KR20200089184A - Method for predicting properties of polyethylene resin, and preparation method of polyethylene resin using the same - Google Patents

Abstract

The present invention relates to a method for predicting physical properties of a polyethylene resin capable of reliably predicting a change in physical properties of a polyethylene resin in accordance with a change in a supported ratio of metallocene catalysts, and to a method for manufacturing a polyethylene resin applying the same. The method for predicting physical properties of a polyethylene resin comprises the steps of: forming a first polyethylene resin; deriving a first molecular weight distribution curve; separating and setting the virtual first and second sub molecular weight distribution curves for deconvolution; forming a second to n^th polyethylene resin; separating and setting first and second sub molecular weight distribution curves for the second to n^th molecular weight distribution curves, respectively; linearly regressing the relationship between y and x as a linear function by setting the first to n^th ratios as x and the area of the first or second sub molecular weight distribution curve to the first to n^th molecular weight distribution curves as y; and predicting the physical properties of the polyethylene resin from the linear regression function.

Description

METHOD FOR PREDICTING PROPERTIES OF POLYETHYLENE RESIN, AND PREPARATION METHOD OF POLYETHYLENE RESIN USING THE SAME}

The present invention relates to a method for predicting physical properties of a polyethylene resin capable of reliably predicting a property change pattern of a polyethylene resin according to a change in a loading ratio of metallocene catalysts and a method for manufacturing a polyethylene resin using the same.

Recently, in order to obtain a polyethylene resin exhibiting improved mechanical properties, a method of manufacturing a polyethylene resin to which a metallocene catalyst is applied has been widely applied. In the production of a polyethylene resin with such a metallocene catalyst, a hybrid supported catalyst having two or more types of metallocene catalysts is typically applied. When such a hybrid supported catalyst is applied, it is possible to simultaneously produce polymerization characteristics of a plurality of metallocene catalysts supported thereon, thereby producing a polyethylene resin satisfying various physical properties simultaneously.

However, in preparing a polyethylene resin using the hybrid supported catalyst, it is difficult to predict to what extent each of the metallocene catalysts supported on the hybrid supported catalyst affects the polymerization process, and as a result, the hybrid supported catalyst is prepared. There is a disadvantage that it is difficult to predict how the properties of the polyethylene resin to be achieved will be achieved.

More specifically, when preparing a polyethylene resin with a hybrid supported catalyst in which a plurality of types of metallocene catalysts are supported, polymer chains of polyethylene resins expressing polymerization characteristics of each metallocene catalyst are formed, respectively, and these polymer chains They gather to determine the overall properties of the polyethylene resin. The overall properties of these polyethylene resins can be predicted/determined by molecular weight distribution curves, which are typically derived from the overall gel permeation chromatography (GPC) analysis results of these resins.

However, according to the loading ratio of each metallocene catalyst supported on the hybrid supported catalyst, it is a reality that it is very difficult to predict whether the polymerization characteristics of each metallocene catalyst will be expressed at a certain ratio in the resin manufacturing process. As a result, as the loading ratio of each metallocene catalyst changes, the overall GPC analysis result (ie, molecular weight distribution curve) of the polyethylene resin prepared from the hybrid supported catalyst and the physical properties of the polyethylene resin determined thereby are difficult to predict. There are disadvantages.

For this reason, before proceeding to the actual manufacturing process, it is difficult to reliably predict the property change pattern of the polyethylene resin according to the change in the loading ratio of the metallocene catalysts, and accordingly, process conditions for achieving the target property of the polyethylene resin, etc. There were disadvantages that were difficult to determine in advance.

Accordingly, the present invention is to provide a method for predicting physical properties of a polyethylene resin that can reliably predict a change in properties of a polyethylene resin according to a change in a loading ratio of metallocene catalysts.

In addition, the present invention is to provide a method of manufacturing a polyethylene resin that enables a polyethylene resin having a target property to be manufactured more effectively by applying the method for predicting the properties of the polyethylene resin.

