JPS606965B2 - Production method of propylene copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing impact resistant ethylene-propylene copolymers with improved moldability.

More specifically, we will develop an ethylene-propylene copolymer with excellent moldability and impact resistance that undergoes solvent-free polymerization in two steps using a stereospecific polymerization catalyst containing a specific trisalt titanium compound and an organoaluminium compound as main components. Regarding the manufacturing method. Highly fed crystalline polypropylene, which has been produced and consumed in large quantities as a general-purpose resin in recent years, has excellent strength, heat resistance, moldability, and dimensional stability, but has the disadvantage of low impact resistance at temperatures below room temperature and easy brittle fracture. Therefore, it is unsuitable for molded products that are subjected to large stress or impact.

On the other hand, high-density polyethylene has excellent low-temperature brittleness resistance and impact resistance, but has a low softening point and poor moldability. Therefore, there has been a demand for a resin that has excellent properties such as strength, heat resistance, dimensional stability, moldability, low-temperature brittleness resistance, and impact resistance.

In order to meet these demands, it is known to improve the low temperature brittleness of polypropylene by blending it with rubber, but this method does not provide fully satisfactory results.

It is also known to combine polypropylene chains by so-called block copolymerization. However, even in this method, when ethylene is polymerized at nearly 100% in the second stage polymerization, there is little side effect of the amorphous polymer soluble in hydrocarbon solvents, and although the rigidity is high, the impact strength is not sufficient. . When random copolymerization with ethylene is carried out in the second stage of polymerization in the presence of excess propylene, the crystallinity of the resulting polymer chain is lost and a rubbery polymer is produced, resulting in a significant improvement in impact resistance. Due to the decrease in crystallinity, the original rigidity of polypropylene is lost, and at the same time, a large amount of hydrocarbon-soluble polymer is created. The secondary property of such amorphous polymers is that during long-term operation, rubber-like polymers adhere to the equipment, causing problems such as poor conduction and clogging. The rubber components will be eluted and the loss will be immeasurable. Furthermore, in block copolymers, if low-temperature brittleness resistance and load resistance are improved, processability is reduced, so it is extremely difficult to produce impact-resistant polypropylene that has both of these desirable properties. In addition, the molding method greatly influences the value of the resin, especially in the injection molding field.
The superiority of polypropylene over polyethylene is largely due to this molding method.

The molding process here refers to the molding cycle and dimensional stability during continuous injection molding of molded products, and includes not only the melt flow but also the microscopic aspects of the polymer such as the crystallization rate and crystallization start temperature. This includes moldability due to the crystal structure. In general, the impact resistance of block copolymers produced by the two-step method is related to the amount of rubber components in the second step. It is industrially preferable to increase the propylene content of the propylene copolymer as much as possible.

By the way, attempts to improve the stereospecificity and catalytic activity of Q-olefin polymerization catalysts have been proposed from various angles, but there are also attempts to improve the catalytic performance of titanium trichloride, the main component of the catalyst, by purchasing it. It has been done.

However, it has not yet been fully clarified which types of modified titanium trichloride among these modified titanium trichlorides are useful in the process for producing ethylene-propylene copolymers. In particular, it was unclear whether any type of modified titanium trichloride could be used to efficiently produce a copolymer with excellent physical properties in a two-step solventless polymerization process of ethylene and propylene. The present inventor conducted various studies on a method for producing an ethylene-propylene copolymer by a two-step solventless polymerization method using various types of recycled titanium trichloride. We discovered that titanium trichloride or its eutectic with aluminum chloride is particularly superior when used as a modified titanium trichloride, and further examined and researched the polymer composition and conditions of the polymerization stage from multiple angles. The present invention was achieved by successfully developing a production method that does not have the above-mentioned drawbacks in production means and produced polymers only under certain selected conditions. That is, the objectives of the present invention are (1) no adhesion of polymer in the reactor; {2
1. No agglomeration of the polymer occurs, {31. There is almost no loss of amorphous polymer during catalyst removal, especially no elution of the rubber component, ■ Excellent molding processability, Hata: Our goal is to provide a propylene copolymer that satisfies the requirements of having both impact resistance and high rigidity, and ■ minimizing the amount of ethylene used, which is an expensive monomer.

