JPH09286881A - Polypropylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin compsn. which exhibits a batter balance among physical properties in many applications than usually used various polypropylene resin compsns. having excellent physical properties. SOLUTION: This compsn, comprises 100 pts.wt. propylene homopolymrr having a mesopentad fraction of 0.970 or higher or propylene-ethylene block copolymer having a mesopented fraction in the polypropylene blocks of 0.970 or higher. 0.1-20 pts.wt. propylene-ethylene copolymer wherein, when attention of paid to three consecutive monomer units, the fraction of chains having at least three linked propylene units is 0.40 or higher and the fraction of chains having at least three linked ethylene units is 0.30 or higher, and 0-140 pts.wt. ethylene-α-olefin random copolymer having an entylene content of 20-90wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel polypropylene resin composition having a good balance of physical properties. Specifically, it relates to a composition containing a special copolymer component.

[0002]

2. Description of the Related Art Polypropylene is an inexpensive polymer which is lightweight and excellent in rigidity, but has poor impact resistance at low temperatures. Therefore, it is possible to maintain rigidity by mixing an ethylene-propylene copolymer with polypropylene by various methods. Moreover, a composition having impact resistance at low temperature has been made, and certain results have been obtained. Among them, the block copolymer obtained by first polymerizing only propylene alone and then copolymerizing ethylene and propylene has an excellent balance, and a specific polymerization method is performed using a specific catalyst system. Is proposed.

[0003]

Although various polypropylene-based compositions have extremely excellent physical properties, it is desired to create compositions having a better balance of physical properties in various applications.

[0004]

Means for Solving the Problems The present inventors diligently studied compositions which solved the above problems and completed the present invention.

That is, in the present invention, the proportion of mesopentad in the homopolymer of propylene or the homopolymerization portion of propylene in which the proportion of mesopentad is 0.970 or more is 0.97.
Focusing on 100 parts by weight of a block copolymer of propylene and ethylene, which is 0 or more, and 3 consecutive monomer units, the proportion of chains in which 3 or more propylene are linked is 0.
40 or more and the proportion of chains in which 3 or more ethylene are connected is 0.30 or more, and the ethylene content is 40 to 5% by weight.
0.1 to 20 parts by weight of a copolymer of propylene and ethylene, ethylene having an ethylene content of 20 to 90% by weight and α-
A polypropylene resin composition comprising 0 to 140 parts by weight of an olefin random copolymer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A propylene homopolymer having a mesopentad ratio of 0.970 or more, or a propylene-ethylene block copolymer having a propylene homopolymerization mesopentad ratio of 0.970 or more, is used in the present invention. It can be produced by various production methods, for example, titanium tetrachloride modified with an electron-donating compound or titanium tetrachloride supported on magnesium chloride modified with an electron-donating compound is used as a transition metal. It can be produced by using a catalyst system comprising a trialkylaluminum or dialkylaluminum chloride as a catalyst component and an electron donating compound as the case requires.

As the block copolymer of propylene and ethylene in which the proportion of mesopentad in the homopolymerized portion of propylene is 0.970 or more, propylene is polymerized alone using the above catalyst, and then ethylene and propylene are copolymerized. can get. The content of ethylene in the block copolymer is 0 to 30% by weight, and the polymerization ratio of ethylene and propylene in the copolymerization portion is 10/90 to 0/1.
00.

The propylene homopolymer having a proportion of mesopentad of 0.970 or more or the block copolymer of propylene and ethylene having a proportion of mesopentad of the homopolymerized portion of propylene of 0.970 or more has an intrinsic viscosity of 0. It is preferably from 0.5 to 3.0 dl / g, and if it exceeds this range, there are problems such as poor moldability and insufficient physical properties.

In the present invention, when attention is paid to three consecutive monomer units, the proportion of chains in which 3 or more propylene are linked is 0.40 or more and the proportion of chains in which 3 or more ethylene is linked is 0.30 or more. Some ethylene content is 40
As a method for producing a copolymer of propylene and ethylene of 5% by weight to 5% by weight, for example, a polymerization system of ethylene and propylene of 5/95 to 40/60% by weight is used by using the above-mentioned catalyst system that gives highly stereoregular polypropylene. Ratio, preferably 1
Polymerized in a weight ratio of 0/90 to 40/60 and then hexane,
It is obtained as a component insoluble in a hydrocarbon compound by dissolving it in a hydrocarbon compound such as heptane, octane, toluene or xylene under heating and then cooling to room temperature.

As for the molecular weight of this copolymer, the intrinsic viscosity number measured with a tetralin solution at 135 ° C. is 1.0-10.
It is preferably 0 dl / g.

It is also possible to use this component in the form of a mixture with other components, for example, in a state where the component soluble in the hydrocarbon compound is not separated.