The present invention is a first step of forming a first polyethylene resin by polymerizing ethylene-containing monomers in the presence of a hybrid supported catalyst in which the first and second metallocene catalysts are supported in a first ratio;

A second step of deriving a first molecular weight distribution curve by analyzing the first polyethylene resin by gel permeation chromatography (GPC);

A third step of separating and setting virtual first and second sub-molecular weight distribution curves included in a region of the first molecular weight distribution curve and having a normal distribution curve shape;

In the presence of a mixed supported catalyst in which the first and second metallocene catalysts are supported in a second to nth ratio different from the first ratio (where n is an integer of 3 or more), the ethylene-containing monomers are polymerized to form a second to second. A fourth step of forming an nth polyethylene resin;

Performing second and third steps on the second to nth polyethylene resins to derive second to nth molecular weight distribution curves, and first and second sub molecular weights to the second to nth molecular weight distribution curves A fifth step of separately setting distribution curves;

Linearly regressing the relationship between y and x as a first-order function, with the first to nth ratios as x and the area of the first or second sub-molecular weight distribution curves relative to the first to nth molecular weight distribution curves as y. step; And

It provides a method for predicting the physical properties of the polyethylene resin, comprising the step of predicting the physical properties of the polyethylene resin from the linear regression function.

The present invention also, determining the target physical properties of the polyethylene resin to be prepared using a hybrid supported catalyst on which the first and second metallocene catalysts are supported;

Comparing the target physical properties of the polyethylene resin and the predicted physical properties of the polyethylene resin according to the prediction method, and determining a loading ratio of the first and second metallocene catalysts to obtain the target physical properties; And

It provides a method for producing a polyethylene resin comprising the step of polymerizing an ethylene-containing monomer in the presence of a mixed supported catalyst in which the first and second metallocene catalysts are supported according to the determined supporting ratio.

Hereinafter, a method and method for predicting physical properties of a polyethylene resin according to an embodiment of the present invention will be described in detail.

According to one embodiment of the invention, in the presence of a hybrid supported catalyst in which the first and second metallocene catalysts are supported in a first ratio, a first step of polymerizing ethylene-containing monomers to form a first polyethylene resin;

A second step of deriving a first molecular weight distribution curve by analyzing the first polyethylene resin by gel permeation chromatography (GPC);

A third step of separating and setting virtual first and second sub-molecular weight distribution curves included in a region of the first molecular weight distribution curve and having a normal distribution curve shape;

In the presence of a mixed supported catalyst in which the first and second metallocene catalysts are supported in a second to nth ratio different from the first ratio (where n is an integer of 3 or more), the ethylene-containing monomers are polymerized to form a second to second. A fourth step of forming an nth polyethylene resin;

Performing second and third steps on the second to nth polyethylene resins to derive second to nth molecular weight distribution curves, and first and second sub molecular weights to the second to nth molecular weight distribution curves A fifth step of separately setting distribution curves;

Linearly regressing the relationship between y and x as a first-order function, with the first to nth ratios as x and the area of the first or second sub-molecular weight distribution curves relative to the first to nth molecular weight distribution curves as y. step; And

It provides a method for predicting the physical properties of the polyethylene resin, comprising the step of predicting the physical properties of the polyethylene resin from the linear regression function.

The present invention also, determining the target physical properties of the polyethylene resin to be prepared using a hybrid supported catalyst on which the first and second metallocene catalysts are supported;

Comparing the target physical properties of the polyethylene resin and the predicted physical properties of the polyethylene resin according to the prediction method, and determining a loading ratio of the first and second metallocene catalysts to obtain the target physical properties; And

A method for producing a polyethylene resin is provided, comprising polymerizing an ethylene-containing monomer in the presence of a hybrid supported catalyst supported by first and second metallocene catalysts according to the determined supported ratio.

According to the method of the embodiment, the present inventors can reliably predict the change in the physical properties of the polyethylene resin according to the change in the loading ratio of the metallocene catalysts, more specifically, the modification of the molecular weight distribution curve by the GPC analysis result of the polyethylene resin. The invention was confirmed and the invention was completed. In the method of one embodiment, the GPC analysis result of the polyethylene resin can be predicted roughly through the following process.

In the method of one embodiment, first, the hybrid supported catalysts in which two types of metallocene catalysts are supported in three or more different ratios are respectively prepared, and the first to nth polyethylene resins are prepared by applying the hybrid supported catalysts, respectively. do. Each of these first to nth polyethylene resins is analyzed by GPC to derive first to nth molecular weight distribution curves for each resin.

Subsequently, for example, as shown in FIGS. 2 to 4, the first to nth molecular weight distribution curves are included in the regions of these molecular weight distribution curves, respectively, and the virtual first and second virtually distributed symmetrical shapes It can be separated and set as a 2 sub molecular weight distribution curve.

