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KR-102964340-B1 - A METHOD FOR PREPARATION OF PROPYLENE COPOLYMER IMPROVED IN COPLYMERIZATION

KR102964340B1KR 102964340 B1KR102964340 B1KR 102964340B1KR-102964340-B1

Abstract

The present invention comprises a method for manufacturing a propylene-based copolymer, comprising a method for manufacturing a solid catalyst composed of a support produced by reacting dialkoxymagnesium with a metal halide, a titanium halide, an organic electron donor, etc. According to the present invention, a propylene-based copolymer having a high comonomer content, high activity, and a low amorphous content can be manufactured, thereby significantly improving the phenomenon of polymer particle aggregation during copolymer manufacturing.

Inventors

  • 이승철
  • 박선재
  • 이영주

Assignees

  • 한화토탈에너지스 주식회사

Dates

Publication Date
20260513
Application Date
20221122

Claims (15)

  1. A method for manufacturing a propylene polymer or a propylene-based copolymer, A) A Ziegler-based catalyst comprising magnesium, titanium, a halogen, and an internal electron donor as main catalyst components; B) an alkylaluminum compound as a co-catalyst; and C) as an external electron donor a) a dialkoxysilane compound represented by the following chemical formula 1, b) a trialkoxysilane compound represented by the following chemical formula 2, and c) a trialkoxysilane compound represented by the following chemical formula 3; Includes, A method using a catalyst system that satisfies the following relationship 1 for the change in amorphous content of activity according to the content of the comonomer of the above propylene polymer or propylene-based copolymer: [Chemical Formula 1] R 1 R 2 Si(OR 3 ) 2 In the above Chemical Formula 1, R1 and R2 each independently represent a C1-12 alkyl group, a C6-12 aryl group, a C4-12 cycloalkyl group, a C1-12 alkylamine group, a C1-12 alkylsilyl group, or a C1-12 alkoxysilyl group, and R3 represents a C1-3 alkyl group. [Chemical Formula 2] R 4 Si(OR 5 ) 3 In the above chemical formula 2, R4 represents an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkylamine group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylsilyl group having 1 to 12 carbon atoms, or an alkoxysilyl group having 1 to 12 carbon atoms, and R5 represents an alkyl group having 1 to 4 carbon atoms, [Chemical Formula 3] R 6 Si(OR 7 ) 3 In the above chemical formula 3, R6 represents an alkenyl group having 2 to 12 carbon atoms, and R7 represents an alkyl group having 1 to 4 carbon atoms, and [Relationship 1] R/A=k*C+m In the above relationship 1, R is the amorphous content of the polymer (X/S wt%), A represents the activity (kg-polymer/g-cat), C is the content of the comonomer in the polymer or copolymer (wt%), k represents the change in amorphous content relative to the activity according to the change in comonomer content, k is within 0.050, and m is a constant of the linear relationship.
  2. delete
  3. A method according to claim 1, characterized in that k is within 0.049.
  4. A method according to claim 1, characterized in that the main catalyst component comprises 5-40 wt% magnesium, 0.5-10 wt% titanium, 50-85 wt% halogen and 0.01-30 wt% internal electron donor.
  5. A method according to claim 1, characterized in that the internal electron donor used in the catalyst system is selected from one or more types from the group consisting of phthalic acid esters, cyclic esters, and 1,3-diethers.
  6. A method according to claim 1, characterized in that the co-catalyst is an alkylaluminum compound represented by the following chemical formula 4: [Chemical Formula 4] AlR 3 Here, R is an alkyl group having 1 to 6 carbon atoms.
  7. A method according to claim 1, characterized in that the molar ratio of aluminum atoms in the co-catalyst component to titanium atoms in the main catalyst component is in the range of 1 to 1000.
  8. A method according to claim 1, characterized in that the total molar ratio of silicon atoms in the external electron donor to titanium atoms in the main catalyst component is in the range of 0.1 to 500.
  9. A method according to claim 1, characterized in that the molar ratio of the total amount of the compound represented by Chemical Formula 1: the compound represented by Chemical Formula 2 + the compound represented by Chemical Formula 3 is 1:0.5 to 2.
  10. A method according to claim 1, characterized in that the molar ratio of the compound represented by Chemical Formula 2 to the compound represented by Chemical Formula 3 is in the ratio of 3:1 to 1:3.
  11. A method according to claim 1, characterized by carrying out copolymerization including propylene and ethylene, or alpha-olefin comonomers in a molar ratio of 1 to 2, after propylene homopolymerization or copolymerization of propylene and ethylene.
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  13. As a catalyst system for the production of propylene polymers or propylene-based copolymers, A) A Ziegler-based catalyst comprising magnesium, titanium, a halogen, and an internal electron donor as main catalyst components; B) an alkylaluminum compound as a co-catalyst; and C) as an external electron donor a) a dialkoxysilane compound represented by the following chemical formula 1, b) a trialkoxysilane compound represented by the following chemical formula 2, and c) a trialkoxysilane compound represented by the following chemical formula 3; Includes, The amount of change in amorphous content regarding activity according to the content of the comonomer of the above propylene polymer or propylene-based copolymer satisfies the following relationship 1 for a catalyst system: [Chemical Formula 1] R 1 R 2 Si(OR 3 ) 2 In the above chemical formula 1, R1 and R2 each independently represent a C1-12 alkyl, a C6-12 aryl, or a C4-12 cycloalkyl group, and R3 represents a C1-3 alkyl group, and [Chemical Formula 2] R 4 Si(OR 5 ) 3 In the above chemical formula 2, R4 represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkylamine group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a silyl group, or an alkoxysilyl group having 1 to 12 carbon atoms, and R5 represents an alkyl group having 1 to 4 carbon atoms, [Chemical Formula 3] R 6 Si(OR 7 ) 3 In the above chemical formula 3, R6 represents an alkenyl group having 2 to 12 carbon atoms, and R7 represents an alkyl group having 1 to 4 carbon atoms, and [Relationship 1] R/A=k*C+m In the above relationship 1, R is the amorphous content of the polymer (X/S wt%), A represents the activity (kg-polymer/g-cat), C is the content of the comonomer in the polymer or copolymer (wt%), k represents the change in amorphous content relative to the activity according to the change in comonomer content, k is within 0.050, and m is a constant of the linear relationship.
  14. delete
  15. A catalyst system according to claim 13, characterized in that k is within 0.049.

Description

A METHOD FOR PREPARATION OF PROPYLENE COPOLYMER IMPROVED IN COPLYMERIZATION The present invention relates to a method for manufacturing a propylene-based copolymer, and in particular, to a method for manufacturing a propylene-based copolymer having a high comonomer content, high activity, and low amorphous content, which can significantly improve the phenomenon of polymer particle aggregation during copolymer manufacturing. The following description merely provides background information related to the present invention and does not constitute prior art. Polypropylene is a highly useful material for both everyday life and commercial applications, and is widely used in a wide range of products, from household goods such as food containers to automobiles and electronic devices. To ensure the diverse performance capabilities of such polypropylene products, it is important to improve rigidity through a high degree of crystallinity. Furthermore, the impact strength required for automotive interior and exterior materials can be met by manufacturing propylene-based block copolymers with a high amorphous content; for this purpose, the role of the polymerization catalyst is critically essential. In other words, the catalyst system must be designed to enhance the stereoregularity of the resulting polymer and satisfy high copolymerization with alpha-olefins. In addition, for the economic efficiency of polymer manufacturing, higher polymerization activity of the catalyst is more advantageous. Meanwhile, catalyst systems used in the gas phase, slurry, and bulk polymerization of propylene are generally composed of Ziegler-Natta catalyst components, alkylaluminums, and external electron donors. In particular, these catalyst components are known to be solid catalysts containing magnesium, titanium, internal electron donors, and halogens as essential components. Internal electron donors are known to have a significant influence on the activity and stereoregularity of the catalyst depending on their molecular structure. External electron donors are well known to improve the isotactic index, or stereoregularity, of the resulting polymer by selectively poisoning or converting asteroregular active sites present on the surface of a solid catalyst. Depending on the molecular structure of the external electron donor used, the stereoregularity, activity, and molecular weight distribution of the polypropylene polymer produced vary. Furthermore, in propylene copolymers using comonomers, the content of the comonomer within the copolymer and the physical properties of the copolymer are affected. Therefore, various conventional technologies are known that utilize various types of silane compounds as external electron donors to obtain polypropylene polymers with improved properties. US7893003B and US8067510B introduce a method for controlling low molecular weight components by combining two types of external electron donors. KR1639497B1 presents a method for improving randomness in which propylene and comonomers within a copolymer randomly form polymer chains. KR1764561B1 presents a method for achieving high transparency and a low melting temperature in propylene-ethylene copolymers. However, the aforementioned patents do not demonstrate a method for controlling the aggregation of polymer particles, which can improve productivity in copolymer manufacturing, and thus, it is necessary to present an improved method for this. Figure 1 is a photograph of a copolymer according to one embodiment of the present invention. Figure 2 is a photograph of a copolymer according to a comparative example of the present invention. The present invention will be explained in detail below through examples and comparative examples, but the present invention is not limited thereby. Example 1 [Preparation of main catalyst component] 112 ml of toluene and 15 g of the diethoxymagnesium prepared above were added to a 1 L glass reactor equipped with a stirrer that was sufficiently purged with nitrogen, and while maintaining the temperature at 10°C, 20 ml of titanium tetrachloride diluted in 30 ml of toluene was added over a period of 1 hour. Then, while raising the temperature of the reactor to 100°C, 5 g of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane was slowly injected. After maintaining the temperature at 100°C for 2 hours, the temperature was lowered to 90°C to stop stirring, the supernatant was removed, and the mixture was washed once using an additional 200 ml of toluene. Then, 120 ml of toluene and 20 ml of titanium tetrachloride were added, the temperature was raised to 100°C and maintained for 2 hours, and this process was repeated once. The above slurry mixture, after the aging process was completed, was washed twice with 200 ml of toluene each time and washed five times with 200 ml of normal hexane each time at 40°C to obtain a pale yellow solid catalyst component. The titanium content of the solid catalyst component obtained by drying in running nitrog