Here, the proportion of the chain in which three or more propylene or ethylene are connected is determined by the carbon of the monomer unit at the center of the three consecutive monomer units observed by ¹³ C-NMR measured by dissolving the polymer in a solvent. The chemical shift is calculated by calculating the ratio of specific ones. Specifically, it can be calculated by absorption of a CH group in a propylene unit and a CH ₂ group in an ethylene unit (Rubber Chemistry
and Technology, 44 , 781 (1971) and Macromolecules , 1
1 , 33 (1978)).

In the present invention, the ethylene content is 20 to 90.
As the random copolymer of ethylene and α-olefin by weight%, a catalyst system which gives the above-mentioned highly stereoregular polypropylene can be used, but ethylene and α are preferable.
-A catalyst for polymerizing olefins with good randomness, generally a homogeneous catalyst can be preferably used, and a catalyst system comprising a vanadium compound and organoaluminum, or a catalyst comprising a metallocene compound and an aluminoxane, or a compound which becomes a stable anion. System is available. In addition, the ratio of the chain in which three or more of the above-mentioned propylene are connected is 0.40.
As a component soluble in a hydrocarbon compound during the production of a propylene-ethylene copolymer having an ethylene content of 40 to 5% by weight, in which the proportion of chains in which three or more ethylene are linked is 0.30 or more. It is also possible to utilize separate parts.

As for the molecular weight of this copolymer, the intrinsic viscosity number measured with a tetralin solution at 135 ° C. is 1.0-10.
It is preferably 0 dl / g.

As the α-olefin, propylene and 1-
Butene, 1-pentene, 1-hexene, 1-heptene,
Examples include 1-octene, 1-nonene, 1-decene, and the like.

Specific examples of the metallocene compound include those having zirconium, titanium, hafnium or the like as a central metal and various symmetries such as plane symmetry, C ₂ symmetry or C _S symmetry.

In the present invention, as a ratio of the above-mentioned three components, a propylene homopolymer having a mesopentad ratio of 0.970 or more, or a propylene-ethylene block copolymer having a mesopentad ratio of 0.970 or more in a homopolymerized portion of propylene. When the combined amount is 100 parts by weight, the proportion of chains in which 3 or more propylene are linked is 0.40 or more, and the proportion of chains in which 3 or more ethylene is linked is 0.
0.1 to 20 parts by weight of a copolymer of propylene and ethylene having an ethylene content of 30 or more and 40 to 5% by weight, and a random copolymer of ethylene and α-olefin having an ethylene content of 20 to 90% by weight 0 to 140 By weight, it is possible to maintain a good balance of physical properties by setting the content in such a range.

[0018]

The present invention will be further described with reference to the following examples. In the examples and comparative examples, melt flow index ASTM D1238 (230 ° C) flexural rigidity ASTM D747-63 (23 ° C) Izod (with notch) impact strength kg / cm / cm ASTM D256-56 (23 ° C, − Melt flow index (MI) is 2.16kg
The weight was measured. The intrinsic viscosity was measured with a 135 ° C tetralin solution.

Example 1 (Synthesis of transition metal catalyst component) In an autoclave having an internal volume of 20 liters, 7 liters of refined kerosene and 10 parts of magnesium chloride were added.
0 g and 370 g of 2-ethylhexanol were added, and 10
The mixture was stirred at 0 ° C. for 24 hours to completely dissolve it. After adding 23 g of phthalic anhydride to the mixture and stirring it, titanium tetrachloride 40 kept at -10 ° C in a 100 liter autoclave.
It was gradually added dropwise to the liter with stirring. Thereafter, the temperature was slowly raised, and when the temperature reached 100 ° C., 56 ml of diisobutyl phthalate was added and treated for 1 hour. Then remove the supernatant,
Further, 20 liters of titanium tetrachloride was added and stirred at 100 ° C., and finally the solid content was washed 10 times with n-heptane to obtain a transition metal catalyst component.

The transition metal catalyst component is 2.8 wt% titanium.
And 7.2 wt% of diisobutyl phthalate.

Using the transition metal catalyst component obtained in the above reaction,
Propylene was pretreated. Into a 5 liter flask containing 3 liters of heptane, 50 g of the above transition metal catalyst component, 10 ml of triethylaluminum and 150 g of propylene were introduced. After stirring for 2 hours at 20 ° C., the mixture was allowed to stand, the supernatant was removed, and the solid content was washed with 3 liters of heptane to obtain a transition metal catalyst component slurry.

