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KR-20260064632-A - OLEFIN-BASED POLYMER

KR20260064632AKR 20260064632 AKR20260064632 AKR 20260064632AKR-20260064632-A

Abstract

The present invention relates to an olefinic polymer that exhibits high mechanical strength by introducing a highly crystalline region.

Inventors

  • 신창훈
  • 정정연
  • 공진삼
  • 박상은
  • 신경수
  • 박근태
  • 김지은

Assignees

  • 주식회사 엘지화학

Dates

Publication Date
20260507
Application Date
20251030
Priority Date
20241031

Claims (10)

  1. Olefinic polymer satisfying the following conditions (a) to (d): (a) Density: 0.855 to 0.880 g/cc (b) Melt index (190°C, 2.16 kg load condition; MI 2.16 ): 0.1 to 35 dg/min (c) Melt flow rate ratio (MFRR, MI 10 / MI 2.16 ): 6.0 to 8.5 (d) When measured by differential scanning calorimetry (SSA), F(30)-F(70) > [1599.2 × density - 1354], where F(30) is the total enthalpy of melting at 30°C or higher, and F(70) is the total enthalpy of melting at 70°C or higher.
  2. In claim 1, The above condition (a) olefinic polymer having a density of 0.865 to 0.880 g/cc.
  3. In claim 1, The above F (30) is an olefinic polymer with a value of 10.0 to 80.0.
  4. In claim 1, The above F (70) is an olefinic polymer with a value of 0.1 to 12.0.
  5. In claim 1, The above olefinic polymer has a melt index of 0.5 to 30 dg/min.
  6. In claim 1, The above olefinic polymer has a melt flow index of 6.2 to 8.3.
  7. In claim 1, The above olefinic polymer is an olefinic polymer having a weight-average molecular weight of 10,000 to 150,000 g/mol.
  8. In claim 1, The above olefinic polymer is an olefinic polymer having a molecular weight distribution of 1.5 to 3.0.
  9. In claim 1, The above olefinic polymer is an olefinic polymer that is a copolymer of ethylene and an alpha-olefinic monomer having 3 to 12 carbon atoms.
  10. In claim 9, The above alpha-olefin monomer is an olefin polymer that is one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, and 1-dodecene.

Description

Olefin-based polymer The present invention relates to an olefinic polymer that exhibits high mechanical strength by introducing a highly crystalline region. Polyolefins are widely used for extrusion, blow molding, and injection molding products due to their excellent moldability, heat resistance, mechanical properties, hygienic quality, water vapor permeability, and appearance characteristics of the molded articles. However, polyolefins, particularly polyethylene, lack polar groups within their molecules, resulting in low compatibility with polar resins such as nylon and poor adhesion to polar resins and metals. Consequently, it has been difficult to blend polyolefins with polar resins or metals, or to laminate them with these materials. Furthermore, polyolefin molded articles suffer from low surface hydrophilicity and antistatic properties. To solve these problems and increase affinity for polar materials, a method of grafting a polar group-containing monomer onto a polyolefin via radical polymerization has been widely used. However, this method had a problem of low miscibility due to poor viscosity balance between the graft polymer and the polar resin caused by intramolecular crosslinking and molecular chain cleavage of the polyolefin during the graft reaction. In addition, there was a problem of poor appearance characteristics of the molded article due to gel components generated by intramolecular crosslinking or foreign substances generated by molecular chain cleavage. In addition, as a method for producing olefin polymers such as ethylene homopolymers, ethylene/α-olefin copolymers, propylene homopolymers, or propylene/α-olefin copolymers, a method of copolymerizing polar monomers under a metal catalyst, such as a titanium catalyst or a vanadium catalyst, has been used. However, when copolymerizing polar monomers using such metal catalysts, there is a problem that the molecular weight distribution or composition distribution is wide and the polymerization activity is low. In addition, another method of polymerization is known in the presence of a metallocene catalyst consisting of a transition metal compound such as zircononocene dichloride and an organoaluminum oxy compound (aluminoxane). When a metallocene catalyst is used, high molecular weight olefin polymers are obtained with high activity, and the resulting olefin polymers have a narrow molecular weight distribution and a narrow compositional distribution. In addition, a method for producing polyolefins containing polar groups using a metallocene catalyst is also known, which uses a metallocene compound having a ligand of a non-crosslinked cyclopentadienyl group, a crosslinked or non-crosslinked bisdenyl group, or an ethylene-crosslinked unsubstituted indenyl/fluorenyl group. However, these methods have the disadvantage of very low polymerization activity. For this reason, a method of protecting polar groups with a protecting group is being implemented, but when a protecting group is introduced, the process becomes complicated because this protecting group must be removed again after the reaction. Ansa-metallocene compounds are organometallic compounds containing two ligands connected to each other by a bridge group, wherein rotation of the ligands is prevented by the bridge group and the activity and structure of the metal center are determined. Such anssa-metallocene compounds are used as catalysts in the production of olefinic homopolymers or copolymers. In particular, it is known that anssa-metallocene compounds containing cyclopentadienyl-fluorenyl ligands can produce high molecular weight polyethylene, thereby enabling control of the microstructure of polypropylene. In addition, anssa-metallocene compounds containing indenyl ligands are known to be capable of producing polyolefins with excellent activity and improved stereoregularity. As such, various studies are being conducted on ansah-metallocene compounds that possess higher activity and can control the microstructure of olefinic polymers, but the extent of such research is still insufficient. Figure 1 is a graph showing the results of differential scanning calorimetry (SSA) measurements for the polymers of Example 3 and Comparative Example 1. FIG. 2 shows F(30)-F(70) according to density for the polymers of Examples 1 to 4 and Comparative Examples 1 and 2. Figure 3 shows the tensile strength according to density for the polymers of Examples 1 to 4 and Comparative Example 1. Figure 4 shows the tear strength according to density for the polymers of Examples 1 to 4 and Comparative Example 1. Hereinafter, the present invention will be described in more detail to aid in understanding the invention. Terms and words used in the description and claims of the present invention shall not be interpreted as being limited to their ordinary or dictionary meanings, and shall be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle th