and propylene homopolymer is contained, and the copolymer itself is not uniform, so that it is not practical. Further, in order to use a propylene-styrene copolymer as a compatibilizing material for a crystalline polyolefin such as syndiotactic polypropylene and an amorphous polystyrene or as a thermoplastic elastomer, the above-mentioned heterogeneous Ziegler-Natta type is used. The propylene-styrene copolymer obtained with the catalyst has many problems such as insufficient styrene content and the polymer itself having a non-uniform composition. Also, due to the fate of the heterogeneous Ziegler-Natta catalyst used, its propylene unit has an isotactic structure. On the other hand, conventionally known block copolymers of styrene-propylene are not suitable for industrialization because they require cryogenic conditions for synthesis and require complicated multi-stage polymerization.

The object of the present invention is to make good use of the excellent properties (flexibility, flexibility, moldability, transparency) of syndiotactic polypropylene, while being excellent in heat oxidation resistance and high energy radiation resistance, and aromatic vinyl. A copolymer of a syndiotactic polypropylene and an aromatic vinyl compound, which has a high compound content and is useful as an additive of a crystalline polypropylene, a thermoplastic elastomer, a compatibilizing material of a syndiotactic polypropylene and an amorphous polystyrene, etc. Another object of the present invention is to provide a method for producing a propylene-aromatic vinyl compound copolymer with a high yield in a simple process suitable for industrialization. As a result of intensive studies by the present inventors, a novel propylene-aromatic vinyl compound copolymer having a propylene chain having a syndiotactic structure, a uniform composition, and a high aromatic vinyl compound content is obtained. It has been found that the combined product can be easily obtained in good yield by using a specific metal compound and a co-catalyst, and has completed the present invention.

[0005]

The propylene-aromatic vinyl compound copolymer of the present invention comprises propylene and an aromatic vinyl compound.
Produced by copolymerizing

[Chemical 3] The propylene structural unit formula (I) represented by

[Chemical 4] (In the formula, n is an integer from 0 to 5. Ph represents a phenyl group. R represents a halogen atom or a substituent having 1 to 8 carbon atoms. When n is plural, each R is the same or different. Of the aromatic vinyl compound structural unit formula (II), wherein the chain of the propylene structural unit formula (I) has a predominantly syndiotactic structure. When the vinyl compound structural unit formula (II) has a chain, it is a novel propylene-aromatic vinyl compound copolymer characterized in that the chain does not have a specific stereoregularity (however, a graft polymer Except if
Ku) . Further, in the propylene-aromatic vinyl compound copolymer of the present invention, a hetero bond of an aromatic vinyl compound unit structure represented by the following general formula (III) may be present.

[Chemical 5] (In the formula, n is an integer from 0 to 5. Ph represents a phenyl group. R represents a halogen atom or a substituent having 1 to 8 carbon atoms. When n is plural, each R is the same or different. May be.)

Examples of aromatic vinyl compounds include styrene and various substituted styrenes such as p-methylstyrene, o-methylstyrene, pt-butylstyrene and p-methylstyrene.
-Chlorostyrene, o-chlorostyrene and the like,
Further, a compound having a plurality of vinyl groups in one molecule such as divinylbenzene may be mentioned, but preferably styrene,
P-methylstyrene, particularly preferably styrene, is preferably used. The propylene-aromatic vinyl compound copolymer of the present invention has a weight average molecular weight of 1,000 to 1,000,000, preferably 2,000 to 500,000, more preferably 5,000 to 3
It is 0,000. If the molecular weight is too small, it is not preferable in terms of polymer physical properties, heat resistance, etc., and if the molecular weight is too large, processability deteriorates.

The tacticity of the chain of the propylene structure of the propylene-aromatic vinyl compound copolymer of the present invention is a syndiotactic index (racemic pentad; r).
rrr) is 20% or more, preferably 30% or more, and more preferably 70% or more. When the syndiotactic index is lower than 20%, the excellent properties (flexibility, suppleness, moldability, transparency) inherently possessed by syndiotactic polypropylene are lost. Aromatic vinyl compound copolymer aromatic vinyl compound in the body - propylene present invention
The content of 0.01 to 15 mol% is particularly preferable.
It is a range. When used for molded products, etc., 0.01 to 1
5 mol% , preferably in the range of 0.1 to 15 mol% . If it is lower than 0.01 mol%, the thermal oxidation resistance and high energy radiation resistance are not improved, and if it exceeds 50 mol%.
Originally, it is difficult to make use of the excellent properties (flexibility, flexibility, moldability, transparency) of syndiotactic polypropylene. Also, an additive of crystalline polypropylene,
When used as a compatibilizer of thermoplastic elastomer or syndiotactic polypropylene and amorphous polystyrene, the content of the aromatic vinyl compound is 1
-15 mol% , preferably 2-15 mol% , more preferably 4-15 mol% . When it is lower than 1 mol% or higher than 98 mol%, the physical properties as a thermoplastic elastomer are Loss, and the compatibility with syndiotactic polypropylene and amorphous polystyrene deteriorates.