The structure of the present invention that achieves this object is: (1) "Titanium trichloride or a eutectic of it and aluminum chloride" co-pulverized with an organic nitrogen-containing compound or an organic phosphorus compound, and (B) an organic aluminum compound as the main components. In the first step, propylene alone or propylene and ethylene are mixed with a monomer composition of 99% in the liquid phase using a stereospecific catalyst.
Solventless polymerization is carried out under conditions in which propylene accounts for 5 mol% or more, and in the third step, propylene and ethylene are polymerized under conditions in which propylene accounts for 70 to 96 mol% of the monomer composition of the liquid phase and the total amount is The present invention relates to a method for producing a fluoropyrene copolymer, which is characterized in that solventless polymerization is carried out so that 5 to 3% by weight of the fluoropyrene copolymer is polymerized.

To outline the present invention, the catalysts used in the first and second stages of the polymerization reaction are: (1) "titanium trichloride or a eutectic of it and aluminum chloride" co-pulverized with an organic nitrogen-containing compound or an organic phosphorus compound; [B
) A stereospecific catalyst mainly composed of an organoaluminum compound, which is a stereospecific catalyst containing an organic nitrogen-containing compound or an organophosphorus compound used as one component of the catalyst and a pulverized catalyst.
"Titanium trichloride or a eutectic of it and aluminum trichloride" is a co-powder with 0.01 to 1 mol, preferably 0.02 to 0.5 mol of an organic nitrogen-containing compound or an organic phosphorus compound per 1 mol of titanium trichloride. It can be manufactured by processing.

Co-pulverization can be obtained by directly mixing appropriate amounts in a pulverizer such as a ball mill and pulverizing the mixture. The titanium trichloride or its eutectic pulverized as described above exhibits a remarkable cost improvement effect as a catalyst for the two-stage solventless polymerization of the present invention.

It is desirable that the grinding be carried out at room temperature or at elevated temperature under an inert atmosphere (for example in nitrogen), with exclusion from air and moisture. It can be produced by using an impact mill, a ball mill, a vibration mill, or other suitable pulverizing means. Suitable grinding conditions vary depending on the grinding means and method, but for example, when using a vibrating mill, titanium trichloride is significantly activated within the first 2 to 3 hours, and as the grinding time is extended further, it is gradually improved to a constant value. It shows a mirror direction that decreases after reaching or passing through a maximum. Therefore, in such a pulverization method, it is not necessary to carry out the pulverization treatment for a particularly long time. The catalyst raw material titanium trichloride or the eutectic of it and aluminum chloride is titanium trichloride produced by an appropriate known method, and the eutectic of titanium trichloride and aluminum trichloride, that is, 3rjC13.AIC13 (hereinafter referred to as "AA type trichloride"). titanium).

Examples of organic nitrogen-containing compounds used in the co-pulverization process include aromatic azo compounds such as azobenzene, azotoluene, and phenazine Z, aromatic isocyanate compounds such as phenyl isocyanate, tolylisocyanate, and naphthyl isocyanate, benzonitrile, tolnitrile, and naphthyl isocyanate. Aromatic nitrile compounds such as nitrile, tertiary amines such as pyridine, ethylpyridine, Q-chloropyridine, picoline, triethylamine, tributylamine,
Secondary amines such as diethylamine, dibutylamine, dibenzylamine, primary amines such as butylamine, aniline, etc.
Among them, ditertiary or secondary amines are preferably used. Examples of organic phosphorus compounds include trialkyl or Organic phosphine compounds such as triallylphosphites, organic phosphine compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, trimethylphosphine oxide, triethylphosphine oxide, tributylphosphine oxide, triphenylphosphine oxide,
Examples include organic phosphine oxides such as hexikimethylphosphoric triamide, but tributylphosphine oxide,
Triphenylphosphine oxide, hexamethylphosphoric triamide (triphenylphosphine) is particularly preferably used.These organic nitrogen-containing compounds and organic phosphorus compounds may be used alone or in combination of two or more. The ``titanium trichloride or a eutectic of it and aluminum chloride'' that was tested is, as in the conventional method, 'B}
By combining it with a component containing an organoaluminum compound, it can be used as a catalyst for olefin polymerization.

