JP2840605B2 - Styrene copolymer and method for producing the same - Google Patents

Description

The present invention relates to a styrene-based copolymer and a method for producing the same, and more particularly, to a copolymer having a specific stereostructure composed of a styrene-based monomer and an olefin-based monomer, and It relates to the efficient manufacturing method.

[Problems to be solved by conventional technology and invention]

Conventionally, a styrene-based polymer produced by a radical polymerization method or the like has a three-dimensional structure having an atactic structure, and various molding methods such as injection molding, extrusion molding, hollow molding, vacuum molding, and injection molding. Depending on the method, it is formed into various shapes and widely used as household electrical appliances, office equipment, household goods, packaging containers, toys, furniture, synthetic paper and other industrial materials.

However, such a styrenic polymer having an atactic structure has a disadvantage that heat resistance and chemical resistance are inferior.

By the way, the group of the present inventors has recently succeeded in developing a styrene-based polymer having high syndiotacticity, and further developed a styrene-based polymer obtained by copolymerizing this styrene monomer and other components ( JP-A-62-10
Nos. 4818 and 63-241009). These syndiotactic polymers or copolymers have heat resistance,
It has excellent chemical resistance and electrical properties, and is expected to be used in various fields.

However, the above polymers, especially syndiotactic polystyrene, have a high glass transition temperature, and have a problem that their properties cannot be sufficiently exhibited unless the injection molding temperature is set high. In addition, molded products molded with a high-temperature mold
There is room for improvement in impact resistance. Further, the above-mentioned polymer has a disadvantage that it has poor compatibility with polyolefins such as polyethylene and polypropylene.

From the viewpoint of olefin polymers characterized by flexibility,
There is room for improvement in solvent resistance, heat resistance, and impact strength.

Accordingly, the present inventors have conducted intensive research to lower the glass transition temperature of syndiotactic polystyrene, thereby enabling low-temperature injection molding, improving impact resistance, and further improving compatibility with polyolefin. Was piled up.

[Means for solving the problem]

As a result, when a styrene monomer and an olefin monomer are copolymerized in the presence of a specific catalyst, a copolymer having a structure in which an olefin component is copolymerized with a styrene-based repeating unit chain having a syndiotactic structure is generated. It has been found that the copolymer has a low glass transition temperature, has good compatibility with polyolefin, and can achieve the desired modification. The present invention has been completed based on such findings.

That is, the present invention provides a compound represented by the general formula [I]: [Wherein R ¹ is a hydrogen atom, a halogen atom or
Or less hydrocarbon groups, and n represents an integer of 1 to 3.
When n is plural, each R ¹ may be the same or different. A styrene-based repeating unit represented by the general formula [II] [In the formula, R ² represents a hydrogen atom or a saturated hydrocarbon group having 20 or less carbon atoms. The olefinic repeating unit represented by the formula (1), containing 0.1 to 99.9% by weight of the olefinic repeating unit, and having an intrinsic viscosity of 0.07 to 20 dl / g measured in 1,2,4-trichlorobenzene at 135 ° C. And a styrenic copolymer characterized by having a syndiotactic structure having a high stereoregularity of the styrenic repeating unit chain, and a compound represented by the general formula [I '] Wherein R ¹ and n are the same as above. A styrene monomer represented by the general formula [II ']: Wherein R ² is the same as above. ] It is intended to provide a process for producing the styrene-based copolymer as described above, wherein the olefin-based monomer represented by the formula is copolymerized in the presence of a catalyst comprising a transition metal compound and an alkylaluminoxane.

The styrenic copolymer of the present invention comprises a repeating unit represented by the general formula [I] and a repeating unit represented by the general formula [II] as described above, wherein the repeating unit represented by the general formula [I] is used. Is derived from the styrenic monomer represented by the general formula [I ']. In the formula, R ¹ is a hydrogen atom, a halogen atom (eg, chlorine, bromine, fluorine, iodine) or 20 or less carbon atoms, preferably 10 to 1 carbon atoms.
Hydrocarbon groups (for example, a saturated hydrocarbon group (especially an alkyl group) such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group) or an unsaturated hydrocarbon group such as a vinyl group. Specific examples of the repeating unit represented by the general formula (I) include styrene units; p-methylstyrene units; m-methylstyrene units; o-methylstyrene units; 2,4-dimethylstyrene units; 2,5- Dimethylstyrene unit; 3,4-dimethylstyrene unit; 3,5-dimethylstyrene unit; p-ethylstyrene unit; m-ethylstyrene unit; alkylstyrene unit such as p-tert-butylstyrene unit, p-divinylbenzene unit m-divinylbenzene unit; trivinylbenzene unit; p-chlorostyrene unit; m-chlorostyrene unit; o-chlorostyrene unit; p-bromostyrene unit; m-bromostyrene unit; o-
Bromostyrene units; p-fluorostyrene units; m-fluorostyrene units; o-fluorostyrene units; halogenated styrene units such as o-methyl-p-fluorostyrene units, or a mixture of two or more of these. Can be

On the other hand, the repeating unit represented by the general formula [II] is derived from the olefin monomer represented by the above general formula [II ']. In the formula, R ² is a hydrogen atom or an olefin having 20 or less carbon atoms, preferably a hydrogen atom or an olefin having 10 to 1 carbon atoms, specifically, ethylene;
Propylene; 1-butene; 1-pentene; 3-methyl-butene-1; 1-hexene; 3-methyl-pentene-1; 4-methyl-
Olefins such as pentene-1; 1-octene; 1-decene are used. Of these, ethylene, propylene,
-Butene, 1-hexene or mixtures thereof are preferred.
More preferably, it is ethylene, propylene or a mixture thereof. In the copolymer of the present invention, the repeating unit (I) may be composed of two or more components,
In this regard, the same applies to the repeating unit [II]. Therefore, it becomes possible to synthesize a binary, ternary or quaternary copolymer. The content of the repeating unit [II] is usually in the range of 0.1 to 99.9% by weight, preferably 1 to 99% by weight, and more preferably 5 to 95% by weight of the whole copolymer. If the content of the repeating unit [II] is less than 0.1% by weight, the desired improvement effects of the present invention, such as lowering of glass transition temperature and improvement of impact resistance, cannot be achieved. On the other hand, when the content exceeds 99.9% by weight, the heat resistance characteristic of the styrene polymer having a syndiotactic structure is not exhibited.

The molecular weight of this copolymer is generally 0.07 as measured by a 1,2,4-trichlorobenzene solution (at a temperature of 135 ° C.).
2020 dl / g, preferably 0.3 to 10 dl / g. If the intrinsic viscosity is less than 0.07 dl / g, the mechanical properties are low and cannot be put to practical use. On the other hand, if the intrinsic viscosity exceeds 20 dl / g, it is not suitable for ordinary melt molding.

In the present invention, a third component may be added within a range that does not significantly impair the properties of the obtained copolymer or the syndiotactic structure in the chain of the repeating unit [I]. Such compounds include, for example, dienes,
Examples include vinylsiloxanes, unsaturated carboxylic esters, acrylonitrile, and the like.

The styrenic copolymer of the present invention has a repeating unit (I),
That is, a chain of styrene-based repeating units has a high syndiotactic structure. Here, the advanced syndiotactic structure in the styrene-based polymer is a syndiotactic structure having a high stereochemical structure, that is, a carbon-
It has a steric structure in which phenyl groups and substituted phenyl groups, which are side chains, are alternately located in opposite directions with respect to the main chain formed from carbon bonds, and its tacticity is determined by a nuclear magnetic resonance method using isotope carbon ( ¹³ C-NMR method). Tacticity measured by ¹³ C-NMR method is
The abundance ratio of a plurality of continuous structural units, for example, two can be indicated by a dyad, three may be indicated by a triad, and five may be indicated by a pentad, the advanced syndiotactic structure referred to in the present invention. A styrene-based copolymer having at least 75%, preferably at least 85%, or at least 30%, preferably at least 50%, of racemic dyads in a chain of styrene-based repeating units. The one having tisity is shown. However, the degree of syndiotacticity slightly varies depending on the type of the substituent and the content of the repeating unit [II].

The copolymer of the present invention as described above has a repeating unit [I],
An embodiment having desired stereoregularity and reactive substituents by copolymerization of a monomer corresponding to [II], and by applying a separation, blending or organic synthesis method using the obtained copolymer as a raw material. Can be manufactured.

Among them, according to the production method of the present invention described above, a styrene-based copolymer with higher efficiency and higher quality can be obtained.

The raw material monomers used in the production method of the present invention are a styrene monomer represented by the general formula [I '] and an olefin monomer represented by the general formula [II']. The styrene monomer and the olefin monomer are copolymerized to form repeating units [I] and [II], respectively.
Therefore, specific examples of the styrene-based monomer and the olefin-based monomer include those corresponding to the specific examples of the above-mentioned repeating units [I] and [II].

In the method of the present invention, these styrene-based monomers and olefin-based monomers are used as raw materials and copolymerized in the presence of a catalyst containing (A) a transition metal compound and (B) aluminoxane as main components.

Here, there are various transition metal compounds as the component (A) of the catalyst. [Wherein, R ^{3 to} R ¹⁴ each represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 7 to 20 carbon atoms. An arylalkyl group, an aryloxy group having 6 to 20 carbon atoms,
It represents an acyloxy group having 1 to 20 carbon atoms, acetylacetonyl group, cyclopentadienyl group, substituted cyclopentadienyl group or indenyl group. A, b, and c each represent an integer of 0 or more satisfying 0 ≦ a + b + c ≦ 4, d and e each represent an integer of 0 or more satisfying 0 ≦ d + e ≦ 3, and f represents 0 ≦ f ≦ 2. And h and k each represent an integer of 0 or more that satisfies 0 ≦ h + k ≦ 3.
Further, M ¹ and M ² represent titanium, zirconium, hafnium or vanadium, and M ³ and M ⁴ represent vanadium. ] At least one compound selected from the transition metal compounds represented by Among these transition metal compounds,
Preferably, M ¹ in the general formula (α) is titanium or zirconium.

Here, among those represented by R ^{3 to} R ¹⁴ in the above formula,
Specific examples of the halogen atom include chlorine, bromine, iodine and fluorine. The substituted cyclopentadienyl group is, for example, a cyclopentadienyl group substituted by one or more alkyl groups having 1 to 6 carbon atoms, specifically, a methylcyclopentadienyl group; Pentadienyl group; 1,3-dimethylcyclopentadienyl group; 1,3,4-trimethylcyclopentadienyl group; pentamethylcyclopentadienyl group and the like.

R ^{3 to} R ¹⁴ in the above formula are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms (specifically, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group) Group, isoamyl group, octyl group, 2-ethylhexyl group), alkoxy group having 1 to 20 carbon atoms (specifically, methoxy group, ethoxy group, propoxy group, butoxy group, hexyloxy group, octyloxy group, 2- Ethylhexyloxy group, etc.), aryl group having 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.), arylalkyl group having 7 to 20 carbon atoms (specifically, benzyl group, phenethyl group, 9 -Anthrylmethyl group) and an acyloxy group having 1 to 20 carbon atoms (specifically, an acetyloxy group, a stearoyloxy group, etc.). These R ^{3 to} R ¹⁴ may be the same or different as long as the above conditions are satisfied. In addition to monodentate ligands,
The ligands may be bonded to each other to form a bidentate or higher polydentate ligand.

More preferably, R is a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z are each independently a hydrogen atom, a carbon atom or a carbon atom. Represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, or a halogen atom. . ] It is a titanium compound represented by these. The substituted cyclopentadienyl group represented by R in the formula has, for example, 1 to 1 carbon atoms.
A cyclopentadienyl group substituted with one or more alkyl groups, specifically a methylcyclopentadienyl group;
-Dimethylcyclopentadienyl group; 1,3-dimethylcyclopentadienyl group; 1,3,4-trimethylcyclopentadienyl group; pentamethylcyclopentadienyl group and the like. X, Y and Z each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (specifically, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, an amyl group, an isoamyl group, Octyl group, 2-ethylhexyl group, etc., alkoxy group having 1 to 12 carbon atoms (specifically, methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy Group), an aryl group having 6 to 20 carbon atoms (specifically, a phenyl group, a naphthyl group, etc.),
20 aryloxy groups (specifically, a phenoxy group, etc.),
It represents an arylalkyl group having 6 to 20 carbon atoms (specifically, a benzyl group) or a halogen atom (specifically, chlorine, bromine, iodine or fluorine).

Specific examples of such a titanium compound represented by the general formula (ζ) include cyclopentadienyltrimethyltitanium, cyclopentadienyltriethyltitanium, cyclopentadienyltripropyltitanium, cyclopentadienyltributyltitanium, methylcyclo Pentadienyltrimethyltitanium, 1,2-dimethylcyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltriethyltitanium, pentamethylcyclopentadienyltripropyltitanium, pentamethylcyclopenta Dienyltributyltitanium, cyclopentadienylmethyltitanium dichloride, cyclopentadienylethyltitanium dichloride, pentamethylcyclopentadienylmethyltitanium dichloride, pentamethyl Cyclopentadienylethyl titanium dichloride, cyclopentadienyl dimethyl titanium monochloride, cyclopentadienyl diethyl titanium monochloride, cyclopentadienyl titanium trimethoxide, cyclopentadienyl titanium triethoxide, cyclopentadienyl titanium trichloride Propoxide, cyclopentadienyl titanium triphenoxide, pentamethylcyclopentadienyl titanium trimethoxide, pentamethylcyclopentadienyl titanium triethoxide, pentamethylcyclopentadienyl titanium tripropoxide, pentamethylcyclopentadienyl Titanium tributoxide, pentamethylcyclopentadienyl titanium triphenoxide, cyclopentadienyl titanium trichloride,
Pentamethylcyclopentadienyl titanium trichloride, cyclopentadienyl methoxy titanium dichloride,
Cyclopentadienyldimethoxytitanium chloride, pentamethylcyclopentadienylmethoxytitanium dichloride, cyclopentadienyltribenzyltitanium, pentamethylcyclopentadienylmethyldiethoxytitanium,
Examples include indenyl titanium trichloride, indenyl titanium trimethoxide, indenyl titanium triethoxide, indenyl trimethyl titanium, indenyl tribenzyl titanium and the like.

On the other hand, aluminoxane is used as the component (B) constituting the main component of the catalyst together with the component (A) of the transition metal compound. [In the formula, R ¹⁵ represents an alkyl group having 1 to 8 carbon atoms, and r represents 2 to 50. ] The alkylaluminoxane represented by these is mentioned. The alkylaluminoxane can be prepared by various methods, for example, a method of dissolving an alkylaluminum in an organic solvent, contacting it with water, initially adding the alkylaluminum at the time of polymerization, and subsequently adding water. In addition, there is a method of reacting water of crystallization contained in a metal salt or the like, or water adsorbed on an inorganic substance or an organic substance with alkyl aluminum. The water may contain up to about 20% of ammonia, amines such as ethylamine, sulfur compounds such as hydrogen sulfide, and phosphorus compounds such as phosphite.

(B) Preferred examples of the alkyl aluminoxane is used as the component, aluminum is observed by proton nuclear magnetic resonance absorption method - methyl (Al-CH ₃₎ high magnetic field component in the methyl proton signal region based on the coupling of the following 50% Things. That is, when the above contact product is observed for proton nuclear magnetic resonance ( ¹ H-NMR) spectrum in a toluene solvent at room temperature, the methyl proton signal based on Al—CH ₃ is based on tetramethylsilane (TMS). 1.0 ~
It is found in the range of -0.5 ppm. TMS proton signal (0
ppm) is in the methyl proton observation region based on Al-CH ₃ , and this methyl proton signal based on Al-CH ₃ is
Toluene methyl proton signal 2.35pp
m, the high magnetic field component (i.e., -0.1 to -0.0.
5 ppm) and another magnetic field component (i.e., 1.0 to -0.1 ppm), the high magnetic field component accounts for 50% or less, preferably 45 to 5% of the total of the catalyst of the present invention. (B) It can be used as a component.

The catalyst used in the method of the present invention comprises the above-mentioned components (A) and (B) as main components. In addition to the above-mentioned components, if desired, other catalyst components may further have a general formula AlR ¹⁶ ₃ [wherein R ¹⁶ Represents an alkyl group having 1 to 8 carbon atoms. Trialkyl aluminum or other organometallic compounds represented by] can be added, also, the general formula W-R ¹⁷ in a range that does not impair the stereoregularity ^{_{- (Q) m -R 18 -W}} '...... (θ Wherein R ¹⁷ and R ¹⁸ are a hydrocarbon group having 1 to 20 carbon atoms, a substituted aromatic hydrocarbon group having 7 to 30 carbon atoms, or a carbon atom having a substituent containing a heteroatom such as oxygen, nitrogen or sulfur. Represents a substituted aromatic hydrocarbon group having the number of 6 to 40, and Q represents a hydrocarbon group having 1 to 20 carbon atoms, -O-, -S-, -SS-, (R ¹⁹ is a hydrocarbon group having 1 to 6 carbon atoms).
W and W 'represent a hydroxyl group, an aldehyde group and a carboxyl group, and m represents an integer of 0 to 5. ] The organic compound represented by these can be added.

Specific examples of the organic compound represented by the general formula (θ) include, for example, 2,2′-dihydroxy-3,3′-di-t-
Butyl-5,5'-dimethyldiphenyl sulfide; 2,2 '
-Dihydroxy-3,3'-di-t-butyl-5,5'-dimethyldiphenyl ether.

