KR-20260065517-A - HIGH DENSITY POLYETHYLENE AND FILM COMPRISING THE SAME

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 (PDI), and tensile viscosity, being able to improve both excellent moisture barrier properties and processability without deterioration of physical properties during film processing, even without blending with low-density polyethylene, etc.

Inventors

• 이진석
• 이효준
• 이대섭
• 이나은
• 조수원
• 권헌용
• 이승묵
• 김명진
• 박나영
• 장창환
• 선가람
• 전만성
• 이정용

Assignees

• 주식회사 엘지화학

Dates

Publication Date

20260508

Application Date

20251020

Priority Date

20241031

Claims (14)

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 , measured at 190 ℃, and a 2.16 kg load) 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 Elongational viscosity (@strain 2.5) of 30,000 Pa·S or more and 90,000 Pa·S or less, 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 , measured at 190 ℃, 21.6 kg load) of 180 g/10 min or more and 300 g/10 min or less, High-density polyethylene.
4. In paragraph 1, A melt flow ratio (MI 21.6 / MI 2.16 ) of 150 or more and 250 or less, High-density polyethylene.
5. In paragraph 1, melting points (Tm) of 130 ℃ or higher and 140 ℃ or lower, High-density polyethylene.
6. In paragraph 1, A weight-average molecular weight (Mw) of 120,000 g/mol to 200,000 g/mol, High-density polyethylene.
7. In paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw/dlogMw, the integral value in the region where the Log Mw value is between 2 and 3 (inclusive) is between 3% and 10% of the total integral value, High-density polyethylene.
8. In paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw/dlogMw, the integral value in the region where the Log Mw value is between 2 and 4 is between 38% and 50% of the total integral value, High-density polyethylene.
9. In paragraph 1, In a GPC curve graph where the x-axis is Log Mw and the y-axis is dw/dlogMw, the integral value in the region where the Log Mw value is 6 or greater and 7 or less is 1% or greater and 5% or less of the total integral value, High-density polyethylene.
10. In paragraph 1, Complex viscosity measured at an angular frequency of 0.1 rad/s is 10,000 Pa·s or more and 16,000 Pa·s or less, High-density polyethylene.
11. In paragraph 1, High-density polyethylene having a complex viscosity of 600 Pa·s or more and 900 Pa·s or less, measured at an angular velocity of 100 rad/s.
12. In paragraph 1, The ratio of the complex viscosity measured at an angular velocity of 0.1 rad/s to the complex viscosity measured at an angular velocity of 100 rad/s (η* (0.1 rad/s)) / η*(100 rad/s)) is between 10 and 30, High-density polyethylene.
13. 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, Polyethylene film.
14. In Paragraph 13, When manufacturing a blown film with a thickness of 50 μm under conditions of a temperature of 230℃, FLH (Frost Line Height) of 160 mm, and BUR 2.5, the resin pressure is 80 bar or less, Polyethylene film.

Description

High Density Polyethylene and Film Comprising the Same The present invention relates to high-density polyethylene having excellent processability along with moisture barrier properties, and a film containing the same. Polyethylene is a general-purpose polymer widely used in various applications such as packaging films, pipes, and containers, and is broadly classified into high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE) depending on its density. Recently, in order to increase the recycling rate of various packaging films for food, household use, and electronic products, there is growing interest in films made entirely of polyethylene (All-PE film), such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), instead of the conventionally used aluminum foil (Al foil), nylon, or ethylene vinyl alcohol (EVOH). In addition, to replace other materials used for barrier applications, it is necessary to ensure the moisture and oxygen barrier properties of 100% polyethylene films (All-PE films). Among polyethylenes, HDPE has a high density and a large number of crystalline regions, so it offers superior moisture and oxygen barrier properties compared to other polyethylenes such as low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). Accordingly, HDPE can serve as a barrier film that blocks moisture penetration. However, because HDPE is non-polar, its oxygen barrier properties are inferior to those of conventionally used materials such as aluminum foil, nylon, and EVOH. Accordingly, in order to increase the recycling rate of various packaging films, there is a need to develop a method that utilizes HDPE films applicable to fields requiring stiffness, such as VFFS (vertical form fill seal), while also significantly improving processability through excellent moisture barrier properties and superior bubble stability at low resin pressures and process temperatures during film processing. 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 graph of the ARES analysis results 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 a graph of the elongation viscosity measured for 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 50 g of substance A, 20 g of substance B, and 30 g 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 content of substance A, substance B, and substance C is 50 weight%, 20 weight%, and 30 weight%, respectively, out of 100% of the total weight of the mixture. At this time, the total content 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 modifi