JP2828716B2 - Highly crystalline polypropylene resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a crystalline polypropylene composition having good physical properties. More particularly, it relates to a composition of polypropylene having a high crystalline isotactic structure or syndiotactic structure or a mixture thereof.

[Prior Art] Crystalline polypropylene having a conventionally known isotactic structure, and using a transition metal catalyst having an asymmetric ligand, has a high syndiotacticity to produce a crystalline syndiotactic. It has been found that polypropylene can be produced. Polypropylene having such a high tacticity structure is crystalline, but it is difficult to say that it has low crystallinity and the original characteristics.In particular, isotactic polypropylene has a higher crystallization nucleating agent than the conventional one. Considerations are being made.

[Problems to be solved by the invention]

As the crystallization nucleating agent, salts of benzoic acid, low-molecular-weight organic compounds such as benzsorbitol-based compounds are usually used, but these compounds have insufficient performance as nucleating agents and need to be used in large amounts. Therefore, there is a problem such as bleeding from a molded product. In contrast, polymer nucleating agents such as crystalline polyvinylcyclohexane are known, but there are problems that they are expensive and their effect is not sufficient for syndiotactic polypropylene. .

[Means for solving the problem]

Means for Solving the Problems The inventors of the present invention have solved the above problems and have intensively searched for a highly crystalline polypropylene composition having good physical properties and completed the present invention.

That is, the present invention is a highly crystalline polypropylene resin composition obtained by mixing 0.0001 to 10 parts by weight of syndiotactic poly 4-methylpentene-1 and 99.9999 to 90 parts by weight of highly crystalline polypropylene.

In the present invention, the highly crystalline polypropylene includes isotactic polypropylene and syndiotactic polypropylene, and as the isotactic polypropylene, an isotactic pentad fraction calculated from a peak of a methyl group measured by ¹³ C-NMR. (A. Zambelli et al. Macr
omolecules vol 6 687 (1973), vol 8 925 (1975)
Are those containing 0.7 or more, preferably 0.8 or more,
Not only various methods are known, but also various brands can be obtained on the market. Previously, syndiotactic polypropylene was not known to be highly crystalline, but according to JAEWEN et al., A catalyst comprising a transition metal compound having an asymmetric ligand and an aluminoxane had a syndiotactic pentad fraction of 0.7. It has been discovered for the first time that a polypropylene having good tacticity can be obtained (J.Am.C.
hem. Soc., 1988, 110, 6255-6256).

According to this method, a syndiotactic polypropylene having a syndiotactic pentad fraction of more than 0.7 can be obtained, and a product having a syndiotactic pentad ratio of 0.9 or more can be produced by washing with a hydrocarbon compound. Even if the catalyst is different from the above-mentioned literature, it can also be produced by using a catalyst which gives a polypropylene having a highly syndiotactic structure as described above. Syndiotactic polypropylene in the present invention includes those having a syndiotactic pentad fraction of 0.6 or more, preferably 0.7 or more, in the present invention. Here, the crystalline polypropylene is not only a homopolymer of propylene but also a copolymer with a small amount of another olefin such as ethylene or an α-olefin having 4 or more carbon atoms, as long as the tacticity is exhibited, about 10 mol% or less, Alternatively, a so-called block copolymer or polymer obtained by polymerizing ethylene and propylene at first, which is obtained by polymerizing substantially propylene, and a mixture of polyethylene or ethylene-propylene copolymer with crystalline polypropylene may be used. It can be used as long as it is a crystalline polypropylene.

The polymer having a syndiotactic structure of 4-methylpentene-1 used in the present invention can be produced by polymerizing 4-methylpentene-1 using a catalyst used for producing the above-mentioned syndiotactic polypropylene. Specifically, it can be obtained by polymerization using a catalyst comprising a transition metal compound having two asymmetric ligands. Preferred examples of the catalyst comprising a transition metal compound having two asymmetric ligands include the catalyst systems described in the above-mentioned documents, and isopropyl (cyclopentadienyl-1-)
A transition metal compound such as fluorenyl) hafnium dichloride or isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride; (Wherein R is a hydrocarbon residue having 1 to 3 carbon atoms). Particularly, a methylaluminoxane in which R is a methyl group and n is 5 or more, preferably 10 or more is used. The use ratio of aluminoxane to the transition metal catalyst is 10 to 100,000
It is 0 mole times, usually 50 to 5000 times times.

The polymerization conditions for polymerizing 4-methylpentene-1 are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method substantially free of an inert medium, and a gas phase polymerization method can be used. As the polymerization temperature -100 ~ 200 ℃,
The polymerization pressure is generally from normal pressure to 100 kg / cm ² . Preferably, it is -100 to 100 ° C and normal pressure to 50 kg / cm ² . The polymer can be further washed with a hydrocarbon solvent before use. Here, the polymer of 4-methylpentene-1 preferably has a melting point of 160 ° C. or higher as measured by heating at a rate of 10 ° C./min by differential scanning calorimetry. Processing conditions of 4-
It is preferable to set the melting point of the polymer of methylpentene-1 to exceed 160 ° C.

In the present invention, the use ratio of the polymer of 4-methylpentene-1 to the crystalline polypropylene is such that when the total composition is 100 parts, the polymer of 4-methylpentene-1 is 100 parts.
0.0001 to 10 parts by weight, with the balance being crystalline polypropylene. If the amount of the polymer of 4-methylpentene-1 is less than this, there is almost no effect.

There is no particular limitation on the method of mixing the polymer of 4-methylpentene-1 and crystalline polypropylene, and the method used for mixing ordinary polyolefins can be used as it is. At the time of mixing, an antioxidant, an ultraviolet absorber and the like used for stabilizing the polyolefin may be mixed at the same time. In general, mixing is performed using a Henschel or the like at a temperature lower than the melting point of the crystalline polypropylene and then melt-mixed using an extruder or the like.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 Isopropylcyclopentadienyl-1-yl which was synthesized in an autoclave having an internal volume of 7 l according to a conventional method and further purified.
Isopropyl (cyclopentadienyl-1) obtained by lithiation of fluorene and reaction with zirconium tetrachloride
-Fluorenyl) zirconium dichloride (10 mg) and Toyo Akzo Co., Ltd.
g was dissolved in 4 l of toluene and polymerized at 30 ° C. for 1 hour at a polymerization pressure of 2 kg / cm ² -G. After the reaction, unreacted propylene is purged, taken out, filtered at 30 ° C., and diluted with 1500 ml of toluene.
Washed twice. Then, the powder was dried under reduced pressure at 80 ° C. The obtained powder was 580 g, and according to ¹³ C-NMR, the syndiotactic pentad fraction was 0.912, and the intrinsic viscosity η measured with a tetralin solution at 135 ° C. was 1.24 dl / g. 30
In a 0 ml flask, 5 mg of the above catalyst, methylaluminoxane 0.
After adding 34 mg and 100 ml of 4-methylpentene-1 and polymerizing at 25 ° C. for 10 hours, the mixture was added to a large amount of methanol to obtain 8.
8 g were obtained. 99.9 parts of the above polypropylene powder
0.1 part of the polymer of 4-methylpentene-1 was added, and 2 parts were added.
A 1 mm sheet was prepared by press molding at 50 ° C., and the following physical properties were measured. When ¹³ C-NMR of the polymer of 4-methylpentene-1 was measured, the peak intensity observed at about 43.1 ppm was 0.85 of the peak intensity observed at about 42.0 to 43.5 ppm, and the syndiotactic The melting point was 215 ° C. as a peak temperature measured at 10 ° C./min by differential scanning calorimetry.

Flexural ^{stiffness: kg / cm 2 ASTM D747 (} 23 ℃) · Tensile Yield ^{Strength: kg / cm 2 ASTM D638 (} 23 ℃) · elongation:% ASTM D638 (23 ° C.), Izod (notched) impact strength: kg · cm / cm ASTM D256 ( 23 ℃, -10 ℃) flexural stiffness is 6400kg / cm ^2, the tensile yield strength 260 kg / cm ^2,
The elongation was 360%, and the Izod impact strength was 14.5 and 2.8 (23 ° C and -10 ° C, respectively) kg · cm / cm.

Comparative Example 1 The same procedures as in Example 1 were carried out except that the physical properties were measured without adding the polymer of 4-methylpentene-1, and the flexural rigidity was 4800 kg / cm ² and the tensile yield strength was 210 kg / cm ^2. , Elongation 680%, Izod impact strength 14.0, 2.1 (23 each
° C, -10 ° C) kg · cm / cm.

Example 2 A composition obtained by adding 0.1 part by weight of syndiotactic poly 4-methylpentene-1 obtained in Example 1 to 99.9 parts by weight of isotactic polypropylene JHH-G manufactured by Mitsui Toatsu Chemicals, Inc. When the physical properties were measured, the flexural rigidity was 20500 kg / cm ² , the tensile yield strength was 370 kg / cm ² , and the elongation was
380%.

Comparative Example 2 The same procedures as in Example 2 were carried out except that the molded article was molded without using poly-4-methylpentene-1 and the physical properties were measured. The flexural rigidity was 18000 kg / cm ² and the tensile yield strength was 350 kg / cm ^2. , And the growth was 680%.

Example 3 Block copolymer BJ of isotactic polypropylene manufactured by Mitsui Toatsu Chemicals, Inc. as crystalline polypropylene
Except that HH-G was used, the same procedures as in Example 2 were carried out. The flexural rigidity was 16,500 kg / cm ² , the tensile yield strength was 310 kg / cm ² , and the elongation was
460%, Izod impact strength 7.0, 3.6 (23 each
° C, -10 ° C) kg · cm / cm.

Comparative Example 3 The physical properties of a molded article without using the polymer of 4-methylpentene-1 were measured, and the flexural rigidity was 15000 kg / c.
m ² , tensile yield strength 290 kg / cm ² , elongation 570%, Izod impact strength 7.1, 3.5 (23 ° C, -10 ° C respectively) kg · cm
/ cm.

〔The invention's effect〕

The composition of the present invention is a highly crystalline polypropylene having excellent physical properties, and is extremely valuable industrially.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08L 23/00-23/36 CAS ONLINE

Claims (2)

(57) [Claims] (1) 0.0001 to 10% by weight of syndiotactic poly-4-methylpentene-1 and 9 of highly crystalline polypropylene;
A highly crystalline polypropylene resin composition obtained by mixing 9.9999 to 90 wt parts. 2. The composition according to claim 1, wherein the melting point of syndiotactic poly-4-methylpentene-1 is 160 ° C. or higher.