KR20220009252A - 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 and a method for preparing a polyethylene resin by applying the same, which can reliably predict a change in physical properties of a polyethylene resin according to a change in a comonomer supply ratio of alpha olefin, in a method for preparing a polyethylene resin to which a metallocene hybrid supported catalyst is applied.

Description

A method for predicting physical properties of a polyethylene resin and a method for manufacturing a polyethylene resin

The present invention relates to a method for predicting the physical properties of a polyethylene resin that can reliably predict a change in physical properties of a polyethylene resin according to a change in the comonomer supply ratio of alpha olefin in a method for producing a polyethylene resin to which a metallocene hybrid supported catalyst is applied, and a polyethylene to which the same is applied It relates to a method for producing a resin.

Recently, in order to obtain a polyethylene resin exhibiting more improved physical properties, a method for producing a polyethylene resin to which a metallocene catalyst is applied has been widely applied. In preparing a polyethylene resin with such a metallocene catalyst, a hybrid supported catalyst in which two or more types of metallocene catalysts are supported is typically applied. When such a hybrid supported catalyst is applied, the polymerization characteristics of a plurality of metallocene catalysts supported thereon are simultaneously expressed, and a polyethylene resin satisfying various physical properties can be prepared at the same time.

In addition, in the production of such a polyethylene resin, typically by using a comonomer having 3 or more carbon atoms together with ethylene, they are copolymerized, and by controlling the copolymerization ratio of the comonomer, the molecular weight, crystallinity, mechanical properties or The thermal properties are variously controlled.

However, in the process of producing a polyethylene resin using the hybrid supported catalyst, the molecular weight of the polyethylene resin and its distribution or related physical properties are controlled and changed to what extent, depending on the supply ratio or copolymerization ratio of the comonomer, It is true that it was very difficult to predict to what extent the supply of the comonomer causes a change in physical properties such as molecular weight for the polymer chains derived from each of the metallocene catalysts supported on the hybrid supported catalyst. As a result, despite the fact that the supply ratio of the comonomer has a great influence on the physical properties of the polyethylene resin itself or the polymer chains derived from each metallocene catalyst, it was difficult to predict the changes and aspects of these properties in advance. There was a disadvantage in that it is difficult to predict in advance how the physical properties of the polyethylene resin prepared with the hybrid supported catalyst will be achieved under the supply of the comonomer.

Due to the above-mentioned difficulty in predicting the physical properties, it was difficult to reliably predict the change in the physical properties of the polyethylene resin according to the change in the supply ratio of the comonomer without going through a lot of trial and error through actual experiments, etc. As a result, the There was a disadvantage in that it was difficult to determine in advance the process conditions for achieving the target physical properties.

Accordingly, the present invention provides a method for predicting the physical properties of a polyethylene resin that can reliably predict a change in physical properties of a polyethylene resin according to a change in the comonomer supply ratio of alpha olefin in a method for producing a polyethylene resin to which a metallocene hybrid supported catalyst is applied will be.

Another object of the present invention is to provide a method for producing a polyethylene resin that enables the production of a polyethylene resin having target properties more effectively by applying the method for predicting physical properties of the polyethylene resin.

In the present invention, in the presence of a supported hybrid catalyst on which the first and second metallocene catalysts are supported, ethylene and a monomer of the alpha olefin such that the supply ratio of the alpha olefin having 3 or more carbon atoms to the total weight of the monomer becomes the first ratio. A first step of supplying and copolymerizing to form a first polyethylene resin;

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

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

The second to nth polyethylene resins are obtained by supplying and copolymerizing the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin is a second to nth ratio different from the first ratio (where n is an integer of 3 or more) a fourth step of forming;

By performing the second and third steps for the second to nth polyethylene resin, a second to nth molecular weight distribution curve is derived, and first and second sub molecular weights for the second to nth molecular weight distribution curve a fifth step of separately setting the distribution curves;

Let the first to nth ratio be x, and the physical property calculated from the first or second sub molecular weight distribution curve for the first to nth molecular weight distribution curve as y, the relationship between y and x is linear as a linear function regressing; and

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

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

Comparing the target physical properties of the polyethylene resin with the predicted physical properties of the polyethylene resin according to the method of claim 1, determining a supply ratio of alpha olefin to obtain the target physical properties; and

Copolymerizing the monomers using a hybrid supported catalyst on which the first and second metallocene catalysts are supported while supplying the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin becomes the determined ratio A method for producing a polyethylene resin is provided.