[B-component organoaluminum compounds include trimethylaluminum, triethylaluminum,
Examples thereof include trialkylaluminum having a lower alkyl group such as triisopropylaluminum and triisobutylaluminum, and alkylaluminum halides such as their monohalides, sesquihalides, and dihalides.

In addition, highly active organoaluminum compounds such as tetrafurkyldialumoxane and its chlorine and or hydrogen derivatives may also be used. In addition, various organic Aluminum compounds can also be used. Various third components can be used in combination with the organoaluminum compounds to further improve the catalytic performance.

For example, tetrabutylammonium iodide, N.N.
-dimethylethanolamine, tributylamine, trimethylsulfonium iodide, pyridine, tetramethylurea, triethylenediamine, diethylene glycol, diethylene glycol, dimethyl ether, dimethylformamide, dimethyl ether, diethylene urethane, diphenyl urethane, triphenylphosphine,
Tributylstipine, triphenylarsine, menthylamine, hexaethylmelamine, dimethylacetamide,
Quinoline, hexamethylphosphoric triamide, trioctylphosphine, triethylphosphine oxide, triethylphosphate, tributylphosphite, polymethylsiloxane, tetrakisdimethylaminosilane, trichloroborazole, trisdimethylaminoborane, dipyridine zinc chloride, Electron-donating compounds such as dipicolinodine dichloride, dibutyl ether, tetrahydrofuran, and sulfonic acid amide can be used as the third component.

Next, to explain the polymerization conditions, in the first step of the polymerization reaction, propylene alone or propylene and ethylene are polymerized without solvent under conditions where the monomer composition of the liquid phase is 99.5 mol% or more of propylene. When propylene alone is polymerized in the first step, liquefied propylene is used, and therefore the monomer composition of the liquid phase is 100 mol% of propylene, producing a propylene homopolymer.

However, when polymerizing propylene and ethylene, in view of the physical properties of the final polymer, it is necessary that the first stage polymer be a propylene polymer containing random ethylene with an ethylene content of approximately 5% by weight or less. In order to do so, it is necessary to maintain a condition in which the monomer composition of the liquid phase is 99.5 mol% or more of propylene.The polymerization temperature and pressure can be the same as those generally used in propylene polymerization. The pressure range is usually 0 to 10 p atm, preferably 50 to 8,500 psm, and 10 to 10 psm, preferably 1 to 5 p atm, and hydrogen is used as the molecular weight regulator.

The polymer obtained in the first step has an intrinsic viscosity (decalin 135°C) of 1.2 in consideration of the balance of physical properties of the final polymer.
It is adjusted to be in the range of ~2.5 d'/evening.

In the first stage polymerization reaction, 70 to 95% by weight, preferably 80 to 9% by weight of the total polymerization amount is polymerized. The first stage polymerization reaction may use one polymerization reactor or two or more reactors. After the first stage, ethylene (
If necessary, propylene, hydrogen, catalyst components) are further introduced, and the process proceeds to the second stage polymerization reaction. In the second stage, the monomer composition of the liquid phase is 70 to 96 mol% propylene and 4 mol% ethylene.
~30 mol% and 5 to 3% by weight of the total polymerization amount
Solventless polymerization is carried out to polymerize.

The second stage of polymerization is also usually 0 to 100 oo, preferably 50 to 100 oo.
It can be carried out in a range of 8,500 and 100 atm or less, preferably 1 to normal atmospheric pressure. The polymerization reaction in the second and second stages may be carried out in a cell or by connecting two or more cells in series. The first and second stage polymerization reactions can be carried out batchwise or continuously using a multi-tank or loop reactor. The propylene copolymer of the present invention obtained in this way has an intrinsic viscosity of 1.5 to 1.5 in terms of moldability and impact resistance.
The optimum range is 4.0 d'/evening.

As mentioned above, the polymer obtained with such a monomer composition and polymerization ratio in the liquid phase is a propylene homopolymer or a propylene polymer chain containing random ethylene with an ethylene content of 5% by weight or less in the first step. The polymer chain produced in the second stage is an ethylene-propylene copolymer chain with a propylene content of 30-7% by weight. It is clear from the description of the examples described below that the polymer produced by the method of the present invention is an impact-resistant propylene copolymer with an excellent balance of physical properties. This is not caused only by the physical properties of 0.

The polymer obtained by the present invention has oxygen, which is generally added to Q-olefin polymers, especially polypropylene.
Light (ultraviolet), ozone, heat stabilizer, nada retardant,
Processability improvers, fillers, reinforcing agents, pigments (colorants), antistatic agents, colorability improvers, such as blowing agents, antiblocking agents, nucleating agents, and metal (e.g. copper) deterioration inhibitors. By incorporating additives, the effect can be further exhibited.

Since the polymer obtained by the present invention has excellent physical properties as described above, it is particularly suitable for use as materials for large containers, large containers, electrical parts, and automobile parts, as well as for daily necessities, toy containers, and sheets. , films, boards, tapes, etc. are also widely used. The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited thereto.

In addition, in the Examples and Comparative Examples, the melt flow index was measured at 230qC load of 2.16k9 based on the method of ASTM D-1238-65T. In addition, the tensile yield strength, tensile breaking strength, and tensile breaking elongation are A
STMD-638-58T method, bending rigidity is AST
M D-74-61T, verticalization temperature is ASTM D-74
6-57T, lzod impact strength is AST
20 based on the method of MD-256-56T, respectively.
It was measured in qo. Example 1 (i- Production of modified titanium) A eutectic of titanium trichloride and aluminum chloride (type AA manufactured by Toyo Stouffer Co., Ltd., hereinafter referred to as "type AA titanium trichloride") was prepared in a dry box purged with nitrogen for 50.0 minutes. ) and y-picoline (1 to 3 molar ratio of AA type titanium trichloride) were mixed, and this mixture was packed with 600 porcelain balls with a diameter of 1 mm.The contents were made of stainless steel. After filling into a ball mill container, the mixture was pulverized in a vibratory pulverizer at room temperature for 1 hour.

(ii) In a stainless steel autoclave with a polymerization internal volume of 1.5 mm, 0.30 mm of the pulverized AA type titanium trichloride, ethylaluminum dichloride, and tributylamine (mixed molar ratio 1:0.70) were added. 4. Toluene solution for aluminum. Then, hydrogen was introduced in an amount corresponding to a liquid layer hydrogen concentration of 0.15 mol % based on propylene at 365 m2 and 75 mq of liquefied propylene.

While praying, the contents were flooded to 75oC and the first stage of polymerization was carried out in 1. I spent a lot of time doing it. By conducting only this first step in another preliminary experiment under exactly the same conditions, it was found that the intrinsic viscosity was 1
．． It has been confirmed that 174 units of 94d'' polypropylene (135o decalin) are produced. Subsequently, without expelling the propylene monomer, the mixture was cooled to 6,500 ℃ and moved to the second stage of polymerization, and polymerization was carried out at 65 0 for 13 minutes while adding ethylene at a partial pressure of 5 k9/l.
The monomer composition in the liquid layer at this time was propylene 91mo.
1% ethylene hol%. The second-stage polymerization was stopped by flashing the ethylene-propylene monomer out of the system, and after extracting the crude polymer after about 10 minutes (used as a sample for heptane extraction), it was heated at 90 CC for 2 minutes with 500 ml of butyl alcohol. After repeating the treatment and filtering at 9000°C three times, it is dried to obtain a white powder.
The yield was 203 kg including the crude polymer, and the high specific gravity was 0.40.
The boiling heptane residue of the crude polymer was 92.7%. Further, the amount of amorphous polymer extracted by the super-butyl alcohol treatment was 0.9%. The amount of ethylene component in purified polymer is 1
8,000 by measuring the infrared absorption spectrum of the molten film at 717 Hada-1 and 735 Hada-1. It was round weight %. The proportion of the second stage polymer in the total polymer is 14.4% by weight, and the propylene content in the polymer produced in the second stage is 42% by weight. The above polymer is lauryl stearyl thiodipropiolede (LSTD).
P) 0.1% by weight and tetrakis[methylene-3-(3.
5-di-tert-butyl-4'-hydroxyphenyl)propionate] methane (trade name: 1granoxlolo)
) was passed through an extruder twice at 20,000 rpm to make a bevellet, which was then press-molded at 230 qo to make a test piece. As a result of measurement, the arming temperature was -20. 3oo, bending rigidity 14.6 x 1 pi/i, tensile yield strength 247k9', cutting strength 342k9'c, fin cutting elongation 790%, Izod impact strength 16kg / suppressed melt flow index (230o○) 3.6mm / It was 10 minutes. Example 2 A test was carried out in the same manner as in Example 1 under the conditions shown in Table 1, using diethyl aluminum chloride as the organic aluminum component (no third component was used).

Comparative Example 1 Same as Example 2 except that commercially available A was used as the titanium trichloride component.
Copolymerization was carried out using A-type titanium trichloride (manufactured by Toyo Stouffer).

Comparative Example 2 Same as Example 2, except that the same mixture of ethylaluminum dichloride and tributylamine (mixed molar ratio 1:7) as in Example 1 was used as the organic aluminum component, and commercially available AA type trichloride was used as the titanium trichloride component. Copolymerization was performed using titanium.

Due to the correspondence between Example 2 and Comparative Examples 1 and 2, the bending rigidity and yield strength of the polymer produced in the present invention were significantly improved, and the amount of amorphous polymer produced was halved. It is clear that the high specific gravity of the residue and polymer powder is very high. The hebutane index and flexural rigidity of the first-stage propylene homopolymer were 98.6% and 98.6% in Example 2, respectively.
20.2×1 pi/in2 91.2% in Comparative Example 1 13
．． 8×1 pi/in2, 96.4% in Comparative Example 2 18.
It is 7×1 pi/in2. However, in the two-stage copolymer, only Example 2 had excellent physical properties, and Comparative Examples 1 and 2 had almost the same physical properties. Thus, there is no correlation with the physical properties of the polymer produced in the first stage. Comparative Example 3 The same procedure as in Example 2 was carried out except that the monomer composition in the second stage was changed to 98 hol% propylene and 2 hol% ethylene.

This shows that impact resistance is not developed when the monomer composition is out of the preferred range. Examples 3 and 4 Experiments were conducted in the same manner as in Example 2, except that the monomer composition in the second stage and the proportion of the second stage polymer were changed.

Comparative Example 4 A copolymer was produced under exactly the same conditions as in Example 4 using commercially available AA titanium trichloride.

Compared to Example 4, the rigidity and yield strength are significantly lower. Examples 5, 6 and 7, Comparative Examples 5 and 6 Pulverized titanium trichloride was produced in the same manner as in Example 1, except that the type and amount of the modifier to be pulverized were changed.

In Comparative Examples 5 and 6, when Esterol 7L was used,
In particular, the bending stiffness decreases, indicating that a large amount of amorphous polymer increases stiffness. (World) Double convex.

...Fritomitomi'li Ikuheo Small construction Example 8 Inner volume 100 In the reactor with concentrated speculum, liquefied propylene monomer 33.2 k9/day and y-picoline modified titanium trichloride used in Example 1 5 49' days, 40 t' days of dimethylaluminum chloride, hydrogen at off gas concentration contr.
ol and the liquid layer hydrogen concentration is 0.1 h relative to propylene.
Continuous feeding was carried out so that the concentration was 0.1%.

Autoclave internal pressure 32k9/polymerization temperature 70pm OC average residence time is 1.5 hours, 22.6k9/day of liquefied propylene monomer and 10% polypropylene from the outlet of the first stage.
．． It is discharged at a rate of 6k9/day, but the internal volume is 40.
feed into the second stage reactor. At this time, ethylene is added to the second stage reactor at a rate of 1.4k9/day. In the second stage polymerization, the polymerization temperature was 60 qo and the average residence time was 28 minutes.
At the outlet of the second stage reactor, the polymer mixture is discharged via a 12.3K9 D-type flash hopper. The resulting polymer mixture was prepared batch-wise with butyl alcohol at 90%
Wash 003 times. The amount of polymerization in the second stage relative to the total amount of polymerization is 13. The intrinsic viscosity of this polymer is 2.3% by weight, the high specific gravity is 0.40tcc, and the ethylene content is 8.5% by weight. % by weight. The verticalization temperature of the product pelletized using the 45 side extruder is -11.6oo, and the bending rigidity is 15.6x.
1Mb/i〆, yield strength 262k9 / enemy cutting strength 351
It had a k9/ground, a cutting elongation of 690%, and a melt o-index of 8.2/1 skin.

The amount of amorphous polymer extracted in the catalyst removal step using butyl alcohol was 0.8%. The above product pellet was molded using a 5-ounce high-speed injection molding machine with a weight of 22 mm and a wall thickness of 0 mm.
5 A thin container made of willow was injection molded (one piece was cut out).

Nozzle temperature 250o, cylinder temperature C. ~C330
0q○ C4290oO C5260 At 0:00, the cooling water temperature is 4°C at the mold inlet, and the injection pressure is 1000k9/block.
As a result of continuous molding, the time required per piece was 7.4 seconds. Differential scanning calorimetry (PerkinElmer DS) for the above polymers
The temperature at which crystallization starts is measured by CO type) at a cooling rate of 1.
The temperature was 120.7°C when measured at 00C/min. The crystallization rate is expressed as the reciprocal of the crystallization time tl/2 (min), 1/t 1'2 (min-1), and is 401oK.
The isothermal crystallization rate at 1/t l/2 was 0.102. Comparative Example 7 In the same manner as in Example 8, AA type titanium trichloride (manufactured by Toyo Stouffer) was fed as the titanium trichloride component at a rate of 6.2 evenings/day to conduct the first stage polymerization.

From the first stage outlet, polypropylene is 9.6k9/H liquefied propylene monomer is discharged at a rate of 23.1 kg/day. The second stage adds ethylene at 1.4k9/day.
The second stage polymerization was carried out at 6000 ml, the average residence time was 19 minutes, and the polymerized product was discharged from the second stage reactor at a rate of 11.1 k9/day. The amount of polymerization in the second stage relative to the total amount of polymerization was 13.5%, and the inherent viscosity of the polymerized product was 2.1 d'' and the bulk specific gravity was 0.37 d/
At CC, the amount of ethylene is 8. It was turtle weight %. The temperature of the pellet's arm is -16.2℃ Yield strength 232k9 / Cutting strength 350k9 / Carp cutting elongation 770% Bending rigidity 12
．． 9×1 pilb'in2 melt flow index8.
It is 0 tata/chihin.

In the catalyst removal step, 3.4% of the amorphous polymer was extracted and removed with butyl alcohol. When molded using a 5-ounce high-speed injection molding machine under exactly the same conditions as in Example 6, the molding time per piece was 8. It was the mother sand. In addition, the crystallization start temperature determined by differential scanning calorimetry is determined by a cooling rate of 10 qC/min.
It was measured at 116.600. The crystallization rate was 1/t 1/2 at 401° K by the same method as in Example 8:
It is 0.078hin-1. Comparison with Example 8 shows that the polymer obtained by the method of the present invention has a molding cycle of 1.
The time is reduced by 4%, the crystallization initiation temperature during the cooling process is high, and the crystallization speed is also fast.

From the above Examples and Comparative Examples, it is clear that the present invention satisfies the above-mentioned requirements, and in particular, the balance between flexural rigidity and late curing temperature, which are physical properties related to zero impact resistance, is outstandingly excellent. For ease of understanding, it is shown in the accompanying drawings.

[Brief explanation of drawings]

The figure shows the balance between flexural rigidity and arming temperature of propylene copolymer produced by the method of the present invention in Examples 1 to 8.
Comparative Examples 1-7 and commercially available impact-resistant polypropylene A-
This is a plot for F. In the figure, 01-08 are Examples 1-8 of the present invention, 0◇1-
07 shows the measured values of Comparative Examples 1 to 7 and A to F show the measured values of commercially available impact-resistant polypropylene, respectively.

Claims (1)

[Claims] 1 Using a stereospecific catalyst whose main components are (A) "titanium trichloride or a eutectic of it and aluminum chloride" co-pulverized with an organic nitrogen-containing compound or an organic phosphorus compound, and (B) an organic aluminum compound. In the first step, propylene or propylene and ethylene are polymerized without solvent under conditions in which the monomer composition of the liquid phase is 99.5 mol% or more of propylene, and in the second step, propylene and ethylene are polymerized in the liquid phase. Under conditions where the monomer composition is 70-96 mol% propylene and 5-30% by weight of the total polymerization
1. A method for producing a propylene copolymer, which is characterized by solvent-free polymerization.