According to the results of the inventors' experiments, the widths of the first and second sub-molecular weight distribution curves and the loading ratios of the two metallocene catalysts can be linearly regressed in a relation of approximately a linear function form, and such linear regression From the equation, it was confirmed that the physical properties of the polyethylene resin can be predicted reliably.

That is, the linear regression equation may be derived as a property prediction equation of a polyethylene resin, and when the loading ratios of the first and second metallocene catalysts among hybrid supported catalysts to be newly applied to the property prediction equation are substituted, these new hybrids The widths and modifications of the first and second sub-molecular weight distribution curves of the polyethylene resin produced using the supported catalyst can be derived. From the area of these first and second sub-molecular weight distribution curves and the modification, the modification of the molecular weight distribution curve of the entire polyethylene resin and its properties can be predicted, and the modification of this molecular weight distribution curve can be actually performed using the hybrid supported catalyst. It was confirmed that the result of the analysis of the prepared resin was almost identical.

Accordingly, according to the method of one embodiment, when the hybrid supported catalysts in which the first and second metallocene catalysts are supported in a new ratio are applied, the polymerization characteristics of these first and second metallocene catalysts are in a certain ratio. What molecular weight distribution curves the polyethylene resin produced therefrom will have, and furthermore, to what extent these resins have physical properties (e.g. molecular weight distribution, number average molecular weight (Mn) and weight average molecular weight) (Mw), etc. can be reliably predicted. Therefore, it is very easy to determine in advance the process conditions for achieving the target properties of the polyethylene resin using the prediction method of one embodiment.

On the other hand, according to the method of one embodiment, the polyethylene resin, which is the object of prediction of physical properties, may be a copolymer of ethylene and an alpha olefin having 3 or more carbon atoms. Accordingly, the monomer may include ethylene and an alpha olefin having 3 or more carbon atoms, and specific examples of the alpha olefin having 3 or more carbon atoms include propylene, 1-butene, 1-hexene, or 1-octene.

In addition, in preparing the first to nth polyethylene resins, as described above, two or more types of metallocene catalyst-supported hybrid supported catalysts are prepared in different proportions, respectively, and In the presence, the above-mentioned monomers can be copolymerized. The copolymerization process may be in accordance with the polymerization conditions and methods of conventional polyethylene resin.

As described above, after preparing the first to nth polyethylene resins, these are analyzed by GPC to derive the first to nth molecular weight distribution curves for each resin. At this time, in analyzing each polyethylene resin by GPC, as described in Examples, the following analysis conditions and methods can be applied.

That is, it can be analyzed using a GPC instrument such as Waters PL-GPC220 using a Polymer Laboratories PLgel MIX-B 300mm length column, the temperature during analysis is about 160°C, and 1,2,4-trichlorobenzene It can be used as a solvent. In addition, the flow rate is measured at a rate of 1 mL/min, and a resin sample can be prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. In addition, as a standard material for GPC analysis, polystyrene resin may be used, and the molecular weight of these standard materials may be 2,000, 10,000, 30,000, 70,000, 200,000, 700,000, 2,000,000, 4,000,000 or 10,000,000. The molecular weight distribution curve can be derived by performing GPC analysis using the calibration curve formed using these standard materials, from which various properties (eg, Mw, Mn or molecular weight distribution) of each resin can be measured and evaluated. have.

On the other hand, in the method of the embodiment, in order to more reliably predict the properties of the polyethylene resin, the n is 3 or more and 10 or less, or 3 or more and 8 or less, or 4 or more and 6 or less, and three or more different loading ratios The same hybrid supported catalyst is prepared, respectively, and data on three or more types of polyethylene resins prepared from these hybrid supported catalysts needs to be collected.

In addition, after deriving the first to nth molecular weight distribution curves for the first to nth polyethylene resins, as shown in FIGS. 2 to 4, they are included in the regions of these molecular weight distribution curves, respectively, and symmetric to the left and right. It can be separated and set into virtual first and second sub-molecular weight distribution curves having a normal distribution curve shape of the structure.

Subsequently, the relationship between the area (y) of the first and second sub-molecular weight distribution curves and the loading ratio (x) of the two metallocene catalysts can be linearly regressed into a relationship of a linear function form. An example of a regression equation is shown in FIG. 5.