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

According to an embodiment of the present invention, in the presence of a supported hybrid catalyst on which the first and second metallocene catalysts are supported, the supply ratio of alpha olefin having 3 or more carbon atoms to the total weight of the monomer becomes the first ratio, so that ethylene and A first step of supplying and copolymerizing the monomer of the alpha olefin to form a first polyethylene resin;

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

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

The second to nth polyethylene resins are obtained by supplying and copolymerizing the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin is a second to nth ratio different from the first ratio (where n is an integer of 3 or more) a fourth step of forming;

By performing the second and third steps for the second to nth polyethylene resin, a second to nth molecular weight distribution curve is derived, and first and second sub molecular weights for the second to nth molecular weight distribution curve a fifth step of separately setting the distribution curves;

Let the first to nth ratio be x, and the physical property calculated from the first or second sub molecular weight distribution curve for the first to nth molecular weight distribution curve as y, the relationship between y and x is linear as a linear function regressing; and

From the linear regression function, there is provided a method for predicting the physical properties of a polyethylene resin, comprising the step of predicting the physical properties of the polyethylene resin.

According to the method of the embodiment, in the method for producing a polyethylene resin to which a metallocene hybrid supported catalyst is applied, the present inventors change the physical properties of the polyethylene resin according to the change in the supply ratio or the copolymerization ratio of the comonomer of the alpha olefin having 3 or more carbon atoms Aspects, more specifically, the modification of the molecular weight distribution curve according to the GPC analysis result of the polyethylene resin, molecular weight-related physical properties derived therefrom, or the first or second metallocene catalyst supported on the hybrid supported catalyst, respectively. The invention was completed after confirming that the expression ratio of the chains and their related physical properties could be reliably predicted. In the method of this embodiment, the physical properties of the polyethylene resin can be roughly predicted through the following process.

In the method of one embodiment, first, in the presence of a supported hybrid catalyst on which two kinds of metallocene catalysts are supported, the homogeneous alpha in different feed ratios (ie, the first to the nth ratio) based on the total weight of the monomers. The first to nth polyethylene resins are prepared by copolymerizing these monomers while supplying the monomers of ethylene and alpha olefin, respectively, so that the olefin is supplied. These first to nth polyethylene resins are analyzed by GPC, respectively, to derive first to nth molecular weight distribution curves for each resin. At this time, in order to more reliably predict the effect of the supply ratio of the alpha olefin on the physical properties of the polyethylene resin, the same hybrid supported catalyst in which the same type of metallocene catalysts are supported in the same content is used as the hybrid supported catalyst. First to nth polyethylene resins can be obtained, respectively.

Thereafter, for example, as shown in FIGS. 2 to 4 , the first to nth molecular weight distribution curves are respectively included in the region of these molecular weight distribution curves, and virtual first and second hypothetical first and second molecular weight distribution curves having a symmetrical normal distribution curve form It can be set (deconvolution) by separating into 2 sub-molecular weight distribution curves.

According to the experimental results of the present inventors, the area of the first and second sub molecular weight distribution curves or physical properties calculated from these curves, for example, the weight average molecular weight calculated from each of the first and second sub molecular weight distribution curves log value (log Mw; y), or the expression ratio of each polymer chain expressed from the first or second metallocene catalyst (derived from the first or second metallocene catalyst contained in the entire first to nth polyethylene resin) The content of each of the polymer chains; weight %; y') and the comonomer supply ratio (weight %; x) can be linearly regressed into a relational expression in the form of an approximately linear function, from which the physical properties of the polyethylene resin are It was confirmed that it can be reliably predicted.

That is, the linear regression equation can be derived as a predictive equation for the physical properties of a polyethylene resin prepared with a specific hybrid supported catalyst, and substituting the supply ratio of the comonomer to be newly applied to this physical property prediction equation, under the comonomer supply of this ratio The width of the first and second sub molecular weight distribution curves of the polyethylene resin to be prepared, the Mw value corresponding to each of them, and the content of polymer chains respectively corresponding to the first and second sub molecular weight distribution curves can be derived. have. From the width of the first and second sub molecular weight distribution curves, the Mw value or the content of polymer chains, etc., the shape of the molecular weight distribution curve of the entire polyethylene resin and its physical properties such as Mw, Mn or molecular weight distribution can be predicted and , furthermore, the expression ratio of the first or second metallocene supported on the hybrid supported catalyst is predicted to predict how much it affects the physical properties of the overall polyethylene resin. From this, it was confirmed that the overall physical properties of the entire polyethylene resin can be reliably predicted, and in particular, the predicted physical properties are almost identical to the results of analyzing the actually prepared resin under the comonomer supply of the corresponding ratio.

