KR20240067627A - Propylene-based polymer and manufacturing method thereof - Google Patents

Abstract

The present disclosure relates to a method for producing a propylene-based polymer having excellent melt strength, a propylene-based polymer produced thereby, and a film containing the same. Specifically, the method for producing a propylene-based polymer according to one embodiment includes polymerizing liquid propylene and diene under a Ziegler-Natta catalyst and polymerizing gaseous propylene and ethylene, and the propylene-based polymer produced thereby Polymers can achieve physical properties of high melt strength. Therefore, the propylene-based polymer according to one embodiment is capable of forming foam at high temperatures and has excellent processability and productivity.

Description

Propylene-based polymer and manufacturing method thereof}

The present disclosure relates to propylene-based polymers and methods for their preparation.

Polypropylene (PP) consists only of carbon and hydrogen and has a low density, so it is easy to reproduce and can achieve excellent chemical resistance and a high tensile modulus at a relatively low cost. However, propylene-based polymers have had limitations in thermoforming and processing because it is difficult to achieve high melt strength. Increasing the melt strength of propylene-based polymers has been an industrial goal for decades, but with limited success.

In order to improve the melting characteristics of the propylene-based polymer, it is desirable for the polypropylene main chain to have a long chain branch (LCB) with a long polymer chain. Methods such as blending, solid phase reaction, reaction extrusion, and electron beam irradiation have been reported as techniques for adding long chain branches to the polypropylene main chain.

One embodiment seeks to provide a method for producing a high melt strength propylene-based polymer.

Another embodiment seeks to provide a propylene-based polymer prepared according to the method for producing a propylene-based polymer according to the above embodiment.

Another embodiment seeks to provide a film containing the propylene-based polymer according to the above embodiment.

One embodiment provides a method for producing a propylene-based polymer comprising the following steps: a first polymerization step of polymerizing liquid propylene and diene under a Ziegler-Natta catalyst to prepare a polymer composition; and a second polymerization step of polymerizing the prepared polymer composition by adding gaseous propylene and ethylene.

Another embodiment provides a propylene-based polymer prepared according to the method for producing a propylene-based polymer according to the above embodiment.

In another embodiment, a film containing the propylene-based polymer according to the above embodiment is provided.

The present disclosure relates to a method for producing a propylene-based polymer having excellent melt strength, a propylene-based polymer produced thereby, and a film containing the same. Specifically, the method for producing a propylene-based polymer according to one embodiment includes polymerizing liquid propylene and diene under a Ziegler-Natta catalyst and polymerizing gaseous propylene and ethylene, and the propylene-based polymer produced thereby Polymers can achieve physical properties of high melt strength. Therefore, the propylene-based polymer according to one embodiment is capable of forming foam at high temperatures and has excellent processability and productivity.

Figure 1 is a diagram showing the results of SAOS (Small amplitude oscillatory shear) analysis to confirm the shear thinning characteristics of propylene-based polymers according to Examples and Comparative Examples. As can be seen in Figure 1, the propylene-based polymer of Example 1 had a higher zero shear viscosity and showed a stronger shear thinning phenomenon than the propylene-based polymers of Comparative Examples 1 to 3.
Figure 2 is a diagram showing the results of measuring the melt strength of propylene-based polymers according to Examples and Comparative Examples. As can be seen in Figure 2, the propylene-based polymer of Example 1 showed significantly higher melt strength than the propylene-based polymers of Comparative Examples 1 to 3, and in particular, the melt strength increased as the pull-off speed increased. was rapidly improved, reaching a melt strength of over 100 cN, and stretching was possible at a stretching speed of over 300 mm/s.
Figure 3 is a diagram showing the results of GPC (Gel permeation chromatography) analysis to confirm the molecular weight distribution of propylene-based polymers according to Examples and Comparative Examples. As can be seen in Figure 3, the propylene-based polymer of Example 1 had a relatively high molecular weight distribution (MWD) compared to the propylene-based polymers of Comparative Examples 1 and 2, resulting in relatively high polymer distribution. In addition, in particular ^, the proportion of polymer groups with a molecular weight of 10 ^6.8 g/mol or more was found to be higher than that of Comparative Example 3.
Figure 4 is a diagram showing the results of measuring the elastic modulus (modulus) to analyze the elasticity of the propylene-based polymer according to Example 1. As can be seen in Figure 4, the propylene-based polymer of Example 1 was confirmed to have two points where the storage modulus and loss modulus intersect, and the relaxation time, which is the reciprocal of the angular frequency value at the cross modulus at one of the points, is in the comparative example. It appeared to be longer than that.

Since the embodiments described in this specification may be modified into various other forms, the technology according to one embodiment is not limited to the embodiments described below. Furthermore, “including” a certain element throughout the specification means that other elements may be further included, rather than excluding other elements, unless specifically stated to the contrary.

Numerical ranges used herein include lower and upper limits and all values within that range, increments logically derived from the shape and width of the range being defined, all doubly defined values, and upper and lower limits of numerical ranges defined in different forms. Includes all possible combinations of As an example, if the content of the composition is limited to 10% to 80% or 20% to 50%, the numerical range of 10% to 50% or 50% to 80% should also be interpreted as described herein. Unless otherwise specified herein, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

Hereinafter, unless otherwise specified in the specification, “about” may be considered a value within 30%, 25%, 20%, 15%, 10% or 5% of the specified value.

One embodiment provides a method for producing a propylene-based polymer, and the production method includes the following steps.

1) A first polymerization step of preparing a polymer composition by polymerizing liquid propylene and diene under a Ziegler-Natta catalyst; and

2) A second polymerization step in which gaseous propylene and ethylene are added to the prepared polymer composition to polymerize it.

In one embodiment, the diene is not particularly limited as long as it is a diene compound, for example, 1,3-butadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8 -Can be any one or more selected from nonadiene, 1,9-decadiene, 1,10-undecadien, 1,11-dodecadiene, 1,12-tridecadiene, and 1,13-tetradediene there is.

In one embodiment, the first polymerization step may be performed at 40°C to 150°C for 30 to 100 minutes. The first polymerization step is carried out at a temperature of 40 ℃ to 120 ℃, 40 ℃ to 100 ℃, 50 ℃ to 100 ℃, 40 ℃ to 80 ℃, 50 ℃ to 80 ℃, 60 ℃ to 80 ℃, or about 70 ℃. It can be performed for 30 minutes to 80 minutes, 30 minutes to 70 minutes, 40 minutes to 70 minutes, 40 minutes to 60 minutes, or about 50 minutes.

In one embodiment, the second polymerization step may be performed at a temperature of 20°C to 70°C for 5 to 60 minutes. The second polymerization step may be performed at a temperature of 20 ℃ to 60 ℃, 30 ℃ to 60 ℃, 30 ℃ to 50 ℃, 35 ℃ to 45 ℃, or about 40 ℃, 5 to 50 minutes, 10 minutes. It may be performed for from 50 minutes to 50 minutes, from 10 minutes to 40 minutes, from 10 minutes to 30 minutes, from 15 minutes to 25 minutes, or about 20 minutes.

In one embodiment, the first polymerization step may include adding 1000 ppm to 3000 ppm, 1500 ppm to 1500 ppm, 1800 ppm to 2200 ppm, or about 2000 ppm.

In one embodiment, the diene may be added in an amount of 1 g to 5 g, 2 g to 4 g, or about 3 g, and the propylene may be added in an amount of 500 g to 2000 g, 500 g to 1500 g, or 600 g to 1300 g. , 700 g to 1200 g, 800 g to 1200 g, 900 g to 1100 g, or about 1000 g. In one embodiment, the weight ratio of diene and propylene is 1:100 to 1:500, 1:200 to 1:400, 1:250 to 1:400, 1:300 to 1:400, and 1:300 to 1:350. , or about 1:330. However, it is not necessarily intended to be limited to the above range.

In one embodiment, in the second polymerization step, the molar ratio of gaseous propylene and ethylene may be 1:9 to 9:1. Or, 2:8 to 9:1, 3:7 to 9:1, 4:6 to 9:1, 5:5 to 9:1, 6:4 to 9:1, 5:5 to 8:2, It may be 6:4 to 8:2, or about 7:3. However, it is not necessarily intended to be limited to the above range.

In one embodiment, the Ziegler-Natta catalyst (or Ziegler-Natta based catalyst) is a transition metal compound containing an element from Group 4, 5, or 6 of the periodic table; and organometallic compounds containing elements of group 13 of the periodic table. The transition metal compound is the main catalyst of the Ziegler-Natta catalyst and may be a compound containing any one or more of magnesium, titanium, a halogen element, and an internal electron donor. The organometallic compound is a cocatalyst of the Ziegler-Natta catalyst and may be an organoaluminum compound, for example, trialkyl aluminum, dialkyl aluminum halide, alkyl aluminum dihalide, aluminum dialkyl hydride, or alkyl aluminum sesquihalide. It may include one or more types. Specifically, for example, the organoaluminum compound is Al(C ₂ H ₅ ) ₃ , Al(C ₂ H ₅ ) ₂ H, Al(C ₃ H ₇ ) ₃ , Al(C ₃ H ₇ ) ₂ H, Al( iC ₄ H ₉ ) ₂ H, Al(C ₈ H ₁₇ ) ₃ , Al(C ₁₂ H ₂₅ ) ₃ , Al(C ₂ H ₅ )(C ₁₂ H ₂₅ ) ₂ , Al(iC ₄ H ₉ )(C ₁₂ H ₂₅ ) ₂ , Al(iC ₄ H ₉ ) ₂ H, Al(iC ₄ H ₉ ) ₃ , (C ₂ H ₅ ) ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl, or (C ₂ H ₅ ) It may be ₃ Al ₂ Cl ₃ .

The molar ratio of the organometallic compound to the transition metal compound may be, for example, 1:1 to 1:50, or 1:5 to 1:50.

In one embodiment, the second polymerization step may further include terminating the reaction by discharging unreacted gas and cooling the temperature to room temperature. Then, the produced polymer is separated and collected and incubated at 40° C. to 80° C. It may further include the step of drying in a vacuum oven at ℃ or about 60 ℃ for about 60 minutes or more to obtain the final product.

Hereinafter, the propylene-based polymer provided in one embodiment will be described in detail.

One embodiment provides a propylene-based polymer prepared according to the method for producing a propylene-based polymer according to the above embodiment.

The propylene-based polymer according to one embodiment has a melt strength of 100 cN or more measured at 200° C., and a significantly higher melt strength can be realized compared to existing propylene-based polymers. In one embodiment, the melt strength may be, for example, 100 cN or more, 105 cN or more, or 110 cN or more, and the upper limit may be, for example, 200 cN or less, 180 cN or less, 160 cN or less, 150 cN or less, 140 cN or less. It may be less than or equal to 130 cN. However, it is not necessarily intended to be limited to the above range. The propylene-based polymer according to one embodiment is useful because processability and productivity can be greatly improved by realizing high melt strength, and transparency and hinge properties can be improved.

The propylene-based polymer having a melt strength of 100 cN or more according to the above embodiment may mean a propylene-based polymer capable of realizing a melt strength of 100 cN or more regardless of the stretching speed.

The propylene-based polymer according to one embodiment has the high melt strength as described above and can be stretched at a pull-off speed of 300 mm/s or more (FIG. 2). Specifically, stretching may be possible even at a stretching speed of 300 mm/s to 400 mm/s, or 300 mm/s to 350 mm/s.

Also, in one embodiment, the melt strength is about 8 g/min to 15 g/min, 8 g/min to about 150°C to 250°C, 180°C to 230°C, 190°C to 210°C, or about 200°C. When extruded at an extrusion rate of 13 g/min, 9 g/min to 13 g/min, 10 g/min to 12 g/min, or about 11 g/min, about 3 mm/s ² to 10 mm/s ² , 4 mm/s ² to 9 mm/s ² , 4 mm/s ² to 8 mm/s ² , 5 mm/s ² to 7 mm/s ² or about 6 mm/s ² so that the test piece is pulled. It may be a measure of the maximum force until it breaks.

In one embodiment, the propylene-based polymer may have a shear thinning index (STI) of 5 or more, defined by Equation 1 below.

[Equation 1]

Shear thinning index = η _0.01 /η ₁₀

In Equation 1, η _0.01 and η ₁₀ are complex viscosity (Pa·s) at angular frequencies of 0.01 rad/s and 10 rad/s at 230°C _, respectively.

The shear thinning phenomenon refers to a phenomenon in which the viscosity of a polymer decreases as the shear rate increases or as the same force is applied for a certain period of time. This shear thinning characteristic is of great importance in the molding method of polymers. It affects. The propylene-based polymer according to one embodiment may have a shear thinning index (STI) of 5 or more, 10 or more, 15 or more, 20 or more, 30 or more, 33 or more, or 34 or more, and the upper limit is 50 or less, 45 or less, or 40 or more. It may be less than or equal to 38, less than or equal to 36, or less than or equal to 35. However, it is not necessarily intended to be limited to the above range.

Specifically, the η _{0 . 01} is 1.0 x 10 ^{4 or} more, 1.5 x 10 ^{4 or} more, 2.0 x 10 ⁴ or more, 2.3 x 10 ⁴ or more, 2.4 x 10 ⁴ or more, ^{2.5 or it} may ^be greater ^{than or equal} to ^3.5 It may be 4.1 x 10 ⁴ or less, 4.0 x 10 ⁴ or less, 3.8 x 10 ⁴ or less, 3.7 x 10 ⁴ or less, or 3.5 x 10 ⁴ or less. ^{In addition , η} ₁₀ ^{is 2.0 ​} x 10 ³ or less, and the lower limit can be, for example, 5.0 x 10 ² or more, 8.0 x 10 ² or more, 9.0 x 10 ² or more, or 1.0 x 10 ³ or more. However, it is not necessarily intended to be limited to the above range. The propylene-based polymer according to one embodiment has a shear thinning index (STI) of about 5 or more, thereby realizing physical properties equivalent to or better than those of existing developed products.

The propylene-based polymer according to one embodiment implements a strain hardening phenomenon that is equivalent to or significantly higher than that of existing developed products, and through this, it can be seen that the propylene-based polymer according to one embodiment includes various long chain branches. Therefore, by using the propylene-based polymer according to one embodiment, a stable state can be effectively maintained during processing.

In one embodiment, the angular frequencies in the Crossover modulus of the storage modulus (G') and the loss modulus (G'') at 230 °C based on the Maxwell model. When the reciprocal of the frequency) value is defined as relaxation time, the relaxation time value of the propylene-based polymer according to one embodiment may be 3.0 s or more. Alternatively, the relaxation time may be 3.3 s or more, 3.5 s or more, 3.7 s or more, 3.8 s or more, 4.0 s or more, or 4.2 s or more. The upper limit may be, for example, 6.0s or less, 5.5s or less, 5.2s or less, 5.0s or less, 4.8s or less, 4.5s or less, or 4.3s or less. However, it is not necessarily intended to be limited to the above range.

The propylene-based polymer according to one embodiment may have a phase difference (tanδ) value of 2.0 or less, defined by Equation 3 below, when the angular frequency is 0.01 rad/s at 230°C based on the Maxwell model.

[Equation 3]

tanδ = G''/G'

In Equation 3 above, G' is the storage modulus, and G'' is the loss modulus.

In one embodiment, the phase difference may be 1.8 or less, 1.5 or less, 1.0 or less, 0.8 or less, 0.6 or less, or 0.5 or less, and the lower limit may be, for example, 0.05 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5. It could be more than that. However, it is not necessarily intended to be limited to the above range. The propylene-based polymer according to one embodiment may have a long relaxation time and a low retardation value, thereby providing excellent elasticity.