More specifically, the linearly regressed first-order function may be represented by y = ax + b, and in this linear regression function, x is a molar ratio of the first or second metallocene catalyst supported on the hybrid supported catalyst. As, is a value calculated according to the formula of "the number of supported moles of the first or second metallocene catalyst / the remaining number of supported metallocene catalysts among the first or second metallocene catalysts"

Wherein y is the first or the second sub-molecular weight distribution curve covering any one of the first to n-th molecular weight distribution curve, when the total area is 1, the first or second target of the physical properties prediction of the total area A value representing an area ratio (%) of the first or second sub-molecular weight distribution curve corresponding to the metallocene catalyst, wherein a and b may be constants determined in the linear regression step.

That is, in a specific example, in order to determine a linear regression equation for the first metallocene catalyst among the first and second metallocene catalysts, x is "the number of moles supported by the first metallocene catalyst / the second metal It can be calculated and defined according to the formula of the supported mole number of the Rosene catalyst", y can be calculated and defined according to the formula of the "first sub-molecular weight distribution curve / 1 * 100 (%)", such x, y If the relationship between the linear regression, the constants a and b can be determined, from which a graph like FIG. 5 can be derived.

As already described above, such a linear regression equation can be derived from a physical property prediction equation of a polyethylene resin, and the loading ratios of the first and second metallocene catalysts in the hybrid supported catalyst to be newly applied to the physical property prediction equation, that is, Substituting a different loading ratio (the m-th ratio) different from the first to n-th ratios, the area of the first and second sub-molecular weight distribution curves of the polyethylene resin (m-th polyethylene resin) produced using this novel hybrid loading catalyst, etc. This can be derived. From the area of these first and second sub-molecular weight distribution curves, etc., the modification of the molecular weight distribution curve of the entire polyethylene resin and its physical properties can be predicted, and as can be seen in the examples and Fig. 6 described later, this molecular weight distribution It was confirmed that the reformation of the curve was almost consistent with the results of analyzing the resin actually produced using the hybrid supported catalyst.

Therefore, according to the method of one embodiment described above, from the linear regression function, a change in physical properties of a polyethylene resin according to a change in a loading ratio of the first and second metallocene catalysts can be reliably predicted. More specifically, when the method of one embodiment is applied, the physical properties of the m-th polyethylene resin prepared by the hybrid supported catalysts in which the first and second metallocene catalysts are supported at m ratios different from the first to n-th ratios, More specifically, the weight average molecular weight (Mw), number average molecular weight (Mn), or molecular weight distribution (Mw/Mn) of these resins can be predicted reliably even before actual production.

Accordingly, when the method for predicting physical properties of one embodiment is applied to a manufacturing process of a polyethylene resin, when the first and second metallocene catalyst-supported hybrid supported catalysts are applied at a new ratio, these first and second metals are applied. To what extent the polymerization properties of the Rosene catalyst will be expressed, what molecular weight distribution curve will the polyethylene resin produced therefrom have, and furthermore, to what extent these resins have physical properties (e.g., molecular weight distribution) , It can be reliably predicted in advance whether to have a number average molecular weight (Mn) and a weight average molecular weight (Mw).

Therefore, using the prediction method of one embodiment, it becomes very easy to determine in advance the process conditions and the like for achieving the target properties of the polyethylene resin.

Accordingly, according to another embodiment of the present invention, a method for manufacturing a polyethylene resin to which the method for predicting physical properties of the above-described embodiment is applied is provided. The method of manufacturing the polyethylene resin includes: determining target physical properties of the polyethylene resin to be produced using a hybrid supported catalyst in which the first and second metallocene catalysts are supported;

Comparing the target physical properties of the polyethylene resin and the predicted physical properties of the polyethylene resin according to the method of claim 1, and determining a loading ratio of the first and second metallocene catalysts to obtain the target physical properties; And

In the presence of a mixed supported catalyst in which the first and second metallocene catalysts are supported according to the determined supporting ratio, the method may include polymerizing an ethylene-containing monomer.

That is, in such a method, in consideration of the target physical properties of the polyethylene resin to be manufactured, an appropriate process condition or a catalyst loading ratio may be determined in advance through a method for predicting physical properties of one embodiment, through which polyethylene having the target physical properties Resin can be produced more effectively.

In the manufacturing method of the other embodiments described above, since the process conditions can be followed by the general polyethylene resin manufacturing method except for determining the process conditions by the physical property prediction method of the above-described embodiment, additional descriptions thereof will be omitted.

As described above, according to the present invention, it is possible to reliably predict the property change pattern of the polyethylene resin according to the change in the loading ratio of the metallocene catalysts in advance.

Therefore, by applying the method for predicting the physical properties of the polyethylene resin of the present invention, it is possible to predict in advance the process conditions for obtaining the polyethylene resin having the target properties, the supported ratio of the catalyst, etc., and apply it to obtain the polyethylene resin having the target properties. It can be produced more effectively.

1 shows the first to third molecular weight distribution curves of the first to third polyethylene resins prepared in Synthesis Examples 1 to 3.
2 to 4 are views showing a state in which the first and second sub-molecular weight distribution curves are separately set for each of the first to third molecular weight distribution curves of the first to third polyethylene resins,
5 is a diagram showing a linear regression equation for each expression ratio of the first and second metallocene catalysts based on the data obtained in FIGS. 2 to 4,
6 is a graph showing the linear regression equation for the first metallocene catalyst obtained in FIG. 5 and the measured data compared to each other.

Hereinafter, preferred embodiments are presented to help understanding of the present invention. However, the following examples are only for illustrating the present invention, and the present invention is not limited thereto.

Synthetic example 1 to 3: Preparation of polyethylene resin

The first to third polyethylene resins were polymerized in the following manner.

In the case of the first to third polyethylene resins, a hybrid supported catalyst was prepared and then obtained through a polymerization process using the same. In the following, the contents of the supported catalyst production method and the polymerization method of each of Synthesis Examples 1 to 3 were described.

<Mixed supported catalyst production (common)>

50 mL of toluene solution was added to a 300 mL glass reactor, and 10 g of silica (Grace Davison, SP2410) was added, followed by stirring while raising the reactor temperature to 40°C. 50 mL of 10 wt% methyl aluminoxane (MAO)/toluene solution (Albemarle) was added, the temperature was raised to 60° C., and stirred at 200 rpm for 12 hours. After the reactor temperature was lowered to 40° C., stirring was stopped, and after settling for 10 minutes, the reaction solution was decantation. After adding 100 mL of toluene and stirring for 10 minutes, stirring was stopped and settling was performed for 10 minutes to decantation the toluene solution.

Catalyst Preparation Example 1: <Preparation of hybrid supported catalyst for production of first polyethylene resin>

50 mL of toluene was added to the reactor, 0.85 g of the first metallocene catalyst K1 and 10 mL of toluene solution were added to the reactor and stirred at 300 rpm for 60 minutes. Here, 3.7 g of a second metallocene catalyst K2 and a 10 ml solution of toluene were added to the reactor and stirred at 300 rpm for 12 hours. After stopping the stirring and settling for 10 minutes, the reaction solution is decantation. 100 mL of hexane was added to the reactor, the hexane slurry was transferred to a 250 mL schlenk flask, and the hexane solution was decantationd. It was dried under reduced pressure at room temperature for 3 hours.

Catalyst Preparation Example 2: <Production of hybrid supported catalyst for production of second polyethylene resin>

50 mL of toluene was added to the reactor, 0.85 g of the first metallocene catalyst K1 and 10 mL of toluene solution were added to the reactor and stirred at 300 rpm for 60 minutes. Here, 2.2 g of the second metallocene catalyst K2 and a 10 ml toluene solution were added to the reactor and stirred at 300 rpm for 12 hours. After stopping the stirring and settling for 10 minutes, the reaction solution is decantation. 100 mL of hexane was added to the reactor, the hexane slurry was transferred to a 250 mL schlenk flask, and the hexane solution was decantationd. It was dried under reduced pressure at room temperature for 3 hours.

Catalyst Preparation Example 3: <Preparation of hybrid supported catalyst for production of third polyethylene resin>

50 mL of toluene was added to the reactor, and 0.95 g of a first metallocene catalyst K1 and a 10 mL solution of toluene were added to the reactor and stirred at 300 rpm for 60 minutes. Here, 2.9 g of the first metallocene catalyst K2 and 10 ml of toluene solution were added to the reactor and stirred at 300 rpm for 12 hours. After stopping the stirring and settling for 10 minutes, the reaction solution is decantation. 100 mL of hexane was added to the reactor, the hexane slurry was transferred to a 250 mL schlenk flask, and the hexane solution was decantationd. It was dried under reduced pressure at room temperature for 3 hours.