Therefore, according to the method of one embodiment, when a polyethylene resin is prepared while supplying a comonomer at a changed ratio in the presence of a supported hybrid catalyst, this polyethylene resin will roughly have a molecular weight distribution curve, each of the supported hybrid catalysts To what extent can the metallocene catalyst be expressed and affect the physical properties of the entire polyethylene resin, and furthermore, what range of physical properties (eg, molecular weight distribution, number average molecular weight (Mn) and weight of the resin as a whole) average molecular weight (Mw, etc.) can be reliably predicted.

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

On the other hand, according to the method of the embodiment, the polyethylene resin, which is the target of the prediction of physical properties, may be a copolymer of ethylene and an alpha olefin having 3 or more carbon atoms. In this case, 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, for example, in the presence of the same supported hybrid catalyst, while supplying three or more different ratio comonomers, the above-mentioned monomers may be copolymerized. This copolymerization process may follow conventional polyethylene resin polymerization conditions and methods.

In this way, after preparing the first to nth polyethylene resins, they 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 long column, and the temperature at the time of analysis is about 160°C, and 1,2,4-trichlorobenzene is 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, a polystyrene resin may be used, and the molecular weight of the standard material may be 2,000, 10,000, 30,000, 70,000, 200,000, 700,000, 2,000,000, 4,000,000, or 10,000,000. A molecular weight distribution curve can be derived by performing GPC analysis using a calibration curve formed using such a standard material, and various physical properties (eg, Mw, Mn or molecular weight distribution) of each resin can be measured and evaluated from this. have.

On the other hand, in the method of the embodiment, in order to more reliably predict the physical 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 conditions ( While supplying the comonomer at a supply ratio or supply amount), three or more kinds of polyethylene resins are prepared, and data on them need to be collected.

And, 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 respectively included within the range of these molecular weight distribution curves, and are symmetrical The first and second hypothetical molecular weight distribution curves having the normal distribution curve of the structure may be separated and set (deconvolution).

Then, the area or physical property derived from the first and second sub molecular weight distribution curves, for example, the log Mw value (y) derived from each sub molecular weight distribution curve, and the supply ratio of the comonomer to the total weight of the monomer ( x; weight %) may be linearly regressed into a relational expression in the form of an approximately linear function, and an example of such a linear regression equation is shown in FIG. 5 .

More specifically, the linearly regressed linear function may be expressed as y = ax + b, in this linear regression function, x represents the supply ratio (wt%) of the alpha olefin to the total weight of the monomer, Wherein y is the log value (log Mw) of the weight average molecular weight (Mw) of the polymer chains derived from the first metallocene catalyst calculated from the area of the first or second sub-molecular weight distribution curve, respectively, or the second metallocene catalyst derived It represents the log value (log Mw) of the weight average molecular weight (Mw) of the polymer chains, wherein a and b may be constants determined in the linear regression step.

That is, in a specific example, when it is desired to determine a linear regression equation for the first metallocene catalyst among the first and second metallocene catalysts, x may be the supply ratio (wt%) of the comonomer, y may be a log Mw value calculated from the first sub-molecular weight distribution curve. If the relationship between x and y is linearly regressed, constants a and b may be determined, and a graph as shown in FIG. 5 may be derived therefrom.

As already described above, this linear regression equation can be derived as a prediction equation for the physical properties of a polyethylene resin, and the supply ratio of the comonomer to be newly applied to this physical property prediction equation, that is, another ratio different from the first to nth ratio ( By substituting the m-th ratio), the shape of the first and second sub-molecular weight distribution curves of the novel polyethylene resin (the m-th polyethylene resin) and their Mw values can be derived. From the shape and Mw of the first and second sub-molecular weight distribution curves, the shape of the molecular weight distribution curve of the entire polyethylene resin and physical properties such as Mw thereof can be predicted, as confirmed in Examples and FIG. 7 to be described later Likewise, it was confirmed that the shape and physical properties of the molecular weight distribution curve were almost identical to the results of the analysis of the actually prepared resin by applying the supply ratio of the comonomer.

Accordingly, according to the method of one embodiment described above, the change in the physical properties of the polyethylene resin according to the change in the supply ratio of the comonomer can be reliably predicted from the linear regression function. More specifically, when the method of one embodiment is applied, when the comonomer supply ratio is applied at an m-th ratio different from the first to n-th ratio, the physical properties of the m-th polyethylene resin prepared as a hybrid supported catalyst, more specifically The weight average molecular weight (Mw), number average molecular weight (Mn), or molecular weight distribution (Mw/Mn) of these resins can be reliably predicted even before actually being manufactured.

Accordingly, when the method for predicting physical properties of one embodiment is applied to the production process of a polyethylene resin, when a new comonomer supply ratio is applied to the mass production process, the polyethylene resin prepared therefrom will have a molecular weight distribution curve roughly, And furthermore, it is possible to reliably predict in advance what range of physical properties (eg, molecular weight distribution, number average molecular weight (Mn), weight average molecular weight (Mw), etc.) of such a resin.

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

On the other hand, in the above, as a method of one embodiment, the method of predicting physical properties such as the weight average molecular weight of the polyethylene resin according to the supply ratio of the comonomer has been mainly described, but according to another embodiment of the invention, in the supply ratio of the comonomer The expression ratio of each of the first or second metallocene catalysts according to the above may be reliably predicted. The expression ratio of each of these first or second metallocene catalysts can be defined as the content (weight %) of polymer chains derived from each of these metallocene catalysts with respect to the total weight of the first to nth polyethylene resins. have. As the expression ratio of each metallocene catalyst is reliably predicted, the physical properties of the entire polyethylene resin prepared according to the supply ratio of the comonomer can be predicted more reliably, and the expression ratio of a specific metallocene catalyst is controlled. In this way, the desired physical properties of the polyethylene resin can be more easily and effectively achieved.

In the method of this other embodiment, from the total area of the first to nth molecular weight distribution curves and the areas of the first and second sub molecular weight distribution curves deconvolved therefrom, respectively, the first to nth polyethylene Based on the total weight of the resin, the content (% by weight) of the polymer chains derived from the first metallocene catalyst or the content (% by weight) of the polymer chains derived from the second metallocene catalyst may be calculated as y'. The relationship between y' and the supply ratio (x; wt%) of the comonomer to the total weight of the monomer can be linearly regressed into a relational expression in the form of an approximately linear function, an example of such a linear regression formula is shown in FIG. is shown.

More specifically, the linearly regressed linear function may be expressed as y' = a'x + b', and in this linear regression function, x is the supply ratio of the alpha olefin to the total weight of the monomer (weight %). ), and y' is the content (wt%) of polymer chains derived from the first metallocene catalyst calculated from the area of the first or second sub-molecular weight distribution curve, respectively, or polymer chains derived from the second metallocene catalyst represents the content (% by weight) of them, and a' and b' may be constants determined in the linear regression step.

In a specific example, when it is desired to predict the expression ratio for the first metallocene catalyst among the first and second metallocene catalysts, x may be the supply ratio (weight%) of the comonomer, and y' is It may be the content (wt%) of polymer chains calculated from the area of the first sub-molecular weight distribution curve. If the relationship between x and y' is linearly regressed, constants a' and b' may be determined, and a graph as shown in FIG. 6 may be derived therefrom.

This linear regression equation can be derived as a predictive equation for the physical properties of a polyethylene resin, and a ratio (m-th ratio) different from the supply ratio of the comonomer to be newly applied, that is, the first to n-th ratio is substituted into this property prediction formula. Then, in this novel polyethylene resin (the mth polyethylene resin), the content ratio (weight %) of each polymer chain derived from the first or second metallocene catalyst can be predicted.

When the predicted values such as the expression ratio of the first or second metallocene catalyst predicted as described above, the modification of the first and second sub-molecular weight distribution curves and their Mw values are considered together, the hybrid supported catalyst It is possible to more reliably predict how each metallocene catalyst is expressed to what extent it can affect the overall physical properties of the mth polyethylene resin and what the overall physical properties of the mth polyethylene resin will be. Through this method, it can be easily predicted and determined what physical properties the polyethylene resins having different comonomer supply and copolymerization ratios will have as a whole depending on the process conditions, without trial and error through actual process application. Therefore, it becomes very easy to determine the process conditions such as the supply ratio of the comonomer of the polyethylene resin to achieve the desired physical properties, which can greatly contribute to the mass productivity of the polyethylene resin.

Meanwhile, according to another embodiment of the present invention, there is provided a method for producing a polyethylene resin to which the method for predicting physical properties of the embodiment is applied. The method for producing such a polyethylene resin includes the steps of: determining target physical properties of a polyethylene resin to be prepared by using a hybrid supported catalyst on which first and second metallocene catalysts are supported;

Comparing the target physical properties of the polyethylene resin with the predicted physical properties of the polyethylene resin according to the prediction method of the embodiment, determining a supply ratio of alpha olefin to obtain the target physical properties; and

Copolymerizing the monomers using a hybrid supported catalyst on which the first and second metallocene catalysts are supported while supplying the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin becomes the determined ratio can

That is, in this method, in consideration of the target physical properties of the polyethylene resin to be manufactured, appropriate process conditions or the supply ratio of the comonomer can be determined in advance through the method of predicting the physical properties of one embodiment, and through this, the target physical properties The polyethylene resin can be produced more effectively.

In the manufacturing method of the other embodiment described above, since the general method for manufacturing a polyethylene resin may be followed, except for determining the process conditions by the method for predicting the physical properties of the embodiment, additional description thereof will be omitted.

As described above, according to the present invention, when a polyethylene resin is prepared using a metallocene hybrid supported catalyst, the change in physical properties of the polyethylene resin according to a change in the supply ratio of the comonomer can be reliably predicted in advance.

Therefore, by applying the method for predicting the physical properties of the polyethylene resin of the present invention, process conditions or comonomer supply ratio for obtaining a polyethylene resin having target properties can be predicted in advance, and by applying this, a polyethylene resin having target properties can be obtained. It can be manufactured more effectively.

1 shows the first to third molecular weight distribution curves of the first to third polyethylene resins prepared in Polymerization Examples 1 to 3;
2 to 4 are views showing a state in which the first to third molecular weight distribution curves of the first to third polyethylene resins are set separately, the first and second sub molecular weight distribution curves, respectively;
5 is based on the data obtained in FIGS. 2 to 4, the supply ratio of alpha olefin (x; wt%), and log Mw (y; unit) of the polymer chains derived from the first and second metallocene catalysts. None) is a diagram showing the relationship of the first and second metallocene catalysts in a linear regression equation,
Figure 6 is based on the data obtained in Figures 2 to 4, the supply ratio of alpha olefin (x; wt%), and the content of polymer chains derived from the first and second metallocene catalysts (y'; weight) %) is a diagram showing a linear regression equation for each of the first and second metallocene catalysts,
FIG. 7 is a graph showing each of the linear regression equations for the first and second metallocene catalysts obtained in FIG. 5 and the measured data compared with each other.

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

Polymerization Examples 1 to 3: Preparation of polyethylene resin

The first to third polyethylene resins were polymerized by the following method.

In the case of the first to third polyethylene resins, since polymerization and preparation were performed using the same supported hybrid catalyst, below, the preparation examples of the hybrid supported catalyst are commonly described, and then polymerization examples of each polyethylene resin are separately described.

Preparation Example: Preparation of Hybrid Supported Catalyst (Common)

After putting 50 mL of toluene solution into a 300 mL glass reactor, 8 g of silica (Grace Davison, SP2410) was added, and stirring while raising the temperature of the reactor to 40 °C. 45 mL of 10wt% methylaluminoxane (MAO)/toluene solution (Albemarle) was added, the temperature was raised to 70°C, and the mixture was stirred at 200rpm for 12 hours. After lowering the reactor temperature to 40°C, stop stirring, settling for 10 minutes, and decantation the reaction solution. After adding 100mL of toluene and stirring for 10 minutes, stop stirring, settling for 10 minutes, and decantation the toluene solution.

50 mL of toluene was put into the reactor, 2.35 g of the first metallocene catalyst K1 and a solution of 10 mL of toluene were put into the reactor, and the mixture was stirred at 300 rpm for 60 minutes. Here, 1.2 g of the second metallocene catalyst K2 and a solution of 10 ml of toluene were put into the reactor and stirred at 300 rpm for 12 hours. Stop stirring, settling for 10 minutes, and decantation the reaction solution. 100mL of hexane is put into the reactor, the hexane slurry is transferred to a 250mL schlenk flask, and the hexane solution is decanted. It was dried under reduced pressure at room temperature for 3 hours.

Polymerization Example 1: Preparation of the first polyethylene resin

TEAL 2ml (1.0 M Hexane) and 1-butene 0.1 g (2.8 wt% based on the total weight of the monomer) were put into a 2L autoclave high-pressure reactor, 0.8 kg of hexane was added, and the temperature was raised to 80 °C while stirring at 500rpm to polymerize proceed with After putting the hybrid supported catalyst and hexane prepared in the above-mentioned Preparation Example in a vial and putting it into the reactor, when the internal temperature of the reactor reaches 78° C., it is reacted for 1 hour while stirring at 500 rpm under an ethylene pressure of 9 bar. After completion of the reaction, the obtained polymer was first removed with hexane through a filter, and then dried in a vacuum oven at 80° C. for 4 hours.

Polymerization Example 2: Preparation of the second polyethylene resin

2ml of TEAL (1.0 M Hexane) and 0.12 g of 1-butene (3.4% by weight relative to the total weight of the monomer) were put into a 2L autoclave high-pressure reactor, 0.8 kg of hexane was added, and the temperature was raised to 80°C while stirring at 500rpm to polymerize proceed with After putting the supported catalyst and hexane prepared in the above-mentioned Preparation Example in a vial and putting it into the reactor, when the temperature inside the reactor reaches 78° C., it is reacted for 1 hour while stirring at 500 rpm under the ethylene pressure of 9 bar. After completion of the reaction, the obtained polymer was first removed with hexane through a filter, and then dried in a vacuum oven at 80° C. for 4 hours.

Polymerization Example 3: Preparation of the third polyethylene resin

2ml of TEAL (1.0 M Hexane) and 0.15 g of 1-butene (4.2% by weight relative to the total weight of the monomer) were put into a 2L autoclave high-pressure reactor, 0.8 kg of hexane was added, and the temperature was raised to 80° C. while stirring at 500 rpm for polymerization proceed with After putting the hybrid supported catalyst and hexane prepared in the above-mentioned Preparation Example in a vial and putting it into the reactor, when the internal temperature of the reactor reaches 78° C., it is reacted for 1 hour while stirring at 500 rpm under an ethylene pressure of 9 bar. After completion of the reaction, the obtained polymer was first removed with 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 are shown in FIG. 1 (Polymerization Example 1 (first polyethylene resin): black line in FIG. 1, Polymerization Example 2 (second polyethylene resin): red line in FIG. 1, Polymerization Example 3 (third polyethylene resin): blue line in FIG. 1 ). In this GPC analysis, the following analysis conditions and methods were applied.

Polymer Laboratories PLgel MIX-B 300 mm length column was used for analysis using GPC instrument of Waters PL-GPC220. 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 the molecular weight of these standard materials was 2,000, 10,000, 30,000, 70,000, 200,000, 700,000, 2,000,000, 4,000,000, or 10,000,000.

Examples 1 to 3: Determination of the formula for predicting physical properties

The first and second sub-molecular weight distribution curves for the first to third molecular weight distribution curves derived in Polymerization Examples 1 to 3 were separated and set, respectively, and shown in FIGS. 2 to 4 ( FIG. 2: Polymerization Example 1 ( (First polyethylene resin)), Fig. 3: Polymerization Example 2 (Second polyethylene resin), Fig. 4: Polymerization Example 3 (Third polyethylene resin)).

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 comonomer supply ratio of 1-butene to the total monomer (wt%) is x, and , and the log Mw (unitless) of the polymer chains derived from the first and second sub-molecular weight distribution curves was taken as y, and the relationship between y and x was linearly regressed as a linear function.