In using this catalyst, the ratio of the component (A) to the component (B) in the catalyst depends on the type of each component, the styrene monomer represented by the general formula [I '] as a raw material, and the general formula [II ']], But it cannot be unambiguously determined depending on the type of the olefin-based monomer and other conditions.
Usually, the ratio of aluminum in component (B) to titanium in component (A), ie, aluminum / titanium (molar ratio)
As, 10 ^6, preferably 10 to 10 ^4.

In the method of the present invention, the styrene monomer represented by the general formula [I '] and the styrene monomer represented by the general formula [II'] are used in the presence of a catalyst containing the above components (A) and (B) as main components. The olefin-based monomer is copolymerized, and this copolymerization can be carried out by various methods such as bulk polymerization, solution polymerization and suspension polymerization. Solvents that can be used in the copolymerization include aliphatic hydrocarbons such as pentane, hexane, heptane, and decane; alicyclic hydrocarbons such as cyclohexane; and aromatic hydrocarbons such as benzene, toluene, and xylene. The polymerization temperature is not particularly limited, but is usually 0 to 100 ° C, preferably 10 to 70 ° C.
The polymerization time is 5 minutes to 24 hours, preferably 1 hour or more.

Further, in order to adjust the molecular weight of the obtained styrenic copolymer, it is effective to carry out the copolymerization reaction in the presence of hydrogen.

The styrenic copolymer obtained by the method of the present invention has high syndiotacticity of a styrenic repeating unit chain, but after polymerization, if necessary, is subjected to deashing treatment with a washing solution containing hydrochloric acid or the like, After washing and drying under reduced pressure, the residue is washed with a solvent such as methyl ethyl ketone to remove soluble components, and a high-purity styrene copolymer having extremely large syndiotacticity can be obtained.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

Glass container of Example 1 (1) (B) internal volume 500ml prepared argon aluminoxane, toluene 200 ml, copper sulfate pentahydrate _{(CuSO 4 · 5H 2 O)} 17.8g (71 mmol) and trimethyl aluminum 24ml (250 mmol) and reacted at 40 ° C. for 8 hours. Thereafter, toluene was further distilled off under reduced pressure from the solution obtained by removing the solid component to obtain 6.7 g of a contact product (methylaluminoxane).
Its molecular weight measured by the freezing point depression method was 610. When the proton nuclear magnetic resonance spectrum was observed in a toluene solution at room temperature at a high magnetic field component by ¹ H-NMR measurement described above, the methyl proton signal based on the (Al—CH ₃ ) bond was 1.0% on the basis of tetramethylsilane.
It is found in the range of -0.5 ppm. Since the protons of tetramethylsilane signal (0 ppm) is in the observation area based on the methyl proton based on Al-CH ₃ bonds, the Al-CH methyl proton signal 2.35 of toluene methyl proton signal at tetramethylsilane reference based on ₃ binding Measured based on ppm, high magnetic field component (ie -0.1 to -0.5pp
m) and other magnetic field components (i.e., 1.0 to -0.1 ppm), the high magnetic field components accounted for 43% of the total.

(2) Production of styrene-ethylene copolymer 20 ml of toluene was placed in a reaction vessel having an internal volume of 1.0 and equipped with a stirrer.
180 ml of styrene and 10.0 mmol of the methylaluminoxane obtained in the above (1) were added as aluminum atoms, followed by stirring at a polymerization temperature of 70 ° C. for 30 minutes. Then, 0.05 mmol of pentamethylcyclopentadienyltitanium trimethoxide was added as a titanium atom. Further, ethylene monomer was introduced into the reaction vessel through a dedicated line, and the pressure in the reaction vessel was increased to 8.0 kg / cm ² · G. Thereafter, polymerization was carried out at 70 ° C. for 4 hours with stirring. After the polymerization, the unreacted gas was depressurized, and methanol was injected to stop the reaction. Further, a mixed solution of methanol and hydrochloric acid was added to decompose the catalyst component. The yield of the styrene-ethylene copolymer obtained here was 12.2 g. In addition, the intrinsic viscosity measured at 135 ° C. in a 1,2,4-trichlorobenzene solution was 1.30 dl / g.

The fact that the styrene chain portion of this styrene-ethylene copolymer has a syndiotactic structure was confirmed by a differential scanning calorimeter (DSC) and a nuclear magnetic resonance spectrum ( ¹³ -N
MR).

(A) Measurement by DSC After sufficiently drying the styrenic copolymer obtained in Example 1, 10 mg was put into a DSC sample container, and 50 ° C to 300 ° C.
After the temperature was raised at a rate of 20 ° C./min, the temperature was maintained at 300 ° C. for 5 minutes, and the temperature was lowered from 300 ° C. to 50 ° C. at a rate of 20 ° C./min. The heat absorption and exothermic pattern when this sample was heated again from 50 ° C. to 300 ° C. at a rate of 20 ° C./min was observed. The apparatus used is DSC-II manufactured by PerkinElmer.

As a result, the copolymer had a glass transition temperature of 80 ° C and a melting temperature of 262 ° C.

Conventional atactic polystyrene has no melting temperature, and isotactic polystyrene has a melting temperature of 23.
0 ° C., the melting temperature of the copolymer will not be higher than the higher melting temperature of each homopolymer,
The styrene chain part of this copolymer has a syndiotactic structure, which indicates that the copolymer is crystalline.

On the other hand, the glass transition temperature of the ethylene homopolymer measured as a reference was -90 ° C, and the melting temperature was 126 ° C. The glass transition temperature of syndiotactic polystyrene is 96.
° C.

Therefore, the glass transition temperature of the obtained copolymer is
It is in the middle of each homopolymer and is expected to be a copolymer.

(B) Measurement by ¹³ C-NMR As a result of measuring the styrene-based copolymer in a 1,2,4-trichlorobenzene solution at 135 ° C., the aromatic signal was 145.1.
ppm, 145.9 ppm. This confirmed that the styrene chain had a syndiotactic structure. The copolymer had a signal derived from an ethylene chain at 29.5 ppm, and the content of the ethylene chain in the copolymer was 4.0% by weight. The used apparatus is FX-200 manufactured by JEOL Ltd.

(C) Morphology of molded article This copolymer was injection molded at a melting temperature of 300 ° C and a mold temperature of 100 ° C. Observation of the cross section of this injection-molded product revealed that fine domains were dispersed in a very good dispersion state that cannot be observed with a normal incompatible mixture. The Izod impact strength of this molded product was measured according to JIS-K7110.

FIG. 1 shows a scanning electron microscope (SEM) photograph of the copolymer obtained above. FIG. 1 clearly shows that both styrene and ethylene structural units are highly dispersed.

From the above, it was found that this copolymer was a crystalline styrene-ethylene copolymer containing a styrene chain having a syndiotactic structure.

Examples 2 to 6 and Comparative Examples 1 and 2 A styrene-ethylene copolymer was obtained in the same manner as in Example 1 using the raw materials, catalysts and polymerization conditions shown in Table 1 below. Table 1 shows the properties of the obtained copolymer together with the results of Example 1.

The copolymer samples obtained in Examples 3 to 5 and, as a comparison, syndiotactic polystyrene (SPS)
Sample, polyethylene (HDPE) sample, and 20% by weight of syndiotactic polystyrene and polyethylene
80% by weight was completely dissolved in 1,2,4-trichlorobenzene at 180 ° C., and then each sample of the blend was precipitated in methanol (tightly interblended state).
A test piece for measuring dynamic viscoelasticity was prepared by press molding. Next, the dynamic viscoelasticity of these four and six test specimens was measured using a Leo Vibron DDV-II-EA type device (frequency: 110 Hz, Linear Rise 2.0) manufactured by Orientec. The results are shown in FIG. In the figure, the horizontal axis indicates the measurement temperature range (° C.), and the vertical axis indicates the storage modulus [E] (dyne / cm ² ).
As a result of measuring the samples according to Examples 3 to 5, it was found that the syndiotactic polystyrene and the polyethylene were artificially tightly blended with each other in a temperature range from low temperature to 95 to 96 ° C. corresponding to the glass transition temperature of the syndiotactic polystyrene. In comparison, the [E] value was reduced, and as a result, it is considered that the copolymer was imparted with flexibility.

Originally, syndiotactic polystyrene and polyethylene are incompatible, so even if an operation that induces a close mutual blend state is performed, as long as the blend is used, phase separation is likely to occur, and therefore delamination occurs during injection molding. Cheap. However, the copolymer of the present invention has a highly dispersed structure as shown in FIG. 1, even during molding, delamination is suppressed, and as apparent from measurement of dynamic viscoelasticity, A molded article having flexibility as compared with syndiotactic polystyrene can be easily obtained.

Examples 7 and 8 A p-methylstyrene-ethylene copolymer was produced in the same procedure as in the method for producing a styrene-ethylene copolymer in Example 1 above. The results are shown in Table 1.

The resulting p-methylstyrene-ethylene copolymer is
An extraction operation was performed with methyl ethyl ketone and the like, and DSC of the extraction residue was measured under the same conditions as in Example 1. As a result, only a melting point (121 to 122 ° C.) derived from the ethylene skeleton was observed. However, when this extraction residue was subjected to ¹³ C-NMR measurement using 1,2,4-trichlorobenzene as a solvent, a sharp unimodal peak appeared at 142.3 to 142.5 ppm. This is the same as the result already described in JP-A-62-187708, suggesting that the p-methylstyrene unit has a syndiotactic structure. Also, as in the first embodiment
A peak due to an ethylene skeleton was observed at 29.4 to 29.6 ppm, indicating that this was a copolymer.

From the above, it was found that this copolymer was a crystalline p-methylstyrene-ethylene copolymer containing a p-methylstyrene chain having a syndiotactic structure.

Example 9 400 ml of toluene and 2.5 ml of triisobutylaluminum were placed in a reaction vessel equipped with a stirrer having an internal volume of 1.0 and replaced with argon.
(5.0 mmol), 5.0 mmol of the methylaluminoxane obtained in Example 1 as an aluminum atom, and 50.0 μmol of pentamethylcyclopentadienyltitanium trimethoxide as a titanium atom.
Kept.

Next, a propylene monomer was introduced into the reaction vessel from a dedicated line, and after sufficiently replacing the inside of the vessel with the propylene monomer, the pressure in the reaction vessel was increased to 4.5 kg / cm ² G.

Next, while keeping the pressure in the vessel at 4.5 kg / cm ² G, the propylene monomer dedicated line was shut off, and ethylene monomer was introduced into the reaction vessel through the dedicated line, and pressurized to 9.0 kg / cm ² G.

After stirring at a polymerization temperature of 50 ° C for 20 minutes, the styrene monomer
70 ml was introduced into the reaction vessel from a dedicated line. afterwards,
Polymerization was carried out at 50 ° C. for 4 hours with stirring. After completion of the polymerization, the unreacted gas was depressurized, and a mixed solution of methanol and hydrochloric acid was added to decompose the catalyst component.

The yield of the styrenic polymer obtained here was 4.32 g. In order to remove atactic polystyrene from the obtained styrene-based polymer, this polymer was washed for 8 hours using a Soxhlet extraction apparatus using methyl ethyl ketone as a solvent.

Next, washing was performed for 8 hours using n-heptane as a solvent in order to remove the ethylene-propylene copolymer alone. Here, the extracted ethylene-propylene copolymer
^The composition calculated from the ¹ H-NMR spectrum is ethylene unit 5
3.7 mol% and propylene unit 46.3 mol%. The melting point was 100 ° C.

Further, in order to remove a single polyethylene from the polymer insoluble in methyl ethyl ketone and n-heptane, extraction was performed for 8 hours using methylene chloride as a solvent. The coalescence was 25.4% by weight.

The atactic polystyrene thus obtained,
The yield of ethylene-propylene copolymer and methylene chloride-soluble styrene-based polymer excluding polyethylene was 0.55.
g in a 1,2,4-trichlorobenzene solution at 135 ° C.
Was 2.06 dl / g.

In addition, from the result of infrared absorption spectrum measurement, ethylene,
Absorption was observed at 720, 1150 and 1378 cm ^-1 due to the propylene structure, and the composition calculated from the ¹ H-NMR spectrum was 67.8 mol% of styrene units, 16.7 mol% of ethylene units, and 15.4 mol% of propylene units.

The composition of the ethylene-propylene component contained here is
It was within the composition range of a single ethylene-propylene copolymer soluble in n-heptane, and it was confirmed that there was no single ethylene-propylene copolymer in this polymer.

Further analysis by ¹³ C-NMR spectrum (solvents 1, 2, 4
-Trichlorobenzene) to 145.15 ppm due to the syndiotactic structure of the styrene chain,
Calculated from the peak area, the syndiotacticity in racemic pentad was 85%. Further, the result of measurement by DSC revealed that the melting point was present only at 233.9 ° C.

The styrenic polymer was injection-molded at a melting temperature of 300 ° C and a mold temperature of 100 ° C, and the cross section of the injection-molded product was observed with an electron microscope. In a good dispersion state, a fine domain structure was observed.

The above results indicate that this methylene chloride-soluble styrene polymer is a crystalline polymer composed of a styrene chain having a syndiotactic structure and an ethylene-propylene structure.