(Polymerization reaction) An internal volume of 500 liters
100 kg of propylene to the toclave, the above as catalyst
0.3 g of the transfer metal catalyst component as the transition metal catalyst component,
2 ml of riethylaluminum, cyclohexylmethyldi
Introduce 0.3 ml of methoxysilane and 100 N liter of hydrogen
After charging, the temperature was raised to 75 ° C and the hydrogen concentration in the gas phase was increased to 1.6.
Polymerize for 2 hours while adding hydrogen so that the amount becomes mol%.
Was. Take out a small amount of polymer here ¹³Min by C-NMR
When analyzed, the mesopentad fraction was 0.985.
Was. Then, the temperature was lowered to 50 ° C, and the vapor phase hydrogen concentration was 1.5 m
And ethylene concentration of 35 mol% for 20 minutes. One
Then, the slurry is purged into the flash tank and unreacted mono
Of the block with ethylene content of 8.5% by weight
12 kg of polymer was obtained.

On the other hand, in an autoclave having an internal volume of 5 liters, 1 kg of propylene was charged, 3.25 N liters of hydrogen and ethylene were charged, and 27 kg / cm ² -G at 50 ° C. (2 kg / cm ² -G as ethylene partial pressure). I tried to become. Then, 0.02 g of the above transition metal catalyst component, 0.1 ml of triethylaluminum, and 0.03 ml of cyclohexyldimethoxysilane.
Was added and polymerized for 20 minutes. The powder was taken out, dissolved in 3 liters of xylene at 130 ° C., cooled to 20 ° C. to separate soluble components, washed well with xylene, and dried. The obtained polymer had an intrinsic viscosity of 2.7 dl / g, an ethylene content of 36.3 wt%, a ratio of 3 or more consecutive propylenes was 0.43, and a ratio of 3 or more consecutive ethylene was 0.
It was 36. 2 parts by weight of this copolymer was added to 98 parts by weight of the above block copolymer and granulated with an extruder of 40 mm,
Then, the physical properties were evaluated as a 1 mm injection sheet. The results are shown in Table 1.

Comparative Example 1 The xylene-soluble matter extracted in Example 1 (ethylene content 26.3 wt%, intrinsic viscosity number 2.2 dl / g, the proportion of 3 or more continuous propylene components is 0.37, and 3 ethylene components are included). The above-mentioned continuous ratio was 0.11.) And 2 parts by weight and 98 parts by weight of the block copolymer obtained in Example 1 were used. The results are shown in Table 1.

Comparative Example 2 Polymerization of ethylene and propylene was carried out by charging 1 kg of propylene into an autoclave having an internal volume of 5 liters and hydrogen 3.95 N.
29 kg / cm ² -G at 50 ° C with liter and ethylene charged
(Ethylene partial pressure is 4 kg / cm ² -G)
Then, 0.02 g of the above transition metal catalyst component, 0.1 ml of triethylaluminum and 0.03 ml of cyclohexyldimethoxysilane were added and polymerization was carried out for 20 minutes, and the xylene-insoluble matter was taken out in the same manner as in Example 1 (ethylene content 64. 7 wt%, an intrinsic viscosity of 2.8 dl / g, a proportion of 3 or more consecutive propylenes was 0.17, and a proportion of 3 or more consecutive ethylene was 0.61. The same procedure as in Example 1 was carried out except that 98 parts by weight of the block copolymer obtained in 1. was used. The results are shown in Table 1.

Example 2 In addition to 98 parts by weight of the composition of Example 1, 2 parts by weight of the xylene-soluble component extracted in Example 1 was added and the results of the same evaluation are shown in Table 1.

Reference Example 1 The physical properties of the block copolymer obtained in Example 1 are shown in Table 1.

[0028]

[Table 1]

[0029]

Industrial Applicability The polypropylene resin composition of the present invention has a good balance of physical properties and is industrially extremely valuable.

Claims (2)

[Claims] 1. A propylene homopolymer having a mesopentad ratio of 0.970 or more, or 100 parts by weight of a propylene / ethylene block copolymer having a mesopentad ratio of 0.970 or more in a homopolymerized portion of propylene,
When attention is paid to three consecutive monomer units, the proportion of chains in which 3 or more propylene are linked is 0.40 or more, and the proportion of chains in which 3 or more ethylene is linked is 0.30 or more. A polypropylene resin composition comprising 0.1 to 20 parts by weight of a copolymer of propylene and ethylene of 5% by weight and 0 to 140 parts by weight of a random copolymer of ethylene and an α-olefin having an ethylene content of 20 to 90% by weight. 2. The intrinsic viscosity number of a homopolymer of propylene or a block copolymer of propylene and ethylene is 0.5.
.About.3.0 dl / g, when paying attention to three consecutive monomer units, the proportion of chains in which three or more propylenes are linked is 0.
Copolymers of propylene and ethylene having a ratio of chains of 40 or more and three or more ethylene units of 0.30 or more have an intrinsic viscosity of 1.0 to 10.0 dl / g, and random ethylene and α-olefins. The intrinsic viscosity of the copolymer is 1.
The polypropylene resin composition according to claim 1, which is 0 to 10.0 dl / g.