JPH0725832B2 - Propylene polymerization method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a highly crystalline polypropylene having an excellent balance of physical properties by using a specific catalyst. More specifically, it relates to a method for producing polypropylene using a catalyst containing a polymer of a specific monomer.

[Prior Art] Crystalline polypropylene is a general-purpose polymer having relatively excellent rigidity and transparency, and is widely used for various purposes.

As a method for improving the physical properties of polypropylene, a method of copolymerizing with other α-olefins such as ethylene for the purpose of improving the impact resistance of polypropylene, especially at low temperature (for example, JP-B-44-20621 and 49-24593). , Ibid 49-1258
9) and the like are known. On the other hand, it is well known that various nucleating agents are added for the purpose of improving rigidity, transparency of a molded product, etc. Among them, a method using a polymer nucleating agent (for example, (Kaisho 60-139710, 60-139711, etc.) is an extremely excellent method in that there is no problem that the nucleating agent bleeds from the molded product and that it is effective even when added in a very small amount.

[Problems to be Solved by the Invention] Although the method using the above-mentioned polymer nucleating agent is an extremely excellent method, the method of pretreating the catalyst and introducing it into polypropylene is not suitable for carrying out on an industrial scale. However, the method of blending the polymer nucleating agent obtained by polymerization is difficult to disperse, and a large amount is required as compared with the method of pretreating the catalyst.

The present inventors have conducted extensive studies on a method for solving the above problems and obtaining a highly crystalline polypropylene, and completed the present invention.

[Means for Solving Problems] That is, the present invention uses a stereoregular catalyst to produce vinylcyclohexane, 3-methylbutene-1,4,4-dimethylpentene-1,4,4-dimethylhexene-1, indene, A titanium halide-containing transition metal catalyst component containing a polymer obtained by polymerizing one monomer selected from the group consisting of alkyl-substituted styrene, trialkylvinylsilane and trialkylallylsilane, and an organoaluminum compound. A propylene polymerization method characterized by using a catalyst.

Hereinafter, the present invention will be described in detail.

In the present invention, the stereoregular catalyst is not particularly limited, and various catalysts used when producing a propylene stereoregular polymer can be used. Usually, a titanium halide is preferably used as a catalyst composed of a transition metal catalyst component and an organoaluminum compound, especially a transition metal catalyst component. For example, titanium tetrachloride obtained by reducing titanium tetrachloride with metal aluminum, hydrogen or organoaluminum A catalyst system consisting of titanium chloride, a modification thereof with an electron-donating compound and an organoaluminum compound and, if necessary, a stereoregularity improving agent such as an oxygen-containing organic compound, or a carrier such as magnesium halide or an electron An example is a catalyst system comprising a titanium halide-supported product obtained by treating with a donor compound, an organoaluminum compound, and optionally a stereoregularity improving agent such as an oxygen-containing compound (see, for example, the following documents). Various examples have been described.Ziegler-N
atta Catalysts and Polymerization by John Boor Jr
(Academic Press), Journal of Macromolecular Sienc
e-Reviews in Macromolecular Chemistry and Physics
C24 (3) 355-385 (1984), C24 (1) 57-97 (198)
Five)).

Here, oxygen-containing compounds such as ethers, esters, orthoesters, and alkoxysilicons are usually preferably used as the stereoregularity improver or electron donor, and alcohols, aldehydes, water and the like can also be used as electron donors.

As the organoaluminum compound, trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, and alkylaluminum dihalide can be used, and the alkyl group is exemplified by methyl group, ethyl group, propyl group, butyl group, hexyl group, and the like. Examples of chlorine include bromine and iodine.

Preferred titanium halides are aluminum or titanium trichloride obtained by reducing titanium tetrachloride with organoaluminum, modified with ether or ester, and magnesium tetrachloride and an organic compound are pulverized and fed into titanium tetrachloride. Or the reaction product of magnesium chloride and alcohol is dissolved in a hydrocarbon solvent and then treated with a precipitating agent such as titanium tetrachloride to make it insoluble in the hydrocarbon solvent, and if necessary, an electron such as ester or ether may be added. A supported titanium halide obtained by, for example, modification treatment with a donor compound and then treatment with titanium tetrachloride.

In the present invention, first, using the above-mentioned stereoregular catalyst,
Vinylcyclohexane, 3-methylbutene-1,4,4-
One monomer selected from dimethylpentene-1, indene, alkyl-substituted styrene, trialkylvinylsilane, and trialkylallylsilane is polymerized. Here, as the alkyl-substituted styrene, pt-butyl styrene, p
Examples are p-alkyl substituted styrenes such as-methyl styrene. As the trialkylvinylsilane and the trialkylallylsilane, the alkyl residue is methyl, ethyl,
Examples thereof include propyl, butyl, pentyl and hexyl groups.

The polymerization reaction can be carried out under the same conditions as those used in ordinary propylene polymerization, usually at room temperature to 100 ° C.
At a temperature of 1, or in the presence or absence of an inert liquid medium such as a hydrocarbon compound.

After the polymerization reaction, a polymer is obtained by separating from the unreacted monomer, but if necessary, the catalyst residue is removed by a deashing operation using alcohols, water, etc. that are adopted in the production of ordinary polypropylene. Things are also done.

Preferably, hexane, heptane, in the presence of an inert hydrocarbon compound such as decane, prepared using the stereoregular catalyst described above, followed by deashing treatment with alcohol, water, etc., and then as an insoluble component by filtration or the like. , A polymer is obtained.

In the present invention, vinyl cyclohexane, 3-methylbutene-1,4,4-dimethylpentene-1,4,4-dimethylhexene-1, indene, alkyl-substituted styrene, trialkylvinylsilane, trialkyl using a stereoregular catalyst. As a titanium halide-containing transition metal catalyst component containing a polymer obtained by polymerizing one kind of monomer selected from allylsilane (hereinafter abbreviated as a polymer obtained by polymerizing a specific monomer) The basic structure of the catalyst is the same as the transition metal catalyst component which is a constituent component of the stereoregular catalyst described above.

The titanium halide-containing transition metal catalyst component containing the polymer obtained by polymerizing this specific monomer is to contain a polymer obtained by polymerizing the specific monomer separately during the production of the transition metal catalyst component. Can be obtained at Specifically, a method in which a polymer obtained by polymerizing titanium trichloride and a specific monomer is co-ground with an electron-donating compound as necessary, or fine particles are used when titanium tetrachloride is reduced with an organoaluminum compound. A method of coexisting a polymer obtained by polymerizing the specific monomer of
Alternatively, a method in which a polymer obtained by polymerizing a specific monomer in the presence or absence of a carrier such as magnesium halide and an electron donor is co-pulverized and then treated with titanium tetrachloride, or halogenated Disperse the polymer obtained by polymerizing finely particulate specific monomers in a solution in which magnesium is insolubilized in a hydrocarbon solvent with an electron donor such as alcohol, and then with a precipitating agent such as an organoaluminum compound or a metal halide. Examples of the method include a treatment, a modification treatment with an electron-donating compound such as ester and ether, and a treatment with titanium tetrachloride. Here, the amount ratio of the polymer obtained by polymerizing the specific monomer per transition metal catalyst component is preferably obtained by polymerizing using the transition metal catalyst component and then polymerizing the specific monomer in polypropylene. The ratio of the polymer is about 0.001 to 1000 wtppm. Therefore, it is usually used in an amount of 0.001 to 10 wt% per transition metal catalyst component.

As the organoaluminum compound used together with the transition metal catalyst component in the present invention, the above-mentioned trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide and alkylaluminum halide are preferably used, and the alkyl group is methyl, ethyl, propyl or butyl. , Pentyl, hexyl and the like can be exemplified.

In the present invention, the polymerization of propylene means not only propylene alone but also a small amount of ethylene, butene-1 hexene-1,
It also includes copolymerization or block copolymerization with other α-olefins such as.

[Examples] The present invention will be further described with reference to Examples.

Reference example Manufacture of polymer obtained by polymerizing specific monomer Highly active titanium catalyst from Marubeni Solvay (Lot No. TGY2
4) was used to obtain a polymer. All polymerization reactions were performed in n-hexane with a monomer concentration of 2 vol% and 300g of highly active titanium catalyst.
/, 6 at a concentration of diethylaluminum chloride 1 kg /
After polymerizing at 0 ° C. for 2 hours and deactivating with methanol, the slurry was washed with water and then filtered to separate the polymer and sufficiently dried.

Example 1 and Comparative Example 1 A vibration mill equipped with two grinding pots having an inner volume of 1 and containing 2 kg of steel balls having a diameter of 12 mm is prepared. Magnesium chloride 20g, tetraethoxysilane 4ml, α, in one pot
3 ml of α, α-trichlorotoluene was added (Comparative Example 1),
To the other pot, 20 g of magnesium chloride, 4 ml of tetraethoxysilane, 3 ml of α, α, α-trichlorotoluene, and 0.2 g of the polymer of vinylcyclohexane obtained in Reference Example were added (Example 1) and pulverized for 40 hours.

10 g of the pulverized product was placed in another 200 ml round bottom flask, and the following operations were performed. In the round bottom flask above
Add 50 ml of toluene and 50 ml of titanium tetrachloride, and add 3 at 100 ℃.
It was stirred for 0 minutes. Then, leave it still to remove the supernatant liquid, and similarly add 50 ml of titanium tetrachloride and 50 ml of toluene, and add 30 ml at 100 ° C.
The mixture was stirred for a minute and then allowed to stand to remove the supernatant, and the solid was washed once with 100 ml of n-heptane 10 times to obtain a transition metal catalyst component. When a part of the sample was sampled and the titanium content was analyzed, it was 1.9 wt% (Comparative Example 1) and 2.0 wt% (Example 1).

Using an autoclave with an internal volume of 5 each 30 mg of the above solid catalyst, 0.128 ml of diethyl aluminum chloride,
Methyl p-toluate 0.06 ml, triethylaluminum
0.08 ml was added, 1.5 kg of propylene and 3.3 Nl of hydrogen were added, polymerization was carried out at 75 ° C. for 2 hours, unreacted propylene was purged, powder was taken out, dried and weighed to calculate the yield per transition metal catalyst component. Extraction residual ratio was measured by extracting with boiling n-heptane using a Soxhlet extract and the intrinsic viscosity of a tetralin solution at 135 ° C. Phenol stabilizer is added to powder at a ratio of 10/10000 and calcium stearate is added at a ratio of 15/10000 to granulate, and the melt flow index is measured to make an injection sheet having a thickness of 1 mm. The physical properties were measured.

Melt flow index ASTM D1238 (230 ℃) Tensile strength ASTM D638-64T (20 ℃) Flexural rigidity ASTM D747-62 (20 ℃) For copolymers Izod (notched) Impact strength ASTM D256-56 (20 ℃) , -10 ℃) DuPont impact strength JIS K 6718 (20 ℃, -10 ℃) was measured. The results are shown in the table.

Example 2 Almost the same as the polymer of vinylcyclohexane obtained by reducing the polymer obtained by polymerizing styrene in Reference Example with hydrogen (performed according to the method described on page 308 of Macromolecular vol 19, No 2 (1986)). The procedure of Example 1 was repeated except that the polymer was changed to a vinylcyclohexane polymer. The results are shown in the table.

Examples 3 to 6, Comparative Example 2 Polymer of 3-methylbutene-1 (Example 3), Polymer of 4,4-dimethylpentene-1 (Example 4), Polymer of 4,4-dimethylhexene-1 A transition metal catalyst component was obtained in the same manner as in Example 1 except that 1 g of the polymer (Example 5) and 1 g of the polymer of pt-butylstyrene (Example 6) were used instead of 0.2 g of the polymer of vinylcyclohexane. It was A block copolymer was produced using this transition metal catalyst component. 30 mg of transition metal catalyst component, 0.128 ml of diethyl aluminum chloride, 0.06 m of methyl p-toluate were placed in an autoclave with an internal volume of 5.
l, triethylaluminum 0.03 ml and propylene 1.5
kg, 3.3Nl of hydrogen was added, polymerization was carried out at 75 ° C for 2 hours, then the internal temperature was lowered to 40 ° C, ethylene was added at 5 kg / cm ² -gauge, and then 0.25 ml of triethylaluminum was added to make ethylene partial pressure 5 kg / cm. Polymerization was carried out for 60 minutes while adding ethylene so that the gauge became ² -gauge. Unreacted propylene and ethylene were purged, dried, weighed, and granulated in the same manner as in Example 1 to measure physical properties. Polymerization was conducted in the same manner using the catalyst of Comparative Example 1, dried and granulated, and the physical properties were measured. The results are shown in the table.

Examples 7 to 8 and Comparative Example 3 Using the same grinder as in Example 1, titanium trichloride (TAC-141 manufactured by Toho Titanium Co., Ltd.) 30 g, diphenyl ether 2.2.
g, and 0.3 g of a polymer of trimethylvinylsilane (Example 7), 0.3 g of a polymer of trimethylallylsilane (Example 8), and n-each after crushing for 20 hours without adding other components (Comparative Example 3). The transition metal catalyst component was extracted with heptane (200 ml per 10 g of co-ground material) three times (30 minutes at 90 ° C.). In an autoclave with an internal volume of 3, n-heptane 1, 630 mg of transition metal catalyst component and 1.2 ml of diethylaluminum chloride are added, 0.2 kg / cm ^{2 of} hydrogen is charged, and propylene is further charged to make the pressure of the gas phase part 2 kg / cm ^2. cm ² · G. Next, after heating the contents of the autoclave for 5 minutes, the internal temperature was brought to 70 ° C., and while charging propylene at this temperature, polymerization was carried out for 150 minutes while maintaining the pressure at 5 kg / cm ² · G. Then, 300 ml of methanol was added and stirring was continued for 30 minutes to decompose the catalyst.

After cooling the autoclave, the contents were taken out, 200 ml of water was added, the mixture was washed 3 times at 60 ° C, filtered and dried under reduced pressure at 60 ° C to obtain polypropylene. The polymer obtained was granulated in the same manner as in Example 1 and the physical properties were measured. The results are shown in the table.

[Effects of the Invention] By carrying out the method of the present invention, it is possible to produce polypropylene having an excellent balance of physical properties, and it is extremely industrially conscious.

[Brief description of drawings]

FIG. 1 is a flowchart of the propylene polymerization catalyst used in the present invention.

Claims (1)

[Claims] 1. A stereoregular catalyst is used for vinylcyclohexane, 3-methylbutene-1,4,4-dimethylpentene-1,4,4-dimethylhexene-1, indene, alkyl-substituted styrene, trialkylvinylsilane and trialkylvinylsilane. A propylene characterized by using a catalyst comprising a titanium halide-containing transition metal catalyst component containing a polymer obtained by polymerizing one kind of monomer selected from the group consisting of alkylallylsilane and an organoaluminum compound. Polymerization method.