Polymer-based film with balanced properties

Patent metadata

Field	Value
Publication number	US-12440823-B2
Application number	US-201917295264-A
Country	US
Kind code	B2
Filing date	Nov 22, 2019
Priority date	Nov 30, 2018
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A film includes 20.0 weight percent to 69.5 weight percent of a linear low density polyethylene (LLDPE) based polymer. The LLDPE having a high density fraction (HDF) from 3.0% to 8.0%, an I 10 /I 2 ratio from 5.5 to 6.9, and a short chain branching distribution (SCBD) of less than or equal to 8.0° C. The film also includes 0.0 weight percent to 10.0 weight percent low density polyethylene (LDPE) based polymer, and 30.0 weight percent to 70.0 weight percent pore former.

First claim

The invention claimed is:

1. A film comprising:
20.0 weight percent to 69.5 weight percent linear low density polyethylene (LLDPE) based polymer, wherein the LLDPE based polymer comprises
a high density fraction (HDF) from 3.0% to 8.0%, wherein the high density fraction is measured by crystallization elution fractionation (CEF) integration at temperatures from 93° C. to 119° C.,
an I 10 /I 2 ratio from 5.5 to 6.9, wherein I 2 is the melt index when measured according to ASTM D 1238 at a load of 2.16 kg and temperature of 190° C. and I10 is the melt index when measured according to ASTM D 1238 at a load of 10 kg and temperature of 190° C., and
a short chain branching distribution (SCBD) of less than or equal to 7.0° C., wherein the short chain branching distribution is measured by CEF full width at half height;

0.0 weight percent to 10.0 weight percent low density polyethylene (LDPE) based polymer; and
30.0 weight percent to 70.0 weight percent pore former.

2. A film according to claim 1 , wherein the film comprises from 40.0 weight percent to 60.0 weight percent LLDPE based polymer.

3. A film according to claim 1 , wherein the LLDPE based polymer has a zero shear viscosity ratio from 1.1 to 3.0.

4. A film according to claim 1 , wherein the LLDPE based polymer has a I 10 /I 2 ratio from 5.5 to 6.5.

5. A film according to claim 1 , wherein:
the LLDPE based polymer has a density of 0.910 to 0.925 g/cm 3 ; and
the density is measured according to ASTM D792, Method B.

6. A film according to claim 1 , wherein:
the LLDPE based polymer has an I 2 from 1.0 to 6.0 g/10 mins; and
the I 2 is measured according to ASTM D 1238 at a load of 2.16 kg.

7. A film according to claim 1 , wherein the LLDPE based polymer has an I 2 from 3.0 to 4.0 g/10 mins.

8. A film according to claim 1 , wherein the film is a machine-direction oriented film.

9. A film according to claim 8 , wherein:
the film has a machine-direction orientation ratio from 2.5× to 6.0×; and
the machine-direction orientation ratio is calculated as ratio of the velocity of the film exiting the MDO unit to the velocity of the film entering the MDO unit.

10. A film according to claim 1 , wherein:
the film has an average machine-direction tear greater than or equal to 5.0 gf; and
the average machine-direction tear is measured according to Elmendorf Tear ASTM D 1922 measured at 14 gsm.

11. A film according to claim 1 , wherein:
the film has an average machine-direction force at 10% elongation of greater than or equal to 16.0 Newtons; and
the average machine-direction force at 10% elongation is measured according to ASTM D 638 at a tensile speed of 20 inch/minute and measured at 14 gsm.

12. A film according to claim 1 , wherein:
the film has an average water vapor transmission rate of greater than or equal to 15,000 g/m 2 /day; and
the average water vapor transmission rate is measured according to ASTM D6701 measured at 14 gsm, 100% RH, and 38° C.

13. A film according to claim 1 , wherein:
the film has a hydrostatic pressure of greater than or equal to 120 cm water; and
the hydrostatic pressure is measured according to ISO 1420 measured at 14 gsm.

14. A film according to claim 1 , wherein
the film has a loudness of less than 5.9 sones, wherein the loudness is measured at 18 gsm and a machine direction orientation ratio of less than or equal to 5.2×, or
the film has a loudness of less than 6.3 sones, wherein the loudness is measured at 18 gsm and a machine direction orientation ratio greater than 5.2× and less than or equal to 5.8×.

15. A hygiene absorbent product comprising the film according to claim 1 .

16. A film according to claim 1 , wherein the film has:
an average water vapor transmission rate (WVTR) of greater than or equal to 15,000 g/m 2 /day, measured according to ASTM D6701 measured at 14 gsm, 100% RH, and 38° C.;
a hydrostatic pressure of greater than or equal to 120 cm water, measured according to ISO 1420 measured at 14 gsm;
an average machine-direction tear (MD tear) of greater than or equal to 5.0 gf, measured according to Elmendorf Tear ASTM D 1922 measured at 14 gsm; and
an average machine-direction force at 10% elongation of greater than or equal to 16.0 Newtons, measured according to ASTM D 638 at a tensile speed of 20 inch/minute and measured at 14 gsm.

17. A film according to claim 1 , wherein:
the LLDPE polymer comprises a SCBD of less than 7.0° C. to 5.0° C.; and
the film has:
an average water vapor transmission rate (WVTR) of greater than or equal to 15,000 g/m 2 /day to 17,000 g/m 2 /day, measured according to ASTM D6701 measured at 14 gsm, 100% RH, and 38° C.,
a hydrostatic pressure of greater than or equal to 120 cm water to 129 cm water, measured according to ISO 1420 measured at 14 gsm,

an average machine-direction tear (MD tear) of greater than or equal to 5.0 gf to 7.0 gf, measured according to Elmendorf Tear ASTM D 1922 measured at 14 gsm, and
an average machine-direction force at 10% elongation of greater than or equal to 16.0 Newtons to 18.0 Newtons, measured according to ASTM D 638 at a tensile speed of 20 inch/minute and measured at 14 gsm.

18. A film according to claim 1 , wherein:
the LLDPE polymer comprises a SCBD of less than 7.0° C. to 6.5° C.; and
the film has:
an average water vapor transmission rate (WVTR) of greater than or equal to 16,000 g/m 2 /day to 16,750 g/m 2 /day, measured according to ASTM D6701 measured at 14 gsm, 100% RH, and 38° C.,
a hydrostatic pressure of greater than or equal to 123 cm water to 127 cm water, measured according to ISO 1420 measured at 14 gsm,
an average machine-direction tear (MD tear) of greater than or equal to 5.0 gf to 5.6 gf, measured according to Elmendorf Tear ASTM D 1922 measured at 14 gsm, and
an average machine-direction force at 10% elongation of greater than or equal to 16.0 Newtons to 16.4 Newtons, measured according to ASTM D 638 at a tensile speed of 20 inch/minute and measured at 14 gsm.

Assignees

• Dow Global Technologies Llc

Inventors

• Heitsch Andrew T
• Lin Yijian
• Bonavoglia Barbara
• Hart Kyle E
• Demirors Mehmet
• Chou Rou Hua
• Thota Manoj

Classifications

• B01J20/3064

  Addition of pore forming agents, e.g. pore inducing or porogenic agents · CPC title

• B01J20/28033

  Membrane, sheet, cloth, pad, lamellar or mat · CPC title

• A61L15/24

  Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof {(A61L15/225 takes precedence)} · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08J2423/06

  Polyethene · CPC title