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KR-20260065072-A - HIGH DENSITY POLYETHYLENE AND FILM COMPRISING THE SAME

KR20260065072AKR 20260065072 AKR20260065072 AKR 20260065072AKR-20260065072-A

Abstract

The high-density polyethylene according to the present invention is characterized by having high density and, through fine control of the melt flow index, polydispersity index, and the ratio of the leaching temperature region below 35°C, it can improve both processability and elongation uniformity along with excellent moisture barrier properties.

Inventors

  • 전만성
  • 유제성
  • 진상훈
  • 김명진
  • 이효준
  • 장창환
  • 선가람
  • 이대섭
  • 홍유식
  • 권헌용
  • 이승묵
  • 이진석

Assignees

  • 주식회사 엘지화학

Dates

Publication Date
20260508
Application Date
20241031

Claims (16)

  1. The density is 0.965 g/cm³ or greater and 0.975 g/cm³ or less, and The melt flow index (MI 2.16 , 190℃, 2.16kg) is 0.1 g/10 min or more and 5.0 g/10 min or less, and The polydispersity index (PDI, Mw/Mn) is between 20 and 60, and In a CEF graph where the x-axis is the dissolution temperature and the y-axis is dw/dT, the proportion of the region with a dissolution temperature below 35℃ (soluble fraction) is between 3% and 10% of the total region, High-density polyethylene.
  2. In paragraph 1, The above polyethylene is an ethylene homopolymer, High-density polyethylene.
  3. In paragraph 1, A high-load melt flow index (MI 21.6 , 190℃, 21.6kg) of 180 g/10 min or more and 300 g/10 min or less, High-density polyethylene.
  4. In paragraph 1, A melt flow rate ratio (MFRR, MI 21.6 / MI 2.16 ) of 150 or more and 250 or less, High-density polyethylene.
  5. In paragraph 1, Having a weight-average molecular weight (Mw) of 120,000 g/mol or more and 200,000 g/mol or less, High-density polyethylene.
  6. In paragraph 1, In a GPC graph where the x-axis is log Mw and the y-axis is dw/dlogMw, the proportion of the region with a log Mw value of 2 or more and 3 or less is 3% or more and 10% or less of the total region, High-density polyethylene.
  7. In paragraph 1, In a GPC graph where the x-axis is log Mw and the y-axis is dw/dlogMw, the proportion of the region with a log Mw value of 2 to 4 is between 38% and 50% of the total region, High-density polyethylene.
  8. In paragraph 1, In a GPC graph where the x-axis is log Mw and the y-axis is dw/dlogMw, the proportion of the region with a log Mw value of 6 or greater and 7 or less is 1% or greater and 5% or less of the total region, High-density polyethylene.
  9. In paragraph 1, In a CEF graph where the x-axis is the dissolution temperature and the y-axis is dw/dT, the proportion of the region with a dissolution temperature below 35℃ is between 3% and 10% of the total region, High-density polyethylene.
  10. In paragraph 1, In a CEF graph where the x-axis is the dissolution temperature and the y-axis is dw/dT, the proportion of the region with a dissolution temperature of 35℃ or higher and less than 95℃ is 45% or higher and 55% or lower of the total region, High-density polyethylene.
  11. In paragraph 1, In a CEF graph where the x-axis is the dissolution temperature and the y-axis is dw/dT, the proportion of the region with a dissolution temperature of 95℃ or higher and 120℃ or lower is 40% or higher and 52% or lower of the total region, High-density polyethylene.
  12. In paragraph 1, In a CEF graph where the x-axis is the dissolution temperature and the y-axis is dw/dT, the maximum dissolution temperature measured relative to the maximum point of dw/dT is between 95℃ and 100℃, High-density polyethylene.
  13. In paragraph 1, High-density polyethylene having a solubility distribution breadth index (SDBI) of 24°C or higher and 30°C or lower in a CEF graph where the x-axis is the elution temperature and the y-axis is dw/dT.
  14. A high-density polyethylene according to claim 1, having a water vapor transmission rate (WVTR) of 1 g/ m² /day or less based on a film thickness of 50 μm, High-density polyethylene film.
  15. In Paragraph 14, A high-density polyethylene film with a thickness of 150㎛, a width of 40㎜, and a length of 120㎜ is divided at its center into rectangular grids of 7 x 5㎜ x 9 x 10㎜, and then uniaxially stretched five times in the longitudinal direction at a speed of 240㎜ per minute at 122℃, wherein the film stretching uniformity (%, Lp / La x 100), expressed as the percentage of the number of parallelogram grids ( Lp ) relative to the total number of grids ( La ) in the film, is 75% or higher. High-density polyethylene film.
  16. In Paragraph 14, When manufacturing a blown film with a thickness of 50㎛ under conditions of a temperature of 230℃, a frost line height (FLH) of 160㎜, and a blow-up ratio (BUR) of 2.5, the resin pressure is 80 bar or less, High-density polyethylene film.