<Polyethylene resin polymerization>

TEAL 2ml (1.0 M Hexane), 1-butene 10g was added to a 2L Autoclave high pressure reactor, 0.8kg of hexane was added, and the temperature was raised to 80°C while stirring at 500 rpm. After the supported catalysts prepared in Examples 1 to 3 of the above-mentioned catalysts and hexane were put in a vial and then put into a reactor, when the reactor internal temperature reached 78°C, the mixture was reacted for 1 hour while stirring at 500 rpm under 9 bar of ethylene pressure. After the reaction was completed, the obtained polymer was first removed by hexane through a filter, and then dried in a vacuum oven at 80° C. for 4 hours.

The first to third polyethylene resins were analyzed by GPC to derive first to third molecular weight distribution curves, respectively, and illustrated in FIG. 1 (Synthesis Example 1 (first polyethylene resin): black line in FIG. 1, Synthesis Example 2 (second polyethylene resin): red line in Fig. 1, Synthesis Example 3 (third polyethylene resin): blue line in Fig. 1). In the GPC analysis, the following analysis conditions and methods were applied.

Polymer Laboratories PLgel MIX-B was analyzed using a GPC instrument of Waters PL-GPC220 using a 300 mm length column. The temperature at the time of analysis was about 160°C, and 1,2,4-trichlorobenzene was used as a solvent. In addition, the flow rate was measured at a rate of 1 mL/min, and the resin sample was prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. In addition, polystyrene resin was used as a standard material for GPC analysis, and molecular weights of these standard materials were 2,000, 10,000, 30,000, 70,000, 200,000, 700,000, 2,000,000, 4,000,000 or 10,000,000.

Example 1 to 3: Physical properties Predictive decision

The first and second sub-molecular weight distribution curves for the first to third molecular weight distribution curves derived from Synthesis Examples 1 to 3 were separated and set, respectively, and shown in FIGS. 2 to 4 (FIG. 2: Synthesis Example 1 ( (1st polyethylene resin)) Related, FIG. 3: Synthesis example 2 (2nd polyethylene resin) connection, FIG. 3: Synthesis example 3 (3rd polyethylene resin) connection).

From the first or second sub-molecular weight distribution curves for the first to third molecular weight distribution curves derived in FIGS. 2 to 4, respectively, the loading ratio in the hybrid supported catalyst applied in Synthesis Examples 1 to 3 is x, and With the area of the 1 or 2nd sub-molecular weight distribution curve as y, the relationship between y and x was linearly regressed as a linear function.

The linearly regressed first-order function is shown in FIG. 5, and y (%) = 172.8x + 4.2 (black line in FIG. 5; related to the first metallocene catalyst K1 catalyst) and y (%) = -172.8. x + 95.8 (red line in Fig. 5; second metallocene catalyst, K2 catalyst).

However, in the black line of FIG. 5, x is calculated and defined according to the formula of "the number of moles of the first metallocene catalyst (K1) supported / the number of moles of the second metallocene catalyst (K2) supported" in each synthesis example. And y is calculated and defined according to the formula of “first sub-molecular weight distribution curve/1*100(%),” in the red line of FIG. 5, x is “the second metallocene catalyst (K2) in each synthesis example. ) Is calculated and defined according to the formula of the number of supported moles / the number of supported moles of the first metallocene catalyst (K1), y is calculated according to the formula of the "second sub-molecular weight distribution curve/1 * 100(%)" and Is defined.

Test example : Reliability evaluation of the prediction results of properties of polyethylene resin

<Production of mth polyethylene resin hybrid supported catalyst>

50 mL of toluene was added to the reactor, x1 g of the first metallocene catalyst K1 and 10 mL of toluene solution were added to the reactor and stirred at 300 rpm for 60 minutes. Here, a solution of y1 g of the second metallocene catalyst K2 and a 10 ml toluene solution were added to the reactor and stirred at 300 rpm for 12 hours. After stopping the stirring and settling for 10 minutes, the reaction solution is decantation. 100 mL of hexane was added to the reactor, the hexane slurry was transferred to a 250 mL schlenk flask, and the hexane solution was decantationd. It was dried under reduced pressure at room temperature for 3 hours.

<Reliability evaluation>

In the equation for predicting physical properties related to K1 obtained in the above example (y (%) = 172.8x + 4.2), x1 was obtained according to the mole ratio of K1 and K2 used in the test example of the m-th polyethylene resin. The y1 value (%) corresponding to K1 can be predicted.

In addition, after measuring the GPC of the m-th polyethylene resin powder obtained through the same polymerization process, the first and second sub-molecular weight distribution curves can be separated from each other to actually calculate the area ratio.

The linear graph of FIG. 6 is a graph for predicting physical properties obtained in Examples, and the blue dots represent values calculated after actually separating each. It can be seen that there is no significant error in the predicted physical properties. (R ² =0.921)

Claims (10)

A first step of forming a first polyethylene resin by polymerizing ethylene-containing monomers in the presence of a hybrid supported catalyst in which the first and second metallocene catalysts are supported in a first ratio;
A second step of deriving a first molecular weight distribution curve by analyzing the first polyethylene resin by gel permeation chromatography (GPC);
A third step of separating and setting virtual first and second sub-molecular weight distribution curves included in a region of the first molecular weight distribution curve and having a normal distribution curve shape;
In the presence of a mixed supported catalyst in which the first and second metallocene catalysts are supported in a second to nth ratio different from the first ratio (where n is an integer of 3 or more), the ethylene-containing monomers are polymerized to form a second to second. A fourth step of forming an nth polyethylene resin;
Performing second and third steps on the second to nth polyethylene resins to derive second to nth molecular weight distribution curves, and first and second sub molecular weights to the second to nth molecular weight distribution curves A fifth step of separately setting distribution curves;
Linearly regressing the relationship between y and x as a first-order function, with the first to nth ratios as x and the area of the first or second sub-molecular weight distribution curves relative to the first to nth molecular weight distribution curves as y. step; And
A method for predicting physical properties of a polyethylene resin, comprising predicting the properties of the polyethylene resin from the linear regression function.
The method of claim 1, wherein the monomer is a ethylene and an alpha olefin having 3 or more carbon atoms.
The linearly regressed linear function is represented by y (unit: %) = ax (unit: none) + b,
The x is the molar ratio of the first or second metallocene catalyst supported on the hybrid supported catalyst, and "the number of moles of the supported first or second metallocene catalyst / the first or second metallocene catalyst It is a value calculated according to the formula of the number of moles of supported metallocene catalyst among the catalysts,
Wherein y is the first or the second sub-molecular weight distribution curve covering any one of the first to n-th molecular weight distribution curve, when the total area is 1, the first or second target of the physical properties prediction of the total area A value representing the area ratio (%) of the first or second sub-molecular weight distribution curve corresponding to the metallocene catalyst,
The a, b is a method for predicting physical properties of a polyethylene resin having a constant determined in the linear regression step.
The method of claim 1, wherein n is an integer of 3 or more and 10 or less.
The method for predicting physical properties of a polyethylene resin according to claim 1, wherein in the physical property prediction step of the polyethylene resin, a physical property change of the polyethylene resin according to a ratio change of the first and second metallocene catalysts is calculated from the linear regression function.
The method of claim 5, wherein in the physical property prediction step of the polyethylene resin, the first and second metallocene catalysts of the mth polyethylene resin made of a mixed supported catalyst supported at a m ratio different from the first to nth ratios. A method for predicting physical properties of a polyethylene resin that predicts physical properties.
The method for predicting physical properties of a polyethylene resin according to claim 6, wherein in the physical property prediction step of the polyethylene resin, the weight average molecular weight (Mw), number average molecular weight (Mn), or molecular weight distribution (Mw/Mn) of the mth polyethylene resin is predicted. .
Determining target physical properties of the polyethylene resin to be produced using the hybrid supported catalysts on which the first and second metallocene catalysts are supported;
Comparing the target physical properties of the polyethylene resin and the predicted physical properties of the polyethylene resin according to the method of claim 1, and determining a loading ratio of the first and second metallocene catalysts to obtain the target physical properties; And
A method for producing a polyethylene resin, comprising polymerizing an ethylene-containing monomer in the presence of a hybrid supported catalyst in which the first and second metallocene catalysts are supported according to the determined loading ratio.
The method of claim 8, wherein the monomer comprises ethylene and an alpha olefin having 3 or more carbon atoms.
The method of claim 8, wherein the predicted physical properties and target physical properties of the polyethylene resin are weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn).

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