The propylene-aromatic vinyl compound copolymer of the present invention can be produced by polymerizing propylene and an aromatic vinyl compound with the following metal compound as a catalyst. That is, the metal compound used as a catalyst in the present invention is a cyclopentadienyl group (Cp) having a substituent.
1) is a complex represented by the chemical formula 6 consisting of a ligand bridging a cyclopentadienyl group (Cp2) with or without a substituent and a metal (provided that two cyclope
Unless the ligands are the same) .

[Chemical formula 6]

Here, the cyclopentadienyl group having a substituent is simply a cyclopentadienyl group having a substituent having 1 to 20 carbon atoms such as an alkyl-substituted pentadienyl group, an allyl-substituted pentadienyl group, an alkoxy-substituted pentadienyl group and the like. Not only that, but having a cyclopentadiene structure in the molecule, for example, fluorenyl group having a substituent having 1 to 20 carbon atoms such as fluorenyl group, alkyl-substituted fluorenyl group, allyl-substituted fluorenyl group, alkoxy-substituted fluorenyl group, indenyl group, alkyl Substituted indenyl group, allyl-substituted indenyl group, shows an indenyl group having a substituent having 1 to 20 carbon atoms such as alkoxy-substituted indenyl group, preferably fluorenyl group, alkyl-substituted fluorenyl group, alkoxy-substituted fluorenyl group,
Particularly preferably, a fluorenyl group is used. The bridging group Y for bridging a substituted or unsubstituted cyclopentadienyl group or two pentadiene structures is substituted with two hydrogen atoms or two alkyl groups having 1 to 20 carbon atoms, an allyl group, a cycloalkyl group and the like. A carbon atom or a silicon atom having a group, for example, —CH ₂ —, —C (Me) ₂ —, —
C (Et) _2- , -C (Ph) _2- , -Si (Me) ₂
-, -Si (Et) _2-, and the like. In this case, the two substituents may be the same or different, and the two substituents may be bonded to each other to form a ring. As crosslinking groups Y, preferably _{-CH 2 -, - C (Me} ) 2 -, - C
(Ph) ₂ − is used. (Here, Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.)

As the metal (M), a transition metal of Group IV of the periodic table is used, and zirconium, hafnium and the like are preferably used. X is a halogen such as chlorine, bromine or iodine, or an alkyl group such as a methyl group, a phenyl group or a benzyl group. n is an integer of 1 to 7, and takes 2 when the metal (M) is zirconium or hafnium, and takes 1 or 2 when the metal (M) is titanium. When n is 2 or more, X may be the same or different.

In copolymerizing propylene and an aromatic vinyl compound in the present invention, it is preferable to use an organoaluminum compound and / or a boron compound as a cocatalyst together with the above metal compound. Alumoxane is suitable as the organoaluminum compound used as a cocatalyst. Alumoxane is the following general formula

[Chemical 7] Or the following general formula

[Chemical 8] (In either of Chemical formula 7 and Chemical formula 8, R may be the same or different and each is an alkyl group having 1 to 5 carbon atoms, most preferably a methyl group having 1 carbon atom, m and n are 2 to 100.
It is a cyclic or chain compound represented by. If desired, a mixture of these different types of alumoxanes may be used. Further, these alumoxanes and alkylaluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum and dimethylaluminum chloride may be used in combination.

The boron compound used as a cocatalyst is N,
N-dimethylanilinium tetra (pentafluorophenyl) borate, trityl tetra (pentafluorophenyl) borate, tri (pentafluorophenyl) borate and the like. The boron compound and the organoaluminum compound may be used at the same time. Particularly when a boron compound is used as a co-catalyst, it is effective to add an alkylaluminum compound such as triisobutylaluminum to remove impurities such as water contained in the polymerization system, which adversely affect the polymerization. .

In producing the copolymer of the present invention, the metal compound and the cocatalyst exemplified above are brought into contact with propylene and an aromatic vinyl compound, but polymerization is carried out in a liquid monomer without using a solvent. , Pentane,
There is a method of using a saturated aliphatic or aromatic hydrocarbon alone or in a mixed solvent such as hexane, heptane, cyclohexane, benzene, toluene, xylene, chloro-substituted benzene, chloro-substituted toluene. Further, if necessary, a method such as batch polymerization, continuous polymerization, batch polymerization, or preliminary polymerization can be used.

The polymerization temperature is suitably -78 ° C to 200 ° C, preferably 0 ° C to 140 ° C. A polymerization temperature lower than -78 ° C is industrially disadvantageous, and a temperature above 200 ° C is not suitable because decomposition of the metal compound occurs. When carrying out the method of the present invention, the concentration of the metal compound in the polymerization reaction solution is 10 ^-9 to 10 ^-2 mol / liter, preferably 10 ^-8.
It is from 10 to ³ mol / liter. When an organoaluminum compound is used as a cocatalyst, the atomic ratio of aluminum to the complex metal is 0.1 to 100,000, preferably 1 to 1000. If it is less than 0.1, the metal compound cannot be effectively activated, and if it exceeds 100,000, it is economically disadvantageous. When a boron compound is used as the co-catalyst, it is used in a boron atom / complex metal atom ratio of 0.01 to 100, preferably 0.00.
1 to 10, particularly preferably 1 is used. If it is smaller than 0.01, the metal compound cannot be effectively activated and 100
If it exceeds, it will be economically disadvantageous. The metal compound and the cocatalyst may be mixed and prepared outside the polymerization tank, or may be mixed inside the tank during the polymerization.

[0015]

The present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited by the examples. The symbols used in the chemical formulas used below are Flu for a fluorenyl group, Ph for a phenyl group, and Cp.
Represents a cyclopentadienyl group, and Me represents a methyl group. (Example 1) {Flu-C (Ph) _2- Cp} ZrCl
₂ in J. Amer. Chem. Soc., 110, 6255 (1988) and Makromol. Chem., Macromol. Symp. 48/49, 253 (19).
It was synthesized with reference to the method described in 91). The chemical structure is represented by:

[Chemical 9]

[Flu-C (Ph) ₂ -Cp} ZrCl _{2 was} added to an autoclave having a capacity of 120 ml which was replaced with nitrogen.
0.023 mmol of methylalumoxane (manufactured by Toso-Akzo, MMAO-3A) was used at 14 mmo based on Al atom.
1, 10 ml of styrene and 16 ml of toluene are charged, and immediately, while cooling the autoclave to about -30 ° C in a liquid nitrogen bath, about 3 L (standard state) of propylene is charged. After that, the autoclave is heated, heated to 50 ° C. over about 30 minutes, and further reacted at 50 ° C. for 1 hour. After completion of the reaction, excess propylene is released. The content solution was poured into a large excess of hydrochloric acid / methanol mixed solution, and the polymer was recovered and dried under reduced pressure at 60 ° C. for 10 hours to obtain 2.5 g of a white polymer.

(Example 2) 0.5 ml of styrene used
Polymerization was carried out in the same manner as in Example 1 except that the above was used to obtain 3.5 g of a white polymer. (Example 3) Polymerization was carried out in the same manner as in Example 1 except that 10 ml of paramethylstyrene was used instead of styrene, and 4 g of a white polymer was obtained.

(Example 4) {Flu-C (Ph) ₂ -C
To a highly dehydrated methylene chloride solution containing 0.046 mmol of p} ZrCl ₂ was added 0.092 mmol of MeLi / diethyl ether solution, and the mixture was stirred at room temperature for 1 hour, and the solvent was sufficiently removed under vacuum to remove {Flu-C (Ph) ₂ -C
p} Zr (Me) ₂ was obtained as a yellow solid. The whole amount of the obtained {Flu-C (Ph) ₂ -Cp} Zr (Me) ₂ was dissolved in 16 ml of dehydrated toluene, and {HPhNMe ₂ B (C
₆ F ₅ ) ₄ } (manufactured by Toso-Akzo Co., Ltd.) at 0.046 mmo
1 was added. The mixture was stirred at room temperature for 1 hour, charged with about 0.5 mmol of triisobutylaluminum and 10 ml of styrene, and then polymerized in the same manner as in Example 1 to give 4.5 g.
Of white polymer was obtained.

Example 5 {Flu-C (Ph)₂-C
p} HfCl₂To {Flu-C (Ph)₂-Cp} Z
rCl₂Was synthesized in the same manner as. {Flu-C (P
h)₂-Cp} ZrCl₂Instead of {Flu-C (P
h) ₂-Cp} HfCl₂Using 0.023 mmol
Polymerization was carried out in the same manner as in Example 1 except that
Then, 0.9 g of a white polymer was obtained.

(Analysis method and analysis results) Examples 1 to 5
The polymer obtained in 1. was analyzed by the following means. ¹³ C-NMR analysis was performed by JEOL Ltd. JNM GX-
270, using a mixed solvent of o-dichlorobenzene and heavy benzene. 1 and 2 show the ¹³ C-NMR chart of the polymer obtained in Example 1. Further, phenyl C1 carbon and phenyl C4 carbon are shown in FIG.
In the alkyl region shown in FIG. 1, large peaks derived from methyl carbon, methine carbon, and methylene carbon of syndiotactic polypropylene are 20.3, 28.6,
It is found near 47.4 ppm. Syndiotactic index (racemic pentad; rrrr) is about 90
%Met. Syndiotactic index of the above propylene chain region (racemic pentad; rrrr)
, Makromol. Chem., Macromol. Symp. 48/49, 2
53 (1991) and determined from the ¹³ C-NMR methyl carbon region. Further, peaks derived from the copolymerization of propylene and styrene are found around 44, 36 to 37, 31, and 18 ppm.

Phenyl C of the styrene unit shown in FIG.
In the 1-carbon region, a peak is recognized around 144.2 to 144.5 ppm. This peak is considered to be phenyl C1 carbon of styrene copolymerized with propylene, unlike 146 ppm of atactic polystyrene, 146.8 ppm of isotactic polystyrene, and 145.2 ppm of syndiotactic polystyrene. FIGS. 4 and 5 show ¹³ C of the polymer obtained in Example 3.
-Indicates NMR. In the alkyl region shown in FIG. 4, the peak derived from syndiotactic polypropylene, the peak derived from the copolymerization of propylene and paramethylstyrene (30 to 31, 35.5 to 36.5, 44 to 45 ppm).
In addition, a peak attributed to the atactic poly (paramethylstyrene) chain is observed around 40.5 ppm.
FIG. 5 shows peaks (141, 143) derived from phenyl C1 carbon of paramethylstyrene copolymerized with propylene.
In addition to (around ppm), a broad peak (142 to 144 ppm) derived from phenyl C1 carbon of an atactic poly (paramethylstyrene) chain is observed. Also, phenyl C of paramethylstyrene copolymerized with propylene
Peak derived from 4 carbons, 135 ppm in addition to phenyl C4 of atactic poly (paramethylstyrene) chain
The broad peak derived from carbon is 134.5-13.
Found at 5.5 ppm. That is, in the polymer obtained in Example 3, there was a specific paramethylstyrene chain having no stereoregularity.

The determination of the styrene content in the polymer is carried out by ¹ H
-It carried out by NMR and it showed in FIG. As for the equipment, JNM GX-270 manufactured by JEOL Ltd. was used, a heavy chloroform solvent was used, and a shift value (TMS standard) of a peak derived from a phenyl group proton of 6 to 7.5 ppm and an alkyl group of 0.5 to 3 ppm. Of the intensity of the proton peak of The glass transition point and the melting point were determined using a DSC-200 manufactured by Seiko Denshi KK under a nitrogen atmosphere at a temperature rising rate of 10 ° C./min.
The above analysis results are shown in Table 1.

[0023]

[Table 1]

The polymer obtained in Example 1 was dissolved in boiling chloroform, and the GPC spectrum was measured by using both RI and UV detectors under the measuring conditions of chloroform at a measuring temperature of 30 ° C. . Equipment is Tosoh SC
-8010 was used. The results are shown in FIGS. 7 and 8. R
Molecular weight distribution curve obtained from I detector (corresponding to the total molecular weight distribution of polypropylene and styrene regions of polymer) and molecular weight distribution curve obtained from UV detector (FIG. 8 (only for phenyl group of styrene)) (Corresponding to the molecular weight distribution of the styrene region in the polymer), the effluent time and the shape of the curve are almost in agreement. Therefore, it can be seen that styrene is uniformly dispersed in the copolymer. As for the molecular weight, the weight average molecular weight (Mw) was 43000, the number average molecular weight (Mn) was 25,000, and the molecular weight distribution (Mw / Mn) was 1.7.

(Comparative Example 1) Nitrogen-substituted capacity 120 m
1 autoclave to {Flu-C (Ph) ₂ -C
p} ZrCl ₂ 0.023 mmol, methylalumoxane (manufactured by Toso-Akzo, MMAO-3A) 14 mmol based on Al atom, styrene 10 ml, toluene 16 m
1 was charged, and homopolymerization of styrene was carried out at 50 ° C. for 1 hour in a nitrogen atmosphere without using propylene. As in the case of Example 1, the content liquid was poured into a large excess of hydrochloric acid / methanol mixed liquid, but no polymer was obtained. From the above results and the results of the examples, {Flu-C (Ph) ₂ -Cp} Z
Although rCl ₂ does not exhibit homopolymerization activity of styrene, it is confirmed that rCl ₂ exhibits a unique polymerization ability of incorporating styrene into a polymer when propylene coexists, that is, developing styrene copolymerization ability.

(Comparative Example 2) {Flu-C (Ph) ₂ -C
p} ZrCl ₂ instead of Cp ₂ ZrCl ₂ 0.02
Polymerization was carried out in the same manner as in Example 1 except that 3 mmol was used, and 2.8 g of a liquid product was obtained.
As a result of ¹³ C-NMR, the propylene chain was atactic, and as a result of GPC measurement, it was found to be an oligomer having a molecular weight of about 1000.

[0027]

EFFECTS OF THE INVENTION According to the present invention, the propylene chain has a syndiotactic structure and a uniform composition, and the aromatic vinyl compound content is high, so that the syndiotactic polypropylene has excellent properties (flexibility, flexibility and flexibility). Stableness, moldability and transparency), while being excellent in heat and oxidation resistance and high energy and radiation resistance, it is also an additive for crystalline polypropylene, a thermoplastic elastomer, a compatibilizing material for syndiotactic polypropylene and amorphous polystyrene. A novel copolymer of syndiotactic polypropylene and an aromatic vinyl compound, which is useful as, for example, was obtained. Further, by using a specific metal compound and a cocatalyst, a production method suitable for industrialization and having a high yield was obtained.

[Brief description of drawings]

FIG. 1 is a ¹³ C-NMR spectrum of the polymer obtained in Example 1. Alkyl carbon region.

FIG. 2 is a ¹³ C-NMR spectrum of the polymer obtained in Example 1. Aromatic (phenyl) carbon region.

FIG. 3. Phenyl C1 carbon and phenyl C4 carbon.

FIG. 4 is a ¹³ C-NMR spectrum of the polymer obtained in Example 3. Alkyl carbon region.

FIG. 5 is a ¹³ C-NMR spectrum of the polymer obtained in Example 3. Aromatic (phenyl) carbon region.

FIG. 6 is a ¹ H-NMR spectrum (solvent: CDCl ₃ ) of the polymer obtained in Example 1.

7 is a GPC spectrum of the polymer obtained in Example 1. FIG. The detector uses RI.

FIG. 8 is a GPC spectrum of the polymer obtained in Example 1. UV is used for the detector.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-178407 (JP, A) JP-A-4-348114 (JP, A) JP-A-4-300904 (JP, A) JP-A-2- 206602 (JP, A) JP-A-63-113002 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 4/60-4/70 C08F 6/00-246/00 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. Produced by copolymerizing propylene and an aromatic vinyl compound, which has the following general formula: The propylene structural unit formula (I) represented by the following general formula: (In the formula, n is an integer from 0 to 5. Ph represents a phenyl group. R represents a halogen atom or a substituent having 1 to 8 carbon atoms. When n is plural, each R is the same or different. A copolymer of the aromatic vinyl compound structural unit formula (II) represented by the formula (II), wherein the content of the aromatic vinyl compound is 0.01 to 15 mol% , and the propylene structural unit is The chain of the formula (I) has a structure having a syndiotactic index of 20% or more, the aromatic vinyl compound structural unit formula (II) has no chain, or the aromatic vinyl compound structural unit formula (II) chain Has no specific stereoregularity, and has a weight average molecular weight of 100.
Propylene-aromatic vinyl compound copolymer of 0 to 1,000,000 (excluding the case of a graft polymer). 2. A metal compound containing a group IV transition metal and a ligand obtained by bridging a cyclopentadienyl group having a substituent and a cyclopentadienyl group having a substituent or not. The propylene-aromatic vinyl compound copolymer according to claim 1, wherein propylene and the aromatic vinyl compound are copolymerized using (as a catalyst) two cyclopentadienyl ligands are the same). Method for producing polymer. 3. The method for producing a propylene-aromatic vinyl compound copolymer according to claim 2, wherein a compound containing organoaluminum and / or boron is used as the cocatalyst.