The propylene-based polymer according to one embodiment may include 0.5 wt% or more, 1.0 wt% or more, 2.0 wt% or more, 2.2 wt% or more, 2.3 wt% or more, or 2.5 wt% or more of xylene solubles (XS). . The upper limit of the xylene soluble matter may be, for example, 10.0 wt% or less, 8.0 wt% or less, 6.0 wt% or less, 5.0 wt% or less, 4.0 wt% or less, 3.0 wt% or less, or 2.8 wt% or less. Xylene soluble matter refers to the portion soluble in cold xylene among the components contained in the polymer, and can be measured by dissolving the polymer in xylene and then determining the insoluble portion (residue) from the cooled solution. Specifically, xylene solubles can be calculated using the following equation.

[Equation 4]

Xylene solubles (XS, %) = (100 xm ₁ xv ₀ ) / (m ₀ xv ₁ )

In equation 4 above, m ₀ is the initial weight of the polymer (g), m ₁ is the weight of the residue (g), v ₀ is the initial volume of the sample (mL), and v ₁ is the volume of the sample after analysis ( mL). Xylene solubles contain polymer chains with low stereoregularity and can be indicative of the amount of non-crystalline regions.

The propylene-based polymer according to the above-mentioned embodiment has the above-mentioned physical properties, so it is easy to handle, including processability and productivity, and can be effectively applied to various fields such as adhesives, films, and packaging materials.

In one embodiment, the propylene-based polymer has ^a ratio of polymer groups having a molecular weight of 10 ^6.5 g/mol to 10 ^8.0 g/mol, as measured by gel permeation chromatography (GPC), of 2 ^. % or more, or 2.5% or more, 3% or more, 3.2% or more, 3.3% or more, or 3.4% or more, or 10% or less, 8% or less, 6% or less, 5% or less, 4% or less, Or it may be 3.5% or less. Alternatively, the proportion of polymer groups having a molecular weight of 10 ^6.5 g/mol or more may be 2% or more, or 2.5% or more, 3% ^or more, 3.2% or more, 3.3% or more, or 3.4% or more, or 10% or less. , may be 8% or less, 6% or less, 5% or less, 4% or less, or 3.5% or less. Specifically, as can be seen in FIG. 3, the propylene-based polymer according to one example has a wider molecular weight distribution than the propylene-based polymer of the comparative example. This shows that the propylene-based polymers of the example are not separated from each other and are uniform ( It can be seen that it is distributed homogeneously. In addition, the propylene-based polymer of the example has a higher ratio of polymer groups with a molecular weight of ^{10 6.5} g/mol or more than the comparative example, which means that the propylene-based polymer of the example has a high molecular weight ratio and various types of long chain branches (long chain branches, This may mean that LCB) is evenly distributed. The propylene-based polymer according to one embodiment has a high proportion of polymer groups as described above and includes various types of long chain branches, so that superior physical properties such as high melt strength can be achieved.

The propylene-based polymer according to one embodiment has a number average molecular weight (Mn) of 30 kg/mol to 80 kg/mol, 40 kg/mol to 60 kg/mol, 45 kg/mol to 55 kg/mol, or about 55 kg. /mol, and the weight average molecular weight (Mw) is 350 kg/mol to 500 kg/mol, 400 kg/mol to 480 kg/mol, 400 kg/mol to 450 kg/mol, 410 kg/mol to 440 kg. /mol, or about 435 kg/mol, and the molecular weight distribution (MWD) can be 5 to 15, 6 to 12, 6 to 11, 6 to 10, 7 to 10, 8 to 10, or 8 to 9. .

One embodiment provides an adhesive, film, or packaging material containing the high melt strength propylene polymer according to one embodiment, and the high melt strength propylene polymer according to one embodiment is very easy to handle due to excellent physical properties such as productivity and processability. Therefore, it can be applied to various fields.

Hereinafter, examples and experimental examples will be described in detail below. However, since the examples and experimental examples described below only illustrate some of the implementation aspects, the technology described in this specification should not be construed as being limited thereto.

< Example 1> Preparation of propylene-based polymer

Step 1: Liquid polymerization

The 5 L capacity reactor was purged with nitrogen at high temperature, and then the reactor temperature was lowered to 5 °C in a nitrogen atmosphere. Here, 20 mg of Ti-based Ziegler-Natta catalyst (TOHO Titanium), 20 mL of methylcyclohexane, 0.754 g (6.6 mmol) of triisobutylaluminum (Al/Ti=10), diethylaminotriethoxysilane (Si /Ti=1) 0.1554 g (0.66 mmol) and 3 g of 1,9-decadiene were added, 1000 g of liquid propylene was added, and 2000 ppm of hydrogen was added and polymerized at 70°C for 50 minutes. After the polymerization reaction was completed, unreacted gas was discharged, the temperature was cooled to room temperature, and the reaction was terminated.

Step 2: Vapor phase polymerization

After the reaction was completed, gaseous propylene and ethylene (molar ratio = 7:3) were added to the reactor, and then the temperature was raised to 40° C. and polymerization was performed for 20 minutes. After the polymerization reaction was completed, unreacted gas was discharged, the temperature was cooled to room temperature, and the reaction was terminated. The produced polymer was separated and collected and dried in a vacuum oven at 60°C for more than 1 hour to obtain a white propylene-based polymer.

< Comparative example 1>

Daploy ^TM WB140HMS, a high melt strength polypropylene (HMSPP) from Borealis, was purchased and prepared.

< Comparative example 2>

H220P, a linear propylene-based polymer from SK, was obtained and prepared.

< Comparative example 3>

A propylene-based polymer was prepared in the same manner as in Example 1, except that 1,9-decadiene was not added in the liquid polymerization step of the method for producing a propylene-based polymer according to Example 1.

The melt indices of the propylene-based polymers according to Example 1 and Comparative Examples 1 to 3 are as follows. The melt index was measured according to ASTM D1238 standard (230°C, 2.16 kg load condition).

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 melt index
(dg/min) 2.0 2.3 2.2 6.0

< Experiment example 1>

1-1. Small amplitude oscillatory shear (SAOS) analysis

SAOS analysis was performed to confirm the shear thinning characteristics of the propylene polymers of Example 1 and Comparative Examples 1 to 3, and the results are shown in Figure 1.

Measurements for SAOS analysis were performed using TA's Strain-Controlled Rheometer (ARES), and an angular frequency sweep was performed using a Plate-Plate Fixture under the conditions of strain 5%, 230°C, and pressure holding time (soak time) of 120 seconds. sweep) was measured in the range of 6.3 x 10 ^-3 to 628 rad/s.

As a result of SAOS analysis, the polymer of Example 1 had a higher zero-shear viscosity and a stronger shear thinning phenomenon than the polymers of Comparative Examples 1 to 3. Through this, it can be confirmed that the propylene-based polymer of the example has excellent shear thinning properties and high processability compared to the propylene-based polymer of the comparative example.

In order to numerically confirm the shear thinning characteristics of the propylene-based polymer according to the examples and comparative examples, the complex viscosity when the angular frequencies are 0.01 rad/s and 10 rad/s, respectively, is specified, and through this, Equation 1 below After calculating the shear thinning index (STI), defined as , the results are shown in Table 2 below.

[Equation 1]

Shear thinning index (STI) = η _0.01 /η ₁₀

At this time, η _0.01 and η ₁₀ are complex viscosity (Pa·s) at angular frequencies of 0.01 rad/s and 10 rad/s at 230°C _, respectively.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 complex viscosity
(η, Pa·s) 0.01 rad/s 3.75 x 10 ⁴ 1.13 x 10 ⁴ 1.13 x 10 ⁴ 6.66 x 10 ³ 10 rad/s 1.08 x 10 ³ 6.75 x 10 ² 2.31 x 10 ³ 9.29 x 10 ² STIs 34.72 16.74 4.89 7.17

From the above results, it can be seen that the propylene-based polymer of Example 1 has a significantly higher shear thinning index than the propylene-based polymers of Comparative Examples 1 to 3.