Description

High Density Polyethylene and Film Comprising the Same The present invention relates to high-density polyethylene having excellent processability and elongation uniformity along with moisture barrier properties, and a film containing the same. Polyethylene is a general-purpose polymer widely used for various applications such as films, pipes, and containers, and there are various types of polyethylene, including high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). Recently, in order to increase the recycling rate of various packaging films for food, household use, and electronic products, there is growing interest in 100% polyethylene films (All PE film), such as high-density polyethylene, low-density polyethylene, and linear low-density polyethylene, instead of the aluminum foil (Al foil), nylon, or ethylene vinyl alcohol (EVOH) that were previously used. To replace existing materials used for barrier applications, it is necessary to ensure moisture and oxygen barrier properties in 100% polyethylene films (All PE film). Among polyethylenes, high-density polyethylene has a high density and a high crystal ratio, so it offers superior moisture and oxygen barrier properties compared to other polyethylenes such as low-density polyethylene and linear low-density polyethylene. Accordingly, high-density polyethylene can serve as a barrier film that blocks moisture penetration. However, because high-density polyethylene is non-polar, its oxygen barrier properties are inferior to those of conventionally used aluminum films, nylon, and ethylene vinyl alcohol. Accordingly, in order to increase the recycling rate of various packaging films, there is a need to develop a method using high-density polyethylene that can be applied to fields requiring stiffness, such as VFFS (vertical form fill seal), while also improving processability and elongation uniformity along with excellent moisture barrier properties. Figure 1 shows a GPC graph measured for high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention. FIG. 2 shows a CEF graph measured for high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention. FIG. 3 shows the results of uniaxial stretching five times in the longitudinal direction at 122°C for films prepared using high-density polyethylene of Examples 1 and 3 and Comparative Example 1 according to one embodiment of the present invention. In the present invention, terms such as first, second, etc. are used to describe various components, and these terms are used solely for the purpose of distinguishing one component from another component. Furthermore, the terms used herein are used merely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. Additionally, terms such as "approximately" and "substantially" used throughout this specification are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values are mentioned to aid in understanding the invention. In addition, in this specification, "part by weight" refers to a relative concept in which the weight of one substance is expressed as a ratio to the weight of another substance. For example, in a mixture containing 50g of substance A, 20g of substance B, and 30g of substance C, the amounts of substance B and substance C are 40 parts by weight and 60 parts by weight, respectively, based on 100 parts by weight of substance A. In addition, "weight % (% by weight)" refers to an absolute concept in which the weight of a substance is expressed as a percentage of the total weight. In the mixture given as an example above, the contents of substance A, substance B, and substance C are 50 weight %, 20 weight %, and 30 weight %, respectively, out of 100% of the total weight of the mixture. At this time, the total sum of the contents of each component does not exceed 100 weight %. The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall