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KR-20260064042-A - POLYPROPYLENE BASED COMPOSITE

KR20260064042AKR 20260064042 AKR20260064042 AKR 20260064042AKR-20260064042-A

Abstract

The present invention relates to a polypropylene-based composite material comprising an olefin-based polymer that exhibits high mechanical strength by introducing a highly crystalline region.

Inventors

  • 정정연
  • 신창훈
  • 공진삼
  • 박상은
  • 신경수
  • 박근태
  • 이태섭

Assignees

  • 주식회사 엘지화학

Dates

Publication Date
20260507
Application Date
20241031

Claims (9)

  1. A polypropylene-based composite comprising: polypropylene; and an olefin-based polymer satisfying conditions (a) to (d) below: (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 F (30) is a polypropylene-based composite material with a value of 10.0 to 80.0.
  3. In claim 1, The above F (70) is a polypropylene-based composite material with a value of 0.1 to 12.0.
  4. In claim 1, The above-mentioned melt index is 0.5 to 30 dg/min, and the polypropylene-based composite material.
  5. In claim 1, The above-mentioned melt flow index is a polypropylene-based composite material of 6.2 to 8.3.
  6. In claim 1, The above olefin-based polymer is a polypropylene-based composite having a weight-average molecular weight of 10,000 to 150,000 g/mol.
  7. In claim 1, The above olefin-based polymer is a polypropylene-based composite having a molecular weight distribution of 1.5 to 3.0.
  8. In claim 1, The above olefin-based polymer is a polypropylene-based composite material that is a copolymer of ethylene and an alpha-olefin monomer having 3 to 12 carbon atoms.
  9. In claim 8, The above alpha-olefin monomer is a polypropylene-based composite material in which one or more are 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

Polypropylene-based composite The present invention relates to a polypropylene-based composite material comprising an olefin-based polymer that exhibits high mechanical strength by introducing a highly crystalline region. Generally, compositions for automotive interior and exterior parts have used polypropylene-based resin compositions containing impact modifiers and inorganic fillers, with polypropylene (PP) as the main component. Until the mid-1990s, prior to the development of ethylene-α-olefin copolymers polymerized using metallocene catalysts, EPR (ethylene propylene rubber) or EPDM (ethylene propylene diene rubber) were primarily used as impact modifiers in polypropylene-based resin compositions for automotive interior and exterior materials, particularly bumper covers. However, since the introduction of ethylene-α-olefin copolymers synthesized by metallocene catalysts, ethylene-α-olefin copolymers have begun to be used as impact modifiers and currently constitute the mainstream. This is because polypropylene-based composites using these copolymers possess many advantages, such as balanced physical properties including impact strength, elastic modulus, and flexural strength, good moldability, and low cost. Polyolefins such as ethylene-α-olefin copolymers synthesized by metallocene catalysts have a narrow molecular weight distribution and good mechanical properties because their molecular structure is more uniformly controlled than that produced by Ziegler-Natta catalysts. Low-density ethylene elastomers polymerized by metallocene catalysts also have good mechanical properties while maintaining low-density rubber characteristics because the α-olefin copolymer monomers are inserted relatively uniformly into the polyethylene (PE) molecules compared to those produced by Ziegler-Natta catalysts. However, there are limitations in ensuring impact resistance depending on the various usage environments, and the development of polypropylene-based composites capable of overcoming these limitations is required. Figure 1 is a graph showing the results of differential scanning calorimetry (SSA) measurements for the polymers of Example 4 and Comparative Example 1. FIG. 2 shows F(30)-F(70) according to density for the polymers of Examples 1 to 5 and Comparative Examples 1 and 2. Figure 3 shows the tensile strength according to density for the polymers of Examples 1 to 5 and Comparative Example 1. Figure 4 shows the tear strength according to density for the polymers of Examples 1 to 5 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 that the inventor can appropriately define the concept of the terms to best describe his invention. In this specification, the term "polymer" means a polymer compound produced by the polymerization of the same or different types of monomers. The general term "polymer" includes the terms "homopolymer," "copolymer," "terpolymer," as well as "copolymer." Furthermore, the term "copolymer" means a polymer produced by the polymerization of two or more different types of monomers. The general term "copolymer" includes the term "copolymer" (commonly used to refer to a polymer produced from two different monomers) as well as the term "terpolymer" (commonly used to refer to a polymer produced from three different types of monomers). This includes a polymer produced by the polymerization of four or more types of monomers. The polypropylene-based composite of the present invention comprises polypropylene and an olefin-based polymer, wherein the olefin-based polymer satisfies 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. The olefin polymer included in the polypropylene-based composite of the present invention exhibits higher tensile strength and tear strength when having the same level of density and melt index, as a highly crystalline region is introduced compared to conventional olefin polymers. The olefin polymer is prepared by polymerizing olefin monomers while introducing hydrogen gas in the presence of an olefin polymerization catalyst composition; the introduction of hydrogen gas during polymerization introduces a highly crystalline region, thereby exhibiting excellent mechanical strength. polypropylene In the present invention, the polypro