1-2. Melt strength analysis

The melt strength of the propylene-based polymers of Example 1 and Comparative Examples 1 to 3 was measured, and the results are shown in Figure 2.

Measurements for melt strength analysis were performed by connecting a Goettfert Rheotens to a Brabender single-screw extruder, and an orifice die mounted on the extruder with a diameter of 1 mm and a length of 40 mm was used. The extrusion speed was set at 11 g/min, and the filament extruded through the die at 200°C was pulled at an acceleration of 6 mm/s ² to measure the maximum force until the filament broke and recorded as melt strength.

As a result, the polymer of Example 1 showed significantly higher melt strength than the polymers of Comparative Examples 1 to 3 having similar melt indexes, and in particular, the melt strength rapidly improved as the pull-off speed increased. It reached a melt strength of over 100 cN, and stretching was possible at a stretching speed of over 300 mm/s. Meanwhile, Comparative Examples 1 to 3 were stretched to a maximum melt strength of 45 cN to 50 cN, 23 cN to 26 cN, and 80 cN to 90 cN, respectively. Through this, it can be confirmed that the propylene-based polymer according to the example is a propylene-based polymer with high melt strength that is significantly higher in melt strength than the polymer in the comparative example.

< Experiment example 2> GPC (Gel permeation chromatography) analysis

GPC analysis was performed to confirm the molecular weight distribution of the propylene polymers of Example 1 and Comparative Examples 1 to 3, and the results are shown in Figure 3 and Table 3 below.

GPC analysis was performed using Polymer Char GPC-IR equipment (standard sample: Easy PS1 Polystyrene, temperature: 160 ℃, solvent: 1,2,4-trichlorobenzene, viscosity constant: K, α of polypropylene). Approximately 1.5 mg of the polymer sample was placed in a high-temperature GPC 1.25 mL vial, 1 mL of 1,2,4-trichlorobenzene (w/BHT) was added, and the mixture was dissolved with stirring at 150°C for more than 3 hours before being used for analysis.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Mn (kg/mol) 51 70 64 50 Mw (kg/mol) 435 399 400 454 MWD 8.6 5.7 6.3 9.1

As a result, the molecular weight distribution of Example 1 was relatively broad compared to the previously developed propylene polymers (Comparative Examples 1 and 2), indicating that the polymers were not separated but were homogeneous. It was found that it was distributed well, and the distribution of polymers was relatively high. In addition, the molecular ^weight distribution of Example 1 shows a shoulder around the molecular weight of about ^{10 6.5} g/mol to 10 ^7.4 g/mol, specifically, the ratio of polymer groups with a molecular weight of 10 ^6.5 g/mol or more ^. This was about 3.5%, which was relatively high compared to the comparative example (Comparative Example 1: about 1%, Comparative Example 2: 0.4%, Comparative Example 3: 2.7%). Through this, it can be seen that the propylene-based polymer of Example 1 has a high molecular weight and various types of long chain branches (LCB) are evenly distributed, which results in superior physical properties such as high melt strength.

< Experiment example 3> modulus (Modulus) measurement

In order to analyze the elasticity of the propylene polymer of Example 1 and Comparative Examples 1 to 3, the storage modulus (G') and loss modulus (G'') were measured by the following method. , the results for Example 1 are shown in Figure 4.

The elastic modulus (modulus) was measured using TA's Strain-Controlled Rheometer (ARES) (Maxwell model), and G' and G'' values were calculated using TRIOS software.

Fit linear rheology data of storage modulus and loss modulus, define the elastic modulus at the point where storage modulus and loss modulus intersect as crossover modulus, and relax the reciprocal of the angular frequency value of the crossover modulus. It is defined as relaxation time, and the values are listed in Table 4 below. Additionally, the phase difference tanδ (=G''/G') value at an angular frequency of 0.01 rad/s is listed in Table 4 below.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Cross modulus (Pa) 8.2 x 10 ² ,
2.1 x 10 ⁴ 1.1 x 10 ⁴ 2.2 x 10 ⁴ 2.5 x 10 ⁴ Relaxation time (s) 4.2,
1.6 x 10 ^-2 0.02 0.056 0.0098 tanδ 0.5 4.8 11 1.1

As a result of the measurement, Example 1 was confirmed to have two cross-elastic moduli, and the relaxation time for one of the cross-elastic moduli was 4.2 s, which was significantly higher than the comparative example, and at the same time, the phase difference value was measured to be very low. Through this, it can be confirmed that the propylene-based polymer of the example has superior elasticity compared to the propylene-based polymer according to the comparative example.

Above, one embodiment has been described in detail through examples and experimental examples, but the scope of one embodiment is not limited to the specific embodiment and should be interpreted in accordance with the attached patent claims.

Claims (17)

A first polymerization step of preparing a polymer composition by polymerizing liquid propylene and diene under a Ziegler-Natta catalyst; and
A method for producing a propylene-based polymer comprising a second polymerization step of polymerizing gaseous propylene and ethylene by adding gaseous propylene and ethylene to the prepared polymer composition.
According to paragraph 1,
The first polymerization step is performed at 40 ° C to 150 ° C for 30 minutes to 100 minutes.
According to paragraph 1,
The second polymerization step is performed at a temperature of 20 ℃ to 70 ℃ for 5 to 60 minutes.
According to paragraph 1,
A method for producing a propylene-based polymer, wherein the molar ratio of gaseous propylene and ethylene is 1:9 to 9:1.
According to paragraph 1,
The diene is 1,3-butadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene A method for producing a propylene-based polymer, which is at least one selected from N, 1,11-dodecadiene, 1,12-tridecadiene, and 1,13-tetradecadiene.
According to paragraph 1,
The Ziegler-Natta catalyst is a transition metal compound containing an element from Group 4, 5, or 6 of the periodic table; And a method for producing a propylene-based polymer, comprising an organometallic compound containing an element of group 13 of the periodic table.
According to clause 6,
A method for producing a propylene-based polymer, wherein the molar ratio of the transition metal compound and the organometallic compound is 1:1 to 1:50.
According to clause 6,
A method for producing a propylene-based polymer, wherein the organometallic compound includes an organoaluminum compound.
According to clause 6,
A method for producing a propylene-based polymer, wherein the weight ratio of diene and propylene in the first polymerization step is 1:100 to 1:500.
A propylene-based polymer produced according to the method for producing a propylene-based polymer according to any one of claims 1 to 9.
According to clause 10,
A propylene-based polymer having a melt strength measured at 200°C of 100 cN or more.
According to clause 10,
The shear thinning index (STI) defined by Equation 1 below is 5 Lee Sang-in, propylene-based polymer:
[Equation 1]
Shear Discourse Index = η _{0 .01} /η ₁₀
In Equation 1, η _0.01 and η ₁₀ are complex viscosity (Pa·s) at angular frequencies of 0.01 rad/s and 10 rad/s at 230°C _, respectively.
According to clause 10,
The η _{0 . 01} is 1.0 x 10 ⁴ or more, and η ₁₀ is 2.0 x 10 ³ or less, a propylene-based polymer.
According to clause 10,
Angular frequency at either the storage modulus (G') and the crossover modulus of the loss modulus (G'') at 230°C based on the Maxwell model. When the reciprocal of the value is defined as relaxation time, a propylene-based polymer wherein the relaxation time is 3.0 s or more.
According to clause 10,
A propylene-based polymer having a phase difference (tanδ) value of 2.0 or less, defined by Equation 3 below when the angular frequency is 0.01 rad/s at 230°C based on the Maxwell model:
[Equation 3]
tanδ = G''/G'
In Equation 3 above, G' is the storage modulus, and G'' is the loss modulus.
According to clause 10,
A propylene-based polymer having ^a ratio of polymer groups having ^a molecular weight of 10 ^6.5 g/mol to 10 ^8.0 g/mol of 2% or more as measured by gel permeation chromatography (GPC).
A film comprising the propylene-based polymer according to claim 10.