BR-112023003076-B1 - Meltblown nonwoven fabric formed from a composition

Abstract

Melt-blown nonwoven fabric formed from a composition, and air filter. This refers to melt-blown nonwoven fabrics and articles thereof. Melt-blown nonwoven fabrics can be formed from a composition comprising an ethylene/alpha-olefin interpolymer and a specific additive. Melt-blown nonwoven fabrics according to the embodiments disclosed in this document exhibit high volume resistivity and can be used in filtration applications.

Inventors

• Xin Huang
• Yunfeng Yang
• Shijie Ren
• Yijian Lin
• Haiyang Yu
• Jingya Li

Assignees

• DOW GLOBAL TECHNOLOGIES LLC

Dates

Publication Date

20260317

Application Date

20200821

Claims (9)

1. 1. A meltblown nonwoven fabric, formed from a composition, characterized in that it comprises: an ethylene/alpha-olefin interpolymer with a density of 0.911 to 0.939 g/cm3, a Brookfield viscosity less than or equal to 50,000 cP and a molecular weight distribution (Mw,cm3/Mn,cm3) of 1.8 to 3.5; and an additive selected from the group consisting of titanium dioxide, bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate, halloysite, organophilic phyllosilicate and combinations thereof; and the composition having a volume resistivity greater than 7.0E+16 ohm.cm at room temperature.
2. 2. Meltblown nonwoven fabric according to claim 1, characterized in that the composition comprises, based on the total weight of the composition, 90 to 99.95% by weight of the ethylene/alpha-olefin interpolymer and 0.05 to 10.00% by weight of the additive.
3. 3. Meltblown nonwoven fabric, according to either claim 1 or 2, characterized in that the additive melts the liquid during the formation of the meltblown nonwoven fabric, or is a solid that has an average particle size (D50) of less than 1 micron.
4. 4. Meltblown nonwoven fabric according to any one of claims 1 to 3, characterized in that the ethylene/alpha-olefin interpolymer has an Mz,cm3/Mn,cm3 ratio less than 5.25 or, alternatively, less than 4.0 or 3.5.
5. 5. Meltblown nonwoven fabric according to any one of claims 1 to 4, characterized in that the ethylene/alpha-olefin interpolymer has a molecular weight fraction (w) greater than 105 g/mol, based on the total weight of the interpolymer, as determined by conventional gel permeation chromatography, of less than 2.5%, or alternatively, less than 1.0%.
6. 6. Meltblown nonwoven fabric according to any one of claims 1 to 5, characterized in that the additive is selected from the group consisting of bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate, titanium dioxide or combinations thereof.
7. 7. Meltblown nonwoven fabric according to any one of claims 1 to 6, characterized in that the additive is bis(2,2,6,6-tetramethyl-1-piperidinoxy-4-yl) sebacate.
8. 8. Meltblown nonwoven fabric according to any one of claims 1 to 7, characterized in that it comprises fibers having a diameter of less than 10 microns.
9. 9. Meltblown nonwoven fabric according to any one of claims 1 to 8, characterized in that the composition has a volume resistivity greater than 5.0E+14 ohm.cm at 60 °C.

Description

Technical field [0001] The embodiments of this disclosure generally refer to meltblown and blown nonwovens and, more particularly, refer to meltblown and blown nonwovens formed from compositions that have high bulk resistivity. Introduction [0002] Electrical properties, such as bulk resistivity and charge retention, are critical for filtration, as they can help improve resistance to electrochemical degradation and reduce electrical charge drop. Articles used for filtration purposes include meltblown and blown nonwovens. Meltblown and blown nonwovens that are formed from polypropylene as opposed to polyethylene are widely used in filtration applications because, among other things, polypropylene exhibits better electrical properties for filtration than polyethylene. For example, a typical meltblown and blown nonwoven formed from polypropylene compositions can be charged to obtain a static charge for dust collection. Although polypropylene is the most popular polyolefin matrix for use in filtration applications, it has several disadvantages compared to polyethylene. For example, polypropylene is rigid, cannot be disinfected by radiation, and can degrade and become odorous. Consequently, there is a need for nonwovens made from polyethylene that can be soft and less odorous and can exhibit good electrical properties, such as high volume resistivity, for use, for example, in filtration applications. Summary [0003] The embodiments of the present disclosure meet the foregoing needs by providing a meltblown nonwoven fabric that includes an ethylene/alpha-olefin interpolymer and a specific additive or combination of additives. [0004] Melt-blown nonwoven fabrics are disclosed in this document. Melt-blown nonwoven fabric is formed from a composition. The composition comprises an ethylene/alpha-olefin interpolymer with a density of 0.911 to 0.939 g/cm3, a Brookfield viscosity less than or equal to 50000 cP and a molecular weight distribution (Mw,cm3/Mn,cm3) of 1.8 to 3.5; and an additive selected from the group consisting of titanium dioxide, bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate, talc, halloysite, organophilic phyllosilicate or combinations thereof; and the composition having a volume resistivity greater than 7.0E+16 ohm.cm at room temperature. [0005] An air filter is also disclosed in this document. The air filter comprises a meltblown nonwoven fabric according to the embodiments disclosed in this document. In embodiments, the air filter comprises a meltblown nonwoven fabric formed from a composition, the composition comprising an ethylene/alpha-olefin interpolymer with a density of 0.911 to 0.939 g/cm3, a Brookfield viscosity less than or equal to 50000 cP and a molecular weight distribution (Mw,cm3/Mn,cm3) of 1.8 to 3.5; and an additive selected from the group consisting of titanium dioxide, bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate, talc, halloysite, organophilic phyllosilicate or combinations thereof; and given that the composition has a volume resistivity greater than 7.0E+16 ohm.cm at room temperature. [0006] These and other modalities are described in detail in the Detailed Description. Detailed description [0007] Aspects of the disclosed meltblown and blown nonwoven fabrics are described in more detail below. Blown nonwoven fabrics can have a wide variety of applications and can be used to produce a wide variety of articles, including, for example, air filters, insulation, face masks, surgical gowns, bandages, and dressings. It should be noted, however, that this is merely an illustrative implementation of the embodiments disclosed in this document. The embodiments are applicable to other technologies susceptible to similar problems as discussed above. [0008] As used herein, the term "interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers. The generic term "interpolymer" includes the term "copolymer" (which is generally used to denote a polymer prepared from two different monomers), as well as the term "terpolymer" (which is usually used to denote a polymer prepared from three different types of monomers). It also encompasses polymers produced by the polymerization of four or more types of monomers. [0009] The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional component, step, or procedure, whether or not specifically disclosed. For the avoidance of doubt, all compositions claimed by the use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless otherwise indicated. Conversely, the term "essentially consisting of" excludes from the scope of any subsequent recitation any other component, step, or procedure, except those not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically outlined or listed. [0010] A meltblown nonwoven fabric