JPS588717A - Block propylene copolymer composition and its production - Google Patents

Abstract

PURPOSE:To obtain a block propylene copolymer composition having a high melt flow index and being excellent in low-temperature impact resistance and rigidity, by polymerizing propylene, an alpha-olefin and ethylene at a specified ratio with the aid of a stereoregular polymerization catalyst and a modifier. CONSTITUTION:Propylene, a 4-6C alpha-olefin and ethylene are copolymerized at a reactant ratio of 99.5-90wt%, 0.1-10wt%, 0-5wt% with the aid of a stereoregular polymerization catalyst to form a copolymer in an amount of 60-95w%, based on the total copolymer. Then propylene, ethylene and a 4-6C alpha-olefin are copolymerized at a reactant ratio of 5-85wt%, 95-15wt%, 0-10wt% to obtain the propylene copolymer composition. Here, in the polymerization, hydrogen is added are used as a modifier. This composition has a melt flow index at 230 deg.C of 1-100g/10min and is characterized by a high elongation at break.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propylene block copolymer composition having excellent low-temperature impact resistance and rigidity, and a method for producing the copolymer assembly. Specifically, a propylene block copolymer composition having high melt flow index: J15 polymer silk composition having properties such as high impact resistance, rigidity, and especially high elongation at break even when released, and the same. 1 relates to a method for producing a polymer composition.

Many studies have been carried out on ways to solve the drawback of crystalline polypropylene being brittle at low temperatures, and among them, the method of copolymerizing propylene with other olefins, especially ethylene, has already been carried out on an industrial scale. Many products are readily available in the market.

However, on the other hand, there is a demand for shortening the cycles during molding and reducing the required energy, and in response, efforts are being made to improve flowability, but simply In order to increase
Simply lowering the molecular weight of the polymer will significantly reduce the impact resistance, and furthermore, when making an actual molded product, the elongation at break (which is said to have a large effect on the impact resistance of the molded product)
ASTM D638) is extremely small, resulting in poor impact resistance in actual molded products. Therefore, a copolymer composition having a relatively high melt flow index and high elongation at break is required.

As a result of extensive research, the present inventors discovered a method of producing a copolymer composition possessing the above-mentioned desirable physical properties through polymerization using a specific method, and completed the present invention.

It is an object of the present invention to provide a propylene block copolymer composition that has a relatively high melt flow index, high stiffness and impact resistance, and high elongation at break.

The propylene block copolymer composition of the present invention (hereinafter referred to as the copolymer composition of the present invention) comprises propylene 99.5
~90 parts by weight, 0.1~ of α-onfin having 4 to 6 carbon atoms
60 to 95 parts by weight of segment 1 to (6) consisting of 0 to 5 parts by weight of ethylene, 5 to 85 parts by weight of topropylene, 95 to 15 parts by weight of ethylene, α-olefin having 4 to 6 carbon atoms 40 to 5 parts by weight of segment l-()3) consisting of 0 to 10 parts by weight, and 23 parts by weight
Melt flow index at 0℃ is 1 to 1001
00g7l0.

The production method of the present invention relates to a method for producing the above copolymer composition of the present invention, that is, using a stereoregular catalyst, propylene 99.5 to 90% by weight, α-olefin having 4 to 6 carbon atoms 0 .1 to 10% by weight, reaction ratio of 0 to 5 parts by weight of ethylene, 60 to 950 to 95 parts by weight of the total polymerization amount, followed by 5 to 85 parts by weight of propylene, 95 to 15 parts by weight of ethylene,
It is characterized by polymerization at a reaction ratio of 0 to 10% by weight of α-olefin having 4 to 6 carbon atoms.

The stereoregular catalyst used in the production of the copolymer composition of the present invention is not particularly limited as long as it provides highly crystalline polypropylene, and a conventional catalyst system consisting of a transition metal compound and an organometallic compound can be used. . in particular,
A combination of titanium, vanadium chlorides, or these transition metal compounds supported on various carriers such as chlorides, oxides, or hydroxides of magnesium, manganese, etc., and organometallic compounds such as aluminum, zinc, magnesium, etc. is used.

The polymerization method for producing the copolymer composition of the present invention includes a solvent polymerization method using an inert solvent, a bulk polymerization method using the monomer itself such as propylene as a solvent, or the presence of a substantially liquid medium. A gas phase polymerization method that does not require this method can be applied.

In the production of the copolymer composition of the present invention, first, a reaction ratio of 99.5 to 90% by weight of propylene and 0.1 to 10% by weight of α-olefin having 4 to 6 carbon atoms - 5% by weight of ethylene The total polymerization amount is 60 to 950 to 95 parts by weight. This step is necessary to maintain a well-balanced stiffness and impact resistance of the resulting copolymer composition, and is also an essential condition to maintain a high elongation at break even if the copolymer composition has a high melt flow index. be.

Examples of α-olefins having 4 to 6 carbon atoms used in the J2 reaction include 1-buty/, 1-pentene, and -hex/, with 1-butene being particularly preferred. Carbon number 4~
The reaction ratio of α-olefin G is 0.1 to 10% by weight, preferably 0.1 to 5% by weight. The reaction ratio of α-olefin having 4 to 6 carbon atoms is n,
% or less, there is almost no effect of keeping the elongation at break to a minimum, and if the weight coefficient is 10 or more, -[, stiffness 1-1] decreases greatly, which is not preferable.

The reaction ratio of ethylene in the above reaction is 0 to 5% by weight.
, preferably from 0 to 2% by weight, and when the reaction ratio is 5% by weight or more, the reduction in stiffness and stiffness of 1:1 is large and the rod portion is not good. In the above reaction, when the reaction ratio of α-olefin and ethylene is relatively high, it is particularly preferable to polymerize propylene alone in an amount of 2 to 10 weight φ of the total polymerization amount prior to the reaction ratio described in 2. Solvent polymerization method or relatively second segment L-B, ie, reaction ratio of 5 to 85 weight percent of propylene, 95 to 15 weight percent of ethylene, and 10 to 10 weight percent of α-olefin having 4 to 6 carbon atoms, of 40 to 40 percent of the total polymerization amount. 5% by weight polymerization. The above steps are necessary for maintaining good impact resistance of the resulting copolymer composition, especially impact resistance at low temperatures.

The α-olefin having 4 to 6 carbon atoms used in the above reaction includes 1-butene, 1-pentene, 1-hexene, etc., and 1-butene is particularly preferred. Carbon number 4-6
The reaction ratio of α-olefin is 0 to 10% by weight,
Preferably it is 0 to 5% by weight. α- having 4 to 6 carbon atoms
If the reaction ratio of the olefin is 10% by weight or more, the rigidity of the obtained polymer will decrease, which is not preferable. The reaction proportion of ethylene is 95 to 155 to 15% by weight, and the appropriate range varies depending on the required physical properties.

It is also possible to further divide the above reaction into several stages and polymerize at different reaction ratios. For example, when high impact resistance is required, the reaction ratio of ethylene is 15-60g5-6
By dividing it into 0% by weight and 950-95% by weight, the
Get the best results. The temperature and pressure at the core of the polymerization reaction depend on the polymerization method used, the catalyst, and the reaction ratio of each monomer: although it is not specified, it is generally between 0°C and 1°C.
00°C, '1' pressure to 50 Kg/cm2-gauge.

By the method of the present invention, it is possible to obtain the copolymer of the present invention which has a high melt flow index, has an impact resistance of 1<Il, and has an excellent balance of physical properties such as rigidity.

EXAMPLES Below, the effects of the present invention will be specifically explained with reference to Examples.

In the Examples and Comparative Examples, the elongation at break, ASTM D638 intrinsic viscosity number (abbreviated as below), is measured at 135° C. Tallery/solution.Bending rigidity: ASTM D747 Dual 7 JIS K6718 Notched ASTM D256 Mel 1-Index (hereinafter abbreviated as MI) JIS K72
The bending rigidity was measured at 20°C based on MI 230°C, load 2°, 16K9, and DuPont Izot (notched) at 0°C and 20°C, respectively.

Examples 1 to 3 Titanium trichloride catalyst (TGY-24) manufactured by Marubeni Solv Kogyo Co., Ltd.
Using IOg, diethylaluminum chloride 50ml as a catalyst, n-
The polymerization reaction was carried out in 100 p of hebutane. The segment) (A) was polymerized in one stage, and the segment) (A) was polymerized in two stages. After the polymerization of segment (A), the gas phase is discharged, and then hydrogen, propylene, and ethylene-1-butene are charged to meet the specified conditions, and the segment (B) is
I got it.

The first stage has a total pressure of 5 K9/crrL2-gauge, the polymerization temperature is 70°C, the second stage has a 2 to 9/Crn2-gauge, the polymerization temperature is 55°C, and the third stage has a 3K97 cm2-gauge.
The polymerization reaction was carried out at a polymerization temperature of 55°C. Detailed reaction conditions are shown in Table 1. After the copolymerization was completed, 50 fl of methanol was charged and stirred at 60° for 30 minutes, and then the aqueous layer was removed. The heptane layer was further washed twice with 50 n of water, cured and dried, and then A powder which is a polymer composition of the invention was obtained. A known stabilizer was added to this powder and the product was granulated and then measured.

The results are shown in Table 2.

Comparative Examples 1-2 Polymerization was carried out in the same manner as in Examples 1-2 except that 1-butene was not used. The results are shown in Table 2.

The products according to the present invention all have a greater elongation at break than the copolymer compositions of comparative examples.

Claims (1)

[Scope of Claims] 1) Segmentary compound I/(A ) G 0~
95 parts by weight, 5 to 85 parts by weight of propylene [I; part, 95 to 15 parts by weight of ethylene, 70 parts by weight of α-olefin having 4 to G carbon atoms]
A copolymer composition of propylene consisting of 40 to 5 parts by weight of segment 1 to 10 parts by weight and having a melt flow index of 1 to 1009/l 0 m1n at 23 I) °C. 2) Using a stereoregular catalyst, propylene 99.5-9
0 weight coefficient, α-olefin having 4 to 6 carbon atoms 0.1 to 10
Weight factor: 0 to 5 weight fff% (ii) Reaction ratio: 60 to 9 of the total polymerization surface! 'l', ', @i Back and forth polymerization, then propylene 5-85% by weight, ethylene 95%
~15 weight factor, α-olefin having 4 to 6 carbon atoms O~10
A method for producing a propylene block copolymer characterized by polymerization at a weight-based reaction ratio 3) Propylene obtained by adding hydrogen during polymerization and using hydrogen as a molecular weight regulator during polymerization 4) The method according to claim 2, wherein the block copolymer has a melt flow index of 1 to 100 g/lom1n at 230° C. 4) The method according to claim 2, wherein the α-olefin having 4 to 6 carbon atoms is 1-butene. A propylene block copolymer composition according to scope 1. 5) The method according to claim 2 or 3, wherein the α-olefin having 4 to 6 carbon atoms is 1-butene.