The linear regression linear function is shown in FIG. 5 by linear regression for each of the first metallocene catalyst (K1) and the second metallocene catalyst (K2), respectively, y = -0.03026x (wt%) + Determined by 4.50658 (red line in FIG. 5; related to the first metallocene catalyst, K1 catalyst) and y = -0.06053x (wt%) + 5.21316 (blue line in FIG. 5; related to the second metallocene catalyst, K2 catalyst) became

However, in the red line of FIG. 5, x is calculated and defined according to "the 1-butene supply ratio in each polymerization example", and y is "the first sub-molecular weight distribution curve in each polymerization example (the first metallocene catalyst ( It is defined according to the "log Mw" of the polymer chains derived from the distribution curve of K1). In the blue line of FIG. 5, x is calculated and defined according to "the 1-butene supply ratio in each polymerization example", and y is "the second sub-molecular weight distribution curve in each polymerization example (the second metallocene catalyst (K2 ) is defined according to the log Mw of the polymer chains derived from the distribution curve).

On the other hand, the physical property prediction formula for the expression ratio y' (wt%) of the first or second metallocene catalyst was determined by the following method.

First, from the area ratio of the first or second sub molecular weight distribution curve to the first to third molecular weight distribution curves derived in FIGS. 2 to 4, respectively, the first metal to the total weight of the first to third polyethylene resins The content (% by weight) of the polymer chains derived from the rosene catalyst (K1) and the content (% by weight) of the polymer chains derived from the second metallocene catalyst (K2) were calculated as y' values, respectively. Then, the comonomer supply ratio of 1-butene to the total monomer (% by weight) is x, and the content (% by weight) of the polymer chains derived from the first or second metallocene catalyst calculated above is y', The relationship between y' and x was linearly regressed as a linear function.

This linear regression linear function is shown in FIG. 6 by linear regression for the expression ratio of each of the first metallocene catalyst (K1) and the second metallocene catalyst (K2), respectively, y = -0.90789x (weight %) + 69.19737 (red line in FIG. 6; related to the first metallocene catalyst, K1 catalyst) and y = 0.90789x (wt%) + 30.80263 (blue line in FIG. 6; related to the second metallocene catalyst, K2 catalyst) was decided

However, in the red line of FIG. 6, x is calculated and defined according to "1-butene supply ratio in each polymerization example", and y' is "the first sub molecular weight distribution curve (first metallocene catalyst in each polymerization example)" The content of polymer chains derived from the distribution curve of (K1)". In the blue line of FIG. 6, x is calculated and defined according to "the 1-butene supply ratio in each polymerization example", and y' is "the second sub-molecular weight distribution curve in each polymerization example (the second metallocene catalyst ( The content of polymer chains derived from the distribution curve of K2)".

Test Example: Evaluation of Reliability of Prediction Results of Physical Properties of Polyethylene Resins

<Polymerization of m polyethylene resin>

TEAL 2ml (1.0 M Hexane), 1-butene 0.5g, 0.8g, 1.0g, 1.2g, 1.5g, 1.6g, 1.7g (1.4 wt% to 4.8 wt% based on the total weight of the monomer) in a 2L autoclave high pressure reactor After adding 0.8 kg of hexane, the temperature was raised to 80° C. while stirring at 500 rpm to proceed with polymerization.

After putting the hybrid supported catalyst and hexane prepared in the above-mentioned Preparation Example in a vial and putting it into the reactor, when the internal temperature of the reactor reaches 78° C., it is reacted for 1 hour while stirring at 500 rpm under an ethylene pressure of 9 bar. After completion of the reaction, the obtained polymer was first removed from hexane through a filter, and then dried in a vacuum oven at 80° C. for 4 hours.

<Reliability Evaluation>

When x1 is obtained and substituted according to the comonomer supply ratio used in the test example of the mth polyethylene resin in the physical property prediction formula of FIG. 5 (y = -0.03026x (weight%) + 4.50658) related to K1 obtained in the above example The y1 value corresponding to K1 of the test example can be predicted. Similarly, if x1 is obtained according to the comonomer supply ratio used in the test example of the mth polyethylene resin in the physical property prediction formula of FIG. 5 (y = -0.06053x (wt%) + 5.21316) related to K2, The y1 value corresponding to 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 are separated, respectively, to actually obtain log Mw values corresponding to the polymer chains.

The red line graph of FIG. 7 is a graph of the physical property prediction formula of K1 obtained in the example, and the red dots indicate values calculated after actually separating each. It can be seen that there is no significant error in the predicted values of actual properties. (R ² =0.958) Similarly in FIG. The blue linear graph is a graph of the physical property prediction equation of K2 obtained in the example, and the blue dots indicate values calculated after actually separating each. It can be seen that there is no significant error in the predicted values of actual properties. (R ² =0.967).

Claims (9)

In the presence of a supported hybrid catalyst on which the first and second metallocene catalysts are supported, ethylene and the alpha olefin monomer are supplied so that the supply ratio of the alpha olefin having 3 or more carbon atoms to the total weight of the monomer becomes the first ratio; A first step of copolymerizing 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 deconvolution of imaginary first and second sub-molecular weight distribution curves included in the region of the first molecular weight distribution curve and having a normal distribution curve shape;
A second to nth polyethylene resin is prepared by supplying and copolymerizing the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin is a second to nth ratio different from the first ratio (where n is an integer of 3 or more) a fourth step of forming;
By performing the second and third steps for the second to nth polyethylene resin, a second to nth molecular weight distribution curve is derived, and first and second sub molecular weights for the second to nth molecular weight distribution curve a fifth step of separately setting the distribution curves;
Let the first to nth ratio be x, and the physical property calculated from the first or second sub molecular weight distribution curve for the first to nth molecular weight distribution curve as y, the relationship between y and x is linear as a linear function regressing; and
From the linear regression function, a method for predicting physical properties of a polyethylene resin comprising the step of predicting the physical properties of the polyethylene resin.
The method according to claim 1, wherein the linearly regressed linear function is expressed as y (unit: none) = ax (unit: wt%) + b,
wherein x represents the supply ratio (wt%) of the alpha olefin to the total weight of the monomer,
Wherein y is the log value (log Mw) of the weight average molecular weight (Mw) of the polymer chains derived from the first metallocene catalyst calculated from the area of the first or second sub-molecular weight distribution curve, respectively, or the second metallocene catalyst derived represents the log value (log Mw) of the weight average molecular weight (Mw) of the polymer chains,
wherein a and b are constants determined in the linear regression step; a method for predicting physical properties of a polyethylene resin.
The method according to claim 1, wherein the linearly regressed linear function is expressed as y' (unit: wt%) = a'x (unit: wt%) + b',
wherein x represents the supply ratio (wt%) of the alpha olefin to the total weight of the monomer,
Wherein y' is the content (weight %) of the polymer chains derived from the first metallocene catalyst calculated from the area of the first or second sub-molecular weight distribution curve, respectively, or the content (weight %) of the polymer chains derived from the second metallocene catalyst %),
Wherein a' and b' are constants determined in the linear regression step. A method for predicting physical properties of a polyethylene resin.
The method according to claim 1, wherein n is an integer of 3 or more and 10 or less.
The method of claim 1 , wherein in the predicting physical properties of the polyethylene resin, a change in the physical properties of the polyethylene resin according to a change in the supply ratio of the alpha olefin is predicted from the linear regression function.
[6] The weight average molecular weight (Mw) of the mth polyethylene resin according to claim 5, wherein in the step of predicting the physical properties of the polyethylene resin, the supply ratio of the alpha olefin is differently adjusted to the mth ratio different from the 1st to nth ratio , A method for predicting physical properties of polyethylene resins for predicting number average molecular weight (Mn) or molecular weight distribution (Mw/Mn).
The method according to claim 5, wherein in the step of predicting the physical properties of the polyethylene resin, the supply ratio of the alpha olefin is differently adjusted to the mth ratio different from the 1st to the nth ratio in the mth polyethylene resin produced,
A method for predicting physical properties of a polyethylene resin for predicting the content ratio (wt%) of each polymer chain derived from the first or second metallocene catalyst.
determining target physical properties of a polyethylene resin to be prepared by using a hybrid supported catalyst on which the first and second metallocene catalysts are supported;
Comparing the target physical properties of the polyethylene resin with the predicted physical properties of the polyethylene resin according to the method of claim 1, determining a supply ratio of alpha olefin to obtain the target physical properties; and
Copolymerizing the monomers using a hybrid supported catalyst on which the first and second metallocene catalysts are supported while supplying the monomers of ethylene and alpha olefin so that the supply ratio of the alpha olefin is the determined ratio A method for producing a polyethylene resin.
The method for producing a polyethylene resin according to claim 8, wherein the predicted physical properties and target properties of the polyethylene resin are a weight average molecular weight (Mw), a number average molecular weight (Mn), and a molecular weight distribution (Mw/Mn).

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