Example 10 400 ml of toluene, 700 ml of styrene monomer, 2.5 ml (5.0 mmol) of triisobutylaluminum and 5.0 mmol of methylaluminoxane obtained in the above Example 1 as aluminum atoms were added to a reaction vessel with stirring and having an inner volume of 1.0 and purged with argon. The mixture was stirred at a polymerization temperature of 50 ° C. for 30 minutes. Next, 50.0 micromoles of pentamethylcyclopentadienyltitanium trimethoxide as titanium atoms were added. Further, a propylene monomer was introduced into the reaction vessel through a dedicated line, and after sufficiently replacing the inside of the vessel with the propylene monomer, the pressure in the reaction vessel was increased to 4.5 kg / cm ² G. Next, after shutting off the propylene monomer dedicated line, ethylene monomer was introduced into the reaction vessel from the dedicated line, and pressurized to 9.0 kg / cm ² G. Thereafter, polymerization was carried out at 50 ° C. for 4 hours with stirring.

Other operations were performed in the same manner as in Example 9 to obtain a styrene-based polymer. The yield of the obtained styrenic polymer was 1.01 g. When the same treatment as in Example 9 was performed, the yield of the component soluble in methylene chloride was 0.03 g.

1,2,4 of this styrene polymer soluble in methylene chloride
-Intrinsic viscosity measured at 135 ° C in trichlorobenzene solution was 0.95 dl / g. The melting point was 24 based on the DSC measurement.
6.0 ° C., the composition calculated from the ¹ H-NMR spectrum,
The styrene unit was 10.8 mol%, the ethylene unit was 47.6 mol%, and the propylene unit was 41.6 mol%.

Example 11 A styrene polymer was obtained in the same manner as in Example 9 except that cyclopentadienyltitanium trichloride was used instead of pentamethylcyclopentadienyltitanium trimethoxide as a catalyst. The yield of the obtained styrenic polymer was 5.50 g, and the same treatment as in Example 9 was carried out. As a result, the yield of the component soluble in methylene chloride was 0.16 g.

The melting point of this styrene polymer soluble in methylene chloride is
232.8 ° C. The intrinsic viscosity measured at 135 ° C. in a 1,2,4-trichlorobenzene solution was 1.08 dl / g. or,
^The composition calculated from the ¹ H-NMR spectrum is styrene unit 3
8.7 mol%, ethylene unit 33.9 mol%, propylene unit 2
7.4 mol%.

(Effect of the Invention) The styrene copolymer of the present invention has a lower glass transition temperature than syndiotactic polystyrene, is capable of injection molding at a low temperature, and has improved impact resistance, Excellent compatibility with polyolefin.

Therefore, the styrenic copolymer of the present invention is useful as a compatibilizer for various structural materials and polyolefins.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a scanning electron micrograph of the styrene copolymer obtained in Example 1. FIG. 2 is a graph showing the results of measuring the dynamic viscoelasticity of the styrene copolymer samples obtained in Examples 3 to 5 and the comparative sample.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08F 212/04-212/14 C08F 12/04-12/30 C08F 210/00-210/14 C08F 10 / 00-10/14 C08F 4/64-4/70

Claims (3)

(57) [Claims] (1) General formula [Wherein R ¹ is a hydrogen atom, a halogen atom or
Or less hydrocarbon groups, and n represents an integer of 1 to 3.
When n is plural, each R ¹ may be the same or different. ] A styrene-based repeating unit represented by the general formula [In the formula, R ² represents a hydrogen atom or a saturated hydrocarbon group having 20 or less carbon atoms. The olefinic repeating unit represented by the formula (1), containing 0.1 to 99.9% by weight of the olefinic repeating unit, and having an intrinsic viscosity of 0.07 to 20 dl / g measured in 1,2,4-trichlorobenzene at 135 ° C. A styrenic copolymer characterized by having a syndiotactic structure having a high stereoregularity of a styrenic repeating unit chain. 2. The general formula Wherein R ¹ and n are the same as above. A styrene monomer represented by the general formula: Wherein R ² is the same as described above. Wherein R is a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z are each independently a hydrogen atom or a carbon atom; It represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, or a halogen atom. The method for producing a styrenic copolymer according to claim 1, wherein the copolymerization is carried out in the presence of a catalyst comprising a titanium compound represented by the formula (1) and an alkylaminoxane. 3. The method according to claim 1, wherein the alkylaluminoxane is formed of an aluminum-methyl group (Al
The high magnetic field component (−0.1 to −0.5 ppm based on 2.35 ppm of the methyl proton of toluene under the measurement conditions of the toluene solvent) in the methyl proton signal region based on the —CH ₃ ) bond is 50.
3. The method for producing a styrenic copolymer according to claim 2, wherein the amount of methylaluminoxane is not more than 5%.